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MIYAKE, KOJI, YOSHIKAZU TSUJI, and MASANORI YAMAMOTO. "Microassay of Sperm Concentration in the Rat Epididymis by Micropuncture Technique." Nagoya University School of Medicine, 1993. http://hdl.handle.net/2237/17535.
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Frayer, Daniel Keith. "Measurement of surface concentration of aqueous copper sulfate solutions: An optical technique." Thesis, The University of Arizona, 2000. http://hdl.handle.net/10150/278740.
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An integrated optical waveguide is described that can measure surface concentrations of ions while immersed in an ionic solution, especially the commercially interesting case of ionic copper. Several such sensors were manufactured and tested. The theory behind this measurement technology is described. Techniques for the manufacture and experimental measurement are described. The devices made were able to measure surface concentrations on the order of 10 12 atoms per square centimeter. Several potential methods for improving the performance are given.
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Ouyang, Wei Ph D. Massachusetts Institute of Technology. "Hierarchical selective electrokinetic concentration : the universal next-generation biomolecule enrichment technique for molecular diagnostics." Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/128323.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2020Cataloged from PDF of thesis.
Includes bibliographical references (pages 182-200).
Rapid and reliable detection of ultralow-abundance nucleic acids and proteins in complex biological media may greatly advance clinical diagnostics and biotechnology development. Because of the slow mass transport and weak binding kinetics at ultralow concentration of target biomolecules, enrichment of target biomolecules plays an essential role in the detection of ultralow-abundance biomolecules. Currently, nucleic acid tests rely on enzymatic processes for target amplification (e.g. polymerase chain reaction), which have many inherent issues restricting their implementation in diagnostics. On the other hand, there exist no protein amplification techniques, greatly limiting the development of protein-based diagnosis.
By learning from the desired and undesired features of existing techniques, we designed the blueprint of the next-generation biomolecule enrichment technique, which should ideally be universally applicable to all kinds of biomolecules and be capable of specifically enriching only the target biomolecules among the background biomolecules by billion-fold rapidly. Electrokinetic concentration is a promising candidate for the next-generation biomolecule enrichment technique, because of its simple architecture and ease of operation, high concentration speed, universal applicability, and the rich physics of the system that may enable the development of new functionalities. We defined a technical roadmap of engineering the primitive electrokinetic concentration technique toward the next-generation biomolecule enrichment technique. We start by deciphering the mechanism of electrokinetic concentration (Chapter 2), which is instrumental in the rational design and innovation of the system.
We next developed specific enrichment of target biomolecules in the electrokinetic concentrator based on electrophoretic mobility-based separation and mobility engineering of affinity binders (Chapter 3). We went on to realize the billion-fold enrichment capability of electrokinetic concentrator by massive parallelization and hierarchical cascading of unit electrokinetic concentrators (Chapter 4). After that, we demonstrated the engineered electrokinetic concentrator as an integrated, self-contained platform for universal amplification-free molecular diagnostics (Chapter 5). Finally, we interfaced the engineered electrokinetic concentrator with standard analytics to enhance their analysis sensitivity and greatly simplify their workflows (Chapter 6). At the end of the thesis, we conclude this thesis and present our outlooks on the future directions (Chapter 7).
by Wei Ouyang.
Ph. D.
Ph.D. Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science
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Furlan, John Michael. "Particle Concentration Measurements in a Centrifugal Slurry Pump Using an A-Scan Ultrasound Technique." Case Western Reserve University School of Graduate Studies / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=case1301325325.
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Tali-Maamar, Nadia. "Modélisation, analyse et commande d'un procédé biotechnologique à gradient spatial de concentration." Toulouse 3, 1994. http://www.theses.fr/1994TOU30031.
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Le procede biotechnologique etudie dans ce memoire est modelise par un systeme d'equations aux derivees partielles non lineaires et non stationnaires. Le modele obtenu est transforme en un systeme d'equations differentielles ordinaires par la methode de collocation orthogonale pour fins de stimulation numerique, d'analyse et, partiellement de synthese de regulateurs. Une etude d'observabilite du systeme en fonction du nombre et de la position des capteurs est exposee. Des algorithmes d'estimation et de commande sont mis en uvre en faisant appel a des techniques non lineaires de type adaptatif exploitant la structure distribuee et non lineaire inherente au modele du bioreacteur a lit fixe etudie. Les differents algorithmes developpes ont ete etudies d'un point de vue theorique puis mis au point en simulation
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Calixto, João Paulo Duarte. "Concentration of tumor biomarkers using aqueous biphasic systems." Master's thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/15353.
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Mestrado em Bioquímica - Bioquímica ClínicaAccording to the World Health Organization, around 8.2 million people die each year with cancer. Most patients do not perform routine diagnoses and the symptoms, in most situations, occur when the patient is already at an advanced stage of the disease, consequently resulting in a high cancer mortality. Currently, prostate cancer is the second leading cause of death among males worldwide. In Portugal, this is the most diagnosed type of cancer and the third that causes more deaths. Taking into account that there is no cure for advanced stages of prostate cancer, the main strategy comprises an early diagnosis to increase the successful rate of the treatment. The prostate specific antigen (PSA) is an important biomarker of prostate cancer that can be detected in biological fluids, including blood, urine and semen. However, the commercial kits available are addressed for blood samples and the commonly used analytical methods for their detection and quantification requires specialized staff, specific equipment and extensive sample processing, resulting in an expensive process. Thus, the aim of this MSc thesis consisted on the development of a simple, efficient and less expensive method for the extraction and concentration of PSA from urine samples using aqueous biphasic systems (ABS) composed of ionic liquids. Initially, the phase diagrams of a set of aqueous biphasic systems composed of an organic salt and ionic liquids were determined. Then, their ability to extract PSA was ascertained. The obtained results reveal that in the tested systems the prostate specific antigen is completely extracted to the ionic-liquid-rich phase in a single step. Subsequently, the applicability of the investigated ABS for the concentration of PSA was addressed, either from aqueous solutions or urine samples. The low concentration of this biomarker in urine (clinically significant below 150 ng/mL) usually hinders its detection by conventional analytical techniques. The obtained results showed that it is possible to extract and concentrate PSA, up to 250 times in a single-step, so that it can be identified and quantified using less expensive techniques.
De acordo com dados disponibilizados pela Organização Mundial de Saúde, cerca de 8,2 milhões de pessoas morrem anualmente com cancro. A elevada taxa de mortalidade associada ao cancro resulta da maioria dos pacientes não efetuar exames de rotina e porque a manifestação dos sintomas, na maioria dos casos, acontece quando o paciente já se encontra numa fase avançada da doença. Atualmente, o cancro da próstata representa a segunda maior causa de morte entre indivíduos do sexo masculino em todo o mundo. Tendo em conta que não existe cura para casos avançados de cancro da próstata, a estratégia passa por um diagnóstico precoce que permita aumentar a taxa de sucesso dos tratamentos. O antigénio prostático específico (PSA) é um biomarcador importante do cancro da próstata que pode ser detetado em fluidos biológicos, nomeadamente sangue, urina e sémen. No entanto, os kits comerciais disponíveis utilizam amostras de sangue e os métodos analíticos normalmente utilizados na sua deteção e quantificação requerem pessoal especializado, equipamento específico e um processamento extensivo das amostras, resultando em processos com um elevado custo associado. Assim, o objetivo deste mestrado passou por desenvolver um método simples, eficiente e menos dispendioso para a extração e concentração de PSA a partir de amostras de urina utilizando sistemas aquosos bifásicos (SAB) constituídos por líquidos iónicos. Numa fase inicial, determinaram-se os diagramas de fases de um conjunto de sistemas aquosos bifásicos constituídos por um sal orgânico e por líquidos iónicos. Em seguida, avaliou-se a capacidade dos mesmos para a extração do PSA. Os resultados obtidos demonstram que, nos sistemas em estudo, o antigénio prostático específico é totalmente extraído para a fase rica em líquido iónico num único passo. Por fim, averiguou-se a aplicabilidade dos SAB estudados para a concentração do PSA a partir de soluções aquosas e de urina. A baixa concentração deste biomarcador na urina (clinicamente significativo abaixo de 150 ng/mL) dificulta a sua deteção através de técnicas analíticas convencionais. Os resultados obtidos demonstraram que é possível extrair e concentrar PSA até 250 vezes, numa única etapa, sendo este detetável através de técnicas menos dispendiosas.
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Kuppuswamy, Anand. "Theoretical and experimental analysis of strain concentration around a broken fiber using the macro-composite technique." Thesis, This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-09182008-063050/.
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White, Andrew Graeme. "The effect of geography, cultivation and harvest technique on the umckalin concentration and growth of pelargonium sidoides (Geraniaceae)." Thesis, Rhodes University, 2007. http://hdl.handle.net/10962/d1003803.
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Pelargonium sidoides DC. (Geraniaceae) root extracts are used in the Eastern Cape Province of South Africa as a traditional medicine for the treatment of respiratory tract and gastro-intestinal infections. Ethanolic extracts are used globally as herbal treatments for bronchitis, asthma and as an immune system booster. Despite documented exploitation of wild populations by illegal harvesters, this species has not been awarded a protected status. The high level of harvest in the years preceding this study prompted this investigation of the prospects for sustainable root harvest through wild harvest and greenhouse cultivation. A novel method was developed for the purification of umckalin, a bioactive constituent in root extracts, such that the root umckalin concentrations of wild and cultivated plants could be quantified by HPLC. As part of the cultivation experiments, the concentration of umckalin in roots was measured for plants across part of the species’ distribution range in the Eastern Cape Province. This survey revealed that root umckalin concentrations were inversely related to the average annual rainfall of the collection site (r² = 0.94, p = 0.007) and directly related to soil pH (r² = 0.97, p = 0.002). Thus, the possibility of inducing high umckalin concentrations in greenhouse-cultivated plants was investigated by subjecting plants to rapid and prolonged water stress treatments. Two leaf applied hormone treatments (cytokinin and gibberellin) and a root competition treatment with a fast growing annual (Conyza albida) were also investigated based on the potential function of umckalin in P. sidoides plants. These five treatments did not significantly affect root umckalin concentrations compared to well-watered controls. The results of further experiments suggested that umckalin production may have been influenced by the geographical origin and genetics of plants rather than environmental variation. Following wild harvest experiments, the regrowth of replanted shoots from which a standard proportion of the root was harvested showed that water availability affected shoot survival but not root regrowth rate. Regrowth rates were low, questioning the viability of wild harvest. In contrast, greenhouse cultivated plants showed ca. six times greater growth rates, supporting the cultivation of roots to supply future market demand.
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Peng, Shuzhi. "Acoustical wave propagator technique for structural dynamics." University of Western Australia. School of Mechanical Engineering, 2005. http://theses.library.uwa.edu.au/adt-WU2005.0069.
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[Truncated abstract] This thesis presents three different methods to investigate flexural wave propagation and scattering, power flow and transmission efficiencies, and dynamic stress concentration and fatigue failures in structural dynamics. The first method is based on the acoustical wave propagator (AWP) technique, which is the main part described in this thesis. Through the numerical implementation of the AWP, the complete information of the vibrating structure can be obtained including displacement, velocity, acceleration, bending moments, strain and stresses. The AWP technique has been applied to systems consisting of a one-dimensional stepped beam, a two-dimensional thin plate, a thin plate with a sharp change of section, a heterogeneous plate with multiple cylindrical patches, and a Mindlin?s plate with a reinforced rib. For this Mindlin?s plate structure, through the comparison of the results obtained by Mindlin?s thick plate theory and Kirchhoff?s classical thin plate theory, the difference of theoretical predicted results is investigated. As part of these investigations, reflection and transmission coefficients, power flow and transmission efficiencies in a onedimensional stepped beam, and power flow in a two-dimensional circular plate structure, are studied. In particular, this technique has been successfully extended to investigate wave propagation and scattering, and dynamic stress concentration at discontinuities. Potential applications are fatigue failure prediction and damage detection in complex structures. The second method is based on experimental techniques to investigate the structural response under impact loads, which consist of the waveform measuring technique in the time domain by using the WAVEVIEW software, and steady-state measurements by using the Polytec Laser Scanning Vibrometer (PLSV) in the frequency domain. The waveform measuring technique is introduced to obtain the waveform at different locations in the time domain. These experimental results can be used to verify the validity of predicted results obtained by the AWP technique. Furthermore, distributions of dynamic strain and stress in both near-field (close to discontinuities) and far-field regions are investigated for the study of the effects of the discontinuities on reflection and transmission coefficients in a one-dimensional stepped beam structure. Experimental results in the time domain can be easily transferred into those in the frequency domain by the fast Fourier transformation, and compared with those obtained by other researchers. This PLSV technique provides an accurate and efficient tool to investigate mode shape and power flow in some coupled structures, such as a ribbed plate. Through the finite differencing technique, autospectral and spatial of dynamic strain can be obtained. The third method considered uses the travelling wave solution method to solve reflection and transmission coefficients in a one-dimensional stepped beam structure in the time domain. In particular, analytical exact solutions of reflection and transmission coefficients under the given initial-value problem are derived. These analytical solutions together with experimental results can be used to compare with those obtained by the AWP technique.
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Gordon, Christopher, and res cand@acu edu au. "Hydrostatic and thermal influences on intravascular volume determination during immersion: quantification of the f-cell ratio." Australian Catholic University. School of Exercise Science, 2001. http://dlibrary.acu.edu.au/digitaltheses/public/adt-acuvp4.14072005.
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Previous data have shown that the most prevalent, indirect plasma volume (PV) measurement technique, which utilises changes in haematocrit (Hct) and haemoglobin concentration ([Hb]), underestimates actual PV changes during immersion, when compared to a direct tracer-dilution method. An increase in the F-cell ratio (whole-body haematocrit (Hctw) to large-vessel haematocrit (Hctv) ratio) has been purported as a possible explanation, probably due to hydrostatic and thermally-mediated changes during water immersion. Previous investigators have not quantified the F-cell ratio during immersion. Therefore, this study sought to determine the effect of the F-cell ratio on the indirect method during both, thermoneutral and cold-water immersions. Seven healthy males were tested three times, seated upright in air (control: 21.2°C SD ±1.1), and during thermoneutral (34.5oC SD ±0.2) and cold-water immersion (18.6oC SD ±0.2), immersed to the third intercostal space for 60 min. Measurements during the immersion tests included PV (Evans blue dye column elution, Evans blue dye computer programme, and Hct [Hb]), red cell volume (RCV; sodium radiochromate), cardiac frequency (fc) and rectal temperature (Tre). Plasma volume during the control trial remained stable, and equivalent across the three tests. There was a hydrostatically-induced increase in PV during thermoneutral immersion, when determined by the Evans blue dye method (16.2%). However, the Hct/[Hb] calculation did not adequately reflect this change, and underestimated the relative PV change by 43%. In contrast, PV decreased during cold immersion when determined using the Evans blue dye method by 17.9% and the Hct/[Hb] calculation by 8.0%, respectively, representing a 52% underestimation by the latter method. There was a non-significant decline in RCV during both immersions. Furthermore, an increase (8.6%) and decrease (-14.4%) in blood volume (BV) was observed during thermoneutral and cold-water immersions, respectively. The decline in RCV during thermoneutral immersion attenuated the BV expansion. Despite the disparity between the PV methods, there was no increase in the F-cell ratio during either immersion. In contrast, there was a significant decline in the F-cell ratio during the control: air and thermoneutral immersion, which may indicate that other, undefined variables may impact on the stability of the red cell compartment. The current study is the first to show that the Hct/[Hb] method clearly underestimates PV changes during both thermoneutral and cold-water immersion. Furthermore, RCV was shown, for the first time, to decline during both immersions. However, the changes in the F-cell ratio during this study, did not account for the underestimation of PV change using the Hct/[Hb] method.
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Koen, Louis Johannes. "Ultrasonic-time-domain-reflectometry as a real time non-destructive visualisation technique of concentration polarisation and fouling on reverse osmosis membranes." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/52042.
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Thesis (MEng)--Stellenbosch University, 2000.ENGLISH ABSTRACT: Fouling is readily acknowledged as one of the most critical problems limiting the wider application of membranes in liquid separation processes. A better understanding of fouling layer formation and its monitoring is needed in order to improve on existing cleaning techniques. Plant operation can be optimised if fouling can be monitored by noninvasion means either on the plant itself or on an attached monitoring device. The overall scope of this research was to develop a non-destructive, real-time, in situ visualisation technique or device for concentration polarisation and fouling layer monitoring. Ultrasonic-time-domain-reflectometry (UTDR) was employed as a visualisation technique to provide real-time characterisation of the fouling layer. A 24 cm-long rectangular flat sheet aluminium cell was designed and used as separation device for a desalination system. The experimental results obtained using this module confirmed that there are an excellent correspondence between the flux decline behaviour and the UTDR response from the membrane. The ultrasonic technique could effectively detect fouling layer initiation and growth on the membrane in real-time. In addition to the measurement of fouling, the ultrasonic technique was also successfully employed for monitoring membrane cleaning. Since no real-time permeation data is available during cleaning operations in industrial applications, a UTDR monitoring device may prove to be a very valuable technique in optimising cleaning strategies. The technique was further tested on an 8-inch diameter spiral wrap industrial module and good results were obtained. Stagnant zones, as well as flux flow behaviour inside the module could be determined. However, more research IS needed to fully understand the complex phenomena inside a spiral wrap module. Overall, the UTDR technique and its use in monitoring devices have a major impact in the membrane industry due to its extremely powerful capabilities.
AFRIKAANSE OPSOMMING: Membraan-bevuiling of -verstopping is die grootste struikelblok wat die algemene aanwending van membrane vir verskillende watersuiweringsprosesse negatief beinvloed. 'n Beter begrip van membraan-bevuiling, asook beter metingsmetodes daarvan is nodig om op bestaande skoonmaaktegnieke te verbeter. Die hoofdoel van hierdie studie was die ontwikkeling van 'n nie-destruktiewe-in-lyn visuele tegniek vir die meting van konsentrasie polarisasie en membraan-bevuiling. Deur gebruik te maak van ultrasoniese klank golwe, is 'n tegniek ontwikkel wat 'n direkte visuele aanduiding kon gee van die toestand van membraan-bevuiling binnein die module. 'n Reghoekige aluminium-module, 24 cm lank, is ontwerp en gebou waarbinne die membraan geplaas is vir die skeidingsproses. Resultate dui daarop dat daar 'n uitstekende verband bestaan tussen die afname in permeaatvloei en die ultrasoniese eggo vanaf die membraan. Die ultrasoniese tegniek kon die vorming van en toename in membraan-bevuiling doeltreffend karakteriseer. In teenstelling hiermee, is die tegniek ook suksesvol aangewend om die skoonmaak-proses van membrane te ondersoek. Met min of geen data beskikbaar vir die skoonmaak-proses van membrane in die industriële sektor, het die tegniek enorme potensiaal in die optimisering van bestaande skoonmaak-tegnieke. Die tegniek is verder aangewend op 'n industriële 8-duim deursnee spiraal-module en goeie resultate is verkry. Stagnante sones asook vloed-vloei-patrone binne-in die module kon suksesvol bepaal word. Baie navorsing is egter nog nodig om die ingewikkelde data wat gegenereer word tydens die ondersoek van 'n spiraal-module ten volle te verstaan. Die enorme potensiaal en moontlikhede van die ultrasoniese tegniek kan die begin wees van 'n revolusie in die membraan-industrie.
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Depussay, Eric. "Developpement d'une technique de mesure de concentration en carburant par fil chaud a effet catalytique : applications aux moteurs a allumage commande." Orléans, 1998. http://www.theses.fr/1998ORLE2035.
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L'objectif de cette etude a ete de developper une sonde de prelevement sequentiel destinee a la mesure de concentration en carburant dans les chambres de combustion des moteurs a allumage commande. Ce dispositif se devait etre d'utilisation aisee, produire une mesure fiable et reproductible et enfin etre capable de s'adapter sur tout type de moteur. A la suite d'une etude bibliographique, il s'est avere que la technique de mesure de concentration par fil chaud catalytique possede les qualites attendues. Cette technique consiste a maintenir un fil chaud, de faible diametre a une temperature de fonctionnement constante et suffisamment elevee afin de realiser a sa surface une catalyse. Cette catalyse a pour but d'accroitre considerablement la sensibilite de la sonde grace a son apport energetique, modifiant par la - meme l'equilibre thermique du fil chaud. Il est alors possible a partir de ce desequilibre et d'un etalonnage d'obtenir l'information richesse du melange. Des essais sur moteur a allumage commande sans combustion ont permis de valider ce principe de mesure mais egalement de mettre en avant la necessite d'avoir un signal de reference afin de tenir compte des variations possibles, au cours de la mesure, de la vitesse de l'ecoulement ou de sa temperature, les mesures etant realisees a pression atmospherique. La mesure differentielle obtenue a partir de deux fils chauds, nous a permis d'obtenir cette reference. La sonde est donc composee d'un premier fil, porte a 573 k nous permettant d'acquerir les caracteristiques vitesse et temperature du prelevement, et d'un second fil, porte a 873 k, celui-ci catalyse et nous informe donc sur les caracteristiques vitesse, temperature et concentration en carburant du prelevement. Cette sonde nous a permis d'effectuer des essais comparatifs avec une autre technique de mesure de concentration : la plif. La similitude des resultats obtenus, nous permet de conclure sur la forte potentialite de notre sonde.
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Brayard, Florent. "La "solution finale de la question juive" : historiographie, technique de mise à mort et chronologie." Paris, Institut d'études politiques, 2002. http://www.theses.fr/2002IEPP0024.
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DeGreeff, Lauryn E. "Development of a Dynamic Headspace Concentration Technique for the Non-Contact Sampling of Human Odor Samples and the Creation of Canine Training Aids." FIU Digital Commons, 2010. http://digitalcommons.fiu.edu/etd/291.
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Human scent and human remains detection canines are used to locate living or deceased humans under many circumstances. Human scent canines locate individual humans on the basis of their unique scent profile, while human remains detection canines locate the general scent of decomposing human remains. Scent evidence is often collected by law enforcement agencies using a Scent Transfer Unit, a dynamic headspace concentration device. The goals of this research were to evaluate the STU-100 for the collection of human scent samples, and to apply this method to the collection of living and deceased human samples, and to the creation of canine training aids. The airflow rate and collection material used with the STU-100 were evaluated using a novel scent delivery method. Controlled Odor Mimic Permeation Systems were created containing representative standard compounds delivered at known rates, improving the reproducibility of optimization experiments. Flow rates and collection materials were compared. Higher air flow rates usually yielded significantly less total volatile compounds due to compound breakthrough through the collection material. Collection from polymer and cellulose-based materials demonstrated that the molecular backbone of the material is a factor in the trapping and releasing of compounds. The weave of the material also affects compound collection, as those materials with a tighter weave demonstrated enhanced collection efficiencies. Using the optimized method, volatiles were efficiently collected from living and deceased humans. Replicates of the living human samples showed good reproducibility; however, the odor profiles from individuals were not always distinguishable from one another. Analysis of the human remains samples revealed similarity in the type and ratio of compounds. Two types of prototype training aids were developed utilizing combinations of pure compounds as well as volatiles from actual human samples concentrated onto sorbents, which were subsequently used in field tests. The pseudo scent aids had moderate success in field tests, and the Odor pad aids had significant success. This research demonstrates that the STU-100 is a valuable tool for dog handlers and as a field instrument; however, modifications are warranted in order to improve its performance as a method for instrumental detection.
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Kurki, Saara. "How to let go : Different ways to detect and release tensions." Thesis, Kungl. Musikhögskolan, Institutionen för klassisk musik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kmh:diva-4186.
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The aim of my project was to find different ways to make playing easier and freer. What does it actually mean to let go and what could help to achieve more secure and relaxed feeling in your body when playing your instrument? I collected and experimented with exercises from a book The Inner Game of Music and Alexander Technique. I found out that knowing more precisely what to focus on and being more aware of the body can have a great effect. I discovered more gentle ways to teach myself and learned about the importance of how we are treating and using our bodies during practicing and in everyday situations.The sounding part consists of the following recording; Esa-Pekka Salonen: Pentatonic Étude.
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Younis, Ahmed. "Protection of Aluminum Alloy (AA7075) from Corrosion by Sol-Gel Technique." Doctoral thesis, Universitätsbibliothek Chemnitz, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-83230.
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Die vorliegende Arbeit beschäftigt sich mit der Entwicklung von Sol-Gel-Beschichtungen durch Optimierung der Ausgangszusammensetzung und der Applikations-Parameter für den Korrosionsschutz der Aluminium-Legierung AA7075. Verschiedene Arten von Silanen, z. B. Tetraethoxysilan (TEOS), Phenyltriethoxysilan (PTES) und Phenyltrimethoxysilan (PTMS) sind verglichen worden: Der Sol-Gel-Film aus PTMS präpariert, weist dabei die höchste Hydrophobizität auf, was sich insbesondere in den Barriere-Eigenschaften dieser Verbindung zeigte. Die Wirkung von Essigsäure als Katalysator in Sol-Gel-Prozessen wurden untersucht, um die optimale Katalysatorkonzentration für den Korrosionsschutz der beschichteten Proben zu ermitteln. Die Korrosionsbeständigkeit der beschichteten Proben sinkt bei höheren Konzentrationen des sauren Katalysators durch die Auflösung des Aluminiumoxids an der Substratoberfläche. Allerdings führten zu niedrige Konzentrationen des Katalysators zur Verlangsamung der Hydrolysereaktionen der Silane und es bildete sich poröse Sol-Gel-Schichten. Die Wärmebehandlung der beschichteten Aluminium-Proben ist für die Vernetzung des Films erforderlich. Eine Wärmebehandlung bei 300 ˚C für 2,5 Stunden ergab dabei den besten Korrosionsschutz. Höhere Temperaturen führten zu einer Verschlechterung der Eigenschaften der Filme, was mit der Zerstörung des organischen Teil des Films erklärt werden kann. Darüber hinaus verursachen zu niedrige Temperaturen einen geringeren Korrosionsschutz der beschichteten Aluminium-Proben. Vermutlich ist die geringe Vernetzung des Sol-Gel-Films bei Temperaturen was für als 300 ˚C verantwortlich. Die beschichteten Aluminium-Proben wuden mittels Raster-Elektronenmikroskopie (SEM), Energiedispersive Röntgenspektroskopie (EDX), Röntgen-Photoelektronenspektroskopie (XPS) und elektrochemischen Techniken charakterisiertThe present work pertains to the development of sol-gel coatings by optimizing the composition and the application parameters for corrosion protection of aluminum alloy AA7075. Different kinds of silanes e.g. tetraethoxysilane (TEOS), phenyltriethoxysilane (PTES) and phenyltrimethoxysilane (PTMS) have been compared: the sol-gel film prepared from PTMS shows highest hydrophobicity manifested by the best barrier property of this compound. The effect of acetic acid as a catalyst on the chemistry of the sol is investigated in order to estimate the best catalyst concentration for better corrosion protection of the coated samples. The corrosion resistance of the coated samples is found to be decreasing at higher concentrations of the catalyst due to the dissolution of the aluminum oxide at the substrate surface in the acid sol. However, lower concentrations of the catalyst lead to low hydrolysis reactions of the silanes and non-dense sol-gel films have been formed. The heat treatment of the coated aluminum samples is required for cross-linking of the film. The heat treatment at 300 ˚C for 2.5 hours exhibits the best corrosion protection. Higher treatment-temperatures lead to degradation of the properties of the film which can be described in terms of destroying the organic part of the film. Moreover, low treatment-temperatures cause low corrosion protection of the coated aluminum samples which is presumably attributed to the low cross-linking of the sol-gel film at temperatures less than 300 ˚C. The coated aluminum samples are characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS) and electrochemical techniques
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Muombwa, Yusuf Idris Haji. "Determination of the concentration of silver (I) species in the presence of its chloro- and hydroxo- complexes by the ion-exchange column equilibration-AAS technique." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq21194.pdf.
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Camci, Gulden. "Application Of Isokinetic Sampling Technique For Local Solid Densities In Upward Liquid-solid Flows Through An Annulus." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/1089796/index.pdf.
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In this study, radial solid density distributions in upward flowing water-feldspar mixtures through a concentric annulus were investigated. Local solid density measurements were performed at a test cross-section in the fully developed flow region of a concentric annulus, which is a part of a closed-loop system consisting of a head tank, a variable speed slurry pump, an orificemeter, a heat exchanger, an annulus, a temperature probe, and a drain line. The solid particles with mean diameters of 72 and 138 
m at two different feed solid concentrations of 1 and 2 % v/v were used in the prepared slurries. The dependent variables being local solid density, local mixture velocity, and axial frictional pressure drop along the test-section, an experimental work was performed to obtain the radial solid density profiles and axial pressure gradients at different operating conditions. To determine the local solid densities, a sampling probe was used. At the beginning, this probe was used as a pitot tube to measure the local velocities in the test cross-section. Making use of these data, local solid densities were measured with the same probe under isokinetic and nonisokinetic conditions to compare both. For this purpose, an isokinetic sampling unit was designed and constructed to withdraw the samples under isokinetic flow conditions, at which the sampling velocity in the probe equated to the true flow velocity in the annulus very closely. The required constant back-pressure was supplied by pressurized N2 gas to equate these velocities to each other. The amounts of solids in the slurry samples collected at seven different radial locations in the test area under isokinetic and non-isokinetic conditions were determined by the gravimetric method. Local solid densities showed more uniform trends at the feed solid concentration of 1% v/v than those at 2% v/v. Increasing the feed solid concentration and particle size changed the shape of these profiles. The obtained local solid densities were generally higher near the outer wall than those near the inner wall
this result was consistent with the literature. As a general trend, local solid densities showed a decreasing trend at around a dimensionless radial distance of &
#61548
=0.4, where the slurry velocity profile had its maximum value. It was observed that the two-phase axial frictional pressure gradients along the test section in the fully developed flow region increased with increasing feed solid concentration and the particle size at a constant slurry flow rate. Isokinetic sampling results showed that the local solid densities increased consistently with the increasing slurry velocity at all radial distances in the annular gap, while this trend was not observed clearly in the non-isokinetic measurements. Also the variations of the local solid densities along the radial distance were more obvious in the isokinetic results while these variations were obscured under nonisokinetic conditions by the experimental error at a higher level.
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Kallel, Sami. "Degradation par voies chimique et biologique de la pollution azotee et carbonee refractaire d'eau residuaire a forte concentration. Application au cas des lixiviats de centre d'enfouissement technique." Paris 6, 1993. http://www.theses.fr/1993PA066130.
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Les lixiviats stabilises de centres d'enfouissement technique sont comparables a des effluents industriels tres charges en azote ammoniacal et en composes organiques refractaires. Ces effluents peuvent constituer un vecteur essentiel de pollution pour l'environnement. Ils doivent a ce titre faire l'objet d'une surveillance particuliere. Le traitement biologique de ces effluents sur filtre biologique permet l'elimination quasi totale de l'azote ammoniacal avec des charges volumiques appliquees de 0,8 kg/m3/j, alors que le lagunage aere ne permet la nitrification que de 0,015 kg nnh4/m3/j. Les traitements biologiques par lagunage aere et par filtre biologique sont peu efficaces en ce qui concerne l'elimination de la charge organique. Le traitement physico-chimique par coagulation-floculation au chlorure ferrique permet l'elimination de 60 a 70% de la dco. Une oxydo-floculation au reactif de fenton ameliore les resultats avec une elimination de 75 a 80% de la charge organique et une augmentation du rapport db05/dco. L'oxydation combinee h2o2/uv apparait comme etant la solution la plus efficace pour l'oxydation de la matiere organique refractaire avec des rendements d'elimination superieurs a 90%. Une filiere composee d'un traitement par une coagulation-floculation au chlorure ferrique, d'une oxydation combinee h2o2/uv suivis d'un traitement sur filtre biologique, nous parait la plus efficace pour le traitement de ce type d'effluent
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Duhamel, Jean-Christophe. "Le pouvoir du capital dans la société anonyme : essai sur la société anonyme en tant que technique d’organisation du pouvoir juridique et structure de concentration du pouvoir économique." Thesis, Lille 2, 2011. http://www.theses.fr/2011LIL20008.
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Une analyse conceptuelle du pouvoir du capital amène à opérer la distinction entre d'une part le pouvoir juridique, et d'autre part le pouvoir économique. Le pouvoir juridique du capital renvoie à la prérogative de l'organe, mais doit surtout être appréhendé conformément à la théorie du pouvoir en droit privé. C'est dire que les actionnaires se doivent d'exercer une prérogative altruiste, dans un intérêt qui les transcende. Intérêt social, intérêt commun, le droit des sociétés s'organise autour d'intérêts transcendants, et donc autour du pouvoir juridique. Pour autant, le pouvoir du capital dans la société anonyme donne lieu à une réflexion rénovée sous l'impulsion des principes de gouvernance d'entreprise. Il s'agit là non plus de la manifestation d'un pouvoir juridique, mais de celle d'un pouvoir économique, dont l'essence est d'opérer la réduction des risques liés à un investissement. L'analyse de ce pouvoir économique amène à douter de sa capacité à réduire effectivement ces risquesA conceptual analysis of the power of capital in a corporation involves distinguishing between legal and economic power. The legal power of capital classically refers to an organic prerogative but also has to be analyzed according to the theory of power in private law. Hence, shareholders have to exercise an altruistic prerogative for the benefit of interests other than their own. Indeed, corporate law is organized around several interests that may conflict with individual shareholder interests, for example the common interest of shareholders or even the purely selfish interest of the corporation. However, this classical theory of legal power is challenged by the doctrine of corporate governance whose current expression of economic power in corporate law can be defined as the capacity of economic entities to reduce risks. By modifying managerial conduct, this doctrine aims to reduce the risks related to the investment in listed companies. Corporate governance is a phenomenon of economic power, not legal power in the corporation. A realistic assessment of this power leads to the conclusion that it is ineffective in reducing investment risks
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Paredes, Valencia Adriana. "Étude comparative de deux méthodes de fabrication de yogourt grec à échelle pilote utilisant l'ultrafiltration comme technique de concentration : étude basée sur la méthode d'analyse de cycle de vie." Master's thesis, Université Laval, 2016. http://hdl.handle.net/20.500.11794/27243.
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Le yogourt grec, pouvant être obtenu par concentration du yogourt traditionnel par ultrafiltration (UF), connaît une croissance exceptionnelle en Amérique du Nord (+100% depuis 2012), et représente le premier segment de marché des produits laitiers fermentés en 2014. Cependant, d'un point de vue environnemental, la production du yogourt grec fait face à plusieurs enjeux et défis. Son élaboration nécessite trois fois plus de lait que le yogourt traditionnel de par l'étape de concentration nécessaire à l'atteinte de la concentration protéique cible. De plus, l'étape d'UF du yogourt génère un perméat acide (coproduit du yogourt) difficilement valorisable. Néanmoins, une alternative consistant à effectuer l'étape d'UF sur le lait avant sa fermentation permet d'éliminer la production du perméat acide, et génère un perméat de lactosérum doux déprotéiné dont les voies de valorisation sont davantage connues. Cette stratégie pourrait donc potentiellement réduire l'impact environnemental du procédé et générer des coproduits plus facilement valorisables, améliorant ainsi l'écoefficience du procédé de fabrication de yogourt grec. Dans cette optique, ce projet de recherche visait à comparer l'impact environnemental sur l'ensemble du cycle de vie de la production de yogourt grec selon deux procédés : en effectuant l'étape de concentration par UF avant l'étape de fermentation (UF LAIT), ou après (UF YOG) comme utilisé dans l'industrie. Ainsi, des expérimentations à échelle pilote ont été réalisées dans le but de comparer ces deux procédés. Le nouveau procédé (UF LAIT) permettrait une réduction des consommations d'énergie à l'étape de transformation étant donné que l'UF du lait avant fermentation permet de réduire la quantité de matière première à transformer d'environ un tiers. Cependant l'Analyse du Cycle de Vie (ACV) des deux procédés donne comme résultat un bilan environnemental défavorable à (UF LAIT) comparativement au procédé traditionnel (UF YOG) à cause d'une plus grande consommation de lait, qui est responsable d'environ 80% des impacts sur le cycle de vie du yogourt grec. Cet impact majeur pour UF LAIT l'est encore même lorsque dans une analyse de sensibilité le perméat doux de UF LAIT est alloué à l'étape d'UF contrairement au perméat acide de UF YOG qui est considéré comme un déchet non valorisable.
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Wahl, Sébastien. "Nouvelle technologie de concentration de CO2 intégrée à la cimenterie : étude d'un nouveau procédé de décarbonatation." Thesis, Toulouse, INPT, 2018. http://www.theses.fr/2018INPT0014/document.
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Cette étude s’inscrit dans le cadre du développement d’une nouvelle technologie de concentration du CO2 intégrée à la cimenterie. Le principe de cette technologie repose sur une décarbonatation de la matière crue par contact avec un solide caloporteur dans un procédé innovant qui conduit à un dégagement de CO2 pur à haute température. Ce CO2 pourra ensuite être stocké dans le sous-sol ou valorisé chimiquement. L’objectif de ce travail est d’étudier la décarbonation du cru dans les conditions opératoires qui simulent le plus fidèlement possible la nouvelle unité industrielle. D’abord, la cinétique de décarbonation est étudiée en thermobalance sur des échantillons de poudre de CaCO3 pur qui est le composé majoritaire du cru. Les résultats conduisent à une meilleure compréhension des phénomènes qui pilotent la réaction ainsi qu’à l’élaboration des lois cinétiques permettant de prédire l’effet de la température entre 600 °C et 930 °C, et de la pression partielle de CO2 entre 0 atm et 1 atm sur l’avancement de la réaction. Ensuite, les interactions pouvant se produire entre le CaCO3 et les autres solides qui composent un cru industriel, lors de sa calcination sous atmosphère de CO2 pur, sont étudiées sur le plan cinétique (thermobalance), thermodynamique (simulations) et morphologique (DRX et DRX in situ). Enfin, dans le but de simuler la décarbonatation du cru et son élutriation dans le procédé réel, et en particulier dans la partie basse du nouveau calcinateur, un pilote fonctionnant à chaud a été réalisé au cours de ce travail. Il permet d’effectuer la décarbonatation du cru alimenté en discontinu et en continu dans un lit de média fluidisé (clinker ou olivine). Ont été examinées les influences de la température, de la vitesse de gaz, du débit de solide et de la nature du gaz de fluidisation (CO2 pur ou mélange air/CO2) sur les phénomènes hydrodynamiques (élutriation, accumulation, temps de séjour …), les interactions cru-média et le degré d’avancement de la réaction de décarbonatationThis study concerns a new CO2 concentration technology integrated into the cement plant. This technology consists in the raw mix decarbonation, induced by its contact with a solid medium in charge of the heat transfer, in an innovative process leading to the emission of pure CO2 at high temperature. This pure gas may be stored underground or used as chemical reactant. This work consists in the study of the decarbonation reaction of the raw mix in operating conditions that are similar to the ones of the new industrial unit. First, the decarbonation kinetics is studied by thermogravimetric analysis on pure CaCO3 powder samples. CaCO3 is the main component of the raw mix. The results led to a better comprehension of the phenomena driving the reaction kinetics and to the determination of kinetic laws in good agreement with the data obtained between 600 °C and 930 °C, and for a partial pressure of CO2 between 0 atm and 1 atm. Then, the interactions between the CaCO3 and the other solids in an industrial raw mix, occurring during its calcination in pure CO2 atmosphere, are studied kinetically (TGA), thermodynamically (simulations) and morphologically (XRD and in situ XRD). Eventually, an experimental device working at high temperatures was built for this study in order to simulate the decarbonation reaction of the raw mix and its elutriation in the real process. This device allows calcining the raw mix in a fluidized bed of media (clinker or olivine). The influences of the fluidized bed temperature, the fluidizing gas velocity, the solid feed rate and the fluidizing gas composition (pure CO2 or air/CO2 mixes) on the hydrodynamic phenomena (elutriation, accumulation, residence time …) , the raw mix-media interactions and the conversion degree are studied
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Horvath, Istva'n. "Extreme PIV Applications: Simultaneous and Instantaneous Velocity and Concentration Measurements on Model and Real Scale Car Park Fire Scenarios." Doctoral thesis, Universite Libre de Bruxelles, 2012. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209641.
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This study is a presentation of an instantaneous and simultaneous velocity and concentration measurement technique and its applications on car park fire scenarios. In this actual chapter 1 general introduction is given to each chapter. Chapter 2 is dedicated to a detailed description of the instantaneous and simultaneous velocity and concentration measurement technique and its associated error assessment methodology. The name of the new technique is derived from the names of the acquired parameters (VELocity and COncentration) and shall be hereafter referred to as VELCO. After having validated and performed an error assessment of this technique, it is applied to an investigation of full-scale car park (30 m x 30 m x 2.6 m – Gent / WFRGENT) fire cases in chapter 3. The measurements were carried out with the financial support of IWT-SBO program. In the full-scale measurements only the velocity part is applied of VELCO, yet it can be considered as its application since the special data treating was developed and implemented in the Rabon (see: §2.1.2) program, which is the software of the new technique along with Tucsok (see: §2.1.1) and they will be both discussed in the related chapter. Here it is enough to mention that the concentration and velocity information can be obtained independently as well. During the full-scale measurements, beyond of VELCO the smoke back-layering distances (SBL) are also derived from the temperature values, which were measured by thermocouples under the ceiling in the midline of the car park. The critical velocity, which is an important measure of fire safety, can be obtained from the SBL results. In chapter 4, isothermal fire modeling is surveyed in order to present how full-scale fires are modeled in small-scale. In this part of the study the theory of fire related formulae and an isothermal model are described. Here it is important to stress the fact that the fire modeling is not directly related to the VELCO technique. However it connects the full-scale to the small-scale measurements, which the technique is applied on. Chapter 5 discusses small-scale measurements (1:25 – Rhode Saint Genese / VKI) on the car park introduced in chapter 3 and their validation. After the validation, more complex car parks scenarios are also investigated due to the easy to change layout in the small-scale model with respect to the full-scale car park. In this chapter the smoke back-layering distances are obtained by VELCO. Finally, in chapter 6 important conclusions are drawn with the objective of increasing fire safety.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished
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Schaaf, Pierre. "La technique de reflectometrie : sa mise en oeuvre et son application a l'etude de l'adsorption de macromolecules a une interface solide/solution." Université Louis Pasteur (Strasbourg) (1971-2008), 1987. http://www.theses.fr/1987STR13039.
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Ito, Masahiko. "Fluorures monocristallins (CaF2, KY3F10, YLiF4) dopés par l'ion Yb3+ tirés par la technique de zone flottante LHPG (Laser Heated Pedestal Growth) : caractérisation spectroscopique, analyse de l'extinction par concentration et application laser." Lyon 1, 2004. http://www.theses.fr/2004LYO10092.
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Des monocristaux de fluorures (CaF2, KY3F10, YLiF4) ont été dopés par l'ion Yb3+ en vue d'application aux lasers IR. En premier lieu, la technique de zone flottante LHPG implantée au Laboratoire pour tirer des fibres cristallines d'oxydes, a été modifiée pour la croissance des fluorures. Les caractérisations spectroscopiques ont permis de tracer les diagrammes de niveaux d'énergie et de mesurer les principaux paramètres utiles à l'application laser. Dans le cas de CaF2:Yb3+, la présence de multisites a été plus spécialement étudiée. La dépendance de la constante de temps du déclin de fluorescence de fibres à gradient de concentration en ions Yb3+ a permis de connaître les mécanismes d'extinction par transferts d'énergie radiatifs et non radiatifs principalement vers des impuretés terres rares. Un modèle théorique interprète les résultats expérimentaux de l'extinction à partir d'un processus de diffusion limitée entre ions terres rares, et la valeur optimale du gain laser a pu en être déduite. Les premiers résultats d'émission laser sont aussi montrés
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Cardin-Bernier, Guillaume. "Observateur pour le suivi en temps réel de cultures cellulaires végétales." Mémoire, Université de Sherbrooke, 2011. http://savoirs.usherbrooke.ca/handle/11143/1591.
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Ce document présente le travail effectué et les résultats obtenus dans le cadre d'un projet visant à associer une technique nouvellement développée, le suivi des biomarqueurs endogènes permettant l'estimation de la concentration cellulaire de cultures végétales en suspensions, à un modèle mathématique décrivant l'évolution de ces cultures en fonction de la consommation des différents nutriments disponibles. Cette association permet d'obtenir une estimation des conditions de cultures cellulaires en temps réel dont la mesure ne peut actuellement être effectuée que par échantillonnages. Les temps d'expériences requis pour obtenir les mesures sont toutefois trop longs pour pouvoir effectuer un contrôle des conditions de cultures advenant une déviation du procédé. L'intérêt de ce projet se situe à deux endroits. Premièrement, la simplicité, la rapidité et l'efficacité de la technique de suivi des biomarqueurs endogènes permet le suivi en temps réel de la quantité de cellules lors de la culture (concentration cellulaire et biomasse). Or, en raison des particularités des cultures de cellules végétales, en particulier l'agglomération cellulaire, il est très difficile d'obtenir une estimation fiable de la concentration cellulaire. Présentement, il n'existe pas de technique commercialement disponible pour effectuer ce suivi. D'où l'intérêt de la méthode des biomarqueurs endogènes. Ensuite, l'association de ces mesures avec un modèle mathématique permet d'obtenir un outil décrivant l'évolution de la culture et de variables importantes qui l'influencent. Le modèle étant indépendant de la technique des biomarqueurs endogènes, il est possible de suivre un grand éventail de procédés et de variables en suivant la même méthodologie, en modifiant le modèle utilisé. Ce projet utilise un cas précis, la culture d'Arabidopsis thaliana dans un milieu standard avec un modèle relativement simple. Cependant, la même démarche peut être appliquée pour d'autres systèmes avec d'autres types d'organismes. Le travail présenté ici ouvre donc la voie à une meilleure compréhension des cultures cellulaires en générale et pourrait permettre l'optimisation de procédés jusqu'ici difficilement contrôlables dû au manque d'information disponible.
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Martin-Fardon, Rémi. "Effets comparés de traitements chroniques par la cocai͏̈ne et la N-[1-(2-benzo(B)thiophényl)cyclohexyl]pipéridine (BTCP), sur la concentration extracellulaire de dopamine dans le striatum de rat." Montpellier 2, 1996. http://www.theses.fr/1996MON20186.
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La microdialyse repetee chez un meme animal permet la mesure a long terme de la concentration de dopamine (da) extracellulaire (dae, 10 fois sur une periode de 23 jours) dans le striatum. La cocaine et la btcp sont des inhibiteurs de la recapture de la da. Aux doses respectives de 20 et 10 mg/kg elles ont des effets comportementaux et sur le niveau de base de da dans le striatum et le nucleus accumbens, similaires. La dialyse repetee a ete appliquee a la mesure d'effets de traitements chroniques (tch) par la cocaine (20 mg/kg), la btcp (10 mg/kg) et croises (tcr). Le premier jour du tch, les deux drogues ont le meme effet sur la quantite totale de da. Pendant le traitement par la cocaine, la dae augmente jusqu'a 297% (jour 7) et revient a la valeur initiale a partir du jour 13. Lors de traitements par la btcp, la dae ne varie pas. La quantite totale de da collectee apres l'administration des deux drogues evolue parallelement a la dae. Apres une semaine de sevrage, les deux drogues ont un effet similaire a celui du premier jour. Lors du tcr, le pre-traitement par la btcp previent l'augmentation de la dae induite par la cocaine et en partie son effet sur la quantite totale de da. Chez des rats pre-traites par la cocaine, la btcp reverse les effets de la cocaine. Au cours des tcr, le jour de la substitution les pre-traitements sensibilisent a l'effet de l'autre drogue. Les effets de la cocaine peuvent etre assimiles a une sensibilisation et ceux de la btcp a une tolerance. Les effets de la btcp pourraient permettre d'envisager une pharmacotherapie de la dependance a la cocaine
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Wang, Jie. "Carrier concentration determination in GaMnAs by optical techniques /." View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?PHYS%202006%20WANGJ.
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Benarfa, Houria. "Proprietes de photoluminescence de gaas : contribution a l'etude de gaas heteroepitaxie sur (ca,sr)f2 par la technique des jets moleculaires." Toulouse, INSA, 1986. http://www.theses.fr/1986ISAT0019.
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ANALYSE DE LA PHOTOLUMINESCENCE DE STRUCTURES GaAs/(Ca,Sr))F2/GaAs, A FLUORURE ACCORDE EN MAILLE AU GAAS; INFLUENCE DES PARAMETRES DE CROISSANCE ET DE LA DISTANCE A L'INTERFACE. COMPARAISON DES PERFORMANCES DE SEMICONDUCTEUR HETEROEPITAXIE A CELLES DE GAAS EPITAXIE; ETUDE DE COUCHES DE GAAS EPITAXIE SUR CAF2 MASSIF
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Dalastra, Cleiton [UNESP]. "Nutrição e produção de alface americana em função da vazão, periodicidade de exposição e condutividade elétrica da solução nutritiva em sistema hidropônico." Universidade Estadual Paulista (UNESP), 2017. http://hdl.handle.net/11449/152065.
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A produção de alimento face a demanda mundial é um desafio para este século, devendo-se, obrigatoriamente, destinar atenção ao ganho de eficiência produtiva, incorporada as tecnologias disponíveis. Dentre as hortaliças folhosas, a alface se destaca em toda culinária global. A produção atual da alface tem passado por grandes avanços, atribuídos especialmente à técnica de produção hidropônica, contudo, ainda é necessita melhorias na adaptabilidade da tecnologia hidropônica às condições climáticas das diversas regiões e às diferentes necessidades da gama de cultivares presentes no mercado. Neste cenário, a proposição desta pesquisa surge em resposta à demanda de informações pelo setor produtivo, cumprindo seu papel na integração entre ensino, pesquisa e extensão rural, de maneira a contribuir modestamente com o setor produtivo. Para isso, foram realizados três experimentos isolados em sistema hidropônico NFT (Técnica de Fluxo Laminar de Nutrientes), com o objetivo de avaliar a nutrição e a produção econômica de alface americana em função da vazão, periodicidade de exposição e condutividade elétrica da solução nutritiva, respectivamente. O delineamento experimental foi em blocos casualisados, com cinco repetições e cada tratamento foi composto por 15 plantas. No experimento 1, os tratamentos utilizados constaram da aplicação de solução nutritiva nas vazões de 0,5; 1; 2 e 4 litros por minuto em cada canal de cultivo. No experimento 2, os tratamentos foram quatro combinações de intermitência de exposição da solução nutritiva em intervalos de bombeamento / intervalo de ausência de bombeamento em minutos: 15/60; 15/30; 15/15 e FI (Fluxo initermitente). No experimento 3, os tratamentos foram a manutenção diária da solução nutritiva em quatro valores de condutividade elétrica, de 0,8; 1,3; 1,8 e 2,3 dS m-1, em função da concentração de nutrientes. A maior produção e lucratividade de alface americana foi obtida com a vazão da solução nutritiva de 1 L/min, devido ao maior acúmulo de nutrientes na parte aérea e eficiência de sua utilização; também houve a maior produção e lucratividade de alface americana obtida com fluxo contínuo da solução nutritiva (FI), devido ao maior acúmulo de nutrientes na parte aérea e raízes, maior assimilação de nitrato e eficiência de utilização de nutrientes; economicamente, a condução em intervalo 15/30 minutos acarreta em prejuízo financeiro; o acompanhamento dos tratamentos de condutividade elétrica no decorrer do ciclo da alface aponta para produção superior com condutividade elétrica recomendada por fase de cultivo, sendo: 0,8 dS m-1 até os 10 dias após o transplantio (DAT); 1,30 dS m-1 dos 10 aos 17 DAT; 1,80 dS m-1 dos 17 aos 24 DAT e 1,30 dS m-1 dos 24 aos 31 DAT.
The food production to meet global demand is a challenge for this century, should be compulsorily intended attention to productive efficiency gains incorporated the available technologies. Among the leafy vegetables, the lettuce stands out in all global cuisine. The current production of lettuce has undergone great advances, especially attributed to the hydroponic production technique. However, it is still necessary to improve the adaptability of hydroponic technology to the climatic conditions of the different regions and to the different needs of the wide range of cultivars present in the market. In this scenario, the proposition of this research arises in response to the demand for information by the productive sector, fulfilling its role in the integration between teaching, research and rural extension, in order to contribute modestly with the productive sector. For that, three experiments were carried out in a NFT hydroponic system, with the objective of evaluating the nutrition and economic production of American lettuce as a function of flow rate, periodicity of exposure and electrical conductivity of the nutrient solution, respectively. The experimental design was in randomized blocks, with five replicates and each treatment consisted of 15 plants. In the experiment 1, the treatments used consisted of the application of nutrient solution at the flow rates of 0.5; 1; 2 and 4 liters per minute in each culture channel. In experiment 2, the treatments were four combinations of intermittent exposure of the nutrient solution at pumping intervals / no pumping interval in minutes: 15/60; 15/30; 15/15 and 15/0. In experiment 3, the treatments were daily maintenance of the nutrient solution in four values of electrical conductivity, of 0.8; 1,3; 1.8 and 2.3 dS m-1, depending on the concentration of nutrients. The conclusions were: The highest production and profitability of American lettuce was obtained with the flow of the nutrient solution of 1 L/min, due to the greater accumulation of nutrients in the aerial part and efficiency of use of these; The highest production and profitability of American lettuce was with cycles of 15/0 minutes, that is, with continuous flow of the nutrient solution due to the greater accumulation of nutrients in the aerial part and efficiency of use of these; Economically, driving in interval 15/30 minutes under the conditions studied, does not supply the cost of production and entails financial loss; The treatments were monitored during the lettuce cycle, indicating a higher yield than the one obtained with the recommended electrical conductivity at each cultivation stage: 0.8 dS m-1 until 10 days after transplanting (DAT) of lettuce; 1.30 dS m-1 from 10 to 17 DAT; 1.80 dS m-1 from 17 to 24 DAT and 1.30 dS m-1 from 24 to 31 DAT.
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Dalastra, Cleiton. "Nutrição e produção de alface americana em função da vazão, periodicidade de exposição e condutividade elétrica da solução nutritiva em sistema hidropônico /." Ilha Solteira, 2017. http://hdl.handle.net/11449/152065.
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Orientador: Marcelo Carvalho Minhoto Teixeira FilhoResumo: A produção de alimento face a demanda mundial é um desafio para este século, devendo-se, obrigatoriamente, destinar atenção ao ganho de eficiência produtiva, incorporada as tecnologias disponíveis. Dentre as hortaliças folhosas, a alface se destaca em toda culinária global. A produção atual da alface tem passado por grandes avanços, atribuídos especialmente à técnica de produção hidropônica, contudo, ainda é necessita melhorias na adaptabilidade da tecnologia hidropônica às condições climáticas das diversas regiões e às diferentes necessidades da gama de cultivares presentes no mercado. Neste cenário, a proposição desta pesquisa surge em resposta à demanda de informações pelo setor produtivo, cumprindo seu papel na integração entre ensino, pesquisa e extensão rural, de maneira a contribuir modestamente com o setor produtivo. Para isso, foram realizados três experimentos isolados em sistema hidropônico NFT (Técnica de Fluxo Laminar de Nutrientes), com o objetivo de avaliar a nutrição e a produção econômica de alface americana em função da vazão, periodicidade de exposição e condutividade elétrica da solução nutritiva, respectivamente. O delineamento experimental foi em blocos casualisados, com cinco repetições e cada tratamento foi composto por 15 plantas. No experimento 1, os tratamentos utilizados constaram da aplicação de solução nutritiva nas vazões de 0,5; 1; 2 e 4 litros por minuto em cada canal de cultivo. No experimento 2, os tratamentos foram quatro combinações de int... (Resumo completo, clicar acesso eletrônico abaixo)
Doutor
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Visentin, Jonathan. "Propriétés des anticorps anti-HLA en transplantation d'organes." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0038/document.
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Les anticorps anti-HLA d’isotype IgG sont une cause de perte de greffon en transplantation d’organes.Les tests « single antigen » (SAFB) sont les outils les plus précis et sensibles pour l’identification desanticorps anti-HLA dirigés contre le donneur (DSA) dans le sérum des receveurs. Leur résultat semiquantitatif,la MFI, n’est pas parfaitement associé à l’issue clinique, ce qui pourrait être dû à plusieursraisons. Premièrement, nous avons montré que les SAFB de classe I détectent fréquemment des anticorpsanti-HLA dénaturé de classe I, incapables de se lier à la surface cellulaire et donc n’ayant pas designification clinique, alors qu’ils ont un impact négatif sur l’accès à la transplantation. Leuridentification a été réalisée par un traitement acide des billes et par un SAFB modifié, les iBeads®.Ces deux tests montraient de bonnes fiabilité et concordance, mais le traitement acide pouvait parfoisêtre mis en défaut alors que les iBeads® auraient une sensibilité légèrement inférieure aux SAFBclassiques. Deuxièmement, nous avons déchiffré l’interférence liée au complément : les IgG anti-HLA de forte MFIsont capables d’activer le complément à la surface des billes, conduisant à une accumulation desproduits de dégradation du C4 et du C3, capables de réduire la détection des IgG anti-HLA. Nousavons également démontré que les IgM anti-HLA étaient capables d’interférer avec la détection desIgG à travers une compétition pour l’épitope, un encombrement stérique et une activation ducomplément. Troisièmement, nous avons montré que la détection des DSA avec les SAFB dans les éluats debiopsies de poumons transplantés, preuve formelle que ces DSA interagissent avec le greffon,constituait un facteur de risque de perte du greffon. Nous avons également développé un système decapture en résonance plasmonique de surface permettant de déterminer la concentration et l’affinitédes anticorps anti-HLA, ce qui pourrait permettre d’étudier la façon dont les DSA interagissent avec legreffonIgG HLA antibodies are a cause of graft loss in organ transplantation. The single antigen flow beadsassays (SAFB) are the most precise and sensitive assays to identify donor specific HLA antibodies(DSA) in recipient’s sera. Their semi-quantitative readout, the mean fluorescence intensity (MFI), is notperfectly associated with graft outcomes, which could be due to several factors.Firstly, we showed that class I SAFB frequently detects denatured class I HLA antibodies which areunable to bind cell surface and then are clinically irrelevant, while they actually impact the access to atransplant. Their identification was performed through SAFB acid-treatment and a modified SAFBassay, the iBeads®. They had a high reliability and a good concordance, but the acid-treatment assaycan be put at fault in a few cases whereas iBeads® appeared slightly less sensitive than classicalSAFB. Secondly, we deciphered the complement interference phenomenon: high MFI level IgG HLAantibodies activate the complement cascade at bead surface, leading to the deposition of C4 and C3degradation products which are able to reduce IgG HLA antibodies detection. We also demonstratedthat IgM HLA antibodies interfere with IgG detection through competition for the epitope, allosterichindrance and complement activation. Thirdly, we demonstrated that the detection of DSA with SAFB in lung biopsy eluates, proving that theDSA interact with the graft, was a risk factor for graft loss. We further developed a capture system insurface plasmon resonance allowing the concentration and affinity of HLA antibodies to bedetermined, which could allow the way that the DSA interact with the graft to be studied
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Kawai, Takayuki. "Studies on High Performance Microscale Electrophoresis Using Online Sample Concentration Techniques." 京都大学 (Kyoto University), 2012. http://hdl.handle.net/2433/157596.
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Lang, Julie, Mark Magbanua, Janet Scott, G. M. Makrigiorgos, Gang Wang, Scot Federman, Laura Esserman, John Park, and Christopher Haqq. "A comparison of RNA amplification techniques at sub-nanogram input concentration." BioMed Central, 2009. http://hdl.handle.net/10150/610005.
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BACKGROUND:Gene expression profiling of small numbers of cells requires high-fidelity amplification of sub-nanogram amounts of RNA. Several methods for RNA amplification are availablehowever, there has been little consideration of the accuracy of these methods when working with very low-input quantities of RNA as is often required with rare clinical samples. Starting with 250 picograms-3.3 nanograms of total RNA, we compared two linear amplification methods 1) modified T7 and 2) Arcturus RiboAmp HS and a logarithmic amplification, 3) Balanced PCR. Microarray data from each amplification method were validated against quantitative real-time PCR (QPCR) for 37 genes.RESULTS:For high intensity spots, mean Pearson correlations were quite acceptable for both total RNA and low-input quantities amplified with each of the 3 methods. Microarray filtering and data processing has an important effect on the correlation coefficient results generated by each method. Arrays derived from total RNA had higher Pearson's correlations than did arrays derived from amplified RNA when considering the entire unprocessed dataset, however, when considering a gene set of high signal intensity, the amplified arrays had superior correlation coefficients than did the total RNA arrays.CONCLUSION:Gene expression arrays can be obtained with sub-nanogram input of total RNA. High intensity spots showed better correlation on array-array analysis than did unfiltered data, however, QPCR validated the accuracy of gene expression array profiling from low-input quantities of RNA with all 3 amplification techniques. RNA amplification and expression analysis at the sub-nanogram input level is both feasible and accurate if data processing is used to focus attention to high intensity genes for microarrays or if QPCR is used as a gold standard for validation.
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Guimarães, Diana Filipa Carmo. "Measurement of lead concentration in biological tissues by atomic spectroscopy techniques." Doctoral thesis, Faculdade de Ciências e Tecnologia, 2011. http://hdl.handle.net/10362/6805.
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Dissertation for the degree of Doctor of Philosophy in PhysicsLead is a toxic element that has no biological role. To increase the knowledge of the mean lead concentrations accumulated and excreted by the organism, a study was developed to measure lead concentrations, using different atomic spectrometry techniques, in several tissues and excretions of Wistar rats. These rats were divided in two groups: one exposed to lead since foetal period, by lead acetate in drinking water, and a control group, not exposed to lead. By collecting samples of rats with different ages it was also studied the influence of age in lead concentrations. The studied organs and excretions were: iliac bone, tibia-fibula, femur, skull, liver, kidney, urine and faeces. When conducting a study like this, the analytical techniques used the knowhow and the ability to understand the physical processes occurring are also of major relevance. In this work it was used the Energy Dispersive X-ray Fluorescence (EDXRF) technique to analyze the solid samples and the Electro Thermal Atomic Absorption Spectrometry (ETAAS) technique to analyze the urine. To carry on with the urine analysis it was developed an Ultrasound Solid-Liquid Extraction (USLE) procedure. This procedure was also applied to analyse brain samples. The Total Reflection X-ray Fluorescence (TXRF) technique was also used to study urine samples and to assess some of the results obtained with ETAAS. In this work, several correlations between the different tissues were found. A possible evidence of pre-natal exposure was verified because the samples belonging to rats with 1 month old presented much higher mean lead concentrations than the concentrations, measured in works of other authors, of rats exposed to lead but not from foetal period. Furthermore, this study seems to corroborate that lead ingestion decreases with age, once it was measured a decrease of lead excretion by faeces with age. It was observed that lead concentration in tissues depends on the type of tissue. Mean lead concentrations measured were higher in bones (iliac, femur, tibia-fibula>skull) - hundreds of ppm, then in kidney - dozens of ppm and finally in liver on the order of ppm. The urine samples had the lowest mean lead concentrations on the order of hundreds/thousands of ppb, and faeces the highest mean lead concentrations, with values of dozens of thousands of ppm. One of the main contributions of this work was to show that lead accumulation and excretion decreases with age by plateaus in all tissues except in the kidneys.
Fundação para a Ciência e Tecnologia - PhD Grant (SFRH/BD/38788/2007); European Community Fund FEDER through the COMPETE - Project No. PEstOE/FIS/UI0303/2011
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Farooqi, Asad Saeed. "Nuclear activation techniques and methods of elemental concentration determination in bioenvironmental studies." Thesis, University of Surrey, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280334.
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Mcvey, White Patrick. "A New Characterization Technique to Analyze Concentrator Photovoltaic Optical System Performance." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/35816.
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Concentrator photovoltaics is a promising renewable energy technology, especially for utility or large-scale deployments. Like all new technologies, it has obstacles and setbacks to overcome. More specifically, the optics in a concentrator photovoltaics system introduce non-uniform spatial and spectral illumination on the cell, which can change under different operating conditions. This work was put together to discover a new characterization technique capable of analyzing the performance of a concentrator photovoltaics and provide insight to the field on what is happening within the system, linking modeling results seen in the literature to these experimental outcomes. The thesis is composed of three journal papers written by the candidate, who’s contributions are outlined at the beginning of each chapter.
In order to study the illumination profiles on the cells, a new method to characterize the optical components had to be developed. Previous version lacked the ability to control the temperature of the lens and had low spectral resolution of the irradiance profiles. To improve, a novel indoor measurement method was developed capable of spectrally imaging concentrator photovoltaics optics and recreate outdoor operating conditions in a controllable environment. With the calibrated system, our test-bench is capable of measuring the spectral distribution with a 10μm2 resolution and characterizing the output of a system to within 3%.
Exploiting this experimental technique, the individual effects of module misalignment, cell to primary distance, and lens temperature was studied for three leading technologies associated with the three generations of concentrator photovoltaics optical architectures. Focusing on Fresnel-based concentrator optics, the performance of silicone on a glass module without a secondary optic is the most sensitive to operating conditions, where lens temperature can decrease the absolute efficiency resulting in a difference of 11% in the annual energy yield. The next two generations have secondary optics but are designed slightly differently. The truncated inverted pyramid, designed independently of the primary optic, favoured higher lens temperature values and there was only a difference of 1% in the energy yield calculation. The primary and secondary optics in the 4-fold Fresnel-Kohler are designed together, due to new development tools, and showed the highest stability under the different operating conditions, demonstrating that concentrator photovoltaics is on the right track to overcoming its onset issue. As the technology matures, future designs can improve on the issues characterized within this thesis.
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Mezzini, Elena <1984>. "New techniques for the remote sensing of foliar nitrogen concentration in forest ecosystems." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5674/.
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During my Doctoral study I researched about the remote detection of canopy N concentration in forest stands, its potentials and problems, under many overlapping perspectives. The study consisted of three parts.
In S. Rossore 2000 dataset analysis, I tested regressions between N concentration and NIR reflectances derived from different sources (field samples, airborne and satellite sensors). The analysis was further expanded using a larger dataset acquired in year 2009 as part of a new campaign funded by the ESA.
In both cases, a good correlation was observed between Landsat NIR, using both TM (2009) and ETM+ (2000) imagery, and N concentration measured by a CHN elemental analyzer.
Concerning airborne sensors I did not obtain the same good results, mainly because of the large FOV of the two instruments, and to the anisotropy of vegetation reflectance. We also tested the relation between ground based ASD measures and nitrogen concentration, obtaining really good results. Thus, I decided to expand my study to the regional level, focusing only on field and satellite measures.
I analyzed a large dataset for the whole of Catalonia, Spain; MODIS imagery was used, in consideration of its spectral characteristics and despite its rather poor spatial resolution. Also in this case a regression between nitrogen concentration and reflectances was found, but not so good as in previous experiences. Moreover, vegetation type was found to play an important role in the observed relationship.
We concluded that MODIS is not the most suitable satellite sensor in realities like Italy and Catalonia, which present a patchy and inhomogeneous vegetation cover; so it could be utilized for the parameterization of eco-physiological and biogeochemical models, but not for really local nitrogen estimate. Thus multispectral sensors similar to Landsat Thematic Mapper, with better spatial resolution, could be the most appropriate sensors to estimate N concentration.
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Grosselin, Nadège. "Mise au point d'une technique voltampérométrique pour la caractérisation de particules individuelles conductrices de quelques dizaines de microns : application à l'étude de l'adsorption des ions argent et mercure ainsi que du thymol sur la pyrite." Nancy 1, 1998. http://www.theses.fr/1998NAN10142.
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Au cours de ce travail, une nouvelle technique ultramicroélectrochimique pour la caractérisation des grains individuels conducteurs de quelques dizaines de microns à été mise au point. Elle permet, en particulier, la détection d'espèces solubles formées à l'électrode sans devoir imposer des vitesses de balayage extrémement élevées comme c'est le cas avec les ultramicroélectrodes conventionnelles (10 MV/S suffisent). Les études sans ajout d'électrolyte support sont aussi possibles. La comparaison des voltampérogrammes de AG#2SE avec ceux obtenus par les méthodes classiques a mis en évidence qu'il est possible de caractériser des grains du minéral sans interférence contrairement aux pates de carbone. La technique a ensuite été utilisée parallélement à des méthodes spectroscopiques pour l'étude de l'adsorption de AG#+ et de HG#2#+ sur la pyrite FES#2 (pulpes à 0,5% en poids). Il s'avère que les spéciations de l'argent et du mercure à la surface de FES#2 dépendent fortement de la concentration des ions métalliques en solution. Dans le cas où l'argent est à faible concentration, seul AG#2S se forme. Quand la concentration est plus forte, de l'argent métallique est aussi présent. De même, selon la concentration en mercure, une ou deux espèces de stabilité différente se fixent à la surface de la pyrite. La quantité maximale de mercure s'adsorbant sur le minéral (3,5 10#-#5 MOL/G) est vingt fois moins importante que celle d'argent (6,6 10#-#4 MOL/G). Quand de la pyrite est conditionnée simultanément avec les ions AG#+ et HG#2#+, seul le mercure est adsorbé à sa surface. Il libère en solution l'argent si ce dernier était préalablement fixe sur le minéral. La quantité de mercure alors adsorbée atteint 3,2 10#-#4 MOL/G. Enfin, l'action du thymol sur la pyrite a été envisagée dans le but d'inhiber l'oxydation chimique du minéral. Les mesures électrochimiques ont montré que c'est le produit d'oxydation du thymol, et non lui-même, qui s'adsorbe sur la pyrite et limite son oxydation
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Heidarkhan, Tehrani Marjan. "Determination of free indium concentration and lability degree of indium complexes using electroanalytical techniques." Doctoral thesis, Universitat de Lleida, 2018. http://hdl.handle.net/10803/620782.
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L'indi és un element que forma amalgames i un dels metalls rars en l'escorça terresre. Té un gran interès aplicat a la indústria (per exemple bateries alcalines, panells solars, pantalles electròniques, etc.). Unes aplicacions tan vastes impliquen que l'indi arribarà finalment al medi ambient i podrien sorgir diversos problemes ecotoxicològics i de salut (per exemple, malalties pulmonars, hepàtiques, renals, etc.).
Per tant, cal trobar tècniques escaients per a determinar concentracions lliures d'indi (III) i paràmetres que indiquin la disponibilitat dels complexos d'indi en diferents medis. En aquesta tesi, proposem que les tècniques electroanalítiques Absence of Gradients and Nernstian Equilibrium Stripping (AGNES) i Accumulation under diffusion limited conditions (ADLC) podrien ser bones opcions. S'han mesurat concentracions lliures d'indi en sistemes amb pH des de 3 fins a 6. S'ha implementat un nou calibratge per a indi i les mesures en dissolucions amb els lligands àcid nitrilotriacètic i oxalat han servit per a triar entre conjunts alternatius de constants d'estabilitat. S'ha aplicat ADLC per a calcular el grau de labilitat de l'oxalat d'indi. Aquesta informació fou una orientació per a trobar temps de deposició adequats en experiments d'AGNES que fins i tot arribaren -en dissolucions precipitades- a concentracions picomolars d'indi lliure. S'ha investigat la dissolució de nanopartícules d'In2O3 en medis sintètics, inclosa l'aigua de mar. Els resultats amb electròlit de fons en dissolucions amb pH des de 2 fins a 4, han revelat que les mesures d'AGNES a cada pH són significativament menors que les predites per NIST 46.7 suposant que la solubilitat fos regida pel In(OH)3. Això és consistent amb el fet que fases menys hidratades presenten menors solubilitats.El indio es un elemento que forma amalgamas y uno de los metales raros en la corteza terrestre. Tiene un gran interés aplicativo en la industria (por ejemplo baterías alcalinas, paneles solares, pantallas electrónicas, etc.). Tan alta aplicabilidad del indio implica que alguna filtración final al medio ambiente es inevitable y podrían aparecer diversos problemas ecotoxicológicos y de salud (por ejemplo, enfermedades pulmonares, hepáticas, renales, etc.). Por lo tanto, es muy necesario encontrar técnicas adecuadas para determinar concentraciones libres de indio y parámetros que indiquen la disponibilidad de complejos de este elemento en diferentes medios. En esta tesis, proponemos que las técnicas electroanalíticas Absence of Gradients and Nernstian Equilibrium Stripping (AGNES) y Accumulation under Diffusion Limited Conditions (ADLC) podrían ser elecciones adecuadas. Se han medido concentraciones libres de indio en sistemas con pH desde 3 hasta 6. Se ha implementado una nueva calibración para indio y las medidas de especiación en soluciones con ligandos ácido nitrilotriacético y oxalato han permitido elegir entre conjuntos alternativos de constantes de estabilidad. Se ha aplicado ADLC para calcular el grado de labilidad de oxalatos e hidróxidos de indio. Esta información es una guía para encontrar tiempos de deposición adecuados en los experimentos AGNES, llegando incluso a determinar en -soluciones precipitadas- concentraciones picomolares de indio libre. Se ha investigado la disolución de nanopartículas de In2O3 en disoluciones sintéticas, incluida el agua de mar. Los resultados en disolución con electrolito de fondo con pH de 2 hasta 4 han revelado que las medidas de AGNES a cada pH son significativamente más bajas que las predicciones de NIST 46.7 si se supone que la solubilidad se rige por In(OH)3. Esto es consistente con el hecho que fases menos hidratadas exhiben solubilidades menores.
Indium is a trivalent amalgamating element and one of the rare metals in the earth crust. It has a vast application interest in the industry (e.g. alkali batteries, solar cells, electronic displays, etc.). Such a high applicability of indium implies that its eventual leakage to the environment is unavoidable and various ecotoxicological and health problems (e.g. lung, liver and kidney diseases, etc.) could appear. Hence, there is a strong need to find proper techniques in order to determine free concentration of indium and parameters indicating the availability of indium complexes in different media. In this thesis, we have proposed that the electroanalytical techniques Absence of Gradients and Nernstian Equilibrium Stripping (AGNES) and Accumulation Under Diffusion Limited Conditions (ADLC) could be proper choices. Free concentration of indium from pH 3 to around 6 has been measured. A new calibration for indium has been implemented and speciation measurements in solutions with nitrilotriacetic acid and oxalate ligands have been carried out successfully. ADLC has been applied to calculate the lability degree of indium oxalate and indium hydroxide compounds. This information is a guideline for adequate deposition times in AGNES experiments. AGNES has been successfully used to determine even picomolar concentration of free indium in precipitated solutions. The dissolution of In2O3 nanoparticles in synthetic solutions including seawater has been investigated. Results in background electrolyte solution from pH 2 to 4, have revealed that AGNES measurements at each pH have been significantly lower than the predictions of NIST 46.7 expectation assuming that solubility was ruled by In(OH)3, consistent with the less hydrated phases exhibiting lower solubilities.
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Paudel, Iru. "Sab Concentration Determines the Chemotherapeutic Efficacy in Gynecological Cancer." FIU Digital Commons, 2018. https://digitalcommons.fiu.edu/etd/3707.
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The American Cancer Society predicts there will be 110,070 new cases and 32,120 deaths due to gynecological malignancies in 2018. A major contributing factor to the high mortality associated with gynecological cancers is the recurrence of treatment-resistant tumors. Ovarian cancer (OC) remains the most lethal gynecological malignancy, yet the mechanisms responsible for regulating tumor resistance and vulnerability are largely unknown or undruggable. Therefore, the goal of this research is to identify mechanisms responsible for therapeutic resistance in gynecological cancers and discover innovative approaches to circumvent these molecular alterations. Our efforts began in OC where secondary analysis of gene expression data from OC studies revealed that Sab, an outer mitochondrial membrane (OMM) scaffold protein, was down-regulated in OC tumors compared to normal tissue controls. Our previous studies demonstrate that Sab-mediated OMM signaling induces cell death in cervical cancer. In the current study, we found that Sab concentrations corresponded to chemoresponsiveness in a panel of OC cells; wherein, OC cells with low Sab levels were chemo resistant. Dynamic BH3 profiling revealed that cells with high Sab expression were primed for apoptosis. Furthermore, over-expression of Sab in chemo resistant cells enhanced apoptotic priming and restored cellular vulnerability to cisplatin/paclitaxel treatment. Additionally, an examination of treatment-resistant metastatic uterine cancer (UC) cells were found to have low Sab concentrations compared to vulnerable primary site-derived UC cells. Ectopic expression of Sab in chemo resistant UC cells enhanced the susceptibility towards megestrol acetate and BH3-mimetic ABT-737. To exploit the relationship between Sab concentrations and chemo-responsiveness in gynecological cancer cells, we developed a high-throughput screening assay to detect Sab levels in chemo-resistant OC cells. In collaboration with the Torrey Pines Institute for molecular studies, we have identified compounds that can increase Sab levels in resistant OC cells. The identified compounds improved the effectiveness of cisplatin/paclitaxel therapy. We propose that Sab may be a prognostic marker to discern personalized treatments for gynecological cancer patients. Furthermore, pharmacologically enhancing Sab-mediated signaling may increase the efficacy of chemotherapeutic agents, which would mean lower doses that would limit toxic side-effects.
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Lao, Martínez Mireia. "Determination of free metal ion concentrations with the speciation techniques agnes and DMT." Doctoral thesis, Universitat de Lleida, 2019. http://hdl.handle.net/10803/667401.
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Des de fa molts anys, els metalls pesants s’han associat amb la contaminació i la toxicitat. Els podem trobar en el medi sota diferents formes químiques, però la comunitat científica coincideix en què els efectes tòxics que provoquen bàsicament depenen de la seva concentració lliure. Per això és important disposar de les tècniques adequades per quantificar-los. Aquesta tesi està centrada en la determinació de la concentració de metall lliure en mostres sintètiques i naturals mitjançant les tècniques analítiques d’AGNES (Absence of Gradients and Nernstian Equilibrium Stripping) i DMT (Donnan Membrane Technique).
En la primera part d’aquest treball, s’ha estudiat el possible impacte en la tècnica electroanalítica AGNES degut a l’adsorció electròdica a través de diferents sistemes (Pb-taronja de xilenol, Cd- àcid poliacrílic i Cd-iodur entre d’altres). S’ha pogut confirmar que quan s’arriba a la situació especial d’equilibri d’AGNES al final de la primera etapa, l’existència d’altres processos d’equilibri (com l’adsorció) no afecta el senyal analític en cap de les variants d’AGNES. També, pels sistemes estudiats, els temps necessaris per arribar a l’estat d’equilibri no es veuen augmentats.
En la segona part, AGNES s’ha aplicat a l’estudi del sistema Zn-glutatió, primer en mostres sintètiques i després en extractes de l’arrel de la planta Hordeum Vulgare, considerant diferents models de complexació. En la determinació en mostres sintètiques, s’ha vist que els resultats teòrics de dos dels models coincideixen amb les determinacions d’AGNES. En el cas de les arrels, la concentració lliure de Zn determinada experimentalment ha estat bastant inferior que la predita teòricament, suggerint per tant la presència d’altres lligands (com altres fitoquelatines) apart del glutatió.
En la tercera part, s’ha estudiat la especiació inorgànica en el vi amb les tècniques AGNES i DMT. Les concentracions de metall lliure determinades en les mostres sintètiques de vi han sigut consistents amb les prediccions teòriques, però el temps necessari per arribar a l’equilibri DMT s’ha vist augmentat. En treballar amb les mostres de vi reals, aquest temps s’incrementa encara més. Pel que fa a la concentració lliure de Zn, els resultats obtinguts amb DMT, utilitzant K i Na com a ions de referència, (1.76 µmol L-1) coincideixen amb els corresponents obtinguts amb AGNES (1.7 µmol L-1). La tècnica DMT s’ha utilitzat també per determinar les concentracions de Fe, Mg i Ca.Desde hace años, los metales pesados se han asociado con la contaminación y la toxicidad. Los podemos encontrar en el medio bajo distintas formas químicas, pero la comunidad científica coincide en que los efectos tóxicos que provocan básicamente dependen de su concentración libre. Por ello es importante disponer de las técnicas adecuadas para cuantificarlos. Esta tesis está enfocada en la determinación de la concentración de metal libre en muestras sintéticas y naturales mediante las técnicas analíticas AGNES (Absence of Gradients and Nernstian Equilibrium Stripping) y DMT (Donnan Membrane Technique). En la primera parte de este trabajo, se ha estudiado el posible impacto en la técnica electroanalítica AGNES debido a la adsorción electródica mediante diversos sistemas (Pb-naranja de xilenol, Cd-ácido poliacrílico y Cd-yoduro entre otros). Se ha confirmado que cuando se llega a la situación especial de equilibrio de AGNES al final de la primera etapa, la existencia de otros procesos de equilibrio (como la adsorción) no afecta a la señal analítica en ninguna de las variantes de AGNES. También para estos sistemas estudiados, el tiempo necesario para llegar al estado de equilibrio no se ve aumentado. En la segunda parte, AGNES se aplica al estudio del sistema Zn-glutatión, primero en muestras sintéticas y después en extractos de la raíz de la planta Hordeum Vulgare, considerando diferentes modelos de complejación. En la determinación en muestras sintéticas, se ha visto que los resultados teóricos de dos de los modelos coinciden con las determinaciones de AGNES. En el caso de las raíces, la concentración libre de Zn determinada experimentalmente ha sido bastante inferior a la predicha teóricamente, sugiriendo por tanto la presencia de otros ligandos (como otras fitoquelatinas) además del glutatión. En la tercera parte, se ha estudiado la especiación inorgánica en el vino con las técnicas AGNES y DMT. Las concentraciones de metal libre determinadas en las muestras de vino sintético han sido consistentes con las predicciones teóricas, pero el tiempo necesario para alcanzar el equilibrio DMT se ve aumentado. Al trabajar con las muestras de vino real, este tiempo todavía se incrementa más. En relación a la concentración libre de Zn, los resultados obtenidos con DMT, utilizando K y Na como iones de referencia, (1.76 µmol L-1) coinciden con los correspondientes obtenidos con AGNES (1.7 µmol L-1). La técnica DMT también se ha utilizado para determinar las concentraciones de Fe, Mg y Ca.
Since many years ago, heavy metals have been associated with contamination and potential toxicity. They can be found in the environment in different chemical forms, but the scientific community agrees that their toxic effects are usually dependent on the concentrations of their free form. So, proper techniques to quantify them are required. This thesis focuses on the determination of free metal concentrations in synthetic or natural samples using the analytical techniques AGNES (Absence of Gradients and Nernstian Equilibrium Stripping) and DMT (Donnan Membrane Technique). In the first part of this work, a possible impact from electrodic adsorption on the electroanalytical technique AGNES has been evaluated through several systems with induced adsorption (Pb-Xylenol Orange, Cd- Polyacrilic Acid and Cd-Iodide among others). It has been confirmed that, when the special AGNES equilibrium situation at the end of the first stage is reached, the existence of other equilibria processes (such as adsorption) does not disturb the analytical signal in any of the AGNES variants. Also, for the assayed systems, the required time to reach the equilibrium state did not need to be extended. In the second part, AGNES has been applied to study the system Zn-Glutathione, first in synthetic samples and later on in root extracts of Hordeum Vulgare, considering different complexation models. In the synthetic samples determination, it has been checked that the theoretical results of two of the models agree with AGNES determinations. With the root extracts, the experimentally determined free Zn concentration was much lower than the predicted one, suggesting the presence of other ligands (such as other phytochelatins) apart from Glutathione. In the third part, the inorganic speciation in wine was studied with AGNES and with the non-electroanalytical technique DMT. Determinations of free metal ion concentrations in synthetic wine were consistent with the predicted ones, but the required time to reach equilibrium with DMT was longer. When working with real wine, it required even longer times. For free Zn concentration, DMT results, using K and Na as reference ions, (1.76 µmol L-1) agreed with the corresponding ones using AGNES (1.7 µmol L-1). The DMT technique has also be used to determine the metal concentrations of Fe, Mg and Ca.
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Verbeke, Véronique. "Concentrations en gaz dans la glace de mer: développements techniques et implications environnementales." Doctoral thesis, Universite Libre de Bruxelles, 2005. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210942.
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La glace de mer couvre jusqu’à 6% de la surface de notre planète. Autour du continent Antarctique, sa superficie varie entre 3.8 et 19 millions de km² (en février et septembre respectivement). Cette superficie présente des variations interannuelles. En parallèle, une évolution de la superficie de la glace de mer a également pour origine le réchauffement climatique global, très médiatisé à l’heure actuelle. Dans ce contexte, et étant donné le rôle que joue la banquise au sein de l’Océan Austral, des études de l’évolution de la glace de mer sont devenues fondamentales. Ce travail a pour objectif d’étudier les relations complexes qui existent entre les processus chimiques, physiques et biologiques qui se déroulent au sein de la glace de mer. La détermination des propriétés physiques et de la composition chimique des glaces de mer correspond en effet à un pré-requis indispensable à l’étude des cycles géochimiques qui existent dans la banquise.
Différentes glaces de mer, naturelles ou artificielles, ont été analysées. Pour ce faire, les caractéristiques spécifiques à ce type de glace font que des méthodes d’analyse de la composition en gaz particulières ont été nécessaires.
Nous avons ainsi pu montrer que le contenu et la composition en gaz des différentes glaces analysées dépendent de facteurs physico-chimiques et de facteurs biologiques. L’impact des facteurs physico-chimiques se marque lors de l’incorporation initiale des impuretés dans la glace de mer et via une diffusion "post-génétique" tant que la glace est plus chaude que –5°C. En outre, les organismes photosynthétiques sont à l’origine d’une production d’oxygène et d’une consommation de dioxyde de carbone. La composition en gaz résultante peut donc être sensiblement différente de la composition atmosphérique ou de celle des gaz dissous dans l’eau de mer sous-jacente, en été comme en hiver. Il s’agit par conséquent de sérieusement envisager l’impact potentiel de la glace de mer et des microorganismes qu’elle contient, lors du réchauffement et de la débâcle, sur les échanges entre atmosphère et océan comme sur leurs compositions respectives.
Doctorat en sciences, Spécialisation géographie
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Rovira, Miquel (Rovira Boixaderas). "Contribution to the development of hydrometallurgical separation and concentration techniques focused on precious metals recovery." Doctoral thesis, Universitat Politècnica de Catalunya, 1998. http://hdl.handle.net/10803/6439.
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Aquesta Tesi Doctoral es centra en la recuperació de metalls precisos presents en dissolucions d'àcid clorhñidric, per mitjà de tècnqiues tant emergents com ben establertes basades en els principis de la tecnologia d'extracció líquid-líquid. La importància d'aquesta temàtica radica en el gran valor i l'escassetat d'aquests metalls. Les principals conclusions extretes d'aquest treball són:- L'extracció liquid-liquid permet una ràpida extracció i stripping de Pd(II) quan s'empra l'extractant DEHTPA dissolt en querosè. El Pd(II) es pot extreure selectivament en presènica d'altres metalls com ara Cu(II), Fe(III), Pt(IV), Rh(III) i Zn(II).
- DEHTPA i Alamine 336 són extractants que han estat emprats en la preparació de resines impregnades que permeten extreure selectivament el Pd(II) així com la co-extracció de Pd(II) i Pt(IV) en presència de Rh(III). Les resines impregnates presenten les avantatges de la tecnologia de bescanvi iònic i mantenen la selectivitat dels extractants. Tot i això, s'ha vist que els processos tant d'extracció com d'stripping presenten cinètiques més lentes en relació amb d'altres tecnologies.. Les resines impregnades també s'han combinat amb la tecnologia de llit fluiditzat permetent el treball en continu.
- Les membranes líquides suportades (MLS) presenten l'atractiu que combinen els processos d'ectracció i stripping en una sola fase. El sistema SLM/DEHTPA permet el transport selectiu de Pd(II), que es troba controlat per fenòmens de difusió. La presència d'impureses en la solució d'alimentació és important donat que pot provocar fenòmens d'obturació en la membrana.
- L'extracció selectiva cloud point (CP) d'Au(III) emprant el surfactant PONPE7.5 s'ha aconseguit a temperatura ambient de forma similar a l'extracció líquid-líquid amb l'avantatge que no es requereix la utilització de dissolvents orgànics. L'aplicació d'aquesta tècnica es va aplicar amjb èxit a la recuperació d'Au provinent de circuits impresos, si bé cal esmentar que en l'etapa d'stripping va ésser necessària la utilització de cloroform.
This thesis is focused on the recovery of precious metals from hydrochloric acid solutions through emergent or well established metal recovery techniques based or on the principles of solvent extraction technology. This subject is of a great importance due to the high value and scarcity of precious metals, consequently the need of developing and consolidating new separation and concentration processes is imperative.
The main conclusions derived from this work are:
- Liquid-liquid extraction allow fast Pd(II) extraction and stripping when the extractant DEHTPA dissolved in kerosene is used as organic phase. Pd(II) can be selectively extracted by DEHTPA over Cu(II), Fe(III), Pt(IV), Rh(III) and Zn(II).
- DEHTPA and Alamine 336 are appropiate extractants for preparation of impregnated resins suitable for selective extraction of Pd(II) over metal impurities and co-extraction of Pd(II) and Pt(IV) against Rh(III). Impregnated resins maintain the advantages of ion-exchange technology, and also keep the selective characteristics of the extractants. However, the extraction and stripping kinetics of impregnated resins are slow compared to solvent extraction. Impregnated resins have also benn combined with fluidized bed technology allowing continuous operation.
- Supported liquid membranes (SLM) are very attractive since they combine the processes of extraction and stripping in a single stage. SLM/DEHTPA system permits selective Pd(II) transport on a diffusion controlled process. The presence of impurities inn the feed solution may cause blockage of the membrane.
- Selective cloud point (CP) extraction of Au(III) using the surfactant PONPE7.5 is achieved at ambient temperature in a similar manner as in solvent extraction not requiring the use of organic solvents. The application of CP extraction is demonstrated for the recovery of Au from a printed substrate, although the usage of an organic solvent, chloroform, is necessary in the stripping step.
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Gudin, de Vallerin Edouard. "Aspects techniques et réglementaires de la concentration des sites de production dans l'Europe de 1992." Paris 5, 1993. http://www.theses.fr/1993PA05P225.
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Kanani, Bahareh. "LIPID PRODUCTION BY SCENEDESMUS DIMORPHUS COMPARISON: OF EXTRACTION TECHNIQUES AND EFFECT OF SODIUM NITRATE CONCENTRATION." Cleveland State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=csu1370519484.
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Reinhardt, Bruno. "Compréhension et évaluation du comportement des suspensions gaz-solide à forte charge dans les techniques de séparation aéraulique." Valenciennes, 1996. https://ged.uphf.fr/nuxeo/site/esupversions/a37df539-7e5e-4347-b8e6-7f15fd2cfb0f.
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L'optimisation du fonctionnement des cyclones peut être réalisée à partir d'études expérimentales sur maquettes. La première partie traite de la similitude: des caractérisations aérodynamiques (à vide) dans deux cyclones homothétiques mettent en évidence deux types d'écoulements et une similitude partielle. Dans une seconde partie, nous exposons les résultats des mesures de vitesse et de concentration qui permettent d'analyser la structure de l'écoulement. Nous présenterons dans la dernière partie les calculs réalisés à l'aide d'un code de simulation numérique.
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Martz-Kuhn, Émilie. "Écritures scéniques de la catastrophe humaine dans le théâtre contemporain : étude de cas et recherche-création." Doctoral thesis, Université Laval, 2013. http://hdl.handle.net/20.500.11794/24393.
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Cette thèse de doctorat en littérature et arts de la scène et de l’écran examine les écritures scéniques de la catastrophe humaine dans le théâtre contemporain. Elle explore les dynamiques qui sous-tendent la représentation de la barbarie au sein de formes spectaculaires marquées par une forte dimension visuelle. Divisé en deux volets – un premier, critique et un second, pratique –, le travail s’articule d’abord autour d’un corpus composé de trois spectacles : Kamp du collectif Hotel Modern, Rwanda 94 du Groupov et Rouge décanté signé par Guy Cassiers. En observant les œuvres à la lumière de la complexité et en les abordant à l’aide d’une approche systémique, l’étude tente de révéler les mouvements – esthétiques, perceptifs et thématiques – qui animent ces écritures hétérogènes. La seconde partie de la thèse rend compte d’un processus d’expérimentation mené dans l’espace scénique. Ce dernier, consacré à esquisser une création artistique originale, questionne les mémoires occidentales du génocide des Tutsi du Rwanda. L’expérience pratique fait écho à plusieurs des problématiques soulevées par l’investigation critique et propose une autre forme de réflexion, menée directement sur le plateau. Mots clés : Théâtre contemporain, Recherche-création, Complexité, Génocide, Images, Europe.This doctoral thesis in performing arts looks into scenic writings of human disasters in contemporary theatre. It examines dynamics underlying the representation of barbarism within spectacular forms imprinted with a visual dimension. Split into two parts – a first one, critical and a second one, practical -, the work is firstly structured around a corpus composed of three shows : Kamp of the Hotel Modern group, Rwanda 94 of Groupov and Rouge décanté by Guy Cassiers. Through the observation of the works in the light of the complexity and by analysing it with a systemic approach, the study attempts to reveal the moves – aesthetic, perceptive and thematic – that drive these heterogeneous writings. The second part of the thesis deals with a process of experimentation led in the scenic space. The latter, dedicated to outline an original artistic creation, questions occidental memories on the Tutsi genocide in Rwanda. The practical experience echoes back to several issues raised by the critical investigation and proposes another form of reflection, directly led on the stage. Keywords : Contemporary theatre, Research-creation, Complexity, Genocide, Images, Europe.
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Kingsnorth, Andrew P. "Measurement of physical activity, sedentary time and continuous glucose concentrations : novel techniques for behavioural profiling." Thesis, Loughborough University, 2017. https://dspace.lboro.ac.uk/2134/25492.
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STUDY 1. INTRODUCTION. Insufficient physical activity is a major risk factor for developing type 2 diabetes. Using isotemporal substitution models, the influence of replacing modest durations of sedentary time with physical activity on diabetes risk scores can be studied. The aims of this study were to examine the relationship between diabetes risk scores, sedentary time and physical activity measured using wrist worn accelerometry, and to model the changes in risk scores by reallocating movement behaviours from lower to a higher intensity. METHODS. Data from 251 (93 males; aged 56.7 ± 8.8) participants from a mixed ethnicity cohort from Leicestershire, UK were selected for analysis. The relationship between diabetes risk (using the Leicester Diabetes Risk Assessment Score), physical activity and sedentary time was identified using multiple linear regressions and isotemporal substitution analysis. Models were calculated for main effects and also adjusted for peak oxygen uptake (VO2) and accelerometer wear time. RESULTS. Both unadjusted and adjusted models revealed that diabetes risk was inversely related to sedentary time, and positively related to light and moderate to vigorous physical activity (MVPA) (p < 0.0005). Unadjusted, the replacement of sedentary time with 10 minutes of either light or MVPA resulted in a reduction in diabetes risk score of -0.22 and -0.54, respectively. There was an eight to nine times greater reduction in risk for the same MVPA replacement models when the least active participants were compared to the pooled analysis (3.601 unadjusted). CONCLUSION. Diabetes risk is associated with sedentary time and physical activity estimated from wrist worn accelerometry. The replacement of sedentary time with MVPA is most beneficial for the least active individuals. STUDY 2. INTRODUCTION. Most associations between physical behaviours and health are assessed using intensity and duration based estimations; however, individuals accrue physical activity in differing ways and behavioural profiles have been linked with varying cardiometabolic risk factors. The frequency or regularity of behaviour may hold additional relationships with health, but have not been extensively explored. Accelerometers provide researchers with a large stream of raw data to analyse. The aim of this paper was to calculate a novel method of behavioural regularity called sample entropy from wrist worn accelerometry and to ascertain whether there are associations with cardiometabolic risk factors in adults. METHODS. Data from 290 (107 males; aged 57.0 ± 8.8) participants from a mixed ethnicity cohort from Leicestershire, UK were selected for analysis. Entropy scores were calculated using 60-second count data within MATLAB. The relationship between entropy scores, physical activity, sedentary time and cardiometabolic risk factors was identified using multiple linear regressions. Models were calculated for main effects and also adjusted for age, sex, accelerometer wear time and body mass index (BMI). RESULTS. Sample entropy scores were significantly related to high-density lipoprotein (HDL) cholesterol (b = 0.148, p = 0.042), triglycerides (b = -0.293, p = 0.042) and glycated haemoglobin (HbA1c) (b = -0.225, p = 0.006), even after adjustment for confounding variables. Traditional intensity estimates of physical activity were not associated; however, the frequency of breaks in sedentary time were significantly related to entropy scores (b = 0.004, p = 0.002). CONCLUSION. Using a novel measure of signal complexity, associations have been revealed with cardiometabolic risk factors; however further analysis in a larger, more diverse dataset is required to ascertain the utility of this technique within behavioural research and if so, what constitutes typical/average levels of entropy within a population. STUDY 3. INTRODUCTION. Acute physiological changes such as reductions in postprandial glucose excursions have been demonstrated within experimental studies that have compared being physically active to sedentary conditions. However, for this information to be truly useful, the coupling of behaviour and glucose data in a free-living environment needs to be achieved. The aim of the study was to ascertain if there is a relationship between objectively measured physical activity, sedentary time and glucose variability using glucose monitoring in an adult population. METHODS. Data from 29 participants recruited from a mixed gender sample from Leicestershire, UK were selected for analysis. Physical activity, sedentary time and interstitial glucose was measured continuously over 14 days using an accelerometer and the Freestyle Libre flash glucose monitor. Daily time (minutes) spent sedentary, and in light activity and moderate to vigorous physical activity (MVPA) were regressed against glycaemic variability indices including daily mean (average) glucose, standard deviation and mean amplitude of glycaemic excursions (MAGE). Generalised Estimating Equations were calculated between behaviour and glycaemic variability variables. Models were calculated for main effects and also adjusted for age, gender and accelerometer wear time. RESULTS. Physical activity and sedentary time were associated with measures of glucose variability, however low fitness individuals showed a stronger relationship between MVPA and MAGE (MAGE: whole sample b = -0.002, low fitness b = -0.012. Additionally, after adjustment for covariates, sedentary time was positively associated with a higher daily mean glucose (b = 0.001, p = 0.001) and MAGE (b = 0.002, p < 0.0005) for the low fitness group. MVPA was negatively associated with mean glucose (b = -0.004, p < 0.0005) and MAGE (b = -0.012, p < 0.0005); however, standard deviation of glucose was not associated with behaviour of any intensity. The magnitudes of the relationships were small, although participants were non-diabetics and exhibited relatively good glucose control i.e. minimal fluctuations in daily glucose variability. CONCLUSION. This study shows that sedentary time, physical activity and glucose variability are related. Despite supporting the previous laboratory research, it is uncertain whether any changes in glucose will reliably occur in all individuals. MVPA confers the largest reductions in glucose variability indices, yet as one of the few studies to couple behaviour and glucose data, more research is needed on larger and more diverse samples.
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Gummadi, Jayaram. "A Comparison of Various Interpolation Techniques for Modeling and Estimation of Radon Concentrations in Ohio." University of Toledo / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1376567646.
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