This study introduces a suite of robust models aimed to advance the determination of physiochemical properties in heavy oil refinery fractions. By integrating real-time analytical technique inside the refinery analysis, we have developed a single analyzer capable of employing six partial least square regression equations. These designed models enable to provide real-time prediction of critical petroleum properties, such as sulfur content, micro carbon residues (MCR), asphaltene content, heating value, and the concentrations of nickel and vanadium metals.
View Article and Find Full Text PDFThis study focuses on addressing the challenges in the dry reforming of propane, a process historically marked by low syngas yields and only moderate conversions of CO and propane. The primary objective was to enhance CO utilization and boost the selectivity of syngas (CO and H) production using titania-based catalysts. For synthesizing these catalysts, an impregnation method was employed with subsequent characterization through X-ray diffraction (XRD), N adsorption-desorption, ammonia temperature-programmed desorption (TPD), and hydrogen temperature-programmed reduction (TPR).
View Article and Find Full Text PDFThis study investigates the reaction pathways and kinetics to comprehend the catalytic cracking of dodecane, a heavy naphtha model compound, over the nanocrystalline ZSM-5 catalyst in the presence and absence of steam with the aim of increasing olefin production. The nanocrystalline zeolite was characterized using XRD and BET, and the surface acidity was measured by NH-TPD and Py-FTIR. The steam treated ZSM-5 contributed to an increase in pore volume with extra-framework alumina, resulting in highly catalytic active sites and hence higher olefin selectivity.
View Article and Find Full Text PDFCatalyst deactivation is a complex phenomenon and identifying an appropriate deactivation model is a key effort in the catalytic industry and plays a significant role in catalyst design. Accurate determination of the catalyst deactivation model is essential for optimizing the catalytic process. Different mechanisms of catalyst deactivation by coke and metal deposition lead to different deactivation models for catalyst activity decay.
View Article and Find Full Text PDFBackground: The aim of this study was to explore potential healthcare workers' (HCWs) concerns about the monkeypox virus in order to create practical solutions to manage this disease.
Methods: Online cross-sectional research was conducted in 11 Arabic countries (Egypt, Saudi Arabia, Yemen, Syria, Libya, Algeria, Tunisia, Iraq, Palestine, Jordan, and Sudan) from 2 August 2022 to 28 December 2022.
Results: Approximately 82% of respondents felt the need to acquire further information.
Background: This study aims to assess the electrocardiographic interpretation abilities of resident doctors at internal medicine and emergency medicine departments in eight Arabic countries.
Methods: An online cross-sectional study was conducted between October 7, 2022 and October 21, 2022 in eight Arabic countries. The questionnaire consisted of two main sections: the first section included sociodemographic information, while the second section contained 12 clinical case questions of the most severe cardiac abnormalities with their electrocardiography (ECG) recordings.
Naphtha reforming to aromatics, naphthenes, and iso-paraffins is an essential process to increase the octane number of gasoline through the utilization of middle naphtha (whole). A ZSM-5 zeolite catalyst with modified medium pores was developed to comprehend the existing limitation of catalytic reforming to the unutilized refinery feedstock of heavy naphtha. The study applied a lower reforming conversion temperature (350 °C) than a conventional reformer without noble metal addition in an effort to lower the carbon footprint of the process and catalyst cost.
View Article and Find Full Text PDFNanozeolite Y was synthesized without a template and modified with phosphorous (P) and metals. P was introduced via impregnation with different weight loadings (0.5, 1, and 2 wt %), while ion exchange was developed to introduce zirconium (Zr) and cobalt (Co).
View Article and Find Full Text PDFNanozeolite-Y was synthesized in the absence of a templating agent with several modification methods. The parent nanozeolite-Y was prepared with different sodium (Na) contents and crystallization conditions. Then, the parent nanozeolite-Y was modified by ion exchange, calcination, and steam treatment.
View Article and Find Full Text PDFThis study emphasizes tuning the synthesis conditions of MFI zeolites to achieve better catalytic properties by optimizing the mesoporosity, the balance between Brønsted and Lewis sites, and the zeolite particle sizes. The MFI zeolites were hydrothermally synthesized at various temperatures employing different silica sources. The synthesis temperature was varied between 110 to 180 °C at constant synthesis time (15 h).
View Article and Find Full Text PDFNano BEA zeolite catalysts were synthesized and modified by desilication and then ion-exchanged with Co. The desilication was carried out using 0.1 M of NaOH.
View Article and Find Full Text PDFClosed gastroschisis is a rare entity usually associated with intestinal atresia and short bowel syndrome. We report two cases of closed gastroschisis presenting with neonatal intestinal obstruction and para-umbilical evisceration without an abdominal defect.
View Article and Find Full Text PDFWe studied the effect of bFGF on human retinal pigment epithelial cells in vitro In ARPE-19 cells, enhanced expression of KLF4 mRNA and reduced expression of PAX6, MITF, and OTX2 mRNA specific for retinal pigment epithelium were observed after bFGF application. The expression of KLF4 mRNA peaked in 72 h after bFGF application and then sharply decreased, which was accompanied by a 3-fold increase in TUBB3 mRNA expression (neuronal marker). Immunocytochemical analysis showed that in the presence of bFGF, some cells retained epithelial properties and showed positive staining for connexin-43, while others had long axon-like processes and demonstrated positive staining for βIII-tubulin, which attests to their neuronal transdifferentiation.
View Article and Find Full Text PDFPurpose: To define the characteristic radiological features following colonic replacement of the esophagus in children.
Materials And Methods: The upper gastro-intestinal contrast studies of 43 patients who underwent colonic replacement of the esophagus at our pediatric surgery unit were available for analysis. UGI contrast studies were performed routinely in the post-surgical period in 17 cases (first asymptomatic group), while the rest of contrast studies (26) belonged to a second group of out-patients complaining of dysphagia (18) or dyspepsia (8) following colonic replacement of the esophagus.
Background: Inflammatory bowel disease (IBD) is increasingly encountered in children. Early disease is associated with higher complication rate with increased incidence of surgical intervention.
Patients And Methods: From January 2010 to June 2015, 25 patients in the pediatric and adolescent age groups with IBD underwent surgical intervention in our center.
Gastrocolic reflux is a troublesome symptom causing repeated aspiration or chocking in patients underwent retrosternal colon interposition. Various techniques were described to avoid such complication, however, they entail complicated technique that may jeopardize the viability of the graft or cause obstructing symptoms. A simple antireflux procedure is described here alleviating this problem.
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