cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Mitigating Cell Breakage Losses in Shingled Strings and Modules
Creators: name: Tune, D.
name: Wienands, K.
name: Ullmann, I.
name: Halm, A.
Publisher: name: WIP
Year: 2022
Subjects: Photovoltaic Modules and BoS Components
PV Module Design and Manufacturing

description: 8th World Conference on Photovoltaic Energy Conversion; 834-836
description: As the shingled module architecture is becoming more widespread and production volumes are increasing, the issue of string breakage and rework is becoming more valuable. In this work, we demonstrate and compare two simple strategies for the rapid rework of broken shingle strings that could be applied in the case when the breakage occurs before lamination. Both strategies are based on the use of conductive patches that are applied to the rear of strings in the area of the damaged cell. One of the strategies is shown to cause losses that are significantly higher than the fractional area loss of the damaged shingle stripe whereas the other is shown to yield only very minor losses.
0.54 μm resolution two-photon interference with dispersion cancellation for quantum optical coherence tomography
Creators: name: Okano, Masayuki
name: Lim, Hwan Hong
name: Okamoto, Ryo
name: Nishizawa, Norihiko
name: Kurimura, Sunao
name: Takeuchi, Shigeki
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Quantum information technologies harness the intrinsic nature of quantum theory to beat the limitations of the classical methods for information processing and communication. Recently, the application of quantum features to metrology has attracted much attention. Quantum optical coherence tomography (QOCT), which utilizes two-photon interference between entangled photon pairs, is a promising approach to overcome the problem with optical coherence tomography (OCT): As the resolution of OCT becomes higher, degradation of the resolution due to dispersion within the medium becomes more critical. Here we report on the realization of 0.54 $μ$m resolution two-photon interference, which surpasses the current record resolution 0.75 $μ$m of low-coherence interference for OCT. In addition, the resolution for QOCT showed almost no change against the dispersion of a 1 mm thickness of water inserted in the optical path, whereas the resolution for OCT dramatically degrades. For this experiment, a highly-efficient chirped quasi-phase-matched lithium tantalate device was developed using a novel $`$nano-electrode-poling$'$ technique. The results presented here represent a breakthrough for the realization of quantum protocols, including QOCT, quantum clock synchronization, and more. Our work will open up possibilities for medical and biological applications.
description: 10 pages, 4 figures
Effect of entrepreneurial education on entrepreneurial university students intent: the moderation effect of family background and role model case study on CBE students
Creators: name: Meron, Dagne
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2019

description: The purpose of this study is to examine the effect of entrepreneurial education on entrepreneurial intention of university students found in Addis Ababa university faculty of business and economics. This study is a cross sectional study designed to investigate the effect of providing entrepreneurial education on creating university students' entrepreneurial intention. The primary data was collected from a total sample size of 123 selected through non probability sampling method allocated among students of the two departments that took entrepreneurial education at that time. Structured survey questionnaire was administered. The research gap to be studied in this research was the moderation effect of family background and role models on the relationship between entrepreneurial education and entrepreneurial intention. The collected data was analyzed using descriptive, correlation and multiple regressions. This study confirmed that entrepreneurial education has positive and statistically significant effect on students' entrepreneurial intention. However the analysis of the moderation effect of family background and role model resulted in rejecting to fail the null hypothesis. Based on the findings it is concluded that entrepreneurial education is important to create and develop a positive mindset on entrepreneurial intention. Recommendation and further studies are also forwarded.
Interconnection Approach for Busbar-Less IBC Cells Based on Printed Solder Paste
Creators: name: Messmer, T.
name: Chu, H.
name: Mihailetchi, V.D.
name: Roescu, R.
name: Libal, J.
name: Halm, A.
Publisher: name: WIP
Year: 2022
Subjects: Photovoltaic Modules and BoS Components
PV Module Design and Manufacturing

description: 8th World Conference on Photovoltaic Energy Conversion; 837-841
description: To decrease the cost for the interdigitated back contact (IBC) cell ZEBRA, a busbar-less interconnection approach is developed in order to reduce the silver consumption. Since the metallization for both polarities is printed on the backside of the cell, a 3D designed metallization layout is used for the ZEBRA cell. Thus, for a busbar-less interconnection approach, the wires must be individually contacted to the fingers between the insulation paste pads, which are printed to insulate the wire from the opposite polarity. Due to the individual contact of the fingers to the wire, the connection area is very small, resulting in a low adhesion between the fingers and the wire, which indicates low reliability of the interconnection approach. A reliable busbar-less interconnection approach is demonstrated by implementing finger pads below the solder paste pads. Due to the finger pads, the connection area between the wire and the fingers is increased, resulting in a higher adhesion. Moreover, it is shown that the reliability of the interconnection approach without finger pads can be significantly increased by adding an adhesion in order to mechanically attach the wires to the cell.
Influence of the Lamination Pressure on the Adhesion, Degree of Cross-Linking, and Bubble Formation of PV Modules
Creators: name: Sraisth, S.
name: Öz, A.K.
name: Klaus, D.
name: Wellens, C.
name: Heinrich, M.
Publisher: name: WIP
Year: 2022
Subjects: Photovoltaic Modules and BoS Components
PV Module Design and Manufacturing

description: 8th World Conference on Photovoltaic Energy Conversion; 823-829
description: The lamination parameters can significantly influence the process to make it defect-free and faster or slower, depending on the production need. In this paper, one of these parameters will be discussed, i.e., lamination pressure. This study is focused only on the pressure influence on the glass-backsheet (GB) modules and further compares the differences in two different encapsulant types, Ethylene-Vinyl Acetate (EVA) and Polyolefin Elastomer (POE). The pressure values tested vary from 500 mbar to 1450 mbar. The paper has presented a detailed study of lamination pressure influence on some of the critical characteristics of the PV module, which can impact the module’s reliability, namely gel content, peel strength, and bubble formation. The degree of crosslinking for encapsulants was also compared using DSC and Soxhlet measurement methods. The results show that the lamination pressure above atmospheric value significantly influences the visual quality of PV modules.
The shape of health: A comparison of five alternative ways of visualizing personal health and wellbeing
Creators: name: Ledesma, Andres
name: Nieminen, Hannu
name: Valve, Päivi
name: Ermes, Miikka
name: Jimison, Holly
name: Pavel, Misha
Publisher: name: arXiv
Year: 2016
Subjects: subject: Human-Computer Interaction (cs.HC)
subject: FOS: Computer and information sciences

description: The combination of clinical and personal health and wellbeing data can tell us much about our behaviors, risks and overall status. The way this data is visualized may affect our understanding of our own health. To study this effect, we conducted a small experiment with 30 participants in which we presented a holistic overview of the health and wellbeing of two modeled individuals, one of them with metabolic syndrome. We used an insight-based methodology to assess the effectiveness of the visualizations. The results show that adequate visualization of holistic health data helps users without medical background to better understand the overall health situation and possible health risks related to lifestyles. Furthermore, we found that the application of insight-based methodology in the health and wellbeing domain remains unexplored and additional research and methodology development are needed.
description: in Engineering in Medicine and Biology Society (EMBC), 2015 37th Annual International Conference of the IEEE
The Compact Star-Forming Complex at the Heart of NGC 253
Creators: name: Davidge, T. J.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We discuss integral field spectra of the compact star-forming complex that is the brightest near-infrared (NIR) source in the central regions of the starburst galaxy NGC 253. The spectra cover the H and K passbands and were recorded with the Gemini NIR Spectrograph during sub-arcsec seeing conditions. Absorption features in the spectrum of the star-forming complex are weaker than in the surroundings. An absorption feature is found near 1.78um that coincides with the location of a C2 bandhead. Emission lines of Brgamma, [FeII], and HeI2.06um do not track the NIR continuum light. Pockets of star-forming activity that do not have associated concentrations of red supergiants, and so likely have ages < 8 Myr, are found along the western edge of the complex, and there is evidence that one such pocket contains a rich population of Wolf-Rayet stars. Unless the star-forming complex is significantly more metal-poor than the surroundings, then a significant fraction of its total mass is in stars with ages < 8 Myr. If the present-day star formation rate is maintained then the time scale to double its stellar mass ranges from a few Myr to a few tens of Myr, depending on the contribution made by stars older than ~ 8 Myr. If -- as suggested by some studies -- the star-forming complex is centered on the galaxy nucleus, then the nucleus of NGC 253 is currently experiencing a phase of rapid growth in its stellar mass.
description: To appear in the Astrophysical Journal
Die Wurzeln der biblischen Auffassung vom Teufel und den Dämonen
Creators: name: Limbeck, Meinrad
Publisher: name: Concilium
Year: 1970

description: Concilium, Bd. 11 Nr. 3 (1975): Concilium: Internationale Zeitschrift für Theologie, Band 11, Heft 3
Potentials and Limits to Basin Stability Estimation
Creators: name: Schultz, Paul
name: Menck, Peter J.
name: Heitzig, Jobst
name: Kurths, Jürgen
Publisher: name: arXiv
Year: 2016
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: Stability assessment methods for dynamical systems have recently been complemented by basin stability and derived measures, i.e. probabilistic statements whether systems remain in a basin of attraction given a distribution of perturbations. This requires numerical estimation via Monte-Carlo sampling and integration of differential equations. Here, we analyze the applicability of basin stability to systems with basin geometries challenging for this numerical method, having fractal basin boundaries and riddled or intermingled basins of attraction. We find that numerical basin stability estimation is still meaningful for fractal boundaries but reaches its limits for riddled basins with holes.
description: 5 pages, 4 figures
Integration of Antenna for IoT Communication in Small Silicon Photovoltaic Module
Creators: name: Wahlgreen, L.R.
name: Thorsteinsson, S.
name: Poulsen, P.B.
name: Petersen, M.N.
Publisher: name: WIP
Year: 2022
Subjects: Photovoltaic Modules and BoS Components
PV Module Design and Manufacturing

description: 8th World Conference on Photovoltaic Energy Conversion; 830-833
description: This study presents proof of concept of a silicon PV module integrated monopole and dipole microstrip antenna made for IoT frequencies in Europe, 868 MHz. Proof of concept for two types of PV integrated antennas is made. A monopole antenna with a length of 50 mm with ground attached to a bike stand and a dipole with each pole the length of 52 mm. Both antennas have been tested and compared to an off-the-shelf stub antenna. The monopole showed close to similar or better readings on SF, RSSI and number of packets. The dipole had better readings on SF and RSSI but had lower number of packets sent. The dipole offers the possibility of easy connection whereas the monopole antenna needs to be connected to both a coax cable and the bike stand.
Novel Photovoltaic Module Design for Desert Climate
Creators: name: Abdallah, A.A.
name: Mroue, K.
name: Samara, A.
name: Aissa, B.
name: Kivambe, M.M.
name: Figgis, B.W.
name: Lopez-Garcia, J.L.
name: Grosser, S.
name: Pander, M.
name: Jäckel, B.
name: Hagendorf, C.
name: Ebert, M.
name: Ilse, K.
Publisher: name: WIP
Year: 2022
Subjects: Photovoltaic Modules and BoS Components
PV Module Design and Manufacturing

description: 8th World Conference on Photovoltaic Energy Conversion; 811-815
description: A wide deployment of Photovoltaics (PV) in desert climate conditions requires overcoming the impact of the environmental factors on PV performance and reliability. High Ultra-violet (UV) irradiance, in combination with high module operating temperature that may reach over 70 C during summer months even for open rack installations, has shown to cause degradation of the PV module material. In this paper, we investigate the impact of UV irradiance on the properties of the PV module back sheet material. The data obtained from real outdoor testing conditions serves as a design guideline to develop a reliable PV module. For instance, FTIR (Fourier Transform Infrared) measurements on the polyamide-based back sheets confirmed the cracking and powdering of the back sheet material after 4 years of exposure in a desert climate.
2.5 Minutes Lamination Process and the Influences of the Degree of Cross-Linking and the Moisture Ingress on the Degradation of PV Modules
Creators: name: Öz, A.K.
name: Wellens, C.
name: Mittag, M.
name: Wiese, M.
name: Sraisth, S.
name: Klaus, D.
name: Neuhaus, D.H.
name: Heinrich, M.
Publisher: name: WIP
Year: 2022
Subjects: Photovoltaic Modules and BoS Components
PV Module Design and Manufacturing

description: 8th World Conference on Photovoltaic Energy Conversion; 816-822
description: Faster lamination processes and more sustainable modules will play a critical role to meet the industries demand for green energy. This study presents the influences of short lamination processes on the moisture balance, achieved by increasing the lamination temperature up to 180 °C, and compares these with modules laminated at a common lamination temperature of 150 °C. The investigations are conducted mainly on mini modules, but additionally to those also a standard 60 cell module is built and exposed to the damp heat (DH) test to have a better understanding of the influences of the fast lamination process. The mini modules were exposed to DH for 1500 and 3000 hours and were measured before and after the accelerated ageing in terms of IV measurements and peel tests. We observed no severe degradation caused by the higher lamination temperature in terms of moisture ingress. During the study we also investigated the cost of the 2.5 minutes curing process and discussed the potential benefit for module production facilities. The results of the simulation showed that module manufacturers could reduce their module costs up to 1.3% per module with the faster process.
Paving the Way for Low Breakage Rates in Industrial Production of N.I.C.E.-Wire Modules
Creators: name: Leibiger, P.
name: Pönisch, C.
name: Seifert, T.
name: Kray, D.
Publisher: name: WIP
Year: 2022
Subjects: Photovoltaic Modules and BoS Components
PV Module Design and Manufacturing

description: 8th World Conference on Photovoltaic Energy Conversion; 807-810
description: Significant improvements in module performance are possible via implementation of multi-wire electrodes [1]. This is economically sound as long as the mechanical yield of the production is maintained. While flat ribbons have a relatively large contact area to exert forces onto the solar cell, wires with round cross section reduce this contact area considerably – in theory to an infinitively thin line. Therefore, the local stresses induced by the electrodes might increase to a point that mechanical production yields suffer unacceptably. In this paper, we assess this issue by an analytical mechanical model as well as experiments with an encapsulant-free N.I.C.E. test setup. From these, we can derive estimations for the relationship between lay-up accuracy and expected breakage losses. This paves the way for cost-optimized choices of handling equipment in industrial N.I.C.E.-wire production lines.
ELLIPTIC INTEGRAL APPROACH TO LARGE DEFLECTION IN CANTILEVER BEAMS: THEORY AND VALIDATION
Creators: name: Shah, Arpit Samir
Publisher: name: Purdue University Graduate School
Year: 2024
Subjects: classificationCode: 401707
subject: Solid mechanics

description: This thesis investigates the large deflection behavior of cantilever beams under various configurations and loading conditions. The primary objective is to uset an analytical model using elliptic integrals to solve the second-order non-linear differential equations that govern the deflection of these beams. The analytical model is implemented in Python and compared against Finite Element Analysis (FEA) results obtained from ANSYS, ensuring the accuracy and reliability of the model. The study examines multiple beam configurations, including straight and inclined beams, with both free and fixed tip slopes. Sensitivity analysis is conducted to assess the impact of key parameters, such as Young’s modulus, beam height, width, and length, on the deflection behavior. This analysis reveals critical insights into how variations in material properties and geometric dimensions affect beam performance. A detailed error analysis using Root Mean Square Error (RMSE) is performed to compare the analytical model's predictions with the FEA results. The error analysis highlights any discrepancies, demonstrating the robustness of the analytical approach. The results show that the analytical model, based on elliptic integrals, closely matches the FEA results across a range of configurations and loading scenarios. The insights gained from this study can be applied to optimize the design of cantilever beams in various engineering applications, including prosthetics, robotics, and structural components. Overall, this research provides a comprehensive understanding of the large deflection behavior of cantilever beams and offers a reliable analytical tool for engineers to predict beam performance under different conditions. The integration of Python-based numerical methods with classical elliptic integral solutions presents a useful approach that enhances the precision and applicability of beam deflection analysis.
Application of SHJ and TOPCon Shingle Cells in Full Format and Integrated Modules
Creators: name: Nikitina, V.
name: Reinwand, D.
name: Fellmeth, T.
name: Neven-Du Mont, S.
name: Von Kutzleben, D.
name: Roessler, T.
name: Neuhaus, D.H.
Publisher: name: WIP
Year: 2022
Subjects: Photovoltaic Modules and BoS Components
PV Module Design and Manufacturing

description: 8th World Conference on Photovoltaic Energy Conversion; 797-802
description: Shingle technology is attractive due to the absence of ribbons or wires, large active module area, module design flexibility and aesthetically appealing appearance [1]. This work is looking into the application of silicon heterojunction (SHJ) and tunnel oxide passivated contact (TOPCon) shingle cells in small-scale and full-format modules as well as into the effects of overlap minimization and electrically conductive adhesive (ECA) reduction. Stringer tests with subsequent microscopic analysis showed that precision of the laser cutting process is crucial for the correct alignment of metallization and ECA during the interconnection process. Shunting as well as ECA smearing can be caused by the inconsistent distance of the metallization to the cell edge. The variation of the ECA, printing pattern and encapsulation material in small-scale modules demonstrated no difference in performance after production. However, after accelerated thermal cycling (aTC) 50 the modules with SHJ cells showed ∆PMPP = −8.2%rel to +0.4%rel, and TOPCon between −4.5%rel and +0.6%rel, depending on the used encapsulation material. No difference in performance for the modules with reduced ECA amount in comparison with the reference was detected after aTC50. Full-size solar modules with bifacial TOPCon shingles (1/6 G1 format, 20.7% − 21.3% efficiency after the scribe and break laser process) were manufactured with 50% ECA reduction and the optimal materials based on the previous investigation. Peak power values of up to 392.8 Wp and Eta of 19.84% were demonstrated.
Photometric Redshift Estimation for Quasars by Integration of KNN and SVM
Creators: name: Han, Bo
name: Ding, Hongpeng
name: Zhang, Yanxia
name: Zhao, Yongheng
Publisher: name: arXiv
Year: 2016
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: The massive photometric data collected from multiple large-scale sky surveys offer significant opportunities for measuring distances of celestial objects by photometric redshifts. However, catastrophic failure is still an unsolved problem for a long time and exists in the current photometric redshift estimation approaches (such as $k$-nearest-neighbor). In this paper, we propose a novel two-stage approach by integration of $k$-nearest-neighbor (KNN) and support vector machine (SVM) methods together. In the first stage, we apply KNN algorithm on photometric data and estimate their corresponding z$_{\rm phot}$. By analysis, we find two dense regions with catastrophic failure, one in the range of z$_{\rm phot}\in[0.3,1.2]$, the other in the range of z$_{\rm phot}\in [1.2,2.1]$. In the second stage, we map the photometric input pattern of points falling into the two ranges from original attribute space into a high dimensional feature space by Gaussian kernel function in SVM. In the high dimensional feature space, many outlier points resulting from catastrophic failure by simple Euclidean distance computation in KNN can be identified by a classification hyperplane of SVM and further be corrected. Experimental results based on the SDSS (the Sloan Digital Sky Survey) quasar data show that the two-stage fusion approach can significantly mitigate catastrophic failure and improve the estimation accuracy of photometric redshifts of quasars. The percents in different |$Δ$z| ranges and rms (root mean square) error by the integrated method are $83.47\%$, $89.83\%$, $90.90\%$ and 0.192, respectively, compared to the results by KNN ($71.96\%$, $83.78\%$, $89.73\%$ and 0.204).
description: 14 pages, 7 figures, 1 table, accepted by Research in Astronomy and Astrophysics
Interconnection Technology for the Next Generation of (Temperature-Sensitive) Solar Cells such as Heterojunction and C-Si/Perovskite Tandem
Creators: name: Zemen, Y.
name: Wendlandt, S.
name: Litzenburger, B.
name: Podlowski, L.
Publisher: name: WIP
Year: 2022
Subjects: Photovoltaic Modules and BoS Components
PV Module Design and Manufacturing

description: 8th World Conference on Photovoltaic Energy Conversion; 803-806
description: The interconnection technology for solar cells is an important component in the PV module production - not only for module reliability but with respect to the sustainability of the PV industry as well. We are proposing the interconnection technology “TECC Wire” (TECC=Thermoplastically and Electrically Conductive Coating) which is a new low-temperature method – and which avoids the usage of any rare or hazardous materials. As rare or critical materials in the PV industry are rated such as silver, bismuth, lead and indium because global resources are considered to be too limited or too expensive for the terawatt production level. And the usage of lead does not comply with the RoHS (Restriction of Hazardous Substances) directive. Although PV modules are still exempt from this directive, efforts to avoid using lead as a solder alloy are consensus in the industry. TECC-Wire is conceptually an improved stage of the multi-busbar or multi-wire concept. However, it allows to further reduce the consumption of silver for the solar cells metallization, and it even enables the vision of totally eliminating silver from solar cell production. The TECC wires have a similar copper core that is typically used for multi-busbar soldering of solar cell – but it is coated with an electrically conductive adhesive instead of a solder alloy. The filler material to achieve the electrical conductivity is based on non-silver particles. The recently built semi-automated stringing machine attaches the TECC wires precisely and in a defined manner. It allows us to build and test standard module configurations. The long-term reliability tests have already passed 3x IEC requirement. After 3000h damp heat test the degradation of the small modules is below 5%. In thermal cycling test the results after TC600 are around 5% for different solar cells. The peel strength is about 1.5 N/mm contact area over the entire solar cell – which is comparable to a solder joints. The homogeneity of the peel strength along the entire surface of the solar cells is remarkable, as the wires adhere to any surface and not only to the printed fingers.
Early and Reliable Detection of Potential-Induced Degradation in Crystalline Silicon PV Module Using Electroluminescence Imaging
Creators: name: Puranik, V.E.
name: Kumar, R.
name: Gupta, R.
Publisher: name: WIP
Year: 2022
Subjects: Photovoltaic Modules and BoS Components
PV Module Performance – Modelling, Testing, Standards

description: 8th World Conference on Photovoltaic Energy Conversion; 787-789
description: Early and reliable detection of PID is essential in a field operation as it poses severe threat to module reliability. Electroluminescence (EL) imaging enables spatial detection of PID based on its characteristic corner pattern, IEC TS 62804-1 and IEC TS 60904-13 have recommended using low and high current EL imaging in PID detection. However, PID detection solely on visual inspection often makes this approach inefficient. In this paper, the method is proposed for early and reliable PID detection using two EL images. The relative difference in cell open- circuit voltage estimated from EL images is used as the PID indicator. The threshold for PID detection is determined equivalent to the pass/fail (5% power loss) criterion used in IEC standards. The proposed method was tested on new and field-aged modules containing multiple defects. Experimental results show that this method effectively detects early phase of PID, which is not possible to detect with the conventional visual inspection approach. Also, reliable detection of PID becomes possible even in the presence of different types of defects and degradation since the used PID index solely indicates shunting defects. Hence, the proposed method would be useful for PID detection in the field as well as in laboratory studies.
Fully Black and Reliable PV Modules with a Cost-Effective Inkjet Coating of Cell Strings
Creators: name: Schiller, C.H.
name: Hoffmann, S.
name: Jahn, M.
name: De Rose, A.
name: Heinrich, M.
Publisher: name: WIP
Year: 2022
Subjects: Photovoltaic Modules and BoS Components
PV Module Design and Manufacturing

description: 8th World Conference on Photovoltaic Energy Conversion; 790-796
description: The energy transition requires a massive expansion of photovoltaics (PV) on all available areas in the next few years. For integrative photovoltaic applications (XIPV), an aesthetically appealing PV module design for acceptance and a high photoconversion efficiency are desirable. To achieve this goal using common PERC solar cells with five-busbar interconnection, we present an inkjet process that complies with the speed of industrial stringers to blacken the cell connectors after soldering, resulting in an unaffected homogeneous black impression. The optical impression of our manufactured PV modules remains intact after extended (400 temperature cycles (TC), 120 kWh/m2 ultraviolet radiation (UV), 2000 h damp heat (DH) exposure) and combined (UV-DH, UV-DH+TC) climate chamber tests following IEC standards. The power loss due to printing on cell connectors is 1.4 % compared to PV modules without blackened cell connectors.
On the origin of the hard X-ray tail in neutron-star X-ray binaries
Creators: name: Reig, P.
name: Kylafis, N.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Neutron star X-ray binaries emit a compact, optically thick, relativistic radio jet during low-luminosity, usually hard states, as Galactic black-hole X-ray binaries do. When radio emission is bright, a hard power-law tail without evidence for an exponential cutoff is observed in most systems. We have developed a jet model that explains many spectral and timing properties of black-hole binaries in the states where a jet is present. Our goal is to investigate whether our jet model can reproduce the hard tail, with the correct range of photon index and the absence of a high-energy cutoff, in neutron-star X-ray binaries. We have performed Monte Carlo simulations of the Compton upscattering of soft, accretion-disk or boundary layer photons, in the jet and computed the emergent energy spectra, as well as the time lag of hard photons with respect to softer ones as a function of Fourier frequency. We demonstrate that our jet model explains the observed power-law distribution with photon index in the range 1.8-3. With an appropriate choice of the parameters, the cutoff expected from Comptonization is shifted to energies above ~300 keV, producing a pure power law without any evidence for a rollover, in agreement with the observations. Our results reinforce the idea that the link between the outflow (jet) and inflow (disk) in X-ray binaries does not depend on the nature of the compact object, but on the process of accretion. Furthermore, we address the differences of jets in black-hole and neutron-star X-ray binaries and predict that the break frequency in the spectral energy distribution of neutron-star X-ray binaries, as a class, will be lower than that of black-hole binaries.
description: 6 pages, 3 figures, accepted for publication in A&A
Job Satisfaction and its Determinants among the Academic Staff at Addis Ababa University
Creators: name: Endalew, Assefa
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2019

description: The purpose of this study was to explore the level of academic staff job satisfaction and its possible predictors at Addis Ababa University. For accomplishing this purpose, primary data were collected from the target population by applying stratified proportionate sampling within which random and availability sampling were involved. The data collection tools were survey questionnaire and key informant interview. Then, data were analyzed descriptively in order to catch the trends in light of the stated issue. Once descriptions were made, ANOVA and T-test were conducted to compare the variation in the average satisfaction values of respondents belonging to different demographic sub-categories. Correlation analysis was also undertaken so as to show the association between predictor variables and the dependent variable. Finally linear multiple regression analysis was run to examine the effect of predictor variables on the dependent variable. The research revealed that, on average, the academic staffs were dissatisfied. Some group of staffs relating to highest extremes of academic rank and age as well as service year were, however, somehow closer to neutral being neither dissatisfied nor satisfied. As per the correlation analysis, overall satisfaction had a fairly moderate positive association with academic rank, and service year, while its correlation with age was weaker being generally positive. Coming to non-demographic variables, job satisfaction had a moderate positive correlation with pay, promotion, fringe benefits and contingent reward, whereas the correlation with supervision, operating procedures, communication, coworkers and nature of work was weak. According to the regression output, on the other hand, pay, promotion and contingent reward were found out to have significant effect on overall job satisfaction, while the other six predictors had no such significant effect.
Identification of high-value bioactive constituents in Northern European willow varieties: S.X. Dasyclados, Endeavour, Cheviot, Tora, Resolution, S. Purpurea, Terranova, endurance
Creators: name: Hijazi, Ayman
name: Pisano, Italo
name: LEAHY, JAMES J
name: KWAPINSKI, WITOLD
name: R Johnson, Christopher
name: PRENDERGAST, JOHN
Publisher: name: University of Limerick
Year: 2023
Subjects: subject: Chemical sciences
subject: FOS: Chemical sciences

description: Willow trees have maintained their place in medicine for many years as they are herbal source of various cures. Willow varieties are considered to contain a wide range of anti-inflammatory and anti-bacterial species such as salicylates and flavonoids. The current work is centred on the presence of high bioactive pharmaceutical constituents other than salicin such as flavan-3-ol catechin, salicortin, and other complex compounds, which contribute to the total medical value of willow extracts. To evaluate the distribution of these bioactives, bark, and wood fractions of 8 different willow varieties (S.X. Dasyclados, Endeavour, Cheviot, Tora, Resolution, S. Purpurea, Terranova, Endurance) were extracted using dispersive solid phase extraction and then analysed using LC-MS comprising a quadrupole time-of-flight spectrometer. Indeed, various high value constituents such as salicortin, catechin, triandrin, acacetin-5-O-xyloside, picein, apigenin-7-O-glucoside, vitexin-2-rhamnoside, luteolin7-glucoside, catechin gallate, and kaempferol as well as giberellic and 5-methoxysalicylic acid were detected in bark and wood fractions of the willow varieties 80:20 ethanol/water extracts.
Algorithmic decidability of Engel's property for automaton groups
Creators: name: Bartholdi, Laurent
Publisher: name: arXiv
Year: 2015
Subjects: subject: Formal Languages and Automata Theory (cs.FL)
subject: Group Theory (math.GR)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: We consider decidability problems associated with Engel's identity ($[\cdots[[x,y],y],\dots,y]=1$ for a long enough commutator sequence) in groups generated by an automaton. We give a partial algorithm that decides, given $x,y$, whether an Engel identity is satisfied. It succeeds, importantly, in proving that Grigorchuk's $2$-group is not Engel. We consider next the problem of recognizing Engel elements, namely elements $y$ such that the map $x\mapsto[x,y]$ attracts to $\{1\}$. Although this problem seems intractable in general, we prove that it is decidable for Grigorchuk's group: Engel elements are precisely those of order at most $2$. Our computations were implemented using the package FR within the computer algebra system GAP.
Well-posedness for the Navier-Stokes equations with data in homogeneous Sobolev-Lorentz spaces
Creators: name: Khai, D. Q.
name: Tri, N. M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 35Q30

description: In this paper, we study local well-posedness for the Navier-Stokes equations (NSE) with the arbitrary initial value in homogeneous Sobolev-Lorentz spaces $\dot{H}^s_{L^{q, r}}(\mathbb{R}^d):= (-Δ)^{-s/2}L^{q,r}$ for $d \geq 2, q > 1, s \geq 0$, $1 \leq r \leq \infty$, and $ \frac{d}{q}-1 \leq s < \frac{d}{q}$, this result improves the known results for $q > d,r=q, s = 0$ (see M. Cannone (1995) and M. Cannone and Y. Meyer (1995)) and for $q =r= 2, \frac{d}{2} - 1 < s < \frac{d}{2}$ (see M. Cannone (1995, J. M. Chemin (1992)). In the case of critical indexes ($s=\frac{d}{q}-1$), we prove global well-posedness for NSE provided the norm of the initial value is small enough. The result that is a generalization of the result of M. Cannone (1997) for $q = r=d, s=0$.
description: arXiv admin note: text overlap with arXiv:1601.01441, arXiv:1601.01726
Arquitectura y sociedad
Creators: name: Sánchez Llorens, Mara
Publisher: name: Zenodo
Year: 2012

description: La arquitectura forma parte de una manera de conocer el mundo y es al viajar cuando la imbricación entre Arquitectura y Sociedad se revela plenamente, cuando se descubre en la “otredad”, la generosidad de la arquitectura de otros lugares, el silencio de la arquitectura que se niega a ser mercantilizada o la preocupación de tantas otras disciplinas en torno a los problemas que a veces creemos exclusivos de nuestra vocación. El objetivo de este artículo es re-descubrir el binomio arquitectura-sociedad, acercar maneras distintas de entender la alianza entre la sociedad y la naturaleza, cavilar sobre la aparente contradicción entre tradición y tecnología; y revelar nuevas experiencias de colectivos generadores de cambio social. La cartografía obtenida finalmente en nuestra imaginación nos permitirá participar, a través de la arquitectura, de algunas de las preocupaciones y retos de nuestro tiempo y deducir, a continuación, un modelo alternativo de cómo ser catalizador de las disciplinas que contribuyen a dar soluciones espaciales, tal y como nos reclama la sociedad contemporánea.
PV DC Yield Determined by Deep Neural Networks: the Case of Building Integrated PV
Creators: name: Shirazi, E.
name: Ozkalay, E.
name: Reinders, A.
Publisher: name: WIP
Year: 2022
Subjects: Photovoltaic Modules and BoS Components
PV Module Performance – Modelling, Testing, Standards

description: 8th World Conference on Photovoltaic Energy Conversion; 780-783
description: PV systems can significantly contribute to achieving the climate neutral goal of the Paris agreement. However, they will present additional challenges to the power grids, due to their intermittent nature. This study aims to model the power output of Building Integrated PV systems (BIPV) on the basis of the application of a Deep Neural Network (DNN) to the following input variables: solar irradiance, module temperature as well as time and location. The DNN has been applied to a dataset containing over four years of data of electrical parameters on module level as well as meteorological data, all at a 5-minutes resolution. The results show that the proposed DNN is able to calculate the PV power output accurately with an R2 score of 0.96 and RMSE of 0.04. Though applied to a BIPV system in this case, the method will be applicable to a myriad of other types of monitored PV systems as well.
Performance Degradation by PID Effect for Different Solar Modules Topologies and Photovoltaic Cell Technologies
Creators: name: Franca Santos, H.
name: Alvarez, H.S.
name: Garcia, R.M.
name: Neves, M.R.M
Publisher: name: WIP
Year: 2022
Subjects: Photovoltaic Modules and BoS Components
Materials for PV Modules, Durability, Reliability and Accelerated Testing Methods

description: 8th World Conference on Photovoltaic Energy Conversion; 784-786
description: The main objective of this work is to observe the potential induced degradation (PID) effect on four types of single-glass photovoltaic (PV) modules. 1) a M6K monocrystalline PERC full-cell module, 72 cells; 2) a MIK monocrystalline BSF half-cell module, 144 cells; 3) a P6K polycrystalline BSF full-cell module; 4) a PHK polycrystalline BSF half-cell module. All PV modules it was mounted using glass, EVA, solar cells, EVA and PYE SPV L backsheet. Their PID effect was induced by applying a - 1500 V DC power, in a damp heat test chamber, 85 °C, with humidity of 85% for two cycles of 96 h. The modules' electrical parameters were obtained in a PASAN Highlight flash tester AAA+++. At the end of the 192 h of process, the polycrystalline modules P6K and PHK presented a pronounceable PID effect, with the decrease of their relative power (RP) output by 1.3% and 2.1%, respectively, and with the darkening of the cells near their edges. For the monocrystalline modules M6K and MIK, RP only decreased by 1.3% and 0.6 %, with the darkening of their cells happening only for the MIK module.
Comparison of the Yield of Miniaturized Bifacial Photovoltaic Modules with the Yield Simulation of Bifiacial Modules
Creators: name: Pillai, A.
name: Depner, K.
name: Ray, C.B.
name: Mebus, S.
name: Grommes, E.M.
name: Blieske, U.
Publisher: name: WIP
Year: 2022
Subjects: Photovoltaic Modules and BoS Components
PV Module Performance – Modelling, Testing, Standards

description: 8th World Conference on Photovoltaic Energy Conversion; 772-776
description: Bifacial photovoltaic (PV) is a field that has seen an increase in research and development in the world market in recent years. Increased module efficiency and reduced Levelized Cost of Energy (LCOE) have led to more focus on bifacial panels. This project aims to develop and manufacture miniaturized bifacial solar modules to compare the energy yield of the test module with the yield simulation of bifacial modules from the python simulation software BifacialSimu, developed at the University of Applied Sciences Cologne. The validation of the software for its accuracy has also been conducted. The miniaturized model can easily be transported to different sites for field studies. This makes it possible to record (preliminary) real-time data on the yield of a bifacial PV ground-mounted system and provide a forecast of the solar energy yield under field conditions. For this purpose, miniaturized bifacial glass-glass PV modules were designed and built with a scaling factor of 1:10 and with module dimensions of 100 x 200 mm. Each module consists of a string of six bifacial PERC cells connected in series, each cell with an area of 2098.63 mm2. The miniaturized modules theoretically deliver the same performance characteristics and behavior as their real-size counterparts under the same test conditions. These modules are assembled into an array, with three rows of three modules and realistic module spacings with sufficient clearance to avoid shading. The I-V characteristics are also recorded under varying ambient conditions. The bifacial module generated a power value between 1.53 W and 2.29 W. The simulated power values calculated showed a deviation from the actual measured values by +2.1 percent and +2.7 percent.
Performance Ratio and Soiling Rate Calculation of PV Modules Installed at Different Tilt Angles in UAE Desert
Creators: name: John, J.J.
name: Chapaneri, K.
name: Pamir Aly, S.
name: Mathiak, G.
name: Alberts, V.
Publisher: name: WIP
Year: 2022
Subjects: Photovoltaic Modules and BoS Components
PV Module Performance – Modelling, Testing, Standards

description: 8th World Conference on Photovoltaic Energy Conversion; 777-779
description: PV modules in desert climate are exposed to environmental stressors cycles such as elevated temperature, UV radiation, sand abrasion and large temperature fluctuations, which can degrade different components of the module and eventually lead to defects. These defects and degradations reduce the power output of the system, as well as the lifetime of PV modules, affecting system reliability. The performance and soiling degradation of 5 different types of PV modules installed in 5 different tilt angles for 5 years in desert condition of Dubai have been reported. NREL RdTools has been used to extract the degradation and soiling rate of all the PV modules. The results from the 5×5 heat map matrix of modules show that the highest degradation and soiling is for the modules installed at 0° angle. The average degradation rates in the desert environment are found to be much higher than the industry average reported values of 0.7%/ year for most commercial PV modules.
Beyond good intentions
Creators: name: Dos Santos Gonçalves, Joana
Publisher: name: A+BE | Architecture and the Built Environment
Year: 2023

description: Sustainable Conservation are the processes of change through which the components of the inherited ecosystem from the past retain their value for present and future generations. As such, the value assessment is critical to recognise the values of heritage, not only by its aesthetical and historical values, but also by its contribution to a more sustainable future. Despite recent policies and standards highlighting the role of heritage for sustainability and encouraging urban conservation, sustainable conservation is not yet the most common practice. The behavioural dimension is intrinsic to the decision-making process; however, studies analysing designers’ decision behaviours regarding sustainability in built heritage are seldom found in recent literature. This research aims to increase the understanding of the gap in the implementation of best practices of sustainable conservation of built heritage, and to achieve solutions for behavioural change. It applies methods from psychology to analyse designers’ decisions behaviours, by eliciting common beliefs, challenges, and opportunities in the implementation of conservation intentions towards heritage buildings. The results demonstrate that design decisions result from conscious and unconscious processes, some of them socially driven, while others result from individual attitudes. Targeting the primary belief in the study population on the (in)compatibility between sustainability and heritage conservation, a building passport for sustainable conservation was developed aiming at raising awareness in the value of built heritage to sustainability. The results of this research can support the redesign of heritage buildings and demonstrate the importance of considering behavioural factors in the development of future sustainable conservation policies and tools.
description: A+BE | Architecture and the Built Environment, No. 21 (2022): Beyond good intentions
Comparative Study on Temperature Coefficient of PERC and HIT Solar Modules under Different Injection Conditions
Creators: name: Nan, C.
name: Hao, Y.
name: Li, X.
name: Feng, Y.
name: Wang, H.
name: Yang, H.
Publisher: name: WIP
Year: 2022
Subjects: Photovoltaic Modules and BoS Components
PV Module Performance – Modelling, Testing, Standards

description: 8th World Conference on Photovoltaic Energy Conversion; 760-762
description: In this paper, the differences of temperature coefficient between the bifacial passivated emitter and rear cell (PERC) and the heterojunction with intrinsic thin-layer (HIT) under different module temperatures and irradiance were given. The results show that the power temperature coefficient of HIT is smaller than that of PERC, which is because of the difference of fill factor (FF) temperature coefficient between the two. A new finding is that this phenomenon is more obvious at high irradiance.