To see the other types of publications on this topic, follow the link: HPDC Al.
Dissertations / Theses on the topic 'HPDC Al'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'HPDC Al.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Tharayil, Pradeep Ambareeksh, and Mohammadali Baradaran. "HPDC Die design for Additive Manufacturing : Simulation and Comparison of Thermal Stresses in HPDC die designed for Additive Manufacture." Thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH, Industriell produktutveckling, produktion och design, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-43319.
Full textAbstract:
Additive manufacturing has a great potential to benefit die manufacture by shortening the lead time considerably and lifting the limitations on design complexity imposed by conventional manufacturing techniques. However, AM has its own requirements that together are known as Design for Additive Manufacturing and account for the process limitations. One of the significant requirements is mass efficiency of the design (it should be as light as possible). If it’s not fulfilled, AM won’t be able to make an economical solution or substitution despite having outstanding benefits. The present investigation has been framed with respect to such concern. This investigation attempts to draw a comparison between the performance of two design variants. Additionally, it has been tried to study the employed method, document implementation of the approach, and identify the challenges in accordance with design for additive manufacturing. Simulation of thermal stresses generated in die inserts for a given component during one cycle of high pressure die casting is presented. Initial design of the die inserts is subjected to redesign with the intention of mass reduction by incorporating honeycomb structure. Temperature evolution and resultant thermal stresses are analyzed for redesign and compared to those of original design. Simulation of high pressure die casting was carried out in MagmaSoft to obtain temperature history of die inserts and cast. Implicit nonlinear elastic fully coupled thermal displacement model was setup in Abaqus in which Magma results were used as input for stress calculation. Results show that according to our specific design, HPDC die with thin walled feature cannot withstand the thermal and mechanical load. However, with iterative analysis and proper topology optimization, a lightweight complex geometry die can be successfully made.
2
Prakash, D. G. Leo. "Microstructural influences on macro properties of hpdc magnesium alloy AZ91 quantification and FE simulations." Magdeburg Docupoint-Verl, 2005. http://deposit.ddb.de/cgi-bin/dokserv?id=2747367&prov=M&dok_var=1&dok_ext=htm.
Full text
3
Zhang, Bohua. "The Influence of Porosity and Its Modeling on Fatigue Behavior of High Pressure Die Cast Aluminum including the Effects of Mean Stress, Stress Gradient and Specimen Size." University of Toledo / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1556259677391458.
Full text
4
Riestra, Perna Martin Ignacio. "TAILORING PROPERTIES TO REPRESENT HPDC TENSILE AND FATIGUE BEHAVIOUR IN ALUMINIUM-SILICON CAST ALLOY PROTOTYPES." Thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH. Forskningsmiljö Material och tillverkning – Gjutning, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-27734.
Full textAbstract:
The work presented aims to find alternatives for the prototyping of components by sand and plaster mold manufacturing processes that deliver properties similar to high pressure die casting (HPDC). Sand and plaster test samples have been casted. The Al-7Si-0.35Mg alloy has been tested in as cast condition and in a heat treated condition; T5 for sand cast samples and T6 for those plaster cast. The Al-7Si-2Cu-0.35Mg alloy was also tested in as cast condition. Tensile, fatigue and hardness tests have been performed. Microstructural investigation comprising secondary dendrite arm spacing, defects, Fe-rich β-phases and Si size measurements has been performed on the different conditions. The results have been compared to available data for Al-9Si-3Cu-(Fe) alloy used in HPDC. The T5 heat treated sand cast condition has shown to have properties similar to HPDC. All other sand cast conditions, including the previously tested Al-9Si-3Cu-(Fe) alloy, have been shown to be reasonable alternatives.
5
Gulizia, Stefan. "Soldering in high pressure die casting (HPDC) performance evaluation and characterisation of physical vapour deposition (PVD) coatings /." Swinburne Research Bank, 2008. http://hdl.handle.net/1959.3/39640.
Full textAbstract:
Thesis (MEng) - School of Engineering and Science, Swinburne University of Technology, 2008.<br>Thesis submitted for the degree of Master of Engineering, School of Engineering and Science, Swinburne University of Technology, 2008. Typescript. Includes bibliographical references (p. 98-101).
6
Lenzi, Daniele. "Analisi dei difetti in componenti meccanici prodotti in lega leggera mediante il processo di colata sotto pressione." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/15209/.
Full textAbstract:
L’elaborato si prefigge l’obbiettivo di analizzare i difetti che si possono riscontrare nel realizzare prodotti in alluminio attraverso il processo di colata sotto pressione. In particolare, si studiano i parametri e i fenomeni che rivestono maggiore importanza nel processo, al fine di ottenere un prodotto finale che presenti una limitata difettosità. Infine si studia un caso di difettosità riscontrato in azienda, analizzando i risultati delle simulazioni del processo, le analisi termiche svolte attraverso l'utilizzo di termocamere e si indaga la microstruttura con l'ausilio di un microscopio ottico.
7
Pereira, Manuel Filipe Viana Teotonio. "ADDITIVE MANUFACTURING OF COMPONENTS FOR IN-DIE CAVITY USE, SUITABLE TO WITHSTAND ALUMINIUM HIGH PRESSURE DIE CASTING (HPDC) PROCESS CONDITIONS." Thesis, Bloemfontein: Central University of Technology, Free State, 2013. http://hdl.handle.net/11462/243.
Full textAbstract:
Thesis (M. Tech. (Engineering: Mechanical)) -- Central University of Technology, Free State, 2013<br>This research examines the suitability of Additive Manufacturing (AM) for manufacturing dies used in aluminium high pressure die casting. The study was guided by the following objectives:
• The reviews of applicable literature sources that outline technical and application aspects of AM in plastic injection moulds and the possibilities of applying it to high pressure casting die.
• To introduce AM grown die components in die manufacture. Further, to develop a methodology that will allow industry to apply AM technology to die manufacture.
• Revolutionise the way die manufacture is done. The potential for AM technologies is to deliver faster die manufacture turnaround time by requiring a drastically reduced amount of high level machining accuracy. It also reduces the number of complex mechanical material removal operations. Fewer critical steps required by suitable AM technology platforms able to grow fully dense metal components on die casting tools able to produce production runs.
• Furthermore, promising competitive advantages are anticipated on savings to be attained on the casting processing side. AM technology allows incorporation of features in a die cavity not possible to machine with current machining approaches and technology. One such example is conformal cooling or heating of die cavities. This approach was successfully used in plastic injection mould cavities resulting in savings on both the part quality as well as the reduction on cycle time required to produce it (LaserCUSING®, 2007).
AM technology has evolved to a point where as a medium for fast creation of an object, it has surpassed traditional manufacturing processes allowing for rapidly bridging the gap between ideas to part in hand. The suitability of the AM approach in accelerating the die manufacturing process sometime in the near future cannot be dismissed or ignored. The research showed that there is promise for application of the technology in the not too distant future.
In the South African context, the current number and affordability of suitable AM platforms is one of the main stumbling blocks in effecting more widespread applied research aimed at introduction of the technology to die manufacture.
8
Law, Madeleine. "Investigations on the Formation of Defect Bands in Semi-Solid High Pressure Die Cast Aluminium-Silicon Alloys." Licentiate thesis, KTH, Materialvetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-272086.
Full textAbstract:
High-pressure die casting of semi-solid aluminium-silicon alloys is used in the automotive industry to manufacture components, like housings, brackets, and bars. It is commonly known that during high-pressure die casting, defect bands may be created that follow the contour of the component surface. These bands consist mainly of a eutectic phase. This phenomenon is also observed in semi-solid metal slurry high-pressure die casting. These bands could lead to premature failure of the component in service. The origin of these bands is not fully understood and so this research focuses on investigating these bands and their origins further. A series of casting trials were conducted with varying plunger velocity. Subsequent investigation using optical and scanning electron microscopy showed that a change of the plunger velocity alters the number of bands present in the samples. Energy dispersive X-ray spectroscopy revealed that a measurable difference in aluminium quantity across the band was noticed and it was postulated that aluminium migrates towards the component centre. Therefore, different mechanisms responsible for particle migrations found in literature were investigated and assessed quantitatively using experimental data and information from published literature. It was found that the Saffman lift force and the Mukai-Lin-Laplace effect were the mechanisms that were most likely to cause such a migration of aluminium. Further experimental investigation is recommended to identify which of the two mechanisms is ultimately responsible for the migration and to optimise the high-pressure die casting procedure to minimise defect band formation.<br>Produktion av högtrycksgjutning av halvfasta aluminium-kisellegeringar används i fordonsindustrin för att tillverka komponenter, som exempel till kåpor, konsoler och stag. Det är allmänt känt att defektband kan formas under högtrycksgjutning som följer konturen av komponentytan. Dessa band består huvudsakligen av eutektisk fas. Detta fenomen har också observerats vid högtrycksgjutning produktion av halvfast slurry. Potentiellt kan dessa band leda till en försämring av komponentens mekaniska egenskaper och resultera i ett förtida brott. Ursprunget av dessa band är inte helt kartlagda och det är därför viktigt att fokusera ytterligare på denna forskning och att undersöka dessa band och deras ursprung. En serie med gjutningsförsök genomfördes med varierande kolvhastighet. Efterföljande undersökning med optisk- och svepelektronmikroskopi visade att en förändring av kolvhastigheten förändrar antalet band som finns i proverna. Energidispersiv röntgenspektroskopi avslöjade en mätbar skillnad i aluminiumkvantitet över bandet, och det antogs att aluminium migrerar mot centrum av komponenten. Därför undersöktes och utvärderades olika mekanismer som ansvarar för partikelmigrationer som finns att finna i litteratur med hjälp av experimentella data och information från publicerad litteratur. Det visade sig att Saffman lyftkraft och Mukai-Lin-Laplace effekten var de mekanismer som mest troligen orsakade migration av aluminium. Ytterligare experimentella försök rekommenderas för att identifiera vilken av dessa två mekanismerna som i slutändan är ansvarig för migrationen. Detta för att optimera gjutningsprocessen och därmed minimera uppkomsten av defektband.
9
Sivertsen, Halses Sebastian. "Die life prediction using High Pressure Die Casting simulations." Thesis, Tekniska Högskolan, Jönköping University, JTH, Material och tillverkning, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-50031.
Full textAbstract:
Global trends in automotive industry for weight reduction drives an interest for casting of structural aluminum parts. High pressure die casting (HPDC) is chosen for this purpose since it enables manufacturing of large series parts where complexity and repeatability is demanded. Aluminum alloys have hence been developed through the years to obtain suitable mechanical properties for high strength parts. These alloys have been investigated to predict the types of potential failure mechanisms during HPDC in order to determine die life through simulations. Die life prediction was performed through simulations in MAGMAsoft 5.4 with the help of a die life module, which is based on thermal stresses generated in the die material during casting cycles. Fatigue data at elevated temperature obtained from literature review of AISI H11 tool steel was complemented to the Wöhler curve in the software database. Comparison of two aluminum alloys showed that chemical composition had a major influence on die life. Chemical composition had a direct impact on solidification time and with longer solidification time, the thermal load on the die increased. Since the stress range on the die is temperature dependent, the ability of heat transfer over time proved to be critical for die life results. The most crucial process parameter to achieve a longer die life was constant cooling by tempering channels, due to their high potential to remove heat. Tempering channels and die spray also prevent the die from exceeding a critical temperature resulting in soldering formation. Mold erosion was consistently observed in the same location for all simulations.
10
Vicario, Gomez Iban. "Influence des nano-particules d’alumine (Al2O3) et de di-borure de titane (TiB2) sur la microstructure et les propriétés de l’alliage Al-Si9-Cu3-Fe1 pour des applications de fonderie à haute pression." Thesis, Bordeaux 1, 2011. http://www.theses.fr/2011BOR14420/document.
Full textAbstract:
Ce travail est dédié á l´étude de l´influence de nano-particules de alumina (Al2O3) et de di-borure de titane (TiB2) sur la solidification, la microstructure et les propriétés thermiques et mécaniques de l´alliage d´aluminium renforcés, Al-Si9Cu3Fe1. Les matériaux ont été obtenus par un procédé de fonderie à haute pression en coulant les alliages dans les mêmes conditions que les alliages non renforcés correspondants.On a constaté que les particules de Al2O3 et de TiB2 ont une influence directe sur les caractéristiques de l´alliage telles que la microstructure, la précipitation des phases pendant la solidification et les propriétés mécaniques et électriques. On a ainsi montré que les particules de Al2O3 et de TiB2 peuvent être utilisées pour ajuster les caractéristiques des alliages et obtenir des propriétés spécifiques pour des applications dans les secteurs de matériaux légers<br>The work has been focused on the study of the influence of TiB2 and Al2O3 nano-particles (up to 1 wt. %) on the properties and physical features of an aluminium casting alloy, Al-Si9Cu3Fe1.Samples have been obtained through the High Pressure Die Casting (HPDC) process and compared with unreinforced samples obtained at the same conditions. It has been observed that the Al2O3 and TiB2 particles have a direct influence on several features of the alloy such as the microstructure and precipitating phases as well as in the improvement of the soundness and mechanical and electrical properties. Al2O3 and TiB2 particles can be used to tailor the properties of the alloy and to match the specifications of light weight applications
11
Albo, Zieme Louise, and Pontus Bergstedt. "A pre-study for functional coatings evaluated on light metals to be applied on a new HPDC Mg-alloy : Investigating tribological and thermophysical properties, as-cast and coated." Thesis, Jönköping University, JTH, Industriell produktutveckling, produktion och design, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-53096.
Full textAbstract:
Magnesium with two-thirds of the density compared to aluminium and one-quarter of steel, intrigues product developers and material scientists due to the light metal’s excellent combination of strength to weight ratio as well as their capability of being produced as a High Pressure Die Cast component compared to other ferrous or light metal alloys. However, a magnesium alloy inherits some concerning drawbacks, limiting the exploitation in structural applications and mechanical design such as automotive, heavy machinery and aerospace components. The need for a magnesium alloy that could withstand a sufficient amount of wear, temperature and corrosive environment, leads towards the investigation and evaluation of a suitable, functional coating as a solution to exploit the evident advantages a magnesium alloy exhibits. A substantial amount of research is required in order to reduce an existing knowledge gap that is the ongoing development in the search for a sufficient functional coating and adherence capability to the highly reactive substrate that is a magnesium alloy. This industrial master thesis is an early stage investigation to evaluate how the currently used aluminium substrate with an electrodeposited coating relate and compares to a heat-treated electroless deposited coating through tribological and thermophysical induced stresses. These properties are tested with proven industrial standard methods resulted in a comprehensive conclusion and discussion regarding the feasibility of applying the coating onto a commercial magnesium alloy closely related to the Mg-alloy developed by Husqvarna and thereby contributing to technological advances to the highly relevant topic within product development in materials engineering.
12
Klarner, Andrew Daniel. "Development of Mg-Al-Sn and Mg-Al-Sn-Si Alloys and Optimization of Super Vacuum Die Casting Process for Lightweight Applications." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1515083355012541.
Full text
13
Vicario, Gomez Iban. "Influence des nano-particules d'alumine (Al2O3) et de di-borure de titane (TiB2) sur la microstructure et les propriétés de l'alliage Al-Si9-Cu3-Fe1 pour des applications de fonderie à haute pression." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2011. http://tel.archives-ouvertes.fr/tel-00670402.
Full textAbstract:
Ce travail est dédié á l'étude de l'influence de nano-particules de alumina (Al2O3) et de di-borure de titane (TiB2) sur la solidification, la microstructure et les propriétés thermiques et mécaniques de l'alliage d'aluminium renforcés, Al-Si9Cu3Fe1. Les matériaux ont été obtenus par un procédé de fonderie à haute pression en coulant les alliages dans les mêmes conditions que les alliages non renforcés correspondants.On a constaté que les particules de Al2O3 et de TiB2 ont une influence directe sur les caractéristiques de l'alliage telles que la microstructure, la précipitation des phases pendant la solidification et les propriétés mécaniques et électriques. On a ainsi montré que les particules de Al2O3 et de TiB2 peuvent être utilisées pour ajuster les caractéristiques des alliages et obtenir des propriétés spécifiques pour des applications dans les secteurs de matériaux légers.
14
Sánchez, Brito Wendy Cecilia. "Estudio comparativo del control de la liberación del valproato de magnesio en matrices hidrofílicas de HPC y HPMC." Tesis de maestría, Universidad Autónoma del Estado de México, 2019. http://hdl.handle.net/20.500.11799/104992.
Full textAbstract:
Es un proyecto vinculado con algunos procesos realizados en la industria farmacéutica<br>En la última mitad de presente siglo se ha tratado de prolongar el efecto de un
principio activo o fármaco a través de la modulación de su liberación desde la forma
farmacéutica. En las formas farmacéuticas sólidas, este tipo de regulación ha sido
posible principalmentea través del uso de matrices sólidas, incluyendo dentro de
ellas a las matrices hidrofílicas.
Dos éteres de la celulosa empleados en la formulación de matrices hidrofílicas,
hidroxipropilmetilcelulosa (HPMC) e hidroxipropilcelulosa (HPC), se utilizarán para
comparar la liberación del fármaco valproato de magnesio, con el objetivo de
estudiar las variaciones individuales en el control de su liberación.
Mediante este proyecto de investigación se generará información científicotecnológica útil para las empresas farmacéuticas en el estudio de matrices de
liberación controlada, ofreciendo establecer posibles ventajas tecnológicas de la
HPC frente a la HPMC. Dado que las matrices hidrofílicas son hoy en día
ampliamente utilizadas en la industria farmacéutica de medicamentos genéricos,
este tema resulta relevante para los laboratorios farmacéuticos asentados en el
país, en tanto que buscan generar ventajas competitivas en el mercado de los
sólidos orales.
La disminución del número de tomas diarias por parte del paciente es una ventaja
competitiva porque aumenta la adherencia posológica y por tanto el éxito del
tratamiento. La administración de los principios activos dentro de matrices
hidrofílicas permite controlar los perfiles de liberación in vitro e in vivo pero además
resulta idónea para la fabricación, ya que no necesita inversión en nueva maquinaria
ni en modificar los procesos productivos de las tabletas de liberación inmediata. Por
ello, en este estudio se comparan los resultados de los lotes fabricados con dos
tipos químicos de excipientes utilizados en la fabricación de matrices hidrofílicas,
determinando dureza, friabilidad, hinchamiento y perfil de disolución in vitro de
tabletas de liberación prolongada de valproato de magnesio.
15
Milhem, Luc. "Fonderie sous pression du cuivre : étude du procédé et caractérisation du matériau." Thesis, Normandie, 2018. http://www.theses.fr/2018NORMIR14.
Full textAbstract:
Ces travaux de recherche portent sur l’étude de l’injection du cuivre. Dans une optique d’amélioration des propriétés du cuivre injecté sous pression, deux grands thèmes de réflexion ont été abordés. La première voie de réflexion porte sur l’influence des paramètres de fusion et d’éléments d’alliages ajoutés en faible quantité sur les caractéristiques des démonstrateurs technologiques produits. La seconde partie discute de l’influence du procédé de fonderie en lui-même, notamment au travers de l’étude de deux paramètres : l’influence du régime d’écoulement du métal en fusion dans l’empreinte, et l’influence de l’emprisonnement de l’air sur les propriétés des pièces injectées<br>This research focuses on the study of high pressure die casting (HPDC) of copper. In order to improve the properties of die-cast copper, two main issues were investigated. In the first part, attention is paid to the influence of melting parameters and of addition of alloying elements in small amounts on the characteristics of the specimen produced. The second part discusses the influence of the foundry process itself on properties of die cast part, in particular by studying two parameters : the metal flow type during cavity filling, and the air entrapment
16
Bakirdere, Sezgin. "Speciation Studies Using Hplc-icp-ms And Hplc-es-ms." Phd thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/3/12611391/index.pdf.
Full textAbstract:
Knowledge about selenium content of foods containing selenium species is very important in terms of both nutrition and toxicity. Bioavailability of selenium species for human body is different from each other. Hence, speciation of selenium is more important than total selenium determination. In the selenium speciation study, chicken breast samples, selenium supplement tablets and egg samples were analyzed for their selenium contents. In chicken breast study, chickens were randomly categorized into three groups including the control group (25 chickens), inorganic selenium fed group (25 chickens) and organic selenium fed group (25 chickens). After the optimization of all the analytical parameters used throughout the study, selenomethionine, selenocystine, Se(IV) and Se(VI) were determined using Cation Exchange-HPLC-ICP-MS system. In selenium supplement tablet study, anion and cation exchange chromatographies were used to determine selenium species.
Arsenic is known as toxic element, and toxicity of inorganic arsenic species, As(III) and As(V), is much higher than organic arsenic species like arsenobetaine and arsenosugars. Hence, speciation of arsenic species in any matrix related with human health is very important. In the arsenic speciation study, Cation Exchange-HPLC-ICP-MS and Cation Exchange-HPLC-ES-MS systems were used to determine arsenobetaine content of DORM-2, DORM-3 and DOLT-4 as CRMs. All of the parameters in extraction, separation and detection steps were optimized. Standard addition method was applied to samples to eliminate or minimize the matrix interference.
Thiols play an important role in metabolism and cellular homeostasis. Hence, determination of thiol compounds in biological matrices has been of interest by scientists. In the thiol study, Reverse Phase-HPLC-ICP-MS and Reverse Phase-HPLC-ES-MS systems were used for the separation and detection of thiols. For the thiol determination, thiols containing &ndash<br>S-S- bond were reduced using dithiothreitol (DTT). Reduction efficiencies for species of interest were found to be around 100%. Reduced and free thiols were derivatized before introduction on the column by p-hydroxymercuribenzoate (PHMB) and then separated from each other by using a C8 column. In the real sample measurement, yeast samples were analyzed using HPLC-ES-MS system.
17
Forss, Erik. "On-line HPLC." Thesis, Karlstads universitet, Avdelningen för kemiteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-16166.
Full textAbstract:
In order to increase the analysis frequency and thereby achieve a better understanding of the kinetics and dynamics of the chemical process without increasing the workload of the already strained analytical laboratory at Cambrex Karlskoga AB, this projects goal was to investigate whether a crude prototype for mobile on-line HPLC-analysis with automatic sampling and dilution could be built based on certain flow-injection analysis techniques. It was possible to achieve dilution with good repeatability even though saturation effects in the filter proved problematic. Separation and dilution of a binary mixture was also successful as proof-ofconcept.
18
Kadkhodaei-Elyaderani, Manizheh. "HPLC detection of haemoglobinopaties." Thesis, University of Salford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308175.
Full text
19
Ertas, Hasan. "Ageing of silica in HPLC." Thesis, Loughborough University, 1998. https://dspace.lboro.ac.uk/2134/33118.
Full textAbstract:
This study may be divided into two sections which cover different aspects of the reproducibility problems encountered in HPLC. In the first, the study has involved the separation of basic drugs, on different manufacturer's reversed-phase columns in conjunction with an acid buffered acetonitrile/water gradient. The retention reproducibility of each drug was assessed and compared on the basis of the retention index scale of 1-nitroalkanes. The effect of changing gradient run time on the reproducibility of the retention values of the 1-nitroalkanes was demonstrated on reversed-phases of different makers. The optimisation of initial isocratic composition of organic (acetonitrile) was carried out and its effect on the reproducibility of retention of basic drugs was evaluated. The effect of a premixed eluent on the retention reproducibility of selected basic drugs with time intervals between injections was demonstrated. The same method was further extended with or without using helium gas with small flow. The prediction of dwell volume and its effect on retention reproducibility was evaluated. Determination of retention times changes for selected aqueous basic solutes against eluent with different pH values on Capcell ODS column was studied. Applicability of each reversed-phases (Cl8) for the separation of basic analytes was demonstrated. In the second section, a number of different unbonded (bare) silicas were studied in terms of surface analysis using of solid state cross-polarisation (CP) magic angle spinning (MAS) NMR and Fourier Transform (FT) Diffuse Reflectance Infrared Spectra (DRIFT-IR) data. It is believed that silica material used for HPLC separation with eluent undergoes an ageing process with acidic (at pH:2–3) and basic eluents (higher than pH:8). To examine this process more clearly, some basic analytes were selected to evaluate each of the accelerated ageing process followed by showing the final surface properties by the method most commonly used such as solid-state NMR and FT-IR along with BET surface analyser.
20
Burr, Christina Mary. "Retention prediction in RP-HPLC." Thesis, Loughborough University, 1988. https://dspace.lboro.ac.uk/2134/27346.
Full textAbstract:
A method of calculating the RP-HPLC retention indices, based on the alkylarylketone scale, has been developed. The retention indices are calculated from the molecular structure of a compound as the sum of the parent contribution, the parent index, the substituent contributions, the substituent indices, and terms to account for the interactions between substituents, the interaction indices.
21
Mayr, Gerhard. "Bildung und Kompensation von Temperaturgradienten in der schnellen HPLC unter Verwendung von Micropartikel-gepackten HPLC-Säulen." Ulm : Universität Ulm, Fakultät für Naturwissenschaften, 1999. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB8303640.
Full text
22
Müller, Sonja. "Analytische Trennungen neuartiger Supramoleküle mittels HPLC." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=980196973.
Full text
23
Thomas, H. D. "Chemiluminescence, a detection method for HPLC." Thesis, University of East Anglia, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383774.
Full text
24
Scholtzova, Angela. "Scale up and modelling of HPLC." Thesis, University College London (University of London), 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368109.
Full text
25
Albishri, Hassan Mabrook. "High-temperature HPLC of pharmaceutical compounds." Thesis, Loughborough University, 2007. https://dspace.lboro.ac.uk/2134/36130.
Full textAbstract:
In this thesis, we established methods that use high-temperature HPLC for the efficient separation of different groups of pharmaceutical compounds. These groups are cephalosporins, non-steroidal anti-inflammatory (NSAID), and diuretic drugs. The effect of changes of the temperature of the column was studied with respect to various chromatographic parameters: retention factors, thermodynamic properties, selectivity, efficiency and peak shape. Three columns (Pathfinder, Xterra RP18, and Selerity's Blaze 200) were examined for the analysis of cephalosporin drugs under high temperature reversed phase HPLC. Several proportions of mobile phases were used with these columns. This study focused on the effect of column temperature on selectivity (α), and efficiency (N/m), van't Hoff plots. The best conditions for the separation of these drugs were 60 °C with 100% water as eluent and these conditions were the best for quantitative applications. This condition was validated according to International Conference on Harmonisation (ICR) with respects of linearity, limit of detection (LOD), limit of quantification (LOQ), and precision (tR, relative peak area %, N/m).
26
Madahar, Kirpal C. "The determination of ethylenethiourea by HPLC." Thesis, Loughborough University, 1986. https://dspace.lboro.ac.uk/2134/32913.
Full textAbstract:
The determination of imidazolidine-2-thione (ETU), at residue levels in crops, in ethylenebisdithiocarbamates (EBDC) and on interaction with microorganisms and soils has been investigated using both a direct HPLC method or after derivatisation with phenacyl halides.
27
Che, Isa Rosmahani. "Analysis of rubber accelerators by HPLC." Thesis, Loughborough University, 2009. https://dspace.lboro.ac.uk/2134/34256.
Full textAbstract:
The analysis of rubber accelerators particularly zinc dithiocarbamates (ZDTCs) was carried out by high performance liquid chromatography (HPLC) to develop an improved analytical method for the determination of rubber accelerators. Further understanding of their chemical and chromatographic behaviour has been established by investigating a few conventional as well as the latest reported methods, which include the pre-column derivatisation of ZDTCs to cobalt (III) complexes, direct determination by the addition of other protective agent and pre-column derivatisation of ZDTCs to copper (III) complexes.
28
Walker, Roderick Bryan. "HPLC analysis and pharmacokinetics of cyclizine." Thesis, Rhodes University, 1995. http://hdl.handle.net/10962/d1003279.
Full textAbstract:
The investigations detailed in this dissertation have been conducted to address the paucity of pharmacokinetic information, in published literature, pertaining to cyclizine. The areas of investigation have included the selective quantitation of both cyclizine and its demethylated metabolite, norcyclizine in serum and urine, assessment of stability of both compounds in stored biological samples, dosage form analysis, dissolution rate testing of tablets, and bioavailability and pharmacokinetics following administration of an intravenous solution, and tablets to humans. High-performance liquid chromatography (HPLC) was used as the main analytical technique throughout these studies. An original HPLC method employing ultraviolet detection with a limit of quantitation of 5μg/ℓ was developed for the determination of cyclizine in serum and both cyclizine and norcyclizine in urine, Solid-phase extraction using extraction columns packed with reversed-phase C18 material, and followed by a simple phase-separation step proved successful for the accurate and precise isolation of the compounds. The validated method was applied to the analysis of serum and urine samples from a pilot study in which a single volunteer was administered 50mg of cyclizine hydrochloride. Several samples collected during the pilot study revealed the presence of both drug and metabolite in concentrations below the limit of detection. In order to improve the selectivity and sensitivity of the analytical method an HPLC method with electrochemical detection operating in the "oxidative-screen" mode was developed. The solid-phase extraction procedure was modified slightly and the method found to be precise, accurate, selective and highly sensitive with a limit of quantitation of Iμg/g/l for both cyclizine and norcyclizine in both serum and urine. This method was applied to the determination of both compounds after intravenous and oral administration of cyclizine to humans. HPLC with electrochemical detection was used for the analysis of samples collected during dissolution studies on the batch of tablets used for pharmacokinetic studies. In addition, this method was used to assess content uniformity of the tablets and of samples from the batch of intravenous ampoules of cyclizine lactate. Dissolution studies showed that all tablets tested passed the compendial specifications for cyclizine. Content uniformity assessment revealed that within-batch uniformity existed for both the tablets and ampoules and, therefore, variations in pharmacokinetic parameters for the drug would more than likely be as a result of inter- and intra-individual variability within the subject population. Pharmacokinetic information for cyclizine was obtained following administration of an intravenous bolus dose of cyclizine lactate as a solution, oral administration of cyclizine hydrochloride as a single dose of 50mg and as fixed multiple doses of 50mg every 8 hours for five days. Further information was acquired following administration of single doses of 100mg and 150mg cyclizine hydrochloride. Data collected from these studies were evaluated using both compartmental and non-compartmental techniques. Cyclizine was rapidly absorbed following oral administration with mean kₐ = 1.54 hr⁻¹ and was found to have an absolute bioavailability (F) of 0.47. The presence of norcyclizine in serum following oral and not intravenous dosing suggests cyclizine is susceptible to "first-pass" metabolism in either the gut wall or the I iver. Mean ClTOT determined following the intravenous dose was 0.865 ℓ/hr/kg. The mean ClTOT of 0.823 ℓ/hr/kg calculated following oral dosing, using a unique value of F for each subject compared favourahly with that obtained following intravenous dosing. Renal clearance of cyclizine is negligihle indicating that non-renal routes of elimination account for the majority of removal of cyclizine form the body. Cyclizine is extensively distributed and the mean Vz following an intravenous dose was 16.70 ℓ/kg. This value is lower than that calculated from all oral studies from which the mean Vz was determined to be 25.74 ℓ/kg. Cyclizine is eliminated slowly with a mean elimination t½ = 20.11 hours. Cyclizine dose not appear to follow dosedependent kinetics and therefore, inability to predict steady state levels are more than likely due to accumulation as a result of frequent dosing rather than saturation of elimination mechanisms. Modelling of intravenous data to one-compartment (lBCM), two-compartment (2BCM) and threecompartment models indicated that the pharmacokinetics of cyclizine can be adequately described by a 3BCM. The drug is rapidly distributed into a "shallow" peripheral compartment (α = 9.44 hr⁻¹ , and k₂₁ = 2.09 hr⁻¹ ), and slowly distributed to the "deep" peripheral compartment (β = 0.451 hr⁻¹ and k₃₁ = 0.120 hr⁻¹ ). Modelling of all oral data indicated that a 2BCM best described the pharmacokinetics of the drug, however, distribution to the peripheral compartment is not as rapid as to the "shallow" peripheral compartment following the intravenous dose. Mean distribution parameters were α = 0.64 hr⁻¹1 and, k₂₁ = 0.39 hr⁻¹. Mean CITOT following intravenous dosing of 0.70 ℓ/hr/kg was similar to the mean CIToT of 0.73 ℓ/hr/kg determined after oral dosing. The mean distribution volume at steady state determined following intravenous dosing (17.78 ℓ/kg) was lower than that obtained from the oral studies (25.52 ℓ/kg). The mean terminal elimination half-lives calculated for cyclizine following fitting of intravenous and oral data was 25.09 hours. In general, mean pharmacokinetic parameters calculated following titting of data to a 2BCM after oral administration correlate closely with those calculated using non-compartmental techniques. However, the pharmacokinetics following intravenous dosing are better described by a 3BCM and a close correlation between parameters estimated using noncompartmental techniques and compartmental techniques is evident when a 3BCM model is used.
29
Mayr, Gerhard [Verfasser]. "Bildung und Kompensation von Temperaturgradienten in der schnellen HPLC unter Verwendung von Micropartikel-gepackten HPLC-Säulen / Gerhard Mayr." Ulm : Universität Ulm. Fakultät für Naturwissenschaften, 1999. http://d-nb.info/1015899285/34.
Full text
30
McCulloch, Melissa. "Development of Quantitative Bioanalytical Methods for the Measurement of Pharmaceutical Compounds via HPLC-UV and HPLC-MS/MS." Cleveland State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=csu1255046678.
Full text
31
Berg, Gustaf, and Magnus Brattlöf. "Distributed Checkpointing with Docker Containers in High Performance Computing." Thesis, Högskolan Väst, Avdelningen för data-, elektro- och lantmäteriteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-11645.
Full textAbstract:
Container-virtualisering har blivit mer och mer använt efter att uppdateringar till cgroups och namespace-funktionerna släpptes i Linuxkärnan. Samtidigt så lider industrins högpresterande beräkningskluster av dyra licenskostnader som skulle kunna hanteras av virtualisering. I den här uppsatsen utformades experiment för att ta reda på om Dockers funktion checkpoint, som fortfarande är under utveckling, skulle kunna utnyttjas i industrins beräkningskluster. Genom att demonstrera detta koncept och dess möjligheter att pausa distribuerade containrar, som kör parallella processer inuti, användes den välkända NAS Parallel Benchmarken (NPB) fördelad över två test-maskiner. Sedan så pausades containrar i olika ordningar och Docker lyckas återuppta benchmarken utan problem både lokalt och distribuerat. Om man försiktigt överväger ordningen som man skriver ner containers till disk (checkpoint) så går det utan problem att återuppta benchmarken lokalt på samma maskin. Slutligen så visar vi även att distribuerade containrar kan återupptas på en annan maskin än där den startade med hög framgång. Dockers prestanda, möjligheter och flexibilitet lämpar sig i framtidens industriella högpresterande kluster där man mycket väl kan köra sina applikationer i containrar istället för att köra dom på det traditionella sättet, direkt på hårdvaran. Genom användning av Docker-containers kan man hantera problemet med dyra licenskostnader och prioriteringar.<br>Lightweight container virtualization has gained widespread adoption in recent years after updates to namespace and cgroups features in the Linux kernel. At the same time the Industrial High Performance community suffers from expensive licensing costs that could be managed with virtualization. To demonstrate that Docker could be used for suspending distributed containers with parallel processes, experiments were designed to find out if the experimental checkpoint feature is ready for this community. We run the well-known NAS Parallel Benchmark (NPB) inside containers spread over two systems under test to prove this concept. Then, pausing containers and unpausing them in different sequence orders we were able resume the benchmark. After that, we further demonstrate that if you carefully consider the order in which you Checkpoint/Restore containers, then the checkpoint feature is also able to resume the benchmark successfully. Finally, the concept of restoring distributed containers, running the benchmark, on a different system from where it started was proven to be working with a high success rate. Our tests demonstrate the performance, possibilities and flexibilities of Dockers future in the industrial HPC community. This might very well tip the community over to running their simulations and virtual engineering-applications inside containers instead of running them on native hardware.
32
Capra, Antoine. "Virtualisation en contexte HPC." Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0436/document.
Full textAbstract:
Afin de répondre aux besoins croissants de la simulation numérique et de rester à la pointe de la technologie, les supercalculateurs doivent d’être constamment améliorés. Ces améliorations peuvent être d’ordre matériel ou logiciel. Cela force les applications à s’adapter à un nouvel environnement de programmation au fil de son développement. Il devient alors nécessaire de se poser la question de la pérennité des applications et de leur portabilité d’une machine à une autre. L’utilisation de machines virtuelles peut être une première réponse à ce besoin de pérennisation en stabilisant les environnements de programmation. Grâce à la virtualisation, une application peut être développée au sein d’un environnement figé, sans être directement impactée par l’environnement présent sur une machine physique. Pour autant, l’abstraction supplémentaire induite par les machines virtuelles entraine en pratique une perte de performance. Nous proposons dans cette thèse un ensemble d’outils et de techniques afin de permettre l’utilisation de machines virtuelles en contexte HPC. Tout d’abord nous montrons qu’il est possible d’optimiser le fonctionnement d’un hyperviseur afin de répondre le plus fidèlement aux contraintes du HPC que sont : le placement des fils d’exécution et la localité mémoire des données. Puis en s’appuyant sur ce résultat, nous avons proposé un service de partitionnement des ressources d’un noeud de calcul par le biais des machines virtuelles. Enfin, pour étendre nos travaux à une utilisation pour des applications MPI, nous avons étudié les solutions et performances réseau d’une machine virtuelle<br>To meet the growing needs of the digital simulation and remain at the forefront of technology, supercomputers must be constantly improved. These improvements can be hardware or software order. This forces the application to adapt to a new programming environment throughout its development. It then becomes necessary to raise the question of the sustainability of applications and portability from one machine to another. The use of virtual machines may be a first response to this need for sustaining stabilizing programming environments. With virtualization, applications can be developed in a fixed environment, without being directly impacted by the current environment on a physical machine. However, the additional abstraction induced by virtual machines in practice leads to a loss of performance. We propose in this thesis a set of tools and techniques to enable the use of virtual machines in HPC context. First we show that it is possible to optimize the operation of a hypervisor to respond accurately to the constraints of HPC that are : the placement of implementing son and memory data locality. Then, based on this, we have proposed a resource partitioning service from a compute node through virtual machines. Finally, to expand our work to use for MPI applications, we studied the network solutions and performance of a virtual machine
33
Curle, Ulyate Andries. "Properties of R-HPDC AI-Zn-Mg-Cu aluminium alloys." Thesis, 2015. http://hdl.handle.net/10539/18507.
Full textAbstract:
Five different Al-Zn-Mg-Cu alloys were produced by rheo-high pressure die
casting (R-HPDC) of which the as-cast microstructures were characterised with
scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy
(EDX). The primary aluminium grains and eutectic phases were observed with SEM
backscattered electrons (BSE). The overall compositions of the eutectics were
measured with EDX and were found to be relatively similar, regardless of the alloy
composition. Two further Al-Zn-Mg-Cu alloys were produced with the same
compositions as the eutectics in the R-HPDC alloys. These eutectic alloys were also
characterised with SEM and EDX. One of the R-HPDC alloys was also cooled in
vacuum and characterised with SEM and EDX.
The as-cast alloys were characterised with differential scanning calorimetry (DSC)
and X-ray diffraction (XRD). DSC results showed that all the as-cast alloys had
different melting points depending on the phases present in the solidified alloy. XRD
showed that the as-cast alloy eutectics had one of two crystal structures for the
second component besides the (Al) phase, which were hexagonal or cubic, or a combination of both depending on the overall composition and cooling rate.
Modelling of non-equilibrium alloy solidification was also done using Thermo-Calc
with the most recent aluminium database. It was found that the calculated and
measured results compared favourably.
The remaining phases in all the alloys, after homogenisation and artificial ageing,
were characterised with SEM and EDX to assess the influence of impurity elements.
It was found that Fe and Mn react with Cu, and Si with Mg.
Experiments were also conducted to assess the effect of composition on the
hardness and yield strength of all the alloys after homogenisation and artificial
ageing. A precipitate composition for the T6 condition, from literature, was used for
the calculations. It was found that there were reasonable straight line relationships if
the impurity elements were neglected. On the other hand, there were near perfect
linear fits when the influence of impurity elements was taken into account.
The optimum Al-Zn-Mg-Cu alloying ratio for a dilute aluminium alloy is the
composition of the precipitate modelled. The ratios were Al7.4Zn45.4Mg38.6Cu8.6 for the
T6 condition and Al15Zn39Mg33Cu13 for the T73 condition.
34
Brites, Catarina Filipa Vieira. "Integridade Estrutural de peças de alumínio obtidas por HPDC e Rheocasting." Master's thesis, 2018. http://hdl.handle.net/10362/63035.
Full textAbstract:
O desígnio desta dissertação assenta numa análise comparativa entre peças produzidas por duas ligas distintas de alumínio, EN AB-42000 e EN AC-46000, manufaturadas por dois processos de fundição em molde permanente, Rheocasting e High Pressure Die Casting (HPDC), respetivamente. A motivação e interesse deste estudo reside sobretudo na similaridade de ambos os processos e o seu interesse para várias e diversas indústrias, sendo este estudo proposto pela Hanon Systems, Portugal.
No âmbito desta investigação, foram estudados os fundamentos teóricos de ambos os processos e levados a cabo estudos experimentais, tais como ensaios de dureza e análises a microscópio de defeitos. Estes estudos permitiram recolher dados, que depois de tratados, levaram à caracterização da microestrutura, da dureza e dos tipos de defeitos intrínsecos aos dois processos de fabrico. Foi investigada a integridade estrutural de ambas as peças, nomeadamente, efetuou-se o cálculo da tensão limite de fadiga, 𝜎𝑤, que se encontra diretamente relacionada com a área de porosidades e durezas, fornecendo, assim, uma previsão de durabilidade.
Emboras os processos Rheocasting e HPDC sejam idênticos o custo de produção e a distribuição de defeitos intrínsecos a cada um dos processos, é diferente. Torna-se, por isso, crucial o seu conhecimento. O software de simulação, QuikCAST, foi usado de modo a averiguar, com a alteração de parâmetros de fabrico, a presença de hotspots, com intuito de minimizar a distribuição de defeitos obtendo informações e considerações a ter em conta na fase conceptual e de produção.
Concluiu-se que embora a peça produzida por HPDC apresente maior distribuição e quantidade de defeitos, a peça produzida por Rheocasting incorpora mais defeitos intrínsecos ao processo. No entanto, no estudo de previsão de vida à fadiga, concluiu-se que ambas as peças de ligas diferentes, e processos diferentes apresentam durabilidade inferior a 10000 ciclos e tensão limite de fadiga de inferiores a 250 MPa.
35
Tuan, Do Anh, and 杜英俊. "Study on design optimization for gating system and casting process in HPDC." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/84363358345102457489.
Full textAbstract:
博士<br>國立高雄應用科技大學<br>機械與精密工程研究所<br>103<br>High-pressure die casting (HPDC) process for non-ferrous casting applications is significantly used in the industry for its high productivity and less post-machining requirement. Due to light weight and good forming-ability, aluminum die casting plays an important role in the production of transportation and vehicle components. It has a much faster production rate in comparison to other methods and it is an economical and efficient method for producing components with low surface roughness and high dimensional accuracy. The development of industrial die-casting and requirements for higher quality product, shorter development times and more complex geometry, the use of computer aided simulation has become essential to stay competitive.
The HPDC castings production process has many defects, such as: shrinkage porosity, misrun, cold-shut, blister, scab, crack… Several previous studies of defects in the aluminum alloy of HPDC method have given many causes and solutions reduce defects. Techniques such as cause-effect diagrams, design of experiments (DOE), casting simulation, if-then rules (Fuzzy Logic Controller), genetic algorithms (GA) and artificial neural networks (ANN) are used by various researchers for analysis of casting defects.
Die design is a very difficult work and the companies not publish because of economic competition. In order to good die design it requires extensive knowledge in mechanical engineering and experience in die-castings foundry factory. In the die design of die casting, the object is to produce profitable at the same time ensure that the castings satisfy the high quality standards. For die design of HPDC, it needs well-design of gating system and die cavity.
Shrinkage porosity is one of the most common defects leading to rejection of aluminum die-casting, but only showing up after other operations such as machining or polishing. The higher rejection ratio of the casting the higher production cost. If you find out the causes and how to reduce the defects of castings will be of great significance in reducing the production cost of die-casting. It is suggested to reduce casting defects, reduce time and money, with better casting product quality and die design die-casting efficiency. Taguchi method is one of the solutions and tools to improve the performance of products and processes with significant reduction in cost and time involved. Taguchi’s parameter design offers a systematic approach for optimization of various parameters with regard to performance, quality and cost.
Today, two fundamental problems set out are to ensure quality of die design and optimization of parameters operating in foundry casting condition. The aim of calculation and die design to minimize the defects can occur in the casting process. Each of these issues, design or production is related to die casting machine, die, casting product for desired, the actual machine operation. Therefore, the solution to optimize the design parameters and real production of HPDC process becomes a very important issue.
36
Hossain, Md Nur. "INFLUENCE OF TEMPERATURE AND STRESS RATIO ON FATIGUE AND FRACTURE RESPONSE OF HPDC AM60B MAGNESIUM ALLOY." Thesis, 2010. http://hdl.handle.net/10222/13080.
Full textAbstract:
The mechanical behavior of a high pressure die cast AM60B Mg alloy is studied. Constant load amplitude fatigue tests were conducted at room, elevated and cold temperatures, with a stress ratio of R=0.1, and frequency of 30 Hz. The objective was to identify the possible effects of temperature on fatigue life cycle. In addition, fatigue crack propagation tests were conducted to ascertain the fatigue response of the alloy and determine its fatigue crack growth rate as a function of the applied stress ratio, experimentally, analytically and computationally, using Walker’s model. The results demonstrated that temperature had a significant influence on the fatigue life, and that the life increased at cold temperature but decreased at elevated temperature as compared to that evaluated at room temperature. In this study, the limit for applicability of LEFM was established for AM60B magnesium alloy. In addition, fatigue crack propagation test results were used to evaluate the coefficients of the Paris model.
37
(9721637), Carl Kuang Yu Shi. "Electric Infrared Die heating for Aluminum High Pressure Die Casting." Thesis, 2020.
Find full textAbstract:
Casting is a substantial part of modern manufacturing and production, typically used in
the production of aluminum alloys. The high pressure die casting process is extremely
suitable for mass production. Due to the high volume, wasted time and resources during
the production cycle become more significant. Aluminum die castings require the die to
be at elevated temperatures to produce acceptable castings. When the inner surfaces of a
die are cold, the outer shell of the casting will cool too rapidly, and solidification of the
outer shell occurs before the aluminum has time to uniformly fill the cavities. Therefore,
without the die being within the proper temperature range, the castings produced will have
significant issues in porosity and casting incompleteness. Furthermore, stresses are
introduced to the casting surfaces when warm-up shots are used to raise the temperature
prior to production. In the present work, research is conducted on designing a heating
method for a casting die used in the manufacturing of an automotive transmission
intermediate plate. An electric, short wave infrared heating system is simple and effective
for the purpose. By utilizing an electric infrared heater in combination with a flat mirror
reflector, the aluminum high pressure die casting die was heated to 300 ◦C surface
temperature within 30 minutes. Further research can be done to optimize heat flux
distribution and minimize energy consumption.
38
Dohnalová, Monika. "HPLC analýza léčiv." Master's thesis, 2019. http://www.nusl.cz/ntk/nusl-397354.
Full textAbstract:
Charles University Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Candidate: Monika Dohnalová Supervisor: Ing. Vladimír Kubíček, CSc. Title of Diploma Thesis: HPLC analysis of drugs The diploma thesis deals with the development and optimization of HPLC method for simultaneous determination of selected polyphenolic compounds: apigenin, acteoside and luteolin. During the experiments, the most suitable conditions for separation were sought, various mobile phases and various types of gradient elution were tested. The Zorbax Eclipse XBD C18 column 250 x 4.6 mm; 5 µm was used for analysis. The detection was performed with diode array detector at wavelengths 249 nm and 350 nm,the column was thermostated at 30 řC. The injected volume was 10 µl. The best results were achieved using mobile phase consisting of acetonitrile and aqueous solution of formic acid (0.03 mol/l) at a flow rate 1ml/min.
39
Kouřil, Tomáš. "HPLC analýza léčiv." Master's thesis, 2018. http://www.nusl.cz/ntk/nusl-388725.
Full textAbstract:
Charles University Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Candidate: Tomas Kouril Consultant: Ing. Vladimir Kubicek, CSc. Title of Thesis: HPLC analysis of Drugs The diploma thesis describes selection of the most suitable conditions for determination of a two enantiomers of drugs betaxolol and bisoprolol with a method HPLC. The aim of the thesis was to find a suitable isocratic method for the substances for extraction from plasma. The chromatographic column Daicel Chiralcel ® OD-R 4,6 mm x 250 m was utilized. The best results were achieved with mobile phase consisting of acetonitrile and aqueous solution of sodium perchlorate (1 molar) in volume ratio 50:50 for betaxolol and 35:65 for bisoprolol. The column was thermostated at 25 řC. UV detection (λ = 190 nm) was applied to get a sufficient sensitivity. Tramadol and O-desmethyltramadol was tested as an internal standard. Biological samples were tested by LLE before the HPLC analyses. Furthermore, the LLE method for biological samples was tested before performing HPLC.
40
Nováková, Markéta. "HPLC analýza podofylotoxinu." Master's thesis, 2021. http://www.nusl.cz/ntk/nusl-446527.
Full textAbstract:
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Candidate: Markéta Nováková Tutor: PharmDr. Pavla Pilařová, Ph.D. Title of Thesis: HPLC Analysis of Podophyllotoxin The diploma thesis is focused on optimalization of HPLC method for the analysis of podophyllotoxin. The method was developed for the analysis of Juniperus virginiana leaves extract. Various stationary phases, mobile phases, temperatures, ultrasonic extraction times were tested. Following conditions were chosen as optimal: 30 minutes ultrasonic extraction time, LiChrospher 100 RP-18 250-4 column, 0,1% CH3COOH:ACN 45:55 mobile phase, temperature 40 řC, flow rate 0,8 ml/min, sample volume 3 μl, fluorescence detection λex 240 nm, λem 320 nm, time of analysis 9 minutes. The method was also developed for the analysis of plant tissue cultures of Juniperus virginiana, for which gradient elution was chosen. This method had following conditions: LiChrospher 100 RP-18 250-4 column, mobile phase 0,1% CH3COOH:ACN, change of acetic acid ratio: 0-8 min 70-10 %, 8-9 min 10 %, 9-10 min 10- 70 %, 10-12 min 70 %, temperature 40 řC, flow rate 0,8 ml/min, sample volume 3 μl, fluorescence detection λex 240 nm, λem 320 nm, time of analysis 12 minutes. Subsequently, both methods were...
41
Lukšíková, Lada. "HPLC analýza léčiv." Master's thesis, 2009. http://www.nusl.cz/ntk/nusl-282942.
Full text
42
Slezáková, Šárka. "HPLC stanovení benzimidazolů." Master's thesis, 2015. http://www.nusl.cz/ntk/nusl-337823.
Full textAbstract:
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of biophysics and physical chemistry Candidate: Šárka Slezáková Supervisor: Ing. Vladimír Kubíček, CSc. Title of diploma thesis: HPLC Determination of Benzimidazoles In this thesis we have investigated the possibility of establishing benzimidazole with HILIC chromatography using a chromatographic column Ascentis Express HILIC 10.0 cm x 3.0 mm; 2.7 microns. Two groups of benzimidazoles were tested. The first one was focused on albendazole and its metabolites. Experiments with these substances did not produce satisfactory results, because the mobile phase composition which enables separation of the studied analytes was not found. The second group was formed by flubendazole and its reduced and hydrolyzed form. In this case, several mobile phase compositions were tested. Finally, distribution of individual analytes in a mixture, using a mobile phase ACN:HCOOH 0.03 mol/l (90:10), was successfully achieved. Ricobendazol was chosen as an internal standard. When separation conditions were found, calibration curve for the determination of reduced flubendazole in biological samples was subsequently constructed using ricobendazol as the internal standard with the use of fluorescence detection. Keywords: HILIC, HPLC, albendazole,...
43
Nováková, Lidmila. "HPLC analýza vybraných isoflavonů." Master's thesis, 2020. http://www.nusl.cz/ntk/nusl-435323.
Full textAbstract:
Charles University Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Author: Lidmila Nováková Supervisor: Ing. Vladimír Kubíček, CSc. Title of thesis: HPLC analysis of selected isoflavones The diploma thesis deals with the development of a method for determination of the concentration of selected isoflavones in samples of biological material by using HPLC. The method is applicable to both glycosylated (daidzeine, genistine and glycitine) and free forms of isoflavones (daidzeine, genisteine). The Ascentis® Express RP column 2,7 µm, 10 cm x 3 mm was used for analysis. The mobile phase was composed of a solution of formic acid and acetonitrile and the measurement was performed in a gradient elution mode. The constant flow rate of the mobile phase was set at 0.5 ml / min. The column was thermostated at 30 ř C. The sample injection volume was 10 µl. UV detection was performed at 249 nm and 260 nm. Six samples of biological material containing isoflavones were analyzed consequently. Based on the calibration previously carried out, concentrations of the isoflavones were determined in the biological samples. Key words: HPLC, daidzine, genistine, glycitine, analysis
44
Koldová, Vendula. "Hodnocení Quetiapinu pomocí HPLC." Master's thesis, 2015. http://www.nusl.cz/ntk/nusl-334696.
Full textAbstract:
Charles University in Praque, Faculty of Pharmacy in Hradci Králové Department: Pharmaceutical Chemistry and Drug Control Candidate: Vendula Koldová Tutor: PharmDr. Pavla Pilařová, Ph.D. Name of Degree Paper: Evaluation of Quetiapine using HPLC In this study was developed a method for separation of quetiapine and its two biologically active metabolites 7-hydroxyquetiapine and norquetiapine. Separation was performed on zirconia reversed-phase column ZirChrom® -PBD (150 x 4.6 mm i.d., 5 µm). The retention behaviour of those three analytes was examined at changing strenght and pH of acetate buffer and changing levels of organic compound (ACN) in eluent. The separation of the mixture of quetiapine and its two metabolites was performed by gradient elution. Mobile phase was composed of acetate buffer (CH3COONH4 6mM , pH 6.0) and acetonitrile. The flow rate of the mobile phase was 1.0 ml/min and temperature in the column was set at 30 řC. Detection was carried out at a wavelength of 254 nm. The method is supposed to be used for determination of quetiapine, 7-hydroxyquetiapine and norquetiapine in plasma.
45
Chang, Chih-Chao, and 張智超. "HPLC quantitative analysis of." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/742tcg.
Full text
46
Juříčková, Markéta. "HPLC analýza léčiv II." Master's thesis, 2010. http://www.nusl.cz/ntk/nusl-282921.
Full textAbstract:
HPLC ANALYSIS OF DRUGS II. Diploma thesis Markéta Juříčková Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Department of Pharmaceutical Chemistry and Drug Control, Heyrovského 1203, Hradec Králové In diploma thesis the optimal condition for analytical determination of tiaprofenic acid in plasma using solid-phase microextraction (SPME) and high performance liquid chromatography (HPLC) was developed. The final analysis was performed on RP18 analytical column. The mobile phase was composed of a mixture of methanol and phosphate buffer. The flow rate of 0.7 ml/min was used. 20 µl of sample was injected on the column. Detection was performed in UV range at 306 nm. PDMS/DVB microextraction fiber was used for the isolation of tiaprofenic acid from the sample. At first tiaprofenic acid was isolated from the water solution. Recovery of the microextraction was 19.46 %. Thereafter, tiaprofenic acid was extracted from model plasma sample. Prior extraction, pH of plasma was adjusted on 2.8. Methanol was used for analyte desorption. Optimal time of sorption and desorption was also determined. Efficiency of the developed extraction was 9.74 %. Quantitative determination of tiaprofenic acid from the plasma sample was performed by calibration curve and using external standard. Key words: HPLC,...
47
Blažková, Petra. "HPLC analýza léčiv III." Master's thesis, 2010. http://www.nusl.cz/ntk/nusl-282925.
Full textAbstract:
ANALYTICAL EVALUATION OF ACTIVE SUBSTANCE BY LIQUID CHROMATOGRAPHY II. Diploma thesis Petra Blažková Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Department of Pharmaceutical Chemistry and Drug Control, Heyrovského 1203, Hradec Králové The subject of this diploma thesis is a determination of active substances by liquid chromatography. In particular it deals with an evaluation of phenobarbital in biological matrix. Solid phase microextraction (SPME) and high performance liquid chromatography (HPLC) with UV detector (218 nm) and reversed phase C18 comlumn were used. The mobile phase consisted of methanol and phosphate buffer in a ratio of 50:50. The flow rate was set to 0,4 ml/min. 20 µl of sample solution was injected on the chromatographic column. Phenobarbital was dissolved in a mixture of methanol and buffer in a ratio of 80:20. For the SPME extraction from water solution was used carbowax/TPR fibre. The analyte was desorbed into methanol. The extraction time was 20 minutes. Phenobarbital extraction from rabbit plasma was performed in the same way, but PDMS/DVB fibre instead of carbowax/TPR fibre was used. Phenobarbital in rabbit plasma was quantified by means of calibration curve.
48
Štichová, Lucia. "HPLC analýza léčiv IV." Master's thesis, 2012. http://www.nusl.cz/ntk/nusl-307831.
Full textAbstract:
HPLC analysis of drugs IV. Diploma Thesis Lucia Štichová Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Department of Pharmaceutical Chemistry and Drug Control, Heyrovského 1203, Hradec Králové In this thesis, conditions were optimized for high-performance liquid chromatography for quantitative evaluation of ibuprofen. It was established solid phase microextraction conditions for which ibuprofen was extracted from whole blood. The fiber was coated with polydimethylsiloxane - divinylbenzene with a thickness of 60 µm. The fiber was immersed in the sample. The blood sample was adjusted to pH 2.6. Sorption time was set at 30 minutes and the methanol desorption time was 15 minutes. The mobile phase consisted of methanol with water in the ratio 8:2 and pH was adjusted to a value of 3. The flow rate was 1 ml / min and detection was carried out at a wavelength of 222 nm. For quantitative evaluation the external standard was used. The detection limit was 0.005 µg / ml and the quantification limit was 0.017 µg / ml.
49
Sochová, Veronika. "HPLC analýza léčiv V." Master's thesis, 2013. http://www.nusl.cz/ntk/nusl-322175.
Full textAbstract:
HPLC analysis of drugs V Diploma thesis Veronika Sochová Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Department of Pharmaceutical Chemistry and Drug Control In this diploma thesis was established the methodology for the evaluation of dexamethasone in biological material using solid phase microextraction and HPLC. For the measurements was used extraction fibre polydimethylsiloxane in combination with divinylbenzene. The fiber was used for microextraction of dexamethasone from water samples and plasma samples. Conditions were optimized for SPME evaluation of dexamethasone and diazepam (internal standard) in plasma sample. Sorption time was 10 minutes, desorption time was 20 minutes to 0,2 ml methanol. Chromatographic conditions - column C18, eluent acetonitrile - water, 55:45 (v/v) and detection at a wavelength of 240 nm.
50
Krouská, Hana. "HPLC studie chemických reakcí." Master's thesis, 2015. http://www.nusl.cz/ntk/nusl-342935.
Full textAbstract:
In this work hydrolysis of phenylisothiocyanate and subsequent decomposition of diphenylthiourea were studied. RP-HPLC with UV detection was selected for monitoring of these reactions. The new method of isocratic elution was developed and mobile phase composition and flow rate were optimized. Hydrolysis of isothiocyanate was studied as a function of pH and reaction temperature. The subsequent decomposition of diphenylthiourea was carried out at 80 řC depending on the pH.