Potensi Sumberdaya Alam Pasir Besipantai Arakan Kabupaten Minahasa Selatan

POTENSI SUMBERDAYA ALAM PASIR BESIPANTAI ARAKAN KABUPATEN MINAHASA SELATAN Adey Tanauma1) dan Ferdy1) 1)Program Studi Fisika FMIPA Universitas Sam Ratulangi, Manado 95115 ABSTRAK Pasir besi merupakan salah satu sumberdaya alam di Sulawesi Utara yang belum dimanfaatkan secara optimal. Salah satu lokasi yang cukup potensial untuk mendapatkan endapan pasir besi ini adalah pesisir pantai Arakan. Penelitian ini bertujuan untuk menentukan sifat-sifat magnetik endapan pasir besi yang terdapat di pesisir Pantai Arakan kabupaten Minahasa Selatan Provinsi Sulawesi Utara. Suseptibilitas magnetik dan magnetisasi saturasi sampel pasir besi Arakan mengindikasikan bahwa kandungan mineral magnetik yang dominan adalah magnetite. Ukuran bulir dari mineral magnetik terutama magnetite didominasi oleh bulir-bulir magnetik berukuran besar atau bulir magnetik dengan domain magnetik antara pseudosingle domain dan multi domain. Tingginya kandungan mineral magnetik berdasarkan nilai karakterisasinya, terutama nilai suseptibilitas magnetik memberikan peluang untuk pemanfaatan lebih lanjut dari sumberdaya alam ini. Kata kunci: histeresis magnetik, pasir besi, suseptibilitas THE POTENTIAL OF NATURAL RESOURCES OF IRON SAND IN ARAKAN COASTAL SUBPROVINCE OF SOUTH MINAHASA ABSTRACT Iron sand represent one of the natural resources in North Sulawesi which not yet been exploited in optimally. One of the location which quite potential to get this iron sand sediment is coastal area of Arakan. This research aim to determine the nature of magnetic of iron sand sediment which there are in coastal area of Arakan, Sub-province of South Minahasa, Province of North Sulawesi. Magnetic suseptibility and saturation magnetization of iron sand sampel of Arakan indicated that dominant magnetic mineral is magnetite. Seed size measure of magnetic mineral especially magnetite predominated by big sized magnetic seeds or magnetic seed with magnetic domain between domain pseudosingle and multi domain. The height content of magnetic mineral based on characteristic value, especially magnetic suseptibility give the opportunity for furthermore exploiting of this natural resources

Pemodelan Sumber Gempa di Wilayah Sulawesi Utara sebagai Upaya Mitigasi Bencana Gempa Bumi

PEMODELAN SUMBER GEMPA DI WILAYAH SULAWESI UTARA SEBAGAI UPAYA MITIGASI BENCANA GEMPA BUMI 1) Guntur Pasau2) dan Adey Tanauma2); e-mail: [email protected])Penelitian IPTEK dan Seni dengan Biaya DIPA Unsrat Tahun 2011 2)Progran Studi Fisika FMIPA Universitas San Ratulangi Manado, 95115 ABSTRAK Pemodelan sumber gempa di wilayah Sulawesi Utara telah dilakukan. Pemodelan sumber gempa menggunakan teori probabilitas total merupakan salah satu upaya mitigasi dalam mengetahui besarnya percepatan suatu gerakan tanah yang diakibatkan oleh suatu gempa bumi. Analisis perhitungan percepatan tanah maksimum di batuan dasar meliputi probabilitas terlampaui 10% dalam 50 tahun. Hasil analisis pemodelan sumber gempa yang telah dilakukan didapatkan bahwa nilai percepatan tanah pada beberapa kota besar di Sulawesi Utara cukup tinggi. Nilai percepatan tanah maksimum yang tertinggi adalah Kota Gorontalo dengan nilai percepatan sekitar 0,5g kemudian disusul oleh Kota Bitung sebesar 0,4g, dan Kota Manado sebesar 0,25g. Kata Kunci: pemodelan, sumber gempa, probabilitas, percepatan, batuan dasar. EARTHQUAKE SOURCE MODELING OF NORTH SULAWESI REGION AS AN EFFORT OF EARTHQUAKE DISASTER MITIGATION ABSTRACT Earthquake source modeling of North Sulawesi region was carried out. The earthquake source modeling using the theory of total probability is one of the mitigation efforts in knowing the magnitude of the acceleration of the ground motion caused by an earthquake. Analysis of the calculation of the maximum ground acceleration at bedrock includes the probability of exceedance 10% in 50 years. The results of the earthquake source modeling analysis has been done found that the ground acceleration values ​​in some major cities in North Sulawesi is quite high. The maximum ground acceleration value of the highest is the of Gorontalo City with a value of about 0.5 g acceleration was followed by the Bitung City of 0.4 g, and the Manado City of 0.25 g

Pola Variasi Reguler Medan Magnet Bumi Di Tondano

Data variasi medan magnet bumi komponen horisontal diambil dari komputer akuisisi yang merekam data secara real time. Dibuat grafik data magnet bumi komponen horisontal versus waktu per hari. Dipilih grafik quite days dan dibandingkan dengan quiet days di Lerwick (Inggris). Dihitung nilai rata-rata dari Quiet days yang sama perbulan untuk dijadikan pola variasi reguler bulanan, sehingga dalam satu tahun dapat dibuat dua belas pola variasi reguler medan magnet bumi. Hasilnya menunjukkan bahwa variasi reguler medan magnet bumi polanya teratur, nilai variasi tertinggi berkisar 39308,3– 39409,5 nT pada kisaran waktu 02:39–03:38 Universal Time. Pola variasi reguler medan magnet bumi digunakan sebagai acuan untuk menganalisis variasi harian medan magnet bumi. Pada tahun 2011 tercatat badai besar geomagnet sebanyak 11 kali yang nilai variasinya berkisar 71–20 nT dengan nilai K indeks sama dengan lima.Data variation of the horizontal component of the earth\u27s magnetic field was taken from the acquisition computer which records data in real time. Graphs describing the horizontal component data versus time were created daily. Graphs of quiet days were selected and compared with quiet days in Lerwick (England). Average value the same of quiet days were calculated in order to create monthly regular variation pattern, so that in one year there were twelve regular variation patterns of the earth \u27s magnetic field created. The results showed that the regular variations of the earth \u27s magnetic field is on a regular pattern, the value of the highest variation ranged 39308.3-39409.5 nT at around 2:39 to 3:38 Universal Time. Regular variation patterns of the earth \u27s magnetic field were used as references for analyzing the daily variation of the earth \u27s magnetic field. In 2011, the large geomagnetic storms were recorded 11 times, the value of the variation range 71–20 nT with the K index value equal to five

Pemetaan Akuifer Air Tanah Di Sekitar Candi Prambanan Kabupaten Sleman Daerah Istimewa YOGYAKARTA Dengan Menggunakan Metode Geolistrik Tahanan Jenis

Telah dilakukan penelitian yang bertujuan untuk memetakan keberadaan akuifer air tanah di sekitar Candi Prambanan Kabupaten Sleman Daerah Istimewa Yogyakarta berdasarkan resistivitas batuan bawah permukaan hasil eksplorasi geofisika dengan metode geolistrik tahanan jenis. Penelitian dilakukan terhadap 31 titik sounding yang terbagi menjadi 6 lintasan. Setiap lintasan dibuat model struktur lapisan tanah di bawah permukaan. Air tanah yang tersimpan dalam akuifer dapat dieksplorasi dengan studi geofisika menggunakan metode geolistrik. Hasil eksplorasi diolah menggunakan software IP2WIN,menghasilkan model perlapisan bawah permukaan Bumi berdasarkan nilai resistivitasnya (2D) yang kemudian dioalah dengan software Surfer 8 untuk menghasilkan gambar tiga dimensi. Berdasarkan model struktur lapisan tanah di bawah permukaan ini diperoleh: a) lapisan akuifer air tanah dangkal dengan kedalaman antara ( 1 – 5 meter ) yang tersebar di Kecamatan Prambanan : Desa Bugisan (titik sounding 7) Desa Taji (titik sounding 14, 15, 23, 24, dan 31). b) lapisan akuifer air tanah dalam dengan kedalaman ( 25 – 100 meter ) yang tersebar di Kecamatan Prambanan : Desa Bugisan (titik sounding 1, 2, 3, 4, dan 5), Desa Tlogo (titik sounding 12, 16, dan 25). Di Kecamatan Kalasan : Desa Taman Martani (titik sounding 8, 9, 10, 17, 18, 19, 20, 21, 26, 27, 28, 29, dan 30

Effects of a cognitive acceleration program in a low socio-economic high school in regional Australia

This paper presents research on the effects of a cognitive acceleration intervention in science lessons on low socio-economic students in a government high school in regional Western Australia. Thinking Science Australia is a program currently being implemented in Australian junior high school classes. The research was conducted over two years as a case study in one school with students as they entered high school in Year 8 (n = 71). Findings show that significant cognitive gains were made, with concomitant improvement in the state-wide testing in science when participating students were in Year 9, aged 13 and 14. Teachers reported changes to the ways they teach and described the challenges in implementing the intervention program

Illuminating Choices for Library Prep: A Comparison of Library Preparation Methods for Whole Genome Sequencing of Cryptococcus neoformans Using Illumina HiSeq.

The industry of next-generation sequencing is constantly evolving, with novel library preparation methods and new sequencing machines being released by the major sequencing technology companies annually. The Illumina TruSeq v2 library preparation method was the most widely used kit and the market leader; however, it has now been discontinued, and in 2013 was replaced by the TruSeq Nano and TruSeq PCR-free methods, leaving a gap in knowledge regarding which is the most appropriate library preparation method to use. Here, we used isolates from the pathogenic fungi Cryptococcus neoformans var. grubii and sequenced them using the existing TruSeq DNA v2 kit (Illumina), along with two new kits: the TruSeq Nano DNA kit (Illumina) and the NEBNext Ultra DNA kit (New England Biolabs) to provide a comparison. Compared to the original TruSeq DNA v2 kit, both newer kits gave equivalent or better sequencing data, with increased coverage. When comparing the two newer kits, we found little difference in cost and workflow, with the NEBNext Ultra both slightly cheaper and faster than the TruSeq Nano. However, the quality of data generated using the TruSeq Nano DNA kit was superior due to higher coverage at regions of low GC content, and more SNPs identified. Researchers should therefore evaluate their resources and the type of application (and hence data quality) being considered when ultimately deciding on which library prep method to use

Arctic sea-ice decline archived by multicentury annual-resolution record from crustose coralline algal proxy

Northern Hemisphere sea ice has been declining sharply over the past decades and 2012 exhibited the lowest Arctic summer sea-ice cover in historic times. Whereas ongoing changes are closely monitored through satellite observations, we have only limited data of past Arctic sea-ice cover derived from short historical records, indirect terrestrial proxies, and low-resolution marine sediment cores. A multicentury time series from extremely long-lived annual increment-forming crustose coralline algal buildups now provides the first high-resolution in situ marine proxy for sea-ice cover. Growth and Mg/Ca ratios of these Arctic-wide occurring calcified algae are sensitive to changes in both temperature and solar radiation. Growth sharply declines with increasing sea-ice blockage of light from the benthic algal habitat. The 646-y multisite record from the Canadian Arctic indicates that during the Little Ice Age, sea ice was extensive but highly variable on subdecadal time scales and coincided with an expansion of ice-dependent Thule/Labrador Inuit sea mammal hunters in the region. The past 150 y instead have been characterized by sea ice exhibiting multidecadal variability with a long-term decline distinctly steeper than at any time since the 14th century

Argumentation in school science : Breaking the tradition of authoritative exposition through a pedagogy that promotes discussion and reasoning

The value of argumentation in science education has become internationally recognised and has been the subject of many research studies in recent years. Successful introduction of argumentation activities in learning contexts involves extending teaching goals beyond the understanding of facts and concepts, to include an emphasis on cognitive and metacognitive processes, epistemic criteria and reasoning. The authors focus on the difficulties inherent in shifting a tradition of teaching from one dominated by authoritative exposition to one that is more dialogic, involving small-group discussion based on tasks that stimulate argumentation. The paper builds on previous research on enhancing the quality of argument in school science, to focus on how argumentation activities have been designed, with appropriate strategies, resources and modelling, for pedagogical purposes. The paper analyses design frameworks, their contexts and lesson plans, to evaluate their potential for enhancing reasoning through foregrounding the processes of argumentation. Examples of classroom dialogue where teachers adopt the frameworks/plans are analysed to show how argumentation processes are scaffolded. The analysis shows that several layers of interpretation are needed and these layers need to be aligned for successful implementation. The analysis serves to highlight the potential and limitations of the design frameworks