| 1. |
- Islam, Md Nazrul, et al.
(författare)
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Raw natural rubber latex-based bio-adhesive for the production of particleboard : formulation and optimization of process parameters
- 2021
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Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 11:46, s. 28542-28549
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Tidskriftsartikel (refereegranskat)abstract
- In this study, bio-adhesives from natural rubber latex (NRL) were combined with starch and formic acid to fabricate jute stick-based particleboards (JSPs). Different blends of NRL, starch, and formic acid, i.e., 6 : 1 : 1, 2 : 1 : 1, and 2 : 3 : 3, were used to produce particleboards using a pressing temperature of 180 °C and applied pressure of 5 MPa using a 5 min pressing time. The particleboards were tested for physical, mechanical, and thermal properties according to ANSI standards. Based on initial screening, the best formula (NRL/starch/formic acid of 2 : 3 : 3) was used to optimize the temperature and pressing time for the highest board performance. The highest density, tensile strength, modulus of elasticity, and modulus of rupture were 830 g cm−3, 10.51, 2380, and 20.05 N mm−2, respectively. Thermo-gravimetric analysis indicated that thermal decomposition of samples primarily occurred in a temperature range of 265 to 399 °C, indicating good thermal performance. The measured physical and mechanical properties of the produced JSPs fulfilled the production standards. However, fulfilling the water absorption and thickness swelling criteria was a challenge. The results indicate that NRL is a promising alternative binder when blended with starch and formic acid.
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| 2. |
- Rana, Md Nasim, et al.
(författare)
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Influence of chemical additive on the physical and mechanical properties of cement-bonded composite panels made from jute stick
- 2020
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Ingår i: Journal of Building Engineering. - : Elsevier BV. - 2352-7102. ; 31
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to observe the effects of chemical additives (calcium chloride (CaCl2) and magnesium chloride (MgCl2)) on the setting time of jute stick cement-bonded composites (CBCs). The setting time was judged based on the measured physical and mechanical properties of the composites as function of the press time. The mixing ratio of jute stick particles, cement and water was set at 2:1:1 for chemical additive (CaCl2/MgCl2) incorporated composites, and a controlled one without additive was manufactured based on jute particles and cement mixing ratio of 2:1. Three concentration levels of 6, 8 and 10% of CaCl2 and MgCl2 were used separately to produce the composite boards. In this study, the composite mixtures were cold-pressed at a pressure of 5 MPa and different pressing duration of 4, 6, 8, 12 and 16 h. Incorporation of the additives reduced the press time, and higher percentage of additives increased the physical and mechanical properties of the composite panels produced. Composite panels made with MgCl2 exhibited better performance compared with those made with CaCl2. The highest modulus of elasticity (MOE) and modulus of rupture (MOR) of the manufactured samples were 10.5 and 4595 MPa, respectively for the maximum percentage of MgCl2 addition with 6 h press time. It appears that these additives especially MgCl2 decreased the setting time of the CBCs, which can be considered as an alternative approach for the industry to produce CBCs in shorter time.
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| 3. |
- Rana, Md Nasim, et al.
(författare)
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Properties of low-density cement-bonded composite panels manufactured from polystyrene and jute stick particles
- 2019
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Ingår i: Journal of Wood Science. - : Springer Nature. - 1435-0211 .- 1611-4663. ; 65:1
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Tidskriftsartikel (refereegranskat)abstract
- This study was conducted to evaluate the properties of cement-bonded composite (CBC) manufactured using jute stick particles and expanded polystyrene (EPS) beads to reduce the density of CBC for mitigating the main limitation of CBC in its applications. The CBCs were manufactured by using cement, jute stick particle, EPS and jute fiber by cold pressing having the pressure of 5 MPa and pressing time of 24 h. CBCs were also manufactured by replacing the jute stick particles with EPS beads, the processing conditions remaining the same. There were at least 5 replications for each type of board. Waste jute fibers were added for improving the degenerated mechanical properties of CBC caused by the addition of EPS beads. Important physical properties, i.e., density, water absorption (WA) and thickness swelling (TS) and mechanical properties, i.e., modulus of elasticity (MOE) and modulus of rupture (MOR) of the manufactured CBCs were tested following the Malaysian Standards. Higher percentage of EPS beads significantly reduced the density of CBCs and the lowest density (0.91 +/- 0.02 g/cm(3)) was found when the EPS beads replaced 30% jute stick particles. As expected, mechanical properties decreased with the gradual replacement of jute stick particles by EPS beads. However, the degraded mechanical properties significantly increased when waste jute fibers were added in the CBCs. Addition of EPS beads in CBCs reduced the density, which might increase the potentiality for the utilization of cement-bonded composites for various applications.
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| 4. |
- Das, Atanu Kumar, et al.
(författare)
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Natural Fiber-based Nanocomposites as Corrosion Inhibitors
- 2022
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Ingår i: Anticorrosive Nanomaterials. - Cambridge : Royal Society of Chemistry (RSC). ; :56, s. 191-206
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Corrosion constitutes one of the troublesome issues in different industries, i.e., automotive, marine, construction, oil and gas. Protection from corrosion aims at reducing maintenance costs with higher production for the industry. Due to high toxicity, chromate-based coatings remain an environmental concern. This has necessitated the development of an organic-based coating with higher anti-corrosive performance. The adhesion capability of coating on metal surfaces can be improved through the incorporation of nanocomposites, which in turn can protect the metal from corrosion. Owing to their novel mechanical and electrochemical properties, types of nanocomposites dictate the types of nanostructured filler. The inclusion of cellulose nanocrystal (CNC) in epoxy-Zn rich coating shows better anti-corrosive performance for mild steel. In addition, silver nanoparticles and chitosan-based nanocomposite coating can protect mild steel from corrosion. However, the performance of the nanocomposite coating depends on the types of nanoparticles and additives, the concentration of the dispersed particles and mixing processes. In this chapter, the use of natural fiber-based nanocomposites in corrosion protection, and their synthesis and performance have been discussed. Alongside this, the potential of natural fiber-based nanocomposites for corrosion protection has been pointed out.
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| 5. |
- Das, Atanu Kumar, et al.
(författare)
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Review on tannins : Extraction processes, applications and possibilities
- 2020
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Ingår i: South African Journal of Botany. - : Elsevier BV. - 0254-6299 .- 1727-9321. ; 135, s. 58-70
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Tidskriftsartikel (refereegranskat)abstract
- Tannins are found in most of the species throughout the plant kingdom, where their functions are to protect the plant against predation and might help in regulating the plant growth. There are two major groups of tannins, i.e., hydrolyzable and condensed tannins. The tannins are being used as important and effective chemicals for the tanning of animal hides in the leather processing industry since the beginning of the industry. Additionally, the tannins have been using as mineral absorption and protein precipitation purposes since 1960s. These are also used for iron gall ink production, adhesive production in wood-based industry, anti-corrosive chemical production, uranium recovering chemical from seawater, and removal of mercury and methylmercury from solution. Presently, tannins are considering as bioactive compound in nutrition science. It has also been considered for advanced applications, i.e., 3D printing and biomedical devices. The application of tannins as medicine is another new dimension in medical science. This paper outlines the general information about tannins followed by their extraction process. The utilization of tannins has also been presented in a broader scale. Depending on all these information, the article also describes the impending utilization of tannins for ensuring high-sustainability and better environmental performance.
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| 6. |
- Islam, Md. Nazrul, et al.
(författare)
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Bio-based composites from bagasse using carbohydrate enriched cross-bonding mechanism : A formaldehyde-free approach
- 2024
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Ingår i: Carbohydrate Polymer Technologies and Applications. - : Elsevier BV. - 2666-8939. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- In this study, cross-bonded self-binding and bone glue-bonded particleboards were manufactured from sugarcane (Saccharum officinarum L.) bagasse with different pre-treatments of particles. Six types of panels were manufactured from bagasse particles with and without bone glue. The physical, mechanical, and thermal properties of the panels were examined according to the standards. Fourier Transform Infrared (FTIR) spectroscopy and thermogravimetric analysis (TG) were performed to investigate the changes in the chemical bonds and thermal stability of the fabricated composites, respectively. It was found that cross-bonded bagasse self-binding (TC) and bone glue-bonded (T3) panels fabricated from non-boiled bagasse particles showed higher physical and mechanical properties compared to the other types of panels. Non-boiled bagasse particles with bone glue panels showed the highest mechanical properties, i.e., modulus of rupture (MOR = 26.22 MPa), modulus of elasticity (MOE = 4302 MPa), tensile strength = 8.35 MPa, and hardness = 1.72 MPa. TC and T3 panels also showed higher thermal stability compared to the other types of panels. A new peak at 3331-3334 cm-1 for the N-H stretching vibration in the FTIR analysis represents the presence of bone glue in the cross-bonded particleboards. Thus, this research advances the production of formaldehyde-free bagasse particleboard, introducing the cross-bonding technique and sustainable bone glue.
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| 7. |
- Islam, Md Nazrul, et al.
(författare)
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Preparation and Evaluation of Rice Bran-Modified Urea Formaldehyde as Environmental Friendly Wood Adhesive
- 2021
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Ingår i: Global Challenges. - : Wiley. - 2056-6646. ; 5:6
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Tidskriftsartikel (refereegranskat)abstract
- In this study, defatted rice bran (RB) is used to prepare an environmentally friendly adhesive through chemical modifications. The RB is mixed with distilled water with ratios of 1:5 and 1:4 to prepare Type A and Type B adhesives, respectively having pH of 6, 8 and 10. Type A adhesive is prepared by treating RB with 1% potassium permanganate and 4% poly(vinyl alcohol), whereas Type B is formulated by adding 17.3% formaldehyde and 5.7% urea to RB. Viscosity, gel time, solid content, shear strength, Fourier transform infrared (FTIR) spectroscopy is carried out, and glass transition temperature (T-g), and activation energy (E-a) are determined to evaluate the performance of the adhesives. E-a data reveal that adhesives prepared at mild alkaline (pH 8) form long-chain polymers. Gel time is higher in the fabricated adhesives than that of the commercial urea formaldehyde (UF). FTIR data suggest that functional groups of the raw RB are chemically modified, which enhances the bondability of the adhesives. Shear strength data indicates that bonding strength increases with increasing pH. Similar results are also observed for physical and mechanical properties of fabricated particleboards with the adhesives. The results demonstrate that RB-based adhesives can be used as a potential alternative to currently used UF-based resin.
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| 8. |
- Islam, Md Nazrul, et al.
(författare)
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Water hyacinth (Eichhornia crassipes (Mart.) Solms.) as an alternative raw material for the production of bio-compost and handmade paper
- 2021
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Ingår i: Journal of Environmental Management. - : Elsevier BV. - 0301-4797 .- 1095-8630. ; 294
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Tidskriftsartikel (refereegranskat)abstract
- Water hyacinth (WH) is considered as the worst aquatic weed in the world because of its rapid growth and fast spread into new areas of fresh water bodies. We investigated the potentiality of using WH as a raw material for production of handmade paper and compost in Bangladesh. Potash pulping was done using potassium hydroxide (KOH) at different alkali concentrations (8–12%) with a liquor to solid ratio of 7:1 at 145 °C for 2 h. The pulp was bleached using hydrogen peroxide (H2O2), and pulp properties (brightness, tear index and tensile index) of bleached and unbleached pulps were analyzed following the respective TAPPI standards. The produced black liquor was mixed with WH along with kitchen bio-wastes to produce compost. The properties of the compost were tested following the published protocols, i.e., wet digestion, Kjeldahl, vanadomolybdophosphoric acid, and Flame Spectrophotometry methods. Brightness, tensile index and tear index of bleached hand sheets were found to be 37.2%, 49.2 N m/g and 6.79 m.Nm2/g, respectively suggesting significant contribution of bleaching on WH paper quality. Addition of black liquor significantly increased the nitrogen and potassium content of bio-waste compost. Thus, WH can be used as a raw material for making handmade paper while the process by-product can be supplemented to improve the nutritional quality of compost. Such cottage-industry fabrication of WH green products could be developed to control the infestation of WH in water bodies, and this technology may provide for new possible sustainable livelihood option.
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| 9. |
- Anik, Asibul Islam, et al.
(författare)
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Urban-rural differences in the associated factors of severe under-5 child undernutrition based on the composite index of severe anthropometric failure (CISAF) in Bangladesh
- 2021
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Ingår i: BMC Public Health. - : BMC. - 1471-2458. ; 21:1
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Tidskriftsartikel (refereegranskat)abstract
- Introduction Severe undernutrition among under-5 children is usually assessed using single or conventional indicators (i.e., severe stunting, severe wasting, and/or severe underweight). But these conventional indicators partly overlap, thus not providing a comprehensive estimate of the proportion of malnourished children in the population. Incorporating all these conventional nutritional indicators, the Composite Index of Severe Anthropometric Failure (CSIAF) provides six different undernutrition measurements and estimates the overall burden of severe undernutrition with a more comprehensive view. This study applied the CISAF indicators to investigate the prevalence of severe under-5 child undernutrition in Bangladesh and its associated socioeconomic factors in the rural-urban context. Methods This study extracted the children dataset from the 2017-18 Bangladesh Demographic Health Survey (BDHS), and the data of 7661 children aged under-5 were used for further analyses. CISAF was used to define severe undernutrition by aggregating conventional nutritional indicators. Bivariate analysis was applied to examine the proportional differences of variables between non-severe undernutrition and severe undernutrition group. The potential associated socioeconomic factors for severe undernutrition were identified using the adjusted model of logistic regression analysis. Results The overall prevalence of severe undernutrition measured by CISAF among the children under-5 was 11.0% in Bangladesh (rural 11.5% vs urban 9.6%). The significant associated socioeconomic factors of severe undernutrition in rural areas were children born with small birth weight (AOR: 2.84), children from poorest households (AOR: 2.44), and children aged < 36 months, and children of uneducated mothers (AOR: 2.15). Similarly, in urban areas, factors like- children with small birth weight (AOR: 3.99), children of uneducated parents (AOR: 2.34), poorest households (APR: 2.40), underweight mothers (AOR: 1.58), mothers without postnatal care (AOR: 2.13), and childrens birth order >= 4 (AOR: 1.75), showed positive and significant association with severe under-5 undernutrition. Conclusion Severe undernutrition among the under-5 children dominates in Bangladesh, especially in rural areas and the poorest urban families. More research should be conducted using such composite indices (like- CISAF) to depict the comprehensive scenario of severe undernutrition among the under-5 children and to address multi-sectoral intervening programs for eradicating severe child undernutrition.
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| 10. |
- Das, Atanu Kumar, et al.
(författare)
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COVID-19 and municipal solid waste (MSW) management : a review
- 2021
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Ingår i: Environmental Science and Pollution Research. - : Springer. - 0944-1344 .- 1614-7499. ; 28:23, s. 28993-29008
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Forskningsöversikt (refereegranskat)abstract
- Municipal solid waste (MSW) represents an inevitable by-product of human activity and a major crisis for communities across the globe. In recent times, the recycling of MSW has drawn attention as the process can add value through resources from the recovered waste materials and facilitates the process of circular economy. However, during the unprecedented coronavirus (COVID-19) outbreak, the risk of infection with the highly contagious virus has proven detrimental to the continuation of MSW as a valuable resource. The volume of waste, especially household waste, is higher; face masks, PPE (personal protective equipment), and hazardous materials such as batteries and empty chlorine bottles are examples of extra waste that have arisen during the pandemic. Various countries have set up initiatives for MSW management, including safety measurements for employees in the MSW management sector. The use of disinfectant prior to sorting waste, as well as storing waste for 9 days, may help to inactivate the COVID-19 virus, ensuring an appropriate safety level for MSW management. This work aimed at studying different MSW management strategies, specific challenges, and possible solutions for better understanding for those involved in waste management, in addition to providing a possible management strategy during and post-COVID-19 pandemic.
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