909 research outputs found
Interconnect resistance of photovoltaic submodules
Small area amorphous silicon solar cells generally have higher efficiencies than large interconnected submodules. Among the reasons for the differences in performance are the lack of large area uniformity, the effect of nonzero tin oxide sheet resistance, and possibly pinholes in the various layers. Another and usually small effect that can contribute to reduced performance of interconnected cells is the resistance of the interconnection i.e., the series resistance introduced by the metal to tin oxide contact through silicon. Proper processing problems to avoid poor contacts are discussed
Div-BLAST: Diversification of sequence search results
Cataloged from PDF version of article.Sequence similarity tools, such as BLAST, seek sequences most similar to a query from a database of
sequences. They return results significantly similar to the query sequence and that are typically highly
similar to each other. Most sequence analysis tasks in bioinformatics require an exploratory approach,
where the initial results guide the user to new searches. However, diversity has not yet been considered an
integral component of sequence search tools for this discipline. Some redundancy can be avoided by
introducing non-redundancy during database construction, but it is not feasible to dynamically set a level
of non-redundancy tailored to a query sequence. We introduce the problem of diverse search and browsing
in sequence databases that produce non-redundant results optimized for any given query. We define
diversity measures for sequences and propose methods to obtain diverse results extracted from current
sequence similarity search tools. We also propose a new measure to evaluate the diversity of a set of
sequences that is returned as a result of a sequence similarity query. We evaluate the effectiveness of the
proposed methods in post-processing BLAST and PSI-BLAST results. We also assess the functional
diversity of the returned results based on available Gene Ontology annotations. Additionally, we include a
comparison with a current redundancy elimination tool, CD-HIT. Our experiments show that the proposed
methods are able to achieve more diverse yet significant result sets compared to static non-redundancy
approaches. In both sequence-based and functional diversity evaluation, the proposed diversification
methods significantly outperform original BLAST results and other baselines. A web based tool
implementing the proposed methods, Div-BLAST, can be accessed at cedar.cs.bilkent.edu.tr/Div-BLAS
Ultraluminous Infrared Galaxies in the AKARI All Sky Survey
We present a new catalog of 118 Ultraluminous Infrared Galaxies (ULIRGs) and
one Hyperluminous Infrared Galaxy (HLIRG) by crossmatching AKARI all-sky survey
with the Sloan Digital Sky Survey Data Release 10 (SDSS DR10) and the Final
Data Release of the Two-Degree Field Galaxy Redshift Survey (2dFGRS). 40 of the
ULIRGs and one HLIRG are new identifications. We find that ULIRGs are
interacting pair galaxies or ongoing/post mergers. This is consistent with the
widely accepted view: ULIRGs are major mergers of disk galaxies. We confirm the
previously known positive trend between the AGN fraction and IR luminosity. We
show that ULIRGs have a large off-set from the 'main sequence' up to z~1; their
off-set from the z~2 'main sequence' is relatively smaller. We find a
consistent result with the previous studies showing that compared to local star
forming SDSS galaxies of similar mass, local ULIRGs have lower oxygen
abundances. We for the first time demonstrate that ULIRGs follow the
fundamental metallicity relation (FMR). The scatter of ULIRGs around the FMR
(0.09 dex - 0.5 dex) is comparable with the scatter of z~2-3 galaxies. Their
optical colors show that ULIRGs are mostly blue galaxies and this agrees with
previous findings. We provide the largest local (0.050 < z < 0.487) ULIRG
catalog with stellar masses, SFRs, gas metallicities and optical colors. Our
catalog provides us active galaxies analogous to high-z galaxies in the local
Universe where they can be rigorously scrutinized.Comment: 31 pages, 19 figure
Binomial Ideals and Congruences on Nn
Producción CientíficaA congruence on Nn is an equivalence relation on Nn that is compatible with the additive structure. If k is a field, and I is a binomial ideal in k[X1,…,Xn] (that is, an ideal generated by polynomials with at most two terms), then I induces a congruence on Nn by declaring u and v to be equivalent if there is a linear combination with nonzero coefficients of Xu and Xv that belongs to I. While every congruence on Nn arises this way, this is not a one-to-one correspondence, as many binomial ideals may induce the same congruence. Nevertheless, the link between a binomial ideal and its corresponding congruence is strong, and one may think of congruences as the underlying combinatorial structures of binomial ideals. In the current literature, the theories of binomial ideals and congruences on Nn are developed separately. The aim of this survey paper is to provide a detailed parallel exposition, that provides algebraic intuition for the combinatorial analysis of congruences. For the elaboration of this survey paper, we followed mainly (Kahle and Miller Algebra Number Theory 8(6):1297–1364, 2014) with an eye on Eisenbud and Sturmfels (Duke Math J 84(1):1–45, 1996) and Ojeda and Piedra Sánchez (J Symbolic Comput 30(4):383–400, 2000).National Science Foundation (grant DMS-1500832)Ministerio de Economía, Industria y Competitividad (project MTM2015-65764-C3-1)Junta de Extremadura (grupo de investigación FQM-024
The Size of the Narrow-Line Emitting Region in the Seyfert 1 Galaxy NGC 5548 from Emission-Line Variability
The narrow [O III] 4959, 5007 emission-line fluxes in the spectrum of the
well-studied Seyfert 1 galaxy NGC 5548 are shown to vary with time. From this
we show that the narrow line-emitting region has a radius of only 1-3 pc and is
denser (n ~ 10^5 cm^{-3}) than previously supposed. The [O III] line width is
consistent with virial motions at this radius given previous determinations of
the black hole mass.Since the [O III] emission-line flux is usually assumed to
be constant and is therefore used to calibrate spectroscopic monitoring data,
the variability has ramifications for the long-term secular variations of
continuum and emission-line fluxes, though it has no effect on shorter-term
reverberation studies. We present corrected optical continuum and broad Hbeta
emission-line light curves for the period 1988 to 2008.Comment: 11 pages, 5 figures, 6 tables. Accepted for publication in Ap
Determination of natural radioactivity levels in soil and travertine of the region of Tokat and Sivas, Turkey
WOS: 000429070100015In this study, the environmental radioactivity measurements for Tokat and Sivas provinces in the northeast of Turkey were performed. Using gamma ray spectrometry, the activity concentrations of natural radionuclides in soil and travertine samples (Th-232, Ra-226, and K-40) were determined. The annual effective dose equivalent, the absorbed doses rate in air, the radium equivalent, and the external hazard index were obtained from these activities. The activity concentrations vary from 9.09 to 17.04 Bq kg(-1) for Th-232, from 36.53 to 76.95 Bq kg(-1) for Ra-226, and from 216.56 to 576.59 Bq kg(-1) for K-40 in soil samples. The activity concentrations in travertines vary from 15.99 to 21.01 Bq kg(-1) for Th-232, from 19.89 to 67.71 Bq kg(-1) for Ra-226, and from 179.89 to 314.43 Bq kg(-1) for K-40. The average dose rate in air for soil and travertine samples was 43.41 and 41.05 nGy h(-1) respectively. The obtained results are presented and compared with other studies, and the results of this study are lower than the international recommended value (55 nGy h(-1)) given by UNSCEAR (2000). The results show that the region has a background radiation level within the natural limits.Gaziosmanpasa University Scientific Research Projects Department (BAP)Gaziosmanpasa University [24/2013]This work is supported by Gaziosmanpasa University Scientific Research Projects Department (BAP) under project no. 24/2013
Nuclear Repulsion Enables Division Autonomy in a Single Cytoplasm
SummaryBackgroundCurrent models of cell-cycle control, based on classic studies of fused cells, predict that nuclei in a shared cytoplasm respond to the same CDK activities to undergo synchronous cycling. However, synchrony is rarely observed in naturally occurring syncytia, such as the multinucleate fungus Ashbya gossypii. In this system, nuclei divide asynchronously, raising the question of how nuclear timing differences are maintained despite sharing a common milieu.ResultsWe observe that neighboring nuclei are highly variable in division-cycle duration and that neighbors repel one another to space apart and demarcate their own cytoplasmic territories. The size of these territories increases as a nucleus approaches mitosis and can influence cycling rates. This nonrandom nuclear spacing is regulated by microtubules and is required for nuclear asynchrony, as nuclei that transiently come in very close proximity will partially synchronize. Sister nuclei born of the same mitosis are generally not persistent neighbors over their lifetimes yet remarkably retain similar division cycle times. This indicates that nuclei carry a memory of their birth state that influences their division timing and supports that nuclei subdivide a common cytosol into functionally distinct yet mobile compartments.ConclusionsThese findings support that nuclei use cytoplasmic microtubules to establish “cells within cells.” Individual compartments appear to push against one another to compete for cytoplasmic territory and insulate the division cycle. This provides a mechanism by which syncytial nuclei can spatially organize cell-cycle signaling and suggests size control can act in a system without physical boundaries
Editorial: Green chemistry biocatalysis
Editorial on the Research Topic: Green chemistry biocatalysi
Solution of the Bosonic and Algebraic Hamiltonians by using AIM
We apply the notion of asymptotic iteration method (AIM) to determine
eigenvalues of the bosonic Hamiltonians that include a wide class of quantum
optical models. We consider solutions of the Hamiltonians, which are even
polynomials of the fourth order with the respect to Boson operators. We also
demonstrate applicability of the method for obtaining eigenvalues of the simple
Lie algebraic structures. Eigenvalues of the multi-boson Hamiltonians have been
obtained by transforming in the form of the single boson Hamiltonian in the
framework of AIM
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