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Cracks in concrete structures due to tensile weakness can be repaired by using fiber concrete, including medical mask waste as an additive in highstrength concrete mixes. This research the influence of polypropylene fiber from medical mask waste on the mechanical characteristics, flexural behavior, and crack width of high-strength reinforced concrete (RC) beams. The initial stage involved examining the properties of the concrete constituent materials. The testing process was based on a highstrength concrete mix design using the Aitchin method mix design sheet. Compressive strength and split tensile strength were tested at fiber content (0 %, 0.15 %, 0.20 %, and 0.25 %). The three-point flexural testing procedure was carried out at 28 days on 1200×100×150 (mm) RC beams. The use of LVDT, strain gauge, and other measuring devices supported the acquisition of the required data. The results showed that the split tensile strength reached the optimum value of 66.19 MPa at 0.24 % fiber content. Polypropylene fiber from medical mask waste in RC beams showed a positive impact on reducing crack width at increased split tensile strength. Waste mask fiber content of 0.15 %, 0.20 % and 0.25 % gave stable and better results compared to 0 % content (no fiber). With high steel stress (fs), and high strain, it offers the potential to improve the mechanical properties of high-strength concrete, thereby reducing the width of cracks that occur. This improves the tensile weakness of the concrete. The effect of split tensile strength on the crack width (w) of beams with the formula approach: wexp=3.74ftf-1.513, wan=0.187ftf-0.022 shows that the experimental results have a significant effect on decreasing the crack width that occurs in high-strength RC beams, thereby improving the quality of concrete. [ABSTRACT FROM AUTHOR]

The coronavirus causing the Covid-19 pandemic has been experienced by us since 2020, which has led to an increase in the use of disposable medical masks in Indonesia and even worldwide. Polypropylene is a thermoplastic polymer used as the main ingredient in medical masks that takes more than 25 years to decompose in landfills. This research offers an innovative way to use medical mask waste in high-performance concrete. The resulting medical mask waste is subjected to a sterilization process and cut into fibers to analyze the effect of its addition on the compressive strength and splitting tensile strength of high-performance concrete. The research began with testing the physical and mechanical properties of the materials, designing a concrete mix using the absolute volume method, and taking samples for compression and splitting tests. The variation in the ratio of water-cement and pozzolanic materials w (c+p) is 0.32. As a result, the compressive strength of concrete increased with a fiber size of 5×0.5 cm and 2×0.5 cm. An increase is up to 7 % with an optimum value of 72.37 MPa with a fiber size of 2×0.5 cm and a content of 0.15 %. However, there was a decrease in the compressive strength with a 5×1 cm mask fiber size. The overall split tensile strength value of all variations in waste fiber size and content increased with an optimum value of 7.29 MPa at 0.20 % fiber content with a fiber size of 5×0.5 cm. This indicates that polypropylene fibers from medical mask waste have a positive effect on high-performance concrete, namely improve the properties of concrete with a low tensile strength, which is expected to inhibit the propagation and reduce the size of cracks in reinforced concrete structures. [ABSTRACT FROM AUTHOR]

Microplastics have been found in the marine environment worldwide. Due to their very small size, it could be ingested by marine organisms from small size plankton to big size fish. The aim of this study is to assess the variability of microplastics in three different organs (gills, gastrointestinal tracts, and muscles) of commercial fishes in five different fishing ports in East Java Province, Indonesia. A total of 137 fish samples from 14 species were extracted to identify the types of microplastics. The microplastics found in the fish samples were mostly dominated by fiber, fragments, and a little quantity of film. In most species, the gills accumulated more microplastics compared to the gastrointestinal tracts and muscles. Gill is the organ that is highly exposed to the environmental conditions, therefore, it is more susceptible to the microplastic contamination. The results showed that there was an inverse relationship between the size of the fish and the occurrence of microplastics (P<0.05). Small size Sardinella lemuru contained more microplastics than bigger size fish such as Katsuwonus pelamis. The variability of microplastics found in this study showed important factors such as habitat, fish size, feeding behavior, and organ function which influenced the ingestion process of microplastic. This study also revealed the presence of microplastics were not only in the gills and gastrointestinal tracts of fish, but also in its muscles. Since this study targeted commercial fishes, further research is needed to know the possible impact on human consumption of fish containing microplastics. [ABSTRACT FROM AUTHOR]

Introduction: In a large-scale immunization program, there are concerns that there will be errors in the immunization program by health workers, such as in terms of storage or at the time of injecting vaccines. This raises a problem regarding the occurrence of adverse events following immunization (AEFI) experienced by people after vaccination. Considering that the government is the party that organizes the immunization program and procures vaccines, technically, the party that administers or injects the vaccine is the health worker. Methods: This research is doctrinal legal research using a conceptual approach and a statute approach. Results: AEFI is a medical event related to vaccine effects or effects, toxicity, side reactions, pharmacological or program errors, co-occurrence, injection reactions, or undetermined causal relationship. The increase in AEFI cases requires the government's role in handling efforts to reduce the number of AEFI cases. Monitoring and evaluation in the implementation of the immunization program is an infection necessary attempt to assess whether the activities have been carried out following applicable regulations. In addition, this activity must be able to identify aspects that cause cases of vaccine recipients experiencing AEFI. Conclusions:: Health workers can be personally responsible for their mistakes in administering vaccines. The government's responsibility is related to compensating people who suffer from AEFI as a form of government protection for their citizens. [ABSTRACT FROM AUTHOR]