Nowadays, photovoltaic (PV) are considered a promising alternative solution as a clean energy source. The power output from the solar PV module is proportional to the amount of solar radiation ...received by its surface. Hence, the determination of the most convenient locations of PV systems is crucial to maximize their output power. In this paper, the most suitable sites of PV farms in Egypt are identified based on the multi-criteria decision-making (MCDM) technique using the geographic information system (GIS) software. Four categories have been taken into acount; location, environment, meteorology, and climatology, to select the suitable locations. Based on experts’ knowledge ten criteria belong to the main categiories have been weighted using the analytical hierarchy process (AHP) and combined in PV land suitabliltiy index which maped using GIS techniques. The conducted suitability map could be used to guiding installation of renewable energy projects in the future.
To help answer questions about availability, accessibility, sustainability and other dimensions of energy security, the vulnerability approach concentrates the attention of policymakers on the ...assessment of risks associated with natural, technical, political and economic factors. This understanding, combined with a focus on energy services (e.g. lighting, heating, telecommunications, mobility, etc.) helps to prioritize actions to achieve the goal of energy security. This paper conceptualizes energy security as low vulnerability of vital energy systems and sustained provision of modern energy services. Taking Tajikistan as a case, this paper highlights key vulnerabilities including neglect of environmental conditions, insufficient energy production capacity, unreliable and expensive energy imports, dwindling power infrastructure causing technical and economic losses, inadequate transparency in the power sector, lack of regional cooperation in energy and water resources sharing, and inadequate financial resources to address these challenges. Three major proposals presented by the World Bank, the United Nations Development Program, and the Government of Tajikistan to achieve energy security in Tajikistan are evaluated. Specifically, they lack a focus on energy services and therefore overlook people's socio-cultural context and appropriate energy needs. This paper highlights energy services as critical to people’s wellbeing and socio-economic development.
•A novel vulnerability approach is applied to energy security assessment.•Key vulnerabilities in energy system are assessed in case of Tajikistan.•Three major pathways to achieve energy security in Tajikistan are evaluated.•A paradigm shift from energy sources to services is recommended to improve access.
Beryllium chloride (BeCl2) is a highly toxic substance that accumulates in different tissues after absorption. The purpose of this study was to investigate protective role of crocin against ...BeCl2-intoxication in rats. Male Wistar rats were used in this study and categorised into four groups (n=8). Group I served as normal control rats. Group II treated orally with BeCl2 86mg/kg b.w. for five consecutive days. This dose was equivalent to experimental LD50. Group III treated intraperitoneally with crocin 200mg/kg b.w. for seven consecutive days. Group IV received crocin for seven consecutive days before BeCl2 administration. Blood samples and liver and brain homogenates were obtained for haematological, biochemical and RT-PCR examinations. The haematocrit value, RBCs count and haemoglobin concentration were significantly decreased in BeCl2-treated rats. A significant increase was observed in rat liver and brain malondialdehyde level and protein carbonyls content in BeCl2 exposed group compared to the control group, and these values were significantly declined upon administration of crocin. Lactate dehydrogenase levels in rat liver and brain significantly increased compared to the control group and was associated with significant decrease in catalase and superoxide dismutase activities. Reduced glutathione hepatic contents of BeCl2-treated rats were significantly decreased. There was significant decline in mRNA expression of catalase and superoxide dismutase genes in BeCl2-intoxicated rats compared to the normal rats. Crocin treatment prior to BeCl2 intake resulted in significant increase in mRNA expressions of catalase and superoxide dismutase genes near to normalcy. The haematological and biochemical parameters were restored near to normal levels. Our results suggested that, BeCl2 induced oxidation of cellular lipids and proteins and that administration of crocin reduced BeCl2-induced oxidative stress combined with initiation of mRNA expression of antioxidant genes.
► Haematological parameters significantly decreased in BeCl2-treated rats. ► Malondialdehyde and protein carbonyls decreased in BeCl2-treated rats. ► Lactate dehydrogenase, catalase and superoxide dismutase decreased after BeCl2. ► mRNA expression of antioxidant enzymes declined after BeCl2 intake. ► Crocin protects against BeCl2-intoxication in rats.
Background and Aims: Regional analgesia may play a role in pain management during breast surgery. Ultrasound approach to paravertebral block may be challenging. This study compared success rates of ...ultrasound-guided erector spinae plane block (ESPB) versus parasagittal in-plane thoracic paravertebral block among senior anaesthesia residents in modified radical mastectomy. Methods: One hundred and two female patients undergoing modified radical mastectomy were randomly categorized into PARA group receiving sagittal in-plane paravertebral block and ESPB group receiving erector spinae plane block. The block in the 1st six cases in each group was done by an experienced consultant as a demonstration for three anaesthesia residents not experienced in either block. Primary endpoint was assessing success rate of the blocks. Secondary endpoint was the haemodynamic response to skin incision and postoperative analgesia. Results: All patients were females undergoing modified radical mastectomy. Success rate among residents was 100% in ESPB versus 77.8% in PARA group (P = 0.002). Duration to perform the block was less in ESPB group (4.39 ± 1.2 min) than PARA group (8.18 ± 2.42 min) (P< 0.0001). Guidance frequency by consultants was significantly higher in PARA than ESPB group. Time to 1st analgesic requirement and morphine consumption postoperatively were insignificant between the groups. There was no significant difference regarding haemodynamics. Conclusion: ESPB may be a simple and safe alternative to parasagittal in-plane paravertebral block to provide postoperative analgesia in modified radical mastectomy especially in novice practitioners. It provides equivalent profile of postoperative analgesia with less time to perform the block.
We consider large-scale wireless sensor networks with n nodes, out of which k are in possession, (e.g., have sensed or collected in some other way) k information packets. In the scenarios in which ...network nodes are vulnerable because of, for example, limited energy or a hostile environment, it is desirable to disseminate the acquired information throughout the network so that each of the n nodes stores one (possibly coded) packet so that the original k source packets can be recovered, locally and in a computationally simple way from any k(1 + ¿) nodes for some small ¿ > 0. We develop decentralized Fountain codes based algorithms to solve this problem. Unlike all previously developed schemes, our algorithms are truly distributed, that is, nodes do not know n, k or connectivity in the network, except in their own neighborhoods, and they do not maintain any routing tables.
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New nanocomposite material containing TiO2/Poly (acrylamide–styrene sodium sulfonate) TiO2/(P (AAm–SSS) was prepared by in-situ intercalative polymerization of poly acrylamide (PAAm) ...and styrene sodium sulfonate (SSS) in the presence of TiO2 nanoparticles as inorganic filler. N, N-methylene bis acrylamide (MBA) was used as a cross linker. The polymerization process was performed using γ-radiation as reaction initiator. Moreover, new nanocomposite material containing poly styrene–TiO2 (PS–TiO2) was also prepared by ionic polymerization method. Styrene was catalytically polymerized by Ti4+ via an ionic polymerization route to produce polystyrene (PS). The structure characteristics of the nanocomposites were investigated by XRD, TGA, SEM, surface area, and FTIR. The nanoparticles and nanocomposites were investigated for removal of some metal ions from aqueous solutions. The effective key parameters on the sorption behavior of radioactive cesium (Cs+), cobalt (Co2+) and europium (Eu3+) were investigated using batch equilibrium technique with respect to solution pH and contact time. The obtained results revealed that the equilibrium for Cs+, Co2+ and Eu3+ is reached at 2–3h for all nanocomposites. The data indicated that there is no significant change in the uptake between TiO2 nanoparticles and TiO2–PS. On the contrary, the uptake process is significantly improved using TiO2/(P (AAm–SSS) nanocomposite and the maximum experimental retention capacities for Cs+, Co2+ and Eu3+ were found to be 120, 100.9 and 85.7mg/g, respectively.
Cancer is the most frequent life-threatening disease which has the highest mortality rate throughout the world. Diagnosis of cancer at the early stage can plays a critical role for its effective and ...successful treatment. Traditional diagnostic methods for cancer screening are costly, time-consuming, and not practical for repeated screenings. However, a biomarker-based cancer diagnosis is emerging as one of the most promising strategies for early diagnosis, monitoring disease progression, and subsequent cancer treatment. This review describes the recent advances and improvements in the electrochemical biosensors designed for detecting various cancer biomarkers using different signal transduction techniques and biological recognition strategies.
•Electrochemical biosensor helps to early diagnosis of cancer biomarkers.•Different electrochemical transduction system strategies are well explained.•More than 75 recent research articles on biosensors for cancer biomarker detection have been reviewed.•The advantages and future perspectives of each biosensor are highlighted.
Gas sensors are important in many fields such as environmental monitoring, agricultural production, public safety, and medical diagnostics. Herein, Tamm plasmon resonance in a photonic bandgap is ...used to develop an optical gas sensor with high performance. The structure of the proposed sensor comprises a gas cavity sandwiched between a one-dimensional porous silicon photonic crystal and an Ag layer deposited on a prism. The optimised structure of the proposed sensor achieves ultra-high sensitivity (S = 1.9×10
nm/RIU) and a low detection limit (DL = 1.4×10
RIU) compared to the existing gas sensor. The brilliant sensing performance and simple design of the proposed structure make our device highly suitable for use as a sensor in a variety of biomedical and industrial applications.
•Boric acid, malic acid and citric acid were used to leach Ln-Y from PGF.•Different parameters affecting citric acid leaching were investigated.•1.0 mol/L citric acid solution was found to be the ...most efficient leaching solution for Ln-Y from PGF than other acids.•At optimum conditions, three stages was developed and successfully tested to leach more than 80% total Ln-Y from PGF.
Phosphogypsum (PG) precipitates as a by-product of the phosphoric acid industry when treating phosphate rocks with H2SO4. Lanthanides and trivalent yttrium content, Ln-Y, in the rock are mostly found in the PG. After a slight modification of the precipitated PG, some portion of the PG containing ˜2.0% P2O5 is used as a low-grade phosphogypsum fertilizer (PGF). In this work, studies on Ln-Y, leaching from PGF were carried out using different concentration of weak acids such as boric acid, malic acid and citric acid at different retention time (Rt). It was found that the leaching efficiency of the total Ln-Y by citric acid solution is more favorable than that using boric or malic acid solutions. In this concern, 1.0 mol/L citric acid solution leach about 40.9% of Ln-Y, when the acid volume (L) to solid mass of PGF (S) ratio equals 2.0, L/S = 2.0, after Rt of 15 min at temperature of 298.0 K. Therefore, leaching of total Ln-Y from PGF by citric acid was investigated in terms of the acid concentration, Rt, and L/S as well as temperature. It is found that one leaching cycle by 1.0 mol/L citric acid solution using L/S ratio of 5.0 and Rt 15.0 min at temperature of 358 K, produced 53.3% from the total Ln-Y present in the used PGF sample. From these result a flow sheet was developed based on three leaching cycles to give a maximum leaching efficiency of 83.4%. Analysis of different Ln-Y in the final product indicated that 1.0 mol/L citric acid solution has high leaching selectivity for Er (89.4%), Ce (88.2%) and La (81.8%) and lower leaching selectivity for Pr (71.9%) and Y(40.7%).
Falciparum malaria is initiated when Anopheles mosquitoes transmit the Plasmodium sporozoite stage during a blood meal. Irradiated sporozoites confer sterile protection against subsequent malaria ...infection in animal models and humans. This level of protection is unmatched by current recombinant malaria vaccines. However, the live-attenuated vaccine approach faces formidable obstacles, including development of accurate, reproducible attenuation techniques. We tested whether Plasmodium falciparum could be attenuated at the early liver stage by genetic engineering. The P. falciparum genetically attenuated parasites (GAPs) harbor individual deletions or simultaneous deletions of the sporozoite-expressed genes P52 and P36. Gene deletions were done by double-cross-over recombination to avoid genetic reversion of the knockout parasites. The gene deletions did not affect parasite replication throughout the erythrocytic cycle, gametocyte production, mosquito infections, and sporozoite production rates. However, the deletions caused parasite developmental arrest during hepatocyte infection. The double-gene deletion line exhibited a more severe intrahepatocytic growth defect compared with the single-gene deletion lines, and it did not persist. This defect was assessed in an in vitro liver-stage growth assay and in a chimeric mouse model harboring human hepatocytes. The strong phenotype of the double knockout GAP justifies its human testing as a whole-organism vaccine candidate using the established sporozoite challenge model. GAPs might provide a safe and reproducible platform to develop an efficacious whole-cell malaria vaccine that prevents infection at the preerythrocytic stage.
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