Photoelectrochemical characteristics of electrodeposited cuprous oxide with protective over layers for hydrogen evolution reactions

Cuprous oxide is one of the inexpensive options of highly efficient visible light-based photocathode for hydrogen generation in photoelectrochemical cells. Highly photoactive cuprous oxide (Cu₂O) films are obtained by cathodic electrodeposition using lactate stabilized copper sulphate precursor exhibiting a photo-current density of ~1 mA/cm² at ?0.1 V vs. RHE. Although Cu₂O is a decent choice for photoelectrochemical applications, including hydrogen evolution reaction (HER), it faces serious issues related to photodegradation and instability. To address this issue, a comparative study of two types of thin films, Al (2%)-doped ZnO (AZO) and NiO_x (usually, x > 2 at low T to x→1 at high T annealing) as photo-corrosion protective overlayers is made. The improved stability of the protected photoelectrodes is observed as noted from the photocurrent degradation of 3.5%, 0.16% and 0.03% in Cu₂O (bare), Cu₂O/AZO, and Cu₂O/NiO_x photocathodes, respectively. Furthermore, the electrochemical impedance spectroscopy reveals that electrode protected with NiO_x exhibit faster charge transfer kinetics and minimum photocurrent degradation as compare to the Cu₂O/AZO and Cu₂O(bare) photoelectrodes, proving its potential in HER kinetics.     

Segmentation of ischemic stroke lesion from 3d mr images using random forest

Multimedia Tools and Applications - This paper focuses on segmentation of ischemic stroke lesion from the dataset contributed by Ischemic Stroke Lesion Segmentation (ISLES)-2015 Sub-acute Ischemic...     

Source apportionment of ambient VOCs in Delhi City

Source apportionment using chemical mass balance (CMB) model was carried using a data set of 360 four hourly samples collected at 15 locations of five categories namely residential, commercial, industrial, traffic intersections and petrol pumps during August 2001-July 2002 in Delhi. The results indicate that emissions from diesel internal combustion engines dominate in Delhi. Vehicular exhaust and evaporative emissions also contribute significantly to VOCs in ambient air. Emission of VOCs associated with sewage sludge was also found to contribute to VOCs in Delhi's air. This points to the fact that open defecation and leaking sewage manholes are a problem in all categories of locations.     

Three stage cervical cancer classifier based on hybrid ensemble learning with modified binary PSO using pretrained neural networks

ABSTRACT

Cervical cancer is one of the major challenges in developing nations like India.In recent years, a lot of research has been done todetect cervical cancer at an early stage through the pap-smear test, human papillomavirus test (HPV), etc. In this study, we have proposed athree-stage cervical cancer classifier to classify cervical cells among normal and abnormal cells using a hybrid ensemble classifier based onfeatures extracted using pre-trained neural networks. Furthermore, this work extends to classify the cells among different levels of dysplastic mainly mild, moderate and severe. The accuracy achieved for 2-class classification among normal and abnormal cells is up to 100% while for 4-class classification among normal, mild, moderate and severe dysplastic cells is up to 98.91% and 99.12% for new and old Herlev university hospital datasets respectively.     

Highly dispersed PVP-supported Ir–Ni bimetallic nanoparticles as high performance catalyst for degradation of metanil yellow

Bimetallic nanoparticles, a new class of materials for catalysis, were intensively investigated. Highly dispersed Ir–Ni bimetallic nanoparticles with varying mole fractions were synthesized by modified polyol reduction method from the solution of iridium trichloride and nickel chloride in ethylene glycol, which acts as both solvent and reducing agent. The particles were characterized for their size, morphology and composition using various techniques like UV–Vis, Fourier transform infrared (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM) and X-ray photo electron spectroscopic (XPS) techniques. The synthesized nanoparticles were in pseudo-spherical morphology and utilized as catalyst for the degradation of dyes. The feasibility of degradation of an azo dye i.e., metanil yellow (MY) in aqueous alkaline medium by hexacynoferrate (III) ions using Ir–Ni bimetals as catalyst, prepared in different molar ratios, was investigated. Results show that Ir–Ni (2:1) bimetals have good catalytic activity and degradation as compared to Ir–Ni (1:2) due to their small size and high stability for the oxidation of MY.     

Recent advancements in visible-light-assisted photocatalytic removal of aqueous pharmaceutical pollutants

Clean Technologies and Environmental Policy - Pharmaceuticals are one of the persistent emerging contaminants that are ubiquitous in the aquatic environment due to their extensive application as...     

Synthesis and characterization of metal-containing coordination polymers of poly(methylene diphenylene terephthalamide)

Amino group-terminated poly(methylene diphenylene terephthalamide) (PMDTA) was prepared using a phosphorylation technique that was then converted into Schiff's base coordination polymers by their reaction with Co(II), Ni(II), and Cu(II) complexes of salicylaldehyde [M(SAL)₂] and 2-hydroxy-1-naphthaldehyde [M (NAPTHAL)₂]. The resulting coordination polymers were characterized by IR, elemental analysis, magnetic susceptibility measurements, and thermogravimetric analysis (TGA). TGA shows that coordination polymers are more thermally stable than is the ligand under similar conditions. On the basis of observed results, an oxygen-and nitrogen-coordinated structure for polyar-amid-metal complexes has been proposed. © 1993 John Wiley & Sons, Inc.     

On the Dielectric Study of Se<Subscript>80−<Emphasis Type="Italic">x</Emphasis></Subscript>Te<Subscript>20</Subscript>Pb<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> (<Emphasis Type="Italic">x</Emphasis> = 0, 1 and 2) Glasses

In the present paper, the dielectric parameters such as the dielectric constant ε′(ω), dielectric loss ε″(ω) and alternating current (ac) conductivity have been investigated for bulk amorphous chalcogenide Se_80?x Te₂₀Pb _x (x = 0, 1 and 2) glasses in the frequency range 10 Hz to 500 kHz and within the temperature range from 300 K to 320 K. Dielectric constant ε′(ω) and dielectric loss ε″(ω) are found to be highly frequency (ω) and temperature dependent, and this behavior is interpreted on the basis of Guintini’s theory of dielectric dispersion. The ac conductivity (σ _ac) is found to be temperature independent and obey the power law ω ^s , where s < 1 and decreases as temperature rises. The obtained results are discussed in terms of the correlation barrier hopping model proposed by Elliot. The composition dependence of the dielectric constant, dielectric loss and ac conductivity are also discussed and reported here.     

Critical state magnetization of hard type-II superconductors with rectangular and cylindrical cross-sections

Magnetization loops in the critical state for the critical current density and are calculated. The geometry considered is an infinitely long superconductor with a finite cross-section in the shape of a rectangle or circle. Explicit formulas are derived for the various branches of the complete high-field hysteresis loop. In the discussion emphasis is put on the behavior of the width, δM, of the hysteresis loop, and a simple graphical method to fit model parameters to experimental data is outlined.     

Application of response surface methodology to evaluate the removal efficiency of Mn(II), Ni(II), and Cu(II) by surfactant-modified alumina

Surfactant-modified alumina (SMA) was prepared and used for the removal of Mn(II), Ni(II), and Cu(II) from aqueous environment. Batch studies were conducted to find out optimum pH of the medium, adsorbent dose of SMA, and contact time. They were further optimized using response surface methodology (RSM). In the present study, a three-factor, three-level Box–Behnken experimental design was used to derive a second-order polynomial equation and construct three-dimensional (3D) surface plots and two-dimensional (2D) contour plots to examine the response. The level of significance for each independent variable and their interaction effects were examined by means of analysis of variance (ANOVA), F test, and Student’s t test results. In addition, the percentage effects of the different factors and their interactions on the removal efficacy were also investigated by plotting a Pareto chart. The models were validated for accurate prediction of the percentage (%) removal by performing numerical optimization. The optimum values of three tested variables were determined at pH 6.2, 8.2, and 5.3; adsorbent dose = 20, 5, and 4 g/L; and contact time = 30, 60, and 75 min for the adsorption of Mn(II), Ni(II), and Cu(II) ions, and the corresponding removal efficiency was found to be 77.04, 93.83, and 97.23 %, respectively.