Optimization The Characteristics of Solar Cell based on InGaN

This work studies and simulates a thin film solar cell based on the InGaN material. The single-junction n/p In0.622 Ga0.378 N (Eg = 1.39 eV) solar cell is the optimal structure found under normalized conditions (AM1.5G, 300K), we exhibit a comparison between three types of cells, with Lambertinne reflectors, textured reflectors, and flat reflectors to study optimum efficiency. The conversion efficiency increased from 16.46% with flat reflectors to18.67%. with textured reflectors, the solar cell exhibits a maximum efficiency of around 19.80 % with Lambertinne reflectors. The investigation results show that the In0.622 Ga0.378 N with Lambertinne reflectors solar cell was inversely proportional to the temperature. The optimum concentration for doping for the donor is 5e17 cm−3 and for the acceptor is 5e17 cm−3

Volatile oils of Thymus serpyllum and Artemisia absinthium: GS-MS analysis and insecticidal activity against Culiseta longiareolata

Culiseta longiareolata (Macquart, 1838) (Diptera, Culicidae) is one of the important mosquito species distributed in Algeria. It acts as a vector of avian malaria, tularemia, Malta fever (brucellosis), and several arboviruses, such as West Nile fever and western encephalitis virus. To eliminate undesirable insect vectors of pathogens, botanical-based insecticides are increasingly recommended. This research was focused on the analysis of the chemical composition of essential oils from Artemisia absinthium (Asteraceae) and Thymus serpyllum (Lamiaceae) obtained by hydrodistillation using gas chromatography – mass spectroscopy (GC-MS). Furthermore, these oils were tested for the first time for their larvicidal activity against fourth-instar larvae of C. longiareolata. In the Th. serpyllum essential oil, linalool (25.40%) was the major constituent, followed by camphor (19.75%) and α-pinene (11.25%). In the A. absinthium essential oil, the major compound was camphor (39.01%), followed by chamazulene (14.51%). Our study found significant larvicidal effects against the fourth-instar larvae, with a direct correlation among the larval mortality rate, applied concentrations, and duration of exposure to the treatment, where the mortality increased over time. Also, the results indicated a significant difference in the mortality rate between the two samples of essential oils. The essential oil extracted from A. absinthium was highly effective against mosquito larvae, achieving the LC50 values of 10.42, 6.19 and 3.82 ppm at 24, 48, and 72 h, respectively, while the essential oil from Th. serpyllum achieved the LC50 values of 12.16, 7.79, and 6.88 ppm. Based on the current results, both the plants could be used as new alternatives for mosquito control

Practical and efficient fair document exchange over networks

This paper presents a practical and efficient protocol to support a common Internet-based e-commerce activity - fair document exchange between two parties. This protocol incorporates a novel RSA-based method for the off-line recovery of a document decryption key of a party. The principal idea for such key recovery is based on a verifiable and recoverable encryption of the document decryption key. The verifiability of the encryption allows another party to verify the correctness of the encrypted key without actually knowing the original key, and the recoverability permits a designated third party to decrypt the encrypted key to recover the original key upon a legitimate request. Such verifiable and recoverable key encryption is essential for ensuring the fairness of the exchange. The protocol presented in this paper is more practical, cost-effective and efficient than other relevant protocols designed for fair document exchange. © 2006 Elsevier Ltd. All rights reserved

Achieving autonomous fair exchange in ubiquitous network settings

This paper addresses the issue of fair (signature or key) exchange in emerging ubiquitous commerce (u-commerce). Such an application poses new security challenges. In particular, it involves distributed and autonomous operations running in a much open, dynamic and resource-diversified networking environment, which makes an exchange highly susceptible to security attacks and system failures. Existing approaches to fair exchange are ineffective in dealing with the new challenges as their design did not envisage such complex operational situations. In this paper, we aim to propose a novel fair exchange protocol specifically for u-commerce in response to the new challenges. The protocol is supported by an integration of several techniques, such as threshold proxy signatures, purpose-restricted encryption key certification and threshold verifiable proxy encryption, to accomplish the fairness of exchange in u-commerce settings. The protocol analysis is also provided for the proof of its fairness. © 2010 Elsevier Ltd. All rights reserved