Effect of prestress level on the strength of CFRP composite laminate

Osama A. Abdullah,Abdul Kareem F. Hassan 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.11

The effect of fiber prestressing has been investigated on the tensile strength, modulus strength, flexural properties and residual stresses of Carbon fiber reinforced polymer (CFRP) composites. Unidirectional carbon fiber in an epoxy resin has been examined under different prestressing levels (0, 5, 10, 15, 20, 30, 45, 60, 80 MPa) at ambient temperature and 50 % fiber volume fraction. A new method was implemented to produce the prestressed laminates for several standard tests. The results showed that prestressing on 3-ply unidirectional carbon fibers improved the fiber tensile strength to 99 % and the tensile modulus to 31 %. Similarly on 8-ply unidirectional carbon fibers has improved the fiber flexural strength to 63 % and flexural modulus to 81 %. A new technique was used to measure the residual stresses and tensile modulus of the composite laminate by recording the final extension and the remaining load directly after the curing process and releasing the applied load.

Micro-grid Monitoring and Supervision: Web-based SCADA Approach

Ali Mohamed A.,Barakat Mahmoud M.,Abokhalaf Masoud M.,Fadel Yasmin H.,Kandil Mohamed,Rasmy Mariam W.,Ali Osama N.,Besheer Ahmad H.,Emara Hassan M.,Bahgat Ahmed 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.5

Owing to the widespread use of the micro-grid concept to serve many real life applications, the main concern of this paper is to monitor, evaluate and manage the operational performance of an existent, already installed micro-grid that consists of On & Off grid PV systems in addition to the main grid supply. With the aid of customized web based SCADA system fully designed by authors, the performance evaluation of the proposed micro-grid is carried out in terms of energy consumption, power quality indices and energy cost based on Egypt’s energy current tariff . The designed system helps in both micro-grid status monitoring as well as load sharing between the main grid supply and the off grid PV energy system. The data of the on grid PV energy system are accessed and collected online directly from the inverter web server instead of downloading them offl ine from the PV inverter. In this case, data are analyzed with a reasonable refresh rate, which saves time and eff ort. Remote access platform is developed securely through a multi-level security authentication and strong data encryption using the OpenVPN protocol under the Dynamic Domain Name System service. Smart wired and wireless technology—used as integrated sensing devices to the developed SCADA system—enables easy system installation and running cost saving. Finally, to validate the collected data from the newly SCADA designed monitoring system, a performance characterization for the on grid PV system following international standards of yields calculations is carried out for 3 months in 2019.

Response of Triple Negative Breast Cancer to Neoadjuvant Chemotherapy: Correlation between Ki-67 Expression and Pathological Response

Elnemr, Gamal M,El-Rashidy, Ahmed H,Osman, Ahmed H,Issa, Lotfi F,Abbas, Osama A,Al-Zahrani, Abdullah S,El-Seman, Sheriff M,Mohammed, Amrallah A,Hassan, Abdelghani A Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.2

Triple-negative breast cancers constitute about 15% of all cases, but despite their higher response to neoadjuvant chemotherapy, the tumors are very aggressive and associated with a poor prognosis as well as a higher risk of early recurrence. This study was retrospectively performed on 101 patients with stage II and III invasive breast cancer who received 6-8 cycles of neo-adjuvant chemotherapy. Out of the total, 23 were in the triple negative breast cancer subgroup. Nuclear Ki-67 expression in both the large cohort group (n=101) and triple negative breast cancer subgroup (n=23) and its relation to the pathological response were evaluated. The purpose of the study was to identify the predictive value of nuclear protein Ki-67 expression among patients with invasive breast cancers, involving the triple negative breast cancer subgroup, treated with neoadjuvant chemotherapy in correlation to the rate of pathological complete response. The proliferation marker Ki-67 expression was highest in the triple negative breast cancer subgroup. No appreciable difference in the rate of Ki-67 expression in triple negative breast cancer subgroup using either a cutoff of 14% or 35%. Triple negative breast cancer subgroup showed lower rates of pathological complete response. Achievement of pathological complete response was significantly correlated with smaller tumor size and higher Ki-67 expression. The majority of triple negative breast cancer cases achieved pathological partial response. The study concluded that Ki-67 is a useful tool to predict chemosensitivity in the setting of neoadjuvant chemotherapy for invasive breast cancer but not for the triple negative breast cancer subgroup.

Oleuropein Induces Anti-metastatic Effects in Breast Cancer

Hassan, Zeinab K.,Elamin, Maha H.,Daghestani, Maha H.,Omer, Sawsan A.,Al-Olayan, Ebtesam M.,Elobeid, Mai A.,Virk, Promy,Mohammed, Osama B. Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.9

Breast cancer causes death due to distant metastases in which tumor cells produce matrix metalloproteinase (MMP) enzymes which facilitate invasion. Oleuropein, the main olive oil polyphenol, has anti-proliferative effects. This study aimed to investigate the effect of oleuropein on the metastatic and anti-metastatic gene expression in the MDA human breast cancer cell line. We evaluated the MMPs and TIMPs gene expression by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) in treated and untreated cells. This study demonstrated that OL may induce anti-metastatic effects on human breast cancer cells. We found that TIMP1,-3, and -4 were over-expressed after all periods of incubation in treated cancer cells compared to untreated cells, while MMP2 and MMP9 genes were down-regulated, at least initially. Treatment of breast cancer cells with oleuropein could help in prevention of cancer metastasis by increasing the TIMPs and suppressing the MMPs gene expressions.

Effects of dietary inclusion of Moringa oleifera leaf meal on growth performance of Muscovy ducklings (Cairina moschata)

Safwat Assem M.,Sarmiento-Franco Luis,El-khalek Enass Abd,Abou-Shehema Bahaa M.,Hassan Osama A.,Elnaggar Asmaa Sh. 아세아·태평양축산학회 2024 Animal Bioscience Vol.37 No.4

Objective: The current experiment was performed to investigate the influence of different dietary levels of Moringa oleifera leaf meal (MOLM) on productive performance, nutrient digestibility, blood parameters, immune response, caecal microbiota, and carcass characteristics of Muscovy ducks (Cairina moschata) during 7 to 63 d of age. Methods: A total of 240 unsexed 7-d-old ducklings were distributed into five (treatment) groups; each one contained six replicates with eight ducklings each. Birds of the first group were fed basal diet without MOLM and served as control, while the other four groups were fed basal diet with 0.25%, 0.50%, 1.0%, and 2.0% MOLM inclusion level, respectively. Results: The obtained results revealed that including MOLM in the diets significantly improved body weight, body weight gain, feed conversion ratio and economic efficiency compared with the control group. Among the different MOLM inclusion treatments, increasing MOLM inclusion level decreased (p<0.05) such previous parameters. Decreasing MOLM inclusion levels in duckling diets increased (p>0.05) the digestibility of organic matter, crude protein, ether extract, and nitrogen free extract, however all MOLM treatments were significantly higher than the control group. Results also revealed that feeding ducks lower MOLM inclusion levels (0.25% or 0.50%) improved blood parameters (p<0.05) compared with the higher inclusion levels (1.0% or 2.0% MOLM) and the control group. Ducks fed different MOLM levels had significantly higher phagocyte index and activity, immunoglobulin G (IgG), IgM, total antioxidant capacity, glutathione peroxidase activity, and superoxide dismutase activity compared with control group. Conclusion: Despite the beneficial effects of all MOLM treatments on growth performance, nutrient digestibility, physiological status, and immune response of duckling, the increasing MOLM inclusion level in the diet had deleterious effects on such studied traits, consequently 0.25% was the best MOLM inclusion level in duckling diets.