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Modification of cotton fabrics by using thiocabonate redox system with peroxydiphosphate (PP), ferouse ammonium sulphate(FAS) and methacrylic acid (MAA) under various conditions tell the optimum condition. The efficiency of the cross linking reaction is monitored via evaluation mechanical tests on tensile properties (i.e. tensile strength (T.S.) and elongation at break (EAB), wrinkle crease recovery angle (CRA), abrasion resistance and finally, created air and water permeability. The results indicate increases in tensile properties, CRA and abrasion resistance with decrease in both air and water permeability. They are compared with the original fabric.

In-situ aluminum metal matrix composites (AMMC) have taken over the use of ex-situ AMMC due to the generation of finer and thermodynamically stable intermetallic compounds. However, conventional processing routes pose inevitable defects like porosity and agglomeration of particles. This paper aims to study current state of progress in in-situ AMMC fabricated by Friction Stir Processing.

Friction stir processing (FSP) has successfully evolved to be a favorable in-situ composite manufacturing technique. The dynamics of the process account for a higher plastic strain of 35 and a strain rate of 75 per second. These processing conditions are responsible for grain evolution from rolled grain → dislocation walls and dislocation tangles → subgrains → dislocation multiplication → new grains. Working of matrix and reinforcement under ultra-high strain rate and shorter exposure time to high temperatures produce ultra-fine grains. Do the grain evolution modes include subgrain boundaries → subgrain boundaries and high angle grain boundaries → high angle grain boundaries.

Further, the increased strain and strain rate can shave and disrupt the oxide layer on the surface of particles and enhance wettability between the constituents. The frictional heat generated by tool and workpiece interaction is sufficient enough to raise the temperature to facilitate the exothermic reaction between the constituents. The heat released during the exothermic reaction can even raise the temperature and accelerate the reaction kinetics. In addition, heat release may cause local melting of the matrix material which helps to form strong interfacial bonds.

This article critically reviews the state of the art in the fabrication of in-situ AMMC through FSP. Further, FSP as a primary process and post-processing technique in the synthesis of in-situ AMMC are also dealt with.

Polyacrylamid-guar gum composite has been prepared via graft copolymerization of acrylamide onto guar gum using the KBrO₃/ thiourea redox system. The amide groups (40%) in the composite are converted to reactive groups through methylolation with formaldehyde, with a view to obtaining reactive composite. The composite and the reactive composite were used as pastes for printing cotton fabrics with pigment dyes. The prints were assessed for color strength (K/S) and overall fastness properties.

Printing was carried out under different conditions, including the amount of composite used as a substitute for kerosene emulsion, the amount of binder incorporated into the printing paste and the types of catalysts. The printed samples were evaluated by monitoring the color strength (K/S) and fastness properties such as washing, rubbing and light. Based on the results obtained, it is concluded that a partial substitution ratio of 20/75 (composite/kerosene emulsion), 8gm binder/100gm printing paste and 1% of catalyst (NH4Cl, DAP, Citric acid or [NH4]2SO4) represent the proper formulation for gaining good dye fixation and excellent fastness properties. The results indicate that the reactive composite prepared is the most suitable thickener for printing cellulosic fabrics with pigment dyes.

This study aims to investigate the corrosion behavior of cold-rolled Fe₃₅Ni₂₀C_r12Mn_(28-x)Al_x high-entropy alloys (HEAs) using the potentiodynamic polarization technique in 1 M H₂SO₄ acid. Additionally, the influence of molybdenum (Mo) additions as inhibitors and the effect of variations in cold rolling reduction ratios and Al content on corrosion behavior are examined.

Two cold rolling reduction ratios, namely, 50% (R50) and 90% (R90), were examined for the cold-rolled Fe₃₅Ni₂₀Cr₁₂Mn₂₈Al₅ (Al₅) and Fe₃₅Ni₂₀Cr₁₂Mn₂₃Al₁₀ (Al₁₀) HEAs. Mo inhibitor additions were introduced at varying concentrations of 0.3, 0.6 and 0.9 Wt.%. The potentiodynamic polarization technique was used to evaluate the corrosion rates (CRs) under different experimental conditions.

The results indicate that the addition of 0.3 Wt.% Mo in 1 M H₂SO₄ yielded the lowest CR for both R50 and R90, irrespective of the Al content in the HEAs. However, the highest CR was observed at 0.6 Wt.% Mo addition. Furthermore, increasing the concentration of Al resulted in a corresponding rise in the CR. Comparatively, the CR decreased significantly when the cold rolling reduction ratio increased from R50 to R90.

This research provides valuable insights into the intricate relationship between Mo inhibitors, cold rolling reduction ratio, Al content and the resulting corrosion behavior of Fe₃₅Ni₂₀Cr₁₂Mn_(28-x)Al_x HEAs. The comprehensive analysis of corroded HEAs, including surface morphology, compositions and elemental distribution mapping, contributes to the understanding of the corrosion mechanisms and offers potential strategies for enhancing the corrosion behavior of HEAs.

Friction stir processing (FSP) as a solid-state process has the potential for the production of effective aluminum matrix composites (AMCs). In this investigation, various ceramic particles including B₄C, TiC, SiC, Al₂O₃ and WC were incorporated as the dispersed phase within AA6082 aluminum alloy by FSP. The wear rate of the composite is then investigated experimentally by making use of a design of experiments technique where wear rate is evaluated as the output parameter. The input parameters considered include tool rotational speed, traverse speed, groove width and ceramic particle type. An artificial neural network (ANN) simulation was then used to describe the wear rate of the surface composites. The weights of the network were adjusted to minimize the mean squared error using a feed forward back propagation technique. The effect of the individual input parameters on wear rate was then inferred from the ANN models. Trends are presented and related to the associated microstructures observed. The TiC infused AMC displayed the lowest wear rate whereas the Al₂O₃ infused AMC displayed the highest, within the scope of the current investigation. The paper aims to discuss these issues.

The paper used ANN for the research study.

The finding of this paper is that the wear rate of AA6063 aluminum surface composites is influenced remarkably by FSP parameters.

Original work of authors.

Friction stir processing (FSP) is overviewed with the process variables, along with the thermal aspect of different metals.

With its inbuilt advantages, FSP is used to reduce the failure in the structural integrity of the body panels of automobiles, airplanes and lashing rails. FSP has excellent process ability and surface treatability with good corrosion resistance and high strength at elevated temperatures. Process parameters such as rotation speed of the tool, traverse speed, tool tilt angle, groove design, volume fraction and increase in number of tool passes should be considered for generating a processed and defect-free surface of the workpiece.

FSP process is used for modifying the surface by reinforcement of composites to improve the mechanical properties and results in the ultrafine grain refinement of microstructure. FSP uses the frictional heat and mechanical deformation for achieving the maximum performance using the low-cost tool; the production time is also very less.

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This study explores the relationships among sustainability implementation barriers (resource, managerial and regulatory barriers), sustainability practices (sustainable construction materials, sustainable construction design, modern construction methods and environmental provisions and reporting) and sustainability performance (environmental, economic and social) in hill road construction (HRC).

Primary data were collected from the 313 HRC practitioners with the help of a questionnaire, and research hypotheses were tested employing structural equation modeling.

The findings reveal a mixed effect of sustainability implementation barriers. Resource (managerial) barriers are negatively related to all practices except environmental provisions and reporting (sustainable construction materials), while regulatory barriers only negatively impact modern construction methods. On the other hand, all sustainability practices positively impact environmental performance, whereas economic (social) performance is positively influenced by all practices, except environmental provisions and reporting (modern construction methods), and positively affects economic performance.

In order to transform HRC toward sustainability, the barriers to sustainability implementation, sustainability practices and performance need to be understood by practitioners; however, the relationships have not previously been empirically assessed in extant literature. Besides, past research appears to be predominantly focused on the environmental aspect, thereby neglecting economic and social aspects. This study is a modest attempt to bridge these research gaps.

This study aims to describe the conversion of rice straw (RS) as an agricultural plant waste to high-performance cationic flocculant for kaolin clay suspension in wastewater treatment as an alternative to synthetic ones.

This was done by grafting rice straw after pretreatment with acrylamide (Aam) using microwave irradiation technique without using an initiator in an open vessel container for wastewater treatment. Radiation time, monomer and rice straw pulp concentration as well as microwave power were scrutinized to examine their impact on maximizing the graft yield %. Application of the resultant copolymers as flocculants for kaolin clay suspension was willful by studying the foremost influences inducing the flocculation process, for instance, flocculent dose, pH, stirring speed and extent of grafting.

It is seen from the obtained results that both FTIR, SEM, X-Ray diffraction, Thermo gravimetric analysis and Zeta potential confirmed the formation of the cationic amide group onto the graft copolymer chain in comparison with the ungrafted one; the microwave initiation method proved to be a very efficient tool concerning maximizing the graft yield % with no harsh chemicals used for initiating grafting; the flocculation efficiency of the prepared copolymers augmented by increasing the flocculant dose, pH and stirring speed to a maximum value signified at 2.0 g, 6.0 and 75 r/min, respectively, then decreased thereafter while increased by increasing the extent of grafting within the range studied; the flocculant reserved high flocculation efficiency even after five cycles of flocculation/regeneration; preliminary bridging mechanism demonstrating the attraction between the kaolin anionic suspended particles and cationic poly (Aam)-rice straw graft copolymer has been predicted.

The novelty addressed here is undertaken by preparing a very efficient cationic flocculant using rice straw waste with different degrees of grafting for the treatment of wastewater using this kind of microwave irradiation approach as an eco-friendly tool. As far as the authors are aware, no thorough investigation has been done in the literature until now dealing with the above-mentioned preparation process.

Environmental risks (ERs) are critical to any highway construction project (HCP). One of the main contracting parties responsible for ERs is the contractor. Hence, it has been crucial to look into ways to control ERs in HCPs from the contractor’s perspective. This study aims to investigate how ERs can be managed in HCP in Sri Lanka.

A quantitative research approach with three rounds of Delphi was used. Statistical techniques were used to analyse and validate the ERs, the parties to whom the risks were to be allocated, and risk management measures identified from the empirical data collection.

The study reveals the 11 most significant ERs for HCP. Further, the most significant ERs in HCP were mainly found to be the responsibility of contractors in Sri Lanka. Twenty-four most appropriate risk response measures were determined; 13 were found to be common measures that could be used to manage two or more risks, while the remaining 11 were unique to specific risks.

Overall, this research determines the most significant ERs in HCP, the best risk allocation among the parties and appropriate risk-handling strategies and measures for each significant ERs. Additionally, the study addresses the demand for ERs management in HCP.

The purpose of this study is to investigate the authors' previously prepared and fully characterized poly (methacrylamide)-chitosan nanoparticles (CNPs) graft copolymer having 50.2% graft yield with respect to flocculation efficiency for ferric laurate aqueous dispersions. This was done to compare the ability of the latter cheap, biodegradable and ecofriendly hybrid natural-synthetic polymeric substrate as a flocculant in comparison with higher cost, nonbiodegradable and harmful polyacrylamide as a well-known synthetic flocculant counterpart.

The graft copolymerization process was carried out at 450°Cfor 120 min using (1.0 g) CNPs, methacrylamide (1.5 g), 100 mmol/l potassium chromate and 80 mmol/l mandelic acid. Fourier transform infrared spectroscopy, thermogravimetric analysis, elemental analysis and specific viscosity were used to characterize and analyze the resultant copolymer. The flocculation efficiency was conferred in terms of transmittance % and weight removal %. The main factors influencing the flocculation process, such as flocculent dose, flocculation medium pH, stirring speed, flocculation temperature and grafting extent, were comprehensively discussed.

The flocculation efficiency of the prepared copolymers revealed the following findings: increased by increasing the flocculant dose, pH, temperature and stirring speed to a maximum values denoted at 30 ppm, 6.0, 30°C and 50 r/min, respectively, then decreased thereafter; increased by increasing the extent of grafting within the range studied; showed a comparable flocculation efficiency in comparison with polyacrylamide as a synthetic polymeric flocculent; and, finally, a preliminary bridging mechanism representing the attraction between the anionic suspended particles ferric laurate and cationic poly (MAam)-CNPs graft copolymer has been projected.

The advancement addressed here is undertaken with using the authors’ poly (MAam)-CNPs graft copolymers having different extent of grafting (a point which is not cited in the literature especially for the authors’ prepared copolymer) as a hybrid natural-synthetic polymeric substrate as a flocculant for ferric laurate aqueous dispersions in comparison with the high cost and nondegradable polyacrylamide synthetic flocculant.