Compartment Fire Toxicity: Measurements and Aspects of Modelling

Fire statistics from the UK and the USA attribute 60% to 70% of fire fatalities in dwellings to the inhalation of fire toxic smoke. The objective of this project was to provide more toxic yield data from typical compartment fires and in the process develop a methodology for faster generation of such data on bench scale apparatus. The models for overall toxicity assessment (for irritants and asphyxiants) were reviewed and the reported threshold limits for typical smoke toxicants, were collected, categorised and compared for increasing levels of harm. An extensive database was created of yields of toxic species from different materials and under different fire conditions. This highlighted the need for more yield data for under-ventilated fires in compartments. Eight full scale tests were carried out in a room enclosure with ventilation through a corridor to a front access door. Fire loads were wood pallets, cotton linen and towels, typical living room furniture and diesel. The fires were allowed to become fully developed before extinguishment by the local FRS team. Toxic concentrations were monitored in the hot layer and the corridor (through a heated sampling line) using a heated FTIR analyser, calibrated for 65 species. An emissions based model, developed as part of this work, was used to quantify the equivalence ratio and also the toxic species yields, even for the cases where the fuel mass loss rate was unknown. An important finding was the overwhelming contribution of Acrolein and Formaldehyde in most tests, in exceeding the impairment of escape threshold. The modified controlled atmosphere cone calorimeter showed comparable results to the full scale tests for lean burning combustion however it proved difficult at this stage to produce combustion in the rich burning regime and further development of the methodology is needed

Fractional electro-magneto transport of blood modeled with magnetic particles in cylindrical tube without singular kernel

The electro-kinetic transport of blood flow mixed with magnetic particles in the circular channel was investigated. The flow was subjected to an external electric and uniform magnetic field. The fluid was driven by pressure gradient and perpendicular magnetic field to the flow direction. Due to the usefulness and suitability of Caputo–Fabrizio fractional order derivative without singular kernel in fluid flow modeling and mass transfer phenomena, the governing equations were modeled as Caputo–Fabrizio time fractional partial differential equations and solved for a 2 ð0; 1�. The analytical solutions for the velocities of blood flow and magnetic particles were obtained by using Laplace, finite Hankel transforms and Robotnov and Hartley’s functions, respectively. Mathematica software was used to simulate the influences of fractional parameter a, Hartmann number and Reynolds number on the velocities of blood and magnetic particles. The findings are important for controlling bio-liquids in the devices used for analysis and diagnosis in biological and medical applications

Sedimentary cover and structural trends affecting the groundwater flow in the Nubian Sandstone Aquifer System: Inferences from geophysical, field and geochemical data

This study combined gravity data from the Earth Gravitational Model (EGM2008) with other data to better understand the spatial variations of the sedimentary cover and the structural trends that affect groundwater flow in the Nubian Sandstone Aquifer System. Our findings were verified and evidenced by geological, geochronological, geochemical data, and earthquake records: 1) The Uweinat-Aswan basement uplift, which runs east-west, partially isolates the Dakhla subbasin from the shallower northern Sudan subbasin, and thereby impeding the south-to-north groundwater flow from northern Sudan platform to the Dakhla subbasin; 2) A thickening of the sedimentary cover in the NE-SW direction from the southern Kufra through the northern Kufra to the Dakhla subbasin; 3) The sedimentary cover was found to increase from less than 500 m in the south (Northern Sudan and Uweinat region) to more than 6 km in the north (Mediterranean coast); 4) A number of structural trends (NE-SW, N-S, E-W, and NW-SE) affecting the region; 5) A large Pelusium megashear system that runs northeast to southwest makes it easier for groundwater to flow from the Kufra subbasin to the Dakhla subbasin; 6) Along the paths that groundwater takes, like from Siwa to Qattara and from northwest Farafra to north Bahariya, and along structures that run in the same direction as the flow, a progressive increase in 36Cl groundwater ages were observed; 7) It is a better way to learn about the hydrogeological context of large aquifers and figure out how to best manage these underground water sources

Assessing geochemical and natural radioactivity impacts of Hamadat phosphatic mine through radiological indices

The utilization of phosphorite deposits as an industrial resource is of paramount importance, and its sustainability largely depends on ensuring safe and responsible practices. This study aims to evaluate the suitability of phosphorite deposits for industrial applications such as the production of phosphoric acid and phosphatic fertilizers. To achieve this goal, the study meticulously examines the geochemical characteristics of the deposits, investigates the distribution of natural Radioactivity within them, and assesses the potential radiological risk associated with their use. The phosphorites are massive and collected from different beds within the Duwi Formation at the Hamadat mining area. They are grain-supported and composed of phosphatic pellets, bioclasts (bones), non-phosphatic minerals, and cement. Geochemically, phosphorites contain high concentrations of P2O5 (23.59-28.36 wt.%) and CaO (40.85-44.35 wt.%), with low amounts of Al2O3 (0.23-0.51 wt.%), TiO2 (0.01-0.03 wt.%), Fe2O3 (1.14-2.28 wt.%), Na2O (0.37-1.19 wt.%), K2O (0.03-0.12 wt.%), and MnO (0.08- 0.18 wt.%), suggesting the low contribution of the detrital material during their deposition. Moreover, they belong to contain enhanced U concentration (55-128 ppm). They are also enriched with Sr, Ba, Cr, V, and Zn and depleted in Th, Zr, and Rb, which strongly supports the low detrital input during the formation of the Hamadat phosphorites. The high Radioactivity of the studied phosphorites is probably due to the widespread occurrence of phosphatic components (e.g., apatite) that accommodate U in high concentrations. Gamma spectrometry based on NaI (Tl) crystal 3×3 has been used to measure occurring radionuclides in the phosphorite samples. The results indicate that the radioactive concentrations' average values of 226Ra, 232Th, and 40K are 184.18±9.19, 125.82±6.29, and 63.82±3.19 Bq Kg-1 , respectively. Additionally, evaluations have been made of the radiological hazards. The calculated risk indicators exceeded the recommended national and world averages. The data obtained will serve as a reference for follow-up studies to evaluate the effectiveness of the Radioactivity of phosphatic materials collected from the Hamdat mine area. © 2023 Fathy et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Physico-mechanical properties and shielding efficiency in relation to mineralogical and geochemical compositions of Um Had granitoid, Central Eastern Desert, Egypt

The current work aims to describe the physico-mechanical characteristics and shielding efficiency with reference to the mineralogical and geochemical compositions of the Neoproterozoic Um Had composite granitoid pluton in order to deduce their favorability as dimension stones. The Um Had granitoid pluton has an elliptical outline with a mean diameter of about 10 km. This pluton is a composite (ranging from white to reddish pink color), hard, massive, and medium- to coarse-grained granitoid body. It is classified as syenogranite according to their modal and bulk chemical compositions. Geochemically, the granitoid pluton is a highly calc-alkaline, peraluminous granite, formed by low degree partial melting of tonalitic source rock in a post-collisional tectonic setting. The physico-mechanical properties of the granitoid pluton under study satisfy the requirements of dimension stone in terms of their bulk density (from 2561 to 2564 kg/m3), and to some extent water absorption capacity (from 0.38% to 0.55%). However, their compressive strength values (50.4–113.4 MPa) do not achieve the minimum requirement for interior use and light duty exterior use. This study delves into the potential of some of our syenogranite samples (I, IIA, IIS, and 10) as gamma radiation shielding materials. We have assessed the mass attenuation coefficient (GMAC), effective atomic number (Zeff), exposure build-up factor (EBF), and energy absorption build-up factor (EABF) for each of these samples. The GMAC and Zeff calculations were performed using the Phy-X online software, across a photon energy range of 0.015–15 MeV. Our findings suggest an inverse relationship between photon energy and GMAC, with the highest values observed for the (I) granite sample (∼18). This study shows the promising radiation shielding capacity of our samples. The insights derived from GMAC, Zeff, EBF, and EABF can serve as a guide for the development of effective, naturally sourced radiation shielding materials. Copyright © 2023 Rashwan, Lasheen, Abdelwahab, Azer, Zakaly, Alarifi, Ene and Thabet.King Saud University, KSUThis research was supported by the Researchers Supporting Project number (RSP2023R496), King Saud University, Riyadh, Saudi Arabia

Petrogenesis and Tectonic Implications of the Cryogenian I-Type Granodiorites from Gabgaba Terrane (NE Sudan)

The widely distributed granitic intrusions in the Nubian Shield can provide comprehensive data for understanding its crustal evolution. We present new bulk-rock geochemistry and isotopic (zircon U-Pb and Lu-Hf) data from the Haweit granodiorites in the Gabgaba Terrane (NE Sudan). The dated zircons presented a 206Pb/238U Concordia age of 718.5 ± 2.2 Ma, indicating that they crystallized during the Cryogenian. The granodiorites contain both biotite and amphibole as the main mafic constituents. The samples exhibit metaluminous (A/CNK = 0.84–0.94) and calc-alkaline signatures. Their mineralogical composition and remarkable low P2O5, Zr, Ce, and Nb concentrations confirm that they belong to I-type granites. They exhibit subduction-related magma geochemical characters such as enrichment in LILEs and LREEs and depletion in HFSEs and HREEs, with a low (La/Yb)N ratio (3.0–5.9) and apparent negative Nb anomaly. The positive Hf(t) values (+7.34 to +11.21) and young crustal model age (TDMC = 734–985 Ma) indicates a juvenile composition of the granodiorites. The data suggest that the Haweit granodiorites may have formed from partially melting a juvenile low-K mafic source. During subduction, the ascending asthenosphere melts might heat and partially melt the pre-existing lower crust mafic materials to generate the Haweit granodiorites in the middle segment of the Nubian Shield. © 2023 by the authors.King Saud University, KSUThis research was supported by Researchers Supporting Project number (RSP2023R496), King Saud University, Riyadh, Saudi Arabia. The author AE would like to thank “Dunarea de Jos” University of Galati, Romania, INPOLDE infrastructure, for the material and technical support.This research was supported by Researchers Supporting Project number (RSP2023R496), King Saud University, Riyadh, Saudi Arabia. The author A.E. would like to thank “Dunarea de Jos” University of Galati, Romania, INPOLDE infrastructure, for the material and technical support. The authors would like to thank the editors and the reviewers for their precious time, detailed and constructive reviews, and additional comments which significantly improved the manuscript

Shear Strength of Copper Joints Prepared by Low Temperature Sintering of Silver Nanoparticles

In this work, mechanical properties of Cu-to-Cu joint samples prepared by low temperature sintering of Ag nanoparticle paste have been investigated. The silver nanopaste was prepared by a controlled thermal decomposition of an organometallic precursor. The as-synthesized Ag particles were spherical, with an average diameter of 8.5 nm. The Cu-to-Cu joint samples were made by placing a small amount of Ag nanopaste between two polished Cu plates and sintering at 150C, 200C, 220C and 350C in air. A normal load was applied to aid sintering. Mechanical properties were measured by imposing a uniform stress across the sample bond area and measuring the corresponding strain. The application of external load was found to have a positive effect on the material’s mechanical properties. Furthermore, interestingly high values of shear strength were observed.Byly zkoumány mechanické vlastnosti Cu-to-Cu spojů připravených nízkoteplotní sintrací pasty Ag nanočástic. Ag nanopasta byla připravena řízeným tepelným rozkladem organokovových prekurzorů. Syntetizované Ag NPs byly kulovité, o středním průměru 8,5 nm. Cu-to-Cu spoje byly vyrobeny umístěním malého množství Ag nanopasty mezi dvě leštěné Cu desky a sintrováním při 150C, 200C, 220C and 350C na vzduchu. Zatížení bylo použito na k podpoře sintrace. Mechanické vlastnosti byly měřeny stanovením napětí lomu a deformace. Bylo zjištěno, že aplikace vnějšího zatížení má pozitivní vliv na mechanické vlastnosti spoje

Developments in Nanoparticles Enhanced Biofuels and Solar Energy in Malaysian Perspective: A Review of State of the Art

The rapid rise in global oil prices, the scarcity of petroleum sources, and environmental concerns have all created severe issues. As a result of the country's rapid expansion and financial affluence, Malaysia's energy consumption has skyrocketed. Biodiesel and solar power are currently two of the most popular alternatives to fossil fuels in Malaysia. These two types of renewable energy sources appear to be viable options because of their abundant availability together with environmental and performance competence to highly polluting and fast depleting fossil fuels. The purpose of adopting renewable technology is to expand the nation's accessibility to a reliable and secure power supply. The current review article investigates nonconventional energy sources added with nanosized metal particles called as nanomaterials including biodiesel and solar, as well as readily available renewable energy options. Concerning the nation's energy policy agenda, the sources of energy demand are also investigated. The article evaluates Malaysia's existing position in renewable energy industries, such as biodiesel and solar, as well as the impact of nanomaterials. This review article discusses biodiesel production, applications, and government policies in Malaysia, as well as biodiesel consumption and recent developments in the bioenergy sector, such as biodiesel property modifications utilizing nanoparticle additions. In addition, the current review study examines the scope of solar energy, different photovoltaic concentrators, types of solar energy harvesting systems, photovoltaic electricity potential in Malaysia, and the experimental setup of solar flat plate collectors (FPC) with nanotechnology

Biomimetic electrospun nanofibrous scaffold for tissue engineering: preparation, optimization by design of experiments (DOE), in-vitro and in-vivo characterization

Electrospinning is a versatile method for fabrication of précised nanofibrous materials for various biomedical application including tissue engineering and drug delivery. This research is aimed to fabricate the PVP/PVA nanofiber scaffold by novel electrospinning technique and to investigate the impact of process parameters (flow rate, voltage and distance) and polymer concentration/solvent combinations influence on properties of electrospun nanofibers. The in-vitro and in-vivo degradation studies were performed to evaluate the potential of electrospun PVP/PVA as a tissue engineering scaffold. The solvents used for electrospinning of PVP/PVA nanofibers were ethanol and 90% acetic acid, optimized with central composite design via Design Expert software. NF-2 and NF-35 were selected as optimised nanofiber formulation in acetic acid and ethanol, and their characterization showed diameter of 150–400 nm, tensile strength of 18.3 and 13.1 MPa, respectively. XRD data revealed the amorphous nature, and exhibited hydrophilicity (contact angles: 67.89° and 58.31° for NF-2 and NF-35). Swelling and in-vitro degradability studies displayed extended water retention as well as delayed degradation. FTIR analysis confirmed solvent-independent interactions. Additionally, hemolysis and in-vitro cytotoxicity studies revealed the non-toxic nature of fabricated scaffolds on RBCs and L929 fibroblast cells. Subcutaneous rat implantation assessed tissue response, month-long biodegradation, and biocompatibility through histological analysis of surrounding tissue. Due to its excellent biocompatibility, this porous PVP/PVA nanofiber has great potential for biomedical applications