34 research outputs found

    Jatropha Biofuel Industry: The Challenges

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    Considering environmental issues and to reduce dependency on fossil fuel many countries have politicized to replenish fossil fuel demand from renewable sources. Citing the potential of Jatropha mostly without any scientific and technological backup, it is believed to be one of the most suitable biofuel candidates. Huge grants were released by many projects for huge plantation of Jatropha (millions of hectares). Unfortunately, there has been no significant progress, and Jatropha did not contribute much in the energy scenario. Unavailability of high-yielding cultivar, large-scale plantation without the evaluation of the planting materials, knowledge gap and basic research gap seem to be the main reasons for failure. Thus, the production of Jatropha as a biofuel has been confronted with various challenges such as production, oil extraction, conversion and also its use as a sustainable biofuel. In this chapter, we disclose the challenges and possible remedy for the contribution in the biofuel industry

    Willingness to pay/use for water supply and sanitation

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    This paper is a sociocultural case study of Dhaka, the capital city of Bangladesh, on the willingness to pay/use for water supply and sanitation. “Willingness to use” is a relatively new concept which can be defined as the maximum amount of desire one can willingly express for a certain commodity or service. Many technical, institutional, financial and legal factors determine the willingness to use. Affordability combined with willingness to use leads to willingness to pay. The low “willingness to pay/use” is one of the reasons behind the unproportional success rate of much of the national and international efforts undertaken for safe water supply and sanitation. However safe water supply and sanitation is an urgent need in Bangladesh where the number of water borne diseases cases per 100,000 persons is 51,000, much higher than other developing countries (WHO, 1992). One of the causes behind this alarming situation is low willingness to pay/use. Along with a brief description of the present situation in Dhaka city, efforts are taken to identify the problems behind the low willingness to pay/use for water supply and sanitation in light of the sociocultural aspects. This may provide useful information for other developing countries. Some improvement strategies are also proposed

    Phytochemical composition of calyx extract of roselle (Hibiscus sabdariffa L.) genotypes

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    Thirty five roselle genotypes were evaluated at the experimental field of Bangabandhu Sheikh Mujibur Rahman Agricultural University during August 2015 to February 2016. Based on agronomic performance 15 genotypes were selected for the analysis of phytochemical composition and the nutritional quality of calyx extract. The objective of the research was to estimate phytochemical constituents such as carotenoid, flavonoid, phenol, anthocyanin, vitamin C content and antioxidant activity of calyx extract of roselle. The genotype BUM-003 (873.61 μg/g) contained high amount of phenol among the 15 genotypes followed by BUM-007 (867.84 μg/g) and the lowest (481.57 μg/g) in genotype 4561. The high amount of carotenoid was estimated in the genotypes BUM-003, BUM-004, BUM-007 (30.18, 30.95, 29.69 μg/g, respectively). The genotypes 1740 (7.07 μg/g) and 4561 (7.73 μg/g) contained less amount of carotenoid. All the genotypes contained high amount of anthocyanin (>80 μg/g) except 1740, 4561, BUM-002. High amount of flavonoid was estimated in the calyx extract of the genotypes BUM-003 (399.15 μg/g) and BUM-004 (407.34 μg/g). The highest amount of antioxidant was estimated in the genotype BUM-002 (492.87 μg/g) followed by 4385 (488.09 μg/g) and 4920 (487.99 μg/g). Antioxidant activity was determined by 2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH) radical scavenging assay and maximum was found in the genotype 4920 (95.09%) followed by 4385 (94.12%), BUM-002 (93.55%) and minimum (72.83%) in the genotype 4537. The highest amount of vitamin C was estimated in the genotypes BUM-003 (312.97 μg/g) and the lowest in the genotype 4561 (26.20 μg/g). From the overall phytochemical composition it might be concluded that the calyces of the genotypes 4385, 4920, BUM-002, BUM-003, BUM-004, BUM-007 are the excellent source of natural antioxidants. The calyx extract of the genotype BUM-004 contain the highest amount of carotenoids (31μg/g), ascorbic acid (424.19μg/g), antioxidant (485.85 μg/g BHT eqv) and antioxidant activity (94.50 %). The genotype 4537 contain the highest amount anthocyanins (87.7 μg/g and) and flavonoid (404.40μg/g). The genotype BUM-003 (869.45 μg/g) contained the highest amount of phenol in the calyx extract.Keywords: Roselle (Hibiscus sabdariffa L.), nutrition, chemical composition, calyx extrac

    Germination of black gram (VIGNA MUNGO L.) seed is influenced by different storage containers and storage periods

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    A laboratory test was carried out to examine the influence of various storage containers and periods on the germination percentage of black gram seed. In this research, three seed containers, viz. sealed tin container, poly bag and gunny bag were used to store the seeds, as well as seeds were stored for three different storage periods, viz. 15, 30 and 45 days and thereby conducted germination tests. The results revealed that storage and storage periods considerably influenced the germination percentage (GP) of black gram seed. The highest GP of 87.73% was found in the seeds stored at sealed tin container, while the lowest GP (71.08%) was observed in the seeds stored in gunny bag. Among the three storage containers, the GP reduced rapidly in the seeds stored in gunny bags (6.52%), followed by poly bag (18.98%). The maximum values of GP (85.43%) of black gram seed were recorded when 15 days after storage (DAS), whereas the lowest GP (68.33%) was at 45 DAS, and the GP decreased noticeably with the increase of storage periods from 15 to 30 and to 45 DAS. In combination influence of storage containers and storage periods, the maximum GP (85.90%) was recorded at when seeds kept in sealed tin container with stored for the shortest duration (15 DAS), while the minimum (58.11%) was recorded in the seeds stored in gunny bag for the longest period with 45 DAS. Seeds stored in the sealed tin containers exhibited an excellent performance regarding GP with the shortest storage periods and, thereby, black gram should be kept in sealed tin containers or like this air tight containers for storage, as well as seeds should be sun dried after a short period for maintaining seed quality

    Susceptibility of microorganism to selected medicinal plants in Bangladesh

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    ABSTRACTObjectiveTo analyze in-vitro antimicrobial activities of some ethno-pharmacologically significant medicinal plants (methanol extract) against the pathogenic microorganisms (Escherichia coli, Salmonella spp., Bacillus cereus, Staphylococcus aureus, Aspergillus niger and Candida albicans).MethodsThe disc diffusion method was applied for antibacterial test and the poisoned food technique was applied for antifungal test.ResultsThe methanol extract of Terminalia chebula (bark), Phyllanthus acidus (fruits), Sarcochlamys pulcherrima (leaves) and Abelmoschus esculentus (fruits) had significant in vitro antibacterial activity angainst the entire test samples in comparison to standard drug ciprofloxacin. Most of the plant extracts showed low activity against Gram negative bacteria while potential activity against Gram positive bacteria. The antifungal activities of methanol extracts of these plants and standard drug griseofulvin were determined against two pathogenic fungi, and Polygonum lapathifolium (leaves) and Cinnamomum tamala (leaves) showed maximum activity, while Erioglossum rubiginosum (leaves) showed no antifungal activity.ConclusionsFurther chemical and pharmacological investigations are required to identify and isolate chemical constituents responsible for these potential bioactivities and thus to determine their full spectrum of efficacy

    Ethnic Association in Primary Systemic Vasculitis: A Systematic Review

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    Background: Literature described wide disparities in incidence and prevalence between different types of vasculitis. There were no comprehensive studies on ethnic or racial associations in all types of primary systemic vasculitis (PSV) in any published article, until this review commenced in 2020. The purpose of the review is to synthesize the evidence regarding the relation of ethnicity and the incidence and/or prevalence of different types of PSV. Methods: A total of 52 selected articles which include Clinical trials, cohorts, cross-sectional studies, case series, and case studies and have been published within the last 10 years in the human population, were reviewed by searching The Medline, PubMed, and Google Scholars databases using predefined keywords. The PRISMA diagrams were followed to identify relevant articles. The methodological qualities of the studies were assessed using the EPHPP tool. Finally, a summary of the evidence on the association between ethnic origin and PSV was painstakingly compiled. Results: The connection between ethnicity and different types of PSV has been found to be significantly diverse in this research such as vasculitis is more common in Asians and Scandinavians, Kawasaki disease and periarteritis nodules are more prevalent in Japanese and Alaska-natives, ANCA-associated vasculitis is more frequent in Caucasians, whereas Henoch-Schonlein purpura and Cogan syndrome more usual in Caucasians and Asians. Furthermore, Behçet's disease more commonly occurs on the "Silk Road", especially in Turkey. Conclusion: Genetic susceptibility and environmental elements could be the contributing factors to the global variation in the incidence and prevalence of primary systemic vasculitis

    A low-profile flexible planar monopole antenna for biomedical applications

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    This article proposes a low profile planar monopole antenna on flexible substrate. The antenna is designed with an elliptical slot inserted in a rectangular patch by utilizing the coplanar waveguide (CPW) feeding technique on a polyimide substrate. The proposed antenna operates within 7–14 GHz (S11 < − 10 dB) with a minimum return loss is observed as low as – 58 dB by simulation, whereas the entire X-band is covered by the – 20 dB bandwidth while maintaining an excellent VSWR of almost 1. Also, the antenna exhibits an average gain of 4 dBi while the average radiation efficiency is 92%. The maximum SAR of the proposed antenna for 1 g mass is below 1.0 W/Kg throughout the entire bandwidth. To observe flexibility, four different bending conditions of the antenna have been analyzed. For experimentation, the antenna has been realized as a prototype by using a low-cost fabrication process. The measurement reveals that the prototype has a −10 dB bandwidth of 5.4 GHz. During In-Vivo test, over the variation of 0 ∼ 3 mm distance between the antenna-prototype and the human chest/chicken breast tissue, the best performance is obtained at 3 mm in terms of the return loss. One of the significant features of the proposed design is its measured average and peak gain of 4.4 dBi and of 6.33 dBi respectively with a measured average efficiency of 65%. The proposed antenna has a compact size of 13 13 mm2 (), and its performance remains nominally constant even under different bending conditions which makes the antenna suitable for biomedical imaging applications. A new figure-of-merit has been introduced to evaluate the overall performance based on different antenna key parameters. The fabricated antenna would contribute to the future biomedical research by utilizing X-band frequencies

    Enhancing genetic gain through the application of genomic selection in developing irrigated rice for the favorable ecosystem in Bangladesh

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    Increasing selection differential and decreasing cycle time, the rate of genetic improvement can be accelerated. Creating and capturing higher genetic with higher accuracy within the shortest possible time is the prerequisite for enhancing genetic gain for any trait. Comprehensive yield testing at multi-locations at early generations together with the shortest line fixation time can expedite the rapid recycling of parents in the breeding program through recurrent selection. Genomic selection is efficient in capturing high breeding value individuals taking additive genetic effects of all genes into account with and without extensive field testing, thus reducing breeding cycle time enhances genetic gain. In the Bangladesh Rice Research Institute, GS technology together with the trait-specific marker-assisted selection at the early generation of RGA-derived breeding lines showed a prediction accuracy of 0.454–0.701 with 0.989–2.623 relative efficiency over the four consecutive years of exercise. This study reports that the application of GS together with trait-specific MAS has expedited the yield improvement by 117 kg ha−1·year−1, which is around seven-fold larger than the baseline annual genetic gain and shortened the breeding cycle by around 1.5 years from the existing 4.5 years

    Dynamic load modeling for bulk load-using synchrophasors with wide area measurement system for smart grid real-time load monitoring and optimization

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    Bulk data modeling in a smart grid dynamic network has been performed using an automated load modeling tool (ALMT), an on-load tap changer, and exponential dynamic load modeling. However, studies have observed that a small parameter variation may lead to considerable variations in measuring grid big data. Therefore, this study presents dynamic real-time load modeling, monitoring, and optimization method for the bulk load. The case study was conducted on Sarawak Energy Berhad (SEB), Malaysia. The grid system’s real-time data and load modeling achieved the objectives. Dynamic load model was achieved by using load response in MATLAB Simulink environment. This paper also includes new parameter estimations of the load composition at the selected bus. The simulation results of load models were compared with the recorded data by applying an event of bus tripping time interval. The Least Square Error Method was used to converge the estimated parameter values on load composition and compared with the actual recorded data until optimized load models were achieved. This work is a precious and significant contribution to utility research to identify, monitor, and optimize the most appropriate representation of system loads
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