Optimization of flocculation process by microbial coagulant for removal of turbidity in river water

The existing process of coagulation and flocculation is using chemicals that known as the cationic coagulant such as alum, ferric sulfate, calcium oxide, and organic polymers. Thus, this study focuses on optimizing of the flocculation process by microbial coagulant in river water. Turbidity and suspended solids are the main constraints of river water quality in Malaysia since they may reduce the dissolved oxygen in the water and affects the aquatic life. Hence, a study is conducted to produce microbial coagulants isolated locally for river water treatment. The chosen microbe used as the bioflocculant producer is Aspergillus niger. The parameters optimized in the flocculation process were pH, bioflocculant dosage and effluent concentration. The research was done in the jar test process and the process parameters for maximum turbidity removal was validated. The highest flocculating activity was obtained on day seven of cultivation in the supernatant. The optimum pH and bioflocculant dosage for an effective flocculation process were between 4-5 and 2-3 ml for 0.3 g/l of effluent concentration, respectively. The model was validated by using a river water sample from Sungai Pusu (Pusu river) and the result showed that the model was acceptable to evaluate the bioflocculation process

The impacts of economic growth, trade openness and technological progress on renewable energy use in organization for economic co-operation and development countries

This study investigates the short-term and long-term impacts of economic growth, trade openness and technological progress on renewable energy use in Organization for Economic Co-operation and Development (OECD) countries. Based on a panel data set of 25 OECD countries for 43 years, we used the autoregressive distributed lag (ARDL) approach and the related intermediate estimators, including pooled mean group (PMG), mean group (MG) and dynamic fixed effect (DFE) to achieve the objective. The estimated ARDL model has also been checked for robustness using the two substitute single equation estimators, these being the dynamic ordinary least squares (DOLS) and fully modified ordinary least squares (FMOLS). Empirical results reveal that economic growth, trade openness and technological progress significantly influence renewable energy use over the long-term in OECD countries. While the long-term nature of dynamics of the variables is found to be similar across 25 OECD countries, their short-term dynamics are found to be mixed in nature. This is attributed to varying levels of trade openness and technological progress in OECD countries. Since this is a pioneer study that investigates the issue, the findings are completely new and they make a significant contribution to renewable energy literature as well as relevant policy development

Efficiency of Polyphenol Extraction from Artificial Honey Using C18 Cartridges and Amberlite„ XAD-2 Resin: A Comparative Study

A comparative study of the extraction efficiency of nine known polyphenols [phenolic acids (benzoic acid, dihydroxybenzoic acid, gallic acid, trans-cinnamic acid, and vanillic acid) and flavonoids (naringenin, naringin, quercetin, and rutin)] was conducted by deliberately adding the polyphenols to an artificial honey solution and performing solid phase extraction (SPE). Two SPE methods were compared: one using Amberlite XAD-2 resin and another one using a C18 cartridge. A gradient high performance liquid chromatography system with an RP18 column and photodiode array detector was utilized to analyze the extracted polyphenols. The mean percent of recovery from the C18 cartridges was 74.2%, while that from the Amberlite XAD-2 resin was 43.7%. The recoveries of vanillic acid, naringin, and rutin were excellent (>90%); however, gallic acid was not obtained when C18 cartridges were used. Additionally, the reusability of Amberlite XAD-2 resin was investigated, revealing that the mean recovery of polyphenols decreased from 43.7% (1st extraction) to 29.3% (3rd extraction). It was concluded that although Amberlite XAD-2 resin yielded a higher number of compounds, C18 cartridges gave a better extraction recovery. The lower recovery seen for the Amberlite XAD-2 resin also cannot be compensated by repeated extractions due to the gradual decrease of extraction recovery when reused

Smartphone addiction and cultural dimensions

Smartphone addiction is causing severe damage to individuals and societies alike. Previous studies have mainly focused on the effects of smartphone addiction, but they hardly focused on the cultural aspects leading to addiction. This study attempts to fill this void by shedding light on how Hofstede\u27s four cultural dimensions, including 1) individualism-collectivism, 2) masculinity-femininity, 3) power distance, and 4) uncertainty avoidance, affect individuals\u27 smartphone addictive behavior through the lens of attachment and coping theories. We offer suggestions for future research and practical implications based on these findings

Smartphone Addiction and Cultural Dimensions

Smartphone addiction is causing severe damage to individuals and societies alike. Previous studies have mainly focused on the effects of smartphone addiction, but they hardly focused on the cultural aspects leading to addiction. This study attempts to fill this void by shedding light on how Hofstede's four cultural dimensions, including 1) individualism-collectivism, 2) masculinity-femininity, 3) power distance, and 4) uncertainty avoidance, affect individuals' smartphone addictive behavior through the lens of attachment and coping theories. We offer suggestions for future research and practical implications based on these findings

Immobilization of fungal biomass with multi-walled carbon nanotubes as biosorbent

An efficient and effective biosorbent with high performance is needed to remove impurities in solution and the conventional method of adsorption of fungal biomass alone not showing a promising removal of impurities. The immobilization of multiwalled carbon nanotubes (MWCNTs) with fungal biomass (A. niger) was good combination since both has potential functional group to bind to each other. This research was basically focused on combination of fungal biomass with MWCNTs to enhance the positive integration of impurities removal in solution. The immobilization of both elements was done in a batch liquid medium with several parameters like pH, agitation speed, dose of MWCNTs and inoculum dosage that were conducted with one factor at one time (OFAT) method. In order to verify the functional group of MWCNTs, A. niger biomass and immobilized A. niger biomass, the FTIR was applied and FESEM was done to demonstrate and compare the image of the immobilized A. niger biomass with MWCNTs and fungal biomass alone. The finding illustrated the best pH, agitation speed, dose of MWCNTs and inoculum dosage were 5-6, 150 rpm, 0.5 grams and 2% respectively. FTIR indicates the presents of the functional groups in before and after immobilization while FESEM showed the images of the wrapped MWCNTs on A.niger biomass

SYNTHESIS, CHARACTERIZATIONAND ANTIMICROBIALACTIVITYOF FRIEDELIN [2, 3-d] SElENADIAZOlE

ABSTRACT The new 1, 2, 3, selenadiazole derivative (3) was prepared from friedelin (1) via the co"esponding semicarbazone (2) using Lalezari cyclization. The compounds were prepared, separated and characterized on the basis of microanalysis and spectral studies. The isolated friedelin and its selenadiazole were screened in vitro for their antimicrobial activities against various pathogenic bacterial were found to be highly active against al/ the selected pathogens. Compound 3 showed an inhibition zone of 14 mm and 12 mm respectively against highly resistant S. albus and C. albicans. A general mechanistic scheme for these reactions is also suggested based on current and previous results

A HISTORICAL PERSPECTIVE OF TRADE LIBERALISATION DYNAMICS IN BANGLADESH: IMPACTS OF NATURAL CALAMITY RISK, GROSS DOMESTIC PRODUCT, FOREIGN EXCHANGE RESERVE, RELATIVE PRICE AND TARIFF ON IMPORT DEMAND

Purpose: After the trade liberation, Bangladesh has faced the crisis of trade imbalance. Therefore, trade liberation is considered as the driving force behind the crisis. To investigate this historical allegation, this study aims at analysing the factors that determined the post trade liberalisation aggregate import demand function of Bangladesh.   Design/Methodology/Approach: Based on quarterly data from trade liberalisation period to reaching the economic stability period, 1992Q1 - 2007Q4, an autoregressive distributed lag (ARDL) approach to cointegration and an error correction model (ECM) have been utilised to estimate the impacts of natural calamity, gross domestic product, foreign exchange reserve, relative price and tariff on aggregate import demand of Bangladesh. Findings: Empirical results revealed that the natural calamity is identified to be nonresponsive to the nation's aggregate import demand both in the short and long run. This indicates that Bangladesh can meet the natural crisis related demand by herself without influencing its aggregate import demand. Results also revealed that the import volume of Bangladesh is cointegrated with relative import price, actual GDP and real foreign exchange reserve of the country. The import demand of the country can largely be described by its real GDP, while it is found inversely associated with relative price ratio in the long run. The long run association among import demand and tariff rate indicates that trade liberalisation has a significant positive impact on the country's aggregate import demand, as well as real foreign exchange reserve, as explained by the reduction in tariff rate.   Research Implication: Developing countries like Bangladesh and the relevant business stakeholders would have considerable implications of such empirical findings with their trade policies, particularly how they should respond to unpredictable scenarios caused by the factors such as natural calamity, foreign exchange reserve, tariff, etc.   Originality Value: The originality of the study lies in its uniqueness in using the historical data and factors that no studies have so far used in analysing the import demand function of Bangladesh.   Keywords: Natural calamity, import demand, foreign exchange reserve, gross domestic product, tariff, trade liberalisation, Bangladesh.   Cite as: Shikha, H. A., Alam, M. M., Murad, M. W., Said, J., & Ahmed, Z. U. (2023). A historical perspective of trade liberalisation dynamics in Bangladesh: impacts of natural calamity risk, gross domestic product, foreign exchange reserve, relative price and tariff on import demand. Journal of Nusantara Studies, 8(TI), 177-208. http://dx.doi.org/10.24200/jonus.vol8issTIpp177-20

Immobilization of fungal biomass with multi-walled carbon nanotubes as biosorbent

Aim: This study was mainly highlighted on a combination of fungal biomass onto MWCNTs in order to enhance the positive integration of impurities removal in aqueous solution. Methodology and results: The immobilization of fungal biomass and MWCNTs was done in a batch liquid medium with several factors such as agitation speed, dose of MWCNTs, pH and inoculum dosage that were conducted with one factor at one time (OFAT) method. Basically, to verify the functional group of MWCNTs, Aspergillus niger biomass and immobilized A. niger biomass, the FTIR was applied and FESEM was done to demonstrate and compare the image of the immobilized A. niger biomass with MWCNTs and fungal biomass alone. The finding showed the best agitation speed, dose of MWCNTs, pH and inoculum dosage were 150 rpm, 0.5 g, 5-6 and 2% respectively. FTIR indicates the presents of the functional groups like –OH (3270 cm -1 ), C-O (1619 cm -1 ) and –CH (2915 cm -1 ) while FESEM illustrates the images of the wrapped MWCNTs on A. niger biomass. Conclusion, significance and impact of study: The conventional technique of adsorption of fungal biomass alone not showing a favorable removal of impurities. Thus, the immobilization of fungal biomass (A. niger) with multi-walled carbon nanotubes (MWCNTs) was a good combination since both have potential functional group to accumulate to each other and has a tendency to remove effectively and efficiently the impurities in aqueous solution