nils-herrmann/clean_scirepeval huggingface dataset:
Reflectivity and absorption of thin ZnTe epilayers near the exciton-polariton

The authors have studied the exciton absorption of single-crystalline ZnTe epilayers grown by metalorganic vapour-phase epitaxy on (001) GaAs substrates. More than 1 mu m of the 2 mu m thick layers, including a dislocation-rich interface region, has been removed by a chemical etching procedure. Transmission and reflectivity measurements have been performed on the same samples with thicknesses below 1 mu m. Samples glued on a glass substrate reveal two exciton absorption structures, which are identified to be the n=1 heavy- and light-hole excitons. This splitting nearly disappears for free-standing layers. The absorption maximum appears at the transverse exciton energy, which has been determined by a polariton model for the reflectivity. The deformation potentials obtained from hydrostatic pressure measurements and from the shift and splitting of the exciton are a=-5.5 eV and b=-1.4 eV at low temperatures.

Field of study: Materials science
Reaction-diffusion kinetics for enzymatic hydrolysis of konjac glucomannan

Enzymatic hydrolysis of konjac glucomannan(KGM)by β-mannanase was studied at constant mass ratio of enzyme to substrate to investigate the reaction-diffusion mechanism.By using size exclusion chromatography(SEC),the changes in molecular weight distribution of KGM were followed during the process of hydrolysis.When the ratio of enzyme to substrate was constant,the changes in molecular weight at different KGM concentrations were remarkably different,which showed that the reaction depended on the diffusion of enzyme.The changes in molecular weight showed a zero-order kinetics.Integrating the empirical reaction kinetics and diffusion characteristics,a reaction-diffusion model was established from a series of chromatographic results.But the degradation rate was shown to be greatly affected by the diffusion of enzyme as well as the concentration of substrate.This equation of reaction kinetics indicated the importance of diffusion,and the experimental data can be well predicted at semi dilute concentrations of KGM.

Field of study: Chemistry, Environmental science
Nutritional potential of nine underexploited legumes in Southwest Nigeria.

There is increasing interest in finding new food sources to alleviate malnutrition in developing countries. Nine little known legumes (Mallotus subulatus (white variety), Cassia hirsutta, Canavalia ensiformis, Vignea subterranean (checkered variety), Vigna racemosa, Mallotus subulatus (red variety), Vignea subterranean (cream variety), Sphenostylis sterocarpa and Cajanus cajan in the South western Nigeria were studied to highlight their nutritional significance. The proximate composition, fatty acid composition, total phenolic content, antioxidant activity and amino acid profile of the legumes were evaluated using standard methods in the literature. Significant (p<0.05) variations existed among the legumes with respect to their proximate composition, fatty acid profile, total phenolic content, antioxidant activity and amino acid composition. Mallotus subulatus (red variety) rated highest in protein, Vigna racemosa and Sphenostylis sterocarpa had high starch contents, while Cajanus cajan rated best in dietary fibre (non starch polysaccharides) among the legumes tested. The total unsaturated fatty acids were much higher than the total saturated fatty acids in all the legumes. Linoleic acid (C18:2) was the most abundant polyunsaturated fatty acid (PUFA) identified, at varying levels, in all the legumes studied. All the legumes had varying levels of linolenic acid (C18:3). Sphenostylis sterocarpa had the least essential fatty acid contents (32.73%) and the highest (57.25%) was found in Cassia hirsutta. Cajanus cajan had the highest total phenolic content (293.23 mg/100g) and also rated best in its antioxidant activity. The percentage total essential amino acids were between 45.53 and 48.44 which are considered adequate for ideal protein foods. All the legumes were good sources of total phenolics and possess moderate to high antioxidant activities suggesting that these lesser known legumes are promising commodities in combating food and nutrition insecurity in Nigeria and other countries where they are known and consumed.

Field of study: Agricultural and Food sciences
Entrepreneurship Education: Towards an Innovative Approach

Over two decades into the introduction of the entrepreneurship education in Polytechnics in Ghana as a compulsory course, little assessment has been done on the teaching and learning of the course. This paper presents the findings on the assessment of the progress of entrepreneurship education in Ghanaian Polytechnics. This study is expected to contribute to existing empirical knowledge regarding the teaching and learning of entrepreneurship in higher educational institutions in a developing country context. The evaluation criteria of entrepreneurship education was based on what is taught, how it is taught and the context in which the entrepreneurship education is taking place in the polytechnics . Mixed method research design was used to collect and analyze data from five Polytechnics out of the ten which were selected in random. It was primarily found that entrepreneurship education in the polytechnics involves more of theoretical and foreign knowledge impartation than the development of practical skills which can be applicable to the Ghanaian ecosystem. It concludes with a discussion on innovative approaches to teaching and learning of entrepreneurship to reflect the needs of the local ecosystem.  entrepreneurship education, higher educational institutions, innovative pedagogy

Field of study: Education
Investigation of Parametrically-Induced Excitation in Concrete Columns

A mathematical model is developed which accounts for the non-linear material characteristic of concrete members. The axial and transverse motions of concrete columns, are found to be second-order and fourth-order, non-linear partial differential equations, respectively. These equations are then reduced to a set of coupled non-linear differential equations in terms of time-dependent modal coefficients. The governing equations are employed to investigate parametric stability of a simply supported concrete column.

Field of study: Engineering
Phosgene in the UTLS: seasonal and latitudinal variations from MIPAS observations

The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) is a Fourier transform spectrometer that measured mid-infrared atmospheric limb emission spectra from July 2002 to April 2012 on board the polar-orbiting satellite ENVISAT. We have used MIPAS data to study the latitudinal variations of phosgene (COCl2 or carbonyl chloride) and, for the first time, its seasonal variation in the upper troposphere/lower stratosphere region (UTLS). Retrievals of phosgene were made using the 830–860 cm−1 region, corresponding to the ν5 bands of COCl2. Unfortunately, in that region, the ν4 band of CFC-11, which is much stronger than COCl2 ν5, hides the phosgene emission. In order to evaluate seasonality and latitudinal distribution of phosgene we have analysed all the measurements made by MIPAS on days 18 and 20 of each month of 2008 with the optimized retrieval model (ORM) recently upgraded with the multi-target retrieval technique and with the optimal estimation functionality to apply external constraints to the state vector. Average seasonal profiles of phosgene show an evident latitudinal variability with the largest values observed in the tropical regions (maximum  ≈  35 parts per trillion by volume (pptv) at about 300 hPa). In the midlatitude and polar regions, the volume mixing ratio (VMR) values do not exceed 30 pptv and the vertical distributions are less peaked. Our analysis highlights that COCl2 seasonal variability is fairly low, apart from the polar regions.

Field of study: Environmental science
Characteristics of the laser emission spectrum of a thallium photodissociation laser

The results are reported of investigations into the spectral and energy characteristics of a thallium photodissociation laser, emitting due to the 7S/sub 1/2/--6P/sub 3/2/ (lambda = 535 nm) and 7S/sub 1/2/--6P/sub 1/2/ (lambda = 337.6 nm) transitions. The experiments were performed using two types of resonator, and this made it possible to increase the radiation power density above the superradiance level and to operate in two-wavelength lasing regimes. On reaching a certain power density the structure of the laser emission spectrum changed, the nature of this change being different for the different lines. A discussion of the results obtained is given.

Field of study: Engineering, Physics
The Governance and Its Impact on the Organizational Intelligence from the Point of View for the Employees of the Social Security Corporation (SSC) in Jordan

This study aimed at analyzing the governance and its impact on the organizational intelligence from the point of view of employees of the Social Security Corporation (SSC) in Jordan.To achieve the objectives of the study, a questionnaire was developed covering the study's variables. The questionnaire was distributed to the entire community of the study, which had 191 managers, deputy directors, heads of department, heads of division as well as employees.The study used analytical descriptive statistical methods, using the Statistical Package for the Social Sciences (SPSS).The study reached a number of results, the most important are the following: The general arithmetic mean of the respondents 'perceptions of the dimensions of governance in the SSC came at a medium rating.Also, the general arithmetic mean of the respondents' perceptions of the dimensions of the organizational intelligence in the SSC came at a medium rating. And, there is a statistically significant relationship between the independent variable (governance) and its different dimensions and the dependent variable (organizational intelligence) and its different dimensions.In light of these results, the study recommended a number of recommendations, the most important are: establishing a governance system that is declared to all parties concerned to implement it, and clarifies the duties and responsibilities of each employee in the corporation.Another recommendation is continuing to develop the capabilities that enhance the company's abilities of sensing and responding because of its positive impact on boosting the organizational intelligence.

Field of study: Business
Monitor System Design for Machine Electric Spindle based on MCGS

This article introduces some principal parameters, which are required to be monitored, of machine electric spindle,hardware components of the system and main functions of configuration software MCGS(Monitor and Control Generated System) in China. The system is a set of online monitoring and analysis system that is designed for machine electric spindle. The system analyzes real-time information acquired from the vibration of machine electric spindle, the rotational speed, the motor, the temperature between front and back bearing, the axial displacement and relative parameters. It can provide information for workers who are not familiar with spindle to recognize spindle condition or discover early fault information, thus it eliminates malfunction and avoids destructive accidents. It also can offer technical information, such as machine electric spindle optimum design and test.

Field of study: Computer science
PLEISTOCENE CLIMATES IN EASTERN AND SOUTHERN AFRICA

Pleistocene climates in the southern half of Africa are indicated by evidence of lakes in regions now dry, ancient soils for whose development the climate is now too dry or too wet, inactive wind-blown sand now covered by vegetation, and signs of former glaciation. Such features indicate climates different from those now prevailing. In addition, anomalies in the distribution of living organisms seem to support the assumption of climatic change. Most of the evidence indicates change in annual amount or seasonal distribution of rainfall, but some suggests former temperatures lower, possibly by as much as 5°C., than those of today. Few of the features discussed are well fixed stratigraphically, but most of them are probably late Pleistocene. The atmospheric-circulation pattern shows that annual amount and seasonal distribution of rainfall differ markedly in various regions in the subcontinent. The current literature contains a start toward a reconstruction of former patterns which are compatible with the geologic and biogeographic evidence, based on analogies with modern anomalies. Although probable, the theory that pluvial climates in Africa were contemporaneous with glacial climates in Europe remains unsupported by geologic evidence, mainly because data are very few.

Field of study: Geology
Semi-inclusive deep inelastic lepton scattering in a pion cloud model

In this note we explore the consequences of the pion cloud model for semi-inclusive deep inelastic lepton scattering. We argue that by scattering on a few-nucleon target, the detection of the recoiling target would provide a valuable test of the meson cloud model. We estimate the semi-inclusive cross section for deep inelastic lepton scattering on a3He target, as function of Bjorkenx and target recoil momentum.

Field of study: Physics
Silicon carbide FETs for high temperature nuclear environments

SiC transistors can operate at very high temperatures and survive very high radiation doses. These characteristics make SiC potentially the ideal technology for nuclear power applications. In this paper we report, for the first time, on the active in-core irradiation of 6H-SiC depletion-mode junction field-effect transistors (IFETs) at 25/spl deg/ and 300/spl deg/C in a nuclear reactor operated at 200 kW. No significant degradation in the device characteristics was observed until the total neutron fluence exceeded 10/sup 15/ n/cm/sup 2/ for irradiation at 25/spl deg/C, and no significant changes were observed even at 5/spl times/10/sup 15/ n/cm/sup 2/ at 300/spl deg/C. The results of this experiment may also indicate exciting evidence for the anneal of neutron displacement damage for devices irradiated at 300/spl deg/C.

Field of study: Physics
Dynamics of artisanal fisheries performed with hook-and-line gear under different management regimes in Brazil

Artisanal fisheries are a source of livelihood for small-scale fishermen around the world. The risk of overfishing is a constant concern. The establishment of conservation units is a strategy to alleviate the pressure on fishing stocks. In the State of Ceara, there are two conservation units in the category of extractive reserves (Resex) 1 . This study characterized the dynamics of the artisanal fishing of the hook-and-line fleet in three communities with different modes of use. Data were collected by monitoring the landings twice a month from 2017 to 2019 at Mucuripe beach, Batoque Resex and Prainha do Canto Verde 2 (PCV) Marine Resex, State of Ceara, Brazil. Data were collected for biomass (B), fishing effort (f), species composition, fishing ground and type of bottom habitat. A total of 234 vessels were sampled and 85 species were identified at the three sites, showing that the use of fisheries targets multiple species. The Kruskal-Wallis test was applied to analyze the production and fishing effort data. The largest landing was shown at Mucuripe (10.16 ton), which also had the highest mean production (224 kg). Mucuripe employed the highest mean effort (2711 hook*hour) and showed the highest number of species per boat, and Batoque the lowest (48 hook*h). Two-way ANOVA was used to test differences in richness and catch per unit effort 3 (CPUE) across sites and between seasons. There was no difference in CPUE across sites. The species richness was different across sites, with the highest average in Mucuripe (6.4 species per boat) and the lowest in PCV (3.6 species per boat). There was no variation in species richness between seasons. The correspondence analysis identified a strong association of the ballyhoo halfbeak, corocoro grunt, chere-chere grunt, Atlantic spadefish and Atlantic thread herring with the artificial hard bottom habitat, and a correlation of the guachanche barracuda and black grouper to the natural hard bottom. In both Resex, more specimens were caught in artificial structures and in Mucuripe in natural bottom habitats. The linear regression analysis indicated a significant relationship between effort (f) and biomass (B) in Batoque and PCV. There was no relationship between f and CPUE in both reserves. In this study, it was observed that the choice of fishing grounds and bottom habitat influenced the composition of species caught by the artisanal fleet. No difference in fishing production was found across the studied sites under different types of management.

Field of study: Environmental science
The Gift of Psychological Closeness: How Feasible Versus Desirable Gifts Reduce Psychological Distance to the Giver

Gift-giving is a common form of social exchange but little research has examined how different gift types affect the psychological distance between giver and recipient. We examined how two types of gifts influence recipients’ perceived psychological distance to the giver. Specifically, we compared desirable gifts focused on the quality of the gift with feasible gifts focused on the gift’s practicality or ease of use. We found that feasible (vs. desirable) gifts led recipients to feel psychologically closer to givers (Studies 1-4). Further clarifying the process by which receiving a desirable versus feasible gift affects perceived distance, when recipients were told that the giver focused on the gift’s practicality or ease of use (vs. the gift’s overall quality), while holding the specific features of the gifts constant, they felt closer to the gift-giver (Study 5). These results shed light on how different gifts can influence interpersonal relationships.

Field of study: Psychology
Oscillations in a white blood cell production model with multiple differentiation stages

In this work we prove occurrence of a super-critical Hopf bifurcation in a model of white blood cell formation structured by three maturation stages. We provide an explicit analytical expression for the bifurcation point depending on model parameters. The Hopf bifurcation is a unique feature of the multi-compartment structure as it does not exist in the corresponding two-compartment model. It appears for a parameter set different from the parameters identified for healthy hematopoiesis and requires changes in at least two cell properties. Model analysis allows identifying a range of biologically plausible parameter sets that can explain persistent oscillations of white blood cell counts observed in some hematopoietic diseases. Relating the identified parameter sets to recent experimental and clinical findings provides insights into the pathological mechanisms leading to oscillating blood cell counts.

Field of study: Biology, Mathematics
Video Feedforward for Reading

Video feedforward can create images of positive futures, as has been shown by researchers using self− modeling methods to teach new skills with carefully planned and edited videos that show the future capability of the individual. As a supplement to tutoring provided by community members, we extended these practices to young children struggling to read. Ten students with special needs participated in a multiple baseline intervention. Each received tutoring only, followed by tutoring plus video feedforward, another phase of tutoring only, and follow-up. Overall, reading fluency improved significantly for all students; in 9 out of 10 cases, rate of improvement was significantly greatest during feedforward. Other measures (e.g., word identification) confirmed student progress from most at-risk to mid-stream status. We conclude that video images of success with challenging materials may enhance the acquisition of reading skills.

Field of study: Education
Direct observation of standing wave formation at surface steps using scanning tunneling spectroscopy.

Using scanning tunneling microscopy and spectroscopy, we have observed the formation of standing waves by the scattering of surface state electrons at steps and defects on the Au (111) surface. From the periods, peak positions, and intensities of the standing waves, the energy dispersion of the surface states, the scattering phase shifts as a function of energy and crystallography direction, and coherence length could be determined

Field of study: Physics
Analysis on the Impact Fracture of In-situ VCp/Fe Composite

VC reinforced Fe matrix composites have been prepared by in-situ reaction synthesis process. The impact fracture morphology of VCp/Fe composites have been analyzed by optical microscopy and SEM. The results show that the failure of VCp/Fe composites are mainly caused by ferrite cleavage and some pearlite noncontinuous laminar particle cleavage fracture The amount and distribution of VC particles have an important effect on VCp/Fe composites; and matrix can be refined by appropriate increase of carbon content.

Field of study: Materials science
Privatisation: A Policy in Search of a Rationale: A Comment

The Kay-Thompson paper interprets privatisation as the sale of public sector industrial assets. It would be best to stick to this interpretation, for the discussion of other aspects of privatisation in the Kay-Thompson paper is not extensive. The authors list five possible aims in the denationalisation of public sector industry. (i) improvement of the economic performance of the industries concerned, (2) resolving the difficulties of relations between government and nationalised industries, (3) revenue raising, (4) reduction of the power of public sector unions, (5) the promotion of a popular capitalism through wider share ownership. Some of these aspects are not analysed at all, and others only partially or indirectly. The authors' interest is obviously mainly in the first aim improved economic performance. Here they provide an illuminating summary of recent academic literature, which suggests that it is the interaction of private ownership and competition which produces efficiency. Competition ensures that low efficiency is penalised by low profits; while private ownership and effective capital markets ensure that low profits are met by eventual withdrawal from the activity concerned. The main thesis of the paper is that the managements of nationalised industries will oppose more competition, either in the form of breaking up existing structures or introducing a more liberal regulatory regime. But as the co-operation of existing managements is important (or essential? the authors are not clear) to the success of privatisation, they have the power to frustrate the competitive objectives. Hence privatisation has not brought competition, but simply involved the transformation of public into private monopolies. Moreover this tendency has increased as the privatisation exercise has got under way. The result, as I understand the authors, is not merely useless or neutral, but positively harmful, because it is more difficult to unscramble organisations or change the rules of the game after denationalisation. My first inclination was to agree with the authors about the broad tendency, although to substitute the slogan 'missed opportunity' for their 'worse than useless' conclusion. But on re-reading the paper doubts grew. Most of the early acts of privatisation did not include public sector monopolies. They were either sales of concerns already operating in highly competitive markets such as Britoil, or Amersham; or they consisted of sales of shares from the Government portfolio such as the successive tranches of BP. The authors list six examples of asset sales involving public sector monopolies or semi-monopolies. These are British Telecom, British Airways, British Airports Authority, National Bus Company, British Gas and the Regional Water Authorities. 2

Field of study: Economics