nils-herrmann/clean_scirepeval huggingface dataset:
Electrokinetic Flow Analysis System for the Determination of Phenols in Water by On-line Liquid-Liquid-Liquid Microextraction

An electrokinetic flow analysis(EFA) system was developed for the determination of phenolic compounds in water samples.The analyte preconcentration and matrix clean-up was performed by an on-line liquid-liquid-liquid microextraction(LLLME) unit.The EFA system consisted of one homemade electroosmotic pump and four solenoid valves,which were controlled by a personal computer with a homemade interface card and Visual C program.The obtained conditions were as follows:dodecanol was used as the orginic solvent of liquid membrane supported by a 10 cm×450 μm i.d.polypropylene hollow fiber,10 μL 0.25 mol/L NaOH was the back-extracting solution,a sample flow rate of 2.0 mL/min and 7.5 times through the extraction channel back and forth were chosen in the analysis.When the total phenolic compounds in 1 mL wastewater was determined,the analytical time needed 9 min,the enrichment factor and limit of detection(LOD) were 53 and 3 μg/L respectively,which were much lower than the maximum allowed level in industrial wastewater.The linear concentration ranged from 9.4×10-3 to 5.7 mg/L phenol,which were adopted as a converted concentration for total phenols.When the total phenolic compounds in 6 mL surface water was determined,the analytical time was 49 min,the enrichment factor and LOD were 300 and 0.6 μg/L respectively,which were lower than the maximum allowed level in surface water.The linear concentration ranged from 1.7 ×10-3 to 1.0 mg/L phenol.

Field of study: Chemistry
Heat transfer in unsteady axisymmetric second grade fluid

This work looks at the heat transfer effects on the flow of a second grade fluid over a radially stretching sheet. The axisymmetric flow of a second grade fluid is induced due to linear stretching of a sheet. Mathematical analysis has been carried out for two heating processes, namely (i) with prescribed surface temperature (PST case) and (ii) prescribed surface heat flux (PHF case). The modelled non-linear partial differential equations in two dependent variables are reduced into a partial differential equation with one dependent variable. The resulting non-linear partial differential equations are solved analytically using homotopy analysis method (HAM). The series solutions are developed and the convergence is properly discussed. The series solutions and graphs of velocity and temperature are constructed. Particular attention is given to the variations of emerging parameters such as second grade parameter, Prandtl and Eckert numbers.

Field of study: Mathematics
An algorithmic strategy for selecting a surgical approach in cervical deformity correction.

Adult degenerative cervical kyphosis is a debilitating disease that often requires complex surgical management. Young spine surgeons, residents, and fellows are often confused as to which surgical approach to choose due to lack of experience, absence of a systematic method of surgical management, and today's plethora of information regarding surgical techniques. Although surgeons may be able to perform anterior, posterior, or combined (360°) approaches to the cervical spine, many struggle to rationally choose an appropriate approach for deformity correction. The authors introduce an algorithm based on morphology and pathology of adult cervical kyphosis to help the surgeon select the appropriate approach when performing cervical deformity surgery. Cervical deformities are categorized into 5 different prevalent morphological types encountered in clinical settings. A surgical approach tailored to each category/type of deformity is then discussed, with a concrete case illustration provided for each. Preoperative assessment of kyphosis, determination of the goal for surgery, and the complications associated with cervical deformity correction are also summarized. This article's goal is to assist with understanding the big picture for surgical management in cervical spinal deformity.

Field of study: Medicine
Detection Uncertainty Matters for Understanding Atmospheric Rivers

Travis A. O’Brien, Ashley E. Payne, Christine A. Shields, Jonathan Rutz, Swen Brands, Christopher Castellano, Jiayi Chen, William Cleveland, Michael J. DeFlorio, Naomi Goldenson, Irina V. Gorodetskaya, Héctor Inda Díaz, Karthik Kashinath, Brian Kawzenuk, Sol Kim, Mikhail Krinitskiy, Juan M. Lora, Beth McClenny, Allison Michaelis, John P. O’Brien, Christina M. Patricola, Alexandre M. Ramos, Eric J. Shearer, Wen-Wen Tung, Paul A. Ullrich, Michael F. Wehner, Kevin Yang, Rudong Zhang, Zhenhai Zhang, and Yang Zhou

Field of study: Environmental science
A recording sampling system for measuring laser energy.

An apparatus has been designed and built which simultaneously measures the energy incident on a biological system which is being exposed to a laser beam. The advantages of the direct reading system are: (1) no attention is required of the laser operator, (2) a permanent record is produced, (3) true integration of the pulse train is accomplished, (4) high inherent accuracy, (5) in conjunction with a fast oscilloscope, it reproduces pulse waveforms with minimum distortion, and (6) calibration is simple and direct. Basically the system employs a fast high-current capability photodiode, a high-quality integrating capacitor, an emission-limited pump diode with a servo-motor amplifier combination for dark current balance. The photodiode cathode surface is S-1 so that both ruby and neodymium wavelengths 694.3 mmicro and 1060 mmicro, respectively, may be measured. Reproducibility is better than 3% when compared with a blackbody receiver (cone radiometer). A Tektronix 585A oscilloscope and P-80 cathode follower probe fitted with a 50-Omega load resistor can be plugged into the photodiode housing in place of the integrating capacitor for waveform observation and power-level measurements. Calibration on an absolute basis is easily accomplished by simultaneous comparison with a calibrated blackbody receiver (cone radiometer).

Field of study: Physics
Bonus or flat wage? An experiment into the principal-agent problem

We conduct a simple principal–agent experiment in order to find the effects of information asymmetry on compensation. Our aim is the analysis of the appropriate compensation and its impact on employee’s effort. Furthermore we want to compare the offered compensation and the supplied effort in the version without communication and we want to know whether the experimental observations are consistent with the theoretical considerations. The experimenters found out that compensations observed during the experiment were different from those suggested by the theory and although they were theoretically not enough to induce high effort, we could observe high performance supplied by the agents.

Field of study: Mathematics
ADSORPTION BEHAVIOR OF SOLID WASTE OF LEATHER MANUFACTURE

The adsorption behavior of chrome-containing and tannins-containing solid waste originated from leather manufacture was investigated. The experimental results indicated that the chrome-containing leather waste could substantially adsorb acid dyes and direct dyes.However it was ineffective for the adsorption of alkali dyes.The adsorption equilibrium of chrome-containing leather waste to acid dyes and direct dyes could be described by the Langmuir equation and the pseudo-second-order rate model gave perfect fitting to the adsorption kinetics.The tannins-containing leather waste exhibited high adsorption capacities to Au 3+、U 6+、Th 4+ and Hg 2+.However the adsorption equilibrium of metal ions on the tannins-containing leather waste could not be described by single equation.The adsorption equilibrium of Cu 2+、U 6+、Pb 2+ and Hg 2+ could be described by the Freundlich equation, while that of Au 3+ and Th 4+ could be described by the Langmuir equation.These facts implied that the different adsorption mechanisms might be involved in the adsorption processes of metal ions on the tannins-containing leather waste. The pseudo-second-order rate model also gave perfect fitting to the adsorption rate data of metal ions on the tannins-containing leather waste. The adsorption column of chrome-containing leather waste could be easily regenerated after adsorption of dyes. Similarly, the adsorption column of tannins-containing leather waste could be also easily regenerated after adsorption of metal ions except Au 3+. The change of adsorption behavior of the regenerated columns was not considerable, which indicated the potential value of a using solid waste of leather processing in environmental protection.

Field of study: Chemistry, Environmental science
XAFS study on gallium ions implanted in silicon carbide.

Local structure of gallium ions implanted in silicon carbide has been investigated using extended X-ray absorption fine structure on the Ga K-edge. The crystallinity of the implantation layer is compared in the samples prepared under several different conditions of implantation temperature and post-implantation annealing. It is found that significant damage is induced by the implantation at room temperature, but the crystallinity recovers by the subsequent annealing at high temperature at 1600 degrees C. On the other hand, the best crystallinity is obtained by the implantation at high temperature of 500 degrees C. but the annealing results in degrading the crystallinity. This indicates an influence of the post-implantation annealing at high temperature on the crystallinity in atomic level, which relates to the secondary defects in lattice observed by electron microscope.

Field of study: Physics
Pilot Safety Evaluation of a Novel Strain of Bacteroides ovatus

Bacteroides ovatus ELH-B2 is considered as a potential next-generation probiotic due to its preventive effects on lipopolysaccharides-associated inflammation and intestinal microbiota disorders in mice. To study safety issues associated with B. ovatus ELH-B2, we conducted comprehensive and systematic experiments, including in vitro genetic assessments of potential virulence and antimicrobial resistance genes, and an in vivo acute toxicity study of both immunocompetent and immunosuppressed mice via cyclophosphamide treatment. The results indicated that this novel strain is non-toxigenic, fragilysin is not expressed, and most of potential virulence genes are correlated with cellular structures such as capsular polysaccharide and polysaccharide utilizations. The antibiotic resistance features are unlikely be transferred to other intestinal microorganisms as no plasmids nor related genomic islands were identified. Side effects were not observed in mice. B. ovatus ELH-B2 also alleviated the damages caused by cyclophosphamide injection.

Field of study: Biology
Structural and conformational study of peptides containing glycine and alanine residues by 13C CPMAS NMR spectroscopy in solid state.

The results of the structural and conformational studies carried out using 13C CPMAS NMR technique on several glycine and alanine containing peptides in the solid state are reported. The study demonstrates the effects of variations in 13C chemical shifts due to conformation and hydrogen bonding. The possibility of applying this technique to obtain insight into the conformational characteristics of peptides of unknown structures is discussed.

Field of study: Biology, Chemistry, Physics
KEM/DEM: Necessary and Sufficient Conditions for Secure Hybrid Encryption

The KEM/DEM hybrid encryption paradigm combines the efficiency and large message space of secret key encryption with the advantages of public key cryptography. Due to its simplicity and flexibility, the approach has ever since gained increased popularity and has been successfully adapted in encryption standards. In hybrid public key encryption (PKE), first a key encapsulation mechanism (KEM) is used to fix a random session key that is then fed into a highly efficient data encapsulation mechanism (DEM) to encrypt the actual message. A composition theorem states that if both the KEM and the DEM have the highest level of security (i.e. security against chosen-ciphertext attacks), then so does the hybrid PKE scheme. It is not known if these strong security requirements on the KEM and DEM are also neccessary, nor if such general composition theorems exist for weaker levels of security. In this work we study neccessary and sufficient conditions on the security of the KEM and the DEM in order to guarantee a hybrid PKE scheme with a certain given level of security. More precisely, using nine different security notions for KEMs, ten for DEMs, and six for PKE schemes we completely characterize which combinations lead to a secure hybrid PKE scheme (by proving a composition theorem) and which do not (by providing counterexamples). Furthermore, as an independent result, we revisit and extend prior work on the relation among security notions for KEMs and DEMs.

Field of study: Computer science, Mathematics
Indigenous Media and Political Imaginaries in Contemporary Bolivia by Gabriela Zambrano Villarreal (review)

Bolivia is well known for its politically engaged film industry. Most famously, Jorge Sanjinés directed a series of films with an explicit political agenda, including Yawar mallku (Blood of the Condor), which resulted in the eviction of the Peace Corps from the country, and El coraje del pueblo (English version title is The Night of San Juan) that used community members to reenact a brutal 1967 massacre of striking miners. Over the past several decades, indigenous activists have taken advantage of technological advances in filmmaking to use this medium to forward their own social and political interests. Bolivia continues to be at the forefront of these developments. Since 1997, the nongovernmental National Plan of Indigenous Audiovisual Communication has worked with indigenous communities and organizations to produce and disseminate videos that explore their concerns. Their productions provide a convenient medium through which to understand indigenous realities.

Field of study: History
Void fraction measurement of oil-gas two-phase flow based on ant system and electrical capacitance tomography

A new method based on electrical capacitance tomography(ECT) in conjunction with the ant system was proposed to measure the void fraction of oil-gas two-phase flow.The 12-electrode capacitance sensor of ECT system could obtain 66 measured capacitance values.The void fraction measurement model parameters f and b,which were obtained by the least square method in advance,were determined according to the flow pattern that was first identified by the ECT system.Then the most important combined capacitance set which had decisive influence on the void fraction of a given state of measurement was obtained based on the ant system,and the corresponding pheromone of the ant system was regarded as the weight of this set.The capacitance set and its weight were simultaneously input to the measurement model to obtain the void fraction.The experimental results showed that the proposed method for the void fraction measurement was effective under different flow patterns owing to avoidance of complex image reconstruction and good real-time performance.The maximum error was less than 5.5% as compared with the quick closing valve method,and the measurement time was within 0.08 s.

Field of study: Chemistry, Environmental science
Role of the proteasome in ethanol-induced liver pathology.

The ubiquitin-proteasome system has come to be known as a vital constituent of mammalian cells. The proteasome is a large nonlysosomal enzyme that acts in concert with an 8.5 kDa polypeptide called ubiquitin and a series of conjugating enzymes, known as E1, E2 and E3, that covalently bind multiple ubiquitin moieties in a polyubiquitin chain to protein substrates in a process called ubiquitylation. The latter process targets protein substrates for unfolding and degradation by the 26S proteasome. This enzyme system specifically recognizes and degrades polyubiquitylated proteins, many of which are key proteins involved in cell cycle regulation, apoptosis, signal transduction, and antigen presentation. The 26S proteasome contains a cylinder-shaped 20S catalytic core that, itself, degrades proteins in an ATP- and ubiquitin-independent manner. The 20S form is actually the predominant enzyme form in mammalian cells. Proteolysis by the constitutive 20S proteasome is vital in removing oxidized, misfolded and otherwise modified proteins. Such degradation is critical as a means of cellular detoxification, as intracellular accumulation of damaged and misfolded proteins is potentially lethal. Studies have shown that inhibition of proteasome activity can lead to cell death. Ethanol and its metabolism cause partial inhibition of the proteasome. This leads to a number of pleiotropic effects that can affect a variety of cellular processes. This critical review describes important aspects of ethanol metabolism and its influence on the proteasome. The review will summarize recent findings on: (1) the interactions between the proteasome and the ethanol metabolizing enzyme, CYP2E1; (2) the dynamics of proteasome inhibition by ethanol in animal models and cultured cells; (3) ethanol-elicited suppression of proteasome activity and its effect on signal transduction; (4) The role of proteasome inhibition in cytokine production by liver cells; and (5) ethanol elicited suppression of peptide hydrolysis and the potential effects on antigen presentation. While the principal focus is on alcohol-induced liver injury, the authors foresee that the findings presented in this review will prompt further research on the role of this proteolytic system in other tissues injured by excessive alcohol consumption.

Field of study: Medicine
Multimedia in Teacher Education: Perceptions & Uses

Educational systems around the world are under increasing pressure to use the new technologies to teach students the knowledge and skills they need in the 21st century. Education is at the confluence of powerful and rapidly shifting educational, technological and political forces that will shape the structure of educational systems across the globe for the remainder of this century. Many countries are engaged in a number of efforts to effect changes in the teaching/learning process to prepare students for an information and technology based society. Multimedia provide an array of powerful tools that may help in transforming the present isolated, teacher-centred and text-bound classrooms into rich, student-focused, interactive knowledge environments. The schools must embrace the new technologies and appropriate multimedia approach for learning. They must also move toward the goal of transforming the traditional paradigm of learning. Teacher education institutions may either assume a leadership role in the transformation of education or be left behind in the swirl of rapid technological change. For education to reap the full benefits of multimedia in learning, it is essential that pre-service and in-service teachers have basic skills and competencies required for using multimedia. This paper, therefore, explores the latent benefit of using multimedia tools particularly in professional teacher education. The paper also discusses why pre-service teachers need to use multimedia technologies within the context of students familiar, technology-rich living spaces to develop their own teaching skills and the technology skills of their students. In addition, the author also explains the role of multimedia in enhancing the 21st century skills.  Multimedia, Teacher Education,, Pre Service Teachers, 21 st Century

Field of study: Education
Enhanced phosphorylation of 65 and 74 kDa proteins by tumor necrosis factor and interleukin-1 in human peripheral blood mononuclear cells.

Tumor necrosis factor (TNF) and interleukin-1 (IL-1) enhanced the phosphorylation of identical cytosolic 65 kDa protein (P65 or l-plastin) and 74 kDa protein (P74) at serine residues in human peripheral blood mononuclear cells (PBMC). The isoelectric points of P65 and P74 were 5.6 and 4.7 to 5.0, respectively. The phosphorylation of these proteins increased with a few minutes and reached maximal levels of approximately 3 times the unstimulated levels by 10 minutes. The phosphorylation of P65 and P74 was extensively enhanced by a potent protein kinase C (PKC) activator, PMA. However, there was no translocation of PKC from cytosol to membrane in PBMC that was stimulated with either TNF or IL-1, which suggests that PKC does not participate in TNF or IL-1 signal transduction. cAMP dependent protein (PKA) activators, forskolin and PGE2, failed to increase the phosphorylation, which is in agreement with the data showing that neither TNF nor IL-1 increased cAMP levels in PBMC. These results suggest that induction of phosphorylation of P65 and P74 by TNF and IL-1 is not mediated by PKC and PKA but may be mediated by another protein kinase and result in overlapping of biological activities between TNF and IL-1.

Field of study: Medicine
Propagation of Pinched Electron Beams for Pellet Fusion

We present results which are encouraging for a multibeam approach to relativistic-electron-beam--induced pellet fusion. A self-pinched relativistic electron beam with nominal parameters of 1.1 MV, 200 kA, and 5-mm radius has been propagated at atmospheric pressure over distances of up to 1 m. Gross beam beam stability and reasonable energy transport efficiency has been achieved. A simple Alfven-type calculation corroborates the propagation result, and a self-consistent particle simulation indicates the possibility of scaling to very high-..nu../..gamma.. beams.

Field of study: Physics
Prose Fiction in Language Teaching

Literature is language in use and is generally seen to play a vital role in language teaching. Literary texts provide us with much aesthetic, intellectual and emotional pleasure in that the writer often seeks to delineate their vision of human experience through a creative, emotive use of language. In essence literature serves to enhance the students’ language competence. This paper examines the relationships between language and literature. This is demonstrated with several prose texts with a view to show their pedagogical relevance to students’ language needs. In the conclusion, it is emphasized that the link between language and literature which had been ignored in the past should now be exploited for the development of students’ performances in the target language.

Field of study: Education