12 research outputs found

    Effects of combined application of chemical fertilizer and vermicompost on soil fertility, leaf yield and stevioside content of stevia

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    Sustainable nutrient management with the combination of organic and chemical fertilizer amendment expects a key part in upgrading stevia yield without harming the environment and to build up the nutrient balance with increasing soil fertility. A pot experiment was conducted in the net house of the Department of Agricultural Chemistry, Bangladesh Agricultural University, Mymensingh to study the combined effect of vermicompost (VC) and chemical fertilizer (CF) on the growth, leaf biomass yield and stevioside content of stevia in acid soil. Six combinations of VC and CF were applied following completely randomized design (CRD) with three replications. Results showed that VC along with different rates of CF exerted significant influence on the growth, leaf biomass yield and stevioside content of stevia and postharvest soil fertility. The highest values for most of the parameters were found from the plant receiving VC @ 7.5 t ha­−1 along with 50% CF. About 578% higher leaf biomass yield was obtained from the treatment VC7.5+CF50 over control. Stevioside content was increased with the increasing levels of VC up to 7.5 t ha−1 along with 75% of CF and also with the advancement of growth period from 30 to 60 days after planting. The highest amount of stevioside (11.05%) was detected in the leaves of plant of the same treatment at harvest. Soil acidity was significantly decreased with the increased levels of VC and CF where as soil fertility in terms of organic matter and nutrient content was increased. Considering the overall performance, farmers may be advised to cultivate stevia in acid soil applying VC @ 7.5 t ha−1 along with 50% chemical fertilizer to boost up stevia production under the agroclimatic condition of the study area in the context of Banglades

    Study on Thermal Degradation Processes of Polyethylene Terephthalate Microplastics Using the Kinetics and Artificial Neural Networks Models

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    Because of its slow rate of disintegration, plastic debris has steadily risen over time and contributed to a host of environmental issues. Recycling the world’s increasing debris has taken on critical importance. Pyrolysis is one of the most practical techniques for recycling plastic because of its intrinsic qualities and environmental friendliness. For scale-up and reactor design, an understanding of the degradation process is essential. Using one model-free kinetic approach (Friedman) and two model-fitting kinetic methods (Arrhenius and Coats-Redfern), the thermal degradation of Polyethylene Terephthalate (PET) microplastics at heating rates of 10, 20, and 30 °C/min was examined in this work. Additionally, a powerful artificial neural network (ANN) model was created to forecast the heat deterioration of PET MPs. At various heating rates, the TG and DTG thermograms from the PET MPs degradation revealed the same patterns and trends. This showed that the heating rates do not impact the decomposition processes. The Friedman model showed activation energy values ranging from 3.31 to 8.79 kJ/mol. The average activation energy value was 1278.88 kJ/mol from the Arrhenius model, while, from the Coats-Redfern model, the average was 1.05 × 104 kJ/mol. The thermodynamics of the degradation process of the PET MPs by thermal treatment were all non-spontaneous and endergonic, and energy was absorbed for the degradation. It was discovered that an ANN, with a two-layer hidden architecture, was the most effective network for predicting the output variable (mass loss%) with a regression coefficient value of (0.951–1.0)

    Study on Thermal Degradation Processes of Polyethylene Terephthalate Microplastics Using the Kinetics and Artificial Neural Networks Models

    No full text
    Because of its slow rate of disintegration, plastic debris has steadily risen over time and contributed to a host of environmental issues. Recycling the world’s increasing debris has taken on critical importance. Pyrolysis is one of the most practical techniques for recycling plastic because of its intrinsic qualities and environmental friendliness. For scale-up and reactor design, an understanding of the degradation process is essential. Using one model-free kinetic approach (Friedman) and two model-fitting kinetic methods (Arrhenius and Coats-Redfern), the thermal degradation of Polyethylene Terephthalate (PET) microplastics at heating rates of 10, 20, and 30 °C/min was examined in this work. Additionally, a powerful artificial neural network (ANN) model was created to forecast the heat deterioration of PET MPs. At various heating rates, the TG and DTG thermograms from the PET MPs degradation revealed the same patterns and trends. This showed that the heating rates do not impact the decomposition processes. The Friedman model showed activation energy values ranging from 3.31 to 8.79 kJ/mol. The average activation energy value was 1278.88 kJ/mol from the Arrhenius model, while, from the Coats-Redfern model, the average was 1.05 × 104 kJ/mol. The thermodynamics of the degradation process of the PET MPs by thermal treatment were all non-spontaneous and endergonic, and energy was absorbed for the degradation. It was discovered that an ANN, with a two-layer hidden architecture, was the most effective network for predicting the output variable (mass loss%) with a regression coefficient value of (0.951–1.0)

    Integrated effects of poultry manure and chemical fertilizer on the growth, leaf yield and stevioside content of stevia

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    Stevia is important for its leaves which are used as non calorie sweetener and also in many therapeutic applications including diabetes. The present investigation was carried out in the net house of the Department of Agricultural Chemistry, Bangladesh Agricultural University, Mymensingh to investigate the integrated effects of poultry manure (PM) and chemical fertilizer (CF) on the growth, leaf biomass yield and stevioside content of stevia grown in two contrasting soils (acid and non-calcareous) of Bangladesh. Six combinations of PM and CF viz. PM0+CF0, PM0+CF100, PM3+CF50, PM3+CF75, PM5+CF50, PM5+CF75 were used. The study revealed that PM along with different percentages of chemical fertilizers exerted significant influence on the growth, leaf yield and stevioside content of stevia. The highest values of all the parameters except stevioside were found from the plant receiving PM @ 3 t ha-1 along with 75% CF. The leaf biomass yield was 1088% and 867% higher in acid soil and non-calcareous soil, respectively, over control. Stevioside content was increased with increasing the levels of PM up to 5 t ha-1 and also with the advancement of growth period from 30 to 60 days after planting. The highest amount of stevioside (10.45%) was detected in the leaves of the plant that received PM @ 5 t ha-1 along with 75% CF at 60 DAP in acid soil and it was 9.11% in non-calcareous soil at the same period. The lowest values of all the parameters including stevioside content were obtained from the plant which received neither PM nor CF. Considering the overall performance, farmers may be advised to cultivate stevia in acid soil applying PM @ 3 t ha-1 along with 75% chemical fertilizer to boost up the production of stevia under the agro-climatic condition of the study area in the context of Bangladesh

    Potassium requirement for leaf biomass yield and K nutrition of stevia

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    Potassium (K) is an essential plant nutrient affecting most of the biochemical and physiological processes. It is classified as a macronutrient due to large quantities being taken up by plants during their life cycle. With the aim of establishing a scientific basis of K fertilization on the growth, leaf production, minimum K requirement and critical leaf K concentration of stevia, a pot experiment was carried out in the net house of the Department of Agricultural Chemistry, Bangladesh Agricultural University. Six levels of K viz. 0 (K0), 50 (K50), 100 (K100), 150 (K150), 200 (K200) and 250 (K250) kg ha-1 were used in acid and non-calcareous soils. Plants were harvested at 60 days after planting (DAP). Results showed that K application significantly influenced the growth attributes, leaf yield and other parameters. Highest values of all the parameters except K content were obtained when K was applied @ 200 kg ha-1 which was significantly different from other levels of K including control. Dry weight of stevia leaves at harvest was increased from 0.77-7.41g and 0.99-7.74g Pot-1 in acid and non-calcareous soils, respectively over control. Potassium content was directly proportional with the increased levels of K though uptake did not follow the same trend. Leaf critical K content was estimated to be ca 1.75 and 1.71% in the plants grown in acid and non-calcareous soils, respectively. The minimum K requirement for maximum leaf biomass production (80%) of stevia was estimated to be ca 220 and 199 kg ha-1 grown in acid and non-calcareous soils, respectively. This study would contribute to improve K fertilization of stevia in various types of soil. [Fundam Appl Agric 2017; 2(3.000): 297-302

    Rise of inflation and formation of interest rate on loans in industrial sector: A VECM approach to assess the impact on total industrial production from evidence of Bangladesh

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    Industrial development is the prerequisite for sustainable economic growth. This study has examined the impact of the interest rate imposed on advances in the small and medium enterprise (SME) industrial sector, the large industrial (LI) sector, and inflation on the total industrial development of Bangladesh. For this purpose, we have used monthly data from January 2015 to June 2021. The weighted average interest rate of advances (WAIRA) is used as a substitute for the interest rate imposed on advances that were sourced from Bangladesh Bank (BB). We have applied Johansen co integration and the VECM technique to investigate long- and short run relationships, and the results have revealed the existence of both. We have observed that, in the short run, only WAIRA on SME industries has a significant negative impact on total industrial development. In the long run, inflation and WAIRA on SME and large industry have a significant impact on industrial development. The long run relationships have indicated that, inflation and WAIRA in the SME sector have a negative influence on total industrial development, but WAIRA in the large industry (LI) sector has a positive influence. Finally, considering the entire situation of the economy of Bangladesh, especially the growing industrial sector, these findings are highly momentous for policy implications and achieving sustainable development in this sector

    New Analytical Approaches for Effective Quantification and Identification of Nanoplastics in Environmental Samples

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    Nanoplastics (NPs) are a rapidly developing subject that is relevant in environmental and food research, as well as in human toxicity, among other fields. NPs have recently been recognized as one of the least studied types of marine litter, but potentially one of the most hazardous. Several studies are now being reported on NPs in the environment including surface water and coast, snow, soil and in personal care products. However, the extent of contamination remains largely unknown due to fundamental challenges associated with isolation and analysis, and therefore, a methodological gap exists. This article summarizes the progress in environmental NPs analysis and makes a critical assessment of whether methods from nanoparticles analysis could be adopted to bridge the methodological gap. This review discussed the sample preparation and preconcentration protocol for NPs analysis and also examines the most appropriate approaches available at the moment, ranging from physical to chemical. This study also discusses the difficulties associated with improving existing methods and developing new ones. Although microscopical techniques are one of the most often used ways for imaging and thus quantification, they have the drawback of producing partial findings as they can be easily mixed up as biomolecules. At the moment, the combination of chemical analysis (i.e., spectroscopy) and newly developed alternative methods overcomes this limitation. In general, multiple analytical methods used in combination are likely to be needed to correctly detect and fully quantify NPs in environmental samples

    Characteristics and Potential Inhalation Exposure Risks of Environmentally Persistent Free Radicals in Atmospheric Particulate Matter and Solid Fuel Combustion Particles in High Lung Cancer Incidence Area, China

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    Environmentally persistent free radicals (EPFRs) were previously considered an unrecognized composition of air pollutants and might help explain the long-standing medical mystery of why non-smokers develop tobacco-related diseases such as lung cancer. However, there is no investigated on EPFRs in Xuanwei rural areas, especially in high prevalence of lung cancer areas. In this study, we selected six types of coal and three types of biomass in Xuanwei, then conducted simulated combustion, and six group of atmospheric particulate matters (APMs) to explore the content and particle size distribution pattern of EPFRs and a new health risk assessment method to evaluate the risk of EPFRs in PM for adults and children. Our results show that the contribution of EPFRs for biomass combustion, coal combustion and APMs were mainly distributed in the size range of <1.1 μm, which accounted for 76.15 ± 4.14%, 74.85 ± 10.76%, and 75.23 ± 8.18% of PM3.3. The mean g factors and ΔHp-p indicated that the EPFRs were mainly oxygen-centered radicals in PM in Xuanwei. The results suggest that the health risk of EPFRs is significantly increased when the particle size distribution of EPFRs is taken into account, and coal combustion particulate matter (174.70 ± 37.86 cigarettes for an adult, 66.39 ± 14.39 cigarettes per person per year for a child) is more hazardous to humans than biomass combustion particulate matter (69.41 ± 4.83 cigarettes for an adult, 26.37 ± 1.84 cigarettes per person per year for), followed by APMs (102.88 ± 39.99 cigarettes for an adult, 39.10 ±15.20 cigarettes per person per year for) in PM3.3. Our results provides a new perspective and evidence for revealing the reason for the high incidence of lung cancer in Xuanwei, China

    Indirect exposure to novel coronavirus (SARS-CoV-2): an overview of current knowledge

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    This review chronicles the indirect transmission method which seems to be overlooked by most people and makes attempts to document the various transmission ways with a hope that such information may strengthen the knowledge base of researchers towards methods of eradicating the pandemic. Current knowledge of transmission and exposure of SARS-CoV-2 has been explained. Various researchers have put forward different ways of exposure and transmission.  Literature does not reveal whether the indirect transmission route is the dominant one. However, total lockdown could be a veritable means to reduce both direct and indirect transmission routes. In many countries where the indirect transmission has been reduced, the scourge of the virus is less. The work creates awareness on the need to watch out for those routes of transmissions that may not be popular and suggested vital knowledge gaps that need to fill. &nbsp
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