Gas-phase dehydration of glycerol over thermally-stable SAPO-40 catalyst

SAPO-40 was used as catalyst for the gas-phase dehydration of glycerol towards acrolein. At 350 ºC the catalyst attained full conversion of glycerol with a negligible deactivation in the first 48 h, a glycerol conversion above 50 % after 120 h on stream and a nearly constant selectivity to acrolein above 70%. This catalyst proved to be highly resistant under the experimental conditions used and can be regenerated without loss of activity or significant structural damage. The comparison of SAPO-40 with SAPO-34 and SAPO-11 illustrates the importance of the porous structure and emphasizes the good catalytic performance of this material

Obstacles That Prevents Better Use of Information Technology: A Case Study of University College Students – Addayer, Jazan University

Learning through technology helps learners to empower their learning experiences and prepares them for a global workforce. The study suggests that students have negative attitude towards using technological devices and there are other obstacles that hinder the University College Students in Addayer to use the educational technology appropriately. The study draws the attention of the decision makers and learners to the meaningful use of technology in educational process. The study is a descriptive and analytical. The (SPSS) tool is used to analyse the data collected by the questionnaire. The study ends up with statistically highlighted results and recommendations to solve the problems of using technology in educational process in Jazan Universit

An investigation on Libyan olive oil in the western region

 Thirteen Olive oil samples were collected from five different places in the western Libyan region with different cultivation periods. The physical and chemical properties of samples were investigated and classified whether they comply with the Libyan standard specification number 8/2002 or not. The density and refractive index of almost all samples were found within the normal range (0.908-0.919) and (1.4688-1.4705) respectively whereas the chemical properties showed a range of fluctuated values such as peroxide number (11.20-60.40), acidity value (0.737-17.94), saponification number (185.34-199.65), esterification number (173.84-194.36) and iodine number (71.00-94.10). A third of the investigated samples are considered to be of good quality mainly the newer samples.

Catalytic gas-phase glycerol processing over SiO2-, Cu-, Ni-and Fe-supported Au nanoparticles

In this study, we investigated different metal pairings of Au nanoparticles (NPs) as potential catalysts for glycerol dehydration for the first time. All of the systems preferred the formation of hydroxyacetone (HYNE). Although the bimetallics that were tested, i.e., Au NPs supported on Ni, Fe and Cu appeared to be more active than the Au/SiO2 system, only Cu supported Au NPs gave high conversion (ca. 63%) and selectivity (ca. 70%) to HYNE

The prevalence of erectile dysfunction and its associated factors among diabetic patients in the Southwestern Region of Saudi Arabia analytical cross-sectional study

Background: Erectile dysfunction (ED) is a common condition among diabetic patients, significantly affecting their quality of life. This study examines the prevalence of ED and the factors contributing to its occurrence among diabetic patients in the southwestern region of Saudi Arabia. Methods: This analytical cross-sectional study was conducted in randomly selected Primary Healthcare Centers (PHCCs) across the Asir region. The sample included 398 married male Saudi nationals aged 18 years and older, diagnosed with diabetes and attending PHCCs. Data collection involved a standardized questionnaire that included the International Index of Erectile Function (IIEF-5) to measure ED severity and explore related factors. Statistical analysis was performed using SPSS v22, with descriptive statistics including Chi-square tests, independent t-tests, analysis of variance (ANOVA) and multiple regression. Results: Most participants were aged 41–60 years (51.5%), with 55.5% having completed high school or bachelor’s education and 67.8% earning an income of ≤10,000 SR. Most participants (82.9%) have Type 2 diabetes and 21.9% reported smoking. Clinical findings revealed a mean body mass index (BMI) of 28.53, glycemic control was poor, with only 29.1% achieving controlled hemoglobin A1C (HbA1C), while 18.3% had severely uncontrolled levels. In terms of ED severity, mild to moderate dysfunction was most common (29.6%), followed by mild dysfunction (25.1%) and moderate dysfunction (20.4%). Severe dysfunction affected 13.1%, while 11.8% reported no dysfunction. Significant correlations were observed between ED severity and factors such as age, education level, income, duration of diabetes and HbA1C levels (p < 0.05). Smoking status was also significantly associated with ED severity (p = 0.0116), while BMI showed no significant correlation (p = 0.791). Conclusions: Erectile dysfunction is prevalent among diabetic patients in the Asir region, with its severity influenced by demographic and clinical factors. Younger age, higher education, and better glycemic control were associated with reduced ED severity

Renewable Chemicals: Dehydroxylation of Glycerol and Polyols

The production of renewable chemicals is gaining attention over the past few years. The natural resources from which they can be derived in a sustainable way are most abundant in sugars, cellulose and hemicellulose. These highly functionalized molecules need to be de-functionalized in order to be feedstocks for the chemical industry. A fundamentally different approach to chemistry thus becomes necessary, since the traditionally employed oil-based chemicals normally lack functionality. This new chemical toolbox needs to be designed to guarantee the demands of future generations at a reasonable price. The surplus of functionality in sugars and glycerol consists of alcohol groups. To yield suitable renewable chemicals these natural products need to be defunctionalized by means of dehydroxylation. Here we review the possible approaches and evaluate them from a fundamental chemical aspect

ELECTRONIC STRUCTURE AND THERMODYNAMIC PROPERTIES OF LI-IONINSERTION IN SULFONAMIDES COMPOUNDS AS ORGANIC HIGH-ENERGY DENSITY CATHODES

The world’s ever-growing energy demand has evoked great interest in exploring renewable energy sources along with sustainable energy storage systems. While inorganic physics of rocking chair mechanism used in Li-ion battery have proven to provide high energy density and high performance, there are problems yet to be overcome in terms of sustainability and recyclability. This is why research in organic batteries has been on the rise, yet the diversity of organic battery frameworks remains limited and requires overcoming multiple obstacles that restrain the performance of an all-organic battery system. A recent advance in the design of organic electrode material by Wang et al. has shown the possibility of a new stable and tunable class of conjugated sulfonamides (CSA) with an experimental voltage range between 2.85V and 3.45V [5]. A theoretical approach to study these organic materials is taken in this thesis research where the effects of such compounds on the redox potential, physics of ion insertion, and other thermodynamical properties are examined. Density Functional Theory (DFT) is employed in this investigation along with an evolutionary algorithm to generate information about the crystal structure of mentioned systems, their density of states (DOS), and charge distribution in pristine form and after lithiation. Quinone systems with oxygen groups were investigated in a previous research project that complements this thesis which looks into a quinone system with sulfonamide compounds where a comparison between the two could offer more understanding of the electrochemistry of such systems for their application in batteries as high performing organic cathode materials on a par with other inorganic materials

Effect of Electronic Exchange-Correlation Interaction in the Physics of Ion Insertion in Organic Salts

The intense increase in energy consumption around the world has prompted a great deal of research on alternative and sustainable energy storage systems such as organic batteries. The fundamental understanding of the physics of organic salts and the ion insertion mechanism plays a key role in the development of electrode materials used in such sustainable batteries. The system studied in this project is of Lithium (2,5-dilithium-oxy)-terephthalate where a previous project studied this system from a different angle.  The electronic structure generation of the system is based on Density Functional Theory (DFT) along with an evolutionary algorithm to find the structures with minimum energy. The effects of varying the description of the exchange-correlation interaction were studied while introducing lithium ions to the system. This was done while also monitoring the repercussions of crystal structure optimization on the voltages, charge redistribution, and bonds of the system. The geometrical optimization of the hybrid functional resulted in the potential of the 2-electron step between Li2-p-DHT/ Li4-p-DHT of 2.6 V being closer to the experimental value recorded at 2.7 V