Identifikasi Deformasi Pulau Bali Berdasarkan Rekaman Data GPS, Menggunakan Software GAMIT/GLOBK 10.6

Telah dilakukan penelitian aktivitas tektonik Pulau Bali yang bertujuan untuk mengidentifikasi dan menentukan arah pergerakan deformasi pulau Bali. Penelitian dilakukan dengan menggunakan data hasil pencatatan GPS lokal di sebelas titik pengamatan di Pulau Bali. Pengolahan data dilakukan menggunakan SOFTWARE GAMIT/GLOBK 10.6 dan beberapa software pendukung seperti teqc untuk menguji kualitas data perekaman GPS dan GMT untuk memplot data hasil pengolahan. Hasil penelitian menunjukkan bahwa terjadi pergeseran titik pengamatan yang mengindikasikan adanya aktivitas tektonik di Pulau Bali. Pola pergeseran titik menunjukkan terjadinya pergeseran yang cenderung ke arah timur hingga tenggara. Pola deformasi tersebut diperkirakan terjadi akibat aktivitas lempeng tektonik yang berada di bagian timur dan selatan pulau Bali.

Jarak Pisah Sudut Puncak Difraksi Antara Bidang (hkl) Utama Sebagai Indikator Keorthorhombikan Struktur Kisi Kristal Fase GdBa2Cu3O7-?

Keothorhombikan suatu struktur kisi kristal ditunjukkan oleh adanya perbedaan nilai parameter kisi a, b dan c. Penelitian ini bertujuan untuk menunjukkan bahwa nilai jarak pisah antara sudut puncak difraksi kedua bidang (hkl) yang paling dekat sama dengan nilai orthorhombisitas struktur kristal pada fase GdBa2Cu3O7-?. Untuk tujuan tersebut, dalam penelitian ini telah disintesis senyawa Gd0,85La0,15Ba2-xSrxCu3O7-dengan variasi x = 0,00, 0,05, 0,10, 0,20, 0,30 dan 0,50. Sampel disintesis menggunakan metode reaksi padatan dengan pencampuran basah, disintering pada suhu 900°C selama 12 jam. Dari hasil analisis spektrum XRD dengan software Match-3 dan Rietica didapatkan bahwa, dengan bertambahnya kandungan Sr pola perubahan nilai jarak pisah sudut puncak difraksi bidang (hkl) terdekat hasil pengukuran dan perhitungan sama dengan pola perubahan nilai keorthorhombikan. Hasil pengukuran dan perhitungan nilai jarak pisah antara sudut puncak difraksi untuk bidang (020) dan (200) hampir sama dengan sepersepuluh dari nilai keorthorhombikan. Dengan demikian, nilai jarak pisah antara sudut puncak difraksi dari dua bidang (hkl) terdekat dapat digunakan sebagai indikator keorthorhombikan struktur kristal fase GdBa2Cu3O7-?.

Sintesis Carbon Dot Dengan Bahan Dasar Asam Sitrat Menggunakan Metode Pemanasan Secara Berulang di Dalam Oven Microwave

Pada penelitian ini telah disintesis carbon dot menggunakan asam sitrat dan polietilen, dengan metode pemanasan secara berulang di dalam microwave. Hasil sintesis dikarakterisasi dengan spektroskopi UV-Vis, FTIR, Fotoluminesensi (PL) dan TRPL. Hasil karakterisasi UV-Vis memperlihatkan bahwa sampel telah menunjukkan dua absorpsi dengan intensitas maksimum pada rentang panjang gelombang antara 200-280 nm dan sekitar 330 nm. Ini menandai transisi eksitasi p®p* dan n®p* yang merupakan karakteristik carbon dot . Karakterisasi FTIR telah menunjukkan adanya pita vibrasi regangan O-H, karbonil aromatik C=O, regangan C-O dan frekuensi vibrasi regangan dari sulfat, masing-masing pada bilangan gelombang 3292, 1623, 1129 dan 996 cm-1. Dari karakterisasi PL dengan menggunakan sinar laser pengeksitasi 320, 420 dan 530 nm (violet, biru dan hijau), sampel carbon dot menghasilkan emisi radiasi masing-masing pada panjang gelombang 453, 525 dan 590 nm. Hasil penghitungan TRPL diperoleh bahwa rata-rata masa hidup fotoluminesensi berada pada orde 10-9 detik, yang merupakan karakteristik dari fotoluminesensi fluoresensi. Hasil-hasil yang diperoleh menunjukkan telah berhasil disintesis carbon dot dengan emisi radiadif yang bergantung pada sinar laser pengeksitasinya.

Pengaruh Variasi Tegangan Tabung Sinar-X terhadap Signal to Noise Ratio (SNR) dengan Penerapan Anode Heel Effect menggunakan Stepwedge

It has been conducted research to determine the effect of X-ray tube voltage variation (kV) on Signal to Noise Ratio (SNR) values by applying the Anode Heel Effect using stepwedge with the addition of 1.5 mm thickness each step. The stepwedge used was 1.5-31.5 mm. The X-ray tube voltage variations used were 40, 50, 60, 70, 80, and 90 kV. Analysis of the effect of X-ray tube voltage variation on SNR values is determined using IMB SPSS Statistics 26 with a simple regression test. The test results showed that variations in X-ray tube voltage affect SNR values, where the greater the variation in X-ray tube voltage then the SNR value would get smaller. The optimal SNR value of 72.685 was obtained at a tube tension of 40 kV and a stepwedge thickness of 27.0 mm.

PEMBUATAN ALAT PANTAU SUHU DAN KELEMBABAN UDARA BERBASIS SHORT MESSAGE SERVICE (SMS) MENGGUNAKAN AWE.2020

Telah berhasil dibuat sebuah alat yang dapat memantau suhu dan kelembaban udara melalui sebuah ponsel berbasis Short Message Service (SMS) dengan nama AWE.2020. Alat ini terdiri dari sensor suhu dan kelembaban DHT22, modul GSM SIM800L, dan mikrokontroler Arduino Uno R3. Hasil pembacaan suhu dan kelembaban dari sensor DHT22 diolah oleh mikrokontroler Arduino Uno R3 dan hasilnya dikirimkan berupa SMS lewat modul GSM SIM800L. Untuk mengukur tingkat keakuratan dari alat rancangan (AWE.2020) telah dilakukan kalibrasi dengan alat standar AWS yang ada di Stasiun Klimatologi Jembrana, Bali. Beberapa parameter dipakai untuk mengukur tingkat keakuratan alat ukur ini yaitu analisis regresi dan uji-t statistik. Hasil pengamatan menunjukkan bahwa kinerja dari AWE.2020 ini sangat bergantung pada kualitas sinyal provider. Saat kondisi sinyal provider bagus, hasil uji-t dan analisis regresi alat ini menunjukan tingkat keakuratan yang tinggi. Demikian sebaliknya. Dari hasil pengamatan, serta uji statistik diperoleh bahwa alat tersebut akurat dan presisi untuk digunakan namun bergantung pada sinyal provider yang digunakan.

Synthesis and Characteristics of CdS Nanoparticles in Normal (1 g) and Simulated Microgravity (SMG)

In the present investigation, the cadmium sulphide (CdS) nanoparticles are synthesized in the normal gravity i.e. 1 g (called as control) and in simulated microgravity (called as SMG). The SMG was created by using an instrument called Random Positioning Machine (RPM). Cadmium sulfide nanoparticles were synthesized by using standard chemical method under normal gravity (1 g) and simulated microgravity conditions. The synthesized CdS nanoparticles were characterized by Ultraviolet Visible spectroscopy, Fourier Transform Infrared Ray spectroscopy (FTIR), X-ray diffraction (XRD). The UV-visible absorption spectrum of CdS nanoparticle solution showed a distinct absorption peak at 472.19 nm in control and 458.26 nm in SMG. The band gap calculated from the absorption edge for microgravity sample was 2.71 eV and for control sample was 2.63 eV. The crystalline size of CdS nanoparticles synthesised in control and Micro-g was determined by XRD. Obtained results showed smaller the particle size in microgravity sample (10.78 nm) as compared to control sample (13.89 nm).

Effect of Pressure on the Synthesis of Compound Ba0.7Ca0.3TiO3 on the Dielectric Constant

Piezoelectric and ferroelectric ceramic materials are widely used for advanced technology. Barium Titanat is one of the ferroelectric materials that are still widely studied today. In this research, Ba0,7Ca0,3TiO3 was synthesized. The compound was synthesized by the solid reaction method with variations in pressure during the sample compacting process include 10, 20, and 30 kN. Samples in the form of solids (pellets) were calcined at 800 °C and sintered at 1000 °C for 4 hours respectively. The synthesized product was characterized by an LCR meter. The characterization results in the frequency range of 100-200000 Hz show that the pressure affects of the parameters value of the dielectric constant, especially at frequencies 100-10000 Hz. In that frequency range the dielectric constant decreases very sharply, then above 100 kHz the dielectric constant is almost unchanged with increasing frequency.

Effects of High g Values on Growth and Chlorophyll Content in Hydrated and Dehydrated Wheat Seeds

Higher g value stimuli (gravitational acceleration more than 1 g and referred as hyper gravity) caused by centrifugation have been shown to inhibit elongation growth of various plants. In the present study, effects of high g values were studied on wheat seeds with and without water medium at the time of exposure to high g values. Wheat seeds (variety: LOK-1) were washed with 0.5% fungicide and then 4-5 times with distilled water (D/W). Seeds were then soaked in D/W for 24 hrs. Two different experiments were performed. In initial experiment, soaked seeds were taken into the centrifuge tubes filled with 1 ml D/W. Seeds were exposed to hypergravity ranging from 500 g to 2500 g for 10 minutes. In another experiment, soaked seeds were taken into the centrifuge tubes without water or any other medium and then exposed to high g values. After exposure seeds were immediately sowed on 0.8% agar gel. Results obtained showed that exposure to high g values suppressed growth in wheat seedlings when seeds were exposed to high g values with water as a medium. Chlorophyll content also decreased with increase in g. However, no change in growth and chlorophyll content were observed when seeds were exposed without water medium up to g values as high as 2500. Thus, effects of high g value stimuli depend not only on how much centrifugal force is applied to the seeds but also depends upon how much force is experienced by the inner part of the seeds. Present observation shows that effective centrifugal force experienced by the seeds is different when applied with and without medium.

Identification of Free Radical in Main Stream Cigarette Smoke in Cigarette with Clove mix (Kretek) and Cigarette without Clove mix (White)

Cigarette smoke is a source of free radicals. Cigarette smoke is a component of Aerosols and free gases that contain large amounts of chemical compounds. Cigarette smoke can be divided into two: main smoke and side smoke. The main smoke of cigarettes inhaled by smokers is known to cause a buildup of harmful substances and causes of oxidative stress so that research is carried out using ESR Leybold Heraeus. The sample used is a smoke sample from two types of cigarettes that are popular in Indonesia. The measurement is done by pulling smoke directly into the measurement tube. Then the resonance pattern is observed and the external magnetic field is calculated and the value of the lande factor is based on frequency and current data. Measurements result showed resonance in both types of cigarettes, at a frequency of 32.4-70.8 MHz and obtained values of lande factors that vary and have a value between 1.9-2.1 with two acquisition values that are outside the range that is 1.8368; and 2.2060. There are differences in the number of resonances that occur for each sample. This difference can be due to differences in the constituent of content and the texture of cigarettes which can affect the results of the combustion process.

Analysis of Superconductor of Nd1Ba2Cu3O7 and Nd3Ba5Cu8O18 Phases Using FTIR Spectrophotometer

I has been synthesized superconducting materials of the Nd1Ba2Cu3O7, Nd3Ba5Cu8O18 and Y3Ba5Cu8O18 phases. The study was conducted to determine whether the data from the phase Y1Ba2Cu3O7 can be used as a base to identify superconducting material of the Nd3Ba5Cu8O18 phase. Synthesis was done by solid state reaction method with initial mixing in HNO3 solution mixture with Y2O3, Nd2O3, BaCO3, and CuO, with the ratio adjusted to the stoichiometry calculation. Samples in the form of pellets with a diameter of 1.5 cm were sintered at 950 oC for 24 hours in an atmospheric environment. The FTIR measurements have been carried out with a standard KBr. The theoretical calculation spectra and vibration mode data from YBa2Cu3O7-d can be used to identify Nd1Ba2Cu3O7, Nd3Ba5Cu8O18 dan Y3Ba5Cu8O18, with peak absorption in the range of wave numbers that are almost the same, namely 400-450 cm-1, which is the four oxygen atoms O(2,3) mode, 426-439 cm-1 is the in-phase mode of oxygen atom O(2,3), and the vibrational mode of peaks O(4) is observed at 488 cm-1.