ADVANCED HYBRID SOLAR CELL DESIGN

Interdigitated back surface contact (IBC) and copper indium gallium diselenide (CIGS) solar cells have been explored by multiple former Naval Postgraduate School (NPS) students with mutual independence. This thesis marries IBC and CIGS into a single cell to explore its optical parameters before introducing a novel cell design to reduce recombination in the absorber by establishing a vertical electric field. Implementing the novel design established up to a 7.5kV/cm electric field in the absorber to promote the separation of charge carriers, resulting in significant increases in short circuit current and I-V curve knee extension to raise cell efficiency to 24.32% at 300 K. Comparing this cell to optimal designs of prior theses, our cell boasts a 79.45% reduction in cell thickness and relative efficiency increase of 5.74%. Modeling of this cell demonstrates its potential for use in low weight, high power equipment such as UAVs, satellites, and solar blankets used by warfighters.Lieutenant, United States NavyApproved for public release. Distribution is unlimited

An Analysis of Expenditure Patterns of Weating Apparel of University of North Dakota Students

This thesis analyzes the expenditures of University of North Da.kota. students on wearing apparel in Grand Forks. The period for which the study was conducted extended from November 1, 1969 to February 1, 1970. The data, used in this thesis were obtained from 100 personal interviews with students attending the University. A structured questionnaire was used to gather the information. Two sta.tistica.l techniques, the multiple linear correlation and the t-test, were used to analyze the data.. Eight factors were selected that would possibly influence the expenditure patterns of U.N.D. students on wearing apparel. The four factors that were continuous by nature were the respondent\u27s monthly income, the age of the respondent, the respondent\u27s parents\u27 yea.rly income if single or the respondent\u27s yearly income if married, and income spent on wearing apparel in cities other than Grand Forks. These four factors had no significance on the expenditure patterns of U.N.D. students on wearing apparel. The four factors that were discrete by nature were sex, marital status, place of residence, and campus fraternity affiliation. Female students did spend significantly more on wearing apparel | than did male students. Students that were members of a. campus fraternity did spend significantly more on wearing apparel than did students that were not members. There was no significant difference in the dollar expenditures on wearing apparel for students that were either married or single or for students that were either living on campus or off campus

Serological evidence for human cystic echinococcosis in Slovenia

<p>Abstract</p> <p>Background</p> <p>Cystic echinococcosis (CE) is caused by the larva of tapeworm <it>Echinococcus granulosus</it>. Dogs and other canids are the primary definitive hosts for this parasite. CE may develop after accidental ingestion of tapeworm eggs, excreted with the feces of these animals. In the intestine, the larvae released from the eggs are nested in the liver, lungs or other organs of livestock as intermediate hosts and humans as aberrant hosts. The aim of this study was to examine serologically whether some of the patients in Slovenia, suspected of CE by imaging findings in the liver or lungs had been infected with the larva of <it>Echinococcus granulosus</it>.</p> <p>Methods</p> <p>Between January 1, 2002 and the end of December 2006, 1323 patients suspected of having echinococcosis were screened serologically by indirect haemagglutination assay (IHA). For confirmation and differentiation of <it>Echinococcus </it>spp. infection, the sera of IHA-positive patients were then retested by western blot (WB).</p> <p>Results</p> <p>Out of 127 IHA-positive sera, 34 sera were confirmed by WB and considered specific for CE. Of 34 sera of CE-positive patients sera, 32 corresponded to the characteristic imaging findings of a liver cysts and 2 to those of lung cysts. The mean age of CE-positive patients was 58.3 years. No significant differences were found between the CE-positive patients in regard to their sex.</p> <p>Conclusion</p> <p>In the study, it was found out that CE was mostly spread in the same area of Slovenia as in the past, but its prevalence decreased from 4.8 per 10⁵inhabitants in the period 1956–1968 to 1.7 per 10⁵inhabitants in the period 2002–2006. In spite of the decreased prevalence of CE in the last years, it is suggested that clinicians and public health authorities, especially in the eastern parts of Slovenia where the most CE patients come from, should pay greater attention to this disease in the future.</p

Modifikacija strukture smektita sumpornom kiselinom i karakteristike modifikovanih smektita

Bentonite samples from Petrovac and Aleksinac were treated with sulfuric acid of different molarities. Differences in structure and texture of the initial and modified bentonite were determined by chemical analysis and Xraypowder diffraction (XRPD), infra-red spectroscopy (FTIR), scanning electron microscopy (SEM) and physisorption nitrogen at -196°C. Sulfuric acid caused an exchange of Al3+, Fe3+ and Mg2+ with H+ ions which led to a modification of the smectite crystalline structure. The Mg and Fe substitution in the octahedral sheet promoted the dispersion of those layers and forming of amorphous silicon. The sequence according to which the cations left the octahedral sheets was as follows: Mg2+>Fe3+>Al3+. The sulfuric acid activated bentonites exhibiting a lower cation exchange capacity (CEC) and a change of specific surface area (SBET) from 6 to 387 for bentonite from Petrovac and from 44 to 1784 m2 g-1 for bentonite from Aleksinac, positioning them as an excellent absorber in wine technology and in the protection of soil and environment.Uzorci bentonita iz Petrovca i Aleksinca tretirani su različitim molaritetima sumporne kiseline. Promene u strukturi i teksturi polaznih i modifikovanih bentonita utvrđene su hemijskom i analizom rendgenske difrakcije praha X-zraka (XRPD), infra crvenom spektroskopijom (FTIR), skening elektronskom mikroskopijom (SEM) i fizisorpcijom azota na -196°C. Dejstvo H2SO4 kiseline izazvalo je zamenu Al3+, Fe3+ i Mg2+ sa H+ jonima što je dovelo do modifikacije kristalne strukture smektita. Supstitucija Mg i Fe u oktaedarskom listu smektita promovisala je raspuštanje tih slojeva i formiranje silikatne faze. Redosled kojim su ovi katjoni napuštali oktaedarske listove bio je sledeći: Mg2+>Fe3+>Al3+. Sumpornom kiselinom aktivirani bentoniti pokazali su niži kapacitet katjonske izmene (CEC) i promenu specifične površine (SBET), od 6 na 387 kod bentonita Petrovca i od 44 na 1784 m2 g-1 kod bentonita Aleksinca, što ih svrstava u odlične absorbente u tehnologiji vina, zaštiti zemljišta i životne sredine

Preparation of basalt-based glass ceramics

Local and conventional raw materials-massive basalt from the Vrelo locality on Kopaonik mountain-have been used as starting materials to test their suitability for the production of glass-ceramics. Crystallization phenomena of glasses of the fused basalt rocks were studied by X-ray phase analysis. optical microscopy and other techniques. Various heat treatments were used, and their influences. on controlling the microstructures and properties of the products were studied with the aim of developing high strength glass-ceramic materials. Diopside CaMg(SiO3)(2) and hypersthene ((Mg,Fe)SiO3) were identifies as the crystalline phases. The final products contained considerable amounts of a glassy phase. The crystalline size was in range of 8-480 mum with plate or needle shape. Microhardness, crashing strength and wears resistence of the glass-ceramics ranged from 6.5-7.5, from 2000-6300 kg/cm(2) and from 0.1-0.2 g/cm, respectively

Enhancing oxygen evolution functionality through anodization and nitridation of compositionally complex alloy

Compositionally complex materials (CCMs) have recently attracted great interest in electrocatalytic applications. To date, very few materials were systematically developed and tested due to the highly difficult preparation of high-surface-area CCMs. In this work, a surface of a compositionally complex FeCoNiCuZn alloy (CCA) was nitridated with subsequent anodization leading to morphological and compositional modifications. Notably, the electrochemical surface area and surface roughness as well as the electrocatalytic activity of the anodized material exhibit significant enhancement. Oxygen evolution reaction (OER) activity by the anodized CCN (CCN–AO) proceeds with remarkably small overpotential (233 mV) at 10 mA cm−2 in 1 M KOH. Experimental characterization indicates that the oxidation state of Co plays a critical role in the Fe–Co–Ni electrocatalyst. The developed approach and design strategy open up immense prospects in the preparation of a new, affordable, scalable and effective type of complex and high-performance electrocatalytic electrodes with tunable properties

Mineralogical Transformations in Copper Concentrate Roasting in Fluo-Solid Reactor

This work presents the results of investigation process of copper concentrate roasting in fluo-solid reactor with the aim of studying a transformation degree of primary ore minerals under various technological parameters. Input material (charge) and roasting products (calcine) were investigated by x-ray diffraction, ore microscopy and chemical analysis. The investigation results have shown that reaction of mineral transformation are not completed, i.e. they are developed only partially (12 - 22%) what is a consequence of insufficient long heating, unsuitable temperature or unfilled other parameters as well as non-uniform grain size

Four-color flow cytometric analysis of peripheral blood donor cell chimerism

Passenger leukocytes have been demonstrated to play significant roles in initiating and also regulating immune reactions after organ transplantation. Reliable techniques to detect donor leukocytes in recipients after organ transplantation are essential to analyze the role, function, and behavior of these leukocytes. In this report we describe a simple, reliable method to detect donor cells with low frequencies using peripheral blood samples. Detection of small numbers of major histocompatibility complex (MHC) mismatched cells was first studied using four-color flow cytometry in artificially created cell mixtures. By selecting the CD45+ population and simultaneous staining with several leukocyte lineage markers (CD3, CD4, CD8, CD56, and CD19), MHC-mismatched leukocytes were consistently detected in cell suspensions prepared from directly stained whole blood samples with a threshold sensitivity as low as 0.1%-0.2%. When the fresh peripheral blood mononuclear cells were separated by conventional Ficoll gradient purification, similar, but slightly lower levels of donor cells were detected. Blood samples obtained 1-5 months after liver, kidney, and intestine transplants revealed that the kind of organ allograft influenced levels and lineage pattern of the circulating donor cells. This procedure provided a simple and reliable method in determining early chimerism in transplant recipients. However, the detection of MHC-mismatched leukocytes of all lineages was much lower when frozen peripheral blood mononuclear cells were used. © American Society for Histocompatibility and Immunogenetics, 2003. Published by Elsevier Inc