nils-herrmann/clean_scirepeval huggingface dataset:
Effects of cooling rate on the microstructure and tensile behavior of a Sn-3.5wt.%Ag solder

The tensile behavior and microstructure of bulk, Sn-3.5Ag solders as a function of cooling rate were studied. Cooling rate is an important processing parameter that affects the microstructure of the solder and, therefore, significantly influences mechanical behavior. Controlled cooling rates were obtained by cooling specimens in different media: water, air, and furnace. Cooling rate significantly affected secondary dendrite-arm size and spacing of the Sn-rich phase, as well as the aspect ratio of Ag3Sn. The Sn-rich dendrite-arm size and spacing were smaller for water-cooled specimens than for air-cooled specimens. Furnace cooling yielded a nearly eutectic microstructure because the cooling rate approached equilibrium cooling. The morphology of Ag3Sn also changed from spherical, at a fast cooling rate, to a needlelike morphology for slower cooling. The changes in the microstructure induced by the cooling rate significantly affected the mechanical behavior of the solder. Yield strength was found to increase with increasing cooling rate, although ultimate tensile strength and strain-to-failure seemed unaffected by cooling rate. Cooling rate did not seem to affect Young’s modulus, although a clear coorelation between modulus and porosity was obtained. The mechanical behavior was correlated with the observed microstructure, and fractographic analysis was employed to elucidate the underlying damage mechanisms.

Field of study: Materials science
Nuclear pairing and Coriolis effects in proton emitters

We introduce a Hartree-Fock-Bogoliubov mean-field approach to treat the problem of proton emission from a deformed nucleus. By substituting a rigid rotor in a particle-rotor model with a mean field, we obtain a better description of experimental data in 141Ho. The approach also elucidates the softening of kinematic coupling between particle and collective rotation, the Coriolis attenuation problem.

Field of study: Physics
Ethno-medicobotany of some tribal communities of Bankura district, West Bengal, India.

Investigation and documentation of the status of medicinal plants and associated knowledge was conducted in Taldangra block situated at south-western part of Bankura district. Data was collected and evaluated with a questionnaire survey, semi-structured interviews, field observations and vegetation surveys. 16 medicinal plant species used to treat 40 different ailments were recorded. Leaves are the most commonly collected plant parts for medicinal purposes. Much of the ethno-medicinal knowledge is concentrated in elderly members of the community. The medicinal plants are facing threats from agricultural expansion, wood extraction and overgrazing as informed by the local authorities. Consequently, medicinal plant resources are declining with time. The study aims to assess the contribution of nonconventional medicinal plants towards community health care. A total of 62 knowledge holders from the tribal community were interviewed and medicinal uses for 16 plants were recorded. The study illustrates that medicinal plant diversity is important for community health care, which in turn, ensures conservation, awareness creation towards sustainable utilization and management of these medicinal plants diversity.

Field of study: Biology
Biochar as electron donor for reduction of N2O by Paracoccus denitrificans

Biochar (BC) has been shown to influence microbial denitrification and mitigate soil N2O emissions. However, it is unclear if BC is able to directly stimulate the microbial reduction of N2O to N2. We hypothesized that the ability of BC to lower N2O emissions could be related not only to its ability to store electrons, but to donate them to bacteria that enzymatically reduce N2O. Therefore, we carried out anoxic incubations with Paracoccus denitrificans, known amounts of N2O, and nine contrasting BCs, in the absence of any other electron donor or acceptor. We found a strong and direct correlation between the extent and rates of N2O reduction with BC's EDC/EEC (electron donating capacity/electron exchange capacity). Apart from the redox capacity, other BC properties were found to regulate the BC's ability to increase N2O reduction by P. denitrificans. For this specific BC series, we found that a high H/C and ash content, low surface area and poor lignin feedstocks favored N2O reduction. This provides valuable information for producing tailored BCs with the potential to assist and promote the reduction of N2O in the pursuit of reducing this greenhouse gas emissions.

Field of study: Biology, Environmental science
A new technique to characterize the early stages of electromigration-induced resistance changes at low current densities

One of the promising tools to study electromigration (EM) in metal lines is the high resolution resistance measuring (HRRM) technique. Since the resistance is sensitive both to structural and geometrical changes in a metal line, this technique is very useful to study the early stages of EM-induced damage. However, with a conventional HRRM-technique it is impossible to separate resistivity from geometrical variations. Here, a new analyzing technique is presented which is able to separate these two contributions during EM-expeniments at low current densities. It is found that only during the very first stage of EM resistance variations are due to resistivity variations. On the contrary, resistance variations /spl Delta/R/R>2000ppm are mainly caused by a decrease in the cross section of the metal line.

Field of study: Engineering
Structure-function relationships in Gan42B, an intracellular GH42 β-galactosidase from Geobacillus stearothermophilus.

Geobacillus stearothermophilus T-6 is a Gram-positive thermophilic soil bacterium that contains a battery of degrading enzymes for the utilization of plant cell-wall polysaccharides, including xylan, arabinan and galactan. A 9.4 kb gene cluster has recently been characterized in G. stearothermophilus that encodes a number of galactan-utilization elements. A key enzyme of this degradation system is Gan42B, an intracellular GH42 β-galactosidase capable of hydrolyzing short β-1,4-galactosaccharides into galactose units, making it of high potential for various biotechnological applications. The Gan42B monomer is made up of 686 amino acids, and based on sequence homology it was suggested that Glu323 is the catalytic nucleophile and Glu159 is the catalytic acid/base. In the current study, the detailed three-dimensional structure of wild-type Gan42B (at 2.45 Å resolution) and its catalytic mutant E323A (at 2.50 Å resolution), as determined by X-ray crystallography, are reported. These structures demonstrate that the three-dimensional structure of the Gan42B monomer generally correlates with the overall fold observed for GH42 proteins, consisting of three main domains: an N-terminal TIM-barrel domain, a smaller mixed α/β domain, and the smallest all-β domain at the C-terminus. The two catalytic residues are located in the TIM-barrel domain in a pocket-like active site such that their carboxylic functional groups are about 5.3 Å from each other, consistent with a retaining mechanism. The crystal structure demonstrates that Gan42B is a homotrimer, resembling a flowerpot in general shape, in which each monomer interacts with the other two to form a cone-shaped tunnel cavity in the centre. The cavity is ∼35 Å at the wide opening and ∼5 Å at the small opening and ∼40 Å in length. The active sites are situated at the interfaces between the monomers, so that every two neighbouring monomers participate in the formation of each of the three active sites of the trimer. They are located near the small opening of the cone tunnel, all facing the centre of the cavity. The biological relevance of this trimeric structure is supported by independent results obtained from gel-permeation chromatography. These data and their comparison to the structural data of related GH42 enzymes are used for a more general discussion concerning structure-activity aspects in this GH family.

Field of study: Chemistry
Screening of Peptides as Broad-spectrum Neuraminidase Inhibitors against Influenza Viruses

In this study,a random duodecimal peptides phage display library was probed with influenza A viruses H1N1 and H3N2,resulting in the identification of 52 positive phage clones by using ELISA and neuraminidase inhibition assay.Based on analysis of peptide sequences displayed by positive phage clones,we picked up six peptides to synthesize which are conserved among several clones,respectively.Among these peptides,54-N1 and 69N2 had strong inhibitory activity against influenza A viral neuraminidase N1 and N2 as well as influenza type B neuraminidase,with IC50 7.486-14.693μmol/L for 54-N1 and IC50 6.605-13.007μmol/L for 69-N2.Peptides 54-N1 and 69-N2 inhibited plaque formation of influenza A and B viruses,with IC50 ranging from 18.38 to 31.76μmol/L and 16.56 to 25.49μmol/L,respectively.No cytotoxicity was observed with 54-N1 and 69-N2 at up to 10mmol/L.Also,54-N1 and 69-N2 were compared with Oseltamivir by neuraminidase inhibition assay and plaque formation assay.54-N1 and 69-N2 peptides therefore have potential values in development of nasal spray as new NA inhibitors for broad-spectrum antivirus therapy.

Field of study: Biology
Botanical characteristics, pharmacological effects and medicinal components of Korean Panax ginseng C A Meyer

AbstractKorean Panax ginseng C A Meyer is mainly used to maintain the homeostasis of the body, and the pharmacological efficacy of Korean ginseng identified by modern science includes improved brain function, pain-relieving effects, preventive effects against tumors as well as anti-tumor activity, enhanced immune system function, anti-diabetic effects, enhanced liver function, adjusted blood pressure, anti-fatigue and anti-stress effects, improved climacteric disorder and sexual functions, as well as anti-oxidative and anti-aging effects. Further clinical studies of these pharmacological efficacies will continue to be carried out. Korean ginseng is found to have such main properties as ginsenoside, ployacety-lene, acid polysaccharide, anti-oxidative aromatic compound, and insulin-like acid peptides. The number of ginsenoside types contained in Korean ginseng (38 ginsenosides) is substantially more than that of ginsenoside types contained in American ginseng (19 ginsenosides). Furthermore, Korean ginseng has been identified to contain more main non-saponin compounds, phenol compounds, acid polysaccharides and polyethylene compounds than American ginseng and Sanchi ginseng.

Field of study: Biology, Chemistry, Medicine
On the Structure of a quotient of the global Weyl module for the map superalgebra $\mathfrak{sl}(2,1)$

Let $A$ be a commutative, associative algebra with unity over $\mathbb{C}$. Using the definition of global Weyl modules for the map superalgebras given by Calixto, Lemay, and Savage we explicitly describe the structure of certain quotients of the global Weyl modules for the map superalgebra $\mathfrak{sl}(2,1)\otimes A$. We also give a nice basis for these modules. This work is an extension of a Theorem of Feigin and Loktev describing the structure of the Weyl module for the map algebra $\mathfrak{sl}_2\otimes A$. This work can naturally be extended to similar quotients of the global Weyl modules for $\mathfrak{sl}(n,m)\otimes A$.

Field of study: Mathematics
Encryptor Combiners: A Unified Approach to Multiparty NIKE, (H)IBE, and Broadcast Encryption

We define the concept of an encryptor combiner. Roughly, such a combiner takes as input n public keys for a public key encryption scheme, and produces a new combined public key. Anyone knowing a secret key for one of the input public keys can learn the secret key for the combined public key, but an outsider who just knows the input public keys (who can therefore compute the combined public key for himself) cannot decrypt ciphertexts from the combined public key. We actually think of public keys more generally as encryption procedures, which can correspond to, say, encrypting to a particular identity under an IBE scheme or encrypting to a set of attributes under an ABE scheme. We show that encryptor combiners satisfying certain natural properties can give natural constructions of multi-party non-interactive key exchange, low-overhead broadcast encryption, and hierarchical identity-based encryption. We then show how to construct two different encryptor combiners. Our first is built from universal samplers (which can in turn be built from indistinguishability obfuscation) and is sufficient for each application above, in some cases improving on existing obfuscation-based constructions. Our second is built from lattices, and is sufficient for hierarchical identity-based encryption. Thus, encryptor combiners serve as a new abstraction that (1) is a useful tool for designing cryptosystems, (2) unifies constructing hierarchical IBE from vastly different assumptions, and (3) provides a target for instantiating obfuscation applications from better tools.

Field of study: Computer science, Mathematics
Improved photoresponse performance of a self-powered Si/ZnO heterojunction ultraviolet and visible photodetector by the piezo-phototronic effect

In this work, we report the fabrication of self-powered Si/ZnO heterojunction ultraviolet and visible photodetectors (PDs) with different doping concentrations. The PDs have a fast response time (shorter than 0.13 s) to the ultraviolet and visible illumination at 0 V bias. The photocurrent of Sample A (high doping concentration) is more than 20 times larger than Sample B (low doping concentration) under 365 nm illumination and more than 150 times larger than Sample B under 450 nm illumination. The larger photoresponse is attributed to the stronger built-in electric field of Si/ZnO heterojunction. Furthermore, we demonstrate the impact of the piezo-phototronic effect for the self-powered Si/ZnO heterojunction ultraviolet and visible photodetector. Under a 0.7N compressive strain, the maximal UV and visible photocurrents are enhanced by about 33.7% and 13.9% for sample A (high doping concentration), about 67.3% and 74.5% for sample B (low doping concentration), respectively. The possible working principle is that the positive piezoelectric charges at the Si/ZnO interface lower the local energy band level of ZnO, thus strengthening the built-in electric field and shift the depletion region to the Si side leading to an increase in the photon-absorption volume. This work may provide a potential approach to enhance the performance of the self-powered Si/ZnO heterojunction ultraviolet and visible photodetector.

Field of study: Materials science
NUMERICAL SIMULATION FOR PRE-STRESSED CONCRETE CONTAINMENT UNDER INTERNAL EXPLOSIVE LOADING

As a nuclear power station might be attacked by pinpointed bombs in the modern war, numerical simulation for nuclear power plant owning pre-stressed reinforced concrete containment subjected to internal explosive loading is presented by employing fluid-structure coupling algorithm LS-DYNA. The material model used is Soil/Concrete constitutive model. The mechanics performance of containment under internal explosive loading is analyzed. The weak parts of the containment under internal explosive loading can clearly be shown by numerical method, and it is implied that the fluid-structure algorithm is effective to analyze mechanical performance of the containment.

Field of study: Engineering
Über einige Heterocyclische Ringsysteme der Silicium chemie

Die Chemie des Siliciums ist zu einem grossen Teil eine Chemie von Hochpolymeren und damit eine Chemie der Ketten und Ringe. In seltenen Fällen, wie in den Siloxenen bildet Silicium selbst Ringe. Besonders zahlreich und wichtig sind Ringsysteme des Siliciums mit den Heteroatomen Sauerstoff, Stickstoff, Kohlenstoff, Schwefel und Phosphor. Bedingt durch eine starke Variation der Ringglieder und ihrer Anordnung ergibt sich eine Vielfalt von verschiedenen Ringsystemen, wie in zahlreichen Vorträgen bereits in Erscheinung getreten ist. Im Rahmen meines Vortrages möchte ich nicht diese Vielfalt besprechen, sondern über einige Versuche am Stuttgarter Institut berichten, bei denen wir Ringbildung beobachteten. Vor einigen Jahren hatten wir uns mit der Silicophosphorsäure beschäftigt!, einer Verbindung, die bei der Umsetzung von Phosphorsäure mit Silicium dioxid erhalten wird. Ihre auffälligste Eigenschaft ist ihre Kristallinität. Auf chemischem Wege gelang uns die Darstellung verschiedener Derivate der Silicophosphorsäure, die sich durch die Formel Si04(POX)2 darstellen lassen mit X = H, D, CHa, C6H5, Cl. Diese Ergebnisse sprachen für ein starkes Ordnungsprinzip beim Aufbau dieser Verbindungen. Aus den i.r.-Spektren und einigen anderen Eigenschaften folgerten wir, dass ein dreifaches Ordnungsprinzip bei der Silicophosphorsäure vorliegt. 1. Kieselsäure und Phosphorsäure treten zusammen unter Bildung von Achtringen der Zusammensetzung Si2P204. 2. Diese Achtringe sind spiranartig über Siliciumatome miteinander zu Ketten verbunden. 3. Diese Ketten sind über Wasserstoffbrücken miteinander verknüpft, wodurch ein weiteres Ringsystem entsteht.

Field of study: Chemistry
Comparing the Cloud Vertical Structure Derived from Several Methods Based on Radiosonde Profiles and Ground-based Remote Sensing Measurements

The cloud vertical distribution and especially the cloud base height, which is linked to cloud type, are important characteristics in order to describe the impact of clouds on climate. In this work, several methods for estimating the cloud vertical structure (CVS) based on atmospheric sounding profiles are compared, considering the number and position of cloud layers, with a ground-based system that is taken as a reference: the Active Remote Sensing of Clouds (ARSCL). All methods establish some conditions on the relative humidity, and differ in the use of other variables, the thresholds applied, or the vertical resolution of the profile. In this study, these methods are applied to 193 radiosonde profiles acquired at the Atmospheric Radiation Measurement (ARM) Southern Great Plains site during all seasons of the year 2009 and endorsed by Geostationary Operational Environmental Satellite (GOES) images, to confirm that the cloudiness conditions are homogeneous enough across their trajectory. The perfect agreement (i.e., when the whole CVS is estimated correctly) for the methods ranges between 26 and 64%; the methods show additional approximate agreement (i.e., when at least one cloud layer is assessed correctly) from 15 to 41%. Further tests and improvements are applied to one of these methods. In addition, we attempt to make this method suitable for low-resolution vertical profiles, like those from the outputs of reanalysis methods or from the World Meteorological Organization's (WMO) Global Telecommunication System. The perfect agreement, even when using low-resolution profiles, can be improved by up to 67% (plus 25% of the approximate agreement) if the thresholds for a moist layer to become a cloud layer are modified to minimize false negatives with the current data set, thus improving overall agreement.

Field of study: Environmental science
Innovative design of a magnetocaloric system

In the present paper we consider the problem of optimizing the cooling of a magnetocaloric refrigerator. In this work we first theoretically and then experimentally study the performance of a single material regenerator under different operating conditions. The basic principles of the design and implementation of our magnetic refrigerator prototype are presented as well as a new magnetic assembly of NdFeB permanent magnets. The design of the equipment uses a movement of relative displacement optimized for the phases of activation and inactivation of the magnetic field. Each part of the equipment is implemented in order to be controlled separately and to allow a large variety of the tests: gear pumps with individual control, sequence of programmable magnetocaloric cycle, unit control by programmable controller and application programming interface by color LCD touch screen, real-time processing data acquisition using a National Instruments System implemented on Independent PC, expelled heat using different standard heat exchangers.

Field of study: Engineering
Investigation of the characteristics of overhang bonding for 3-D stacked dies in microelectronics packaging

It is indicated that the impact and deflection of overhang die during overhang bounding process results in considerable impact of performance of bonding in this paper. Specifically, the deflection is unstable and up to 27 μm for the given parameters, which results in low shear force strength and low success rate of overhang bonding. To improve the performance of the overhang bonding, an effective and novel approach, overhang bonding with thick Al, is presented. The approach decreases hardness of bonding die, which makes the bonding die more compliant during bonding process than that in the traditional approach, thus the shear strength and bonding success rate of overhang bonding will be improved. Finally, effects of ultrasonic and force to overhang bonding indicates that excessively low or excessively high ultrasonic power results in weak bonding performances, and so did the force.

Field of study: Engineering
Detection of Antibiotic Resistance Determinants and Their Transmissibility among Clinically Isolated Carbapenem-Resistant Escherichia coli from South India

The aim of this study was to analyze the prevalence of the CTX-M, TEM, SHV, VIM, NDM, and OXA genes in carbapenemase-producing Escherichia coli and their transmissibility at a tertiary care hospital in south India.  Twenty-one carbapenem-resistant E. coli (carbapenem-resistant Enterobacteriaceae; CRE) were collected from the Sri Sathya Sai Institute of Higher Medical Sciences (Puttaparthi India). Resistance to antibiotics was analyzed by Vitek-2, and the identity of the isolates was confirmed by 16S rDNA sequencing. RAPD and enterobacterial repetitive intergenic consensus (ERIC)-PCR were performed for molecular typing. Metallo-β-lactamase production was confirmed by a double disc synergy test. The presence of the extended-spectrum β-lactamases CTX-M, TEM, and SHV and of the carbapenemases NDM, VIM, and OXA was determined by PCR. Carbapenemase variants were further confirmed by sequencing. The transmissibility of the genes was tested by conjugation.  Twelve of the 21 (57%) carbapenem-resistant E. coli isolates were community acquired, indicating the spread of CRE in environmental samples. TEM and NDM-5 were found to be the major β-lactamases produced by the pathogens. OXA-181 was found in 5 of the isolates. All 21 isolates were found to harbor more than one of the tested β-lactamases, and all of the isolates were found to have the capacity to participate in conjugation; 15 of the transconjugants were found to have acquired the tested β-lactamases, substantiating their ability to be transferred to other strains of bacteria.  Monitoring of community-acquired carbapenem-resistant bacteria is very important as the association of resistance determinants with mobile genetic elements would present a serious clinical challenge.

Field of study: Medicine
A Method for Determining Relative Permeability Coefficient of Metal Fiber Filter

The relative water-permeability coefficients of metal fiber filter was measured by home-made test platform for determining water-permeability of porous material.The rationality of measurement results was verified.The relation between relative gas-permeability coefficients and relative water-permeability coefficients was obtained.The results show that the relation can provide guides for the characterization of relative permeability of metal fiber filter.

Field of study: Materials science