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Widyariset
Published by Lembaga Ilmu Pengetahuan Indonesia
ISSN : 14117932     EISSN : 24610976     DOI : -
Core Subject : Engineering,
Engineering
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).
Arjuna Subject : -
Articles 485 Documents
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REDUCE CO ON CAR BY USING ZEOLITE MIFTAH FARHANA; Budiyono Budiyono; Nikie Astorina Yunita Dewanti; Wahyu Bambang Widayatno
Widyariset Vol 6, No 2 (2020): Widyariset
Publisher : Pusbindiklat - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/widyariset.6.2.2020.107-115

Abstract

The number of vehicles in Jakarta increased by 5.66% from 2016. Vehicles have the highest contribution to air pollution, which is 70% of other activities. The purpose of this study was to determine the reduction of CO with zeolite pellets. This type of research is a quasi-experimental design with a non-equivalent control group design pre-test post-test design. The emission test instrument uses the automotive gas analyzer HESBOHN, a tachometer to measure engine speed, laptops, and stopwatches. The material used is activated natural zeolite pellets. Data were analyzed by univariate in the form of CO adsorption power efficiency, average, minimum, and maximum. The variables used are pellet drying time (3 hours and 24 hours) and engine speed (idle and 1250 rpm). The result of CO adsorption power efficiency using the most optimal zeolite pellets is Pellet I with 3 hours drying at 1250 rpm by 52%. While the lowest yield is Pellet II with 24-hour drying at idle conditions of 22%. The most effective CO emission reduction is by using Pellet I at 1250 rpm.
Optimalisasi Lateks Tetesan Lanjut Menggunakan Berbagai Koagulan Anjuran Afrizal Vachlepi
Widyariset Vol 6, No 1 (2020): Widyariset
Publisher : Pusbindiklat - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/widyariset.6.1.2020.1-21

Abstract

Natural rubber latex will coagulate naturally about 4-6 hours after tapping. This coagulation will produce low quality rubber and inconsistent. In addition, latex will be easily lost by rain because long coagulation time, especially continuous latex droplet. The use of coagulant in the continuous latex droplet can reduce yield losses and improve quality. The purposes were to identify and study the effect of coagulants on the dry rubber content and technical quality of the rubber from continuous latex droplet of clone BPM 24. The treatments was type of coagulants consist of formic acid, pure liquid smoke, liquid smoke DS, liquid smoke DK and control (auto coagulation). Each treatment use 10 rubber tree of clone BPM 24. The parameters consists of dry rubber content, initial plasticity (Po), plasticity retention index (PRI), Mooney viscosity, viscosity stability index (SVI), volatile matter content and ash content. The quality will be analyzed statistically using the completely randomized design non factorial and will be compared with Indonesian National Standard 06-1903-2000 about Standard Indonesian Rubber (SIR). The results showed that the use of coagulant to continuous latex droplet had significant effect on PRI and Mooney viscosity of rubber. The best treatment was obtained liquid smoke DS which produce rubber with quality standards for Po 36, PRI 80.8, Mooney viscosity 68, SVI 4, ash content 0.27% and volatile matter content 0.48%. The coagulated natural rubber with liquid smoke DS can produce rubber with quality specifications SIR 20 grade CV 70.
SINTESIS, PENGUJIAN, DAN KARAKTERISASI HIDROGEL BERBASIS SODIUM CARBOXYMETHYL CELLULOSE DAN CHITOSAN Setyono Hari Adi; Nani Heryani
Widyariset Vol 5, No 1 (2019): Widyariset
Publisher : Pusbindiklat - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/widyariset.5.1.2019.1-10

Abstract

Hydrogel, as a water super absorbent polymer, has a potential to improve irrigation efficiency in agricultural land. The objective of this research was to optimize hydrogel syntheses using environmentally friendly natural polymers, including sodium carboxymethyl cellulose (NaCMC), chitosan, and citric acid. Hydrogel was synthesized using the hydrothermal method at a temperature below 100 °C and using water as the primary medium. The results of this research showed that hydrogel which was synthesized with 2% w/v of NaCMC and 5% w/w of citric acid in 10% v/v of chitosan, which was cross-linked in 80 °C for 2 hours, was able to absorb water up to 350 times of its dry weights for 30 minutes. The maximum absorption rate of the produced hydrogel was up to 55 grams per minutes and was achieved during the first 3 minutes of free absorbency test.
CO-PYROLYSIS CANGKANG KELAPA SAWIT DAN LIMBAH PLASTIK KEMASAN Sabar Pangihutan Simanungkalit; Dieni Mansur
Widyariset Vol 6, No 2 (2020): Widyariset
Publisher : Pusbindiklat - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/widyariset.6.2.2020.62-74

Abstract

In the present study, the co-pyrolysis of biomass waste, i.e. palm kernel shells (PKS) and industrial packaging plastic waste, namely polyethylene terephthalate (PET) and polyethylene (PE) were conducted. Prior to the pyrolysis, the raw materials were analyzed by thermogravimetric and elemental procedures. The pyrolysis was conducted in a fixed bed reactor which was heated from room temperature to 500 °C in an N2 atmosphere with a heating rate of 10 °C/min. The raw materials were weighted and mixed together manually with variations of weight composition ratios between biomass and plastic, i.e. 100% biomass (100/0); 90% biomass and 10% plastic (90/10); 70% biomass and 30% plastic (70/30); 50% biomass and 50% plastic (50/50); and 100% plastic (0/100). Then, they were put under pressure to obtain a pellet. The synergistic effect of biomass and plastic was investigated to see the difference between the pyrolysis products yields in theory and experiment. The bio-oil products were characterized by several methods and showed the potential to be used as a fuel. The optimum condition was obtained from 50/50 weight composition ratio. It was gained 30% improvement of the higher heating value of bio-oil, and the percentage area of hydrocarbon was contained in bio-oil increased from 4.68% to 53.40%.
IDENTIFIKASI PERUBAHAN POLA CURAH HUJAN DAN PERIODE MASA TANAM DI LAHAN KERING UNTUK ADAPTASI PERUBAHAN IKLIM (STUDI KASUS KABUPATEN BONE, SULAWESI SELATAN) yeli sarvina
Widyariset Vol 5, No 2 (2019): Widyariset
Publisher : Pusbindiklat - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/widyariset.5.2.2019.54-64

Abstract

Identification of climate change impacts on spatial and temporal rainfall pattern and length of growing period are very important for climate change adaptation strategy. Rainfed is an agro-ecosystem most sensitive to changes in rainfall patterns. Bone Regency is a center of agriculture in South Sulawesi and has considerable rainfed potentials. This study aims to identify changes of rainfall patterns and length of growing period (LGP) for paddy and upland rice in Bone Regency. Data of three rain stations with a 55-year period were used and Oldeman methods was applied to determine rainfall pattern and LGP. Data was separated in two period, period 1 (1961-1990) and period II (1991-2016). The pattern of changes were identified by comparing rainfall patterns in LGP I and II. This analysis was grouped by wet year, normal year and dry year with criteria developed by BMKG. The results of the analysis showed that the rainfall pattern and LGP had changed of which pattern of change varies between regions. The LGP of paddy in Macope were three months shorter in all years, while for upland rice were two months shorter in wet year, and 1 month in normal year. In Katumpi, the LGP of paddy fields were 2 months shorter comparing to the wet year and 1 month shorter in normal and dry year for upland rice. LGP for paddy in Cellu was lengthened 1 month in wet year and shortened 2 months in dry year for upland rice.
Eddy Currents Variablity from Satellite Altimetry and Its Relation to Physical Conditions of Java Sea Kautsar Fadlih Akbar; Ahmad Bayhaqi; Khikmah Muliati; Denny Darmawan
Widyariset Vol 6, No 1 (2020): Widyariset
Publisher : Pusbindiklat - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/widyariset.6.1.2020.22-28

Abstract

Current pattern in Java Sea highly depends on monsoonal cycles, which create alternating conditions according to the seasons throughout the year and potential impacts on eddy currents variability. Using the surface geostrophic current data from satellite altimetry during 2013-2017, this study aims to understand the variability of eddy currents and its relations to the physical condition of the Java Sea such as sea surface temperature (SST), sea surface height (SSH), and chlorophyll-a concentration (CHL). Results showed 60 occurrence of eddy currents in the study area, 40 cyclonic and 20 anticyclonic. The largest cyclonic eddy observed in April 2013 (112.05, -5.37) with a diameter of 134.07 km, while the largest anticyclonic eddy observed in October 2017 (114.54, -6.24) with a diameter of 159.69 km. Cyclonic eddy has lower SSH and cold core while anticyclonic eddy has higher SSH and warm core. Despite having an unclear pattern during the five years period, the occurence of Eddy current has a potentially indirect influence on Chl-a concentration.
PENGARUH KOMPOSISI LELEHAN DAN WAKTU CELUP TERHADAP STRUKTUR MIKRO LAPISAN HOT DIP ALUMINIZING PADA BAJA TAHAN KARAT MARTENSITIK moch syaiful anwar; Kevin Kevin; saefudin saefudin; Alfirano Alfirano; Efendi Mabruri
Widyariset Vol 5, No 1 (2019): Widyariset
Publisher : Pusbindiklat - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/widyariset.5.1.2019.21-29

Abstract

Pada material aplikasi suhu tinggi, pelapisan permukaan merupakan hal penting dalam memberikan ketahanan oksidasi dan korosi suhu tinggi, ketahanan erosi dan abrasi. Pelapisan alumunium pada baja tahan karat martensitik AISI 410 melalui metode celup panas (hot dip) cukup efektif untuk memberikan perlindungan pada substrate melalui senyawa-senyawa intermetalik yang terbentuk. Proses hot dip aluminizing dilakukan dengan preparasi penghalusan permukaan sampel menggunakan amplas grit 100, 400, 800, dan 1200. Kemudian sampel dibersihkan menggunakan larutan 15% H2SO4 sebelum dilakukan proses celup panas. Spesimen tersebut dikaitkan menggunakan kawat nikel untuk memudahkan proses pencelupan. Komposisi lelehan Al-Si, waktu pencelupan, dan waktu difusi memberikan pengaruh terhadap lapisan intermetalik yang terbentuk beserta sifat mekanisnya. Telah dilakukan karakterisasi morfologi lapisan hot dip aluminizing pada spesimen baja tahan karat martensitik yang dilapisi oleh Al Murni, 5 %wt Si, 10 %wt Si, dan 15 %wt Si dengan variasi waktu pencelupan 1 menit, 3 menit, dan 5 menit dengan menggunakan SEM – EDS. Pada komposisi lelehan dengan komposisi 5%wt Si dengan perlakuan permukaan yang sama oleh larutan H2SO4 memberikan hasil lapisan intermetalik yang lebih baik. Dapat dilihat dari kehalusan struktur mikro dan ketebalan lapisan yang dihasilkan berdasarkan variasi waktu pencelupan. Unsur Si memberikan pengaruh dalam merubah morfologi struktur antarmuka antara intermetalik dengan substrate.
EVALUASI HASIL PEMODELAN BATIMETRI DARI BEBERAPA KOMBINASI SATELIT ALTIMETRI PADA LAUT NATUNA DAN LAUT SULAWESI Yustisi Ardhitasari Lumban-Gaol; Nadya Oktaviani; Prayudha Hartanto; Ibnu Sofian
Widyariset Vol 6, No 2 (2020): Widyariset
Publisher : Pusbindiklat - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/widyariset.6.2.2020.75-87

Abstract

Indonesia is an archipelago country where 77% of its territory is waters. National marine mapping has been carried out based on depth measurement data obtained using echosounders. However, this method requires a lot of time and cost. One solution to provide Indonesian bathymetry data is by utilizing altimetry satellite data to model the bathymetry of the seafloor. This study aims to evaluate bathymetric model generated from three combinations of five altimetry satellites in shallow and deep seas. We use least square collocation gravity anomaly and geological gravity for bathymetry modeling. The results of the model show variations in deviations with sounding data available at the Geospatial Information Agency (BIG). The resulting residual trend differs between shallow and deep sea. The optimum results in shallow area is obtained by the combination of Cryosat-2, Jason-1/C, and SARAL while in deep area is obtained by the combination of ERS-1/E-F and Geosat GM. In general, the bathymetry model produced in this study has a similar profile with the sounding data.
Pengawetan Kayu Karet Menggunakan Asap Cair dan Ekstrak Kunyit dengan Teknik Perendaman Dingin Sherly Hanifarianty; Afrizal Vachlepi
Widyariset Vol 5, No 2 (2019): Widyariset
Publisher : Pusbindiklat - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/widyariset.5.2.2019.65-74

Abstract

Rubber wood (Hevea brasiliensis) is a wood with low durability wood. In general, rubber wood is preserved by chemicals which are relatively not environmental friendly. This study was conducted to evaluate the potential of liquid smoke from pyrolysis of palm oil kernel and turmeric extract as wood preservatives. Rubber wood was soaked in 5% w/v of liquid smoke and turmeric extract, respectively for 2, 8, and 14 days which preservation was carried out for six months. Formaline and boric acids was used for comparison as well. The used parameters were preservative retention, moisture content during storage, color changes, and damage level. The results indicated that the longer the immersion, the greater the preservative retention and water content. Turmeric extract and liquid smoke provided a brownish yellow and light brown color. In general, liquid smoke for two days of immersion adequate for six months preservation whereas turmeric acid for two months.
FAKTOR PENGUNGKIT DAN STRATEGI PENINGKATAN PENGELOLAAN LINGKUNGAN OLEH PERKEBUNAN DAN PABRIK KELAPA SAWIT DI KABUPATEN BATANG HARI novia susianti; Sukmal Fahri; Abdul Salam Lubis
Widyariset Vol 6, No 1 (2020): Widyariset
Publisher : Pusbindiklat - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/widyariset.6.1.2020.29-42

Abstract

Environmental management by the oil palm plantation industry has become a necessity in minimizing negative impacts on the environment that have emerged from the construction to the operation stage. The government has made a preventive effort by requiring every industry performer to manage the environment by following the ownership of the company's environmental documents. However, in reality, there are still companies that have not implemented this effort, including in Batang Hari Regency as the regency with the highest number of oil palm companies in Jambi Province. This study aims to identify the lever factors and environmental management strategies by oil palm industry players in Batang Hari District. Data collection was carried out through in-depth interviews with the government, companies and village communities in the study areas, document review, observation, and focus discussion group (FGD) to the district, sub-district and village government research sites. The determination of priority levers is done by determining the important levers first with an average criterion of ≥75%, followed by fit/gap analysis by mapping important factors in quadrant I, and strategies to improve environmental management efforts are carried out using a prospective promethee analysis. The results showed that there were three priority lever factors and six factors that were advantages to improve environmental management. The strategy through the Walfare Pluralism (WP) approach is the best approach with the support of the contribution of the nine factors. This approach emphasizes the role of government, companies and communities through the principle of a five-sector approach (public sector, private sector, voluntary sector, mutual aid, and informal sector) in improving environmental management.

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