Tap Water Disinfection in the Electrochemical Precipitation Process by Using Novel Conductive Concrete

Electrochemical precipitation (EP) is tested to learn about its impact on disinfectants in tap water. The EP process involves applying electricity through electrodes submerged in water to precipitate dissolved metals like water hardness out without chemical additives. In the study, tap water was tested to learn about EP’s impact on disinfectants. Tap water contains not only hardness but also residual disinfectants. It is very essential for the safety of drinking water against the potential ingress of pathogens before the water reaches the end-users. USEPA mandates that the free chlorine level in drinking water should be 0.2mg/L to 4 mg/L. Since pH near the electrodes changes during the electrochemical precipitation (EP) process, the chemical composition of chlorine species may change as well. In conventional EP, sacrificial metallic cathodes are widely used. Instead, a newly developed conductive concrete block is used in this study. Conductive concrete blocks are made of concrete and conductive graphite flakes. Total and free chlorine concentrations in tap water during the EP process will be collected per different chloride concentrations, current density, treatment time, and pH. Preliminary research findings showed that an increase in the chloride concentration, time, and current density resulted more free chlorine disinfectant concentration in water. This study will introduce a novel hardness removal method, EP with conductive concrete, and provide preliminary proof of its added value as a disinfecting technolog

An Evaluation of Economic Prospects and Constraints of the Sundarbans - A Rising Tourist Spot in Khulna

Sundarban is the largest mangrove forest of the earth which covers almost 10000 square kilometers (3,900 sq. mi) in the Northern Bay of Bengal of which 6017 km2 (2323 sq ml) extended through the Khulna division of Bangladesh. Mangrove forests are extremely prolific and diverse ecosystems, providing a comprehensive array of direct ecosystem facilities for inhabitants. Dhaka & Kolkata is the most crowded cities in the world and Sundarban helps the people who lived in those cities from the different natural calamities like cyclone, strong disaster, and their worst effects. Bangladesh is a country where nature has exposed all its beauties. The aesthetic beauty of mountains, a unique ecosystem of the Sundarbans, the amity of mountains and clouds, bright shade of green trees and forests, the vastness of the sea, the world's longest sea beach, archaeological sites, religious places, ample tea gardens have brought the great potential for Bangladesh in the world tourism industry.Though the Sundarbans is one of the three world heritage sites in Bangladesh, it badly lacks proper tourist facilities. Proficient supervision of the tourist economy at any destination not only contributes to the visitors’ experience augmentation but supplements the opportunities available also and guards the atmosphere whilst safeguarding the interest of the host municipal and businesses functioning within it. The main purpose of this study was to find out how to develop the tourism economy in the Sundarbans effectively. Using a comparison with a high-quality visitor's gladness can be confirmed and the impact of tourism on Sundarbans’ atmosphere and to its host municipal can be accomplished.The study found, two main reasons are liable not to fostering the tourism economy in Bangladesh. The first one is the lack of resource constraints and the second is inadequate initiatives from the government to uplift (particularly infrastructural facilities) tourism in the country to make it known to prospective visitors in the world. The study recommends public and private investments and initiatives to foster the potential of the Sundarbans. Keywords: Sundarbans, World Heritage, Tourism Economy, Tourism Products, Growth Trend of Tourism, Public and Private Sector Initiatives Towards Tourism. DOI: 10.7176/RJFA/12-6-01 Publication date:March 31st 202

Estimation of Optimum Number of Poles for Random Signal by Yule-Walker Method

The Yule-Walker method is an effective method to estimate the system response or spectrum for random signal. Hence most of the noise and spurious signals are random in nature, so it is very convenient to estimate their spectrum by Yule-Walker method successfully. The Yule-Walker method is an autoregressive process to estimate the poles and errors also based on the number of poles for Wide Sense Stationary (WSS) process as well. Moreover the value of zero will be correspondingly calculated based on the poles in case of all poles model. The main concern of this paper is to analyze the Yule-Walker method and estimate the poles and zero along with the error based on the number of poles for a random signal. Moreover analyze the results to find out the optimum number of poles for least possible error

A Novel Jamming Attacks Detection Approach Based on Machine Learning for Wireless Communication

Jamming attacks target a wireless network creating an unwanted denial of service. 5G is vulnerable to these attacks despite its resilience prompted by the use of millimeter wave bands. Over the last decade, several types of jamming detection techniques have been proposed, including fuzzy logic, game theory, channel surfing, and time series. Most of these techniques are inefficient in detecting smart jammers. Thus, there is a great need for efficient and fast jamming detection techniques with high accuracy. In this paper, we compare the efficiency of several machine learning models in detecting jamming signals. We investigated the types of signal features that identify jamming signals, and generated a large dataset using these parameters. Using this dataset, the machine learning algorithms were trained, evaluated, and tested. These algorithms are random forest, support vector machine, and neural network. The performance of these algorithms was evaluated and compared using the probability of detection, probability of false alarm, probability of miss detection, and accuracy. The simulation results show that jamming detection based random forest algorithm can detect jammers with a high accuracy, high detection probability and low probability of false alarm

Human Resource Management Practices and Firms Performance in Bangladesh: An Empirical Study on Pharmaceutical Industry

This research work has been conducted in the field of human resource management (HRM), more specifically on firm performance. The aim of the study is to show the relationship between HRM practices and firms performance of pharmaceutical industry in Bangladesh. It is assumed that HRM practices could positively influence profitability and growth and depressingly bias employee turnover. The primary data were collected using structured questionnaire sent to employees of different departments having different job status of some pharmaceutical companies in Bangladesh. Secondary data were collected from annual reports of the selected companies for measuring and finding out their performance. The paper has tried to elucidate the role of HRM practices and to test the relationship among the variables indicating that HRD has a relationship with performance like inventory turnover, total assets turnover, net profit margin, gross profit margin etc. It is found that HRM practices enhance performance of the pharmaceutical firms in Bangladesh

The Use of E-Recruitment Process with the Comparison of Traditional Recruitment Process in Bangladesh: A Case Study on BRAC Bank Ltd.

This paper discusses the comparison of e-recruitment and traditional recruitment processes and their merits and demerits. The figure of this process is arranged in such a way that in the static equilibrium, the e-recruitment process takes the horizontal position, while the traditional recruitment process takes the vertical position. Here are presented the characteristics of both e-recruitment and traditional recruitment processes that are used in Bangladesh for attracting and selecting qualified candidates through the analysis of a case of BRAC Bank Ltd. Obtained results proved to be in accordance with the motion of the real physical system. The difference between the two processes is illustrated in the figure and the merits and demerits of the two processes are discussed in the table

Human Resource Management Practices and Firms Performance in Bangladesh: An Empirical Study on Pharmaceutical Industry

This research work has been conducted in the field of human resource management (HRM), more specifically on firm performance. The aim of the study is to show the relationship between HRM practices and firms performance of pharmaceutical industry in Bangladesh. It is assumed that HRM practices could positively influence profitability and growth and depressingly bias employee turnover. The primary data were collected using structured questionnaire sent to employees of different departments having different job status of some pharmaceutical companies in Bangladesh. Secondary data were collected from annual reports of the selected companies for measuring and finding out their performance. The paper has tried to elucidate the role of HRM practices and to test the relationship among the variables indicating that HRD has a relationship with performance like inventory turnover, total assets turnover, net profit margin, gross profit margin etc. It is found that HRM practices enhance performance of the pharmaceutical firms in Bangladesh

A 3D printed electronic wearable device to generate vertical, horizontal and phono-articulatory jaw movement parameters: A concept implementation.

PurposeThe current research aimed to develop a concept open-source 3D printable, electronic wearable head gear to record jaw movement parameters.Materials & methodsA 3D printed wearable device was designed and manufactured then fitted with open-source sensors to record vertical, horizontal and phono-articulatory jaw motions. Mean deviation and relative error were measured invitro. The device was implemented on two volunteers for the parameters of maximum anterior protrusion (MAP), maximum lateral excursion (MLE), normal (NMO), and maximum (MMO) mouth opening and fricative phono-articulation. Raw data was normalized using z-score and root mean squared error (RMSE) values were used to evaluate relative differences in readings across the two participants.ResultsRMSE differences across the left and right piezoresistive sensors demonstrated near similar bilateral movements during normal (0.12) and maximal mouth (0.09) opening for participant 1, while varying greatly for participant 2 (0.25 and 0.14, respectively). There were larger differences in RMSE during accelerometric motion in different axes for MAP, MLE and Fricatives.ConclusionThe current implementation demonstrated that a 3D printed electronic wearable device with open-source sensor technology can record horizontal, vertical, and phono-articulatory maxillomandibular movements in two participants. However, future efforts must be made to overcome the limitations documented within the current experiment

Inorganic novel cubic halide perovskite Sr3AsI3: Strain-activated electronic and optical properties

In recent years, inorganic perovskite materials have attracted a lot of attention in the field of solar technology due to their exceptional structural, optical, and electronic properties. This study thoroughly investigated, using first-principles density-functional theory (FP-DFT), the impact of compressive and tensile strain on the structural, optical, and electrical properties of the inorganic cubic perovskite Sr3AsI3. The unstrained planar Sr3AsI3 molecule exhibits a direct bandgap of 1.265 eV value at Γ point. The bandgap of the Sr3AsI3 perovskite is lowered to 1.212 eV when the relativistic spin-orbital coupling (SOC) effect is subjected in the observations. In addition, the structure's bandgap exhibits a falling prevalence due to compressive strain and a slight rise due to tensile strain. The optical indicators such as dielectric functions, absorption coefficient, reflectivity, and electron loss function show that this component has a great ability to absorb in the visible range in accordance with band characteristics. When compressive strain is raised, it is discovered that the spikes of the dielectric constant of Sr3AsI3 move to lower photon energy (redshift), and conversely, while growing tensile strain, it exhibits increased photon energy changing behavior (blueshift). As a result, the Sr3AsI3 perovskite is regarded as being ideal for use in solar cells for the production of electricity and light management

Effects of electrolyte variation on ammonia sensing temperature for BiVO4 sensing electrode in mixed potential gas sensor

The aim of the present study is to investigate BiVO4 sensing electrode (SE) based electrochemical gas sensor for ammonia (NH3) sensing. Additionally, this study is also focused to reduce the operating temperature of sensor by applying different electrolytes i.e., yttria stabilized zirconia (YSZ) and gadolinia doped ceria (GDC). The maximum sensor response obtained for YSZ and GDC based cells towards 80 ppm NH3 were 103.03 and 78.81 mV at 600. and 550., respectively. Corresponding sensitivity of YSZ and GDC based cells for NH3 sensing were 99.24 and 42.66 mV/decade, respectively. Both the sensors demonstrate excellent selectivity as well as stability against 80 ppm NH3 (10 cycles) and humidity variation (pH(2)O = 0-0.12 atm.). Electrochemical impedance spectra (EIS) and dc polarization (I-V) curves confirms the mixed-potential sensing mechanism of the sensors. The systematic dependency of electrode's resistance at a given frequency on the gas concentration reveals a novel pathway for prediction of sensors' behavior. Additionally, the presence of GDC electrolyte decreases the response/recovery time (16/125 s) compared to YSZ-based cells (21/159 s) against 320 ppm NH3 at 550. which demonstrate its low temperature sensing capability. This 50. reduction in the operating temperature can be useful for extension of lifetime of sensor