nils-herrmann/clean_scirepeval huggingface dataset:
Flame Retardant Polyethylene with Intumescent System Containing Macromolecule-Encapsulated Low Molecular Weight Charring Agent

Intumescent flame retardants are important halogen-free products used in polyethylene. However, their thermal stability and water-resistance are major shortcomings. In this work, a composite charring agent, pentaerythritol (PER) encapsulated by thermoplastic polyurethane (TPU) was used in an intumescent system to improve the flame retardancy of high density polyethylene (HDPE). The encapsulation of macromolecular charring agent TPU can effectively suppress the esterification reaction of PER and acid source in the intumescent system during processing. It can also remarkably decrease the water absorption, thus producing flame retardant HDPE with high performance. The synergistic effects of other common flame retardants including melamine phosphate, melamine polyphosphate and ammonium polyphosphate with TPU-encapsulated PER, as well as the ratio of charring agent to acid source were investigated so as to determine the optimum formula for use in HDPE. The flame retardant HDPE can reach limiting oxygen index of 33 and achieve UL-94 V-0 rating at 3.2 mm thickness when the ratio of MP/composite charring agent is 2:1 w/w.

Field of study: Materials science
Equivalent model and output characteristics for multi-stage balanced Cockcroft-Walton circuit

Based on the output effect of the circuit, the study used the charge transfer principle to describe the relative complex physical processes of balanced Cockcroft-Walton(C-W) circuit. Given the periodically turning model to mathematical analysis is equivalent to nonlinear conduction properties of the diode, theoretical model output formulas of ripple voltage and load-dropping output voltage that describe the output characteristics of C-W circuit are derivated. With circuit simulation software, the ripple voltage and the output voltage waveforms of the basic and balanced C-W circuit are simulated, and it illustrates that the ripple voltage of the balanced topology is far less than the basic, approximately the value percentage of 8%. The outputs of the theoretical model established in this paper are verified, and the results show that the calculated ripple voltage from the theoretical model is slightly lower than the simulation values, and the relative error between the calculated output voltage and simulation values is less than 10%.

Field of study: Physics
Effectiveness of Science, Technology, Engineering and Mathematics Programmes Offered in Kenyan Universities

The purpose of the study was to assess the effectiveness of Science, Technology, Engineering and Mathematics (STEM) programs offered in Kenyan universities. The study sought to answer questions about the adequacy of STEM programmes training facilities, qualification of academic staff and competency of academic staff. The study also sought to assess the adequacy of STEM curriculum, and the level of achievement of STEM learning outcomes. The study adopted a census survey and targeted 66 lecturers, 59 laboratory technologists and 275 students from Jomo Kenyatta University of Agriculture and Technology, Dedan Kimathi University of Technology and Technical University of Kenya which are technology-based universities in Kenya.  Data was collected through three sets of questionnaires each for lecturers, laboratory technologists and students. Analysis of the data was done through descriptive and inferential statistics. The findings were that there was lack of adequate facilities for training STEM programmes in the Kenyan universities and that the inadequacy varies from university to university with younger universities having the severest inadequacy. The study also found out that all the lecturers and Laboratory Technologists met the minimum requirements in terms of qualification and experience for their responsibilities and were competent.  The STEM curriculum and practical sessions were either well or satisfactorily prepared and the graduates were adequately prepared. It was also found out that STEM learning outcomes were achieved by the time of graduation. From the research results, it can be concluded that although there were inadequacies in the STEM training facilities, these inadequacies did not significantly affect the overall effectiveness of the programs.  Science, Technology, Engineering and Mathematics, Kenyan Universities DOI: 10.7176/JEP/11-21-09 Publication date: July 31 st 2020

Field of study: Education
Early Modern Diplomacy, Theatre and Soft Power: The Making of Peace. Nathalie Rivère de Carles. ed. Early Modern Literature in History. London: Palgrave Macmillan, 2016. xvi + 240 pp. $99.99.

sive, one wonders what the inclusion of and focus on additional texts written by women, or attention to texts by authors of color (especially in modern literature), might have revealed about the patterns and meanings she uncovers. That said, Rose makes a persuasive case for the plotting of maternal authority as an important structural and narrative device and, as a result, makes an important contribution to the understanding of maternity and gender as represented in Western literature across the centuries.

Field of study: History
Exploiting the fungal highway: development of a novel tool for the in situ isolation of bacteria migrating along fungal mycelium.

Fungi and bacteria form various associations that are central to numerous environmental processes. In the so-called fungal highway, bacteria disperse along fungal mycelium. We developed a novel tool for the in situ isolation of bacteria moving along fungal hyphae as well as for the recovery of fungi potentially involved in dispersal, both of which are attracted towards a target culture medium. We present the validation and the results of the first in situ test. Couples of fungi and bacteria were isolated from soil. Amongst the enriched organisms, we identified several species of fast-growing fungi (Fusarium sp. and Chaetomium sp.), as well as various potentially associated bacterial groups, including Variovorax soli, Olivibacter soli, Acinetobacter calcoaceticus, and several species of the genera Stenotrophomonas, Achromobacter and Ochrobactrum. Migration of bacteria along fungal hyphae across a discontinuous medium was confirmed in most of the cases. Although the majority of the bacteria for which migration was confirmed were also positive for flagellar motility, not all motile bacteria dispersed using their potential fungal partner. In addition, the importance of hydrophobicity of the fungal mycelial surface was confirmed. Future applications of the columns include targeting different types of microorganisms and their interactions, either by enrichment or by state of the art molecular biological methods.

Field of study: Biology, Environmental science
Determination of Monosaccharide Constituents in Lycium Barbarum Polysaccharide Using Capillary Ion Chromatography with Pulsed Amperometric Detection

A method for the determination of ten kinds of monosaccharide in Lycium barbarum polysaccharide was established using ICS-5000 Capillary IC system.In the pretreatment process,the type and concentration of acid,the hydrolysis temperature and lasting time were selected or optimized.The optimized hydrolysis condition was 100 ℃ lasting 120 min with 2 mol/L trifluoroacetic acid solution.Under this condition the recovery rate of fructose was about 50%.Recovery rate of the rest monosaccharide was 84% to 104%.In the experiment,new type of Eluent Generator,Capillary CarborPac PA20 column,and improved capillary amperometric detection cell were used.The calibration curves of ten kinds of monosaccharide showed good linearity with correlation coefficient above 0.999.The LOD is between 2.5 to 75 μg/L.It is suitable for the determination of monosaccharide constituents in Lycium barbarum polysaccharide.

Field of study: Chemistry
Topic Information Collection Based on the Hidden Markov Model

The topic information collection algorithm is widely used for its accuracy. The Hidden Markov Model (HMM) is used to learn and judge the relevance between the Uniform Resource Locator and the topic information. The Rocchio method is used to construct the prototype vectors relevant to the topic information, and the HMM is used to learn the preferred browsing paths. The concept maps including the semantics of the webpage are constructed and the web’s link structures can be decided. The validity of the algorithm is proved by the experiment at last. Comparing with the Best-First algorithm, this algorithm can get more information pages and has higher precision ratio.

Field of study: Computer science
Door-in-the-Face: Is it Really Necessary That Both Requests Be Made by the Same Requester?

The door-in-the-face technique increases the likelihood of individuals accepting a target request by confronting them, beforehand, with an extreme request. The present research tests a new door-in-the-face technique in which the two requests are formulated by two different requesters during the same interaction. 160 participants were asked to help a charity organization following a door-in-the-face procedure. According to the experimental conditions, requests were formulated by one or two requesters during the same or a different interaction. As predicted, the door-in-the-face effect was observed even if two requests are formulated by two requesters, but only if both are present during the interaction. Results are discussed in terms of a reciprocal concessions interpretation and a motivational interpretation.

Field of study: Psychology
Charge dynamics of a single donor coupled to a few-electron quantum dot in silicon

We report on the charge transfer dynamics between a silicon quantum dot and an individual phosphorous donor extracted from the current through the quantum dot as a probe for the donor ionization state. We employ a silicon n-metal-oxide-semiconductor field-effect transistor (MOSFET) with two side gates at a single metallization level to control both the device conductance and the donor charge. The elastic nature of the process is demonstrated by temperature and magnetic field independent tunneling times. The Fano factor approaches 1/2 revealing that the process is sub-poissonian.

Field of study: Physics
A Multivariate Quantile Predictor

We introduce a nonparametric quantile predictor for multivariate time series via generalizing the well-known univariate conditional quantile into a multivariate setting for dependent data. Applying the multivariate predictor to predicting tail conditional quantiles from foreign exchange daily returns, it is observed that the accuracy of extreme tail quantile predictions can be greatly improved by incorporating interdependence between the returns in a bivariate framework. As a special application of the multivariate quantile predictor, we also introduce a so-called joint-horizon quantile predictor that is used to produce multi-step quantile predictions in one-go from univariate time series realizations. A simulation example is discussed to illustrate the relevance of the joint-horizon approach.

Field of study: Mathematics
Anomalous Hall effect in magnetized graphene: intrinsic and extrinsic transport mechanisms approaching the quantized regime

We present a unified theory of the anomalous Hall effect (AHE) in magnetized graphene sheets in the presence of dilute disorder. The analytical study of Berry curvature and transport coefficients in a 4-band Dirac model [2 (spin) $\times$ 2 (pseudo-spin)] unveils a delicate balance between intrinsic and extrinsic contributions owing to the skyrmionic spin texture of magnetic Dirac bands. We show that the anomalous Hall conductivity changes sign when the Fermi energy approaches the topological gap as result of competing spin Lorentz forces. The predicted effect foreruns the quantum anomalous Hall regime and allows estimation of proximity spin-orbit strength directly from a Hall measurement. Our findings are relevant to outline a systematic route towards the demonstration of novel topological insulating phases in magnetized Dirac fermion systems.

Field of study: Physics
The s-process in the Galactic halo: the fifth signature of spinstars in the early Universe?

Very old halo stars were previously found to show at least four different abundance 'anomalies', which models of fast rotating massive stars (spinstars) can successfully account for: rise of N/O and C/O, low 12C/13C and a primary-like evolution of Be and B. Here we show the impact of these same stars in the enrichment of Sr and Ba in the early Universe. We study if the s-process production of fast rotating massive stars can offer an explanation for the observed spread in [Sr/Ba] ratio in halo stars with metallicity [Fe/H]< -2.5. By means of a chemical inhomogeneous model we compute the enrichment of Sr and Ba by massive stars in the Galactic halo. Our model takes into account, for the first time, the contribution of spinstars. Our model (combining an r-process contribution with a s-process from fast rotating massive stars) is able to reproduce for the first time the observed scatter in the [Sr/Ba] ratio at [Fe/H]< -2.5. Toward higher metallicities, the stochasticity of the star formation fades away due to the increasing number of exploding and enriching stars, and as a consequence the predicted scatter decreases. Our scenario is again based on the existence of spinstars in the early Universe. Very old halo stars were previously found to show at least four other abundance 'anomalies', which rotating models of massive stars can successfully account for. Our results provide a 5th independent signature of the existence of fast rotating massive stars: an early enrichment of the Universe in s-process elements.

Field of study: Physics
The effects of fixed-interval schedules on variability of pigeons' pecking location.

Many studies that have investigated performance under reinforcement schedules have measured response rate or interresponse time, which reflect the temporal dimension of responding; however, relatively few studies have examined other dimensions. The present study investigated the effects of fixed-interval schedules on the location of pigeons' pecking response. A circular response area 22.4 cm in diameter was used so that the pecking responses were effective over a wide range. Pigeons were exposed to a fixed-interval schedule whose requirement was systematically varied between conditions. Response location moved closer to the location of the last reinforced response as time elapsed in each trial. Additionally, as the fixed-interval duration requirement increased, response locations shifted to the border of the response area and the variability of response locations increased. These results suggest that fixed-interval schedules systematically control response location.

Field of study: Biology, Psychology
G-CSF-induced evacuation of sinusoidal NK cells and the facilitation of liver regeneration in a partial hepatectomy.

Since liver regeneration after partial hepatectomy (PHx) is known to improve by pretreatment with recombinant human G-CSF (rhG-CSF), we investigated the mechanism by evaluating the distribution and activity of sinusoidal NK cells. F344 rats were treated with rhG-CSF (250 microg/kg/day) for 5 days before PHx. Pretreatment with rhG-CSF improved the serum ALT levels and DNA biosynthesis of the remnant liver tissues at 20 h after PHx. Notably, the rhG-CSF pretreatment decreased the number of NK cells in the liver determined by immunohistochemistry using anti-NKR-P1A mAb before and at 20 h after PHx with no significant change in the NK activity per cell base, while also increasing the number of NK cells in the peripheral blood detected by flow cytometry. The rhG-CSF induced a pre-PHx downregulation of the IL-12p70 protein levels, while also promoting the post-PHx reduction of the protein levels of IL-12p70 and IFN-gamma. Conversely, rhG-CSF had no effect on the pre-PHx mRNA levels or the PHx-induced upregulation of mRNA levels of TNF-alpha, IL-1beta, IL-6, TGF-beta, IL-10, HGF, and c-Met determined by real-time RT-PCR. These results strongly suggest that rhG-CSF-induced facilitation of liver regeneration is achieved by immunoregulation through the intrahepatic IL-12 downregulation and evacuation of sinusoidal NK cells.

Field of study: Medicine
Flexible and accurate inference and learning for deep generative models

We introduce a new approach to learning in hierarchical latent-variable generative models called the “distributed distributional code Helmholtz machine”, which emphasises flexibility and accuracy in the inferential process. Like the original Helmholtz machine and later variational autoencoder algorithms (but unlike adver- sarial methods) our approach learns an explicit inference or “recognition” model to approximate the posterior distribution over the latent variables. Unlike these earlier methods, it employs a posterior representation that is not limited to a narrow tractable parametrised form (nor is it represented by samples). To train the genera- tive and recognition models we develop an extended wake-sleep algorithm inspired by the original Helmholtz machine. This makes it possible to learn hierarchical latent models with both discrete and continuous variables, where an accurate poste- rior representation is essential. We demonstrate that the new algorithm outperforms current state-of-the-art methods on synthetic, natural image patch and the MNIST data sets.

Field of study: Computer science
[Characteristics of the pre-manifest stage in young patients with the first episode endogenous psychosis].

: A retrospective study of pre-manifest personality traits in 120 young patients (16-25 years old) identified the clinical heterogeneity of the period preceding the first episode of juvenile endogenous attack-like psychosis. Depending on the degree of personality abnormalities, patients were stratified into 3 groups as having accentuated personality traits, personality disorders (psychopathy) or pseudopsychopathy, the latter divided into deficit and degenerative subgroups. Correlations between the degree of personality abnormality and the type of manifest episode and its nosological status were found.

Field of study: Medicine, Psychology
Thermophysical Properties of Meat Products: General Bibliography and Experimental Values

Experimental values for thermophysical properties of different kinds of meats are here presented such as: thermal conductivity, enthalpy, heat capacity, thermal diffusivity and density. All these values were obtained from an extensive selection of the existent bibliography. They correspond to measurements made at the normal temperature range during cooling and freezing processes. In the present work a complete and detailed table of bibliography is presented in order to facilitate the attainment of information about experimental data, measurement techniques and mathematical equations.

Field of study: Agricultural and Food sciences
Reprogramming, Circular Reasoning and Self versus Non-self: One-Stop Shopping with RNA Editing

Transcription of genetic information from archival DNA into RNA molecule working copies is vital for proper cellular function and is highly accurate. In turn, RNAs serve structural, enzymatic, and regulatory roles, as well as being informational templates for the ribosomal translation of proteins. Following RNA synthesis, maturing of RNA molecules occurs through various RNA processing events. One component of the collection of processes involving RNA species, broadly defined as RNA metabolism, is the RNA-editing pathway and is found in all animals. Acting specifically on RNA substrates with double-stranded character, RNA editing has been shown to regulate a plethora of genomic outputs, including gene recoding, RNA splicing, biogenesis and targeting actions of microRNAs and small interfering RNAs, and global gene expression. Recent evidence suggests that RNA modifications mediated via RNA editing influence the biogenesis of circular RNAs and safeguard against aberrant innate immune responses generated to endogenous RNA sources. These novel roles have the potential to contribute new insights into molecular mechanisms underlying pathogenesis mediated by mishandling of double-stranded RNA. Here, we discuss recent advances in the field, which highlight novel roles associated with the RNA-editing process and emphasize their importance during cellular RNA metabolism. In addition, we highlight the relevance of these newly discovered roles in the context of neurological disorders and the more general concept of innate recognition of self versus non-self.

Field of study: Biology
Pressure Transient Behavior for Alternating Polymer Flooding in a Three-zone Composite Reservoir

Alternating polymer flooding has achieved great attractions recently in oil industry, however, the research of pressure analysis in alternating polymer flooding reservoir is rare. This work presents a numerical pressure analysis method of three-zone composite model for formation evaluation. A new numerical pressure analysis model (three-zone composite model) is established by considering diffusion, convection, shear, and inaccessible pore volume, which is based on the rheology experiments. Based on this model, the type curves are then developed and sensitivity analysis is further conducted. The type curves have seven regimes in three-zone composite model. The characteristic is the obvious upturn of pressure derivative curve in transient regime between low concentration and high concentration polymer solution. Formation parameters can be interpreted by history matching and formation evaluation can be conducted based on this model. As an important part of formation evaluation, formation damage as a result of adsorption of polymers in porous media is evaluated by comparing the interpreted permeability with the original value before polymer flooding. The field test data proves that this proposed method can accurately evaluate reservoir characteristics in alternating polymer flooding reservoirs, which emphasizes the potential application of this method in petroleum industry.

Field of study: Materials science
Training Design for Repetitive-Slot-Based CFO Estimation in OFDM

Carrier frequency offset (CFO) estimation is a key challenge in wireless systems employing orthogonal frequency-division multiplexing (OFDM) modulation. Often, CFO estimation is carried out using a preamble made of a number, say J , of repetitive slots (RS). We here focus on the issue of optimal RS preamble design using the Cramer-Rao bound (CRB) averaged over the channel, which is assumed to be Rayleigh. We show that the optimal value of J is a tradeoff between the multipath diversity gain and the number of unknowns to be estimated. In the case of correlated channel taps, we also show that uniform power loading of the active subcarriers is not optimal (in contrast with the uncorrelated case) and better power loading schemes are proposed. The proposed power loading schemes consist of allocating more power to activated carriers with higher signal-to-noise ratios. Simulation-based performance results of the maximum likelihood estimator support the CRB-based theoretical results.

Field of study: Engineering