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When designing and modernizing existing sound-absorbing structures (SAS) of an aircraft engine (AE) made of polymer composite materials, an urgent task is to conduct computational and experimental studies of the influence of its design parameters on natural frequencies and waveforms to predict resonant phenomena in order to exclude them. In this paper, the height of the tubular panel of the SAS is selected as the investigated parameter. A modal analysis of the tubular panel of the SAS made of materials VPS–33 and VCU–39 was carried out. The influence of the height parameter on the natural frequencies and waveforms of the tubular panel of the SAS has been studied. [ABSTRACT FROM AUTHOR]

Polymer composites have garnered significant attention due to their lightweight nature and high strength-to-weight ratio, making them promising materials for various engineering applications. However, their inherent brittleness often limits their practical utility, especially in high-impact scenarios. To address this challenge, advanced techniques for toughening polymer composites have been developed, aiming to enhance their fracture toughness and energy absorption capabilities. This comprehensive review highlights recent advancements in toughening mechanisms and strategies employed in polymer composites. Various approaches such as interface engineering, incorporation of toughening agents, and hierarchical structures are discussed in detail, elucidating their underlying mechanisms and effects on the mechanical properties of composites. Furthermore, advanced characterization techniques for evaluating toughening mechanisms and assessing the performance of toughened composites are reviewed. The potential applications of toughened polymer composites across diverse fields including aerospace, automotive, and sports equipment are also explored. Through a thorough examination of recent research, this review provides valuable insights into the state-of-the-art in toughening polymer composites, offering guidance for future developments and applications in engineering materials science. [ABSTRACT FROM AUTHOR]

The effect of different quantum dots (QDs) such as CdS, ZnO, ZnS, InP/ZnS, and Pervoskite QDs etc. on the electro-optical and morphological behavior of polymer dispersed liquid crystal (PDLC) has been analyzed in this short review. The fabrication techniques of PDLCs of these composite systems and liquid crystal (LC) droplets behavior in polymer matrix along with transmission, contrast ratio, threshold and operating voltages etc. as well as mutuality of these parameters on overall performance of the PDLC film have also been examined. Further, the future prospective of QDs-PDLC for various applications has also been described. [ABSTRACT FROM AUTHOR]

This paper presents the results of an experimental study conducted on Glass Fibre Reinforced Polymer (GFRP) reinforced concrete slabs subjected to impact load test. Conventional steel rebars are also considered for comparison purpose. GFRP rebars can be used as a reinforcing material to enhance the impact resistance of structural elements. GFRP is more durable compared to conventional steel reinforcement and possesses high strength to weight ratio. The current study aims to provide an overall idea of the impact resistance of slabs reinforced with GFRP rebars at different proportions. The comparison of results between GFRP and steel reinforced concrete slabs under impact loading is also performed. The number of blows taken for getting initial cracks and collapse is observed. The results prove that replacement of conventional steel reinforcement by GFRP rebars is beneficial. [ABSTRACT FROM AUTHOR]

Recently, polymeric materials have been used to improve the properties of bitumen which is used in the process of road construction. Polymeric materials, such as styrene-butadiene-styrene, polystyrene, and others, especially in paving materials, have received increasing attention. Our study focused on the effect of adding polymers type styrene-butadiene styrene grade - 6302 on the volumetric properties and mechanical performance of the produced hot asphalt binder. This was done through, the study of mixing conditions on the dispersion of the polymer in asphalt to obtain a homogeneous bond was studied. Therefore several variables were taken into account; temperature at different levels (170, 175, 180, 185, and 190 °C), different weight percent of styrene-butadiene-styrene grade - 6302 (2, 3, 4, 5, and 6%) and mixing time (30, 45, 60, 75, and 90 min). To determine the number of practical experiments and reveal the most controlled variables, the Taguchi method of the experimental design was used in this study. Bitumen was mixed with polymer by a thermal mixer at 2800 rpm and the mixer was a mixer and grinder. The polymeric material is placed as soon as the bitumen reaches the flow stage, in order to maintain the quality of the bitumen when the temperature rises to more than 150 °C. [ABSTRACT FROM AUTHOR]

In this work, aluminum alloy AA6061-T6 with a thickness of 1.5 mm is lap-joined with a polymer, High-Density Polyethylene (HDPE) with 4 mm using the friction lap joining (FLJ) technique. To increase the pore size, the aluminum alloy surface area underwent the anodizing process. The effects of joining factors such as transverse speed (50, 70, 90, and 160 mm/min) and rotational tool speed (920 and 1500 rpm) were examined. Tensile shear, Scanning Electron Microscopy (SEM), and the X-Ray Diffraction test (XRD) were all performed on each specimen. Two different failure types were noted; the first involved the lap joint (shear), while the second involved the side polymer. According to the most recent failure, the anodized process produced a good pore size where the melted polymer could pass through it. This suggests that the transverse and rotating speed processing factors impact joint efficiency. The highest joint performance is at 1500 rpm and 70 mm/min. The outcomes of the design of experiments are analyzed using the Minitab application. The shear force for joints was shown to be most affected by transverse speed. In the re-solidification zone, the interaction between aluminum and polymer is clearly visible. According to the SEM test, the bonding zone has a depth of roughly 17 µm. Additionally, the analysis's findings showed that for the Al/HDPE joint, this layer was primarily made of oxygen and aluminum. Aluminum and AL2O3 make up most of the phases, according to the XRD study. [ABSTRACT FROM AUTHOR]

Present work starts with a brief introduction 'Cassava' and its material potential are; food application, gelation with other non-toxic organic/inorganic compound, electroactivity and its role in gelation development, new material using its electroactivity and potential application to that will be considered as new applications in the view of physical/material use. Complex of few natural exudates from plants will also be probed for development of new material from Cassava. Attempt will also be made to examine the effect of (i) cross-linking (ii) increase in polymer chain length of the material and their derivatives on material application [ABSTRACT FROM AUTHOR]

The commercial Polyvinyl butyral (PVB) and Poly (vinylidenefuoride-co-Hexafluoropropylene) (PVDF-HFP-HFP) used in the present investigation were prepared by the solution cast technique. Blend samples of wt% compositions PVB: PVDF-HFP-HFP:: 95:05; 90:10; 85:15 and 80:20 were prepared. The prepared films were characterized by FTIR and XRD techniques for structural and morphological studies. FTIR and XRD analysis confirms the molecular interaction between the two polymers and also the dominating presence of α-phase PVDF-HFP-HFP in blends. Studies also reveal that the crystallinity occurs in blend samples with increase of PVDF-HFP-HFP wt%. Different characterization in present investigation indicates that prepared blends are compatible in selected composition range. [ABSTRACT FROM AUTHOR]

This study aims to compare the effectiveness of two polymer mobility design methods, namely Endpoint and James Sheng methods, for optimizing the viscosity target in polymer injection enhanced oil recovery (EOR). Coreflood tests were conducted to evaluate the impact of the mobility design method on injected polymer viscosity and oil recovery. The results showed that the choice of mobility design method significantly affected the injected polymer viscosity and ultimate oil recovery. A higher polymer viscosity was found to increase sweep efficiency, resulting in better oil recovery, but also led to injectivity issues. Thus, careful consideration is required when selecting a polymer mobility design method to achieve optimum oil recovery while minimizing injectivity issues. These findings have significant implications for optimizing the polymer injection process for EOR applications. [ABSTRACT FROM AUTHOR]

The most prevalent kind of flaw that may readily arise in concrete constructions is cracking, which can be caused by a variety of factors. Those fissures might potentially have an impact on the building's strength. In order to fix these gaps, it is necessary to locate a different source of supply. Materials such as GFRP Sheets and Nansosilica Gel have been selected for the objective of the inquiry being conducted. GFRP sheets are used for the aim of cost-effectiveness, and they are able to bear severe weights. As a result of its ability to fill minute holes, nanosilica gel has superior sealing properties. For the purpose of conducting an investigation, six rectangular beams with a cross section of 150x200 millimetres and a span of 1000 millimetres were cast using concrete of grade M25 and steel of grade Fe 500. For about 28 days, the cast beams are allowed to cure. The six beams are put through their paces after the curing procedure. As a control beam, the first two beams are selected once the testing has been completed. The next two beams are going to be coated with Nanosilica Gel, and the remaining two beams are going to be rolled and bound with GFRP sheets. In conclusion, a comparison has been conducted between the beams that are coated with Nanosilica Gel and the beams that are bound together with GFRP sheets. [ABSTRACT FROM AUTHOR]

Pavement structures are subjected to high traffic loads, which deteriorates the pavement over time. In recent years, various techniques for improving the performance of asphalt pavements have gained popularity. One of these technologies is polymer-modified-binders (PMB) in asphalt mixtures, which are gaining popularity due to reduction in thermal susceptibility and increase in fatigue and rutting resistance. As a result, this paper provides a relative assessment of the recycled polymers utmost recently addressed as bitumen modifiers to enable their selection and cover the utilization of bitumen. The melting point of the polymer, the mixing environments, and the maximum amount of polymer supplemented are all studied. Their influences on the mechanical performance and constancy of asphalt binders in the pavement with and without additives are also discussed. Polymer modification has a major consequence on the rheological characteristics of asphalt binder, according to the findings. The findings of this paper will be useful to the local road construction industry in determining the properties of locally available asphalts and modified versions. A case study of the performance of 3 polymer forms in asphalt paving mixtures is provided; namely Polystyrene-Polymer, Polyvinyl-chloride (PVC), and Phenol-resin. These modified asphalt mixtures were made with asphalt cement that had been modified previously with 2%, 4%, and 6% with weight of asphalt polymer. The effect of polymer modification on mix performance was investigated utilizing Retained Stability Tests (RST) and Indirect Tensile Strength (ITS). Two separate measuring temperatures (25°C and 45°C) are used to evaluate the behavior of the mixture due to the change in the temperature. According to the findings of a case study, using a small percentage of polystyrene polymer lead to an increase in tensile strength, permitting polystyrene modified asphalt mixtures to be used in cold climates. The test results also revealed that offering phenol resin in modified asphalt mixes can increase deformation resistance and strength, allowing it to be used in hot climates. [ABSTRACT FROM AUTHOR]

This study adopted a review of bond strength and discussed the research in geopolymer concrete. Studies and research on the structural properties of geopolymer concrete are relatively limited in comparison to ordinary concrete. As a result, this review covers the majority of the research on the Bond Strength of geopolymer concrete, cementitious materials and curing regimes. Many investigations on several researchers have worked on geopolymer concrete. Geopolymer Concrete has the advantage of using extra cementitious materials in conjunction with alkali-activated solutions to substitute cement (The reaction of geopolymer concrete materials is activates by it). After doing a study on previous researches, the output of reviewed papers explained that the pozzolanic materials and curing conditions are affected in the clear for the bond strength; it has been discovered that geopolymeric concrete made from fly ash performs better than Conventional Concrete based on Portland cement in terms of mechanical properties, withstanding high temperature, and preservation of fundamental physical characteristics including permeability and water absorption. Whereas few studies exanimated the effect of fiber on bond strength. [ABSTRACT FROM AUTHOR]

The utilization of advanced materials in polymer composites has gained significant attention due to their enhanced properties and performance in various applications. The current work is an attempt to optimize the mechanical properties of GNP (graphene nanoplatelets) and h-BN (Hexagonal Boron Nitride) based polymer composites using fuzzy and neural-based Adaptive Neuro-Fuzzy Inference System (ANFIS). The current work investigates the effects of nanofiller (both GNP & h-BN) content on the composite's mechanical properties (tensile and flexure strength). A series of tensile and flexure experiments were conducted to fabricate composite samples with varying concentrations of GNP and h-BN. The ANFIS algorithm was employed as a predictive modeling tool to optimize the composite properties. The ANFIS model was trained and tested using the data gathered from the experimental trials, and its ability to predict the mechanical properties of the composite was assessed. Various input parameters, including GNP, h-BN content, and dosage, were considered to determine the optimal composition for maximizing the desired mechanical properties. The training results of membership function Trimf under backpropagation and Dsigmf under hybrid configuration have shown the least root mean square error (RMSE) of 0.022842 and 3.8043 for Tensile and Flexure tests respectively. [ABSTRACT FROM AUTHOR]

Additive manufacturing technologies for plastics are typically used in industry for prototypes, presentation models and small batches but also additive tooling. Especially for low volumes, this manufacturing method offers a high degree of efficiency, since no special tools or fixtures are required, which leads to a significant reduction in manufacturing costs and manufacturing time. Up to now, applications have usually been made using only one material, as the use of different materials in a single printing process is a particular challenge. In this contribution, the state of the art for printing processes suitable for multi-material printing and associated application examples are first presented in a literature search. The focus of this contribution is on the fused layer modeling (FLM) process with experiments and analysis on the application of different materials (PLA, PETG, ASA and PC Blend). A 3D-printer with a single nozzle is available for the practical experiments. Due to an additional multi-material device this 3D-printer is capable of processing up to five different materials in one printing process. Colorful presentation models are the first step to gain experience in multi-material printing. The investigation will then be extended to include the combination of different materials. For this purpose, standardized plastic tensile specimens are additively manufactured and subjected to tensile testing in order to analyze material properties. The tensile specimens are manufactured in different patterns and material combinations. This results in measurements that allow a comparison with the initial materials. In addition, the challenges in the printing process, material selection and material arrangement are demonstrated. In order to develop a functional multi-material component, sufficient fusion in the bonding layer between the materials must be ensured. [ABSTRACT FROM AUTHOR]

The document provides brief biographies of members of the scientific committee for the 2nd International Symposium on Plastics Technology. It includes information about their expertise in polymer engineering and science, as well as their contributions to the field through research, teaching, and industry collaborations. The document also provides brief biographical information about other experts in the field of polymer processing, including their background, education, research interests, and notable achievements. These individuals have made significant contributions to the field through their research, publications, and involvement in professional organizations. [Extracted from the article]

Currently, the majority of laser based powder bed fusion of polymers (PBF-LB/P) processes use polyamides, which prevent the components from exhibiting the mechanical characteristics of traditional manufacturing techniques; since there is a deficit of specific materials. Therefore, highly ductile materials are needed to cover further areas of application. The preferred material thereby is polypropylene with its various structures and settings. Available research demonstrates that while isotactic polypropylene can be processed, it has brittle properties that require the use of additional structures. To address this challenge and to exploit the full potential of PBF-LB/P, the first part of this work investigates the material properties in order to make a statement about the process performance, while the second step analyzes the processability and component properties of the heterophasic polypropylene grade. [ABSTRACT FROM AUTHOR]

Bioresorbable polymers are of great interest to the medical sector as a means of invasive interventions, as they can be subjected to degradation in the human body. The increasing prevalence and incidence of chronic wounds is a considerable source of patient morbidity and financial burden to the healthcare system, a field where tunable biocomposites may facilitate a means of ameliorating persistent factors and warranting proximal tissue remodeling. In the development of a biopolymer medical device, there are several material considerations to note such as physicochemical, biological, and degradation profiles. Polylactic acid (PLA) and polycaprolactone (PCL) have been applied in a plethora of medical fields such as regenerative medicine, cardiovascular implants, pharmaceutical delivery, orthopedic interventions and cancer therapy. Although biocompatible, PLA and PCL have degradation profiles that can extend from months to years. In the development of medical devices, the degradation time of a biomaterial complex should coincide with the regeneration process of proximal tissue to ensure proper remodeling of the tissue. Polydioxanone (PDO) is a synthetic bioresorbable polymer with a short-term degradation profile and weak material strength that has been around since the 1980's, yet the majority of its medical application has been as suture material. The limited supply and expensive nature of PDO are considerable factors as to why minimal research has been conducted to date. To address these limitations, independent composite formulations of PDO/PLA and PDO/PCL were produced by solvent emulsion. The physicochemical and processing characteristics of all composites were determined by FT-IR, DSC, TGA, rheology and XRD. Polymers were observed to retain their crystalline nature in FTIR and XRD analysis; however, the rheological and thermal properties of PDO were noted as tunable depending on the percent concentration of PLA / PCL respectfully. [ABSTRACT FROM AUTHOR]

Mechanical recycling of polymers often involves mixing polymer types with the same chemical structure but different properties, e.g., two PP grades with different melt flow rates. The change in the physical properties is of great interest. In this study, the rheological behavior of two types of virgin PP and blends of these with different weight fractions were studied using high-pressure capillary rheometry. A new method that considers the shear-rate-dependent viscosity based on the shear stress is presented. The method allows to consider various mixing rules. Four existing mixing rules to predict the viscosities of mixed miscible polymers were applied. The comparison of the predicted values to experimental investigations shows that the application of the mixing rule of Arrhenius, which is also known as the rule of Bersted delivers the most accurate results. The mean absolute deviations are between 3.38% and 5.06% for all models. Tendentially the predicted values are slightly below the measured values, especially at high shear rates. [ABSTRACT FROM AUTHOR]

Microcrystalline structure developed during transformation processes influences the final properties of polymeric parts. Indeed, many polymer processes involve shear and elongational forces that impart orientation in polymer chains and the degree of orientation enhances the final properties such as mechanical strength and barrier properties. Moreover, many industrial technologies, such as film blowing, double bubble processing or tentering, involve biaxial orientation. Nevertheless, if in general the relationship between process conditions, microcrystalline structure and final proprieties is rather complex, it is notably even more complex in case of biaxial orientation. With the aim of a better understanding of the effect of biaxial orientation on the microstructure, a new device was designed and assembled on a monoaxial testing machine. In the present work, the new device is described and used to obtain biaxially stretched cruciform samples of LLDPE at 100°C and 115°C. [ABSTRACT FROM AUTHOR]

Biodegradable polymers have gained lots of interest and publicity. Polyhydroxyalkanoates (PHAs) are a member of biodegradable thermoplastic polyesters, biologically derived by bacterial fermentation. These biodegradable, compostable and biocompatible polymers are of great interest in the production of medical textiles, disposable materials and packaging. However, slow crystallization rate and low thermal stability of PHAs limits the melt spinning of fibers and results in inadequate mechanical properties. In this study, two biodegradable polymers were coaxially combined in a spinneret for bicomponent fiber production with islands-in-the-sea geometry. The co-extrusion of a poly(3-hydroxybutyrate)-co-(3-hydroxyvalerate) (PHBV) as the island polymer and a polyvinyl alcohol (PVA) as the sea polymer having a higher thermal stability and faster crystallization enabled the stable winding of filaments. Following the filament production, the filaments were soaked in distilled water to remove the PVA sea polymer and PHBV micro fibers were obtained. Thermal analysis revealed that the complete removal of PVA was possible. Microscopic analysis showed that PHBV microfilaments (single filament diameter < 7 µm) have been successfully melt-spun. [ABSTRACT FROM AUTHOR]

Syndiotactic polystyrene (s-PS) is a crystalline polymer with good thermal properties, high chemical resistance, and low water absorbance. Therefore, s-PS is expected to be applied to fiber products for apparel and industrial uses. High-speed melt spinning of s-PS of three different molecular weights (HM-Homo, MM-Homo, and LM-Homo) and one co-polymer (HM-Copoly) was performed. The attainable highest take-up velocity increased from 3.6 to 4.0 km/min with the reduction of molecular weight for homo-polymers, while the highest take-up velocity of 4.2 km/min was achieved for the HM-Copoly. From the measurement of the thinning behavior of the spin-line, it was speculated that the improvement of spinnability resulted from the shifting of the position of neck-like deformation downstream, which was probably caused by the suppression of orientation-induced crystallization. Restrained crystallizability through molecular weight reduction and copolymerization was also confirmed through the measurement of the wide-angle X-ray diffraction patterns of the as-spun fibers. Differential scanning calorimetry measurement suggested the increase of melting temperature of as-spun fibers with the increase of crystallization temperature in the spin-line and the highest melting temperature of 277 °C was found for the HM-homo fibers obtained at 3.6 km/min. Analysis of mechanical properties indicated that, for each polymer, the as-spun fibers exhibited the maximum tensile strength of around 120 MPa at the take-up velocity immediately before the onset point of orientation-induced crystallization. [ABSTRACT FROM AUTHOR]

The employment of geopolymer mortar composite as a more environmentally friendly alternative to cement composite has been widely acknowledged. Nonetheless, the full practical application of geopolymer mortar is hindered by various factors affecting its performance. To address these limitations, scientists have been investigating inventive methods to enhance the properties of geopolymers. One particularly promising strategy entails integrating ceramics particles within the structure, as they have the potential to substantially improve the performance of geopolymer materials. The present study investigated the impact of silica powder as a substitute material for fly ash weight at varying weight ratios (10, 20, and 30 wt. %) and the influence of adding zirconium oxide at different percentages of weight (2.5%, 5%, 7.5%, and 10%) on the mechanical and physical properties of fly ash class F based geopolymer via a series of tests represented by density, apparent porosity, flexural and compression tests. Activator solutions were made using a Na2SiO3 to NaOH ratio of 2.5:1 with 16 M of NaOH. The specimens were cured at a high temperature of 100°C in a furnace for duration of three hours and left at ambient temperature for intervals of 7 and 28 days. The obtained results revealed that the incorporation of the zirconium oxide resulted in enhancements in mechanical and physical properties through the filling of interstitial spaces and retard the initiation and propagation of cracks within the structure. The optimal combination was achieved through the substitution of 20% of fly ash weight with silica powder and adding 7.5% weight of zirconium oxide. [ABSTRACT FROM AUTHOR]

The article substantiates the feasibility of producing a dry plaster mixture based on a lime-sand mixture, which is an intermediate product in the production of sand-lime brick. The results of a study of the influence of an additive - redispersible polymer powder on the structure and properties of a plaster mortar based on a lime-sand mixture - are presented. It has been established that when the content of redispersible polymer powder is 2.5% by weight of the dry mixture, almost complete filling of the pores in the hardened plaster mortar with a polymer binder is achieved, which leads to the achievement of its required performance characteristics. [ABSTRACT FROM AUTHOR]

The application of Portland cement as a cementitious binder has been used widely in the construction industry. However, the application of geopolymer has equal popularity nowadays, especially for concrete repair works and rehabilitation. Research and development of high-performance geopolymer binders or known as alkali-activated materials is increasing worldwide. There are various precursors that have been investigated to optimize the performance of the geopolymer binders such as kaolin, slag, and many others. The application of fly ash is popularly being tested and proved to be the most efficient precursor owing to its excellent properties and performance. The performance of this precursor is being reviewed and presented in this paper and the high calcium fly ash is notably the most suitable precursor for fast setting and high early strength geopolymer. This paper presents an overview of fly ash, in terms of its properties, reaction, and mechanism. Several significant properties affecting the performances of fly ash-based geopolymer were discussed. It is being highlighted in this paper that fly ash has various microstructures which produced different geopolymerization reaction mechanisms. [ABSTRACT FROM AUTHOR]

Superabsorbent polymers, a three-dimensional cross-linked polymer, show excellent properties in retaining a large amount of water and have been widely applied in various fields. This report studied the synthesis of chitosan-strach superabsorbent by chemical crosslinking. The polymers were prepared by using 1:1 ratio of chitosan and starch in a concentration of 2% w/v with 2-25% v/v of glutaraldehyde as cross-linker. The characterization of chitosan-starch polymers was performed by using analytical tools, such as FTIR and SEM. Water absorption capacity was evaluated by swelling ability followed by the batch sorption of different 0.9% w/v salt solutions of NaCl, MgCl2, FeCl3 and synthetic urine composed of urea, NaCl, KCl, and Na3PO4. The biodegradation was evaluated by the difference mass of polymers before and after plantation in soil. The optimum polymers were obtained by using 5% of glutaraldehyde with water sorption capacity of 349.68%. The water absorbency capacity of different salts was 121.37%, 138.59%, and 165.20% for NaCl, MgCl2, FeCl3, respectively. The absorption capacity of SAP in synthetic urine, 1% w/v NaCl, 0.64% w/v Na3PO4, 0.6% w/v KCl, and 2.43% w/v urea solutions was 87.83%, 117.72%, 103,39%, 99.28%, and 91.08%, respectively. The degradation study indicated that the polymers were completely degraded in 14 days. [ABSTRACT FROM AUTHOR]

This document explores the use of a PDMS layer on a PSF membrane to enhance the separation of CO2 and CH4 gases in biogas. The addition of the PDMS coating improves the selectivity of CO2/CH4 separation by 47.16% and increases the concentration of CH4 by 7.96%. The study conducted by Suleman et al. found that the PDMS/PSF membrane had higher CH4 purity production compared to the neat membrane. The authors suggest that coating the PSF membrane with PDMS is a simple and effective method to improve gas separation performance, but further research is needed to optimize the coating parameters. The study was financially supported by the Palm Oil Plantation Fund Management Agency of Republic Indonesia. [Extracted from the article]

One of the largest issues in our society is the energy crisis. Although we are shifting to renewable energy, petroleum is still going to be our main energy source in the decades to come. Moreover, global oil demand is expected to rise in the next decades. One of the promising enhanced oil recovery schemes is polymer flooding. A polymer solution can be hundreds of times more viscous than water, and its shear-thinning property could also improve viscosity as the fluid travels further from the injection well. To compensate for the high-pressure burden for the fluid injection, an in-situ chemical reaction can also be incorporated. In this work, polymer flooding experiments were performed in porous media generated from granular packing. Micro-tomography and image processing techniques were used to monitor and assess the fluid in the porous media. Three experiments with different fluid systems were performed under two different flow rates to investigate the effects of polymer flooding, shear-thinning properties, and in-situ chemical reaction of viscosity improvement. We found that polymer flooding improved oil production significantly than water flooding. Due to its shear-thinning property, oil production improved with lower injection velocity. In addition, the in -situ chemical reaction was also found to improve the oil production although only slightly. [ABSTRACT FROM AUTHOR]

The paper presents an analysis and review of sources considering temperature-dynamic characteristics as performance indicators of agricultural automotive and tractor equipment, the impact of energy efficiency of automotive equipment on the temperature and dynamic characteristics of cooling systems, an analysis of the impact of performance indicators of automotive equipment on the efficiency of a block cooling system. An improved scheme of a block-modular cooling system and a method for determining its main indicators during operation for functional units of automotive equipment using innovative materials are proposed. A complex method was used, including an analysis of the state of the issue, theoretical studies of the operating parameters of the polymer radiator of the cooling system with the inclusion of thermal, aerodynamic and hydrodynamic calculations, both in steady and unsteady modes of operation of the MTZ-82 tractor engine. At the same time, analytical and numerical methods, a set of mathematical models and graphic visualization of solutions using the Excel, KOMPAS-3D, Statistica software packages were used. An improved theory of temperature-dynamic characteristics of automotive equipment is used in the cooling system of the MTZ-82 tractor equipped with a polymer radiator, while combined options for using both liquid and oil-liquid engine cooling are possible. [ABSTRACT FROM AUTHOR]

The increase in eco-technological requirements in manufacturing processes leads to activities that reduce the carbon footprint. Methods for introducing graphic symbols on polymer moldings lead to the use of technologies consistent with the guidelines of the circular economy. The use of LMA additives (Laser Marking Additives) allows for precise and contrasting marking of polymer moldings. Additional effects can be achieved by modifying the surface condition or processing parameters of the injection process. The article presents the results of research on the influence of selected surface treatments of molding cavities on the effects of laser marking of the surfaces of molded parts. The tests used polypropylene moldings modified with an addition that allowed obtaining a contrasting boundary mark (the change in the surface condition was determined). The use of a laser beam to modify the surface allows the selection of parameters to obtain favorable light effects on a dark background. It was noticed in the research that the finish of the marked surface has an influence on the intensity of graphic symbols. Changing the selected parameters of the laser beam in some cases may result in various interference with the marked material. [ABSTRACT FROM AUTHOR]

A numerical investigation was conducted for clarifying the influence of the technological parameters of the process of a fibre-reinforced polymer bar curing in a curing oven on the fibre-reinforced polymer bar thermal state and the degree of the binder curing. The temperature fields and the degree of the binder curing in the fibre-reinforced polymer bar 10 mm in diameter were calculated after the fibre-reinforced polymer bar needletrusion at speed of 1.5 m/min in a four- section curing oven 4 m in length. A temperature condition was selected for each section of the oven, which provided the required degree of the binder curing and prevented thermal destruction of the fibre-reinforced polymer bar material. [ABSTRACT FROM AUTHOR]

This article presents the design schemes of lubricating and drying devices for greasing and drying seams of materials with different characteristics, the principle of their operation. Changes in the mechanical properties of polymer compositions as a result of exposure to the material are also determined. [ABSTRACT FROM AUTHOR]

In order to reduce the raw material consumption of building materials based on gypsum, this article describes the possibilities of using various polymer compositions based on agricultural waste - straw. The polymer compositions included agricultural waste straw, polyvinyl acetate and liquid glass, and tests were carried out on the basis of compositions containing straw waste from 1% to 5%. The physical and mechanical properties of the obtained samples, such as water absorption, bending strength and compression, were also studied. Based on the results, it was determined that the optimal value of polymer compositions is 3%. The decrease in the water absorption index of gypsum samples from straw waste by 38% was achieved through the use of the optimal ratio of compositions. [ABSTRACT FROM AUTHOR]

In this research bioabsorbable implants have been made using metal-polymer composite (PLA/ABS/Mg). The purpose of this study was to determine the optimal variation of PLA/ABS/Mg composites on the characteristics of mechanical properties, morphological structures, and corrosion rates. Comparison of the composition of PLA and ABS used is 70:30, 60:40, and 80:20 with the addition of variations of Mg, respectively 5, 10, and 15%. In this study, PLA/ABS/Mg composites were made using the solvent casting method, and the polymer was dissolved using 20 mL of chloroform and then molded to obtain a sample in the form of a film. The observation of the morphological structure of the PLA70 ABS30 composition shows that the homogeneity of Mg in the polymer has been achieved well, and the corrosion rate results with the composition of PLA60 ABS40 with Mg 10% variation show a significant weight reduction. From the UV-VIS results in total at a wavelength of 230-240 nm, there was an absorption of ester groups in the polymer PLA. [ABSTRACT FROM AUTHOR]

Delamination was the primary reason for carbon fiber reinforced polymer (CFRP) parts rejection in the aircraft industry which led to a tremendous amount of profit losses. Therefore, a lot of research aimed to tackle this problem by studying the influence of drilling parameters and their optimization to minimize delamination in CFRP drilling processes. In this study, a backpropagation neural network (BPNN) is deployed to model the CFRP drilling process. Further, adaptive large neighborhood search (ALNS) is utilized to minimize the surface delamination on the CFRP materials' hole entry (SDen) and the hole exit (SDex). ALNS is used to find the best combination of drilling bit geometry (DG), feed rate (FR), and spindle speed (SS). The best obtained BPNN architecture from the trial-and-error method is 2-12-2, which means that there are two neurons in the input layer, twelve neurons in the hidden layer, and two neurons in the output layer tansig activation function type. Optimum CFRP drilling parameters obtained using ALNS optimization are X-type drill bit geometry, 136 mm/min feed rate, and 3000 rpm spindle speed. The minimized SDen and SDex using the optimum drilling parameters are 1.074 and 1.009. [ABSTRACT FROM AUTHOR]

Recently, the advancement of nanotechnology is focused to fabricate innovative packaging, as it is solely responsible for the protection, preservation and presentation of the food product. Plastic or petroleum-based polymer packages are commercially popular because of their low cost, good barrier and mechanical properties. Since the last decade, a significant amount of research has been devoted to evaluating various bio-based polymers to replace plastic-based packaging for their negative impact on the environment for the generation of solid waste and depletion of fossil fuel reserves. Biopolymers are very similar to synthetic polymer's structure and characteristics, additionally, they are biodegradable and available from renewable resources. Chitosan is the world's second most abundantly available polysaccharide biopolymer and the most abundant biopolymer of animal origin. Biodegradability, non-toxicity, excellent film-forming ability and inherent antimicrobial activity make chitosan a potential candidate to be applicable in food packaging industries. Chitosan being a sea-food industry waste when transformed into a new product, encourages industrial symbiosis, which can be implicated for sustainability. However, chitosan poses some limitations, such as low mechanical strength and low water resistance, that can be enhanced with the addition of other polymers, nanoparticles, nanoclays etc. This review aims to summarize the knowledge and update the information about recent research trends and developments about chitosan-based biodegradable nanocomposites coating and films to wrap fresh perishables for their prolonged shelf life. The article extensively explores the research to analyze advancement in achievements of mechanical, barrier and antimicrobial properties. [ABSTRACT FROM AUTHOR]

Experimentation regarding the study of the properties of reinforced concrete, including its behavior and its strength (RC) In this study, we illustrate how deep beams may be strengthened using near surface mounted (NSM) glass fiber reinforced plastic (GFRP) bars. In the experiment, five RC deep beams were used, each with a cross-sectional size of (400×160) mm and a total length of (1500) mm. These beams were then reinforced with NSM GFRP bars, using various strengthening configurations. One of the beam specimens was left unreinforced and serves as a control beam; the other beam specimens were reinforced using various NSM GFRP bar techniques. Each RC deep beam was put through four stress points up to failure, with varying shear spans to effective depth ratios. This research investigates and discusses the effects of GFRP bar spacing and GFRP bar inclinations on the performance of reinforced deep beams. Both impacts were examined and explored. According to the findings, the ultimate load bearing capacity of the enhanced RC deep beams was increased by around (19.6–36.3) % when compared to the capacity of the beams before they were strengthened. In addition to this, the ductility and diagonal fracture width of the strengthened RC deep beams were significantly improved. [ABSTRACT FROM AUTHOR]

The high strength-to-weight ratio of advanced polymer composites as compared to standard metallic materials makes them, particularly in demand. As with the reinforcement of carbon nanotubes (CNTs) into epoxy resins and reinforcement of carbon nanofibers (CNFs) into the polyvinylidene fluoride (PVDF) matrix, the addition of fibers to the polymer matrix boosts their directional strength. The advanced polymer composites also referred to as electroactive polymers (EAPs), produce voltage upon deformation and become deflected by an applied voltage. In this study, a composite PVDF/CNF sheet is modeled with the assumption that it will act similarly to a cantilever beam. In order to use finite element analysis (FEA) theory to calculate the stress distribution and reaction forces on the fixed side of the sheet, the sheet is exposed to an equal magnitude of tensile and compressive loads. According to the FEA results, the PVDF/CNF sheet's produced stress and reaction force are greater under compressive load than under tensile load. The results of this study can be used to determine the EAP composites' safe working conditions. [ABSTRACT FROM AUTHOR]

Nowadays, the adaptability of biodegradable Polyhydroxyalkanoates (PHA) polymer has been thoroughly assessed to its full potential including shape, mechanical characteristics, thermal properties and biocompatibility. Additionally, PHA has been produced as biomaterials with potential applications in bone regeneration. Similar to the mineral apatite found in human bones, nano calcium phosphates (nCaP) are minerals that are necessary for tissue development and cell adhesion, which have an impact on newly formed apatite. This study aims to investigate the influence of additives on thermal stability of biocomposite via thermogravimetric analysis (TGA) machine. PHA pellets were mixed with nCaP as filler ranging from 3-15wt% and 10wt% of chitosan binder via conventional melt compounding. Thermal analysis showed that the addition of bio-filler improves thermal stability of PHA with highest onset temperature recorded at 208.1°C. Morphological analysis showed that the addition of nCaP and chitosan alters the flow characteristics of the composite resulting in surface roughness. Subsequently, in order to prevent the biocomposite from decomposing, all heat-related activities particularly those involving machining, it is recommended to perform at temperatures that do not exceed the onset temperature. [ABSTRACT FROM AUTHOR]

Conventional cell culture on 2D surfaces such as culture flasks and tissue culture dishes have limited surface area for cell growth. Additionally, as cells reach confluence, standard cell harvesting techniques utilizing enzyme or mechanical scraping could cleave proteins on cell membranes resulting in reduced cell yield. This work presents the fabrication of a thermally responsive poly(N-isopropylacrylamide) (PNIPAm) nanofibrous scaffold by electrospinning. Electrospun nanofibrous scaffold presents a 3D microenvironment with high surface area for cell attachment, and PNIPAm based scaffolds offer the potential for a non-invasive cell harvesting mechanism by temperature control. PNIPAm was synthesized via radical polymerization yielding polymer with an average molecular weight of 381,000 g/mol and electrospun into randomly aligned nanofibers. Since linear uncross-linked PNIPAm exhibit poor aqueous stability, the electrospun nanofibrous scaffold was cross-linked with octaglycidyl polyhedral oligomeric silsesquioxane (OPEPOSS) to mitigate the instant aqueous dissolution of PNIPAm during cell culture. The OPEPOSS cross-linked PNIPAm nanofibrous scaffold was cured for 4 h at 120 °C under atmospheric pressure and its resulting difference in nanofibrous morphology is highlighted in this work. Prior to curing, PNIPAm nanofibrous scaffold exhibit fiber diameter of 369.24 ± 154.38 nm, pore size of 2.63 ± 2.98 µm and porosity of 74.4 %. After curing, its fiber diameter increased to 436.35 ± 187.04 nm while pore size and porosity decreased to 1.24 ± 1.27 µm and 63.6 %, respectively. Additionally, cross-linking with OPEPOSS showed significant improvement in the aqueous stability of electrospun PNIPAm nanofibers as compared to electrospun neat PNIPAm. [ABSTRACT FROM AUTHOR]

Conducting polymers have many applications because of their unique structural, optical and electrical properties. Supercapacitors and solar cells benefit from polythiophene and its derivatives shows excellent capacitive energy density and low material cost respectively. FTIR Spectrum indicates the presence of Cd-S, C=C & CH2 groups in prepared samples. The CdS and P3HT materials were blended as seen in the FESEM images to increase both the conductivity and size of the porous grains. XRD pattern reveals the structural modification in the P3HT-CdS compared to P3HT pattern. The fabricated supercapacitor using P3HT based material exhibits specific capacitance 510 F/g to 240 F/g over 2500 GCD cycles with 47% of capacitance retention. This study demonstrates clearly that P3HT-CdS is a promising material for energy-related applications. [ABSTRACT FROM AUTHOR]

A series of flexible polymer composite films with rGO as conducting filler and PVDF-HFP as polymer matrix having general formula: PVDF-HFP + φ wt% rGO (φ = 0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 4.0) are prepared by solution casting technique. The structural, vibrational and dielectric properties of the composite films are studied as a function of rGO concentration. XRD analysis shows that the β phase fraction increases with the increase of rGO concentrations up to φ = 1.5wt% and after that its value decreases. The dielectric constant of the composites also increases with increase in filler concentrations and the maximum value of dielectric constant is observed for φ = 1.5 wt% similar to the variation of β phase fraction in XRD data. There is an enhancement of the dielectric constant of two times for φ = 1.5 wt%. i.e., 17 at 10 kHz as compared to the pure polymer matrix PVDF-HFP (εr = 8). FTIR analysis suggests that the interactions between the carboxyl functional group of rGO sheets with fluorine atom of PVDF-HFP is responsible for the enhancement of β phase which is well correlated with XRD study. The work shows that the polymer composite could be useful as flexible sensor or self-powered devices. [ABSTRACT FROM AUTHOR]

Photopolymerization of product blending methyl methacrylate with reactive mesogen RM257 using the UV Curing method with time variations. UV radiation formed a new polymer by adding the Benzoyl Peroxide (BPO) initiator. Polymerization was carried out at a temperature of 120°C in time variations of 5 minutes, 10 minutes, 15 minutes, and 20 minutes. Polymers were characterized using FTIR, SEM, XRD, and LCR Meter. FTIR spectrum showed the absorption peak at 2950 cm−1 indicating–C-H3 bonds, 1721 cm−1 indicating C=O bonds, 1604 cm−1 indicating aromatic functional group, 1248 cm−1 indicating C-O-C bonds, 1144 and 1060 cm−1 indicates of C-O bonds. Morphology analysis by SEM shows that polymer has uniform textures and visible molecular shape of rods. Pattern peaks of XRD appeared at an angle range of 2θ 10°-90°, there was a broad peak at 2θ 10°-38°, the appearance of sharp peaks with moderate intensity at 2θ 13.90° and 16.83°, high intensity appeared at 2θ 44.66°. This pattern XRD indicates that the polymer of product blending is semicrystalline. An LCR meter's measurement conductivities show that the highest conductivity value of a thin film is 2.245 x 10−6 S/cm. [ABSTRACT FROM AUTHOR]

There are limited previous investigations on the contributory factors to the relationship between California bearing ratios (CBR) of top and bottom surfaces of chemically stabilised sandstone samples. The aim of this paper is to consider three of these factors: gradation, stabilisation type and soaking condition. Three sandstone gradations of different gravel-to-sand ratios were considered: 2.1, 1.2 and 0.4. Four stabilisation types were inspected: unstabilised, cement-stabilised, polymer-stabilised and polymer-cement stabilised. Two soaking conditions were examined: unsoaked and 4-day soaked. The conclusions from the investigation were: (1) CBR values of samples increased with increasing G:S ratios, (2) cement stabilisation provided the greatest CBR values and this was followed by polymer-cement and lastly, polymer, (3) bottom surfaces of unsoaked samples generally had greater CBR values than those of top surfaces, and the opposite was true for soaked samples and (4) bottom surfaces of the samples were more sensitive to soaking than top surfaces. [ABSTRACT FROM AUTHOR]

The article analyzes damage to 6-10 kV overhead lines designed to power signaling, centralization and blocking devices from lightning overvoltages. The protection devices against lightning overvoltages used for overhead lines and the principle of their operation are considered. The requirements for operation of the protective devices are taken into account. A comparative analysis of the technical characteristics of traditional insulation and insulating polymer brackets is carried out. The installation of the surge arresters on an 6-10 kV overhead line of signaling, centralization and blocking and a longitudinal power supply line located on the field side of the contact network towers on polymer brackets is considered. Recommendations on the choice of the surge arrester are given. [ABSTRACT FROM AUTHOR]

The work involves the utilizing of solid-state nuclear track detector CN-85, to study the irradiated impact through incident alpha particles at different angles (80°, 90°), and irradiation time (5) min, after etching with 2.5N of NaOH solution at 60°±1 C, for different etching time between (0.5-4) hr. The results showed that both D and L for CN-85 exhibited an enhancement when exposed to Alpha particles, the alpha-particle track diameters and Length increased with Etching time but it decreased with the increased Energy of alpha particles. The experiment results also show that the D and L were affected due to the exposure to alpha particles and incident angles. This study is the first-time investigation CN-85 Nuclear track detector experimentally under the impact of alpha particles and suitable polymer for the detection alpha particles. [ABSTRACT FROM AUTHOR]

Several past research studies have demonstrated the fast fabrication of hygroscopic actuators using additive manufacturing (AM) technology. However, further insight is needed to assess the confounding effect of material types on the structure-property correlations in AM-produced hygroscopic bi-material actuators (BA). Premised on the above, this study sets out to quantify the responsiveness of BA produced by fused filament fabrication (FFF). The primary aim is to assess the influence of two FFF process parameters and the choice of materials on the BA's responsiveness. In this vein, the investigation examined the effect of FFF's layer height and extrusion width on the hygroscopic swelling coefficient of wood-filled polylactic acid polymers, pure polylactic acid (PLA) and thermoplastic polyurethane (TPU) polymers. Carried out also is the quantification of the hygromorphic response of monolithic FFF-printed BA derived from these materials. Deformation tests on the BA revealed its responsiveness to correlate positively with printing layer height, extrusion width, and the materials' hygroscopic coefficient of expansion. Besides, the monolithic BA derived from the combination of the Wood-filled PLA/TPU composite specimens were found to generate mean/maximum tip deflections of 6.44 mm/9.5 mm, which are 4% and 11% more than what was obtained for the Wood-filled PLA/PLA composite specimens. [ABSTRACT FROM AUTHOR]

Polymer flooding has shown to be effective in Enhanced Oil Recovery (EOR). In recent years biopolymers have attracted the attention of the petroleum Industry. Recently, it was identified that using biopolymer schizophyllan for polymer flooding operations has advantages primary benefit being environmentally friendly factor as well as stability under high salinity and temperature conditions. This biopolymer is commercially produced from the fungus schizophyllum commune using glucose as a carbon source via a fermentation process. However, the processing of this biopolymer is not economical due to the sources utilized in its production. This study aims to investigate the biopolymer schizophyllan produced utilizing locally and cheaply available sources in Malaysia for its rheological property at various range of salinity and temperature conditions. The experimental results showed that, viscosity of schizophyllan remains independent of salinity because of its non-ionic nature. Further, it was found that the loss in viscosity at high temperature was insignificant. This study will provide an alternative schizophyllan biopolymer from local sources that has potential in terms of properties and economics, making it available at any time of year and contributing to the field of polymer flooding. [ABSTRACT FROM AUTHOR]

Experiments on products modeling and design from the new environmentally friendly polymeric materials based on polylactide and coffee waste are carried out in this work. New wares are pots for seedlings and vases for planting greenery that can be used for landscaping for urban territories. Optimization researches on most effective structure of the new ecologically safe polymeric materials based on polylactide and coffee waste are carried out. The products design was made, the mathematical modeling of the designed products was carried out. [ABSTRACT FROM AUTHOR]

Doping with graphene nanosheets has attracted significant interest from researchers to enhance the structure and properties of nanomaterials because of graphene's unique properties and broad and essential applications. The study aims to focus on the effect of functional groups of both polymers and nanomaterials to fabricate a new nanocomposite consisting of poly (acrylamide) (PAAm) with poly (vinyl alcohol) (PVA) before and after the addition of graphene oxide nanosheets (GO) and studying its structural and optical properties. The developed method (dissolving with water, mixing, sonication, and casting) showed success in fabricating new nanocomposites for the first time by mixing these components with a ratio of 4.5: 4.5: 1 as percentages (PAAm: PVA: GO). Samples showed homogeneity of the polymer mixtures with each other and the excellent dispersion of graphene oxide nanosheets in the new polymer nanocomposite as exhibited by optical microscopy. The spectra of the Fourier infrared spectroscopy showed the strong interfacial interaction of the two polymers in the polymeric mixture with GO nanoparticles as nanocomposites. Also, X-ray diffraction showed shifting in some peak positions and increased crystallization of the polymers in the nanocomposites. The nanocomposites showed a notable improvement in the optical properties due to doping the polymeric mixture with graphene oxide compared with their blended polymers. The energy gap also significantly decreased after the contribution of graphene oxide up to 136% and 900% for the permitted and prohibited direct transfers, respectively. These results exposed promising nanocomposites for widespread applications such as solar cells. [ABSTRACT FROM AUTHOR]

An effective plasma treatment method is used to improve and cure the surfaces of polythiophene polymer and increase the surface roughness. In this paper, polythiophene polymer was prepared using electrochemical method using two electrodes cell, one of platinum (counter electrode) and the other of ITO (working electrode), with a voltage of 5 volts, a current of 3 mA, and a time of 5 minutes. The films were prepared and optical (UV-Vis) and morphological (AFM) measurements were taken. The properties of the polythiophene polymer were modified by dielectric barrier plasma (DBD) in the presence of air. The membrane surfaces were treated with 15 kV dielectric barrier-vacuum plasma and at different exposure times (0, 10, 30, 70) seconds. When exposed to plasma, the energy gap was decreased, and the surface roughness of the polythiophene polymer increased. Which gives an indication of the improvement and treatment of these films and their use in many applications [ABSTRACT FROM AUTHOR]