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Journal : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

MODEL POLA LAJU ALIRAN FLUIDA DENGAN LUAS PENAMPANG YANG BERBEDA MENGGUNAKAN METODE BEDA HINGGA Vira Marselly; Defrianto '; Rahmi Dewi
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 2, No 1 (2015): Wisuda Februari 2015
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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Abstract

The writer has done a research on the model of rate pattern of liquid fluid flow by using flow model that has different pattern. The Equation of continuity was used to solve flow rate case, while Equation of Laplace two dimensions was used for numerical case by finite difference methods by using MATLAB R2009b (version 7.9.0.529). The purpose of fluid research was making flow pattern then analyzing fluid flow to each point in dimensions on Equation of Laplace. The methodology used in this research was evaluating Equation of Laplace concept, identifying the problems, two dimensions of Laplace equation used, completing the numerics by using finite difference methods, and completing analitics for simple cases. The results showed that there was no significant between analytical and computation of fluid flow rate. It can be seen the average of error value is close to zero and the highest error value is 0,000,778 % . Even in various geometry problems, the flow pattern can is be also visualized.
PEMBUATAN KARBON AKTIF DARI CANGKANG KELAPA SAWIT DENGAN MENGGUNAKAN H 2 O SEBAGAI AKTIVATOR UNTUK MENGANALISIS PROKSIMAT, BILANGAN IODINE DAN RENDEMEN Hafnida Hasni Harahap; Usman Malik; Rahmi Dewi
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 1, No 2 (2014): Wisuda Oktober 2014
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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Abstract

Activated carbon from shells of oil palm has succesfully been made. It was carbonizedat 400 ̊C, 500 ̊C and 600 ̊C for 20, 40 and 60 minutes. The physical activation wascarried out at the temperature of 900 ̊C for 20, 40 and 60 minutes. This activation wasdone by flowing the water vapor as an activated agent. The objective of this researchwas to characterize palm oil shells that was carried out through proximate test whichwere water content and ash content, the absorbane of activated carbon toward iodinevalue and yield. The best results after carbonization were the samples that werecarbonized at 600 ̊C for 60 minutes, with proximate content : water content of 4,5% andash content of 9.7%. The iodine number at activation of 900 ̊C for 60 minutes was 353mg/ gr and yield of 48%.
KARAKTERISASI BAHAN FERROELEKTRIK BARIUM STRONTIUM TITANAT (Ba0.3 Sr 0.7TiO3) DENGAN MENGGUNAKAN DIFRAKSI SINAR-X (XRD) Rahmad Efendi; Rahmi Dewi; Krisman '
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 1, No 2 (2014): Wisuda Oktober 2014
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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Abstract

Ferroelectric materials of  Barium Strontium Titanate  (BST) with its  composition  of Ba0,3Sr0,7TiO3  was  succesfully deposited by a solid solution method. The samples were prepared in the form of pellets  and then  were annealed  at  the temperature of 600, 700, 800oC.   Characteritation of the samples was performed  using X-Ray diffraction (XRD). The results of characteritation using XRD was described on a graph  of the intensity  vs. 2 theta. The XRD  patterns of  Ba0,3Sr0,7TiO3  have  peaks. It was confirmed that the material of Ba0,3Sr0,7TiO3 has cubic crystalline structure, and its lattice parameter was  in average of 3,961 Å. The particle sizes (D) and lattice strains (η) of the material that was annealed at temperature of 600, 700, 800°C for 1 hour were 42.60, 44.43, 46.89 nm and -4,49x 10-3, -4,05 x 10-3,  -2,96 x 10-3, respectively. The increase in annealed temperature will raise the particle size and lattice strain.
KARAKTERISASI SEMI KOKAS DAN ANALISA BILANGAN IODIN PADA PEMBUATAN KARBON AKTIF TANAH GAMBUT MENGGUNAKAN AKTIVASI H2 0 Handri Anjoko; Rahmi Dewi; Usman Malik
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 1, No 2 (2014): Wisuda Oktober 2014
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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Abstract

A  research  has been  conducted  to   analyze  characteristics  of  semi-coke  and  the best activated carbon  absorption  after  the activation process  by  determining the  iodine number and refering to  the  Indonesian National Standard  of  activated carbon  materials. The  carbonization  temperatures of peat  soil  were  400oC,  500oC,  and  600°C.  Activated process was carried out at  temperature of 900 °C with  duration time  20, 40  and 60 minutes. Result of the  research  showed that the  best sample of semi-coke  was the sample which was carbonized at  600oC  and  with its duration  time of  60  minutes.  The sample characteristics of the moisture content, ash content, volatile matter content,  fixed carbon content  and heat value,  respectively were 4.91%, 12.24%, 13.43%, 69.42% and 4085.22  Kal/g.  The highest  iodine  number of the best sample was  686  mg/g  and yield was 38% at  600oC  carbonization temperature  and duration time of  60  minutes  with  theactivation temperature of 900oC and duration time of 60 minutes.