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The purpose is to focus on improving the water or metal ion uptake of modified cellulose.

Grafting copolymerisation of hydrophilic monomers such as acrylamide or hydrophobic monomers as acrylonitrile onto cotton linters was performed.

The grafting process has two advantages. The first is to replace the hydroxyl group of C₆ of the glucose units in the substrate by carboxyl group that attract the metal ions from the solution. The second is to decrease the number of the hydroxyl groups in the cotton linters so that the hydrogen bonding between the cotton linters strands decreases and so the crystallinity index of substrate decreases by introduction of this hydrophilic group so it becomes more chemically active.

Partial substitution of hydroxyl groups of cellulose by more hydrophilic ones via grafting reaction followed by alkaline hydrolysis was performed. The effects of different conditions such as temperature, time, initiator concentration, monomer concentration and kind of substrate were studied. The polymerisation per cent, grafting per cent, the grafting efficiency and the nitrogen per cent of the grafted samples were determined. The molecular structures of cotton linters, grafted cotton linters with acrylamide and its hydrolysis product were studied using infrared spectroscopy, which indicates the fixation of the monomers on the cotton linters. Sodium binding capacity and the metal ion uptake of some metal ions by the product were determined.

The water or metal ion uptake of the modified cellulose was improved.

This chapter dives deeper into how the circular economy is important for the tourism industry in the United Arab Emirates (UAE). In a region known for its remarkable growth and innovative endeavors, this chapter meticulously investigates how the principles of the circular economy hold the potential to not only shape the trajectory of sustainable development but also to become a catalyst for heightened economic growth and an embodiment of environmental stewardship within the UAE's dynamic tourism sector. It begins by explaining the multifaceted concept of the circular economy and its compelling relevance to the diverse realm of tourism. It also emphasizes the role of community involvement in making these principles work. The chapter showcases successful case studies in UAE's tourism sector, from eco-friendly hotels to innovative food services and community-based tourism. Finally, it ends with recommendations for stakeholders to work together for sustainable tourism development. As the chapter draws toward a conclusion, it ends with a collection of recommendations that underscore the essence of collaborative engagement among stakeholders – a driving force that is poised to propel the narrative of sustainable tourism development forward with unwavering resolve and unwavering impact.

The purpose of this paper is to investigate steady state creep behavior of a functionally graded rotating disc under varying thermal gradient (TG).

The steady state creep in a rotating FGM disc with linearly varying thickness has been investigated by using von-Mises yield criterion. The disc under investigation is assumed to be made of FGM containing non-linear distribution of silicon carbide particle (SiC_p) in a matrix of pure aluminum along the radial distance. The creep behavior of the FGM composite disc is described by threshold stress-based law. The stresses and strain rates in the FGM disc have been estimated for different kinds of TG.

The results indicate that when the FGM disc is subjected to a radial TG, with temperature increasing with increasing radius, the radial stress in the disc increases over the entire disc but the tangential and effective stresses increase near the inner radius and decrease toward the outer radius. The imposition of such a radial TG in the FGM disc leads to significant reduction in the radial and tangential strain rates. With the increase in magnitude of TG in the FGM disc, the inhomogeneity in creep stresses increases but the inhomogeneity in strain rates decreases significantly, thereby reducing the chances of distortion in the FGM disc.

The creep strain rates in rotating FGM disc could be significantly reduced when the disc is subjected to a radial TG, with temperature increasing with increasing radius.

The “chiralisation” of Euclidean polygonal tessellations is a novel, recent method which has been used to design new auxetic metamaterials with complex topologies and improved geometric versatility over traditional chiral honeycombs. This paper aims to design and manufacture chiral honeycombs representative of four distinct classes of 2D Euclidean tessellations with hexagonal rotational symmetry using fused-deposition additive manufacturing and experimentally analysed the mechanical properties and failure modes of these metamaterials.

Finite Element simulations were also used to study the high-strain compressive performance of these systems under both periodic boundary conditions and realistic, finite conditions. Experimental uniaxial compressive loading tests were applied to additively manufactured prototypes and digital image correlation was used to measure the Poisson’s ratio and analyse the deformation behaviour of these systems.

The results obtained demonstrate that these systems have the ability to exhibit a wide range of Poisson’s ratios (positive, quasi-zero and negative values) and stiffnesses as well as unusual failure modes characterised by a sequential layer-by-layer collapse of specific, non-adjacent ligaments. These findings provide useful insights on the mechanical properties and deformation behaviours of this new class of metamaterials and indicate that these chiral honeycombs could potentially possess anomalous characteristics which are not commonly found in traditional chiral metamaterials based on regular monohedral tilings.

To the best of the authors’ knowledge, the authors have analysed for the first time the high strain behaviour and failure modes of chiral metamaterials based on Euclidean multi-polygonal tessellations.

The purpose of this paper is to find the impact of various design variables on the composite shaft, and also the effect of newly developed resin (NDR) on the strength of the fibers of the composite shaft.

The Taguchi method is used to optimize the design variables. Also, GRG approach is used to validate the result.

NDR improves the bonding strength of fiber than the epoxy resin. With the grey relational analysis (GRA) method, the initial setting (A1B4C4D1) was having grey relational grade 0.957. It was enhanced by using a new optimum combination (A2B2C4D2) to 0.965. It indicates that there is an enhancement in the grade by 0.829 percent. Thus, using the GRA approach of analysis, design variables have been successfully optimized to achieve improved dynamic properties of hybrid composite shaft.

The findings of this research are helping to optimize the design variables for the composite shaft. Also, the NDR gives the good bonding strength of carbon/glass fibers in dynamic loading condition than the epoxy resin.

The purpose of this paper is to present an optimisation of four-point star-shaped structures produced through additive manufacturing (AM) polylactic acid (PLA). The study also aims to investigate the compression failure mechanism of the structure.

A Taguchi L₉ orthogonal array design of the experiment is adopted in which the input parameters are resolution (0.06, 0.15 and 0.30 mm), print speed (60, 70 and 80 mm/s) and bed temperature (55°C, 60°C, 65°C). The response parameters considered were printing time, material usage, compression yield strength, compression modulus and dimensional stability. Empirical observations during compression tests were used to evaluate the load–response mechanism of the structures.

The printing resolution is the most significant input parameter. Material length is not influenced by the printing speed and bed temperature. The compression stress–strain curve exhibits elastic, plateau and densification regions. All the samples exhibit negative Poisson’s ratio values within the elastic and plateau regions. At the beginning of densification, the Poisson’s ratios change to positive values. The metamaterial printed at a resolution of 0.3 mm, 80 mm/s and 60°C exhibits the best mechanical properties (yield strength and modulus of 2.02 and 58.87 MPa, respectively). The failure of the structure occurs through bending and torsion of the unit cells.

The optimisation study is significant for decision-making during the 3D printing and the empirical failure model shall complement the existing techniques for the mechanical analysis of the metamaterials.

To the best of the authors’ knowledge, for the first time, a new empirical model, based on the uniaxial load response and “static truss concept”, for failure mechanisms of the unit cell is presented.

Bearings and gears are major components in any rotatory machines and, thus, gained interest for condition monitoring. The failure of such critical components may cause an increase in down time and maintenance cost. Condition monitoring using the machine learning approach is a conceivable solution for the problem raised during the operation of the machinery system. The paper aims to discuss these issues.

This paper aims engine gearbox fault diagnosis based on a decision tree and artificial neural network algorithm.

The experimental result (classification accuracy 85.55 percent) validates that the proposed approach is an effective method for engine gearbox fault diagnosis.

This paper attempts to diagnose the faults in engine gearbox based on the machine learning approach with the combination of statistical features of vibration signals, decision tree and multi-layer perceptron neural network techniques.

Auxetics metamaterials show high performance in their specific characteristics, while the absolute stiffness and strength are much weaker due to substantial porosity. This paper aims to propose a novel auxetic honeycomb structure manufactured using selective laser melting and study the enhanced mechanical performance when subjected to in-plane compression loading.

A novel composite structure was designed and fabricated on the basis of an arrowhead auxetic honeycomb and filled with polyurethane foam. The deformation mechanism and mechanical responses of the structure with different structural parameters were investigated experimentally and numerically. With the verified simulation models, the effects of parameters on compression strength and energy absorption characteristics were further discussed through parametric analysis.

A good agreement was achieved between the experimental and simulation results, showing an evidently enhanced compression strength and energy absorption capacity. The interaction between the auxetic honeycomb and foam reveals to exploit a reinforcement effect on the compression performance. The parametric analysis indicates that the composite with smaller included angel and higher foam density exhibits higher plateau stress and better specific energy absorption, while increasing strut thickness is undesirable for high energy absorption efficiency.

The results of this study served to demonstrate an enhanced mechanical performance for the foam filled auxetic honeycomb, which is expected to be exploited with applications in aerospace, automobile, civil engineering and protective devices. The findings of this study can provide numerical and experimental references for the design of structural parameters.

The study explored how supplier evaluation, selection, development and segmentation affect supply chain performance in pharmaceutical organizations. It also determined the moderating influence of top management support on the link between supply chain performance and organizational performance.

The research philosophy of this study was positivism, leading to the adoption of a quantitative research method. Empirical data were gathered from a significant sample of supply chain experts at leading pharmaceutical companies in South Africa. Data collection scales were derived from existing studies. The collected data were analysed using structural equation modelling.

The results confirmed the validity of the proposed model, which is based on selected criteria (latent variables). This study emphasizes the crucial influence of supplier evaluation, selection, development and segmentation on supply chain performance in pharmaceutical organizations. The research shows a positive correlation between supply chain performance and organizational performance, with top management support playing a moderating role.

The study’s originality and value stem from its thorough examination of how supplier relationship management practices affect supply chain performance and organizational performance in the pharmaceutical industry of South Africa. Furthermore, the research adds to the current body of knowledge by considering the moderating influence of top management support on the link between supply chain performance and organizational performance. These findings offer valuable insights for academics and industry professionals in the realm of supply chain management.

Through the scientific and reasonable evaluation of the site selection of the emergency material reserve, the optimal site selection scheme is found, which provides reference for the future emergency decision-making research.

In this paper, we have chosen three primary indicators and twelve secondary indicators to construct an assessment framework for the determination of suitable locations for storing emergency material reserves. By mean of the improved entropy weight-order relationship weight determination method, the evaluation model of kullback leibler-technique for order preference by similarity to an ideal solution (KL-TOPSIS) emergency material reserve location based on relative entropy is established. On this basis, 10 regional storage sites in Beijing are selected for evaluation.

The results show that the evaluation model of the location of emergency material reserve not only respects the objective knowledge, but also considers the subjective information of the experts, which makes the ranking result of the location of the emergency material reserve more accurate and reliable.

Firstly, the modification factor is added to the calculation formula of traditional entropy weight method to complete the improvement of entropy weight method. Secondly, the order relation analysis method is used to assign subjective weights to the indicators. The principle of minimum information entropy is introduced to determine the comprehensive weight of the index. Finally, KL distance and TOPSIS method are combined to determine the relative entropy and proximity degree of alternative solutions and positive and negative ideal solutions, and the scientific and effective of the method is proved by case study.