Removal of rhodamine B from aqueous solution by adsorption onto sodium montmorillonite

The adsorption of rhodamine B dye was carried out using sodium montmorillonite clay. The effect of parameters such as pH, adsorbent dosage and initial dye concentration was studied. The Langmuir and Freundlich isotherm models were applied and the Langmuir model was found to best fit the equilibrium isotherm data. Langmuir adsorption capacity was found to be 42.19 mg/g. Kinetic data followed pseudo-second-order kinetics. Maximum color removal was observed at pH 7.0. The ΔG° value was found to be negative, the adsorption process was feasible. The results indicate that sodium montmorillonite clay can be used for the removal of basic dyes from aqueous solutions.     

A case of hypothermia on CRRT

A 64‐year‐old Asian man, with past medical history of hypertension, hypothyroidism, and hyperlipidemia, presented with 3 days history of fever associated with cough and worsening shortness of breath. Subsequent clinical course was complicated by acute lung injury leading to acute respiratory distress syndrome requiring positive pressure ventilation, septic shock requiring inotropic support, and acute kidney injury requiring continuous renal replacement therapy (CRRT). On day 3 of CRRT, the patient developed significant hypothermia (temporal temperature 27.5°C), which was successfully managed. Continuous renal replacement therapy was subsequently discontinued as renal function recovered and the patient was discharged home after a prolonged hospital stay. He currently remains off dialysis and is being followed as an outpatient for chronic kidney disease. In this article, we examine various aspects of pathophysiology and management of hypothermia on CRRT and review relevant literature in this field.     

The uncanny valley does not interfere with level 1 visual perspective taking

When a computer-animated human character looks eerily realistic, viewers report a loss of empathy; they have difficulty taking the character’s perspective. To explain this perspective-taking impairment, known as the uncanny valley, a novel theory is proposed: The more human or less eerie a character looks, the more it interferes with level 1 visual perspective taking when the character’s perspective differs from that of the human observer (e.g., because the character competitively activates shared circuits in the observer’s brain). The proposed theory is evaluated in three experiments involving a dot-counting task in which participants either assumed or ignored the perspective of characters varying in their human photorealism and eeriness. Although response times and error rates were lower when the number of dots faced by the observer and character were the same (congruent condition) than when they were different (incongruent condition), no consistent pattern emerged between the human photorealism or eeriness of the characters and participants’ response times and error rates. Thus, the proposed theory is unsupported for level 1 visual perspective taking. As the effects of the uncanny valley on empathy have not previously been investigated systematically, these results provide evidence to eliminate one possible explanation.     

Two-phase flow in GDL and reactant channels of a proton exchange membrane fuel cell

Understanding the effect of two-phase flow in the components of proton exchange membrane fuel cells (PEMFCs) is crucial to water management and subsequently to their performance. The local water saturation in the gas diffusion layer (GDL) and reactant channels influences the hydration of the membrane which has a direct effect on the PEMFC performance. Mass transport resistance includes contributions from both the GDL and reactant channels, as well as the interface between the aforementioned components. Droplet–channel wall interaction, water area coverage ratio on the GDL, oxygen transport resistance at the GDL–channel interface, and two-phase pressure drop in the channels are interlinked. This study explores each factor individually and presents a comprehensive perspective on our current understanding of the two-phase transport characteristics in the PEMFC reactant channels.     

Control of UFG Microstructure in Welded Carbon Steel Tubes by Cold Drawing and Annealing

The present study is made to develop ultra fine grained microstructure in welded steel tubes, through multiple cold drawing passes followed by an annealing treatment. The average ferrite grain size is reduced from 16 to 1.9 μm. SAE 1019M steel grade used for a typical automotive driveline component is studied. Strains between 0.3 and 1.4 followed by annealing at 400, 450 and 500 °C are considered to optimize the combination of cold drawing strain and temperature required to produce ultra fine grained microstructure in steel tubes. At a strain value of 1.4 and annealing temperature, 500 °C, polygonal ferrite grains and fine carbide particles are obtained. This microstructure is found to be suitable owing to its combination of high strength and good ductility in steel tubes. Tensile strength as high as 1,061 MPa and 9 % elongation is obtained due to microstructural refinement. The strength is increased by 350 MPa compared to the strength of conventional cold-drawn welded tubes.     

Two-dimensional (2D) Ti3C2Tx MXene nanosheets with superior adsorption behavior for phosphate and nitrate ions from the aqueous environment

With the advancement of modern industries and metropolitan areas, negative environmental impacts such as eutrophication have become serious issues obstructing the usage of water sources in many countries. In this study, two-dimensional (2D) MXene materials were employed for the adsorptive removal of phosphate and nitrate ions from waters. The adsorption parameters of the sorption system including reaction time, solution pH, background ions, and reusability, were evaluated in batch experiments. Material characterization techniques, including X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, energy-dispersive X-ray analysis, Fourier transform infrared spectroscopy, thermal gravimetric analysis, Brunauer–Emmett–Teller analysis, and high-resolution transmission electron microscopy were performed. The mechanism of removing phosphate and nitrate was clearly described by various kinds of interactions such as electrostatic interactions, and the complexation was significant to elucidate the adsorption mechanism. The adsorption data for phosphate and nitrate update was determined using different isotherms and kinetic models. Reusability and field studies on the MXenes were also conducted. The above findings demonstrate that 2D MXenes could act as promising adsorbents for the elimination of toxic ions from water/wastewater.     

Lattice-based group signature scheme without random oracle

ABSTRACT

Group signature is a cryptographic primitive where any member can anonymously sign a message on behalf of the population they belong to. Several group signatures were proposed based on number-theoretic assumptions. All these schemes are insecure in the presence of quantum computers. Group signatures based on lattice assumptions are believed to be quantum-resistant. In the past few years, group signatures based on lattice assumptions have been proposed and most of them are proved to be secure in random-oracle model. This paper presents a lattice-based group signature scheme without using random-oracle. Our scheme is based on correlation-intractable function ensembles for all evasive relations which are constructed recently based on well-defined assumptions. Security of our scheme is proved based on correlation-intractable function ensembles and hardness of Short Integer Solution and Learning With Errors problem.     

Refractory orthostatic hypotension after creation of a brachio‐basilic arteriovenous fistula

Arteriovenous fistulas (AVFs) are preferred vascular access in patients with end‐stage renal disease (ESRD) undergoing hemodialysis (HD). However, AVFs, can occasionally lead to clinically significant complications. Of these, cardiovascular complications have been well described in the literature. In this report, we describe a case of a 78‐year‐old Caucasian male with ESRD who presented with severe debilitating dizziness and orthostatic hypotension that started soon after the creation of left brachiobasilic AVF. The patient had no significant cardiovascular history apart from essential hypertension. His symptoms persisted despite extensive evaluation and interventions, and abated only after banding of the AVF. This report describes the timeline of the patient's clinical course beginning from the day of creation of his AVF, through the course of his hospitalization leading to AVF banding and ending with postoperative recovery phase with resolution of symptoms. We will also review the pathophysiologic effects of AVF on cardiovascular system, as well as the potential causes of our patient's clinical presentation.     

Graded Dielectric Inhomogeneous Planar Layer Radome for Aerospace Applications

Controllable artificial dielectrics are used in the design of radomes to enhance their electromagnetic (EM) performance. The fabrication of such radome wall structures with controllable dielectric parameters seems to be an arduous task. Further even minor fluctuations of dielectric properties of radome wall due to fabrication uncertainties tend to result in drastic degradation of radome performance parameters. In the present work, a novel inhomogeneous radome with graded variation of dielectric parameters is proposed which limits the constraints on fabrication and facilitates excellent EM performance characteristics. This radome wall consists of five dielectric layers cascaded such that the middle layer has maximum dielectric constant and electric loss tangent. The dielectric parameters of the layers on both sides of the middle layer decrease in a graded (or step-wise) manner. The EM performance characteristics of the IPL radome with graded dielectric parameters are superior to that of conventional monolithic half-wave radome.     

Electrochemical and quantum chemical study to assess the role of (2E)-2-(furan-2-ylmethylidene) hydrazine carbothioamide as inhibitor for acid corrosion of mild steel

Journal of Applied Electrochemistry - Synthesis and inhibition effectiveness of (2E)-2-(furan-2-ylmethylidene) hydrazine carbothioamide (FMHC) as an inhibitor for corrosion of mild steel in...