591 |
Adaptive Voltage Control Methods using Distributed Energy ResourcesLi, Huijuan 01 December 2010 (has links)
Distributed energy resources (DE) with power electronics interfaces and logic control using local measurements are capable of providing reactive power related to ancillary system services. In particular, local voltage regulation has drawn much attention in regards to power system reliability and voltage stability, especially from past major cascading outages. This dissertation addresses the challenges of controlling the DEs to regulate the local voltage in distribution systems.
First, an adaptive voltage control method has been proposed to dynamically modify the control parameters of a single DE to respond to system changes such that the ideal response can be achieved. Theoretical analysis shows that a corresponding formulation of the dynamic control parameters exists; hence, the adaptive control method is theoretically solid. Also, the field experiment test results at the Distributed Energy Communications and Controls (DECC) Laboratory in single DE regulation case confirm the effectiveness of this method.
Then, control methods have been discussed in the case of multiple DEs regulating voltages considering the availability of communications among all the DEs. When communications are readily available, a method is proposed to directly calculate the needed adaptive change of the DE control parameters in order to achieve the ideal response. When there is no communication available, an approach to adaptively and incrementally adjust the control parameters based on the local voltage changes is proposed. Since the impact from other DEs is implicitly considered in this approach, multiple DEs can collectively regulate voltages closely following the ideal response curve. Simulation results show that each method, with or without communications, can satisfy the fast response requirement for operational use without causing oscillation, inefficiency or system equipment interference, although the case with communication can perform even faster and more accurate.
Since the proposed adaptive voltage regulation method in the case of multiple DEs without communication, has a high tolerance to real-time data shortage and can still provide good enough performance, it is more suitable for broad utility applications. The approach of multiple DEs with communication can be considered as a high-end solution, which gives faster and more precise results at a higher cost
|
592 |
Molecular-Level Modeling of Proton Transport in Aqueous Systems and Polymer Electrolyte Membranes: A Reactive Molecular Dynamics StudyEsai Selvan, Myvizhi 01 December 2010 (has links)
Proton exchange membrane (PEM) fuel cells are an eco-friendly power source that has great potential to reduce our oil dependence for our stationary and transportation applications. In order to make PEM fuel cells an economically viable option, further effort is needed to improve proton conduction under wide operating conditions and reduce the cost of production. Design and synthesis of novel membranes that have superior characteristics require a fundamental molecular-level understanding of the relationship between the polymer chemistry, water content and proton conduction. The performance of a fuel cell is influenced by the electrochemical and molecular/proton transport processes that occur at the catalytic sites in the electrode/electrolyte interface. Therefore, understanding the molecular-level details of proton transport and structure of the multi-phase interfaces is critical.
This work is subdivided into two main tasks. The first task is to model membrane/water vapor interfaces and to study their morphology and the transport properties of water and hydronium ions. Classical molecular dynamics simulation is used as the modeling tool for the characterization of the interface. The second task is to model proton transport through the aqueous domains of PEM. Such a model is inherently challenging since proton transport occurs through a combination of structural and vehicular diffusions that are associated with disparate time scales. Toward this end, we have developed and implemented a new reactive molecular dynamics algorithm to model the structural diffusion of proton that involves breaking and forming of covalent bonds. The proton transport through aqueous channels in PEM is governed by acidity and confinement. Therefore, systems in which the acidity and confinement can be independently varied, including bulk water, aqueous hydrochloric acid solutions and water confined in carbon nanotubes are also examined in addition to the application in PEM.
We have developed an understanding of how acidity and confinement independently impact proton transport. The correlation between the two components of charge diffusion and their contribution to the total charge diffusion has also been explored for a basic understanding of the proton transport mechanisms. These studies will eventually help us establish the correlation between the morphology of the membrane and proton conduction.
|
593 |
Caractérisation de couches minces d’oxynitrures de chrome produites par pulvérisation cathodique réactive en présence d’air : influence de la vapeur d’eau contenue dans du plasma./ Influence of the water vapor concentration into the reactive plasma during the deposition of chromium oxynitrides layers on steel.Agouram, Saïd 26 September 2003 (has links)
Le but de ce travail est d’étudier l’effet de la vapeur d’eau contenue dans le plasma sur
la composition et la vitesse de dépôt des couches minces d’oxynitrures de chrome déposées
par pulvérisation cathodique magnétron réactive avec l’air contenant différentes teneurs en
vapeur d’eau (humidité relative). Les techniques d’analyses par faisceau d’ions énergétiques :
RBS et réactions nucléaires nous ont permis de déterminer les concentrations relatives des
éléments déposés. Les profils d’hydrogène et d’azote ont été déterminés par RNRA et Tof-
SIMS. La liaison chimique a été identifiée par LEEIXS et XPS. Les mesures XPS ont dévoilé
la présence d’une phase autre que Cr, CrN, Cr2O3 et CrO2 ; cette nouvelle phase possède une
stoechiométrie (CrO2)3-N. La teneur en Cr et ses composés varie en fonction du flux et de
l’humidité relative de l’air. En mode métallique de la pulvérisation cathodique, la
stoechiométrie Cr2O3 est majoritaire en coexistence avec de faibles teneurs et CrN, CrO2 et (CrO2)3-N alors qu’en mode composé, c’est la stoechiométrie CrO2 qui prédomine./
The aim of this work is to study the stoichiometry of chromium oxynitride thin films
deposited by reactive magnetron sputtering in presence of air with various relative humidities.
Ion Beam Analysis methods: RBS (Rutherford Backscattering Spectroscopy) and resonant
nuclear reaction (RNRA) were used to determine the thickness and the composition of the
films. Hydrogen and nitrogen profiles were obtained by RNRA and Tof-SIMS. The chemical
bonds were investigated by XPS and LEEIXS. The chromium metallic and chromium
compounds concentrations were measured versus the flow and relative humidity of the air.
During sputtering in metallic mode, Cr2O3 stoichiometry is observed with low contents of
CrN, CrO2 and (CrO2)3-N whereas in compound mode the CrO2 stoichiometry predominates.
|
594 |
"Reactive hard templating" : from carbon nitrides to metal nitridesFischer, Anna January 2008 (has links)
Nanostructured inorganic materials are routinely synthesized by the use of templates. Depending on the synthesis conditions of the product material, either “soft” or “hard” templates can be applied. For sol-gel processes, usually “soft” templating techniques are employed, while “hard” templates are used for high temperature synthesis pathways. In classical templating approaches, the template has the unique role of structure directing agent, in the sense that it is not participating to the chemical formation of the resulting material. This work investigates a new templating pathway to nanostructured materials, where the template is also a reagent in the formation of the final material. This concept is described as “reactive templating” and opens a synthetic path toward materials which cannot be synthesised on a nanometre scale by classical templating approaches. Metal nitrides are such kind of materials. They are usually produced by the conversion of metals or metal oxides in ammonia flow at high temperature (T > 1000°C), which make the application of classical templating techniques difficult.
Graphitic carbon nitride, g-C3N4, despite its fundamental and theoretical importance, is probably one of the most promising materials to complement carbon in material science and many efforts are put in the synthesis of this material. A simple polyaddition/elimination reaction path at high temperature (T = 550°C) allows the polymerisation of cyanamide toward graphitic carbon nitride solids. By hard templating, using nanostructured silica or aluminium oxide as nanotemplates, a variety of nanostructured graphitic carbon nitrides such as nanorods, nanotubes, meso- and macroporous powders could be obtained by nanocasting or nanocoating. Due to the special semi-conducting properties of the graphitic carbon nitride matrix, the nanostructured graphitic carbon nitrides show unexpected catalytic activity for the activation of benzene in Friedel-Crafts type reactions, making this material an interesting metal free catalyst. Furthermore, due to the chemical composition of g-C3N4 and the fact that it is totally decomposed at temperatures between 600°C and 800°C even under inert atmosphere, g-C3N4 was shown to be a good nitrogen donor for the synthesis of early transition metal nitrides at high temperatures. Thus using the nanostructured carbon nitrides as “reactive templates” or “nanoreactors”, various metal nitride nanostructures, such as nanoparticles and porous frameworks could be obtained at high temperature. In this approach the carbon nitride nanostructure played both the role of the nitrogen source and of the exotemplate, imprinting its size and shape to the resulting metal nitride nanostructure. / Die Nanostrukturierung anorganischer Materialien, d.h. die Kontrolle ihrer Form und Größe auf der Nanometerebene durch unterschiedliche Herstellungsverfahren, ist ein sich immer noch erweiterndes Forschungsgebiet. Eine solche Nanostrukturierung wird oft über sogenannte Templatierungsverfahren erreicht: Hier werden Formgeber (Template) mit definierter Morphologie und Größe verwendet und deren Struktur in ein neues Material abgebildet. Templatierungsverfahren können, je nach der Beschaffenheit des Templats, zwischen „weich“ und „hart“ unterschieden werden. Die Begriffe beziehen sich dabei vor allem auf die mechanische und thermische Stabilität der Template, d.h. weiche Template sind vornehmlich organischer, harte Template anorganischer Natur. Wo weiche Template in milden chemischen Verfahren eingesetzt werden, werden harte Template zur Herstellung von Materialien bei Hochtemperaturverfahren verwendet (z. B. poröse Kohlenstoffe). Allgemein dienen Template ausschließlich als Strukturgeber und gehen in keiner Weise in Form einer chemischen Reaktion in die Synthese des gewünschten Materials mit ein. Gegenstand dieser Arbeit ist ein neues Templatierungsverfahren: Die „reaktive Templatierung“. Hierbei wird das Templat - neben seiner Funktion als Strukturgeber – auch als Reagenz für die Synthese des Produktes verwendet. Dieser Synthese-Ansatz öffnet damit neue Wege für die Synthese von nanostrukturierten Materialien, die durch klassische Templatierungsansätze schwer zugänglich sind. Hierzu zählen zum Beispiel die Metallnitride. Üblicherweise werden Metallnitride über die Umsetzung von Metallen oder Metalloxiden in einem Ammoniakstrom bei Mindesttemperaturen von 1000°C gewonnen, was die Anwendung klassischer Templatierungsverfahren beinahe unmöglich macht. Darüber hinaus sind konzentrierte Lauge oder Flusssäure, welche zur Entfernung klassischer harter Template benötigt werden auch Aufschlussmittel für Metallnitride.
Graphitisches Kohlenstoffnitrid, g-C3N4, ist wohl eines der meistversprechendsten Materialien um Kohlenstoff in der Materialwissenschaft zu ergänzen. Es wurden bereits viele potentielle Syntheseansätze beschrieben. Eine durch Groenewolt M. erstellte Route ist die thermisch induzierte Polykondensation von Cyanamid (NCNH2) bei 550°C. Da g-C3N4 sich zwischen 600°C und 800°C vollständig in NH3 und CxNyH-Gase zersetzt, ist es eine geeignete Festkörper-Stickstoffquelle für die Herstellung von Metalnitriden. Daher boten sich nanostrukturierte graphitische Kohlenstoffnitride als geeignete reaktive Template oder Nanoreaktoren zur Herstellung von nano-strukturierten Metalnitriden an. Die Templatierung der g-C3N4-Matrix wurde über klassische Harttemplatierungsverfahren erreicht. So konnte eine Vielzahl nano-strukturierter g-C3N4 Materialien synthetisiert werden wie zum Beispiel Nanostäbchen, Nanoröhren, mesoporöse oder makroporöse graphitische Kohlenstoffnitride. Diese haben sich interessanterweise, als metalfreie Katalysatoren für die Aktivierung von Benzol in Friedel-Crafts-Acylierung und -Alkylierung erwiesen. Durch die Infiltrierung der nano-strukturierten g-C3N4-Materialien mit diversen Metal-Präkursoren und nachfolgendem Tempern bei 800°C unter Schutzgas, konnten entsprechende nano-strukturierte Metalnitride, als Nanoabdrücke der vorgegebenen Kohlenstoffnitrid Nanostrukturen hergestellt werden. So konnten TiN, VN, GaN, AlGaN und TiVN Nanopartikel synthetisiert werden, macroporöse TiN/Kohlenstoff Komposite sowie TiN Hohlkugeln. Die so hergestellten Materialien erwiesen sich als effektive basische Katalysatoren für Aldol-Kondensations Reaktionen.
|
595 |
Contaminant transport in non-uniform streams and streambedsForsman, Jonas K. January 2000 (has links)
The interplay between hydraulic and chemical processes in streams and adjacent storage zones, e.g. streambed sediments, is of crucial importance for the large-scale transport of released contaminants. This thesis presents a methodology for tracer experiments and the development of mechanistic transport models. We conducted four field tracer experiments with the reactive tracer chromium, 51Cr(III) and/or the conservative tracers potassium iodide (KI) and tritium (3H2O), along 11 km of the Lanna Stream in Skara County, Sweden, and along a 30 km reach of the Säva Stream in Uppland County, Sweden. The field monitoring included sampling of tracer in the surface water as well as in the streambed sediments. A simultaneous injection of tritium and chromium facilitated an independent evaluation of the hydraulic transport into and out of the sub-surface storage zones. The difference in transport behaviour between the two tracers, were attributed to chemical reactivity. In terms of idealised transport models we found that the reactivity of chromium could be characterised by simple chemical concepts. The local equilibrium assumption (LEA), the irreversible kinetics assumption (IKA) and the reversible kinetics assumption (RKA) were applied in the experimental evaluations. An independent evaluation of the streambed transport revealed that the impact of reaction kinetics was substantial. Model calculations and results from a chemical extraction procedure indicated that the chemical reactions affecting the chromium transport were to some extent irreversible. This thesis presents a number of exact analytical solutions to the governing partial differential equations. The main theoretical contribution is the incorporation of variable coefficients for stream discharge and sediment porosity, which were measured in field.
|
596 |
Mechanisms and genes controlling the signalling network for biotic and abiotic stress defences in Arabidopsis thaliana (L.) Heyhn : Functional cross-talk between photo-produced reactive oxygen species, photosynthesis and plant disease defence responsesChang, Christine Chi-Chen January 2005 (has links)
Excess excitation energy, mechanical injury and defence against pathogens, each trigger rapid production of reactive oxygen species (ROS) in Arabidopsis thaliana leaves. ROS, such as hydrogen peroxide (H2O2), are required for the induction of systemic acquired acclimation and may lead to redox changes in photosynthetic electron transport (PET). On one hand, enhanced ROS production during stress can destroy cells, and on the other, ROS can also act as signals for the activation of stress responsive and defensive pathways. In this work, physiological and molecular analyses of Arabidopsis mutants and transgenic lines were applied to investigate the signalling network controlling biotic and abiotic stress responses. A key enzyme of the antioxidant network is encoded by ASCORBATE PEROXIDASE 2 (APX2). Wounded leaves showed low induction of APX2 expression and when exposed to excess light, APX2 expression was increased synergistically. Signalling pathways dependent upon jasmonic acid, chitosan and abscisic acid were not involved in the wound-induced expression of APX2, but PET was required, and APX2 induction was preceded by a depressed rate of CO2 fixation. Analysis of lsd1 (LESION SIMULATING DISEASE 1) strongly suggests that light acclimatory processes and pathogen defences are genetically and functionally linked. It is important to know that LSD1 type of mutants have mainly been studied with regard to pathogenesis. From this work, it reveals that association of LSD1 with hypersensitive response may only be supplementary. GLUTATHIONE PEROXIDASES (GPXs) are another major family of ROS scavenging enzymes. Analysis of the Arabidopsis genome database revealed a new open-reading frame, thus increasing the total number of AtGPX gene family to eight (AtGPX1-AtGPX8). Arabidopsis thaliana transgenic lines with reduced expression of both putative chloroplastic isoforms (AtGPX1 and AtGPX7) and AtGPX7 knock-out mutant (ko-GPX7) were more sensitive to photo-oxidative stress but had a reduced bacterial growth rate when inoculated with virulent strains Pseudomonas syringae pv. tomato DC3000 and P.s.t. maculicola strain ES4326, indicating increased resistance to pathogenesis. This, to our knowledge, is the first functional and genetic analysis of chloroplastic GPXs in plants, and confirms that light and chloroplastic ROS metabolism is important for basal resistance against virulent pathogens. The above results confirm that light sensing, light acclimatory processes and photo-produced ROS also govern pathogen defence pathways. This has a great ecological relevance for Darwinian fitness of plants growing in the natural environment, where simultaneous pathogen attack and fluctuations in light, temperature and other environmental factors make rapid acclimation a constant necessity. Molecular, biochemical and physiological analysis of pathogen responses in mutants impaired in light sensing, EEE-dissipatory mechanisms, and similar analysis of light acclimatory processes in mutants impaired in pathogen defences may prove to be seminal.
|
597 |
Studies of the Reactive Sputtering Process and its Application in Electro-Acoustic DevicesRosén, Daniel January 2006 (has links)
Electro-acoustic devices such as surface acoustic wave (SAW) and bulk acoustic wave (BAW) devices have been in commercial use for over 60 years and can be found in applications ranging from specialised scientific and military equipment to consumer products, such as mobile telephones, TV and radio receivers, etc. Today by far the largest market for electro-acoustic devices is the telecommunication industry which annually consumes approximately three billion acoustic wave filters for frequency control alone. The development of new materials and technologies for electro-acoustic devices has gained a substantial and growing interest from both academic and industrial research communities in recent years due to the enormous growth in the telecommunication industry and other forms of wireless data communication. One of the bigger issues has been to replace the single crystalline substrates with thin film piezoelectric materials deposited by reactive sputtering. This would not only reduce the manufacturing costs but will also enable high frequency of operation and a wider choice of substrate materials. However, in order to obtain the material properties required for the intended application a detailed theoretical description of the reactive sputtering process is necessary since the texture and other functional properties of the piezoelectric material are extremely sensitive to the process parameters in addition to the structure of the underlying material. This thesis studies the reactive sputtering process and its application for the fabrication of thin film electro-acoustic devices. The aim has been to gain a further insight into the process and make use of this knowledge to improve the fabrication of electro-acoustic devices. In this work modelling of the reactive sputtering process has been improved by studying certain fundamental aspects of the process and in particular the dynamics of the processes taking place during sputtering both at the target and the substrate surfaces. Consequently, highly textured thin piezoelectric aluminium nitride films have been synthesized and thin film bulk acoustic resonators (FBAR) operating in the GHz range have been fabricated and studied.
|
598 |
Har storleken någon betydelse? : En studie av den svenska aktiemarknadens reaktion på varsel om uppsägning av personalDanielsson, Robert, Fredlund, Oscar January 2009 (has links)
Background: The reasons why this study is conducted is because of the latest recession in the global economy. The current recession has made a lot of companies more aware of its cost, and in order to fit the new harsher economic climate the companies has to be more cost efficient. In order to do so many companies choose to reduce their amount of employees. When this happens in a recession, most of the layoffs are an effect of reactive causes, such as lower incoming orders, and fewer customers. This leads to a problem for the companies that don’t know how these kinds of layoffs will affect the value of the company’s stock. This leads to a question whether there is a significant pattern between layoffs that are a result of reactive reasons and the number of employees that are being laid off, in percentage of the total number of employees of the companies in question? Purpose: The reason for this study is to find out if there is any correlation between how many employees that is laid off, in percentage of the company’s total employees, and if different percentages have different impact in the valuations of the company’s stock. Approach: This study is made in the form of a modified event study and narrows down to the recession during 2008-01-01 to 2009-10-01, and only involves companies that are on trade on the stock market in Stockholm Sweden. The objects that are involved in this study are from the stock markets large and mid-cap sections. The criteria for companies in this study are that they should have made layoffs for reactive reasons in the time period that we are interested in. The variations in the company’s stock are compared to Stockholm’s stock markets OMX-index. The information needed to conduct this study is gathered from press realises and from financial reports made by the companies. Result and conclusions: The study shows that there is a correlation between how large percentage of the company’s total employees that are laid off and the effect of variations in the stock. The correlation is -0,306 but it is not statistical verified. This result was not in line with our hypotheses that we had concluded from earlier research and theories that are in the study. Earlier research on the American stock market shows a stronger connection between large percentage layoffs and how this makes the stock value to decrease.
|
599 |
The Downward Effect of Ethics in the Value ChainBöke, Nicole, Mulder, Dewy F. January 2009 (has links)
The media has responded toward unethical behavior in rainforests during the ‘80’s, triggering the still upcoming trend of investigation of ethical considerations, as described by Macfarlane (1995). Many researchers are constantly improving the ethical theories and showing continued change in the perception of ethics (Svensson & Wood, 2007) The purpose of this research is to identify the effect of ethics on the proactive or reactive behavior of companies, with a downward tendency provided in the value chain. The theoretical framework consists out of a set of theories supporting the goal of identifying ethics within a company, applying a new business ethics model and measuring the pro-active and re-active behavior of the stakeholder in the value chain. Finally, all the theories used, are combined in an integrated theoretical model used to justify the collection of empirical data and to give structure to the analysis. The empirical data has been gathered through non structured and semi-structured interviews with customers, employees within the case company, and a supplier to the case company. These findings are complemented with secondary data gathered through websites, annual reports, codes of conduct, media articles and others sources. The findings of the study showed that the (in the theoretical framework) assumption of a downward effect in perception and change in ethical considerations is not as obvious as previously thought. Within this case study, the ethical influences come from the case company, situated in the middle of the value chain, influencing both the consumer and the supplier, in ethical considerations.
|
600 |
A matched case control study of the nutritional status of newly diagnosed tuberculosis patients and tuberculosis free contacts in Delft, Western CapeLombardo, Candice Clarissa January 2011 (has links)
<p><!--[if gte mso 9]><xml>
<w:LatentStyles DefLockedState="false" DefUnhideWhenUsed="true"
DefSemiHidden="true" DefQFormat="false" DefPriority="99"
LatentStyleCount="267">
<w:LsdException Locked="false" Priority="0" SemiHidden="false"
UnhideWhenUsed="false" QFormat="true" Name="Normal" />
<w:LsdException Locked="false" Priority="9" SemiHidden="false"
UnhideWhenUsed="false" QFormat="true" Name="heading 1" />
<w:LsdException Locked="false" Priority="9" QFormat="true" Name="heading 2" />
<w:LsdException Locked="false" Priority="9" QFormat="true" Name="heading 3" />
<w:LsdException Locked="false" Priority="9" QFormat="true" Name="heading 4" />
<w:LsdException Locked="false" Priority="9" QFormat="true" Name="heading 5" />
<w:LsdException Locked="false" Priority="9" QFormat="true" Name="heading 6" />
<w:LsdException Locked="false" Priority="9" QFormat="true" Name="heading 7" />
<w:LsdException Locked="false" Priority="9" QFormat="true" Name="heading 8" />
<w:LsdException Locked="false" Priority="9" QFormat="true" Name="heading 9" />
<w:LsdException Locked="false" Priority="39" Name="toc 1" />
<w:LsdException Locked="false" Priority="39" Name="toc 2" />
<w:LsdException Locked="false" Priority="39" Name="toc 3" />
<w:LsdException Locked="false" Priority="39" Name="toc 4" />
<w:LsdException Locked="false" Priority="39" Name="toc 5" />
<w:LsdException Locked="false" Priority="39" Name="toc 6" />
<w:LsdException Locked="false" Priority="39" Name="toc 7" />
<w:LsdException Locked="false" Priority="39" Name="toc 8" />
<w:LsdException Locked="false" Priority="39" Name="toc 9" />
<w:LsdException Locked="false" Priority="35" QFormat="true" Name="caption" />
<w:LsdException Locked="false" Priority="10" SemiHidden="false"
UnhideWhenUsed="false" QFormat="true" Name="Title" />
<w:LsdException Locked="false" Priority="1" Name="Default Paragraph Font" />
<w:LsdException Locked="false" Priority="11" SemiHidden="false"
UnhideWhenUsed="false" QFormat="true" Name="Subtitle" />
<w:LsdException Locked="false" Priority="22" SemiHidden="false"
UnhideWhenUsed="false" QFormat="true" Name="Strong" />
<w:LsdException Locked="false" Priority="20" SemiHidden="false"
UnhideWhenUsed="false" QFormat="true" Name="Emphasis" />
<w:LsdException Locked="false" Priority="59" SemiHidden="false"
UnhideWhenUsed="false" Name="Table Grid" />
<w:LsdException Locked="false" UnhideWhenUsed="false" Name="Placeholder Text" />
<w:LsdException Locked="false" Priority="1" SemiHidden="false"
UnhideWhenUsed="false" QFormat="true" Name="No Spacing" />
<w:LsdException Locked="false" Priority="60" SemiHidden="false"
UnhideWhenUsed="false" Name="Light Shading" />
<w:LsdException Locked="false" Priority="61" SemiHidden="false"
UnhideWhenUsed="false" Name="Light List" />
<w:LsdException Locked="false" Priority="62" SemiHidden="false"
UnhideWhenUsed="false" Name="Light Grid" />
<w:LsdException Locked="false" Priority="63" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Shading 1" />
<w:LsdException Locked="false" Priority="64" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Shading 2" />
<w:LsdException Locked="false" Priority="65" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium List 1" />
<w:LsdException Locked="false" Priority="66" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium List 2" />
<w:LsdException Locked="false" Priority="67" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Grid 1" />
<w:LsdException Locked="false" Priority="68" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Grid 2" />
<w:LsdException Locked="false" Priority="69" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Grid 3" />
<w:LsdException Locked="false" Priority="70" SemiHidden="false"
UnhideWhenUsed="false" Name="Dark List" />
<w:LsdException Locked="false" Priority="71" SemiHidden="false"
UnhideWhenUsed="false" Name="Colorful Shading" />
<w:LsdException Locked="false" Priority="72" SemiHidden="false"
UnhideWhenUsed="false" Name="Colorful List" />
<w:LsdException Locked="false" Priority="73" SemiHidden="false"
UnhideWhenUsed="false" Name="Colorful Grid" />
<w:LsdException Locked="false" Priority="60" SemiHidden="false"
UnhideWhenUsed="false" Name="Light Shading Accent 1" />
<w:LsdException Locked="false" Priority="61" SemiHidden="false"
UnhideWhenUsed="false" Name="Light List Accent 1" />
<w:LsdException Locked="false" Priority="62" SemiHidden="false"
UnhideWhenUsed="false" Name="Light Grid Accent 1" />
<w:LsdException Locked="false" Priority="63" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Shading 1 Accent 1" />
<w:LsdException Locked="false" Priority="64" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Shading 2 Accent 1" />
<w:LsdException Locked="false" Priority="65" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium List 1 Accent 1" />
<w:LsdException Locked="false" UnhideWhenUsed="false" Name="Revision" />
<w:LsdException Locked="false" Priority="34" SemiHidden="false"
UnhideWhenUsed="false" QFormat="true" Name="List Paragraph" />
<w:LsdException Locked="false" Priority="29" SemiHidden="false"
UnhideWhenUsed="false" QFormat="true" Name="Quote" />
<w:LsdException Locked="false" Priority="30" SemiHidden="false"
UnhideWhenUsed="false" QFormat="true" Name="Intense Quote" />
<w:LsdException Locked="false" Priority="66" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium List 2 Accent 1" />
<w:LsdException Locked="false" Priority="67" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Grid 1 Accent 1" />
<w:LsdException Locked="false" Priority="68" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Grid 2 Accent 1" />
<w:LsdException Locked="false" Priority="69" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Grid 3 Accent 1" />
<w:LsdException Locked="false" Priority="70" SemiHidden="false"
UnhideWhenUsed="false" Name="Dark List Accent 1" />
<w:LsdException Locked="false" Priority="71" SemiHidden="false"
UnhideWhenUsed="false" Name="Colorful Shading Accent 1" />
<w:LsdException Locked="false" Priority="72" SemiHidden="false"
UnhideWhenUsed="false" Name="Colorful List Accent 1" />
<w:LsdException Locked="false" Priority="73" SemiHidden="false"
UnhideWhenUsed="false" Name="Colorful Grid Accent 1" />
<w:LsdException Locked="false" Priority="60" SemiHidden="false"
UnhideWhenUsed="false" Name="Light Shading Accent 2" />
<w:LsdException Locked="false" Priority="61" SemiHidden="false"
UnhideWhenUsed="false" Name="Light List Accent 2" />
<w:LsdException Locked="false" Priority="62" SemiHidden="false"
UnhideWhenUsed="false" Name="Light Grid Accent 2" />
<w:LsdException Locked="false" Priority="63" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Shading 1 Accent 2" />
<w:LsdException Locked="false" Priority="64" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Shading 2 Accent 2" />
<w:LsdException Locked="false" Priority="65" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium List 1 Accent 2" />
<w:LsdException Locked="false" Priority="66" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium List 2 Accent 2" />
<w:LsdException Locked="false" Priority="67" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Grid 1 Accent 2" />
<w:LsdException Locked="false" Priority="68" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Grid 2 Accent 2" />
<w:LsdException Locked="false" Priority="69" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Grid 3 Accent 2" />
<w:LsdException Locked="false" Priority="70" SemiHidden="false"
UnhideWhenUsed="false" Name="Dark List Accent 2" />
<w:LsdException Locked="false" Priority="71" SemiHidden="false"
UnhideWhenUsed="false" Name="Colorful Shading Accent 2" />
<w:LsdException Locked="false" Priority="72" SemiHidden="false"
UnhideWhenUsed="false" Name="Colorful List Accent 2" />
<w:LsdException Locked="false" Priority="73" SemiHidden="false"
UnhideWhenUsed="false" Name="Colorful Grid Accent 2" />
<w:LsdException Locked="false" Priority="60" SemiHidden="false"
UnhideWhenUsed="false" Name="Light Shading Accent 3" />
<w:LsdException Locked="false" Priority="61" SemiHidden="false"
UnhideWhenUsed="false" Name="Light List Accent 3" />
<w:LsdException Locked="false" Priority="62" SemiHidden="false"
UnhideWhenUsed="false" Name="Light Grid Accent 3" />
<w:LsdException Locked="false" Priority="63" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Shading 1 Accent 3" />
<w:LsdException Locked="false" Priority="64" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Shading 2 Accent 3" />
<w:LsdException Locked="false" Priority="65" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium List 1 Accent 3" />
<w:LsdException Locked="false" Priority="66" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium List 2 Accent 3" />
<w:LsdException Locked="false" Priority="67" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Grid 1 Accent 3" />
<w:LsdException Locked="false" Priority="68" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Grid 2 Accent 3" />
<w:LsdException Locked="false" Priority="69" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Grid 3 Accent 3" />
<w:LsdException Locked="false" Priority="70" SemiHidden="false"
UnhideWhenUsed="false" Name="Dark List Accent 3" />
<w:LsdException Locked="false" Priority="71" SemiHidden="false"
UnhideWhenUsed="false" Name="Colorful Shading Accent 3" />
<w:LsdException Locked="false" Priority="72" SemiHidden="false"
UnhideWhenUsed="false" Name="Colorful List Accent 3" />
<w:LsdException Locked="false" Priority="73" SemiHidden="false"
UnhideWhenUsed="false" Name="Colorful Grid Accent 3" />
<w:LsdException Locked="false" Priority="60" SemiHidden="false"
UnhideWhenUsed="false" Name="Light Shading Accent 4" />
<w:LsdException Locked="false" Priority="61" SemiHidden="false"
UnhideWhenUsed="false" Name="Light List Accent 4" />
<w:LsdException Locked="false" Priority="62" SemiHidden="false"
UnhideWhenUsed="false" Name="Light Grid Accent 4" />
<w:LsdException Locked="false" Priority="63" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Shading 1 Accent 4" />
<w:LsdException Locked="false" Priority="64" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Shading 2 Accent 4" />
<w:LsdException Locked="false" Priority="65" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium List 1 Accent 4" />
<w:LsdException Locked="false" Priority="66" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium List 2 Accent 4" />
<w:LsdException Locked="false" Priority="67" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Grid 1 Accent 4" />
<w:LsdException Locked="false" Priority="68" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Grid 2 Accent 4" />
<w:LsdException Locked="false" Priority="69" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Grid 3 Accent 4" />
<w:LsdException Locked="false" Priority="70" SemiHidden="false"
UnhideWhenUsed="false" Name="Dark List Accent 4" />
<w:LsdException Locked="false" Priority="71" SemiHidden="false"
UnhideWhenUsed="false" Name="Colorful Shading Accent 4" />
<w:LsdException Locked="false" Priority="72" SemiHidden="false"
UnhideWhenUsed="false" Name="Colorful List Accent 4" />
<w:LsdException Locked="false" Priority="73" SemiHidden="false"
UnhideWhenUsed="false" Name="Colorful Grid Accent 4" />
<w:LsdException Locked="false" Priority="60" SemiHidden="false"
UnhideWhenUsed="false" Name="Light Shading Accent 5" />
<w:LsdException Locked="false" Priority="61" SemiHidden="false"
UnhideWhenUsed="false" Name="Light List Accent 5" />
<w:LsdException Locked="false" Priority="62" SemiHidden="false"
UnhideWhenUsed="false" Name="Light Grid Accent 5" />
<w:LsdException Locked="false" Priority="63" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Shading 1 Accent 5" />
<w:LsdException Locked="false" Priority="64" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Shading 2 Accent 5" />
<w:LsdException Locked="false" Priority="65" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium List 1 Accent 5" />
<w:LsdException Locked="false" Priority="66" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium List 2 Accent 5" />
<w:LsdException Locked="false" Priority="67" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Grid 1 Accent 5" />
<w:LsdException Locked="false" Priority="68" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Grid 2 Accent 5" />
<w:LsdException Locked="false" Priority="69" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Grid 3 Accent 5" />
<w:LsdException Locked="false" Priority="70" SemiHidden="false"
UnhideWhenUsed="false" Name="Dark List Accent 5" />
<w:LsdException Locked="false" Priority="71" SemiHidden="false"
UnhideWhenUsed="false" Name="Colorful Shading Accent 5" />
<w:LsdException Locked="false" Priority="72" SemiHidden="false"
UnhideWhenUsed="false" Name="Colorful List Accent 5" />
<w:LsdException Locked="false" Priority="73" SemiHidden="false"
UnhideWhenUsed="false" Name="Colorful Grid Accent 5" />
<w:LsdException Locked="false" Priority="60" SemiHidden="false"
UnhideWhenUsed="false" Name="Light Shading Accent 6" />
<w:LsdException Locked="false" Priority="61" SemiHidden="false"
UnhideWhenUsed="false" Name="Light List Accent 6" />
<w:LsdException Locked="false" Priority="62" SemiHidden="false"
UnhideWhenUsed="false" Name="Light Grid Accent 6" />
<w:LsdException Locked="false" Priority="63" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Shading 1 Accent 6" />
<w:LsdException Locked="false" Priority="64" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Shading 2 Accent 6" />
<w:LsdException Locked="false" Priority="65" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium List 1 Accent 6" />
<w:LsdException Locked="false" Priority="66" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium List 2 Accent 6" />
<w:LsdException Locked="false" Priority="67" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Grid 1 Accent 6" />
<w:LsdException Locked="false" Priority="68" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Grid 2 Accent 6" />
<w:LsdException Locked="false" Priority="69" SemiHidden="false"
UnhideWhenUsed="false" Name="Medium Grid 3 Accent 6" />
<w:LsdException Locked="false" Priority="70" SemiHidden="false"
UnhideWhenUsed="false" Name="Dark List Accent 6" />
<w:LsdException Locked="false" Priority="71" SemiHidden="false"
UnhideWhenUsed="false" Name="Colorful Shading Accent 6" />
<w:LsdException Locked="false" Priority="72" SemiHidden="false"
UnhideWhenUsed="false" Name="Colorful List Accent 6" />
<w:LsdException Locked="false" Priority="73" SemiHidden="false"
UnhideWhenUsed="false" Name="Colorful Grid Accent 6" />
<w:LsdException Locked="false" Priority="19" SemiHidden="false"
UnhideWhenUsed="false" QFormat="true" Name="Subtle Emphasis" />
<w:LsdException Locked="false" Priority="21" SemiHidden="false"
UnhideWhenUsed="false" QFormat="true" Name="Intense Emphasis" />
<w:LsdException Locked="false" Priority="31" SemiHidden="false"
UnhideWhenUsed="false" QFormat="true" Name="Subtle Reference" />
<w:LsdException Locked="false" Priority="32" SemiHidden="false"
UnhideWhenUsed="false" QFormat="true" Name="Intense Reference" />
<w:LsdException Locked="false" Priority="33" SemiHidden="false"
UnhideWhenUsed="false" QFormat="true" Name="Book Title" />
<w:LsdException Locked="false" Priority="37" Name="Bibliography" />
<w:LsdException Locked="false" Priority="39" QFormat="true" Name="TOC Heading" />
</w:LatentStyles>
</xml><![endif]--><!--[if gte mso 10]>
<style>
/* Style Definitions */
table.MsoNormalTable
{mso-style-name:"Table Normal" / mso-tstyle-rowband-size:0 / mso-tstyle-colband-size:0 / mso-style-noshow:yes / mso-style-priority:99 / mso-style-parent:"" / mso-padding-alt:0cm 5.4pt 0cm 5.4pt / mso-para-margin-top:0cm / mso-para-margin-right:0cm / mso-para-margin-bottom:10.0pt / mso-para-margin-left:0cm / line-height:115% / mso-pagination:widow-orphan / font-size:11.0pt / font-family:"Calibri","sans-serif" / mso-ascii-font-family:Calibri / mso-ascii-theme-font:minor-latin / mso-hansi-font-family:Calibri / mso-hansi-theme-font:minor-latin / mso-bidi-font-family:"Times New Roman" / mso-bidi-theme-font:minor-bidi / mso-ansi-language:EN-US / mso-fareast-language:EN-US / }
</style>
<![endif]--><b style="mso-bidi-font-weight:
normal"><span lang="EN-GB">Background</span></b><span lang="EN-GB">: Malnutrition is a risk factor for the development of pulmonary tuberculosis (TB) and may be responsible for the premature deaths of patients with active disease. An adequate nutritional status may therefore be protective in delaying the onset from latent infection to active disease. In South Africa, very little data is available on the nutritional status of adults who present with tuberculosis. This study therefore aims to compare the nutritional status of newly diagnosed pulmonary tuberculosis patients with TB-free controls.</span> <b style="mso-bidi-font-weight:
normal"><span lang="EN-GB">Study population & / Design</span></b><span lang="EN-GB">: This is a community based case-control study. Forty-three newly diagnosed pulmonary tuberculosis patients were recruited as cases and matched according to age, gender and race to 43 TB-free close contacts. HIV positive subjects were excluded from the study.</span> <b style="mso-bidi-font-weight:
normal"><span lang="EN-GB">Methods</span></b><span lang="EN-GB">: Each participant was interviewed and completed a structured questionnaire to obtain demographic information. Weight was measured to the nearest 0.1kg and height to the nearest 1mm. A 24-hr dietary recall method was used to obtain dietary information. Biochemical analysis was carried out to measure  / concentrations of transferrin, albumin, CRP, ferritin, zinc, copper, vitamin A and E.</span> <b style="mso-bidi-font-weight:
normal"><span lang="EN-GB">Results</span></b><span lang="EN-GB">: The median Body Mass Index (BMI) for cases was 18.80kg/m² / (IQR 14.35, 32.11) and TB-free contacts 21.17 kg/m² / (IQR 16.75, 34.98) with a significant difference between the groups of p=0.001. There was significant difference in weight (p=0.002) and MUAC (p=0.000) between groups. No significant difference in dietary intake of energy (KJ) (p=0.695), protein (p=0.804), CHO (p=0.801) and fat ( p=0.796) was found between groups. There was a statistically significant increase in ferritin (p=0.000) and C-reactive protein (CRP) (p=0.000) in TB patients, while albumin (p=0.000), serum zinc (p=0.000) and serum vitamin A (p=0.000) were statistically significantly lower among cases.</span> <b style="mso-bidi-font-weight:normal"><span lang="EN-GB">Conclusion</span></b><span lang="EN-GB">: There was no significant difference in the macronutrient intake of TB cases and TB-free contacts, although a significant difference was seen in BMI, MUAC and weight between groups, with all these parameters being lower in TB patients. Ferritin and CRP levels were markedly increased in TB cases while serum zinc, vitamin A and albumin are all significantly lower in  / TB patients than TB free contacts.</span> <b style="mso-bidi-font-weight:normal"><span lang="EN-GB">  / </span></b></p>
<p>  / </p>
|
Page generated in 0.0428 seconds