Degumming of Hemp Fibers Using Combined Microwave Energy and Deep Eutectic Solvent

Hemp is considered as one of the sustainable agricultural fiber materials. Degumming or surface modification of hemp bast is needed to produce single fibers for ensuing textile and industrial applications. The traditional degumming process necessitates a high amount of alkali, which causes detrimental environmental pollution. This study offers a new method to degum hemp fibers with reduced use of harmful alkali and precious water resources. In this work, hemp bast fibers were degummed by using combined microwave energy and deep eutectic solvent (DES). The properties of hemp fibers manufactured by this method were investigated and compared with the traditional alkali process. Several analytical techniques were used to characterize and perform a comparative analysis of the degummed fibers. Results revealed that the fiber qualities, including fiber surface morphology and UV shielding performance of DES-treated fibers at 1:20 solid-liquor ratio (UPF value was 183.67) were higher than these from the traditional alkali treated (140.75) and untreated raw hemp fibers (127.47). FT-IR, SEM, NMR, and XRD confirmed that degumming using a Microwave-DES treatment at 1:20 solid-liquor ratio had a higher yield with respect to removal of gummy materials (lignin and hemicellulose, etc.). TGA and DSC also confirmed the higher thermal stability of DES-treated fibers. In addition, cellulose content in the Microwave-DES treated samples was increased to 44.82% - 49.95% which was comparable with the increased cellulose content (49.49%) of alkali treated fibers. All these data indicate the effective, less time-consuming, green, and environmentally sustainable protocol for manufacturing hemp fibers

Analysis and design of rectangular concrete-filled steel tubular members by considering size effect

The aim of this research was to develop an accurate and versatile FE model for rectangular CFST members by considering the size effect. The developed FE model could then be used to generate numerical data for developing accurate design equations to predict the ultimate strengths of rectangular CFST members. For this purpose, only reliable test data of composite stub columns tested in a displacement-controlled mode were used for calibrating the key parameters of the refined concrete model used in the FE analysis. It was found that the refined FE model could provide reasonable predictions about these specimens in terms of the initial stiffness, ultimate strength and post-peak behaviour. An extensive parametric analysis was then conducted using the refined FE model to generate a numerical database of short columns covering a wide range of geometric and material parameters. The revised design equations incorporating the size effect were suitable for use in the design of rectangular CFST stub columns, which was verified by both numerical and test data. The prediction errors were normally within 10% for both the small and the large columns. Reliability analysis was further performed for rectangular CFST stub columns, indicating that the revised design equations significantly improved the design reliability of large columns. Reliability analysis was further performed for rectangular CFST stub columns, indicating that the revised design equations significantly improved the design reliability of large columns. A parametric analysis was further conducted for slender CFST columns with slenderness ratios varying from 10 to 200. Meanwhile, the geometric and material parameters were also varied in the same ranges as in the previous analyses of stub columns. It was found that the ultimate moment of a CFST beam should be defined on the basis of the curvature instead of extreme fibre strains or deflection at mid-span. After evaluation, the EC4 equations were modified to improve the prediction accuracy of the ultimate strengths of RCFST beams and short beam-columns by incorporating the size effect and/or the local buckling effect. Finally, the proposed equations were used to predict the ultimate strengths of slender beam-columns. A significant improvement in prediction accuracy over that of the existing EC4 approach was also found, and the prediction errors were normally within the 10% discrepancy limit

The Aging of Adipocytes Increases Expression of Pro-Inflammatory Cytokines Chronologically

Adipose tissue is a significant producer of pro-inflammatory cytokines in obese and old individuals. However, there is no direct evidence of whether and how aged adipocytes enhance the production of pro-inflammatory markers. We aimed to investigate whether the aging adipocytes increase pro-inflammatory markers. Swiss mouse embryonic-tissue-derived 3T3-L1 cells were differentiated into adipocytes and maintained for 60 days in the conditioned medium or 35 days in the unconditioned medium. Additionally, 20-month-old male C57BL/6 mice were fed a standard chow diet for 37 weeks until they were extremely aged, when ~75% of mice died because of aging. Accumulated lipids, pro-inflammatory markers, and nuclear factor kappa B (NF-κB) pathway markers from differentiated adipocytes were analyzed. Pro-inflammatory markers and NF-κB pathway markers of epididymal white adipose tissues (EWATs) and adipocytes from EWATs were also analyzed. We found that the aging adipocytes chronologically accumulated lipids and increased pro-inflammatory markers interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and tumor necrosis factor-alpha (TNF-α); at the same time, NF-κB p50 markers were also increased while IκBα protein was decreased significantly in conditioned medium. Similar results were observed when differentiated adipocytes were maintained in the unconditioned medium and the adipocytes from EWATs of aged mice. We demonstrated that aging augmented chronic inflammation through the NF-κB signaling pathway in adipocytes and adipose tissue

Damage Characterization in Building Structures due to Blast Actions

Structural identification is a technique that can be used to assess/characterize the damage state through the variation in eigenfrequencies, damping ratios and modal shapes in a structure or element. It has recently received more attention for the practical implementation in several fields, including damage assessment for structures following blast or explosion events. At present, large infrastructure components, like civil engineering structures, are the most turning point for the consideration for structural identification. Structures can be moderately or severely deteriorated due to accidental or intentional blasts or explosions. The structural engineers but also other stakeholders, like rescue and emergency agencies, are more concerned about the design of structures, design life span, proper maintenance, repair and residual capacity of structural systems in many countries.This dissertation work focuses on the experimental and analytical modal analysis of a full-scale steel frame structure building aiming to develop coherent scenarios that combine the probability of the hazard event with the structural vulnerability in case of a close in detonation. The field tests were carried out by forced vibration testing under hammer excitations. First series of tests were done for the undamaged structure using classical experimental modal analysis. Then, in order to model a structural damage, a secondary beam was dismantled (thus a damage was created artificially) and the measurements were repeated. The change in structural behaviour was observed by identifying the changes in the stiffness and natural frequencies of the structure. The modal parameters measured from field test were used then to validate finite element models using SAP2000 program. They were corrected so that the numerical natural frequencies and mode shapes match the experimental data. Good agreement was obtained in identifying the frequencies for the three-dimensional finite element models for both damaged and undamaged structure. Then, using the calibrated numerical model, several blasts induced damages were used in a numerical study. For the internal damage or non-visible crack, four different damage scenarios were made by the FE model for internal and external blast actions. The modal parameters changed significantly for higher modes for higher reduction of stiffness at the column-beam and base connections. The results (experimental data, calibrated numerical model) will be used as reference values of the undamaged structure for further investigations after blast tests will be performed. This research is a part of FRAMEBLAST project supported by a grant of the Romanian National Authority for Scientific Research and Innovation, CNCS/CCCDI-UEFISCDI, project number PNIII-P2-2.1-PED-2016-0962, within PNCDI III. ?Experimental validation of the response of a full-scale frame building subjected to blast load?-FRAMEBLAST (2017-2018)?.Structural identification is a technique that can be used to assess/characterize the damage state through the variation in eigenfrequencies, damping ratios and modal shapes in a structure or element. It has recently received more attention for the practical implementation in several fields, including damage assessment for structures following blast or explosion events. At present, large infrastructure components, like civil engineering structures, are the most turning point for the consideration for structural identification. Structures can be moderately or severely deteriorated due to accidental or intentional blasts or explosions. The structural engineers but also other stakeholders, like rescue and emergency agencies, are more concerned about the design of structures, design life span, proper maintenance, repair and residual capacity of structural systems in many countries.This dissertation work focuses on the experimental and analytical modal analysis of a full-scale steel frame structure building aiming to develop coherent scenarios that combine the probability of the hazard event with the structural vulnerability in case of a close in detonation. The field tests were carried out by forced vibration testing under hammer excitations. First series of tests were done for the undamaged structure using classical experimental modal analysis. Then, in order to model a structural damage, a secondary beam was dismantled (thus a damage was created artificially) and the measurements were repeated. The change in structural behaviour was observed by identifying the changes in the stiffness and natural frequencies of the structure. The modal parameters measured from field test were used then to validate finite element models using SAP2000 program. They were corrected so that the numerical natural frequencies and mode shapes match the experimental data. Good agreement was obtained in identifying the frequencies for the three-dimensional finite element models for both damaged and undamaged structure. Then, using the calibrated numerical model, several blasts induced damages were used in a numerical study. For the internal damage or non-visible crack, four different damage scenarios were made by the FE model for internal and external blast actions. The modal parameters changed significantly for higher modes for higher reduction of stiffness at the column-beam and base connections. The results (experimental data, calibrated numerical model) will be used as reference values of the undamaged structure for further investigations after blast tests will be performed. This research is a part of FRAMEBLAST project supported by a grant of the Romanian National Authority for Scientific Research and Innovation, CNCS/CCCDI-UEFISCDI, project number PNIII-P2-2.1-PED-2016-0962, within PNCDI III. ?Experimental validation of the response of a full-scale frame building subjected to blast load?-FRAMEBLAST (2017-2018)?

Sustainable livelihood approach of prawn production and marketing systems in Mymensingh, Bangladesh

An investigation was carried out in Phulpur upazila, Mymensingh to examine the current production practices of freshwater giant prawn, Macrobrachium rosenbergii and its marketing systems with sustainable livelihood approach. The livelihoods of a considerable number of rural poor are associated with prawn production in Phulpur upazila. Based on a sample of 50 farmers, about 94% farmers were found to culture prawn with fish in their ponds. Only 4% and 2% farmers were found to culture prawn-fish-dike crops and only prawn respectively. Prawn marketing is almost exclusively a preserve of the private sector where the livelihoods of a large number of people are associated with its distribution and marketing systems. The market chain from producers to consumers passes through a number of intermediaries. About 40% of the produced prawns are exported and the rest 60% are sold to local markets. The price of prawn depends on quality, size and weight. The average farm-gate price of prawn varied from Tk. 110 to 160/kg, whereas it's [sic] market price varied from Tk. 150 to 350/kg. Most of the farmers and traders have improved their socio-economic conditions through prawn farming and marketing activities. However, concerns arise about the long-term sustainability of prawn farming and marketing systems due to lack of technical knowledge of prawn farming, poor road and transport facilities, higher transport cost, poor supply of ice, lack of cash and credit facilities. It is therefore essential to provide institutional and organizational support and credit facilities for sustainable prawn production and marketing systems

Woolenization of Jute Fibre

Once upon a time, Jute was called the golden fibre of Bangladesh. Due to some problems and growth of modern technology, the market share of jute has decreased. In this paper, the effect of Woolenization of jute fibre was described. It also shows how the physical and chemical properties of jute have been changed by alkali-treatment as well as its structure. It was demonstrated that this kind of treatment leads to several changes in its structure which has turned to a near wool structure. These works are done by different concentrations of different alkalis. Finally, 15% NaOH treatment of jute show maximum woolenized properties where we obtain softened and swollen jute. Conclusively, we have made some other products from woolenized jute fibres such that if introduced into our world market, it can increase the market share of jute fibre

Behaviour and design of bolt-coupler connections under compression in prefabricated CFST columns

The paper presents the investigated results of bolt-coupler connections under compression experimentally. Bolt-coupler connections have been developed recently for prefabricated column-to-column (PCC) connections to simplify the construction process of prefabricated concrete-filled steel tubular (CFST) columns and to transfer the upper column load to the bottom column through bolt-coupler connections. However, the behaviour of bolt-coupler connections under compression has not been investigated in the past although there are some experimental and numerical studies conducted on bolt-coupler connections under tension. To address these research gaps, the behaviour of bolt-coupler connections under compression has been investigated. The main parameters considered in this study are bolt diameters (M16, M20, M24), bolt grades (8.8, 10.9 grade), gap inside the coupler between two bolts of bolt-coupler connection (0, 10, 20 mm), and coupler grade (5.6, 8.8 grade). It is observed that the ultimate capacity of bolt-coupler connections is reduced significantly with an increase in the bolt gap inside the coupler of the bolt-coupler connection. Based on the test data, a design equation is developed to determine the design capacity of bolt-coupler connections under compression, which will be very useful in designing the PCC connections of sustainable prefabricated CFST columns

Comparative Study of the Dynamics of Cosmic Rays for the Pakistan and China Atmospheric Regions

This paper presents an analysis of cosmic ray intensity in Pakistan air space using spatial interpolation, comparing it with Chinese cosmic ray records from 1984 to 1993. The Exploratory Data Analytic (EDA) approach was applied to compare the cosmic ray fluctuations in both countries. The time series plot of the monthly cosmic rays showed relatively flatter counts in Pakistan than in China. The cosmic ray data for the years 1984 to 1993 fell within Solar Cycle 22, which lasted from 1986 to 1996, with its maximum phase in 1989 to 1991. The cosmic radiation varies between the atmospheric regions of Pakistan and China due to modulations in intensity that are accessible accordingly. It can be explained by purely astrophysical phenomena: (1) the source of emission of cosmic radiation may be different, (2) the rate at which emanation takes place depends on bursts of deep space dynamical objects from their sources that may be affected by solar wind and other solar radiations. Therefore, modulations in intensity are not only due to different geophysical locations. This study will help government organizations to predict and forecast cosmic rays values

Persistence of chloramphenicol in the fish flesh patin (Pangasius hypothalamus) and tilapia (Oreochromis niloticus)

Introduction: Increasing antibiotic resistance in bacteria is a serious global problem. This study was aimed to extract the antibiotic Chloramphenicol (CAP) from different parts of the fish flesh. Methods: Fish fleshes were excised from two commercially important fishes: Oreochromatis niloticus.(Red Tilapia) and Pangasius hypothalamus (Patin). The fleshes were chosen form head and tail region where generally antibiotics are spiked to avoid bacterial contamination while kept in cold storages of supermarkets. Each fish fleshes were weighed and spiked with 20,40,80 and 160ppm of CAP and stored at 4°C. The CAP residue from the flesh was extracted immediately after the first spiking was considered as Day-1. The whole extraction processes were done for 1,7,14 and 28 days. HPLC (High Performance Liquid Chromatography) was used to determine the presence of CAP residue in the tested fish flesh. Results: The results showed variations on the percentage of antibiotic residue recoveries at different concentration. In this study, CAP did not degrade and showed variations on the presence of antibiotic residue in the fish flesh. The recoveries of the entire CAP spiking samples ranged from 4.0% -100%. It also revealed the presence of antibiotic residue in Malaysian freshwater cultured fishes. Thus, the relevant authorities should take immediate action regarding this issue in order to prevent the harmful effects especially to human. Conclusions: Nevertheless, the study portrays that antibiotic residues can be sustained long time in the food products under storage conditions, which might have harmful effects on human when they consumed these frozen fishes