Characteristics of Bilayer Molybdenum Films Deposited Using RF Sputtering for Back Contact of Thin Film Solar Cells

Mo films prepared under a single deposition condition seldom simultaneously obtain a low resistivity and a good adhesion necessary for use in solar cells. In order to surmount the obstacle, bilayer Mo films using DC sputtering at a higher working pressure and a lower working pressure have been attempted as reported in the literature. In this study, RF sputtering with different powers in conjunction with different working pressures was explored to prepare bilayer Mo film. The first bottom layer was grown at a RF sputtering power of 30 W and a working pressure of 12 mTorr, and the second top layer was deposited at 100 W and 4.5 mTorr. The films revealed a columnar growth with a preferred orientation along the (110) plane. The bilayer Mo films reported an electrical resistivity of 6.35 × 10−5 Ω-cm and passed the Scotch tape test for adhesion to the soda-lime glass substrate, thereby qualifying the bilayer Mo films for use as back metal contacts for CIGS substrates

Direct pyrolysis and ultrasound assisted preparation of N, S co-doped graphene/Fe3C nanocomposite as an efficient electrocatalyst for oxygen reduction and oxygen evolution reactions

Bifunctional electrocatalysts to enable efficient oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are essential for fabricating high performance metal–air batteries and fuel cells. Here, a defect rich nitrogen and sulfur co-doped graphene/iron carbide (NS-GR/Fe3C) nanocomposite as an electrocatalyst for ORR and OER is demonstrated. An ink of NS-GR/Fe3C is developed by homogeneously dispersing the catalyst in a Nafion containing solvent mixture using an ultrasonication bath (Model-DC150H; power − 150 W; frequency − 40 kHz). The ultrasonically prepared ink is used for preparing the electrode for electrochemical studies. In the case of ORR, the positive half-wave potential displayed by NS-GR/Fe3C is 0.859 V (vs. RHE) and for the OER, onset potential is 1.489 V (vs. RHE) with enhanced current density. The optimized NS–GR/Fe3C electrode exhibited excellent ORR/OER bifunctional activities, high methanol tolerance and excellent long-term cycling stability in an alkaline medium. The observed onset potential for NS–GR/Fe3C electrocatalyst is comparable with the commercial noble metal catalyst, thereby revealing one of the best low-cost alternative air–cathode catalysts for the energy conversion and storage application

Consumers’ raw poultry washing practices: A cross-sectional and observational study in eight Southeast Asian countries

Consumers are recommended not to wash raw poultry before cooking since this practice increases risks of cross contamination with foodborne pathogens. However previous studies had identified that consumers were unaware of this incorrect behaviour. This study aims to assess consumers' self-reported and observed raw poultry washing practices in Southeast Asian (SEA) countries. A mixed method design was employed, with data collected via a cross-sectional survey across eight SEA countries, observational studies and semi-structured interviews conducted in Indonesia and Malaysia. Ninety-six percent (n = 2009) of surveyed participants reported that they washed raw poultry at home. Participants from Laos and Philippines, older, married and low-income participants reported washing raw poultry more frequently. The main reasons for washing raw poultry were to remove dirt, slime, blood or feathers and the act of washing makes them feel safer. Participants from Cambodia (OR = 2.855, p < 0.001), Indonesia (OR = 3.208, p < 0.001), Laos (OR = 3.012, p < 0.05), Malaysia (OR = 2.003, p < 0.05) and Thailand (OR = 2.148, p < 0.001) were 2.00–3.21 times more confident about not washing raw poultry upon understanding the rationale that washing does not reduce microbial load. Participants who purchased from supermarkets (OR = 1.785, p < 0.05) were significantly more confident about not washing raw poultry compared to other sources of raw poultry. Our observation study identified various cross contamination pathways including lack of hand hygiene practices, inadequate cleaning and sanitation procedures, and cross contamination of raw poultry and washed water to surrounding areas. Semi-structured interviews revealed that participants preferred to wash raw poultry due to the lack of cleanliness of raw poultry purchased from traditional markets and the act is ingrained in their cultural practice. Due to consumers' preference for freshly slaughtered poultry and perceived cleanliness of raw poultry purchased from traditional markets, hand hygiene practices during and after handling raw poultry and cleaning of kitchen sinks and surrounding areas with soap should be emphasised. Targeted food safety messages and educational campaigns suited to local cultural differences should be conducted. This study presents the first empirical findings on consumers’ raw poultry washing practices in eight SEA countries. Practical implications and further recommendations are provided

How Social Communications Influence Advertising Perception and Response in Online Communities?

This research aims to explore how social communications of online communities affect users’ perception and responses toward social media advertising. We developed a conceptual model based on the SBT, encapsulating 9 constructs and 10 hypothesis extracted from the extant social media advertising literature. Our research outcome proves that social communications can effectively boost users’ behaviors to be in accordance with an online social community, thus facilitate their acceptance and responses toward social media advertising, with users’ group intention as an intervening factor. From an operational standpoint, it’s an effective way to build and maintain social bonds between users and the community by boosting social communications, supporting fluent interpersonal communications. In addition, managers of an online community should elaborate on users’ group intentions to increase users’ advertising acceptance and response

Comparative Study on Macro-Tribological Properties of PLL-g-PEG and PSPMA Polymer Brushes

An ultra-low friction and high load capacity could be obtained on the surfaces grafted by a polymer brush even at relatively slow friction speeds in aqueous lubrication environments, which has attracted widespread attention to study the lubrication mechanism of polymer brushes; however, it has yet to be fully understood. The macroscopic tribological performance of two different polymer brushes, which were prepared by the method of &ldquo;grafting to&rdquo; and &ldquo;grafting from&rdquo; and named as PLL-g-PEG and PSPMA, respectively, were investigated. The friction results demonstrated that PLL-g-PEG obtained a lower friction coefficient than polymer brush PSPMA, which was ascribed to its unique &ldquo;self-healing&rdquo; behavior. The lubrication film was in situ observed and the film thickness induced by the polymer brush was measured using a laboratory set for film thickness measurement apparatus based on interference technology. It was found that PSPMA exhibited excellent lubrication performance not found in PLL-g-PEG, and two film-forming mechanisms highly dependent on velocity were revealed, which may be important to interpret the lubrication mechanism of polymer brushes in aqueous lubricants

Backscattering Echo Intensity Characteristics of Laser in Soil Explosion Dust

Soil dust generated by explosions can lead to the absorption and scattering of lasers, resulting in low detection and recognition accuracy for laser-based devices. Field tests to assess laser transmission characteristics in soil explosion dust are dangerous and involve uncontrollable environmental conditions. Instead, we propose using high-speed cameras and an indoor explosion chamber to assess the backscattering echo intensity characteristics of lasers in dust generated by small-scale explosive blasts in soil. We analyzed the influence of the mass of the explosive, depth of burial, and soil moisture content on crater features and temporal and spatial distributions of soil explosion dust. We also measured the backscattering echo intensity of a 905 nm laser at different heights. The results showed that the concentration of soil explosion dust was highest in the first 500 ms. The minimum normalized peak echo voltage ranged from 0.318 to 0.658. The backscattering echo intensity of the laser was found to be strongly correlated with the mean gray value of the monochrome image of soil explosion dust. This study provides experimental data and a theoretical basis for the accurate detection and recognition of lasers in soil explosion dust environments