Remote Sensing Satellites Planning System

A Remote Sensing Satellites Planning system (RSSP) for satellite constellations is responsible for managing these satellites by assigning the imaging tasks to each satellite in the constellation such that the loads are balanced and the resources are well used. The proposed system can be used with heterogeneous constellations that consist of satellites whose different specifications, different orbits' types and/or different payload types. This problem is a combinatorial optimization NP-hard problem modeled in this paper as a Constraint Satisfaction Problem using the Constraint Programming Technique. The output plan is obtained using one of three objective functions (gain maximization, area maximization, and image quality maximization) using four search algorithms (simulated annealing, hill climbing, tabu search and late acceptance) and different planning horizons (one track, one day and one month)

Frequency-dependent magnetotransport and particle dynamics in magnetic modulation systems

We analyze the dynamics of a charged particle moving in the presence of spatially-modulated magnetic fields. From Poincare surfaces of section and Liapunov exponents for characteristic trajectories we find that the fraction of pinned and runaway quasiperiodic orbits {\em vs}. chaotic orbits depends strongly on the ratio of cyclotron radius to the structure parameters, as well as on the amplitude of the modulated field. We present a complete characterization of the dynamical behavior of such structures, and investigate the contribution to the magnetoconductivity from all different orbits using a classical Kubo formula. Although the DC conductivity of the system depends strongly on the pinned and runaway trajectories, the frequency response reflects the topology of all different orbits, and even their unusual temporal behavior.Comment: Submitted to PRB - 14 figure files - REVTEX tex

Energy, Exergy, and Environmental (3E) Analysis of Hydrocarbons as Low GWP Alternatives to R134a in Vapor Compression Refrigeration Configurations

The phase-down of hydrofluorocarbons and substitution with low global warming potential values are consequences of the awareness about the environmental impacts of greenhouse gases. This theoretical study evaluated the energy and exergy performances and the environmental impact of three vapor compression system configurations operating with the hydrocarbons R290, R600a, and R1270 as alternatives to R134a. The refrigeration cycle configurations investigated in this study include a single-stage cycle, a cycle equipped with an internal heat exchanger, and a two-stage cycle with vapor injection. According to the results, the alternative hydrocarbon refrigerants could provide comparable system performance to R134a. The analysis results also revealed that using an internal heat exchanger or a flash tank vapor injection could improve the system’s efficiency while decreasing the heating capacity. The most efficient configuration was the two-stage refrigeration cycle with vapor injection, as revealed by the exergy analysis. The environmental impact analysis indicated that the utilization of environmentally-friendly refrigerants and improving the refrigeration system’s efficiency could mitigate equivalent CO2 emissions significantly. The utilization of hydrocarbons reduced the carbon footprint by 50%, while a 1% to 8% reduction could be achieved using the internal heat exchanger and flash tank vapor injection

Numerical Experimental Investigation of Solidification Thickness around Cylindrical Surfaces for HVAC Cold Storage Systems

Thermal Ice Storage System (TISS) is an innovative way of storing night-time off-peak energy for daytime peak USAge. In many locations, demand for electrical power peaks during summer time. Air-conditioning equipment are the main reason accounting for as much as half of the power demand during the hot mid-day hours when electricity is most expensive. Since utilities have spare electrical generating capacity at night, electricity generated during this ldquo;off-peakrdquo; is much less expensive. In this research a numerical model for Latent Heat Storage (LHS) cylindrical tank has been obtained from a numerical package, ANSYS software ver. 15, and compared to an experimental data gathered from similar tank. The data showed good agreement with the experimental data with an error of 9%. The numerical model can be used to estimate ice thickness and tank geometries for any future work

MicroRNAs in Cardiac Hypertrophy

Like other organs, the heart undergoes normal adaptive remodeling, such as cardiac hypertrophy, with age. This remodeling, however, is intensified under stress and pathological conditions. Cardiac remodeling could be beneficial for a short period of time, to maintain a normal cardiac output in times of need; however, chronic cardiac hypertrophy may lead to heart failure and death. MicroRNAs (miRNAs) are known to have a role in the regulation of cardiac hypertrophy. This paper reviews recent advances in the field of miRNAs and cardiac hypertrophy, highlighting the latest findings for targeted genes and involved signaling pathways. By targeting pro-hypertrophic genes and signaling pathways, some of these miRNAs alleviate cardiac hypertrophy, while others enhance it. Therefore, miRNAs represent very promising potential pharmacotherapeutic targets for the management and treatment of cardiac hypertrophy. - 2019 by the authors. Licensee MDPI, Basel, Switzerland

ANN Modeling to Analyze the R404A Replacement with the Low GWP Alternative R449A in an Indirect Supermarket Refrigeration System

Artificial neural networks (ANNs) have been considered for assessing the potential of low GWP refrigerants in experimental setups. In this study, the capability of using R449A as a lower GWP replacement of R404A in different temperature levels of a supermarket refrigeration system is investigated through an ANN model trained using field measurements as input. The supermarket refrigeration was composed of two indirect expansion circuits operated at low and medium temperatures and external subcooling. The results predicted that R449A provides, on average, a higher 10% and 5% COP than R404A at low and medium temperatures, respectively. Moreover, the cooling capacity was almost similar with both refrigerants in both circuits. This study also revealed that the ANN model could be employed to accurately predict the energy performance of a commercial refrigeration system and provide a reasonable judgment about the capability of the alternative refrigerant to be retrofitted in the system. This is very important, especially when the measurement data comes from field measurements, in which values are obtained under variable operating conditions. Finally, the ANN results were used to compare the carbon footprint for both refrigerants. It was confirmed that this refrigerant replacement could reduce the emissions of supermarket refrigeration systems

ESSENTIAL OIL AND CHEMICAL CONESTITUENTS OF FENNEL PLANTS AS AFFECTED BY COMPOST/NPK AND BIOFERTILIZATION TREATMENTS

A field experiment was conducted during the two successive seasons of 2012/2013 and 2013/2014 to explore the effect of compost/NPK and biofertilization treatments on essential oil, photosynthetic pigments and herb NPK content of fennel plants. Obtained results revealed that the best three essential oil characteristics (essential oil %, essential oil yield per plant and per feddan), photosynthetic pigments (chlorophylls a, b and carotenoids) and herb content of N, P and K values were obtained due to the use of the full dose of mineral NPK, ¼ compost + ¾ NPK dose or ½ compost + ½ NPK dose with no significant differences being detected between such three fertilization treatments. Concerning biofertilization treatments, all of the prementioned essential oil determinations, photosynthetic pigments and herb NPK content traits were considerably augmented due to the dual treatment (Minia Azotein + phosphorein) followed by Minia Azotein, while phosphorein gave the least values. In regard to the interaction gave between the, two involved factors, the highest volatile oil determinations and chemical compositions values were given by fertilizing fennel plants with the full dose of mineral NPK, 25% compost + 75% NPK or 50% compost + 50% NPK in combination with dual biofertilizer treatments (Minia Azotein + phosphorein). It is recommended, to supply fennel plants with 50% compost + 50% NPK in combination with the dual biofertilization treatment (Minia Azotein + phosphorein), from the environmental and economical point of view, in order to maximize the fruit essential oil productivity

EFFECT OF COMPOST FERTILIZATION LEVELS ON GROWTH, YIELD AND CHEMICAL COMPOSITION OF SANDY SOIL GROWN AMMI VISNAGA PLANTS

The present investigation was conducted at the nursery of Fac. of Agric., Minia Univ. during the two successive seasons of 2014/2015 and 2015/2016 to explore the most suitable level of compost for Ammi visnaga plants grown in sandy soil. All studied vegetative growth characters (plant height, branch number and herb dry weight/plant); yield parameters (number of umbels/plant and seed yield per plant and per fed); and chemical constituents (photosynthetic pigments and herb percent and content of N, P and K) were gradually increased parallel to the increase in compost level added to the soil. However, no clear difference was obtained, for all prementioned traits, between the medium compost level (12.5 ton/fed) and the high one (17.5 ton/ fed). In general, seed yield per fed, due to medium or high compost rate was increased by about 30%