Greenery systems are sustainable ecosystems for buildings. Many studies on greenery systems, such as green roofs and green walls, have demonstrated that greenery systems support energy saving and improve thermal conditions in the building sector. This paper summarizes, discusses, and compares greenery systems and their contributions to the reduction of the urban heat index, the reduction of internal and external buildings’ wall temperatures, and the reduction of the energy consumption of buildings. The fundamental mechanisms of greenery systems, which are thermal insulation, evapotranspiration, and shading effect, are also discussed. The benefits of greenery systems include the improvement of stormwater management, the improvement of air quality, the reduction of sound pollution, the reduction of carbon dioxide, and the improvement of aesthetic building value. The summarized materials on the greenery systems in the article will be a point of references for the researchers, planners, and developers of urban and rural areas, as well as the individual’s interest for future urban and rural plans.

The photovoltaic panel has become the most promising alternative technology for energy demand. Solar trackers have been used to improve the efficiency of a photovoltaic panel to maximize the sun’s exposure. In high temperatures, however, the photovoltaic efficiency is significantly reduced. This study observes photovoltaic/thermoelectric generator performance driven by a dual-axis solar tracking system. A photovoltaic/thermoelectric generator panel was built and equipped with angle and radiation sensors. A microcontroller processes the sensor signal and drives the motor to follow the sun’s movement in two-axis directions. Thermocouples are mounted on the photovoltaic and thermoelectric generator surfaces to monitor the temperature. The result shows that the temperature of the photovoltaic/thermoelectric generator is lower than that of the photovoltaic one. However, a contradiction occurred in the output power. The efficiency of the combined photovoltaic/thermoelectric generator was 13.99%, which is higher than the photovoltaic panel at 10.64% and the thermoelectric generator at 0.2%. The lower temperature in the photovoltaic/thermoelectric generator is responsible for increasing its performance. Although the thermoelectric generator contributes modest efficiency, its role in reducing the temperature is essential. Analyses of some cooling techniques for photovoltaic panels prove that the combined thermoelectric generator and heat sink improves photovoltaic performance with simplified technology.

Two third of the total energy in the internal combustion engine (ICE) system is lost and turns as waste heat through the exhaust system and coolant circulations. Therefore, it is necessary to have a technology that is able to convert waste heat from ICE into electrical energy using thermal electric generator (TEG). To have the best thermoelectric generator (TEG) performance in terms of higher electricity generation, the temperature on the hot surface should be higher, and the temperature on the cold surface should be as low as feasible. The goal of the study was to study how differences in TEG cooling systems affected the overall performance. Water block and heatsink-fan are two different types of cooling systems that have been used in this experiment. The water flow rate in water block cooling systems varies between 200, 300, 400, 500, and 600 l/h. The TEG module was heated with gas-fired lighters. Arduino-based data loggers were used to record hot and cold temperatures on the TEG surface. A USB multimeter is used to measure TEG performance as electrical voltage. The results showed that 300 l/h was the best water flow rate for TEG cooling. When using a water block cooling system instead of a heat sink, the electrical voltage generated by the TEG module is 12 percent higher. This study found that a cooling system with water blocks is superior to heatsink-fan.

Multilayer armour system (MAS) becomes the best choice in reinforcing protection for military officers against projectile attack which has a high velocity of up to 7.62×51 mm NATO ball lead core (projectile level III NIJ standard) or AP 7.62×51 mm hard steel core (projectile level IV NIJ standard). This study aimed to analyze the damage formation of wolfram carbide (WC) ceramic and ramie fiber composites. The frontmost MAS uses WC ceramic and is enveloped by a back layer of ramie fiber composites with epoxy resin reinforcing material as the matrix. Ballistic testing was carried out in this study using a long-barreled rifle to determine the resistance of the MAS from projectile impact. The speed meter in ballistic testing uses a velocity sensor type light screen B 471 and clay witness is used to measure back face signature (BFS). The results show that 7.62 lead core and hard steel core projectiles were unable to penetrate the 3-layer ceramic MAS in the front. The results are marked by a relatively low BFS value of 1.45 and 1.17 mm, so that the energy in the MAS with 3 ceramic layer is absorbed efficiently but with the phenomenon of rupture ceramic failure. Ceramic rupture failure needs to be overcome by bonding several layers of ramie so that MAS can be used in the next stage. MAS with 1 and 2 ceramic layers are unable to withstand projectile level III and level IV NIJ standard. From these results it is known that the MAS limit can withstand the projectile level III and IV NIJ standard, namely MAS with 3 ceramic layers. The damage formation of ceramic was rupturing ceramic failure. Therefore, it is necessary to design a ceramic binder by placing some ramie fibers in front of the ceramic

This research aims to design an induction heating system and to investigate the effect of power supply and specimen diameter on specimen temperature and frequency on the coil. This study began with the development of an induction heating system that made use of circulating coolers outfitted with Thermoelectric Cooler Materials (TEC). It was intended to keep the temperature of the coil and the Printed Circuit Board (PCB) as low as possible. This study used AISI 4140 steel material with diameter variations of 7 mm, 14 mm, 21 mm, and 28 mm, with power levels of 60 W, 240 W, 540 W, and 960 W. The temperature was measured using a thermocouple connected to the specimen, and the frequency value obtained was measured using an oscilloscope. The research findings show that varying the applied power affects the frequency of the coil and the temperature of the specimen, with the higher the power, the faster the temperature of the specimen rises. The 60 W power can heat the specimen at an average temperature of 470°C and a frequency of 102 kHz. When the power variation is 960 W, the temperature in the specimen is 746°C, and the frequency is 110 kHz. On the temperature and frequency gradient pattern in the 0-600 s period, there are two stages, the first of which is ferromagnetic and the second of which is paramagnetic.