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Development of (Nb,Ta)3Sn multifilamentary superconductor wire for high current applications

Rodrigues Jr.,Durval; Machado,João Paulo Barros
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2000 EN
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The optimization of the energy generated by a MagnetoHydroDynamic (MHD) channel using a superconducting magnet demands the optimization of the magnetic field of the system and of the critical points on the magnet winding. This work must include the development of a high performance superconductor wire suitable for this system. Aiming to the construction of improved performance MHD channel, it was developed a low cost superconductor wire, with the required characteristics. The wire was made using a technology compatible with the assembling steps and heat treatment conditions of the MHD superconducting magnets fabrication. It was used the internal Sn method in Nb-7.5wt%Ta tube to fabricate a 271-filament wire with a diameter of 0.81 mm and a Cu/nonCu ratio of 2.3. The wire was heat treated at 200 °C to diffuse the Sn into the Cu shell, producing bronze, followed by the final reaction at temperatures ranging from 670 °C to 730 °C during 25 to 150 h, to produce (Nb,Ta)3Sn. The superconducting wire characterization was made measuring the critical current Ic versus the applied magnetic field in the range of 5 to 20 T, the critical temperature Tc and the residual resistivity ratio (RRR). The wire transported critical currents above those available in commercial superconducting wires. These values of Ic are higher than the expected values for the optimization of the MHD channel.

Native Polycystin 2 Functions as a Plasma Membrane Ca2+-Permeable Cation Channel in Renal Epithelia

Luo, Ying; Vassilev, Peter M.; Li, Xiaogang; Kawanabe, Yoshifumi; Zhou, Jing
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /04/2003 EN
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Mutations in polycystin 2 (PC2), a Ca2+-permeable cation channel, cause autosomal dominant polycystic kidney disease. Whether PC2 functions in the endoplasmic reticulum (ER) or in the plasma membrane has been controversial. Here we generated and characterized a polyclonal antibody against PC2, determined the subcellular localization of both endogenous and transfected PC2 by immunohistochemistry and biotinylation of cell surface proteins, and assessed PC2 channel properties with electrophysiology. Endogenous PC2 was found in the plasma membrane and the primary cilium of mouse inner medullar collecting duct (IMCD) cells and Madin-Darby canine kidney (MDCK) cells, whereas heterologously expressed PC2 showed a predominant ER localization. Patch-clamping of IMCD cells expressing endogenous or heterologous PC2 confirmed the presence of the channel on the plasma membrane. Treatment with chaperone-like factors facilitated the translocation of the PC2 channel to the plasma membrane from intracellular pools. The unitary conductances, channel kinetics, and other characteristics of both endogenously and heterologously expressed PC2 were similar to those described in our previous study in Xenopus laevis oocytes. These results show that PC2 functions as a plasma membrane channel in renal epithelia and suggest that PC2 contributes to Ca2+ entry and transport of other cations in defined nephron segments in vivo.

Na+ channel mis-expression accelerates K+ channel development in embryonic Xenopus laevis skeletal muscle.

Linsdell, P; Moody, W J
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 01/11/1994 EN
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1. The normal developmental pattern of voltage-gated ion channel expression in embryonic skeletal muscle cells of the frog Xenopus laevis was disrupted by introduction of cloned rat brain Na+ channels. 2. Following injection of channel mRNA into fertilized eggs, large Na+ currents were observed in muscle cells at the earliest developmental stage at which they could be uniquely identified. Muscle cells normally have no voltage-gated currents at this stage. 3. Muscle cells expressing exogenous Na+ channels showed increased expression of at least two classes of endogenous K+ currents. 4. This increase in K+ current expression was inhibited by the Na+ channel blocker tetrodotoxin, suggesting that increased electrical activity caused by Na+ channel mis-expression triggers a compensatory increase in K+ channel expression. 5. Block of endogenous Na+ channels in later control myocytes retards K+ current development, indicating that a similar compensatory mechanism to that triggered by Na+ channel mis-expression operates to balance Na+ and K+ current densities during normal muscle development.

Development and Validation of Fluorescence-Based and Automated Patch Clamp–Based Functional Assays for the Inward Rectifier Potassium Channel Kir4.1

Raphemot, Rene; Kadakia, Rishin J.; Olsen, Michelle L.; Banerjee, Sreedatta; Days, Emily; Smith, Stephen S.; Weaver, C. David; Denton, Jerod S.
Fonte: Mary Ann Liebert, Inc. Publicador: Mary Ann Liebert, Inc.
Tipo: Artigo de Revista Científica
Publicado em 01/12/2013 EN
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The inward rectifier potassium (Kir) channel Kir4.1 plays essential roles in modulation of neurotransmission and renal sodium transport and may represent a novel drug target for temporal lobe epilepsy and hypertension. The molecular pharmacology of Kir4.1 is limited to neurological drugs, such as fluoxetine (Prozac©), exhibiting weak and nonspecific activity toward the channel. The development of potent and selective small-molecule probes would provide critically needed tools for exploring the integrative physiology and therapeutic potential of Kir4.1. A fluorescence-based thallium (Tl+) flux assay that utilizes a tetracycline-inducible T-Rex-HEK293-Kir4.1 cell line to enable high-throughput screening (HTS) of small-molecule libraries was developed. The assay is dimethyl sulfoxide tolerant and exhibits robust screening statistics (Z′=0.75±0.06). A pilot screen of 3,655 small molecules and lipids revealed 16 Kir4.1 inhibitors (0.4% hit rate). 3,3-Diphenyl-N-(1-phenylethyl)propan-1-amine, termed VU717, inhibits Kir4.1-mediated thallium flux with an IC50 of ∼6 μM. An automated patch clamp assay using the IonFlux HT workbench was developed to facilitate compound characterization. Leak-subtracted ensemble “loose patch” recordings revealed robust tetracycline-inducible and Kir4.1 currents that were inhibited by fluoxetine (IC50=10 μM)...

Funding Economic Development: A Comparative Study of Financial Sector Reform in Vietnam and China

Rosengard, Jay K.; Thế Du, Huỳnh
Fonte: United Nations Development Programme and Fulbright Economics Teaching Program Publicador: United Nations Development Programme and Fulbright Economics Teaching Program
Tipo: Research Paper or Report
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Although there is considerable debate among economists as to the impact of financial sector development on economic growth, empirical evidence indicates a strong, direct link between the two. A recent comprehensive review of both the theory and research on this link between financial sector policies and economic development had a clear and unambiguous conclusion on the causal relationship between the two: A growing body of empirical research produces a remarkably consistent narrative: The services provided by the financial system exert a first-order impact on long-run economic growth. Building on work by Bagehot (1873), Schumpeter (1912), Gurley and Shaw (1955), Goldsmith (1969), and McKinnon (1973), recent research has employed different econometric methodologies and data sets in producing three core results. First, countries with better-developed financial systems tend to grow faster. Specifically, countries with (i) large, privately-owned banks that funnel credit to private enterprises and (ii) liquid stock exchanges tend to grow faster than countries with corresponding lower levels of financial development. The level of banking development and stock market liquidity each exerts an independent, positive influence on economic growth. Second...

Political Instability: Effects on Financial Development, Roots in the Severity of Economic Inequality

Roe, Mark J.; Siegel, Jordan
Fonte: Academic Press Publicador: Academic Press
Tipo: Artigo de Revista Científica
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We here bring forward strong evidence that political instability impedes financial development, with its variation a primary determinant of differences in financial development around the world. As such, it needs to be added to the short list of major determinants of financial development. First, structural conditions first postulated by Engerman and Sokoloff (2002) as generating long-term inequality are shown here empirically to be exogenous determinants of political instability. Second, that exogenously-determined political instability in turn holds back financial development, even when we control for factors prominent in the last decade’s cross-country studies of financial development. The findings indicate that inequality-perpetuating conditions that result in political instability are fundamental roadblocks for international organizations like the World Bank that seek to promote financial development. The evidence here includes country fixed effect regressions and an instrumental model inspired by Engerman and Sokoloff’s (2002) work, which to our knowledge has not yet been used in finance and which is consistent with current tests as valid instruments. Four conventional measures of national political instability - Alesina and Perotti’s (1996) well-known index of instability...

Channel estimation and optimal resource allocation of relay assisted communication systems

Jia, Yupeng ; Vosoughi, Azadeh
Fonte: University of Rochester Publicador: University of Rochester
Tipo: Tese de Doutorado Formato: Number of Pages:ix, 147 leaves; Illustrations:ill. (some col.)
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Thesis (Ph. D.)--University of Rochester. Dept. of Electrical and Computer Engineering, 2012.; Exploding demand for various wireless services has fueled significant development of wireless communication systems and networks in the past few decades. Wireless service providers are continuously striving to improve the design of communication systems and to enable higher data rate and more reliable wireless transmission. A major challenge in designing these systems is the random nature of the wireless transmission media due to the fading process. A recent paradigm shift from the conventional point-to- point communications is relay assisted communications. Motivated by the great success of multiple-input multiple-output (MIMO) wireless communication systems, with multiple transmit and receive antennas, researchers have considered relay assisted communications. Relying on the broadcast nature of the wireless media, a relay assisted communication system emulates a virtual MIMO system and exploits the spatial diversity, also known as cooperative diversity. Cooperative diversity increases the transmission reliability and coverage, without expanding the expenditure of the scarce transmission resources (power and bandwidth). Recently...

Development Economics and the International Development Association

Denizer, Cevdet; Dethier, Jean-Jacques; Gelb, Alan
Fonte: Banco Mundial Publicador: Banco Mundial
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Prevailing economic ideas -- and fashions -- about development have influenced the International Development Association (IDA) since its creation in 1960. The creation of the organization itself is the result of two contemporaneous facts: an urgent need to channel development finance to least-developed countries and an increasing pressure on World Bank management to directly address the issue of poverty in developing countries. Changing views, over time, have been a rationale -- and, at times, a justification -- for emphasizing poverty and social sectors; for providing grants to particular groups of countries; and for strategic choices and sectoral priorities. IDA has been influential in development debates and been an advocate for specific views about development policy. This paper gives an overview of these views and documents how they have shaped the activities of the organization since its creation. After a brief review of development thinking and of the organization of research at the World Bank, the paper documents the shifts that have taken place in country allocations and in sector emphasis in IDA over the past 50 years and highlights the strategic themes that have guided its development agenda: toward increasing country selectivity; from projects to programs; from conditionality to country ownership of reforms; and from input-based to results-based performance.

Secure on-off transmission design with channel estimation errors

Zhou, Xiangyun; He, Biao
Fonte: IEEE Xplore Publicador: IEEE Xplore
Tipo: Artigo de Revista Científica Formato: 14 pages
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Physical layer security has recently been regarded as an emerging technique to complement and improve the communication security in future wireless networks. The current research and development in physical layer security are often based on the ideal assumption of perfect channel knowledge or the capability of variable-rate transmissions. In this paper, we study the secure transmission design in more practical scenarios by considering channel estimation errors at the receiver and investigating both fixed-rate and variable-rate transmissions. Assuming quasi-static fading channels, we design secure on-off transmission schemes to maximize the throughput subject to a constraint on secrecy outage probability. For systems with given and fixed encoding rates, we show how the optimal on-off transmission thresholds and the achievable throughput vary with the amount of knowledge on the eavesdropper’s channel. In particular, our design covers the interesting case where the eavesdropper also uses the pilots sent from the transmitter to obtain imperfect channel estimation. An interesting observation is that using too much pilot power can harm the throughput of secure transmission if both the legitimate receiver and the eavesdropper have channel estimation errors...

Dominant-negative suppression of big brain ion channel activity by mutation of a conserved glutamate in the first transmembrane domain

Yool, A.
Fonte: Cognizant Communication Corp Publicador: Cognizant Communication Corp
Tipo: Artigo de Revista Científica
Publicado em //2006 EN
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The neurogenic protein Drosophila big brain (BIB), which is involved in the process of neuroblast determination, and the water channel aquaporin-1 (AQP1) are among a subset of the major intrinsic protein (MIP) channels that have been found to show gated monovalent cation channel activity. A glutamate residue in the first transmembrane (M1) domain is conserved throughout the MIP family. Mutation of this residue to asparagine in BIB (E71N) knocks out ion channel activity, and when coexpressed with BIB wild-type as shown here generates a dominant-negative effect on ion channel function, measured in the Xenopus oocyte expression system using two-electrode voltage clamp. cRNAs for wild-type and mutant BIB or AQP1 channels were injected individually or as mixtures. The magnitude of the BIB ionic conductance response was greatly reduced by coexpression of the mutant E71N subunit, suggesting a dominant-negative mechanism of action. The analogous mutation in AQP1 (E17N) did not impair ion channel activation by cGMP, but did knock out water channel function, although not via a dominant-negative effect. This contrast in sensitivity between BIB and AQP1 to mutation of the M1 glutamate suggests the possibility of interesting structural differences in the molecular basis of the ion permeation between these two classes of channels. The dominant-negative construct of BIB could be a tool for testing a role for BIB ion channels during nervous system development in Drosophila.

The contribution of voltage-gated Ca²⁺ currents to K⁺ channel activation during ovine adrenal chromaffin cell development; The contribution of voltage-gated Ca(2+) currents to K(+) channel activation during ovine adrenal chromaffin cell development

Keating, D.; Rychkov, G.; Roberts, M.
Fonte: Pergamon-Elsevier Science Ltd Publicador: Pergamon-Elsevier Science Ltd
Tipo: Artigo de Revista Científica
Publicado em //2009 EN
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Prior to the development of adrenal innervation, the adrenal medulla is capable of responding to low blood oxygen directly. However, this response is lost once adrenal innervation is established. Previous work by our group has outlined mechanisms involved in this direct hypoxic response and the means by which innervation causes the loss of the direct hypoxic response in the ovine adrenal. The current study further investigates mechanisms which may underlie the developmental loss of the direct hypoxic response by concentrating on two aspects of cell function which regulate catecholamine secretion: the contribution of different types of Ca2+ channels to the total Ca2+ current and the contribution of each Ca2+ channel type to K+ channel activation. We identified that Ca2+ current size at -40 to -10 mV is increased in amplitude in fetal chromaffin cells. This is not due to the increased prevalence or size of T-type Ca2+ currents present at these voltages. The relative contribution of L-, N- or P/Q-type Ca2+ channels to total Ca2+ current and to activation of the K+ current is unchanged during chromaffin cell development, however K+ current density increases with age. Our results indicate that there is a developmental shift in relative expression of T-type...

Genetische Ablation des natrium- und chloridabhängigen Kaliumkanals Slo2.1 (SLICK) in der Maus; Genetic ablation of the sodium- and chloride dependent potassium channel Slo2.1 (SLICK) in the mouse

Gassner, Claus
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
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Als membrandurchspannende Proteine regulieren Ionenkanäle das Stoffwechselgeschehen auf zellulärer Ebene. Sie sorgen für einen reibungslosen Ablauf bei der Weitergabe von Information durch elektrische Signale. In der vorliegenden Arbeit wird beschrieben, wie mithilfe molekularbiologischer Techniken gezielt das slo2.1-Gen in der Maus ausgeschaltet wird (slo2.1-Knockout-Maus). Das slo2.1-Gen codiert für den natrium- und chloridabhängigen Kaliumkanal, welcher in der Literatur als Slo2.1 oder SLICK (Sequence like an intermediate conductance K+-channel) bekannt ist. Slo2.1 zählt zur Familie der Slo-Kanäle. Slo2.1 ist als jüngstes Mitglied der Slo-Familie nur wenig erforscht und seine biologische Funktion ist unbekannt. Als Ziel dieser Arbeit sollte ein Tiermodell entwickelt werden, in welchem genau dieser Kanal inaktiviert wird (Knockout). Damit können die physiologischen Besonderheiten (Phänotypen) dieser Tiere mit den entsprechenden unveränderten Wildtyp-Mäusen verglichen, und dadurch Rückschlüsse auf die biologische Funktion von slo2.1 gezogen werden. Zusätzlich zum totalen Knockout, bei welchem im gesamten Organismus kein intaktes Protein mehr vorliegt, war es weiteres Ziel der Arbeit, s.g. konditionale Knockout-Mäuse zu erzeugen...

Localization of the calcium channel subunits Cav1.2 (a1C) and Cav2.3 (a1E) in the mouse organ of Corti

Waka, N.; Knipper, M.; Engel, J.
Fonte: Murcia : F. Hernández Publicador: Murcia : F. Hernández
Tipo: Artigo de Revista Científica Formato: application/pdf
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Voltage-activated Ca2+ channels play an important role in synaptic transmission, signal processing and development. The immunohistochemical localization of Cav1.2 (a1C) and Cav2.3 (a1E) Ca2+ channels was studied in the developing and adult mouse organ of Corti using subunit-specific antibodies and fluorescent secondary antibodies with cochlear cryosections. Cav1.2 immunoreactivity has been detected from postnatal day 14 (P14) onwards at the synapses between cholinergic medial efferents and outer hair cells as revealed by co-staining with antisynaptophysin and anti-choline acetyltransferase. Most likely the Cav1.2 immunoreactivity was located presynaptically at the site of contact of the efferent bouton with the outer hair cell which suggests a role for class C L-type Ca2+ channels in synaptic transmission of the medial efferent system. The localization of the second Ca2+ channel tested, Cav2.3, showed a pronounced change during cochlear development. From P2 until P10, Cav2.3 immunoreactivity was found in the outer spiral bundle followed by the inner spiral bundle, efferent endings and by medial efferent fibers. Around P14, Cav2.3 immunoreactivity disappeared from these structures and from P19 onwards it was observed in the basal poles of the outer hair cell membranes.

A highly adaptable generic event-based message channel design for loosely coupling software modules

Eryigit, Cihat
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Tese de Doutorado Formato: xvi, 157 p. : ill. ;
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Approved for public release, distribution is unlimited; Component-based software engineering is an emerging software development approach based on the fundamentals of object-oriented technology. This approach moves programmers' focus from component development to component assembly. Event-based programming is one of the techniques that can be used to assemble software components into applications. In this thesis, a new, generic, highly adaptable and flexible event channel has been designed and implemented. The main product is a Java utility package, called "channel package", which should help Java application developers create or enhance large systems using an event-based programming approach. The new channel design has several demonstrated performance advantages over existing event channel implementations. The flexibility and adaptability of the channel package has also been validated by a successful upgrade of the channel mechanism of the SAAM prototype system.; Lieutenant Junior Grade, Turkish Navy

On the Channel and Type of International Disaster Aid

Raschky, Paul A.; Schwindt, Manijeh
Fonte: Banco Mundial Publicador: Banco Mundial
Tipo: Publications & Research :: Policy Research Working Paper
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Research suggests that a donor country s decision to provide post-disaster assistance is not only driven by the severity of a disaster and the resulting humanitarian needs in the recipient country, but also by strategic considerations. The authors argue that the identification of the determinants of the size of disaster assistance is a first step in the analysis of the donor s behavior. Since all aid is not motivated by the same reasons, the evaluation of the donor country s behavior requires a second step accounting for the type and the channel of aid provided. Using data on international disaster assistance between 2000 and 2007, the analysis examines both the donor countries' decision on the channel (bilateral versus multilateral) and the type of disaster relief (cash versus in-kind). The empirical results suggest that international disaster relief is not as much driven by the needs of the recipient country, but also by strategic interests (for example, oil or trade relationships) of the donor country. Bilateral and cash transfers are used as a vehicle to signal strategic interests...

Arrested Development e o Futuro das Séries (de Tevê?); Arrested Development and the future of television series

Silva, Marcel Vieira Barreto
Fonte: Universidade de São Paulo. Escola de Comunicações e Artes Publicador: Universidade de São Paulo. Escola de Comunicações e Artes
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 09/08/2014 POR
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Esta é a história de uma série de tevê que foi abruptamente cancelada e do serviço de streaming que surgiu para trazê-la das cinzas. Arrested Development foi uma série exibida entre 2003 e 2006 pela FOX, em canal aberto nos EUA, e se notabilizou por investir em estratégias narrativas e estilísticas pouco habituais à sitcom, como uma encenação mais realista e arco dramático metaficcional. O seu cancelamento causou alvoroço nos fãs, que ficaram anos em comunidades e redes sociais sonhando com o seu retorno. Ao realizar esse sonho, o Netflix trouxe de volta a série e colocou em pauta o futuro da ficção audiovisual seriada. O objetivo deste artigo é demonstrar como a estrutura narrativa da nova temporada ampliou a fruição televisiva sincrônica para a manipulação diacrônica da história, comum à internet. Isso é Arrested Development.; This is a story about a TV series that was abruptly cancelled and about the streaming service that brought it from the ashes. Arrested Development was a TV series exhibited between 2003 and 2006 by FOX channel, an open TV channel, and that has been recognized for investing in narrative and stylistic strategies that are unusual in sitcoms, as a more realistic staging and metafictional dramatic arch. The cancellation of the series provoked bustle in the fans...

Identifying Temporary Headwater Streams and Channel Heads in the North Carolina Piedmont

Miller, John Paul
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Masters' project
Publicado em 24/04/2015
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Headwater streams begin upstream at the channel head and extend downstream to the confluence of second or third order streams. They may exhibit ephemeral, intermittent, or perennial flow regimes and often comprise a disproportionate share of the drainage network. Recent studies estimate that intermittent and ephemeral streams comprise 59% (3,200,000 km) of total stream length in the United States. Dense, dendritic and fractal networks exponentially expand the extent of stream reaches. These vast networks are squeezed into the landscape and thus unsurprisingly have a substantial impact on downstream water quality, biodiversity, water supply, nutrient cycling, and water treatment costs. However, despite the importance and predominance of headwater streams in the landscape, their extent remains poorly mapped and understood. The National Hydrography Dataset (NHD) is the digitized version of USGS 1:24,000 scale topographic maps, which are typically used to locate streams for a variety of planning and regulatory purposes. Numerous studies have found the NHD to be inadequate for determining the extent of stream networks, with underestimations of 56 percent in North Carolina and up to 300 percent in urban areas reported. Moreover, the Piedmont eco-region is expected to urbanize by 165 percent over the next 50 years. Since these small streams thoroughly perfuse the landscape and serve as the most proximate intersection of the lotic and terrestrial environments...

Gate-to-channel parasitic capacitance minimization and source-drain leakage evaluation in germanium PMOS

Krom, Raymond T.
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
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This work studies the behavior of both gate-to-channel capacitance (CGC) and source-channel-drain/well leakage in metal-gate/high-κ/Ge PMOS technology (W = 10 μm and L = 10; 5; 1 μm) under development at IMEC. The hole drift-mobility of germanium is ~4X that of silicon, leading researchers to evaluate germanium as a possible channel material replacement for PMOS expected at the 32 nm technology node. In particular this study focuses on—but is not restricted to—(1) the presence of a parasitic gate-to-channel capacitance (CGC), the large non-ideal trap assisted conductance which contributes to it, and its function versus Ge-PMOS architecture and gate length; (2) the existence of C-V tool compensation error due to CGC measurement technique resulting in conductance measurement error; (3) the presence of large source-channel-drain/well leakages characterized using a new MOS gated-diode measurement technique; (4) extrinsic capacitance (CEXT), flatband voltage (VFB), and effective oxide thickness (EOT) parameter extraction with discussion on inversion layer quantization. This study found that excessive current leakages from the Ge-PMOS source-anddrain into the channel led to a chuck-dependent parasitic capacitance during CGC measurement. This excessive leakage is identified as a trap-assisted leakage through both AC and DC analysis. The chuck-dependent parasitic capacitance was an unexpected side effect of the PMOS architecture: namely the lack of N-Well isolation. The parasitic capacitance—dependent on both applied bias and frequency—was separated into two main capacitive components: a frequency-dependent source/well and drain/well trapassisted leakage capacitance (CPara_SD) and a frequency-voltage-dependent gate-induced iv junction leakage capacitance (CPara_GIJL). A third parasitic capacitance due to interface trap (IT) contribution (CIT) during channel depletion was also identified. This study also found that the new MOS gated-diode measurement technique designed to separate and evaluate the source...

Recent Advances in Ion Channel Research

Chung, Shin-Ho; Kuyucak, Serdar
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
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The field of ion channels has entered into a rapid phase of development in the last few years, partly due to the breakthroughs in determination of the crystal structures of membrane proteins and advances in computer simulations of biomolecules. These advances have finally enabled the long-dreamed goal of relating function of a channel to its underlying molecular structure. Here we present simplified accounts of the competing permeation theories and then discuss their application to the potassium, gramicidin A and calcium channels.

Breaking Free of the Branch; Designing Alternative Delivery Channel Projects for Microfinance Banks in Africa

Gutin, John
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Brief; Publications & Research :: Brief; Publications & Research
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Nearly 80 percent of adults in Sub-Saharan Africa do not have an account with a formal financial institution. Despite recent well-publicized successes in increasing financial inclusion in a small number of African markets, such as Kenya, hundreds of millions of African adults still lack access to affordable financial services. In response to this need, International Finance Corporation (IFC) and The MasterCard Foundation partnered to introduce alternative delivery channels in IFC’s key microfinance partners in Africa. Although the partnership is still at an early stage, this smart lesson distills some general lessons from two of the first alternative delivery channel engagements. These lessons may be useful for other IFC teams in structuring such projects with microfinance clients.