cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
DEFORMATION EVENTS AND STRUCTURAL HISTORY OF THE HIGH GRADE GRANULATE TERRINE AROUND POLUR, THIRUVANNAMALA DISTRICT TAMILNADU, SOUTH INDIA.
Creators: name: George, Aikara Varkey
name: Shankar, K.
Publisher: name: Ethiopian Journal of Sciences and Sustainable Development
Year: 2019

description: Detailed Study of an area of 700sq. km reveals that the complex structural pattern observed is the result of overprinting and interference of structures generated during two different deformation episodes imprints of both penetrative and non-penetrative secondary planar and linear structures and folds of different generations are present throughout the area. At places F1 folds are intrafolial and rootless. Due to the tightness of F1 fold So and S1 are effectively parallel, except in F1 fold closures where S1 cuts across So. Map scale F2 folds identified Kommandal antiform and Padagam synform, are characterized by thickening of the hinges and thinning of the limbs indicating that the rocks were sufficiently ductile to allow flowage during deformation. F3 folds were characterized by an E-W to NW-SE axial trend with constant orthogonal thickness. All the pre F3 planner and linear fabrics are affected by F3 folds. Interference of F3 with F1 and F2 has resulted in plunging and eyed folds. F4 folds are expressed as extremely broad open flexures that have resulted in regional variations in the strikes of the litho units. Faults observed in the area have a constant NW-SE trend and post dates major folds. However, faults trending E-W affect F3 folds and pre date F4. Detailed study shows that various structures found in the area were formed during two deformational events. - D1and D2. During the initial phase of (DI1), tightly appressed, mapable F1 folds with synchronous development of penetrative foliation S1, axial planer to F1 were formed. The co-axial nature and geometrical similarities of F1 and F2 suggest their formation during progressive deformation. This often gives rise to hook-shaped interference pattern. The second event D2 indicates a stress field different from that of D1. During the first phase of (DII1) fracture cleavage S2 were formed. The evolutionary history of the area worked out on the basis of structural analysis can serve as a model for similar of high-grade granulate terrains in other parts of the world.
description: Ethiopian Journal of Sciences and Sustainable Development, Vol 6 No 1 (2019): EJSSD
An Architecture for Coordinating Multiple Self-Management Systems
Creators: name: Shang-Wen  Cheng
name: An-Cheng  Huang
name: Garlan, David
name: Schmerl, Bradley
name: Steenkiste, Peter
Publisher: name: Carnegie Mellon University
Year: 2007
Subjects: subject: 89999 Information and Computing Sciences not elsewhere classified
subject: FOS: Computer and information sciences

description: A common approach to adding self-management capabilities to a system is to provide one or more external control modules, whose responsibility is to monitor system behavior, and adapt the system at run time to achieve various goals (configure the system, improve performance, recover from faults, etc.). An important problem arises when there is more than one such self-management module: how can one make sure that they are composed to provide consistent and complementary benefits? In this paper we describe a solution that introduces a self-management coordination architecture and infrastructure to support such composition. We focus on the problem of coordinating self-configuring and self-healing capabilities, particularly with respect to global configuration and incremental repair. We illustrate the approach in the context of a self-managing video teleconference system that composes two preexisting adaptation modules to achieve synergistic benefits of both.
Phase-ordering kinetics in the Allen-Cahn (Model A) class: universal aspects elucidated by electrically-induced transition in liquid crystals
Creators: name: Almeida, Renan A. L.
name: Takeuchi, Kazumasa A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: The two-dimensional (2d) Ising model is the statistical physics textbook example for phase transitions and their kinetics. Quenched through the Curie point with Glauber rates, the late-time description of the ferromagnetic domain coarsening finds its place at the scalar sector of the Allen-Cahn (Model A) class. Resisting exact results sought since Lifshitz's account in 1962, central quantities in 2d Model A $-$ most scaling exponents and correlation functions $-$ remain known up to approximate theories whose disparate outcomes urge experimental assessment. Here, we perform such assessment from a comprehensive study of the coarsening of 2d twisted nematic liquid crystals whose kinetics is induced by a super-fast switching from a spatiotemporally chaotic state to a two-phase concurrent, equilibrium one. Tracking the dynamics via optical microscopy, we firstly show the sharp evidence of well-established Model A aspects, such as the dynamic exponent $z=2$ and the dynamic scaling hypothesis, to then move forward. We confirm the Bray-Humayun theory for Porod's regime describing intradomain length scales of spatial correlators, and show that their nontrivial decay beyond that regime is captured in a free-from-parameter fashion by Gaussian theories. These paradigmatic theories, however, do not perform well for time-related Model A statistics. We reveal that the collapsed form of two-time correlators is best accounted for by the local scaling invariance theory, along with the Fisher-Huse conjecture. We also suggest the true value for the local persistence exponent, in disfavour of Gaussian models, and extract a universal fractal dimension for the morphology of persistence clusters that is notably close to the golden ratio. Given its accuracy and possibilities, this experimental setup may work as a prototype to address universality issues in the realm of nonequilibrium systems.
description: 19 pages, 10 figures, 2 tables
Electronic structure of negative charge transfer CaFeO3 across the metal-insulator transition
Creators: name: Rogge, Paul C.
name: Chandrasena, Ravini U.
name: Cammarata, Antonio
name: Green, Robert J.
name: Shafer, Padraic
name: Lefler, Benjamin M.
name: Huon, Amanda
name: Arab, Arian
name: Arenholz, Elke
name: Lee, Ho Nyung
name: Lee, Tien-Lin
name: Nemšák, Slavomír
name: Rondinelli, James M.
name: Gray, Alexander X.
name: May, Steven J.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We investigated the metal-insulator transition for epitaxial thin films of the perovskite CaFeO3, a material with a significant oxygen ligand hole contribution to its electronic structure. We find that biaxial tensile and compressive strain suppress the metal-insulator transition temperature. By combining hard X-ray photoelectron spectroscopy, soft X-ray absorption spectroscopy, and density functional calculations, we resolve the element-specific changes to the electronic structure across the metal-insulator transition. We demonstrate that the Fe electron valence undergoes no observable change between the metallic and insulating states, whereas the O electronic configuration undergoes significant changes. This strongly supports the bond-disproportionation model of the metal-insulator transition for CaFeO3 and highlights the importance of ligand holes in its electronic structure. By sensitively measuring the ligand hole density, however, we find that it increases by ~5-10% in the insulating state, which we ascribe to a further localization of electron charge on the Fe sites. These results provide detailed insight into the metal-insulator transition of negative charge transfer compounds and should prove instructive for understanding metal-insulator transitions in other late transition metal compounds such as the nickelates.
description: Minor typographic changes made
The Achievements and Challenges of Kaizen Implementation: A Case Study on Asela Malt Factory
Creators: name: Deti, Hailu Beyecha
Publisher: name: Ethiopian Journal of Sciences and Sustainable Development
Year: 2019

description: This study assesses kaizen implementation of Asela Malt Factory with respect to 5s, Deming cycle suggestion system, Fishbone Diagram, and Pareto analysis tools. Achievements and challenges encountered in the kaizen implementation are also addressed. Both qualitative and quantitative research methods were employed and SPSS (Scientific Package for Social Science) tool were used to analyze and present quantitative data. Descriptive statistics tools such as frequency and percentage were used to analyze and present qualitative data obtained from questionnaire and interview. The results revealed that kaizen tools are inconsistently implemented in the factory. The study also shows that improvements are achieved in the factory with some variations. On the contrary, numerous challenges are discovered due to the inconsistency of kaizen tools implementation. Therefore, the factory should implement kaizen tools continuously to identify the root causes of the problems, prioritize the problems according to their severity and solve the problems step-by-step in order to further improve quality, productivity and profitability through proper design and innovation.
description: Ethiopian Journal of Sciences and Sustainable Development, Vol 6 No 2 (2019): EJSSD
Incorporación del crimen ecológico internacional dentro de la jurisdicción especial para la paz
Creators: name: Ramírez Pulgarín, Jorge Enrique
Publisher: name: Universidad Externado de Colombia
Year: 2023
Subjects: subject: Conflicto armado
subject: Ecología
subject: Derecho internacional
subject: Crimen
subject: Ecológico
subject: Delito
subject: Normas
subject: Autónomo

description: En el presente texto se va analizar si el crimen ecológico internacional o “ecocidio” puede ser incorporado como delito autónomo dentro de la Jurisdicción Especial la Paz, con el fin que los diferentes actores ilegales comparezcan y respondan por la comisión de estos delitos ambientales en el contexto del conflicto armado. Para este propósito, se va a examinar la evolución del crimen ecológico en el marco de las normas internacionales, analizándose los sujetos activos y pasivos de este delito global, el bien jurídico que protege, su clasificación como crimen autónomo, de guerra o lesa humanidad y los problemas relativos a su tipificación. Posteriormente se realizará un análisis del proceso de justicia transicional colombiano frente a los crímenes ambientales, para lo cual se van enunciar los múltiples delitos contra el medio ambiente que han cometido los grupos armados y la aplicación de estándares de justicia, verdad, reparación y no repetición frente a esos crímenes. Por último se va a identificar de acuerdo a la ponderación de múltiples razones a favor y en contra, si eventualmente es posible incorporar el delito ecológico internacional para sea objeto de investigación y juzgamiento por el actual sistema de enjuiciamiento transicional.
description: This text will analyze whether international ecological crime or "ecocide" can be incorporated as an autonomous crime within the Special Jurisdiction of the Peace, so that the different illegal actors appear and answer for the commission of these environmental crimes in the context of the armed conflict. For this purpose, the evolution of ecological crime within the framework of international norms will be examined, analyzing the active and passive subjects of this global crime, the legal good it protects, its classification as an autonomous crime, war crime or crime against humanity and the problems related to its typification. Subsequently, an analysis of the Colombian transitional justice process in the face of environmental crimes will be carried out, for which the multiple crimes against the environment committed by armed groups and the application of standards of justice, truth, reparation and non-repetition in the face of these crimes. Finally, it will be identified according to the weighing of multiple reasons for and against, if it is eventually possible to incorporate international ecological crime to be investigated and prosecuted by the current transitional prosecution system.
Alternative Method for Determining the Feynman Propagator of a Non-Relativistic Quantum Mechanical Problem
Creators: name: Moshinsky, Marcos
name: Sadurni, Emerson
name: del Campo, Adolfo
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A direct procedure for determining the propagator associated with a quantum mechanical problem was given by the Path Integration Procedure of Feynman. The Green function, which is the Fourier Transform with respect to the time variable of the propagator, can be derived later. In our approach, with the help of a Laplace transform, a direct way to get the energy dependent Green function is presented, and the propagator can be obtained later with an inverse Laplace transform. The method is illustrated through simple one dimensional examples and for time independent potentials, though it can be generalized to the derivation of more complicated propagators.
description: This is a contribution to the Proc. of the Seventh International Conference ''Symmetry in Nonlinear Mathematical Physics'' (June 24-30, 2007, Kyiv, Ukraine), published in SIGMA (Symmetry, Integrability and Geometry: Methods and Applications) at http://www.emis.de/journals/SIGMA/ In v2 misprints are corrected
Effects of the growth kinetics on solute diffusion in porous films
Creators: name: Correa, Gabriela B.
name: Almeida, Renan A. L.
name: Reis, Fabio D. A. Aarao
Publisher: name: arXiv
Year: 2021
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: For the development of porous materials with improved transport properties, a key missing ingredient is to determine the relations between growth kinetics, structure, and transport parameters. Here, we address these relations by studying solute diffusion through three-dimensional porous films produced by simple deposition models with controlled thickness and porosity. We simulate growing films with competitive aggregation rules that incorporate lateral aggregation (relative rate proportional to $p$), which leads to pore formation, and surface relaxation ($1-p$) that favors compaction. By connecting a solute source at the basis and a drain at the top outer surface of the films, we extract the effective diffusion coefficients from steady-state simulations. We find that for a given film thickness, the larger the $p$, the larger the effective porosity and diffusivity, but the smaller the tortuosity. Keeping constant growth conditions (i.e., same $p$), the increase of thickness always leads to an increase of effective porosity, but a nontrivial behavior in the diffusivity occurs: for $p\leq 0.7$, the diffusion coefficient is larger in thicker films; this is accompanied by a decrease of the tortuosity with the thickness, thus indicating that growth continuously improves pore structure for diffusion. Microscopically, such a result is associated with narrower distributions of local solute currents at higher points of films. Particularly for $p\geq 0.9$, in which film porosity is $\sim 0.65-0.7$, the tortuosity is between $1.3$ and $2$, increases with the thickness, and has maximal changes near $25\%$. Pairs of values of porosity and tortuosity that we obtain here, for the thickest films, agree with those experimentally measured in some porous electrodes. Noteworthy, the increase of film thickness is generally favorable for diffusion in their pores, and exceptions have small losses in tortuosity.
description: Main: 37 pages, 11 figures, 2 tables. Suppl. Mat.: 7 pages, 4 figures. Paper written by F. Reis
Multiple critical end points in magnetized three flavor quark matter
Creators: name: Ferreira, Márcio
name: Costa, Pedro
name: Providência, Constança
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The magnetized phase diagram for three-flavor quark matter is studied within the Polyakov extended Nambu--Jona-Lasinio model. The order parameters are analyzed with special emphasis on the strange quark condensate. We show that the presence of an external magnetic field induces several critical endpoints (CEPs) in the strange sector, which arise due to the multiple phase transitions that the strange quark undergoes. The spinodal and binodal regions of the phase transitions are shown to increase with external magnetic field strength. The influence of strong magnetic fields on the isentropic trajectories around the several CEPs is analyzed. A focusing effect is observed on the region towards the CEPs that are related with the strange quark phase transitions. Compared to the chiral transitions, the deconfinement transition turns out to be less sensitive to the external magnetic field and the crossover nature is preserved over the whole phase diagram.
description: 12 pages, 10 figures; PRD version
Simulation studies of annihilation-photon's polarisation via Compton scattering with the J-PET tomograph
Creators: name: Krawczyk, N.
name: Hiesmayr, B. C.
name: Curceanu, C.
name: Czerwiński, E.
name: Dulski, K.
name: Gajos, A.
name: Gorgol, M.
name: Gupta-Sharma, N.
name: Jasińska, B.
name: Kacprzak, K.
name: Kapłon, Ł.
name: Kisielewska, D.
name: Klimaszewski, K.
name: Korcyl, G.
name: Kowalski, P.
name: Kozik, T.
name: Krawczyk, N.
name: Krzemień, W.
name: Kubicz, E.
name: Mohammed, M.
name: Niedźwiecki, Sz.
name: Pałka, M.
name: Pawlik-Niedźwiecka, M.
name: Raczyński, L.
name: Raj, J.
name: Rakoczy, K.
name: Rudy, Z.
name: Sharma, S.
name: Shivani
name: Shopa, R. Y.
name: Silarski, M.
name: Skurzok, M.
name: Wiślicki, W.
name: Zgardzińska, B.
name: Moskal, P.
Publisher: name: arXiv
Year: 2019
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: J-PET is the first positron-emission tomograph (PET) constructed from plastic scintillators. It was optimized for the detection of photons from electron-positron annihilation. Such photons, having an energy of 511 keV, interact with electrons in plastic scintillators predominantly via the Compton effect. Compton scattering is at most probable at an angle orthogonal to the electric field vector of the interacting photon. Thus registration of multiple photon scatterings with J-PET enables to determine the polarization of the annihilation photons. In this contribution we present estimates on the physical limitation in the accuracy of the polarization determination of $511$~keV photons with the J-PET detector.
description: Submitted to Hyperfine Interactions
Spherical Cap Harmonic Analysis (SCHA) for Characterising the Morphology of Rough Surface Patches
Creators: name: Shaqfa, Mahmoud
name: Choi, Gary P. T.
name: Beyer, Katrin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Graphics (cs.GR)
subject: FOS: Computer and information sciences

description: We use spherical cap harmonic (SCH) basis functions to analyse and reconstruct the morphology of scanned genus-0 rough surface patches with open edges. We first develop a novel one-to-one conformal mapping algorithm with minimal area distortion for parameterising a surface onto a polar spherical cap with a prescribed half angle. We then show that as a generalisation of the hemispherical harmonic analysis, the SCH analysis provides the most added value for small half angles, i.e., for nominally flat surfaces where the distortion introduced by the parameterisation algorithm is smaller when the surface is projected onto a spherical cap with a small half angle than onto a hemisphere. From the power spectral analysis of the expanded SCH coefficients, we estimate a direction-independent Hurst exponent. We also estimate the wavelengths associated with the orders of the SCH basis functions from the dimensions of the first degree ellipsoidal cap. By windowing the spectral domain, we limit the bandwidth of wavelengths included in a reconstructed surface geometry. This bandlimiting can be used for modifying surfaces, such as for generating finite or discrete element meshes for contact problems. The codes and data developed in this paper are made available under the GNU LGPLv2.1 license.
description: Preprint accepted for publication in Powder Technology
After Effect of Pump Supply Disruption
Creators: name: Hatsey, Niguss Haregot
Publisher: name: Ethiopian Journal of Sciences and Sustainable Development
Year: 2019

description: The aim of this study is to investigate on the aftereffect of pump supply disruption in ground water irrigation in Northern Ethiopia. Failure is inevitable and the failure of a submersible pump, critical equipment in irrigation infrastructure, is considerably high according to the survey conducted. In the other side, there is also uneven pump supply. A survey is conducted in 16 sample drilled wells (DWs) to reveal the losses after pump supply delay. According to the survey, the downtime delay is the aggregation of purchasing order process delay, transportation delay and replacement/installation delay. Discrete time probability distribution function is used to estimate the economic loss of the aftereffect by determining the cost, production volume and profit of the irrigation business using triangular probability distribution functions. The downtime delay is analyzed under the discrete time of 1 week downtime, 2 weeks downtime, 3 weeks downtime, and greater than 3 weeks downtime horizon. Finally, the study ascertains that downtime in ground water irrigation results in sizable economic losses like yield loss, total vegetables/crops loss, and opportunity cost. When the downtime duration extends, the loss upturns radically. For instance, if the downtime duration extends from 1 week to 3 weeks, the expected monetary loss might increase in 10 folds.
description: Ethiopian Journal of Sciences and Sustainable Development, Vol 6 No 2 (2019): EJSSD
To Code or Not to Code Across Time: Space-Time Coding with Feedback
Creators: name: Lin, Che
name: Raghavan, Vasanthan
name: Veeravalli, Venu
Publisher: name: arXiv
Year: 2007
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: Space-time codes leverage the availability of multiple antennas to enhance the reliability of communication over wireless channels. While space-time codes have initially been designed with a focus on open-loop systems, recent technological advances have enabled the possibility of low-rate feedback from the receiver to the transmitter. The focus of this paper is on the implications of this feedback in a single-user multi-antenna system with a general model for spatial correlation. We assume a limited feedback model, that is, a coherent receiver and statistics along with B bits of quantized channel information at the transmitter. We study space-time coding with a family of linear dispersion (LD) codes that meet an additional orthogonality constraint so as to ensure low-complexity decoding. Our results show that, when the number of bits of feedback (B) is small, a space-time coding scheme that is equivalent to beamforming and does not code across time is optimal in a weak sense in that it maximizes the average received SNR. As B increases, this weak optimality transitions to optimality in a strong sense which is characterized by the maximization of the average mutual information. Thus, from a system designer's perspective, our work suggests that beamforming may not only be attractive from a low-complexity viewpoint, but also from an information-theoretic viewpoint.
description: 22 pages, 4 figures, Submitted to IEEE JSAC, Nov. 2007
Dual representation of lattice QCD with worldlines and worldsheets of abelian color fluxes
Creators: name: Marchis, Carlotta
name: Gattringer, Christof
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We present a new dual representation for lattice QCD in terms of wordlines and worldsheets. The exact reformulation is carried out using the recently developed abelian color flux method where the action is decomposed into commuting minimal terms that connect different colors on neighboring sites. Expanding the Boltzmann factors for these commuting terms allows one to reorganize the gauge field contributions according to links such that the gauge fields can be integrated out in closed form. The emerging constraints give the dual variables the structure of worldlines for the fermions and worldsheets for the gauge degrees of freedom. The partition sum has the form of a strong coupling expansion and with the abelian color flux approach discussed here all coefficients of the expansion are known in closed form. We present the dual form for three cases: pure SU(3) lattice gauge theory, strong coupling QCD and full QCD, and discuss in detail the constraints for the color fluxes and their physical interpretation.
description: Final version to appear in Phys. Rev. D
Análisis del trabajo en casa, el estrés laboral y la calidad de vida en los trabajadores administrativos de la empresa de seguridad privada OMNITEMPUS S.A. en el periodo 2020 -2021
Creators: name: Castro Neira, Luisa Alejandra
Publisher: name: Universidad Externado de Colombia
Year: 2022
Subjects: subject: Administración de personal
subject: Desarrollo integrado
subject: Trabajo y trabajadores
subject: Calidad de vida
subject: Estrés laboral
subject: Desarrollo humano
subject: Riesgos sicosociales

description: La emergencia sanitaria mundial dada por el COVID -19 llevo a diversos procesos, entre ellos la implementación de la modalidad de trabajo en casa, por lo cual el presente estudio evidencia su surgimiento en Colombia durante el año 2020. Se realiza una revisión de su trayectoria, mostrando su diferencia con el teletrabajo; así como la normatividad vigente, para analizar esta modalidad laboral con el estrés y la calidad de vida de los trabajadores del área administrativa de una empresa de seguridad privada. OMNITEMPUS, empresa dedicada a la prestación de servicios de seguridad privada, en coherencia con los parámetros establecidos para el momento, implementa la modalidad de trabajo en casa para sus trabajadores del área administrativa, la falta de conocimiento de la modalidad, la falta de herramientas tecnológicas y su uso, así como, el desconocimiento de metodologías para cumplir con las metas laborales, y las diversas variables a nivel familiar y de espacio físico caracterizaron este momento en los trabajadores de esta empresa. Por lo anterior, se aplicó el cuestionario de estrés, se realizaron entrevistas a profundidad y se desarrollaron grupos focales con los trabajadores administrativos de OMNITEMPUS; encontrando que en dichos trabajadores, no se presentan estrés laboral; sin embargo, si se puede evidenciar que se presentó un desmejoramiento de la calidad de vida, al tener una interferencia permanente entre su vida familiar y laboral, agudizada por la poca confianza de los jefes, la sobrecarga laboral y la extensión permanente de los horarios laborales, entre otros aspectos.
description: The global health emergency caused by COVID -19 leads to various processes, including the implementation of the work-at-home modality, for which this study shows its emergence in Colombia during the year 2020. A review of its trajectory is carried out , showing its difference with teleworking; as well as the current regulations, to analyze this work modality with the stress and quality of life of workers in the administrative area of a private security company. OMNITEMPUS, a company dedicated to the provision of private security services, in coherence with the damages established for the moment, implements the work-at-home modality for its workers in the administrative area, the lack of knowledge of the modality, the lack of technological tools and its use, as well as the knowledge of methodologies to meet work goals, and the various variables at the family level and physical space characterized this moment in the workers of this company.
THE PREVALENCE OF STUDENTS’ DRUG ADDICTION IN HIGHER LEARNING INSTITUTIONS: A COMPREHENSIVE REVIEW OF LITERATURE
Creators: name: Likisa, Kumsa Donis
Publisher: name: Ethiopian Journal of Sciences and Sustainable Development
Year: 2019

description: Abstract A number of studies have been carried out on the prevalence of drug addiction by college and/or university students. However, little literature has been attempted to comprehensively indicate the challenges of drug use among university students, strategies utilized to overcome the challenges and implications of the challenges for integrated prevention and intervention approaches. Thus, the objective of this comprehensive review of the literature was to assess and organize the literature on the challenges of substance abuse among university students and seek out alternative solutions that have implications for Adama Science and Technology University (ASTU) and beyond. The literature has been organized on the prevalence of drug abuse among college/university students’ worldwide and specifically Ethiopian universities. Some criteria were set to review the most relevant local and international studies that are rigorous in design, adequate sample size, vigilant sample selection procedures and those which have utilized data gathering instruments with high validity and reliability. The findings from the literature indicated that there is a high prevalence of drug abuse among university students worldwide and in Ethiopia. The problem is attributed to economic, social, psychological and health factors that demand integrated prevention and intervention approaches. Keywords: Prevalence, drug abuse, university, students.
description: Ethiopian Journal of Sciences and Sustainable Development, Vol 6 No 2 (2019): EJSSD
Additional file 1 of Exploring the genomic resources and analysing the genetic diversity and population structure of Chinese indigenous rabbit breeds by RAD-seq
Creators: name: Liu, Chenmiao
name: Wang, Shuhui
name: Dong, Xianggui
name: Zhao, Jiping
name: Ye, Xiangyang
name: Gong, Ruiguang
name: Ren, Zhanjun
Publisher: name: figshare
Year: 2021
Subjects: subject: Genetics
subject: FOS: Biological sciences

description: Additional file 1: Supplementary Figure S1. Principal component analysis (PCA) of the Chinese indigenous rabbit breeds based on autosome (PC1=5.59%, PC3=3.41%).
Analyse des facteurs de l'anxiété vécue par les élèves en milieu scolaire
Creators: name: Zouggari, Adnane
Publisher: name: My University
Year: 2019

description: Cette recherche présente les principales conclusions de la littérature sur les facteurs de risque de troubles anxieux chez les enfants en contexte scolaire. Nous y présentons d'abord, les variables individuelles de l'enfant, telles que le sexe, le tempérament, l'estime de soi. Les facteurs génétiques, familiaux et sociaux sont ensuite examinés. Notre proposition dans ce travail est d’esquisser un modèle qui intègre tous ces facteurs et aide à comprendre le développement des troubles anxieux chez l’enfant. Nos conclusions sont que, même si les facteurs qui interviennent dans ces troubles sont largement connus, leur étiologie doit encore être clarifiée. L'accent est mis sur la nécessité de considérer la confluence ou l'interaction de multiples facteurs afin de comprendre l'étiologie des troubles anxieux en milieu scolaire, plutôt que leurs effets isolés.
Constraining the Symmetry Energy: A Journey in the Isospin Physics from Coulomb Barrier to Deconfinement
Creators: name: Di Toro, M.
name: Colonna, M.
name: Greco, V.
name: Ferini, G.
name: Rizzo, C.
name: Rizzo, J.
name: Baran, V.
name: Gaitanos, T.
name: Prassa, V.
name: Wolter, H. H.
name: Zielinska-Pfabe, M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Heavy Ion Collisions (HIC) represent a unique tool to probe the in-medium nuclear interaction in regions away from saturation. In this work we present a selection of reaction observables in dissipative collisions particularly sensitive to the isovector part of the interaction, i.e. to the symmetry term of the nuclear Equation of State (EoS). At low energies the behavior of the symmetry energy around saturation influences dissipation and fragment production mechanisms. We will first discuss the recently observed Dynamical Dipole Radiation, due to a collective neutron-proton oscillation during the charge equilibration in fusion and deep-inelastic collisions. Important Iso-EOS effects are stressed. Reactions induced by unstable 132Sn beams appear to be very promising tools to test the sub-saturation Isovector EoS. New Isospin sensitive observables are also presented for deep-inelastic, fragmentation collisions and Isospin equilibration measurements (Imbalance Ratios). The high density symmetry term can be derived from isospin effects on heavy ion reactions at relativistic energies (few AGeV range), that can even allow a ``direct'' study of the covariant structure of the isovector interaction in the hadron medium. Rather sensitive observables are proposed from collective flows and from pion/kaon production. The possibility of the transition to a mixed hadron-quark phase, at high baryon and isospin density, is finally suggested. Some signatures could come from an expected ``neutron trapping'' effect. The importance of studying violent collisions with radioactive beams from low to relativistic energies is finally stressed.
description: 15 pages, 5 figures, Int.Workshop on Nuclear Dynamics in Heavy Ion Reactions and Neutron Stars, Beijing Normal Univ. July 07, to appear in Int.Journ.Modern Physics E (2008)
Semi-classical eigenvalue estimates under magnetic steps (Former title: Hearing the shape of a magnetic edge in the semiclassical limit)
Creators: name: Assaad, Wafaa
name: Helffer, Bernard
name: Kachmar, Ayman
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mathematical Physics (math-ph)
subject: Spectral Theory (math.SP)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We establish accurate eigenvalue asymptotics and, as a by-product, sharp estimates of the splitting between two consecutive eigenvalues, for the Dirichlet magnetic Laplacian with a non-uniform magnetic field having a jump discontinuity along a smooth curve. The asymptotics hold in the semiclassical limit which also corresponds to a large magnetic field limit, and is valid under a geometric assumption on the curvature of the discontinuity curve.
description: 34 pages
Las T(R)IC en el aula de segundas lenguas
Creators: name: Rojas Valbuena, Liliana
Publisher: name: Universidad Externado de Colombia
Year: 2020

description: Objetivos generales: * Elaborar propuestas digitales para el aula de L2. Objetivos específicos: Solventar dudas sobre la utilización de herramientas digitales. * Analizar y reflexionar sobre los nuevos usos didáctico-tecnológicos. * Evaluar contenidos, estrategias y valores en un entorno digital educativo.
description: Este curso de 96 horas de duración, busca que el estudiante elabore propuestas digitales para el aula de L2, Solvente dudas sobre la utilización de herramientas digitales, Analice y reflexionar sobre los nuevos usos didáctico-tecnológicos, evalué contenidos, estrategias y valores en un entorno digital educativo.
Necessary Density Conditions for Sampling and Interpolation in Spectral Subspaces of Elliptic Differential Operators
Creators: name: Gröchenig, Karlheinz
name: Klotz, Andreas
Publisher: name: arXiv
Year: 2021
Subjects: subject: Functional Analysis (math.FA)
subject: Information Theory (cs.IT)
subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences
subject: 46E22, 47B32, 35J99, 42C40, 94A20, 54D35

description: We prove necessary density conditions for sampling in spectral subspaces of a second order uniformly elliptic differential operator on $R^d$ with slowly oscillating symbol. For constant coefficient operators, these are precisely Landaus necessary density conditions for bandlimited functions, but for more general elliptic differential operators it has been unknown whether such a critical density even exists. Our results prove the existence of a suitable critical sampling density and compute it in terms of the geometry defined by the elliptic operator. In dimension 1, functions in a spectral subspace can be interpreted as functions with variable bandwidth, and we obtain a new critical density for variable bandwidth. The methods are a combination of the spectral theory and the regularity theory of elliptic partial differential operators, some elements of limit operators, certain compactifications of $R^d $, and the theory of reproducing kernel Hilbert spaces.
description: 32 pp. We modified Section 6 to cover the case of slowly oscillating symbols. Some minor errors are corrected
A general framework for cyclic and fine-tuned causal models and their compatibility with space-time
Creators: name: Vilasini, V.
name: Colbeck, Roger
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Statistics Theory (math.ST)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: Causal modelling is a tool for generating causal explanations of observed correlations and has led to a deeper understanding of correlations in quantum networks. Existing frameworks for quantum causality tend to focus on acyclic causal structures that are not fine-tuned i.e., where causal connections between variables necessarily create correlations between them. However, fine-tuned causal models (which permit causation without correlation) play a crucial role in cryptography, and cyclic causal models can be used to model physical processes involving feedback and may also be relevant in exotic solutions of general relativity. Here we develop a causal modelling framework capable of dealing with these general scenarios. The key feature of our framework is that it allows operational and relativistic notions of causality to be independently defined and for connections between them to be established in a theory-independent manner. The framework first gives an operational way to study causation that allows for cyclic, fine-tuned and non-classical causal influences. We then consider how a causal model can be embedded in a space-time structure (modelled as a partial order) and propose a compatibility condition for ensuring that the embedded causal model does not allow signalling outside the space-time future. We identify several distinct classes of causal loops that can arise in our framework, showing that compatibility with a space-time can rule out only some of them. We discuss conditions for preventing superluminal signalling within arbitrary (and possibly cyclic) causal structures and consider models of causation in post-quantum theories admitting so-called jamming correlations. Finally, this work introduces the concept of a "higher-order affects relation", which is useful for causal discovery in fined-tuned causal models.
description: 56 pages (38 + 18), 15 figures (12 + 3). This work is an updated version of parts of V. Vilasini's PhD thesis arXiv:2102.02393
Low-Frequency Radio Absorption in Cassiopeia A
Creators: name: Arias, M.
name: Vink, J.
name: de Gasperin, F.
name: Salas, P.
name: Oonk, J. B. R.
name: van Weeren, R. J.
Publisher: name: arXiv
Year: 2018
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Cassiopeia A is one of the best-studied supernova remnants. Its shocked ejecta emits brightly in radio and X-rays. Its unshocked ejecta can be studied through infrared emission, the radio-active decay of $^{44}$Ti, and low frequency free-free absorption due to cold gas internal to the shell. Free-free absorption is affected by the mass, geometry, temperature, and ionisation conditions in the absorbing gas. Observations at the lowest radio frequencies constrain a combination of these properties. We use LOFAR LBA observations at 30-77 MHz and L-band VLA observations to compare $u-v$-matched images with a common resolution of 17". We simultaneously fit, per pixel, for the emission measure and the ratio of the emission from the unabsorbed front of the shell versus the absorbed back of the shell. We explore the effects that low temperatures and a high degree of clumping can have on the derived physical properties, such as mass and density. We also compile published radio flux measurements, fit for the absorption processes that occur in the radio band, and consider how they affect the secular decline of the source. We find a mass in the unshocked ejecta of $M = 2.95 \pm {0.48} \,M_{\odot}$ for an assumed gas temperature of $T=100$ K. This estimate is reduced for colder gas temperatures and if the ejecta are clumped. We measure the reverse shock to have a radius of $114$" $\pm $6". We also find that a decrease in the amount of mass in the unshocked ejecta (as more and more material meets the reverse shock and heats up) cannot account for the observed low frequency behaviour of the secular decline rate. To reconcile our low frequency absorption measurements with models that predict little mass in the unshocked ejecta we need the ejecta to be very clumped, or the temperature in the cold gas to be low ($\sim10$ K). Both conditions can jointly contribute to the high absorption.
description: Accepted for publication in A&A v2: including the DOI, language edits
Extraction of Papain from Papaya (Carica papaya L.) Fruit Latex and Its Application in Transforming Tannery Raw Trimming
Creators: name: Urgessa, Olyad Erba
name: Itana, Duguma Dibbisa
name: Raga, Tamiru Oljira
Publisher: name: Ethiopian Journal of Sciences and Sustainable Development
Year: 2019

description: The leather industry is one of the major polluting industries in Ethiopia. Environment protection has prompted industrialists and scientists to re-look at transformation of tannery solid waste materials to valuable products using enzymatic hydrolysis. Acid and liming process of gelatin production generate large amount of wastes and used limited raw materials. This study was therefore, aimed to extract papain from papaya fruit latex and use it for transforming raw trimming to gelatin. Extraction and purification was carried out using Three Phase Partitioning. Protein content and protease activity were determined using lowry and casein hydrolysis method, respectively. Effect of agitation time taken, crude extract to t-butanol ratio, ammonium sulphate concentration and temperature on purification fold and activity recovery of papain was evaluated and process was optimized. At its optimized parameters, the intermediate phase of TPP showed 94.14% percentage of protease activity recovery and 8.31 purification fold. At its optimized parameters, bottom phase showed 75.15% percentage of protease activity recovery and 6.61 purification fold. Enzymatic hydrolysis of raw trimming produced 68 wt% and 64 wt% gelatin recovery from the use of crude and intermediate phase papain, respectively. Relatively low gel strength of gelatin with bloom value of 95g and 87g were obtained from hydrolysis of raw trimming by intermediate and crude papain, respectively. This study showed that the use of crude extract for transforming raw trimming to gelatin was found good as it showed comparable protease activity. The TPP can be employed for the extraction and purification of proteases from papaya fruit for industrial application that requires it in partial pure form.
description: Ethiopian Journal of Sciences and Sustainable Development, Vol 6 No 2 (2019): EJSSD
Carbon stars identified from LAMOST DR4 using Machine Learning
Creators: name: Li, Yin-Bi
name: Luo, A-Li
name: Du, Chang-De
name: Zuo, Fang
name: Wang, Meng-Xin
name: Zhao, Gang
name: Jiang, Bi-Wei
name: Zhang, Hua-Wei
name: Liu, Chao
name: Qin, Li
name: Wang, Rui
name: Du, Bing
name: Guo, Yan-Xin
name: Wang, Bo
name: Han, Zhan-Wen
name: Xiang, Mao-sheng
name: Huang, Yang
name: Chen, Bing-Qiu
name: Chen, Jian-Jun
name: Kong, Xiao
name: Hou, Wen
name: Song, Yi-Han
name: Wang, You-Fen
name: Wu, Ke-Fei
name: Zhang, Jian-Nan
name: Zhang, Yong
name: Wang, Yue-Fei
name: Cao, Zi-Huang
name: Hou, Yong-Hui
name: Zhao, Yong-Heng
Publisher: name: arXiv
Year: 2017
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: In this work, we present a catalog of 2651 carbon stars from the fourth Data Release (DR4) of the Large Sky Area Multi-Object Fiber Spectroscopy Telescope (LAMOST). Using an efficient machine-learning algorithm, we find out these stars from more than seven million spectra. As a by-product, 17 carbon-enhanced metal-poor (CEMP) turnoff star candidates are also reported in this paper, and they are preliminarily identified by their atmospheric parameters. Except for 176 stars that could not be given spectral types, we classify the other 2475 carbon stars into five subtypes including 864 C-H, 226 C-R, 400 C-J, 266 C-N, and 719 barium stars based on a series of spectral features. Furthermore, we divide the C-J stars into three subtypes of CJ( H), C-J(R), C-J(N), and about 90% of them are cool N-type stars as expected from previous literature. Beside spectroscopic classification, we also match these carbon stars to multiple broadband photometries. Using ultraviolet photometry data, we find that 25 carbon stars have FUV detections and they are likely to be in binary systems with compact white dwarf companions.
description: 72 pages, 23 figures. accepted by ApJS, lal@nao.cas.cn
Additional file 2 of Exploring the genomic resources and analysing the genetic diversity and population structure of Chinese indigenous rabbit breeds by RAD-seq
Creators: name: Liu, Chenmiao
name: Wang, Shuhui
name: Dong, Xianggui
name: Zhao, Jiping
name: Ye, Xiangyang
name: Gong, Ruiguang
name: Ren, Zhanjun
Publisher: name: figshare
Year: 2021
Subjects: subject: Genetics
subject: FOS: Biological sciences

description: Additional file 2: Supplementary Figure S2. Principal component analysis (PCA) of the Chinese indigenous rabbit breeds based on autosome (PC2=4.10%, PC3=3.41%).
On blowup for the supercritical quadratic wave equation
Creators: name: Csobo, Elek
name: Glogić, Irfan
name: Schörkhuber, Birgit
Publisher: name: arXiv
Year: 2021
Subjects: subject: Analysis of PDEs (math.AP)
subject: Mathematical Physics (math-ph)
subject: Spectral Theory (math.SP)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: We study singularity formation for the focusing quadratic wave equation in the energy supercritical case, i.e., for $d \geq 7$. We find in closed form a new, non-trivial, radial, self-similar blowup solution $u^*$ which exists for all $d \geq 7$. For $d=9$, we study the stability of $u^*$ without any symmetry assumptions on the initial data and show that there is a family of perturbations which lead to blowup via $u^*$. In similarity coordinates, this family represents a co-dimension one Lipschitz manifold modulo translation symmetries. In addition, in $d=7$ and $d=9$, we prove non-radial stability of the well-known ODE blowup solution. Also, for the first time we establish persistence of regularity for the wave equation in similarity coordinates.
description: 61 pages, typos corrected, to appear in Analysis & PDE