cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Characterization and Modelling of the Dynamic Electrical Behaviour of Triple Junction Solar Cells
Creators: name: Chouffot, R.
name: Gueunier-Farret, M.E.
name: Kleider, J.P.
name: Baur, C.
name: De Luca, A.
name: Barde, H.
name: Neugnot, N.
name: Roy, X.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Advanced Photovoltaics
Solar Cells, Modules and PV Systems for Space Applications

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 104-109
description: The knowledge of the dynamic behaviour of solar cells is necessary for a proper design of solar array regulators. However, it is not easy to reproduce real operating conditions of a solar array particularly for space applications. Thus, a model based on experimental results of the electrical behaviour of solar cells needs to be built as accurately as possible. For that purpose, measurements in both ac and transient electrical conditions have been performed on GaInP/GaInAs/Ge triple-junction solar cells. The evolution of the cells’ capacitance versus voltage is discussed taking into account space charge region and diffusion capacitance. The parameters deduced from steady-state and ac measurements are used to build a dynamical solar cell model which can also be used in its integral form for a large signal model. This is justified by experimental transient measurements
Distinguishing `disks' from `mergers': tracing the kinematic asymmetries in local (U)LIRGs using `kinemetry'-based criteria
Creators: name: Bellocchi, Enrica
name: Arribas, Santiago
name: Colina, Luis
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The kinematic characterization of different galaxy populations is a key observational input to distinguish between different galaxy evolutionary scenarios, since it helps to determine the number ratio of rotating disks to mergers at different cosmic epochs. Local (U)LIRGs offer a unique opportunity to study at high linear resolution and S/N extreme star forming events and compare them with those observed at high-z. We obtained Very Large Telescope (VLT) VIMOS optical integral field spectroscopy (IFS) data of a sample of 38 (U)LIRGs. The `unweighted' and `weighted' {kinemetry}-based methods are used to kinematically classify our galaxies in `disk' and `merger'. We simulate our systems at z=3 to evaluate how a loss of angular resolution affects our results. From the kinemetry-based analysis we are able classify our local (U)LIRGs in three distinct kinematic groups according to their total kinematic asymmetry values (K$_{tot}$) as derived when using the weighted (unweighted) method: 1) 25 out of 50 galaxies are kinematically classified as `disk', with a K$_{tot}\leq$ 0.16 (0.14); 2) 9 out of 50 galaxies are kinematically classified as `merger', with a K$_{tot}\geq$ 0.94 (0.66); 3) 16 out of 50 galaxies lie in the `transition region', in which disks and mergers coexist, with 0.16 (0.14) $
description: 17 pages, 7 figures, 4 tables
Impact of Thermal Cycles on the Material Quality of Metamorphic III-V Solar Cell Structures
Creators: name: Schöne, J.
name: Peharz, G.
name: Hoheisel, R.
name: Siefer, G.
name: Guter, W.
name: Dimroth, F.
name: Bett, A.W.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Advanced Photovoltaics
Terrestrial Concentrator Systems

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 118-122
description: This paper presents results of a study on the temperature-dependent behavior of GaAs single-junction solar cells, in which both experimental and simulation tools were used. In order to enable measurements at different temperatures a cryostat was integrated into the corresponding experimental setup at Fraunhofer ISE. Measurements of the external quantum efficiency (EQE) and the IV curve under illumination were carried out in a wide temperature range between 200 K and 400 K. An exemplary GaAs solar cell was modeled numerically in a semiconductor simulation environment to obtain a deeper understanding of the cell’s temperature-dependent behavior as well as to enable future structure optimization for different operating temperatures.
Voltage-driven magnetization switching and spin pumping in Weyl semimetals
Creators: name: Kurebayashi, Daichi
name: Nomura, Kentaro
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We demonstrate electrical magnetization switching and spin pumping in magnetically doped Weyl semimetals. The Weyl semimetal is a new class of topological semimetals, known to have nontrivial coupling between the charge and the magnetization due to the chiral anomaly. By solving the Landau-Lifshitz-Gilbert equation for a multilayer structure of a Weyl semimetal, an insulator and a metal whilst taking the charge-magnetization coupling into account, magnetization dynamics is analyzed. It is shown that the magnetization dynamics can be driven by the electric voltage. Consequently, switching of the magnetization with a pulsed electric voltage can be achieved, as well as precession motion with an applied oscillating electric voltage. The effect requires only a short voltage pulse and may therefore be more energetically efficient for us in spintronics devices compared to conventional spin transfer torque switching.
description: 5 pages, 4 figures
Optimum Design for Super-High Efficiency Concentrator Solar Cell
Creators: name: Sasaki, K.
name: Yoshida, A.
name: Juso, H.
name: Agui, T.
name: Jitsumasa, N.
name: Takamoto, T.
name: Saga, T.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Advanced Photovoltaics
Terrestrial Concentrator Systems

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 123-125
description: A very high efficiency solar cell for concentrator application was developed by improving the concentration ratio which gave the maximum efficiency utilizing the conventional InGaP/GaAs/Ge triple junction cells. Calculations were done about efficiency under high illumination in the cells with different sheet resistance 60Ω/sq and 6Ω/sq as a function of cell size. The calculations suggested that high efficiency more than 40% were achievable in small cells with less than 5 x 5 mm2 size and with 60Ω/sq sheet resistance. Sheet resistance of 60Ω/sq
was confirmed experimentally under high concentration ratio over 1,000 suns. We evaluated the increase in intensity by reducing cell size experimentally. It was confirmed that the concentration ratio which gave the maximum efficiency was increased by reducing cell size and high efficiency of 40% was achieved under 1,100 suns in a 4.5 x 4.5 mm2 size cell with 125μm grid pitch. Good agreement between theoretical and experimental studies was confirmed.
Determination of O/Si in Single Nanometer Thin Silicon Rich Oxide Films by Reflectance and Transmittance Spectroscopy
Creators: name: Perez-Wurfl, I.
name: Gentle, A.
name: Hao, X.J.
name: Conibeer, G.
name: Green, M.A.
name: Park, S.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Advanced Photovoltaics
Fundamental Studies

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 83-85
description: The use of spectroscopic reflectance and transmittance to extract the silicon content of a single four nanometer thick silicon rich oxide (SRO) layer is discussed. The samples reported here were sputter-deposited on 1mm thick quartz using Silicon and Quartz targets. By independently varying the sputtering rate of each target the O/Si of the SRO layer was varied between 0 and 1. The Si content in these layers is calculated by fitting the measured spectra with the required index of refraction for the SRO layer. Using a Bruggeman model for an effective medium approximation we are able to extract the volume percent of Si and SiO2 to satisfy the calculated index of refraction. With the technique presented here we extract an O/Si within 2% of the nominal value for O/Si ≤ 0.85. The technique was also successfully used to extract the Si content on stacks of one, five and fifteen bilayers of alternating SiO2 and SRO layers.
Wasserstein convergence in Bayesian and frequentist deconvolution models
Creators: name: Rousseau, Judith
name: Scricciolo, Catia
Publisher: name: arXiv
Year: 2023
Subjects: subject: Statistics Theory (math.ST)
subject: FOS: Mathematics

description: We study the multivariate deconvolution problem of recovering the distribution of a signal from independent and identically distributed observations additively contaminated with random errors (noise) from a known distribution. For errors with independent coordinates having ordinary smooth densities, we derive an inversion inequality relating the $L^1$-Wasserstein distance between two distributions of the signal to the $L^1$-distance between the corresponding mixture densities of the observations. This smoothing inequality outperforms existing inversion inequalities. As an application of the inversion inequality to the Bayesian framework, we consider $1$-Wasserstein deconvolution with Laplace noise in dimension one using a Dirichlet process mixture of normal densities as a prior measure on the mixing distribution (or distribution of the signal). We construct an adaptive approximation of the sampling density by convolving the Laplace density with a well-chosen mixture of normal densities and show that the posterior measure concentrates around the sampling density at a nearly minimax rate, up to a log-factor, in the $L^1$-distance. The same posterior law is also shown to automatically adapt to the unknown Sobolev regularity of the mixing density, thus leading to a new Bayesian adaptive estimation procedure for mixing distributions with regular densities under the $L^1$-Wasserstein metric. We illustrate utility of the inversion inequality also in a frequentist setting by showing that an appropriate isotone approximation of the classical kernel deconvolution estimator attains the minimax rate of convergence for $1$-Wasserstein deconvolution in any dimension $d\geq 1$, when only a tail condition is required on the latent mixing density and we derive sharp lower bounds for these problems
description: arXiv admin note: text overlap with arXiv:2111.06846
How to "Display" the Angle-Resolved Transmission Efficiency of a Solar Concentrator Reversing the Light Path
Creators: name: Parretta, A.
name: Antonini, A.
name: Butturi, M.A.
name: Di Benedetto, P.
name: Milan, E.
name: Stefancich, M.
name: Uderzo, D.
name: Zurru, P.
name: Roncati, D.
name: Martinelli, G.
name: Armani, M.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Advanced Photovoltaics
Fundamental Studies

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 95-98
description: A novel, powerful method for the optical characterization of solar concentrators is presented. It requires the reversing of light path, realized through the backward illumination of the concentrator from the receiver
surface, and the measuring of intensity distribution of light projected on a far, diffusive screen. If the source of back illumination is spatially uniform and has a Lambertian angular distribution, then the angle-resolved relative radiance
derived from the projected light intensity perfectly coincides with the relative angle-resolved transmission efficiency of the concentrator operating in the normal, direct mode. Respect to the conventional method for deriving the angleresolved efficiency, which requires an expensive apparatus and long measurements at different orientations of the concentrator respect to a parallel beam, the presented, inverse, method is extremely simple to apply and requires only the recording of an image, that displayed on the screen, by a camera or a CCD. The inverse method, previously validated with simple ideal, reflective non-imaging (CPC) concentrators, is here applied to real (absorbing) reflective non-imaging and refractive Fresnel lens systems.
Far field photoluminescence imaging of single AlGaN nanowire in the sub-diffraction length scale using optical confinement of polarized light
Creators: name: Sivadasan, A. K.
name: Sardar, Manas
name: Dhara, Sandip
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Till now the nanoscale focussing and imaging in the sub-diffraction limit is achieved mainly with the help of plasmonic field enhancement assisted with noble metal nanoparticles. Using far field imaging technique, we have recorded polarized spectroscopic photoluminescence (PL) imaging of a single AlGaN nanowire (NW) of diameter ~ 100 nm using confinement of polarized light. The nanowires on the substrate have a nematic ordering. It is found that the PL from a single NW is influenced by the proximity to other NWs with the PL intensity scaling as 1/(lxd), where l and d are the NW length and the separation from the neighbouring NW, respectively. We show that this proximity induced PL intensity enhancement can be understood, if we assume the existence of reasonably long lived photons in the intervening space between the NWs. A nonzero non-equilibrium population of such photons causes stimulated emission leading to the enhanced PL emission with the intensity scaling as 1/(lxd). The effect is analogous to the Purcell enhancement of polarized optical emissions induced by confined photons in micro-cavities. The enhancement of PL emission facilitated the far field spectroscopic imaging of a single semiconducting nanowire in the sub-diffraction regime.
description: 22 pages, 4 figures, Communicated to journal
Uncertainty in Photoconductance Lifetime Measurements that Use an Inductive-Coil Detector
Creators: name: McIntosh, K.R.
name: Sinton, R.A.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Advanced Photovoltaics
Fundamental Studies

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 77-82
description: Photoconductance (PC) lifetime measurements are used widely within the photovoltaic industry but rarely are the results reported with any uncertainty. While nontrivial to determine, a knowledge of the experimental uncertainty is necessary to distinguish significant from insignificant differences between samples. This paper presents a preliminary study into the experimental uncertainty associated with PC instruments using inductive-coil detectors. Equations that express the uncertainty of (i) the excess carrier concentration and (ii) the effective lifetime are expressed in terms of the uncertainty of the input parameters, such as wafer width, calibration constants, and voltage resolution. The derivations illustrate why there is significantly less uncertainty in parameters extracted through transient rather than quasi-steady-state analyses. The paper also describes the difficulties associated with quantifying PC uncertainties that arise from the implicit relationship between carrier concentration and mobility, from the quantification of calibration errors, and in the case of transient analyses, from the quantification of the error in the voltage decay constant. One transient and one quasi-steady-state example is provided.
Characterizing GaInP/GaInAs/Ge Multijunction Solar Cells With Electroluminescence
Creators: name: Kirchartz, T.
name: Helbig, A.
name: Hermle, M.
name: Rau, U.
name: Bett, A.W.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Advanced Photovoltaics
Fundamental Studies

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 86-89
description: We show how characterization of GaInP/GaInAs/Ge multijunction solar cells benefits from the use of electroluminescence (EL) measurements. Usual characterization methods involving optical excitation and measurement of electrical response are challenging when they are applied to multijunction concentrator cells due to the necessity of high optical power and the precise simulation of sunlight. By inversing the direction of excitation and response, individual information about the subcells becomes accessible at high injection conditions. We show how to use an electro-optical reciprocity theorem that describes the link between solar cell quantum efficiency and
electroluminescent emission to extract the current/voltage curves of the individual subcells from EL spectra. This is accomplished by comparing the spectra with the solar cell quantum efficiency and an independently measured
current/voltage curve. The comparison with the solar cell quantum efficiency allows us to determine the relative voltage differences between the three junctions, while the current/voltage curve allows us to adjust the offset of the
voltage axis. The final results are internal voltages at all currents, where the spectra were measured. This information yields for example the individual diode quality factors of the cells as well as the difference to their respective
radiative limits.
CMB all-scale blackbody distortions induced by linearizing temperature
Creators: name: Notari, Alessio
name: Quartin, Miguel
Publisher: name: arXiv
Year: 2016
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Cosmic Microwave Background (CMB) experiments, such as WMAP and Planck, measure intensity anisotropies and build maps using a \emph{linearized} formula for relating them to the temperature blackbody fluctuations. However such a procedure also generates a signal in the maps in the form of y-type distortions, and thus degenerate with the thermal SZ (tSZ) effect. These are small effects that arise at second-order in the temperature fluctuations not from primordial physics but from such a limitation of the map-making procedure. They constitute a contaminant for measurements of: our peculiar velocity, the tSZ and of primordial y-distortions, but they can nevertheless be well-modelled and accounted for. We show that the largest distortions arises at high ell from a leakage of the CMB dipole into the y-channel which couples to all multipoles, but mostly affects the range ell
description: Withdrawn because it was supposed to be a replacement of arXiv:1510.08793 instead of a new paper altogether. It will then re-appear as arXiv:1510.08793v2
Progress With Silicon-Based Tandem Cells Using Group IV Quantum Dots in a Dielectric Matrix
Creators: name: Green, M.A.
name: Conibeer, G.
name: Perez-Wurfl, I.
name: Huang, S.J.
name: König, D.
name: Song, D.
name: Gentle, A.
name: Hao, X.J.
name: Park, S.
name: Gao, F.
name: So, Y.H.
name: Huang, Y.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Advanced Photovoltaics
New Types of Cells and Modules

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 1-4
description: Material costs will continually push photovoltaics to ever increasing efficiency to take advantage of the cost leverage thereby available. Although a range of “third generation” approaches have been suggested for improving cell efficiency beyond that of a single cell, the tandem cell approach is the only one yet to have
demonstrated improved experimental performance. The reliability of silicon wafer-based modules is well established. However, there are no obvious candidates for suitable high-bandgap cells to use with silicon in a tandem device that would not, to some extent, compromise this reliability and stability or depend upon toxic or scarce elements. This work seeks to engineer wide-bandgap silicon-based materials by using quantum-confinement in silicon quantum dots or quantum dots from other Group IV elements dispersed in a matrix of silicon carbide, nitride or oxide.
An Ultra-Fast X-ray Disk Wind in the Neutron Star Binary GX 340+0
Creators: name: Miller, J. M.
name: Raymond, J.
name: Cackett, E.
name: Grinberg, V.
name: Nowak, M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We present a spectral analysis of a brief Chandra/HETG observation of the neutron star low-mass X-ray binary GX~340+0. The high-resolution spectrum reveals evidence of ionized absorption in the Fe K band. The strongest feature, an absorption line at approximately 6.9 keV, is required at the 5 sigma level of confidence via an F-test. Photoionization modeling with XSTAR grids suggests that the line is the most prominent part of a disk wind with an apparent outflow speed of v = 0.04c. This interpretation is preferred at the 4 sigma level over a scenario in which the line is H-like Fe XXVI at a modest red-shift. The wind may achieve this speed owing to its relatively low ionization, enabling driving by radiation pressure on lines; in this sense, the wind in GX 340+0 may be the stellar-mass equivalent of the flows in broad absorption line quasars (BALQSOs). If the gas has a unity volume filling factor, the mass ouflow rate in the wind is over 10^-5 Msun/year, and the kinetic power is nearly 10^39 erg/s (or, 5-6 times the radiative Eddington limit for a neutron star). However, geometrical considerations - including a small volume filling factor and low covering factor - likely greatly reduce these values.
description: Accepted for publication in ApJ Letters
Demonstration and Analysis of the Photocurrent Produced by Absorption of Two Sub-Bandgap Photons in a Quantum Dot Intermediate Band Solar Cell
Creators: name: Antolín, E.
name: Martí Vega, A.
name: Linares, P.G.
name: Cánovas, E.
name: Fuertes Marrón, D.
name: Luque, A.
name: Farmer, C.D.
name: Stanley, C.R.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Advanced Photovoltaics
Fundamental Studies

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 5-10
description: In order to surpass the efficiency limit of single gap solar cells, intermediate band solar cells (IBSC) have to fulfill two requirements: the production of extra photocurrent by absorption of sub-bandgap photons in electronic transitions involving the intermediate band (IB) and the preservation of a high output voltage, not limited by the existence of this band. This work presents experimental evidence of the production of electron-hole pairs by absorption of two sub-bandgap photons in IBSC prototypes fabricated with InAs/GaAs QD material. The experiments were carried out at low temperatures using a specifically designed modulated photocurrent measurement set-up with two light beams. The results are analysed with the help of a simple equivalent circuit model. This analysis is also used to highlight the relevance of the two-photon mechanism demonstrated in the experiment. It is discussed that, although the absorption of sub-bandgap photons in one of the IB transitions and subsequent thermal escape of carriers is a sufficient mechanism to obtain a photocurrent enhancement, the absorption of sub-bandgap photons in both transitions involving the IB is a requisite for the voltage preservation in IBSCs.
Epidemiological and clinical characteristics of fall-related injuries: a retrospective study
Creators: name: Mekkodathil, Ahammed
name: El-Menyar, Ayman
name: Kanbar, Ahad
name: Hakim, Suhail
name: Ahmed, Khalid
name: Siddiqui, Tariq
name: Al-Thani, Hassan
Publisher: name: Manara - Qatar Research Repository
Year: 2022
Subjects: Public health

description: Background Fall-related injuries are important public health problem worldwide. We aimed to describe the epidemiological and clinical characteristics of fall-related injuries in a level 1 trauma center. Method A retrospective analysis of Qatar Trauma Registry data was conducted on patients admitted for fall-related injuries between 2010 and 2017. Comparative analyses of data by gender, age-groups and height of falls were performed to describe the epidemiological and clinical characteristics of patients, and in-hospital outcomes. Results A total of 4040 patients with fall-related injuries were identified in the study duration which corresponds to the rate of 2.34 per 10,000 population. Although the rate of fall-related injuries decreased over the years, the average number of patients per year remained high accounting for 32% of the hospitalized patients with moderate to severe injuries. Most of the injuries affected the head (36%) followed by spines (29%) and chest (23%). Males were predominant (89%), more likely to fall at workplace, fall from a greater height and have polytrauma than females. The working age-group (20–59 years) constituted the majority of injured (73%) and were more likely to fall at workplace, and to fall from higher heights compared to the older adults who sustained more fall at home. Overall in-hospital mortality was 3%. Outcomes including longer hospital length of stay and mortality were generally correlated with the height of fall except for the fall at home. Conclusion Fall-related injuries remain as significant burden even in a level 1 trauma center. Variations in the pattern of injuries by age, gender and height of fall provide important information for targeted preventive measures.Other Information Published in: BMC Public Health
 License: https://creativecommons.org/licenses/by/4.0
See article on publisher's website: http://dx.doi.org/10.1186/s12889-020-09268-2
Suspected Agomelatine-induced restless legs syndrome: a case report
Creators: name: Abdul Karim, Mustafa
name: Al-Baz, Nadeen
name: Ouanes, Sami
name: Alabdulla, Majid
name: Haddad, Peter M.
Publisher: name: Manara - Qatar Research Repository
Year: 2022
Subjects: Clinical sciences

description: Background Restless Legs Syndrome (RLS) is a sensorimotor disorder characterized by unpleasant and distressing sensations in the lower limbs that are more pronounced in the evening, commence or worsen at rest, and show partial or complete relief following movement. It can occur as a primary disorder, secondary to medical conditions or treatment with medications including but not limited to antidepressants or antipsychotics. Case presentation A 32-year old man with major depressive disorder showed partial response to Escitalopram 10 mg daily. Agomelatine 25 mg at night was added to Escitalopram to treat his residual depressive symptoms, namely insomnia and tiredness. Within two days he developed restlessness and unpleasant sensations in his legs which were worse at night. Symptom severity increased over the following days, prompting an urgent consultation a week later. The patient’s presentation met the criteria for RLS. Agomelatine was discontinued leaving the patient on Escitalopram alone. The patient’s symptoms improved within 24 h of stopping Agomelatine, with complete resolution four days later. There was no recurrence of RLS during follow-up. The patient scored 6 on Naranjo’s adverse drug reaction probability scale, indicating a probable adverse drug reaction caused by Agomelatine. Conclusions To the best of our knowledge, this is the first case report of suspected Agomelatine-induced RLS. Clinicians need to be aware of RLS to enable prompt diagnosis and management. We suggest adding Agomelatine to the list of agents that can potentially induce RLS.Other Information Published in: BMC Psychiatry
 License: http://creativecommons.org/licenses/by/4.0/
See article on publisher's website: http://dx.doi.org/10.1186/s12888-021-03175-5
Numerical Simulation and Modeling of III-V Multi-Junction Solar Cells
Creators: name: Philipps, S.P.
name: Hermle, M.
name: Letay, G.
name: Guter, W.
name: George, B.M.
name: Dimroth, F.
name: Bett, A.W.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Advanced Photovoltaics
Fundamental Studies

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 90-94
description: This paper presents results of numerical simulations of a III-V dual-junction solar cell including tunnel diode and Bragg reflector. The simulations are carried out in a commercially available semiconductor simulation environment. For the computation of the quantum efficiency of the subcells a special procedure using biasillumination and bias-voltage is implemented. The model is validated by a comparison of simulated external quantum efficiency (EQE) and IV curve with experimental data. A very good agreement is achieved. Simulations are used to
illustrate the influence of the Bragg reflector and the tunnel diode on the EQE. Additionally, the capabilities of the model for design optimization are exemplified by an adaption of the subcells’ thicknesses.
The Self and Interpersonal Functioning Scale – SIFS (Russian version)
Creators: name: Samylkin, Denis
name: Demidova, Liubov
name: Gadisov, Timur
name: Nikitskiy, Ivan
name: Tkachenko, Andrey
Publisher: name: figshare
Year: 2023
Subjects: Psychiatry (incl. psychotherapy)
Clinical psychology

description: Russian version of SIFS (D. Gamache, G. Savard, P. Leclerc, et al)
Quality of diabetes care in patients with schizophrenia: a case-control study in Qatar
Creators: name: Karim, Mustafa Abdul
name: Al-Baz, Nadeen
name: Ouanes, Sami
name: Khalil, Ali
name: Assar, Ahmed H.
name: Alsiddiqi, Abdulkarim
name: Dabbous, Zeinab
name: Zirie, Mahmoud
name: Woodruff, Peter
name: Malik, Rayaz A.
name: Haddad, Peter M.
Publisher: name: Manara - Qatar Research Repository
Year: 2022
Subjects: Clinical sciences

description: Background Patients with schizophrenia are at least twice as likely to develop diabetes mellitus compared to the general population. This is of significance in Qatar given the high prevalence of obesity and diabetes. Furthermore, the lifespan of people with schizophrenia is shortened by approximately 15 years, partly due to long-term microvascular and macrovascular complications. High quality diabetes care can significantly reduce morbidity and mortality. We assessed the level of diabetes care delivered to patients in Qatar with schizophrenia and diabetes compared to those with diabetes alone. Methods We performed a retrospective chart review of patients with diabetes mellitus with (n = 73) and without (n = 73) schizophrenia. Demographic information and electronic medical records were reviewed to determine adherence to American Diabetes Association standards of diabetes care in the last 6 and 12 months. Optimal diabetes care was defined as having completed glycated hemoglobin (HbA1c), lipid profile and retinal examination within 12 months. Results Optimal diabetes care was significantly lower in patients with schizophrenia and diabetes compared to diabetes alone [26.0% (n = 19/73) vs 52.1% (n = 38/73), p = 0.002]. Patients with diabetes and schizophrenia were also significantly less likely to have had body mass index recorded within 6 months (p = 0.008) and HbA1c (p = 0.006), lipid profile (p = 0.015), estimated glomerular filtration rate (eGFR) (p = 0.001) and order for retinal examination (p = 0.004) over 12 months. After adjusting for multiple comparisons, only assessment of eGFR (p = 0.01) and order for retinal examination (p = 0.04) remained significant. Conclusion Patients in Qatar with schizophrenia and diabetes, receive sub-optimal diabetes care compared to those with diabetes alone.Other Information Published in: BMC Psychiatry
 License: http://creativecommons.org/licenses/by/4.0/
See article on publisher's website: http://dx.doi.org/10.1186/s12888-021-03121-5
Prevalence and associated factors of DSM-5 insomnia disorder in the general population of Qatar
Creators: name: Khaled, Salma Mawfek
name: Petcu, Catalina
name: Al-Thani, Maryam Ali
name: Al-Hamadi, Aisha Mohammed H. A.
name: Daher-Nashif, Suhad
name: Zolezzi, Monica
name: Woodruff, Peter
Publisher: name: Manara - Qatar Research Repository
Year: 2022
Subjects: Clinical sciences

description: Background Epidemiological studies of insomnia in the Middle East remain scarce. The present study aimed to estimate the prevalence of insomnia and explore its associations in the general population of Qatar. With almost 100 nationalities, Qatar is one of the most culturally diverse, richest, and fastest developing countries in the Arabian Peninsula. Methods A probability sample of community-dwelling adults were surveyed in February of 2019. A total of 1611 respondents completed face-to-face interviews in Arabic or English. Logistic regression modeled associations with insomnia, our dependent variable, as defined by a score of ≤16 on the eight-item Sleep Condition Indicator or according to criteria for insomnia in the Diagnostic & Statistical Manual of Mental Disorders, fifth edition or DSM-5. Results Approximately, 5.5% of the sample screened positive for insomnia and the 30-day prevalence of those who met all the DSM-5 criteria for insomnia disorder was 3.0%. In addition, 2.0% of the sample screened positive for depression and 3.4% for anxiety in the past 2 weeks. Multivariable analysis showed the following were significantly associated with insomnia: Arab ethnicity, young age, unemployment, being married, having less than high school education, fair or poor health, anxiety, and depression. Conclusions Insomnia prevalence was in the lower range of previously reported DSM-defined estimates from developed Western countries. Our findings highlight the need for raising awareness and improving sleep hygiene in potential risk groups such as younger adults and those of Arab ethnicity, in addition to incorporating insomnia screening in the provision of mental health services.Other Information Published in: BMC Psychiatry
 License: http://creativecommons.org/licenses/by/4.0/
See article on publisher's website: http://dx.doi.org/10.1186/s12888-020-03035-8
A Note on the least squarefree number in an arithmetic progression
Creators: name: Nunes, Ramon M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 1N37

description: We prove an asymptotic formula for squarefree in arithmetic progressions with squarefree moduli, improving previous results by Prachar. The main tool is an estimate for counting solutions of a congruence inside a box that goes beyond what can be obtained by using the Weil bound.
description: 6 pages, no figures
Development of Numerical Model and Design Framework for Mixed-Mode Ventilation in the Tropics
Creators: name: Wang, Pengcheng
name: Beh, Hsiung Wei Luke
name: Jusuf, Steve Kardinal
name: Po, Ken
Publisher: name: Singapore Institute of Technology
Year: 2023

description: In Singapore, the building sector is responsible for consuming about one-third of the country’s total energy consumption (BCA, 2020). This is because more buildings are being built over the years to cater to the increasing population size and economic activities. To mitigate climate change, Singapore has unveiled a green plan where there is a target by the Government to green 80% of Singapore’s buildings by the year 2030 (MND, 2021). To improve energy efficiency and reduce energy consumption in building, alternative cooling systems such as mixed-mode ventilation is recommended in this paper. Mixed-mode ventilation for building concepts have been explored and used in other countries (Etheridge, D., & Ford, B. (2008); Ezzeldin, S., & Rees, S. J. (2013); Keep, T., Lavedrine, I., Wood, J., & Arup. (2008).). Literature study shows that by using mixed-mode ventilation system, there is potential to save about half of the energy consumed as compared to conventional mechanical ventilation system (Ezzeldin, S., & Rees, S. J. (2013)). Furthermore, mixed-mode cooling strategies should be able to provide a satisfactory indoor environment (Ezzeldin, S., & Rees, S. J. (2013)). For this paper, the use of simulation techniques such as Computational Fluid Dynamics (CFD) is adopted to accurately predict both spatial and temporal field solutions as well as the overall system evaluation and design.
Carrier Collection Process in InGaAs/GaAs Superlattice Structured Solar Cells
Creators: name: Yagi, S.
name: Nagamochi, S.
name: Oshima, R.
name: Okada, Y.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Advanced Photovoltaics
Fundamental Studies

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 45-48
description: The effect of carrier transport via tunneling on the carrier collection process in multi-quantum well (MQW) solar cells was studied. Dependence of photocurrent and photoluminescence on the thickness of barrier layers in InGaAs/GaAs MQW solar cells were investigated. We show that the escape of photocarriers from MQWs and hence, suppression of radiative recombination are promoted with decreasing thickness of GaAs barriers. For MQW cells with GaAs barrier thickness of <10 nm, photocarriers can tunnel through the miniband, and consequently the activation energy of carrier escape from quantum wells is reduced due to acceleration of photocarriers by the electric field. A fast spatial separation of electron-hole pairs and enhancement of carrier escape result in a rapid quenching of PL emission and efficient carrier collection even at low temperatures. This result verifies that the enhancement of carrier collection is as a result of formation of superlattice minibands in periodic nanostructures, and is an important observation in order to achieve high efficiencies in nanostructured solar cells using QWs and quantum dots (QDs).
An Encrypted Trust-Based Routing Protocol
Creators: name: Gahi, Youssef
name: Guennoun, Mouhcine
name: Guennoun, Zouhair
name: El-Khatib, Khalil
Publisher: name: arXiv
Year: 2015
Subjects: subject: Cryptography and Security (cs.CR)
subject: FOS: Computer and information sciences

description: The interest in trust-based routing protocols has grown with the advancements achieved in ad-hoc wireless networks.However, regardless of the many security approaches and trust metrics available, trust-based routing still faces some security challenges, especially with respect to privacy. In this paper, we propose a novel trust-based routing protocol based on a fully homomorphic encryption scheme. The new protocol allows nodes, which collaborate in a dynamic environment, to evaluate their knowledge on the trustworthiness of specific routes and securely share this knowledge.
Development of Numerical Model and Design Framework for Mixed-Mode Ventilation in the Tropics
Creators: name: Beh, Hsiung Wei Luke
name: Wang, Pengcheng
name: Jusuf, Steve Kardinal
name: Po, Ken
Publisher: name: Singapore Institute of Technology
Year: 2023

description: In Singapore, the building sector is responsible for consuming about one-third of the country’s total energy consumption (BCA, 2020). This is because more buildings are being built over the years to cater to the increasing population size and economic activities. To mitigate climate change, Singapore has unveiled a green plan where there is a target by the Government to green 80% of Singapore’s buildings by the year 2030 (MND, 2021). To improve energy efficiency and reduce energy consumption in building, alternative cooling systems such as mixed-mode ventilation is recommended in this paper. Mixed-mode ventilation for building concepts have been explored and used in other countries (Etheridge, D., & Ford, B. (2008); Ezzeldin, S., & Rees, S. J. (2013); Keep, T., Lavedrine, I., Wood, J., & Arup. (2008).). Literature study shows that by using mixed-mode ventilation system, there is potential to save about half of the energy consumed as compared to conventional mechanical ventilation system (Ezzeldin, S., & Rees, S. J. (2013)). Furthermore, mixed-mode cooling strategies should be able to provide a satisfactory indoor environment (Ezzeldin, S., & Rees, S. J. (2013)). For this paper, the use of simulation techniques such as Computational Fluid Dynamics (CFD) is adopted to accurately predict both spatial and temporal field solutions as well as the overall system evaluation and design.
Top quark mass determination from the energy peaks of b-jets and B-hadrons at NLO QCD
Creators: name: Agashe, Kaustubh
name: Kim, Doojin
name: Franceschini, Roberto
name: Schulze, Markus
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We analyze the energy spectra of $single$ b-jets and B-hadrons resulting from the production and decay of top quarks within the SM at the LHC at the NLO QCD. For both hadrons and jets, we calculate the correlation of the peak of the spectrum with the top quark mass, considering the "energy-peak" as an observable to determine the top quark mass. Such a method is motivated by our previous work where we argued that this approach can have reduced sensitivity to the details of the production mechanism of the top quark, whether it is higher-order QCD effects or new physics contributions. As part of the NLO improvement over the original proposal, we assess the residual sensitivity of the extracted top quark mass to perturbative effects both in top quark production and decay. For a 1% jet energy scale uncertainty (and assuming negligible statistical error), the top quark mass can then be extracted using the energy-peak of b-jets with an error +- (1.2 (exp) + 0.6(th)) GeV. We note that recently the CMS collaboration reported a top quark mass measurement based on the original proposal (with b-jets) so that our result contributes to a precise evaluation of the associated theory uncertainty. In view of the dominant jet energy scale uncertainty in the measurement using b-jets, we also investigate the extraction of the top quark mass from the energy-peak of the corresponding B-hadrons which, in principle, can be measured without this uncertainty. The calculation of the B-hadron energy spectrum is carried out using fragmentation functions at NLO. The dependence on the fragmentation scale turns out to be the largest theoretical uncertainty in this extraction of top quark mass. Future improvement of the treatment of bottom quark hadronization can reduce this uncertainty, rendering methods based on the B-hadron energy-peak competitive for the top quark mass measurement.
description: 5 figures, 12 pages
Synthesis and Characterization of Transition Metal-Substituted Indium Thiospinels as Intermediate Band Materials for High Efficiency Solar Cells
Creators: name: Conesa, J.C.
name: Lucena, R.
name: Wahnón, P.
name: Palacios, P.
name: Aguilera, I.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Advanced Photovoltaics
Fundamental Studies

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 41-44
description: It was recently proposed that higher efficiency can be achieved in PV cells having a single-absorbent if for the latter an intermediate band (IB) material is used which contains a partially filled, isolated band within the gap of an otherwise normal semiconductor. In2S3 and related compounds in which octahedrally coordinated In is substituted by a light transition metal are IB material candidates according to solid state chemistry concepts, this having been confirmed by quantum calculations. Here materials of this type have been chemically synthesized in powder form using wet solvothermal methods. Especially for vanadium-substituted In2S3, incorporation of the metal into the lattice is supported by XRD and TEM data, and only minor oxidation of vanadium from the VIII state to the VIV state is evidenced by EPR. New sub-bandgap features appear in the diffuse reflectance optical spectra upon incorporation of vanadium; these coincide with the spectra that had been predicted by the quantum calculations as corresponding to the IB electronic structure. The realization of the IB concept in a single compound, that furthermore should be easy to prepare in the form needed for PV thin film cells, is thus achieved for the first time.
Mobility-Assisted on-Demand Routing Algorithm for MANETs in the Presence of Location Errors
Creators: name: Vu, Trung Kien
name: Kwon, Sungoh
Publisher: name: arXiv
Year: 2016
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: We propose a mobility-assisted on-demand routing algorithm for mobile ad hoc networks in the presence of location errors. Location awareness enables mobile nodes to predict their mobility and enhances routing performance by estimating link duration and selecting reliable routes. However, measured locations intrinsically include errors in measurement. Such errors degrade mobility prediction and have been ignored in previous work. To mitigate the impact of location errors on routing, we propose an on-demand routing algorithm taking into account location errors. To that end, we adopt the Kalman filter to estimate accurate locations and consider route confidence in discovering routes. Via simulations, we compare our algorithmand previous algorithms in various environments. Our proposed mobility prediction is robust to the location errors.
description: Special Issues on Recent Advances in Communications and Networking, The Scientific World Journal, 11 figures
Exciton Broadening in Quantum Well Solar Cells
Creators: name: Führer, M.
name: Connolly, J.P.
name: Mazzer, M.
name: Ballard, I.M.
name: Ekins-Daukes, N.J.
name: Johnson, D.
name: Barnham, K.
name: Bessière, A.
name: Roberts, J.
name: Airey, R.
name: Calder, C.
name: Hill, G.
name: Tibbits, T.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Advanced Photovoltaics
Fundamental Studies

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 58-61
description: The incorporation of quantum wells into GaAs solar cells extends the absorption edge towards lower energy, which can lead to higher efficiencies. At concentrator current levels the main carrier loss mechanism is radiative recombination from the quantum wells. We have previously reported on a high-bias effect in the e1-hh1 exciton electroluminescence (EL) in strain-balanced quantum well solar cells. In this paper, we define a metric for this effect by fitting a Lorentzian line shape to the exciton absorption as calculated from EL spectra using a generalised Planck approach, examine the effect in light of the full width half maximum, height, and area of the Lorentzian, and consider possible sources of the effect.
CELLO Measurements With FFT Impedance Analysis: Drastic Increase of Measurement Speed for Analysis of Local Solar Cell Defects
Creators: name: Carstensen, J.
name: Schütt, A.
name: Föll, H.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Advanced Photovoltaics
Fundamental Studies

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 73-76
description: The CELLO set up can be used to generate maps of the linear short circuit current response upon various frequencies. New implemented hard- and software allow to apply the FFT algorithm, which reduces the measurement time drastically because several maps can be obtained simultaneously from one scan. A model for the frequency dependent solar cell short circuit current impedance has been developed which allows to determine local solar cell properties like lifetime , back side recombination velocity Sb, and the time constant related to the Rser CD (local serial resistance, local diode capacitance). The technique is discussed for the example of a mc-Si solar cell.