ABSTRAKLithium adalah salah satu mineral yang mempunyai permintaan yang paling tinggi dalam Revolusi Industri Keempat. Indonesia yang kekayaan alam nikelnya besar, ingin menjadi negara penghasil baterai. Oleh karena itu, diperlukan investigasi sumber bahan baku utama lainnya dalam produksi baterai. Sumber daya bahan baku utama baterai adalah Lithium. Penyelidikan litium sebagai sumber bahan baku di Indonesia telah dilakukan melalui tinjauan pustaka. Sumber daya alam litium ditemukan di air laut, Brine, mineral, dan tanah liat. Endapan yang mengandung Mineral Lithium terdapat di beberapa tempat di Indonesia dalam jumlah dan konsentrasi yang kecil. Sebagai negara yang dilalui cincin api, Indonesia memiliki banyak mata air panas dan Brine yang mengandung Lithium. Tanah liat yang mengandung litium ditemukan dalam bentuk slurry (brine dan lumpur tanah liat), seperti pada lumpur Bleduk Kuwu dan lumpur Sidoharjo. Bittern sebagai limbah industri garam memiliki potensi besar untuk dikembangkan sebagai sumber Lithium di IndonesiaKata kunci: Lithium, Sumber Air Panas, Brine, Clay, Bittern   ABSTRACTLithium is one of most demanding minerals in The Fourth Industrial Revolution. Indonesia whose large Nickel natural resources, wants to become a battery producing country. Therefore an investigation of other main raw material sources in battery production is needed. The main raw material resource for batteries is Lithium. The investigation of lithium as raw material resource in Indonesia has been carried out through a literature review. Lithium natural resources are found in sea water, Brine, minerals, and clay. Mineral Lithium containing deposits are found in several places in Indonesia in small amounts and concentrations. As a country through which the ring of fire passes, Indonesia has a lot of hot spring water and Brine containing Lithium. Clay containing lithium is found in the form of slurry ( brine and clay mud), such as in the Bleduk Kuwu mud and the Sidoharjo mud. Bittern as a waste of salt industries has great potential to be developed as a source of Lithium in IndonesiaKeywords: Lithium, Hot Spring Water, Brine, Clay, Bittern

Right now the world is facing the Covid-19 outbreak virus, not least in Indonesia. This outbreak has been a pandemic since its inception at the end of 2019. The whole world is struggling to fight this pandemic, as well as in Indonesia where every struggle is increasing so much. All public places are temporarily closed to prevent the spread of the Covid-19 virus. The school became one of the public places that was temporarily closed in order to prevent the spread of the Covid-19 virus in the school environment. There are many causes for the transmission of the Covid-19 virus and the losses that can result from the Covid-19 virus. Therefore the purpose of this study is to be able to use hazards, risks and risk control using the Danger Identification, Risk Assessment and Risk Control (HIRARC) methods in the school environment. Risk identification is done by descriptive research methods, namely the results of research data and related journals available. The results of the study can be known about the activities that exist in the school environment that are needed for distribution and transmission of the Covid-19 virus. There are 14 main activities with 34 potential hazards, expected 13 activities with a high risk category and 1 activity with a high risk category. To be able to control the danger, use protection, wear a mask, always wash your hands using soap and running water and always be ready for hand sanitizer. Saat ini dunia sedang dihadapkan dengan wabah virus Covid-19, tak terkecuali di Indonesia. Wabah tersebut sudah menjadi pandemi sejak awal kemunculannya di akhir tahun 2019. Seluruh dunia sedang berjuang untuk melawan pandemi tersebut, begitu juga di Indonesia yang setiap harinya mengalami kenaikan yang begitu besar. Semua tempat umum di tutup untuk sementara untuk mencegah penyebaran virus Covid-19. Sekolah menjadi salah satu tempat umum yang ditutup untuk sementara guna untuk mencegah penyebaran virus Covid-19 di lingkungan sekolah. Terdapat banyak sekali penyebab penularan virus coviddan kerugian yang didapat dari virus Covid-19. Karena tujuan dari penelitian ini untuk dapat mengidentifikasi bahaya, penilaian risiko dan pengendalian risiko dengan menggunakan metode Hazard Identification, Risk Assessment and Risk Control (HIRARC) di lingkungan sekolah. Identifikasi risiko dilaksanakan dengan metode penelitian deskriptif yaitu hasil riset data dan jurnal-jurnal terkait yang tersedia. Hasil penelitian dapat diketahui bahwa terdapat kegiatan-kegiatan yang terdapat di lingkungan sekolah yang berpotensi untuk terjadinya penyebaran dan penularan virus Covid-19. Terdapat 14 kegiatan utama dengan 34 potensi bahaya, diantaranya 13 kegiatan dengan kategori risiko ekstrim dan 1 kegiatan dengan kategori risiko tinggi. Untuk dapat mengendalikan bahaya terdapat beberapa alternatif diantaranya melakukan kegiatan belajar mengajar secara online dan mematuhi seluruh protokol kesehatan seperti menjaga jarak (Physical Distancing dan Sosial Distancing), menggunakan masker, selalu mencuci tangan menggunakan sabun dan air mengalir juga selalu membawa hand sanitizer.

Mathematics is a discipline that can improve thinking skills. However, in reality, the mathematics thinking skills of elementary school students are still low. This is because the mathematics learning used is not optimal and still uses conventional learning. In the process of mathematics learning, there is an integration of character values with mathematics material. Character building through mathematics learning has not been done relatively. The current mathematical concept can be related to cultural activities called ethnomathematics. Through ethnomathematics, mathematics learning becomes more realistic. The purpose of this research is to build students’ character and improve student’s mathematic learning achievement through developing student worksheets with a mathematical approach based on ethnomathematics. The methods of the research were research and development by using steps including preliminary study, design, development, and dissemination. The result of the research is student's worksheets fulfill valid, practical, and effective criteria. The result of the validity of teaching media shows that the average number is 96 % with very good criteria. The effectiveness test shows that there is a distinction of student’s achievement before and after the treatment and the student’s achievement on average is increased. Based on the analysis of student's answers on student worksheets, four characters are built through the learning process with a realistic mathematic approach based on ethnomathematics, such as creativity, independence, curiosity, and nationality. Keywords: character building, realistic mathematics learning, ethnomathematics.

ABSTRAK Pertumbuhan biomassa terlekat ditentukan oleh proses seeding dan aklimatisasi. Tujuan penelitian ini yaitu mengetahui proses seeding dan aklimatisasi pada anaerobic trickling reactor. Metoda penelitian yang digunakan meliputi persiapan reaktor hidrolisis dan 3 buah anaerobic trickling reactor dengan media yang berbeda, serta persiapan bahan meliputi inokulum dan substrat. Parameter yang diukur yaitu densitas, kadar air dan volatil, C-Organik, NTK, pH, temperatur, TAV, COD, dan alkalinitas mengacu pada SNI dan standard methods. Hasil penelitian ini yaitu saat proses seeding, nilai pH 6,87 hingga pH 7,52, temperatur 27oC hingga 28oC, dan ketiga media mengalami pertambahan berat rata-rata sebesar 0,5421 gram/media (bioball rambutan) (12,93 %), 0,7158 gram/media (bioball bola) (11,47 %), dan 0,0449 gram/media (media straws) (13,95 %). Steady state aklimatisasi terjadi pada hari ke-14 hingga hari ke-20 yang ditandai dengan penurunan konsentrasi COD yang konstan. Selama seeding dan aklimatisasi terbentuk biogas. Kesimpulan penelitian ini yaitu proses seeding dan aklimatisasi ditandai dengan terbentuknya lapisan biofilm dan adanya penurunan konsentrasi COD substrat.Kata kunci: Anaerob, Seeding dan Aklimatisasi, Anaerobic Trickling Reactor

Corona virus or what can be called Covid-19 has become a pandemic throughout the world, many activities such as teaching and learning, work, and even sports were suspended because of the Covid-19. Covid-19 can spread very quickly because this virus makes use of various types of crowds and can cause death. With the termination of various kinds of activities that involve physical contact and human encounters can reduce the spread of the Covid-19 virus significantly. The virus that can develop for 14 days on its host body is very dangerous so that Social Distancing and even Physical Distancing activities are carried out to reduce the spread of Covid-19. With the implementation of Physical Distancing for 14 days, humans who are infected without symptoms can get out of the house but with a health protocol by wearing a mask, not close to each other, and always washing hands. By maintaining health as well as sports, the development of this virus in the body can slow down. Usually sports are carried out in city parks, health protocols and facilities that can help reduce the spread of the Covid-19 virus can be done in city parks. Virus Corona atau yang bisa disebut dengan Covid-19 sudah menjadi pandemi di seluruh dunia, banyak kegiatan seperti belajar mengajar, bekerja, bahkan olahraga diberhentikan sementara karena adanya Covid-19 ini. Covid-19 yang dapat menyebar dengan sangat cepat karena virus ini memanfaatkan berbagai jenis keramaian dan dapat menyebabkan kematian. Dengan diberhentikannya berbagai macam kegiatan yang melibatkan kontak fisik dan pertemuan antar manusia dapat membuat penyebaran virus Covid-19 berkurang dengan signifikan. Virus yang dapat berkembang selama 14 hari pada tubuh inangnya ini sangat berbahaya sehingga kegiatan Social Distancing bahkan Physical Distancing dilakukan untuk mengurangi angka penyebaran Covid-19 ini. Dengan diberlakukannya Physical Distancing selama 14 hari, manusia yang tertular tanpa gejala sudah dapat keluar dari rumah tetapi dengan protokol kesehatan dengan cara memakai masker, tidak berdekatan satu sama lain, dan selalu cuci tangan. Dengan menjaga kesehatan pula seperti olahraga, perkembangan virus ini pada tubuh dapat melambat. Biasanya olahraga dilakukan di taman kota, protokol kesehatan dan fasilitas yang dapat membantu mengurangi penyebaran virus Covid-19 ini dapat dilakukan pada taman kota.