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1

Iglesias, Angel Moises. "Investigating Various Modal Analysis Extraction Techniques to Estimate Damping Ratio." Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/35890.

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Many researchers have devoted their work to the development of modal analysis extraction techniques in order to obtain more reliable identification of the modal parameters. Also, as a consequence of all this work, there are some other works devoted to the evaluation and comparison of these methods in order to find which one is the most reliable method with respect to certain characteristics. In this thesis the Rational Fraction Polynomial (RFP) Method, the Prony or Complex Exponential Method (CEM), the Ibrahim Time Domain (ITD) Method, and Hilbert Envelope Method are used to evaluate how the accuracy of the damping ratio is affected with respect to various parameters and conditions. The investigation focuses in the estimation of damping ratio because among the modal parameters, it is the most difficult to model. Each method is evaluated individually in order to understand how the damping ratio estimation is affected with respect to each method when the characteristics of the FRF are changed. Also, they are compared to show that, in general, the Rational Fraction Polynomial Method is a more reliable method than the other methods. To investigate this, a simulated analytical data and an experimental data are processed to estimate the modal parameters, but focusing in the damping ratio. For the simulated analytical data the damping ratio's percent of error were calculated. The highest damping ratio's percent of error of the RFP was 0.0073501%. In the other hand, for the CEM, ITD, and Hilbert Envelope Method their highest damping ratio's percent of error were 83.02%, 99.82%, and 4.077%, respectively.<br>Master of Science
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2

Shilstone, Gavin Forbes. "Physical properties in supercritical fluids applied to extraction and chromatography." Thesis, University of Leeds, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277481.

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3

Erdem, Mehmet Erkut. "Image-based Extraction Of Material Reflectance Properties Of A 3d Object." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/1128784/index.pdf.

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In this study, an appearance reconstruction method based on extraction of material re&amp<br>#64258<br>ectance properties of a three-dimensional (3D) object from its twodimensional (2D) images is explained. One of the main advantages of this system is that the reconstructed object can be rendered in real-time with photorealistic quality in varying illumination conditions. Bidirectional Re&amp<br>#64258<br>ectance Distribution Functions (BRDFs) are used in representing the re&amp<br>#64258<br>ectance of the object. The re&amp<br>#64258<br>ectance of the object is decomposed into di&amp<br>#64256<br>use and specular components and each component is estimated seperately. While estimating the di&amp<br>#64256<br>use components, illumination-invariant images of the object are computed from the input images, and a global texture of the object is extracted from these images by using surface particles. The specular re&amp<br>#64258<br>ectance data are collected from the residual images obtained by taking di&amp<br>#64256<br>erence between the input images and corresponding illumination-invariant images, and a Lafortune BRDF model is &amp<br>#64257<br>tted to these data. At the rendering phase, the di&amp<br>#64256<br>use and specular components are blended into each other to achieve a photorealistic appearance of the reconstructed object.
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4

Wright, Stewart Victor. "Chiral symmetry and the extraction of hadron properties from lattice QCD." Title page, abstract and contents only, 2001. http://web4.library.adelaide.edu.au/theses/09PH/09phw953.pdf.

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"December 2001." Author's previously published articles appended. Bibliography: leaves 138-147. Describes a method of extrapolating from the heavy quark regime, where lattice caculations now occur, to physical quark masses, which carefully incorporates key model independent constraints, especially those imposed by chiral symmetry. This extrapolation method allows the extraction, not only of physical hadron masses with high accuracy, but also the of other properties, including the pion-nucleon sigma term and the J parameter for the vector mesons.
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5

Maia, Nuno Manuel Mendes. "Extraction of valid modal properties from measured data in structural vibrations." Thesis, Imperial College London, 1989. http://hdl.handle.net/10044/1/47551.

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6

Paredes, Heller Juan Jacobo. "The Influence of Hot Water Extraction on Physical and Mechanical Properties of OSB." Fogler Library, University of Maine, 2009. http://www.library.umaine.edu/theses/pdf/ParedesJJ2009.pdf.

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7

Lewis, Jacob Christian. "Extraction of Electromagnetic Properties of Metamaterials with Branch Compensation from Phase Tracking." Thesis, North Dakota State University, 2020. https://hdl.handle.net/10365/31848.

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In the field of electromagnetism, there are materials known as metamaterials which exhibit unique properties that can be exploited. Permittivity, defined as capacitance per meter, of a metamaterial can vary over frequency , time, or even be negative. This can be useful for tuning antennas, changing their operating frequency or direction of propagation, or even designing cloaking systems. However, the theory behind metamaterials needs to be studied further. One of the biggest issues to address is in determining the constitutive parameters of metamaterials which may be varying. Previous research has shown the issue of branches, or mathematical discontinuities, occurring in the derivation of permittivity from the scattering parameters of a metamaterial. This thesis provides further understanding to the theory behind these branches and presents a new method to compensate for them. This new method, called the phase tracking method, may be considered a modern adaptation of the Nicolson-Ross-Weir method.
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8

Wicker, Jerome. "Crystallization properties of molecular materials : prediction and rule extraction by machine learning." Thesis, University of Oxford, 2017. https://ora.ox.ac.uk/objects/uuid:34beef4e-e499-4248-8fa6-7e8d8344f02c.

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Crystallization is an increasingly important process in a variety of applications from drug development to single crystal X-ray diffraction structure determination. However, while there is a good deal of research into prediction of molecular crystal structure, the factors that cause a molecule to be crystallizable have so far remained poorly understood. The aim of this project was to answer the seemingly straightforward question: can we predict how easily a molecule will crystallize? The Cambridge Structural Database contains almost a million examples of materials from the scientific literature that have crystallized. Models for the prediction of crystallization propensity of organic molecular materials were developed by training machine learning algorithms on carefully curated sets of molecules which are either observed or not observed to crystallize, extracted from a database of commercially available molecules. The models were validated computationally and experimentally, while feature extraction methods and high resolution powder diffraction studies were used to understand the molecular and structural features that determine the ease of crystallization. This led to the development of a new molecular descriptor which encodes information about the conformational flexibility of a molecule. The best models gave error rates of less than 5% for both cross-validation data and previously-unseen test data, demonstrating that crystallization propensity can be predicted with a high degree of accuracy. Molecular size, flexibility and nitrogen atom environments were found to be the most influential factors in determining the ease of crystallization, while microstructural features determined by powder diffraction showed almost no correlation with the model predictions. Further predictions on co-crystals show scope for extending the methodology to other relevant applications.
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9

Suleiman, David. "A new apparatus for the determination of phase equilibrium properties of heavy hydrocarbon systems." Thesis, Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/10087.

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10

TRIPATHY, SAKYASINGH. "EXTRACTION OF NON-LINEAR MATERIAL PROPERTIES OF BIO-GELS USING ATOMIC FORCE MICROSCOPY." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1123381089.

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11

Mamidanna, Pranav. "Optimizing Neural Source Extraction Algorithms: A Performance Measure Based on Neuronal Network Properties." Thesis, KTH, Numerisk analys, NA, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-210052.

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Extracting neural activity from electrophysiological and calcium All existing automated algorithms for this purpose, however, rely heavily on manual intervention and parameter tuning. In this thesis, we introduce a novel performance measure based on well-founded notions of neuronal network organization. This enables us to systematically tune parameters, using techniques from statistical design of experiments and response surface methods. We implement this framework on an algorithm used to extract neural activity from microendoscopic calcium imaging datasets, and demonstrate that this greatly reduces manual intervention.<br>Extraktion av neuronal aktivitet från elektrofysiologiska och kalciumavbildningsmätningar utgör ett viktigt problem inom neurovetenskapen. Alla existerande automatiska algoritmer för detta ändamål beror dock i dagsläget på manuell handpåläggning och parameterinställning. I detta examensarbete presenterar vi ett nytt prestandamått baserat på välgrundade begrepp rörande organisationen av neuronala nätverk. Detta möjliggör en systematisk parameterinställning genom att använda tekniker från statistisk experimentdesign och response surface-metoder. Vi har implementerat detta ramverk för en algoritm som används för att extrahera neuronal aktivitet från mikroendoskopisk kalciumavbildningsdata och visar att detta förfarande avsevärt minskar behovet av manuell inblandning.
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12

Gastaldello, Silvia <1986&gt. "Emerging plant-based proteins: comparison from extraction to functional properties and food application." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amsdottorato.unibo.it/9846/1/SilviaGastaldello%20Dissertation.pdf.

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The increasing demand for alternatives to meat food products, which is linked to ethical and environmental reasons, highlights the necessity of using different protein sources. Plant proteins provide a valid option, thanks to the relative low costs, high availability and wide supply sources. The current process used to produce plant concentrates and isolates is the alkaline extraction followed by isoelectric precipitation. However, despite the high purity of the proteins, it presents some drawbacks. Innovative protein extraction processes are emerging, with the aim of reducing the environmental impact and the costs, as well as improving the functional properties. In this study, the traditional wet protein extraction and another simplified wet process were used to obtain protein-rich extracts out of different plants. The sources considered in the project were de-oiled sunflower and canola, chickpea, lentils, and the camelina meal, an emerging oleaginous seed interesting for its high content of omega 3. The extracts obtained from the two processes were then analysed for their capacities to hold water and fat, to form gel and a stable foam. Results highlighted strong differences concerning the protein content, yield and functionalities. The extracts obtained with the alkaline process confirmed the literature data about the four plant sources (sunflower, canola, chickpea and lentils) and allow to obtain a camelina concentrate with a protein content of 63 % and a protein recovery of 41 %. The second easiest process was not effective to obtain a protein enrichment in oleaginous sources, whereas an enrichment of 10 and 15 % was obtained in chickpea and lentils, respectively. The functional properties were also completely different: the easiest process produced protein ingredients completely water-soluble at pH 7, with a discrete foaming capacity compared to the extracts obtained with alkaline process. These characteristics could make these extracts suitable for the plant milk-analogue products.
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13

Chen, Ting. "Physicochemical properties of nickel and cobalt sulphate solutions of hydrometallurgical relevance." Thesis, Chen, Ting (2003) Physicochemical properties of nickel and cobalt sulphate solutions of hydrometallurgical relevance. PhD thesis, Murdoch University, 2003. https://researchrepository.murdoch.edu.au/id/eprint/653/.

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Producing nickel and cobalt metal by high pressure acid leaching (HPAL) of nickel laterites is becoming one of Australia's largest mineral processing industries. However, the background chemical information for this process, including the fundamental physicochemical properties of acidic metal sulphate leachate solutions, is not well known. In order to improve the efficiency of current and future HPAL plants, high quality physicochemical and thermodynamic data will be necessary. This thesis reports measurements on the densities and heat capacities of nickel and cobalt sulphate solutions and their mixtures along with detailed studies of the nature of the species present and the thermodynamics of their interconversions. Densities and heat capacities of nickel and cobalt sulphate and perchlorate solutions and their ternary mixtures were measured using a vibrating tube densimeter and a flow microcalorimeter respectively. These data were used to calculate the apparent molal volumes and heat capacities of these solutions. Standard partial molal quantities were then obtained by appropriate extrapolation procedures, along with the volume and heat capacity changes of ion pair formation. A comparison has been made between experimental densities and heat capacities with those predicted by Young's rule. Good agreement was obtained except when the degree of complexation varied significantly in the mixtures. The various ion pair species in nickel and cobalt sulphate solutions, along with those of magnesium sulphate (which is a major impurity in HPAL leachates), were reinvestigated by dielectric relaxation spectroscopy. Doubly solvent separated ion pairs, solvent shared ion pairs and contact ion pairs were shown to exist simultaneously in solution and their concentrations were determined from dilute to near-saturated concentrations. Evidence for the possible existence of a triple ion, M2SO4 2+, was also obtained in highly concentrated solutions. The equilibrium constants of the stepwise reactions and the effective hydration numbers of ions and ion pairs were also calculated. The heats of complexation of nickel(II) and cobalt(II) sulphate were determined at different ionic strengths in sodium perchlorate media by titration calorimetry. These data were fitted to a specific ion interaction model to obtain the standard state values. The corresponding entropies of complexation were calculated and were found to be the major contributor to the stability of the complexes.
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14

Chen, Ting. "Physicochemical Properties of Nickel and Cobalt Sulphate Solutions of Hydrometallurgical Relevance." Murdoch University, 2003. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20040706.144034.

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Producing nickel and cobalt metal by high pressure acid leaching (HPAL) of nickel laterites is becoming one of Australia's largest mineral processing industries. However, the background chemical information for this process, including the fundamental physicochemical properties of acidic metal sulphate leachate solutions, is not well known. In order to improve the efficiency of current and future HPAL plants, high quality physicochemical and thermodynamic data will be necessary. This thesis reports measurements on the densities and heat capacities of nickel and cobalt sulphate solutions and their mixtures along with detailed studies of the nature of the species present and the thermodynamics of their interconversions. Densities and heat capacities of nickel and cobalt sulphate and perchlorate solutions and their ternary mixtures were measured using a vibrating tube densimeter and a flow microcalorimeter respectively. These data were used to calculate the apparent molal volumes and heat capacities of these solutions. Standard partial molal quantities were then obtained by appropriate extrapolation procedures, along with the volume and heat capacity changes of ion pair formation. A comparison has been made between experimental densities and heat capacities with those predicted by Young's rule. Good agreement was obtained except when the degree of complexation varied significantly in the mixturesThe various ion pair species in nickel and cobalt sulphate solutions, along with those of magnesium sulphate (which is a major impurity in HPAL leachates), were reinvestigated by dielectric relaxation spectroscopy. Doubly solvent separated ion pairs, solvent shared ion pairs and contact ion pairs were shown to exist simultaneously in solution and their concentrations were determined from dilute to near-saturated concentrations. Evidence for the possible existence of a triple ion, M2SO4 2+, was also obtained in highly concentrated solutions. The equilibrium constants of the stepwise reactions and the effective hydration numbers of ions and ion pairs were also calculated. The heats of complexation of nickel(II) and cobalt(II) sulphate were determined at different ionic strengths in sodium perchlorate media by titration calorimetry. These data were fitted to a specific ion interaction model to obtain the standard state values. The corresponding entropies of complexation were calculated and were found to be the major contributor to the stability of the complexes.
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15

McKim, Artie S. "Synthesis and Alkali Metal Extraction Properties of Novel Cage-Functionalized Crown Coronands and Cryptands." Thesis, University of North Texas, 1999. https://digital.library.unt.edu/ark:/67531/metadc277666/.

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16

Muthukumarasamy, Muthulakshmi. "EXTRACTION AND PREDICTION OF SYSTEM PROPERTIES USING VARIABLE-N-GRAM MODELING AND COMPRESSIVE HASHING." UKnowledge, 2010. https://uknowledge.uky.edu/gradschool_diss/800.

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In modern computer systems, memory accesses and power management are the two major performance limiting factors. Accesses to main memory are very slow when compared to operations within a processor chip. Hardware write buffers, caches, out-of-order execution, and prefetch logic, are commonly used to reduce the time spent waiting for main memory accesses. Compiler loop interchange and data layout transformations also can help. Unfortunately, large data structures often have access patterns for which none of the standard approaches are useful. Using smaller data structures can significantly improve performance by allowing the data to reside in higher levels of the memory hierarchy. This dissertation proposes using lossy data compression technology called ’Compressive Hashing’ to create “surrogates”, that can augment original large data structures to yield faster typical data access. One way to optimize system performance for power consumption is to provide a predictive control of system-level energy use. This dissertation creates a novel instruction-level cost model called the variable-n-gram model, which is closely related to N-Gram analysis commonly used in computational linguistics. This model does not require direct knowledge of complex architectural details, and is capable of determining performance relationships between instructions from an execution trace. Experimental measurements are used to derive a context-sensitive model for performance of each type of instruction in the context of an N-instruction sequence. Dynamic runtime power prediction mechanisms often suffer from high overhead costs. To reduce the overhead, this dissertation encodes the static instruction-level predictions into a data structure and uses compressive hashing to provide on-demand runtime access to those predictions. Genetic programming is used to evolve compressive hash functions and performance analysis of applications shows that, runtime access overhead can be reduced by a factor of ~3x-9x.
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17

Bates, Gareth William. "An investigation into the molecular recognition, structural and extraction properties of hydrogen bonding anion receptors." Thesis, University of Southampton, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.445502.

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18

Zhou, Junchao. "LIGHT EXTRACTION EFFICIENCY IN III-NITRIDE LIGHT-EMITTING DIODES AND PIEZOELECTRIC PROPERTIES IN ZNO NANOMATERIALS." Case Western Reserve University School of Graduate Studies / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=case1465399583.

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19

Kalmoni, Iman. "Extraction and determination of chemical and physical properties of antimicrobial compounds from a Swedish mushroom." Thesis, Umeå universitet, Kemiska institutionen, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-137294.

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20

Tangkhavanich, Boonnakhom. "Properties of Extracts Obtained from Rice Straw by Its Subcritical Fluid Treatment." Master's thesis, Kyoto University, 2013. http://hdl.handle.net/2433/180516.

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Kyoto University (京都大学)<br>0048<br>新制・課程博士<br>博士(農学)<br>甲第17899号<br>農博第2022号<br>新制||農||1017(附属図書館)<br>学位論文||H25||N4795(農学部図書室)<br>30719<br>京都大学大学院農学研究科食品生物科学専攻<br>(主査)教授 安達 修二, 教授 入江 一浩, 教授 谷 史人<br>学位規則第4条第1項該当
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21

Kanter, Claudia. "Extraction of Driving Modes for Dynamic Speed Adaptation in Curves." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-215059.

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Modern cars have a multitude of driver assistance functions that aim to support the driver in his/her everyday driving. One part of this is the Adaptive Cruise Control (ACC) that aims to keep a driver-specified speed. However, this set speed might be perceived as too high for some curves and as a result the driver will interrupt the system and take control again. To avoid this, a Curve Speed Adaptation (CSA) system aims to adapt the speed for an upcoming curve. Such a system should aim to mimic a driver and take into consideration how the driver would behave if he/she were to drive. This work aims to find a set of so-called Driving Modes that can describe how drivers with different driving styles drive through curves with different road properties by analysing recorded manual driving. A nested clustering approach is tested to divide curves into groups based on the driving style they were driven at and their road properties. The results show that this approach is able to capture different driving behaviours through curves. The road type and speed limit of a curve seem thereby to have the main influence on the driving behaviour. Clustering curves first by their driving style followed by the road properties yields thereby the more distinguishable Driving Modes. However, further improvements of the clustering methods are necessary to improve the obtained Driving Modes. The results of this thesis can form the basis for the development of a Curve Speed Adaptation system that adjusts for both the individual driver as well as particular road properties to improve the driver's comfort.<br>Moderna bilar har en mängd förarstödsystemer som syftar till att stödja föraren i sin dagligakörning. En av dem är Adaptive Cruise Control (ACC) som syftar till att hålla en hastighetspecificerad av föraren. Men denna hastighet kan uppfattas som för hög för vissa kurvoroch som resultat tar föraren kontrollen igen själv. För att undvika detta ska ett Curve SpeedAdaptation (CSA) system anpassa hastigheten för en kommande kurva. Ett sådant systembör sträva efter att efterlikna en förare och ta hänsyn till hur föraren skulle köra själv. Dethär examensarbetet syftar till att hitta så kallade körlägen som kan beskriva hur förare medolika körstilar kör genom kurvor med olika omständigheter genom att analysera manuellakörningar. En nestad klustringsmetod testas för att dela upp kurvor i grupper baserat påkörstilen som de kördes på och deras vägegenskaper. Resultaten visar att denna metod kanfånga olika körningsbeteenden genom kurvor. Vägtypen och hastighetsbegränsningen fören kurva verkar därmed ha huvudinverkan på körbeteendet. Att dela kurvorna först efterderas körstil följt av vägegenskaper ger bättre körlägena. Men ytterligare förbättringar avklustringsmetoderna är nödvändig för att förbättra de erhållna körningsmetoderna. Resul-taten av detta examensarbetet kan utgöra grunden för utvecklingen av ett kurvhastighetsanpassningssystem som anpassar både för den enskilda föraren och speciella vägegenskaperför att förbättra förarens komfort.
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Islam, Muhammad Aminul. "Microalgae: An alternative source of biodiesel for the compression ignition (CI) engine." Thesis, Queensland University of Technology, 2014. https://eprints.qut.edu.au/79551/4/Muhammad%20Aminul%20Islam%20Thesis.pdf.

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This thesis is a comprehensive study of microalgae biodiesel for the compression ignition engine. It examines microalgae growing conditions, the extraction process and physiochemical properties with a wide range of microalgae species. It also evaluates microalgae biodiesel with regards to engine performance and emission characteristics and explains the difficulties and potentiality of microalgae as a biodiesel. In doing so, an extensive analysis of different extraction methods and engine testing was conducted and a comprehensive study on microalgae biodiesel is presented.
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Dai, Jin. "PREPARATION AND CHARACTERIZATION OF BLACKBERRY EXTRACTS AND THEIR ANTICANCER AND ANTI-INFLAMMATORY PROPERTIES." UKnowledge, 2009. http://uknowledge.uky.edu/gradschool_diss/739.

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Blackberries are rich in polyphenols including anthocyanins. Polyphenols are hypothesized to have biological activities that impact positively on human health. The purpose of these studies was to develop phenolic extracts from selected cultivars of blackberries currently grown in Kentucky as potential Botanical Drug Products for the treatment and prevention of cancer and inflammatory diseases. An ultrasound-assisted ethanol extraction method was employed to obtain anthocyanin-containing extracts (ACEs) from puree or powder (lyophilized puree) of blackberries. ACEs were analyzed for total anthocyanin and phenolics content, polymeric color, and total antioxidant capacity (TAC). The influence of water content in the extraction system was evaluated. A 90 day stability study of the extract and a 48 h stability study of the extract in biologically relevant buffers were completed. HPLC-MS results showed the anthocyanins in ACE were mainly cyanidin-based. As compared to powder-derived ACEs, puree-derived ACEs contained similar amounts of anthocyanins, but greater levels of phenolics and increased TAC. The in vitro antiproliferative effects of ACEs were evaluated in human leukemia (HL- 60), colon (HT-29), and breast (MCF-7) cancer cells. The anticancer mechanism involving reactive oxygen species (ROS) generation was investigated. It was found puree-derived ACEs significantly enhanced production of H2O2 and cytotoxicity in all cell lines as compared to powder-derived ACEs. Cyanidin 3-glucoside exerted anticancer effect by acting synergistically or additively with other active components in the extracts. Furthermore, the phenolic-enriched fractions were separated from non-phenolic fractions in ACEs and found to have potent antioxidant and antiproliferative activities. Pureederived ACE and corresponding phenolic-enriched methanol fraction (MF) induced cell death through ROS-independent caspase 3 pathway whereas the cytotoxicity induced by powder-derived ACE and corresponding MF is related to ROS mechanisms. The in vitro anti-inflammatory studies showed ACEs inhibited Lipid A-induced Interleukin-12 (IL-12) release from mouse dendritic cells, and modulated lipopolysaccharide (LPS)-induced secretion of tumor necrosis factor-α (TNF-α) and Interleukin-6 (IL-6) from murine macrophages. These studies have important implications for the potential use of blackberry extracts for the treatment and prevention of cancer and inflammation diseases and provide essential information for the development of Botanical Drug Products from extracts derived from blackberries and other fruits.
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24

Guthenberg, Kristoffer. "The impact of the pulping process on the properties of lignin nanoparticles." Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-278834.

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Lignin valorization is a key component of the total utilization of biomass in the biorefinery industry. Lignin has seen some use in several different applications, but a breakthrough is still yet to happen, and there is still a need to find more areas where lignin can be used as an alternative feedstock or as the main component. Lignin nanoparticles (LNPs) could be an alternative route towards lignin valorization offering many areas of application. However, research around LNPs still has to overcome many challenges, primarily related to the complex structure of lignin, with composition and structure of lignin depending on its botanical origin and on the pulping process used to isolate the lignin from other components in biomass. This study investigates how spruce lignin originating from Kraft and Organosolv pulping will affect the properties of lignin nanoparticles. Particles from organosolv spruce lignin were prepared using a solvent exchange method with acetone/water as solvent and water as antisolvent. This resulted in spherical LNPs with hollow centers, sizes ranging from 104.6- 270.3 depending on initial lignin concentration and average zeta-potential of -35mV. Comparing Organosolv LPN’s with Kraft LNPs produced with the same experimental procedure, reviled that Organosolv LNPs were larger in and had lower absolute zeta potential, presumably due to the kraft lignin having higher phenolic-OH content. Furthermore, a larger comparison is made with LNPs from previous studies which indicated that LNP properties are further dependant Mw of lignin raw material, phenolic-OH content, and the method applied to produce the particles. In conclusion, this study proves that the pulping process used to isolate lining will affect the properties of NPs. But to strengthen and generalize this conclusion beyond the limitations of this study, more experimental data are needed, to further investigate the relationship between LNP properties and the properties of lignin raw material.<br>En av utmaningarna för framtidens bioraffinaderier är att fullständigt utnyttja samtliga komponenter av råvaran. Historiskt sett har cellulosa varit den mest värdefulla komponenten av biomassan medan lignin har klassats som en biprodukt och har därför primärt bränts som bränsle vid framställning av pappersmassa. Även om lignin produceras på industriell skala saknas idag värdeskapande applikationsområden där lignin kan utnyttjas ur ett ekonomiskt hållbart perspektiv. Ett alternativ till valorisering av lignin är att använda det som råmaterial för framställande av nanopartiklar , vilket är ett relativ nytt område med stor potential framförallt inom biomedicin. Dock kvarstår en del utmaningar i forskningen runt lignin nanopartiklar. Framförallt relaterat till lignins komplexa och inhomogena struktur, som varierar beroende på botaniskt ursprung och vilken typ av massaframställningsprocess som används för att isolera ligninet från biomassan. Den här studien undersöker hur granlignin från två olika massaframställningsprocesser, Organosolv- och Kraftprocessen, påverkar egenskaper hos NP av lignin. Under den experimentella delen av arbetet framställdes NP från Organosolv granlignin, vilket resulterade i sfäriska och ihåliga partiklar som varierade i storlek mellan 104.5–270.3 nm, beroende på den initiala lignin koncentrationen, samt en genomsnittlig zeta potential kring -35 mV. Egenskaperna hos Organosolv nanopartiklarna som jämfördes med nanopartiklar av Kraflignin som producerats med samma metod. Slutsatsen drogs att organosolv partiklar var större och hade lägre absolut zeta-potential. Vilket troligtvis kan förklaras med den betydligt högre halten av fenoliska-OH enheter i Kraft ligninet. En bredare jämförelse med tidigare studier som producerat olika lignin nanopartiklar visar dessutom att molekylvikten, fenolisk-OH halt och produktionsmetoden, är bidragande faktorer till lignin nanopartiklars egenskaper. Sammanfattnings visar den här studien att den massaframställningsprocess som används för att isolera lignin kommer påverka egenskaperna hos lignin nanopartiklar. Men för att kunna generalisera och stärka slutsatsen krävs dock utökad experimentella, för att vidare undersöka hur lignin nanopartiklars egenskaper beror på egenskaperna hos ligninet som använts för att producera partiklarna.
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25

Dodge, Luke A. "FRACTIONATION OF LIGNIN DERIVED COMPOUNDS FROM THERMOCHEMICALLY PROCESSED LIGNIN TOWARDS ANTIMICROBIAL PROPERTIES." UKnowledge, 2018. https://uknowledge.uky.edu/bae_etds/54.

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The overuse of antibiotics in agriculture is an emerging concern, due to their potential detrimental impact to the environment. This study focuses on exploring antimicrobial properties of lignin derived compounds. Lignin is of interest as a feedstock to replacing some petroleum-based chemicals and products because it is the most abundant source of renewable aromatic compounds on the planet. Two lignin rich streams, residues from the enzymatic hydrolysis of dilute acid and alkaline pretreated corn stover, were decomposed via pyrolysis and hydrogenolysis, respectively. The resulting liquid oils were subjected to sequential extractions using a series of solvents with different polarities. Chemical compositions of the extracted fractions were characterized through HPLC and GC/MS. These extracted compounds were screened against Saccharomyces cerevisiae (S. cerevisiae), Escherichia coli, and Lactobacillus amylovorus for antimicrobial properties. Six lignin model monomers: guaiacol, vanillin, vanillic acid, syringaldehyde, 2,6-dimethoxyphenol, and syringic acid were compared to the oils and extracted fractions for antimicrobial properties. Development of lignin-derived chemicals with antimicrobial properties could provide a novel use for this underutilized natural resource.
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26

Turek, Iga Anna. "The effect of microwave extraction on the chemical composition and the antioxidant properties of the coffee residue." Master's thesis, Universidade de Aveiro, 2010. http://hdl.handle.net/10773/3523.

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Mestrado em Biotecnologia Alimentar<br>O presente trabalho, pretendeu estudar o efeito da extracção em microondas na composição química do resíduo de café. As analises ao resíduo de café incluíram: conteúdo em açucares e aminoácidos (GC-FID), conteúdo em gordura (extracção em Soxhlet), composição volátil do óleo do resíduo de café (GCxGC), e capacidade antioxidante (espectrofotometria) do óleo, supernadantes, e resíduos após as extracções com microondas. As extracções com microondas foram efectuadas em ciclos de 8 minutos atingindo uma temperatura de 200°C. Ambos os supern adantes e resíduos for examinados pelo seu rendimento em massa, conteúdo e composição em polissacarídeos e aminoácidos, conteúdo em óleo e capacidade antioxidante. Os rendimentos obtidos por extracção com microondas atingiram 20-25% em massa, da qual cerca de 41-63% são açucares solúveis em água. A composição em polissacarídeos alterou-se do primeiro para o segundo ciclo de extracção, sendo que as arabinogalactanas são preferencialmente extraídas durante o primeiro ciclo, enquanto que no segundo ciclo se obtém uma mistura de arabinogalactanas e galactomananas. O resíduo de café insolúvel (79 %, w/w) continua rico em polissacarideos (46- 55% w/w), sendo enriquecido em glucose ao longo dos ciclos. A maioria dos aminoácidos continuam no resíduo, mesmo após os tratamentos com microondas. Também a composição permanece inalterada, com excepção para as percentagens dos ácidos glutâmico e aspártico, cuja quantidade aumenta significativamente após os tratamentos. A maioria do óleo remanesce no resíduo após os tratamentos. Uma elevada capacidade antioxidante (AOC) foi encontrada no óleo extraído do resíduo de café inicial, supernadantes, e extractos de resíduo finais. O óleo extraído após o primeiro ciclo de extracção apresenta uma diminuição da sua AOC quando comparada com a actividade do resíduo inicial, sendo detectada uma redução considerável após o segundo ciclo, ainda assim com valores superiores quando comparados com os valores de AOC apresentados por amostras comerciais de óleo de azeitona. Todos os supernadantes apresentam uma AOC superior a qualquer um dos resíduos, incluindo o resíduo inicial e os resíduos obtidos após os vários tratamentos com microondas. Quando comparados com o resíduo inicial de café antes de qualquer tratamento com microondas, ao qual corresponde uma actividade de 15 gsoluto/ Lsolução, o supernadante obtido apos o primeiro ciclo de extracção apresentou um AOC de 5 gsoluto /Lsolução, reduzindo a sua actividade para metade após o segundo ciclo. Foram identificados ~170 compostos no espaço de cabeça do óleo obtido a partir do resíduo de café, incluindo furanos e pirazinas, compostos identificados como sendo responsáveis pelo aroma semelhante a café. Ainda no espaço de cabeça do óleo foram identificados novos compostos os quais são: 1-metil-ciclopentanol; fenilacetaldeído; propanoato de 2-furano metanol; acetato de 2-furano metanol, 2-acetil-3-metilpirazina; 1-etil-1Hpyrrole- 2-carboxaldeído; 2-pineno; (1S)-2,6,6-trimetil biciclo(3,1,1)heptano-2- eno; p-xileno;1-fenil-etanona; 5-metil-2(3H)-furanona.<br>The present work, studied the effect of microwave extraction on the chemical composition of the coffee residue. The analysis of the coffee residue included: sugars and amino-acids content (by GC-FID), fat content (by Soxhlet extraction), coffee residue oil volatile composition (GCxGC), and the antioxidant capacity (by spectrophotometry) of the oil, supernatants, and residues after microwave extractions. The microwave extractions were performed in two 8-minutes cycles reaching 200°C. Both supernatants and residues were examined for their mass yield, polysaccharides and amino acids content and composition, fat content and antioxidant capacity. The microwave extraction yields about 20-25% of mass, of which 22-38% are water soluble sugars. The polysaccharides composition changes from the first to the second cycle, being the arabinogalactans preferentially extracted during the first microwave cycle, and a mixture of arabinogalactans and galactomannans extracted to supernatant during the second cycle. The insoluble coffee residue (79 %, w/w) remains rich in polysaccharides (20- 39%, w/w), being enriched in glucose over the cycles. Most of the amino acids remain in the residues, even after the microwave treatments. The composition remains almost unchanged, with the exception for the percentage of glutamic and aspartic acid, which rise significantly after the treatments. Most of the oil is also maintained in the residue after the treatments. The oil extracted from the coffee initial residue, supernatant, and final residue extracts, all have high antioxidant capacity (AOC). The oil obtained after the first cycle of microwave extraction slightly lowered its AOC when compared to the initial activity, while a considerably reduction was detected after the second cycle, which is still higher that the AOC showed by commercial olive oil samples. The supernatants all have higher AOC when compared to the residues, both the initial as the ones after the microwave treatments. When compared to the initial residue, which correspondent EC50 is 15 gsolute/Lsolution before microwave extraction, the supernatant after the first microwave extraction cycle has an AOC of 5 gsolute/Lsolution, reducing its activity to half after the second microwave cycle. In the headspace of the oil obtained from the coffee residue ~170 compounds were identified, including furans and pyrazines, which are compounds identified as being responsible for the coffee-like aroma. Among the new compounds, which were found in head-space of coffee oil are: 1-methyl-cyclopentanol; phenyl acetaldehyde; 2-furanmethanol, propanoate; 2-furanmethanol, acetate; 2-acetyl-3-methylpyrazine; 1-ethyl-1H-pyrrole-2carboxaldehyde; 2-pinene; (1S)- 2,6,6-trimethylbicyclo(3,1,1)hept-2-ene; p-xylene; 1-phenyl-ethanone; 5-methyl- 2(3H)-furanone.
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27

Castellano, Simone. "Multiscale study and modeling of dispersion properties relevant for liquid-liquid extraction : adaptation of breakup and coalescence kernels to industrial processes." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSE1243.

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Ce projet de thèse porte sur l'étude de l'hydrodynamique des dispersions dans les extracteurs liquide-liquide utilisés dans l'industrie du recyclage nucléaire. Dans la première partie du projet, un modèle de bilan de population homogène (0D-PBM), basé sur l'évaluation des taux moyens en volume de coalescence et de rupture, est proposé. La méthode tient compte des inhomogénéités spatiales dans le mélange, notamment de la fonction de densité de probabilité de la dissipation de l’énergie cinétique turbulente dans l’appareil. Le modèle est capable de reproduire les expériences de dispersion liquide-liquide turbulentes à faible viscosité. Dans la deuxième partie de cette étude, un modèle généralisé pour les noyaux de rupture et coalescence, valable pour l’ensemble du spectre de la turbulence, est proposé et validé. La plupart des noyaux disponibles dans la littérature sont basés sur la fonction de structure de second-ordre de Kolmogorov, qui n'est valable que dans le domaine inertiel. Cependant, dans des nombreuses situations rencontrées au niveau industriel, la plupart des gouttes peuvent avoir une taille dans le domaine dissipatif, où la fonction de structure de second-ordre de Kolmogorov ne s'applique pas. Le modèle généralisé est basé sur la fonction de structure de second ordre de Davidson, valable dans tout le spectre de la turbulence. Dans la dernière partie de l'étude, un modèle permettant de simuler le comportement hydrodynamique d'une colonne pulsée est proposé. Le modèle est basé sur un bilan de population 1D, dont les termes source ont été modélisés à l'aide des noyaux de Coulaloglou et Tavlarides généralisés. Les inhomogénéités turbulentes dans la colonne pulsée ont été prises en compte par la fonction de densité de probabilité du taux de dissipation turbulent. Un bon accord modèle-expérience est obtenu en ce qui concerne le diamètre et la concentration moyenne des gouttes dans un compartiment<br>This PhD project deals with the study of the hydrodynamics of the dispersions in the liquid-liquid extractors employed in the nuclear recycle industry. In the first part of the project, a zero-dimensional homogenous Population Balance Model (0D-PBM), based on the evaluation of the volume-averaged coalescence and breakup rates, is adopted to fit low-viscosity turbulent liquid-liquid dispersion experiments. The method accounts for the spatial inhomogeneities in mixing, namely for the probability density function of the turbulent kinetic energy dissipation in the apparatus. In the second part of this study, a generalized model for the breakage and coalescence kernels, valid for the entire spectrum of turbulence, is proposed and validated. Most of the available kernels in literature indeed are based on the Kolmogorov second-order structure function, which is only valid in the inertial subrange. However, in many industrially encountered situations, most of the droplets may have size in the dissipation range, where the Kolmogorov second-order structure function does not apply. The generalized model is based on the Davidson second-order structure function, valid in the entire spectrum of turbulence. In the last part of the study, a model that allows to simulate the hydrodynamic behavior of a pulsed column is proposed. The model is based on a 1D Population Balance Equation (1D-PBE), whose source terms were modeled through the generalized Coulaloglou and Tavlarides kernels. The turbulent inhomogeneities in the pulsed column were accounted through the probability density function of the turbulent dissipation rate. The model well reproduces the experimental Sauter mean diameters and the dispersed phase volume fractions in a compartment of the pulsed column
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28

Puspita, Maya. "Extraction assistée par enzyme de phlorotannins provenant d’algues brunes du genre Sargassum et les activités biologiques." Thesis, Lorient, 2017. http://www.theses.fr/2017LORIS440/document.

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En France et Indonésie, Sargassum est une espèce abondante mais elle algue n’a pas encore été exploitée de façon optimale. Sargassum contient de nombreux métabolites primaires ainsi que des composés bioactifs, dont les phlorotannins, ayant une large gamme de propriétés pharmacologiques intéressantes à valoriser. L’hétérogénéité et la complexité de la paroi cellulaire des algues réduisent fortement l’efficacité d’extraction conventionnelle. Cette étude a eu trois principaux objectifs (1) la caractérisation de la composition biochimique de Sargassum et ses variations saisonnières, (2) l'extraction solide-liquide et (3) l'extraction assistée par enzymes des phlorotannins et l’étude de leurs activités biologiques. Dans cette étude, les minéraux de Sargassum représentent d’une valeur importance avec une teneur qui atteint 33% suivi par les protéines avec 24% de la matière sèche. Les sucres ne représentent que 13% de la matière sèche. La composition biochimique de Sargassum, comme pour la plupart des algues, est fortement affectée par les saisons et est liée au cycle de vie de l’algue. La saisonnalité affecte également la production de phlorotannins. L’étude des différents procédés d’extraction montre que les rendements sont plus faibles pour une extraction solide-liquide traditionnelle (5 à 24% de la matière sèche de l'algue) par rapport à l'extraction assistée par enzyme (21 à 38% de la matière sèche de l'algue). L’extraction assistée par enzymes augmente le rendement d’extraction des polyphénols par rapport à l'extraction solide-liquide. Les extraits obtenus par extraction assistée par enzymes présentent une forte activité antiradicalaire<br>In France and Indonesia, Sargassum is quite abundant yet this alga has not been optimally exploited. Sargassum contains macro and micro molecules and also bioactive compounds, the most known is phlorotannins, showing a wide range of pharmacological properties. Therefore, it is interesting to further valorize this alga. The heterogeneity and complexity of algal cell wall strongly reduces the extraction efficiency application of conventional extraction. Subjects of interest in this study were to characterize the seasonal variation of Sargassum biochemical composition and to extract phlorotannins using conventional and alternative method, i.e. solid-liquid and enzyme- assisted extraction. In this study, minerals represented a significant value with a content reaching 33% followed by proteins with 24% of algal dry material. In the contrary, sugars showed only 13% of algal dry material. Further, the biochemical composition of Sargassum, like most algae, was highly affected by the seasons and related to Sargassum life cycle. In terms of polyphenol compounds in Sargassum, season might be the most influential factor but suitable methods of extraction determine the efficiency to collect these compounds from Sargassum. Solid-liquid extraction, in certain extent, yielded lower (ranging from 5 to 24% of dry algal material) than the enzyme-assisted extraction (ranging from 21 to 38% of dry algal material). Concerning the polyphenol content of Sargassum extracted with these two methods, enzyme-assisted extraction, in certain extent, had higher content than the solid-liquid extraction. Enzymatic extracts showed a strong antiradical activity
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29

Payne, Dean W. "Enterotoxigenic escherichia coli infection of pigs: expression, extraction, purification and the adhesive properties of the K88 fimbrial adhesin." Thesis, Aston University, 1992. http://publications.aston.ac.uk/12591/.

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The ability of Escherichia coli to express the K88 fimbrial adhesin was satisfactorily indicated by the combined techniques of ELISA, haemagglutination and latex agglutination. Detection of expression by electron microscopy and the ability to metabolize raffinose were unsuitable. Quantitative expression of the K88 adhesin was determined by ELISA. Expression was found to vary according to the E.coli strain examined, media type and form. In general it was found that the total amount was greater, while the amount/cfu was less on agar than in broth cultures. Expression of the K88 adhesin during unshaken batch culture was related to the growth rate and was maximal during late logarithmic to early stationary phase. A combination of heat extraction, ammonium sulphate and isoelectric precipitation was found suitable for both large and small scale preparation of purified K88ab adhesin. Extraction of the K88 adhesin was sensitive to pH and it was postulated that this may affect the site of colonisation of by ETEC in vivo. Results of haemagglutination experiments were consistent with the hypothesis that the K88 receptor present on erythrocytes is composed of two elements, one responsible for the binding of K88ab and K88ac and a second responsible for the binding of the K88ad adhesin. Comparison of the haemagglutinating properties of cell-free and cell-bound K88 adhesin revealed some differences probably indicating a minor conformational change in the K88 adhesin on its isolation. The K88ab adhesin was found to bind to erythrocytes over a wide pH range (PH 4-9) and was inhibited by αK88ab and αK88b antisera. Inhibition of haemagglutination was noted with crude heparin, mannan and porcine gastric mucin, chondrosine and several hexosamines, glucosamine in particular. The most potent inhibitor of haemagglutination was n-dodecyl-β-D-glucopyranoside, one of a series of glucosides found to have inhibitory properties. Correlation between hydrophobicity of glucosides tested and degree of inhibition observed suggested hydrophobic forces were important in the interaction of the K88 adhesin with its receptor. The results of Scatchard and Hill plots indicated that binding of the K88ab adhesin to porcine enterocytes in the majority of cases is a two-step, three component system. The first K88 receptor (or site) had a K2. of 1.59x1014M-1 and a minimum of 4.3x104 sites/enterocyte. The second receptor (or site) had a K2 of 4.2x1012M-1 with a calculated 1.75x105 sites/enterocyte. Attempts to inhibit binding of cell-free K88 adhesin to porcine enterocytes by lectins were unsuccessful. However, several carbohydrates including trehalose, lactulose, galactose 1→4 mannopyranoside, chondrosine, galactosamine, stachyose and mannan were inhibitory. The most potent inhibitor was found to be porcine gastric mucin. Inhibition observed with n-octyl-α-D-glucopyranose was difficult to interpret in isolation because of interference with the assay, however, it agreed with the results of haemagglutination inhibition experiments.
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30

Zhang, Hua-Xiao. "Effects of flour proteins, dough rheological properties, and flour extraction rates on northern-style Chinese steamed bread making /." Search for this dissertation online, 2003. http://wwwlib.umi.com/cr/ksu/main.

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31

Povolo, Chiara. "Extraction and characterization of chemicals from vegetal matrices and assessment of their properties for nutraceutical and cosmetic applications." Doctoral thesis, Università degli studi di Padova, 2018. http://hdl.handle.net/11577/3425744.

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Present days lifestyles increase the number of free radicals in our body and predispose people to oxidative stress, responsible for the development of several diseases as well as aging. The need for inhibitors of oxidative processes has become essential. Plant-derived antioxidant compounds are preferred. Hibiscus sabdariffa L. belongs to the Malvaceae family. Its calyces contain anthocyanins, responsible for the antioxidant activity reported for the extracts. Moringa oleifera Lam. belongs to the Moringaceae family. Its antioxidant properties are mainly attributed to its phenolic compounds and, recently, to its isothiocyanates, deriving from the enzymatic hydrolysis of glucosinolates. Both the plants are source of oils with an interesting composition in antioxidant compounds. This research work was divided into three lines: The first line focused on H. sabdariffa calyces. It was performed the selection of a variety of calyces rich in anthocyanins. It was optimized an extraction method suitable for the recovery of anthocyanins in high yield but transferable on large scale, too. It were tried different procedures to obtain an extract enriched in anthocyanins using polyvinylpolypyrrolidone. The second line was devoted to M. oleifera tissues. This comparative study concerns plant material grown in Paraguay and therefore extends the information available on the chemical composition of M. oleifera plants cultivated in different areas of the world. As far as we know, this is the first study about the characterization of both direct and indirect antioxidant compounds in different tissues of M. oleifera. Branches and the patented matrix “EDYNEA” are investigated besides seeds and leaves. In the first part of the study, it was compared the total phenolic content (TPC), the direct total antioxidant capacity (TAC) and the glucomoringin content (GMG) of aqueous extracts of different tissues of M. oleifera. Two different drying treatments (freeze-drying and oven drying, 40°C) were performed on the samples before extraction, to verify their influence on the chemical composition of the final extracts. The study was continued with the selection of an extraction condition able to maintain a high extraction yield of TPC and suitable for the conversion of GMG into its bioactive isothiocyanate (GMG-ITC) inside the extracts that were obtained from the tissues selected in the first part of the study because of their richness in GMG or TPC. A further objective was the determination of GMG, GMG-ITC, TPC and TAC in the extracts. In the applied extraction conditions, the branches (that have a lower TPC and TAC than leaves) could bring to an extract with an equal TPC but a higher TAC than the extract of leaves, becoming a valid alternative to leaves in the preparation of extracts rich in antioxidant compounds. The matrix “EDYNEA” showed to be an interesting alternative to leaves for the preparation of extracts richer in GMG-ITC. The third project was dedicated to oilseeds and oily extracts. The perspective was the production of an oily extract enriched in antioxidant compounds, with a higher TAC than the pure oil. It was decided to use M. oleifera oil and H. sabdariffa oils for the preparation of the extracts together with two commonly used oils in the preparation of cosmetics and for human consumption (refined olive oil and sunflower oil). The oil of H. sabdariffa was selected between different varieties of H. sabdariffa oils. The oleolites were prepared by ultrasonic extraction. The main classes of antioxidant compounds were determined as well as the TAC. The production of an oily extract higher in antioxidant components has not lead to a better TAC compared to the pure oil, at least in the extraction conditions used. Among the oils, the more active was the one extracted from the selected variety of H. sabdariffa seeds.<br>Gli stili di vita attuali causano un aumento del numero di radicali liberi nel nostro corpo e predispongono le persone allo stress ossidativo, responsabile dello sviluppo di diverse patologie e dell'invecchiamento. La necessità di inibitori dei processi ossidativi è diventata essenziale. Si preferiscono i composti antiossidanti derivati da piante. L’Hibiscus sabdariffa L. appartiene alla famiglia delle Malvaceae. I suoi calici contengono antocianine, responsabili dell'attività antiossidante riportata per gli estratti. La Moringa oleifera Lam. appartiene alla famiglia delle Moringaceae. Le sue proprietà antiossidanti sono principalmente attribuite ai suoi composti fenolici e, recentemente, ai suoi isotiocianati, derivanti dall'idrolisi enzimatica dei glucosinolati. Entrambe le piante sono fonte di oli con una composizione interessante in composti antiossidanti. Questo lavoro di ricerca è diviso in tre linee: la prima linea è incentrata sui calici di H. sabdariffa. È stata eseguita la selezione di una varietà di calici ricchi di antocianine. È stato ottimizzato un metodo di estrazione adatto al recupero di antocianine ad alto rendimento ma trasferibile anche su larga scala. Sono state provate diverse procedure per ottenere un estratto arricchito in antocianine usando il polivinilpolipirrolidone. La seconda linea è dedicata ai tessuti di M. oleifera. Questo studio comparativo riguarda il materiale vegetale coltivato in Paraguay e quindi amplia le informazioni disponibili sulla composizione chimica delle piante di M. oleifera coltivate in diverse aree del mondo. Per quanto ne sappiamo, questo è il primo studio sulla caratterizzazione di composti antiossidanti diretti e indiretti in diversi tessuti di M. oleifera. I rami e la matrice brevettata "EDYNEA" sono stati studiati oltre a semi e foglie. Nella prima parte dello studio, è stato confrontato il contenuto fenolico totale (TPC), la capacità antiossidante totale diretta (TAC) e il contenuto di glucomoringina (GMG) di estratti acquosi di diversi tessuti di M. oleifera. Due diversi trattamenti di essiccazione (liofilizzazione e asciugatura in forno, 40 ° C) sono stati eseguiti sui campioni prima dell'estrazione, per verificarne l'influenza sulla composizione chimica degli estratti finali. Lo studio è proseguito con la selezione di una condizione di estrazione in grado di mantenere un alto rendimento di estrazione di TPC e adatta per la conversione di GMG nel suo isotiocianato bioattivo (GMG-ITC) all'interno degli estratti che sono stati ottenuti dai tessuti selezionati nella prima parte dello studio per la loro ricchezza in GMG o TPC. Un ulteriore obiettivo è la determinazione di GMG, GMG-ITC, TPC e TAC negli estratti. Nelle condizioni di estrazione applicate, i rami (che hanno un TPC e TAC inferiori rispetto alle foglie) portano a un estratto con un TPC uguale ma un TAC superiore rispetto all'estratto di foglie, diventando una valida alternativa alle foglie nella preparazione di estratti ricchi in composti antiossidanti. La matrice "EDYNEA" si è rivelata un'alternativa interessante alle foglie per la preparazione di estratti più ricchi in GMG-ITC. Il terzo progetto è dedicato ai semi oleosi e agli estratti oleosi. L’obiettivo è la produzione di un estratto oleoso arricchito in composti antiossidanti, con un TAC superiore rispetto all'olio puro. Si è deciso di utilizzare l'olio di M. oleifera e gli oli di H. sabdariffa per la preparazione degli estratti insieme a due oli comunemente usati nella preparazione di cosmetici e per il consumo umano (olio di oliva raffinato e olio di girasole). L'olio di H. sabdariffa è stato selezionato tra diverse varietà di oli di H. sabdariffa. Gli oleoliti sono stati preparati mediante estrazione a ultrasuoni. Le principali classi di composti antiossidanti sono state caratterizzate così come il TAC. La produzione di un estratto oleoso più ricco in componenti antiossidanti non ha portato a un TAC migliore rispetto all'olio puro, almeno nelle condizioni di estrazione utilizzate. Tra gli olii, il più attivo è quello estratto dalla varietà selezionata di semi di H. sabdariffa.
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ALAHMAD, MOUHAMAD. "Developpement de methodes de vision par ordinateur : extraction de primitives geometriques." Université Louis Pasteur (Strasbourg) (1971-2008), 1986. http://www.theses.fr/1986STR13192.

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Cette these concerne le developpement de methodes de vision par ordinateur, destinees a l'extraction de caracteristiques geometriques (barycentre, surface, perimetre, axe principal et orientation) pour identifier, localiser et comparer des objets a partir d'images en deux dimensions
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Jayarathne, Ayomi L. "Transformation of physical and chemical properties of metals built-up on urban road surfaces." Thesis, Queensland University of Technology, 2018. https://eprints.qut.edu.au/122560/1/Ayomi_Jayarathne_Thesis.pdf.

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This project was a step forward in developing new knowledge relating to the influence of transformations that metals undergo during dry weather periods whilst they are deposited on urban road surfaces, on stormwater quality. Further, a new risk assessment method was proposed based on the transformation characteristics of metals. The generic outcomes of this study are expected to contribute to the implementation of appropriate stormwater pollution mitigation strategies to enhance stormwater reuse.
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34

Hadidi, Milad. "Optimization of Extraction of Protein from Alfalfa Leaf (Medicago sativa) for Human Consumption." Doctoral thesis, Universitat de Lleida, 2019. http://hdl.handle.net/10803/671186.

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La creixent població mundial està augmentant la demanda de fonts de proteïnes vegetals dietètiques barates i més sostenibles per a complementar o fins i tot reemplaçar fonts cares i limitades de proteïna animal. L'alfals (Medicago sativa) és una important lleguminosa productiva farratgera, àmpliament conreada a tot el món. A causa de la seva alta qualitat nutricional i adaptabilitat, la proteïna de la fulla d'alfals s'usa principalment com un suplement alimentós, mentre que només juga un paper menor en el sector de l'alimentació humana. L'ús de concentrats de proteïnes vegetals derivats de l'alfals en l'alimentació humana està limitat per la seva qualitat negativa, com el color marró, el sabor amarg i els compostos antinutricionals. Després de la collita de les fulles d'alfals, les proteases endògenes de la fulla estan degradant la proteïna, mentre que els enzims polifenoloxidasa (PPO) i peroxidasa (POD) amb alta activitat inicial estan causant simultàniament l'ennegriment del teixit. El resultat d'aquestes accions és una proteïna fosca i parcialment degradada. Per a evitar aquests efectes negatius en la proteïna extreta, es va dur a terme un primer estudi sobre els efectes del blanqueig en vaporitzar les fulles d'alfals des del començament de la collita. El primer objectiu de la tesi va ser optimitzar la inactivació de PPO, POD i proteases de plantes en fulles d'alfals a través del procés de blanqueig de vapor. També es va investigar l'efecte d'aquest procés en l'índex d’enfosquiment, el color, el nitrogen no proteic i el pes molecular. Algunes de les propietats indesitjables de l'alfals poden deure's als nivells més alts de saponina com un factor antinutricional principal que es troba en l'alfals. La segona part de la tesi va tenir com a objectiu descobrir les condicions òptimes d'extracció assistida per ultrasò per a obtenir el major rendiment de soponines totals i la seva bioaccesibilitat per a la seva posterior aplicació en els aliments utilitzant la tècnica RSM. A més, s’ha emprat la irradiació UV per a la degradació de les saponines d'alfals a diferents temperatures i pH. En conseqüència, el procés d'extracció de la proteïna d'alfals com a aliment és extremadament important per aconseguir una proteïna d'alta qualitat sense cap problema de seguretat. Així, s’ha desenvolupat i utilitzat la tècnica de precipitació isoelèctrica alcalina assistida per ultrafiltració ultrasònica (UUAAIP) com un nou procés en l'extracció de proteïnes de les fulles d'alfals. Finalment, es van investigar la composició, les propietats fisicoquímiques i funcionals de la proteïna extreta i es van comparar amb els resultats d'altres mètodes comuns d'extracció. En cobrir tots els problemes esmentats, aquesta tesi tracta de proporcionar un aïllat de proteïna d'alfals d'alta qualitat sense cap problema de seguretat. Aquesta recerca suggereix que el blanqueig amb vapor de fulles d'alfals senceres fresques en condicions òptimes va ser útil per a evitar l'aparició del color fosc i la degradació de la proteïna extreta. Per tant, la combinació de mètodes d'extracció i purificació va crear un mètode nou i eficient, que pot millorar la puresa, la seguretat, la qualitat i les propietats funcionals de la proteïna d'alfals. La UUAAIP és una tècnica apropiada per a fabricar aïllats de proteïna d'alfals i podria resoldre les restriccions del consum humà de proteïna d'alfals.<br>La creciente población mundial está aumentando la demanda de fuentes de proteínas vegetales dietéticas baratas y más sostenibles para complementar o incluso reemplazar fuentes caras y limitadas de proteína animal. La alfalfa (Medicago sativa) es una importante leguminosa productiva forrajera, ampliamente cultivada en todo el mundo. Debido a su alta calidad nutricional y adaptabilidad, la proteína de la hoja de alfalfa se usa principalmente como un suplemento alimenticio, mientras que solo juega un papel menor en el sector de la alimentación humana. El uso de concentrados de proteínas vegetales derivados de la alfalfa en la alimentación humana está limitado por su calidad negativa, como el color pardo, el sabor amargo y los compuestos antinutricionales. Después de la cosecha de las hojas de alfalfa, las proteasas endógenas de la hoja están degradando la proteína, mientras que las enzimas polifenoloxidasa (PPO) y peroxidasa (POD) con alta actividad inicial están causando simultáneamente el pardeamiento del tejido. El resultado de estas acciones es una proteína oscura y parcialmente degradada. Para evitar estos efectos negativos en la proteína extraída, se llevó a cabo un primer estudio sobre los efectos del blanqueo al vaporizar las hojas de alfalfa desde el comienzo de la cosecha. El primer objetivo de la tesis fue optimizar la inactivación de PPO, POD y proteasas de plantas en hojas de alfalfa a través del proceso de blanqueo de vapor. También se investigó el efecto de este proceso en el índice de pardeamiento, el color, el nitrógeno no proteico y la masa molecular. Algunas de las propiedades indeseables de la alfalfa pueden deberse a los niveles más altos de saponina como un factor antinutricional principal que se encuentra en la alfalfa. La segunda parte de la tesis tuvo como objetivo hallar las condiciones óptimas de extracción asistida por ultrasonido para obtener el mayor rendimiento de saponinas totales y su bioaccesibilidad para su posterior aplicación en los alimentos utilizando la técnica RSM. Además, se ha utilizado la irradiación UV para la degradación de las saponinas de alfalfa a diferentes temperaturas y pH. En consecuencia, el proceso de extracción de la proteína de alfalfa como alimento es extremadamente importante para lograr una proteína de alta calidad sin ningún problema de seguridad. Así, se ha desarrollado y utilizado la técnica de precipitación isoeléctrica alcalina asistida por ultrafiltración ultrasónica (UUAAIP) como un nuevo proceso en la extracción de proteínas de las hojas de alfalfa. Finalmente, se investigaron la composición, las propiedades fisicoquímicas y funcionales de la proteína extraída y se compararon con los resultados de otros métodos comunes de extracción. Al cubrir todos los problemas mencionados, esta tesis trata de proporcionar un aislado de proteína de alfalfa de alta calidad sin ningún problema de seguridad. Esta investigación sugiere que el blanqueo con vapor de hojas de alfalfa enteras frescas en condiciones óptimas fue útil para evitar la aparición del color oscuro y la degradación de la proteína extraída. Por lo tanto, la combinación de métodos de extracción y purificación creó un método nuevo y eficiente, que puede mejorar la pureza, la seguridad, la calidad y las propiedades funcionales de la proteína de alfalfa. La UUAAIP es una técnica apropiada para obtener aislados de proteína de alfalfa y podría resolver las restricciones del consumo humano de proteína de alfalfa.<br>The world’s growing population is raising the demand for sources of cheap and more sustainable dietary plant proteins to supplement or even replace expensive and limited sources of animal protein. Alfalfa (Medicago sativa) is an important productive forage legume, widely cultivated around the world. Owing to its high nutritional quality and adaptability, the alfalfa leaf protein is mainly used as a feed supplement, while it only plays a minor role in the human food sector. The use of plant protein concentrates derived from alfalfa in human food is limited by their negative quality such as brown color, bitter taste, and anti-nutritional compounds. After harvesting of the alfalfa leaves, the endogenous proteases of the leaf are degrading the protein while the polyphenol oxidase (PPO) and peroxidase (POD) enzymes with high initial activity are simultaneously causing browning in the tissue. The result of these actions is a dark and a partially degraded protein. To avoid these negative effects in the extracted protein, the authors carried out a first study on the effects of blanching by steaming the leaves of alfalfa from the beginning of the harvest. The first aim of the thesis was to optimize the inactivation of PPO, POD and plant proteases in alfalfa leaves through the steam blanching process. The effect of this process on the browning index, color, non-protein nitrogen and molecular weight was also investigated. Some of undesirable properties of alfalfa may be due to the higher levels of saponin as a main anti-nutritional factor found in alfalfa. The second part of thesis aimed to find out the optimal conditions of ultrasound-assisted extraction for obtaining the highest yield of total saponins and their bioaccessibility for further application in the food using the RSM. Beside, UV irradiation has been employed for degradation of alfalfa saponins in different temperature and pH. Accordingly, the extraction process of alfalfa protein as a food is extremely important for achieving a high quality protein without any safety concerns. So the ultrasonic-ultrafiltration-assisted Alkaline Isoelectric precipitation (UUAAIP) technique as a new process was developed and employed in the alfalfa leaves’ protein extraction. Finally, the composition, physiochemical and functional properties of the extracted protein were investigated and compared with the results of other extraction common methods. By covering all the mentioned issues, this thesis tries to provide alfalfa protein isolate with high quality without any safety concerns. This research suggests that steam blanching of fresh whole alfalfa leaves under the optimum conditions was helpful for avoiding the appearance of the dark color appears and the degradation of the extracted protein. Thus, the combination of methods of extraction and purification created a new and efficient method, which is able to improve the purity, safety, quality and functional properties of alfalfa protein. UUAAIP is an appropriate technique for manufacturing alfalfa protein isolates and could resolve restrictions of human consumption of alfalfa protein.
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35

Jang, Do Young. "Transport properties and low-frequency noise in low-dimensional structures." Thesis, Grenoble, 2011. http://www.theses.fr/2011GRENT096/document.

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Les propriétés électriques et physiques de structures à faible dimensionalité ont été étudiées pour des applications dans des domaines divers comme l’électronique, les capteurs. La mesure du bruit bruit à basse fréquence est un outil très utile pour obtenir des informations relatives à la dynamique des porteurs, au piègeage des charges ou aux mécanismes de collision. Dans cette thèse, le transport électronique et le bruit basse fréquence mesurés dans des structures à faible dimensionnalité comme les dispositifs multi-grilles (FinFET, JLT…), les nanofils 3D en Si/SiGe, les nanotubes de carbone ou à base de graphène sont présentés. Pour les approches « top-down » et « bottom-up », l’impact du bruit est analysé en fonction de la dimensionalité, du type de conduction (volume vs surface), de la contrainte mécanique et de la présence de jonction metal-semiconducteur<br>Electrical and physical properties of low-dimensional structures have been studied for the various applications such as electronics, sensors, and etc. Low-frequency noise measurement is also a useful technique to give more information for the carrier dynamics correlated to the oxide traps, channel defects, and scattering. In this thesis, the electrical transport and low-frequency noise of low-dimensional structure devices such as multi-gate structures (e.g. FinFETs and Junctionless FETs), 3-D stacked Si/SiGe nanowire FETs, carbon nanotubes, and graphene are presented. From the view point of top-down and bottom-up approaches, the impacts of LF noise are investigated according to the dimensionality, conduction mechanism (surface or volume conduction), strain technique, and metal-semiconductor junctions
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36

Karaj, Shkelqim [Verfasser]. "Characterization of physico-chemical properties of Jatropha curcas L. and optimization of mechanical oil extraction and sedimentation / Shkelqim Karaj." Aachen : Shaker, 2014. http://d-nb.info/1049380452/34.

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37

Dube, Cyril Simbarashe. "Sorptive and microbial properties of low-cost adsorbents used in the extraction of ciprofloxacin and isoniazid from aqueous solution." Thesis, Rhodes University, 2018. http://hdl.handle.net/10962/59178.

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38

Coughenour, Christopher Lynn Lacovara Kenneth J. "An analysis of cyclic tidal deposits : statistical time series properties, extraction of earth-moon parameters, and observed intertidal sedimentation /." Philadelphia, Pa. : Drexel University, 2009. http://hdl.handle.net/1860/3135.

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39

Cesari, Laëtitia. "Extraction de composés phénoliques à partir d’une bio-huile de lignine." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0148/document.

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La biomasse ligno-cellulosique est principalement constituée de cellulose, d’hémicellulose et de lignine. Par conversion thermochimique, la lignine se transforme en bio-huile riche en composés phénoliques. Ces composés phénoliques sont généralement récupérés à l’aide de plusieurs étapes d‘extractions liquide-liquide consécutives impliquant des solvants aqueux et organiques. À l’aide d’une approche multi-échelle, nous avons étudié, la faisabilité et l’efficacité d’un liquide ionique, la [Choline][NTf2], pour l’extraction liquide-liquide de ces composés. En effet, l’utilisation de ce solvant permettrait d’améliorer l’efficacité d’extraction, tout en diminuant la toxicité et les coûts liés à l’utilisation de solvants organiques classiques. Des calculs quantiques ont été effectués afin de mieux comprendre les interactions régissant les systèmes clés de ces extractions. Les structures des composés phénoliques dans leur état isolé ou en présence de solvant montrent que les conformations sont stabilisées par la présence de liaisons hydrogène. De plus, la détermination des énergies d’interaction indique que la [Choline][NTf2] est efficace pour l’extraction de composés phénoliques présents en solution aqueuse. Par ailleurs, la détermination des diagrammes de phases des systèmes binaires {eau-composé + phénolique} et des systèmes ternaires {eau + composé phénolique + [Choline][NTf2]} montre que l’extraction des composés est également possible à une échelle macroscopique. Les paramètres NRTL issus de ces expériences ont permis de simuler l’extraction de trois composés phénoliques majoritairement présents dans les bio-huiles, i.e. le phénol, le guaiacol et le syringol, et ce, à moindre coût. Enfin, l’extraction de ces composés à partir d’une bio-huile obtenue par pyrolyse rapide de lignine a également été particulièrement efficace avec le liquide ionique [Choline][NTf2]. De ce fait, cette étude multi-échelle a permis de montrer que la [Choline][NTf2] est un excellent solvant pour la récupération des composés phénoliques. Enfin, l’étude des propriétés anti-oxydantes témoigne de la valeur ajoutée de ces composés, notamment à travers leur pouvoir réducteur et leur propriété anti-radicalaire<br>The lignocellulosic biomass is mostly composed of cellulose, hemicellulose and lignin. Upon thermal conversion of lignin, a bio-oil rich in phenolic compounds is obtained. These latter are then generally recovered through several liquid-liquid extraction involving aqueous and organic solvents. In this work we investigated, by a multi-scale study, the feasibility and the efficiency of the ionic liquid [Choline][NTf2] for the extraction of these phenolic compounds by liquid-liquid extraction. Indeed, such a solvent could improve the extraction efficiency and at the same time, reduce the toxicity and the cost of the classic organic solvents. Quantum calculations were performed in order to better understand the interaction governing the key systems of these extractions. The structures of the phenolic compounds in their isolated forms and in contact with solvents show that the conformations are stabilized by the presence of hydrogen bonds. More, the determination of the interaction energies indicates that the [Choline][NTf2] ionic liquid is efficient for the extraction of phenolic compounds present in aqueous solution. Furthermore, the study of phase diagrams of binary systems {water-phenolic compound} and ternary systems {water-phenolic compound-[Choline][NTf2]} show that the extraction of these compounds is also possible at a macroscopic scale. Then, the NRTL parameters coming from these experiments allowed the simulation of the extraction of three compounds mostly present in the bio-oils, namely phenol, guaiacol and syringol, as so at low cost. Finally, the extraction of these compounds from bio-oil obtained from lignin fast pyrolysis was also particularly efficient with the [Choline][NTf2] ionic liquid. Therefore, this multi-scale study demonstrated that [Choline][NTf2] is an excellent solvent for the recovery of phenolic compounds. Lastly, the study of the antioxidant properties testify the added-value of these compounds, especially through their reducing power and their radical scavenging capacity
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40

SREENIVASARAGHAVAN, SOWMYANARASIMHAN. "A Study of the Effects of Supercritical CO 2 Treatment on Physicochemical Properties of Spray-Dried Buttermilk Powder to Develop a Novel Dairy Processing Operation." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1534685778937538.

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41

Thys, Roberta Cruz Silveira. "Caracterização e avaliação de amido nativo e modificado de pinhão mediante provas funcionais e térmicas." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2009. http://hdl.handle.net/10183/18598.

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O pinhão é a semente comestível da Araucaria angustifolia, sendo consumido no sul e sudeste do Brasil principalmente na sua forma in natura. A falta de diversidade em relação ao seu consumo acarreta a sobra da safra e a sua utilização como ração animal, o que diminui o valor de comercialização do produto, prejudicando os ganhos econômicos do produto. A semente do pinhão é composta de 34% de amido e um conteúdo muito baixo de proteínas e lipídios, o que a torna favorável para a obtenção de amido, aditivo amplamente utilizado pela indústria de alimentos. O objetivo deste trabalho foi caracterizar uma nova fonte de amido a partir de semente de Araucária angustifolia, através de um estudo detalhado da metodologia de extração do amido de pinhão, das características físico-químicas, funcionais e reológicas do grânulo e de sua modificação estrutural. Primeiramente foi determinado um protocolo para a extração do amido e realizado o estudo do efeito do tratamento alcalino (NaOH 0,05 mol.l-1 e NaOH 0,1 mol.l-1), em relação ao tratamento com água, na estrutura dos grânulos do amido extraídos. Para tanto foram feitas análises de fluorescência intrínseca, microscopia eletrônica de varredura e de força atômica e difractometria de raios X. A estrutura granular do amido de pinhão foi alterada significativamente quando as soluções alcalinas foram utilizadas durante a extração. O amido de pinhão apresentou estrutura do tipo C. Foram determinadas as características do grânulo de amido nativo, através de análises físico-químicas, MEV, microscopia ótica e sinerese, onde se verificou que o diâmetro médio dos grânulos de amido varia de 7 a 20 μm e as formas geométricas variam entre a oval, a elipsóide truncada e a hemisférica. O amido de pinhão mostrou-se menos propenso à retogradação, comparado ao amido de milho. Foram elaboradas as isotermas de adsorção do amido nativo às temperaturas de 10°, 20°, 30° e 40°C a partir do ajuste dos dados experimentais a diversos modelos de sorção, sendo os modelos de Peleg, seguidos pelos de Chung-Pfost e GAB os que tiveram os maiores coeficientes de correlação. A partir do modelo de GAB foram calculados os valores de umidade de monocamada, entalpia e entropia diferenciais de sorção. Foi realizado também um planejamento experimental a fim de estudar a reação de hidrólise do amido, através da influência das variáveis temperatura (30°a 44°C) e concentração de ácido clorídrico (1,2 a 3,2 mol.l-1) no valor de dextrose equivalente (DE) e na capacidade de formação do gel e de sua termorreversibilidade. Foi observado que sob os maiores valores de temperatura e concentração de ácido empregados, o valor de DE foi maior. No tratamento que resultou no maior valor de DE (3,2 mol.l-1 de HCl e 44°C) foi observada a formação de gel termorreversível, o que indicou a potencialidade do amido modificado como substituto de gordura e agente ligante, em alimentos. A funcionalidade do amido de pinhão foi verificada através das análises de formação, fusão e termorreversibilidade do gel, tendência à retrogradação, estabilidade ao congelamento e descongelamento, poder de inchamento, índice de solubilização, MEV, viscosidade de pasta e propriedades térmicas, como temperatura e entalpia de gelatinização. Os resultados indicaram que: somente os amidos modificados apresentam géis termorreversíveis; os amidos de pinhão nativo e modificados possuem menor tendência à retrogradação do que seus similares de milho; a modificação do amido reduziu a tendência à retrogradação das pastas de amido; o amido de pinhão mostrou menor sinerese sob armazenamento à 5°C e após ciclos de congelamento e descongelamento; a temperatura de armazenamento influi significativamente no poder de inchamento (PI) e no índice de solubilização dos amidos de pinhão e milho nativos; os amidos modificados apresentaram menor PI do que os nativos; a viscosidade máxima do amido de pinhão foi maior à encontrada para o amido de milho, sendo ele menos resistente à agitação mecânica à quente (maior breakdown); a hidrólise ácida reduziu drasticamente a viscosidade das pastas formadas; a temperatura de gelatinização do amido de pinhão é de 47,64°C e a entalpia de gelatinização de 15,23 J.g-1; a hidrólise ácida aumentou a temperatura de gelatinização das espécies testadas.<br>Pinhão is the edible seed of Araucaria angustifolia, being consumed in the south and southeastern Brazil mainly in the natural form. The lack of diversity in relation to its consumption results in plenty of crop and its use as animal feed, which reduces the value of product marketing and affect the economic gains of the product. The pinhão seed is composed of 34% starch and a very low content of proteins and lipids, making it favorable for obtaining starch that is widely used by the food industry. The objective of this study was to characterize a new source of starch from seeds of Araucaria angustifolia, through a detailed study of the method for starch extraction, the physical-chemical, functional and rheological properties of the granules and their structural modification. To do this, a protocol for the starch extraction and a study of the effect of alkaline treatment (NaOH 0.05 mol.l-1 NaOH and 0.1 mol.l-1) compared to water treatment, was first established. Therefore, intrinsic fluorescence analysis, scanning electron and atomic force microscopy and x-ray diffractometry were carried out. The granular structure of pinhão starch was changed significantly when the alkaline solutions were used during extraction. The pinhão starch had a type C structure. The characteristics of native starch granules, through physical and chemical analysis, SEM, optical microscopy and syneresis were determined which found that the average diameter of starch granules varies from 7 to 20 μm and geometric shapes range from oval, the ellipsoid truncated and hemispheric. The pinhão starch was less prone to retrogradation compared to maize starch. The adsorption isotherms of native starch at temperatures of 10 °, 20 °, 30 ° and 40 ° C were drafting from fitting the experimental data to various sorption models. The Peleg model, followed by Chung-Pfost and GAB model had the highest correlation coefficients. From the GAB model were calculated monolayer moisture, enthalpy and entropy differential sorption. It was also carried out an experimental design to study the reaction of starch hydrolysis, through the influence of temperature (30° to 44°C) and hydrochloric acid concentration (1.2 to 3.2 mol.l- 1) on the dextrose equivalent value (DE) and on the ability of the gel formation and its thermoreversibility. It was observed that under the highest values of temperature and concentration of acid, the value of DE was higher. In larger value of DE (3.2 mol l-1 HCl and 44°C) was observed the formation of thermoreversible gel, which indicated the potential of modified starch as a fat substitute and a binder in food. The functionality of the pinhão starch was verified by analyzing the gel formation and fusion, gel thermoreversibility, tendency to retrogradation, stability to freezing and thawing, swelling power, solubility index, SEM, pasting viscosity and thermal properties such as temperature and enthalpy of gelatinization. The results showed that: only the modified starches exhibit thermoreversible gels, the native and modified pinhão starch have less tendency to retrograde than their counterparts in maize, the modification of starch reduced the tendency to retrogradation of starch pastes, the pinhão starch showed lower syneresis under storage at 5°C and after freezing and thawing, storage temperature affects significantly the swelling power (SP) and the solubility index of pinhão and maize native starches, the modified starches had lower SP of the natives, the maximum viscosity of pinhão starch was higher than that found for maize starch, the pinhão starch is less resistant to hot mechanical stirring (greater breakdown) than for maize starch, the acid hydrolysis reduced the viscosity of the pulp formed, the gelatinization temperature of pinhão starch is 47.64°C and its gelatinization enthalpy is 15.23 Jg-1; acid hydrolysis increased the gelatinization temperature of the species tested.
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42

AbuHassan, Yazeed. "EFFECT OF CHEMICAL SOLVENTS ON RHEOLOGICAL PROPERTIES OF RECOVERED ASPHALT BINDERS." University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1470053704.

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43

Gonçalves, Daniel. "Citrus essential oil fractionation using ethanol with different water contents as solvents: phase equilibrium, physical properties and continuous equipment extraction." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/74/74132/tde-22092017-150246/.

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Essential oils are featured commodities in the global market due their many applications in food and chemical industries, in different medicine areas, and as antibacterial, antifungal, and antioxidant agent. One of the phenomena accountable for the loss of essential oils quality may be associated with the degradation of terpene hydrocarbons by oxidation when exposed to air, light or heat, causing disagreeable odors. The procedure of terpenes content reducing, known as deterpenation, can be performed by diverse techniques, among which the liquid-liquid extraction can be highlighted since this process can be operated without the use of heating and pressure changes, causing low impact on the essential oil sensory qualities and low energy consumption. This research was focused on the fractionation process of citrus essential oils, by liquid-liquid extraction, using ethanol/water mixtures as solvents. Experimental liquid-liquid equilibrium data of model and real citrus systems were obtained. The aroma profile of the crude citrus essential oils (orange - Citrus sinensis and lime - Citrus aurantifolia) and the phases from the liquid-liquid equilibrium was also evaluated. Moreover, the crude citrus essential oils were fractionated in a continuous operation equipment (perforated rotating disc contactor, PRDC). It was verified that the water has an important influence over the fractionation performance, but not over the aroma profile of the phases. The experimental data from the model systems (citrus essential oil model mixture + ethanol + water) were used to adjust parameters of empirical and thermodynamic models, which provided satisfactory results on the calculation of physical property values and compositions of the phases from the real systems (crude citrus essential oil + ethanol + water). The fractionation of citrus essential oils by liquid-liquid extraction technology was technically feasible and can be accomplished into continuous apparatus such as PRDC column. The solvents employed provided extract phases enriched in oxygenated compounds.<br>Óleos essenciais são importantes produtos comercializados mundialmente devido às suas diversas aplicações em indústrias alimentícias e químicas, em diferentes áreas da medicina, e como agentes antibacteriano, antifúngico e antioxidante. Um dos fenômenos responsáveis pela sua perda de qualidade pode estar associado à degradação dos hidrocarbonetos terpênicos por oxidação, quando estes são expostos ao ar, luz ou calor, ocasionando odor desagradável. O procedimento para redução do teor de terpenos no óleo essencial, conhecido como desterpenação, pode ser realizado por diferentes técnicas, entre as quais a extração líquido-líquido se destaca uma vez que pode ser conduzida sem o emprego de calor e mudanças na pressão, o que atenua o impacto nas qualidades sensoriais e demanda menor gasto energético. Este estudo se concentrou no processo de fracionamento de óleos essenciais cítricos, pela técnica de extração líquido-líquido, empregando misturas de etanol e água como solventes. Foram obtidos dados de equilíbrio líquido-líquido de sistemas cítricos modelo e reais. O perfil de aroma dos óleos essenciais brutos (laranja - Citrus sinensis e lima ácida Citrus latifolia) e das fases provenientes do equilíbrio líquido-líquido também foram avaliados. Além disso, os óleos essenciais brutos foram submetidos ao processo de fracionamento em equipamento de operação contínua (coluna de discos rotativos perfurados, PRDC). Verificou-se que a água possui uma importante influência sobre o desempenho do processo de fracionamento, mas não afetou o aroma das fases. Os dados experimentais dos sistemas modelo (mistura modelo de óleo essencial cítrico + etanol + água) foram utilizados para o ajuste de parâmetros de modelos empíricos e termodinâmicos, os quais apresentaram bons resultados no cálculo de valores de propriedades físicas e da composição das fases oriundas dos sistemas reais (óleo essencial cítrico bruto + etanol + água). O fracionamento de óleos essenciais cítricos pela tecnologia de extração líquido-líquido mostrou-se tecnicamente viável e pode ser conduzido em equipamentos contínuos como a coluna de extração PRDC. Os solventes empregados permitiram a obtenção de fases extrato enriquecidas com compostos oxigenados.
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44

Boscolo, Lorenzo. "Extraction of antioxidants from corn by-products for applications in bio-based polymer matrices." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/22415/.

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The objective of this dissertation is the evaluation of the exploitability of corn cobs as natural additives for bio-based polymer matrices, in order to hone their properties while keeping the fundamental quality of being fully bio-derived. The first part of the project has the purpose of finding the best solvent and conditions to extract antioxidants and anti-degrading molecules from corn cobs, exploiting room and high-temperature processes, traditional and advanced extraction methods, as well as polar and nonpolar solvents. The extracts in their entirety are then analysed to evaluate their antioxidant content, in order to select the conditions able to maximise their anti-degrading properties. The second part of the project, instead, focuses on assessing chemical and physical properties of the best-behaving extract when inserted in a polymeric matrix. To achieve this, low-density polyethylene (LDPE) and poly (butylene succinate – co – adipate) (PBSA) are employed. These samples are obtained through extrusion and are subsequently characterised exploiting the DSC equipment and a sinusoidally oscillating rheometer. In addition, extruded polymeric matrices are subjected to thermal and photo ageing, in order to identify their behaviour after different forms of degradation and to assess their performances with respect to synthetically produced anti-degrading additives.
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45

Karacabey, Erkan. "Grape Juice Filtration, Thermopyhsical Properties Of Clear Fruit Juices And Pressurized Low Polarity Water (plpw) Extraction Of Polyphenolic Compounds From Grape Canes." Phd thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/2/12610989/index.pdf.

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Filtration of grape juice was investigated. Effects of process parameters of filtration were examined. The usage of precoating material and filter aid were found to be necessary to prolong the filter life. Filter cake was found to be incompressible with the effect of increasing pressure. Increase in temperature caused increase in flow rate due to the reduction in viscosity. The influences of depectinization and clarification on filtration process were also examined. Depectinization and clarification decreased the resistance and increased the flow rate. Improvement in the quality of the grape juice was observed when these pretreatments were employed. The effects of temperature and soluble solid concentration on physical properties of clarified fruit juices were investigated. High temperature and soluble solid content dependencies of density, viscosity and heat capacity were detected. Experimental data were fitted as a function of temperature and soluble solid content. Models being valid for studied clarified fruit juices were achieved for density and viscosity with the regression coefficients (R2) higher than 0.90. Optimization of the solid-liquid extraction conditions for trans-resveratrol, trans-&amp<br>#949<br>-viniferin, ferulic acid, and total phenolics from milled grape canes has been investigated. Temperature and ethanol concentration were found to be major process variables for all responses. Maximum yields of trans-resveratrol, trans-&amp<br>#949<br>-viniferin, ferulic acid, and total phenolics were predicted as 4.25 mg/g dw, 2.03 mg/g dw, 1.05 mg/g dw, and 9.28 mg/g dw, respectively. Optimization of extraction conditions for antioxidant activity of grape cane extracts measured by the Trolox equivalent antioxidant capacity (TEAC) and the oxygen radical absorbance capacity (ORACFL) assays was carried out using solid-liquid extraction and response surface methodology. Ethanol concentration and temperature employed for the extraction of antioxidant agents from grape cane samples were found to be statistically significant process variables affecting antioxidant activity measured by the TEAC and ORAC methods. trans-Resveratrol and trans-&amp<br>#949<br>-viniferin were extracted from milled grape canes using pressurized low polarity water (PLPW). The extraction temperature was significant for both compounds: extraction at 160oC resulted in a 40% loss of trans-resveratrol compared to 95oC while reduction of trans-&amp<br>#949<br>-viniferin at both temperatures remained at 30%. Increasing ethanol concentration from 0 to 25% increased the extraction of total phenolics and trans-&amp<br>#949<br>-viniferin by 44% and 489%, respectively. Solvent flow rate also influenced trans-&amp<br>#949<br>-viniferin extraction. Effective diffusivities of trans-resveratrol increased by three times with increasing temperature. The modified Gompertz equation satisfactorily explained the extraction of the stilbenes investigated.
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46

Lee, Ryan S. "Effect of the Ca2+ Binding Properties of Troponin C On Skeletal and Cardiac Muscle Force Development." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1274968255.

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47

Liu, Lanfa, Manfred Buchroithner, Min Ji, Yunyun Dong, and Rongchung Zhang. "Quantitative Retrieval of Organic Soil Properties from Visible Near-Infrared Shortwave Infrared (Vis-NIR-SWIR) Spectroscopy Using Fractal-Based Feature Extraction." Molecular Diversity Preservation International (MDPI), 2016. https://tud.qucosa.de/id/qucosa%3A30203.

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Visible and near-infrared diffuse reflectance spectroscopy has been demonstrated to be a fast and cheap tool for estimating a large number of chemical and physical soil properties, and effective features extracted from spectra are crucial to correlating with these properties. We adopt a novel methodology for feature extraction of soil spectroscopy based on fractal geometry. The spectrum can be divided into multiple segments with different step–window pairs. For each segmented spectral curve, the fractal dimension value was calculated using variation estimators with power indices 0.5, 1.0 and 2.0. Thus, the fractal feature can be generated by multiplying the fractal dimension value with spectral energy. To assess and compare the performance of new generated features, we took advantage of organic soil samples from the large-scale European Land Use/Land Cover Area Frame Survey (LUCAS). Gradient-boosting regression models built using XGBoost library with soil spectral library were developed to estimate N, pH and soil organic carbon (SOC) contents. Features generated by a variogram estimator performed better than two other estimators and the principal component analysis (PCA). The estimation results for SOC were coefficient of determination (R2) = 0.85, root mean square error (RMSE) = 56.7 g/kg, the ratio of percent deviation (RPD) = 2.59; for pH: R2 = 0.82, RMSE = 0.49 g/kg, RPD = 2.31; and for N: R2 = 0.77, RMSE = 3.01 g/kg, RPD = 2.09. Even better results could be achieved when fractal features were combined with PCA components. Fractal features generated by the proposed method can improve estimation accuracies of soil properties and simultaneously maintain the original spectral curve shape.
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48

Liu, Lanfa, Manfred Buchroithner, Min Ji, Yunyun Dong, and Rongchung Zhang. "Quantitative Retrieval of Organic Soil Properties from Visible Near-Infrared Shortwave Infrared (Vis-NIR-SWIR) Spectroscopy Using Fractal-Based Feature Extraction." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-220555.

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Visible and near-infrared diffuse reflectance spectroscopy has been demonstrated to be a fast and cheap tool for estimating a large number of chemical and physical soil properties, and effective features extracted from spectra are crucial to correlating with these properties. We adopt a novel methodology for feature extraction of soil spectroscopy based on fractal geometry. The spectrum can be divided into multiple segments with different step–window pairs. For each segmented spectral curve, the fractal dimension value was calculated using variation estimators with power indices 0.5, 1.0 and 2.0. Thus, the fractal feature can be generated by multiplying the fractal dimension value with spectral energy. To assess and compare the performance of new generated features, we took advantage of organic soil samples from the large-scale European Land Use/Land Cover Area Frame Survey (LUCAS). Gradient-boosting regression models built using XGBoost library with soil spectral library were developed to estimate N, pH and soil organic carbon (SOC) contents. Features generated by a variogram estimator performed better than two other estimators and the principal component analysis (PCA). The estimation results for SOC were coefficient of determination (R2) = 0.85, root mean square error (RMSE) = 56.7 g/kg, the ratio of percent deviation (RPD) = 2.59; for pH: R2 = 0.82, RMSE = 0.49 g/kg, RPD = 2.31; and for N: R2 = 0.77, RMSE = 3.01 g/kg, RPD = 2.09. Even better results could be achieved when fractal features were combined with PCA components. Fractal features generated by the proposed method can improve estimation accuracies of soil properties and simultaneously maintain the original spectral curve shape.
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49

Ayarza-León, Jorge Luis. "Alginates: 20000 applications of submarine algae." Revista de Química, 2014. http://repositorio.pucp.edu.pe/index/handle/123456789/100618.

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Desde la antigüedad, el ser humano ha encontrado recursos de gran utilidad en el mar. Las algas pardas marinas de la clase Phaeophyceae son la fuente de un biopolímero con propiedades muy interesantes, denominado alginato. En la actualidad, el alginato  es extraído y comercializado en muchos lugares del mundo, es un componente importante en muchos productos de uso diario, e incluso se le emplea a nivel de investigación académica.<br>Since antiquity, mankind has depended on the sea to obtain valuable resources. Marine brown algae from the class Phaeophyceae are the source of a biopolymer with very interesting properties called alginate. Nowadays, alginate is extracted and commercialized around the world, it is an essential component in many everyday products, and it is even used in academic research.
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50

ROCCHI, ELISA. "STRUCTURAL PROPERTIES AND FUNCTIONAL TAILORING OF REFINED OR UNREFINED PLANT-BASED MATERIALS OBTAINED BY EXTRACTION OR BIO-TRANSFORMATION OF AGRO-FOOD WASTES." Doctoral thesis, Università degli Studi di Milano, 2018. http://hdl.handle.net/2434/603778.

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L’impiego delle risorse in maniera efficiente è una tematica di interesse globale, sia da un punto di vista ambientale che economico. La produzione di grandi quantità di residui agro-alimentari è una delle principali cause di inefficienza a livello di produzione industriale. Questi materiali hanno ancora un elevato contenuto di materiale organico, ricco in composti naturali preziosi e peculiari strutture che, una volta identificati, possono essere estratti e valorizzati per via fisica, chimica o biotecnologica. Per queste ragioni, negli ultimi anni si osserva un crescente interesse sia scientifico che industriale per il recupero e la valorizzazione di materiali di scarto. In questo contesto, questo progetto di dottorato si propone di investigare le potenzialità di ingredienti derivati da residui agro-alimentari per la formulazione alimentare. La caratterizzazione strutturale e funzionale delle matrici considerate ha seguito un approccio tipico della scienza dei materiali, basato sull’analisi quantitativa mediante modelli matematici per promuovere e controllare specifici fenomeni e modificazioni in grado di migliorare le proprietà funzionali del sistema formulato. Nella presente tesi di dottorato sono stati considerati quattro diversi materiali. La cellulosa nano cristallina è stata caratterizzata da un punto di vista reo-ottico per meglio comprendere quale sia relazione esistente tra l’organizzazione nematica e lo stato cineticamente arrestato. Gli estratti di parete vegetale (CWM) sono stati studiati nell’ottica di un loro impiego come sistemi per il trasporto di composti bioattivi, agendo soprattutto sull’organizzazione della matrice polimerica di parete con lo scopo di poter meglio controllare il rilascio dei composti di interesse. Le frazioni di farina di semi di canapa sono state valutate in termini di capacità texturizzante e strutturante. La cellulosa batterica si è dimostrata invece un eccellente supporto per la ritenzione di molecole volatili.<br>The efficient exploitation of resources is a topic of concern worldwide, from both an environmental and economic point of view. The production of large amounts of agro-food residues is one of the main causes for the inefficiency of industrial-scale food production. These are materials of high organic load, where valuable natural compounds and structures can be identified and extracted in order to valorize wastes via physical, chemical or biotechnological processing. For this reason, an intensive investigation for the recovery of materials with improved functional properties has been carried out in the last years. In this framework, this PhD doctoral project aimed to explore the potentiality of residue-derived ingredients for the food formulation. Structural and functional characterization of the proposed matrices was performed with a material science point of view, based on the quantitative analysis through mathematical models to promote and control adequate changes which can improve some functional properties in the food. In the present thesis, four different materials were considered. Cellulose nanocrystals were characterized with a rheo-optical approach in order to provide an insight into the relationship between nematic ordering and kinetic arrest. Cell wall materials were studied as carrier of bioactive compounds, with the purpose of tuning the wall matrix organization to obtain a sustained release. Hemp seed meal fractions were evaluated because of their texturing and structuring abilities. The use of bacterial cellulose as support for the retain of volatile molecules was also investigated, along with its thickening ability.
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