Simulation of tunnel junction in cascade solar cell (GaAs/Ge) using AMPS-1D

The development of the tunnel junction interconnect was key the first two-terminal monolithic, multijunction solar cell development. This paper describes simulation for the tunnel junction (GaAs) between top cell (GaAs) and bottom cell (Ge). This solar cell cascade was simulated when using one dimensional simulation program called analysis of microelectronic and photonic structures (AMPS-1D). In the simulation, the thickness of the tunnel junction layer was varied from 10 to 50 nm. By varying thickness of tunnel junction layer the simulated device performance was demonstrate in the form of current-voltage(I-V) characteristics and quantum efficiency (QE)

Numerical simulation of graded band gap GaAs/AlGaAs heterojunction solar cell by AMPS-1D

The conduction band discontinuity or spike in an abrupt heterojunction p+ GaAs / NAl0.4 Ga0.6As solar cell can hinder the separation of hole-electron by electric field. This paper analyzes the GaAs /AlxGa1-xAs/Al0.4Ga0.6As based solar cell performance by AMPS-1D numerical modeling. The affect of graded band gap region in the interface between the emitter (GaAs) and base (Al0.4Ga0.6As) on the solar cell’s performance is investigated. Among the factors studied are thickness of graded band gap region, thickness of emitter layer of the cells. In this study, a width 0.14µm has been required to eliminate the spike and improved the performance of solar cell. Keywords: heterojunction solar cell; graded band gap; AMPS-1D

The Effect of Graded Band Gap Structure Inserted in the Multijunction Solar Cell

We have theoretically calculated the photovoltaic conversion efficiency of a monolithic dual-graded junction AlGaAs/GaInAs device, which can be experimentally fabricated. By optimizing the band-gap combination of the considered structure, an improvement of conversion efficiency has been observed in comparison to the conventional AlGaAs/GaInAs system. For the suggested graded band-gap combination, our calculation indicates that the attainable efficiency can be enhanced up to 34% ( AM1.5d). Keywords: band gap gradient, multijunction solar cells, AlGaAs, GaInA

Simulation of tunnel junction in cascade solar cell (GaAs/Ge) using AMPS-1D

The development of the tunnel junction interconnect was key the first two-terminal monolithic, multijunction solar cell development. This paper describes simulation for the tunnel junction (GaAs) between top cell (GaAs) and bottom cell (Ge). This solar cell cascade was simulated when using one dimensional simulation program called analysis of microelectronic and photonic structures (AMPS-1D). In the simulation, the thickness of the tunnel junction layer was varied from 10 to 50 nm. By varying thickness of tunnel junction layer the simulated device performance was demonstrate in the form of current-voltage(I-V) characteristics and quantum efficiency (QE)

Awareness of the Importance of and Adherence to Patients’ Rights Among Physicians and Nurses in Oman: An analytical cross-sectional study across different levels of healthcare

Objectives: This study aimed to determine the extent to which physicians and nurses in Oman were aware of the importance of and adhere to patients’ rights and whether this differed according to role, nationality, position and institutional healthcare level. Methods: This analytical cross-sectional study was carried out between December 2015 and March 2016 at various governmental healthcare institutions in Oman. A self-administered questionnaire was distributed to 1,385 practitioners at all healthcare levels. Results: A total of 1,213 healthcare practitioners (response rate: 87.58%) completed the survey, of which 685 (56.47%) were nurses and 528 (43.53%) were physicians. Overall, awareness of the importance of patients’ rights was high (91.51%), although adherence to these rights in practice was low (63.81%). The right of the patient to be informed was considered least important and was least adhered to (81.2% and 56.39%). Nationality, role and institutional level were significantly associated with awareness (P = 0.002, 0.024 and 0.034, respectively). Non-Omani staff were significantly more likely than Omani staff to be aware of (odds ratio [OR] = 1.696; P = 0.032) and adhere to (OR = 2.769; P <0.001) patient rights. Furthermore, tertiary care staff were twice as likely as primary care staff to perceive the importance of patient rights (OR = 2.076; P = 0.019). While physicians were more likely than nurses to be aware of the importance of patient rights, this difference was not significant (OR = 1.516; P = 0.126). Conclusion: These findings may help inform measures to enhance awareness of and adherence to patients’ rights in Oman.Keywords: Medical Ethics; Patient Rights; Awareness; Adherence; Physicians; Nurses; Oman

Advanced Low-Temperature Fluid Bed Sorbents

This paper discusses the results obtained in an ongoing study geared towards developing advanced mixed-metal oxide sorbents for desulfurization of coal-derived fuel gases in the temperature range of 350 to 550{degrees}C. The paper focuses on the study related to the development of durable sorbents suitable for fluidized-bed application and addresses thermodynamic considerations, sulfidation kinetics, regenerability, and the physical and chemical characteristics of a number of novel sorbents

Inter-model comparison of global hydroxyl radical (OH) distributions and their impact on atmospheric methane over the 2000–2016 period

The modeling study presented here aims to estimate how uncertainties in global hydroxyl radical (OH) distributions, variability, and trends may contribute to resolving discrepancies between simulated and observed methane (CH4) changes since 2000. A multi-model ensemble of 14 OH fields was analyzed and aggregated into 64 scenarios to force the offline atmospheric chemistry transport model LMDz (Laboratoire de Meteorologie Dynamique) with a standard CH4 emission scenario over the period 2000–2016. The multi-model simulated global volume-weighted tropospheric mean OH concentration ([OH]) averaged over 2000–2010 ranges between 8:7*10^5 and 12:8*10^5 molec cm-3. The inter-model differences in tropospheric OH burden and vertical distributions are mainly determined by the differences in the nitrogen oxide (NO) distributions, while the spatial discrepancies between OH fields are mostly due to differences in natural emissions and volatile organic compound (VOC) chemistry. From 2000 to 2010, most simulated OH fields show an increase of 0.1–0:3*10^5 molec cm-3 in the tropospheric mean [OH], with year-to-year variations much smaller than during the historical period 1960–2000. Once ingested into the LMDz model, these OH changes translated into a 5 to 15 ppbv reduction in the CH4 mixing ratio in 2010, which represents 7%–20% of the model-simulated CH4 increase due to surface emissions. Between 2010 and 2016, the ensemble of simulations showed that OH changes could lead to a CH4 mixing ratio uncertainty of > 30 ppbv. Over the full 2000–2016 time period, using a common stateof- the-art but nonoptimized emission scenario, the impact of [OH] changes tested here can explain up to 54% of the gap between model simulations and observations. This result emphasizes the importance of better representing OH abundance and variations in CH4 forward simulations and emission optimizations performed by atmospheric inversions