cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Thermal Influences of Rooftop Photovoltaic Panels on Building Performance: a Meta-Analysis
Creators: name: D'Agostino, D.
name: Parker, D.
Publisher: name: WIP
Year: 2022
Subjects: PV Systems Engineering, Integrated/Applied PV
PV and Buildings

description: 8th World Conference on Photovoltaic Energy Conversion; 1180-1183
description: Solar electric photovoltaic (PV) panels are becoming common worldwide and are increasingly integrated as a building material. However, an advantage of conventional rooftop stand-off PV arrays on rack-mounting with an air space below the panels, comes from roof shading of direct sun and modification to roof surface long-wave radiation to the sky. These influences affect thermal transmittance and, consequently, cooling and heating loads of the roof structure underneath. Thermal impacts of PV stand-off array on roof heat transfer performance are complex depending on array shadow, spacing, tilt, wind as well as roof view-factor to the sky and infrared heat exchange at night. Arrays also strongly influence thermal long-wave radiation exchange to the sky for both cooling and heating. When arrays cover much of buildings’ roof surfaces, these impacts begin to exert a larger influence on roof/ceiling related heat gains and building thermal performance. This can be particularly important for existing buildings with lower levels of roof insulation. This paper summarizes a meta-analysis the existing research into this influence as well as EnergyPlus simulation analysis conducted by the authors for specific examples. Our evaluation is bolstered by infrared thermography illustrating the phenomenon as well as experimental temperature data taken from actual roof assemblies. Simulation analysis is used to examine array shading impacts and interaction with exiting roof insulation levels. Potentials for existing buildings are discussed as well as how these influences might become more important with increased summer heat waves associated with climate change. Comfort impacts are simulated for residential buildings without mechanical cooling systems.
Development from a Small to Large Scale Luminescent Downshift Layer Fabrication on Silicon Solar Cells
Creators: name: Cass, B.
name: Chandra, S.
name: Ortega, A.
name: McCormack, S.
Publisher: name: WIP
Year: 2022
Subjects: PV Systems Engineering, Integrated/Applied PV
PV and Buildings

description: 8th World Conference on Photovoltaic Energy Conversion; 1170-1173
description: This paper present the issues that have been faced during the scaling up fabrication of a Luminescent Downshifting layer (LDS) for large-scale compound parabolic photovoltaic system-based requirement. The development process in fabricating large-scale LDS layers changes significantly through the upscaling process. The requirement of these LDS layers remain the same from being applied on a 2 x 2cm PV cell onto two different 12.5 x 12.5 cm PV cell systems. During this process, the characteristics which influence the LDS’ efficiency on the PV cell were altered to remain giving the best possible output. From the upscaling process, it will be shown that various issues arise for the larger cell but can be fixed with a change in fabrication processes.
Hijacking natural systems a journey of discovery inside our cells
Creators: name: Berry-Frith, Joanne
name: Self, Tim
Publisher: name: Loughborough University
Year: 2024
Subjects: classificationCode: 31
subject: Biological sciences
subject: FOS: Biological sciences

description: Hijacking natural systems: a journey of discovery inside our cellsIn 2010, artist Jo Berry embarked on a period of research within the School of Biomedical Sciences at Nottingham University Medical School, alongside Tim Self and Dr Nicholas Holliday. Here they recount the experience of an artist working in a 'live' scientific research environment and the ways that the two disciplines of art and science can benefit each other to a wider audience.
A New Star-Formation Rate Calibration from Polycyclic Aromatic Hydrocarbon Emission Features and Application to High Redshift Galaxies
Creators: name: Shipley, Heath V.
name: Papovich, Casey
name: Rieke, George H.
name: Brown, Michael J. I.
name: Moustakas, John
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We calibrate the integrated luminosity from the polycyclic aromatic hydrocarbon (PAH) features at 6.2\micron, 7.7\micron\ and 11.3\micron\ in galaxies as a measure of the star-formation rate (SFR). These features are strong (containing as much as 5-10\% of the total infrared luminosity) and suffer minimal extinction. Our calibration uses \spitzer\ Infrared Spectrograph (IRS) measurements of 105 galaxies at $0 < z < 0.4$, infrared (IR) luminosities of $10^9 - 10^{12} \lsol$, combined with other well-calibrated SFR indicators. The PAH luminosity correlates linearly with the SFR as measured by the extinction-corrected \ha\ luminosity over the range of luminosities in our calibration sample. The scatter is 0.14 dex comparable to that between SFRs derived from the \paa\ and extinction-corrected \ha\ emission lines, implying the PAH features may be as accurate a SFR indicator as hydrogen recombination lines. The PAH SFR relation depends on gas-phase metallicity, for which we supply an empirical correction for galaxies with $0.2 < \mathrm{Z} \lsim 0.7$~\zsol. We present a case study in advance of the \textit{James Webb Space Telescope} (\jwst), which will be capable of measuring SFRs from PAHs in distant galaxies at the peak of the SFR density in the universe ($z\sim2$) with SFRs as low as $\sim$~10~\sfrunits. We use \spitzer/IRS observations of the PAH features and \paa\ emission plus \ha\ measurements in lensed star-forming galaxies at $1 < z < 3$ to demonstrate the ability of the PAHs to derive accurate SFRs. We also demonstrate that because the PAH features dominate the mid-IR fluxes, broad-band mid-IR photometric measurements from \jwst\ will trace both the SFR and provide a way to exclude galaxies dominated by an AGN.
description: Accepted for publication in ApJ
Influence of Construction Supply Chain Challenges on project progress, Case of 40/60 Housing program of Addis Ababa!
Creators: name: Assefa, Gelana
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2016

description: Construction projects of 40/60 housing program, located in different parts of Addis Ababa city, suffer from many problems. Consequently, the objective of this research is to identify and examine the construction supply chain challenges and to elicit their effect on the progress of construction projects. A comprehensive literature review was deployed to generate a set of CSC concepts, benefits, and factors believed to affect construction project progress. A total of 143 questionnaires were distributed to 4 key groups of CSC participants; namely owner (government), consultants, MSEs and contractors. The survey findings indicate that all 4 groups agree that actors involved in the construction of 40/60 housing projects have poor knowledge of Construction Supply Chain Management which is an indicative of poor Construction supply chain management practices within the chain. It also revealed that factors such as 'Poor integration among the stake holders', 'Shortage of construction material' and 'capacity problems of contractors' sequentially have the highest impact on the construction supply chain of 40/60 project. The actors in the CSC need to work towards more aligned and structured ways of working. Specially the government should work towards creating strong CSC by applying a system that increase integration and collaboration within and between project supply chains. Continuous coordination and relationship between project participants are required through project life cycle for solving problems and enhancing project progresses. Keywords: supply chain management, construction supply chain management, supply chain integration
Microinverter PV Systems: New Efficiency Rankings and Formula for Energy Yield Assessment for any PV Panel Size at Different Microinverter Types
Creators: name: Krauter, S.
name: Bendfeld, J.
Publisher: name: WIP
Year: 2022
Subjects: PV Systems Engineering, Integrated/Applied PV
Power Electronics and Electrical Grid Interface

description: 8th World Conference on Photovoltaic Energy Conversion; 1165-1169
description: The market for microinverters is growing, especially in Europe. Driven by rising electricity prices, many small photovoltaic energy systems are being installed. Since 2014, microinverters have been studied indoors and outdoors at Paderborn University. In the indoor lab, conversion efficiencies as a function of load have been measured with high accuracy and ranked according to Euro- & CEC weightings: The latest rankings of 2022 are included in this paper. In the outdoor lab, energy yields have been measured using identical and calibrated crystalline silicon PV modules. Until 2020, measurements were carried out initially with 215Wp modules. Because of increasing module power nowadays, 360 Wp modules are now being used. These extremes have been investigated: An older module with 215 Wp and a new module offering 360 Wp (both with 60 cells). Appling the low-power modules, the challenge for the microinverters was during weak-light conditions, for high-power modules, some inverters temporarily reached their power limits, so output was reduced. A method to determine actual energy yield has been developed, using a linear equation and a reference configuration: So yield for any module & inverter configuration can be determined by just two coefficients.
A Model Correcting the Effect of Sub-Hourly Irradiance Fluctuations on Overload Clipping Losses in Hourly Simulations
Creators: name: Villoz, A.
name: Wittmer, B.
name: Mermoud, A.
name: Oliosi, M.
name: Bridel-Bertomeu, A.
Publisher: name: WIP
Year: 2022
Subjects: PV Systems Engineering, Integrated/Applied PV
Engineering Design and Installation of PV Systems

description: 8th World Conference on Photovoltaic Energy Conversion; 1151-1156
description: Simulations of PV systems that proceed in hourly steps can underestimate overload losses arising from sub-hourly irradiance fluctuations. The aim of this study is to estimate and address these additional overload clipping losses to improve the accuracy of the simulations in PVsyst. The current trend for designing PV systems is to increase the DC/AC ratio. This trend is mainly due to PV modules plummeting in price and PV plants being constrained by grid limitations. The increase in DC/AC ratio allows PV systems to maximize production for the same AC capacity, by having the inverters operating at full output power for more hours during the day. When the inverter is operating close to maximal power, it can happen that irradiance spikes drive it into clipping conditions. This behavior is not captured by a simulation that proceeds in hourly steps, which leads to a systematic underestimation of the clipping losses (1-5% or more over a year). The purpose of this study is to find a way to estimate from sub-hourly irradiance fluctuations a correction that can be applied in a general way to the clipping losses of an hourly simulation. In a first step, an analysis of hourly average irradiation data and sub-hourly data was done, to identify a way to calculate the behavior of overload clipping losses when applying a threshold. The analysis then went on using the same irradiation data for complete simulations in four climates and covering multiple cases of orientations of PV modules and DC/AC ratios. The goal of the study, to improve simulations in PVsyst that are done in hourly steps, was achieved by using coefficients extracted from the sub-hourly data, applied on a simple geometrical model. This model corrects the error on overload losses significantly and thereby reduces the average difference of minute- and hourly-based AC generation below 1% for each DC/AC ratio.
Challenges and Prospects of Human Capital Development of Ethiopian Cement Industry
Creators: name: Negash, Solomon
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2018

description: This study conducted to assess the challenges and prospects of human capital development of Ethiopian cement industry. A semi structured interview was held with the Human resource managers of the four cement factories under the study and one representative of Ethiopian cement Association as well as one representative of chemical and construction inputs industry development institute. The results of the study show that the main challenges of Ethiopian cement industry with regards to human capital development were accepting the challenges of modern technological changes, attracting and retaining qualified personnel, winning the war for talent, maintaining competitive compensation offerings, retaining highest performing employees, lack of well-trained & experienced domestic workforce in cement production technologies due to absence of cement technology institute resulted for the dependency of Ethiopian cement industry on foreign employment due to the introduction of new cement technologies. The finding also identified that lack willingness foreign employees to share knowledge and skills, absence of teamwork among different departments and language barrier has limited knowledge and skill sharing and transfer practices of the Ethiopian cement factories. The study implied that the major negative consequences of imported experts on the development of Ethiopian cement industry were foreign currency leakage, lose of job opportunity for foreigners. The study also found the main reasons for an employee poaching practices were lack of well-experienced & skilled professionals in cement technologies in the country and the newly established cement factories' capacity in soliciting experienced and skilled employees with better benefits. The study recommended that Ethiopia cement industry should work on human capital development with collaboration of all stakeholders of the industry in order to alleviate the human capital deficit of the industry.
title: Введение в магистерскую программу
Creators: name: ELS IPR BOOKS
Publisher: name: Ай Пи Ар Медиа
Year: 2022

description: Учебное пособие состоит из 2-х частей. Первая знакомит пользователей с особенностями российской системы обучения в магистратуре / аспирантуре инженерно-технического вуза и с требованиями, предъявляемыми к магистрантам в процессе обучения. Вторая часть готовит к написанию отдельных разделов выпускной квалификационной работы на материале фрагментов аутентичных текстов магистерских диссертаций. Грамматический материал соответствует программе по русскому языку как иностранному подготовительного факультета российских вузов. Лексика представлена терминологией метаязыка науки. Для усвоения материала учебного пособия требуется 72 часа (2 кредита), распределенных следующим образом: 36 аудиторных часов (1 кредит) + 36 часов (1 кредит) самостоятельной работы. Издание предназначено для работы под руководством преподавателя. Учебное пособие соответствует Приказу Министерства образования и науки Российской Федерации (Минобрнауки России) от 1 апреля 2014 г. № 255 г. Москва «Об утверждении уровней владения русским языком как иностранным языком и требований к ним», адресовано иностранным слушателям подготовительных факультетов российских вузов, владеющим русским языком на уровне, приближенном к В1 (ТРКИ 1), и планирующим обучение в магистратуре инженерно-технического вуза.
GaN based Module-Integrated, High-Efficiency DC/DC Optimizer for Maximizing the Yield of the Large Photovoltaic Power Plant
Creators: name: NGUYEN, V.S.
name: Catellani, S.
name: Bier, A.
name: Delaplagne, T.
name: Lespinats, S.
name: Merhej, P.
name: Greco, C.
name: Bizzarri, F.
Publisher: name: WIP
Year: 2022
Subjects: PV Systems Engineering, Integrated/Applied PV
Power Electronics and Electrical Grid Interface

description: 8th World Conference on Photovoltaic Energy Conversion; 1157-1160
description: In a photovoltaic (PV) power plant, due to the low-voltage standard regulation, the maximum opencircuit voltage of a string of PV module cannot exceed 1500 VDC. This work deals with the design, characterization and optimization of PV modules integrating a 400 W DC-DC converter (optimizer). These PV modules with integrated power electronics will be implemented in a 1500 V PV string. These optimizers will allow regulating the output voltage of each PV module to a value inferior to the open-circuit voltage. Consequently, we can increase the number of PV modules connected in series in a single string and raise the power of the string. In this work, two compact demo-boards of a 400 W hardware are developed for complete characterizations in different systems configurations using Silicon based transistors for the first one and Gallium Nitride HEMT (high electron mobility transistor) for the second one; respectively. Finally, this works shows a comparison of the electrical behaviour of both hardware solutions.
Logistics Performance on Service Delivery the Case of Ethiopian Shipping and Logistics Service Enterprise
Creators: name: Godana, Addis
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2017

description: The objective of this study is to assess the logistics performance of Ethiopia Shipping and Logistic Service Enterprise. Specifically, simple random sampling is deployed as a sampling technique since the list of target population is known. They are 1060 employee and more than 300 importers, exporter and transport association selected as respondents of the study. However, primary sources of data gathered from Ethiopia Shipping and Logistic Service Enterprise library and yearly report of the enterprise to assess their logistics performance. The data is collected through structured interviews based on questionnaire, which is developed based on the three dimensions of logistics performance. The respondents have been approached by the data collectors at either their office or on their seals area. In order to examine the date correlation analysis were used. The data entry and analysis was conducted by using Statistical Package for Social Since version 20 and chi-square used to correlation analysis between customer and employee of the enterprise. It is concluded that Ethiopia Shipping and Logistic Service Enterprise were less performing in their logistics performance. The findings of the study revealed that each dimensions of logistics performance (logistics differentiation, logistics efficiency and logistics effectiveness) have under performance. The study recommended for Ethiopia Shipping and Logistic Service Enterprise to continuously improve their logistical performance, among other things, through strengthening and developing a good relationship with others modernize their order management practice. Furthermore, it is also advisable for them to further improve the relationship between customer and other sister company or enterprise of in a foreign country. Keywords/phrases: logistics performance, logistics differentiation, logistics efficiency, logistics effectiveness
Fast, low-ionization emission regions of the planetary nebula M2-42
Creators: name: Danehkar, A.
name: Parker, Q. A.
name: Steffen, W.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Spatially resolved observations of the planetary nebula M2-42 (PN G008.2-04.8) obtained with the Wide Field Spectrograph on the Australian National University 2.3 m telescope have revealed the remarkable features of bipolar collimated jets emerging from its main structure. Velocity-resolved channel maps derived from the [N II] $λ$6584 emission line disentangle different morphological components of the nebula. This information is used to develop a three-dimensional morpho-kinematic model, which consists of an equatorial dense torus and a pair of asymmetric bipolar outflows. The expansion velocity of about 20 km s$^{-1}$ is measured from the spectrum integrated over the main shell. However, the deprojected velocities of the jets are found to be in the range of 80-160 km s$^{-1}$ with respect to the nebular center. It is found that the mean density of the collimated outflows, 595 $\pm$ 125 cm$^{-3}$, is five times lower than that of the main shell, 3150 cm$^{-3}$, whereas their singly ionized nitrogen and sulfur abundances are about three times higher than those determined from the dense shell. The results indicate that the features of the collimated jets are typical of fast, low-ionization emission regions.
description: 6 pages, 4 figures, 4 tables, accepted for publication in The Astronomical Journal
The Globular Cluster System of the Coma cD Galaxy NGC 4874 from Hubble Space Telescope ACS and WFC3/IR Imaging
Creators: name: Cho, Hyejeon
name: Blakeslee, John P.
name: Chies-Santos, Ana L.
name: Jee, M. James
name: Jensen, Joseph B.
name: Peng, Eric W.
name: Lee, Young-Wook
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present new HST optical and near-infrared (NIR) photometry of the rich globular cluster (GC) system of NGC 4874, the cD galaxy in the core of the Coma cluster (Abell 1656). NGC 4874 was observed with the HST Advanced Camera for Surveys in the F475W (g) and F814W (I) passbands and the Wide Field Camera 3 IR Channel in F160W (H). The GCs in this field exhibit a bimodal optical color distribution with more than half of the GCs falling on the red side at g-I > 1. Bimodality is also present, though less conspicuously, in the optical-NIR I-H color. Consistent with past work, we find evidence for nonlinearity in the g-I versus I-H color-color relation. Our results thus underscore the need for understanding the detailed form of the color-metallicity relations in interpreting observational data on GC bimodality. We also find a very strong color-magnitude trend, or "blue tilt," for the blue component of the optical color distribution of the NGC 4874 GC system. A similarly strong trend is present for the overall mean I-H color as a function of magnitude; for M_814 < -10 mag, these trends imply a steep mass-metallicity scaling with $Z\propto M_{\rm GC}^{1.4\pm0.4}$, but the scaling is not a simple power law and becomes much weaker at lower masses. As in other similar systems, the spatial distribution of the blue GCs is more extended than that of the red GCs, partly because of blue GCs associated with surrounding cluster galaxies. In addition, the center of the GC system is displaced by 4+/-1 kpc towards the southwest from the luminosity center of NGC 4874, in the direction of NGC 4872. Finally, we remark on a dwarf elliptical galaxy with a noticeably asymmetrical GC distribution. Interestingly, this dwarf has a velocity of nearly -3000 km/s with respect to NGC 4874; we suggest it is on its first infall into the cluster core and is undergoing stripping of its GC system by the cluster potential.
description: 24 pages, 20 figures, accepted for publication in ApJ
When are the Rees algebras of parameter ideals almost Gorenstein graded rings?
Creators: name: Goto, Shiro
name: Mehran, Rahimi
name: Taniguchi, Naoki
name: Truong, Hoang Le
Publisher: name: arXiv
Year: 2016
Subjects: subject: Commutative Algebra (math.AC)
subject: FOS: Mathematics
subject: 13H10, 13H15, 13A30

description: Let $A$ be a Cohen-Macaulay local ring with $\operatorname{dim} A = d\ge 3$, possessing the canonical module ${\mathrm K}_A$. Let $a_1, a_2, \ldots, a_r$ $(3 \le r \le d)$ be a subsystem of parameters of $A$ and set $Q= (a_1, a_2, \ldots, a_r)$. It is shown that if the Rees algebra ${\mathcal R}(Q)$ of $Q$ is an almost Gorenstein graded ring, then $A$ is a regular local ring and $a_1, a_2, \ldots, a_r$ is a part of a regular system of parameters of $A$.
description: 9 pages
Data-Driven PV System Engineering: Comprehensive Modelling and Simulation of a Grid-Connected Three-Phase Inverter
Creators: name: Titova, V.
name: Lahrmann, L.
name: Alves, A.A.
name: Haase, F.
name: Khadiri-Yazami, Z.
name: Lapke, M.
Publisher: name: WIP
Year: 2022
Subjects: PV Systems Engineering, Integrated/Applied PV
Power Electronics and Electrical Grid Interface

description: 8th World Conference on Photovoltaic Energy Conversion; 1161-1164
description: In a data-driven modelling approach, the intelligent integration of data between physical and virtual entities of a photovoltaic (PV) system can facilitate innovation, control and optimization of the entire PV power plant. In an inverter, the insulated-gate bipolar transistor (IGBT) power electronics are used to distribute and convert the direct current from the PV module to alternating current. Due to the demand for performance improvements, the need to model these IGBT stacks is constantly increasing [1, 2]. Consequently, to reduce thermal resistance and improve the reliability of power electronics, new data points such as thermal loading and internal humidity are increasingly moving into the scientific focus [3]. In this contribution, we pursue two approaches towards anomaly detection in the operation of a PV plant. A comparison-based approach, analyzing the operation-induced data of an inverter to a physically motivated inverter model, and a failure-motivated approach using numerical modelling methods to reveal the hidden characteristics for latter data analysis. We present a MATLAB/Simulink model of a three-phase grid-connected inverter. We demonstrate the responsiveness of our model by changing the polarity in the active and reactive current control. This model shall serve as an idealized digital twin of the inverter to aid in anomaly detection within measured inverter data. Furthermore, we present initial ideas on a failure-motivated modelling approach to improve our model’s accuracy and enable optimized predictive maintenance algorithms. The use of hidden characteristics, such as IGBT junction temperature and power module interior humidity can serve as markers for failure detection in the operation of a PV system. Therefore, we have analyzed initial power loss calculations of an IGBT, which serve as a basis for thermal loss simulations to predict overheating of the switch components within the inverter. We examine the correlation between modelled and measured temperatures of the IGBT stacks. In addition, we propose a humidity model to prevent humidity-induced failures in power electronics.
Study of Hydrogen Manipulation on Silicon Surfaces for Programmable Memristor Devices
Creators: name: Nipu, Naznin Nahar
Publisher: name: Purdue University Graduate School
Year: 2024
Subjects: classificationCode: 401604
subject: Elemental semiconductors

description: As edge computing architectures bring processing closer to data sources, there is an increasing need for memory technologies that can work effectively and consistently in a variety of situations while using minimal energy. Memristors are memory devices that have the potential to greatly increase the performance and scalability of edge devices. However, a key challenge is to achieve precise resistance switching. Silicon (Si) surfaces embedded in a proton-conducting polymer can demonstrate controllable memristor behavior wherein hydrogen (H) atoms are deposited onto the surface. When H is inside the polymer, its conductivity decreases. When H is on the silicon surface, its bulk conductivity increases due to more mid-gap traps. Migration of H atom placement can make a memristor unit cell whose impedance modulates in response to electrical signals. This study investigates the critical function of H atoms by deliberately altering their position and concentration within and upon silicon-based memristor devices. Using the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS), we investigate the impact of temperature (T) and electric field (EF) on H migration. We define a polygonal volume of Si and deposit H atoms on its top surface. After energy minimization, we apply T and EF to observe diffusion and drift of H atoms. The hopping rate depends on applied T and EF. We thus establish a relationship between the three-dimensional velocity of H and applied T and EF. We simulate several movement pathways of H atoms over time under the influence of varying T and EF acting separately or simultaneously. Therefore, we can determine the required magnitude and direction of EF and T to be introduced to the system to achieve desired H location, concentration, and configuration. Finally, we assess the device performance at different T and EF to assess memory retention rate. Our approach aims to enhance the functionality of edge computing devices and enable more effective neuromorphic computing that can emulate human brain operations. However, the limitations of this study include potential scalability issues and the necessity for precise control over hydrogen dispersion. Despite these challenges, the research provides valuable insights on how to modify the electrical characteristics of memristors, offering a way forward in the development of advanced silicon based electronic devices.
Valley Plasmonics in the Dichalcogenides
Creators: name: Groenewald, R. E.
name: Rösner, M.
name: Schönhoff, G.
name: Haas, S.
name: Wehling, T. O.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The rich phenomenology of plasmonic excitations in the dichalcogenides is analyzed as a function of doping. The many-body polarization, the dielectric response function and electron energy loss spectra are calculated using an ab initio based model involving material-realistic Coulomb interactions, band structure and spin-orbit coupling. Focusing on the representative case of MoS$_2$, a plethora of plasmon bands are observed, originating from scattering processes within and between the conduction or valence band valleys. We discuss the resulting square-root and linear collective modes, arising from long-range versus short-range screening of the Coulomb potential. We show that the multi-orbital nature of the bands and spin-orbit coupling strongly affects inter-valley scattering processes by gapping certain two-particle modes at large momentum transfer.
Assessment on Enterprise Resource Planning System Utilization with Special Reference to Supply Chain Management in the Case of Ethio Telecom Sourcing
Creators: name: Ermias, Minas
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2016

description: Different major changes have enabled companies to actualize the power of supply chains to a degree impossible in the past. Among those technologies have enabled the convergence of SCM and computerized networking toolsets capable of linking all channel partners into a single trading community. Depending on this the research tries to address the importance of Enterprise Resource Planning System Utilization with special reference to Supply Chain Management by focusing the relation between system features and the supply chain management performance in case of ethio telecom. The researcher distributed questionnaire and conduct interview to collect data from employees and managers those who have close- fitting with the supply chain management activities which are sourcing department and supply chain management department. The data analysis is conducted through statistical technique using SPSS. The result of the analyses indicate that system features have positive correlation with supply chain management and each system features are explained. Finally, the researcher provides valuable conclusion and recommendation based on the analysis result
Bayesian model comparison for one-dimensional azimuthal correlations in 200GeV AuAu collisions
Creators: name: Eggers, Hans C.
name: de Kock, Michiel B.
name: Trainor, Thomas A.
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In the context of data modeling and comparisons between different fit models, Bayesian analysis calls that model best which has the largest evidence, the prior-weighted integral over model parameters of the likelihood function. Evidence calculations automatically take into account both the usual chi-squared measure and an Occam factor which quantifies the price for adding extra parameters. Applying Bayesian analysis to projections onto azimuth of 2D angular correlations from 200 GeV AuAu collisions, we consider typical model choices including Fourier series and a Gaussian plus combinations of individual cosine components. We find that models including a Gaussian component are consistently preferred over pure Fourier-series parametrizations, sometimes strongly so. For 0-5% central collisions the Gaussian-plus-dipole model performs better than Fourier Series models or any other combination of Gaussian-plus-multipoles.
description: 6 pages, 4 figures. Proceedings of the XLV International Symposium on Multiparticle Dynamics, Wildbad Kreuth, 5-9 October 2015
The Trispectrum in the Effective Field Theory of Large Scale Structure
Creators: name: Bertolini, Daniele
name: Schutz, Katelin
name: Solon, Mikhail P.
name: Zurek, Kathryn M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We compute the connected four point correlation function (the trispectrum in Fourier space) of cosmological density perturbations at one-loop order in Standard Perturbation Theory (SPT) and the Effective Field Theory of Large Scale Structure (EFT of LSS). This paper is a companion to our earlier work on the non-Gaussian covariance of the matter power spectrum, which corresponds to a particular wavenumber configuration of the trispectrum. In the present calculation, we highlight and clarify some of the subtle aspects of the EFT framework that arise at third order in perturbation theory for general wavenumber configurations of the trispectrum. We consistently incorporate vorticity and non-locality in time into the EFT counterterms and lay out a complete basis of building blocks for the stress tensor. We show predictions for the one-loop SPT trispectrum and the EFT contributions, focusing on configurations which have particular relevance for using LSS to constrain primordial non-Gaussianity.
description: 25+3 pages, 7 figures
Optical Design and Optics Manufacturing of a Highly Integrated Micro-CPV for Space Applications
Creators: name: Bermudez-Garcia, A.
name: Voarino, P.
name: Raccurt, O.
Publisher: name: WIP
Year: 2022
Subjects: PV Systems Engineering, Integrated/Applied PV
PV for Space Applications

description: 8th World Conference on Photovoltaic Energy Conversion; 1142-1147
description: This work presents the first optical developments of a novel concept of micro-Concentrators PhotoVoltaic (CPV), based on a highly integrated miniaturized mirror. This approach is performed with the objective of significantly reducing the recurring cost of the standard PhotoVoltaic Assembly (PVA) made with classical Coverglass Interconnected Cells (CIC) for space applications. Optics have been optimized for < 1 mm² micro solar cells. Free forms optics, primary and secondary elements have been studied and an acceptance angle along the y-axis of 8.2° has been obtained. A parabolic shape has then been chosen for proof-of-concept testing. The concentration ratio is 26X and the first estimate of optical efficiency is of 82 % without any antireflective optimization. For the experimental part, honeycomb structural assemblies, optical molds and optics have been realized. The fabrication process is described, and the first characterizations are achieved.
Welche charakteristischen Züge kennzeichnen das Phänomen "Jugend in der Dritten Welt"?
Creators: name: Michel, Frere
Publisher: name: Concilium
Year: 1970

description: Concilium, Bd. 11 Nr. 6/7 (1975): Concilium: Internationale Zeitschrift für Theologie, Band 11, Heft 6/7
Analysis of Power Grids with High-Penetration of Photovoltaics: the Case of Honduras
Creators: name: Gómez-Ramírez, G.
name: Meza, C.
name: Mora-Jiménez, G.
name: Luévano-Reyes, I.A.
name: García-Santander, L.
name: Rojas, J.R.
Publisher: name: WIP
Year: 2022
Subjects: PV Systems Engineering, Integrated/Applied PV
Power Electronics and Electrical Grid Interface

description: 8th World Conference on Photovoltaic Energy Conversion; 1148-1150
description: In 2020, Honduras was the country with the highest penetration of solar energy in its electricity matrix. Moreover, the Honduran power system is interconnected with other countries in the Central American region, with a common regional market. On the other hand, the Honduran electricity system has a high impedance and low inertia. The conditions described above make this country an interesting case study to analyse the behaviour of a weak power grid with a high penetration of solar photovoltaic energy. This paper briefly discusses these conditions and analyses an event where a blackout occurs in Nicaragua due to the shutdown of several PV plants in Honduras. This paper also explores a solution that avoids the blackout by integrating distributed storage. The analysis and proposed solution are performed using a model of the Central American electricity grid developed using ETAP software.
Green Procurement: The Practice & Challenges in Three Selected UN Agencies in Ethiopia
Creators: name: Begashaw, Achamyeleh
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2016

description: e main objective of this research is to assess the practice and challenges of Green Procurement in three selected UN agencies in Ethiopia namely UNECA, UNDP & UNOPS. The gap identified in this research is the implementation problem of green procurement in the procurement activities at sourcing, bid evaluation and technical evaluation stages. According to the preliminary interview conducted at the beginning of the research stage the main reasons for the gap was lack of management support and the awareness level of procurement practitioners and employees. The researcher employed mixed research design method to assess the practice by raising four basic questions that revolve around awareness, management support and challenges of green procurement. The researcher developed his tools based on the four basic questions and the required information was retrieved from the respondents. The respondents were the procurement practitioners, requistioners, technical evaluation committee, procurement cases reviewing committees and employees who works in the area of climate change. The data collected through structured questionnaire analyzed using descriptive statistical technique which includes frequencies & mean using and tables along with the interview. From this particular research in adequate management support and lack of awareness is found to be one of the reasons for the implementation problem. In addition to this additional reasons are identified. These are the usage of whole life cycle approach is complex particularly for the environmental attributes of the product and the member states are not in agreement to fully implement the green procurement concept since it discriminates vendors from the developing nations. The researcher also comes up with some possible suggestions & recommendations so as to tackle the problems. These are, arrange capacity development and awareness creation programme for both the procurement practitioners and vendors and integrating sustainable procurement rules with main procurement rules. Key Words: Green Procurement, Sustainable Procurement
Entanglement entropy of excited states in conformal perturbation theory and the Einstein equation
Creators: name: Speranza, Antony J.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: For a conformal field theory (CFT) deformed by a relevant operator, the entanglement entropy of a ball-shaped region may be computed as a perturbative expansion in the coupling. A similar perturbative expansion exists for excited states near the vacuum. Using these expansions, this work investigates the behavior of excited state entanglement entropies of small, ball-shaped regions. The motivation for these calculations is Jacobson's recent work on the equivalence of the Einstein equation and the hypothesis of maximal vacuum entropy [arXiv:1505.04753], which relies on a conjecture stating that the behavior of these entropies is sufficiently similar to a CFT. In addition to the expected type of terms which scale with the ball radius as $R^d$, the entanglement entropy calculation gives rise to terms scaling as $R^{2Δ}$, where $Δ$ is the dimension of the deforming operator. When $Δ\leq\frac{d}{2}$, the latter terms dominate the former, and suggest that a modification to the conjecture is needed.
description: 31 pages + appendices and references, 2 figures
title: Русский язык в многоязычном мире: вопросы статуса и билингвального образования
Creators: name: ELS IPR BOOKS
Publisher: name: Ай Пи Ар Медиа
Year: 2022

description: В монографии рассматриваются место и роль русского языка на постсоветском пространстве и в дальнем зарубежье: языковая ситуация в разных странах, статус русского языка (юридический, социолингвистический, образовательный), а также проблемы сохранения национальной идентичности в русскоязычных диаспорах и содержания билингвального образования как транслятора цивилизационного кода в Российской Федерации и за рубежом. Книга адресована специалистам по социолингвистике, по русскому языку и методике его преподавания, культурологам, а также широкому кругу читателей, которых интересуют вопросы продвижения русского языка в мире.
title: Motive, Chancen und Risiken für einen angewandten Mergers & Acquisitions-Ansatz für kleine und mittlere Unternehmen
Creators: name: Beck, Dominik
Publisher: name: FH CAMPUS 02 (CAMPUS 02 Fachhochschule der Wirtschaft)
Year: 2024
Subjects: subject: 658 Allgemeines Management

description: Eine beachtliche Anzahl an Unternehmen, werden in den Bereich der kleinen und mittelständischen Unternehmen (KMU) zugeordnet. Diese unterlaufen eine Veränderung dahingehend, dass innerfamiliäre Nachfolgelösungen in vergangenen Jahren abgenommen haben. Erschwerend können sich noch finanzielle Krisen abzeichnen und ein zunehmender internationaler Wettbewerb. Durch den Faktor der steigenden Internationalisierung von mittelständischen Unternehmen, wird ein Mergers-&-Acquisition-Ansatz immer wichtiger. Dieses Themengebiet ist inzwischen nicht nur bei Großunternehmen im Einsatz, sondern auch im Bereich von kleinen und mittelständischen Unternehmen. 
Das erklärte Ziel der Masterarbeit ist die Darlegung von kritischen Erfolgsfaktoren, die in einem angewandten Mergers-&-Acquisition-Ansatz zum Vorschein kommen. Dabei wird detailliert auf die damit verbundenen Themenbereiche eingegangen. Die Herausforderungen die sich in der Praxis in den entsprechenden Prozessphasen auftun werden im Detail erörtert. Dabei kann dies als Hilfestellung für Unternehmen die solch eine Transaktion bisher noch nicht vollzogen und möglicherweise Vorhaben haben durchaus wertvoll sein, da diese aus Fehlern von bisherigen Unternehmen, Rückschlüsse und Erfahrungen für ihre eigene Transaktion ziehen können 
Zu diesem Themengebiet hat die Fachliteratur einige Ansätze und Perspektiven dargelegt, überwiegend für Großunternehmen. Dabei konnten Modelle auf den Bereich von kleinen und mittelständischen Unternehmen übertragen werden. Dies hat sich im Zuge der qualitativen Forschung ausreichend belegen lassen. Dabei gibt es für kleine und mittlere Unternehmen diverse Beweggründe und Chancen einen Mergers-&-Acquisition Prozess zu vollziehen. Dabei gibt es auch potenzielle Hürden und Risiken die mit solch einer Transaktion einhergehen.
A New Method to Analyse the Soiling in Multi-Junction III-V Based CPV Modules
Creators: name: Timò, G.
name: Castagnetti, N.
name: Minuto, A.
name: Celi, E.
name: Rizzi, S.
Publisher: name: WIP
Year: 2022
Subjects: PV Systems Engineering, Integrated/Applied PV
PV for Space Applications

description: 8th World Conference on Photovoltaic Energy Conversion; 1137-1141
description: The side-by-side (SBS) method allows evaluating the concentrator photovoltaic (CPV) performance degradation due to soiling by monitoring the power or current ratio between a module under test and a reference module that must always be kept clean. For monitoring the performance of the soiling in CPV power plants, the SBS method introduces cost issues as a continuous cleaning of the reference module must be guaranteed by manual or automatic means. With this contribution, a new data filtering method is proposed that allows evaluating the photovoltaic performance degradation due to soiling in multi-junction based CPV modules without the need of using a reference module. The new method is based on the measurement of the electrical parameters of the CPV module along with the direct irradiance data in the spectral bands of the top and middle sub-cells and on the subsequent application of a proper filtering procedure. For a validation of the new methodology, a ten-month testing campaign has been carried out and the results obtained by the data filtering method have been compared with those obtained by the SBS one.
Low-Complexity Iterative Sinusoidal Parameter Estimation
Creators: name: Valin, Jean-Marc
name: Smith, Daniel V.
name: Montgomery, Christopher
name: Terriberry, Timothy B.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Sound (cs.SD)
subject: FOS: Computer and information sciences

description: Sinusoidal parameter estimation is a computationally-intensive task, which can pose problems for real-time implementations. In this paper, we propose a low-complexity iterative method for estimating sinusoidal parameters that is based on the linearisation of the model around an initial frequency estimate. We show that for N sinusoids in a frame of length L, the proposed method has a complexity of O(LN), which is significantly less than the matching pursuits method. Furthermore, the proposed method is shown to be more accurate than the matching pursuits and time frequency reassignment methods in our experiments.
description: 8 pages. arXiv admin note: substantial text overlap with arXiv:1602.05900