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Studi Kerusakan Jalan Piyungan - Wonosari dari Aspek Geoteknik
Full text linkSome road sections in Yogtakarta sufer from frequent damage following the rainy season. Repairs have been conducted regularly and various efforts to improve the road condition have also been done, however, this probletn always comes every year. Soil condition below the road pavement is suspected to give a major contribution on road damage in this region.A series of investigation was carried out on the soil beneath the road of Piyungan-Wonosari section. Field observation on road damage condition was conducted and it was followed by in situ tests, consisting of hand boring, sampling and cone penetration test. Properties of soil were obtained from several laboratory tests. To simulate effect of water changes on soil strength, a series of shear strength tests were performed on the samples made of soil with various water contents.The results indicate that the road damages in this region are resulted by several reasons. At road section built on slope, the damage was mainly caused by downward movement of the Jill which was not rnassive enough standing on the original slope. Soil softening due to water changes is identified to give a major contribution on this problem, especially for road constructed on clays. Expansive soil was also found at some road section. This soil type produces signiJicant amount of pressure and volume changes which lead to movement of the adjacent structures.Keywords : road-damage, soil, strength, water, softe
Laju Reaksi Hidrolisis Herbisida Glifosat di Tanah Jenuh Air
No full textThe objectives of the research were to find out the parameters of the hydrolysis reaction rate (k,,) and partition coefficien (Kr) of glyphosate herbicide in saturated soil system, to identify the variables affecting those parameters, and to develop the empirical equations corelating those parameters to the pertinent variables.The experimental work or physical simulation in laboratory was conducted in a batch reactor. The sterilized soil 5 gram put into a 1000 cm3 of Erlenmeyer glass and 500 cm3 of glyphosate solution with 8 g/1 concentration was added. The Erlenmeyer mouth was covered with plastic film and the entire Erlenmeyer surface was covered with aluminium foil to minimize vaporization and photolysis reaction. The solution was mixed continuously with magnetic stirrer. At the initial time and selected time intervals, 5 cm3 of the samples were taken with syringe. The samples were centrifuged and filtered, 1 cm3 of the filtrate were analyzed its glyphosate concentration with UV- VIS. The experiments were conducted for various soil types, and the empirical correlation between the hydrolysis reaction rate (k,,) and partition coefficien (Kr) with the affecting variables can be developed.Based on the laboratory data and the simulation of mathematical model, it could be concluded that the empirical correlation between the Kr and kh values with the affecting variables could be represented in the equations:Kr =11.035 (%organic matter) + 0.25 (%clay mineral) mL gramkh =1.0810 (%organic matter) + 1.5310-5 (%clay mineral) min-
Penentuan Daerah Rawan Kebakaran dengan Sistem Informasi Geografik (Kasus Pooncarie Region, New South Wales, Australia)
Full text linkThe research was done to produce o map showing areas of a high bushfire risk and to create a statistic table shov'ing,.for each properfy, the totsl area with a high bushfire risk and proportion ofthe high bushfire risk area lo the total area ofthe property.The research was carried out in Pooncarie region, south western New South Wales Australia, which is best described as an area of semiarid rangeland. GIS (Geographic Information Systems) spatiul analysis was conducted usingfour coverages: Iand system, roads, bores, and property, including their coruesponding attribute data. Bffiring technique and overlay operations for spatial analysis were done using Arcllnfo GIS sofrware based on some determined criteria, yielding a map showing areas of a high bushfire risk. Five properties had the highest proportion of their land being identified as with a high bushfire risk. Keywords: bushfire, geographic information ststenn, buffering, spatia\ analysis
Pengaruh Potongan Harga pada Sistem Inventori (Q,R) yang Mempertimbangkan Ketergantungan antara Lot Size dan Lead Time
Full text linkThis paper is concerned with lot size dependent lead times in a (Q,R) inventory system considering-quantity discounts offered by suppliers. With regards to the existing model that considers the impact of lot size on lead time and safety stock equirements, we present an efficient iterative algorithm to decide lot size that minimizes total inventory cost. The algorithm simultaneously determines lot size and safety stock based on the tradeoff between inventory holding cost and shortage cost. A nurnerical example is provided to clarify the iteration procedure. In addition, we identify the effict of shop floor queing factor on lot size decision.The result of the study shows that purchasing larger lot size does not always result in minimum total inventory cost. Larger lot size reduces per unit ordering cost and shortage cost, but increases the holding cost due to more inventories. Moreover, we conclude that increased shop floor queuing factor leads to increased production lead time, resulting in larger lot size.Keywords: (Q,R) inventory system, lot size dependent lead times, quantity discount
Pengaruh Kondisi Lapangan terhadap Perancangan Menara Komunikasi Tipe Standar SST E-60
Full text linkIn the recent years, the communication sector has made a progressive development. The development is not only in the cornmunication technology, but also its supporting equipment. Communication tower is among the supporting equipments as a transmitter which is designed using steel material.At the design stage, companies that design communication tower, have one or few models that hqs been used. Among the communication towers that have been used is communication tower of SST(Self Supporting Tower) E-60 type with 60 m height. The preliminary model is designed with certain field conditions, and came into a question, what will occur if communication tower be built in different field conditions?In this Steady, analysis is conducted to SST E-60, if it can be built in all earthquake zone inIndonesia, can be put in oblique land or with different elevation, how big differential settlement is allowed to happen cmd how many extra antennas can be put on the tower structure. The result shows that commtmication tower of SST E-60 type can be used in all earthquake zone inIndonesia, can be built vith dffirent elevation, has a dffirential ,seltlement ntaxintwn of 2.5 cm, and can he put extra antenna as much as 26 antennas. Keywords: Communicalion tower, SST E-60, self supporting tower, wilayah gempa (earth zone), tanah miring (oblique land), differential settlement, antena.
Koefisien Perpindahan Massa pada Ekstraksi Aspal Buton dari Kabungka dan Bau-Bau dengan Pelarut n-Heksan
Full text linkButonion natural asphalt can be used for binder in road construction after its impurities were removed by extraction using suitable solvent. Researches on extraction of Butonion asphalt have been done. However, most of them are explorative research.This experiment tried to find mass transfer coeficient for Butonion asphalt extraction. The mass tronsfer coefficient will be used in extraction tower design. In this experiment, multi-stage cross-cwrent extraction was used using n-hexane as a solvent. The number of stages was seven. Bitumen obtained was then distilled to separate the n-hexane. The operation variables were : size of solid, rotation and extTaction time.The relationship of the mass transfer coefficient with other variables can be written as:The constant values of Kabungka asphalt are : K=6.43558x10tt, a=0.141569, b=0.2825804, c =1.76857, d= - 1.381755, e=t.636537x102 ; those of Bau-Bau asphalt are : K= 6.3x I0tt'a = 0.0891, b= 0.28258, c= L7699, d = -1.3821Keywords : extraction, mass transfer, Butonion asphal
Pengembangan CNC Retrofit Milling untuk Meningkatkan Kemampuan Mesin Milling Manual Dalam Pemesinan Bentuk-bentuk Kompleks
Full text linkIn small-size mould manufacturing industry, milling process is an important element because this process consumes the longest produclion time. AIso, milling process needs great investments in tools. Most of the small-size mould manufacturing industries uses manual-milling machine for roughing process. Manual milling machine is used because of capacity limitation of the CNC milling machine and high investment of CNC machines.A prototype of low-cost CNC retrofit milling system is developed in this research, to enhance manual milling machine capabilities, in accuracy, speed, and process complexity. The advantage of the prototype results in reduced manufacturing cost and reduced lead time. This research also compare the capabilities of the prototype to others milling systems.The prototype results in accuracy of X axis and Y axis respectively 0.013 mm and 0.009 mm. This system is capable to set the feed rate of minimum 1 mm/min and maximum 250 mm/min, depending on the material being processed.Keywords: prototype, retrofit, CNC millin
Evaluasi terhadap Waktu Tunggu dan Jarak Berjalan Penumpang pada Perpindahan Moda di Stasiun Lempuyangan Yogyakarta
Full text linkLempuyangan Railway Station is located in Jogjakarta. To get to or to leave the station passengers using the railway services take other modes, such as becak, buses, taxis, and motorcycles (ojek). The process of mode changing is very importanl. To do so, passengers have to walk to the next mode stop and sometimes they have to wait for the vehicle arrival. Research was undertaken to investigate the performance of the mode changing process, in terms of waiting time and walking distance, based on site measurement and on what passengers perceived, to model the relationship between the performance expected and what perceived by the passengers, and to evaluate the performance using standards set by Directorate General of Land Transport. It was found that based on both direct measurement and passengers perception, the performance of the changing process was good. There was a very good relationship between what expected and what perceived by passengers. The waiting time and walking distance met the standards required.Kata kunci: perpindahan moda, waktu tunggu, jarak berjalan kaki
Pengembangan Auto CAD dengan vB untuk Desain Pola Coran dan Cetakan Produk Pulley Standar Tipe Taper Lock
Full text linkdan Adi NugrohoJl. Grafika No. 2, Kampus UGM, Yogtakarta 55281AbstractThis paper presents the development of automatic casting design system for Taperlockpulley type. This system is intended to assist casting designer in pattern design, to reduce designtime, and to minimize error in transfering product design data into pattern design.The input of this system is data base of taper lock pulley's catalogue in mdb format, whilethe output is design of the pattern drawing in 2D and 3D solid. Moreover to generate patterndesign is around 59 second.Keywords: casting, pattern, automat ic.l
Pengaruh Pengoperasian Reaktor Kartini terhadapKadar DO, BOD, dan COD Air Pendingin primer
Full text link Affiliation—Country—Bio Statement Principal contact for editorial correspondence. NameTri Wulan Tjiptono Affiliation—Country—Bio StatementPusat Penelitian dan Pengembangan Teknologi Maju - BATAN, Yogyakarta NameTony Dwi Susanto Affiliation—Country—Bio StatementFakultas Teknik Industri, UPN Veteran, YogyakartaTitle and AbstractTitle AbstractIn light water reaclor (LWR) systems, water coolant passes through reactor core to remove heat generated by fission processes. Therefore, the temperature of water coolant raise and thewater coolant is irradialed by neutrons from reactor core.The research was directed to explorethe influences of both of them to the contents of Dissolved Oxygen (DO), Biological OrygenDentand (BOD) and Chemical Oxygen Demand (COD).The research wss done by chemical titration method to measure the content of DO, BOD5,and COD in the water coolant in which the reactor was operated at critical condition andconstant power. water samplingwere done after 45',90', l3s', IB0',225', and 270', reactoroperation.The results of this research are: (1) the temperature of the coolant is increasing asoperating time function, (2) the content of DO is also increasing, while BOD5 and COD tends tobe constant, and (3)in general the reactor water coolant is safe to be released to the environment.Keywords: water coolant, heat, irradiation, chemical titration, D