• Title/Summary/Keyword: channeling effect

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Formation of the Shallow $p^+$ -n Junction by As-Preamorphization Method and Characterization (비소 비정질화 방법에 의한 얕은 $p^+$-n 접합의 형성과 특성분석)

  • Sang Jik Kwon
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.30A no.11
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    • pp.113-121
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    • 1993
  • In the formation of the shallow p$^{+}$-n junction, the preamorphization method by As$^{+}$ ions was applied in order to avoid the boron channeling effect which is occured during the B$^{+}$ implantation especially with low energy. By As$^{+}$ pre-implant with 60KeV energy and 2*10$^{14}$ cm$^{-2}$ dose, the channelinf of B$^{+}$ ions implanted with 10keV/1.5*10$^{14}$ cm$^{-2}$ can be avoded completely. After the RTA of 1050.deg. C and 10sec, the junction depth was 0.14.mu.m, the leakage current was 20nA/cm$^{2}$(at-5V bias) and the sheet resistance was 107.OMEGA./ㅁ. And the preamorphized Si layer was changed into the perfect crystal si after the RTA.r the RTA.

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Simulation Study of ion-implanted 4H-SiC p-n Diodes (이온주입 공정을 이용한 4H-SiC p-n Diode에 관한 시뮬레이션 연구)

  • Lee, Jae-Sang;Bahng, Wook;Kim, Sang-Cheol;Kim, Nam-Kyun;Koo, Sang-Mo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.22 no.2
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    • pp.128-131
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    • 2009
  • Silicon carbide (SiC) has attracted significant attention for high frequency, high temperature and high power devices due to its superior properties such as the large band gap, high breakdown electric field, high saturation velocity and high thermal conductivity. We performed Al ion implantation processes on n-type 4H-SiC substrate using a SILVACO ATHENA numerical simulator. The ion implantation model used Monte-Carlo method. We simulated the effect of channeling by Al implantation in both 0 off-axis and 8 off-axis n-type 4H-SiC substrate. We have investigated the effect of varying the implantation energies and the corresponding doses on the distribution of Al in 4H-SiC. The controlled implantation energies were 40, 60, 80, 100 and 120 keV and the implantation doses varied from $2{\times}10^{14}$ to $1{\times}10^{15}\;cm^{-2}$. The Al ion distribution was deeper with increasing implantation energy, whereas the doping level increased with increasing dose. The effect of post-implantation annealing on the electrical properties of Al-implanted p-n junction diode were also investigated.

Determinants of Bank Credit Distribution in Supporting Regional Economic Growth in South Sulawesi Province

  • Emily Nur SAIDY;Muhammad AMRI;Sanusi FATTAH;Sri Undai NURBAYANI
    • Journal of Distribution Science
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    • v.22 no.8
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    • pp.17-27
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    • 2024
  • Economic growth is influenced by various factors, including support from the banking world in channeling funds ownedthrough bank credit which will be a stimulus from economic activities as a source of economic growth. Purpose: Thisstudy aims to analyze the determinants of bank lending in supporting regional economic growth in South Sulawesi Province. Research Design, Data, and Methodology: This study uses secondary data taken from banking data and analyzed using path analysis Data analysis is carried out using the help of SPSS statistical analysis tools. Results: Non-Performance Loan, Three Partied Fund, Inflation, Exchange Rate directly affect economic growth. For the analysis of the indirect effect of Non-performance loans and Three Partied Funds have an indirect effect on economic growth through lending while the Loan to deposit Ratio, Inflation and exchange rate do not indirectly affect economic growththrough lending. Credit disbursement has a positive and significant effect on economic growth Conclusion: Economicgrowth of a region is influenced by many factors and these factors are influences from the banking world, the results ofthis study show that economic growth is strongly influenced by bank support through lending to support the economy by considering other factors such as interest rates and currency exchange rates

Study on Detailed Air Flows in Urban Areas Using GIS Data in a Vector Format and a CFD Model (벡터 형식의 GIS 자료와 CFD 모델을 이용한 도시 지역 상세 대기 흐름 연구)

  • Kwon, A-Rum;Kim, Jae-Jin
    • Korean Journal of Remote Sensing
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    • v.30 no.6
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    • pp.755-767
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    • 2014
  • In this study, detailed air flow characteristics in an urban areas were analyzed using GIS data and a Computational Fluid Dynamics (CFD) model. For this, a building construction algorithm optimized for Geographic Information System (GIS) data with a vector format (Los Angeles region imagery acquisition consortium 2 geographic information system, LARIAC2 GIS) was used. In the LARIAC2 GIS data, building vertices were expressed as latitude and longitude. Using the model buildings constructed by the algorithm as the surface boundary data in the CFD model, we performed numerical simulations for two building-congested areas in Los Angeles using inflow information provided by California Air Resources Board. Comparing with the inflow, there was a marked difference in wind speed and direction within the target areas, which was mainly caused by the secondarily induced local circulations such as street-canyon vortices, horse-shoe vortices, and recirculation zones. In street canyons parallel to the inflow direction, wind speed increased due to a channeling effect and, in street canyons perpendicular to the inflow direction, vertically well developed vortices were induced. In front of a building, a horse-shoe vortex was developed near the surface and, behind a building, a recirculation zone was developed. Near the surface in the areas where the secondarily induced local circulations, wind speed remarkably increased. Overall, wind direction little (largely) changed at the areas where wind speed largely increased (decreased).

Effects of an Apartment Complex on Flow and Dispersion in an Urban Area (도시 지역에서 아파트 단지가 흐름과 확산에 미치는 영향)

  • Lee, Young-Su;Kim, Jae-Jin
    • Atmosphere
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    • v.21 no.1
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    • pp.95-108
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    • 2011
  • The effects of an apartment complex on flow and pollutant dispersion in an urban area are numerically investigated using a computational fluid dynamics (CFD) model. The CFD model is based on the Reynolds-averaged Navier-Stokes equations and includes the renormalization group k-${\varepsilon}$ turbulence model. The geographic information system (GIS) data is used as an input data of the CFD model. Eight numerical simulations are carried out for different inflow directions and, for each inflow direction, the effects of an apartment complex are investigated, comparing the characteristics of flow and dispersion before and after construction of the apartment complex in detail. The observation data of automatic weather system (AWS) is analyzed. The windrose analysis shows that the wind speed and direction after the construction of the complex are quite different from those before the construction. The construction of the apartment complex resulted in the decrease in wind speed at the downwind region. It is also shown that the wind speed increased partially inside the apartment complex due to the channeling effect to satisfy the mass continuity. On the whole, the wind speed decreased at the downwind region due to the drag effect by the apartment complex. As a result, the passive pollutant concentration increased (decreased) near the downwind region of (within) the apartment complex compared with that before the construction.

Channeling of Intermediates Derived from Medium-Chain Fatty Acids and De novo-SYnthesized Fatty Acids to Polyhydroxyalkanoic Acid by 2-Bromooctanoic Acid in Pseudomonas fluorescens BM07

  • LEE, HO-JOO;RHO, JONG-KOOK;KAMBIZ AKBARI NOGHABI,;LEE, SEUNG-EUN;CHOI, MUN-HWAN;YOON, SUNG-CHUL
    • Journal of Microbiology and Biotechnology
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    • v.14 no.6
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    • pp.1256-1266
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    • 2004
  • 2-Bromooctanoic acid (2-BrOA) is known to block the formation of polyhydroxyalkanoic acid (PHA) in Pseudomonasfluorescens BM07 without any influence on the cell growth when grown on fructose, but it inhibits the cell growth when grown on octanoate (OA) (Lee et al., Appl. Environ. Microbiol. 67: 4963- 4974, 2001). We investigated the role of 2-BrOA in the PHA synthesis of the bacterium grown with mixtures of fructose and fatty acids. OA, 11­phenoxyundecanoic acid (1 1-POU), and 5-phenylvaleric acid (5-PV) were selected as model substrates. When supplemented with 50 mM fructose, all these carboxylic acids suppressed the formation of PHA from fructose, however, the ~-oxidation coenzyme A monomers derived from the carboxylic acids were efficiently polymerized, but the conversion yield [(mol of carboxylate substrate converted into PHA)/(mol of carboxylate substrate in the feed)] was low (e.g., maximally $\~53\%$ for 5 mM 11-POU). Addition of 2-BrOA (up to 5 mM) to the mixed carbon sources raised the conversion yield sensitively and effectively only at low levels of the acid substrates (e.g., 2 mM 1 1-POU or 5 mM OA): For instance, $100\%$ of 2 mM ll-POU were converted into PHA in the presence of 5 mM 2-BrOA, whereas only $\~10\%$ of the 1 1-POU were converted in the absence of 2-BrOA. However, at highly saturated suppressing levels (e.g., 5 mM ll-POU), 2-BrOA inhibitor showed no significant additional effect on the conversion ($60- 70\%$ conversion irrespective of 2-BrOA level). The existence of competitive and compensative relationship between 2­BrOA and all the carboxylic acid substrates used may indicate 'Present address: Section on Brain Physiology and Metabolism, Bldg. 10, Rm. 6N202, National Institute on Agmg, National Institute of Health, Bethesda, MD 20892, U.S.A. that all the acid substrate-derived inhibiting species bind to the same site as the 2-BrOA inhibiting species does. We, therefore, suggest that 2-BrOA can be used for efficiently increasing the yield of conversion of expensive substituted fatty acids into PHA and then substituted 3-hydroxyacids by hydrolyzing it.

Foreign Remittances, Banking Sector Development and Private Sector Investment

  • GITHAIGA, Peter Nderitu
    • Asian Journal of Business Environment
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    • v.10 no.1
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    • pp.7-18
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    • 2020
  • Purpose- This study seeks to investigate the impact of foreign remittances on private sector investment and the moderating role of banking sector development in Sub-Saharan African Countries. Research design, data, and methodology-The study has used a sample of 15 Sub-Saharan African countries and data for the years 1986 - 2017. Data was obtained from the World Bank Development Indicator (WDI) Database. Panel data diagnostic tests were conducted to ascertain the suitability of the data for regression analysis. The data was analyzed through descriptive and inferential statistics, while the hypothesis was tested through hierarchical regression analysis. Results- The finding of this study indicates that foreign remittances and banking sector development had a significant and positive effect on private investment in Sub-Saharan Africa. Besides, the banking sector development significantly moderated the foreign remittances and private sector investment relationship. Conclusions- Based on the results, the study concludes that banking sector development has an important influence on foreign remittances and private sector investment nexus. Due to the antagonistic interaction between foreign remittance and banking sector development, the study recommends the use of alternative ways of channeling remittances to private investment such as; issuance of diaspora bonds and appeal for direct investment by citizens living abroad.

Numerical method study of how buildings affect the flow characteristics of an urban canopy

  • Zhang, Ning;Jiang, Weimei;Hu, Fei
    • Wind and Structures
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    • v.7 no.3
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    • pp.159-172
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    • 2004
  • The study of how buildings affect wind flow is an important part of the research being conducted on urban climate and urban air quality. NJU-UCFM, a standard $k-{\varepsilon}$ turbulence closure model, is presented and is used to simulate how the following affect wind flow characteristics: (1) an isolated building, (2) urban canyons, (3) an irregular shaped building cluster, and (4) a real urban neighborhood. The numerical results are compared with previous researchers' results and with wind tunnel experiment results. It is demonstrated that the geometries and the distribution of urban buildings affect airflow greatly, and some examples of this include a changing of the vortices behind buildings and a "channeling effect". Although the mean air flows are well simulated by the standard $k-{\varepsilon}$ models, it is important to pay attention to certain discrepancies when results from the standard $k-{\varepsilon}$ models are used in design or policy decisions: The standard $k-{\varepsilon}$ model may overestimate the turbulence energy near the frontal side of buildings, may underestimate the range of high turbulence energy in urban areas, and may omit some important information (such as the reverse air flows above the building roofs). In ideal inflow conditions, the effects of the heights of buildings may be underestimated, when compared with field observations.

Hydrophobicity and Nanotribological Properties of Silicon Channels coated by Diamond-like Carbon Films

  • Pham, Duc Cuong;Na, Kyung-Hwan;Pham, Van Hung;Yoon, Eui-Sung
    • KSTLE International Journal
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    • v.10 no.1_2
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    • pp.1-5
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    • 2009
  • This paper reports an investigation on nanotribological properties of silicon nanochannels coated by a diamond-like carbon (DLC) film. The nanochannels were fabricated on Si (100) wafers by using photolithography and reactive ion etching (RIE) techniques. The channeled surfaces (Si channels) were then further modified by coating thin DLC film. Water contact angle of the modified and unmodified Si surfaces was examined by an anglemeter using the sessile-drop method. Nanotribological properties, namely friction and adhesion forces, of the Si channels coated with DLC (DLC-coated Si channels) were investigated in comparison with those of the flat Si, DLC-coated flat Si (flat DLC), and Si channels, using an atomic force microscope (AFM). Results showed that the DLC-coated Si channels greatly increased hydrophobicity of silicon surfaces. The DLC coating and Si channels themselves individually reduced adhesion and friction forces of the flat Si. Further, the DLC-coated Si channels exhibited the lowest values of these forces, owing to the combined effect of reduced contact area through the channeling and low surface energy of the DLC. This combined modification could prove a promising method for tribological applications at small scales.

Internal Company Factors as Determining Variables for Improving Bank Lending

  • PRAWITASARI, Dian;KADARNINGSIH, Ana;MACHMUDDAH, Zaky;UD-DIN, Maaz
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.8
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    • pp.205-212
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    • 2020
  • This study seeks to examine the main factors, external and internal to the bank, that enhance bank lending. Bank lending is one of the connecting bridges in sustaining society. Internal factors consist of ROA, DPK, and CAR. External factors are economic growth and interest rate of Bank Indonesia. The population of this research consists of traditional commercial banks listed on the IDX over the 2014-2017 period. Samples were chosen by purposive sampling method. This study uses secondary data with 56 samples; data analysis uses multiple linear regression. The findings of the study show that internal factors have a greater impact on increasing bank lending than external factors. The main variable among internal factors that influences increase in bank lending is ROA. DPK is the internal factor with the smallest impact on increasing bank lending. The implication of the study is that determining the bank lending should take more account of CAR, DPK, ROA, BI interest rates, and economic growth in making decisions about the amount of lending. These variables can only have a slight effect on increasing lending, though. Besides, internal factors such as NPL, LDR or non-economic factors also need to be considered in channeling bank credit.