Improving the Potable Water from Tubular Solar Still Using Eggshell Powder as an Natural Energy Storage Medium - An Experimental Approach

It seems like every hour, there is a greater need for fresh water. The demand for fresh water is rapidly growing as a consequence of the expanding population and the increased urbanization of the world's population. The tubular solar still offers much larger evaporative and condensing surface areas than normal single slope solar still. The scope of this study is to improve the performance of tubular solar still by employing eggshells as the bed material, which has good heat absorption properties. Results showed that the influence of eggshell powder as energy storage material in the basin improved the average water temperature by 10.8, 10.9, and 8.73% for the water thickness of 10, 15, and 20 mm respectively. The usage of eggshells as an energy store in the basin results in an increase of about 60.77 % potable water produced. The maximum observed distillate output from the solar still is 0.6 kg for solar stills with eggshell powder as energy storage material and 0.34 kg for solar stills without eggshell powder in the absorber of TSS at peak solar radiation and at the lowest water thickness of 10 mm. The hourly potable water generated from TSS using eggshell as an energy storage material increased by roughly 47% compared to the flat absorber without eggshell powder. TSS with eggshell powder as energy storage has a daily energy efficiency of 79.19, 75.49, and 44.18 % for water thicknesses of 10, 15, and 20 mm in the basin. Tubular solar still using eggshell as energy storage material and tubular solar still without any material produced 3.62 kg and 1.42 kg average yields at a water thickness of 10 mm. Water thickness of 10, 15, and 20 mm has performance improvement ratios of 2.54, 2.51, and 2.18 respectively.

Crystal structures of glycogen-debranching enzyme mutants in complex with oligosaccharides

Debranching is a critical step in the mobilization of the important energy store glycogen. In eukaryotes, including fungi and animals, the highly conserved glycogen-debranching enzyme (GDE) debranches glycogen by a glucanotransferase (GT) reaction followed by a glucosidase (GC) reaction. Previous work indicated that these reactions are catalyzed by two active sites located more than 50 Å apart and provided insights into their catalytic mechanisms and substrate recognition. Here, five crystal structures of GDE in complex with oligosaccharides with 4–9 glucose residues are presented. The data suggest that the glycogen main chain plays a critical role in binding to the GT and GC active sites of GDE and that a minimum of five main-chain residues are required for optimal binding.

Enhancing The Hemispherical Solar Distiller Performance Using Internal Reflectors And El Oued Sand Grains As Energy Storage Mediums

The current comprehensive work deals with different solutions, all of which aim to overcome the problem of low productivity of drinking water from solar distillers. Experimental work was carried out on hemispherical distillers which are characterized by a large area of receiving and condensation. This study presented the results of two experimental scenarios to illustrate the influences of internal reflective on hemispherical distiller’s performance in the first scenario. In the second scenario, the influences of internal reflective with El-Oued sand grains as the energy store medium on hemispherical distiller performances was studied. Two experimental scenarios aim to achieve the best configurations that achieve a highest hemispherical distillers performances. To achieves this goal, we designed and fabricated the three hemispherical distillers, the first distiller represents the reference case (Conventional Hemispherical Solar Still - CHSS), the second is the Hemispherical Solar Still with Internal Reflective Mirrors and El-Oued sand grains (HSS-IRM & SG), and a third is the Hemispherical Solar Still with Internal Reflective Aluminum Foil and El-Oued sand grains (HSS-IRAF & SG). The results presented that the cumulative production of reference distiller (CHSS) up to 4750 mL/m2, while use of internal reflective mirrors and El-Oued sand grains (HSS-IRM & SG) increases the production to 9400 mL/m2 day. The maximum improvement in cumulative distillate production, exergy efficiency, and thermal efficiency was recorded for utilization of internal reflective mirrors and El-Oued sand grains (HSS-IRM & SG) which reached 98, 200.9, and 96%, respectively, compared to reference case (CHSS).

An Evolutionary Optimization Algorithm to Planning the Time of Delivery Schedule and Factor in a Hydroelectric Power Plant with Battery Energy Storage Capability

The modernization of regulation and legislation rules of the power systems in nowadays is partially due the penetration of renewable resources generation and an energy store capability. The generation based on alternative source has an intermittent pattern and its linkage with a hydroelectric generation plant should be considered in the expansion of generation matrix. Some pioneer projects are conducted in Brazil that confirms this relevance. The battery energy storage is another functionally possible today and must be considered in the technical and economic analysis. This paper presents a method based on evolutionary approach that intends to optimize a time of delivery schedule and factor with objective of the decrease the payback time. In front of the optimized time of delivery schedule and factor is proposed an optimal law of control of a battery storage system. Experimental data was employed and the results reached could be used to better operate energy storage systems and deal with regulation aspects.

Attenuation of DC-Link Pulsation of a Four-Wire Inverter during Phase Unbalanced Current Operation

This paper proposes a control algorithm for a hybrid power electronic AC/DC converter for prosumer applications operating under deep phase current asymmetry. The proposed system allows independent control of active and reactive power for each phase of the power converter without current pulsation on the DC link connected to an energy store. The system and its algorithm are based on a three-phase converter in four-wire topology (AC/DC 3p-4w) with two dual-active bridge (DC/DC) converters, interfaced with a supercapacitor and an energy storage. The control algorithm tests were carried out in a Hardware in the Loop environment. Obtained results indicate that operation with deep unbalances and powers of opposite signs in individual phases leads to current oscillations in the DC link. This phenomenon significantly limits energy storage utilization due to safety and durability reasons. The proposed algorithm significantly reduces the level of pulsation in the DC link which increases safety and reduces strain on lithium-ion storage technology, enabling their application in four-wire converter applications.

The Role of Lipid Metabolism in COVID-19 Virus Infection and as a Drug Target

The current Coronavirus disease 2019 or COVID-19 pandemic has infected over two million people and resulted in the death of over one hundred thousand people at the time of writing this review. The disease is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Even though multiple vaccines and treatments are under development so far, the disease is only slowing down under extreme social distancing measures that are difficult to maintain. SARS-COV-2 is an enveloped virus that is surrounded by a lipid bilayer. Lipids are fundamental cell components that play various biological roles ranging from being a structural building block to a signaling molecule as well as a central energy store. The role lipids play in viral infection involves the fusion of the viral membrane to the host cell, viral replication, and viral endocytosis and exocytosis. Since lipids play a crucial function in the viral life cycle, we asked whether drugs targeting lipid metabolism, such as statins, can be utilized against SARS-CoV-2 and other viruses. In this review, we discuss the role of lipid metabolism in viral infection as well as the possibility of targeting lipid metabolism to interfere with the viral life cycle.

Acquiring electric energy from the transport conveyor roller movement for distributed sensors network

The paper presents the concept of installation of an electricity generator and en energy store inside a roller of belt or roller conveyor. Accordingly, the use of a generator-pulley does not require any structural changes to be made to an existing conveyor. In addition, the user will be able to power distributed sensors network for monitoring the operation of the belt conveyor anywhere on its route.

Flight Strategy Optimization for High-Altitude Solar-Powered Aircraft Based on Gravity Energy Reserving and Mission Altitude

High-altitude long-duration (HALE) flight capability is one of the ultimate goals pursued by human aviation technology, and the high-altitude solar-powered aircraft (SPA) is the most promising technical approach to achieve this target as well as wide application prospects. Due to the particularity of the energy system, the flight strategy optimization through the storage of gravity potential energy and other methods is a significant way to enhance the flight and application abilities for the SPA. In this study, a flight strategy optimization model has been proposed for the aim of HALE flight capability, which is based on the gravity energy reserving and mission altitude in practical engineering applications. This integrated model contains the five flight path phase model, the three-dimensional kinematic model, aerodynamic model, solar irradiation model and energy store and loss model. To solve the optimization problem of three-dimensional flight strategy, the Gauss pseudo-spectral Method (GPM) was employed to establish and calculate the optimal target as its advantages in treating process constraints and terminal constraints for the multiphase optimization problem. At last, the flight trajectory optimization with minimal battery mass for Zephyr 7 was studied by the GPOPS with some function files in MATLAB. The results indicate that the Zephyr 7 can reduce the battery mass from 16 kg to 12.61 kg for the day and night cycle flight and missions, which equals to increasing the battery specific energy by 23.1%. Meanwhile, the optimization results also show that the attitude angel may contribute to increasing the energy gained by photovoltaic cells. In addition, this optimized flight strategy brings the possibility of monthly or annual continuous flight for SPA as the simulation date is set to the autumnal day.