Miracle-dz/UniFAR-FTUs huggingface dataset:
Rill erosion in contrasting landscapes

The data from the national project to monitor water erosion has mostly been treated in an aggregate form, because in many of the monitored transects in any year too few fields were eroded for the data to be split into its component parts. However, in crop year 1983 erosion affected enough fields in two localities with contrasting soils for their data to be compared. Rainfall patterns in the two localities were similar. The transects covered a sandland area in Nottinghamshire and an area of clayland in and on the margins of Bedfordshire. Compared with the clayland, rilling of the sandland was widespread, related to the greater range of crops grown there, and more severe. On clayland, rills were mainly confined to valley floors, and slopes flanking these valleys generally had lower gradients than those on the sandland. On sandland, slopes were steeper in eroded fields drilled to winter cereals than they were in fields planted to potatoes or sugarbeet. Such field- based studies hint at the complex interactions of rain falling on a cropped field. Erosional thresholds are not static. The areas of fields affected by erosion and deposition were mostly very small. This helps us understand why the farmer often considers erosion unimportant.
Church encodings in higher-dimensional type theory Toward a theory of abstraction

The past four years of my intellectual life have been dominated by the urge to better understand just what such abstraction consists in. Initially, the problem posed itself to me in my first forays into computer science – any half-decent introduction to programming will make at least a passing mention of abstraction and the essential role it plays in managing the complexity of programs. Yet for all its ubiquity, such talk of abstraction tends to be light on detail. Even those texts that make abstraction a central topic, such as Abelson & Sussman’s classic The Structure and Interpretation of Computer Programs (SICP),[1] never explicitly define abstraction, but rather illustrate the concept and its utility by way of multifarious examples. The way one is meant to become acquainted with this notion is evidently by ostension.
Megalocytiviruses in ornamental fish: A review

Iridoviruses, especially megalocytiviruses, are related to severe disease resulting in high economic losses in the aquaculture industry worldwide. The ornamental fish industry has been affected severely due to Megalocytivirus infections. Megalocytivirus is a DNA virus that has three genera; including red sea bream iridovirus, infectious spleen and kidney necrosis virus, and turbot reddish body iridovirus. Megalocytivirus causes non-specific clinical signs in ornamental fish. Cell culture, histology, immunofluorescence test, polymerase chain reaction (PCR) assay, and loop-mediated isothermal amplification assay have been used to diagnose megalocytiviruses. Risk factors such as temperature, transportation (export and import), and life stages of ornamental fish have been reported for the previous cases due to Megalocytivirus infections. In addition, other prevention and control methods also have been practiced in farms to prevent Megalocytivirus outbreaks. This is the first review of megalocytiviruses in ornamental fish since its first detection in 1989. This review discusses the occurrences of Megalocytivirus in ornamental fish, including the history, clinical signs, detection method, risk factors, and prevention measures.
Scaﬀolded Meta-Learner for Eﬃcient Teaching of Human Learners

An appropriate choice of practice task w.r. t. their diﬃculty, and monitoring of progress are central for successful learning of most skills [3]. Motivated by the wish to accelerate and assist a human who is learning a new skill, we propose an extension of MAML for reinforcement learning [1] with a scaﬀold [3]. We exemplify our approach on the most basic but newly shaped teacher-learner interaction scenario during piano practice. The main idea is to have a model that on one hand guides the human learning process, but on the other hand, adapts to the user and their individual learning needs. By monitoring human performance and its improvement, scaﬀolded MAML (sMAML) manages task complexity levels, represented by task sets provided for practice. Similar to the MAML concept, for a given complexity level, the meta-learner part of sMAML samples tasks out of the current task set, while the composition of the tasks and their number in the set is monitored by the scaﬀolding part of sMAML. For each sampled task within the inner loop, the reinforcement learning (RL) model generates concrete score pieces with practice instructions for the learner. During the RL model parameter optimization, the loss is evaluated based of the performance of the human learner. Larger rewards correspond to a more accurate performance of the practice example. Concurrent to the human learning process, the policy update seeks to generate practice examples that maximize reward for a given task level. The scaﬀolding part of sMAML decides to either stay on the same complexity level, or to change the task set if the performance of the human learner on the test task rapidly improves. The complexity is not raised as long as the human learner is still improving and is not capable to learn a previously unpracticed and slightly more challenging practice piece quickly enough. Analysis of midi produced by the learner and/or capture of movement data may allow us a very detailed error analysis.
An Investigation of the Android Kernel Patch Ecosystem

open-source projects are often reused in commercial software. Android, a popular mobile operating system, is a great example that has fostered an ecosystem of open-source kernels. However, due to the largely decentralized and fragmented nature, patch propagation from the upstream through multiple layers to end devices can be severely delayed. In this paper, we undertake a thorough investigation of the patch propagation behaviors in the entire Android kernel ecosystem. By analyzing the CVEs and patches available since the inception of the Android security bulletin, as well as open-source upstream kernels ( e.g., Linux and AOSP) and hundreds of mostly binary OEM kernels ( e.g., by Samsung), we ﬁnd that the delays of patches are largely due to the current patching practices and the lack of knowledge about which upstream commits being security-critical. Unfortunately, we ﬁnd that the gap between the ﬁrst publicly available patch and its ﬁnal application on end devices is often months and even years, leaving a large attack window for experienced hackers to exploit the unpatched vulnerabilities.
Bank capital: Excess credit and crisis incidence

There are large and long-lasting negative effects on output from recurrent financial crises in market economies. Policy makers need to know if these financial crises are endogenous and subject to policy interventions or are exogenous events like earthquakes. We survey the literature about the links between credit growth and crises over the last 130 years. We then go on to look at the determinants of financial crises both narrowly and broadly defined in market economies, stressing the roles of bank capital, available on book liquidity, property price bubbles and current account deficits. We look at the role of credit growth, which is often seen as the main link between the macroeconomy and crises, and stress that it is largely absent. We look at the role of the core factors discussed above in market economies from 1980 to 2017. We suggest that crises are largely unrelated to credit developments but are influenced by banking sector behaviour. We conclude that policy makers need to contain banking excesses, not constrain the macroeconomy by directly reducing bank lending.
Condicionamento de superfícies na Odontologia com plasma de argônio: uma revisão de literatura

O objetivo deste estudo foi de verificar, por meio de revisao de literatura, os resultados do tratamento de diferentes superficies de interesse para a Odontologia com gas argonio, um plasma frio a pressao atmosferica. Este vem sendo recentemente estudado e aplicado com o intuito de aumentar a molhabilidade do substrato condicionado, como zirconia, um material conhecidamente acido resistente; dentina e pinos de fibra de vidro, interferindo positivamente na adesao. Diferentes estudos foram revisados, podendo-se concluir que o condicionamento com plasma frio de argonio alterou a superficie dos substratos testados, aumentando a area de superficie e, com isso, reduzindo o ângulo de contato. Isto contribui para uma maior molhabilidade do substrato e aumento da adesao as superficies testadas. DOI: 10.18363/rbo.v71i1. 541
Gas Permeation through Micropores of Carbon Molecular Sieve Membranes Derived from Kapton Polyimide

The evolution of micropores and the gas permeation properties have been investigated on carbon molecular sieve dense membranes prepared by pyrolysis of Kapton polyimide films under several conditions. With decreasing the pore sizes upon pyrolization under vacuum, the gas permeability decreased, whereas the permselectivity increased. The change in the heating rate was found to affect the permeation properties to a lesser extent; however, the pyrolysis atmosphere (vacuum or inert purge pyrolysis) did not appreciably influence the properties within the experimental conditions studied. The highest permselectivities attained by a membrane were H2/N2 4700, He/N2 2800, CO2/N2 122, and O2/N2 36, respectively, at 308 K. The permeabilities of the selected gases were shown to be in the order H2 > He > CO2 > O2 > N2 for almost all the membranes, whose order was not exactly in accordance with the order of kinetic gas diameters. From the temperature dependencies of permeability, diffusivity, and sorptivity of the membr.
Intracellular Calcium and Membrane Potential Oscillations in the Guinea Pig and Rat Pulmonary Vein Myocardium

Myocardial intracellular Ca2+ and membrane potential oscillations were studied in the isolated guinea-pig and rat pulmonary veins with immunohistochemical, confocal microscopic and electrophysiological analyses. The myocardial layer was present between the smooth muscle layer and the adventitia, and was more developed in the guinea-pig than in the rat. Intracellular Ca2+ oscillations were observed in both species, which were inhibited by ryanodine. Spontaneous Ca2+ waves were observed to propagate along the longitudinal axis of the cell or as a spiral rotating around a subcellular core; the propagation velocity of these Ca2+ waves was similar to that reported in atrial and ventricular cardiomyocytes. Spontaneous action potentials were present in about 35% and 4% of the preparations from the guinea-pig and rat, respectively. In quiescent preparations from the guinea-pig, noradrenaline induced a slow depolarization of the resting membrane potential followed by constant repetitive generation of action potentials, which were inhibited by ryanodine. In quiescent preparations from the rat, noradrenaline induced an initial hyperpolarization and a subsequent depolarization of the resting membrane potential. This was followed by generation of automatic action potentials which occurred in repetitive bursts. Ryanodine either abolished or reduced the duration of action-potential bursts. These results indicate that the pulmonary vein myocardium generates automatic electrical activity under adrenergic influence, which is probably triggered by intracellular Ca2+ oscillations. The difference in firing pattern between the guineapig and rat may be due to the difference in hyperpolarizing mechanisms. Abstract Conclusion
Isothermal Crystallization of Poly(l-lactide) Induced by Graphene Nanosheets and Carbon Nanotubes: A Comparative Study

Low-dimensional nanoparticles have a strong ability to induce the crystallization of polymer matrices. One-dimensional carbon nanotubes (CNTs) and two-dimensional graphene nanosheets (GNSs), both of which are both carbon-based nanoparticles, provide a good opportunity to investigate the effects of differently dimensional nanoparticles on the crystallization behavior of a polymer. For this purpose, respective nanocomposites of CNTs and GNSs with poly(l-lactide) (PLLA) as matrix were prepared by solution coagulation. Time-resolved Fourier-transform infrared spectroscopy (FTIR) and synchrotron wide-angle X-ray diffraction (WAXD) were performed to probe chain conformational changes and to determine the crystallization kinetics during the isothermal crystallization of the PLLA nanocomposites and neat PLLA, especially in the early stages. Both CNTs and GNSs could serve as nucleating agents in accelerating the crystallization kinetics of PLLA; however, the ability of CNTs to induce crystallization was stronger t.
Development of a Phosphorus Spray Diffusion System for Low-Cost Silicon Solar Cells

Phosphoric acid was used an n-type doping source to make an emitter for silicon solar cells. This paper reports on a cold spray method to coat phosphoric acid on the silicon wafer without any additional complicated and corrosive heating system. The key spray parameters such as belt speed, flow rate of the carrier gas, and concentration of phosphoric acid are optimized to get uniform and reproducible sheet resistance for the emitter. The diffusion process has been studied by firing silicon wafers that are spray-coated with phosphoric acid. screen printed solar cells have been fabricated using the emitter formed by the spray coating. The effects of the emitter on cell performance have been investigated and compared with those of the conventional POCl 3 -diffused emitter. screen printed/spray-diffused cells give impressive cell efficiencies of ∼ 16.6% on 1 Ω cm float zone wafers, which is nearly equal to those of POCl 3 emitter cells (∼16.9%). Compared with the POCl 3 emitter cell, the spray-diffused cells show slightly lower quantum efficiency at the short-wavelength response and slightly higher emitter saturation current density (∼3.59 X 10 -13 A/cm2 compared with 2.73 X 10 -13 A/cm2). Further optimization can eliminate this small difference in efficiency.
A Membrane Free Amperometric Gas Sensor Based on Room Temperature Ionic Liquids for the Selective Monitoring of NOx

A conveniently assembled, sensitive and fast-responding membrane free amperometric sensor is described for the detection of nitrogen oxides in gaseous atmospheres which exploits some profitable properties of room temperature ionic liquids (RTILs), such as high electrical conductivity, negligible vapor pressure and good thermal stability. It consists of three Pt wires piercing through a Teflon rod, whose exposed head is coated with a steadily adhesive thin RTIL film assuring the necessary electrical conductivity among the electrodes. The negligible vapor pressure of the immobilized RTIL layer makes possible to eliminate the need for the use of membranes, thus avoiding the involvement of a slow limiting step such as analyte permeation. Preliminary voltammetric tests performed at this sensor in gaseous atmospheres proved that the oxidation of NO2 and NO occurs at very close potentials, thus allowing effective NOx determinations. Instead, other atmospheric components able to act as possible interfering species (CO, H2S and SO2) were found to undergo oxidation only at quite higher potentials. The performance of this device was assayed under flowing conditions on synthetic nitrogen atmospheres with controlled NOx contents, which was changed in a wide range (0.01–103 ppm v/v). At room temperature, repeatable (±3.9 %) and linearly dependent current signals were recorded, allowing a detection limit of 0.96 ppb v/v to be inferred. At higher temperatures (100 °C) a lower detection limit (0.55 ppb v/v) could be instead estimated. The possibility of using this sensor for monitoring NOx in reduced pressure atmospheres was also assayed.
Reversibly Compressible, Highly Elastic, and Durable Graphene Aerogels for Energy Storage Devices under Limiting Conditions

High porosity combined with mechanical durability in conductive materials is in high demand for special applications in energy storage under limiting conditions, and it is fundamentally important for establishing a relationship between the structure/chemistry of these materials and their properties. Herein, polymer‐assisted self‐assembly and cross‐linking are combined for reduced graphene oxide (rGO)‐based aerogels with reversible compressibility, high elasticity, and extreme durability. The strong interplay of cross‐linked rGO (x‐rGO) aerogels results in high porosity and low density due to the re‐stacking inhibition and steric hinderance of the polymer chains, yet it makes mechanical durability and structural bicontinuity possible even under compressive strains because of the coupling of directional x‐rGO networks with polymer viscoelasticity. The x‐rGO aerogels retain >140% and >1400% increases in the gravimetric and volumetric capacitances, respectively, at 90% compressive strain, showing reversible change and stability of the volumetric capacitance under both static and dynamic compressions; this makes them applicable to energy storage devices whose volume and mass must be limited.
An eternal domination problem : graph classes, solving methods, and practical standpoint

The m-eternal dominating set problem is a graph-protection optimization problem that has been an active research topic in the recent years and reported to have applications in various domains. It asks for the minimum number of guards that can eternally defend attacks on the vertices of a graph; this number is called the m-eternal domination number of the graph. In this thesis, we study the m-eternal dominating set problem by dealing with aspects of theoretical and practical nature and tackling the problem restricted to speci c classes of graphs and in the general case. We examine the m-eternal dominating set problem for two classes of graphs: Cayley graphs and the well-known proper interval graphs. First, we disprove a published result on the m-eternal domination number of Cayley graphs, show that the result is valid for a subclass of these graphs, and report further ndings. Secondly, we present several discoveries regarding proper interval graphs, including that, for these graphs, the meternal domination number equals the maximum size of an independent set and, as a consequence, the m-eternal domination number can be computed in linear time. We address an issue that is fundamental to practical applications of the m-eternal dominating set problem but that has received relatively little attention. To this end, we introduce two heuristic methods, in which we propose and solve integer and constraint programming models to compute bounds on the m-eternal domination number. By performing an extensive experiment to validate the features of these methods, we generate a 750-instance benchmark and carry out a practical evaluation of bounds for the m-eternal domination number available in the literature. Finally, we propose and implement an exact algorithm for the m-eternal dominating set problem and contribute to the knowledge on its complexity: we prove that the decision version of the problem is NP-hard. As far as we know, the proposed algorithm was the rst developed and implemented exact method for the m-eternal dominating set problem.
Microalgae as biodiesel & biomass feedstocks: Review & analysis of the biochemistry, energetics & economics

Following scrutiny of present biofuels, algae are seriously considered as feedstocks for next-generation biofuels production. Their high productivity and the associated high lipid yields make them attractive options. In this review, we analyse a number aspects of large-scale lipid and overall algal biomass production from a biochemical and energetic standpoint. We illustrate that the maximum conversion efficiency of total solar energy into primary photosynthetic organic products falls in the region of 10%. Biomass biochemical composition further conditions this yield: 30 and 50% of the primary product mass is lost on producing cell protein and lipid. Obtained yields are one third to one tenth of the theoretical ones. Wasted energy from captured photons is a major loss term and a major challenge in maximising mass algal production. Using irradiance data and kinetic parameters derived from reported field studies, we produce a simple model of algal biomass production and its variation with latitude and lipid content. An economic analysis of algal biomass production considers a number of scenarios and the effect of changing individual parameters. Our main conclusions are that: (i) the biochemical composition of the biomass influences the economics, in particular, increased lipid content reduces other valuable compounds in the biomass; (ii) the “biofuel only” option is unlikely to be economically viable; and (iii) among the hardest problems in assessing the economics are the cost of the CO2 supply and uncertain nature of downstream processing. We conclude by considering the pressing research and development needs.
Chemical Reactions of Organic Molecules Adsorbed at Ice: 2. Chloride Substitution in 2-Methyl-2-propanol

A new reaction is reported on the ice surface, namely the conversion of adsorbed 2-methyl-2-propanol [(CH3)3COH] to adsorbed 2-chloro-2-methylpropane [(CH3)3CCl] in the presence of absorbed HCl. The reaction was studied using temperature-programmed desorption mass spectrometry on ultrathin ice films under ultrahigh vacuum. Formation of (CH3)3CCl occurs at two temperatures: at or below 155 K and at 185 K. The lower-temperature process occurs at the surface of the film, but the origin of product at 185 K is unclear. The yield of the surface reaction product is low, approximately 0.04 monolayers. Importantly, adsorbed HCl is unreactive toward 2-methyl-2-propanol; reactive chlorine is derived from a dissociatively ionized state in the very near surface region of the film. The lower-temperature pathway for chloride substitution is observed only at the surface of an amorphous film, an observation that may have implications regarding the nature of surface reaction sites. Possible mechanisms of the surface react.