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Metal-organic framework (MOF) nanomaterials offer a wide range of promising applications due to their unique properties, including open micro- and mesopores and richness of functionalization. Herein, a facile synthesis via a solvothermal method was successfully employed to prepare amine-functionalized Cu-MOF nanospheres. Moreover, the growth and the morphology of the nanospheres were optimized by the addition of PVP and TEA. By functionalization with an amine group, the immobilization of a bioreceptor towards the detection of hepatitis B infection biomarker, i.e., hepatitis B surface antigen (HBsAg), could be realized. The immobilization of the bioreceptor/antibody to Cu-MOF nanospheres was achieved through a covalent interaction between the carboxyl group of the antibodies and the amino-functional ligand in Cu-MOF via EDC/NHS coupling. The amine-functionalized Cu-MOF nanospheres act not only as a nanocarrier for antibody immobilization, but also as an electroactive material to generate the electrochemical signal. The electrochemical sensing performance was characterized using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV). The results showed that the current response proportionally decreased with the increase of HBsAg concentration. More importantly, the sensing performance of the amine-functionalized Cu-MOF nanospheres towards HBsAg detection was found to be consistent in real human serum media. This strategy successfully resulted in wide linear range detection of HBsAg from 1 ng mL-1 to 500 ng mL-1 with a limit of detection (LOD) of 730 pg mL-1. Thus, our approach provides a facile and low-cost synthesis process of an electrochemical immunosensor and paves the way to potentially utilize MOF-based nanomaterials for clinical use.

This paper exhibits a method to predict the remaining service lifetime of inflatable rubber dam by considering the appearance of deep hole damage. The material used for the rubber dam is a composite comprising three layers of woven fabric as fiber and EPDM/SBR 64 474 rubber as a matrix. The service lifetime is predicted by calculating the degradation of rubber dam’s material properties. Simple Rate Law model and Time-Temperature Superposition model are employed to calculate the rubber properties degradation. A finite element analysis is then conducted to investigate stress and strain distributions which occur in the rubber dam membrane during operational loading. Furthermore, the effect of deep hole damage in the rubber dam, which is caused by improper maintenance, is modeled as well. The results show that a 7 mm depth of the hole can accelerate rubber degradation, which causes catastrophic failure. This can happen because two layers of the woven fabric in the rubber dam have been broken. Suggestion to hold up the degradation is also discussed.

With the increasing global concern on negative environmental effect from the transportation sector, conventional automobile technologies will not be viable for much longer. Countries like the EU and China have introduced emission related regulations which are stricter than ever. This has compelled automotive manufacturer to turn to Electric Vehicles (EV) as the most effective solution to this issue. There are mainly two types of EV, namely Battery Electric Vehicle (BEV) and Hybrid Electric Vehicle (HEV). Both has its own strength and shortcomings, BEV with zero emission but limited range while HEV has better range at the expense of higher emission. Extended Range Electric Vehicle (EREV) provides a midpoint between these options. This option provides the best of both worlds by allowing users to switch between both systems depending on the vehicle’s operating condition. This paper aims to presents a variety of Range Extender (RE) configurations based on its working principle and type of fuel used. Internal combustion engine, fuel cell, and microturbine are what RE is commonly powered by. The advantages and disadvantages are evaluated and compared to determine the optimal option. It was concluded that depending on fuel availability, space, and efficiency requirement, each configuration has its own merit.

Temperature management for battery packs installed in electric vehicles is crucial to ensure that the battery works properly. For lithium-ion battery cells, the optimal operating temperature is in the range of 25 to 40 °C with a maximum temperature difference among battery cells of 5 °C. This work aimed to optimize lithium-ion battery packing design for electric vehicles to meet the optimal operating temperature using an air-cooling system by modifying the number of cooling fans and the inlet air temperature. A numerical model of 74 V and 2.31 kWh battery packing was simulated using the lattice Boltzmann method. The results showed that the temperature difference between the battery cells decreased with the increasing number of cooling fans; likewise, the mean temperature inside the battery pack decreased with the decreasing inlet air temperature. The optimization showed that the configuration of three cooling fans with 25 °C inlet air temperature gave the best performance with low power required. Even though the maximum temperature difference was still 15 °C, the configuration kept all battery cells inside the optimum temperature range. This finding is helpful to develop a standardized battery packing module and for engineers in designing low-cost battery packing for electric vehicles.

This work investigates the influence of fiber surface profile and roughness to fiber–matrix interfacial properties. A series of the push-out test is performed using specimens with different fiber surface profile and roughness. Numerical simulation is then carried out by employing a finite element method to fit the experimental data. The model contains an indenter which pushes in a single fiber from the matrix, while the cohesive zone model is applied to represent the interface resulting in force–displacement curves. Our results suggest that continuous cavities formed in graphite-based fiber may not be beneficial to interfacial properties since it can accelerate a debonding process along with the interface. In contrast, scattered cavities on the fiber surface create strong mechanical locking, which increases the interfacial strength. These results broaden the understanding of the surface profile, which would shed light on a new perspective in designing composite structures.

Ultrasound technology employs cavitation to generate high-pressure soundwaves to disrupt bacterial cells. This study reveals the effectiveness of a single frequency ultrasound device for bacterial cell inactivation. A low-cost ultrasound device having a single frequency, i.e. 22 kHz for lab-scale application, was developed first, and the prototype was mechanically designed and analyzed using the finite-element method to assure the targeted natural frequency could be achieved. The prototype was then tested inactivating bacterial cells, Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis), in a simple medium and a food system, and the results were then compared to a commercial system. A treatment time of up to 15 minutes was able to reduce E. coli and B. subtilis cells by 3.3 log and 2.8 log, respectively, and these results were similar to those of the commercial system. The effectiveness of bacterial cell inactivation using the developed single-frequency ultrasound device is then discussed. The findings are useful for designing low-cost ultrasound devices for application in the food industry.

This paper demonstrates the design of an electric trike&rsquo, s energy management system for a goods delivery service via various possible component configurations. A model of the energy management system was first developed based on general engineering vehicles&rsquo, equations using Matlab software. Various component configurations, such as the usage of two battery types (lithium iron phosphate (LFP) and lithium nickel cobalt aluminum oxide (NCA)), implementation of three braking strategies (full mechanical, parallel, and series strategies), the presence of a range extender (RE), and various masses of range extenders were simulated by using the model. The driving cycle of the e-trike as input data in the simulation was obtained by driving the vehicle around Bandung City. Speed, distance, and elevation were obtained by using GPS-based software. The simulation results showed that the most efficient and effective component configuration was to use the serial regenerative braking strategy with no RE equipped. This configuration achieved an efficiency of 18.07 km/kWh. However, for a longer route, the usage of a 20-kg RE was required to prevent the state of charge drop below 30%. The NCA with serial regenerative braking and 20-kg RE had an efficiency of 17.47 km/kWh for the complete route.

Pouch battery has lightweight structure compared to other battery type because it consists of thin layered sheets of anode, cathode, and separator, covered by thin metal-based casing. Due to the thin layered structure, pouch battery has low structural integrity compared to other battery types. Thus, the structural damage, which initiates short circuit and thermal runaway, can easily occur on the pouch battery. The structural integrity of the battery is determined by the mechanical properties of each battery part besides its size and geometry. For that reason, it is important to study each part’s properties. The structural integrity can also be optimized by increasing the battery’s thickness, but the availability of space and aim to maintain good specific spatial energy of pouch battery should be considered. Therefore, the study on mechanical properties of the battery constituents and the casing are required to later improve the structural integrity of the battery which can avoid the structural damage and boost overall battery’s performance.

This paper reveals the role of interfacial rigidity in a fiber reinforced polymer (FRP) composite to crack propagation path and its reinforcement, investigated by simulating a plane-strain model – containing the matrix with a fiber inclusion – loaded transversely. Two fibers, i.e. carbon fiber and glass fiber, were examined. The interface between fiber and matrix was pre-defined using the spring model characterized by a stiffness parameter. A range of interfacial stiffness values from infinity (rigid bonding) to low stiffness were carefully investigated. The results suggested that direction of crack propagations inclined to approach the fiber when the interfacial stiffness was low, even if the fiber had much higher elastic modulus than the matrix – this finding is in contrast to the inclusion theory that merely considers rigid bonding interface. It also suggests that there existed a transition region in which the crack propagation path was altered, from approaching to avoiding the fiber. The region occurred when the interfacial stiffness was in the range between 105 and 106 MPa/mm, within which mechanical properties of the model were recorded to vary notably

Floating solar still is a suitable technology for remote or rural coastal area applications. The device should be made of low-cost materials available locally to provide more access to the broader community. However, the low-cost materials usually do not have the best physical properties, decreasing the overall solar still performance. This work demonstrated a low-cost floating solar still prototype entirely made of locally available materials. To further understand the influence of different parameters on the solar still performance and guide the prototyping process, we also performed the system's heat and mass transfer analysis. Our experimental results indicate a high absorber temperature (59.5 °C), even on a cloudy day. Our model also fits the temperature measurement reasonably. However, the recorded overall efficiency still suffers mainly due to the collection system, which decreases the overall performance; an example of a practical challenge, which is often overlooked but plays a crucial role in increasing the readiness level of the prototype.

The research in the electric vehicle requires a safe Reserved Energy Storage System (RESS) that is durable and crashworthy to withstand a harsh environment, especially ground impact from stone debris on the road. RESS, which typically uses lithium-ion type battery, is posed to the danger of thermal runaway as an aftermath of intrusion into the battery cell structures. Thermal runaway might happen because the separators between the anode and cathode damage and fail that result in a short circuit. Nowadays, metallic structures have been applied underneath the cells to protect RESS. However, the protection cannot hold high-speed impact properly. This research focuses on a composite-based protective layer by using sandwich panel constructions to achieve a stiffer structure. The design and analysis of the sandwich composite structure was conducted using non-linear finite element analysis. The study involves multiple design variables to take into account variations such as layer thickness, topology, and fiber orientation. This research only uses plain weave Carbon Fiber Reinforced Polymer (CFRP). The variables that are set as performance indicators are mainly cell deformation and energy absorbed. Among the two topologies tested, Navy Truss (NavTruss) model is proven to have better performance compared to the Blast Resistant Adaptive Sandwich (BRAS) model. This due to the NavTruss structure absorbs energy by undergoing progressive crushing, while BRAS structure collapse within the supports. In the NavTruss itself, various orientations are tested, and it is found that the most effective orientation is [(0/90)2/[(±45)/(0/90)]3]s. The optimum NavTruss composite structure configuration appears to be more superior with 36 percent mass saving compared to the metallic structure.

With the grcopyowing size of the electric vehicle (EV) market, the study of the battery system is paramount. Lithium-ion batteries have a high risk of flammability in the event of an accident or a collision that causes a short circuit. One of the highest potential threats to EVs is ground impact from stones or projectiles impingement that can hit and penetrate the battery pack. Therefore, it is necessary to develop a lightweight structure that can protect batteries in the event of dynamic impact load. The material used for the protection structure is fiber metal laminate (FML), which is a hybrid material consists of thin metal layers bonded together by intermediate composite. Evaluation of the risk of battery fire due to short circuit (battery shortening) and energy absorption of the protection structure is done by using the nonlinear finite element method. Parametric studies were conducted to investigate the effect of thickness, bonding strength, as well as two damage parameters such as failure and softening effect. Simulation results show that increasing the softening parameter can increase energy absorption but also increase the battery shortening. While increasing all the other parameters can increase energy absorption and reduce battery shortening. In this study, the most effective design for the protection structure was obtained, which is 1 mm-thick aluminum as the top and bottom layer, and 4.8 mm-thick carbon fiber reinforced polymer (CFRP) as the intermediate layer.

Degrees of human intervention for vehicular technology have been decreasing in the past few years. Automated cars and even autonomous ones have been appearing in successive events. One aspect to note is that automated systems for automobiles are believed to follow the technology for electric vehicles. For instance, with electric cars, people no longer have to worry about maintenances for valves, camshafts, connecting rods, crankshafts, transmission gears, clutches, and any other complexities of a car with an engine and a transmission. With a simpler environment for car interiors, we could focus more on enhancing its performance with even less monitoring utilizing automation. It will then require a real-time control system to guarantee timely responses and task priority setups for internal and external events of real-time systems, especially for the migration of Internal Combustion Engine (ICE) vehicles to electric cars.

The rapid development of renewable energy generation and electric vehicle utilization has effect on increasing demand of battery performance as the energy storage, including lithium-ion and well-developed and commercially available type of battery. In order to increase energy density, silicon is employed as anode electrodes due to its high specific capacity. However, silicon electrode has a limited cycle due to expansion and shrinkage during operation cycle, which leads to the mechanical failure. Nanostructured silicon has been reported to enhance the life cycle with various combination with other materials, including polymer. In this paper, silicon nanoparticles (SiNPs) are produced plasma chemical vapor deposition with controllable particle size. SiNPs with different particle size were produced while maintaining the crystallinity and narrow size distribution. Nanocomposite of SiNPs and polymer were produced by solution processing at low temperature, enabling a low cost of fabrication and preserves the unique properties of SiNPs. Material characterization on nanocomposite provides a potential application of SiNPs as anode material in li-ion batteries.

Battery development is essential to satisfy the green technology trend that requires electric-based technology. Lithium-ion battery (LIB) is the most popular battery that has been used in various electric technology. However, LIB has a concern on the safety aspect by using liquid electrolyte which is prone to thermal failure that leads to flame or explosion. Solid- state battery (SSB) recent development could handle such thermal problems due to the non-flammable characteristic of the solid electrolyte. SSB also has potential for future main battery candidates due to high energy & power density. Although there are many advantages, SSB also has several problems in recent development. Interfacial stability, low ionic conductivity on room temperature, mechanical properties, etc. need to be studied further to make an adjustment for further development. This review would give information regarding recent progress on SSB development from various types of electrolyte and failure mechanisms.

One of the main problems in designing battery packing for electric vehicles is the appearance of deformation in the components due to vibration generated by road profile. The vibration brings the most significant effect on the battery packing due to low frequency and high amplitude. Resonance occurs at low frequency since most of the E-trike components have a low natural frequency. This should be avoided to increase the reliability of the battery pack due to mechanical loadings. Modal analysis, Quarter Car Model (QCM), and optimization were conducted in this work. Modal analysis is used to find the natural frequencies of the battery pack on several modes of vibrations. Simulink of the Quarter Car Model (QCM) produces the load from the road profiles based on ISO 8608. The load from the road profiles is used as the input in the Ansys 16.0 Harmonic Analysis. The output is the deformation frequency response for the bottom side case of the battery pack. To reduce the outcome of resonance, a damping mechanism is selected to reduce maximum amplitude from road profile at a resonance frequency. The simulation results show that the damping mechanism is the suitable technology to decrease the major amplitude of the deformations from road profile with reduction up to 54% lower than the previous model. The lower deformations of the battery pack component reduce the battery pack’s possible accident due to vibration.

Energy storage devices, such as batteries are expected to store large amount of energy while delivering the energy rapidly. Particularly, Zn-air battery offers high specific energy and low production cost. We present a method to improve the cycle life of the rechargeable Zn-air battery by introducing additives into the alkaline electrolyte. Thiourea and polyethylenimine are chosen as the additive to suppress the growth of Zn dendrite during the charging process. Combination of thiourea and polyethylenimine as electrolyte additives is shown to produce smooth and compact Zn deposits. As a result, charging profile and cycling stability of rechargeable Zn-air battery with thiourea and polyethylenimine as electrolyte additives are improved as compared to the Zn-air battery without any electrolyte additives. The battery with electrolyte additives shows a stable performance for up to 250 discharge/charge cycles, which is higher than the battery without any electrolyte additives (187 cycles). This study illustrates a method to design a robust electrolyte system for a long cycle life of rechargeable Zn-air battery.

Electric vehicles (EVs) have received massive attention in their adoption as transportation and energy-assisting instruments. This phenomenon has been led mainly by the increased awareness and experience of the user (driver) on EVs regarding their excellent driving convenience, clean environment, and energy efficiency. Besides, several government policies also have driven the new user to shift from conventional vehicles to EVs following several favorable treatments, especially related to taxes. Generally, EVs have large battery capacity which can be controlled in both charging and discharging. Therefore, the idea of Vehicle-Grid Integration (VGI) has emerged recently, following the increased grid stress due to the massive charging of EVs and the opportunities to control and utilize EVs to participate in grid ancillary services. Several possible ancillary services include frequency regulation, load leveling (peak shaving), renewable energy storage, voltage regulation, and congestion mitigation. In this study, a preliminary analysis on the implementation of VGI in Indonesian grid, especially related to load leveling and frequency regulation, is discussed. Indonesian grid currently faces several problems, especially related to its quality and capability to balance and response to the fluctuating supply and demand. The well-coordinated EVs give high opportunity to the grid to utilize them as huge and responsive power storage to balance and maintain the electrical grid quality.

Safety is the primary concern in developing Electric Vehicles (EVs). Recent accidents on electric vehicles involving thermal runaway event have set drawbacks in EVs deployment around the world. Battery thermal management needs to be considered carefully during the design process. This work uses an integrated model of Li-ion batteries starting from the electrochemical process in the electrodes. The model is used to analyze the effect of both dimensions and materials on thermal behavior of Li-ion batteries. The results demonstrate that different designs are prone to suffer from the distinct risk of thermal runaway event. The results are expected to be a guideline to design batteries for EVs.

Graphite is a fascinating material to study in nanotechnology. Surface profile and roughness of the graphite are some of the most important parameters to determine many physical and mechanical behaviors including friction or bonding condition. To acquire certain surface profile, mechanical polishing treatment is one of the easiest ways that can be applied. In this work, graphite is polished by three different grades of sandpapers (P800, P400, and P220) and cellulose-based paper. The surface properties are observed by a laser microscope and various surface roughness parameters were quantified. The sequential polishing process employed in this work is able to modify the surface roughness and might improve the physical properties. This work sheds light on the importance of the mechanical surface treatment on graphite.

The alternative electric vehicle for delivery (E-Trike) is a developing three-wheel electric vehicle for goods delivery. Small size and its three-wheel mobility are required for flexible manoeuvrability on urban space due to traffic, parking and alley road. In this study, three different Alpha frames (Alpha-0, Alpha-1, and Alpha-2) of E-Trike vehicle are analysed using numerical simulation LS-DYNA. This study is conducted to obtain the modal response E-Trike vehicle. Eigenvalues of dynamics properties are investigated to avoid a resonance on excitation frequency. LS-DYNA implicit simulation used for simulating quadrangular shell element for the surface geometry of the frames. Boundary conditions are applied to the steering and suspension joints represent the real field. The result shows the amplitudes and the natural frequencies of Alpha frames. Bending mode and torsion mode can be determined. Based on the simulation, there is a pattern of vibration modes. Alpha-2 which is the latest version of three configurations has better response on vibration modes. There is about 3% reduction of vibration amplitude at Alpha-2 than Alpha-0 and Alpha-1. Natural frequency response for each mode occurs at similar range. Furthermore, a shifted natural frequency of Alpha-2 combination mode occurs due to addition of the stretched frame.

Concurrent calorimetric and interferometric studies have been conducted to investigate the effect that reduction of the base-plate dimensions has on the steady-state performance of the rate of natural convection heat transfer from miniaturized horizontal single plate-fin systems and plate-fin arrays. The effect was studied through comparison of the present results with those of earlier relevant calorimetric, interferometric, or numerical studies. Results shown that a reduction of the base-plate area by 74% increased natural convection coefficient by 1.5 times to 26.0 W m−2 K−1 for single fin systems and by 1.8 times to 18 W m−2 K−1 for fin arrays in the range of the base-plate temperature excess of 20–50°C. A simple correlation for the Nusselt number of miniaturized horizontal plate-fin arrays is proposed in the range of Rayleigh number divided by the number of fins to the 2.7 power from 2 × 10 to 5 × 105.

In this letter, we measured the nanoscale thermal radiation between a microsphere and a substrate which were both coated with thick goldfilms. Although gold is highly reflective for thermal radiation, the radiative heat transfer between two goldsurfaces was demonstrated to be significantly enhanced at nanoscale gaps beyond the blackbody radiation limit due to the tunneling of non-resonant evanescent waves. The measured heat transfer coefficient between two goldsurfaces agreed well with theoretical prediction. At a gap d = 30 nm ± 5 nm, the heat transfer coefficient between two goldsurfaces was observed to be as large as ∼400 W/m2·K, much greater than the blackbody radiation limit (∼5 W/m2·K).

Many devices and instruments such as magnetic hard disk drives and atomic force microscopes (AFM) rely on the stable operation of their small probing heads at nanoscale gaps. Due to the small scale of the probing heads, the force interactions (Casimir force and electrostatic force) between the small probes and the surrounding become more significant. The local heating caused by read/write electric currents in hard disk drives or probing laser beams in AFM on the probes inevitably leads to the heat transfer between them and the surrounding. The nanoscale heat and force interactions play a critical role in the performances of those instruments. In this paper, we use a bimaterial AFM cantilever to measure the nanoscale air heat conduction, radiation and force between a microsphere and a substrate. The resulting “heat transfer-distance” and “force-distance” curves clearly show the strong dependence of nanoscale interactions with gap distances.