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STUDI OPTIMASI PENENTUAN Cu(II) DENGAN MENGGUNAKAN KALKON SEBAGAI PENGOMPLEK SECARA VOLTAMMETRI STRIPPING ADSORPTIF (AdSV) -, Deswati; Suyani, Hamzar; Arifin, Bustanul; -, Imelda; Salamah, Yunita
Jurnal Riset Kimia Vol 4, No 2 (2011): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v4i2.131

Abstract

 ABSTRACT The research about determination of Cu(II) by adsorptive stripping voltammetry (AdSV) was conducted. AdSV method was applied to the determination of copper in ultra trace concentration. The parameters of ligand, accumulation potential, accumulation time, pH and ligand concentration was studied. Calcon was found as complexing agent that give the highest peak current. The optimum condition are accumulation potential -0,7 V, accumulation time 60 s, pH 10, and calcon concentration 0.12 mM. The relative standar deviation (n=8) at 10 µg/L standard concentration were obtained 4,27 %. This method was applied to determination of Cu(II) in sample from Batang Air Dingin, Lubuk Minturun and Muara Padang. The sample concentration were 4,778 µg/L and 5,189 µg/L for Batang Air Dingin and Muara Padang, respectively. The recovery of this method was studied for sample from Muara Padang and 98,31 % was obtained. Key words :   Adsorptive, Stripping, Voltammetry, Calcon and Copper    
RANTAI NILAI AGRIBISNIS KOPI SERTIFIKASI DI KABUPATEN LAMPUNG BARAT Dewi, Aisyah Nur Citra; Arifin, Bustanul; Marlina, Lina
Jurnal Ilmu-Ilmu Agribisnis Vol 7, No 3 (2019)
Publisher : Lampung University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (576.111 KB) | DOI: 10.23960/jiia.v7i3.3764

Abstract

This research aims to analyze certified and non-certified coffee agribusiness value chains found in West Lampung District, analyze the efficiency of certified and non-certified coffee agribusiness value chains and, the formulation of coffee price in the certified and non-certified coffee agribusiness value chains in West Lampung District. The study is conducted in three sub-districts namely Air Hitam, Kebun Tebu and Sumber Jaya. Total respondents coffee farmers are 146 coffee farmers, consist of 85 certified coffee farmers and 61 non certified coffee farmers’ chosen by cluster random sampling method. Total respondents are 20 sellers; consist of 9 group sellers’ collector, 7 local sellers’ collector, 2 wholesalers and 2 exporters chosen by snowball sampling method. Research data was collected in November 2016 to January 2017 and analyzed by qualitative and quantitative analysis. The research result showed that there were three channels in the agribusiness value chain of certified coffee and two channels in the agribusiness value chain of non-certified coffee. Channel three in the agribusiness value chain of certified coffee and channel two in the agribusiness value chain of non-certified coffee have been efficient with formulation process of price certified and non-certified coffee in the agribusiness value chain of coffee in West Lampung, the buyer was a price setter and the seller was as a price taker.Key words: certified coffee, non-certified coffee, value chain
Analisis Pengaruh Institusi terhadap Strategi dan Kinerja Badan Usaha Milik Negara (BUMN) Siswaji, Bambang; Nuryartono, Nunung; Arifin, Bustanul; Said Didu, Muhammad
Jurnal Manajemen Teknologi Vol 12, No 3 (2013)
Publisher : SBM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (996.071 KB)

Abstract

Based on literatures, institutions (rules of the game) influence strategy that leads to performance of enterprise. If the relationships hold for SOE, the improvement of institutional environment will enable the improvement of SOE's performance. The aim of this research is to prove the causal relationship of institution-strategy and strategy-performance in SOE environment, and to extend the relationship to institution-performance of SOE. Likert-scaled data have been collected from expert's opinion survey. Structural equation modeling analyses found: 1) institutions significantly influence strategy; 2) strategy does not influence performance significantly; and 3) institutions directly affect performance of SOE. The reserach has been completed with historical institutional analysis to elaborate how institutional factors have emerged and developed. It found a chain of historical events that have become critical junctures and shaped the institutional factors of SOE. The research showed that favorable institutional environment is importance as pre-condition to improve SOE's performance, and it needs time and consistent efforts to develop.Keywords: enterprise performance, historical institutional analysis, institution-based strategy, state-owned enterprise, structural equation modeling
ANALISIS PERILAKU PETANI KOPI SERTIFIKASI DALAM MENGELOLA RISIKO LINGKUNGAN DI KABUPATEN TANGGAMUS Wulandari, Rizka Esty; Arifin, Bustanul; Abidin, Zainal
Jurnal Ilmu-Ilmu Agribisnis Vol 7, No 3 (2019)
Publisher : Lampung University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (607.806 KB) | DOI: 10.23960/jiia.v7i3.3775

Abstract

This research aims to analyze coffee farming income in Tanggamus District, behavior of coffee farmers in managing environmental risk, and factors that influence behavior of coffee farmers in managing environmental risk. This research was conducted in Sinar Sekampung Village, Air Naningan Sub-District and Gunung Meraksa Village, Pulau Panggung Sub-District in August 2017. The sample in this study involved 44 certification coffee farmers chosen using cluster random sampling method and 24 noncertification coffee farmers chosen using census method. The difference of coffee farming income is analyzed using Independent Sample t-test, while the difference of behavior is analyzed using Mann Whitney Test and the factors is analyzed using binary logistic regression. The results showed that there was no difference in coffee farmers income between certification farmers and noncertification coffee farmers. Sixty-three percents of certification coffee farmers were risk takers and 87,50% of nonacertification coffee farmers were risk neutral. Factors that influence behavior of coffee farmers in managing environmental risk were land area, coffee farming income, and participation of farmers in 4C certification program.Key words: coffee certification, environmental risk, coffee farming income
PENGARUH MEDIA PEMBELAJARAN AUDIO VISUAL TERHADAP HASIL BELAJAR SENAM ROLL DEPAN (SISWA KELAS V MI AL-AZHAR MODUNG BANGKALAN ARIFIN, BUSTANUL
Jurnal Pendidikan Olahraga dan Kesehatan Vol 1, No 1 (2013): Volume 1 Nomor 1 Tahun 2013
Publisher : Jurnal Pendidikan Olahraga dan Kesehatan

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Abstract

Abstract Physical education seeks to help learners to use his body more efficient and proficient in basic skills and complex skills required in life. One lesson that was taught in school gymnastics is gymnastics floor foward roll. During this school have not used the audio visual in the learning process and just use the lecture method, demonstrations so researchers want to use the audio visual media in teaching and learning in schools to facilitate the teacher in explaining and guiding students in movement and the expected learning outcomes better than ever. In this research 2 times the test (pre-test and post-test) to grade V MI AL-Azhar in Modung Bangkalan time 3 meetings. in this study a sample to get treatment by introducing and implementing a media learning audio visual in teaching and learning. The research was conducted in 3 Time meeting. Type of research there is a quantitative approach experiment done strictly to determine a causal relationship between these variables. Of research and data processing of data obtained pre-test results gymnastic foward roll obtained the value 3170, the average value of 75.47, the lowest 60, highest score a 100, the standard deviation of 14,003. While the goal should Post-test exercise roll sum of the values ??obtained before 3420, the average value 81.43, the lowest 60, highest score a 100, the standard deviation of 11.959. In the t test (difference test) the results obtained by studying gymnastics foward roll with the results of statistical tests 0.001 it can be concluded there are significant differences between result study gymnastic foward roll pre test and post test. The conclusions of the study, namely audio visual learning media can improve learning outcomes gymnastics floor foward roll. Improved learning outcomes acquired gymnastic foward roll of 7,8%. Keywords: learning audio visual, gymnastics roll foward, learning outcomes
Effect of Contact Time on Interface Reaction between Aluminum Silicon (7% and 11%) Alloy and Steel Dies SKD 61 Suharno, Bambang; Nurhayati, Neni; Arifin, Bustanul; Harjanto, Sri
Makara Journal of Technology Vol 11, No 2 (2007)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (355.121 KB) | DOI: 10.7454/mst.v11i2.132

Abstract

Die soldering (die sticking) is a defect of metal casting in which molten metal “welds” to the metallic die mold surface during casting process. Die soldering is the result of an interface reaction between the molten aluminum and the die material. Aluminum alloy with 7 and 11% silicon and SKD 61 die steel are the most common melt and die material used in aluminum die casting. This research is done to study the morphology and the characteristics of the formed AlxFeySiz intermetallic layer during interface reaction at dipping test. The samples of as-anneal SKD 61 tool steel was dipped into the molten of Al-7%Si held at temperature 680oC and into molten Al-11%Si held at temperature 710oC with the different contact time of 10 minutes; 30 minutes; and 50 minutes. The research results showed that the interface reaction can form a compact intermetallic layer with AlxFey phase and a broken intermetallic layer with AlxFeySiz phase on the surface of SKD 61 tool steel. The increasing of the contact time by the immersion of material SKD 61 tool steel in both of molten Al-7%Si and Al-11%Si will increase the thickness of the AlxFeySiz intermetallic layer until an optimum point and then decreasing. The micro hardness of the AlxFeySiz intermetallic layer depends on the content of the iron. Increasing of the iron content in intermetallic layer will increase the micro hardness of the AlxFeySiz. This condition happened because the increasing of Fe content will cause forming of intermetallic AlxFeySiz phase becomes quicker.
Effects Of 0.25 % Mo (Molybdenum) Which Is Contained In The Ductile Cast Iron On Mechanical Properties Of Austempered Ductile Iron (ADI). Nukman, Nukman; Arifin, Bustanul; Sugiarto, Bambang
Makara Journal of Technology Vol 6, No 1 (2002)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1557.947 KB) | DOI: 10.7454/mst.v6i1.42

Abstract

The aim of this research is to investigate the effects of 0.25 % Mo (Molybdenum) which is contained in the ductile cast iron on mechanical properties of Austempered Ductile Iron (ADI). The various temperatures and the holding times are used in the heat treatment processes. Using a given 0.25 % Mo in the ductile iron, ADIs alloyed developes a higher ultimate tensile stress value and decreases the elongation if we compare with the as cast (non alloy ductile iron). The higher impact energy value obtained at 9000 C austenization and 375o C austempering temperatures during 60 minutes holding times. The structure changes into ausferrit.
ISOLASI FLAVONOID DARI BIJI KAKAO (Theobroma cacao) Arifin, Bustanul; Afrizal, Afrizal; Hasnirwan, Hasnirwan; Rinaldo, Rio
Jurnal Zarah Vol 5 No 2 (2017): Jurnal Zarah
Publisher : Program Studi Pendidikan Kimia, Fakultas Keguruan dan Ilmu Pendidikan Universitas Maritim Raja Ali Haji

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Abstract

PENGARUH AKTIVASI TERHADAP MEMBRAN KERAMIK MODIFIKASI SEBAGAI BAHAN DASAR ELEKTRODA SUPERKAPASITOR Tetra, Olly Norita; Aziz, Hermansyah; Alif, Admin; Arifin, Bustanul; Joni, Rahma; Wahyuni, Hanif
Jurnal Zarah Vol 5 No 2 (2017): Jurnal Zarah
Publisher : Program Studi Pendidikan Kimia, Fakultas Keguruan dan Ilmu Pendidikan Universitas Maritim Raja Ali Haji

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Abstract

Pengaruh aktivasi dengan KOH dan NaOH terhadap performance TiO2/C berpendukung keramik sebagai elektroda superkapasitor telah diteliti. Sintesis sol TiO2 dilakukan dengan menggunakan metode sol-gel. Membran keramik sebagai template penumbuhan TiO2/C yang diaktivasi dengan  KOH dan NaOH disiapkan sebagai bahan elektroda superkapasitor dengan menggunakan elektrolit hidrogel polimer yaitu polivinil alkohol sebagai separator dan asam fosfat (H3PO4) sebagai elektrolit. Pengaruh aktivator NaOH memberikan peningkatan kapasitansi 1,5 kali lebih besar dibandingkan dengan aktivasi  KOH.  Nilai kapasitansi dengan aktivator NaOH adalah 14540 nF menggunakan konsentrasi elektrolit H3PO4 0,5 M dan waktu pengisian 30 menit dengan nilai konduktivitas sebesar 45,4 x 10-5 S/cm
STRUKTUR, BIOAKTIVITAS DAN ANTIOKSIDAN FLAVONOID Arifin, Bustanul; Ibrahim, Sanusi
Jurnal Zarah Vol 6 No 1 (2018): Jurnal Zarah
Publisher : Program Studi Pendidikan Kimia, Fakultas Keguruan dan Ilmu Pendidikan Universitas Maritim Raja Ali Haji

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (402.521 KB)

Abstract

Di antara produk-produk alami, flavonoid  adalah yang sangat menarik untuk dipelajari dan merupakan salah satu senyawa yang menjanjikan  untuk mengobati kanker, antioksidan, bakteri patogen, radang, disfungsi kardio-vaskular, dan lain-lain. Kemampuan dan bioaaktiftas terutama antioksidan dari  flavonoid telah dipelajari, dalam hal ini ditunjukkan bahwa metilasi flavonoid dapat meningkatkan peranan flavonoid dalam bidang obat-obatan. Metilasi dari flavonoid melalui kelompok hidroksil bebasnya atau atom C yang dapat meningkatkan stabilitas metaboliknya dan meningkatkan transportasi membran. Review ini menjelaskan struktur dasar dan klasifikasi flavonoid, dan isolasi dan bioaktiftas dari flavonoid yang khususnya dalam peranannya sebagai antioksidan. Mekanisme flavonoid sebagai antioksidan secara kimia dan tahapannya juga dipelajari.