Niobium carbide/reduced graphene oxide hybrid porous aerogel as high capacity and long‐life anode material for Li‐ion batteries

Two‐dimensional material MXenes owing to their hydrophilic nature, surface termination, and high conductivity can be used in the energy storage device as an anode material. However, poor ion transfer and less available intercalating sites due to self‐stacking of MXene sheets prevent comprehensive utilization of their electrochemical properties. To resolve this problem, a facile method is introduced in this paper to disperse MXene sheets onto reduced graphene oxide sheets to form a porous structure by enhancing electrostatic interactions between two components, which can facilitate ion movement and provide access of ions to more intercalating sites. This hybrid material delivered a capacity of 357 mAh g^?1 at 0.05 A g^?1 as anode in case of lithium‐ion batteries. Furthermore, the hybrid material showed exceptional stability even after 1000 cycles at 1 A g^?1. Current work offers an easy approach for the synthesis of high‐performance niobium carbide‐based hybrid energy storage materials.     

A novel image encryption scheme based on Arnold scrambling and Lucas series

Secure data transmission over the public channels have high impact and increasingly important due to theft and manipulation in contents. The requirement of public/ private organizations to develop an efficient scheme to provide security to their contents. We developed a digital contents encryption scheme based Arnold scrambling and Lucas series, which is very simple to implement but almost impossible to breach in this article. We perform encryption at standard images by using Lucas series at different iterations of scrambled images of Arnold transform. Numerical simulation analyses performed to analyze the efficiency and effectiveness of the projected structure.

     

Enhanced photoelectrochemical water splitting using zinc selenide/graphitic carbon nitride type-II heterojunction interface

The objective of this research is to construct a type-II heterojunction interface for effective photoelectrochemical (PEC) water splitting for hydrogen generation. A series of ZnSe/g-C₃N₄ heterojunctions is prepared by ultrasonication procedure and tested for PEC water splitting for the first time. The successful formation of ZnSe/g-C₃N₄ is confirmed by phase, morphological and optical analysis. Linear sweep voltammetry of 0.05 ZG (0.05% ZnSe/g-C₃N₄) showed a six-fold higher photocurrent density of 500 μA than g-C₃N₄. These results are supported by the Tafel slopes and PL (photoluminescence spectroscopy) studies by showing the smallest slope and lesser electron-hole recombination for 0.05 ZG. Increased lifetime of 107 ms and a higher donor density of 3.6 × 10¹⁹ cm^?3 for 0.05 ZG is observed. The smallest semicircle for 0.05 ZG in EIS implies the least charge transfer resistance among the prepared heterojunctions. All the results comply with each other showing the successful formation of type-II heterojunction for enhanced PEC water splitting.     

Contrived approach to novel antibacterial poly(vinyl acetate-co-[2-(methacryloyloxy)ethyl]trimethylammonium chloride) and poly(vinyl acetate-co-[vinylbenzyl]trimethylammonium chloride) via RAFT polymerization with multi-characterization

Journal of Polymer Research - The complex and incompletely understood phenomenon of shear-induced crystallization of polymers may be nowadays analysed via the in situ POM-shear stage methodology....     

Prediction of industrial debutanizer column compositions using data-driven ANFIS- and ANN-based approaches

Neural Computing and Applications - The work in this paper is based on an industrial debutanizer column in a petroleum refinery located in Malaysia, which produces LPG (liquefied petroleum gas) as...     

Protein Adsorption on Grafted Zwitterionic Polymers Depends on Chain Density and Molecular Weight

This study demonstrates that protein adsorption on end‐grafted, zwitterionic poly(sulfobetaine) (pSBMA) thin films depends on the grafting density, molecular weight, and ionic strength. Zwitterionic polymers exhibit ultralow nonspecific fouling (protein adsorption) and excellent biocompatibility. This picture contrasts with a recent report that soluble pSBMA chains bind proteins and alter the protein folding stability. To address this apparent contradiction, the dependence of protein adsorption on the chain grafting parameters is investigated: namely, the grafting density, molecular weight, and ionic strength. Studies compared the adsorption of phosphoglycerate kinase and positively charged lysozyme versus the scaled grafting parameter s/2R_F, where s is the distance between grafting sites and R_F is the Flory radius. Plots of the adsorbed protein amount versus s/2R_F exhibit a bell‐shaped curve, with a maximum near s/2R_F ≈ 1 and an amplitude that decreases with ionic strength. This behavior is qualitatively consistent with theoretical models for colloid interactions with weakly attractive, grafted chains. The results confirm that proteins do adsorb to pSBMA thin films, and they suggest an underlying mechanism. Comparisons with polymer models further identify design rules for pSBMA films that effectively repel protein.     

Long-term results of subtotal colectomy and evidence of noncolonic involvement in patients with idiopathic slow-transit constipation

BACKGROUND: Patients with chronic idiopathic constipation can be difficult to manage either medically or surgically. We report our experience of long-term follow-up of 21 patients who had undergone colectomy with ileorectal anastomosis for difficult chronic idiopathic constipation. METHODS: The patients (19 female, 2 male) were aged 26-68 (median = 46) years and had undergone subtotal colectomy 5-12 (median = 8) years before their assessment. They answered a questionnaire about severity of abdominal pain, bloating, urgency, and straining. They also completed the hospital anxiety and depression questionnaire. Fifteen ulcerative colitis patients with panproctocolectomy and 13 colon cancer patients with colonic resection who had a similar follow-up period served as control groups. The following assessments were performed in chronic idiopathic constipation patients with subtotal colectomy: a) oesophageal manometry; b) scintigraphic gastric emptying test; c) review of barium follow-through; d) glucose H2 breath test; e) urodynamic studies; and f) autonomic function tests. RESULTS: Twenty-four per cent of patients with chronic idiopathic constipation had a family history of difficult constipation requiring hospital investigations and treatment. At the time of assessment abdominal pain, bloating, urgency, and straining at defecation were all significantly more frequent in patients with chronic idiopathic constipation with colectomy than in the control groups with colectomy. Seventy-one per cent of chronic idiopathic constipation patients had at least one episode of intestinal obstruction after subtotal colectomy, which is significantly higher (P < 0.01) than in the control groups (ulcerative colitis, 13%; colonic carcinoma, 8%). In patients with chronic idiopathic constipation, among those studied, 68% had some oesophageal motor dysfunction: 19% delayed gastric emptying; 10%, prolonged small-bowel transit on barium follow-through; 54%, abnormal urodynamic variables; and 14%, abnormal autonomic function tests. CONCLUSIONS: This study shows considerable morbidity in a selected cohort of patients with chronic idiopathic constipation who were sufficiently disabled by their symptoms to undergo subtotal colectomy. They had more abdominal and rectal symptoms and more frequent intestinal obstructive episodes than control groups with colonic resection. Evidence of generalized smooth-muscle dysfunction and familial occurrence of constipation suggests a primary chronic intestinal pseudo-obstruction-like disorder in some of these patients.     

Influence of end-group modification on interaction of amphiphilic poly(oxyethylene)-<Emphasis Type="Italic">b</Emphasis>-poly(oxybutylene) block copolymers with ionic surfactants

Amphiphilic poly(oxyethylene)-b-poly(oxybutylene) block copolymers having hydrophilic block end-capped with neutral dimethylamino (DE₇₉B₃₄) and cationic trimethyl ammonium (TE₇₉B₃₄) groups, respectively were investigated for their interactions with ionic surfactants, sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB) using tensiometry, conductometry and dynamic light scattering. The self-assembly of DE₇₉B₃₄ and TE₇₉B₃₄ occur at 0.7 g/dm³ and 0.8 g/dm³, respectively. TE₇₉B₃₄ binds favorably with oppositely charged SDS, causing a substantial change in surface tension compared to other surfactant-polymer systems. In mixed polymer-surfactant systems, the micellization was promoted in the presence of SDS, but it was suppressed with CTAB. Such behavior is expected for cationic block copolymers, since they can engage into ion-pair formation with anionic SDS. For neutral polymers, the behavior is reflective of surfactants’ head group hydrophobicity. The head groups of CTAB are more hydrophobic and their existence in the proximity of hydrophobic segments of polymers induces shape transition to non-spherical morphologies. Gibb’s free energy of adsorption at air – water interface is negative for SDS, CTAB and surfactant-block copolymer systems, indicating that the process is highly spontaneous. The increase in entropy of TE₇₉B₃₄ during micelle formation with temperature is due to disturbance of hydrophobic structure of water molecules, thus hydrophobic parts are removed from bulk solution to the interface and also in the interior of micelle the freedom of hydrophobic part is increased. The dynamic laser light scattering results revealed that due to presence of block copolymers pre-micellar aggregates were favored.     

An efficient deep learning technique for facial emotion recognition

Emotion recognition from facial images is considered as a challenging task due to the varying nature of facial expressions. The prior studies on emotion classification from facial images using deep learning models have focused on emotion recognition from facial images but face the issue of performance degradation due to poor selection of layers in the convolutional neural network model.To address this issue, we propose an efficient deep learning technique using a convolutional neural network model for classifying emotions from facial images and detecting age and gender from the facial expressions efficiently. Experimental results show that the proposed model outperformed baseline works by achieving an accuracy of 95.65% for emotion recognition, 98.5% for age recognition, and 99.14% for gender recognition.

     

Conceivable security risks and authentication techniques for smart devices: A comparative evaluation of security practices

With the rapidly escalating use of smart devices and fraudulent transaction of users data from their devices, efficient and reliable techniques for authentication of the smart devices have become an obligatory issue. This paper reviews the security risks for mobile devices and studies several authentication techniques available for smart devices. The results from field studies enable a comparative evaluation of user-preferred authentication mechanisms and their opinions about reliability, biometric authentication and visual authentication techniques.