Metal hydrides such as MgH₂ and NaBH₄ are among the materials for with the highest potential solid-state hydrogen storage. However, unlike gas and liquid storage, a dehydrogenation process has to be done prior to hydrogen utilization. In this context, the hydrolysis method is one of the possible methods to extract or generate hydrogen from the materials. However, problems like the MgH₂ passivation layer, high cost and sluggish self-hydrolysis of NaBH₄ are the known limiting factors for this process, but they can be overcome with the help of catalysts. In this works, selected studies have been reviewed on the performance of catalysts like chloride, oxide, fluoride, platinum, ruthenium, cobalt and nickel-based on the MgH₂ and NaBH₄ system. These studies show a significant enhancement in the amount of hydrogen released as compared to the hydrolysis of the pure MgH₂ and NaBH₄. Therefore, the addition of catalysts is proven as one of the options in improving hydrogen generation via the hydrolysis of MgH₂ and NaBH₄.

Acoustic energy transfer (AET) technology has drawn significant industrial attention recently. This paper presents the reviews of the existing AETs sequentially, preferably, from the early stage. From the review, it is evident that, among all the classes of wireless energy transfer, AET is the safest technology to adopt. Thus, it is highly recommended for sensitive area and devices, especially implantable devices. Though, the efficiency for relatively long distances (i.e., >30 mm) is less than that of inductive or capacitive power transfer; however, the trade-off between safety considerations and performances is highly suitable and better than others. From the presented statistics, it is evident that AET is capable of transmitting 1.068 kW and 5.4 W of energy through wall and in-body medium (implants), respectively. Progressively, the AET efficiency can reach up to 88% in extension to 8.6 m separation distance which is even superior to that of inductive and capacitive power transfer.

A Midimew connected Mesh Network (MMN) is a MInimal DIstance MEsh with Wrap-around links network of multiple basic modules, in which the basic modules are 2D-mesh networks that are hierarchically interconnected for higher-level networks. In this paper, we present the architecture of the MMN, addressing of node, routing of message, and evaluate the static network performance of MMN, TESH, mesh, and torus networks. It is shown that the MMN possesses several attractive features, including constant degree, small diameter, low cost, small average distance, moderate bisection width, and high fault tolerant performance than that of other conventional and hierarchical interconnection networks. It is also shown that with the same node degree, arc connectivity, bisection width, and wiring complexity, the diameter and average distance of the MMN is lower than that of the TESH network.

The new Covid-19 pandemic is affecting many economic sectors, such as the agricultural industry. The farmers faced many challenging constraints during the pandemic due to the enforcement of the Movement Control Order (MCO), resulting the unproductive crops. This paper proposed smart agriculture adopted with the Internet of Things (IoT) and Low Power Wide Area Networks (LPWAN) technology to be one of the possible solutions for the problems. Early precautions will minimize unproductive crops by monitoring the soil for healthy crops by monitoring the moisture and the pH level of the soil in real time. In this paper, a soil monitoring system using (Long-range) LoRa technology as one of the solutions for LPWAN to monitor the soil for agriculture has been set up. The soil moisture and pH sensors used to monitor the condition of the soil. The monitoring system uses LoRa as the communication network for the two sensors integrated into the Arduino Uno microcontroller as the transmitter and a receiver to monitor the status of the soil. This project enables the user to monitor the soil conditions and control the watering of the crops. The result concludes that this system shows 100% accuracy of the packet data received by the receiver, where the location of transmitter to the receiver was 1.4 meters apart.

This paper discusses the recent progress in micromachined energy harvesting for low power applications. Especially, the combination of piezoelectric and magnetic energy harvesting technologies are focused here. From the review, it is evident that, using the combined platform of piezo and magnetic device is more beneficial compared to the standalone system. It is found that, the proposed combined platform can achieve the output ranged from 40.8μW to 176μW based on the given load mass. Most of the cases it is proven that, the outcome of the hybrid harvester is superior than that of the standalone ones.

This paper presents an alternative approach to power up unmanned aerial vehicle (UAV) system using inductive approach. The main issue of utilizing UAV in any application especially in precision agriculture is the lifetime of the battery. This limits the flight time of the UAV which makes the system is unable to be efficiently applied for precision agriculture purpose. Hence, this paper proposes a new approach of powering UAV system by using so called inductive power transfer (IPT) technology. Through this approach, the system can be powered up wirelessly with no physical link in between transmitter and receiver. To be specific, class E inverter circuit has been designed together with impedance matching circuit to ensure higher efficiency is obtained. Finally, a prototype of IPT system for powering up the UAV system was successfully developed, which is able to transmit 23.32 W of power at 1 MHz operating frequency from 12 V input supply. The system achieved up to 95.73% efficiency.