Transformation of significant wave height and set-up due to entrained air bubbles effect in breaking waves

Hossain M.N., Araki S. Transformation of significant wave height and set-up due to entrained air bubbles effect in breaking waves. Ocean Modelling 190, 102403 (2024); https://doi.org/10.1016/j.ocemod.2024.102403.The transformation of wave height is of paramount significance in coastal engineering and the design of coastal structures. Considering the influence of air bubbles, this study devised an optimal dissipation model for accurately calculating changes in significant wave height (Hm0) and wave set-up for irregular waves undergoing breaking. Existing regular wave breaking models, which consider the effects of air bubbles, were adapted for direct application to irregular waves by deriving novel formulations. The proposed models leverage the probability of the fraction of broken waves. Hm0 was computed using the energy balance equation, while the wave set-up was calculated based on the momentum balance equation. A wide range of test scenarios, incorporating diverse scales (small and large) and experimental field data, was considered for validation. One of the proposed models, namely model-I (M-I), particularly demonstrated superior performance, manifesting lower error indices (P20), root-mean-square relative error (RMSRE), and Brier skill score (BSS) values in computing both Hm0 and wave set-up. Therefore, utilising M-I is strongly recommended for the precise estimation of Hm0 and set-up transformation

Feasibility Study of Integrated Desizing, Scouring and Bleaching of Cotton Woven Fabric with H2O2 and Investigation of Various Physical Properties with Traditionally Treated Fabric

Pre-treatment plays a significant role for the successful coloration of any kind of natural textile fiber like cotton, wool, flax, silk etc. This research work overview the influence of various types of traditional preparation techniques applied on cotton fiber before coloration such as desizing, scouring and bleaching. The traditional pre-treatment processes consume plenty of environmentally unfriendly chemicals those generate pollution in the effluents. In this research work an endeavour has been made to desize, scour and bleach grey cotton woven fabric simultaneously using caustic soda and hydrogen peroxide. The physical properties like whiteness, percent loss in fabric weight, tensile strength of the treated fabric have been compared with those of the fabric treated to conventional desizing, scouring and bleaching process. It is observed that the whiteness (ready for colouration) obtained by this process is quite satisfactory. Moreover, this process has some other merits such as ecological, economical, energy conserving and time saving aspect

Ageing Effects of Na-Alginate/PEO Spinning Solution on Electrospinnability and Morphology of Nanofibres

Poly(ethylene oxide) (PEO) loaded alginate nano-fibres were produced by electrospinning of the 4 % (w/w) of 70:30 Na-alginate/PEO spinning solution. In this research, the effects of solution viscosity and storage time of the spinning solution on fibre diameter and morphology were studied. Results show that the viscosity of the spinning solution was 2284 cP at the age of day 1, which was dropped slowly and reached at 2184 cP until day 5. However, the viscosity sharply decreased after 5 days of storing and the mean diameter of the fibres remain similar until 20 days though the uniformity of the fibre diameters decreased significantly. At day 40, the viscosity of the spinning solution dropped 48 cP which yields beads-onstring fibres. The solutions of 5 days and 10 days old produced smooth and uniform nanofibres having mean diameter of 133 nm and 132 nm, respectively. They also produced stable electrospinning fibre jet compared to other solutions. Overall, the results revel that the electrospinnability of Naalginate/PEO spinning solution remain suitable until 10 days of storing time

Development of Cost-Effective Menstrual Absorbent Pad with Eco-Friendly Antimicrobial Finish

Management of menstrual hygiene is a critical problem for Bangladeshi women and girls as the sanitary pads are expensive. Therefore, purchasing sanitary napkins for incredibly poor and middle-class families is very challenging. Many retail sanitary napkins are available on the local market, but most of them are costly. However, poor women’s are unable to purchase or use high-quality sanitary napkins. Thus, a maximum of nine sanitary napkin pad samples with very cheap raw materials (natural fibres) have been produced in this study. Newly manufactured products even undergo antimicrobial treatment with natural antimicrobial agents such as Tulshi and Aloe Vera accompanied by a simple production process, which ultimately makes the product cheaper and safer for the consumer during use. A maximum of nine samples were produced and compared with commercial samples for cost analysis. The primary objective of this research is to develop such a kind of sanitary napkin that will be cheaper as well as user-friendly in contrast to commercial samples. More interestingly, poor women are not used to wear underwear, because of which they are not interested in using pads as commercial sanitary napkins; panty or other underwear is required. For this reason, an adjustable waistband support is used in this experiment to easily attach the sanitary napkin without any gum. Since menstruation is directly linked to the human reproductive process, it is important for women and girls to manage menstruation appropriately. In addition, the material (especially sanitary napkin core forming materials) used in commercial sanitary napkins is synthetic and may lead to accelerated growth of bacteria and germs by long term use of the pad. The goal of this research was to construct an inexpensive sanitized pad that was treated with Aloe Vera and Tulshi extract. Tulshi and Aloe Vera modified non-woven fabrics incorporate antimicrobial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Therefore, as it can be used without undergarments, sanitary napkin is not only hygienic but also inexpensive and comfortable with effective protection against leakage. Findings demonstrate the newly developed prototype's substantial design and cost-effectiveness. &nbsp

Synthesis, Characterization and Biological Activity of Oxovanadium(IV) Complexes Containing α-Amino Acid Schiff Bases and 5,6-Dimethyl-1,10-phenanthroline Ligands

Five oxovanadium(IV) complexes of the type [VO(L)(DPhen)], containing Schiff base derived from α-amino acid, [where L = 3-hydroxybenzaldehyde-α-alanine (hb-Ala), 3-hydroxybenzaldehyde-DL-phenylalanine (hb-Phe), 3-hydroxybenzaldehyde-leucine (hb-Leu), 3-hydroxybenzaldehyde-glycine (hb-Gly) and 3-hydroxybenzaldehyde-DL-methionine (hb-Met) & DPhen = 5,6-Dimethyl-1,10-phenanthroline] have been synthesized and characterized by some physicochemical properties, molar conductance, magnetic susceptibilities measurements, elemental analysis, UV-Visible, FT-IR and EIS-MS spectral studies. The molar conductance values evidenced the non-electrolytic nature of the complexes. The magnetic moment values of the complexes are in accordance with the d1 electronic configuration of the VIVO2+ moiety and indicates the paramagnetic behavior of the complexes. IR spectral data indicates the coordination of tridentate amino acid Schiff base ligands to the vanadyl (VO2+) ion through O, N, O-donor. ESI-MS spectral study confirmed the proposed structure of the complexes. All the analytical data suggested that all the complexes possess to have distorted octahedral geometry. The complexes were screened for their antibacterial activity against four human pathogenic bacteria; two Gram positive Escherichia coli & Pseudomonas aeruginosa and two Gram negative Staphylococcus aureus & Bacillus cereus with Kanamycin (K-30) standard. The result shows that all the complexes have moderate to strong potential antibacterial activity against all the pathogenic bacteria. This work is licensed under a Creative Commons Attribution 4.0 International License

Improved Solar Photovoltaic Array Model with FLC Based Maximum Power Point Tracking

This paper presents an improved model of solar photovoltaic (PV) array along with the implementation of fuzzy logic as maximum power point tracking (MPPT). The proposed PV array behavioral model is more accurate and with reduced complexity though considered discrete components. The PV array model was well verified by considering the effect of change of environmental conditions, mainly intensity of solar irradiation (insolation) and temperature. The model was tested by feed a single phase inverter. MPPT control the operating voltage of  PV arrays in order to maximize their power output as a result maximize the array efficiency and minimize  the overall system cost. Using a Fuzzy logic based algorithm, the duty cycle of the converter inserted between source and load is adjusted continuously to track the MPP and compared with the conventional perturb and observed (P&O) method for changing environmental conditions. It was found that the Fuzzy logic based method can track the MPP more precisely and rapidly than the conventional one. In P&O method, if step size of input variable is very small, the accuracy in tracking MPP is sufficient but tracking speed becomes too slow. On the other hand if the step size is increased to imitate the rapidly changing weather conditions, accuracy deteriorates and unexpected results occur due to oscillation around a mean point although tracking speed increased. But in the case of proposed FLC whatever the step size of input variable it best suited to track MPP continuously and accurately. The obtained simulation results validate the competent of the solar PV array model as well as the fuzzy controller.DOI:http://dx.doi.org/10.11591/ijece.v2i6.132

Wave height distribution for plunging breakers induced by air bubbles

Hossain M.N., Araki S., Hoque A., et al. Wave height distribution for plunging breakers induced by air bubbles. Ocean Engineering 309, 118472 (2024); https://doi.org/10.1016/j.oceaneng.2024.118472.This study highlights the wave height distributions based on plunging breaking waves and air bubble effects in the surf zone. Wave height distributions predicted previously by different models have been reformulated in terms of air bubble effects. Some of the most commonly applied wave height distributions are judged using laboratory observations in a custom-built wave flume. Results have revealed a notable deviation from the Rayleigh distribution, with the proposed model demonstrating a closer match to experimental data, particularly for larger wave heights. Probability densities of larger wave heights are reduced significantly by entrained air bubbles, leading to measured wave heights below Rayleigh distribution predictions. In addition, the different wave height parameters derived from the proposed model exhibited good agreement with laboratory data compared to the Rayleigh distribution. Furthermore, theoretical analysis shows the scale parameter's dependence on the decay coefficient, aligning well with measurements and simplifying the proposed distribution to a one-parameter model. Again, based on the error analysis, the proposed model's results show good performance compared to others

Word level Bangla Sign Language Dataset for Continuous BSL Recognition

An robust sign language recognition system can greatly alleviate communication barriers, particularly for people who struggle with verbal communication. This is crucial for human growth and progress as it enables the expression of thoughts, feelings, and ideas. However, sign recognition is a complex task that faces numerous challenges such as same gesture patterns for multiple signs, lighting, clothing, carrying conditions, and the presence of large poses, as well as illumination discrepancies across different views. Additionally, the absence of an extensive Bangla sign language video dataset makes it even more challenging to operate recognition systems, particularly when utilizing deep learning techniques. In order to address this issue, firstly, we created a large-scale dataset called the MVBSL-W50, which comprises 50 isolated words across 13 categories. Secondly, we developed an attention-based Bi-GRU model that captures the temporal dynamics of pose information for individuals communicating through sign language. The proposed model utilizes human pose information, which has shown to be successful in analyzing sign language patterns. By focusing solely on movement information and disregarding body appearance and environmental factors, the model is simplified and can achieve a speedier performance. The accuracy of the model is reported to be 85.64%

Role of Internet of Things (IoT) in Retail Business and Enabling Smart Retailing Experiences

Internet of Things (IoT) is anticipated to be one of the primary megatrends up in innovation. Integrated with the current and upcoming mobility of digital gadgets, it offers ground to applications in numerous domains, including retail. The capability of sensors for setting applicable, customized, real-time, and intuitive communication with buyers and customers is considered to be a driving force of traffic and exchange, a facilitator of development along the way to elevate their purchasing experience. Simultaneously, IoT can serve to further develop relationships and foundations for more viable retail business and digital store management. Currently, digitally savvy customers expect an Omnichannel experience at each touchpoint. They need to track down the ideal data at the perfect time at the right location. Location-based innovation in a retail setting identifies the way that users take to arrive at specific areas of a retail store and helps upgrade the shopping experience. This is the reason the Internet of Things (IoT) is beginning to take the online business to a higher level, and will probably disrupt the conventional retail processes on a significant scale in the coming time. This paper surveys and arranges the most common applications of IoT and solutions for successful marketing at retail from the point of retailers and customers as well as from the point of manufacturers confronting framework or communication-related issues. We propose a model that demonstrates the potential that IoT has as compared to standard industry practices of retail to drive business results and gain an upper hand. In this paper, we’ve likewise talked about the new developments and new techniques for the organizations to accomplish competitive advantage brought about by the uses cases of IoT, particularly in the field of mobile sensors. Such developments are likely the most prominent factor in the coming years to make progress in the advanced economy