Abstract Permeable reactive barrier technology is a cost effective means of treating near surface groundwater contaminant plumes. However, current reactive barrier technology lacks the capacity to manipulate flow rates and thus hydraulic retention time (HRT) within the barriers in order to maximize the effectiveness and longevity of the media. This study examines the effectiveness of tile drains as passive controls on the flow rate of ground-water through an existing wood particle media permeable reactive barrier treating agricultural nitrate. The use of upgradient and downgradient tile drains allowed HRT to be increased from 4.5 to 10 days in one trial and then to be decreased from 11.1 to 0.8 days in a second trial. Influent groundwater NO3-N concentrations of ~100 mg/L were attenuated to detection limit (0.02 mg/L) only 12% of the 4 m long barrier with HRTs of 4.5 to 10 days. During the second trial, HRT was decreased to 0.8 days and NO3-N penetrated to the downgradient edge of the PRB at 1.8 mg/L. The behaviour of SO4 in the PRB was also affected by flow rate. SO4 entered the PRB at 60 to 71 mg/L during the first trial. Under a HRT of 10 days it was depleted to detection limit after traveling through only 13% of the barrier. When HRT was decreased to 4.5 days, SO4 was able to penetrate the downgradient edge of the PRB at concentrations from 4 to 6 mg/L. With a 0.8 day HRT SO4 reduction was highly restricted as calculations showed 90% of available carbon in the PRB was being used to reduce NO3-N, compared to 7.5% being used for SO4 reduction at that time. In comparison, at the 10 day HRT, 61% of carbon being used for NO3-N reduction, 8.7% for SO4 reduction, 0.7 for dissolved oxygen and 29% was lost through DOC leaching. These calculations suggest that barrier efficiency can be greatly enhanced by manipulation of HRT through use of tile drains.

In this thesis, a novel fully self-aligned bulk-Si device named dual-channel source/drain-tied (DC-SDT) MOSFET with extremely thin (ET) body is proposed. The process utilizes the multiple epitaxial growths of SiGe/Si layers, so the starting material is bulk-Si wafer instead of the SOI wafer. We have investigated the RF/analog performance, and the high temperature induced device stability degradation has also been also investigated. Moreover, we have compared this structure with the other similar transistors such as: body-tied MOSFET (DC-BT MOSFET) and conventional dual-channel MOSFET (DC-SOI MOSFET). Based on the simulation results, for the DC-BT MOSFET, our proposed DC-SDT MOSFET has improved the device performances such as: Ioff decreased 47.6%, switching speed increased 18.1%, S.S. improved 13%, and voltage gain increased 25%. Whereas for the DC-SOI MOSFET, our proposed DC-SDT MOSFET has also improved the device performances such as: Ion increased 11.3%, reduction of lattice temperature 35.7% and 35.5 in the top and bottom channels, voltage gain increased 15%. We not only compared with the above two similar transistors, but also compared to the other mainstream devices, such as: FinFET and Gate-all-around. After the comparisons, we confirm that the proposed DC-SDT MOSFET has better ON-state current and short-channel behaviors. For the scaling, DC-SDT MOSFET can truly become one of the strong candidates.

In this thesis, we carefully investigate the electrical characteristics of junctionless vertical MOSFET (JLVMOS) compared with the junctionless planar MOSFET (JLPMOS) and conversional junction vertical MOSFET (JVMOS). Also, we examine the advantages of the double-gate structure and the short-channel behavior of the junctionless transistors. According to the 2D simulation studies, the proposed JLVMOS can achieve better short-channel characteristics (JLVMOS: 62.04 mV/dec S.S., 23.96 mV/V DIBL; JLPMOS: 77.67 mV/dec S.S., 146.07 mV/V DIBL) as compared with the planar transistor, chiefly owing to the double-gate scheme. This proves that only the double-gate device has better gate controllability over the channel region to reduce the short-channel effect. More importantly is that the JLVMOS has a bulk Si starting material, in which the SOI-induced self-heating effects and the fabrication cost can be well suppressed and reduced, respectively. In comparison with the JVMOS, our proposed JLVMOS exhibits better S.S. and reduced DIBL. Furthermore, although the analog/RF properties of the JLVMOS are somewhat degraded, due to its simple fabrication process, our proposed JLVMOS can become one of the mainstream technology for future CMOS applications.

The purpose of this study is to assess the dewatering requirements of planned open pit nickel mining at &Ccedil / aldag Site in Western Turkey. Dewatering is required for safe and efficient working conditions and pit wall stability. With this scope, a groundwater model of the study area is developed and used to predict the dewatering rate. The methodology mainly involves data collection, site hydrogeologic characterization and development of conceptual model, followed by construction and use of a groundwater model to predict the dewatering requirements of the mine site. The groundwater flow modeling is carried out using MODFLOW software and the dewatering simulations are carried out using MODFLOW Drain package. The drain cell configuration is determined by pit boundaries and invert elevations of drains corresponded to the bench elevations that will be achieved with respect to the mining schedule. In the transient model runs, monthly time steps were used. Using the outflow from in-pit drain cells, the v monthly dewatering rates are calculated. In order to assess the impacts of the hydraulic conductivity of the laterite on the pit inflow rates, simulations were carried out for different values of hydraulic conductivity of laterites. The predicted flow rate using the calibrated model is 107.54 L/s. A tenfold reduction in the hydraulic conductivity of laterite resulted in three fourths of decrease in the flow rate (24.42 L/s). Consequently, a wide range of flow rates for different hydraulic conductivity values of laterite was calculated. In order to confirm the hydraulic conductivity of laterites in the area, and to obtain a realistic dewatering rate, further pumping tests are needed.

This thesis is mainly proposed and discussed the characteristics of polycrystalline silicon thin film transistor putting forward and probing into four kinds of novel buried-oxide structures. Because of the shortcoming of the traditional polycrystalline silicon thin film transistor, like leakage current (On/Off state current), subthreshold swing, floating body effect (kink effect), self-heating effect, and short channel effect etc.. Thus, we propose and fabricate four kinds of novel structural polycrystalline silicon thin film transistors that are involved in the following, indicating to improve the critical issues of polycrystalline silicon thin film transistor mentioned above. 1. We propose and fabricate the multiple/dual trenched-body polycrystalline silicon thin film transistor. This proposed structure is demonstrated to obviously suppress the off-state leakage up to 70% reduction, comparing with the conventional device. Also, we survey the reliability of this proposed device included temperature and DC hot-carrier stress effects. We found that the trenched-body TFTs perform more rapid degradation than the conventional TFT does after the temperature and stress durations, but their electrical characteristics are still superior to the conventional counterparts. Importantly, we demonstrate that this proposed device have a dramatic potential to be a novel capacitorless 1T-DRAM, because of its large floating-body-charge storages. As the experiment, the large threshold voltage shift is examined apparently after a certain write and erase operations, leading to a manifest programming window. 2. We propose and fabricate the block-oxide polycrystalline silicon thin film transistor. This proposed structure can not only improve the leakage issue of conventional device seriously, but also avoid fluctuating threshold voltage attributed from the ultra-thin film effect. 3. We propose and fabricate the floating-body contact polycrystalline silicon thin film transistor. This structure is modified by the conventional contact window in order to effectively improve the kink effect, utilizing the bottom gate polycrystalline silicon thin film transistor. 4. Finally, we propose and simulate the non-continuous buried layer polycrystalline silicon thin film transistor. This structure built upon the field oxidation layer can effectively improve the self-heating effect and kink effect. Furthermore, this structure is simple to fabricate, practical, and completely compatible on CMOS technology.

„Protų nutekėjimo“ samprata apima ne tik fizinį aukštos kvalifikacijos asmenų išvykimą iš vienos šalies į kitą, bet ir perėjimą iš vienos organizacijos ar padalinio į kitą, bet kokį kitą vieno ekonominio subjekto įgūdžių ir žinių, reikalingų ekonominiam augimui ir vystimuisi, netekimą kito ekonominio subjekto naudai. „Protų nutekėjimas“ atsiranda veikiant aukštos kvalifikacijos specialistų, mokslininkų, studentų migracijos traukos ir stūmos faktoriams. Išskiriami trys protų nutekėjimo priežasčių lygiai: individo, organizacijos ir valstybės. “Protų nutekėjimą” patiria visos pasaulio šalys, tik skiriasi šio reiškinio mastai ir charakteristikos. Ekonomiškai išsivysčiusiose šalyse „protų nutekėjimo“ problematikai skiriama daugiau dėmesio, ja domėtis ir tyrinėti pradėta anksčiau nei pereinamosios ekonomikos šalyse. Tai patvirtina išsamesnė ir tikslesnė statistika, pateikiama įvairiuose šaltiniuose, bei atskirų tyrimų gausa. Lietuvoje šis reiškinys yra mažai nagrinėtas. „Protų nutekėjimo“ iš Lietuvos apimtį sunku įvertinti dėl statistinių duomenų ir išsamių sociologinių tyrimų stokos. Darbe akcentuojama, kad aukščiausios kvalifikacijos Lietuvos specialistų emigracija gali turėti neigiamas ekonomines, socialines, kultūrines ir net politines pasekmes šalies raidai. Šiame darbe išskirtos kelios protų nutekėjimo“ fenomenui „jautrios“ Lietuvos visuomenės grupės. Nagrinėjamos verslo, akademinio jaunimo, mokslininkų ir kitų aukštos kvalifikacijos specialistų, valstybės... [toliau žr. visą tekstą] / The concept of brain drain includes not only a physical emigration of highly qualified persons from one country to another but also a transfer from one department of an organization to another, as well as any other loss of skills and knowledge of one economic unit necessary for economic growth and development in favour of another economic unit. Brain drain occurs as a result of the factors of attraction and repulsion of migration of qualified specialists, scientists and students. Three levels of the reasons for brain drain can be distinguished: individual, organization, and state. Brain drain occurs in all countries of the world with a varying extent and character. In the economically developed countries more attention is given to the problem of brain drain. It has become an object of interest and research in these countries much earlier than in the economies of transition. This can be proven by a more extensive and accurate statistics provided in different sources, as well as the abundance of different research. In Lithuania little analysis has been made on this phenomenon. It is difficult to determine the extent of brain drain from Lithuania due to the lack of statistical data and sociological research. The thesis underlines that the emigration of highly educated specialists from Lithuania may have negative economic, social, cultural and even political effects on the development of the country. Several social groups of Lithuania sensitive to the phenomenon of emigration... [to full text]

Magistro baigiamojo darbo tema yra aktuali tiriant Lietuvos gyventojų migracijos procesus. Lyginant su kitais demografiniais reiškiniais, emigracija įgyja vis didesnę reikšmę pastaraisiais dešimtmečiais. Globalizacija skatindama emigraciją leidžia žmonėms visame pasaulyje ieškoti geresnių darbo sąlygų, didesnio darbo užmokesčio, realizuoti savo idėjas ir galimybes, bet tai teigiamas globalios darbo rinkos aspektas, netinkantis atskiroms valstybėms. Emigracijos problematika Lietuvai ypač aktuali, nes dideli emigracijos mastai turi nemažai įtakos Lietuvos gyventojų skaičiaus mažėjimui, o netiesiogiai - kitiems demografiniams bei socialiniams, ekonominiams procesams. Tokia emigracija Lietuvoje jau laikytina viena rimčiausių grėsmių šalies demografinei raidai, ūkio augimui ir kultūrinio savitumo išsaugojimui. Magistro baigiamajame darbe buvo naudojamasi moksline literatūra, statistiniais duomenimis, atliktų tyrimų rezultatais, oficialiais pranešimais, publikacijomis bei analitiniais straipsniais, kuriuose apibūdinami gyventojų migracijos procesai, jų pasireiškimo formos, pateikti emigracijos iš Lietuvos mastai po nepriklausomybės atkūrimo 1990 m. bei įstojimo į Europos Sąjungą. Įvardinti veiksniai, įtakojantys migracijos mobilumą bei nustatytos emigracijos iš Lietuvos pasekmės šaliai. Mokslinės literatūros analizė leidžia teigti, kad emigracijos priežasčių nustatymas, paprastai yra viena sudėtingiausių visų migracijų problemų todėl, kad dažnai priežastys supainiojamos su tikslu... [toliau žr. visą tekstą] / Master's thesis topic is relevant to the investigation of migration processes in the Lithuanian population. Compared to other demographic phenomena, emigration is becoming increasingly important in recent decades. Globalization allows people to promote the emigration of the world to seek better working conditions, higher wages, to realize their ideas and opportunities, but this is a positive aspect of the global labor market, unsuitable for individual countries. Emigration problem is particularly urgent in Lithuania. Large scale emigration has affected a number of Lithuanian population declines. Also indirectly it affected other demographic and social, economical processes. This emigration is regarded as one of Lithuania the most serious threats to the country's demographic development, economic growth and the preservation of cultural identity. In this Master's thesis was used in the scientific literature, statistical data, results of research conducted, official reports, publications and analytical articles, which describes the population of migratory processes in the form of their expression, the magnitude of emigration from Lithuania after regaining independence in 1990 and accession to the European Union. The factors that effect migration mobility and causes of migration from Lithuania were identified. The scientific literature suggests that the causes of emigration, is usually one of the most difficult problems to identify in migration. This is due to reasons that are... [to full text]

This dissertation explores how migration responds to economic conditions, particularly differences in responsiveness for various segments of the population. After a brief introduction and motivation of my work in Chapter One, Chapter Two estimates the responsiveness of households’ interstate migration to origin state labor market conditions and surrounding state labor market conditions. Each percentage point increase in origin state unemployment insurance claims leads to a 3.2 percent increase in household’s propensity to migrate interstate and each percentage point increase in the unemployment insurance claims rate of surrounding states reduces interstate migration propensity by 5.2 percent. I then examine how this responsiveness varies by demographics and how it has changed over time. I determine that the responsiveness of migration to labor market conditions is weaker for several groups at high poverty risk, including less educated, non-employed and rural households and households with children present. I also show that between the early 1980s and mid 1990s labor market conditions became a smaller factor in household migration decisions, but since then labor market conditions have gained in importance. While Chapter Two examines short-run migration responsiveness, Chapter Three explores the size of the long-run outflow (or inflow) of skilled labor occurring in local areas in response to economic conditions, amenities and other area characteristics. I estimate the extent of this brain gain and brain drain within localities in the United States between the early 1990s and late 2000s, describing both absolute changes (percentage growth in the stock of educated individuals) and relative changes (growth in the share of educated individuals). For each of three measures of brain gain estimated, I show substantially more positive flows of educated individuals towards local areas with strong initial economic conditions. I also show that non-metropolitan areas are more likely to experience all three measures of brain drain. I present evidence that nonmetropolitan areas’ inability to attract and retain educated individuals stems primarily from labor market disparities including the urban-rural wage differential.

In Canada, the non-recognition of foreign credentials remains a considerable policy issue as well as a challenge for skilled immigrants. Many studies have shed light on the difficulties that foreign professionals face when seeking a placement in the Canadian job market. This thesis focused on the experiences of professional women from Morocco on the basis of the premise that every racialized group’s immigration experience deserves a space in the literature to voice their realities and inspire policy considerations. As a result, this study focused on examining the experiences of Moroccan women in the Canadian job market and the impact thereof, on their socio-economic status, and as such, health and well-being. In order to effectively capture the experiences of this particular community, a fieldwork study was conducted in the form of semi-structured individual interviews with twelve women who immigrated to Canada from Morocco with professional qualifications. Based on the participants’ accounts, I described that systemic discrimination as manifested in Othering and racialization remain major obstacles to the realization of equal access in the Canadian labour market. All in all, this research provides valuable insight into the plight of skilled immigrants in Canada and thus, offers strong policy recommendations to facilitate a more effective integration process for this group into the Canadian Job market.

This thesis predominantly seeks to explore the entanglements of class, patriarchy and global capital embedded within North Indian domestic work. The thesis firstly examines how the neoliberal policies of the 1980s and 90s shattered village economies and brought about the mass displacement of tribals and landless farmers, forced to leave the land they have cultivated for generations in pursuit of employment in India’s urban centers. While male migrants often find work in the informal sector and settle in slum communities, female rural migrants constitute the immense population of domestic workers within the confines of urban middle class homes. This thesis explores the histories, past and present, of Indian cultures of servitude that have brought migrant motherhood to a crisis point. The interdisciplinary analyses of the political economy of intimate labor are supplemented by a micro-level analysis of my own positionality within a middle class urban home in Jaipur, Rajasthan to bring an alternative perspective to the multiplicity of dialogues about ethical relationships with domestic workers. This thesis ultimately aims to open lines of inquiry about the inequalities embedded within domestic work in order to bring about a radical re-imagining of one’s own participation in the layers and chains of exploitative labor.