nils-herrmann/clean_scirepeval huggingface dataset:
Absorption system based on the refrigerant R134a

The possibility of using 1,1,1,2-tetrafluoroethane (R134a) as a refrigerant in combination with different organic absorbents, such as dimethylether tetraethyleneglycol (DMETEG), N-methyl ϵ-caprolactam (MCL) or dimethyl-ethyleneurea (DMEU), in absorption units was investigated. The procedures in this paper are presented for the model working pair R134a-DMETEG. Temperature-pressure-concentration curves were constructed on the basis of vapour-liquid equilibrium measurements. Excess thermodynamic properties of the mixture were calculated, and enthalpy-concentration diagrams were constructed. The density and viscosity of the working fluids were measured. Thermostability testing of R134a-DMETEG showed that no changes were found in either of the phases over the course of the test. The performances of the investigated working fluids were compared in terms of the coefficient of performance (COP) and circulation ratio (f), which were evaluated by a computerized simulation program based on a single-stage absorption cycle containing a jet ejector as a mixer and preabsorber. The values of the COP for the three combinations were similar (R134a-DMEU reached 0.49, R134a-MCL 0.47 and R134a-DMETEG 0.46), but the value of f for R134a-DMTEG was lower than for the other two pairs. R134a-DMETEG was therefore the best of the three candidate working pairs.

Field of study: Engineering
Selection harvest in temperate deciduous forests: impact on herb layer richness and composition

Herb layer richness and composition of four forest types and three different management treatments were investigated in 16 deciduous forest stands of northern Germany. Specifically, we compared the species richness and composition occurring in mature forest stands that were single-tree and group selection harvested to those in unmanaged reference stands. Mean species richness of all herb layer species increased significantly with increasing harvest severity. When analyzing plant groups separately, it became obvious that this overall pattern was not consistent. While a negative relationship was detected between vernal herb richness and harvest severity, group selection harvest significantly increased species richness of summer herbaceous forest species and generalists. Woody species richness was not related to harvest severity. Community composition of the spring aspect was not significantly affected by selection harvest, whereas herb layer species composition in the summer aspect differed significantly among the three harvest treatments. A dominance of highly competitive shrub and generalist species was confined to some parts of the most intensively harvested stands. Overall, our results indicate that the herb layer community was not severely adversely affected by selection harvest at the intensities used in the studied stands. It is suggested that selection harvest systems may be feasible tools with which to conserve local forest vascular plant diversity and at the same time to meet the demand for timber products. However, information about forest history and the implementation of the selection harvest system are basic requirements when interpreting the results of studies on understorey response to selection harvest.

Field of study: Environmental science
Ronchi shearing interferometry for wavefronts with circular symmetry.

Ronchi testing of a focused electromagnetic wave has in the last few years been used extensively at X-ray free-electron laser (FEL) facilities to qualitatively evaluate the wavefront of the beam. It is a quick and straightforward test, is easy to interpret on the fly, and can be used to align phase plates that correct the focus of aberrated beams. In general, a single Ronchigram is not sufficient to gain complete quantitative knowledge of the wavefront. However the compound refractive lenses that are commonly used at X-ray FELs exhibit a strong circular symmetry in their aberration, and this can be exploited. Here, a simple algorithm that uses a single recorded Ronchigram to recover the full wavefront of a nano-focused beam, assuming circular symmetry, is presented, and applied to experimental measurements at the Matter in Extreme Conditions instrument at the Linac Coherent Light Source.

Field of study: Physics
The horseshoe kidney: Surgical anatomy and embryology.

Horseshoe kidneys are a common, yet enigmatic, renal malformation. This review critically appraised the literature surrounding the embryology, etiology and clinical anatomy of horseshoe kidneys. The systematic literature search produced 104 articles, and 56 primary and further secondary references. There were several etiological theories regarding horseshoe kidneys. The established view was that during ascent, the kidneys come into close apposition as they pass through an arterial fork. Another possible mechanism related to lateral flexion of the trunk or rotation of the caudal embryo; the association of asymmetrical horseshoe kidneys with a number of vertebral conditions supported this hypothesis. More recent animal models implicated the notochord and sonic hedgehog signaling. Furthermore, it has been suggested that the isthmus may be the result of ectopic mesenchymal tissue. Surgical anatomy of the horseshoe kidney is complex, due to variability in location, orientation and blood supply. Both arterial and venous anatomy is highly variable. This raised the question of whether anomalous blood supply is the cause or result of abnormal renal position. In the majority of cases, the isthmus contained functional renal parenchyma. In over 90% of cases, fusion between the kidneys occurred at the lower pole. Despite commonly being quoted as 'held back by the inferior mesenteric artery' at L3, in reality the isthmus was only found immediately inferior to this in 40% of cases.

Field of study: Medicine
X-ray structures of Mn, Cd and Tb metal complexes of troponin C.

The crystal structures of three metal complexes of troponin C (TnC) have been determined and refined where the two occupied structural Ca(2+) sites in the C domain have been substituted by Mn(2+), Cd(2+) and Tb(3+). The X-ray intensity data were collected to 2.1, 1.8 and 1.8 A resolution, respectively, on the three metal complexes, which are isomorphous with Ca-TnC. The three complexes have r.m.s. deviations of 0.27, 0.25 and 0.35 A, respectively, for all protein atoms, from Ca-TnC. Irrespective of the charge on the metal (+2 or +3), the occupied sites 3 and 4 exhibit a distorted pentagonal bipyramidal coordination, like Ca-TnC, with seven ligands, six from the 12-residue binding loop and the seventh from a water molecule. Mn(2+) at site 4 seems to display a longer distance to one of the carboxyl bidentate ligands representing an intermediate coordination simulating the six-coordinate Mg(2+). The carboxyl O atoms of the bidentate Glu12 are displaced on the side of the equatorial plane passing through the remaining three ligands with one O atom closer to the plane (Delta of 0.11 to 0.76 A) than the other (Delta of 0.93 to 1.38 A). The two axial ligands are an aspartic carboxyl O atom and a water molecule. The metal is displaced (0.18 to 0.56 A) towards the water facing the water channel.

Field of study: Chemistry
Lateral relations of deltaic palaeosols from the Lower Jurassic Rønne formation on the island of Bornholm, Denmark

The Ronne Formation, which crops out on the southern coast of the Danish island of Bornholm, consists of coal-bearing siliciclastic strata. A major feature in these sediments is successions of different types of stacked palaeosol profiles beneath coal seams of varying thickness. The most obvious and diagnostic properties of these palaeosols are the occurrence of fossil roots and the colour of the horizons penetrated by roots. Three types of palaeosol profiles represent an association of soils that developed on the ancient, tidally influenced lower deltaic plains. Low relief areas were characterized by hydromorphic conditions due to poor drainage. This resulted in the development of waterlogged Gleysols in backswamp areas, and less acid Histosols in closed bays of coastal swamps. In the latter case peat-bogs were formed. In topographically higher areas, as levee banks and crevasse splays, freely drained Podzols developed. This soil-type was dominated by kaolinite in the clay fraction, promoted by acid leaching. The morphology and geochemistry of all palaeosols were controlled by the position of the ground-water table, topography, climate, and rate of subsidence. In the Podzol profiles occasional flooding resulted in the formation of spodic B horizons, accumulated close to the contemporaneous water-table of that time. The organic-rich top horizons of the Podzol and Histosols profiles acted as a geochemical barrier and trapped various elements. Litter decomposition by microorganisms in these soils resulted in a concentration of potassium at the surface, thus giving an opportunity to form illite. The presence of siderite in the peat-bogs suggests that reducing conditions prevailed here at the time of their formation. The soils were formed in a humid tropical climate. This is indicated by the overall leaching pattern on cations in the Podzols and Histosols, the accumulation of peat in the Histosols, and the fossil flora.

Field of study: Environmental science, Geography
Preparing for task: linguistic formats for procedural instructions in early years schooling

This paper presents an analysis of the linguistic design of teacher turns that can be characterised as procedural instructions. Adopting an Interactional Linguistic framework, we examine a corpus of around 100 h of classroom interaction in early years classrooms in Australia. Procedural instructions were delivered to the whole class during ‘carpet time’, and are used to direct students to follow the steps of a planned activity in a subsequent phase of the lesson. Unlike previous studies of the linguistic formats of teacher directives, these procedural instructions were predominantly found to occur in declarative formats of various kinds (future or present tense, modalised), rather than imperatives. However, there is a range of formats for procedural instructions found over the corpus, and it is shown how their linguistic design is highly sensitive to the kinds of actions being undertaken and to the local contingencies in which such actions appear in the course of classroom interaction.

Field of study: Education, Linguistics
Joint moments of the total discounted gains and losses in the renewal risk model with two-sided jumps

This paper considers a renewal insurance risk model with two-sided jumps (e.g. Labbe et al., 2011), where downward and upward jumps typically represent claim amounts and random gains respectively. A generalization of the Gerber–Shiu expected discounted penalty function (Gerber and Shiu, 1998) is proposed and analyzed for sample paths leading to ruin. In particular, we shall incorporate the joint moments of the total discounted costs associated with claims and gains until ruin into the Gerber–Shiu function. Because ruin may not occur, the joint moments of the total discounted claim costs and gain costs are also studied upon ultimate survival of the process. General recursive integral equations satisfied by these functions are derived, and our analysis relies on the concept of ‘moment-based discounted densities’ introduced by Cheung (2013). Some explicit solutions are obtained in two examples under different cost functions when the distribution of each claim is exponential or a combination of exponentials (while keeping the distributions of the gains and the inter-arrival times between successive jumps arbitrary). The first example looks at the joint moments of the total discounted amounts of claims and gains whereas the second focuses on the joint moments of the numbers of downward and upward jumps until ruin. Numerical examples including the calculations of covariances between the afore-mentioned quantities are given at the end along with some interpretations.

Field of study: Mathematics
Water stress effects on guard cell anatomy and the mechanical advantage of the epidermal cells

Vicia faba plants grown under water deficit were found to have guard cells considerably smaller than those of plants grown under well-watered conditions. Stomala of plants adapted to drought conditions have been observed in past studies to maintain opening at plant water potentials lower than those of plants not so adapted. By employing the geometric interpretation of the mechanical advantage (Wu, Sharpe & Spence, 1985), an anatomical/mechanical basis was found that helps explain how such opening in drought conditions can occur. The geometry and resulting mechanical properties of small stomata, in contrast to larger stomata, give them the capability of opening or maintaining open pores with lower guard cell turgor pressures, relative to the turgor of the surrounding epidermal cells.

Field of study: Environmental science
A new highly integrated sample environment for protein crystallography.

Protein crystallography is becoming a popular technique that is routinely used to access structural information. At one end of the process, sample preparation is now facilitated by commercially available crystallization kits. At the other end, structure determination has been made easier by automated software. Data collection, the step in between, is now usually performed on synchrotron sources. However, it is still restricted to experienced users and requires significant help from beamline staff. Part of this difficulty arises from the sophisticated experimental setup, which comprises a goniometer, a magnetic head, a device for changing the sample and monitoring accessories. It was proposed that this setup could be simplified by replacing these elements by a robotic arm that can perform all of the required tasks. In the present paper, it is demonstrated that this new setup can be used on a synchrotron beamline to mount and centre the sample and to collect diffraction data. This new system completely changes the design of the experimental setup by merging functions that were previously considered to be distinct. Moreover, automation of sample handling need not be considered as a specific development and is now included in a unique multipurpose device.

Field of study: Chemistry
Vested Interests and Political Institutions

VESTED INTERESTS ARE PARTOF THE EVERYDAY LANGUAGE of political science. But they are not part of its theories, at least not in any explicit or systematic way. My argument here is that, particularly in our efforts to understand the stability and change of political institutions, vested interests are not only substantively important—which is why political scientists cannot help but talk about them—but also have great analytic value and provide an especially productive basis for theory. If we think about political institutions in terms of the formal structures of government, including governmental programs and the structural arrangements surrounding them, a good place to begin is with a few simple but profound facts. Vested interests are present in every realm of public policy—in health care, defense, agriculture, transportation, international trade, you name it—in every part of the world. All institutions, across all policy arenas, everywhere, naturally and inevitably generate them, simply because certain people and groups reap benefits (often in very different ways) from what the institutions do. Vested interests then have strong incentives to protect those institutions when faced with threatening reforms—and in the politics of change, therefore, they have the potential to be powerful forces for stability. This is a universal phenomenon that, when built into our theories, stands to tell us a great deal about the political

Field of study: Political science
Effect of Temperature Cycling on Conduction Mechanisms 
in CdTe Thin Films

CdTe thin films of 500 Å thickness prepared by thermal evaporation technique were analyzed for leakage current and conduction mechanisms. Metal–insulator–metal (MIM) capacitors were fabricated using these films as a dielectric. These films have many possible applications, such as passivation for infrared diodes that operate at low temperatures (80 K). Direct-current (DC) current–voltage (I–V) and capacitance–voltage (C–V) measurements were performed on these films. Furthermore, the films were subjected to thermal cycling from 300 K to 80 K and back to 300 K. Typical minimum leakage currents near zero bias at room temperature varied between 0.9 nA and 0.1 μA, while low-temperature leakage currents were in the range of 9.5 pA to 0.5 nA, corresponding to resistivity values on the order of 108 Ω-cm and 1010 Ω-cm, respectively. Well-known conduction mechanisms from the literature were utilized for fitting of measured I–V data. Our analysis indicates that the conduction mechanism in general is Ohmic for low fields <5 × 104 V cm−1, while the conduction mechanism for fields >6 × 104 V cm−1 is modified Poole–Frenkel (MPF) and Fowler–Nordheim (FN) tunneling at room temperature. At 80 K, Schottky-type conduction dominates. A significant observation is that the film did not show any appreciable degradation in leakage current characteristics due to the thermal cycling.

Field of study: Materials science
Interresponse time structures in variable-ratio and variable-interval schedules.

The interresponse-time structures of pigeon key pecking were examined under variable-ratio, variable-interval, and variable-interval plus linear feedback schedules. Whereas the variable-ratio and variable-interval plus linear feedback schedules generally resulted in a distinct group of short interresponse times and a broad distribution of longer interresponse times, the variable-interval schedules generally showed a much more continuous distribution of interresponse times. The results were taken to indicate that a log survivor analysis or double exponential fit of interresponse times may not be universally applicable to the task of demonstrating that operant behavior can be dichotomized into bouts of engagement and periods of disengagement.

Field of study: Biology, Psychology
The central velocity dispersion of the Milky Way bulge

Recent spectroscopic and photometric surveys are providing a comprehensive view of the MW bulge stellar population properties with unprecedented accuracy. This in turn allows us to explore the correlation between kinematics and stellar density distribution, crucial to constraint the models of Galactic bulge formation. GIBS revealed the presence of a velocity dispersion peak in the central few degrees of the Galaxy by consistently measuring high velocity dispersion in three central most fields. Due to suboptimal distribution of these fields, all being at negative latitudes and close to each other, the shape and extension of the sigma peak is poorly constrained. In this study we address this by adding new observations distributed more uniformly and in particular including fields at positive latitudes that were missing in GIBS.MUSE observations were collected in four fields at (l,b)=(0,+2),(0,-2),(+1,-1),(-1,+2). Individual stellar spectra were extracted for a number of stars comprised between ~500 and ~1200, depending on the seeing and the exposure time. Velocity measurements are done by cross-correlating observed stellar spectra in the CaT region with a synthetic template, and velocity errors obtained through Monte Carlo simulations, cross-correlating synthetic spectra with a range of different metallicities and different noise characteristics. We measure the central velocity dispersion peak within a projected distance from the Galactic center of ~280pc, reaching sigma~140 km/s at b=-1. This is in agreement with the results obtained previously by GIBS at negative longitude. The central sigma peak is symmetric with respect to the Galactic plane, with a longitude extension at least as narrow as predicted by GIBS. As a result of the Monte Carlo simulations we present analytical equations for the Rvel measurement error as a function of metallicity and SNR for giant and dwarf stars.

Field of study: Physics
On the Legal Protection of Transformation of Results in Agricultural Science and Technology

The transformation of scientific and technological achievements in agriculture is the key measurement of achieving scientific and technological progress in agriculture and promoting rural economic development. The transformation of scientific and technological achievements in agriculture needs legal protection as well as financial support. In view of the facts that transformation rate of agricultural scientific and technological results is low, that the responsibilities of technological personnel in the transformation of scientific and technological results is indefinite, that the transformation expenditure is insecure, and that the farmers don't provide enough support in achievements transformation, we should perfect the relevant legislation, provide a strong legal protection for transformation of the agricultural science and technology outcome, and help the agricultural science and technology achievements transit into agricultural productivity fast and well.

Field of study: Agricultural and Food sciences
A Place in the Story: Servants and Service in Shakespeare's Plays (review)

Elizabethan Catholic resistance as a corrective to the domination of the academic WASP patriarchy, given that the Vatican is such a repressive tyranny, with its medieval doctrines on women, contraception and divorce,” to which “litany of hate” Professor Wilson himself adds “the Church’s murderous bigotry on gay rights” (4). Shakespeare, we learn in the course of the book, was not that kind of Catholic. A pair of examples of Professor Wilson’s remarkable ingenuity in finding specifically Catholic allusions in Shakespeare’s work will have to suffice. Although Belmonte is the home of the widow whom Giannetto finally wins in Il Pecorone, the principal source for The Merchant of Venice, Professor Wilson maintains that “Belmont” actually refers to the Hampshire seat of the Catholic Montagues, “famous as a Mass centre” (255). It thus follows that Lorenzo’s condemnation of “the man that hath no music in himself,” who “is fit for treasons, stratagems, and spoils” (5.1.83, 85), is intended to distinguish the “loyalism” of the Montagues from “the politics of traitors” (256). Since Jesuits were caricatured by Protestant polemicists as “massing crows,” “the picture of the Jesuit ‘black-robe’ as a carrion crow was one which Shakespeare would himself use to dissociate from papist terrorism, when he wrote of the evil hour when ‘the crow / Makes wing to th’ rooky wood’ (Macbeth 3.3.51–52) in denunciation of the Masses hosted by the conspirator Ambrose Rookwood at Clopton House, near Stratford, in the darkening days before the Gunpowder Plot” (12). Shakespeare may well have had such notions cross his mind as he was writing, but even if we could prove that it were so, it is difficult to see how such knowledge enhances the public meaning of the plays or adds to the depth of their meaning or the power of their appeal. Homer may have been thinking of Ionian political events of the eighth century BCE or sleeping with his own “Dark Lady,” but our ignorance of such incidents in the poet’s life hardly diminishes the Iliad or the Odyssey. It is doubtful that ferreting out Shakespeare’s precise political and religious predilections (and so making them compatible with our own) will serve to advance our understanding of his literary and dramatic legacy. R. V. YOUNG North Carolina State University

Field of study: History