A Study of Nanogenerator Based Flow Sensor

The utilization of kinetic energy from fluid flow to power sensory systems is experiencing an all-time high research focus. Invention of nanogenerators have fueled this research focus with unprecedented flexibility of applications. Many studies have reported on utilizing the mechanism of nanogenerator for sensing fluid flow. In this short work, we have summarized different types of self-powered nanogenerator-based flow sensors and their applications. We have also classified the use of Nanogenerator based flow sensors in different fields, such as Bio-medical Application, Fluid velocity sensing, and Chemical Detection. In the Bio-medical field, the flow sensor can be used for the patient’s infusion process and respiratory monitoring. In the fluid velocity sensing field, the flow sensor can work as a detector for the airflow and humidity percentage. The sensor can act as an anemometer (wind flow meter), Wind Vector Sensor, along with velocity measurement. In the reported chemical detection application, a nanogenerator was used to analyze the alcohol breath and measure the rising speed of bubbles of the coal bed. All these discussed flow sensors demonstrated the ability to scavenge energy while acting as a potential sensor. We further included that, most of the reported flow sensors are triboelectric, piezoelectric, and electromagnetic nanogenerator mechanisms. The hybrid system of nanogenerators was also reported. These engineered sensors can be the cutting-edge solution for several problems on current flow sensing problems and future obstacles. In this work, a Rotating Sliding mode Triboelectric Nanogenerator (RS-TENG) was designed. Teflon (PTFE) tape was introduced to work as a tribo-negative layer and the copper sheet and copper tape were worked as an electrode, whereas the adhesive tape was used between two PTFE tapes to create multiphase TENG. This RS-TENG was fabricated to demonstrate the applications as a self-powered flowmeter for detecting wind speed. Also, in this thesis, we have included an experimental study of triboelectric nanogenerator bases self-powered flow sensors. The experimented flow sensor demonstrated a promising result and potentials to be used in industrial applications

Relative Importance of Food in Tourism: A Study on Domestic Tourists in Bangladesh

The phenomenon of food tourism becomes a growing interest among many researchers as food is an important component of the travel and tourism industry. Demographic characteristics of tourists of food tourism, food preference, tourists’ perceptions regarding food, aesthetic and authenticity of food, potentials of food tourism business are widely covered by the researchers’ community in different contexts. To address the contextual gap, this research aims to reveal the relative roles of food in tourism along with the demographic nature of tourists who are concern to the local food of domestic tourism destinations in Bangladesh. Quantitative techniques including univariate analysis, bivariate analysis, and logistic regression have been utilized to explore the research aim. This research has found that food has a strong influence in traveling behavior of the domestic tourists in Bangladesh. In relation to demographic characteristics, male and higher educated tourists have exhibited more concern regarding local food of tourist destination. Besides, this research has found that food is one of the considerable purposes of tourism, local food is more important to the frequent travelers, and tourists consider characteristics such as healthiness, famous qualities and restaurant environment before consuming local food. Keywords: Food tourism, demographic characteristics, univariate and bivariate analysis, logistic regression DOI: 10.7176/JTHS/51-06 Publication date:November 30th 202

Exploring the self-preparedness of frontline healthcare workers in a low- and middle-income country from a humanitarian context during the COVID-19 pandemic: A constructivist grounded theory study

BackgroundWhile research has been conducted on the availability, accessibility, and affordability of personal protective equipment for healthcare workers during the COVID-19 pandemic, little information is available on the ways in which health workers, especially those in humanitarian settings see themselves, and engage in self-preparedness for social, physical, and mental health and practical care in the pandemic. We sought to address this gap.MethodsWe followed a constructivist grounded theory approach to guide in-depth interviews with 30 frontline doctors, nurses, and community healthcare workers recruited from the Rohingya refugee camps in Bangladesh using the purposive and snowball sampling methods. Analyses were carried out through the identification of codes in three phases: an initial line-by-line open coding, then focused axial coding, and finally selective coding.FindingsAn emergent-grounded theory of “Navigating Self-Preparedness through Pandemics” was developed as we built a five-phased theoretical framework examining health worker responses with the following pillars: (a) pandemic shock; (b) pandemic awareness; (c) pandemic learning; (d) pandemic resilience, and (e) pandemic resurgence.InterpretationThe theory emerged as a realistic, socially, and culturally sensitive COVID-19 strategy to support healthcare workers. Self-preparedness was characterized by two interwoven processes: (1) the experiences of the daily life span of healthcare workers attempting to improve their own protection using all their potential while providing care for patients in a vulnerable setting and time and (2) the inseparable role of physical, psychological, social, and spiritual factors in each stage of learning during the pandemic to achieve better outcomes

KNN based piezo-triboelectric lead-free hybrid energy films

In recent times, the triboelectric and piezoelectric effects have garnered significant attention towards developing advanced material composites for energy harvesting and sensory applications. In this work, potassium sodium niobate (KNN) based energy films (EF) have been developed to utilize mechanical energy while simultaneously taking advantage of triboelectric and piezoelectric mechanisms. The KNN particles were synthesized using a wet ball milling technique and then incorporated into a polyvinylidene difluoride (PVDF) matrix together with addition of multi wall carbon nanotubes (MWCNT). The film was used to develop a piezoelectric nanogenerator (PENG) fitted with copper electrodes. The piezoelectric output of the film was further tested utilizing copper electrodes, at variable tapping frequency (60 BPM to 240 BPM) and pressure (10–40 psig) were used when activating the pneumatic piston. The open circuit voltage increased with the increase of both tapping frequency and pressure. The maximum piezoelectric output voltage was observed to be 35.3 V while the maximum current was noted as 15.8 µA. The films also showed unique output signals for different types of deformations performed under hand pressure. The film was further utilized to build a piezo-triboelectric hybrid nanogenerator to check its hybrid performance. The maximum output was observed to be 54.1 V and 29.4 µA. This film was integrated with conventional electronic components (bridge rectifiers, resistors, and capacitors) and tested for its ability to harvest energy. The hybrid nanogenerator can charge a 0.1 µF capacitor to 9.4 V in 60 s. The optimum output power for the device was measured to be 0.164 W. The film was further attached with a Kapton film and showed a hybrid output of 113.2 V. This experiment endorsed the potential of the KNN based energy films for multifunctional applications like force, pressure, and motion sensing as well as lead free energy harvesting

Evaluation of Potential Antioxidant Activity of Leaves of Bauhinia Acuminate

Abstract The methanol extracts of leaves of Bauhinia acuminata (MESF) and their different fractions obtained fro

Effect of early tranexamic acid administration on mortality, hysterectomy, and other morbidities in women with post-partum haemorrhage (WOMAN): an international, randomised, double-blind, placebo-controlled trial

Background Post-partum haemorrhage is the leading cause of maternal death worldwide. Early administration of tranexamic acid reduces deaths due to bleeding in trauma patients. We aimed to assess the effects of early administration of tranexamic acid on death, hysterectomy, and other relevant outcomes in women with post-partum haemorrhage. Methods In this randomised, double-blind, placebo-controlled trial, we recruited women aged 16 years and older with a clinical diagnosis of post-partum haemorrhage after a vaginal birth or caesarean section from 193 hospitals in 21 countries. We randomly assigned women to receive either 1 g intravenous tranexamic acid or matching placebo in addition to usual care. If bleeding continued after 30 min, or stopped and restarted within 24 h of the first dose, a second dose of 1 g of tranexamic acid or placebo could be given. Patients were assigned by selection of a numbered treatment pack from a box containing eight numbered packs that were identical apart from the pack number. Participants, care givers, and those assessing outcomes were masked to allocation. We originally planned to enrol 15 000 women with a composite primary endpoint of death from all-causes or hysterectomy within 42 days of giving birth. However, during the trial it became apparent that the decision to conduct a hysterectomy was often made at the same time as randomisation. Although tranexamic acid could influence the risk of death in these cases, it could not affect the risk of hysterectomy. We therefore increased the sample size from 15 000 to 20 000 women in order to estimate the effect of tranexamic acid on the risk of death from post-partum haemorrhage. All analyses were done on an intention-to-treat basis. This trial is registered with ISRCTN76912190 (Dec 8, 2008); ClinicalTrials.gov, number NCT00872469; and PACTR201007000192283. Findings Between March, 2010, and April, 2016, 20 060 women were enrolled and randomly assigned to receive tranexamic acid (n=10 051) or placebo (n=10 009), of whom 10 036 and 9985, respectively, were included in the analysis. Death due to bleeding was significantly reduced in women given tranexamic acid (155 [1·5%] of 10 036 patients vs 191 [1·9%] of 9985 in the placebo group, risk ratio [RR] 0·81, 95% CI 0·65–1·00; p=0·045), especially in women given treatment within 3 h of giving birth (89 [1·2%] in the tranexamic acid group vs 127 [1·7%] in the placebo group, RR 0·69, 95% CI 0·52–0·91; p=0·008). All other causes of death did not differ significantly by group. Hysterectomy was not reduced with tranexamic acid (358 [3·6%] patients in the tranexamic acid group vs 351 [3·5%] in the placebo group, RR 1·02, 95% CI 0·88–1·07; p=0·84). The composite primary endpoint of death from all causes or hysterectomy was not reduced with tranexamic acid (534 [5·3%] deaths or hysterectomies in the tranexamic acid group vs 546 [5·5%] in the placebo group, RR 0·97, 95% CI 0·87-1·09; p=0·65). Adverse events (including thromboembolic events) did not differ significantly in the tranexamic acid versus placebo group. Interpretation Tranexamic acid reduces death due to bleeding in women with post-partum haemorrhage with no adverse effects. When used as a treatment for postpartum haemorrhage, tranexamic acid should be given as soon as possible after bleeding onset. Funding London School of Hygiene & Tropical Medicine, Pfizer, UK Department of Health, Wellcome Trust, and Bill & Melinda Gates Foundation

Effect of incorporation of soy flour on functional, nutritional, and sensory properties of mushroom–moringa‐supplemented healthy soup

The research study was conducted to evaluate the effect of soy flour on functional, nutritional, and sensory properties of mushroom–moringa‐supplemented soup which could be used as a protein‐supplemented ready‐to‐eat food. In this study, corn flour was supplemented with soy flour at different levels such as 20% (T4), 15% (T3), 10% (T2), and 5% (T1), and without soy flour was kept as control (T0). Fixed amount of mushroom and moringa leaf powder was added in all soup powders. Soup powders were analyzed for functional, nutritional, and sensory parameters. Bulk density (0.82–0.74 g/ml), dispersibility (82.1%–75.9%), pH (6.17–6.13), swelling capacity (3.98–3.65 ml/g), and viscosity were decreased, while water absorption capacity (70%–94%) was increased with increasing of soy flour percentages. Protein content of all the treatment groups increased from 10.66% to 19.97% along with a significant increased in fat (1.43%–6.97%), fiber (1.10%–2.30%), ash (15.77%–16.40%), and energy value (328.38–353.21 kcal/100 g) while decreased in moisture and carbohydrate content. On sensory evaluation, soup powders with 10% (T2) level of soy flour incorporation had highest scores for all the sensory attributes evaluated. Based on these results, it can be concluded that soy flour has effect on functional, nutritional, and sensory properties of soup powders and 10% supplementation of soy flour is suitable for ready‐to‐eat soup formulation. Besides these, use of mushroom and moringa leaf may also increase its nutritional value. Soup developed in this way may be sufficient to meet day‐to‐day nutritional requirements as a supplement

Exploring the impact of pumpkin and sweet potato enrichment on the nutritional profile and antioxidant capacity of noodles

Sweet potato and pumpkin are abundant in β-carotene, fiber, and essential minerals. The use of pumpkin and sweet potato with wheat flour to prepare noodles may increase their nutritional value and provide several health benefits. The purpose of the study was to develop pumpkin, sweet potato, and wheat composite flour noodles with improved nutritional and sensory qualities. All of the quality parameters like nutritional value, water activity, color intensity, β-carotene content, antioxidant capacity, and sensory characteristics were analyzed according to the standard procedures. The addition of pumpkin and sweet potato flour to prepared noodles significantly (p < 0.05) increased the β-carotene (18.30 – 713.99 μg/100 g), protein (8.75 – 14.75 g/100 g), crude fiber (0.38 – 3.84 g/100 g), and minerals like potassium, calcium, iron, and zinc contents. In addition, the DPPH scavenging activity, phenolic and flavonoid content of the noodles were significantly (p < 0.05) higher than those of the control noodles. On the contrary, the noodles redness (a*) and yellowness (b*) increased and their lightness (L*) decreased as the incorporation of sweet potato and pumpkin increased. However, sensory assessment results suggested that noodles containing 15 % pumpkin, 10 % sweet potato, and 75 % wheat composite flour were more appealing than other developed noodles. Newly developed noodles will play a crucial role in increasing nutritional diversity and reducing food insecurity among low-income families

Physicochemical and structural impact of CMC-hydrocolloids on the development of gluten-free foxtail millet biscuits

Patients with celiac disease and those who are gluten intolerant have a need for gluten-free bakery items but developing them is a challenge for technologists and dietitians. Foxtail millets are naturally gluten-free and nutrient-dense grains. Herein, CMC-modified foxtail millet biscuits (CFMBs) were prepared using 0.01%, 0.05%, and 0.1% of CMC hydrocolloids with foxtail millet flour. The effects of CFMBs on the physicochemical properties, sensory, and morphology were investigated and compared with wheat (WB-100) and foxtail millet (FMB-100) products. CFMBs were thicker, had a larger specific volume, and had a lower diameter and spread ratio than FMB-100. CFMB-0.1 exhibited higher moisture content, higher water activity, and lower fat content than FMB-100 and WB-100. The hardness of CFMB-0.1 (35.08 ± 0.26 N) was close to WB-100 (37.75 ± 0.104 N) but higher than FM-100 (21.61 ± 0.064 N). The scanning electron microscope (SEM) study indicated that incorporating CMC influenced the morphology and microstructure of CFMBs. Skilled panelists gave WB-100 and CFMB-0.1 the highest sensory ratings and FMB-100 the lowest due to their color, appearance, flavor, and overall acceptability. Finally, CMC may be easily included in FMB manufacturing and supported like gluten in the food sector to suit the nutritional demands of customers

A Study of the Electrical Resistivity of Sintered Copper Nanoparticles

Microscale Selective Laser Sintering is a novel Additive Manufacturing process being built to fabricate parts with microscale resolution for applications in the microelectronics industry where small feature sizes are critical. This process works by sintering nanoparticles to give a better control on feature sizes. To get an idea of the mechanical strength of the parts fabricated with this process, it is important to be able to quantify the density in the manufactured parts. However, the parts fabricated with this process are too thin to physically handle enough to measure the density, but it is possible to measure the electrical resistance of these parts. So, in order to get the density of these parts, the relationship between electrical resistance and density has to be known. As such this paper presents an experimental study done on sintered copper nanoparticles to relate density to electrical resistance.Mechanical Engineerin