East Nusa Tenggara is a region in Indonesia which included in the category of hazard prone to earthquakes, because it is flanked by two earthquakes zones, (subduction zone at the south and back arc trust in the north). It is also vulnerable to earthquake disasters because of high population density. These conditions would threaten the safety of lives and property of the population, so it needs to be research to analyze the level of earthquake hazard and vulnerability in East Nusa Tenggara. For identification of the level of hazard and the vulnerability of the earthquake in this study using two factors: the danger factor with indicator Peak Ground Acceleration, vulnerability factors with indicators of population density districts in East Nusa Tenggara. The calculation of the value of PGA use attenuation function of Fukushima and Tanaka. From the calculation of the data obtained that has a very high earthquake hazard is in Ende and Alor district, while the district has a very high risk of vulnerability is in Sikka, Sumba Barat Daya and Sabu Raijua.

Telah diteliti pengaruh slice thickness (ketebalan irisan) terhadap kualitas citra dengan metode parameter Contrast to Noise Ratio (CNR) menggunakan phantom Toshiba (TOS). Variasi slice thickness yang digunakan yaitu 1, 2, 3, 4, 6, dan 8 mm. Tegangan tabung dan arus waktu sinar-X yang digunakan adalah 80 kV dan 100 mAs, sesuai dengan protokol pemeriksaan kepala pasien. Analisis pengaruh variasi slice thickness terhadap CNR ditentukan dengan uji regresi sederhana menggunakan kurva eksponensial. Hasil uji tersebut menunjukkan variasi slice thickness mempengaruhi nilai CNR, dimana semakin besar slice thickness maka nilai CNR semakin besar dan kualitas citra yang semakin baik.

No abstract

Research has been carried out to identify the presence of subsurface water in Selulung Village, Kintamani District, Bangli Regency using 2D geoelectric methods. The work process of this research is the first to collect data directly by using a geoelectric device with Wenner configuration. Electric currents are injected from the surface to the subsurface through the current electrodes which are put on the earth's surface. The collected data is then processed using the Res2Din software version 3.71.118. The software results in the form of 2D images are direct lateral images of subsurface structures. From the three trajectories identified, namely at the coordinates  8°12'18.7"S 115°16'08.3"E the lowest resistivity value was 178 Ohm m with a depth of 10 m which was thought to be a rock layer with surface water content. On line 2 at coordinates 8°12'16.1"S 115°16'09.7"E the resistivity value is 6 ohm.m up to 660,000 ohm.m, the maximum depth obtained is 24 m. This line is thought to be a water-bearing layer because the value of resistance is low. Line 3 which is in the coordinates 8°12'16.3"S 115°15'50.0"E the distribution of resistivity values varies from 42 - 9,400 Ohm m.

Telah dilakukan penelitian pemodelan 3D struktur bawah permukaan Gunung Anak Ranakah dan sekitarnya. Penelitian ini bertujuan untuk membuat peta serta menentukan nilai anomali bouguer lengkap, anomali regional, anomali residual, nilai densitas bawah permukaan serta membuat model 3D struktur bawah permukaan. Data yang digunakan merupakan data sekunder yaitu data anomali gravitasi satelit yang diperoleh dari website Topex. Pengolahan data dalam penelitian ini menggunakan metode gravitasi. Pada metode ini akan dilakukan koreksi gravitasi, membuat peta anomali bouguer lengkap, melakukan analisis spektrum, melakukan pemisahan anomali regional dan residual menggunakan filter butterworth serta melakukan inverse modelling dengan menggunakan software ZondGM3D untuk membuat model 3D struktur bawah permukaan. Hasil peta anomali bouguer lengkap menunjukkan nilai anomali  daerah penelitian antara 134,6-209,3 mGal, anomali regional 147,4-205,9 mGal dan anomali residual antara (-12,8)-11,0 mGal. Hasil inverse modelling menunjukkan bahwa struktur geologi bawah permukaan Gunung Anak Ranakah dan sekitarnya memiliki rentang densitas antara 1,2-3,0 g/cm3, sehingga dari rentang nilai densitas batuan dapat diperkirakan struktur geologi bawah permukaan Anak Gunung Ranakah dan sekitarnya terdiri dari batuan soil (1,2-2,3 g/cm3 , andesit 2,40-2,80 g/cm3) dan basalt (2,70-3,0 g/cm3).