The Effect of High Loaded Multiwall Carbon Nanotubes in Natural Rubber and Their Nonlinear Material Constants

The aim of this paper is to study the high load of multiwall carbon nanotubes (MWCNTs) in natural rubber (NR) matrix. Firstly, the rubber matrix, fillers, and crosslinker are thoroughly mixed together in two-roll mill. Rheological tests are done from which scorch time, cure time, and cure index are estimated. The kneaded mixer is then compression molded, dumb bell samples as per ASTM D412 are prepared, and tensile strength, tensile modulus, elongation at break, and hardness are measured. It is noticed that NR/30% MWCNT has shown the highest tensile strength of 23.38 MPa and Shore A hardness of 90, which is 78.18% and 91.5%, respectively, higher than the unfilled NR. The increase in strength and hardness, the ductility loss, and decrease in elongation at break are observed upon increase in filler. FTIR, SEM, and AFM examinations are done and the results show high dispersion of nanofillers and strong interfacial interaction with rubber, which is responsible for overall enhancement in mechanical properties of the nanocomposites. Furthermore, the nonlinear material constants are evaluated through extended tube model and corresponding nonlinear material constants of different filler compositions are presented for the designers to use them in their component design and analysis

Sifat magnet, mikrostruktur dan morfologi komposit getah asli termoplastik berpengisi Ferit NiZn/MwNT

Ferit NiZn dan nanotiub karbon diadunkan ke dalam getah asli termoplastik mengikut nisbah campuran 1:1. Kesan penambahan pengisi ke atas sifat magnet, struktur dan morfologi nanokomposit dikaji. Dua parameter magnet, iaitu pemagnetan tepuan dan daya koersif nanokomposit didapati bergantung kepada penambahan pengisi dalam matriks. Interaksi antara kedua-dua pengisi dalam matriks TPNR juga mempengaruh sifat magnet. Pengisi hibrid (ferit NiZn dan nanotiub karbon) bertabur sekata dalam matriks termoplastik getah asli. Kehabluran semi-amorfus fasa polipropilena didapati berlawanan dengan peningkatan kehabluran pengisi apabila kandungan pengisi bertambah

Advanced automation and robotics for high volume labour-intensive manufacturing

High volume, labour-intensive manufacturing operations pose several challenges for successful operations. It is an even bigger challenge to move away from manual dependency and shift towards automation of production processes. There seems to be no general agreement among researchers on what are the critical success factors (CSFs) on the implementation of advanced automation and robotics processes in the manufacturing environment. Success factors vary across the manufacturing industry and also organizational units. This paper attempts to elicit the opinion and perception of academic professionals with links to high volume labour-intensive manufacturing industry. A systematic literature search was conducted on the topic and semi-structured interviews were conducted with experts to gather their views on CSFs. Results from the literature search and interviews revealed that factors related to Organization Strategy, Culture, and Structure; Top management support; Past experience, staffing, and learning; Project management, planning, and control; Finance, and resource availability; Technology maturity and vendor support; to be critical for the success of the production process automation project initiatives. Findings from this study can be used as guidelines to ascertain CSFs for organizations and strategy planning. Manufacturing organizations can also use this study to evaluate their organizational readiness and enhance the level of automation further

Protein reduction of natural rubber films through leaching solvent

The finished product natural rubber latex gloves consist of latex proteins, which may pose a risk of allergic reactions in some latex-sensitive individuals. The allergic reactions depend on mild exposure to heavy exposure. An alternative solution to allergic users, usage of latex-free gloves are lack of elasticity and less comfort. This study aims to investigate natural rubber films protein reduction via three types of leaching solvent: acetic acid, sodium hydroxide, and ethanol in the leaching process. Then the influence of leaching solvent concentration on the physical properties of natural rubber gloves was analyzed. It was found that the acetic acid performed greater protein reduction effect (30.07%), followed by sodium hydroxide (27.77%), whereas the ethanol was shown to be less significant to protein reduction. All samples were fulfilling the mechanical properties as required in ASTM standard

Water Absorbing Plantation Clay for Vertical Greenery System

With the arises of environmental conscious, the usage of vertical garden system has become more popular in urban cities. Citizens can enjoys the benefits of energy and cost saving besides ornamental effect. More investigations have been conducted on green facades led to the cities ecological enhancement.However, limited plants species can be planted for green facades systems as this system does not provide sufficient soil and nutrients for common plants. Alternative plantation methods such as planted box and felt system required additional maintenance attention. The idea of using clay composite which consists of nutritious soil, water absorbing polymer and flexible cement clay potentially become alternative vertical greenery systems that offers economic and sustainable plantation platform for more variety of plants.The fabricating of clay composite involved three processes, they are: mixing, moulding and drying. Physical properties characterisation (density, pH, compression test, aging test and water immersion test) were tested on the dried fabricated clay composite to ensure their sustainability in tropical climate. The results showed that clay composite with 1.5 wt% of cement and 0.3 wt% superabsorbent polymer shows optimum water absorbing properties. This system are expected to enable more agriculture activities in urban living

Properties enhancement of TPNR-MWNTs-OMMT hybrid nanocomposites by using ultrasonic treatment

The main goal of this paper was to study the effect of ultrasonic treatment time on the mechanical properties of thermoplastic natural rubber (TPNR) reinforced with hybrid MWNTs-OMMT. The intercalation of TPNR enhancement into layers of clay by increasing the d-spacing was found using X-ray diffraction. The tensile properties of nanocomposites treated with ultrasonic increased when compared with untreated nanocomposites. The optimum ultrasonic treatment time was obtained at 3 h. The transmission electron microscope micrograph showed a combination of intercalated-exfoliated structure of the TPNR composites with organic clay and dispersion of MWNTs. The ultrasonic treatment can promote the dispersion of MWNTs-OMMT in TPNR and also improved the compatibility of hybrid filler and the TPNR matrix

Room Temperature Dynamic Control and Energy-saving System

According to statistics, the energy consumption of building air conditioning system operation accounts for about 50% of the energy consumption in the building operation phase. Therefore, reducing the energy consumption of building air conditioning systems is of great significance for building energy conservation. The traditional air conditioning system sets a constant temperature during operation and then adopts the PID control method to gradually approach this target value. This method does not take into account dynamic factors such as the building environment, personnel activities, and startup equipment rates, resulting in a large waste of energy consumption and poor comfort. This paper proposes a solution combining the Internet of Things and a heuristic optimization algorithm, in which the Internet of Things is responsible for collecting real-time parameters, and the optimization algorithm is responsible for solving the optimal control strategy, to realize intelligent real-time dynamic adjustment of indoor temperature. By comparing the actual operation results, it can be seen that the control system can reduce power consumption by about 10% and increase user satisfaction by about 8%

Protein reduction of natural rubber films through leaching solvent

The finished product natural rubber latex gloves consist of latex proteins, which may pose a risk of allergic reactions in some latex-sensitive individuals. The allergic reactions depend on mild exposure to heavy exposure. An alternative solution to allergic users, usage of latex-free gloves are lack of elasticity and less comfort. This study aims to investigate natural rubber films protein reduction via three types of leaching solvent: acetic acid, sodium hydroxide, and ethanol in the leaching process. Then the influence of leaching solvent concentration on the physical properties of natural rubber gloves was analyzed. It was found that the acetic acid performed greater protein reduction effect (30.07%), followed by sodium hydroxide (27.77%), whereas the ethanol was shown to be less significant to protein reduction. All samples were fulfilling the mechanical properties as required in ASTM standard

Moving magnet linear compressor: Operating characteristics under resonance and off-resonance frequencies

Objectives: This study compared the accuracy of a Linear Equivalent model and a Fourier Transform model in approximating the resonant frequency of a moving magnet oil-free linear compressor. Furthermore, moving magnet linear compressor performance under resonance and off-resonance frequencies was also examined via an experimental approach. Methods: A Linear Equivalent model and a Fourier Transform model were developed and compared with experimental results at low-pressure ratios of 2–2.5. By varying the operating frequency and compressor piston stroke, the power consumption, compressor losses, efficiency, and cooling capacity are assessed experimentally. Results: This study showed that the disparities between resonance frequencies estimated by theoretical models and experimental data were below 10 %. However, the Linear Equivalent model was more accurate than the Fourier Transform model in forecasting the resonance frequency of the linear compressor at a low-pressure ratio of 2–2.5. Both experimental and modelling results showed that the resonance frequency of a linear compressor declined with the increasing compressor stroke but increased with increasing pressure ratio. Experiments were also carried out to compare the performance of linear compressors in resonance and off-resonance frequencies. Results showed that the lowest compressor input power of 91.96 W and the highest motor efficiency of 81.98 % was achieved when the linear compressor was operated at 38 Hz resonance frequency. Moreover, the cooling capacity has been found to increase by 270 W approximately when the linear compressor piston operating stoke extends from 10 mm to 13 mm. Conclusions: In all, this study showed that the linear compressor motor efficiency is the highest when operating at resonance frequency. However, the cooling capacity of the linear compressor system does not vary significantly with operating frequency. A higher cooling capacity can be achieved by increasing compressor piston stroke

One-pot extraction of nanocellulose from raw durian husk fiber using carboxylic acid-based deep eutectic solvent with in situ ultrasound assistance

Nanocellulose (CNF) has emerged as a promising alternative to synthetic petroleum-based polymers, but the conventional preparation process involves multiple tedious steps, heavily dependent on chemical input, and proves cost-inefficient. This study presented an, in situ ultrasound-assisted extraction using deep eutectic solvent (DES) based on choline chloride and oxalic acid for more facile production of CNF from raw durian husk fibers. FESEM analysis confirmed the successful extraction of web-like nanofibril structure with width size ranging from 18 to 26 nm. Chemical composition analysis and FTIR revealed the selective removal of lignin and hemicellulose from the raw fiber. As compared to post-ultrasound treatment, in situ ultrasound-assisted extraction consistently outperforms, yielding a higher CNF yield with finer fiber width and significantly reduced lignin content. Integrating this eco-friendly in situ ultrasonication-assisted one-pot extraction method with a 7.5 min interval yielded the highest CNF yield of 58.22 % with minimal lignin content. The superior delignification ability achieved through the proposed in situ ultrasound-assisted protocol surpasses the individual efficacy of DES and ultrasonication processes, neither of which yielded CNF in our experimental setup. This single-step fabrication process significantly reduces chemical usage and streamlines the production steps yielding web-structured CNF that is ideal for sustainable application in membrane and separator