PENGARUH WAKTU KALSINASI TERHADAP KARAKTERISTIK KRISTAL CaO DARI LIMBAH CANGKANG KEPITING

Crab is one of the commodities exported by Indonesia in the fisheries sector. Crab processing to be exported produces crab waste. Crab shells contain high calcium carbonate. With a large CaCO3 content, crab shells can be used as a precursor of CaO in hydroxyapatite synthesis. CaO can be obtained by calcining calcium carbonate contained in the crab shell waste content. The calcination process is the process of decomposition of calcium carbonate (CaCO3) compounds into calcium oxide compounds (CaO) through heating at high temperatures. In this study the calcination temperature used was 1000 oC while the calcination time was varied ie 6 hours and 10 hours. The results showed that the crab shell, which is a source of CaCO3, which was calcined at 1000 oC for 6 hours and 10 hours both produced CaO compounds. CaO compounds produced have a crystalline form and are not in the form of amorphous. This can be observed from the XRD diffraction pattern, which is seen many peaks with varying intensity values. The second crystal system of the sample is cubic. There was no significant difference in the pattern of XRD calcination results of 6 hours and 10 hours, the difference only lies in the value of the variation in intensity of the peaks that formed. So it can be concluded that calcination at a temperature of 1000 oC with a length of 6 hours and 10 hours produces CaO crystals with a crystal size at a maximum peak is around 10 A.Crab is one of the commodities exported by Indonesia in the fisheries sector. Crab processing to be exported produces crab waste. Crab shells contain high calcium carbonate. With a large CaCO3 content, crab shells can be used as a precursor of CaO in hydroxyapatite synthesis. CaO can be obtained by calcining calcium carbonate contained in the crab shell waste content. The calcination process is the process of decomposition of calcium carbonate (CaCO3) compounds into calcium oxide compounds (CaO) through heating at high temperatures. In this study the calcination temperature used was 1000 oC while the calcination time was varied ie 6 hours and 10 hours. The results showed that the crab shell, which is a source of CaCO3, which was calcined at 1000 oC for 6 hours and 10 hours both produced CaO compounds. CaO compounds produced have a crystalline form and are not in the form of amorphous. This can be observed from the XRD diffraction pattern, which is seen many peaks with varying intensity values. The second crystal system of the sample is cubic. There was no significant difference in the pattern of XRD calcination results of 6 hours and 10 hours, the difference only lies in the value of the variation in intensity of the peaks that formed. So it can be concluded that calcination at a temperature of 1000 oC with a length of 6 hours and 10 hours produces CaO crystals with a crystal size at a maximum peak is around 10 A

Sustainability in construction work: A perspective on accidents and building failure mitigation in Indonesia

Sustainability in construction sector implementation depends to a wide range of level at national, regional, and local level. Also, it depends on the social and cultural aspect. Construction site safety is an essential aspect of sustainable construction. This paper proposes to identify the causes of accidents and building failure; to mitigate construction safety and building failure, and to describe the development and implementation of safety construction in order to improve safety culture according to the Law of Indonesia Republic No. 2/2017 of Construction Service and Decree of Minister of Public Works and Housing No. 21/PRT/M/2019 of Implementation Guideline of Construction Safety Management. Furthermore, the awareness of d from considering the underlying causes of accidents. This paper suggested, for the prevention of COVID-19 control and the accordance of construction safety; the optimization of digital services in coordination, supervision, control, and administrative governance is urgently needed. Moreover, the development of information technology and legal basis are required to achieve zero construction accidents and high quality infrastructure for both the service providers and users