Effect of Bottom Blowing Mode on Fluid Flow and Mixing Behavior in Converter

Bottom blowing agitation plays a crucial role in improving the reaction kinetics condition of molten bath during the steelmaking process. Herein, the influence of bottom blowing mode on the flow and mixing characteristics of molten bath and the abrasion characteristics of refractory lining in a 6:1 scaled-down model of a 100 t converter were investigated using physical and numerical simulations together. Eight bottom blowing modes were designed (uniform, three-point linear co-direction, three-point linear unco-direction, two-point linear, circumferential linear, A-type, V-type, and triangle alternating). The results indicated that bottom blowing mode has a significant effect on the local flow field at the inner ring of bottom tuyeres, the velocity interval distribution, and the turbulent kinetic energy, which in turn determines the tracer diffusion path and rate as well the mixing time of molten bath. Reasonable non-uniform bottom blowing modes promote the interaction between the various stirring sub-zones of the molten bath. Among them, the three-point linear co-direction mode and A-type mode have the highest mixing efficiency under the conditions of bottom blowing and combined blowing, respectively, which is superior to the uniform mode. In addition, the bottom blowing mode changed the location and degree of abrasion of the refractory lining, and the total abrasion of the non-uniform mode was reduced. The average value and fluctuation degree of integral wall shear stress for the A-type mode were minimal.

An Updated Review on Nanomaterials for Biomedical Advancements: Concepts and Applications

The sphere of Nanotechnology encompasses most of our lives and houses biomedicine and biomedical advancements. Nanoparticles owing to their minuscule sizes and due to various physicochemical and electrical properties have been exploited in pharmaceutical industries, agriculture, packaging, cosmetic, food industries. Nanomedicine is a laboratory-designed molecular-level pharmaceutical material that has revolutionized diagnostic techniques and therapeutics. Nanoscience and nanotechnology and their wide applications have become spread field worldwide because nanomaterials have novel and unique properties. Nanotechnology involves understanding and manipulating materials normally in the size range of 1 to 100 nm, where they show completely novel physicochemical properties from their bulk counterpart. The capacity to study compounds at the molecular level has aided the hunt for materials with exceptional qualities for medical applications. Nanotechnology in recent days is applied in the designing of nano biosensors. Nanobiosensors are biological molecules immobilized onto the surface of a signal transducer. The application of nano biosensors in the field of disease detection has increased in recent years which has influenced in research of cancer and biosensing. Due to the high surface area of nanoparticles, they are important in the production of nano biosensors with high levels of sensitivity and diminish the response times. However, a comprehensive review regarding the type, mode of function, and their application in various diseases is missing. Nano Deterministic lateral displacement technology that provided exosome splitting based on size differences has resulted in providing the much-needed boost to cancer research. The time taken for cancer screening has been reduced drastically. that This review aims to describe the utilization of nano deterministic lateral displacement technology, nano biosensors, and their applications in certain disease diagnoses.

Experimental Investigation on Hydraulic Fracture Morphology of Inter-Salt Shale Formation

The inter-salt shale in the Qianjiang formation of Jianghan Basin in China is characterized by multiple salt-shale bedding planes, various rock strength, and high heterogeneity of rock mechanics. In this paper fracturing experiments under different conditions were carried out to study the effects of the injection velocity, type of fracturing fluid and interface strength on the propagation law of hydraulic fracture in the salt sedimentary rhythm there. In the meantime, Acoustic emission system and radial strain sensor were applied to monitor experimental process. The result indicates that 1) compared with the shale, there are four fracture propagation modes mainly being observed: passivating type (Mode I), “I”-type (Mode II), penetration type (Mode III) and mixed type ((Mode IV)), among which the mixed type is the relatively complex crack propagation mode. 2) With the increase of injection rate and viscosity of fracturing fluid, the hydraulic fracture will penetrate cementation surface more easily. 3) The increase of flow rate and viscosity will increase the breakdown pressure. The breakdown pressure of high strength cementation surface is 16.70% higher than that of low strength.

Community Interpreting: signed or spoken? Types, modes, and methods

This article focuses on the similarities and differences between spoken and signed language Community Interpreting (CI). After a briefoverview of the various terms that are generally used in the relevant literature – albeit in- consistently – to categorize various sorts of interpreting (type, mode, setting), we examine a number of typologies of interpreting events that have been developed in order to allowfor a more complex categorization of such events. A briefoutline of the history of research into spoken and signed language CI is complemented by a short description of the similarities and differences between spoken and signed language CI. We also discuss various examples of research methods that have been applied to spoken and signed language CI.

Elderly Anticoagulated Patient in General Dental Practice Case Reports from everyday Life

The anticoagulated elderly patient represents a major and sometimes dreaded challenge for the dentist on a daily basis, as postoperative bleeding can lead to serious problems, especially during dental surgical procedures. Knowledge of the various anticoagulants with regard to type, mode of action and influences on dental surgical procedures is indispensable for the dentist. Using case studies from the everyday life of a dental practice in a small town in Thuringia, this problem will be examined in more detail.

What factors are associated with forms of mistreatment during facility-based childbirth? A survey of referral health facilities in south-east Nigeria

Mistreatment during childbirth in health facilities contributes significantly to suboptimal levels of skilled birth attendance. This study determined the factors associated with mistreatment during facility-based childbirth in two referral facilities in south-east Nigeria. A survey of 620 women whose childbirth occurred in two high-patronage referral hospitals of Ebonyi, Nigeria, was conducted in July–September 2018 using interviewer-administered questionnaires. Data analysis was performed using SPSS version 20. Logistic regression was used to identify predictors. The mean age of the respondents was 29.86 ± 4.4 years. Most had post-secondary education (71.0%), and had attended at least four antenatal visits (83.4%). The prevalence of any mistreatment during childbirth was 56%. Rural residence (adjusted odds ratio [AOR]: 0.53; CI: 0.35, 0.78, p = 0.002) and childbirth facilitated by a doctor (AOR: 1.7; CI: 1.14, 2.39, p = 0.007) were predictors of reporting at least one form of mistreatment during childbirth. Childbirth facilitated by a doctor (AOR: 1.66; CI: 1.05, 2.63, p = 0.031) and unemployment (AOR: 1.84; CI: 1.01, 3.07, p = 0.011) increased the odds of non-consented and non-dignified care, respectively. Rural residence (AOR: 0.57; CI: 0.37, 0.88, p = 0.011) and childbirth facilitated by a doctor (AOR: 0.65; CI: 0.45, 0.94, p = 0.020) were protective against abandonment/neglect. Vaginal birth (AOR: 0.33; CI: 0.16, 0.69, p = 0.003) reduced the odds of detention in the health facility following childbirth. Almost three-fifths of the women whose childbirths occurred in the surveyed facilities experienced at least one form of mistreatment during childbirth. Place of residence, health professional type, mode of childbirth, employment status and frequency of antenatal attendance were predictors of mistreatment during childbirth. Rights-based sensitization for women, especially in the rural areas, female empowerment, provider capacity-building on respectful client care and provision of subsidized maternal health services are recommended.

Hall instability: origin, properties and asymptotic theory for its tearing mode

Hall instability in electron magnetohydrodynamics is interpreted as the shear-Hall instability driven jointly by helicoidal oscillations and shear in the electron current velocity. This explanation suggests an antiparallel orientation of the background magnetic field and vorticity of the current velocity as the necessary condition for Hall instability. The condition is tested and generally confirmed by numerical computations in plane slab geometry. Unstable eigenmodes are localized in the spatial regions of the antiparallel field and vorticity. Computations of the tearing-type mode of the instability are complemented by (and generally agree with) asymptotic analytical estimations for large Hall numbers. The stabilizing effect of perfect conductor boundary conditions is found and explained. For large Hall numbers, the growth rates approach the power-law dependence $\sigma \propto B^\alpha \eta ^{1-\alpha }$ on the magnetic field ( $B$ ) and diffusivity ( $\eta$ ). Almost all computations give the power index $\alpha = 3/4$ with one exception of the tearing-type mode with vacuum boundary conditions for which case $\alpha = 2/3$ .

A novel approach to trypsin inhibition by flavonoids

Trypsin is a key protease related to digestion and absorption of proteins, which its inhibition must be studied when natural compounds, such as flavonoids, are used as part of alternative treatments for obesity and diabetes mellitus type 2, since trypsin and together with other pancreatic enzymes worked at small intestine. Considering that flavonoids are good lipase and amylase inhibitors, trypsin-flavonoids interactions were analyzed through UV-Vis, intrinsic and extrinsic fluorescence spectroscopies, circular dichroism, and molecular docking. The interaction between porcine pancreas trypsin and five flavonoids: hesperetin (HES), luteolin (LUT), quercetin (QUE), catechin (CAT), and rutin (RUT) was evaluated. Most of them exhibited a mixed-type mode. LUT was the best trypsin inhibitor (e.g., lower IC50, 45.20±1.00 µM). All flavonoids-trypsin complexes showed static quenching, and QUE and LUT exhibited higher affinity (higher Ka values, 0.90±0.10 and 1.60±0.20·10-1 mM-1, respectively). Hydrophobic interactions between trypsin and flavonoids were predominant.

Nordihydroguaiaretic Acid as a Novel Substrate and Inhibitor of Catechol O-Methyltransferase Modulates 4-Hydroxyestradiol-Induced Cyto- and Genotoxicity in MCF-7 Cells

Nordihydroguaiaretic acid (NDGA) is a major lignan metabolite found in Larrea spp., which are widely used in South America to treat various diseases. In breast tissue, estradiol is metabolized to the catechol estrogens such as 4-hydroxyestradiol (4-OHE2), which have been proposed to be cancer initiators potentially involved in mammary carcinogenesis. Catechol-O-methyltransferase (COMT) catalyzes the O-methylation of catechol estrogens to their less toxic methoxy derivatives, such as 4-O-methylestradiol (4-MeOE2). The present study investigated the novel biological activities of NDGA in relation to COMT and the effects of COMT inhibition by NDGA on 4-OHE2-induced cyto- and genotoxicity in MCF-7 human breast cancer cells. Two methoxylated metabolites of NDGA, 3-O-methylNDGA (3-MNDGA) and 4-O-methyl NDGA (4-MNDGA), were identified in the reaction mixture containing human recombinant COMT, NDGA, and cofactors. Km values for the COMT-catalyzed metabolism of NDGA were 2.6 µM and 2.2 µM for 3-MNDGA and 4-MNDGA, respectively. The COMT-catalyzed methylation of 4-OHE2 was inhibited by NDGA at an IC50 of 22.4 µM in a mixed-type mode of inhibition by double reciprocal plot analysis. Molecular docking studies predicted that NDGA would adopt a stable conformation at the COMT active site, mainly owing to the hydrogen bond network. NDGA is likely both a substrate for and an inhibitor of COMT. Comet and apurinic/apyrimidinic site quantitation assays, cell death, and apoptosis in MCF-7 cells showed that NDGA decreased COMT-mediated formation of 4-MeOE2 and increased 4-OHE2-induced DNA damage and cytotoxicity. Thus, NDGA has the potential to reduce COMT activity in mammary tissues and prevent the inactivation of mutagenic estradiol metabolites, thereby increasing catechol estrogen-induced genotoxicities.

A new imaging concept in spin polarimetry based on the spin-filter effect

The concept of an imaging-type 3D spin detector, based on the combination of spin-exchange interactions in the ferromagnetic (FM) film and spin selectivity of the electron–photon conversion effect in a semiconductor heterostructure, is proposed and demonstrated on a model system. This novel multichannel concept is based on the idea of direct transfer of a 2D spin-polarized electron distribution to image cathodoluminescence (CL). The detector is a hybrid structure consisting of a thin magnetic layer deposited on a semiconductor structure allowing measurement of the spatial and polarization-dependent CL intensity from injected spin-polarized free electrons. The idea is to use spin-dependent electron transmission through in-plane magnetized FM film for in-plane spin detection by measuring the CL intensity from recombined electrons transmitted in the semiconductor. For the incoming electrons with out-of-plane spin polarization, the intensity of circularly polarized CL light can be detected from recombined polarized electrons with holes in the semiconductor. In order to demonstrate the ability of the solid-state spin detector in the image-type mode operation, a spin detector prototype was developed, which consists of a compact proximity focused vacuum tube with a spin-polarized electron source [p-GaAs(Cs,O)], a negative electron affinity (NEA) photocathode and the target [semiconductor heterostructure with quantum wells also with NEA]. The injection of polarized low-energy electrons into the target by varying the kinetic energy in the range 0.5–3.0 eV and up to 1.3 keV was studied in image-type mode. The figure of merit as a function of electron kinetic energy and the target temperature is determined. The spin asymmetry of the CL intensity in a ferromagnetic/semiconductor (FM-SC) junction provides a compact optical method for measuring spin polarization of free-electron beams in image-type mode. The FM-SC detector has the potential for realizing multichannel 3D vectorial reconstruction of spin polarization in momentum microscope and angle-resolved photoelectron spectroscopy systems.