cover
Article Per Year (5 Year)
All
Home Page
OAI Link
Editorial Team
Contact
Reviewer
Google Scholar
Contact Name
-
Contact Email
-
Phone
-
Journal Mail Official
-
Editorial Address
-
Location
Kota semarang,
Jawa tengah
INDONESIA
SAINS DAN MATEMATIKA
Published by Universitas Diponegoro
ISSN : -     EISSN : -     DOI : -
Core Subject : Education,
Mathematics
Arjuna Subject : -
Articles 169 Documents
 4   5   6   7   8 
Studi Pendahuluan Pemanfaatan Whey Tahu sebagai Substrat dan Efek Luas Permukaan Elektroda dalam Sistem Microbial Fuel Cell Sinaga, David Hamonangan; Suyati, Linda; Aminin, Agustina L. N.
JURNAL SAINS DAN MATEMATIKA Volume 22 Issue 2 Year 2014
Publisher : JURNAL SAINS DAN MATEMATIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (4726.349 KB)

Abstract

Studi ini bertujuan mengkaji potensi whey tahu sebagai substrat menggunakan Saccharomyces cerevisiae dan mempelajari pengaruh luas permukaan elektroda dalam menghasilkan beda potensial pada sistem MFC. Tahapan penelitian meliputi konstruksi reaktor MFC, pengukuran beda potensial pada variasi substrat yaitu membandingkan beda potensial yang dapat dihasilkan oleh substrat whey tahu dengan substrat glukosa, dan pengukuran beda potensial pada variasi luas permukaan elektroda dengan masing-masing luas permukaan elektroda grafit sebesar 13,29 cm2, 26,58 cm2, 39,87 cm2, dan 53,16 cm2. Hasil penelitian menunjukkan bahwa whey tahu memiliki potensi dengan dihasilkannya beda potensial maksimum 11,73 mV/100 ml substrat dalam sistem MFC menggunakan S. cerevisiae. Hasil studi juga menunjukkan bahwa semakin besar luas permukaan elektroda, semakin besar pula beda potensial yang dihasilkan. Hal ini dibuktikan dengan luas elektroda grafit 53,16 cm2 menghasilkan beda potensial 40,67 mV/100 mL substrat whey tahu dan 300 mV/100 mL substrat glukosa.   Kata kunci: Whey tahu, Microbial fuel cell, Saccharomyces cerevisiae, dual-chamber MFC    The preliminary research about the utilization of soy whey as a substrate and the effect of electrode surface area in microbial fuel cell (MFC) system has been conducted. Laboratory-scale experiment of MFC was carried out in order to determine the ability of soy whey to act as substrate using Saccharomyces cerevisiae and the influence of electrode surface area to generate a potential difference in MFC system. The study includes the MFC reactor design, measuring a potential difference at variation of substrate (soy whey and glucose), and evaluate a potential difference at a variation of graphite electrode surface area. The results show that soy whey has an ability to be applied as a substrate in the MFC system using S. cerevisiae with potential difference 11,73 mV/100 ml. The variation of electrode surface area in the MFC system with four graphite electrodes (53.16 cm2) give the best potential difference with 40,67 mV/100 ml of soy whey and 300 mV/100 ml of glucose substrate.   Keywords: Soy whey, Microbial fuel cell, Saccharomyces cerevisiae, dual-chamber MFC
Identifikasi Faktor-Faktor Penyebab Kejadian Diare Di Kota Semarang Dengan Pendekatan Geographically Weighted Poisson Regression Yasin, Hasbi; Rusgiyono, Agus
JURNAL SAINS DAN MATEMATIKA Volume 21 Issue 3 Year 2013
Publisher : JURNAL SAINS DAN MATEMATIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (5013.469 KB)

Abstract

The percentage of people affected by diarrheal diseases are still quite high, reaching 5.2%. Therefore we need an effort to identify the factors that cause diarrhea efforts of the government in order to reduce morbidity of diarrhea optimally. Such efforts include reviewing of the factors causing the incidence of diarrhea by focusing on linkages between regions or spatial aspects. Spatial aspect is considered important to study because between regions must have different characteristics. One approach that can be used is a spatial model Geographically Weighted Poisson Regression (GWPR) which is a local form of the Poisson Regression. This research was conducted in Semarang city with the unit of observation is the 16 districts in Semarang city. The results showed that the locally influential variable is the number of protected drinking water facilities and the number of medical personnel available. This model has a level of accuracy of 84.33%.
ANALISIS KUANTITATIF B-KAROTEN DAN UJI AKTTVITAS KAROTENOID DALAM ALGA COKLAT TURBINARIA DECURRENS Biranti, Fransisca; Nursid, Muhammad; Cahyono, Bambang
JURNAL SAINS DAN MATEMATIKA Volume 17 Issue 2 Year 2009
Publisher : JURNAL SAINS DAN MATEMATIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (6725.173 KB)

Abstract

ABSTRACT---One of the Indonesian marine natural resources, brown alga of Turbinaria decurrens, used in pharmacy in order of carotenoid pigment as antioxidant. We interested in analysis B-caroten in Turbinaria decurrens and antioxidant and anti-tumor activity. The method that is use to divide carotenoid is the hierarchy maseration method using n-hexane, ethyl acetate  and methanol  and  then using chromatography column. To analyze the qualitative carotenoid uses HPLC  by Crc column and eluenmethanol-acetonitrile  (3:I).  Meanwhile,  the test of bioactivity carotene  uses  radical DPPH  (1I'difenil-2-pibilhidrozil)  to  test  of  antioxidant  qnd  sitotoksik asscy with  MTT  [3,(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrcaolium  bromideJ  for  HeLa tumor cells  to test of anti-tumor. The  result of this research  is  B -caroten  thqt is in qctract  has 0.00387%.  Moreover,  bioacttvity  test  shows  that B -caroten  fraction does  notactive  to neutralize  of DPPHfree radical than  ascorbic  aci{  but  it shows  the  acttvity  to kill HeLa  tumor  cells.Keywords  : Turblnaria decunens,  Carolenoid,  Antioksidan,  Antitumor
Pemodelan Regresi untuk Rancangan Percobaan Faktor Tunggal Ispriyanti, Dwi
JURNAL SAINS DAN MATEMATIKA Volume 15 Issue 2 Year 2007
Publisher : JURNAL SAINS DAN MATEMATIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (482.926 KB)

Abstract

ABSTRAK---Metode Statistik yang sering digunakan dalam percobaan adalah analisis ragam. Dalam tulisan ini akan dibahas analisis ragam dengan pengaruh tetap diselesaikan dengan pendekatan metode regresi,hal itu dapat dilakukan kalau modelnya diindetifikasi secara benar dan kalau langkah-langkah pencegahan telah diambil agar diperoleh persamaan normal yang bebas. Suatu ciri analisis ragam adalah bahwa model analisis ini terparameterisasi secara berlebih (Overparameterized), sehingga perlu membuat kendala terhadap parameter-parameternya. Pendekatan model regresi terhadap masalah analisis ragam mengharuskan peubah bebas X dalam bentuk katagori, yaitu nol dan satu. Kata kunci : analisis ragam, kendala
The Effect of BaCO3 Compound Changes on the Formation of Magnetic Material BaFe12O19 Priyono, Priyono; Cahyono, Agung; Marhaendrajaya, Indras; Subagio, Agus; Gunawan, Vincensius
JURNAL SAINS DAN MATEMATIKA Volume 23 Issue 4 Year 2015
Publisher : JURNAL SAINS DAN MATEMATIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (601.073 KB)

Abstract

BaFe12O19 is a permanent magnetic material which has superior properties to be excellent until the late of twentieth century. Some of the obstacles in the synthesis of the material using a stoichiometric composition is a difficulty to obtain a single phase and the second phase is always found. This research attempted to make modifications on the initial non-stoichiometric composition by varying the fraction of Ba/Fe through BaCO3 and Fe2O3 compound through solid state reaction mechanism. This solid state reaction was initiated by mixing various fractions of BaCO3 and Fe2O3 powder composition and compacted to produce a homogeneous mixture using a planetary milling. After drying and molding, it was obtained a homogeneous mixture like a cylinder with a diameter of 2:54 cm and a thickness of 0.5 cm. The BaFe12O19 phase was obtained by heating the sample at a temperature of 1200 ° C for 4 hours. To determine changes in the fraction of Ba/Fe before and after sintering, the samples were tested by X-Ray Fluorescence (XRF), while the structure and crystallinity were tested by X-ray diffraction (XRD) and Scanning Electron Microscope (SEM). The results showed that during the heating process, the reduction of barium fractions exceeded 5% from of their initial weight, while changes in the fraction of Fe was not significant. The results of structure and crystallinity measurement showed that the addition a substantial amount of barium carbonate can lead to the decrease of crystallinity from 35.271 nm to 11.265 nm.
Zooplankton Diversity and Abundance in Shrimp Pond Ecosystem in the Presence of Sargassum plagyophyllum and Gracilaria verrucosa Izzati, Munifatul
JURNAL SAINS DAN MATEMATIKA Volume 19 Issue 1 Year 2011
Publisher : JURNAL SAINS DAN MATEMATIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2499.489 KB)

Abstract

We studied zooplankton community structure in defferent ecosystem type where different species of aquatic plants are presented. The different in zooplankton community structure can be attributed to different aquatic plant species. We used two different species of aquatic plants, Sargassum plagyophyllum and Gracilaria verrucosa in shrimp pond ecosystem. Every aquatic plant species were replicated three times, and three enclosures without aquatic plant were used as controls. The different in morphological complexity of aquatic plant may affect zooplankton community structure. Our results indicated that the presence of aquatic plant differ in affecting zooplankton community structure. In general, pond with aquatic plant indicate more abundant and diverse of zooplankton. In the presence of Sargassum zooplankton was more abundant compared to the presence of Gracilaria. Whereas with Gracilaria, zooplankton biodiversity index were higher than with Sargassum.   Keywords: zooplankton, sargassum plagyophyllum, Gracilaria verrucosa.
Evaluasi Ketebalan Irisan (Slice Thickness) pada Pesawat CT-Scan Single Slice Makmur, I Wayan Ari; Setiabudi, Wahyu; Anam, Choirul
JURNAL SAINS DAN MATEMATIKA Volume 21 Issue 2 Year 2013
Publisher : JURNAL SAINS DAN MATEMATIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3895.227 KB)

Abstract

An evaluation of the value of the slice thickness due to changes in tube voltage and tube current on the CT scan have been performed. The evaluation is done by making images using CT performance test phantom. Testing is done by performing three scanning on each slice. Exposure factors used were 120 kVp-60 mA, 160 mA 120-kVp, 140-kVp 60 mA, and 140 kVp 160 mA. Nominal beam width were 2 mm, 3 mm, 5 mm, 7 mm, and 10 mm. Once the axial image was obtained (on the area for slice thickness determination),  then calculated the average CT number on the region of interest (ROI). After it was made graphs to determine the value of FWHM which indicates the magnitude of the thickness of the slice. From the test results obtained that changes in tube voltage and tube current does not affect the value of the thickness of the slice. Also found that the value of slice thickness for each thickness, greater than the nominal beam width.   Keywords: Phantom CT Performance Test, Slice Thickness, CT-Scan    Telah dilakukan evaluasi terhadap nilai slice thickness terhadap perubahan tegangan tabung dan arus tabung pada pesawat CT scan. Pengujian dilakukan dengan membuat citra menggunakan fantom CT performance test. Pengujian dilakukan dengan melakukan eksposi sebanyak tiga kali pada tiap-tiap slice. Faktor eksposi yang digunakan yaitu 120 kVp-60 mA, 120 kVp-160 mA, 140 kVp-60 mA, dan 140 kVp-160 mA. Slice thickness yang diuji adalah ketebalan 2 mm, 3 mm, 5 mm, 7 mm, dan 10 mm. Setelah didapatkan citra aksial pada bagian daerah uji slice thickness, maka diambil beberapa lokasi ROI dan dihitung rerata CT Number, kemudian nilai tersebut dibuat grafik dan ditentukan nilai FWHM yang menunjukkan besarnya slice thickness. Dari hasil pengujian diketahui perubahan tegangan tabung dan arus tabung tidak berpengaruh terhadap nilai slice thickness. Hasil pengukuran diketahui bahwa nilai slice thickness untuk masing-masing ketebalan, lebih besar dibanding nominal beam width. Kata kunci : Simulasi Monte Carlo, Percentage Depht Dose (PDD), Dose Profile, Inhomogenitas Jaringan.
KUALITAS DAN MORFOLOGI HASIL ELEKTRODEPOSISI KOBAL PADA SUBSTRAT TEMBAGA TERHADAP PENGARUH RAPAT ARUS DAN ASAM BORAT Huriati, Siti Elin; Haris, Abdul; Widodo, Didik Setiyo
JURNAL SAINS DAN MATEMATIKA Volume 18 Issue 2 Year 2010
Publisher : JURNAL SAINS DAN MATEMATIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (4032.022 KB)

Abstract

ABSTRAK--Telah dilakukan penelitian tentang pengaruh rapat arus dan asam borat terhadap kualitas dan morfologi hasil elektrodeposisi kobal pada substrat tembaga. Elektrodeposisi kobal pada substrat tembaga dilakukan selama 1 jam dengan anoda karbon dan katoda tembaga pada larutan tanpa asam borat dan penambahan asam borat 1,20 M dengan variasi rapat arus 0,005; 0,010; 0,015; 0,020; 0,025 A/cm2. Hasil elektrodeposisi dianalisis menggunakan Atomic Absorption Spectrophotometry (AAS), Scanning Electron Microscopy (SEM) dan Energy Dispersive X-ray Spectroscory (EDS). Hasil analisis AAS menunjukkan bahwa kandungan logam kobal meningkat seiring dengan meningkatnya rapat arus. Hasil analisis SEM menunjukkan morfologi endapan dengan penambahan asam borat menghasilkan diameter danketebalan yang lebih kecil dengan butiran endapan yang lebih rata dan halus. Hasil analisis EDS menunjukkan komposisi endapan dengan penambahan asam borat memiliki kemurnian lebih tinggi yakni sebesar 100 %. Keberadaan asam borat mampu meningkatkan kualitas dan morfologi endapan kobal.Kata kunci: elektrodposisi, kobal, asan borat, rapat arus.Permalink : http://ejournal.undip.ac.id/index.php/sm/article/view/3028
Sintesis Etil Sinamat dari Sinamaldehid pada Minyak Kayu Manis (Cinnamomum cassia) dan Uji Aktivitas sebagai Antidiabetes Amalia, Dian; Ngadiwiyana, Ngadiwiyana; Fachriyah, Enny
JURNAL SAINS DAN MATEMATIKA Volume 21 Issue 4 Year 2013
Publisher : JURNAL SAINS DAN MATEMATIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3930.412 KB)

Abstract

Minyak kayu manis diperoleh dengan cara distilasi dari kulit batang kayu manis. Komponen utama dalam minyak kayu manis adalah sinamaldehid (42-75%). Sinamaldehid merupakan senyawa yang memiliki gugus aldehid yang dapat dimodifikasi menjadi gugus ester yang dapat digunakan sebagai antidiabetes. Tujuan penelitian ini adalah mensintesis etil sinamat dari asam sinamat dan menguji aktivitas etil sinamat sebagai antidiabetes. Metode dari penelitian ini adalah oksidasi dan esterifikasi. Etil sinamat diperoleh dari hasil sintesis merupakan cairan berwarna kuning jernih dan berbau harum dengan rendemen sebesar 98,86%. Hasil dari FTIR menunjukkan terbentuknya etil sinamat dengan adanya gugus C-O ester, sedangkan dari hasil GC-MS diperoleh kelimpahan etil sinamat sebesar 99,01%. Hasil uji aktivitas antidiabetes menunjukkan bahwa, senyawa etil sinamat memiliki nilai IC50 sebesar 215,509 ppm.   Keywords: sintesis; oksidasi; esterifikasi; sinamaldehid; antidiabetes.
Kerapatan Jenis Lichenes Di Sekitar Kawah Sikidang Pegunungan Dieng (Density of Lichens Arround Sikidang Creater of Dieng Plateau) Widodo, Edy; Utami, Sri
JURNAL SAINS DAN MATEMATIKA Volume 15 Issue 1 Year 2007
Publisher : JURNAL SAINS DAN MATEMATIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

ABSTRACT---Lichens are symbiotic plant composed of two different types of organisms i.e. fungi and algae. Lichens sensitive to air pollutan of sulfur dioxide (SO2). Sikidang creater are still active to emist off SO2 and will be affected the availability of lichens as well as the their individual density along SO2 gradient. Sampling of lichens taken with sistematic method. Point sampling four were taken along transect line and sample plot 5 m x 5 m in size was applied..The occurance of species and density was record in every sampling plot. The environment factor measured were air SO2, pH, moisturized and air temperature. There were three species of lichens in Sikidang Creater, those are Cladonia beaumontii, Dactylina artica abd Parmelia cumberlandia. The highets density of species lichens is Cladonia beaumontii.   Keywords : density, Lichens. Sikidang Creater

Page 6 of 17 | Total Record : 169

 4   5   6   7   8 

Filter by Year

2006 2015


Reset
Filter By Issues
All Issue Volume 23 Issue 4 Year 2015 Volume 23 Issue 3 Year 2015 Volume 23 Issue 2 Year 2015 Volume 23 Issue 1 Year 2015 Volume 22 Issue 4 Year 2014 Volume 22 Issue 3 Year 2014 Volume 22 Issue 2 Year 2014 Volume 22 Issue 1 Year 2014 Volume 21 Issue 4 Year 2013 Volume 21 Issue 3 Year 2013 Volume 21 Issue 2 Year 2013 Volume 21 Issue 1 Year 2013 Volume 20 Issue 4 Year 2012 Volume 20 Issue 3 Year 2012 Volume 20 Issue 2 Year 2012 Volume 20 Issue 1 Year 2012 Volume 19 Issue 4 Year 2011 Volume 19 Issue 3 Year 2011 Volume 19 Issue 2 Year 2011 Volume 19 Issue 1 Year 2011 Volume 18 Issue 4 Year 2010 Volume 18 Issue 3 Year 2010 Volume 18 Issue 2 Year 2010 Volume 18 Issue 1 Year 2010 Volume 17 Issue 3 Year 2009 Volume 17 Issue 2 Year 2009 Volume 17 Issue 1 Year 2009 Volume 15 Issue 2 Year 2007 Volume 15 Issue 1 Year 2007 Volume 14 issue 4 Year 2006 More Issue