Biobased Packaging Materials from Cellulose Nanofibrils Produced from Virgin Wood Pulp or Recycled Cardboard Pulp

Self-standing cellulose nanofibril (CNF) films are regarded as one of the promising alternatives to current petroleum-based packaging materials. The mechanical and barrier properties of CNF films are not yet up to the mark for certain applications, especially at high relative humidity. Those properties of CNF films can be tuned by the drying methods of films, degree of fibrillation, cross-linking, and controlled shrinkage. A comprehensive understanding of these processes and their influence on the structure and properties of CNF films have been presented in this thesis. First, we prepared CNF films from CNF suspensions with two different degrees of fibrillation- standard CNF (90% fine) and high-fine CNF (97% fine) by casting and filtration. These were dried in four different ways: air, oven, heat gun, and hot press drying. The CNF films made by hot press drying showed the highest tensile strength (98.82 MPa) and lowest water vapor permeability (13.91 g.mm/m2.day.kPa). A facile thermal compression on the dried films further improved the strength by 13.1%, reduced the water vapor permeability by 22% and oxygen permeability by 43%. With the hot-press drying and thermal compression technique, we created self-standing films of lignin-containing cellulose nanofibrils (LCNFs) derived from recycled old corrugated cardboard (OCC) pulp that cost considerably less than bleached softwood Kraft (BSK) pulp yet only use half as much energy for refining to obtain the same fines content. The low zeta potential (-3.83 mV) of OCC-derived LCNFs (OCC-LCNFs) resulted in aggregation of the fibrils in aqueous suspension, leading to considerable unpredictability in oxygen permeability values (coefficient of variation 36%). The addition of 3 wt.% (based on the dry weight of LCNF) carboxymethyl cellulose (CMC) lowered the coefficient of variation with an average oxygen permeability of 1478 (cc.μm/m2.atm.day) at 80% relative humidity. We demonstrated that ionic crosslinking with Al3+ or covalent crosslinking with polyamide epichlorohydrin could decrease the oxygen permeability by 30% at 23 °C and 80% relative humidity, while also significantly enhancing the tensile strength and modulus. Finally, the shrinkage in CNF films upon drying has been studied. The shrinkage was classified into the radial and vertical directions. Two types of CNF films were prepared: one in a restrained condition that did not allow shrinkage in the radial direction but enabled it in the vertical direction and another one with 11% radial shrinkage but limited vertical shrinkage. The radial shrinkage led to a more porous and less dense structure than the vertical shrinkage, which brought about poorer oxygen and moisture barrier performance than its counterpart. Interestingly, radial shrinkage resulted in 140% and 90% higher strain at break and toughness in films with a significant sacrifice in strength and modulus. The structural changes caused by the radial and vertical shrinkage were revealed by scanning electron and optical microscope images

Factors affecting the construction quality in Bangladesh

Purpose: Quality is a sensitive and high-priority issue in the global construction including in Bangladesh. This research is intended to provide necessary information to stakeholders and authorities for better management of the construction quality in Bangladesh. Therefore, this study seeks to find and prioritize the factors affecting the construction quality in Bangladesh. Design/methodology/approach: In total 65 factors were extracted and categorized from the literature and expert panel discussion. Subsequently, these factors were designed in a questionnaire under 13 major groups for a survey where 176 construction professionals participated and returned their completed survey form. Collected data were tested by the Cronbach Alpha to check the reliability before proceeding to the Relative Importance Index (RII) analysis for determining the relative ranks of identified factors. Findings: Statistical analysis of survey data represents that the most significant factors are: lack of management commitment, lack of technical skill and experience of the consultant, delays in progress investigation, political interference and contractor's desire for unrealistic profit. The most crucial major groups of factors influencing the construction quality are management, material, consultant, cost and time and contract-related major groups. Originality/value: It will contribute to the body of knowledge, as it points out the impact of factors affecting quality in Bangladeshi construction. Authorities and stakeholders can be helped by the overview of the high and low ranks factors, understanding the diverse characteristics of factors and making more aware the industry about the quality issues which need to be a top concern to solve. Other developing countries that share the same socio-economic context as Bangladesh can be benefit from the results of this study to control quality issues in construction

Exploiting Unique Structural and Functional Properties of Malarial Glycolytic Enzymes for Antimalarial Drug Development

Metabolic enzymes have been known to carry out a variety of functions besides their normal housekeeping roles known as “moonlighting functions.” These functionalities arise from structural changes induced by posttranslational modifications and/or binding of interacting proteins. Glycolysis is the sole source of energy generation for malaria parasitePlasmodium falciparum, hence a potential pathway for therapeutic intervention. Crystal structures of severalP. falciparumglycolytic enzymes have been solved, revealing that they exhibit unique structural differences from the respective host enzymes, which could be exploited for their selective targeting. In addition, these enzymes carry out many parasite-specific functions, which could be of potential interest to control parasite development and transmission. This review focuses on the moonlighting functions ofP. falciparumglycolytic enzymes and unique structural differences and functional features of the parasite enzymes, which could be exploited for therapeutic and transmission blocking interventions against malaria.</jats:p

Effect of waste plastic strip on the shear strength and permeability characteristics of black cotton soil

The use of plastic bottles is on the rise, causing lots of new environmental issues. It is now extremely difficult to dispose of plastic waste without damaging the ecosystem. As black cotton soil for embankments and foundations has limited use due to its swelling and hrinkage property as well as its bearing capacity, utilizing plastic bottles to enhance soil strength parameters can be a cost-effective solution. This study investigates the possibility of improving the characteristics of soil by using leftover strips of plastic that have been cut from plastic water bottles. The black cotton soil is amended with about 0%, 5%, 6%, 7%, 8%, 9%, and 10% plastic strips. On the black cotton soil that had been strengthened with plastic waste, direct shear and falling head water permeability tests were executed as part of the experiment. The test results under the circumstances are provided to evaluate the change in soil strength characteristics. In the aspects of shear strength, friction angle, and cohesiveness, it was determined that soil samples containing 5-9% plastic strips performed better than soil samples containing no plastic strips. Therefore, shear strength can assist in resisting deformation under stress caused by the weight of an embankment. Moreover, the friction angle determines the embankment slope stability and the material’s ability to withstand deformation caused by water flow, freeze-thaw cycles, or other environmental factors. On the other hand, the inclusion of the plastic strip enhanced the permeability of black cotton-reinforced soil. This innovative approach may be utilized to successfully address socioeconomic issues, such as recycling waste materials

Why banks should consider ESG risk factors in bank lending?

Why banks should be concerned about incorporating environmental, social and governance (ESG) criteria in the lending process? What is the motivation? This study aims to find the motives for considering environmental, social and governance (ESG) criteria in bank lending process. A primary survey has been conducted to know the current status and motivation for incorporating ESG factors in investment decisions. Sample comprised 30 private commercial banks (PCBs) operating in Bangladesh. Data collected were analyzed with graphs, descriptive statistics, and regression analysis. Findings of the study indicate that banks are mostly considering basic environmental, social and governance factors set by regulators qualitatively. They are lagging behind in considering the advanced ESG criteria needed for sustainable and efficient credit risk management. Based on motivation for incorporating ESG factors, it was found that banks pioneering in incorporating ESG factors in lending decisions are compensated through better financial performance. Findings of the study are expected to encourage practitioners and policy-makers to take more pragmatic steps to incorporate ESG risk factors quantitatively in lending decision-making process

Undrained shear strength of soft clay reinforced with encapsulated stone dust columns

Purpose: The stone dust column was used to strengthen the sample and had a significant effect on improving the shear strength of the kaolin clay. The application of stone columns, which can improve the overall carrying capacity of soft clay as well as lessen the settlement of buildings built on it, is among the most widespread ground improvement techniques throughout the globe. The performance of foundation beds is enhanced by their stiffness values and higher strength, which could withstand more of the load applied. Stone dust is a wonderful source containing micronutrients for soil, particularly those derived from basalt, volcanic rock, granite and other related rocks. The aim of this paper is to evaluate the properties of soft clay reinforced with encapsulated stone dust columns to remediate problematic soil and obtain a more affordable and environmentally friendly way than using other materials. Design/methodology/approach: In this study, the treated kaolin sample's shear strength was measured using the unconfined compression test (UCT). 28 batches of soil samples total, 12 batches of single stone dust columns measuring 10 mm in diameter and 12 batches of single stone dust columns measuring 16 mm in diameter. Four batches of control samples are also included. At heights of 60 mm, 80 mm and 100 mm, respectively, various stone dust column diameters were assessed. The real soil sample has a diameter of 50 mm and a height of 100 mm. Findings: Test results show when kaolin is implanted with a single encased stone dust column that has an area replacement ratio of 10.24% and penetration ratios of 0.6, 0.8 and 1.0, the shear strength increase is 51.75%, 74.5% and 49.20%. The equivalent shear strength increases are 48.50%, 68.50% and 43.50% for soft soil treated with a 12.00% area replacement ratio and 0.6, 0.8 and 1.0 penetration ratios. Originality/value: This study shows a comparison of how sample types affect shear strength. Also, this article provides argumentation behind the variation of soil strength obtained from different test types and gives recommendations for appropriate test methods for soft soil

Shear Strength of Soft Clay Reinforced with Single Encased Stone Dust Columns

The application of stone columns, which can improve the overall carrying capacity of soft clay as well as lessen the settlement of buildings built on it, is among the most widespread ground improvement techniques throughout the globe. The performance of foundation beds is enhanced by their stiffness values and higher strength, which could withstand more of the load applied. Therefore, the cost of construction can be decreased by using recycled stone dust as granular material in vertical granular columns, which can then be strengthened with a singular stone dust column that is covered in geotextile for enhancing soft clay’s overall strength. A further unconfined compression test was performed on remolded specimens of soft kaolin clay measuring 50 mm in diameter and 100 mm in height and mounted with a single encapsulated stone dust column measuring 10 mm and 16 mm in diameter. Test results show that when kaolin is implanted with a single encased stone dust column that has an area replacement ratio of 10.24% and penetration ratios of 0.6, 0.8, and 1.0, the shear strength increases are 51.75%, 74.5%, and 49.20%, respectively. The equivalent shear strength increases are 48.50%, 68.50%, and 43.50% for soft soil treated with a 12.00% area replacement ratio and 0.6, 0.8, and 1.0 penetration ratios, respectively. The diameter and height of the column had an impact on the shear strength parameters, which significantly improved for both encased and non-encased stone dust columns

Effect Of Waste Plastic Strip On The Shear Strength And Permeability Characteristics Of Black Cotton Soil

The use of plastic bottles is on the rise, causing lots of new environmental issues. It is now extremely difficult to dispose of plastic waste without damaging the ecosystem. As black cotton soil for embankments and foundations has limited use due to its swelling and shrinkage property as well as its bearing capacity, utilizing plastic bottles to enhance soil strength parameters can be a cost-effective solution. This study investigates the possibility of improving the characteristics of soil by using leftover strips of plastic that have been cut from plastic water bottles. The black cotton soil is amended with about 0%, 5%, 6%, 7%, 8%, 9%, and 10% plastic strips. On the black cotton soil that had been strengthened with plastic waste, direct shear and falling head water permeability tests were executed as part of the experiment. The test results under the circumstances are provided to evaluate the change in soil strength characteristics. In the aspects of shear strength, friction angle, and cohesiveness, it was determined that soil samples containing 5-9% plastic strips performed better than soil samples containing no plastic strips. Therefore, shear strength can assist in resisting deformation under stress caused by the weight of an embankment. Moreover, the friction angle determines the embankment slope stability and the material’s ability to withstand deformation caused by water flow, freeze-thaw cycles, or other environmental factors... On the other hand, the inclusion of the plastic strip enhanced the permeability of black cotton-reinforced soil. This innovative approach may be utilized to successfully address socioeconomic issues, such as recycling waste materials

Laboratory tests based strength evaluation of alluvial soil: A case study

This article represents an analysis of alluvial soil behaviour using laboratory tests where samples being collected from different parts of Khulna, Bangladesh. Bangladesh is a riverine country and 80% of soil in Bangladesh is alluvial. Especially, the Khulna region stands on the Gangetic alluvial soil track that poses a challenge to the foundation engineers. Determination of shear strength parameters comprising of cohesion (c) and internal friction angle (Φ) plays a vital role in soil mechanics. These parameters are often used in quantification of soil strength and thereby play an important role in designing the foundation. In this study, direct shear tests and triaxial tests have been conducted to investigate the shear strength parameters of alluvial soil. Four soil samples were collected from four distinct locations (Rupsha-22˚47’58.01” N, 89˚34’45.82” E; Boyra-22˚50’30.33” N, 89˚32’.63” E; Sonadanga-22˚49’7”.00” N, 89˚32’47.07” E; Fulbarigate 22˚53’56.90” N89˚32’47.07” E) of Khulna. Test results show a significant change in the value of the internal friction angle of the soil samples while its shear strength parameter is measured by a direct shear test compared to triaxial testing on the undisturbed specimen. Whereas, the discrepancy of results is less significant for samples in remoulded conditions. The disparity of shear strength results obtained by different test methods has been explained by analyzing soil sample structure at different states

Municipal solid waste management in Khulna City Corporation Bangladesh

Bangladesh has the eighth-highest population in the world and the sixth-highest population density. In Bangladesh, a 3.09% urban population growth rate is anticipated between 2016 and 2020. Waste management is becoming a bigger issue as a result of the exponential population growth rate, especially in the bigger cities. The amount of trash produced in Bangladesh's cities now is about 25000 tons per day or 170 kg per person each year (as of 2021). Only around 37% of garbage is collected in big cities. However, once this garbage is collected, handling it in a way that is acceptable to society and the environment is difficult. Solid waste management accounts for 15– 25% of the budgets of municipal entities. Incorporating the informal garbage industry in rising cities presents a barrier for effective data collection and analytical management. This essay intends to shed light on Khulna, a significant Bangladeshi city, and its municipal solid waste management system. This study focuses on the municipal solid waste of Khulna City Corporation (KCC) and examines the creation and management status of several types of garbage. It also demonstrates the damaging effects of inadequate garbage management. Finally, it makes some appropriate and costeffective recommendations for trash management