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

Spaces generated by the cone of sublinear operators

This paper deals with a study on classes of non linear operators. Let $SL(X,Y)$ be the set of all sublinear operators between two Riesz spaces $X$ and $Y$. It is a convex cone of the space $H(X,Y)$ of all positively homogeneous operators. In this paper we study some spaces generated by this cone, therefore we study several properties, which are well known in the theory of Riesz spaces, like order continuity, order boundedness etc. Finally, we try to generalise the concept of adjoint operator. First, by using the analytic form of Hahn-Banach theorem, we adapt the notion of adjoint operator to the category of positively homogeneous operators. Then we apply it to the class of operators generated by the sublinear operators

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

Lightweight Scheme for Smart Home Environments using Offloading Technique

Internet of Things (IoT) as an emerging technology has been transforming the different aspects of our world from simple preprogrammed coffee machine to smart farming. Due to the human nature to simplify and ease of living, human are becoming dependent on these automated IoT devices and smart environments like smart phones, wearable devices, smart home and etc. In order to provide better QoS, these devices needs to work together and share data among them, also to the service providers and the cloud. Since these devices are resource constrained, IoT technology heavily depends on the cloud for processing, analytics and storage. But these data coming from the devices contains lot of personal identity information (PII). Almost all the time, the users of these devices are unaware of these information that is being transmitted or they do not possess the control over the data that they are being sent to the service provider, as well as to the cloud. Even the cloud services and service providers are secured but they are always curious. There are lot of security measures implemented for end to end communication but IoT lacks the mechanism for securing the data that the devices are generating along with access control. In this article we are proposing an approach for the security, privacy and access control of user data using Attribute Based Encryption (ABE) in smart home as the case study

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)

Effect of diet supplementation on growth and reproduction in camels under arid range conditions

Eighteen pregnant dromedary females (Camelus dromedarius) were used to determine the effect of concentrate supplement on growth and reproductive performances in peri-partum period. The females were divided into supplemented (n = 9; S) and unsupplemented (n = 9; C) experimental groups. All animals grazed, with one mature male, 7 to 8 hours per day on salty pasture rangelands. During night, they were kept in pen, where each female of group S received 4 kg per day of concentrate supplement during the last 3 months of gestation and 5 kg per day during the first 3 months post-partum. During the last 90 days of gestation daily body weight gain (DBG) was at least tenfold more important in group S than in group C (775 g vs. 72 g respectively). Supplementation affected birth weight of offspring (30.3 kg vs. 23.4 kg) and its DBG (806 g vs. 430 g) in group S and group C respectively. During the post-partum period, females in group S gained in weight (116 g per day) whereas females in group C lost more than 200 g per day. The mean post-partum interval to the first heat and the percentage of females in heat were 29.5 day and 44.4/ vs. 41.2 day and 71.4/ for the C and S groups, respectively. We conclude that under range conditions, dietary supplementation of dromedary during late pregnancy stage and post-partum period improves productive and reproductive parameters