A comprehensive understanding of physiochemical properties, thermal degradation behavior and chemical composition is significant for biomass residues before their thermochemical conversion for energy production. In this investigation, teff straw (TS), coffee husk (CH), corn cob (CC), and sweet sorghum stalk (SSS) residues were characterized to assess their potential applications as value-added bioenergy and chemical products. The thermal degradation behavior of CC, CH, TS and SSS samples is calculated using four different heating rates. The activation energy values ranged from 81.919 to 262.238 and 85.737-212.349 kJ mol-1 and were generated by the KAS and FWO models and aided in understanding the biomass conversion process into bio-products. The cellulose, hemicellulose, and lignin contents of CC, CH, TS, and SSS were found to be in the ranges of 31.56-41.15%, 23.9-32.02%, and 19.85-25.07%, respectively. The calorific values of the residues ranged from 17.3 to 19.7 MJ/kg, comparable to crude biomass. Scanning electron micrographs revealed agglomerated, irregular, and rough textures, with parallel lines providing nutrient and water transport pathways in all biomass samples. Energy Dispersive X-ray spectra and X-ray diffraction analysis indicated the presence of high carbonaceous material and crystalline nature. FTIR analysis identified prominent band peaks at specific wave numbers. Based on these findings, it can be concluded that these residues hold potential as energy sources for various applications, such as the textile, plastics, paints, automobile, and food additive industries.
The inerter is a two-terminal component that can be added to the spring-and-damper configuration of a suspension system. It has the property that the force exerted is proportional to the relative acceleration at its terminals. Studies have demonstrated the inerter's benefit of providing superior vibration isolation when it is used in the vehicle suspension of passenger cars. However, similar benefit on another common vehicle class on the roads, namely heavy vehicles, remain to be shown, as these vehicles have vastly different parameter values than passenger cars. This study is an investigation on the performance improvement brought by an inerter in the suspension of common heavy vehicles. In the study, the parameter values of a truck and a bus were adopted in the quarter vehicle model with two different spring-damper-inerter configurations (parallel and serial inerter), and the improvements in vibration isolation and road holding capability were determined by optimization of inertance. Results show that the inerter is similarly effective in providing the said improvements when implemented on heavy vehicles instead of on passenger cars, judging from reductions in sprung mass acceleration and dynamic tire load. It is also observed that the performance benefit is associated with larger optimum inertance than that for passenger cars. Overall, the inerter has been shown to be beneficial in the parallel and serial configurations, both of which are common and can be practically implemented in the suspension of heavy vehicles.
The existing literature in road safety revealed that the relationship between motorcycle deaths and per-head income follows a Kuznets or reverse U-curve pattern, whereby motorcycle deaths incline at lower income levels but decline once the per-head income has exceeded a threshold level. The same reverse U-curve relationship was also observed between per-head income and other road injury-related variables, including road deaths, road injuries, as well as road deaths to road injuries ratio. Evidence showed that motorcycles and passenger cars are the dominant vehicle modes and contributed significantly to global road deaths. The main objective of this study is to examine the relationship between the motorcycle deaths to passenger car deaths (MDC) ratio and per-head Gross Domestic Product (GDP). Examining the relationship between the MDC ratio and GDP per capita can be effective in understanding the relative change between motorcycle and passenger car deaths at different economic development stages, as well as identifying appropriate preventive measures. We apply a panel linear regression analysis on a panel of 38 countries over the period 1965-2013. Result demonstrated that there is a reverse U-curve relationship between the MDC ratio and the logarithm of GDP per capita. This implies that, at lower levels of GDP per capita, motorcycle deaths were more prevalent than passenger car deaths, whereas as the level of GDP per capita rises, passenger car deaths became relatively prevalent than motorcycle deaths. Moreover, there is a reverse U-shaped relationship between motorcycle ownership to passenger car ownership ratio (MPC) and the MDC ratio, while a U-shaped relationship exists between relative growth in higher mobility roads as compared to higher accessibility roads (MPA) and the MDC ratio. Based on our results, policies and interventions to reduce motorcycle and passenger car deaths were suggested in the conclusion of the paper.
The application of natural fibers is rapidly growing in many sectors, such as construction, automobile, and furniture. Kenaf fiber (KF) is a natural fiber that is in demand owing to its eco-friendly and renewable nature. Nowadays, there are various new applications for kenaf, such as in absorbents and building materials. It also has commercial applications, such as in the automotive industry. Magnesium hydroxide (Mg(OH)2) is used as a fire retardant as it is low in cost and has good flame retardancy, while polyester yarn (PET) has high tensile strength. The aim of this study was to determine the horizontal burning rate, tensile strength, and surface morphology of kenaf fiber/PET yarn reinforced epoxy fire retardant composites. The composites were prepared by hybridized epoxy and Mg(OH)2 PET with different amounts of KF content (0%, 20%, 35%, and 50%) using the cold press method. The specimen with 35% KF (epoxy/PET/KF-35) displayed better flammability properties and had the lowest average burning rate of 14.55 mm/min, while epoxy/PET/KF-50 with 50% KF had the highest tensile strength of all the samples. This was due to fewer defects being detected on the surface morphology of epoxy/PET/KF-35 compared to the other samples, which influenced the mechanical properties of the composites.
While previous research has shown that during mental imagery participants look back to areas visited during encoding it is unclear what happens when information presented during encoding is incongruent. To investigate this research question, we presented 30 participants with incongruent audio-visual associations (e.g. the image of a car paired with the sound of a cat) and later asked them to create a congruent mental representation based on the auditory cue (e.g. to create a mental representation of a cat while hearing the sound of a cat). The results revealed that participants spent more time in the areas where they previously saw the object and that incongruent audio-visual information during encoding did not appear to interfere with the generation and maintenance of mental images. This finding suggests that eye movements can be flexibly employed during mental imagery depending on the demands of the task.
Over the last decade, the progressive application of natural fibres in polymer composites has had a major effect in alleviating environmental impacts. Recently, there is a growing interest in the development of green materials in a woven form by utilising natural fibres from lignocellulosic materials for many applications such as structural, non-structural composites, household utilities, automobile parts, aerospace components, flooring, and ballistic materials. Woven materials are one of the most promising materials for substituting or hybridising with synthetic polymeric materials in the production of natural fibre polymer composites (NFPCs). These woven materials are flexible, able to be tailored to the specific needs and have better mechanical properties due to their weaving structures. Seeing that the potential advantages of woven materials in the fabrication of NFPC, this paper presents a detailed review of studies related to woven materials. A variety of factors that influence the properties of the resultant woven NFRC such as yarn characteristics, fabric properties as well as manufacturing parameters were discussed. Past and current research efforts on the development of woven NFPCs from various polymer matrices including polypropylene, polylactic acid, epoxy and polyester and the properties of the resultant composites were also compiled. Last but not least, the applications, challenges, and prospects in the field also were highlighted.
Recycling automotive waste has increasingly become an alternative solution towards producing sustainable materials given the rising issue of raw material shortages and waste management challenges at global level. The improper end-of-life vehicle (ELV) waste management poses detrimental impacts on the environment. This paper proposes a novel method to develop thermal insulation sandwich panels using ELV waste, motivated by the critical needs of creating high-performance thermal insulation for buildings. Six sandwich panels (P1-P6) of different weight and ratio of shredded ELV particles were manufactured. The sandwich panels structure was made of three layers: a core, and a glass face sheet bonded to each side. The core structure composed of Polycarbonate (PC) from headlamp lenses and polyurethane (PU) from seat, bonded using resin casting approach. Thermal conductivity of the samples was measured using guarded hot-plate apparatus. Results corroborated that thermal conductivity of ELV-based sandwich panels reduced remarkably compared to panel without ELVs, recorded at 15.51% reduction. Composition gives the best thermal performance was made of mixed ELV core materials of ratio 50%PC:50%PU, it has a thermal conductivity value of 0.1776 W/mK. The transparency data were obtained using Haze-gard plus haze meter. The best luminous transmittance value was exhibited by P2 (100% PC), 67.47%. The best clarity value and haze value were shown by P6 (25% PC: 75% PU), 55.13% and 52.6% respectively. ELV waste can be recycled to develop useful sustainable thermal insulation to improve thermal and optical transparency performance of buildings as a substitute for conventional materials which have a relevance for future façade concepts.
The incorporation of kenaf fiber fillers into a polymer matrix has been pronounced in the past few decades. In this study, the effect of multiwalled carbon nanotubes (MWCNTs) with a short kenaf fiber (20 mesh) with polypropylene (PP) added was investigated. The melt blending process was performed using an internal mixer to produce polymer composites with different filler contents, while the suitability of this melt composite for the injection molding process was evaluated. Thermogravimetric analysis (TGA) was carried out to investigate the thermal stability of the raw materials. Rheological analyses were conducted by varying the temperature, load factor, and filler content. The results demonstrate a non-Newtonian pseudoplastic behavior in all samples with changed kenaf fillers (10 to 40 wt %) and MWCNT contents (1 to 4 wt %), which confirm the suitability of the feedstock for the injection molding process. The addition of MWCNTs had an immense effect on the viscosity and an enormous reduction in the feedstock flow behavior. The main contribution of this work is the comprehensive observation of the rheological characteristics of newly produced short PP/kenaf composites that were altered after MWCNT additions. This study also presented an adverse effect on the composites containing MWCNTs, indicating a hydrophilic property with improved water absorption stability and the low flammability effect of PP/kenaf/MWCNT composites. This PP/kenaf/MWCNT green composite produced through the injection molding technique has great potential to be used as car components in the automotive industry.
Friction and wear are the main factors in the failure of the piston in automobile engines. The objective of this work was to improve the tribological behaviour and lubricant properties using hybrid Cellulose Nanocrystal (CNC) and Copper (II) oxide nanoparticles blended with SAE 40 as a base fluid. The two-step method was used in the hybrid nanofluid preparation. Three different concentrations were prepared in a range of 0.1% to 0.5%. Kinematic viscosity and viscosity index were also identified. The friction and wear behavior were evaluated using a tribometer based on ASTM G181. The CNC-CuO nano lubricant shows a significant improvement in term of viscosity index by 44.3-47.12% while for friction, the coefficient of friction (COF) decreases by 1.5%, respectively, during high and low-speed loads (boundary regime), and 30.95% during a high-speed, and low load (mixed regime). The wear morphologies results also show that a smoother surface was obtained after using CNC-CuO nano lubricant compared to SAE 40.
Consumer interest in privately managed urban transport services in Indonesia are showing a declining trend. On the other hand, the presence of Transportation on Demand (ToD) based on Internet of Things (IoT) has attracted the majority of conventional fleet customers which contribute to the declining trend of occupancy. Therefore, this study aims to present a feasibility study of a small car RE60 Three Passenger and One Driver (3P+1D) four-wheeler as an alternative to replace conventional fleets. The Break-Even Point (BEP), Net Present Value (NPV), Internal Rate of Return (IRR), and Payback Period (PP) are analyzed based on vehicle operating data. The analysis shows that there is an additional monthly income flow of IDR 1,533,122 and IDR 2,536,946 from RE60 operations compared to the high and low consumption of fuel from existing fleets, respectively. In conclusion, it is feasible to invest in small car RE60 as a replacement for the existing fleets since the fundamental indicators (BEP, NPV, IRR, and PP) showed positive results before the specified instalment period. Sensitivity analysis also shows good results, NPV shows positive results (>0) although the input conditions are made pessimistic to -30% from NPV base case. The BEP of RE60 will cut distance travelled at 190,670 km and 115,225 km, respectively. NPV of IDR 33,088,000 and IDR 80,841,000 will be obtained at the 60th month after the operation and IRR also enabled good scores, at 2.24% and 4.17%.
The relationship between typicality and novelty was discussed in order to identify the significant emotional value arising in the compact car design of Malaysian manufacturers. Typicality and novelty usually are associated with the aesthetic preference of human artefacts as in this study in compact car design. Considering a typical product is rarely new and, conversely, a novel product often labelled as typical, the positive effects of both features seem incompatible. This paper discusses the history of the Malaysian manufacturer’s compact car design according to its timeline and the current market based on its model and achievement. Furthermore, the relationship between compact car design such as the limitation of emotional value arising through typicality and novelty of specific compact car design and how it triggers the user’s perception through its aesthetics form. Hence, a pilot study was conducted to validate a set of stimulus and questionnaires as a way to formulate an actual survey. Finally, the outcome of this study will suggest a way forward in exploring typicality and novelty through a reliable method of compact car design
Automobile, aerospace, and shipbuilding industries are looking for lightweight materials for cost effective manufacturing which demands the welding of dissimilar alloy materials. In this study, the effect of tool rotational speed, welding speed, tilt angle, and pin depth on the weld joint were investigated. Aluminum 5052 and 304 stainless-steel alloys were joined by friction stir welding in a lap configuration. The design of the experiments was based on Taguchi's orthogonal array for conducting the experiments with four factors and three levels for each factor. The microstructural analysis showed tunnel defects, micro voids, and cracks which formed with 0° and 1.5° tilt angles. The defects were eliminated when the tilt angle increased to 2.5° and a mixed stir zone was formed with intermetallic compounds. The presence of the intermetallic compounds increased with the increase in tilt angle and pin depth which further resulted in obtaining a defect-free weld. Hooks were formed on either side of the weld zone creating a mechanical link for the joint. A Vickers hardness value of HV 635.46 was achieved in the mixed stir zone with 1000 rpm, 20 mm/min, and 4.2 mm pin depth with a tilt angle of 2.5°, which increased by three times compared to the hardness of SS 304 steel. The maximum shear strength achieved with 800 rpm, 40 mm/min, and a 4.3 mm pin depth with a tilt angle of 2.5° was 3.18 kN.
This study analyzes the association between trait driving anger and driving styles in a sample of Colombian professional drivers. Additionally, the internal and external validity of the Deffenbacher's Driving Anger Scale (DAS-14) was examined in the study population. The DAS-14 and the Spanish Version of the Multidimensional Driving Style Inventory (S-MDSI) were administered to 492 urban bus and taxi operators. Average trait driving anger scores in the study population were similar to those reported in previous validation studies from Spain, Argentina, China, and Malaysia. After deleting three cross-loaded items, confirmatory factor analyses revealed a three-dimensional latent structure for the DAS-14, similar but not equal to the previous Spanish speaking validations. This factorial structure fits the data reasonably well. Finally, linear regression analyses revealed that the three factors of the DAS-14 (impeded progress by others, illegal driving, and direct hostility) significantly predict adaptive and maladaptive driving styles. Overall, the results of this study suggest that the DAS-14 is a reasonably reliable measure of driving anger traits among professional drivers, and it also provides relevant insights for the prevention of risky driving styles in this occupational group.
This study proposes a neural network (NN) model to predict and simulate the propagation of vehicular traffic noise in a dense residential area at the New Klang Valley Expressway (NKVE) in Shah Alam, Malaysia. The proposed model comprises of two main simulation steps: that is, the prediction of vehicular traffic noise using NN and the simulation of the propagation of traffic noise emission using a mathematical model. First, the NN model was developed with the following selected noise predictors: the number of motorbikes, the sum of vehicles, car ratio, heavy vehicle ratio (e.g. truck, lorry and bus), highway density and a light detection and ranging (LiDAR)-derived digital surface model (DSM). Subsequently, NN and its hyperparameters were optimised by a systematic optimisation procedure based on a grid search approach. The noise propagation model was then developed in a geographic information system (GIS) using five variables, namely road geometry, barriers, distance, interaction of air particles and weather parameters. The noise measurement was conducted continuously at 15-min intervals and the data were analysed by taking the minimum, maximum and average values recorded during the day. The measurement was performed four times a day (i.e. morning, afternoon, evening, and midnight) over two days of the week (i.e. Sunday and Monday). An optimal radial basis function NN was used with 17 hidden layers. The learning rate and momentum values were 0.05 and 0.9, respectively. Finally, the accuracy of the proposed method achieved 78.4% with less than 4.02 dB (A) error in noise prediction. Overall, the proposed models were found to be promising tools for traffic noise assessment in dense urban areas.
This paper describes the Malaysian car owners’ preference to purchase their car through car lease swap arrangement. Since owning a car nowadays is a necessity for most individuals, people will try to find the easiest and fastest way to own a car. Hence, the aim of this paper is to describe the issues of car lease swap businesses conducted in Malaysia, in particular to understand the reasons, business mechanism, and benefits of buying a car via this method. Due to limited empirical studies on car lease swap arrangement in Malaysia, the research adopted a qualitative approach, which utilises the snowball method to identify its participants. Interviews were conducted with relevant parties, who were directly involved in car lease swap business, which include the car lease dealers, the car owners and third parties (buyers). The findings indicate that the car lease dealers were the most to gain out of this business, meanwhile the car owners were worse off. Compared to the third parties, the car owners benefited from the convenient arrangement of the business. Nevertheless, due to its vague legality, it is possible to have negative implications on all parties involved. As such, future research should look at all parties involved in investigating the issues of this car lease swap business, such as relevant government agencies and all other stakeholders.
The purpose of this case study is to look at how “Lean Techniques and Principles” can be successfully introduce and implement in the higher education institution or university context. In the last two decades, Lean techniques and principle has been applied to improve production system in manufacturing processes. Lean was introduced in the 1950s by Womack and Jones known as the Toyota Production System (TPS) by the legendary car manufacturer Toyota, the world’s most profitable automaker and have spent decades perfecting lean practices in the production. The method used was to produce more productivity while using fewer resources and identifying activities which creates value for customers, activities which do not create value but are required and actions which do not create value and can be eliminated. This case study demonstrates how “Lean Principles” can be adopted to the administration services particularly in the registration process for new student intake in USIM. The objective of this case study includes : to identify the needs of improving the registration process by eliminating the waste (Muda) such as time wastage, human resource wastage, to introduce the apparatus required to reduce and eliminate waste, to redesign the process using the lean techniques and principles to eliminate waste and to continually improve the process with the goal to achieve perfection for customer satisfaction and university’s reputation. How Lean Principles can transform the work process in the registration procedure, process efficiency, the reasons for implementing Lean in the process, minimize the lead time, minimize the financial cost and the role of management. This paper contains a comprehensive discussion and findings of the development of Lean principles and management through one of the models, namely; Value Stream Mapping (VSM) process which can enhance the operational process in the university environment to improve the process, particularly in the new student registration process.
Inventory Routing Problem (IRP) has been continuously developed and improved due to pressure from global warming issue particularly related to greenhouse gases (GHGs) emission. The burning of fossil fuel for transportations such as cars, trucks, ships, trains, and planes primarily emits GHGs. Carbon dioxide (CO2) from burning of fossil fuel to power transportation and industrial process is the largest contributor to global GHGs emission. Therefore, the focus of this study is on solving a multi-period inventory routing problem (MIRP) involving carbon emission consideration based on carbon cap and offset policy. Hybrid genetic algorithm (HGA) based on allocation first and routing second is used to compute a solution for the MIRP in this study. The objective of this study is to solve the proposed MIRP model with HGA then validate the effectiveness of the proposed HGA on data of different sizes. Upon validation, the proposed MIRP model and HGA is applied on real-world data. The HGA is found to be able to solve small size and large size instances effectively by providing near optimal solution in relatively short CPU execution time.
Taxis, being a significant element of mobility, play a sufficiently great role in public transportation. However, the issues towards taxi services have gradually increaseddue tothe poor servicesgiven to passengers by taxi operators,leadingto the demand for otherride servicealternatives.With the developmentof technology, GrabCarwasdeveloped and launched asanonline taxi booking through smartphone application which can easily connectpassengers and drivers. The main purpose of this study is to find out the perception of taxi operators towards GrabCar service and vice versa sothatthere will be a clear point of view to identify opportunities andchallenges for taxi operators. Standardized open-endedinterviews were conducted with5taxi and 5 GrabCar operatorsin Kuala Terengganu and Kuala Nerus. Interview transcriptswere analyzed using content analysis. The findingsshowedthat there weremore challenges than opportunities for the taxi operators. This studycould help the government to improvetaxi services in general and GrabCar servicesin sharing economy.
The topcoat color of motor vehicles offers vital information while investigating vehicular accidents, especially in instance of hit-and-run, since witnesses seldom perceive and retain the plate details. Differences in color perceptions among individuals with normal vision may lead to confusion in determining the color of the car involved. In this way, witnesses of crash accidents could potentially initiate flawed leads in forensic investigation, and thus affect the administration of justice. In this study, the inter-rater reliability of vehicle color determination by different volunteers was explored. Six individuals observed the topcoat colors of 500 stationary and 500 moving vehicles from five locations, employing a common system of color gradation. The outcome was binary: the vehicle color was either a "match" or "non-match". This was followed by statistical analysis in terms of the colors' frequencies and inter-rater reliability, based on which more suitable color descriptions were determined for subsequent comparisons of stationary and moving vehicles. Higher match frequencies and greater inter-rater reliability were observed when color gradations were disregarded. The frequency of correct matches could have been closely related to their relative on-the-road distribution, regardless of the statuses of observed vehicles. It was also found that black and white were associated with a greater number of matches than were intermediate colors, which should be carefully interpreted during forensic investigation to avoid wrong leads. In conclusion, the present study demonstrated the forensic significance of vehicle topcoat color determination, particularly in cases where witness statements are crucial.
Fused deposition modelling (FDM) has been widely used in medical appliances, automobile, aircraft and aerospace, household appliances, toys, and many other fields. The ease of processing, low cost and high flexibility of FDM technique are strong advantages compared to other techniques for thermoelectric polymer composite fabrication. This research work focuses on the effect of two crucial printing parameters (infill density and printing pattern) on the tensile, dynamic mechanical, and thermoelectric properties of conductive acrylonitrile butadiene styrene/zinc oxide (CABS/ZnO composites fabricated by FDM technique. Results revealed significant improvement in tensile strength and Young's modulus, with a decrease in elongation at break with infill density. Improvement in dynamic storage modulus was observed when infill density changed from 50% to 100%. However, the loss modulus and damping factor reduced gradually. The increase of thermal conductivity was relatively smaller compared to the improvement of electrical conductivity and Seebeck coefficient, therefore, the calculated figure of merit (ZT) value increased with infill density. Line pattern performed better than rectilinear, especially in tensile properties and electrical conductivity. From the results obtained, FDM-fabricated CABS/ZnO showed much potential as a promising candidate for thermoelectric application.