Absorption and Desorption of Hydrogen in Metal Hydrides

The purpose of this project is to study the reaction rate during the absorption process of hydrogen in metal hydrides. Magnesium Hydride (MgH2) was chosen to be the metal hydride material for the storage medium. A car was modelled to calculate the theoretical consumption of hydrogen fuel during an hour drive at a constant cruising speed. The reaction equilibrium constant was derived from Vant Hoff equation with variable values of operating conditions. Then, the rate equation role was to determine the reaction rate of the absorption process of hydrogen by magnesium. This report contains new aspects, which show the conditions of obtaining hydrogenation rates and represents new approach of improvement of hydrogen absorption process in light metals, such as magnesium, that can provide promising results for the hydrogen storage applications

Progressive collapse analysis of RC building frames with different seismic design levels

Progressive collapse prevention of buildings has recently become the focus of many researchers, design engineers, and officials all over the world particularly after the failure of the twin World Trade Center towers, New York City, USA in September 2001 and the increasing terrorist acts against governmental buildings. The progressive collapse is defined in the commentary of the American Society of Civil Engineers Standard 7-02 Minimum Design Loads for Buildings and Other Structures (ASCE 7-02) as “the spread of an initial local failure from element to element, eventually resulting in the collapse of an entire structure or a disproportionately large part of it . To date, there is no design code for blast resistant building design and progressive collapse prevention, but only design guideline sexist which are prepared by different bodies like Departments of defense (DoD) in USA as well as other countries and the General Service Administration (GSA) and the Federal Emergency Management Agency (FEMA). While design for progressive collapse prevention is possible at design stage, it becomes more challenging for already existing buildings. On the other hand, almost all recently designed and constructed buildings are designed for seismic resistance according to the seismic zone they are located in according to existing codes. Seismic design provisions allows for higher resistance to lateral reversible loads, and more ductility of structural frames and systems. Determining how much such provision adds to the building resistance to progressive collapse help when upgrading existing building for progressive collapse or when designing new ones. Furthermore, utilizing this seismic resistance and added ductility saves when designing for progressive collapse. This research focuses on identifying the effect of seismic design level on resisting progressive collapse. In this research the progressive collapse of three-story, multi-bay reinforced concrete structure is conducted. The procedure was conducted according to GSA and DoD guidelines. At first the building was designed according to Egyptian Code of Practice for design and construction of concrete structures (ECP203-2007). Three different levels of seismic design are considered by assuming that the building can be located in seismic zones 1, 3, and 5 according to the Egyptian Code for Calculating Loads and Forces on Structures and Buildings (201-2003). GSA guidelines and procedures are followed for progressive collapse analysis. All the three stages; gravity load, seismic load, and progressive collapse load analyses; are performed using commercially general purpose software computer program, SAP2000, that is available in the Construction lab, AUC. . Nonlinear static analysis was carried out where plastic hinges were allowed to form at designated locations of maximum moment. A total of 39 design and analysis case were considered and the results were analyzed to evaluate the effect of the different parameters on the building performance and its resistance to progressive collapse. The resistance to progressive collapse is measured by the number of formed plastic hinges and the resulting failed beams. The relationship between the seismic design levels, the slab thickness, number of formed plastic hinges and failed beams are presented graphically. The results showed that the vulnerability to progressive collapse becomes less as the seismic design level increased in higher seismic zone. This is mainly due to the increased member capacity, added ductility, and the seismic requirement for reinforcement details. It was also found that the slab membrane and bending actions contribute significantly in resisting progressive collapse and thus must be considered in the analysis

Comparative studies on the efficacy of lincomycin and bacitracin for the control of necrotic enteritis in broiler chickens

Background: The present study was conducted to evaluate the efficacy of lincomycin and/or bacitracin for control of experimentally-induced Clostridium perfringens (CP) infection in broiler chickens.Methods: A total of 100 one-day-old Cobb-mixed chicks were divided into five groups (A, B, C, D and E, each of 20 bird). At the 15th day of age, all birds (except group A) were inoculated orally with CP broth culture (109 CFU/mL). Two days later, drugs were orally administered once daily for five consecutive days as follow; Group A and B were left untreated. Group C, D, and E were treated with lincomycin (0.5 g/l), bacitracin (100 mg/l), lincomycin and bacitracin, respectively. The efficacy of used drugs was estimated based on clinical symptoms, body weight, weight gain, feed conversion rate. Hematobiochemical changes were also determined.Results: Necrotic enteritis in broiler chickens induced a significant decrease in body weight, weight gain, erythrocytic count, hemoglobin content, PCV %, serum proteins, catalase, and superoxide dismutase. Additionally, a marked decrease in serum lipids was obtained. Furthermore, a significant increase in feed conversion rate, leukocytic count, phagocytic activity, phagocytic index, serum total globulin, γ globulin and malondialdehyde coupled with a marked increase in β and α globulins were determined. Medication of infected broilers with lincomycin and/or bacitracin improved clinical signs and reduced mortality rate to 8, 6 and 2%, respectively, as well as restored the performance and hematobiochemical alterations.Conclusions: a combination of lincomycin and bacitracin was of considerable value for the control of necrotic enteritis in broiler chickens

Influence of alpha linolenic acid on the motility, viability, antioxidant activity and fertility of frozen-thawed New Zealand white rabbit buck semen

[EN] Freezing and thawing processes result in production and accumulation of high concentrations of reactive oxygen species that are detrimental to spermatozoal motility and fertility. Therefore, supplementation of exogenous source of antioxidants to freezing diluent is crucial. The aim of the present study was to investigate for the first time whether supplementation of semen diluent with alpha linolenic acid (ALA) can improve motility, viability, membrane integrity, antioxidant status and fertility of post-thaw rabbit spermatozoa. Semen was collected and pooled from fifteen New Zealand white rabbit bucks. Semen samples were diluted with a tris-citrate-glucose (TCG) extender supplemented with ALA (0, 50, 75 and 100 μmol). Then, extended rabbit semen was cooled at 5°C and cryopreserved in liquid nitrogen. After thawing, spermatozoal quality parameters (individual motility %, viability %, osmotic resistance %, and acrosome integrity %), antioxidant activity (SOD, CAT, and GSH activities), lipid peroxidation (malondialdehyde) and fertility (conception and kindling rates) were evaluated. Results revealed that supplementation of rabbit semen extender with 50 μmol ALA significantly (P<0.05) increased spermatozoal characteristics including motility (56.54%), viability (60.01%), acrosome status (72.66%) and membrane integrity (59.13%). The activity of semen antioxidant enzymes (SOD, CAT, and GSH) showed a significant improvement with a marked decrease in lipid peroxidation. Moreover, the conception (73.30%) and kindling (70.00%) rates were significantly (P<0.05) higher in does inseminated with thawed semen treated with 50 μmol ALA in comparison with other concentrations (0, 75 and 100 μmol). In summary, supplementation of rabbit semen extender with 50 μmol ALA improved motility, viability, membrane integrity, acrosome integrity, antioxidant enzymes activity and fertility of post-thaw rabbit spermatozoa. Our findings suggested that higher concentrations of ALA are detrimental to post-thaw characteristics of New Zealand white rabbit buck spermatozoa. To achieve better results, the semen freezing extender should be supplemented with ALA at lower concentrations, especially 50 μmol.El-Shahat, KH.; Fadl, AM.; Abdelnaby, EA. (2022). Influence of alpha linolenic acid on the motility, viability, antioxidant activity and fertility of frozen-thawed New Zealand white rabbit buck semen. World Rabbit Science. 30(3):219-226. https://doi.org/10.4995/wrs.2022.1704221922630

Evaluations of Ovarian and Luteal Blood Flow Waveform Patterns in Buffalos Subjected to OvSynch Protocol in Cold and Hot Seasons

This current study aimed to determine ovarian and luteal blood flow waveform patterns in buffalos synchronized using OvSynch protocol in cold and hot seasons. Six cyclic buffalo cows aged 6±0.5 years old, having a weight of 400 ± 50 kg, were scanned daily along three successive estrous cycles transrectally by Doppler ultrasonography to evaluate the normal ovarian hemodynamic during the normal spontaneous ovulation and before the start of experiments. Buffaloes were synchronized with gonadotropin[GnRH] –prostaglandin[P] –gonadotropin (GPG) protocol in which animals received 10μg of GnRH on day ??, 0.250μg of PGF2α on day 7, and another dose of 10μg of GnRH was administered 48h after the PGF2α injection. Blood sampling and ovarian ultrasound examinations (color and spectral Doppler modes) were conducted on the day of the estrous and luteal phases. Results revealed that peak systolic velocity waveform (PSV) was significantly (P&lt;0.05) increased in the cold season compared to the hot season. The Luteal blood flow after the end of OvSynch protocol on days (5,7,9, and 11) was significantly increased in the cold season than that in the hot one. The serum levels of estradiol (E2) and nitric oxide (NO) after the second GnRH injection in the OvSynch protocol were significantly (P&lt;0.05) elevated in the cold season as compared to the hot one. Moreover, the progesterone (P4) levels had risen in OvSynch-treated buffaloes on days 5,7,9, and 11 of the cycle in the cold season compared to the hot one. Conclusion: In the cold season, ovarian hemodynamics was significantly improved compared to the hot one; this may influence the reproductive efficiency of buffaloes. Further studies were needed to prove it

Platinum 1,10-phenanthroline: Photosensitizer for photocatalytic degradation of 4-chlorophenol

It is more economic to apply photodegradation of organic pollutants in presence of the visible light irradiation (sunlight) than applying more costfull ultraviolet lamps. Hence, platinum 1,10-phenanthroline complex has been prepared and tested as a photosensitizer for photodegrading 4-chlorophenol in water, which has been found almost completely achieved (98.5 %) after three hours of visible irradiation. Nevertheless, irradiation at 364 and 254 nm exhibits lower efficiencies. At visible irradiation, the platinum complex gives the highest activation of singlet state oxygen formation (1O2) compared to 364 and 254 nm irradiation as supported by electron para-magnetic resonance data. On the other hand, the behavior of formation and disappearance of photodegradation intermediates: hydroquinone, benzoquinone, hydroxybenzoquinone, using the platinum complex applying the three current irradiations are found to supports these findings. However, organic acids have accumulated as a function of irradiation time and hence considered to be rate-controlling

Adverse effects of energy drink on rat pancreas and the therapeutic role of each of bone marrow mesenchymal stem cells and Nigella Sativa oil

Background: Energy drinks have been observed to threaten public health leading to many medical problems. Bone marrow-derived mesenchymal stem cells (BMSCs) have broad prospects in tissue regeneration. Nigella Sativa (NS) possess great therapeutic properties for the treatment of a wide range of diseases. Materials and methods: Forty adult male albino rats were divided into: control group and treated group. The treated group was further subdivided into: energy drink subgroup 2a, BMSCs-injected subgroup 2b, NS-injected subgroup 2c. Histological, immunohistochemical and biochemical assessment was performed. Results: Administration of energy drink revealed that it adversely affected the pancreatic cytoarchitecture. BMSCs and NS have been similarly observed to significantly ameliorate the histological, biochemical and immunohistochemical changes induced by energy drink. Conclusions: The extent of pancreatic regeneration, exerted by each of BMSCs and NS oil, is nearly similar but the effect of BMSCs is more superior; however, NS could be privileged to BMSCs as a line of treatment being easily accessible and of lower cost

Novel and Green Modification of Shrimp Shells for the Determination and Extraction of Some Toxic Metal Ions from Real Water Samples

In the present work, raw shrimp shells were modified by sodium chloride, sodium carbonate and sodium acetate. Bioextraction of Cd (II), Mn(II) and Fe(III) ions from real water by the new and safe modified shrimp shells were studied as a function of initial solution pH, shaking time and initial metal ions concentration. The bioextraction is more efficient in pH ≤ 6 for all the three modified extractor than the unmodified shrimp shells. The adsorption capacities of the three modified shells for Cd (II), Mn (II) and Fe (II) were evaluated using static mode and they are found to be 556,478 and 438 for sod.chloride, 557,492 and 502 for sod. Carbonate and 537,437 and 417 for sod.acetate modified shells, respectively. The results also revealed that the modified extractor show high selectivity toward the analyteions in the presence of Cl‑, Br-, I-, SO4--, NO3- ,K+, Ca++, Mg++ and Na+ ions. Based on these results the use of such bioextractor for the environmental application is encouraged

In vitro differentiation of human umbilical cord blood mesenchymal stem cells into functioning hepatocytes

Mesenchymal stem cells (MSCs) were isolated by gradient density centrifugation from umbilical cord blood. Spindle-shaped adherent cells were permitted to grow to 70% confluence in primary culture media which was reached by day 12. Induction of differentiation started by culturing cells with differentiation medium containing FGF-4 and HGF. Under hepatogenic conditions few cuboidal cells appeared in culture on day 7. From day 21 to day 28, most of cells became small and round. The control negative cells cultured in serum free media showed fibroblast-like morphology. Urea production and protein secretion by the differentiated hepatocyte-like cells were detected on day 21 and increased on day 28. Protein was significantly increased in comparison with control by day 28. The cells became positive for AFP at day 7 and positive cells could still be detected at days 21 and 28. The cells in the control group were stained negative for AFP. The cells expressed albumin gene at the 14th day that became markedly increased at the 28th day of culture with HGF and FGF-4. No albumin expression was observed in the 7th day sample and the control. This study demonstrated that UCB-derived MSCs had the ability to differentiate into functioning hepatocyte-like cells starting from the 7th day after culturing under hepatogenic conditions and became well functioning at days 21 and 28. These data indicated that UCB-derived MSCs can be a promising source of cell therapy for intractable liver diseases.Keywords: Umbilical cord blood; Mesenchymal stem cells; Culture; Hepatocytes; HGF; FGF-

Cytotoxic effects of Smp24 and Smp43 scorpion venom antimicrobial peptides on tumour and non-tumour cell lines

Smp24 and Smp43 are novel cationic AMPs identified from the venom of the Egyptian scorpion Scorpio maurus palmatus, having potent activity against both Gram-positive and Gram-negative bacteria as well as fungi. Here we describe cytotoxicity of these peptides towards three non-tumour cell lines (CD34+ (hematopoietic stem progenitor from cord blood), HRECs (human renal epithelial cells) and HACAT (human skin keratinocytes) and two acute leukaemia cell lines (myeloid (KG1a) and lymphoid (CCRF-CEM) leukaemia cell lines) using a combination of biochemical and imaging techniques. Smp24 and Smp43 (4–256 µg/mL) decreased the cell viability (as measured by intracellular ATP) of all cells tested, although keratinocytes were markedly less sensitive. Cell membrane leakage as evidenced by the release of lactate dehydrogenase was evident throughout and was confirmed by scanning electron microscope studies