68 research outputs found

    The engineering behaviour of the tropical clay soils of Dhaka, Bangladesh

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    This research has evaluated the engineering behaviour of the tropical clay soils of Dhaka, Bangladesh. Attempts have been made to show the relationship of mineralogy and fabric with engineering properties. The engineering behaviour has been investigated by comparing the soil properties in a natural and destructured state at the same void ratio. Consolidation behaviour of the soils are discussed, based on oedometer and triaxial tests. Undrained and drained mechanical behaviour have been evaluated from triaxial tests in terms of stress-strain curves, stress paths, bonding effects, critical state conditions, stiffness and yielding behaviour. A framework for the tropical clay soils of Dhaka is presented. The tropical clay soils of Dhaka are intermediate to high plasticity inorganic clay. These soils are mainly composed of illite,. kaolinite, chlorite and some non clay minerals mainly quartz and feldspar. It was observed that these sods showed a random open microfabric of silt and clay. There was also some evidence that aluminosilicates, iron compounds and silica formed bonds between and within the grains. An apparent preconsolidation pressure of 170 kPa to 250 kPa was estimated for the natural soils, which is likely to be due to the bonded structure of the soils. The compressibility of the soil is very low to medium. The consolidation results are consistent with the mineralogy of the soils. It is established that the tropical clay soils of Dhaka are bonded. Bonding has an influence on the development of stress-strain and stiffness of these soils. Under undrained shearing, samples initially showed peak positive values of excess pore water pressure followed by negative values at higher strains due to the tendency of the samples to dilate. No negative pore water pressures were observed at high confining pressures. Only a few samples at low confining pressures reach the critical state at very large strains approximately in excess of 20%. High confining pressure samples may not have reached the critical state due to the formation of distinct shear surfaces. A significant difference between the natural and destructured failure surfaces was observed due to the presence of bonds in the natural soils. Differences in failure type were observed between the natural and destructured soils of three boreholes. It was observed that stiffness values gradually decreased with increasing strain. For the natural soils, two yield points could be identified at low confining pressures below the final yield. It was also observed that bond breakdown would occur in isotropic compression for tests at high confining pressures. At the final yield, the soil looses almost all of its stiffness due to bonding. After final yield, a soil’s behaviour is controlled only by friction. It was observed that three zones of behaviour could be identified for these soils in the stress space

    Corporate Social Responsibility Practices in Garments sector of Bangladesh, A Study of Multinational Garments, CSR view in Dhaka EPZ

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    This study has been conducted to explore the real scenario of present CSR practices by multinational companies of Bangladesh. Here we have assembled information from a renowned multinational company Hop lun (BD) as well as different secondary sources. After examining literature review and Hop lun (BD)’s information we can say that, today’s CSR practices is not spread properly. Some of organization trying their best, but in the most of cases organization are not aware about that. Without proper take care of society none of the business organization can’t go through their operation for long run. That’s why Hop Lun (BD) believes in CSR. And they are trying to do something for the further development of employee as well as stakeholders. We believe that social awareness can change the situation of Bangladesh. Government initiative and corporate organizations positive thinking can brand revolution positively in CSR. Keywords: CSR, Business, Banglades

    Opportunistic Relay Selection over Generalized Fading and Inverse Gamma Composite Fading Mixed Multicast Channels : A Secrecy Tradeoff

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    This work was supported in part by the National Research Foundation of Korea funded by the Korean Government, Ministry of Science and ICT, under Grant ICT-NRF-2020R1A2B5B02002478; and in part by Sejong University through its Faculty Research Program under Grant 20212023.Peer reviewedPublisher PD

    Kinematic measurements of novel chaotic micromixers to enhance mixing performances at low reynolds numbers : Comparative study

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    Funding Information: Funding: This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (No. 2019R1A2C1007657). The authors gratefully acknowledge this support.Peer reviewedPublisher PD

    Security at the Physical Layer over GG Fading and mEGG Turbulence Induced RF-UOWC Mixed System

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    This work was supported in part by the National Research Foundation of Korea grant funded by the Korean Government (Ministry of Science and ICT) under Grant 2019R1A2C1083988, in part by the Ministry of Science and ICT, South Korea, under the Information Technology Research Center Support Program supervised by the Institute for Information and Communications Technology Planning and Evaluation, under Grant IITP-2021-2016-0-00313, and in part by Sejong University through its Faculty Research Program under Grant 20202021.Peer reviewedPublisher PD

    Ketorolac and pethidine in post-operative pain relief

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    The study was designed to compare the analgesic efficacy and safety of ketorolac and pethidine in pain relief after major surgeries. A prospective, interventional study was conducted on 71 patients under-going major surgical intervention. Thirty six patients received ketorolac (15 mg, intramuscularly 6 hourly) and the rest 35 patients received pethidine (100 mg, intramuscularly 6 hourly) for 48 hours post-operatively. Analgesic efficacy and safety of ketorolac were compared with that of pethidine after 1, 6, 12, 24, 32 and 48 hours of drug administration. Analgesic efficacy was measured using Visual Analogue Scale (VAS) and Verbal Rating Scale (VRS). Safety of the drugs was assessed by using sedation score and also recording adverse drug events. Ketorolac showed equianalgesic effect as pethidine estimated by VAS score at 12th and 48th hour and by VRS score at 1st and 48th hour of post-operative period. In other periods of observation, pethidine exhibited better analgesic effects than ketorolac. Ketorolac was better tolerated than pethidine and had less adverse effects compared to pethidine. This study showed that post-operative pain during the first 48 hours can be relieved by either ketorolac or pethidine. Ketorolac appeared safer than pethidine while pethidine appeared more effective analgesic than ketorolac in the management of post-operative pain. Further studies including double-blind randomized trial have been suggested to confirm the present study

    On effective secrecy throughput of underlay spectrum sharing α - μ/ Málaga hybrid model under interference-and-transmit power constraints

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    The underlay cognitive radio-based hybrid radio frequency/free-space optical (RF/FSO) systems have emerged as a promising technology due to their ability to eliminate spectrum scarcity and spectrum under-utilization problems. The physical layer security of such a network with a primary user, a secondary source, a secondary receiver, and an eavesdropper is therefore examined in this work. In this network, secret communication occurs between two reliable secondary peers over the RF and FSO links simultaneously, and the eavesdropper can only overhear the RF link. In particular, the maximum transmits power limitation at the secondary user as well as the permissible interference power restriction at the primary user are also taken into consideration. All the RF and FSO links are modeled with α - μ fading and Málaga turbulence with link blockage and pointing error impairments. At the receiver, the selection combining diversity technique is utilized to select the signal with the best electrical signal-to-ratio (SNR). Furthermore, to examine the secrecy performance taking into account the effects of each system parameter, closed-form expressions for the secrecy outage probability and effective secrecy throughput are derived. The resultant expressions are finally verified by Monte-Carlo simulations

    Polyphenols and extracts from Zingiber roseum (Roxb.) Roscoe leaf mitigate pain, inflammation and pyrexia by inhibiting cyclooxygenase-2: an in vivo and in silico studies

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    Zingiber roseum (Roxb.) Roscoe, a perennial herb from the Zingiberaceae family, has a long history of traditional use in the treatment of several ailments including pain, inflammation, fever, cough, arthritis, skin diseases, and liver infections. This study sought to confirm the efficacy of Zingiber roseum (Roxb.) Roscoe leaves methanol extract (ZrlME) as reported in traditional usage by evaluating its analgesic, anti-inflammatory, and antipyretic capabilities. In addition, in silico molecular docking of the metabolites identified in ZrlME was studied to verify the experimental outcomes. ZrlME demonstrated strong dose-dependent analgesic efficacy against all analgesic tests. ZrlME (400 mg/kg) showed higher anti-inflammatory activity than the standard in the carrageenan-induced paw edema test model. A significant reduction of rectal temperature (3.97°F↓) was also recorded at the same dose of ZrLME after 24 h of treatment. Seven polyphenolic metabolites were identified and quantified by HPLC-DAD analysis, including 3, 4- dihydroxy benzoic acid, (-) epicatechin, rutin hydrate, p-coumaric acid, trans-ferulic acid, rosmarinic acid, and myricetin. Strong binding affinities (ranges from −5.8 to −8.5 Kcal/mol) between the aforesaid polyphenols and cyclooxygenase-2 were discovered. Moreover, molecular dynamics simulations (MDS) demonstrated that these polyphenols exhibit significant COX-2 inhibitory activity due to their high stability in the COX-2 active site. In computational prediction, the polyphenols were also found to be nontoxic, and a variety of biological activities, such as antioxidant, analgesic, anti-inflammatory, antipyretic, and hepatoprotective, were observed. The results of this study revealed that ZrlME possesses notable analgesic, anti-inflammatory, and antipyretic properties

    Enhanced Case Detection and Improved Diagnosis of PKDL in a Kala-azar-Endemic Area of Bangladesh

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    PKDL is a skin disorder which usually develops in 10–20% and about 60% of patients with visceral leishmaniasis (VL) after treatment respectively in the Indian subcontinent and Sudan. However, cases among people without prior VL have also been reported. Except skin lesion, PKDL patients are healthy and usually do not feel sick. However, persistence of a few PKDL cases is sufficient to initiate a new epidemic of anthroponotic VL. Thus, identifying and treating people with PKDL is a key strategy for the elimination of kala-azar. Diagnosis of PKDL relies upon clinical criteria and a serological test which is not specific for PKDL. The use of the existing laboratory diagnostic tools for confirmation of PKDL among PKDL suspects is unknown. In the Indian subcontinent, PKDL is not self-limited and needs to be treated with sodium stibogluconate injections for 4–6 months. No data are available relating to treatment compliance by patients, particularly in Bangladesh. The results of the present study showed that trained village volunteers were useful for identifying PKDL suspects, and diagnostic confirmation improved with the use of PCR. However, patients' adherence to prescribed treatment was poor
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