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IPTEK The Journal for Technology and Science
ISSN : 08534098     EISSN : 20882033     DOI : -
Core Subject : Science,
IPTEK The Journal for Technology and Science (eISSN: 2088-2033; Print ISSN:0853-4098), is an academic journal on the issued related to natural science and technology. The journal initially published four issues every year, i.e. February, May, August, and November. From 2014, IPTEK the Journal for Technology and Science publish three times a year, they are in April, August and December in online version.
Arjuna Subject : -
Articles 317 Documents
Optimization Using Solvent-Free Microwave Hydro-diffusion Gravity Extraction of Onion Oil from Allium cepa by Response Surface Methodology Yeni Variyana; Mahfud Mahfud
IPTEK The Journal for Technology and Science Vol 30, No 3 (2019)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v30i3.5474

Abstract

Extraction from Allium cepa using solvent-free microwave extraction (SFME) without solvent was chosen as a method in the extraction process. The method is combined with microwave hydro-diffusion gravity (MHG) technique. In this paper, onion oil was extracted from Allium cepa using solvent-free microwave hydro-diffusion gravity extraction which is as an alternative technique to produce onion oil and it has several advantages in terms of product quality and high yield. The highest yield was obtained from this research at 100 g, 450 W and 15 min is 2.5875%. Furthermore, response surface methodology (RSM) was designed to evaluate the effects of mass of raw material (g), microwave power (W) and extraction time (min) for optimization of experimental data. Response surface methodology gave the optimum condition at 99.738 g, 465.067 W, and 17.817 min is 2.677%. The error rates between the experimental and predicted model which are less than 5% indicate that values obtained in optimal conditions correspond to theoretical values and it can be used as a reference for optimizing
Synthesis N-Doped Activated Carbon from Sugarcane Bagasse for CO2 Adsorption Randy Yusuf Kurniawan; Irsandi Dwi Oka Kurniawan; Lukman Atmaja; Nurul Widiastuti
IPTEK The Journal for Technology and Science Vol 30, No 3 (2019)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v30i3.5469

Abstract

Nitrogen-doped activated carbon (SBACN) was synthesized from sugarcane bagasse waste as acarbon source and urea as nitrogen source through potassium hydroxide (KOH) activation for 2 h at high temperature via two step methods. The synthesized SBCN was characterized using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Fourier Transform Infrared (FTIR). The results showed that the SBCN has low degree crystallinity and graphitization with highly developed micropores due to synergistik activation effect of KOH and urea. These characteristics provide an important contribution to carbon dioxide adsorption capacity, which can reach up to 11,20% wt and this value is higher than pristine activated carbon. The results indicating that the presence of this nitrogen functionalities is found to have a beneficial influence on the carbon dioxide adsorption characteristic in standart condition and exhibit considerable potential in solid adsorption.
Experimental and Numerical Bending Analysis of Steel/Resin-Talk Sandwich Material Pratama Arianto; Achmad Zubaydi; Bambang Piscesa; Tuswan Tuswan
IPTEK The Journal for Technology and Science Vol 30, No 3 (2019)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (979.686 KB) | DOI: 10.12962/j20882033.v30i3.5496

Abstract

Sandwich material can be used as the substitute for the ship conventional material. The core sandwich material used in this study consisted of a talk-resin-catalyst. The core mixture proportion is 90% resin and 10% talk. A thick steel plates is used as the face of the core sandwich material. Both experimental and numerical simulations are carried out to investigate the bending or flexural behavior of the proposed sandwich material. Three-point bending test has been carried out to determine the yield stress and maximum stress as well as the damage mechanism of the specimen up-to failure. From the investigation, the first failure process occurred at the mid-span as flexural cracks. As the load continue, these flexural cracks progressed until fully fracture of the core material take places. From the experimental investigation, it was found that the yield stress and maximum stress of the sandwich panel are 22.88 MPa and 28.63 MPa. On the other hand, numerical simulation is carried out using ABAQUS which has shown to be sufficient to predict the response of the sandwich-panel. However, a more sophisticated constitutive model is required to successfully model the experimental behavior in close agreement.
6β-hydroxyipolamiide of Stachytarpheta jamaicensis Leaves Yuliana Yuliana; Fithrotul Auwaliyah; Sri Fatmawati
IPTEK The Journal for Technology and Science Vol 30, No 3 (2019)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (516.156 KB) | DOI: 10.12962/j20882033.v30i3.5408

Abstract

Stachytarpheta jamaicensis is one species of Verbenaceae family that is used as a traditional medicine. 6β-hydroxyipolamiide is a natural occuring compound that was successfully isolated from S. jamaicensis leaves. The identification of compound was analyzed by using UV-Vis, Infra-Red (IR) spectrophotometry and Nuclear Magnetic Resonance (NMR) spectrometry. This is the first report that the compound has isolated from this plant.
Fluid-Soil-Structure Interaction Phenomena on Vibration Case at Pump Station Building Hendri Hermawan; Data Iranata; Djoko Irawan
IPTEK The Journal for Technology and Science Vol 30, No 3 (2019)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v30i3.5470

Abstract

Excitation at low-rise reinforced concrete building had occurred within the first-year post-construction phase. It is found that the structures laying on thick soil layer while performing up to 4 kPa water transport activity. Three approaches have been adopted to investigate the dynamic behavior and the interaction the phenomenon commonly called fluid-soil-structure interaction. Applying the finite element computation to represent the dynamic of the soil-fluid and structure, existing and ideal-fixed base condition are modeled and compared each. It was found that the structure’s modes frequencies, much depend on the rigidity of the base and the fluids traffic on the pump station. Time history string of displacements at the arbitrary point shows that the vibration does occurs and it tendentious increase by time
Free Radical Scavenging Activity of Chromolaena odorata L. Leaves Putri Anni Maulida; Devi Anggraini Putri; Sri Fatmawati
IPTEK The Journal for Technology and Science Vol 30, No 3 (2019)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (467.233 KB) | DOI: 10.12962/j20882033.v30i3.5409

Abstract

Chromolaena odorata is one of the plants used by the community as traditional medicine. Some of community in Ambon, Indonesia used C. odorata leaves as wound medicine. This study aims to evaluate free radical scavenging activity from fraction of methanol extract of C. odorata. Methanol extract of C. odorata leaves is known have good free radical scavenging activity. The fractionation from methanol extract of the C. odorata leaves obtained A-E fraction, where fractions C, D and E showed inhibitory activity against DPPH radicals (2,2-difenill-1-pikrilhidrazil) with IC50 values 63,95; 64.38 and 202.15 μg/mL. Positive control, which is gallic acid, has an IC50 value of 5.29 μg/mL.
Modification of Chitosan-Chitosan Phtalate Anhydrides Matrices Lukman Atmaja; Herianus Manimoy; Lina Eka Arizka
IPTEK The Journal for Technology and Science Vol 30, No 3 (2019)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v30i3.5504

Abstract

Chitin and chitosan are natural biopolymers on shrimp shells. Chitosan is used extensively as a raw material in various industries. The study aimed to extract chitin and chitosan from fanami shrimp skin through deproteinization, demineralization, and deastilation reactions and to modify the matrix to improve the physical properties. The results of the analysis of the FTIR chitin spectrum shows several major peaks at wave number 3446.91 cm-1 which showed the vibrations of bending secondary amide and amine (NH) secondary amides at 1654.98 cm-1 indicating the presence of vibration stretching CH. The results of the chitosan FTIR spectrum analysis shows symmetrical stretching vibrations at 3433.41 cm-1 due to overlapping OH and amines (NH), stretching vibrations of 1653.05 cm-1 caused by the propagation of C = O stretching and stretching vibrations of 1587.47 cm-1 indicating secondary amide. The results of the characterization with XRD shows that the extracted compounds were chitin and chitosan. In modifying the chitosan matrix, the spectra result show peak at 1656.91 - 1564.32 cm-1 indicating the presence of an amide group. New aromatic group peak found in the area of 1631.83 cm-1 which not found in chitosan. Diffract gram XRD from pure chitosan shows three highest peak peaks at 2θ equal to 609.2; 609.88 and 550 while chitosan-anhydrous modification shows a peak at 2θ equal to 609.8. The addition of anhydrous phthalates to chitosan has reduced its crystallinity which results in an increase in the hydrophilic characteristics of the membrane. The results of this study are expected to be one of the references in further research regarding the manufacture of phthalate chitosan-anhydrous based composite membranes for DMFC
Visual Indicator Based on Leuco Crystal Violet for Radiation Processing Technology Shinde, Santosh Harsichandra; Mondal, Suvendu; Sathian, Vilippalil
IPTEK The Journal for Technology and Science Vol 30, No 3 (2019)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (284.858 KB) | DOI: 10.12962/j20882033.v30i3.5045

Abstract

One of the important technologies for food preservation and processing is radiation processing, which is growing at ever increasing rate in India. Efforts are being done to make it more cost-effective, so there is always a need for cost-effective, indigenously developed visual indicators for providing an easy identification and segregation of irradiated products. Thus development of cost-effective visual indicator based on leuco crystal violet for doses ≥ 10 kGy was under taken. Current research works deals with fabrication and characterization of various parameters such as optimum composition, light stability, temperature effect and effect of relative humidity on the new indicator.
Study of UV-B Mutation Effect on pH Resistance and Lipid Production of Microalgae Botryococcus braunii Soedarmodjo, Thea Prastiwi; Rachma, Fanina Aulia; Aparamarta, Hakun Wirawista; Widjaja, Arief
IPTEK The Journal for Technology and Science Vol 30, No 3 (2019)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v30i3.5475

Abstract

Microalgae Botryococcus braunii is a potential biodiesel producer as an alternative for fossil fuels due to its high lipid content. UV-B mutations were carried out to see the effect in microalgae growth at various pHs (3-8). Reduction of nitrogen levels was carried out to see the effect on the growth and lipid production of microalgae. UV-B mutation increased the ability of growth and resistance of B. braunii against low pH. Under low nitrogen conditions, the growth of B. braunii cells would not continue for a longer time. B. braunii which grow in nitrogen depletion medium produced lipid content greater than normal nitrogen. UV-B light mutation also increased the lipid content of B. braunii. At 7 days of incubation, the mutation not only increased lipid content, but also significantly increased the TAG content of B. braunii lipids.
Analysis of Quality Improvement of Finishing Work in The Development of Puncak CBD Surabaya Apartment Damayanti, Safira; Wiguna, I Putu
IPTEK The Journal for Technology and Science Vol 30, No 3 (2019)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v30i3.5509

Abstract

The quality is one of the important factors in the success of construction project. In fact, cost of construction is vain until 6-15% because reworking and process of work is late. Wika Building Contractor have standart of quality, name is QPASS ( Quality Performance Assessment Support System ) for all projects. Puncak CBD Surabaya Apartment,is one of Wika Building Project that having lower quality standart value in 2018. In this study, the six sigma method with the DMAIC (Define, Measure, Analyze, Improve, Control) approach was used to improve low quality values. Starting with identify works with defect largest based on QPASS monthly report, then calculate the dominant defect using a level of sigma. The research results show the wall work having highest total number of defects. The wall work defect with sigma value under 3 level are joint of wall is not perpendicular, cracked plaster seen from 1.5 m distance and flaking paint. At the improve phase, determined the best action plan for handle cause factor of the three such defect. The best action was determined are do thickening and adjust the angle of wall for defect “Joint of wall is not perpendicular”, giving direction for workers about correct plaster mixture for defect “Cracked plaster seen from 1.5 m distance”, and cleaning of wall before painting for defect “ Flaking paint”.

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