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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 6 Documents
Search results for , issue "Vol 22, No 1 (2011)" : 6 Documents clear
Plane Wall Effect of Flow around Two Circular Cylinders in Tandem Arrangement Triyogi Yuwono; Wawan Aries Widodo; Heru Mirmanto; Fahmi Fahreza
IPTEK The Journal for Technology and Science Vol 22, No 1 (2011)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v22i1.56

Abstract

The flow characteristic around two circular cylinders in tandem arrangement located near a plane wall were investigated experimentally in a uniform flow at a Reynolds Number of 5.3 x 104. The center to center spacing between the two cylinders relative to the cylinder diameter was constantly maintained at P/D = 1.5. The pressure distributions along the surface of the cylinder and the plane wall were measured by varying the gap-to-diameter of cylinder ratio (G/D) in the range of 0 < G/D < 0.467. Surface oil-film techniques were used to investigate the flow patterns on the cylinder. The result showed that for upstream cylinder, in the gap-to-diameter ratio G/D < /D, there is no stagnation point at front side of the upstream cylinder; it is gradually raised as the gap increase. For the downstream cylinder, a peak on the lower side of the front side of the cylinder is apparent in each of the pressure distributions. This peak represents the reattachment of shear layer that separates from lower side of the upstream cylinder. The reattachment point tends to move forward close to the angular position of  = 0o as the gap ratio increase. The shear layer bifurcates into two shear layers. One shear layer continues in the downstream direction, and the other shear layer flows in the upstream direction.
Histology of Mice Skin Tissue Based on in Vivo Evaluation of the Anticancer Extracts of Marine Sponge Aaptos Suberitoides Awik Puji Dyah Nurhayati; Dewi Hidayati; Rarastoeti Prastiwi; Sitarina Widyarini; Sukardiman Sukardiman; Wijayanti Pujitono
IPTEK The Journal for Technology and Science Vol 22, No 1 (2011)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v22i1.88

Abstract

The sponge Aaptos suberitoides can produce high secondary metabolite with some farmocological activities as antimicrobial, antiviral, antiinflamatory, and anticancer agents. The purpose of this research is to find out correlations between activities of the etanol extracts of marine sponges Aaptos suberitoides on the cancer growth of subcutaneous mice (Mus musculus) injected by Benzo(a)piren. For the purpose the mice were divided into six groups, i.e. I, II, III, IV, V, and VI. Each group was treated with carcinogenic inductions by intravenously injecting the Benzo(a)piren concentration of 0.3g/0.2 ml oleum olivarum. After the cancer was appeared at the fifteenth day, the mice were treated by the anticancer extracts of marine sponges Aaptos suberitoides with concentrations of 500 mg/kg BB (Group IV), 1000 mg/kg BB (Group IV), and 1500 mg/kg BB (Group IV). The treatments were orally done each day for two weeks. At the twentieth week, subcutaneous cancer tissues were taken to make histological preparates using a parafin method. Result of the histological observation indicates that cancer in the mice was fibrosarcoma characterized by the thickening dermis layers, necrosis, mitosis, and nuclear polymorphsm. Necrosis, mitosis, and nuclear polymorphism occurred in Groups II, IV, V, and VI, and did not in Groups I and II. Presentation of necrosis was 20-60%, mitosis was in 3-4 cells, and nuclear polymorphism was 100%. Result of the statistical analyses by using the Kruskal-Wallis method and the Pair Comparison test indicates that the anticancer extracts of marine sponges with the concentrations of 500 mg/kg BB, 1000 mg/kg BB, and 1500 mg/kg BB had no activity inducing mice skin cancer.
Support System Model for Value based Group Decision on Roof System Selection Christiono Utomo
IPTEK The Journal for Technology and Science Vol 22, No 1 (2011)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v22i1.55

Abstract

A group decision support system is required on a value-based decision because there are different concern caused by differing preferences, experiences, and background. It is to enable each decision-maker to evaluate and rank the solution alternatives before engaging into negotiation with other decision-makers. Stakeholder of multi-criteria decision making problems usually evaluates the alternative solution from different perspective, making it possible to have a dominant solution among the alternatives. Each stakeholder needs to identify the goals that can be optimized and those that can be compromised in order to reach an agreement with other stakeholders. This paper presents group decision model involving three decision-makers on the selection of suitable system for a building’s roof. The objective of the research is to find an agreement options model and coalition algorithms for multi person decision with two main preferences of value which are function and cost. The methodology combines value analysis method using Function Analysis System Technique (FAST); Life Cycle Cost analysis, group decision analysis method based on Analytical Hierarchy Process (AHP) in a satisfying options, and Game theory-based agent system to develop agreement option and coalition formation for the support system. The support system bridges theoretical gap between automated design in construction domain and automated negotiation in information technology domain by providing a structured methodology which can lead to systematic support system and automated negotiation. It will contribute to value management body of knowledge as an advanced method for creativity and analysis phase, since the practice of this knowledge is teamwork based. In the case of roof system selection, it reveals the start of the first negotiation round. Some of the solutions are not an option because no individual stakeholder or coalition of stakeholders desires to select it. The result indicates the alternative solution that will be the best-fit solution. In this problem, a space frame system is the ‘best-fit’ solution for the roof system.
Non-Catalytic and MgSO4 - Catalyst based Degradation of Glycerol in Subcritical and Supercritical Water Media Yuniati, Yuyun; Sumarno, Sumarno; Mahfud, Mahfud
IPTEK The Journal for Technology and Science Vol 22, No 1 (2011)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v22i1.53

Abstract

This research aims to study the glycerol degradation reaction in subcritical and supercritical water media. The degradation of glycerol into other products was performed both with sulphate salt catalysts and without catalyst. The reactant was made from glycerol and water with the mass ratio of 1:10. The experiments were carried out using a batch reactor at a constant pressure of 250 kgf/cm2, with the temperature range of 200-400oC, reaction time of 30 minutes, and catalyst mol ratio in glycerol of 1:10 and 1:8. The products of the non-catalytic glycerol degradation were acetaldehyde, methanol, and ethanol. The use of sulphate salt as catalyst has high selectivity to acetaldehyde and still allows the formation alcohol product in small quantities. The mechanism of ionic reaction and free radical reaction can occur at lower temperature in hydrothermal area or subcritical water. Conversion of glycerol on catalytic reaction showed a higher yield when compared with the reaction performed without catalyst
Generating Hourly Rainfall Model using Bayesian Time Series Model (A Case Study at Sentral Station, Bondowoso) Entin Hidayah; Nur Iriawan; Nadjadji Anwar; Edijatno Edijatno
IPTEK The Journal for Technology and Science Vol 22, No 1 (2011)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v22i1.57

Abstract

Disaggregation of hourly rainfall data is very important to fulfil the input of continual rainfall-runoff model, when the availability of automatic rainfall records are limited. Continual rainfall-runoff modeling requires rainfall data in form of series of hourly. Such specification can be obtained by temporal disaggregation in single site. The paper attempts to generate single-site rainfall model based upon time series (AR1) model by adjusting and establishing dummy procedure. Estimated with Bayesian Markov Chain Monte Carlo (MCMC) the objective variable is hourly rainfall depth. Performance of model has been evaluated by comparison of history data and model prediction. The result shows that the model has a good performance for dry interval periods. The performance of the model good represented by smaller number of MAE by 0.21 respectively.
Development of Geopolymer Concrete with Different Curing Conditions Nuruddin, M.F. Nuruddin; Kusbiantoro, A. Kusbiantoro; Qazi, S. Qazi; Darmawan, M.S. Darmawan; Husin, N.A. Husin
IPTEK The Journal for Technology and Science Vol 22, No 1 (2011)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v22i1.54

Abstract

Environmental issues resulted from cement production have become a major concern today. To develop a sustainable future it is encouraged to limit the use of this construction material that can affect the environment. Cement replacement material was proposed to partially replace cement portion in concrete. Geopolymer is a part of inorganic polymer material that has similar bonding function like cement in concrete. It consists of alkaline solutions and geological source material. Alkaline liquids used in this research are 8 M sodium hydroxide (NaOH) solution and sodium silicate (Na2SiO3) solutions, while source materials are fly ash and microwave incinerated rice husk ash (MIRHA). Three different curing regimes, namely hot gunny curing, ambient curing, and external exposure curing, were applied to obtain suitable method that was suitable with cast in situ application. Geopolymer concrete samples were tested on their compressive strength and microstructure properties. It was found that external exposure curing had the highest compressive strength compared to other two curing methods. Scanning electron microscopy analysis also showed better improvement in interfacial transition zone for concrete sample with external exposure curing.

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