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

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

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

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

Disposal Options of Bamboo Fabric-Reinforced Poly(Lactic) Acid Composites for Sustainable Packaging: Biodegradability and Recyclability

The present study was conducted to determine the recyclability and biodegradability of bamboo fabric-reinforced poly(lactic) acid (BF-PLA) composites for sustainable packaging. BF-PLA composite was recycled through the granulation, extrusion, pelletization and injection processes. Subsequently, mechanical properties (tensile, flexural and impact strength), thermal stability and the morphological appearance of recycled BF-PLA composites were determined and compared to BF-PLA composite (initial materials) and virgin PLA. It was observed that the BF-PLA composites had the adequate mechanical rigidity and thermal stability to be recycled and reused. Moreover, the biodegradability of BF-PLA composite was evaluated in controlled and real composting conditions, and the rate of biodegradability of BF-PLA composites was compared to the virgin PLA. Morphological and thermal characteristics of the biodegradable BF-PLA and virgin PLA were obtained by using environment scanning electron microscopy (ESEM) and differential scanning calorimetry (DSC), respectively. The first order decay rate was found to be 0.0278 and 0.0151 day�1 in a controlled composting condition and 0.0008 and 0.0009 day�1 in real composting conditions for virgin PLA and BF-PLA composite, respectively. Results indicate that the reinforcement of bamboo fabric in PLA matrix minimizes the degradation rate of BF-PLA composite. Thus, BF-PLA composite has the potential to be used in product packaging for providing sustainable packaging

Documentation, anti-aging activities and phytochemical profiling of selected medicinal plants used by Jakun women in Kampung Peta, Mersing, Johor

Traditional knowledge of indigenous people could become the baseline information for the discovery of anti-aging agent. The objectives of this study were to document the knowledge of Jakun people in Kampung Peta, Mersing, Johor on medicinal plants for women’s healthcare; to investigate the optimal formulations of herbal mixture used by Jakun women based on phytochemicals content and antioxidant activity; to determine the anti-aging potential of the selected formulations; and to investigate the major phytochemical constituents in the formulations. Based on qualitative analysis from semi-structured interview, twelve species of medicinal plants have been documented for women’s healthcare. Among species documented, four species, Cnestis palala (Pengesep), Urceola micrantha (Serapat), Labisia pumila (Kacip fatimah) and Microporus xanthopus (Kulat kelentit kering) that were prepared in the form of mixture have been used for formulation study. About 24 formulations have been developed from the simplex centroid design and tested for total phenolic content (Folin-Ciocalteu method), total flavonoid content (aluminium chloride colorimetric method) and three different antioxidant assays (DPPH scavenging, ABTS decolourization and FRAP assays). Single formulation of Cnestis palala, single formulation of Urceola micrantha and binary mixture of C. palala and U. micrantha are among the optimal formulations with high phytochemicals content and antioxidant activities that were further evaluated for anti-aging activities. For anti-aging activities, five enzymatic assays have been tested on the three formulations which are matrix metalloproteinase-1 (MMP-1) inhibition, elastase inhibition, tyrosinase inhibition, acetyl- and butyrylcholinesterase inhibition assays. Single formulation of U. micrantha showed the highest inhibition towards MMP-1 (49.44 ± 4.11 %) and elastase enzymes (20.33±2.52%), while single formulation of C. palala showed highest inhibitions towards tyrosinase (14.06±0.31%), acetylcholinesterase (32.92±2.13%) and butyrylcholinesterase (34.89±2.84%) enzymes. The identification of phytochemicals compound have been carried out using gas chromatography-mass spectrometer (GC-MS), which showed the presence of 2,2-dimethoxybutane and 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP) in the three formulations extract. The presence of catechol and quinic acid in U. micrantha extract might possibly contribute to anti-aging activities of the extract. These findings could become baseline for the exploration of novel anti-aging agents from natural source by using the traditional knowledge of indigenous people

Framework of property rating practice for financing neighbourhood facilities provision in Nigeria

This study proposed a framework of property rating practice for financing neighbourhood facilities provision in Bauchi metropolis of Nigeria. The deplorable condition of neighbourhood facilities in the study area persists, while the existing initiative aimed at maintaining and redeveloping the community facilities has not been implemented. This study examined the existing condition of neighbourhood facilities in the study area, and evaluated the most significant factors that militated against the implementation of property rating practice for financing neighbourhood facilities provision. The study has collected quantitative data, and used SPSS for the descriptive analysis, reliability analysis and exploratory factor analysis; and applied Structural Equation Modelling (SEM) with Analysis of Moment Structure (AMOS) for the analyses of the measurement and the structural measurement models. Findings revealed that Over-Reliance on Crude Oil Revenue and Poor Taxation System are the most significant factors militating against the implementation of property rating practice in Bauchi metropolis. And that ‘lack of political will’ is a factor that significantly affects the existing condition of neighbourhood facilities in the study area. In conclusion the study has proposed Land area-based assessment for rating valuation, using Google Earth/Map for property identification, enumeration and measurement in the proposed framework in order to achieved cost-effectiveness in assessment. The significant contribution is that, the study has proposed a new costeffective framework of Property Rating Practice for financing neighbourhood facilities in the study area. It was recommended that the government should diversify revenue source from oil-based to harness all avenues like property rating at municipal level so as to finance neighbourhood facilities provision and maintenance. Future studies should find out, apart from Over Reliance on Crude Oil Revenue and Poor Taxation System, whether some other factors militate against the implementation of property rating in the study area and beyond

Avenues in supercritical carbon dioxide extraction and fractionation of lipids.

Supercritical carbon dioxide (scCO2) offers an alternative ecofriendly method for the conventional solvent extraction of lipids. CO2-based fluids are ideal supercritical fluids thanks to their distinct characteristics, such as nonflammability, nontoxicity, abundance, and recyclability, as well as their ability to solubilize lipophilic substances. Many studies have been conducted on the lipids extraction and fractionation from various lipid sources using scCO2 with or without a co-solvent. These studies revealed that scCO2 is a predominant technology for the lipids extraction and fractionation from various lipid sources. The present review was conducted to determine the influence of scCO2 process parameters on the extraction and fractionation of lipids from various plant and animal sources. Further, the influences of various operating parameters for the lipid extraction and fractionation subjected scCO2 extraction technology were also reviewed

High-pressure enzymatic hydrolysis to reveal physicochemical and thermal properties of bamboo fiber using a supercritical water fermenter

Bamboo fiber was treated using a high-pressure enzyme hydrolysis process. The process performance was compared with the pulping and bleaching process for bamboo fiber.Several analytical methods, including field emission scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetry, and differential scanning calorimetry, were employed to determine the physicochemical and thermal properties of the treated cellulosic bamboo fiber. It was found that the pressurized enzyme hydrolysis treated bamboo fiber had the most uniform morphological structure, along with lowest crystallinity and highest thermal stability. Thus, utilizing high-pressure enzyme hydrolysis is the most effective process for treating fiber to remove non-cellulosic components from the raw material, including lignin, hemicelluloses, and waxy materials