Solar cell degradation under open circuit condition in out-doors-in desert region

AbstractThe reliability of solar cells is an important parameter in the design of photovoltaic systems and particularly for cost estimation. Solar cell degradation is the result of various operating conditions; temperature is one of most important factors. Installed PV modules in desert regions are subjected to various temperature changes with significant gradient leading to accelerated degradation. In the present work, we demonstrate the influence of open-circuit condition on the degradation of PV modules. The experiment is carried out in the desert region of ADRAR (southern Algeria) using two modules IJISEL of single-crystal silicon. A continuous monitoring allows analysis of both performances of modules for duration of 330days. The module in open-circuit condition reaches higher temperature means than the module in charging condition; therefore, it undergoes a higher degradation. By simulation, we found that the life of a PV module (whose power output is close to 50%) in a condition of an open-circuit in the desert region could be reduced to 4years, and that has a significant impact on economy

Using LDGM Codes and Sparse Syndromes to Achieve Digital Signatures

In this paper, we address the problem of achieving efficient code-based digital signatures with small public keys. The solution we propose exploits sparse syndromes and randomly designed low-density generator matrix codes. Based on our evaluations, the proposed scheme is able to outperform existing solutions, permitting to achieve considerable security levels with very small public keys.Comment: 16 pages. The final publication is available at springerlink.co

Effect of Partial Root Zone Drying on Growth, Yield and Biomass Partitioning of a Soilless Tomato Crop

The object of the present research was to assess the effects of partial root zone drying (PRD) as a water supply strategy on tomato growth, productivity, biomass allocation and water use efficiency (WUE). Plants were grown under greenhouse, on a sand substrate. Three treatments were applied: a control that was fully and conventionally irrigated, PRD-70 and PRD-50 in which, respectively, 70% and 50% of water requirements were supplied using PRD. At planting, the root volume was devided into two halves each half was irrigated separately. Alternation of irrigation between the two root halves took place each three days. The total yield statistically differed (P < 0.05) with control giving the highest total yield (252 tons/ha). Compared to PRD-70 and control, PRD-50 yield decrease rates were, respectively, 16% and 30%. In terms of fruit number, PRD-50 showed 23% and 16% less fruits than PRD-70 and control, respectively. Fruit size was affected by treatment with PRD-50 treatment producing 66% and 53% more class 3 fruits (small size) than, control and PRD-70 (P< 0.05), respectively. For plant growth, the difference was not significant when comparing control to PRD-70 but was significant when comparing PRD-70 and control to PRD-50 (P < 0.05). No effect was on total biomass but root biomass was higher for stressed plants compared to control (P<0.05). WUE was 66% and 27% higher for PRD-50 and PRD-70 respectively compared to control

Study of Cu/In/Se/Se thin films prepared by the Stacked Elemental Layer (SEL) technique

CuInSe2 thin films have been grown on Corning glass and Si (100) substrates using stacked elemental layers (SEL) processing. The influence of substrate’s nature and substrate’s temperature were studied. X-ray diffraction and SEM measurements have shown that the films exhibit an excellent crystallinity and crystallize in a tetragonal structure. Scanning electron microscopy investigations have shown that the films consist in a structure with large grains in the range 80 – 200 nm. Increasing the deposition temperature from room temperature to 300 °C has lead to a change in the composition and morphology of the films. Characteristic peaks of the chalcopyrite structure such as (101), (211) and (311) were clearly observed for both layers upon annealing at 450°C as evidenced by X-ray diffraction study. The determined lattice parameters were a = 0.57725 (6) nm, b = 1.1621 (2) nm for sample prepared at room temperature and a = 0.57770 (4) nm, b = 1.1602 (1) nm for Ts = 300°C. The crystallographic structure of the CuInSe2 sample was analyzed by Rietveld analysis using X-ray powder diffraction data. UV-Vis-NIR Spectrophotometry was used to investigate the optical characteristics of different Cu/In/Se/Se thin layers in the spectral range between 300 – 2000 nm. The optical band-gap of our materials increases from 0.98 to 1.01 eV

Effects of yellow mealworm larvae (Tenebrio molitor) and turmeric powder (curcuma) on laying hens performance, physical and nutritional eggs quality

peer reviewedSoybean meal is the main source of protein in laying hens’ diet that is generally imported. This study aims to explore the yellow mealworm larvae (Tenebrio molitor) “TM”, and curcuma effects on laying hens’ performances, and physical and nutritional eggs quality. One hundred laying hens were divided randomly into 4 groups. The first group (Control) received a standard commercial diet (SCD), while test groups (TM, TP, and TM-TP) received SCD with respectively 5% TM, 0.50 % curcuma, and 5% TM and 0.50% curcuma. According to the results, Control and TM reduced significantly hen’s bodyweight in the experiment end. However, the curcuma incorporation and TM (TP and TM-TP) kept the stability of bodyweight during the whole period. No effect of diet was observed on feed intake and egg laying rate. Diet had a significant effect on eggs physical parameters (weight, freshness, thickness and rupture force). The mixture of TM and curcuma permitted eggs with good physical parameters. For nutritional quality of eggs, all groups had the same content of ALA and DHA. However, eggs of group receiving a mixture of TM and curcuma had the lowest cholesterol content. Thus, TM and curcuma could reduce soybean importation dependence with improving eggs quality

Wave: A New Family of Trapdoor One-Way Preimage Sampleable Functions Based on Codes

We present here a new family of trapdoor one-way Preimage Sampleable Functions (PSF) based on codes, the Wave-PSF family. The trapdoor function is one-way under two computational assumptions: the hardness of generic decoding for high weights and the indistinguishability of generalized $(U,U+V)$-codes. Our proof follows the GPV strategy [GPV08]. By including rejection sampling, we ensure the proper distribution for the trapdoor inverse output. The domain sampling property of our family is ensured by using and proving a variant of the left-over hash lemma. We instantiate the new Wave-PSF family with ternary generalized $(U,U+V)$-codes to design a "hash-and-sign" signature scheme which achieves existential unforgeability under adaptive chosen message attacks (EUF-CMA) in the random oracle model. For 128 bits of classical security, signature sizes are in the order of 15 thousand bits, the public key size in the order of 4 megabytes, and the rejection rate is limited to one rejection every 10 to 12 signatures.Comment: arXiv admin note: text overlap with arXiv:1706.0806