Probing the influence of superhydrophobicity and mixed wettability on droplet displacement behavior

The importance of fundamental understanding of droplet dynamics and the concomitant implications of wall wettability are critical in the emergent science and technology areas including digital microfluidics and clean energy conversion. In this work, mesoscopic illustration, based on the two-phase lattice Boltzmann model, of droplet dynamics in a microchannel is presented in order to unveil the role of superhydrophobicity and mixed wettability. The impact of critical physicochemical determinants, including capillary number and droplet size, is explored in the context of droplet–wettability interactions. Temporal evolution of wetted length and wetted area for a combination of wettability scenarios is furnished in detail in order to elucidate the droplet displacement dynamics. Capillary number plays an important role with disparate droplet behavioral patterns stemming from superhydrophobic and mixed-wet wall characteristics.     

Novel approach for the development of dietary fibre-anthocyanin enriched functional bread from culinary banana bract

Dietary fibre (DF)-anthocyanin formulation was incorporated in bread to develop anthocyanin rich DF powder (ARDFP) fortified bread. Prior to incorporation of DF-anthocyanin formulation in bread preparation, the cytotoxicity of DF and anthocyanin extracts was assessed. The effect of incorporation of different level of ARDFP with moisture on bread quality characteristics such as specific volume, textural, colour, sensory properties and starch digestibility was studied. The results revealed that extracted DF and anthocyanin of culinary banana bracts were nontoxic towards peripheral blood mononuclear cell and cytotoxic towards HT29 cancerous cell line. Incorporation of 2% ARDFP with 68% moisture was rated as best with higher specific volume (5.50 cm³ g⁻¹), improved textural properties (high springiness and cohesiveness), anthocyanin content (9.08 mg per 100 g), colour characteristics and sensory acceptability next to control. The in vitro digestibility study suggested increased incorporation of ARDFP in bread flour reduced the rate of starch digestibility (0.0035 min⁻¹).     

Implications of non-uniform porosity distribution in gas diffusion layer on the performance of a high temperature PEM fuel cell

The present study discusses a detailed investigation on the implications of non-uniform porosity distribution in the gas diffusion layer (GDL) on the performance of proton exchange membrane fuel cell (PEMFC). A three-dimensional, single-phase, isothermal model of high-temperature PEMFC is employed to study the effect of non-uniform porosity distribution in GDL. The different porosity configurations with stepwise, sinusoidal, and logarithmic variation in porosity along the streamwise direction of GDL are considered. The numerical experiments are performed, keeping average porosity as constant in the GDL. The electrochemical characteristics such as the oxygen molar concentration, power density, current density, total power dissipation density, average diffusion coefficient, vorticity magnitude, and overpotential are studied for a range of porosity distributions. Furthermore, the variations of oxygen concentration, average diffusion coefficient, and vorticity magnitude are also discussed to showcase the influence of non-uniform porosity distribution. Our study reveals that the PEM fuel cell performance is the best when the porosity of the GDL decreases logarithmically in the streamwise direction. On the contrary, the performance deteriorates when the GDL porosity decreases sinusoidally. Also, it has been observed that the effects of non-uniform porosity distribution are more pronounced, especially at higher current densities. The outcomes of present investigation have potential utility in GDL fabrication and membrane assembly's sintering process for manufacturing high valued PEMFC products.     

An overview of the Web of Science record of scientific publications (2004–2013) from Nepal: focus on disciplinary diversity and international collaboration

This study attempts to use bibliometry as a tool for exploration of the passage of development of the science and technology through analysis of the scientific publications from a developing country by taking into account its state of higher education and the unique political, economic and geo-bio-environmental conditions. It deals with Nepal considering its scientific output during 1966–2016 reflected as publications indexed in the Web of Science Database. Preliminary examination of the publication record for Nepal reveals a number of the following characteristics: (1) low volume, negligible growth and lack of distinct trend until 1989; (2) a marked growth followed by stagnation linked to political instability during the next 15 years; and (3) recovery and accelerated growth thereafter. Research publications during 2004–2013 increased thrice compared to 1994–2003, with expansion and shifts in disciplinary profile expressed in Essential Science Indicators 22 fields. Detailed bibliometric analysis of the 2004–2013 publications (3011 articles and reviews) from Nepal suggests the citation impact of about the world average, but very high (76%) average international co-authorship. The disciplinary profile is diverse judging from seven most productive fields (clinical medicine, plant and animal science, environment/ecology, geosciences, agricultural sciences, and chemistry) with 4–40% national disciplinary share. Clinical medicine, geosciences and agricultural sciences exhibit relatively high impact. Fields with the smaller share (< 3%), such as molecular biology and genetics, economics and business, psychiatry and psychology, materials science, and biology and biochemistry, exhibit citation impact distinctly higher than the world average. Publications from Nepal show the presence of a vast international collaborative network that is dominated by authors affiliated to institutions in the USA, India, UK, Japan, South Korea and Germany. Based on the analysis of the disciplinary diversity and the national versus global relative disciplinary shares, Nepal’s publication profile is inferred to be a hybrid of the ‘bio-environmental’ and ‘western’ models. Concerning the state of the development of science and technology in Nepal during 2004–2013, the high dependence on international collaboration in the internationally visible publications in most of the bio-environmental, physico-chemical and engineering fields points to basically a ‘building-up stage’. In clinical medicine (with a large share of public health) and geosciences, however, Nepal has demonstrated research strengths evident from the high citation impact in these fields. Moreover, the available data suggest that significant advances were made in higher education sector in both fields during the last 25 years. Despite the notable negative effect of the prolonged domestic armed political conflict on the research activities and acquisition of new data in the field-based sciences, the post-conflict period shows signs of recovery in both domestic and international collaborations leading to again an accelerated growth in scientific publications.     

Assessment of the fuel wood of India: A case study based on fuel characteristics of some indigenous species of Arunachal Pradesh

Biomass in the form of fuelwood has been a source of energy for many centuries all over the world. In rural India, fuelwood remains the first choice of energy source. Arunachal Pradesh is home to many different tree species; so far most of the fuelwoods of Arunachal Pradesh have never been studied for their fuel characteristics. This study is carried out with the following objectives: (i) Identification and selection of indigenous fuelwood species, which are widely distributed throughout Arunachal Pradesh, North East India; (ii) quantitative and qualitative analysis of these fuelwoods; and (iii) to rank these fuelwoods according to their fuel value index.     

Reflection of cross-disciplinary research at Creative Research Institution (Hokkaido University) in the Web of Science database: appraisal and visualization using bibliometry

This study describes the results of a preliminary bibliometric analysis of 611 research items, published between 1996 and 2011 by researchers affiliated with Creative Research Institution (CRIS) and the Center for Advanced Science and Technology (CAST), Hokkaido University (HU), retrieved from the Web of Science (WoS) database. CRIS has a primary mission to promote cutting-edge, world-class, trans-departmental research within HU, and it conducts fundamental, commercialization-related, cross-disciplinary research and nurtures young in-house/recruited researchers through targeted, innovative tenure-track programs in multiple disciplines. Its research output derives from 3- to 7-year-long time-bound projects funded strategically by HU, external grants [e.g., MEXT Super-COE HU Research and Business Park Project (FY2003-7)], industry-university collaboration with regional businesses, and endowments (e.g., Meiji Dairies). Analyses using co-words, bibliographic coupling, overlay map aided with visualization, etc., lead to the following inferences: (i) The published items comprise a dozen well-defined (inter-)disciplinary clusters, dominated by 3 macro-disciplines (biomedical science, 33%; chemistry, 21%; agricultural science, ca. 10%) that constitute 18 clusters used for mapping; (ii) research conducted by externally funded or endowed projects in the biomedical, physical and environmental science and technology fields (3 broad areas of aggregation derived from the Science Overlay Map) is interdisciplinary; and (iii) there is an apparently low visibility of publications from projects jointly executed with industries to an almost complete absence of output from CRIS in the fields of social sciences in the WoS database.     

A new fibre optic pulse oximeter probe for monitoring splanchnic organ arterial blood oxygen saturation

A new, continuous method of monitoring splanchnic organ oxygen saturation (SpO(2)) would make the early detection of inadequate tissue oxygenation feasible, reducing the risk of hypoperfusion, severe ischaemia, and, ultimately, death. In an attempt to provide such a device, a new fibre optic based reflectance pulse oximeter probe and processing system were developed followed by an in vivo evaluation of the technology on seventeen patients undergoing elective laparotomy. Photoplethysmographic (PPG) signals of good quality and high signal-to-noise ratio were obtained from the small bowel, large bowel, liver and stomach. Simultaneous peripheral PPG signals from the finger were also obtained for comparison purposes. Analysis of the amplitudes of all acquired PPG signals indicated much larger amplitudes for those signals obtained from splanchnic organs than those obtained from the finger. Estimated SpO(2) values for splanchnic organs showed good agreement with those obtained from the finger fibre optic probe and those obtained from a commercial device. These preliminary results suggest that a miniaturized 'indwelling' fibre optic sensor may be a suitable method for pre-operative and post-operative evaluation of splanchnic organ SpO(2) and their health.     

LES study on the effect of cavity configuration on combustion characteristics of a scramjet combustor with air-throttling

Three-dimensional Large Eddy Simulation (LES) is performed to numerically investigate the implication of air throttling on the combustion performance of ethylene fueled dual-cavity scramjet combustor. The augmentation of combustion performance with the conjunction of throttling and dual cavity being established, the effects of L/D ratio and interspacing distance between the cavities is discussed. Our results indicate that combustion efficiency is enhanced owing to the pre-combustion shock train generated because of the introduction of air throttling for different configurations of cavity. Further, the combination of air-throttling with dual cavity improves combustion performance in comparison with dual cavity without air throttling. Also, dual cavity with L/D = 7 and spacing S = 12 mm displays intense and larger recirculation zones in comparison with other configurations being considered. It is found that for dual cavity with L/D = 7 and S = 12 mm, shorter mixing length and higher penetration height is attained.