Flexural and Shear Capacities of Reinforced Concrete Beams with Volcanic Tuff

An experimental investigation was carried out to study the effect of volcanic tuff (V.T.), as a fine aggregate on the flexural and shear capacities of reinforced concrete beams. Three different types of volcanic tuff which is a local material that is available at different locations in Jordan (known as yellow, gray and brown volcanic tuff) were used in this study. Four grades of concrete compressive strengths (20, 30, 40 and 50 MPa) are also used. The experimental program consisted of testing 64 beams (16 beams with 0% of volcanic tuff and 16 beams with 20% volcanic tuff as a fine aggregate for each type of volcanic tuff). The analysis showed that replacing the fine aggregate by 20% volcanic tuff will improve the flexural and shear capacities of the reinforced concrete beams by 6% to 16% for brown tuff, 3% to 8% for gray tuff and 10 % to 26 % for yellow tuff for the four concrete strength grades.Key Words: Pozzolan (Volcanic tuff), flexural and shear capacities, Reinforced concrete beam

Optimization of Tuff Stones Content in Lightweight Concrete Using Artificial Neural Networks

Tuff stones are volcanic sedimentary rocks formed by the consolidation of volcanic ash. They possess unique geological properties that make them attractive for a variety of construction and architectural applications. Considerable amounts and various types of Tuff stones exist in the eastern part of Jordan. However, the use of Tuff stones often requires experimental investigations that can significantly impact the accuracy of their physical and mechanical characteristics. To ensure consistent and predictable properties in their mix design, it is essential to minimize the effects of these experimental procedures. Artificial neural networks (ANNs) have emerged as a promising tool to address such challenges, leveraging their ability to analyze complex data and optimize concrete mix design. In this research, ANNs have been used to predict the optimum content of Tuff fine aggregate to produce structural lightweight concrete with a wide range (20 to 50 MPa) of compressive strength. Three different types of Tuff aggregates, namely gray, brown, and yellow Tuff, were experimentally investigated. A set of 68 mixes was produced by varying the fine-tuff aggregate content from 0 to 50%. Concrete cubes were cast and tested for their compressive strength. These samples were then used to form the input dataset and targets for ANN. ANN was created by incorporating the recent advancements in deep learning algorithms, and then it was trained, validated using data collected from the literature, and tested. Both experimental and ANN results showed that the optimum content of the various types of used Tuff fine aggregate ranges between 20 to 25%. The results revealed that there is a clear agreement between the predicted values using ANN and the experimental ones. The use of ANNs may help to cut costs, save time, and expand the applications of Tuff aggregate in lightweight concrete production. Doi: 10.28991/CEJ-2023-09-11-013 Full Text: PD

Antibody loaded collapsible hyaluronic acid hydrogels for intraocular delivery

Injectable gels have the potential to encapsulate drugs for sustained release of protein therapeutics for use in the eye. Hyaluronic acid (HA) is a biodegradable clinically used material and poly N-isopropylacrylamide (pNIPAAM) is a stimuli responsive polymer that can display a lower critical solution temperature (LCST) at physiological conditions. Two gel systems incorporating HA were prepared in the presence of the antibody infliximab (INF): i) 1% and 5 % tyramine-substituted HA (HA-Tyr) was enzymatically crosslinked in the presence of INF to form HA-Tyr-INF and ii) NIPAAM was chemically crosslinked in the presence of HA and INF with 1 and 3% poly(ethylene glycol) diacrylate (PEGDA) to form PEGDA-pNIPAAM-HA-INF. The PEGDA-pNIPAAM-HA-INF hydrogels displayed LCSTs at temperatures ranging from 31.4 ± 0.2 to 35.7 ± 0.3°C. Although all the gels prepared were injectable, INF-loaded gels with lower crosslinking density (1% PEGDA-pNIPAAM-HA and 1% HA-Tyr) showed lower elastic (G') and viscous (G'') moduli compared to higher crosslinked gels (3% PEGDA-pNIPAAM-HA-INF and 5% HA-Tyr-INF) resulting in differences in swelling ratio (SR). Moduli may be correlated with overall stiffness of the gel. All hydrogels demonstrated sustained release of INF in a two-compartment in vitro outflow model of the human eye called the PK-Eye. The 1% PEGDA-pNIPAAM-HA-INF hydrogel displayed the slowest release (24.9 ± 0.4% INF release by day 9) in phosphate buffered saline (PBS, pH 7.4), which is a better release profile than the free drug alone (tested under the same conditions). These results suggest that PEGDA-pNIPAAM-HA has potential for the continued development of formulations to prolong the intraocular release of proteins

Big data fusion to estimate urban fuel consumption: A case study of Riyadh

This is the author accepted manuscript. The final version is available from SAGE Publications via the DOI in this recordFalling oil revenues and rapid urbanization are putting a strain on the budgets of oil-producing nations, which often subsidize domestic fuel consumption. A direct way to decrease the impact of subsidies is to reduce fuel consumption by reducing congestion and car trips. As fuel consumption models have started to incorporate data sources from ubiquitous sensing devices, the opportunity is to develop comprehensive models at urban scale leveraging sources such as Global Positioning System (GPS) data and Call Detail Records. This paper combines these big data sets in a novel method to model fuel consumption within a city and estimate how it may change in different scenarios. To do so a fuel consumption model was calibrated for use on any car fleet fuel economy distribution and applied in Riyadh, Saudi Arabia. The model proposed, based on speed profiles, was then used to test the effects on fuel consumption of reducing flow, both randomly and by targeting the most fuelinefficient trips in the city. The estimates considerably improve baseline methods based on average speeds, showing the benefits of the information added by the GPS data fusion. The presented method can be adapted to also measure emissions. The results constitute a clear application of data analysis tools to help decision makers compare policies aimed at achieving economic and environmental goals.MIT Energy Solutions InitiativeCenter for Complex Engineering Systems, King Abdulaziz City for Science and TechnologyRoyal SocietyBritish AcademyAcademy of Medical Science

Cytokine storm of a different flavor: the different cytokine signature of SARS-CoV2 the cause of COVID-19 from the original SARS outbreak.

We present a case series of three patients with COVID-19 who had a cytokine panel which revealed elevation of interleukin-6 (IL-6), but normal levels of interleukin-10 (IL-10), interferon-gamma (INF-γ) and interleukin-8 (IL-8) in contrast to the cytokine signature described in Severe Acute Respiratory Syndrome (SARS) and Middle Eastern Respiratory Syndrome (MERS). We also documented evidence of a compromised T-cell IFN-gamma response in two of these patients

Effects of esomeprazole on healing of non-steroidal anti-inflammatory drug (NSAID)-induced gastric ulcers in the presence of a continued NSAID treatment: characterization of molecular mechanisms

Proton pump inhibitors promote ulcer repair in nonsteroidal anti-inflammatory drug (NSAID)-treated patients with ongoing NSAID-induced gastric toxicity, although the underlying mechanisms remain unclear. We examined the healing mechanisms of esomeprazole on NSAID-induced gastric ulcerations in the presence of a continued NSAID treatment. Ulcerations were induced in rats by oral indomethacin (6 mu mol/kg/day) for 14 days. Indomethacin administration was continued, alone or combined with equivalent acid inhibitory doses of esomeprazole (5 mu mol/kg/day), lansoprazole (15 mu mol/kg/day) or famotidine (20 mu mol/kg/day), for additional 7 days. Stomachs were then processed for: histomorphometric analysis of mucosal injury; mucosal levels of prostaglandin E-2 (PGE(2)) and malondialdehyde (MDA); expression of vascular endothelial growth factor (VEGF), proliferating cell nuclear antigen (PCNA), caspase-3, and cyclooxygenase-2 (COX-2) (Western blot); expression of Ki-67 (immunohistochemistry). Indomethacin for 14 days elicited mucosal damage, reduced PGE(2) levels and increased MDA. After additional 7 days, indomethacin induced the following effects: further enhancement of mucosal damage and MDA content; decrease in PGE(2) levels; increase in COX-2 and activated caspase-3 expression; decrease in VEGF. PCNA and Ki-67 expression. In the presence of indomethacin, esomeprazole and lansoprazole were more effective than famotidine in promoting resolution of mucosal damage. Concomitantly, esomeprazole and lansoprazole, but not famotidine, restored PCNA and Ki-67 expression, and normalized MDA levels. Moreover, esomeprazole, lansoprazole and famotidine partly counteracted caspase-3 activation, without affecting VEGF expression. The healing activity of esomeprazole on indomethacin-induced gastric ulcerations can be ascribed to two mechanisms: (1) acid-dependent reduction of pro-apoptotic signalling; (2) acid-independent restoration of proliferating/repairing pathways. (C) 2010 Elsevier Ltd. All rights reserved