• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 3
  • 2
  • 1
  • Tagged with
  • 8
  • 3
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 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.
1

Effects of Combustion Characteristics and Pollution Formations in Flue Gas Recirculation and Plate Angle Under Oil-Boiler

Chou, Ming-Fuei 06 July 2000 (has links)
In this research a modified commercial boiler,which burns diesel oil,is used to study the combustion characterisics and the pollution of the exhausting products under various operating conditions.The controlling ranges of the various experimental parameters include equivalence ratio from 0.8to1.1,swirl number 0 and 0.6, the flue rate of the recirculated flue gas from 0% to 12%, and jet spray angle 80. The effect of the above various operating conditions on the combustion characteristics and the formation of pollutants are studied in this research. A photographic technology is used to study the combustion behaviors of the flame under various operating condition. Flame structures display that when the flow rate of the recirculated flue gas increase, the flame color in primary combustion zone will change gradually from high temperature white-yellow flame to low temperature orange-red flame. At plate angle 0 and 45, the primary combustion zone with plate angle 45 occurs near burner so that we cannot see too much white-yellow zone from quartz window. The flame outside of the primary combustion region exhibits the red color which is due to the radition of CO2 and water vapor. In addition, when the strength of the swirl increases the contour of the flame will change gradually from smooth shape to strongly distortion.
2

Two alleles of Med31 provide a model to study delayed fetal growth, proliferation and placental development

Wolton, Kathryn January 2016 (has links)
Fetal growth restriction (FGR) is the failure of a fetus to reach its pre-determined genetic growth potential during development. FGR is associated both with poor outcome in the neonatal period, and the onset of major adult diseases such as diabetes, hypertension and obesity. Therefore understanding what causes restricted fetal growth is important both for improving neonatal health, and for the minimization of major worldwide healthcare burdens. Described here are two mutant mouse lines, each with a distinct mutation in the Mediator complex gene Med31. These mutations result in reduced fetal growth, allowing for the investigation of the role of Med31 in the proper control of growth during development. The first mutant mouse line (Med31 Null) carries a C/T point mutation in exon 4 of Med31. Homozygous mutant embryos display reduced growth during development, characterized by their reduced size and smaller forelimbs compared to their heterozygous littermate controls. The second mutant mouse line (Med31 Y57C) carries a T/C point mutation in exon 3 of Med31. Similarly, homozygous mutant embryos display reduced fetal growth with reductions in forelimb length compared to their heterozygous littermate controls. In both mutant lines whole embryo growth and endochondral ossification within the limbs is perturbed. This is due to defects in cellular proliferation and the misexpression of the cell cycle genes Ccnb1 and Mtor within the mutant embryos. Additionally, the Med31 Null line is embryonic lethal by E18.5 and displays morphological defects of the placenta compared to heterozygous littermate controls. These morphological differences are suggestive of defects in the function of the placenta, and are proposed as the cause of embryonic lethality. In support of this the Med31 Y57C line is viable with no defects in placental development. New roles for Med31 in embryonic growth, cellular proliferation and placental development are identified. Moreover the two mutant lines constitue an allelic series of Med31, and the two mutations provide insights into the various ways Med31 is able to regulate transcription during development.
3

IMPLEMENTATION OF OXYFUEL COMBUSTION IN A WASTE INCINERATION CHP PLANT : A Techno-Economic Assessment

Saleh, Mostafa, Hedén Sandberg, Anton January 2021 (has links)
Global energy demand is predicted to rise in the coming decades, necessitating a shift to renewable energy sources to mitigate greenhouse gas emissions. However, due to the inability to supply renewable energy around the clock, it is estimated that only by adding an important technology, carbon capture and storage (CCS), it could be possible to reduce 80% of the 1990s greenhouse gas emissions. CCS aims to reduce anthropogenic carbon emissions by capturing CO2 from flue gases, transporting, and permanently storing or reutilizing industrially. The CCS approach includes three technologies: post-combustion capture, pre-combustion capture, and oxyfuel combustion, with the latter being the emphasis of this thesis. Based on the case study of Mälarenergi’s Refused-derived waste-fired CHP plant, this thesis investigates the viability of converting existing non-fossil fueled CHP plants to oxyfuel combustion. A thorough technical investigation based on analyzing the impact of oxyfuel combustion on system performance was conducted through system modeling using a process simulator, Aspen plus. The model in this thesis considers the development of an air separation unit (ASU), a CHP plant, and a cryogenic CO2 purification unit (CPU). All of which are validated through calibration and comparison with real-world data and similar work. To investigate the influence of employing oxyfuel combustion on the generation of both heat and electricity, two different scenarios were comprised, including recirculating flue gas before and after flue gas condensation. In addition, an analysis of the oxygen purity was conducted to assess the most optimal parameters with the least impact on system performance. Moreover, a detailed eco- nomic assessment comprising the costs of integrating oxyfuel combustion was also conducted. The findings of this thesis show that integrating waste incineration CHP plants with oxyfuel combustion for CO2 capture entails promising features under the condition of 97% oxygen purity and a flue gas recirculation system taking place after flue gas condensation. This is owing to (i) modest imposed energy penalty of approximately 8.7%, (ii) high CO2 recovery ratio, around 92.4%, (iii) total investment cost of approximately 554 M$ during a 20-year lifetime, and (iv) cost of captured CO2 of around 76 $/ton. Aside from system modeling, this thesis pre- sents an overview of the current state-of-the-art technology on the different separation and capture mechanisms. It is important to highlight that the goal of this thesis is not to provide a comprehensive review but rather to present an overall picture of the maturity of the different mechanisms. The findings point to the cryogenic separation mechanism as the most mature technology for both oxygen production and capturing of CO2 during oxyfuel combustion.
4

Risk of Fetal Growth Restriction in United States Live Births with Cleft Lip and Palate

Kulkarni, Nina January 2019 (has links)
No description available.
5

Azylová politika SRN od znovusjednocení / Asylum policy of Germany (FGR) since reunification

Rynešová, Lenka January 2011 (has links)
Germany was, is and will be an immigration country. We talk about an asylum policy since the reunification of Germany in 1990. Germany needed immigrants during the whole 21st century, on the other hand struggled with fear of their negative impacts on the economy and society. One hundred and thirty years since the recruitment of seasonal workers from abroad in the German Empire and 50 years from the recruitment of Turkish guest workers undoubtedly indicates a good (and necessary) time to create a more effective immigration and asylum policy. The integration of foreigners, especially Turks, is nowadays the main goal. As the social climate of German society has never been characterized by diversity, the main task of current German government is to create an opened German society towards foreigners and their integration.
6

The Composition and Morphology of Coal Ash Deposits Collected in an Oxy-Fuel, Pulverized Coal Reactor

Stimpson, Curtis K. 31 May 2012 (has links) (PDF)
Coal ash deposits were collected in a 160 kWth, down-fired oxy-coal reactor under staged and unstaged conditions for four different coals (PRB, Gatling, Illinois #6, and Mahoning). Concentration measurements of carbon, oxygen, sodium, magnesium, aluminum, silicon, phosphorus, sulfur, chlorine, potassium, calcium, titanium, chromium, manganese, iron, nickel, strontium, and barium were gathered from each deposit sample using scanning electron microscopy and energy dispersive spectroscopy (SEM-EDS). Backscattered electron micrographs for each deposit sample were analyzed to gather morphological data. Particle size and shape were studied for each deposit collected. The average particle sizes of the particles in upstream deposits were much larger than the average particle sizes of the downstream deposits. The downstream deposits consisted primarily of spherical particles while the upstream deposits consisted of round, irregular polygonal, and porous particles. Deposit particles are believed to have deposited at all stages of burnout; those depositing early during pyrolysis may have continued to react after deposition. Element maps for the aforementioned elements were collected with SEM-EDS and analyzed to quantify both average composition and composition of individual particles. These values were compared to ASTM ash analyses performed for each coal and ash collected from the flue gas stream with a cyclonic particle separator. It was found that sulfur concentrations of deposits do not correlate with corresponding sulfur concentrations of the coal. Comparison of similar experiments performed with air-combustion show that oxy-combustion deposits contain about twice as much sulfur as air-combustion deposits when burning the same coal. Deposition propensity of each coal was also examined, and the PRB and Gatling coals were found to have a moderately high deposition propensity whereas the deposition propensity of the Mahoning and Illinois #6 coals was fairly low.
7

Význam proteinů tepelného šoku v diagnostice a prognostice těhotenských komplikací / Heat shock proteins - - their role in diagnosis and prognosis of pregnancy related complications

Dvořáková, Lenka January 2013 (has links)
Heat shock proteins increase their gene expression after exposure of cells or organisms to some forms of stress, which may be high temperature, infection, inflammation, hypoxia, lack of nutrients and water. Stressful situations for the body are also pregnancy-related complications associated with placental insufficiency - preeclampsia and IUGR, as well as other pregnancy-related complications such as fetal growth restriction and gestational hypertension. Therefore, I examined whether the occurrence of pregnancy-related complications (preeclampsia, fetal growth retardation, gestational hypertension) affect the gene expression of heat shock proteins. Five hsp systems was detected, namely Hsp27, Hsp60, Hsp70, Hsp90 and HspBP1 in placental tissue samples and whole maternal peripheral blood. Samples came from women with physiological pregnancy and from women with certain pregnancy-related complications (PE, FGR, GH). RNA was isolated from the samples. Detection of hsp expression was performed by using real-time RT-PCR and the comparative Ct method. Changes in gene expression between the test samples and reference sample were examined. To assess the difference between physiological pregnancies and pregnancies with selected pregnancy- related complications, an analysis of variance (ANOVA) was used....
8

Point Cloud Registration in Augmented Reality using the Microsoft HoloLens

Kjellén, Kevin January 2018 (has links)
When a Time-of-Flight (ToF) depth camera is used to monitor a region of interest, it has to be mounted correctly and have information regarding its position. Manual configuration currently require managing captured 3D ToF data in a 2D environment, which limits the user and might give rise to errors due to misinterpretation of the data. This thesis investigates if a real time 3D reconstruction mesh from a Microsoft HoloLens can be used as a target for point cloud registration using the ToF data, thus configuring the camera autonomously. Three registration algorithms, Fast Global Registration (FGR), Joint Registration Multiple Point Clouds (JR-MPC) and Prerejective RANSAC, were evaluated for this purpose. It was concluded that despite using different sensors it is possible to perform accurate registration. Also, it was shown that the registration can be done accurately within a reasonable time, compared with the inherent time to perform 3D reconstruction on the Hololens. All algorithms could solve the problem, but it was concluded that FGR provided the most satisfying results, though requiring several constraints on the data.

Page generated in 0.0358 seconds