Improvement of hydrogenated amorphous silicon germanium thin film solar cells by different p-type contact layer

Cho, J.,Pham, D.P.,Jung, J.,Shin, C.,Park, J.,Kim, S.,Tuan Le, A.H.,Park, H.,Iftiquar, S.M.,Yi, J. Pergamon 2016 Materials science in semiconductor processing Vol.41 No.-

In this study, we report an appreciably increased efficiency from 6% up to 9.1% of hydrogenated amorphous silicon germanium (a-SiGe:H) thin film solar cells by using a combination of different p-doped window layers, such as boron doped hydrogenated amorphous silicon (p-a-Si:H), amorphous silicon oxide (p-a-SiO<SUB>x</SUB>:H), microcrystalline silicon (p-@?c-Si:H), and microcrystalline silicon oxide (p-@?c-SiO<SUB>x</SUB>:H). Optoelectronic properties and the role of these p-layers in the enhancement of a-SiGe:H cell efficiency were also examined and discussed. An improvement of 1.62mA/cm<SUP>2</SUP> in the short-circuit current density (J<SUB>sc</SUB>) is attributed to the higher band gap of p-type silicon oxide layers. In addition, an increase in open-circuit voltage (V<SUB>oc</SUB>) by 150mV and fill factor (FF) by 6.93% is ascribed to significantly improved front TCO/p-layer interface contact.

Influence on SERS enhancement factor of the components of an artificial opal loaded with metal NPs: A systematic study

De León Portilla P.,Sánchez-Mora E.,González A.L. 한국물리학회 2022 Current Applied Physics Vol.39 No.-

We have inquired about the influence of composite artificial opal components on its SERS enhancement factor (EF). Particularly, we considered metal (100 nm) and dielectric spheres (290 nm), and an excitation wavelength of 632 nm. We show that the electric field of a SiO2 sphere is weaker and more uniform as its porosity increases. Additionally, a porous sphere promotes a lower EF compared to that of a non-porous sphere. The optical response of the composite opal is insensitive to the polarization state of the incident field. A SERS EF of 104 is reachable with an opal loaded with Au or Ag NPs. In general, the dielectric spheres affect the SERS EF intensity of the metal NPs. From the optical spectra, we observed that with a 632 nm wavelength, the composite opal is out of resonance.

Localization techniques in quantum field theories

Pestun, Vasily,Zabzine, Maxim,Benini, Francesco,Dimofte, Tudor,Dumitrescu, Thomas T,Hosomichi, Kazuo,Kim, Seok,Lee, Kimyeong,Le Floch, Bruno,Mariñ,o, Marcos,Minahan, Joseph A,Morrison, David R,P IOP 2017 JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL Vol.50 No.44

<P>This is the foreword to the special issue on localization techniques in quantum field theory. The summary of individual chapters is given and their interrelation is discussed.</P>

Postharvest physiology and technology of the tuberose ( Polianthes tuberosa L.): an ornamental fl ower native to Mexico

Gloria Alicia Pérez-Arias,Iran Alia-Tejacal,María Teresa Colinas-León,Luis Alonso Valdez-Aguilar,Clara Pelayo-Zaldívar 한국원예학회 2019 Horticulture, Environment, and Biotechnology Vol.60 No.3

The tuberose ( Polianthes tuberosa L.) is an ornamental plant native to Mexico with fl owers that are popular due to theirdelicate beauty and intense fragrance. However, as a plant resource, it has not been well studied or commercialized. If properlymanaged and/or exploited, this cut fl ower crop has the potential to further develop and expand the Mexican ornamentalhorticultural industry. At present, few studies have focused on increasing its relatively short shelf-life, which lasts about7–10 day postharvest. As a result, this review focuses on basic aspects of the cut fl ower’s physiology, biochemistry, waterrelations, and postharvest fl oral opening. Also included are its response to cooling, the implementation of diff erent packingstrategies, the application of pulsing, preservative, and hydrating solutions, and the use of 1-methylcyclopropene as aninhibitor of ethylene action. A thorough analysis of all these technologies, their mode of action, and their infl uence on thephysiological response of cut tuberose is essential for the improvement of postharvest management strategies. It is hopedthat both handlers and distributors can benefi t from this information and be successful in prolonging the shelf-life of thisvaluable ornamental resource.

Catalytic hydrothermal conversion of CO2 captured by ammonia into formate using aluminum-sourced hydrogen at mild reaction conditions

Juan I. del Río,Eduardo Pérez,David León,Ángel Martín,María D. Bermejo 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.97 No.-

The catalytic conversion of CO2 captured in aqueous media into formate was studied using aluminum-sourced hydrogenin a batch reaction system. To do so, themain ammonia-basedCO2absorption derivatives:ammoniumcarbamate,carbonate and bicarbonateandsodiumbicarbonatewere selectedasCO2source.Theperformance of the different species was determined under mild hydrothermal reaction conditions (120 C),using Pd/C 5 wt% catalyst. In these conditions, the formate yield and selectivity increase in the orderammonium bicarbonate < sodium bicarbonate < ammonium carbonate < ammonium carbamate. Ammo-nium bicarbonate and sodium bicarbonate reagents needed higher temperature (250 C) for an increasedyield. Results with ammonium carbamate as starting material indicate a significant effect of time andcatalyst content on formate yield, which ranged between 4 and 38%. Experiments with gaseous H2 showedthat a comparable yield with Al can be obtained at a similar level of pressure. The reutilization andcharacterization of the reaction solid, comprising exhausted aluminum and Pd/C catalyst, showed that thealuminum was not completely oxidized up to the 5th re-use, and Pd can play a reducing role through theformation of palladium hydride species. The process can be improved by operating at higher pressure andlower temperature, to avoid loss of yield by dehydration of formate.

Multi-Platform Next-Generation Sequencing of the Domestic Turkey (<i>Meleagris gallopavo</i>): Genome Assembly and Analysis

Dalloul, Rami A.,Long, Julie A.,Zimin, Aleksey V.,Aslam, Luqman,Beal, Kathryn,Ann Blomberg, Le,Bouffard, Pascal,Burt, David W.,Crasta, Oswald,Crooijmans, Richard P. M. A.,Cooper, Kristal,Coulombe, Rog Public Library of Science 2010 PLoS biology Vol.8 No.9

<P>A synergistic combination of two next-generation sequencing platforms with a detailed comparative BAC physical contig map provided a cost-effective assembly of the genome sequence of the domestic turkey (<I>Meleagris gallopavo</I>). Heterozygosity of the sequenced source genome allowed discovery of more than 600,000 high quality single nucleotide variants. Despite this heterozygosity, the current genome assembly (∼1.1 Gb) includes 917 Mb of sequence assigned to specific turkey chromosomes. Annotation identified nearly 16,000 genes, with 15,093 recognized as protein coding and 611 as non-coding RNA genes. Comparative analysis of the turkey, chicken, and zebra finch genomes, and comparing avian to mammalian species, supports the characteristic stability of avian genomes and identifies genes unique to the avian lineage. Clear differences are seen in number and variety of genes of the avian immune system where expansions and novel genes are less frequent than examples of gene loss. The turkey genome sequence provides resources to further understand the evolution of vertebrate genomes and genetic variation underlying economically important quantitative traits in poultry. This integrated approach may be a model for providing both gene and chromosome level assemblies of other species with agricultural, ecological, and evolutionary interest.</P><P><B>Author Summary</B></P><P>In contrast to the compact sequence of viruses and bacteria, determining the complete genome sequence of complex vertebrate genomes can be a daunting task. With the advent of “next-generation” sequencing platforms, it is now possible to rapidly sequence and assemble a vertebrate genome, especially for species for which genomic resources—genetic maps and markers—are currently available. We used a combination of two next-generation sequencing platforms, Roche 454 and Illumina GAII, and unique assembly tools to sequence the genome of the agriculturally important turkey, <I>Meleagris gallopavo</I>. Our draft assembly comprises approximately 1.1 gigabases of which 917 megabytes are assigned to specific chromosomes. Comparisons of the turkey genome sequence with those of the chicken, <I>Gallus gallus</I>, and the zebra finch, <I>Taeniopygia guttata</I>, provide insights into the evolution of the avian lineage. This genome sequence will facilitate discovery of agriculturally important genetic variants.</P>

CFD simulations of the flow field of a laboratory-simulated tornado for parameter sensitivity studies and comparison with field measurements

Kuai, Le,Haan, Fred L. Jr.,Gallus, William A. Jr.,Sarkar, Partha P. Techno-Press 2008 Wind and Structures, An International Journal (WAS Vol.11 No.2

A better understanding of tornado-induced wind loads is needed to improve the design of typical structures to resist these winds. An accurate understanding of the loads requires knowledge of near-ground tornado winds, but observations in this region are lacking. The first goal of this study was to verify how well a CFD model, when driven by far field radar observations and laboratory measurements, could capture the flow characteristics of both full scale and laboratory-simulated tornadoes. A second goal was to use the model to examine the sensitivity of the simulations to various parameters that might affect the laboratory simulator tornado. An understanding of near-ground winds in tornadoes will require coordinated efforts in both computational and physical simulation. The sensitivity of computational simulations of a tornado to geometric parameters and surface roughness within a domain based on the Iowa State University laboratory tornado simulator was investigated. In this study, CFD simulations of the flow field in a model domain that represents a laboratory tornado simulator were conducted using Doppler radar and laboratory velocity measurements as boundary conditions. The tornado was found to be sensitive to a variety of geometric parameters used in the numerical model. Increased surface roughness was found to reduce the tangential speed in the vortex near the ground and enlarge the core radius of the vortex. The core radius was a function of the swirl ratio while the peak tangential flow was a function of the magnitude of the total inflow velocity. The CFD simulations showed that it is possible to numerically simulate the surface winds of a tornado and control certain parameters of the laboratory simulator to influence the tornado characteristics of interest to engineers and match those of the field.

Synthesis, structure and catalytic activities for hydrogen transfer reaction of the carbonyl ruthenium(II) complex containing polypyridine and phosphine ligands

Moya, S.A.,Vidal, M.,Abarca, G.,Martinez, C.,Guerchais, V.,Le Bozec, H.,Garland, M.T.,Rodriguez, S.,Aguirre, P. Elsevier 2010 Inorganic chemistry communications Vol.13 No.12

<P><B>Abstract</B></P><P>The synthesis and characterization of new ruthenium(II) carbonyl complexes containing polypyridine and triphenylphosphine ligands is reported. Crystallographic information obtained for the <I>trans-</I>PPh<SUB>3</SUB>-[Ru(biq)(PPh<SUB>3</SUB>)<SUB>2</SUB>(CO)]Cl<SUB>2</SUB> complex (biq=2,2’-biquinoline<B>)</B> reveals five-coordination on the metal. The complexes were studied as catalysts in hydrogen transfer reactions in basic solution. Turnover frequencies in the 2250-817h<SUP>-1</SUP> range were determined in 1 hour of reaction with a substrate/catalysts ratio of 830.</P> <P><B>Graphical Abstract</B></P><P>The synthesis and characterization of new ruthenium(II) carbonyl complexes containing polypyridine and triphenylphosphine ligands is reported. The complexes were studied as catalysts in hydrogen transfer reactions in basic solution.<ce:figure id='f0015'></ce:figure></P>

Test of Special Relativity Using a Fiber Network of Optical Clocks

Delva, P.,Lodewyck, J.,Bilicki, S.,Bookjans, E.,Vallet, G.,Le Targat, R.,Pottie, P.-E.,Guerlin, C.,Meynadier, F.,Le Poncin-Lafitte, C.,Lopez, O.,Amy-Klein, A.,Lee, W.-K.,Quintin, N.,Lisdat, C.,Al-Maso American Physical Society 2017 Physical Review Letters Vol.118 No.22

<P>Phase compensated optical fiber links enable high accuracy atomic clocks separated by thousands of kilometers to be compared with unprecedented statistical resolution. By searching for a daily variation of the frequency difference between four strontium optical lattice clocks in different locations throughout Europe connected by such links, we improve upon previous tests of time dilation predicted by special relativity. We obtain a constraint on the Robertson-Mansouri-Sexl parameter |alpha| <= 1.1 x 10(-8), quantifying a violation of time dilation, thus improving by a factor of around 2 the best known constraint obtained with Ives-Stilwell type experiments, and by 2 orders of magnitude the best constraint obtained by comparing atomic clocks. This work is the first of a new generation of tests of fundamental physics using optical clocks and fiber links. As clocks improve, and as fiber links are routinely operated, we expect that the tests initiated in this Letter will improve by orders of magnitude in the near future.</P>

An Optimal Design of an Electromagnetic Actuator for Targeting Magnetic Micro-/Nano-Carriers in a Desired Region

Le, T. A.,Bui, M. P.,Yoon, J. IEEE 2018 IEEE transactions on magnetics Vol.54 No.11

<P>Magnetic drug targeting (MDT) by using magnetic nano-particles (MNPs) is a technique used to deliver drug molecules to a desired location. One of the major challenges in MDT is to develop an electromagnetic actuator to focus micro-/nano-particles into a desired deep region. A novel electromagnetic actuation scheme for pushing micro-/nano-particles has been designed to accumulate MNPs in the brain, and an optimal design is studied for the actuation system. The suggested design maximizes the magnetic gradient within a focusing field workspace and allows the accumulation of nano-particles on a specified surface. The configuration and specifications of the optimal design are introduced. Performance of the proposed design was examined through simulations with COMSOL Multiphysics software. The results show that applicability of this scheme is very high in practice because of the simple coil structure and easy guidance scheme.</P>