Dielectric studies of molecular motions in some solids

Dielectric absorption of a number of nonpolar, weakly polar and fairly polar molecules in the pure solid state are studied. Measurements of these solids using either a General Radio 1621 Precision Capacitance Measurement System or a General Radio 1615-A Capacitance bridge with appropriate temperature-controllable cells are described. The glass transition (Tg) measurements using the Glass Transition Measurement Apparatus are also described. The experimental data as a function of frequency at different temperatures are subjected to analysis by a series of computer programmes written in the APL language. The activation energy barriers for the dielectric relaxation processes were obtained by the application of ;the Eyring rate equation. The dielectric absorption of some spherically shaped nonpolar molecules are observed, the energy barrier values of which agree well with those found from other measurements. It is suggested that this absorption might be due to the interaction of the radiofrequency radiation with an induced moment which results from multiple interaction. Of the spherically-shaped polar molecules examined, both molecular and co-operative relaxations are detected in all the alkylhalides. Dielectric data for molecular relaxations are described by the Cole-Cole plots, whereas those for co-operative motion, in most of the cases, cannot be accurately represented by the Davidson-Cole skewed-arc function. Low temperature molecular relaxations are detected in some nonpolar and weakly polar aromatic hydrocarbons. The results of these molecules are used to suggest a possible correlation between enthalpy and entropy of activation and ionization potential and enthalpy of activation. The dielectric absorption of apparently nonpolar aromatic hydrocarbons are explained on the basis of quadrupole or octupole induced moment which may be of significant magnitude when the internuclear distances are small as in the solid state. Co-operative relaxations of some of the nonpolar and weakly polar hydrocarbons are found above the glass transition temperature (Tg). The variation in the energy barrier values for these relaxations are explained in terms of molecular interaction which is measured either by ionization potential or by the stretching frequency of a suitable solute molecule such as pyrrole (e.g. N-H) with which the aromatic hydrocarbon can form hydrogen bond. The molecular relaxation processes of a number of rigid arylhalides in the pure solid state are found almost in the same temperature and frequency regions as those found in different viscous media. A similar enthalpy of activation values are also observed. For some rigid heterocyclic molecules, except N-methyIpyrrole, no molecular relaxation is observed and this could be accounted for by the crystal structure and the lack of free volume for these molecules to relax

Supercritical Fluid Carbon Dioxide Sterilization Of Clinical Solid Waste

There is growing awareness on safe handling and management of clinical solid waste. The aim of the present study was to determine an effective sterilization method for safe handling and recycle-reuse of clinical solid waste materials. A preliminary study on the clinical waste management practice was conducted at Hospital Lam Wah Ee, Penang, Malaysia. The management practices encompasses segregation, collection, transportation and require high financial investments. Despite these practices, the infectious risk is still at hand. The existing recycling programs of general solid waste materials remains unchanged of the amount of clinical solid waste generation, its hazard and the disposal cost. In this study, several types of nosocomial and opportunistic pathogenic bacteria have been identified and sterilization of clinical solid waste is requisite to minimize infectious risks to the workers. Comparison on the sterilization efficiency of steam autoclave and supercritical carbon dioxide (SF-CO2) on clinical solid waste was conducted. Steam sterilization inactivation of bacteria depended on temperature and treatment time and types of bacterial species. The most effective experimental condition for the autoclave treatment was found to be temperature 121 0C and 131 0C for the exposure time 60 min and 30 min, respectively. SF-CO2 inactivates the bacteria in clinical solid waste including E. coli, E. faecalis, S. marcescens and S. aureus, B. sphaericus at a relatively lower temperature at 60 0C and moderate pressure of 20 MPa

Bipolar rechargeable lithium battery for high power applications

Viewgraphs of a discussion on bipolar rechargeable lithium battery for high power applications are presented. Topics covered include cell chemistry, electrolytes, reaction mechanisms, cycling behavior, cycle life, and cell assembly

Does Employee Involvement Really Increase Employee Productivity? – An Employee Perception Based Study

The purpose of this paper is to analyze the relationship between employee involvement and productivity evidence from banking industry. Self-administrated survey method was used to conduct the study. Data were collected from 100 bank employees through a well-structured questionnaire. The results were analyzed through frequency analysis, mean and standard deviation, t-test and canonical correlation by using SPSS 23 package software. For demographic information of gender of the respondents sample t-test was used and found that there is no significant difference of response between male and female also difference of response between public banks and private banks towards employee involvement and employee productivity. Canonical Correlation shows the relationship between employee involvement and employee productivity. The research helps to understand the relationship between employee involvement and employee productivity in baking industry of Bangladesh. It will also make worthy contribution to the literature and enhance the knowledge in this subject area as it provides authentic results that can be used in further research

evidence from Bangladesh

Thesis(Master) --KDI School:Master of Public Policy,2011Development economics could not able to give any direct answer about the impact of foreign aid on poverty alleviation specifically. Different economists opined differently. Some argued that it has a positive impact on poverty alleviation or economic growth and some opposed that. In consideration with the alleviation of poverty of Bangladesh through foreign aid is still an unresolved issue. Bangladesh is one of the poorest countries in the world. Bangladesh has received a huge amount of foreign aid since her independence in 1971 from various country of the world for economic development. Although Bangladesh achieved some specific areas of progress but still aggregate poverty rates remain dauntingly high. Pockets of extreme poverty persist. Inequality is a rising concern. The paper examines the effectiveness of foreign aid in eradicating poverty through human poverty indicators in Bangladesh. In this paper the basic questions which will be discussed about is 'does foreign aid play any role to eradicate poverty in Bangladesh?'masterpublishedby A S M Sohrab Hossain

ANTIOXIDANT, ANTIBACTERIAL AND CYTOTOXIC ACTIVITIES OF VARIOUS EXTRACTS OF THYSANOLAENA MAXIMA (ROXB) KUNTZE AVAILABLE IN CHITTAGONG HILL TRACTS OF BANGLADESH

Objective: To evaluate the presence of different phytoconstituents and investigate in vitro bioactivities of petroleum ether, chloroform and methanol extracts of Thysanolaena maxima available in Bangladesh.Methods: Phytochemical screening was conducted using the specific standard procedure. Antioxidant activity of the extracts was evaluated using DPPH radical scavenging assay and reducing power assay. Determination of total phenolic and flavonoid contents was also carried out. Antibacterial and cytotoxic activities were investigated using disc diffusion method and brine shrimp lethality bioassay, respectively.Results: The methanol extract showed highest DPPH radical scavenging activity as well as possessed highest phenolic content (IC50 value for DPPH is 36.94±0.62 μg/ml and total phenolic content is 74.39±2.87 in mg/g, GAE) compared to the petroleum ether and chloroform extracts. On the other hand, chloroform extract possessed maximum flavonoid content (81±7.542 in mg/g, QE) and highest reducing power compare to other extracts. All the extracts showed mild to moderate in vitro antibacterial activity with a zone of inhibition ranging from 7 mm to 16 mm. In brine shrimp lethality bioassay, the LC50 values for petroleum ether, chloroform and methanol extracts were found to be 579.05±78.08 μg/ml, 386.92±80.47 μg/ml and 494.29±104.82 μg/ml, respectively which revealed weak cytotoxic potentials of the extracts compared to the positive control.Conclusion: The results indicated that T. maxima could be a very potent source of natural radical scavenger. Isolation of active compounds from this plant responsible for producing such bioactivities is underway.Keywords: Thysanolaena maxima, DPPH, Total phenolic contents, Total flavonoid contents, Reducing power, Cytotoxicity, Antimicrobial activit

Effects of Recruitment and Selection Process on Employee Turnover and Its Consequence on Organization’s Profitability- A Study on Financial Sector of Bangladesh

Possessing a strong employee team, being profitable and achieving less turnover are desired by every organization. In country like Bangladesh, it is crucial to manage the recruitment and selection process properly to reduce turnover for both government and non-government sectors. This study aims at pointing out the effect of recruitment and selection process on employee turnover and its consequence on the organization’s profitability. The research has been conducted through a multiple case study method. Data has been collected with semi-structured interviews with twenty individual cases where the individuals are chosen from selected financial organizations. Analysis was done through pattern matching technique, based on the theoretical framework expected patterns were formulated and from the semi–structured interviews, empirical patterns were defined. Two propositions were proposed - appropriate recruitment and selection process affects employee turnover and proper recruitment and selection affects employee turnover which increases organization’s profitability. The study initiates that a small number of turnover factors can be controlled during the recruitment and selection process; thus organization becomes capable of reducing turnover up to a definite level and this reduced turnover eventually boosts up organization profitability. Thus the study partially confirmed the first proposition and completely confirmed the second proposition. Keywords: Recruitment, Selection, Turnover, Profitability

Internet of Things Based Smart Vending Machine using Digital Payment System

The advent of the Internet envisions a cashless society by enabling financial transactions through digital payments. Significantly, the emergence of coronavirus (COVID-19) disrupted our traditional cash handling means and triggered an inflection point for switching towards contactless digital payments from physical cash payments. Furthermore, Internet of Things (IoT) technology escalates digital payments to the next level by enabling devices to render goods and services without requiring any human interaction. This research proposed an IoT-enabled cashless vending machine that incorporates both cloud computing and payment gateway for ordering and purchasing items through digital payment systems by using a mobile application. The system enables a pre-installed mobile application to scan the Quick Response (QR) code attached to the body of a vending machine, opens the portal of a web-based virtual machine through the code, allows user to choose and order items from the virtual vending, initiates and authorizes a digital payment through an IoT gateway installed inside the physical vending machine by establishing a connection between user's and vendor's financial entities, and finally, dispenses the ordered items by unlocking the shelves of the vending machine after the successful payment transaction. It operates in the Arduino platform with an ATmega 2560 Microcontroller and Esp8266 Wi-fi module as hardware components, mobile application software, and payment gateway API. The system performed an average response time of 14500 milliseconds to pick a product after running 150 consecutive API test calls. This result shows a satisfying time for enhancing customers' buying experiences with digital payment systems and a customizable and cost-effective IoT-based intelligent vending machine to introduce for mass production

Performance of tropical sugar beet (Beta vulgaris L.) as influenced by date of harvesting

An experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh during November 2017 to April 2018 to study the effect of date of harvesting on the yield and quality of tropical sugar beet. The experiment comprised seven varieties viz. SV 889, SV 892, SV 893, SV 894, SZ 35, KWS Serenada and KWS Danicia and two dates of harvesting viz. 135 days after sowing (DAS) and 155 DAS. The experiment was laid out in a randomized complete block design with three replications. Variety, date of harvesting and their interaction showed significant effect on crop characters, beet yield and juice quality of tropical sugar beet. The highest beet length (23.50 cm), individual beet weight (591.6 g) and beet yield (59.16 t ha-1) were recorded in SV 894 while the highest brix (15.42%) was observed in SV 893. The lowest beet yield (40.25 t ha-1) and brix (13.92%) were observed in KWS Danicia. In case of date of harvesting, the highest beet length (24.26 cm), beet girth (25.40 cm), individual beet weight (536.07 g) and beet yield (53.60 t ha-1) were observed at 155 DAS harvest while the highest brix (14.66%) was recorded at 135 DAS harvest. In interaction, the highest beet length (25.67 cm), individual beet weight (681.2 g) and beet yield (68.12 t ha-1) were recorded in SV 894 with 155 DAS harvest whereas the lowest beet yield (32.03 t ha-1) was recorded in the interaction in KWS Danicia with 135 DAS harvest. From this study, it may be concluded that SV 894 appears as the promising variety that can be harvested at 155 DAS