Push Tests on Innovative Shear Connector for Composite Beam with Cold-formed Steel Section

In this study, experimental tests were conducted to investigate the ductility and strength capacity of new shear connector. Push test specimens were prepared and tested according to EN1994-1-1 standard. The push test specimen consists of two cold-formed steel lipped channel sections oriented back-to-back to form an I-section beam, transverse metal deck and normal concrete slabs grade C25/30. Angle brackets were obtained from the same section of the beam and fastened to the web of steel beam to provide the shear connection. Two shear connectors were tested namely; “SC1” and “SC2” shear connectors. Both shear connectors showed a ductile behavior and had satisfied the ductility requirements of EN1994-1-1 standard. It was concluded that the ductile behavior of shear connectors could enhance the design of composite beam

Chloride Resistance of Concrete Containing Palm Oil Fuel Ash

Experimental study was conducted to investigate the chloride resistance of concrete containing palm oil fuel ash (POFA). Ground POFA was used to partially replace Portland cement Type I, by 20% by weight of binder in order to prepare POFA concrete.  Water cement ratio of 0.28 was used and high water reducing admixture was added to maintain workability. POFA concrete was investigated and tested for compressive strength at ages of 7, 28 and 90 days. Rapid chloride penetration test (ASTM C1202) and salt ponding test (ASTM C1543) were conducted on standard concrete specimens to investigate the chloride resistance of concrete.  The results showed that the compressive strength of POFA concrete was improved comparing with plain concrete. The results of chloride penetration tests revealed that significant improvement in terms of chloride resistance could be obtained by using 20 % of ground POFA in concrete mix as cementing replacement material

Methane Gas Hydrate Formation by Using Sodium Dodecyl Sulfate Additives

Gas Hydrates (G. Hyd) such as methane (CH4) hydrates are forming of water molecules in ice-like crystals (lattice shape) with cavities where the methane gas (gust gas) molecules are engaged in, and this process is conducted in a certain condition, mainly in low temperature and high pressure. The objective of the current work is to study the effect of Sodium Dodecyl Sulfate (SDS) additives on Methane gas hydrate performance. Two solutions were prepared. The first solution consists of distilled water (100 ml), methane gas and SDS additives (0.10 g). The second solution consists of same ingredient with seawater (100 ml) instead of distilled water. A stirred tank with 750 psi has been utilized. The highest recovery ratio was 42.15% for distilled water using SDS additives with a pressure cycle duration of 120 minutes. Significant improvement in the hydrate water recovery ratio can be obtained with distilled water and seawater by about 42 % and 15.6% respectively. Generally, SDS additives improve the recovery rate for water in the presence of methane

Assessment of knowledge of pharmacies and drug stores workers toward dengue and its management at Al-Mukalla district – Hadhramout-Yemen

Dengue fever (DF) is a mosquito borne disease that has spread rapidly in Al-Mukalla city in the last ten years, so a necessary requirement is to analyze the knowledge of healthcare providers, including pharmacists, toward dengue management and control in the country. This paper aims to assess the knowledge of pharmacies and drug store workers toward dengue management at Al-Mukalla district. A descriptive cross-sectional study was conducted among 384 pharmacies and drug store workers in Al-Mukalla district in 2020. A random sampling method was used to select the pharmacies and drug stores and data was collected by using pretest questionnaires. All statistical analyses were performed by using SPSS software, version 24. A total of 384 workers of pharmacies and drug stores, were enrolled. 361 were male (94%), and 23 were female (6%). The pharmacy diploma was the most qualified of the participants (58.1%). The majority of participants had 1–5 years’ experience (45.3%). The result showed that most workers of pharmacies and drug stores had knowledge of dengue fever disease (82.1%). Medical consultation was the most common choice of participation regarding dealing with warning signs of dengue fever (red spots or patches on the skin (59.1%) , nasal or gingival bleeding(66.9%), vaginal bleeding(74.2%), hematemesis (72.7%), and severe abdominal pain (46.4% ). The larger proportion of participants did not have knowledge of the WHO clinical management of dengue guideline (75.5%). This study showed that more than half of pharmacies and drug stores workers had knowledge toward management of dengue fever (57 %). This study revealed that the knowledge of pharmacy and drug store workers in Al-Mukalla district toward dengue fever management was not satisfactory. This result highlights the need for extensive scientific programs to increase the knowledge of pharmacies and drug store workers toward dengue management so this gap will be plugged

Identification and characterisation of an Old Yellow Enzyme (OYE) - NamA from Listeria monocytogenes

The food-borne pathogene Listeria monocytogenes has been considered a significant threat to human health worldwide. It mainly infects individuals suffering insuffecint immunity such as pregnant women. During pregnancy, L. monocytogenes is capable of causing a serious damage to the mother and the fetus. It can spread to different organs including the placenta via adaptation to interacellular lifestyle. To maintain pregnancy, the levels of the hormones progesterone and ?-estradiol increase and reduction in hormone levels was proposed to be associated with fetal death and abortion. The objectives of this project therefore were to investigate the role of pregnancy hormones on the growth and virulence of L. monocytogenes, and to identify bacterial genes with possible roles in binding to pregnancy hormones. It was obsereved that the growth of L. monocytogenes in the presence of progesterone under anaerobic condition was affected by the action of the hormone and the effect was dose/time-dependent of exposure as increasing concentrations showed greater effect on the bacterial growth. Interestingly, bacterial growth was restored within 24 h of exposure to the hormone. In parallel, a Tn917-LTV3 insertion library was constructed and a number of mutants isolated that had reduced growth in the presence of ?-estradiol were identified. However, reduction in growth was not microbiologically significant. Furthermore, bioinformatics analysis was performed to identify listerial genes with possible role in hormones degradation. It was observed that L. monocytogenes encodes for a protein that is possibly involved in steroid degradation; therefore, gene expression and a clear-deletion mutant were performed to test this hypothesis. This revealed no significant role of this protein in the growth restoration observed in the presence of progesterone. Also, the deleted gene was investigated of its ability to reduce NADPH in the presence of a possible substrate (progesterone, ?-estradiol). This showed that this gene could possess an enzymatic activity toward pregnancy hormones. An attempt to purify this protein for further investigation was performed and protein expression in a soluble form was unsuccessful. The findings presented in this thesis represent an important view when considering the relation between pregnancy hormones and L. monocytogenes; however, further investigations of hormone-degrading proteins from L. monocytogenes are needed. This knowledge may form the basis of a therapy to protect pregnant individuals

Understanding the use of LMS in Saudi Arabia Higher Education : a study of Blackboard in King Abdulaziz University

First, LMSs play an essential role in higher education. COVID-19 has made them essential for the delivery of educational activities. making the most of them is vital for educational success. Second, Although they are widely used in Saudi higher education the full extent of their features is not fully utilized. Third, The survey was conducted in King Abdulaziz University (KAU) to determine the extent of the problem

Quality factors impacting e-learning within the mobile environment in Saudi Arabia universities : an interview study

Mobile e-learning within the education domain is now an integral part in education technology. However, there has been little discussion about the benefits and the challenges of the use of M-learning in the higher education system in KSA. Interviews were the primary instruments used for data collection in identifying the enabling and deterring the quality attributes of mobile e-learning use in the context in Saudi Arabia higher education. The research results revealed that learning content/information quality, system quality, service quality and instructional quality were the primary antecedents of Blackboard as a Learning Management System (LMS) in general and within the mobile devices, and this situation can enhance user’s attitude towards the use of E-learning. Data were analyzed and results were discussed. Recommendations were made based on the findings