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Published By Indonesian Institute Of Sciences

2303-1913, 0126-1533

2018 ◽  
Vol 40 (2) ◽  
pp. 97 ◽  
Author(s):  
Ignasius Dwi Atmana Sutapa

Surface water, including rivers, lakes or ponds, in peatland areas has specific characteristics. Generally, this type of water has high level of acidity, organic matter, and high concentration in several metalic ions, like manganese and iron. The content of organic matter is usually indicated by dark brown color of water. In term of quality, this water is not suitable to be used directly for covering daily needs, such as drinking, cooking, and bathing by the local people. IPAG60 was proven as a small scale plant which has a good ability for treating different types of peat water to produce clean water as per the standards. This plant gives alternative technology to support clean water services in peatland areas.


2018 ◽  
Vol 40 (2) ◽  
pp. 66
Author(s):  
Ignasius Dwi Atmana Sutapa ◽  
Eni Maftuah ◽  
Astried Sunaryani ◽  
Hidayat Pawitan

Peat swamp forest is a unique and fragile ecosystem, with specific flora and fauna that play important roles in maintaining healthy natural conditions with high economic values. This habitat also has important role for equilibrium and maintenance of living environment such as water reservoir, carbon storage, climate change, and biodiversity. Utilization of peatland for agriculture, plantations, and other activities often lead not only to controversy, but also cause land and ecosystem degradation, including water resources availability. The objective of this research was to study comprehensive ecohydrology aspects in ex-mega rice project in Central Kalimantan in order to support sustainable agricultural practices and water resources management in peatland areas. The results of the study showed that the sustainability of agricultural systems in peatland was strongly influenced by ecological aspect. This aspect can be carried out from the condition of water management system, water color condition, and possible incidence of fires. The level of suitability for crops plantation was low (S3), with the limiting factors of pH, nutrient availability, and the risk of inundation. In this case, water gates should be installed to improve water management system. Water quality in this area was typical of peat water and do not meet the requirement for daily use for the local people.


2018 ◽  
Vol 40 (2) ◽  
pp. 76
Author(s):  
Lies Sriwuryandari ◽  
Ekaputra Agung Priantoro ◽  
Tarzan Sembiring

Renewable energy plays an important role for a sustainable future and the use of microalgae Nannochloropsis sp., as a potential source of biofuel due to its high lipid content, makes a good option. The nutrient found in the growth medium of microalgae have been found to affect cell synthesis, lipid synthesis, as well as its fatty acid profile. This study was conducted to observe the effects of the N-P concentration utilizing multistage feeding on the performance of Nannochloropsis sp. Sodium bicarbonate, urea, and sodium dihydrogen phosphate monohydrate were used as sources of C, N, and P for the microalgae. The nutrient feeding needed was calculated based on a molecular formula of microalgae(CO0.48H1.83N0.11P0.01) with a production target 1g.L-1 cell biomass. Element C is an iso-molar. The concentration of N- P varies: corresponding to the mol-fraction of the microalgae cell (as a control) and 10% excess. There were four levels of treatment: A (U0P0); B (U10P0); C (U0P10); and D (U10P10) with three replicants in the batch culture system. Nutrient feeding was conducted in three stages: I (40%); II (30%);and III (30%) and incubated in a neutral environment. Nannochloropsis sp. was able to grow well at a temperature of 24–35°C and an acidity level (pH) of 9.0–10.5. The culture (on the 21st day) produced DCW 0.93; 1.04; 0.86;1.12g.L-1, Chlorophyll-a 7.08; 7.62; 4.64; 6.85% DC, lipid 19.2; 15.5; 27.3; and 21.6% DC for treatments A; B;C; and D, respectively.The maximum lipid level resulted in an N deficiency and a P surplus (C). The lipids of the Nannochloropsis sp. composed of 66.0–81.1% saturated fatty acid which is suitable to be used as a biofuel.


2018 ◽  
Vol 40 (2) ◽  
pp. 57
Author(s):  
Edwar Yazid ◽  
Rifa Rahmayanti

Controlling the rigid gantry crane system is challenging due to it being an under-actuated system. This paper addresses the challenge by presenting the fuzzy logic controller (FLC) with Mamdani and the 1 st -order Takagi Sugeno Kang (TSK) types presenting it in this comparative study. Both controllers are proposed to control the position of the crane while suppressing the swing of the payload. Simulation results show that the Mamdani type outperforms the 1 st -order Takagi Sugeno Kang (TSK) type in terms of no overshoot, though the earlier controller (Mamdani) has a slower rise time, settling time and peak time than the latter controller (TSK).


2018 ◽  
Vol 40 (2) ◽  
pp. 116
Author(s):  
Ismail Budiman ◽  
Widya Fatriasari

Recently, pulp fiber-cement composites have found a practical application in the commercial market to replace hazardous asbestos fibers. For exterior applications, the effects of cyclical wetting and drying on the performance of cement composites were studied. The objective of this study was to investigate the influence of filling wood fibers in cement composites prior to and after a wet/dry cycling treatment. The testing of kraft pulp fiber filling consisted of a 3, 5, and 7% of volume fraction of the composite. The target density and water to cement ratio of the composites produced was 1.5 gcm -3 , with a 0.50 base on weight, respectively. Cement composites were formed and pressed into a mold to the targeted dimensions of 30 cm × 2.5 cm × 2.5 cm (length × width × thickness) for 24hours, before they were removed from the mold. They were then subjected into two curing system conditions. First, the boards were immersed in a water tank at 18 ± 2 °C for 28 days and then tested for their mechanical properties. Secondly, the samples were immersed in the same conditions as before, but followed by a wet/dry curing cycling for 6 times before the mechanical properties were tested. Mechanical characteristics were observed according to ASTM C293-94 for flexural strength and ASTM C116-90 for compressive strength by using a Universal Testing Machine (UTM). The addition of pulp fiber and the wet/dry cycling treatment gave a significantly linear effect on the mechanical properties of composites. The higher amount of wood fiber filling in the cement composites resulted in a lower flexural and compressive strength of the composites. Furthermore, the wet/dry cycling treatment tended to lower the flexural strength, but not the compressive strength of the composites.


2018 ◽  
Vol 40 (2) ◽  
pp. 87
Author(s):  
Joni Welman Simatupang ◽  
Puspa Devi Pukhrambam

In this paper, a rigorous theoretical analysis on optical beat interferometric (OBI) noises caused by the Rayleigh backscattering (RB) and Fresnel reflection (FR) effects on the performance of a single-fiber single-wavelength WDM-PON (wavelength division multiplexing-passive optical network) transmission system has been presented. Two categories of PON are evaluated: a conventional and a long-reach WDM-PON system. The conventional WDM-PON took place in an access network for a typical transmission distance of 20 km without any optical amplification at the remote node (RN). In this case, the gain of the optimal reflective optical network unit (ONU) will depend on the relative RB power and also the FRs magnitudes and locations along the optical fiber channel/transmission link. However, in the cases of the long-reach WDM-PON deployed at a transmission distance of 100 km or further, the optical amplifiers are indispensable to enhance the optical power budget and to prevent the effect of fiber nonlinearities that may occur at high power injection levels. Although the presence of an optical amplifier (OA) in a long-reach WDM-PON will actually give some additional gain to the whole system, as a result it also produces the worse RB and FR effects to the system itself. A crosstalk to signal (C/S) ratio is used as a key performance indicator of whether the transmission system is in good working order or not. Therefore, this study may provide insight and relevant information in terms of transmission optimization for WDM-PON systems and developments in the future. To educate on the current technologies and developments surrounding conventional and long-reach WDM-PON, a brief overview is provided in the background part of the introduction.


2018 ◽  
Vol 40 (2) ◽  
pp. 108 ◽  
Author(s):  
Dwi Susilaningsih ◽  
Tami Astie Uhtiza ◽  
Khairul Anam

Employing the Rhodobium marinum bacteria as an agent of hydrogen bioproduction with facultative fermentation condition needs two steps of cultivations, i.e., pre-culture and hydrogen production periods with different media.  The two steps cultivation is important state for hydrogen gas production rate. ASY (Ammonium, Succinate, and Yeast extract) is usually used as standard medium in biohydrogen production and mostly the component is analytical grade of chemicals. Series of cultivation media substitution by combining ASY with other cost-effective chemicals were investigated. The total of sixteen combinations of media were observed (P0-P15). Cultivation condition of R. marinum was set in an illuminated light of 31.17 µmol s-1m-2photon and agitated in shaker of 120 rpm for nine days. The experiment was designed as random selection with anova analyses. The results exhibited that P7 medium combination released the highest hydrogen gas of 61.29±0.52 ml/80 ml media among the others combination media. Using one-way ANOVA, there was a statistically significant difference between the mean number and condition and it was found P7 was significantly different with the others combination media, except P7 was insignificantly different with P3 only. Overall, the combination media is cheaper than the ASY medium. The ASY medium price is about USD 677, and the substitution media prices were ranging from USD 4.24 to USD 613.47. However, the further research on optimisation cultivation condition is needed.


2017 ◽  
Vol 39 (3) ◽  
pp. 158
Author(s):  
Jovita Tri Astuti ◽  
Lies Sriwuryandari

Source separation of domestic wastewater into greywater (GW) and blackwater (BW) streams is important in decentralizing treatment due to its different characteristics. GW is generated from bathroom, washing machine,kitchen sink, and vehicle washing. Meanwhile, BW is produced from toilet, urinal or bidet. In developing countries, untreated wastewater is widely used in agricultural and risk to human health and living organisms. The appropriate treatment is required to prevent water degradation. Phytoremediation is a sustainable way to mitigate pollution with using plant. This study was conducted to observe the characteristics of vetiver grass as phytoremediator for GW. There are two factors of treatment. First is growth media (M), i.e. tap water (TW) as control (M0) and GW (M1). The second is vetiver (V), i.e. without (V0) as control and with planting (V1). Three glass aquariums are used for each treatment as replicates. Eight individual stem bases of vetiver were placed at aquarium and allowed hydroponically growing. At harvesting (49th day), vegetative organs were collected and observed separately, i.e. root, stem and leaf. Pollutant removal was calculated by comparing the content before and after treatment of media with vetiver. Cultivation of vetiver in GW (M1V1) could increase the root number, total root length, and total root diameter as much as 54%, 92.2%, and 51%, respectively. Individual root length was in the range of 2.3-78.5cm and root diameter was 0.35-2.10mm. Compared to the initial, stem number increased 99%, while leaf number increased 4 times. Root/Shoot (R/S) ratio was 0.80±0.14. Polutant removal of GW by vetiver achieved 72.86% BOD5; 65.51% COD; 66.55% TN; 67.67% TP; 80.77% Fe; 71.43% Zn; 60% Pb; 65.81% detergent, and 100% phenol. Vetiver could reduced TPC 29.13%, MPN coliform 78.18%, and MPN fecal coli 91.54%. After treated with vetiver, GW complied to criteria of water Class IV that can used for irrigation in agricultural.


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