Thermal performance enhancement of evacuated tube solar collector using MWCNT, Al2O3, and hybrid MWCNT/ Al2O3nanofluids

Nanofluids have numerous applications in heat transference procedures due to their exceptional thermal characteristics. The most desirable parameter to enhance the solar collector's performance is the enhancement of the convective heat transfer coefficient between the working fluid tubes and the absorber. As a result, nanofluids have gained prominence as working fluids in solar thermal systems. The trendsetting review reveals that mostly the nanofluids in solar collectors are based on water employing nanoparticles of Al2O3, TiO2, SiO2, and CuO. Besides, nanoparticle concentration is a challenging factor in using nanofluids. In this research, under controlled conditions, the working fluids multi-wall carbon nanotube, Aluminum Oxide, and hybrid MWCNT/Al2O3 50:50% were experimentally examined for the thermal efficiency enhancement of the evacuated tube solar collector. For each type of nanofluid, four volume concentration percentages (0.5%, 0.025%, 0.01%, and 0.005%) were examined along with three distinct mass flow rates. According to the findings, using hybrid MWCNT/Al2O3 50:50% delivers an efficiency boost of about 20% overusing Al2O3, as was previously reported. Finally, it was found that the utilization of 0.5% MWCNT/water nanofluid at 3.5 L/m can enhance the ETSC's energy and exergy efficiency to reach 73.5% and 51% respectively while reaching approximately 60% and 44% for AL2O3, and 69% and 38% for hybrid MWCNT/Al2O3 (50:50%) under the same test conditions

Production of Prednisolone by Pseudomonas oleovorans Cells Incorporated Into PVP/PEO Radiation Crosslinked Hydrogels

In order to rise the yield of prednisolone from hydrocortisone, the Pseudomonas oleovorans cells were entrapped into radiation crosslinked poly (vinyl pyrrolidone)/poly(ethylene oxide) (PVP/PEO) hydrogel of different gel contents. The factors affecting the gel content and swelling behavior of the polymeric gel, such as polymer composition, polymer blend concentration, and irradiation doses, were investigated. The formation of gels having a good strength with the ability to retain a desirable amount of water in their three-dimensional network can be achieved by using PVP/PEO copolymer of composition (90 : 10) and concentration of 15% prepared at 20 kGy irradiation dose. At these conditions the prepared hydrogel is considered the most favorable one that gave the highest hydrocortisone bioconversion and prednisolone yield, 81% and 62.8%, respectively. The improvement of prednisolone yield was also achieved by increasing substrate concentration. Maximum hydrocortisone bioconversion (86.44) was obtained at 18 hours by using substrate concentration of 30 mg. Reusability of immobilized Pseudomonas oleovorans entrapped into PVP/PEO copolymer hydrogel was studied. The results indicated that the transformation capacity of hydrocortisone to prednisolone highly increased by the repeated use of copolymer for 4 times. This was accompanied by an increase in prednisolone yield to 89% and the bioconversion of hydrocortisone was 98.8%

(E)-4-[(5-Methyl-2-fur­yl)methyl­ene­amino]benzene­sulfonic acid

The title compound, C12H11NO4S, is a Schiff base derived from the condensation reaction of equimolar quanti­ties of sulfamide and furfural. The mol­ecule has a trans configuration with respect to the imine C=N double bond. The N atom is involved in an inter­molecular O—H—N hydrogen bond

Application of block Krylov subspace algorithms to the Wilson-Dirac equation with multiple right-hand sides in lattice QCD

It is well known that the block Krylov subspace solvers work efficiently for some cases of the solution of differential equations with multiple right-hand sides. In lattice QCD calculation of physical quantities on a given configuration demands us to solve the Dirac equation with multiple sources. We show that a new block Krylov subspace algorithm recently proposed by the authors reduces the computational cost significantly without loosing numerical accuracy for the solution of the O(a)-improved Wilson-Dirac equation.Comment: 12 pages, 5 figure

Inhibitive action of Cystine on the corrosion of low alloy steel ASTM A213 grade T22 in sulfamic acid solutions

AbstractThe effect of Cystine on the corrosion behavior of low alloy steel ASTM A213 grade T22 in 0.5M sulfamic acid solutions have been investigated by various electrochemical techniques. The study was performed using electrochemical impedance spectroscopy (EIS) and the recent technique electrochemical frequency modulation (EFM). The results of the investigation show that the inhibition efficiency increased with increasing inhibitor concentration, but decreased with increasing the solution temperature and stirring velocity. All the collected results from the two techniques are in good agreements, which confirm the ability of EFM technique for monitoring the corrosion inhibition under the studied conditions

Preparation of Low Molecular Weight Natural Polymers by gamma-Radiation and Their Growth Promoting Effect on Zea Maize Plants

Preparation of oligosaccharides from chitosan and Na-alginate were done using ?-rays and H2O2 as oxidizing agent. Structural and molecular weight changes of such oligosaccharides were determined by GPC, FT-IR and UV-Vis. spectroscopy. FT-IR and UV-Vis. studies revealed that during radiation degradation process, the main polysaccharide chain structure was almost remained. The effects of spraying 100 ppm of oligochitosan or oligoalginate or both of them with different ratios on the growth of zea maize plants showed an enhancement of plant growth performance and the productivity at the same time suggesting their possible use in agriculture purposes as growth promoters for plants

Environmental studies on coastal zone soils of the north Sinai peninsula (Egypt) using remote sensing techniques

The northern part of the Sinai peninsula is one of the most strategic projects for agriculture extension in Egypt. This project (the El-Salam Canal) supplies about 168.000 hectares soils with mixed water from the Nile and agricultural drainage water to reclaim and cultivate these soils. The principle goals of this study are the environmental study and soil survey of the coastal zone soils along the El-Salam Canal project to assess the development activities in this area and evaluate the soils of project. To achieve this aims, image data analysis of remote sensing data (Landsat TM) was performed. In addition to this, field soil survey were done through field work trips, meteorological, hydrological, physical and chemical soil analysis. This work of study reports on how remote sensing data together with a land evaluation system can be used to assess the quality of the soils in this area for agricultural use. The results show that remote sensing data is a very efficient way to evaluate large areas quickly and with sufficient accuracy. In addition to fieldwork, using of satellite images is necessary to construct a soil map for the north Sinai. The results of such as evaluation process will help developing countries like Egypt, specially in the northern part of the Sinai peninsula area, to put their scarce resources on the most rewarding land in order to speed up the process of improving the welfare of the country and especially the rural population. The supervised classes by the maximum likelihood algorithm method in the studied areas were discriminated from the Landsat TM images about 19 classes in the north Sinai total area The correlation coefficient relationships among spectral properties bands and soil properties are as Band 4 more correlated with EC, CEC, CaCO3, Gypsum and soil texture.The contour line image maps were achieved from the Landsat TM image and the results of the soil properties, such as EC, CEC, OM, CaCO3, Gypsum and pH values in the studied area.Das starke Bevölkerungswachstum in Ägypten führt zu der Notwendigkeit, neue Flächen für die landwirtschaftliche Produktion zu gewinnen, um ausreichend Lebensmittel produzieren zu können. Der nördliche Bereich der Sinai-Halbinsel ist eine der bedeutendsten Regionen für die Neulandgewinnung in Ägypten. Durch das El-Salam Kanal Projekt sollen 168000 Hektar Land mit einer Mischung aus Nil- und Drainage-Wasser versorgt werden, um die dortigen Böden zu kultivieren. Das Ziel dieser Studie war eine Bewertung der Böden entlang des El-Salam Kanals hinsichtlich ihrer natürlichen Eigenschaften und ihrer Nutzbarkeit für eine landwirtschaftliche Bearbeitung. Zu diesem Zweck wurden im Untersuchungsgebiet Bodenproben gezogen und bodenphysikalisch und chemisch analysiert. Satellitenbilddaten (Landsat TM) wurden klassifiziert und mit den Bodendaten in Beziehung gesetzt. Des weiteren wurden meteorologische und hydrologische Daten analysiert. Abschließend wurde die Eignung der Böden für die landwirtschaftlich Nutzung evaluiert. Die Ergebnisse zeigen, daß mit Hilfe von Fernerkundungsdaten sehr effizient größere Regionen mit einer ausreichender Genauigkeit bewertet werden können. Zudem wurde eine Bodenkarte für das nördliche Sinai hergestellt. Die Ergebnisse einer solchen Bodenbewertung helfen Entwicklungsländern wie Ägypten, ihre knappen Ressourcen auf erfolgversprechende Flächen zu konzentrieren, um die Lebensbedingungen, insbesondere die der ländlichen Bevölkerung, nachhaltig zu verbessern. Eine überwachte Maximum Likelihood Klassifikation der Satellitenbilder führte zu folgenden Klassen (19 Klassen) für den gesamten nördlichen Sinai konnten. Die Beziehungen zwischen den Spektralbändern und den Bodeneigenschaften waren im Einzelnen Band 1 Korrelation mit der organischen Substanz, Band 3 Korrelation mit elektrischer Leitfähigkeit, KAK und Gips, Band 4 Korrelation mit elektrischer Leitfähigkeit, KAK, Kalziumcarbonat, Gips und der Bodentextur