Widyariset
Widyariset is a scientific journal which publishes the results of research and development, assessment and systematic thinking about science and technology. The writers of the scientific papers in this journal come from researchers/researcher candidates from various institutions' research and development (R&D), and universities. Widyariset is published regularly three times a year: in April for the issue of Social Sciences and Humanities (IPSK), in August for the issue of Natural Sciences (IPA) and in December for the issue of Engineering Sciences (IPT).
Articles
485 Documents
<![CDATA[THE INFLUENCE OF HEAT TREATMENT ON MICROSTRUCTURE AND MECHANICAL STRENGTH OF LATERITIC NICKEL STEEL ]]>
<![CDATA[Satrio Herbirowo]]>;
<![CDATA[Bintang Adjiantoro]]>
<![CDATA[ Widyariset Vol 2, No 2 (2016): Widyariset ]]>
Publisher : <![CDATA[Pusbindiklat - LIPI ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
Full PDF (2701.502 KB)
|
DOI: 10.14203/widyariset.2.2.2016.153-160
<![CDATA[Indonesia has abundant resources of lateritic nickel ore and coal. However, this resource has not been considered as a main raw material in the Indonesian steel industry. Therefore, this study are aimed to investigate several aspects of lateritic nickel intrinsic propertiesand its potency through heat treatment process. Nickel laterite steels are usually used for bridge and building construction steel. Their properties can be improved in various ways, such as by conducting temper heat treatment. This research reported the influences of heat treatment on microstructure and mechanical strength in nickel laterite steel. Samples were austenitized at 900ºC and subsquently tempered at 100 ºC, 200 ºC, 300 ºC, 400 ºC, 500 ºC, and 600ºC. Metallographic observation was conducted by using an optical microscope meanwhile mechanical strength were conducted by tensile test and surface hardness. The results showed evolution of mictrostructure in nickel laterite steel after heat treatment. The microstructure formed consisted of martensite temper. The presence of inclusion can affect brittle behavior of the lateritic nickel. The optimum tempering temperature was 200 ºC. The result of Scanning Electron Microscope (SEM) fractography showed the dimple and intergranular fracture has caused a more ductile and mechanical behavior which is compatible with construction steels standard.]]>
<![CDATA[WASTEWATER SPECIFIC EMISSION FACTOR FROM COMMUNAL WASTEWATER TREATMENT PLANT (WWTP) ]]>
<![CDATA[Reni Nuraeni]]>;
<![CDATA[Amallia Ashuri]]>
<![CDATA[ Widyariset Vol 4, No 1 (2018): Widyariset ]]>
Publisher : <![CDATA[Pusbindiklat - LIPI ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
Full PDF (611.961 KB)
|
DOI: 10.14203/widyariset.4.1.2018.37-48
<![CDATA[Greenhouse gasses (GHG) that produced by anaerobic digestion of wastewater consists of CH4 gas and NO2 gas. Beside the data of specific activity, the specific emission factor also plays important part to determinate GHG emission. The aim of this paper is to know specific emission factor value from communal wastewater treatment plant (WWTP), as an input to determinate GHG emission for determination of GHG emission reduction rate. The data was collected by taking sample of BOD, CH4 gas, and CO2 gas from communal WWTPs. Sampling location were communal WWTPs in Jakarta City, Bandung City, and Yogyakarta City. Those WWTPs using anaerobic baffle reactor as their treatment system with capacity varied between 40-200 EP. The parameters were BOD and CH4 that measured using grab sampling in the morning and evening. Data analyzed by quantitative methods. The specific emission factor value was determined from CH4 gas measurement which affected by wastewater treatment unit dimension, gas catcher chamber, and air suction pump capacity. The analysis results showed specific emission factor for communal WWTPs from the three cities is 0.00171 kg CH4/kg BOD. The value has bid difference when compared to IPCC’s default that is 0.48 kg CH4/kg BOD. This is due to the formation of CH4 gas and CO2 gas was strongly influenced by environmental condition in real time condition. This factor is not taken into consideration in IPCC’s default.]]>
<![CDATA[ADAPTATION TEST OF FIVE NEW HYBRID MULBERRY TO IMPROVE NATURAL SILK PRODUCTIVITY ]]>
<![CDATA[Lincah Andadari]]>;
<![CDATA[Rosita Dewi]]>;
<![CDATA[Sugeng Pudjiono]]>
<![CDATA[ Widyariset Vol 2, No 2 (2016): Widyariset ]]>
Publisher : <![CDATA[Pusbindiklat - LIPI ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
Full PDF (516.038 KB)
|
DOI: 10.14203/widyariset.2.2.2016.96-105
<![CDATA[One of the problems faced by silk production in Indonesia is low productivity of mulberry that is currently planted by the farmers. Therefore, it is necessary to develop new hybrid of mulberries that have a higher leaves production. Before the new hybrid of mulberry can be cultivated by farmers, the new hybrid plant should be tested first. Adaptation test is required to view genetic response of the plant with the environment in which mulberry grows. The purpose of this study is conducting adaptation test of mulberry’s five types new hybrid to measure the growth and the productivity of plants. Adaptation test research of mulberry’s five new hybrids has been conducted from 2012 until 2014 in Cipeuteuy Village, Sub District Kabandungan, District of Sukabumi. This research used randomized block design method with six treatments and three replications. The results showed that two types of hybrid mulberry showed high percentage growth on average 99%. The use of hybrid mulberry Morus cathayana x Morus amakusaguwa IV.12 in natural silk production can increase 59,60 % of productivity, while Morus cathayana x Morus amakusaguwa IV.10 can increase 47,83% of productivity. Two types of hybrid mulberry, Morus cathayana x Morus amakusaguwa IV.12 and Morus cathayana x Morus amakusaguwa IV.10 have excellent potential in silkworm feed productivity development.]]>
<![CDATA[CHARACTERISTICS OF ORGANIC AND NUTRIEN REMOVAL ON LOOP BIOFILTER SYSTEM FOR PEAT WATER AND WASTEWATER TREATMENT ]]>
<![CDATA[Elis Hastuti]]>;
<![CDATA[Fitrijani Anggraini]]>;
<![CDATA[Reni Nuraeni]]>
<![CDATA[ Widyariset Vol 3, No 1 (2017): Widyariset ]]>
Publisher : <![CDATA[Pusbindiklat - LIPI ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
Full PDF (1302.054 KB)
|
DOI: 10.14203/widyariset.3.1.2017.55-66
<![CDATA[Domestic wastewater pollution in the watershed area which has ecologically sensitive area, such as peat water, can be resolved by water management that combines raw water treatment and wastewater treatment with closed loop system on a community scale. This paper describes the removal characteristics of organic and nutrient in biofilters loop system to treat raw water that contains color <300 units PtCo, COD 102-116 mg/L, and domestic wastewater. Water treatment system which consists of a biological treatment and multimedia filtration is used to supply drinking water and to conduct wastewater treatment on a community scale by using the potential of ecosystems and chemical-physical characteristics of peat. The study was conducted by applying method of field scale to serve 50 families and method of performance evaluation models based on approach of first-order kinetics plug flow and Kadlec and Knight k-C* model. The case study is located in downstream of Siak watershed areas, as one of the national strategic watersheds, which is packed with urban slum areas with low access to surface water utilization and good sanitation infrastructure. Water treatment unit that consists of peat biofilter systems, hybrid aerobic biofilter, and zeolite cation-anion filtrationcan support water supply in public sanitation facilities. The biofilters loop model for wastewater treatment consists of hybrid Upflow Anaerobic Sludge Blanket (UASB), biofilters, and constructed wetlands which its media is a combination between porous media and peat soils. At steady state, the removal of organic and nitrogen is larger than 90%.]]>
<![CDATA[MICROSTUCTURES AND MAGNETIC PROPERTIES OF BaFe12O19 WITH MgO-Al2O3 ADDITIVES ]]>
<![CDATA[Eko Arief Setiadi]]>;
<![CDATA[Fitri Permata Sari]]>;
<![CDATA[Ayu Yuswita Sari]]>;
<![CDATA[Ramlan Ramlan]]>;
<![CDATA[Perdamean Sebayang]]>
<![CDATA[ Widyariset Vol 2, No 1 (2016): Widyariset ]]>
Publisher : <![CDATA[Pusbindiklat - LIPI ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
Full PDF (1341.196 KB)
|
DOI: 10.14203/widyariset.2.1.2016.1-8
<![CDATA[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.]]>
<![CDATA[REYNOLDS NUMBER ESTIMATION OF ROTAMETER BASED ON K-EPSILON MODEL ]]>
<![CDATA[Bahrudin Bahrudin]]>;
<![CDATA[Hilman Syaeful Alam]]>
<![CDATA[ Widyariset Vol 3, No 1 (2017): Widyariset ]]>
Publisher : <![CDATA[Pusbindiklat - LIPI ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
Full PDF (1945.59 KB)
|
DOI: 10.14203/widyariset.3.1.2017.9-18
<![CDATA[Measurement of fluid flow with the aid of a floating element (rotameter) is a simple method used to measure the velocity of the fluid with a better degree of accuracy. However, there is still a tendency for turbulence flow around the floating element (annular area) due to narrowing of the flow area and the geometry shape of the floating element that can reduce the level of the rotameter accuracy. Single phase turbulent flow through rotameter was estimated using k-epsilon turbulence model. Detailed study has been performed to investigate the influence of turbulence characteristics from the Reynolds Number ( ) as a benchmark for predicting the level of turbulence. The results showed that at the velocity of 800 l/h the level is arounds 450, which show that the fluid flow on the rotameter categorized as turbulence]]>
<![CDATA[EVALUATION OF THE EXISTENCE OF Shorea platyclados Slooten ex Endert IN THE BUKIT DAUN PROTECTED FOREST ]]>
<![CDATA[Marfuah Wardani]]>;
<![CDATA[Adi Susilo]]>
<![CDATA[ Widyariset Vol 3, No 2 (2017): Widyariset ]]>
Publisher : <![CDATA[Pusbindiklat - LIPI ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
Full PDF (286.371 KB)
|
DOI: 10.14203/widyariset.3.2.2017.151-160
<![CDATA[Study on the evaluation of the existence of Shorea platyclados Slooten ex Endert (meranti bukit, meranti gunung, meranti tenam) on its natural habitat was conducted on May 2014 in Bukit Daun Protection Forest, Central Bengkulu District, Bengkulu. Exploration and inventarisation were designed in a semi-permanent plot, in which S. platyclados is used as the center of circle plot for vegetation analysis. Results showed that the distribution of S. platyclados is clump on steep valley, with its altitude is in between 400 – 600 m asl. Shorea platyclados was a dominant species on tree stage with good regeneration in all stage with IVI = 88.00%. Pole stages were dominated by Lindera subumbelliflora (Blume) Kostermans with IVI =10.58%, and seedling stage was dominated by Syzygium cymosum DC. with IVI =7.48%. The existence of S. platyclados in Bukit Daun Protected Forest, Central Bengkulu District was not endangered.]]>
<![CDATA[AUTOMATION SINGLE AXIS TYPE OF ACTIVE SYSTEM TRACKING ON PHOTOVOLTAIC ]]>
<![CDATA[Deny Suryana]]>
<![CDATA[ Widyariset Vol 2, No 1 (2016): Widyariset ]]>
Publisher : <![CDATA[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
<![CDATA[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.]]>
<![CDATA[VISION SYSTEM DEVELOPMENT IN ECCENTRICITY TESTING FOR KWH METER UPPER BEARING ]]>
<![CDATA[Emilham Mirshad]]>
<![CDATA[ Widyariset Vol 4, No 1 (2018): Widyariset ]]>
Publisher : <![CDATA[Pusbindiklat - LIPI ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
Full PDF (682.909 KB)
|
DOI: 10.14203/widyariset.4.1.2018.49-60
<![CDATA[Eccentricity measurement techniques are developed to ensure optimization of operational works, either for large or small objects such as upper bearing kWH meter. Small object eccentricity testing has been done by using precise and sensitive touch trigger probing and a special sofware that makes it expensive. This study developed a more economical vision systemin eccentricity testing. It consists of bearing holder and CCD microscope as an image recorder and computerized image processing. It uses three tested bearing during image recording process, which obtained 12 images from each tested bearing taken from every 30o angle, and one image as registration reference. Image registration process is conducted to correct imperfections bearing mounting into its holder and use centroid method to test the eccentricity of upper bearing kWH meter. This study is succeed in making an eccentricity testing prototype of upper bearing kWH meter which obtained result of 2nd bearing has its largest standard deviation. From all standard deviation value obtained that x -axis (horizontal) standard deviation is larger than y-axis (vertical) which means that detection of x direction is more accurate than y direction. To enhance precision image acquisition in the next study, it is expected the use of a computer system with homogeneous illumination is enabled.]]>
