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Search Results: 1 - 10 of 462169 matches for " Layla A. Taib "
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Synthesis and Antifungal Activity of Some New Fluorine-Substituted 4-Thiazolidinone Bearing 1,2,4-Triazinone  [PDF]
Layla A. Taib
International Journal of Organic Chemistry (IJOC) , 2018, DOI: 10.4236/ijoc.2018.81012
Abstract: Fluorine substituted 4-thiazolidinone 5 bearing 1,2,4-triazinone obtained from the condensation of 3-Amino-6(2’-aminophenyl)-1,2,4-triazin-5(4H)-one (2) with an aromatic aldehyde followed by cycloaddition with mercaptoacetic acid afforded the thiazolidinone (4), and treatment with ethyl trifluoroacetate. Structure of the products has been deduced from their correct elemental analysis and spectral measurements. The antifungal activity of the new fluorinated target also has been evaluated.
Synthesis of New Fluorinated Fused Heteropolycyclic Nitrogen Systems Containing a Pyrazolotriazine Moiety as Antimicrobial Agents Part I  [PDF]
Layla A. Taib, Sofiyah A. Adibani
International Journal of Organic Chemistry (IJOC) , 2018, DOI: 10.4236/ijoc.2018.81013
Abstract: A simple route to synthesize novel fluorinated fused hetero-polycyclic nitrogen systems containing a pyrazolotriazine moiety (5,8,11) have been deduced from cyclization of 2-aminothiocarbonyl-5-arylidene-3-phenyl-1,2,4-triazin-6(1H)one (2) with diethoxy-phosphine, diethyl carbonate and/or diethyl oxalate in boil THF followed by cyclo condensation with aryl sulfonic acid hydrazide in EtOH/piperidine and finally fluorination with trifluoroethyl acetate. Structures of the products have been established from their elemental analysis and spectral measurements. The antimicrobial activity of the targets has also been evaluated.
Estimating Aluminum Leaching into Meat Baked with Aluminum Foil Using Gravimetric and UV-Vis Spectrophotometric Method  [PDF]
Layla A. Al Juhaiman
Food and Nutrition Sciences (FNS) , 2015, DOI: 10.4236/fns.2015.65056
Abstract: Baking meat by wrapping them in Aluminum (Al) foil is common in many countries. The excessive use of Al foil in baking and the disagreement about using Al foils were the motivation to do this study especially after the 2007 WHO/FDA Report. In this investigation, a gravimetric and a UV-Vis spectrophotometric method are used to estimate Aluminum (Al) leaching into meat baked by wrapping in Al foil. Three kinds of meat were used fish, cow stakes and chicken. The importance of Al exposure area was neglected by many studies. Five factors affecting Al leaching into meat are studied (baking temperature, baking time, additives, Al exposure area and weight of meat). The effect of cooking times (20, 40, 60 minutes) at 180 and cooking temperatures (160, 180, 200) at 60 minutes on the amount of Al leaching were evaluated. It was found that Al leaching into meat increased with increasing temperature, baking time, additives and Al exposure area. Moreover, Al exposure area was more effective than the weight of the meat. The Al leaching was highest in fish and lowest in chicken. Comparing the present results with the Provisional Tolerance Weekly Intake of Al approved by WHO/FDA, it shows that Al leaching into meat baked by wrapping in Al foil may add considerable doses into the diet. Continuous monitoring of Al foil used for baking meat is recommended.
Curcumin Extract as a Green Inhibitor of Leaching from Aluminum Cookware at Quasi-Cooking Conditions  [PDF]
Layla A. Al Juhaiman
Green and Sustainable Chemistry (GSC) , 2016, DOI: 10.4236/gsc.2016.62005
Abstract: Curcumin aqueous extract is used successfully as a green corrosion inhibitor at quasi-cooking conditions (90℃) to inhibit leaching from Aluminum cook wares in solutions containing vegetables or meat. Aluminum cook wares were bought from the market from four countries and cut to make the Aluminum samples. Six types of vegetables and three kinds of meat were chosen. Each type of vegetable and meat was used to prepare 30% w/v aqueous solutions. Three methods were used in the present study: Gravimetric method, Atomic Absorption and FTIR. Gravimetric method was applied to determine the leaching rate and the corrosion inhibition efficiency with/without NaCl. The effect of Curcumin concentration, Tab water, immersion time, alloying elements was investigated. There was a good consistency between Gravimetric and Atomic Absorption methods. The adsorption of Curcumin on the aluminum surface was in accordance with Langmuir isotherm. The values of the adsorption constant (Kads) and the free energy of adsorption (Gadso) were calculated and discussed. FTIR spectrum indicated that Curcumin coordinated with Al3+ resulting in the formation of Al3+-Curcumin complex on the metal surface. Using a small amount of Curcumin decreased leaching from Aluminum cook wares into food by 60% - 80% depending about the type of food.
Prevalence of Hydatid Cysts in Slaughtered Animals from Different Areas of Libya  [PDF]
Layla O. Elmajdoub, Wahab A. Rahman
Open Journal of Veterinary Medicine (OJVM) , 2015, DOI: 10.4236/ojvm.2015.51001
Abstract: The present study reports on the infection rates of hydatid cysts in both sexes and different age groups of sheep, camels and cattle from government abattoirs in different parts of Libya. An infection rate of 10.06% was recovered among 32,971 all ruminants (sheep, camels and cattle). Out 25314 of sheep, 2659 (10.52%) were infected. Out 7496 of camels, 940 (12.54%) were infected. Out 161 of cattle, 17 (10.56%) were infected. As regards to the infected organs, liver was seen to be the most commonly infected organ in sheep and cattle (46.03%; 52.94%, respectively), but in camels, it was the lung (55.21%). The fertility rates of hydatid cysts were 80% in sheep, 84% in camels and 0% in cattle. In sheep, the fertility rate of liver hydatid cysts was higher than that in other organs (53.85%), but in camels, the fertility rate in the lung was higher than that of other infected organs (66.7%). Thus, the incidence of echinococcosis in slaughtered livestock is noticeably high and denotes some hazards in control measures in Libyan abattoirs.
Systematic Stock Market Characterisation and Development: Perspectives from Random Matrix Theory, Option Pricing, Genetics, and Global Economics  [PDF]
Patrick Oseloka Ezepue, Thomas Chinwe Urama, Mahmoud A. Taib Omar
Journal of Mathematical Finance (JMF) , 2019, DOI: 10.4236/jmf.2019.92007
Abstract: We explicate the need and pathways for systematic stock market characterisation and development (SSMCD) and the role of Random Matrix Theory (RMT) in SSMCD research. This is the first time SSMCD, itself a nascent area of empirical finance introduced by the first author, is linked to RMT. Our focus is on the Nigerian Stock Market, particularly using RMT techniques to correlate respective asset prices in the NSM. The resulting insights are combined with those from related works on stochastic-times series analyses of stylised facts and six main market issues typically explored in empirical finance (efficiency, bubbles, anomalies, volatility, valuation and predictability), to illustrate SSMCD pathways in the NSM. Specifically, the RMT analyses focus on the cross-correlation matrix C of the stock index returns in the Nigerian Stock Market (NSM) from the period 2009 to 2013. Within this purview, we test the eigenvalues of the selected assets from the NSM and use their respective eigenvectors and inverse participation ratios to determine the stocks that drive the market dynamics. A method of obtaining a realistic implied correlation matrix for a hypothetical portfolio of some given assets selected from those considered in the empirical correlation matrix of the assets is considered. The positive implied correlation matrix shows that the corresponding assets in the NSM move in the same direction, meaning that portfolio diversification is not an optimal investment strategy. Hence, investing on derivative assets like call and put options is recommended. Further SSMCD implications of the analyses are foreshadowed. Also, we develop the links among SSMCD, macroeconomic modelling of national and global economic trends amid cycles of booms and crises. Highlights of an econome derived from analogies with sequencing and editing of genomes in molecular biology are provided.
Predicting Molecular Weight at Certain Temperature Isothermally using Neural Network
Norhana Taib,Z. Ahmad,Suhairi A. Sata
Journal of Applied Sciences , 2012,
Abstract: In this study, molecular weight control studies and the development of advance control were carried out. In-line measurement device such as Gel Permeation Chromatography (GPC) has become available, however, it is very expensive and the results always posses substantial time-delayed measurements from analytical laboratory measuring devices. A method of predicting molecular weight performance during polymerization process was proposed using neural network system. A neural network model was developed to predict leading moments of molecular weight using backpropagation algorithm of neural networks system for Methyl methacrylate (MMA) polymerization. Plant input and output were simulated from the first principle model for MMA polymerization and then been utilized to train multilayer neural network system. Process inputs such as reaction temperature, monomer conversion and initiator concentration were the main variables affecting properties of molecular weight averages. A neural network model was generated from the training process after it successfully learned the relationship between process inputs and product outputs. This neural network model was applied when predicting molecular weight of Polymethyl methacrylate (PMMA) which is useful in implementation of the on-line control of polymerization process.
Mapping the Relationship among Quality Management Practices, Organizational Learning, Organizational Culture, and Organizational Performance in Higher Education: A Proposed Framework  [PDF]
Ahmed Hani Mohammed, Che Azlan Bin Taib, Santhirasegaran a/l S.R. Nadarajan
American Journal of Industrial and Business Management (AJIBM) , 2016, DOI: 10.4236/ajibm.2016.64036
Abstract: The challenges in higher education and global competition encouraged performance excellence and the pursuit towards providing educational services characterized by high quality. To ensure performance excellence, quality management practices are considered as one of the variables that affect the organizational performance. On the other hand, organizational learning is a method that facilitates the process of improving the organizational performance. The results of organizational performance vary according to environmental conditions, especially an organizational culture that is one of the important indicators that are characterized by organizations. This encourages choosing the organizational culture as a moderating variable. However, this paper highlights organizational performance through a proposed conceptual framework to be considered in higher education institutes.
The Inhibition Effect of Cinnamon Extract on Leaching of Aluminum Cook Wares in NaCl Solutions at Quasi-Cooking Condition  [PDF]
Layla A. Al Juhaiman, Raesah A. Al-Shihry, Hassan M. Al Hazmei
Journal of Surface Engineered Materials and Advanced Technology (JSEMAT) , 2015, DOI: 10.4236/jsemat.2015.54020
Abstract: The contribution of cinnamon extract on leaching of aluminum (Al) cook wares was investigated using two aluminum alloys (Indian and Egyptian) and pure Al. The cinnamon (Cin) was extracted by heating the Cin sticks at 90°C in distilled water for an hour to make the 10% stock solution. This study was done in aqueous solutions in presence and absence of 1% NaCl using weight loss at 90°C. Moreover surface study (SEM and EDX) and electrochemical methods (Open Circuit Potential and Tafel plot) were applied. The addition of Cin solutions to 1% NaCl decreased the corrosion rates in weight loss and electrochemical method compared to 1% NaCl solutions which showed an inhibitive property of Cin solution. The inhibition was found to obey the modified Langmuir isotherm with a negative Langmuir ΔGads indicating the spontaneous nature of adsorption even at 90°C. The EDX surface analysis of the Al surface immersed in Cin + NaCl revealed the composition of the pits formed. From Tafel method, it was found that the corrosion current density of pure Al was more than that of the Egyptian alloy. The apparent activation energy values for Cin, Cin + NaCl and NaCl solution were evaluated and discussed.
Porcelain fracture of metal-ceramic tooth-supported and implant-supported restorations: A review  [PDF]
Rola M. Shadid, Nasrin R. Sadaqah, Layla Abu-Naba’a, Wael M. Al-Omari
Open Journal of Stomatology (OJST) , 2013, DOI: 10.4236/ojst.2013.38069
Abstract:

Metal-ceramic restorations are widely used in dentistry with a high degree of general success. However, fracture of these restorations does occur and usually frustrates both the dentist and the patient. Objective: This literature review discusses the factors that may lead to the fracture of these restorations whether they are tooth-supported or implant-supported with the aim of making dentists and technicians aware of these factors to avoid them. Factors reviewed include: technical factors, dentist-related factors, inherent material properties, direction, magnitude and frequency of applied loads, environmental factors, screw-retained implant-supported restorations, and posterior cantilevered prostheses. Material and Methods: A netbased search in “Pubmed” was performed and combined with a manual search. The search was limited to articles written in English. Conclusions: the published literature revealed that the factors predisposing to fracture of metal-ceramic restorations may be related to the technician, dentist, patient, environment, design of the restoration, or to inherent structure of ceramics and others. However, if the dentist and technician understand these factors and respect the physical characteristics of the materials, most of those are avoidable.

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