Predicting PVT properties of Egyptian crude oils by a modified Soave–Redlich–Kowng equation of state

The study aims to predict the physical properties of Egyptian crude oils using modified Soave–Redlich–Kowng equation of state. The modification was theoretically developed and then performed by using data of 43 black oil samples representing all active oil producing areas of Egypt. The equation enables to predict the bubble-point pressure, oil formation volume factor, gas–oil ratio, oil density, crude oil gravity, gas gravity and gas formation volume factor of black oils with average relative errors ranging from 0.01% to 10.713%.Calculation sensitivity of the proposed MSRKE is determined by testing four oil samples collected from different locations in Egypt and comparing the measured PVT properties with those calculated from MSRKE. These evaluations show an excellent agreement between the measured properties and calculated ones.The estimation of reservoir liquid and gas properties from MSRKE is often needed when detailed laboratory PVT data are not available.     

Design and testing of SMA temperature-compensated cavity resonators

In this paper, we present a method for designing temperature-compensated cavity resonators using shape memory alloys (SMAs). This paper gives an expression for the temperature drift of resonant frequency, which is valid for any conductor-loaded cavity regardless of its shape. This formula, combined with a field perturbation model, is used to derive the resonant frequency of an SMA-compensated resonator subject to temperature fluctuation. Experimental results are given that confirm the feasibility of the proposed design approach. A design method is proposed for specifying SMA alloys to build the actuator. An expression is derived to accurately predict the performance of an actuator design.     

Bioactive lipids and antioxidant properties of wild Egyptian Pulicaria incise, Diplotaxis harra, and Avicennia marina

Fatty acids, sterols and tocopherols profile of Pulicaria incise, Diplotaxis harra and Avicennia marina grown wild in Egypt were investigated. Linoleic acid followed by palmitic and oleic acids were the major fatty acids in P. incise. Oleic followed by stearic were the main acids in D. harra, while palmitic followed by oleic were the major fatty acids found in A. marina. Sterol markers of P. incise were campesterol followed by stigmasterol and β-sitosterol. In D. harra β-sitosterol followed by stigmasterol and ?5-avensterol were the major sterols, while campesterol followed by β-sitosterol and ?7-avensterol were main sterols of A. marina. Tocopherols were also estimated in high levels, wherein δ-tocopherol was the main tocopherol in all plants. Antioxidant properties of methanolic extracts of the plants were compared with methanolic solution of butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and ascorbic acid during thiocyanate assay. Moreover, methanolic extracts of the whole plants exhibited strong antiradical potential against DPPH radicals. Information provided by the present study is of importance for further investigations of P. incise, D. harra and A. marina and utilization of these plants as a raw material of bioactive compounds.     

Variations in tomato (Lycopersicon esculentum) cultivars grown under heat stress

Tomato (Lycopersicon esculentum Mill) is considered as important and economic agricultural crop all over the world. For improving the yield and yield attributes, varieties are often produced and evaluated under different growth condition. In the study presented morphological (growth and yield parameters), biochemical (oil, moisture content and radical scavenging activity) and molecular diversity (RAPD and ISSR) of eleven freshmarket tomato (L. esculentum) cultivars (Aledo VF, Carmeuco 201M, Castle-rock, Falkon, Money Maker, Peto 86, Red Star, Super Marmande, Super Queen, Super Strain B, and UC97–3) were analyzed under heat stress in Egypt to assist breeders in selecting heat tolerant cultivars and nutritional quality. Cultivars Aledo, Peto86 and Red Star were found to have the most vigorous growth habit, while cv. Super Queen has the most significant average fruit weight, yield/plant and total yield/m² under heat stress. For nutritional quality cv. Super marmande and cv. Aledo showed the highest oil content while cv. Aledo and cv. Money Maker showed the highest radical scavenging activities (RSA). Molecular polymorphism among cultivars was detected using two molecular markers systems, RAPD (random amplified polymorphic DNA) and ISSR (inter-simple sequence repeat), providing further facilities for molecular comparison.     

New Approaches for Estimation of Monthly Rainfall Based on GEP-ARCH and ANN-ARCH Hybrid Models

Accurate estimation of rainfall has an important role in the optimal water resources management, as well as hydrological and climatological studies. In the present study, two novel types of hybrid models, namely gene expression programming-autoregressive conditional heteroscedasticity (GEP-ARCH) and artificial neural networks-autoregressive conditional heteroscedasticity (ANN-ARCH) are introduced to estimate monthly rainfall time series. To fulfill this purpose, five stations with various climatic conditions were selected in Iran. The lagged monthly rainfall data was utilized to develop the different GEP and ANN scenarios. The performance of proposed hybrid models was compared to the GEP and ANN models using root mean square error (RMSE) and coefficient of determination (R²). The results show that the proposed GEP-ARCH and ANN-ARCH models give a much better performance than the GEP and ANN in all of the studied stations with various climates. Furthermore, the ANN-ARCH model generally presents better performance in comparison with the GEP-ARCH model.     

Impact of Climate Change on Future Flood Susceptibility: an Evaluation Based on Deep Learning Algorithms and GCM Model

Floods are common and recurring natural hazards which damages is the destruction for society. Several regions of the world with different climatic conditions face the challenge of floods in different magnitudes. Here we estimate flood susceptibility based on Analytical neural network (ANN), Deep learning neural network (DLNN) and Deep boost (DB) algorithm approach. We also attempt to estimate the future rainfall scenario, using the General circulation model (GCM) with its ensemble. The Representative concentration pathway (RCP) scenario is employed for estimating the future rainfall in more an authentic way. The validation of all models was done with considering different indices and the results show that the DB model is most optimal as compared to the other models. According to the DB model, the spatial coverage of very low, low, moderate, high and very high flood prone region is 68.20%, 9.48%, 5.64%, 7.34% and 9.33% respectively. The approach and results in this research would be beneficial to take the decision in managing this natural hazard in a more efficient way.

     

Improvement in volume resistivity and morphology of a blend of polyolefin elastomer with linear low-density polyethylene

A silane moisture-cured polyolefin elastomer/linear low-density polyethylene (LLDPE) blend was prepared through a two-step silane-grafting method (Sioplas Process) in an industrial scale twin-screw extruder. The silane-grafted compound was used to make wire and cable coatings. In this work, the effect of some interactive parameters on quality of the products prepared by the above method has been studied, while so far, there have been less experimental investigations. The volume resistivity of cross-linked compound was changed from 2.96 × 10¹⁴ to 7.41 × 10¹⁴ Ω cm with increasing LLDPE component by maximum 10 wt%. Surface morphology of the product was corrected with reduction in benzoyl peroxide (BPO) concentration from 0.2 wt% to 0.13 wt%. BPO at this level acted as an initiator in grafting reaction of vinyl trimethoxysilane. The curing condition and specimen preparation method by injection molding and/or extrusion were factors which influenced the hot-set test results at 200 °C. The results of tensile and elongation studies showed a maximum value of 9 MPa and 397% for the tests, after 6 h curing. With increases in curing time at a specified temperature, the gel content of the cross-linked compound was increased and reached its maximum value. The maximum gel content values were found to be approximately 60%, 80%, and 82% at temperatures of 25, 60, and 85 °C, respectively. The hardness, density, and tear strength of the samples did not vary significantly with the curing temperature.

     

Dynamic security constrained optimal power flow/VAr planning

Traditionally security constrained optimal power flow and VAr planning methods consider static security observing voltage profile and flow constraints under normal and post contingency conditions. Ideally, these formulations should be extended to consider dynamic security. This paper reports on a BC Hydro/CEPEL joint effort establishing a dynamic security constrained OPF/VAr planning tool which considers simultaneously static constraints as well as voltage stability constraints. This paper covers the details of formulation and implementation of the tool together with the test results on a large scale North American utility system and a reduced Brazilian system