Experimental investigation on the effect of MgO and TiO2 nanoparticles in stepped solar still

This work aims at augmenting the amount of potable water using MgO and TiO₂ in stepped solar still. Experiments were carried out for the climatic conditions of Chennai, India, with two different concentrations of nanofluids inside a stepped basin under three different cases. Results show that there is an improvement in yield of fresh water from stepped solar still by 33.18% and 41.05% using 0.1% and 0.2% volume concentration of TiO₂ nanofluid, respectively, whereas the freshwater yield from stepped still with MgO nanofluids improved by 51.7% and 61.89%. Furthermore, the economic analysis revealed that the cost of potable water from the modified solar still reduced from 0.029 to 0.016 $/kg. Similarly, the useful annual energy, yearly cost per kilogram, and annual cost per kilowatt hour are significantly profitable with the use of MgO nanofluid in the stepped basin and found as 512.46 kWh, 0.025 $/kg, and 0.026 $/kWh, respectively. It is also found that the cost of potable water from the modified still significantly increases as the amount of fresh water produced is decreased with increased fabrication cost of the solar still.     

Synthesis of Ag@TiO2/NiFe2O4 ternary nanostructures and evaluation of their photocatalytic activities

Journal of Materials Science: Materials in Electronics - Synthesis and characterization of novel and ternary photocatalysts Ag@TiO2/NiFe2O4 for the three potential applications, such as...     

The Perils and Promises of Self-Disclosure on Social Media

In addition to their professional social media accounts, individuals are increasingly using their personal profiles and casual posts to communicate their identities to work colleagues. They do this in order to ‘stand out from the crowd’ and to signal attributes that are difficult to showcase explicitly in a work setting. Existing studies have tended to treat personal posts viewed in a professional context as a problem, since they can threaten impression management efforts. These accounts focus on the attempts of individuals to separate their life domains on social media. In contrast, we present the narratives of professional IT workers in India who intentionally disrupt the boundaries between personal and professional profiles in order to get noticed by their employers. Drawing on the dramaturgical vocabulary of Goffman (1959) we shed light on how individuals cope with increased levels of self-disclosure on social media. We argue that their self-presentations can be likened to post-modern performances in which the traditional boundaries between actor and audience are intentionally unsettled. These casual posts communicate additional personal traits that are not otherwise included in professional presentations. Since there are no strict boundaries between formal front-stage and relaxed back-stage regions in these types of performance, a liminal mental state is often used, which enables a better assessment of the type of information to present on social media.     

Contact-Barrier Free,High Mobility,Dual-Gated Junctionless Transistor Using Tellurium Nanowire

The gate-all-around nanowire transistor, due to its extremely tight electrostatic control and vertical integration capability, is a highly promising candidate for sub-5 nm technology nodes. In particular, the junctionless nanowire transistors are highly scalable with reduced variability due to avoidance of steep source/drain junction formation by ion implantation. Here a dual-gated junctionless nanowire p-type field effect transistor is demonstrated using tellurium nanowire as the channel. The dangling-bond-free surface due to the unique helical crystal structure of the nanowire, coupled with an integration of dangling-bond-free, high quality hBN gate dielectric, allows for a phonon-limited field effect hole mobility of 570 cm² V⁻¹ s⁻¹ at 270 K, which is well above state-of-the-art strained Si hole mobility. By lowering the temperature, the mobility increases to 1390 cm² V⁻¹ s⁻¹ and becomes primarily limited by Coulomb scattering. The combination of an electron affinity of ≈ 4 eV and a small bandgap of tellurium provides zero Schottky barrier height for hole injection at the metal-contact interface, which is remarkable for reduction of contact resistance in a highly scaled transistor. Exploiting these properties, coupled with the dual-gated operation, we achieve a high drive current of 216 μA μm⁻¹ while maintaining an on-off ratio in excess of 2 × 10⁴. The findings have intriguing prospects for alternate channel material based next-generation electronics.     

Polymer assisted hydroxyapatite microspheres suitable for biomedical application

Hollow Microspheres of hydroxyapatite-polymer composite can be used as carriers in drug delivery and fillers in tissue engineering. Based on the concept of soft chemistry, a battery of technique is available in the literature to synthesize hollow microspheres, however, an economically viable synthesis route, having good control over the microarchitect and easy to be scaled up, is yet to be developed. Polymer matrix mediated synthesis of inorganic nanoparticles is known to synthesize nanoparticles with controlled morphology and dimensions. It is termed as biomimetic synthesis. Integrating the biomimetic synthesis of nano-particles and spray drying techniques, a novel process of producing hydroxyapatite-polymer composite hollow microspheres is briefly discussed here.     

A comparative study of 3E (energy,exergy, and economy) analysis of various solar stills

In this paper, an experimental study of the conventional solar still (CSS), the conventional solar still with glass cooling (CSSGC), the conventional solar still with basin heating (CSSBH), and the conventional solar still with glass cooling and basin heating (CSSGCBH) was carried out on the basis of the distilled water production, the energy efficiency (EnE), the exergy efficiency (ExE), and economic analysis. The CSSGC and CSSBH contain Peltier modules for cooling the glass and heating the basin. The evaporative heat transfer coefficient for all the experimental stills was calculated. The values of daily distilled water production from the CSSGCBH, CSSBH, CSSGC, and CSS were 4.56, 3.79, 2.49, and 1.89 kg/m², respectively. The daily distilled yield of the CSSBH and CSSGCBH were increased by 58.55% and 50.13%, respectively, as compared with the CSS. Moreover, the daily EnE and ExE of the CSSGCBH were 27.03% and 3.5%, respectively, whereas the EnE and ExE of the CSS were 10.88% and 1.3%, respectively. Furthermore, the cost of distilled water production was found to be 0.26, 0.35, 0.53, and 0.64 $/day for the CSS, CSSGC, CSSBH, and CSSGCBH, respectively, if the selling price of the distilled water was Rs10.     

Nucleotide breakdown products of seer fish (Scomberomorus commerson) steaks stored in O2 scavenger packs during chilled storage

Freshness of seer fish (Scomberomorus commerson) steaks packed with and without O₂ scavenger was assessed by sensory and chemical methods. O₂ scavenger used in the present study reduced the O₂ level in the pack to less than 0.01% within 24 h. Samples in air packs were sensorily acceptable only up to 12 days compared to 20 days in O₂ scavenger packs. TVB-N levels were 37 and 34 mg N₂/100 g and TMA-N levels were 16.4 and 15.2 mg N₂/100 g on the day of sensory rejection for air and O₂ scavenger packs, respectively. IMP decrease and Hx increase was significantly (P < 0.05) faster in air packed samples compared to O₂ scavenger packs. On sensory rejection day, the average K, Ki, P and H values were 63–65%, Fr value was 34% and G value was 178% for O₂ scavenger packed samples compared to 81%, 18% and 443% for air packed samples, respectively.Industrial relevanceThe O₂ scavenger is an innovative active packaging technique, which is highly effective in reducing the O₂ present inside the pack. This can be used in place of traditional vacuum packaging for extending the shelf life of fish products, which reduces the use of vacuum packaging equipments thereby making the process cost effective.     

High-surface step density on dendritic pd leads to exceptional catalytic activity for formic acid oxidation

Dendritic Pd with corrugated surfaces, obtained by a novel AC technique, exhibits an exceptionally high catalytic activity for the oxidation of formic acid because of the presence of a high density of surface steps. The formation of twinned dendrites leads to a predominance of exposed 111 facets with a high density of surface steps as evident from high resolution electron microscopy investigations. These surface sites provide active sites for the adsorption of the formic acid molecules, thereby enhancing the reaction rate. Control experiments by varying the time of deposition reveal the formation of partially grown dendrites at shorter times indicating that the dendrites were formed by growth rather than particle attachment. Our deposition method opens up interesting possibilities to produce anisotropic nanostructures with corrugated surfaces by exploiting the perturbations involved in the growth process.     

Exergy Analysis of Solar Still with Sand Heat Energy Storage

This paper studies the experimental and exergy analysis of solar still with the sand heat energy storage system. The cumulative yield from solar still with and without energy storage material is found to be 3.3 and 1.89 kg/m², respectively for 8-h operation. Results show that the exergy efficiency of the system is higher with the least water depth of 0.02 m (m_w = 20 kg). Competitive analysis of second law efficiency shows that the exergy efficiency improves the system by 30% than conventional single slope solar still without any heat storage. The maximum exergy efficiency with energy storage material is found as 13.2% and it is less than the conventional solar still without any material inside the basin.     

Antimicrobial activity of different copper alloy surfaces against copper resistant and sensitive Salmonella enterica

Copper has shown antibacterial effects against foodborne pathogens. The objective of this study was to evaluate the antibacterial activity of copper surfaces on copper resistant and sensitive strains of Salmonella enterica. Six different copper alloy coupons (60–99.9% copper) were tested along with stainless steel as the control. The coupons were surface inoculated with either S. Enteritidis or one of the 3 copper resistant strains, S. Typhimurium S9, S19 and S20; stored under various incubation conditions at room temperature; and sampled at various times up to 2 h. The results showed that under dry incubation conditions, Salmonella only survived 10–15 min on high copper content alloys. Salmonella on low copper content alloys showed 3–4 log reductions. Under moist incubation conditions, no survivors were detected after 30 min–2 h on high copper content alloys, while the cell counts decreased 2–4 logs on low copper content coupons. Although the copper resistant strains survived better than S. Enteritidis, they were either completely inactivated or survival was decreased. Copper coupons showed better antimicrobial efficacy in the absence of organic compounds. These results clearly show the antibacterial effects of copper and its potential as an alternative to stainless steel for selected food contact surfaces.