nils-herrmann/clean_scirepeval huggingface dataset:
Social Capital and the Teacher Student Relationship

This study was develop to solve the problem of students poor performance in public examinations from the view of teacher/ student relationship, giving specific attention to social capital formation as a determinant for its improvement. To achieve the above objective, the researchers developed a survey method of study with the help of questionnaires distributed to a sample size of 120 that was randomly selected, primary data was collected to test the research hypotheses. The researchers used correlation co-efficient with the help of Statistical Package for Social Sciences (SPSS) to determine the relations between the variables. The study revealed that social capital determines a good teacher/student relationship which enhances an effective teaching and learning process and student’s performance in public examinations. Again in most schools there is a zero base social capital accumulation, poor teacher/student relationship and ineffective teaching/learning process which accounts for the poor students performance in public examinations. The researchers recommended that a good social capital development by means of seminars should be established by school leaders and managers, and social capital and moral values should be introduced as a subject in the SS III school curriculum and as a general studies course for all students in the faculty of education in Nigerian universities and all colleges of education.

Field of study: Education
Corn leaf nitrate reductase--a nontoxic alternative to cadmium for photometric nitrate determinations in water samples by air-segmented continuous-flow analysis.

Development, characterization, and operational details of an enzymatic, air-segmented continuous-flow analytical method for colorimetric determination of nitrate + nitrite in natural-water samples is described. This method is similar to U.S. Environmental Protection Agency method 353.2 and U.S. Geological Survey method 1-2545-90 except that nitrate is reduced to nitrite by soluble nitrate reductase (NaR, EC 1.6.6.1) purified from corn leaves rather than a packed-bed cadmium reactor. A three-channel, air-segmented continuous-flow analyzer-configured for simultaneous determination of nitrite (0.020-1.000 mg-N/L) and nitrate + nitrite (0.05-5.00 mg-N/L) by the nitrate reductase and cadmium reduction methods-was used to characterize analytical performance of the enzymatic reduction method. At a sampling rate of 90 h(-1), sample interaction was less than 1% for all three methods. Method detection limits were 0.001 mg of NO2- -N/L for nitrite, 0.003 mg of NO3-+ NO2- -N/L for nitrate + nitrite by the cadmium-reduction method, and 0.006 mg of NO3- + NO2- -N/L for nitrate + nitrite bythe enzymatic-reduction method. Reduction of nitrate to nitrite by both methods was greater than 95% complete overthe entire calibration range. The difference between the means of nitrate + nitrite concentrations in 124 natural-water samples determined simultaneously bythe two methods was not significantly different from zero at the p = 0.05 level.

Field of study: Environmental science
Poison-Pen Diplomacy: Mexico, 1913

Following more than three decades of conservative dictatorship in Mexico Porfirio Diaz was overthrown by the idealistic Francisco Madero in 1911. Madero was impractical and disorganized and the unrest, which had characterized the last years under Diaz, continued throughout the brief presidency of his successor. In February 1913 a rising under Felix Diaz, nephew of the old dictator, led to civil war within the capital. The fall of Madero was assured when General Victoriano Huerta, who commanded the government forces, switched sides and implemented the arrest of the President. A pact between Felix Diaz and Huerta led to the provisional presidency of Huerta with Diaz lurking in the background as potential candidate for the permanent presidency.

Field of study: History
Kinetics and polarization phenomena of a sulfate electrolyte cell

A low-current galvanostatic technique has been used to study the polarization phenomena at the gaseous electrode of a two-phase sulfate electrolyte cell. Experimental results show that the variation of polarization current with overpotential is linear. The slope of the polarization lines varies with sulfur trioxide and oxygen partial pressures. The exchange current density is proportional to the SO 3 partial pressure and to the square root of the oxygen partial pressure. The exchange current density for the platinum-mesh electrode is four times greater than that obtained with the gold-mesh electrode.

Field of study: Materials science
A Simplification of the BLUS Procedure for Analyzing Regression Disturbances

This article deals with BLUS residuals in regression analysis, which have the property of being uncorrelated and having constant variance under the null hypothesis that the “true” disturbances have the same property. It is a continuation of the author's earlier article in this journal [7] and the results reported here are the following: (1) the BLUS residuals can be expressed conveniently in terms of the least-squares residuals by means of matrix operations of the order K (K being the number of unknown coefficients in the regression), (2) the BLUS residuals satisfy a stronger optimality condition than the one stated in , and (3) a simple expression is obtained for the coefficient vector which is implied by the BLUS residuals.

Field of study: Mathematics
Dynamic Mechanical Behaviour of Banana-pseudostem-filled Unplasticised Polyvinyl Chloride Composites

The dynamic mechanical behaviour of unplasticized polyvinyl chloride (UPVC) and its composites reinforced with banana pseudostem (BPS) fibres has been studied, with special reference to the effect of filler loading and temperature. Dynamic properties such as the storage modulus (E’) and damping behaviour (tan d) were evaluated as a function of BPS volume fraction. It was found that the storage modulus increased with increasing BPS content in the samples. At lower temperatures (in the glassy region), the E’ values of the samples were highest in both unmodified and acrylic-modified BPS/UPVC composites with 40% fibres. The glass transition temperature (Tg) associated with the damping peaks of BPS/UPVC composites reached its highest value at 94.9 °C with 20% fibre loading for unmodified BPS/UPVC composites, whereas, in the case of acrylic-modified composites, CA4 had the highest Tg at 98.7 °C.

Field of study: Materials science
Structural Evolution Mechanism of Early-Stage Nanocrystallization of Finemet Amorphous Ribbons

The Finemet alloy is used to make transformers for its excellent soft magnetic property. In order to study its distinctive character, it is essential to clarify the structural evolution mechanism especially in early nanocrystallization. The Fe73.5Si13.5B9Nb3Cu1 amorphous ribbons were prepared by single-roller melt-spinning process under argon atmosphere, and then annealed at 350°C, 380°C and 400°C for 10 mins respectively. We conduct the X-ray photoelectron spectrum (XPS) and the atom force microscope (AFM) to investigate the structural evolution mechanism in early nanocrystallization of Finemet. The X-ray photoelectron spectrum present the Cu atoms enrich in the surface and the Nb atoms redistribute to the iron-rich layer following with the increasing annealing temperature. The atomic force micrographs for the annealed specimens present a significant increase in the amount of the clusters and a dramatic drop in their average size. The structure evolution as observed is subjected to the atomic redistribution, which is crucial to the formation of the Cu-enriched clusters. In this paper, we discuss the behavior of different elements and elaborate the transformation of microstructure during the process of atomic migration.

Field of study: Physics
Doping evolution of the electronic specific heat coefficient in slightly-doped La2-xSrxCuO4 single crystals

Detailed doping dependence of the electronic specific heat coefficient gamma is studied for La2-xSrxCuO4 (LSCO) single crystals in the slightly-doped regime. We find that gamma systematically increases with doping, and furthermore, even for the samples in the antiferromagnetic (AF) regime, gamma already acquires finite value and grows with x. This suggests that finite electronic density of states (DOS) is created in the AF regime where the transport shows strong localization at low temperatures, and this means the system is not a real insulator with a clear gap even though it still keeps long range AF order.

Field of study: Physics
Evaluation of the heat pulse velocity technique for measurement of sap flow in rainforest and eucalypt forest species of south‐eastern Australia

Sap flow in the stems of two cut saplings each of Eucalyptus maculata (a canopy eucalypt forest tree), Doryphora sassafras and Ceratopetalum apetalum (both canopy rainforest trees of south-eastern coastal Australia) was measured by the heat pulse velocity technique and compared with water uptake from a potometer. Scanning electron micrographs of wounding caused by implantation of temperature sensor and heater probes into the sapwood showed that wounding was similar in rainforest and eucalypt species and was elliptical in shape, A circular wound has been implicitly assumed in previous studies, Accurate measurements of sapling water use were obtained using the smaller transverse wound dimension rather than the larger longitudinal dimension because maximum disruption of sap flow through the xylem vessels occurred in the transverse plane, Accurate measurements of sap flux were obtained above a minimum threshold sap velocity, These velocities were 15.7, 10.9 and 9.4 cm h(-1) for E. maculata, C. apetalum and D. sassafras, respectively, Below the threshold sap velocity, however, sap flow could not be accurately calculated from measurements of heat pulse velocity, The minimum threshold sap velocity appeared to be determined by probe construction and xylem anatomy. Despite the elliptical wounding and inaccurate measurement of sap flow below the threshold sap velocity, total sap flow over the experimental period for two saplings of each species was within 7% of water use measured by the potometer.

Field of study: Environmental science
SU-E-T-708: Spatial Accuracy of Small-Target SRS Using Conebeam CT Guidance and Static Arcs with MLC-Defined Fields

To measure the spatial accuracy of dose delivery under conebeam CT guidance to small targets using static arcs with MLC-defined fields.  A plastic (PMMA) phantom simulating a small brain lesion was constructed. The lesion was a cylindrical air cavity having 3 mm length and 3.175 mm diameter. Gafchromic EBT 2 film passing through the cavity was pin pricked at the exact geometric cavity center. Following CT simulation treatment plans involving static arcs with MLC-defined fields were designed, similar to radiotherapy with circular tertiary cones. 5×2 mm fields were generated by opening two centrally located leaf pairs of a high-definition MLC to 2.0 mm. The target was irradiated with 6 MV photons on a STx linac under conebeam CT image guidance to 600 cGy at isocenter. Films from coronal and sagittal planes were scanned and evaluated using the ImageJ software. The distance between the centroid of the 50% isodose line and the center of the pin prick was the measure of geographic accuracy.  Single arcs resulted in ellipsoidal 50% isodose surfaces having diameters of 5.0 mm along the gantry axis and 7.7 mm in the cross-sectional directions. 4-arc delivery at couch angles of 0, 45, 90 and 315 degrees produced 50% isodose surfaces having diameters of 5.6, 5.7 and 7.5 mm diameters along the lateral, longitudinal and anterior-posterior directions, respectively. In any of the experiments, the largest distance by which the centroid of the 50% isodose line missed the center of the target was 0.36 mm or less.  MLC-defined static arcs delivered under conebeam CT guidance provide precise irradiation of small targets. The method is very efficient since no special attachments or modifications of the accelerator are required. Since MLC leaves are stationary throughout the treatment, patient-specific QA involving phantoms should not be required.

Field of study: Medicine, Physics
Si(001)表面における酸化膜形成とSiO脱離の共存機構

Oxidation reactions at Si(001) surfaces have been studied via real-time in-situ photoemission spectroscopy for chemical bonding states of Si and O atoms, and mass spectrometry for desorbing SiO molecules with synchrotron radiation and supersonic O2 molecular beams in the temperature range from 900 K to 1300 K. In our previous studies, the SiO desorption yield decreased with increasing incident energy in the temperature range from 900 K to 1000 K,. In that case, the time evolutions of Si 2p photoemission spectra showed that SiO2 structure on the surface was easily formed by the action of larger incident energy and the increased SiO2 coverage correlated with the decreased SiO desorption yield. In this study, coincidence measurements of Si 2p photoemission spectra and SiO desorption yield revealed that the decrease of SiO correlated with the increase of Si2+ component, and the SiO desorption was terminated at the oxide thickness of 0.22 nm. These facts indicate that the SiO desorption takes place at the topmost Si dimmers and its precursor is so called T site, in which O atoms are bonding with the dangling bonds of the dimmers. Consequently, M1 and M2 in the Dual-Oxide-Species (DOS) model were clarified to be T sites and Si2+ states, respectively.

Field of study: Computer science
BRIEF COMMUNICATIONS: Investigation of a chemical HF laser utilizing a highpressure H2-SF6 mixture

An investigation was made of the energy characteristics of a chemical HF laser utilizing an H2–SF6 mixture and excited by a beam of relativistic electrons. Efficient lasing was obtained at gas mixture pressures up to 4.5 atm, a specific output energy of 50 J/liter being obtained at 1.5 atm. It should be possible to tune continuously the lasing frequency in a range 2.2 cm−1 centered on each vibrational-rotational line and thus build a highpower tunable laser of the kind required in laser-chemical investigations.

Field of study: Engineering, Physics
Interplay between oxidative stress and autophagy function and its role in inflammatory cytokine expression induced by palmitate in skeletal muscle cells.

Autophagy is a cellular process activated in response to various stresses such as starvation, hypoxia, and oxidative stress. Autophagy was reported to modulate the inflammatory pathways. However, whether autophagy is involved in regulation of palmitate-induced inflammation of skeletal muscle C2C12 cells is still unknown. The present study aimed to investigate the autophagic pathway in C2C12 cells treated with 0.5 mM palmitate. The results showed that the protein levels of LC3BII and P62 were increased in C2C12 cells after 12 h palmitate treatment. Besides, inhibition of autophagy by chloroquine or 3-methyladenin and its activation by rapamycin were associated with elevated mRNA and protein levels of IL-6 and TNF-α inflammatory cytokines in C2C12 cells. To study the mechanism by which autophagy impairment leads to activation of inflammatory responses, reactive oxygen species (ROS) levels in palmitate-treated cells were measured. The results showed that while palmitate stimulates ROS production, pretreatment of the cells with N-acetyl cysteine (NAC), a ROS scavenger, reduced inflammatory responses and also improved LC3-BII and P62 protein in the C2C12 cells exposed to palmitate. These findings suggest that palmitate-induced defect of autophagic flux leads to elevated inflammatory cytokine expression in the skeletal muscle cells by regulating the oxidative stress process.

Field of study: Medicine
Response of switchgrass yield to future climate change

A climate envelope approach was used to model the response of switchgrass, a model bioenergy species in the United States, to future climate change. The model was built using general additive models (GAMs), and switchgrass yields collected at 45 field trial locations as the response variable. The model incorporated variables previously shown to be the main determinants of switchgrass yield, and utilized current and predicted 1 km climate data from WorldClim. The models were run with current WorldClim data and compared with results of predicted yield obtained using two climate change scenarios across three global change models for three time steps. Results did not predict an increase in maximum switchgrass yield but showed an overall shift in areas of high switchgrass productivity for both cytotypes. For upland cytotypes, the shift in high yields was concentrated in northern and north-eastern areas where there were increases in average growing season temperature, whereas for lowland cultivars the areas where yields were projected to increase were associated with increases in average early growing season precipitation. These results highlight the fact that the influences of climate change on switchgrass yield are spatially heterogeneous and vary depending on cytotype. Knowledge of spatial distribution of suitable areas for switchgrass production under climate change should be incorporated into planning of current and future biofuel production. Understanding how switchgrass yields will be affected by future changes in climate is important for achieving a sustainable biofuels economy.

Field of study: Environmental science
Critical phases of viral production processes monitored by capacitance.

Over the last decade industrial manufacturing of viral vaccines and viral vectors for prophylactic and therapeutic applications is experiencing a remarkable growth. Currently, the quality attributes of viral derived products are assessed only at the end-point of the production process, essentially because in-process monitoring tools are not available or not implemented at industrial scale. However, to demonstrate process reproducibility and robustness, manufacturers are strongly advised by regulatory agencies to adopt more on-line process monitoring and control. Dielectric spectroscopy has been successfully used as an excellent indicator of the cell culture state in mammalian and yeast cell systems. We previously reported the use of this technique for monitoring influenza and lentiviral productions in HEK293 cell cultures. For both viruses, multi-frequency capacitance measurements allowed not only the on-line monitoring of the production kinetics, but also the identification of the viral release time from the cells. The present study demonstrates that the same approach can be successfully exploited for the on-line monitoring of different enveloped and non-enveloped virus production kinetics in cell culture processes. The on-line monitoring multi-frequency capacitance method was assessed in human HEK293 and Sf9 insect cells expression systems, with viral productions initiated by either infection or transfection. The comparative analyses of all the data acquired indicate that the characteristic capacitance signals were highly correlated with the occurrence of viral replication phases. Furthermore the evolution of the cell dielectric properties (intracellular conductivity and membrane capacitance) were indicative of each main replication steps. In conclusion, multi-frequency capacitance has a great potential for on-line monitoring, supervision and control of viral vector production in cell culture processes.

Field of study: Biology, Engineering
Mach number measurement of the gas flow from the supersonic nozzle in gas-puff Z-pinch

The Mach number of the gas flow from the supersonic nozzle in a gas puff Z pinch was determined by the two pressure transducer method. The measured Mach number rises with time and reaches to a maximum value of 4.25 that is close to 4.8, the value from a steady state gas flow calculation. This result shows that the steady state gas flow calculation can be used to estimate the Mach number of gas flow from a supersonic nozzle in gas puff Z pinch.

Field of study: Physics
Middle Precambrian and Older Apparent Age Values in Basement Gneisses of South Korea, and Relations with Southwest Japan

Rb-Sr whole-rock model age dates on Precambrian gneisses in South Korea have values that are greatly scattered owing to lower Mesozoic thermotectonic activity which caused an isotopic homogenization at about 180 m.y. The Rb-Sr data indicate, however, that the general original age of the province was within the range 2,000 ± 500 m.y. This belt is bordered on the southeast by a region invaded by Cretaceous granitic plutons that are approximately 100 m.y. old.

This sequence may be correlated with a similar sequence in southwest Japan, proceeding from north to south across the section: 1. A now-submerged source-region for the 2,000-m.y.-old pebbles in the Kamiaso conglomerate; 2. a 200-m.y. metamorphism of the Hida gneiss complex; and 3. a belt of Cretaceous and younger granite plutons. This matching yields an estimate of 2.6° lat as the total southward shift of southwest Japan from a former Precambrian position. This shift almost exactly matches the north-south opening of the Japan Basin, and suggests that the Kita-Yamato Bank and sea floor to the south of it is a submerged platform of 2,000-m.y.-old continental crust.

Field of study: Geology
Evaluation of Tube Diameter and Fan Induced Swirl in Polyethylene Ventilation Tubes

THE influence of flow swirl and tube diameter reduction have been examined for polyethylene ventilation tubes suitable for greenhouse applications. It was found that a conventional unmodified ventilation fan provided nearly identical flow rates from a 610 mm or 457 mm perforated ventilation tube, provided that swirl control was employed at the tube inlets. A six vane antiswirl device was installed that removed swirl for free fan exhaust. The antiswirl device can be made by a greenhouse operator or tradesman. Operation of the 457 mm tube without swirl control was found to be unacceptable, since the required contraction piece increased the fan induced swirl, causing tube vibration and poor flow distribution. Measurements of discharge from the ventilation holes were obtained along both tubes for flow with and without swirl control. The total discharge was found to be in good agreement with the measured flow into the fan in all cases. Friction factors were obtained for a nonperforated 610 mm tube. A cosine correction for swirl was included in the analysis to account for the actual length of flow path. The resulting friction factors were slightly lower than smooth pipe values in all cases. Polyethylene tubes can be reduced in size for a number of applications if flow swirl is controlled. Smaller tube sizes for overhead ventilation are of interest to greenhouse operators, because size reduction leads to less light blockage and hence to greater crop productivity.

Field of study: Agricultural and Food sciences
Effect of AlGaAs composition on the type-I to type-II transition in AlInAs/AlGaAs self-assembled quantum dots

We study the transition from type-I to type-II AlInAs/AlGaAs self-assembled quantum dots (QDs) which is induced by changing the Al composition of an AlGaAs matrix. We found theoretical evidence for type-II band alignment above the crossover Al concentration . For this purpose, we obtained the phase diagram for different QD radii, and we can identify the region where the electron states derived from the X-valley are lower than those derived from the Γ-point. The spatial distribution of electrons and holes is very sensitive to QD size variations. Furthermore, the effect of the QD type on the exciton binding energy is investigated. The ground-state exciton binding energy is always significantly smaller for type-II than for corresponding type-I systems, which originates from the redistribution of the electron and hole wave function.

Field of study: Materials science