TESTING MICROCRYSTALLINE CELULLOSE USING SPECTROMETER AND POLARIZED LIGHT MICROSCOPE

It has been proposed to test the microcrystalline of cellulose materials using polarized light microscope (PLM) and uv-visible spectrometer . The microcrystalline cellulose was prepared from kenaf bast fibers while the nano crystalline was prepared from alpha cellulose using thermal acid hydrolysis. We use at 20% (v/v) and 40% (v/v)H2 SO4 in the experiment mixed and stirred within an hour up to hours. The testing using PLM clearly indicates the existence of microcryatalline cellulose while the use of uv-visible spectrometer can reveal the effectiveness of the acid hydrolysis in extracting the nanofibril from the alpha cellulose

PKM REVITALISASI SISTEM PENYEDIAAN AIR RAWA MENJADI AIR BERSIH LAYAK KONSUMSI DI DESA LANGKITIN DENGAN MENGGUNAKAN TEKNOLOGI TEPAT GUNA

Air bersih merupakan salah satu kebutuhan pokok manusia. Air bersih dapat diperoleh dari berbagai sumber di sekitar tempat tinggal manusia. Tetapi tidak semua tempat memiliki air bersih yang layak konsumsi. Salah satu air yang tidak layak konsumsi adalah air gambut. Air gambut tidak memenuhi persyaratan standar kualitas air layak konsumsi, sehingga dibutuhkan pengolahan terhadap air tersebut. Kabupaten Rokan Hulu memiliki beberapa daerah yang masih kesulitan air bersih karena daerah tersebut merupakan daerah gambut. Melalui Program Kemitraan Masyarakat ini dibuatlah pengolahan air gambut menjadi air bersih layak konsumsi. Metode pelaksanaannya yaitu melakukan sosialisasi kepada masyarakat setempat tentang pentingnya air bersih, melakukan pembuatan alat  teknologi tepat guna sistem pengolahan air rawa gambut menjadi air bersih layak konsumsi dan melakukan proses pengolahan air rawa gambut menjadi air bersih yang layak konsumsi. Proses pengolahan ini terdiri dari proses netralisasi, oksidasi, koagulasi-flokulasi, pengendapan, penyaringan atau filtrasi serta proses disinfeksi berfungsi untuk membunuh kuman di dalam air. Upaya ini bertujuan untuk memberikan kesadaran kepada masyarakat akan pentingnya air bersih yang dapat mempengaruhi kesehatan. Program ini juga membuat teknologi tepat guna dalam pengolahan air gambut menjadi air bersih layak konsumsi yang memenuhi standar kualitas air bersih yang sesuai dengan PERMENKES RI NO.416/Menkes/Per/ IX/1990

Effect of Precursor Molar Ratio on the Yield of Cu Nanowires Synthesized using Aqueous Solution Method

Synthesis yield of Cu nanowires using aqueous solution method has been controlled by varying the precursor molar ratios. The main materials in this experiment consisted of (1) a precursor of copper (II) nitrate trihydrate or Cu(NO3)2.3H2O, (2) a capping agent of ethylenediamine, and (3) a reducing agent of hydrazine. The synthesis process was carried out on the hot plate for 60 min with stirring rate of 60 rpm. For this purpose, the molar ratio of the precursor was varied from 0.012 to 0.2 M. Based on SEM images, we found that the ratio between nanowires and nanoparticles increased by decreasing precursor molar ratio. Furthermore, the Cu nanowires resulted from the synthesis were analyzed by XRD and SEAD, SEM-EDX, and UV-Vis spectroscopy to confirm crystalline properties, morphology and element distribution, and optical properties.

Simulated Interannual Modulation of Intraseasonal Kelvin Waves in the Equatorial Indian Ocean

Outputs from a high-resolution ocean general circulation model (OGCM) for the period of 1990-2003 indicate an interannual modulation of intraseasonal Kelvin waves along the equatorial Indian Ocean. During normal conditions without IOD event, the first mode explains about 30-40% of the total variance in the western (60-65ºE) and central (75-80ºE) basin, while the second mode contributes up to 45% to the total variance in the central basin around the longitude of 82ºE. In contrast, during the 1997/98 IOD event, the fourth mode caused about 40% of the total variance in the central and eastern basin. During the 1994 IOD event, the contribution from the fourth baroclinic mode in the eastern basin caused 45% of the total variance. In the central basin, the second and the fourth baroclinic mode caused almost the same variance (~40%). The variations in the characteristics of the intraseasonal Kelvin waves are related to variations in the vertical stratification. During the IOD event, the pycnocline in the eastern basin was raised by about 50 m and the stratification at the upper level is strengthened, while it is weakened at lower levels. These changes lead to an increase in the contribution of higher-order baroclinic modes

Analisis Dosis OAR Pada Radioterapi Kanker Payudara Sinistra Di Rumah Sakit Universitas Andalas

Kanker payudara menempati urutan pertama di Indonesia dan menjadi salah satu penyumbang kematian utama akibat kanker. Penanganan Kanker payudara dapat dilakukan menggunakan terapi radiasi atau biasa disebut radioterapi. Salah satu modalitas yang sering digunakan dalam radioterapi adalah Linear Accelerator (Linac). Agar terapi radiasi dapat mengenai target kanker dan aman Organ-At-Risk (OAR) perlu dilakukan evaluasi perencanaan terapi radiasi. Evaluasi dilakukan terhadap dua teknik perencanaan terapi radiasi yaitu teknik Three Dimensional Conformal Radiotherapy (3D-CRT) dan Intensity Modulated Radiation Therapy (IMRT). Uji terapi radiasi dilakukan terhadap 3 orang pasien kanker payudara kiri. Hasil analisis dosis pada OAR menggunakan teknik 3D-CRT diperoleh sebaran dosis target dan perlindungan terhadap OAR lebih baik dibandingkan dengan teknik perencanaan 2D. Perencanaan terapi radiasi terbaik diperoleh pada teknik IMRT. Pada teknik perencanaan tersebut diperoleh sebaran dosis lebih homogen pada target maupun capaian dosis pada OAR sekitar target kanker

On the Influence of Enso And IOD on Rainfall Variability Over The Musi Basin, South Sumatra

The southern Sumatera region experiences one rainy season and one dry season in a year associated with seasonal change in monsoonal winds. The peak of rainy season is occurring in November-December-January during the northwest monsoon season, while the dry season comes in June-July-August during the southeast monsoon season. This study is designed to evaluate possible influence of the coupled ocean-atmospheric modes in the tropical Indo-Pacific region, namely the El Niño-Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) on the rainfall variability over the catchment area of the Music Basin, South Sumatera. The ENSO and IOD occurrences were reflected by the variability of sea surface temperature (SST) in the tropical Pacific and Indian Ocean, respectively. During El Niño and/or positive IOD episode, negative SST anomalies cover the eastern tropical Indian Ocean and western tropical Pacific including the Indonesian seas, leading to suppress convective activities that result in reduce precipitation over the maritime continent. The situation is reversed during La Niña and/or negative IOD event. The results revealed that the high topography area (e.g. Bukit Barisan) was shown to be instrumental to the pattern of rainfall variability. During the 2010 negative IOD co-occurring with La Niña event, the rainfall was significantly increase over the region. This excess rainfall was associated with warm SST anomaly over the eastern tropical Indian Ocean and the Indonesian seas. On the other hand, extreme drought event tends to occur during the 2015 positive IOD simultaneously with the occurrence of the El Niño events Investigation on the SST patterns revealed that cold SST anomalies covered the Indonesian seas during the peak phase of the 2015 positive IOD and El Niño event

EDUKASI FISIKA DAN PRAKTIK ROKET AIR DI MTS N 6 SIJUNJUNG

ABSTRAKBelajar Fisika bagi beberapa siswa dirasa sulit dan membosankan. Sehingga banyak dari siswa cendrung menghindari Pelajaran fisika. Pelaksanaan pembelajaran yang monoton tanpa praktikum kurang mengembangkan proses berfikir siswa. Padahal kemampuan berfikir siswa dalam membangun konsep Fisika juga bisa dikembangkan melalui kegiatan praktikum. Kegiatan praktikum dapat mengasah rasa ingin tahu siswa dan keterlibatan siswa menjadi lebih besar. Atas dasar itulah kegiatan pengabdian dilakukan dengan tema edukasi Fisika dan praktik roket air di MTSN 6 Sijunjung Sumatera Barat. Siswa diminta terlibat langsung dalam proses kegiatan pembelajaran. Prinsip dasar roket merupakan implemantasi dari perubahan momentum serta Hukum III Newton mengenai aksi-reaksi. Pelaksanaan kegiatan ini dilakukan dengan 3 langkah, yaitu: 1. Ceramah singkat, 2. Demonstrasi langsung, dan 3. Diskusi dan tanya jawab. Dari hasil yang di dapatkan, siswa-siswi lebih antusias belajar fisika karena mereka terlibat langsung didalam praktikum. Diharapkan kedepannya pembelajaran sains juga bisa menggunakan praktikum sebagai salah satu metode untuk meningkatkan minat siswa. Kata kunci: fisika; hukum newton; roket air. ABSTRACTLearning Physics if it is only carried out in class without practical work does not develop students' thinking processes. In fact, students' thinking abilities in building Physics concepts can also be developed through practical activities. Practical activities can hone students' curiosity and increase student involvement. On this basis, service activities were carried out with the theme of Physics education and water rocket practice at MTs N 6 Sijunjung. The basic principle of a rocket is the implementation of changes in momentum and Newton's Third Law regarding action-reaction. From the results obtained, students were more enthusiastic about studying physics because they were directly involved in the practicum. It is hoped that in the future science learning can also use practicums as a method to increase student interest. Keywords: physics; newton's laws; water rocket

Equatorial Oceanic Waves and the Evolution of 2007 Positive Indian Ocean Dipole

The role of equatorial oceanic waves on the evolution of the 2007 positive Indian Ocean Dipole (pIOD) event was evaluated using available observations and output from a quasi-analytical linear wave model. It was found that the 2007 pIOD event was a weak and short-lived event: developed in the mid-summer (July), matured in the early-fall (September), and terminated in the mid-fall (October). The evolution of the 2007 pIOD event was linked to the equatorial wave dynamics. The event development was associated with the generation of upwelling equatorial Kelvin waves (westward current anomalies) generated by easterly wind anomalies. The event termination was associated with the occurrence of eastward zonal current anomalies resulting from a complex interplay between the wind-forced down welling Kelvin waves and the eastern-boundary-reflected Rossby waves. Results from a quasi-analytical linear wave model show that during the event development and maturation, the wind-forced Kelvin waves played a dominant role in generating zonal current anomalies along the equatorial Indian Ocean, while the eastern-boundary-reflected Rossby waves tended to weaken the wind-forced Kelvin wave signals. During the event termination our model shows that the initiation of anomalous eastward current resulted from the reflected Rossby waves at the eastern boundary. The wind-forced Kelvin waves associated with the seasonal reversal of the monsoon further strengthened the eastward zonal currents generated by the boundary-generated Rossby waves in late-October/early-November. This highlights the importance of the eastern-boundary-reflected Rossby waves on the IOD event termination