High-Gradient Magnetic Separator (HGMS) combined with adsorption for nitrate removal from aqueous solution

© 2018 Elsevier B.V. This paper investigates the adsorption of nitrate anions from aqueous solutions on ammonium-functionalized magnetic mesoporous silica. The adsorbent was prepared via two-step coating process of silica on magnetic core (Fe3O4). The resultant structure was modified by 3-aminopropyl triethoxysilane (APTES), and finally acidified in HCl solution to convert the grafted amino groups to ammonium ones. Field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), vibration sample magnetometer (VSM), Energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FT-IR), and N2 adsorption/desorption were used to characterize the obtained samples. Experimental results showed that several factors affected the uptake behavior such as pH, contact time, and initial concentration of nitrate. The amount of sorbent loading were examined and the adsorbent shows great adsorption capacity for NO3¯ (ca.51.28 mg g−1 at 25 °C). The nitrate loaded multifunctional microsphere can be easily regenerated with NaOH solution. The separation of multifunctional magnetic microspheres from solution by novel high gradient magnetic separation (HGMS), using the collection of rods, was also investigated in details. Contrast to other methods based on filter and batch conditions, large volumes of water can be easily handled by the new designed HGMS due to the decreasing pressure drop and retention times. The effect of a set of two different experimental variables, i.e. flowrate and magnetic field strength, were investigated to identify the best working conditions for the separation of adsorbent from treated water. The most efficient backwash system was offered to reuse the magnetic particles, too. The removal efficiency of NO3¯ from solution was around 86.24% by the constructed HGMS under the optimal experimental conditions of 7.5 mL s −1 flowrate and: 3.49 mT magnitude of the magnetic field

Sex and Race Disparities in Mortality and Years of Potential Life Lost Among People With HIV: A 21-Year Observational Cohort Study

BACKGROUND: Since the availability of antiretroviral therapy, mortality rates among people with HIV (PWH) have decreased; however, this does not quantify premature deaths among PWH, and disparities persist. METHODS: We examined all-cause and premature mortality among PWH receiving care at the Vanderbilt Comprehensive Care Clinic from January 1998 to December 2018. Mortality rates were compared by demographic and clinical factors, and adjusted incidence rate ratios (aIRRs) were calculated using multivariable Poisson regression. For individuals who died, age-adjusted years of potential life lost (aYPLL) per total person-years living with HIV were calculated from US sex-specific life tables, and sex and race differences were examined using multivariable linear regression. RESULTS: Among 6531 individuals (51% non-Hispanic [NH] White race, 40% NH Black race, 21% cis-gender women, 78% cis-gender men) included, 956 (14.6%) died. In adjusted analysis, PWH alive in the most recent calendar era (2014-2018) had decreased risk of mortality compared with those in the earliest calendar era (1998-2003; aIRR, 0.22; 95% CI, 0.17-0.29), and women had increased risk of death compared with men (aIRR, 1.31; 95% CI, 1.12-1.54). Of those who died, Black women had the highest aYPLL (aIRR, 592.5; 95% CI, 588.4-596.6), followed by Black men (aIRR, 470.7; 95% CI, 468.4-472.9), White women (aIRR, 411.5; 95% CI, 405.6-417.4), then White men (aIRR, 308.6; 95% CI, 308.0-309.2). In adjusted models, higher YPLL remained associated with NH Black race and cis-gender women, regardless of HIV risk factor. CONCLUSIONS: Despite marked improvement over time, sex disparities in mortality as well as sex and race disparities in YPLL remained among PWH in this cohort

Analysis for the design of a U.S. Navy diving and salvage smart stage

The Navys Dive and Salvage community is in need of a new dive stage, called the SMART Stage, which will increase the productivity and safety of its users along with matching their capabilities to that of the commercial industry. The existing dive stage is a stainless steel cage that merely transports divers and their tools from the surface towards the worksite at a maximum depth of 300 feet. What modifications and improvements can be made to make the divers safe? Improve productivity? Should this new stage be comprised of commercial off-the-shelf parts or can it be purchased as a pre-fabricated system? This thesis will investigate what is needed to improve the safety and productivity for the community as well as the possible design alternatives of a SMART Stage. This study will perform the Systems Engineering process by carrying out a stakeholder needs analysis to help define the functions and requirements that must be met by the SMART Stage.http://archive.org/details/analysisfordesig1094534688Lieutenant, United States NavyApproved for public release; distribution is unlimited

Enhancement of Cd²⁺ removal from aqueous solution by multifunctional mesoporous silica: Equilibrium isotherms and kinetics study

© 2019 In this work, a novel amino-functionalized mesoporous microsphere was synthesized to remove cadmium ions from water. The Fe3O4@SiO2@m-SiO2–NH2 micro-spheres were successfully prepared via a facile two-stage process by coating of the as-synthesized magnetic cores with a silica shell followed by increasing the porosity of the structure using a cationic surfactant as structure-directing agents. The template removal from the structure has been performed following the method of solvent extraction and methanol-enhanced supercritical fluid CO2 (SCF-CO2)extraction. This novel approach provides the multifunctional microspheres with a high surface area, which improves the adsorption capacity of adsorbent. Characterization of the as-synthesized adsorbent were analytically determined showing that as-prepared adsorbent has a significant surface area of 637.38 m2 g−1. The kinetic data agreed with pseudo-second-order model and Langmuir isotherm. The maximum adsorption capacity of the synthesized adsorbent was about 884.9 mg g−1, and can be easily separated from solution under an external magnetic field. The synthesized microspheres were recycled using HCl and cadmium removal was over 92% after 6 cycles, which confirms the chemical stability and reusability of the manufactured particles

The effect of ketamine on shivering in patients undergoing spinal anesthesia

Background: Sever shivering is the most common adverse effect of spinal anesthesia during and after operation that causes physiologic complication. One of the drugs that could decrease operative shivering is ketamine. Objective: The aim of this study is the effect of ketamine to reduce shivering, during spinal anesthesia. Methods: This prospective randomized, and double-blind clinical trial was conducted on 355 patients of candida different surgeries with spinal anesthesia in Bu-Ali and Velayat Hospitals in Qazvin (2017). Patients were randomly divided into experimental (n=175) and control (n=180) groups. For the experimental and control groups, ketamine (0.2 ml/kg) or an equal volume of distilled water were administered with intravenous infusion pumps immediately after initiating spinal anesthesia, respectively. Then degree of shivering checked by anesthesiologist with visual scale during surgery. Findings: The rate and intensity of shivering at ketamine group significantly decreased compared to the control group. Shivering during surgery was less than in men, urological surgery and age (20-40 years) in both groups. Conclusion: Adding ketamine to drug’s pump in patients undergoing spinal anesthesia could be effective method to control shivering during operation

The role of selenium in the secretion of very-low-density lipoprotein in the isolated perfused rat liver.

A recirculating liver perfusion system was used to study the effects of dietary selenium (Se) on the hepatic secretion of very-low-density lipoprotein (VLDL). The perfusate from livers of rats fed on a Se-deficient diet incorporated about 50% more [1-14C]oleic acid into triacylglycerol (TG) and cholesteryl esters (ChoEs) than did the perfusate from livers of rats fed on a Se-supplemented diet. Similarly, livers from rats fed the Se-deficient diet secreted more VLDL and incorporated about 60% more [1-14C]oleic acid into VLDL TG and ChoEs than did livers from rats fed the Se-supplemented diet. The liver perfusate from rats in the Se-deficient group also showed significantly decreased fatty acid oxidation. We conclude that Se is a potent modulator of lipoprotein metabolism. A primary action of Se deficiency appears to be a decrease in fatty acid oxidation and a stimulation of fatty acid esterification, leading to increased VLDL TG and ChoEs formation and secretion

Genetic Algorithm-Based Sliding Mode Control of a Human Arm Model

Spinal cord injured patients cannot move their segments by their intact muscles. A suitable controller can be used to help them move their arm. In this study, the kinematics and dynamics of right-hand movement are modeled considering planar three links. A genetic algorithm-based sliding mode (GASM) controller is designed to move the human arm model for tracking a desired trajectory in the sagittal plane. The GA is used to tune the convergence rate of the sliding mode controller for having an appropriate tracking performance. The summation of errors is considered as a cost function and GA is proposed to find the controller gains to minimize the difference between the outputs of the model and nominal trajectories. To the best of the author\u27s knowledge, it is for the first time that the GA-sliding mode controller has been used for controlling the human hand so as to have a particular movement. Simulation results are evaluated in upward and downward movements of the human arm to affirm the effectiveness of the proposed controller

Personalised drug prescription for dental clinics using word embedding

The number of drugs in drug databases is constantly expanding with novel drugs appearing on the market each year. A dentist cannot be expected to recall all the drugs available, let alone potential drug-drug interactions (DDI). This can be problematic when dispensing drugs to patients especially those with multiple medical conditions who often take a multiple medications. Any new medication prescribed must be checked against the patient’s medical history, in order to avoid drug allergies and reduce the risk of adverse reactions. Current drug databases allowing the dentist to check for DDI are limited by the lack of integration of the patient’s medical profile with the drug to be prescribed. Hence, this paper introduces a software which predicts the possible DDI of a new medication against the patient’s medical profile, based on previous findings that associate similarity ratio with DDI. This system is based conceptually on a three-tier framework consisting of a knowledge layer, prediction layer and presentation layer. The novel approach of this system in applying feature vectors for drug prescription will be demonstrated during the conference (http://r.glory.sg/main.php). By engaging with the interactive demonstration, participants will gain first-hand experience in the process from research idea to implementation. Future work includes the extension of use from dental to medical institutions, and it is currently being enhanced to serve as a training tool for medical students