Blends of cardanol-based epoxidized novolac resin and CTBN for application in surface coating: a study on thermal,mechanical, chemical,and morphological characteristics

Blend samples of cardanol-based epoxidized novolac resin and different weight percentages of carboxyl-terminated butadiene acrylonitrile (CTBN) were developed and cured with stoichiometric amounts of aliphatic amine. The formation of various products during the curing of blend samples has been studied by Fourier-transform infrared spectroscopy. The dynamic differential scanning calorimeter scans showed that the pure epoxies and their blend samples with CTBN cured in the temperature range of 100–150°C. The blend sample containing 15 wt% CTBN showed the least cure time (at 120°C) among all other blend samples. Upon evaluation, it was found that blend samples exhibit better properties compared to pure epoxy resin in terms of increase in impact strength and elongation-at-break of the casting and gloss, scratch hardness, adhesion, and flexibility of the film. The improvement in these properties indicates that the rubber modified resin would be more durable than the epoxy based on cardanol. Chemical and morphological properties of the formulated resins were also determined. The thermal stability of the blend samples containing 15 wt% CTBN in epoxy resin was the highest among all other prepared systems. The blend morphology, studied by scanning electron microscope, showed the presence of precipitated discrete rubber particles, which dispersed throughout the epoxy matrix—i.e., they revealed the presence of two-phase morphological features.     

The First Example of Saccharin‐Lithium Bromide Catalysis: Direct Synthesis of N‐Tosylimines from Alcohols

The first procedure to access N‐tosylimines directly from alcohols under mild and neutral conditions is reported. The protocol involves saccharin‐lithium bromide‐catalyzed oxidation of alcohols to aldehydes/ketones with chloramine‐T followed by their condensation with the in situ generated oxidation by‐product p‐toluenesulfonamide in the same reaction vessel to afford N‐tosylimines in 40–90% overall yields. The present work opens up a new and efficient synthetic route to N‐tosyimines directly from alcohols in a one‐pot procedure.     

Interface Trap Charges Analysis on DC and High Frequency Characteristics of UTBB-FDSOI FET

Silicon - In this paper, we have studied effect of localised charges on performance of UTBB FDSOI FET. Purpose behind this work is to understand the performance of UTBB FDSOI FET under the...     

Comparative Performance of Different Sector Arrangement in a Desiccant Wheel Using a Mathematical Model

A one‐dimensional mathematical model has been used for a three‐sector desiccant wheel (two sectors with purge) with different flow arrangements. The model considers both gas and solid side resistance and shows a good agreement with experimental results. This model has been used to conduct a comparative performance analysis in both the effective adsorption and effective regeneration sector of a desiccant wheel. It was found that an effective regeneration sector gives better results for the performance parameters (rotation of wheel, regeneration temperature, velocity, and ambient moisture) as compared to an effective adsorption sector. © 2013 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library ( wileyonlinelibrary.com/journal/htj ). DOI 10.1002/htj.21103     

Fabrication of portable solar thermal bank for indoor cooking

The aim of this report is to build a portable solar thermal bank based on a Scheffler reflector that is capable of boiling-type cooking using HITEC as a thermal storage material. This report reviews the problems related to solar cooking and evaluates the novel layout of a portable solar thermal bank which includes a daily thermal storage vessel. This stove is in the shape of a cylindrical container filled with phase-changing latent heat storage material. Inside the container, we provide a small gap taking into account the volumetric expansion of the phase change material (PCM) during the melting process. The solar thermal bank is charged in the sun. It is placed directly for a few hours under the focus of a Scheffler reflector, which charges the solar thermal bank with enough thermal energy stored. After a while, the cooking process can be completed by users using that stored heat. The top cavity is used as a cooking pot in a solar thermal bank. Cooking meals do not require direct sunlight, which is typical for most solar cookers. The portable solar thermal bank is an alternative for low-income households and adapts to local traditions of indoor cooking. It is portable and can be used safely to cook indoors or outdoors. In this study, a solar cooker with a thermal storage device was developed using a PCM. The size of the stove has been calculated by calculating the energy consumption for two to three people. HITEC salt has been chosen as a phase change material for thermal storage, which will be used for cooking when there is no sunlight. It enhances the applicability of solar cooking and preserves cooking possibilities using energy stored throughout the day at low production costs.     

Hybrid connection algorithm: A strategy for efficient restoration in WDM optical networks

In present communication, we propose a modified resource allocation strategy, namely, hybrid connection algorithm, for achieving efficient restoration in WDM optical networks. The main theme of the algorithm is that, while attempting connection establishment, a wavelength is reserved in advance for providing resources for backup lightpaths. The analysis and the comparison of the proposed strategy with other existing strategies has been undertaken using metrics such as, restoration efficiency, number of wavelength links used by primary and backup lightpaths, and the percent link utilization. The proposed strategy provides 100% restoration efficiency and much better performance than the existing techniques.     

Correction of high gradient quadrupole harmonics with magneticshims

Superconducting quadrupole magnets with 70 mm aperture and nominal field gradient of 215 T/m are being developed by the US-LHC Accelerator Project for the Interaction Regions of the Large Hadron Collider. Due to large beam size and orbit displacement in the final focusing triplet, these magnets are subject to stringent field quality requirements. For this reason, a correction scheme based on design calculations, fabrication issues and tests results involving magnetic shims     

Thermal instability of rotating nanofluid layer

In the present paper we have considered thermal instability of rotating nanofluids heated from below. Linear stability analysis has been made to investigate analytically the effect of rotation. The more important effect of Brownian motion and thermophoresis has been included in the model of nanofluid. Galerkin method is used to obtain the analytical expression for both non-oscillatory and oscillatory cases, when boundaries surfaces are free–free. The influence of various nanofluids parameters and rotation on the onset of convection has been analysed. It has been shown that the rotation has a stabilizing effect depending upon the values of various nanofluid parameters. The critical Rayleigh number for the onset of instability is determined numerically and results are depicted graphically. The necessary and sufficient conditions for the existence of over stability are also obtained.     

Dielectric and impedance study of lead-free ceramic: (Na<Subscript>0.5</Subscript>Bi<Subscript>0.5</Subscript>)ZrO<Subscript>3</Subscript>

Polycrystalline sample of (Na_0.5Bi_0.5)ZrO₃ was prepared using a high-temperature solid-state reaction technique. XRD analysis indicated the formation of a single-phase orthorhombic structure. Dielectric study revealed the diffuse phase transition at 425 °C. AC impedance plots were used as tools to analyse the electrical behaviour of the sample as a function of frequency at different temperatures. The ac impedance studies revealed the presence of grain boundary effect at and above 350 °C. Complex impedance analysis indicated non-Debye type dielectric relaxation and negative temperature coefficient of resistance (NTCR) character of (Na_0.5Bi_0.5)ZrO₃. AC conductivity data were used to evaluate the density of states at Fermi level and activation energy of the compound. DC electrical and thermal conductivities of grain and grain boundary have been assessed.     

Theoretical analysis of absorption of chlorine in aqueous slurries of calcium hydroxide: Desorption of hypochlorous acid gas

A theory has been developed for the absorption of chlorine in aqueous slurries of calcium hydroxide accompanied by a two-step instantaneous reaction and desorption and simulation is carried out to study the effects of various parameters. The rates of absorption of chlorine and desorption of HOC1 from the aqueous slurry are enhanced when fine particles are present in two diffusion film regions on the liquid side. It is concluded that intensification in the rates of absorption of chlorine and rates of desorption can be realized by using high loading of smaller particle size. An optimum k_L must be used to enhance rates of Cl₂ absorption and HOG desorption in order to permit the formation of two reaction planes in the diffusion film. Rates can be intensified by an order of magnitude by the proper selection of operating conditions.