Corrosion behaviour of AISI type 304L stainless steel in nitric acid media containing oxidizing species

The corrosion behaviour of AISI type 304L stainless steel (SS) in different concentration of 0.01 M, 1 M and 5 M HNO₃ in presence of oxidizing ions at different temperatures has been evaluated. The main objective of this study is to assess the corrosion resistance of type 304L SS in non-radioactive conditions encountered during storage of liquid nuclear waste. Electrochemical impedance spectroscopy (EIS) and laser Raman spectroscopy (LRS) has clearly brought out the deleterious effect of oxidizing species on the passive film leading to increased corrosion along with increase in HNO₃ concentration and higher temperature.     

Interpretation of Electrochemical Potentiokinetic Reactivation data in the presence of sulphide/oxysulphide inclusions in 316LN stainless steel

This paper presents the Electrochemical Potentiokinetic Reactivation (EPR) parameters obtained for non-sensitised 316LN stainless steel containing sulphide/oxysulphide inclusions. Even in the absence of sensitization, reactivation peaks were obtained in single loop and double loop EPR experiments for longitudinal and cross transverse sections. Using Laser Raman Spectroscope, Raman maps of Cr (VI) oxide were obtained around the inclusions. It was inferred that the reactivation peak is due to dissolution of sulphide inclusions and chromium depleted zones arising around chromium segregated flow lines. The need to interpret EPR parameters carefully in the presence of sulphide inclusions is emphasised.     

Synthesis and analysis of injection‐molded nanocomposites of recycled high‐density polyethylene incorporated with graphene nanoflakes

Recycled high‐density polyethylene (HDPE) was incorporated with graphene nanoflakes in a solvent at different concentrations (0, 1, 2, 4, and 8 wt%), and then the mechanical, thermal, electrical, and surface hydrophobic properties of the resultant nanocomposites were determined using universal tensile testing, thermal comparative, capacitance bridge, and goniometer techniques, respectively. The test results revealed that the mechanical, thermal, and dielectric properties of the polymer matrix nanocomposites were increased as a function of graphene concentrations, whereas the surface hydrophobic values were slightly increased at lower concentrations and then reduced at higher concentrations. These improvements occur mainly because of the excellent properties of graphene nanoflakes, such as tensile strength (150 GPa), Young's modulus (1.0 TPa), thermal conductivity (4,840–5,300 W/m K), electrical conductivity (1.3 × 10⁶ S/cm), electrical current density (10¹³ A/cm²), surface hydrophobicity (>120°), and surface smoothness/roughness (<1 nm). The worldwide consumption of polymeric products has been drastically growing, and consequently polymeric waste materials have been rising up, as well. Although the plastic recycling and reprocessing rates are considerably high, physical properties and economical values of the recycled plastics are significantly low, limiting the reuse of recycled plastics in many industrial applications. As a result, this study provides a detailed explanation of how to improve recycled plastics into highly valued new products for applications in various industries, such as transportation, energy, electronic, construction, and so forth. POLYM. COMPOS., 36:1565–1573, 2015. © 2014 Society of Plastics Engineers     

Montmorillonite/graphene oxide nanocomposite as superior adsorbent for the adsorption of Rhodamine B and Nickel ion in binary system

A series of montmorillonite reduced graphene oxide (MrGO) composites were synthesized using different ratios (5, 10, 15 and 20) of montmorillonite (MMt) to GO. The synthesized composites were characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, surface area analyzer (BET), and Fourier transform- infrared spectroscopy. The adsorption capacity and efficiency of the synthesised composites were examined towards removal of Rhodamine B (RhB) and Nickel ion (Ni²⁺). The results were compared with that of GO and commercial MMt clay. The kinetic sorption models were evaluated, and it was observed that sorption follows the pseudo-second-order kinetics. Adsorption isotherm was best fit into the Langmuir model (R²?=?0.996 for RhB & 0.957 for Ni²⁺). Among all the synthesized composites, MrGO-2, a composite of GO and montmorillonite with (1:10) ratio, showed maximum activity towards the adsorption of Rhodamine B and Ni²⁺ calculated to be 625?mg/g and 178?mg/g respectively at neutral pH condition. From the calculated ΔG⁰ (?3.99 & ?0.71?kJ?mol^?1), ΔH (28.6 & 4.61?kJ?mol^?1) and ΔS (?107.5 & ?17.8?J?mol^?1 K) values for RhB & Ni²⁺ respectively, it can be unambiguously inferred that the adsorption process was feasible, endothermic and exhibiting least randomness, respectively. The prepared MrGO composites showed good adsorption capacity towards efficient removal of RhB and Ni²⁺ in single as well as binary system.     

Design of a bone-attached parallel robot for percutaneous cochlear implantation

Access to the cochlea requires drilling in close proximity to bone-embedded nerves, blood vessels, and other structures, the violation of which can result in complications for the patient. It has recently been shown that microstereotactic frames can enable an image-guided percutaneous approach, removing reliance on human experience and hand-eye coordination, and reducing trauma. However, constructing current microstereotactic frames disrupts the clinical workflow, requiring multiday intrasurgical manufacturing delays, or an on-call machine shop in or near the hospital. In this paper, we describe a new kind of microsterotactic frame that obviates these delay and infrastructure issues by being repositionable. Inspired by the prior success of bone-attached parallel robots in knee and spinal procedures, we present an automated image-guided microstereotactic frame. Experiments demonstrate a mean accuracy at the cochlea of 0.20 ± 0.07 mm in phantom testing with trajectories taken from a human clinical dataset. We also describe a cadaver experiment evaluating the entire image-guided surgery pipeline, where we achieved an accuracy of 0.38 mm at the cochlea.     

Synthesis and characterization of SnS/ZnO nanocomposite by chemical method

SnS nanorods and SnS/ZnO nanocomposite have been synthesized by chemical method. Structure and phase purity of the samples were confirmed by powder X-ray diffraction. Transmission electron microscope image of SnS nanorods showed the average diameter of nanorods was about 85 nm and length was several micrometers. Transmission electron microscope image of SnS/ZnO nanocomposite showed the average particle size of ZnO nanoparticle was about 12 nm. The formation of SnS/ZnO nanocomposite was confirmed by elemental analysis using energy dispersive X-ray spectroscopy. From the microRaman spectrum of SnS/ZnO nanocomposite, it was observed that the intensity of B_2g mode of SnS nanorods decreased dramatically compared to that of pure SnS nanorods, since the surface of the SnS nanorods were coated with ZnO nanoparticles. Both direct and indirect band gap transitions were observed for SnS nanorods from the optical absorption spectrum and the optical absorption spectrum of SnS/ZnO nanocomposite showed absorption in the visible region.     

Capacitated lot-sizing problem with production carry-over and set-up splitting: mathematical models

This work proposes mathematical models (MMs) for the capacitated lot-sizing problem with production carry-over and set-up splitting, which can handle two scenarios, namely (1) situation/scenario where the set-up costs and holding costs are product dependent and time independent, and with no backorders or lost sales, and (2) situation where the set-up costs and holding costs are product dependent and time dependent, and with no backorders or lost sales. Previously, in an existing study the authors had developed a MM for the same problem and situation where the set-up costs and holding costs are product dependent and time independent, i.e. our Scenario 1. We compare our proposed models with the model in the existing study that appears to be incorrect.     

Folate: A Functional Food Constituent

ABSTRACT:  Folate, a water-soluble vitamin, includes naturally occurring food folate and synthetic folic acid in supplements and fortified foods. Mammalian cells cannot synthesize folate and its deficiency has been implicated in a wide variety of disorders. A number of reviews have dwelt up on the health benefits associated with increased folate intakes and many countries possess mandatory folate enrichment programs. Lately, a number of studies have shown that high intakes of folic acid, the chemically synthesized form, but not natural folates, can cause adverse effects in some individuals such as the masking of the hematological manifestations of vitamin B₁₂ deficiency, leukemia, arthritis, bowel cancer, and ectopic pregnancies. As fermented milk products are reported to contain even higher amounts of folate produced by the food-grade bacteria, primarily lactic acid bacteria (LAB), the focus has primarily shifted toward the natural folate, that is, folate produced by LAB and levels of folate present in foods fermented by/or containing these valuable microorganisms. The proper selection and use of folate-producing microorganisms is an interesting strategy to increase "natural" folate levels in foods. An attempt has been made through this review to share information available in the literature on wide ranging aspects of folate, namely, bioavailability, analysis, deficiency, dietary requirements, and health effects of synthetic and natural folate, dairy and nondairy products as a potential source of folate, microorganisms with special reference to  Streptococcus thermophilus  as prolific folate producer, and recent insight on modulation of folate production levels in LAB by metabolic engineering.     

Advance electrochemical oxidation of fipronil contaminated wastewater by graphite anodes and sorbent nano hydroxyapatite

Degradation of C₁₂H₄Cl₂F₆N₄OS phenylpyrazole insecticide (Fipronil) by advance electrochemical oxidation in aqueous water solution was studied. The process efficiency was figured based on the COD, chloride, and fluoride reduction from fipronil. Further, we tried to highlight the importance of nano-hydroxyapatite (n-Hap) as a cost-effective nano sorbent for removal of fluoride from fipronil. From the advance electrochemical oxidation experiment, it was found that the COD removal was 79%, chloride 52%, and fluoride 80%. The intermediate of fipronil compounds was examined by GC-MS. The final results conclude that advance electrochemical oxidation process was effective for removal of fipronil synthetic wastewater.