A combined effect of adsorption and reduction potential of biochar derived from Mentha plant waste on removal of methylene blue dye from aqueous solution

ABSTRACT

Plant biochars were prepared by slow pyrolysis of Mentha plant waste to remove cationic dye methylene blue (MB) from aqueous solution. The biochars were characterized by X-Ray diffraction, IR-spectroscopy, thermogravimetric analysis, scanning electron microscope, cyclic voltammetry (CV), Brunauer-Emmett-Teller analysis, and zeta potential analyzer. Adsorption isotherms and kinetics applied on the MB dye removal by biochars showed monolayer chemisorption of MB dye. Present investigation revealed that removal of MB dye was due to synergistic action of chemisorption coupled with reductive electron transfer mechanisms. CV test showed a reversible, coupled redox reaction at interface of MB dye and biochar particles.     

A high efficiency inductor‐less broadband fully integrated CMOS power amplifier

This work presents the design and implementation of a novel broadband completely inductor‐less 300 MHz–2.4 GHz power amplifier (PA) in 180 nm CMOS, primarily for applications in the ultrahigh frequency (UHF) industrial scientific and medical band. This is capable of delivering up to 15.6 dBm saturated output power with an associated peak power added efficiency of 31% in measurement. Although amplifiers with higher output power have been reported, this amplifier occupies only 0.086 mm² and does not require any off chip component for its operation, even at the UHF band. It also achieves the highest power density among a similar class of PA's below 10 GHz. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:311–320, 2015.     

Interactions between the nematode parasite of pigs, Ascaris suum, and the earthworm Aporrectodea longa

BACKGROUND: Hypothermia during and after major abdominal surgery decreases host defenses, increases the incidence of coagulopathy and may alter blood pressure, cardiac contractility and myocardial stability. METHODS: We designed a prospective randomized study to compare the benefits of a forced air warming system with warm blanket treatments in minimizing the effects of hypothermia on 64 morbidly obese patients undergoing Roux-en-Y gastric bypass. RESULTS: Patients in the forced air warming group (n = 32) had significantly higher perioperative body core temperature, lower central venous pressure and blood pressure readings, lower incidence of shivering, less blood loss intraoperatively and achieved a higher post anesthesia Aldrete Score than those patients in the warmed blanket group (n = 32). CONCLUSION: The forced air warming system is safe, cost effective and beneficial in minimizing the undesirable consequences of hypothermia in morbidly obese patients undergoing Roux-en-Y gastric bypass.     

A Magnetic Electron Analyzer for Plasma Focus Electron Energy Distribution Studies

The paper describes the construction of a magnetic electron analyzer for pulsed beam electron energy distribution studies. The single shot information is obtained using a NMOS linear image sensor. Both the energetical and the sensitivity calibration were performed using careful numerical simulations. For simplicity, the signals can be read on an oscilloscope, and they are transmitted via an optic fiber, which allows the analyzer to work while connected to high voltage. The analyzer was successfully implemented on a 15 kV/3 kJ plasma focus device and was used to study the electron energy distribution in the 30–660 keV range..     

Case report: rapidly progressive neuropathic arthropathy in syringohydromyelia--radiographic and magnetic resonance imaging findings

A rapidly progressive neuropathic shoulder joint in a patient with syringohydromyelia is presented. He developed marked destruction of the shoulder joint over 5 weeks. The MRI findings in the pre- and post-resorptive phases of the arthropathy are presented for the first time. Low signal intensity areas are observed in the medullary cavity of the bone on both T1- and T2-weighted spin-echo images even before the actual resorptive process starts. Additional major findings are the joint effusion and synovial thickening.     

Microencapsulation of a eutectic PCM using in situ polymerization technique for thermal energy storage

In the present work, microencapsulated phase change material (M-PCM) has been synthesized with eutectic mixture (75% SA + 25% CA) as core and melamine formaldehyde (MF) as shell using in situ polymerization. Advanced instrumental techniques like field emission scanning electron microscopy (FE-SEM), Fourier-transform infrared spectroscopy (FT-IR), particle size analyzer (PSA), thermogravimetric/differential thermal analysis (TG/DTA), differential scanning calorimetry (DSC), and thermal conductivity analyzer (TCi) were used to characterize the synthesized M-PCM, and impact of effective parameters like pH and agitator speed on the encapsulation process was also elucidated. Results obtained reveal that at the optimized pH (3.2) and agitator speed (1500 rpm) M-PCM possess smooth surface morphology, spherical in shape with particle size of 10.41 μm. Based on FT-IR analysis, it was observed that the synthesized M-PCM was uniformly encapsulated by MF resin with eutectic mixture in the core. The encapsulation process results in the improvement of the thermal stability of eutectic mixture, it increases from 202.5 to 212.3°C, and the encapsulation efficiency of the M-PCM is found to be 85.3%. The melting point and latent heat of fusion of M-PCM were found to be 34.5°C and 103.9 kJ/kg, respectively.     

Grafting onto wool. XXIII. Graft copolymerization of methyl methacrylate by use of chromium acetyl acetonate–perchloric acid system: Effect of tertiary butyl hydroperoxide

Methyl methacrylate (MMA) has been graft copolymerized onto Himachali wool in an aqueous medium by using chromium acetyl acetonate in the presence of perchloric acid at 45, 55, 65, and 75°C for various reaction periods. Percentage of grafting has been determined as functions of various reaction variables. Tertiary butyl hydroperoxide (TBHP) was found to influence grafting of MMA. Rate of grafting (R_p) and induction period (I_p) of MMA towards graft copolymerization were determined as function of total initial monomer concentrations. In the absence of TBHP, R_p does not change markedly with the increase in monomer concentration. When the graft copolymerization was carried out in the presence of TBHP, an increase in R_p and a decrease in I_p were observed.     

Effect of grain hardness on bioavailability of iron in wheat as determined using the coupled invitro digestion/Caco-2 model

The impact of grain hardness on iron bioavailability from a set of wheat genotypes with varying hardness indices was determined. This may help us to consider grain hardness as an important parameter along with other established parameters for selecting food crops for future biofortification programs to combat iron deficiency linked to global health problem. The bioavailability and dialysability of iron were determined using the coupled in vitro digestion/Caco-2 model. The grain hardness and its molecular basis along with grain iron, phytate and inorganic phosphorous (Pi) contents were also evaluated. The data indicated that iron concentration in the genotypes ranged from 21 to 50 μg/g of dry matter. The hardness indices varied from as low as 28 for the derivative BTC17 to as high as 92 for the landrace IITR 26, almost similar to that of WL711, a wild type cultivar considered as control in this study. Low variability was however observed for the phytate and Pi contents. A significant negative correlation was observed between grain hardness vs. dialysability (r = −0.73) and bioavailability (r = −0.75) of iron. The results suggest that the hardness index which profoundly affects milling process, particle size of flour, milling yield and end-use also influences dialysability and bioavailability of iron from wheat.