Judul: Dampak Kebijakan Pembatasan Ekspor Nikel Terhadap Hilirisasi Nikel di Indonesia
Abstrak: Indonesia merupakan salah satu negara yang memiliki cadangan nikel terbesar dan penghasil nikel nomor satu di dunia. Dengan hasil tambang nikel yang melimpah, diperlukan adanya hilirisasi untuk meningkatkan nilai tambah komoditas hasil tambang. Hilirisasi dilakukan untuk komoditas ekspor yang awalnya masih dalam keadaan mentah, diolah menjadi barang setengah jadi atau jadi. Kebijakan hilirisasi ini diharapkan mampu memberikan dampak positif bagi perekonomian serta menjadi salah satu penopang perekonomian Indonesia di masa mendatang. Oleh karena itu, penelitian ini dilakukan untuk mengetahui dampak kebijakan pembatasan ekspor nikel terhadap hilirisasi nikel selama periode 1997 – 2021 dengan metode ARDL-ECM. Selain itu, penelitian ini juga melihat dinamika ekspor bijih nikel dan ekspor produk turunan nikel terhadap kebijakan pembatasan ekspor nikel melalui metode deskriptif. Hasil penelitian menunjukkan bahwa kebijakan pembatasan ekspor nikel, jumlah perusahaan, GDP current dunia, dan pandemi Covid-19 berpengaruh positif signifikan terhadap hilirisasi nikel., Indonesia is one of the countries that has the largest nickel reserves and is the number one producer of nickel in the world. With abundant nickel mines, downstream is needed to increase the added value of mining commodities. Downstreaming is carried out for export commodities which are initially still in a raw state, processed into semi-finished or finished goods. This downstream policy is expected to have a positive impact on the economy and become one of the pillars of the Indonesian economy in the future. Therefore, this research was conducted to determine the impact of nickel export restriction policies on nickel downstream during the period 1997 – 2021 using the ARDL-ECM method. In addition, this study also looks at the dynamics of nickel ore exports and exports of nickel derivative products against nickel export restriction policies through a descriptive method. The results showed that the policy of limiting nickel exports, the number of companies, the current world GDP, and the Covid-19 pandemic had a significant positive effect on downstream nickel.
Keyword: ARDL-ECM, Covid-19 Pandemic, Downstream, Export Restrictions

Judul: Dampak Pertambangan Nikel Terhadap Sosial – Ekonomi – Ekologi Masyarakat di Kecamatan Wasile Kabupaten Halmahera Timur
Abstrak: Wasile, one of the East Halmahera district contained nickel mining, and a great influence on the social, economic and environmental life of the community. Thus this study refers to the theory and previous studies, researchers tried to base it on a frame of mind that the Sustainability of social, economic society strongly influenced by; carrying capacity of the environment, natural resources, human resources, facilities and infrastructure, the financial, social and cultural rights. The purpose of this study was to analyze the impact of nickel mining on socio - economic - ecological communities in the sub District Wasile, East Halmahera. The research center is a sample of 2 (two) villages that are near and far away from the mining of nickel, the village of Batu Raja (near the village) and Subaim Desa (village far). By sampling in this study consisted of local people to be around and who are far away from the nickel mining company, yet to feel the impact of the mining question. The number of samples taken from the respondents ie 80 people consisting of 40 people from each village who are near and far away from the mine site consisting of local people actively working. Direct Observation Field Interviews In-depth interviews using questionnaires Change in Productivity analysis or can be referred to as the Productivity method, Chi-square analysis, and SWOT. Based on the results of mining in the region contribute to the local economy are significant in terms of: (a) regional Revenue, (b) Expansion of employment opportunities, (c) Reduction of unemployment in the area. But the social and ecological impact is not profitable to society. The formulation of the proposed policy are: (1) there was no issuance of new licenses. The hold and maintain the position of the SWOT analysis, meaning that the company's existing nickel can be allowed to continue operations, but the company must pay attention to social and ecological impacts that adversely affect local communities and the environment. Suggestions policies proposed by this research is to increase CSR schemes to improve the adverse effects of mining companies operating in the fields of social and ecological.
Keyword: 

Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology