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PENGARUH PANJANG SERAT TERHADAP SIFAT BENDING PAPAN KOMPOSIT POLIESTER BERPENGUAT SERAT BUAH LONTAR
Get PDFThe need for wood as a building material is increasing, but the existing forest conditions are difficult to meet the demand. Several alternatives have been developed as an effort to overcome the lack of wood, for example by creating wood derivative products such as fiberboard, particle board, and cement board. The raw materials for making fiberboard usually use natural fibers derived from plants containing fibers such as kenaf, banana, hemp, sisal, lontar and flax. The prospect of fiberboard development is very potential, because Indonesia has a suitable climate overgrown by these fibrous plants.The purpose of this study is to determine the effect of fiber length on the bending properties of polyester composite board reinforced by palm fibers. The material used in this research is lontar fibers with fiber length 1 cm, 2 cm and 3 cm and polyester resin. Before the fiber is used as a reinforcing medium, the fibers are first treated with 5% alkali by soaking for 1 hour. After the fibers were removed, then rinsed with clean water to free the fiber from alkali and then dried. The ratio of fiber-matrix composition used in this study was adjusted to the rule of mixture (ROM), wherein the volume fraction of fiber (Vf) used was 30%. The composite board is made by hand-lay-up method and continued with 24 hours by pressing with hydraulic jack. Furthermore, the molded composite is cut into bending test specimen according to ASTM D790 standard. The nature of bending of composite board is known through the process of testing three point bending by using universal testing machine.The result of bending test shows that the test specimen with 3 cm fiber length has a higher bending strength value of 18.42 Mpa, while the composite with 2cm fiber length is 16.35 Mpa and 15,44 Mpa for 1cm fiber length.
Keywords: composite, lontar fiber, fiber length, bendin
PENGARUH LAJU ALIRAN UDARA TERHADAP KINERJA SISTEM REFRIGERASI PADA TATA UDARA SENTRAL
Get PDFThe work of refrigeration system incentral air conditioning should be set to the cooling load to obtain the peak performance of the system with efficient energy consumption. One factor that affect to the the cooling load is the conditioned air flow rate suppliedin the system.The experiment is conducted by varying air flow rate (with 4 variations which is 1,152; 1,184; 1,216 and 1,280 m3/s respectively), to aim the optimum performance of the refrigeration system in the air conditioning system (central AHU) to consumption efficient levelof power.
The results is that the refrigeration system performance is not much influenced by variations ofair flow rate,where the highest coefficient of performance (COP) of the refrigeration system (5.69) was obtained by air flow rate (debit) of 1,184 m3/s, about 4% of the COP on the largest debit. The highest compression ratio (3.5) was obtained at lowest air flow rate (1.152 m3/s), and the lowest average of power consumption is obtained at the lowest air flow rate 1.152 m3/s, 9% lower than power consumption at thegreatest air flow.While the performance of the HVAC system is affected by variations in air flow rate, where is the greatest cooling capacity (62.364 kW) and the highest EER (3.99) was obtained at the highest flow rate of 1.280 m3/s.
Keywords: air flow rate, performance, central air conditioning
PENINGKATAN PERFORMA KEMASAN DAN STRATEGI PEMASARAN(IbM UKM Pengerajin Kerupuk Getas)
Get PDFKerupuk getas and kemplang are snacks from Bangka Island made from a mixture of mackerel and corn starch. The snacks are produced by snack food home industry. The production center located in Belinyu and Pangkalpinang City. The main problem of industry is lack of knowledge about the packaging technology and sales strategy. The product packaging is an important part of a sales strategy. In this report, the authors proved statistically that the product packaging can increase revenue. The packaging system by using vacuum packaging machine. Furthermore, sales strategy be developed into an online system.The results show that sales of products with packaging boxes significantly affect gross income partners. Correlation test showed that the value of pearson product moment (r) is 0.862. The value of the Pearson product moment means that there is a very close relationship between the product packaging boxes with gross revenue and P-value is 0.05 so it was concluded that the relationship is significant.
Keywords: product packaging, sales strategy, online system, pearson product moment, P-value
SINTESIS BIODIESEL DARI MINYAK KESAMBI (Schleichera Oleosa L.) MENGGUNAKAN KATALIS BASA HETEROGEN DARI LIMBAH KARBIT
Get PDFBiodiesel is a kind of alternative fuels to replace fossil fuels as form as diesel can be obtain through out transesterification process of vagetable oils and methanol with catalyst. One of all vegetables oil that able to use as biodiesel’s material is kesambi seeds oil. The objective of this study is to determine the number of calcium carbide residual catalyst effect to the number of biodiesel’s production. Biodiesel produce by esterification-esterification-transesterification (EET) method. Esterification process using methanol amount of 20% w/v, sulfuric acid is 5% w/v, while the reactive temperature is 60oC and stirring duration about 60 minutes. Transesterification process using methanol amount of 75% w/v while the reactive temperature is 60oC, stirring duration is 120 minutes and calcium carbide residue will be variated to 2,3,4,5 and 6% w/v. The highest biodiesel’s production in amount of 51.4% is achieved by 6% catalyst number. While the lowest number in amount of 34.32% is achieved by 2% catalyst number. R2 number is about 93% which positive correlation slope number reached 475,7x according to correlation between calcium carbide catalyst number and biodiesel’s production number. Therefore it has more and more catalyst calcium carbide residue used will obtain the greater biodiesel yield.
Keywords: : Biodiesel, Kesambi seeds oil, Calcium Carbide Residue,Esterification,Transesterificatio
ANALISIS DIAMETER GELEMBUNG PADA KERUGIAN TEKANAN ALIRAN FLUIDA
Get PDFIn the development of science studies have been conducted to observe the losses that occur in piping systems. During the fluid flowing through the pipe friction losses will occur between the fluid with the walls of the pipes, which are called by major losses. In general, the greater the loss of majorlosis on rough surfaces and can be reduced by using a more smooth surface such as glass, acrylic or with other coating materials. Gas bubbles that occur from the reaction of water with very influential magnesium in lowering the pressure in a turbulent flow. With the gas bubbles in the fluid flow creates the effect of two-phase flow. This study reviewed the effect of gas bubbles to the pressure drop (pressure drop) that occurs. The working fluid used is water that flowed through the channel with a square acrylic 18´9 mm size. The bottom of the channel is mounted ribbon mg powder grain size 160mm to create the effect of bubbles in the fluid flow. The powder iron (Fe) used as comparison with the same grain size. The results showed when the turbulent flow mg tape coating is more effective to reduce pressure losses due to flow into two phases and some bubbles that can survive will shrink the size of its diameter so it does not impede the flow rate.
Keywords: Piping systems, major losis, bubbles of gas, two-phase flow, bubble effect
OPTIMASI MULTIRESPON PADA PROSES EDM SINKING BAJA ST 42 DENGAN MENGGUNAKAN METODE TAGUCHI DAN FUZZY LOGIC
Get PDFThe optimization technique of machining parameters considering multiple performance characteristics of non conventional machining EDM process using Taguchi method combined with fuzzy logic is presented in this study. ST 42 steel was chosen as material workpiece and graphite as electrode during this experiment. Performance characteristics such as material removal rate and overcut are selected to evaluated the effect of machining parameters. Current, pulse on time, pulse off time and discharging time/ Z down were selected as machining parameters. The experiments was conducted by varying that maching parameters in three different levels. Based on the Taguchi quality design concept, a L27 orthogonal array table was chosen for the experiments. By using the combination of fuzzy logic and Taguchi, the optimization of complicated multiple performance characteristics was transformed into the optimization of a single response performance index. Optimal levels of machining parameters were identified by using fuzzy logic method. The statistical application of analysis of variance was used to determine the relatively significant machining parameters. The result of confirmation test indicted that the determined optimal combination of machining parameters effectively improve the performance characteristics of the machining EDM process on ST 42 steel.
Keywords: EDM, Taguchi, Fuzzy logi
PEMANFAATAN LIMBAH PABRIK KELAPA SAWIT SEBAGAI MATERIAL TEKNIK
Get PDFPalm oil mill issuesbyproducts in the form of 0.70 tons of cubic meters of fiber, 0.35 tons of cubic meters of shell,and 1.1 tons of cubic meters of oil palm empty fruit bunches palm (EFBP) to yield 1 ton cubic meters of crude palm oil.The fiber content consisted in the EFB is a source of fiber for a variety of industries such as manufacturing of composites, fillers for thermo-plastic, paper-making and sound insulation as well as soil erosion control.Manufacturing of a natural fiber reinforced cement board is an effort to reduce the use of synthetic fibers and asbestos fibers which cause side effects for its users.So this research is one of the breakthroughs to obtain new materials as substituteto asbestos fibers. This research used portland cement, marble powder, CaCO3 and EFBP fiber as reinforcement.EFBP fibers were arranged randomly in the form of short fibers. Percentage of the mixture of 16%, 12% marble powder, and portland cement was varied with a percentage of 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15% and the volume percentage of CaCO3 inverse of the percentage of portland cement. The results showed that the characteristics of fibrous EFBP cementboard in the optimum condition to produce value of tensile strength of 1.96 MPa, flexural strength of 2.61 MPa, compressive strength of 14.35 MPa, density (Ï) of 1519 kg/cm3, water absorption of 24.28 and flame propagation velocity between 54.4 to 61.5 FS.By the standard of JIS A 5417-1992 that the requirements of density in the construction of cement board is of 0.8 g/ cm3, so that the material is appropriate to be applied.Its thermal conductivity lower than fibrous congseted asbestos cement board λ = 0.576 kcal/mhoC, meaning that the cement board is worthy applied as a ceiling of the house.
Keywords:EFPB, fiber, cement board, engineering materia
PENGARUH PERLAKUAN PANAS PADA PEMBENTUKAN PELAT BERALUR PANEL KENDARAAN TERHADAP PENINGKATAN FREKUENSI ALAMIAH DIUKUR PADA KONDISI BATAS JEPIT-JEPIT
Get PDFVehicle Comfortability in a minibus is highly influenced by the noise level and the mechanical vibration on the cabin. Sound and vibration can come from the engine excitation, the pressure difference in both inside and outside of the cabin, the road roughness and the primary vehicle’s structure. The ground, wall and floor of the cabin in a vehicle are the most influenced parts in the role of transmitting sounds and vibrations. These can be reduced by means of increasing the cabin’s stiffness. Sheet metal is mainly used as the cabin’s material. Its stiffness can also be increased by means of thickening, grooving and embossing the plate. The aims of this experimental work are to increase both the natural frequency and the stiffness of the plate by means of forming and grooving in the cabin’s plate. The material used in this paper is mild steel plate 0,8 mm from galvanized steel that is generally used in manufacturing of the minibus vehicle (ASTM A 29 coated with zinc and aluminum). The research method is derived as follows: determining the panel dimension, calculating the number of the groove, designing both the heating temperature and the cooling media, grooving process, measuring and analyzing the natural frequency and the stiffness. The length and the width of the panel dimension are determined by 550 mm and 550 mm, respectively. Trapezium cross-section is used as groove’s design. The results show that the natural frequency and the stiffness are linearly influenced by residual stress. The highest frequency, reached at 258,06 Hz, is to be found at 10 groove with temperature of 700 °C and followed by water cooling. In addition, this frequency is increased nine times compared with plain panel without groove in which it has 27,55 Hz.
Keywords: natural frequency, vehicle panel, heat treatment, fixed-end, stiffnes
STUDI EKSPERIMEN BENTUK KACA PENUTUP UNTUK MENINGKATKAN PRODUKTIFITAS DAN EFISIENSI SOLAR STILL
Get PDFBased on the previous research, it’s needed a research on the development of solar distillation model. The development of a concrete absorbed plate with fin has been conducted and resulted on improving productivity and efficiency of solar still. The development is continued by making a model using the glass covered model with roof shape and V. Experimental method is used in this work. Absorbent plate from concrete with fins models and some gravel are used in this solar still research. The concrete composition is determined by two parts of iron sand and one part of PCC cement. The cover glass design is determined by roof model, V model and conventional model (flat model). Water volume is designed as varied variables. The results show that V model can increase the productivity of freshwater and efficiency of the solar still compared with roof model and conventional model under different water volume. The absorber plate temperature, water temperature and cover glass temperature satisfy the solar radiation pattern.
Keywords: solar distillation, cover glass shape, water volum
ANTHROPOMETRI PEKERJA INDUSTRI DAN PERTANIAN DI BEBERAPA NEGARA TERTENTU: SEBUAH STUDI LITERATUR
Get PDFResearch on anthropometry has been widely carried out using different objects and methods. The researchers conducted a study with measurements of anthropometric dimensions to body dimensions in particular where the number of body dimensions which measures are different among studies. Thus the result of measurements of body dimensions of each study is not the same. However there are having similar method of research on the measurement of the same body dimensions. Body dimensions data that obtained from measurements can be used as designers reference in the design of ergonomic tools or machinery. From the anthropometric data in the same industry and agriculture workers can be done several comparative dimensions of the body of workers and farmers. This study is comparing anthropometric of worker among in industrial population and among agricultural workers/ farmer. Base on review of data, the study has resulted that each people in different country has its own characteristic form of body dimensions which differ from another. The comparison of body dimensions among workers who work in industrial show that they have variation Mean (M) value of body dimension. Characteristic body dimension of Algerian agriculture workers, except foot breadth, have highest Mean (M) value compare with others countries. Thai female agriculture workers have lower Mean (M) value of body dimension in almost all parts compare with others countries.
Keywords: anthropomety, industrial, agricultur