Sharif Digital Repository

For heating, ventilation or air conditioning purposes in massive multistory building constructions, ducts are a common choice for air supply, return, or exhaust. Rapid population expansion, particularly in industrially concentrated areas, has given rise to a tradition of erecting high-rise buildings in which contaminated air is removed by making use of vertical ducts. For satisfying the enormous energy requirements of such structures, high voltage wires are used which are typically positioned near the ventilation ducts. This leads to a consequent motivation of studying the interaction of magnetic field (MF) around such wires with the flow in a duct, caused by vacuum pump or exhaust fan etc.... 

Metal manufacturing plants, nuclear power plants (which produce steam, by using thermal energy yielded during the nuclear fission, for spinning enormous turbines to generate electricity), and geothermal power plants are a few in the extensive list of technologies where different processes occur in high temperature environment in the presence of strong magnetic fields. Nanofluids (NFs), on the other hand, have been successful in achieving wide acceptance as the next generation coolant in the above mentioned industries as well as in the automobiles, heat exchangers, and steam boilers, owing to their remarkable thermal performance. These observations motivate the authors to explore the change... 

The features of heat transferral capability between metallic (Cu) and non-metallic (TiO2) nanoparticles suspended in the engine-oil (EO) third-grade base-liquid has been analysed under the influence of strong magnetic field. The numerical investigation of system of coupled differential equations for third-grade nanofluid flow model is accomplished via Quasi-linearization method (QLM). The stretching horizontal sheet is heated through convective heat process assuming the special effects of thermal radiation, joule heating, heat generation and viscous dissipation in the energy equation. The mass suction and slip velocity at the boundary of the sheet has been taken into account to enhance... 

The present work numerically investigates the mass and heat transport flow of micropolar fluid in a channel having permeable walls. The appropriate boundary layer approximations are used to convert the system of flow model equations in ODEs, which are then numerically treated with the quasi-linearization method along with finite difference discretization. This technique creates an efficient way to solve the complex dynamical system of equations. A numerical data comparison is presented which assures the accuracy of our code. The outcomes of various problem parameters are portrayed via the graphs and tables. The concentration and temperature accelerate with the impacts of the Peclet numbers... 

Background: Combating viral hepatitis is part of the UN Sustainable Development Goals (SDGs), and WHO has put forth hepatitis B elimination targets in its Global Health Sector Strategy on Viral Hepatitis (WHO-GHSS) and Interim Guidance for Country Validation of Viral Hepatitis Elimination (WHO Interim Guidance). We estimated the global, regional, and national prevalence of hepatitis B virus (HBV), as well as mortality and disability-adjusted life-years (DALYs) due to HBV, as part of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019. This included estimates for 194 WHO member states, for which we compared our estimates to WHO elimination targets. Methods: The primary... 

Thermal performance of magnetically driven Casson nanofluid over a nonlinear stretching sheet under the influence of entropy, activation energy and convective boundary conditions was analyzed numerically, employing the quasi-linearization method (QLM). The collective behavior of thermophoretic diffusion and Brownian motion along with special effects of viscous dissipation, thermal radiation, heat generation and joule heating are considered in the energy equation for the flow problem. The addition of nanoparticles helps to stabilize the flowing of a nanofluid and maintain the symmetry of the flowing structure. The governing highly nonlinear coupled differential equations of velocity,... 

An enhancement in heat transfer due to nanofluids is essentially required in various thermal systems. Hybrid nanofluids possess high thermal conductivity and, have ability to embellish and enhance the thermal strength of common fluids. Our concern in this paper is to examine the innovative attributes of hybrid nanofluids like Manganese zinc ferrite (MnZnFe2O4) and Nickel zinc ferrite (NiZnFe2O4) in the bio-convective flow of motile gyrotactic microorganisms subject to Darcy Forchheimer medium. The effect of activation energy has also been taken into account. Mathematical treatment is carried out via MATLAB software. The use of MnZnFe2O4 - NiZnFe2O4/H2O exhibits improved thermal... 

Interpreting the complex interaction of nanostructured fluid flow with a dipole in a duct, with peripherally uniform temperature distribution, is the main focus of the current work. This paper also sheds light on the changes in the Nusselt number, temperature profiles, and velocity distributions for the fully developed nanofluid flow in a vertical rectangular duct due to a dipole placed near a corner of the duct. A finite volume approach has been incorporated for the numerical study of the problem. It is interesting to note the unusually lower values of the Nusselt number for the higher values of the ratio Gr/Re. Due to the nanostructure in the fluid, an enhancement in the Nusselt number has... 

Nano-fluids have considerable importance in the field of thermal development that relates to several industrial systems. There are some key applications in recent construction systems flow, as well as microscale cooling gadgets and microstructure electric gadgets for thermal migration. The current investigation concludes the study of electrically conducting nano-fluid flow and heat transfer analysis in two-dimensional boundary layer flow over a curved extending surface in the coexisting of magnetic field, heat generation and thermal radiation. The small sized particles of copper (Cu) are taken as nanoparticles and water is assumed to be the base fluid. We used quasi-linearization and central... 

Volatile organic compounds (VOCs) represent a very important class of pollutants that causes serious health effects. There is an urgent requirement to establish efficient technologies that can reduce and control VOCs. Non-thermal plasma (NTP) is an emerging technology that can decompose low concentration VOCs. However, the low efficiency and high power cost are major hindrances in its commercialization. In this work, Co–Cu with TiO2 support catalysts are prepared by using the deposition precipitation method and utilized in post-plasma catalysis for the efficient degradation of toluene selected as a model VOC. The synergistic effect of Co–Cu/TiO2 with different Co/Cu molar ratios along with... 

In drilling industry, energy consumption counts from 20 to 40 percent of total costs. Enhanced water-based mud (WBM) drilling fluids with nanoparticles can save energy in drilling processes. An in-house Taylor-Couette flow system (TCS) was developed at Australian University (AU) to study WBM enhanced by Al2O3, SiO2, and TiO2 nanoparticles. The TCS is really a practical tool to help well drillers with a rough idea of viscosity when nanoparticles are added. The TCS for sure cannot substitute advanced rheometry. The goal of the present experiment is to produce a rough estimate in field operation. Experimental results were examined with several rheology models in our previous publications. In... 

The effect of bisulfite (HSO3–) in nCaO2/Fe(III)/HSO3– system on improving HO• generation and trichloroethene (TCE) removal was innovatively reported. The enhancement mechanism of HSO3– for TCE removal in nCaO2/Fe(III)/HSO3– system was caused not only by the complexing and reducing effects on promoting the conversion of Fe(III) to Fe(II), but also due to the reaction with O2 in water to produce SO4–• for accelerating TCE degradation. A double effect of nCaO2 as an oxidant source to generate HO• and as a O2 source to promote SO4–• generation was revealed. A pseudo-second-order kinetic model of TCE removal was determined and 94.6% TCE degradation was achieved within 60 min at the... 

Magnetic field effects are encountered in many engineering applications which include but are not limited to metal casting, nuclear reactor coolers, and geothermal energy extraction. On the other hand, due to their outstanding thermal performance, nanofluids have been successful in obtaining acceptability as per the new generation of heat transfer fluids in automotive cooling devices, in heat exchangers, and building heating. Therefore, this research is carried out to understand how the nanofluid flow in a cavity is affected by a magnetic field (due to a dipole placed nearby). The single-phase model is employed for modeling the nanofluid, whereas the governing partial differential equations... 

The authors regret that during Proof of the article by Sun et al. [1], Fig. 6 and Fig. 7 were wrong. We reproduce below the relevant part of correct Fig. 6 and Fig. 7. Fig. 6. The concentration of SO42− in nCP/Fe(II)/FeS system. [nCP]0 = [Fe(II)]0 = 0.30 mM, [FeS]0 = 0.60 mM, [TCE]0 = 0.15 mM. [Figure presented] Fig. 7. Chloride ion liberation and its mass balance in nCP/Fe(II)/FeS system along with TCE degradation. [nCP]0 = [Fe(II)]0 = 0.30 mM, [FeS]0 = 0.60 mM, [TCE]0 = 0.15 mM. [Figure presented] © 2021 Elsevier B.V  

Dopamine is one of the most important neurotransmitters released by neurons in the central nervous system, and a variety of neurological illnesses and mental disorders are associated with impairments in the secretion and functionality of dopamine. Dopamine, depending on the type of receptors, can act as a stimulant or an inhibitor. In this study, dendrimer-conjugated dopamine was utilized as a chelating agent for Technetium-99m to investigate the organ distribution of this compound in vivo using the single-photon emission computed tomography (SPECT) technique. For this purpose, dendrimers were synthesized using polyethylene glycol diacid and citric acid precursors, and dopamine was... 

In this paper, heat and mass transportation flow of swimming gyrotactic microorganisms (microbes) and solid nanoparticles under the viscous dissipation effect is investigated. The flow model PDEs are renovated with ordinary ones using suitable boundary layer approximations. The system governing the flow model dimensionless equations as well as boundary conditions is numerically treated with the SOR (successive over relaxation) technique. The flow, heat, and mass transport characteristics are examined against the prime parameters. A comparison is examined to be in a good agreement with the earlier results. It is found here that flow and thermal characteristics of the problem are substantially... 

IMPORTANCE The Global Burden of Diseases, Injuries, and Risk Factors Study 2019 (GBD 2019) provided systematic estimates of incidence, morbidity, and mortality to inform local and international efforts toward reducing cancer burden. OBJECTIVE To estimate cancer burden and trends globally for 204 countries and territories and by Sociodemographic Index (SDI) quintiles from 2010 to 2019. EVIDENCE REVIEW The GBD 2019 estimation methods were used to describe cancer incidence, mortality, years lived with disability, years of life lost, and disability-adjusted life years (DALYs) in 2019 and over the past decade. Estimates are also provided by quintiles of the SDI, a composite measure of educational... 

Network function virtualization (NFV) and software-defined networking (SDN) are two promising technologies to enable 5G and 6G services and achieve cost reduction, network scalability, and deployment flexibility. However, migration to full SDN/NFV networks in order to serve these services is a time-consuming process and costly for mobile operators. This paper focuses on energy efficiency during the transition of mobile core networks (MCN) to full SDN/NFV networks and explores how energy efficiency can be addressed during such migration. We propose a general system model containing a combination of legacy nodes and links, in addition to newly introduced NFV and SDN nodes. We refer to this... 

Background: Diesel mainly consists of paraffin and thio-aromatic compounds. Sulfur present in diesel exhaust is the major challenge for oil refineries. Sulfur is an oxidizing element that discharges as acute pollutant in the environment, having adverse effects on human and animal life. Introduction: The scope of this review paper is to discuss and highlight the recent advancements in the process of desulfurization of diesel oil to explore the less energy-intensive and more economical process. Methods: Recently, different techniques are widely used for desulfurization of diesel oil to remove sulfur containing compounds from diesel. These techniques mainly involve hydrodesulfurzation,... 

Background: Water contamination by noxious heavy metals due to urbanization is a global environmental problem. Heavy metal ions pollution makes the water unsuitable for drinking and is also highly toxic to human beings and eco-system. The remediation of heavy metals is therefore very crucial. Methods: Adsorbents based on biopolymer and eco-friendly polymer composites have been developed and fabricated to remediate and remove heavy metals from the ecosystem. Results: In recent years biocomposites have been successful as cost-effective adsorbents for the remediation of various contaminants with their eco-friendly nature and sustainability. Conclusion: This review article gives an overview on...