The Education Department is a core unit within the faculty, responsible for planning, organizing, and overseeing educational activities. It works closely with academic staff to design and update course curricula, coordinate class schedules, and enhance the overall quality of teaching. The department aims to provide a supportive environment for effective learning and the academic development of students. It also plays a key role in academic advising, addressing educational concerns, and organizing consultation sessions. By applying modern teaching methods and responding to current educational needs, the Education Department strives to improve the learning process and contribute to student success.
Ferrocement has been increasingly used as a structural material which competes favorably with reinforced concrete and other building materials. The durability of ferrocement depends on several factors including the quality of ferrocement, mesh type, depth of cover over the mesh, the direction and magnitude of applied load(s) and its resistance to corrosion. Corrosion of mesh reinforcement in ferrocement is one of the important aspects which has not received sufficient attention from research workers. This paper presents the results of monitoring the corrosion performance of ferrocement specimens exposed to extremely aggressive conditions (6% NaCl solution at 60°C). Several parameters have been considered in this study, including type and arrangement of mesh reinforcement and depth of mortar cover over the meshes. Four methods were used for corrosion examination of the specimens; visual examination, corrosion potential, corrosion rate and microscopic examination.
Over the past decade, corrosion became a crucial problem on two counts: (a) it is expensive to repair and (b) it has widespread occurrence. The research evaluated the effects of corrosion on the properties and flexural behavior of ferrocement. Two series of specimens were tested. The first series were cast, placed in water and a suitable environment for 28 days, and then subjected to flexural test. The second series were placed in a weather simulator tank, with corrosive environmental conditions and after three months, were tested for flexure. From a careful examination of the results of the flexural tests it emerges that: 1. The presence of NaCl and temperature, as well as the prevalence of wet and dry conditions, have a considerable effect on the flexural behavior of ferrocement: it increases the brittleness of mortar, reduces the number of cracks and increases the crack width. 2. Slight increase in the first crack strength and maximum strength of specimens. 3. The effect of corrosion in reducing the strength of ferrocement specimens with ungalvanized wire meshes, is greater than its effect on specimens with galvanized wire meshes.
Ferrocement is a type of thin wall reinforced concrete construction where real composite action between the matrix phases and the reinforcement exists. This composite action results in excellent control of cracking, high tensile strength and durability [1]. This investigation is concerning with the experimental and theoretical behavior of ferrocement under tension. The effects of different arrangements of mesh reinforcement, with particular respect to the specimen thickness and mortar cover, on the cracking behavior and both first crack strength and ultimate strength were studied. The mechanical properties of the wire mesh and mortar which was used in this investigation were also studied. The results show that, under direct tension, the strength of ferrocement at first crack and ultimate load is not affected significantly by the arrangement of the reinforcement. However, specimens having reinforcement evenly distributed with minimum cover showed reduced crack widths and an increased number of small cracks at failure. The contribution of the tensile strength of the mortar and the specimen thickness on first crack strength is considered to be significant, while it can be considered negligible at ultimate strength.
The aim of this paper is to review and compare various analytical procedures which have been developed to predict the ultimate moment of ferrocement under flexure. One such procedure has been used as the basis of the computer program FAOFERRS, which has then been used to compare predictions with experimental results for specimens having various mesh arrangements. An attempt is made to predict the ultimate moment for specimens reported by other investigators and the results are compared and discussed.
Daru Journal Of Pharmaceutical Sciences (15608115)(3)pp. 82-87
Majority of the currently available anticancer drugs are designed to have selective toxicity to rapidly dividing cells. Among these agents the focus of many studies are compounds obtained from natural products with high therapeutic index. In this study the cytotoxicity of HESA-A, a marine compound, on cancer and normal cells was evaluated. HESA-A was prepared in normal saline as a stock solution (0.8 mg/ml, pH=7.4), sterilized and further diluted to final concentrations of 0.4, 0.2, 0.1 and 0.05 mg/ml. Cells (MDA-MB-468, Hep-2, Hela as cancer cells; L929 and McCoy as normal cells) were grown in completed RPMI 1640 and seeded in 96 well micro plates at a concentration of 1-5 × 104 cells/ml. After incubation for 24 h, different concentrations of HESA-A were added and cells were further incubated for 72 h. Using MTT assay, percent cell survival was determined by ELISA at 540 nm. Doxorubicin was used as a positive control (20 μg /ml). HESA-A (0.4 mg/ml) reduced the number of viable MDA-MB-468 and Hela cells to less than 50%. For Hep-2 cells the IC 50 was 0.8 mg/ml. In normal cells IC50 could not be obtained at any given concentrations. These results suggest that HESA-A in therapeutic doses and in a concentration dependent manner inhibits the growth of cancer cells more selectively than normal cells.
Breast cancer is the most prevalent type of cancer in pre- and postmenopausal women in most Western countries. In the treatment of metastatic breast cancer, doxorubicin has the broadest spectrum of antitumor activity of any drug currently available but produces a dose-dependent cardiomyopathy that limits its clinical usefulness. The aim of this research project was to target the affected tissues, which contain estrogen receptors (ERs). Initially, a series of estrogen derivatives with side chains linked at the 3- and 17-positions of estrone were synthesized, and then novel anticancer prodrugs were obtained from these by further linking these compounds to doxorubicin by means of various alkyl spacer groups. These estrogenic prodrugs were designed to target tumor cells containing ERs, found in human breast cancer cells, and to release the active anticancer moiety when internalized. The estrogenic prodrugs were then biologically evaluated using in vitro chemosensitivity assays against human ER-positive (MCF-7) and ER-negative (MCF-7ADR and MT-1) breast tumor cells and a leukemia (K562) cell line. The results showed that estrone derivatives with substituted aminoalcohol side chains of various lengths (2-6 carbons) linked to the 17-position of estrone were mostly inactive. Estronedoxorubicin prodrugs containing doxorubicin at the 3-position of estrone (CCRL 1042 and CCRL 1036) were relatively inactive and nonselective against all cell lines tested. However, when doxorubicin was linked to the 17-position of estrone, these prodrugs had at least an order greater activity than their 3-linked counterparts. Using a short aminoxyspacer group (2 carbons) at this position produced CCRL 1035, which had a lower activity against all cell lines tested compared to doxorubicin. In contrast, the prodrug incorporating doxorubicin at the 17-position of estrone via a long spacer group (12 carbons, CCRL 1033) was both potent and selective against ER-positive cells MCF-7. These studies have shown that linking doxorubicin to the 17-position of estrone via a long alkyl spacer group conferred selectivity of cytotoxic action against ER-positive breast cancer tumor cells.
