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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Choosing Color Palettes for Statistical Graphics

Zeileis, Achim, Hornik, Kurt January 2006 (has links) (PDF)
Statistical graphics are often augmented by the use of color coding information contained in some variable. When this involves the shading of areas (and not only points or lines) - e.g., as in bar plots, pie charts, mosaic displays or heatmaps - it is important that the colors are perceptually based and do not introduce optical illusions or systematic bias. Here, we discuss how the perceptually-based Hue-Chroma-Luminance (HCL) color space can be used for deriving suitable color palettes for coding categorical data (qualitative palettes) and numerical variables (sequential and diverging palettes). / Series: Research Report Series / Department of Statistics and Mathematics
22

Effects of Ractopamine HCL, L-Carnitine and dried distillers grains with solubles on growth, carcass traits, loin and jowl fat quality of finishing pigs, and energy and protein sources in nursery diets

Ying, Wei January 1900 (has links)
Master of Science / Department of Animal Sciences and Industry / Joel DeRouchey / Mike Tokach / Six experiments using 3,862 pigs were conducted to evaluate effects of ractopamine HCl (RAC) feeding programs, dietary L-Carnitine and dried distillers grains with solubles (DDGS) on growth, carcass traits, loin and jowl fat quality of pigs, and energy and protein sources in nursery diets. In Exp. 1 and 2, RAC-fed pigs had greater (P<0.05) ADG, G:F and HCW compared with the control. Within RAC treatments, there were no differences in growth. Pigs fed step-up RAC had increased (P<0.01) percentage lean, fat-free lean index and loin depth but decreased (P<0.01) backfat than the control or constant treatment. In Exp. 2, pigs fed step-up RAC program had greater (P<0.05) ADG and G:F than the constant treatment. Pigs fed constant RAC had greater (P=0.002) carcass yield than controls. There were no overall differences in other carcass traits among treatments. In Exp. 3, dietary L-Carnitine improved (P<0.02) ADG and final BW. A DDGS × L-Carnitine interaction (quadratic, P<0.01) was observed for G:F. Pigs not fed DDGS had similar G:F, but in DDGS diets pigs fed 50 ppm L-Carnitine had worse G:F than those fed 100 ppm. Pigs fed L-Carnitine had greater (P<0.02) HCW compared with those not fed L-Carnitine. Increasing L-Carnitine up to 100 ppm increased HCW (quadratic, P<0.03) and backfat (quadratic, P<0.04), with the maximum response at 50 ppm dietary L-Carnitine. Increasing L-Carnitine increased (linear, P<0.04) purge loss of loin. Feeding DDGS increased (P<0.001) linoleic acid and iodine value of jowl fat compared with feeding no DDGS. However, feeding L-Carnitine did not change jowl fatty acid composition. In Exp. 4, 5 and 6, nursery pigs fed choice white grease (CWG) had improved (P<0.02) G:F than pigs fed a control diet or an alcohol based energy source. Also, pigs fed CWG had greater (P<0.04) ADG in Exp. 4 and 6 and had reduced (P<0.01) ADFI in Exp. 5. The alcohol based energy source improved (P<0.04) ADG and ADFI with no change in G:F in Exp. 4; but did not affect growth in Exp. 5 and 6. In Exp. 6, pigs fed AV-E Digest had equal performance as nursery pigs fed other specialty proteins.
23

Photoelectron Spectroscopy on HCl and DCl : Synchrotron Radiation Based Studies of Dissociation Dynamics

Burmeister, Florian January 2003 (has links)
<p>Dissociation dynamics of the ionized molecules HCl and the deuterated system DCl has been studied in gas-phase using synchrotron based photoelectron spectroscopy (PES).</p><p>The inner-valence "(4σ)<sup>-1</sup>" photoionization band for DCl and HCl was recorded using maximum resolution in order to probe an interference pattern between a dissociative and a bound electronic state. For HCl<sup>+</sup>, we clearly observed distorted Fano-type peaks even for modest resolution, whereas for DCl<sup>+</sup>, the pattern was hardly discernible. The observation in HCl<sup>+</sup> has been explained by a coupling between two adiabatic electronic states, where the bound state was populated through non-adiabatic curve-crossing. The nuclear motion of HCl<sup>+</sup> is too fast for the Born-Oppenheimer approximation to be fully valid in this case. Whereas for DCl<sup>+</sup>, with larger reduced mass and therefore slower nuclear motion, the non-adiabatic coupling is less pronounced, and the vibrational progression vanishes.</p><p>A comparative study between PES and threshold photoelectron spectra (TPES) of the inner-valence bands of HCl and DCl has been performed, showing differences in intensities and shapes of the vibrational bands. These differences were attributed to the fact that the sudden approximation, which can be assumed to be valid for PES, is violated in the case of TPES.</p><p>A resonant Auger electron spectroscopy study of HCl and DCl has been performed, which shows an interference pattern between atomic and molecular Auger- and photoelectron channels. The atomic features are associated with ultra-fast dissociation of the molecules, on the same time scale as the Auger decay. The observation shows that the excited molecular system has to be regarded as a superposition of fragmented and molecular states.</p><p>A study of the <i>X</i>-state of HCl<sup>+</sup>, populated via a core-excited state, shows a selective population of the final state. The explanation was shown to be that the magnetic orientation of the core-hole is transferred to the final state of the molecule.</p><p>A setup for data acquisition of Photo-Electron Photo-Ion Photo-Ion COincidence (PEPIPICO) measurements using a Time-Of-Flight (TOF) spectrometer has been developed. A Time-to-Digital Converter (TDC) card has been linked together with the data treatment program Igor as a user interface. Furthermore, the PEPIPICO spectrometer has been characterized to provide a solid basis for the analysis of experimental data.</p>
24

Photoelectron Spectroscopy on HCl and DCl : Synchrotron Radiation Based Studies of Dissociation Dynamics

Burmeister, Florian January 2003 (has links)
Dissociation dynamics of the ionized molecules HCl and the deuterated system DCl has been studied in gas-phase using synchrotron based photoelectron spectroscopy (PES). The inner-valence "(4σ)-1" photoionization band for DCl and HCl was recorded using maximum resolution in order to probe an interference pattern between a dissociative and a bound electronic state. For HCl+, we clearly observed distorted Fano-type peaks even for modest resolution, whereas for DCl+, the pattern was hardly discernible. The observation in HCl+ has been explained by a coupling between two adiabatic electronic states, where the bound state was populated through non-adiabatic curve-crossing. The nuclear motion of HCl+ is too fast for the Born-Oppenheimer approximation to be fully valid in this case. Whereas for DCl+, with larger reduced mass and therefore slower nuclear motion, the non-adiabatic coupling is less pronounced, and the vibrational progression vanishes. A comparative study between PES and threshold photoelectron spectra (TPES) of the inner-valence bands of HCl and DCl has been performed, showing differences in intensities and shapes of the vibrational bands. These differences were attributed to the fact that the sudden approximation, which can be assumed to be valid for PES, is violated in the case of TPES. A resonant Auger electron spectroscopy study of HCl and DCl has been performed, which shows an interference pattern between atomic and molecular Auger- and photoelectron channels. The atomic features are associated with ultra-fast dissociation of the molecules, on the same time scale as the Auger decay. The observation shows that the excited molecular system has to be regarded as a superposition of fragmented and molecular states. A study of the X-state of HCl+, populated via a core-excited state, shows a selective population of the final state. The explanation was shown to be that the magnetic orientation of the core-hole is transferred to the final state of the molecule. A setup for data acquisition of Photo-Electron Photo-Ion Photo-Ion COincidence (PEPIPICO) measurements using a Time-Of-Flight (TOF) spectrometer has been developed. A Time-to-Digital Converter (TDC) card has been linked together with the data treatment program Igor as a user interface. Furthermore, the PEPIPICO spectrometer has been characterized to provide a solid basis for the analysis of experimental data.
25

Hydrophilic Polymers of Poly (2-Hydroxy Ethyl Methacrylate) with Tunable Properties for Drug Release, Sequestration of Blistering Agent, Preparation of Ultra-Strong Hydrogels & Thermal Stability of Various Organic Azides

Ananthoji, Ramakanth 01 January 2012 (has links)
The design and synthesis of new finely tunable porous materials has spurred interest in developing novel uses in a variety of systems. Zeolites, inorganic materials with high thermal and mechanical stability, in particular, have been widely examined for use in applications such as catalysis, ion exchange and separation. A relatively new class of inorganic-organic hybrid materials known as metal-organic frameworks (MOFs) has recently surfaced, and many have exhibited their efficiency in potential applications such as ion exchange and drug delivery. A more recent development is the design and synthesis of a subclass of MOFs based on zeolite topologies (i.e. ZMOFs), which often exhibit traits of both zeolites and MOFs. Bio-compatible hydrogels already play an important role in drug delivery systems, but are often limited by stability issues. Thus, the addition of ZMOFs to hydrogel formulations is expected to enhance the hydrogel mechanical properties, and the ZMOF-hydrogel composites should present improved, symbiotic drug storage and release for delivery applications. Herein we present the novel composites of a hydrogel with a zeolite-like metal-organic framework, rho-ZMOF, using 2-hydroxyethyl methacrylate (HEMA), 2,3-dihydroxypropyl methacrylate (DHPMA), N-vinyl-2-pyrolidinone (VP) and ethylene glycol dimethacrylate (EGDMA), and the corresponding drug release. An ultraviolet (UV) polymerization method is employed to synthesize the hydrogels, VP 0, VP 15, VP 30, VP 45 and the ZMOF-VP 30 composite, by varying the VP content (mol%). The rho-ZMOF, VP 30, and ZMOF-VP 30 composite are all tested for the controlled release of procainamide (protonated, PH), an anti-arrhythmic drug, in phosphate buffer solution (PBS) using UV spectroscopy. Blister agents are chemical compounds that induce severe skin, eye, mucosal pain and irritation. The research focuses on sequestering a blister agent analog, thioanisole in hydrogels. HEMA polymers and copolymers of HEMA with 2,3-dihydroxyproyl methacrylate (DHPMA) and vinyl pyrrolidone (VP) were synthesized with crosslinkers of various dimensions. These were: ethylene glycol dimethacrylate (EGDMA), diethylene glycol dimethacrylate (DiEGDMA), triethylene glycol dimethacrylate (TriEGDMA), tetraethylene glycol dimethacrylate (TetEGDMA) and neopentyl glycol dimethacrylate (NPEGDMA). Equilibrium swelling was characterized gravimetrically and pore size was estimated via scanning electron microscopy (SEM). Glass transition temperatures were measured by differential scanning calorimetry (DSC). The absorption of thioanisole in methanol was characterized with via ultra-violet (UV) spectroscopy. Poly(2-hydroxyethyl methacrylate) (PHEMA) composites constructed from a paddle-wheel, a secondary building unit (SBU) for metal organic frameworks, Cu2(p-OH benzoate)4(DMSO)2*2DMSO (CPW) were also investigated for a broad analysis of dielectric spectra. The dielectric spectrum of poly(2-hydroxyethyl methacrylate) and its copolymer with Poly(2,3-dihydroxy propyl methacrylate) (PDHPMA) are already reported in the literature. This study delineates the effects on the dielectric behavior as a result of CPW addition. The dielectric permittivity and the loss factor were measured using a dielectric analyzer in the frequency range of 1 Hz to 100 k Hz and between the temperature range of -140 and 250°C. The electric modulus formalism was used to reveal the viscoelastic and conductivity relaxations present in the polymers. Significant changes were observed as CPW concentration increased from 0.1 to 0.5 wt%. It was determined through DSC that the glass transition temperature increased with the filler concentration. The secondary dielectric relaxations were also affected as it was recorded that the activation energy for the γ, Β, and conductivity relaxation increased with CPW content. AC and DC conductivity are also evaluated. The ionic conductivity data revealed that the CPW impedes the ion mobility when compared to the neat PHEMA. Organic azides have become a very vital class of chemical compounds in synthetic organic chemistry and in many more fields due to their applications. Azido compounds are considered high-energetic compounds and are studied very little due to their explosive nature. There is an urge to evaluate the thermal stability of this wide variety of compounds which have tremendous applications in synthetic as well as organic chemistry. Here in we report the thermal stability of some organic azides such as sulfonyl, phosphoryl and carbonyl azides using differential scanning calorimetry (DSC) as an evaluating tool. Initial temperature of decomposition (Ti) and temperature of maximum decomposition (Tmax) are recorded. The area under exotherm peak during decomposition is used to determine the energy of decomposition (Ed) and is compared to threshold value for hazardous/explosive compounds. The effect of substituent groups at different positions, nature of the substituent groups (electron donating or electron withdrawing) and the steric hindrance on the thermal stability of these azides is studied in detail to verify the explosive nature of these compounds.
26

Kan hållbarheten på referenslösningar förlängas? / Can the Life Time of Reference Solutions be Extended?

Kourieh, Ilona January 2019 (has links)
Läkemedelsföretagen måste säkerställa att produkterna som tillverkas uppnår de krav som finns och är kvalitetssäkra. Företaget Recipharm Karlskoga AB måste kontrollera sina produkter och det görs till exempel med hjälp av referenslösningar. I metoderna användes referenslösningar med kända koncentrationer som har en viss hållbarhet och företaget vill hitta ett sätt att förlänga hållbarheten på tre referenslösningar tillhörande deras analysmetoder med high-performance liquid chromatography (HPLC). Detta kommer leda till en minskad arbetstid för företagets personal, kostnadsreduktion och minskning av utsläpp/användning av aktiva substanser. Det kan därmed vara gynnsamt för miljön. Arbetets mål är att hitta ett sätt att förlänga hållbarheten på tre referenslösningar. R2-värdet och relativa standardavvikelsen för dubbelinjektion och replikat ett och två beräknades. Detta gjordes för att kunna bedöma om hållbarheten på referenslösningarna som sätts i de olika provförvaringarna som är rumstemperatur, kyl och frys. Produkterna som analyseras innehåller aktiva substanser. Produkt ett innehåller Lidokain, Hydrokortisionacetat och Hydrokortison och som idag har en hållbarhet bara för tillfället enligt kontrollmetoden. De olika förvaringar som testades för denna referenslösning var frys. Referenslösning har hållbarhet i sex dagar i frys. Produkt två innehåller Metagin, Propagin och Lidokain HCl. Dagens hållbarhet är på femd agar enligt kontrollmetoden. Produkten analyserades i tre olika förvaringar, rumstemperatur, kyl och frys. Referenslösningens hållbarhet i frys varade i 12 dagar medan hållbarheten i rumstemperatur och kyl pågick i 15 dagar. Vilken förvaring som väljs ut för produkt två beror på företaget då både rumstemperatur och kyl är lika bra. Produkt tre innehåller 2,6-Xylidin med en dags hållbarhet enligt kontrollmetoden. Förvaringarna som testades var kyl och frys. Dag två för frys uppnådde inte kraven medan dag sex för frys uppnådde kraven för R2 på grund av denna inkonsekvens och osäkerhet är inte frys ett alternativ. Produkt 3 har därför en hållbarhet på två dagar i kyl. / Drug companies must ensure that the products that are manufactured meet the requirements and are of approved quality. The company Recipharm Karlskoga AB must control their products and this is done by example using reference solutions. These reference solutions have certain life time and the company wants to find a way to extend the life time of three reference solutions belonging to the company's analytical methods for high-performance liquid chromatography (HPLC.). This will lead to reduced working hours for the company employees, a cost reduction and a reduction of emissions/use of active pharmaceutical ingredient. This can therefore benefit the environment. The aim of this workis to find a way to extend the life time of the three reference solutions. R2 value and relative standard deviation for the double injection and replicas one and two were calculated in order to be able to estimate the life time of the products from the various sample storages placed in room temperature, refrigerator and freezer. The products that are analysed contain active pharmaceutical ingredient. Product one contains Lidocaine, Hydrocortisone acetate and Hydrocortisone and is currently sustainable according to the control method. The sample storage for product one was in the freezer and it had a prolonged life time of six days. Product two contains Metagin, Propagine and Lidocaine HCl. Today’s life time is five days according to the control method. It was analysed in three different sample storage rooms, room temperature, refrigerator and freezer. The product stored in the freezer lasted for 12 days while the product stored in both room temperature and in the refrigerator was able to sustain for 15 days. The choice of selected sample storage room for product 2 depends on the company. However, because there is more room for storage in room temperature it is therefore considered as a better alternative than refrigerator. Product three contains 2,6-Xylidine with a life time of one day. The sample storage rooms were the refrigerator and the freezer. Day two for the freezer did not fulfil the requirements while day six for the freezer met the requirements. Because of this inconsistency and uncertainty, the freezer should not be used as an option. Product three has therefore a prolonged life time of two days in the refrigerator.
27

Effects of Anisosmotic Medium on Cell Volume, Transmembrane Potential and Intracellular K<sup>+</sup> Activity in Mouse Hepatocytes

Howard, Larry D., Wondergem, Robert 01 December 1987 (has links)
Mouse hepatocytes in primary monolayer culture (4 hr) were exposed for 10 min at 37°C to anisosmotic medium of altered NaCl concentration. Hepatocytes maintained constant relative cell volume (experimental volume/control volume) as a function of external medium relative osmolality (control mOsm/experimental mOsm), ranging from 0.8 to 1.5. In contrast, the relative cell volume fit a predicted Boyle-Van't Hoff plot when the experiment was done at 4°C. Mouse liver slices were used for electrophysiologic studies, in which hepatocyte transmembrane potential (Vm) and intracellular K+ activity (aKi) were recorded continuously by open-tip and liquid ion-exchanger ion-sensitive glass microelectrodes, respectively. Liver slices were superfused with control and then with anisosmotic medium of altered NaCl concentration. Vm increased (hyperpolarized) with hypoosmotic medium and decreased (depolarized) with hyperosmotic medium, and ln [10(experimental Vm/control Vm)] was a linear function of relative osmolality (control mOsm/experimental mOsm) in the range 0.8-1.5. The aKi did not change when medium osmolality was decreased 40-70 mOsm from control of 280 mOsm. Similar hypoosmotic stress in the presence of either 60 mm K+ or 1 mm quinine HCl or at 27°C resulted in no change in Vm compared with a 20-mV increase in Vm without the added agents or at 37°C. We conclude that mouse hepatocytes maintain their volume and aKi in response to anisosmotic medium; however, Vm behaves as an osmometer under these conditions. Also, increases in Vm by hypoosmotic stress were abolished by conditions or agents that inhibit K+ conductance.
28

Development of an Orally Disintegrating Mini-Tablet (ODMTs) Containing Metoclopramide HCl to Enhance Patient Compliance

Alanezi, Abdulkareem Ali January 2014 (has links)
No description available.
29

Development of a novel gastro-retentive delivery system using alfuzosin HCl as a model drug

Liu, Quan. January 2010 (has links)
The objectives of this project encompass the design and development of a drug delivery system to continuously deliver therapeutic agents from the stomach to the proximal region of the intestine. The delivery system designed would have sufficient gastric residence time together with near zero-order release kinetics. The physicochemical properties pertaining to the formulation development of the model drug (alfuzosin HCl) were evaluated. Excipients were selected based on the studies of their physicochemical properties and compatibility with the active ingredient. Gastro-retentive dosage forms have been the topic of interest in recent years as a practical approach in drug deliveries to the upper GI tract or for release prolongation and absorption. These dosage forms are particularly suitable for drugs that have local effects on the gastric mucosa in the stomach. Other candidates include drugs that are likely to be absorbed in the upper small intestine, or drugs that are unstable in basic environment of distal intestine and colon or those with low solubility at elevated pH conditions (i.e. weak bases). To develop a gastro-retentive delivery system the following steps were taken. First, to investigate the possible incompatibility issues between the model drug and excipients to be used for the delivery system. Stability and physicochemical properties of the active agent and its mixture with excipients were studied using analytical techniques such as Raman spectroscopy and Differential scanning calorimetry (DSC). No incompatibility issues were detected. Second, Kollidon SR as a relatively new release-rate controlling polymer was incorporated in the final formulation. For solid dosage form the ability of the final powder mix to flow well during manufacturing and the intrinsic characteristics that make it compressible are critical. The in-depth compaction study of Kollidon SR was assessed with the help of a compaction simulator. The flowability, swelling and erosion behavior together with release-rate retarding properties of Kollidon SR were also assessed. The final oral delivery system was based on Kollidon SR and Polyethylene Oxide (PEO) 303 as a monolithic matrix system. The noneffervescent monolithic matrix was made by direct compression. In vitro evaluation of the designed system released the active content in a near zero manner. The dosage form was bouyant in pH 2.0 acidic buffer with no floatation lag time which minimizes the possibility of early gastric emptying. / Pharmaceutics
30

Atomic Force Microscopy Study of Clay Mineral Dissolution

Bickmore, Barry Robert 03 February 2000 (has links)
An integrated program has been developed to explore the reactivity of 2:1 phyllosilicates (biotite and the clays montmorillonite, hectorite, and nontronite) with respect to acid dissolution using in situ atomic force microscopy (AFM). Three techniques are described which make it possible to fix these minerals and other small particles to a suitable substrate for examination in the fluid cell of the atomic force microscope. A suite of macros has also been developed for the Image SXM image analysis environment which make possible the accurate and consistent measurement of the dimensions of clay particles in a series of AFM images, so that dissolution rates can be measured during a fluid cell experiment. Particles of biotite and montmorillonite were dissolved, and their dissolution rates normalized to their reactive surface area, which corresponds to the area of their edge surfaces (A<sub>e</sub>). The A<sub>e</sub>-normalized rates for these minerals between pH 1-2 are all ~10E<sup>-8</sup> mol/m<sup>2</sup>*s, and compare very well to other A<sub>e</sub>-normalized dissolution rates in the literature. Differences between the A<sub>e</sub>-normalized rates for biotite and the BET-normalized rates (derived from solution chemical studies) found in the literature can be easily explained in terms of the proportion of edge surface area and the formation of leached layers. However, the differences between the A<sub>e</sub>-normalized montmorillonite rates and the literature values cannot be explained the same way. Rather, it is demonstrated that rates derived from solution studies of montmorillonite dissolution have been affected by the colloidal behavior of the mineral particles. Finally, the dissolution behavior of hectorite (a trioctahedral smectite) and nontronite ( a dioctahedral smectite) were compared. Based on the differential reactivity of their crystal faces, a model of their surface atomic structures is formulated using Hartman-Perdock crystal growth theory, which explains the observed data if it is assumed that the rate-determining step of the dissolution mechanism is the breaking of connecting bonds between the octahedral and tetrahedral sheets of the mineral structure. / Ph. D.

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