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Widyariset
Published by Pusbindiklat Peneliti LIPI
ISSN : -     EISSN : 24610976     DOI : 10.14203
Core Subject : Science, Engineering,
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Widyariset is a scientific journal which publishes the results of research and development, assessment, and systematic thinking about Natural Science.
Arjuna Subject : Umum - Umum
Articles 10 Documents
 1 
Search results for , issue "Vol 2, No 1 (2016): Widyariset" : 10 Documents clear
THE EFFECT OF EL-NINO 2015 ON THE RUBBER PLANT (HEVEA BRASILIENSIS) GROWTH IN THE EXPERIMENTAL FIELD SEMBAWA RESEARCH CENTRE Jamin Saputra; Charlos Togi Stevanus; Andi Nur Cahyo
Widyariset Vol 2, No 1 (2016): Widyariset
Publisher : Pusbindiklat - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (92.869 KB) | DOI: 10.14203/widyariset.2.1.2016.37-46

Abstract

Dry season is a fator affecting plant growth. If climate anomaly El-Nino that causing prolonged dry season happens, the effect on the plant growth will be bigger. On 2015, El-Nino is happening. The presence of climate anomaly like La-Nina and El-Nino can be predicted by SOI (South Oscilation Index) released by Australian Bureau of Meteorology. Continued positive SOI value indicates symptomps of La-Nina climate anomaly and continued negative SOI value indicates symptomps of El-Nino climate anomaly. This research was aimed to determine the effect of El-Nino climate anomaly that causing prolonged dry season on the growth of PB 260 clone in Sembawa Research Centre Experimental Field. This research was conducted by comparing the growth of PB 260 clone during wet season and prolonged dry season. The result shows that under condition of 2015 El-Nino phenomenon, the growth rate of PB260 clone was decreased until 75%. The attemps to minimalize the effect of El-Nino on the growth of rubber clone was by selecting appropriate clone and location where the clone was planted, water conservation, and K fertilization with double dosage.
AUTOMATION SINGLE AXIS TYPE OF ACTIVE SYSTEM TRACKING ON PHOTOVOLTAIC Deny Suryana
Widyariset Vol 2, No 1 (2016): Widyariset
Publisher : Pusbindiklat - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (263.817 KB) | DOI: 10.14203/widyariset.2.1.2016.27-36

Abstract

Power generation from photovoltaic (PV) power is affected by radiation intensity of the sun and temperature of the environment. PV can produce maximum power when its position to the sun is optimum. The objective of this research is to control PV position toward the sun by using an active tracking system in order to produce optimum electric power. Two Light DependentResistor (LDR) sensors were placed on the east and west side of the PV, and a balance was placed in between. When the sun is on the east side from 7 a.m to 11 a.m the east LDR was exposed to light, while the west LDR was covered by balancer. When the sun is on the west side from 1 p.m to 5 p.m, west LDR was exposed to the light, while the east LDR was covered by balancer. The light intensity difference that is received by each LDR showed that an active tracking system would conduct a control action to PV position so that it will be perpendicular to the sun. The testing result showed that the difference of maximum power was 39,88 watt. It also showed that the active tracking system with single axis type could become a reference for maximum solar utilization.
MICROSTUCTURES AND MAGNETIC PROPERTIES OF BaFe12O19 WITH MgO-Al2O3 ADDITIVES Eko Arief Setiadi; Fitri Permata Sari; Ayu Yuswita Sari; Ramlan Ramlan; Perdamean Sebayang
Widyariset Vol 2, No 1 (2016): Widyariset
Publisher : Pusbindiklat - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (479.63 KB) | DOI: 10.14203/widyariset.2.1.2016.1-8

Abstract

Barium hexaferrite (BaFe12O19) is a permanent magnet material known as a hard magnet. Microstructures and magnetic properties of MgO-Al2 O3 (0.3 0.9; and 1.5 % mole) addition in BaFe12O19 have been investigated. The mixing powders of Barium Hexaferrite have been prepared by the mechanical alloying method. Particle sizes of the mixing powder show that the particle size increases with the higher concentration of MgO-Al2 O3 additives. The mixing powders are compacted into pellets and sintered with temperatures of 1,100 and 1,200 °C for 2 hours. Herein, X-Ray Diffraction (XRD), and Scanning Electron Microscopy (SEM) results show that the samples have a hexagonal structure, and their sizes and shapes are not homogeneous. Hardness values linearly decrease with the increasing of MgO-Al2 O3 (908.58 to 531.81 HV) comparable with bulk density measurements (4.85 to 4.52 g/cm2 ). On the other hand, Paragraph and Gaussmeter measurement shows a decreasing trend as the MgO-Al2 O3 additives content increased. Flux density results decline from 816.00 to 706.20 G, then magnetic remanence decreases from 2.29 to 1.92 kG and saturation magnetization drops from 3.44 to 2.93 kG. In addition, coercivity decreases from 3.83 to 2.52 kOe in proportion to the increasing of sintering temperature.
THE EFFECTS OF BACILLUS SUBTILIS CELLULASE ENZYME ON THE DECREASING OF CRUDE FIBER OF CASSAVA PEELS FOR FISH FOOD INGREDIENTS Irma Melati; MasTri Djoko Sunarno
Widyariset Vol 2, No 1 (2016): Widyariset
Publisher : Pusbindiklat - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (404.296 KB) | DOI: 10.14203/widyariset.2.1.2016.57-66

Abstract

The high content of crude fiber in cassava peel limits its digestion ability in fish. Cellulose enzyme from Bacillus subtilis is known to be able to degrade crude fiber. This study was aimed to obtain an effective dose of cellulase enzyme which was added to cassava peel to reduce its crude fiber content. The research was conducted in a completely randomized design with three treatments and two replications. The cellulase enzyme was extracted from Bacillus subtilis. Three different doses of the enzyme including control agent (0%, 25%, and 50%) were tested to degrade the crude fiber of cassava peels during two days of incubation period. Measured parameter is the fiber fraction of Neutral Detergent Fiber, Acid Detergent  Fiber, lignin, cellulose, hemicellulose, reducing sugar, and soluble proteins. The data were analyzed using analysis of variance (F-test) and further with Duncan test to determine the mean difference between groups. The results of this study indicated that the most effective dose of cellulase enzyme to decrease the cassava peel crude fiber was 25%, in which the decrease of NDF, cellulose, and hemicellulose fractions were 16.27%, 18.04%, and 40.82% respectively, while reducing sugars and soluble protein contents increased into 57.50% and 38.94%, respectively.Our findings suggested that the addition of cellulose enzyme could improve cassava peels quality for fish food ingredients. 
THE INFLUENCE OF HEAT TREATMENT ON MICROSTRUCTURE AND CORROSION RESISTANCE OF 13Cr-1Mo MARTENSITIC STAINLESS STEEL Siska Prifiharni; Moch. Syaeful Anwar; Efendi Mabruri
Widyariset Vol 2, No 1 (2016): Widyariset
Publisher : Pusbindiklat - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/widyariset.2.1.2016.9-16

Abstract

Martensitic stainless steels have been extensively used for a turbine blade. Their properties can be improved in various ways, such as by heat  treatment. This paper aims to investigate the influence of heat treatment on microstructure and corrosion resistance in martensitic stainless steel 13Cr-1Mo. Samples were austenitized at 950 ºC, 1.000 ºC, 1.050 ºC, 1.100 ºC, and tempered at 600 ºC. Austenitized sample at 1.050 ºC was subsequently tempered at 300 ºC, 400 ºC, 500 ºC, 550 ºC, 600 ºC, 650 ºC, and 700 ºC. The tests consist of metallographic observation which was conducted by using an optical microscope and corrosion tests which were conducted by using 3,5% NaCl solution. The results show the evolution of microstructure in martensitic stainless steel 13Cr-1Mo after heat treatment. The microstructure formed consists of tempered martensite, delta ferrite, retained austenite, and carbides. The presence of carbides can also affect corrosion resistance, which will increase along with the increase of tempering temperature due to the increased content of Cr in the carbides. The highest value corrosion resistance was obtained at the austenitizing temperature of 1.050 ºC and tempering temperature of 600 ºC.
Kumpulan Abstrak Bahasa Indonesia Abstrak Indonesia
Widyariset Vol 2, No 1 (2016): Widyariset
Publisher : Pusbindiklat - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/widyariset.2.1.2016.%p

Abstract

LENGTH DISTRIBUTION AND SEX RATIO TO INVESTIGATE SPAWN ELIGIBILITY OF BIGEYE TUNA(THUNNUS OBESUS LOWE, 1839) IN THE INDIAN OCEAN Arief Wujdi; Fathur Rochman; Irwan Jatmiko
Widyariset Vol 2, No 1 (2016): Widyariset
Publisher : Pusbindiklat - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/widyariset.2.1.2016.67-76

Abstract

Bigeye tuna (Thunnus obesus Lowe, 1839) is the important commodity for the fishing industry in Indonesia. Increased exploitation is threatening their population, so that is necessary to monitor the size composition that meets the eligibility to be captured, as well as the sex ratio as a management measure. Data was collected by scientific observers program which was following commercial tuna longline operation mainly based in Benoa, Palabuhanratu and Bungus Fishing Port from August 2005 to December 2014. Chi-Square analysis with 95% of confidence level also implemented to determine the sex ratio of female and male. The result showed that BET caught ranged from 30 to 192 cm, mode size ranged from 121 to 125 cm and mean 111,76 cm. As much as 69,5% of them was greater than a length at first maturity (Lm) and that means have been worthy to be captured. The sex ratio of (F:M) 1:1,32 was observed which indicates male was  dominant  than  female.  Correlation  between  sex  ratio  and  length proved to be significant where the female was increasing in size between 95-145 cm, as described a regression equation. However, an equal sex ratio occurred during December to January and also from April to June along the southern part of Java and East Nusa Tenggara and western part of Australia waters.
COMPARATIVE STUDY OF CORROSION INHIBITORS FOR REBAR STEELS IN SIMULATED PORE SOLUTION CONTAINING SEAWATER AND CARBONATES Arini Nikitasari; Faty Alvina; Efendi Mabruri
Widyariset Vol 2, No 1 (2016): Widyariset
Publisher : Pusbindiklat - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/widyariset.2.1.2016.47-56

Abstract

The performances of sodium nitrite and dimethylethanolamine (DMEA) inhibitors have been compared in mitigating corrosion of rebar steels in simulated pore solution containing sea water and carbonates. The simulated solution was prepared by dissolving saturation amounts of alkali hydroxides and sulphates in sea water  and adding carbonates subsequently. The inhibitor of sodium nitrite and DMEA with various concentration was then added to the respective simulated solution. The corrugated rebar steels were immersed in the solutions and electrochemical corrosion was measured using potentiodynamic polarization method. The experimental results showed that sodium nitrite exhibited more effective performance compared to DMEA in mitigating rebar steel corrosion  in sea water and carbonated media. The lowest steel corrosion rate of 0.27 M Sodium nitrite with 0.3 M concentration decreased corrosion rate of the steel to 0.27 M, the lowest values of the measured corrosion rates this work.
Kumpulan Abstrak Bahasa Inggris Abstrak Inggris
Widyariset Vol 2, No 1 (2016): Widyariset
Publisher : Pusbindiklat - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/widyariset.2.1.2016.%p

Abstract

ZIRCONIUM POLYMER CHARACTERISTIC AS 99Mo / 99mTc GENERATOR ABSORBENT FOR DIAGNOSTIC RADIOPHARMACEUTICALS Umi Nur Sholikhah; Hotman Lubis; Endang Sarmini; Herlina Herlina; Kadarisman Wisnukaton
Widyariset Vol 2, No 1 (2016): Widyariset
Publisher : Pusbindiklat - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/widyariset.2.1.2016.17-26

Abstract

One of the radiopharmaceuticals that were used for diagnostic is conducted by using Technetium-99m (99mTc), which could be obtained from Molybdenum-99 (99Mo) separation. This research was conducted to determine the adsorbent polymer variation effect at two zirconium chromatography systems to obtain 99mTc yield more than 80%. Polymers were used zirconium-TEOS as adsorbents in the first system while the second system used Zirconium-TEOS-methanol. The same method was conducted for both systems. The preparation was done by adding 99Mo on both polymers and heated at 90 °C temperature for three hours. Elution process of 99Mo and 99mTc was conducted by using column chromatographic system, in which the column filled with Alumina is connected to the Zirconium polymer column. The elution process was conducted on the next day until 10th fractions. Both of the systems showed the 99mTc radionuclides were highest eluted at the 3rd fraction then they decline to constant at the 10th fraction. The 99mTc yield in the system 1 was 58% and the system 2 was 96.23%. The elution from the system 1 was not analyzed by Atomic Absorption Spectrometer (AAS) because the 99mTc yield was less than 80%. Analysis results using AAS on the system 2 found out that the system 2 contained Si 1.11 ppm, and no other elements (Mo and Zr) was obtained. Based on Lethal Dose 50 (LD50), it is showed that the elution of system 2 is below the threshold (Mo = 4000 mg /kg, Zr = 489 mg /kg and Si = 22.5mg /kg), therefore it was safe to be used for diagnostic radiopharmaceuticals.

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