Analysis of Titanium-Coated Glass and Imidex (PI) Laser Bonded Samples

Based on previous results of bond strength, scanning electron microscopy(SEM)/energy dispersive spectroscopy (EDS) and x-ray photoelectron spectroscopy (for thin film thickness in the range of 50 to 200 nm range), it is expected for a moderate film thickness of titanium (over 50 nm) for the system of sputtered Ti-coated glass/polymer two factors play important roles in getting strong bond between Ti/Polyimide interface: (i) mechanical interlocking property and (ii) chemical bond formation such as Ti-C, Ti-O between Ti and imidex (PI) film. In this study, a systematic investigation has been conducted to understand the effects of thin films on bond quality and on failure mechanism of the interface between 400 nm sputtered Ti-coated glass/imidex (PI) system. This article basically studies if for this higher film thickness the failure pattern and bond strength are consistent with the previous data. From previous studies (for thin film thickness of 50 to 200 nm) the conclusion extracted is thin film with thickness of less than 50 nm exhibited low bond strength when compared to film thickness over 50 nm and from the results obtained in this study it is concluded that the bond reliability and failure modes of sputtered Ti film on glass are consistent even for a film thickness as high as 400 nm and three types of failure modes are found : (i) cohesive failure mode, (ii) Ti/glass interface failure mode, and (iii) glass failure mode. The roughness value for this coating thickness is 17 nm.     

Growth and optical properties of Sn–Si nanocomposite thin films

The growth and optical properties of nanocomposite thin films comprising of nanocrystalline Sn and Si are reported. The nanocomposite films are produced by thermal annealing of bilayers of Sn and Si deposited on borosilicate glass substrates at various temperatures from 300 to 500 °C for 1 h in air. X-ray diffraction reveals that the as-deposited bilayers consist of nanocrystalline Sn films with a crystallite size of 30 nm, while the Si thin films are amorphous. There is onset of crystallinity in Si on annealing to 300 °C with the appearance of the (111) peak of the diamond cubic structure. The crystallite size of Si increases from 5 to 18 nm, whereas the Sn crystallite size decreases with increase in annealing temperature. Significantly, there is no evidence for any Sn–Si compound, and therefore it is concluded that the films are nanocomposites of Sn and Si. Measured spectral transmittance curves show that the films have high optical absorption in the as-deposited form which decreases on annealing to 300 °C. The films show almost 80 % transmission in the visible-near infrared region when the annealing temperature is increased to 500 °C. There is concomitant decrease in refractive index from 4.0, at 1750 nm, for the as-deposited film, to 1.88 for the film annealed at 500 °C. The optical band gap of the films increases on annealing (from 1.8 to ~2.9 eV at 500 °C). The Sn-Si nanocomposites have high refractive index, large band gap, and low optical absorption, and can therefore be used in many optical applications.     

Molecular beam epitaxial growth and characterization of catalyst-free InN/InxGa1-xN core/shell nanowire heterostructures on Si(111) substrates

We report on the achievement of, for the first time, InN/InGaN core/shell nanowire heterostructures, which are grown directly on Si(111) substrates by plasma-assisted molecular beam epitaxy. The crystalline quality of the heterostructures is confirmed by transmission electron microscopy, and the elemental mapping through energy dispersive x-ray spectrometry further reveals the presence of an InGaN shell covering the sidewall and top regions of the InN core. The optical characterizations reveal two emission peaks centered at ～1685?nm and 1845?nm at 5?K, which are related to the emission from the InGaN shell and InN core, respectively. The InN/InGaN core/shell nanoscale heterostructures exhibit a very high internal quantum efficiency of ～62% at room temperature, which is attributed to the strong carrier confinement provided by the InGaN shell as well as the nearly intrinsic InN core.     

Mebendazole: New and efficient corrosion inhibitor for mild steel in acid medium

The inhibition performance of mebendazole, a drug, on mild steel in molar hydrochloric acid solution was studied by weight loss and electrochemical methods. The maximum inhibition efficiency 96.2% was observed in presence of 2.54 × 10⁻⁴ M inhibitor. Polarization measurements showed that the inhibitor is mixed type. Data obtained from EIS studies were analyzed to model inhibition process through appropriate equivalent circuit models. The results obtained from the different methods are in good agreement. The various thermodynamic parameters of dissolution and adsorption processes were evaluated in order to elaborate adsorption mechanism. Adsorption of inhibitor obeyed Langmuir adsorption isotherm model.     

Inhibition of mild steel corrosion in acid solution by Pheniramine drug: Experimental and theoretical study

Inhibition of mild steel corrosion in 1 M HCl solution by Pheniramine drug was studied using weight loss, electrochemical impedance spectroscopy, linear polarization resistance, and potentiodynamic polarization measurements. The values of activation energy (E_a) and different thermodynamic parameters such as adsorption equilibrium constant (K_ads), free energy of adsorption , adsorption enthalpy and adsorption entropy were calculated and discussed. The adsorption process of studied drug on mild steel surface obeys the Langmuir adsorption isotherm. Potentiodynamic polarization measurements showed that Pheniramine is mixed-type inhibitor. Further, theoretical calculations were carried out and relations between computed parameters and experimental inhibition efficiency were discussed.     

Food and nutrition security in the Hindu Kush Himalayan region

The status of food and nutrition security and its underlying factors in the Hindu‐Kush Himalayan (HKH) region is investigated. In this region, one third to a half of children (<5 years of age) suffer from stunting, with the incidence of wasting and under‐weight also being very high. The prevalence of stunting, wasting and under‐weight in children is particularly high in some mountain areas such as Meghalaya state in India, the western mountains and far‐western hills of Nepal, Balochistan province in Pakistan, eastern Afghanistan, and Chin state in Myanmar. Food habits in the HKH region are changing. This has led to a deterioration in traditional mountain food systems with a decline in agrobiodiversity. Factors such as high poverty and low dietary energy intakes, a lack of hygienic environments, inadequate nutritional knowledge, and climate change and environmental degradation are also influencing food and nutrition security in the HKH region. To achieve sustainable food and nutrition security in the mountains, this study suggests a multi‐sectoral integrated approach with consideration of nutritional aspects in all development processes dealing with economic, social, agricultural and public health issues. © 2017 Society of Chemical Industry     

Breakthrough studies with mono- and binary-metal ion systems comprising of Fe(II) and As(III) using community prepared wooden charcoal packed columns

Groundwater of Assam (India) contains excessive amounts of As(III) and Fe(II). The rural and semi-urban population of Assam uses indigenous household iron filters fabricated using community prepared wooden charcoal (CPWC) to reduce Fe(II) concentration, however no efforts are made to reduce As(III) concentrations before use. The present work is directed toward assessing the potential of CPWC for metal removal from mono- and binary-metal ion systems comprising of Fe(II) and As(III) through continuous mode column studies. A decrease in breakthrough throughput volumes (V_B) from mono- and binary-metal ion systems is observed with increase in flow rates and decrease in bed depths. The order of breakthrough of metal ions observed as As(III) followed by Fe(II) from binary-metal ion system and hence the V_B for As(III) is termed as critical V_B as Fe(II) is yet to breakthrough through the beds. An early breakthrough for Fe(II) and As(III) from binary-metal ion system compared to respective mono-metal ion systems is observed for all the cases of flow rates and bed depths. It indicates impact on the uptake of a selected metal ion [either Fe(II) or As(III)] by the presence of the other metal ion [either As(III) or Fe(II)] present in the binary-metal ion system. The minimum and maximum errors involved between the predicted and experimental BDST curves for As(III) uptake till critical V_B from the binary-metal ion system varied between 1.0% and 24.8%.     

On the quality of VoIP with DCCP for satellite communications

We present experimental results for the performance of selected voice codecs using Datagram Congestion Control Protocol (DCCP) with CCID4 congestion control over a satellite link. We evaluate the performance of both constant and variable data rate speech codecs for a number of simultaneous calls using the ITU E‐model. We analyse the sources of packet losses and additionally analyse the effect of jitter, which is one of the crucial parameters contributing to Voice over IP (VoIP) quality and has, to the best of our knowledge, not been considered previously in the published DCCP performance results. We propose modifications to the CCID4 algorithm and demonstrate how these improve the VoIP performance, without the need for additional link information other than what is already monitored by CCID4. We also demonstrate the fairness of the proposed modifications to other flows. Although the recently adopted changes to TCP‐Friendly Rate Control specification alleviate some of the performance issues for VoIP on satellite links, we argue that the characteristics of commercial satellite links necessitate consideration of further improvements. We identify the additional benefit of DCCP when used in VoIP admission control mechanisms and draw conclusions about the advantages and disadvantages of the proposed DCCP/CCID4 congestion control mechanism for use with VoIP applications. Copyright © 2012 John Wiley & Sons, Ltd.     

Molecular Beam Epitaxy of Graded-Composition InGaN Nanowires

We report the growth of graded InGaN nanowires by plasma-assisted molecular beam epitaxy. Wire composition is linearly graded from InN to GaN along the length of each wire. The large lattice mismatch between GaN and InN (11%) introduces tensile strain in the graded region, which results in cracking of the wires. Growing with reverse grading (i.e., GaN to InN) results in crack-free nanowires. The composition is measured by energy-dispersive x-ray spectroscopy of individual nanowires performed in a scanning transmission electron microscope, and strain is measured by high-resolution x-ray diffraction.     

Fabrication of Bone Scaffolds from Cockle Shell Waste

Bone scaffold is a three‐dimensional structure composed of materials that could enhance bone regeneration. Bone scaffolds were prepared using freeze‐drying by varying the cockle shell powder concentration where sodium alginate acted as matrix. The scaffolds were then characterized by X‐ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, texture analyzer, and liquid displacement method. The bioactivity of the scaffolds was evaluated by immersion into a simulated body fluid solution. Cockle shell powder concentrations affected the bone scaffold characteristics. The increment of the powder concentrations improved the physicochemical properties and bioactivity of the scaffolds.