Investigation of interface properties of sputter deposited TiN/CrN superlattices by low-angle X-ray reflectivity

Approximately 1.8 m thick nanolayered multilayer coatings of TiN/CrN (also known as superlattices) were deposited on silicon (100) substrates at different modulation wavelengths (4.6–12.8 nm), substrate temperatures (50-400 °C) and substrate bias voltages (-50 to -200 V) using a reactive direct current magnetron sputtering system. X-ray reflectivity (XRR) technique was employed to determine various properties of the multilayers such as interface roughness, surface roughness, electron density, critical angle and individual layer thicknesses. The modulation wavelengths of the TiN/CrN superlattice coatings were calculated using modified Bragg’s law. Furthermore, the experimental X-ray reflectivity patterns were simulated using theoretically generated patterns and a good fit was obtained for a three layer model, i.e., (1) top surface roughness layer, (2) TiN/CrN multilayer coating (approximately 1.8 m) and (3) Ti interlayer (~ 0.5 m) at the film-substrate interface. For the superlattice coatings prepared at a modulation wavelength of 9.7 nm, a substrate bias of -200 V and a substrate temperature of 400 C the XRR patterns showed Bragg reflections up to 5th order, indicating well-defined periodicity of the constituent layers and relatively sharp interfaces. The simulation showed that the superlattice coatings prepared under the above conditions exhibited low surface and interface roughnesses. We also present the effect of substrate temperature and substrate bias, which are critical parameters for controlling the superlattice properties, onto the various interface properties of TiN/CrN superlattices

A production inventory model with exponential demand rate and reverse logistics

The objective of this paper is to develop an integrated production inventory model for reworkable items with exponential demand rate. This is a three-layer supply chain model with perspectives of supplier, producer and retailer. Supplier delivers raw material to the producer and finished goods to the retailer. We consider perfect and imperfect quality products, product reliability and reworking of imperfect items. After screening, defective items reworked at a cost just after the regular manufacturing schedule. At the beginning, the manufacturing system starts produce perfect items, after some time the manufacturing system can undergo into “out-of-control” situation from “in-control” situation, which is controlled by reverse logistic technique. This paper deliberates the effects of business strategies like optimum order size of raw material, exponential demand rate, production rate is demand dependent, idle times and reverse logistics for an integrated marketing system. Mathematica is used to develop the optimal solution of production rate and raw material order for maximum expected average profit. A numerical example and sensitivity analysis is illustrated to validate the model

Benefits of retailer-supplier partnership initiatives under time-varying demand:a comparative analytical study

This paper aims to help supply chain managers to determine the value of retailer-supplier partnership initiatives beyond information sharing (IS) according to their specific business environment under time-varying demand conditions. For this purpose, we use integer linear programming models to quantify the benefits that can be accrued by a retailer, a supplier and system as a whole from shift in inventory ownership and shift in decision-making power with that of IS. The results of a detailed numerical study pertaining to static time horizon reveal that the shift in inventory ownership provides system-wide cost benefits in specific settings. Particularly, when it induces the retailer to order larger quantities and the supplier also prefers such orders due to significantly high setup and shipment costs. We observe that the relative benefits of shift in decision-making power are always higher than the shift in inventory ownership under all the conditions. The value of the shift in decision-making power is greater than IS particularly when the variability of underlying demand is low and time-dependent variation in production cost is high. However, when the shipment cost is negligible and order issuing efficiency of the supplier is low, the cost benefits of shift in decision-making power beyond IS are not significant

Analysing the feasibility of financial rewards for mentors engaged in entrepreneurial mentoring

In the domain of entrepreneurship, mentors are considered as volunteers and philanthropists yet their value is undermined, the purpose of this paper is to explore the feasibility of financial rewards for mentors, which could help in understanding the perspective of mentors towards the opportunity cost associated with mentoring. This study uses a survey to explore the viability of different types of financial reward models based on the responses of mentors engaged in the mentoring of entrepreneurs. The results are analysed using multivariate techniques, followed by post hoc analysis; a combination of both approaches helps to increase the validity of findings in an exploratory study. The findings of this study show that there is a need to restructure the mentoring system in the entrepreneurship domain, wherein the findings reveal that mentors are more professional in today’s competitive business environment, with intentions to receive financial rewards for the long term showing a possible link between mentor growth and the growth of mentees. The pattern found in this study describes a new approach for mentoring in entrepreneurship and for this reason more research is needed to confirm the emerging pattern underlined in this research. This study is first of its kind that reviews the financial opportunities for mentors, especially in context of India, and develops groundwork for future empirical research in this area

Metamaterial enhancement of metal-halide perovskite luminescence

Metal-halide perovskites are rapidly emerging as solution-processable optical materials for light emitting applications. Here we adopt a plasmonic metamaterial approach to enhance photoluminescence emission and extraction of methylammonium lead iodide (MAPbI3) thin films, based on the Purcell effect. We show that hybridization of the active metal-halide film with resonant nanoscale sized slits carved into a gold film can yield more than one order of magnitude enhancement of luminescence intensity, and nearly threefold reduction of luminescence lifetime. This shows the effectiveness of resonant nanostructures in controlling metal-halide perovskite light emission properties over a tunable spectral range, a viable approach toward highly efficient perovskite light emitting devices and single-photon emitters

SYNTHESIS AND INVESTIGATION OF ANTHELMINTIC, ANTIBACTERIAL AND ANTIFUNGAL ACTIVITY OF 3,3-DIPHENYL PROPANAMIDE DERIVATIVES

Objective: A novel series of substituted 3,3-diphenyl propanamide derivatives (I-VIII) were synthesized by reacting 3,3-diphenyl propanoyl chloride with different amines/amino acids, and all the derivatives were investigated for anthelmintic, antibacterial, and antifungal activity.Methods: All the compounds were characterized by infrared (IR) and1H- nuclear magnetic resonance spectrometry data. The synthesized derivatives were investigated for their anthelmintic activity employing housefly worms method and earthworm species model. The antibacterial and antifungal activity was performed employing cup plate method.Results: The synthesized compounds (VII and VIII) exhibited maximum anthelmintic activity as compared with standard drug albendazole at doses of 50 and 100 mg/mL, due to minimal paralyzing and death time in both housefly and earthworm models. The compounds (IV, VII, and VIII) at 50 μg/mL exhibited maximum activity against Gram-negative bacterial strains, namely, Escherichia coli, Pseudomonas aeruginosa as compared with ciprofloxacin and same compounds exhibited maximum antifungal activity against Candida albicans and Aspergillus niger in comparison with standard drug griseofulvin at 50 μg/mL.Conclusion: The synthesized compounds bearing amino acid moiety in their structure (VII-VIII) exhibited impressive anthelmintic activity in comparison with albendazole. This suggests that amino acid/peptide derivative of diphenyl propanamides can act as great anthelmintic agents. Further, the research can be performed to design potent antimicrobial diphenyl propanamide derivatives.Â

Wettability of Y2O3: A relative analysis of thermally oxidized, reactively sputtered and template assisted nanostructured coatings

The wettability of reactively sputtered Y2O3, thermally oxidized Y-Y2O3 and Cd-CdO template assisted Y2O3 coatings has been studied. The wettability of as-deposited Y2O3 coatings was determined by contact angle measurements. The water contact angles for reactively sputtered, thermally oxidized and template assisted Y2O3 nanostructured coatings were 99°, 117° and 155°, respectively. The average surface roughness values of reactively sputtered, thermally oxidized and template assisted Y2O3 coatings were determined by using atomic force microscopy and the corresponding values were 3, 11 and 180 nm, respectively. The low contact angle of the sputter deposited Y2O3 and thermally oxidized Y-Y2O3 coatings is attributed to a densely packed nano-grain like microstructure without any void space, leading to low surface roughness. A water droplet on such surfaces is mostly in contact with a solid surface relative to a void space, leading to a hydrophobic surface (low contact angle). Surface roughness is a crucial factor for the fabrication of a superhydrophobic surface. For Y2O3 coatings, the surface roughness was improved by depositing a thin film of Y2O3 on the Cd-CdO template (average roughness = 178 nm), which resulted in a contact angle greater than 150°. The work of adhesion of water was very high for the reactively sputtered Y2O3 (54 mJ/m2) and thermally oxidized Y-Y2O3 coatings (43 mJ/m2) compared to the Cd-CdO template assisted Y2O3 coating (7 mJ/m2)

Influence of sodium hexa metaphosphate antiscalant on the corrosion of carbon steel in industrial cooling water system

181-190In order to have clear understanding about the contribution of antiscalant and zinc ions separately towards the corrosion control of carbon steel in six different synthetic cooling waters, a single antiscalant, sodium hexa meta phosphate (SHMP), was tried with and without zinc ions, which may control scaling as well as corrosion problem in cooling water system (CWS). Weight loss, electrochemical polarization and metallurgical research microscopy technique were carried out at 30, 40 and 50°C using different concentrations of the inhibitor and zinc ions. Mechanism of inhibition is explained on the basis of molecular structure of the inhibitor. The inhibitor provides good inhibition efficiency and acts as anodic inhibitor when present alone and mixed inhibitor with zinc ions. SHMP due to its cyclic structure, forms cage-complex with Fe2+ ions from any two adjacent negatively charged phosphoryl oxygen anions. Moreover, addition of zinc ions to cooling water along with SHMP, do not increase inhibition efficiency to an appreciable extent

Nanometric multi-scale rough CuO/Cu(OH)2 superhydrophobic surfaces prepared by facile one step solution-immersion process: Transition to superhydrophilicity with oxygen plasma treatment

An inexpensive and facile one step method to develop the superhydrophobic coating on copper surface is reported. Superhydrophobic CuO/Cu(OH)2 surfaces Prepared by a simple solution-immersion process at room temperature, without using a low surface energy material. The structure and composition of as-prepared CuO/Cu(OH)2 hierarchical structure was confirmed by X-ray diffraction (XRD), micro-Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The growth stage was carefully examined by using field emission scanning electron microscopy (FESEM) and it was observed that Cu(OH)2 nanoneedle arrays were formed in the beginning on the copper surface, after that CuO micro-flowers were formed on the nanoneedle arrays. The contact angle as a function of immersion time was studied using contact angle goniometer. The correlation between the microstructure of the immersed copper surface and the contact angle was examined carefully using FESEM and atomic force microscopy (AFM). Our studies based on FESEM and AFM show that the CuO/Cu(OH)2 coatings demonstrate superhydrophobicity only for an optimal combination of solid region (i.e., microflowers and nanoneedle) and air pockets (i.e., voids). The maximum static water contact angle on the prepared surface was 159. The wettability transition of the CuO/Cu(OH)2 surface from superhydrophobicity to superhydrophilicity was studied by the alteration of oxygen plasma treatment and dark storage. FESEM, AFM and XPS studies show that this transformation was mainly due to the morphological changes that occur in addition to the chemical changes taking place on the CuO/Cu(OH)2 surface under the influence of oxygen plasma. XPS analysis demonstrates that the incorporation of oxygen species by oxygen plasma activation accounted for the highly hydrophilic character of the surface