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Mosquitoes are insects that are detrimental to human health because they act as disease vectors, such as dengue fever. Surabaya was known for its high risk of dengue fever. This study aims to describe the diversity of mosquitoes and breeding site distribution in Eastern Surabaya. The study was conducted in 2021 during the end of the wet season in different habitat types in the eastern Surabaya (residential, city park, bamboo forest, and mangrove forest). Eggs, larval, and adult-stage mosquitoes were collected and stored in the Entomology Laboratory for morphological identification. Adult mosquito was collected by using a sweep net and light trap method, while the larva and egg were collected incidentally from breeding sites. The diversity of mosquitoes in the Eastern Surabaya was determined by using the Shannon-Wiener diversity index (H’), dominance, species richness (R), and breeding site distribution. Eleven species were obtained in this study, namely Aedes aegypti, Aedes albopictus, Aedes annandalei, Anopheles subpictus, Anopheles vagus, Anopheles barbirostris, Culex bitaeniorhynchus, Culex pseudovishnui, Culex quinquefasciatus, Mansonia uniformis, and Malaya genurostris. The H’ index of 1.63 indicates the mosquito community was at a moderate level. The R-value of 1.56 indicates a low level of mosquito species richness. The most abundant species was Cx. quinquefasciatus (37.2%). Most of the breeding sites with mosquito larval infested were found in open areas (79.3%). These numbers mean the total of individuals of each species tends to be low and its dominance shows no effect on other species. The data on mosquito species and their distribution in Surabaya could be used as base information for vector control strategies.

The invasion of nipah (Nypa fructicans) occurred in the Air Telang Protected Forest (ATPF), Indonesia, as a result of mangrove forest degradation caused by anthropogenic activities in the area. This research aims to analyze the distribution of nipah populations in the ATPF and at the same time describe the benefits and potential of nipah both in the ATPF and in various regions in the world. The data collected in this research consists of two types, namely primary data and secondary data. Primary data was obtained through field surveys in the ATPF area, while secondary data was obtained through literature studies of relevant research results. Nipah populations can be widely distributed in degraded mangrove forest ecosystems and invade areas outside their natural habitat because they have high adaptability to the environment, high seed productivity and effective and adaptive seed distribution. Even though the spread of nipah in the ecosystem can hinder the succession of mangrove forests, it turns out that nipah has great benefits for the community and contains important compounds that are useful for making foods, drinks and medicine..

The goal of this research is to improve the mechanical properties such as strength, hardness and wear resistance for automotive application such as brake shoe and bearings due to high cycle, load and impact during their usage. Therefore, another alloying element or reinforcement addition is necessary. In this work, the composites are made by ADC 12 (Al-Si aluminum alloy) as the matrix and reinforced with micro SiC through stir casting process and TiB is added various from (0.04, 0.06, 0.15, 0.3 and 0.5) wt.% that act as grain refiners and 5 wt.% of Mg is added to improve the wettability of the composites. The addition of TiB improves the mechanical properties because the grain becomes finer and uniform, and the addition of Mg makes the matrix and reinforce have better adhesion. The results obtained that the optimum composition was found by adding 0.15 wt.% of TiB with tensile strength improve from 98 MPa to 136.3 MPa, hardness from 35 to 53 HRB and wear rate reduced from 0.006 2 mm3 s−1 to 0.002 3 mm3 s−1 respectively.

The addition of silicon carbide (SiC) as a reinforce in a composite can improve mechanical properties. In this study aluminium ADC 12 (Al-Si-Aluminium Alloy) is treated with an addition of SiC varied from (1; 1.5; 2; 2.5 to 3) vf% and mixed with 0.18 wt% Sr to change the morphology of the silicone eutectic phase and 0.15 wt% titanium boron (TiB) was added as a grain refiner as well as the addition of 5 wt% magnesium (Mg) to increase the wettability. All materials were fabricated by stir cast method. This research is conducted to obtain the candidate material for application in train's brake shoe and bearing. This kind of usage requires high mechanical properties such as wear resistance, thermal resistance, good elastic modulus and lightweight. The composites were characterised by both mechanical properties and microstructure. The result shows that there is an increase in the mechanical properties of aluminium ADC 12 /SiC composite compared to unreinforced with the value of 144 MPa of strength, 53 HRB of hardness, and 0.0049 mm3 m–1 of wear rate. As a result, the higher addition of the SiC results in the better mechanical properties for the composite.

A study of ADC12 (Al-Si aluminium alloy) composite is conducted to obtain a more sustainable material with enhanced properties for automotive industry purpose, such as train's brake shoe and bearing application. For those kind of utilization, material with durability, good elastic modulus, thermal stability, wear resistance, and high strength properties is needed due to its exposure to high temperature and heavy continuous application. ADC 12 acts as the matrix, reinforced with 3 vf% micro-SiC with 5 wt% Mg wetting agent was fabricated by the stir casting method. The addition of 0.18 wt% Sr and 0.15 wt% TiB were expected to finer the grain morphology of the silicone eutectic phase and to acts as the grain refiner, respectively. Furthermore, T6 heat treatment was applied with aging temperature 150 °C, 170 °C, 190 °C, 210 °C, and 230 °C, following the prior 1 h 490 °C solution treatment. The results obtained in this work showed enhancement in tensile strength with the value of 213 MPa, hardness value 75 HRB, and wear resistance. These values increase up to 115 MPa for the UTS and 38 HRB for the hardness value, as the impact of the refined grains from both modifiers and heat treatment.