Pringgo Widyo Laksono

Synthesis and Characterization of Hydroxyapatite Powder from Natural Gypsum Rock

This study prepared hydroxyapatite powder that synthesized from natural gypsum rock and find out physicalchemical and cytotoxicity properties. The synthesis realized by reacting natural gypsum powder with 1M of (NH4)2HPO4 solutions using a microwave. Characterizations of natural gypsum powder and hydroxyapatite powder were conducted by XRD, XRF and SEM. In vitro cytotoxicity testings of hydroxyapatite powder were conducted by MTT method using vero cells. XRD patterns of gypsum powder closed to JCPDF 33-0311 (gypsum standard). Characteristics of gypsum powder i.e. contained 41.72% CaO, level of purity 91,6 % and crystal size 7,147 nm. Charateristic of hydroxyapatite powder that synthesized from natural gypsum powder i.e. contained 46.91% CaO and 40.20% P2O5, XRD patern closed to JCPDF 09-432 (hydroxyapatite standard), level of purity 99 % and crystal size 1.243 nm. There were not significantly difference in cytotoxicity properties of hydroxyapatite powder that synthesized from natural gypsum rock and commercial hydroxyapatite powder (p= 0.086). These results indicated hydroxyapatite powder that synthesized from natural gypsum rock possible to be used as bone substitutes.

Ergonomic checkpoints as the base of stamping station work facilities improvement

Work productivity in the stamping station in Batik Merak Manis Laweyan is one of the key components to the business continuity. Using ergonomics checkpoints with results validated through a Focus Group Discussion, hand tools and machine safety was identified as the major area for production process improvement. This research aims to improve the production process by designing ergonomic work facilities. From observation, the hand tools and machine safety is primarily associated with the work table, the cooker table for the candle, and the batik stamp. In formulating the improved design, the rational method by Cross was used, specifically the four stages design process; clarifying objectives, establishing function (penetapan fungsi), setting requirements, and determining characteristics. Improved stamping stations work facilities such as the work table and batik stamps handle cover were designed, incorporating the workers need, ergonomic principles, and anthropometric measurement.

Applying deep fryer and spinner experiments for optimization multiresponse water content and fat content of oyster mushroom chips using Taguchi and PCR-TOPSIS methods

Experiments the deep fryer and the spinner for productipn the oyster mushroom chips was needed to optimize the setting level optimally. The purpose of this experiment was to obtain the oyster mushroom chips with water content, and fat content optimized simultaneously. These experiment used the Taguchi and the PCR-TOPSIS method. Improved the quality of products and processes as well as in reduced the cost and resources to a minimum by Taguchi Method. The ability of a process to meet design specifications set by PCR method. The optimal combination multiresponse obtained by Technique for Order Performance by Similarity to Ideal Solution (TOPSIS). The target both of this experiment response were smaller the better. Based on the result of multiresponse experiment analysis, optimal setting of this conditions was the combination of a factor of the type of flour at 80% rice flour and tapioca flour 20%, the factor of frying temperature at 150–160°C, and the factor of time for the draining process in 1 minute.

Design and Manufacturing Bio Composite (Sugarcane Bagasse – Polyvinyl Acetate) Panel that Characterized Thermal Conductivity

The use of sugarcane bagasse for providing avaibility of raw material have been attracting attention. The benefits using natural fiber such as sugarcane bagasse are eco-friendly, low cost considerations because widespread avaibility, high stiffness, better thermal stability, and biodegradability. Sugarcane bagasse and (Polyvinyl acetate, PVAc) have been shown to possess the ability of being applied as raw material for manufacturing of bio composite panel at 10mm thickness (fixed variable) by three mesh sizes (20,30 dan 40) with ratio of the composition 95:5, 90:10 and 85:15%. The specimen have been emphasized at 3:2 and 2:1. This research was conducted to investigate possibility of manufacturing bio composite panel that its characteristic resistance to the thermal conductivity. This bio composite speciments were tested for thermal conductivity test according to ASTM E-1225. The results revealed that optimum design for bio composite panel obtained that emphasis at 3:2, filtered by mesh size 20, ratio composition sugarcane bagasse 85% and PVAc 15%. The test result shown that panel has thermal conductivity resistance value (R) 17,089 °C/W. Thus, it can be concluded that bio composite panel can be manufactured successfully from sugarcane bagasse and PVAc as the matrix mixture.

Performance evaluation of solar dryer with a biomass stove to meet Indonesian National Standard of ginger simplisia

In Indonesia, ginger simplisias (dried form) quality standards is regulated in SNI 01-7087-2005. The conventional drying method, direct open sun drying, has several weaknesses. It could reduce the quality of products that do not meet standards. Relating with these problems, one of the improvement efforts that can be done is by using the solar dryer technology. In this study, design and prototype of the mixed passive solar dryer has been made. Then, the solar dryer was tested to evaluate its performance. Tests were done through simulation and direct (prototype) tests. Based on the results of simulation and prototype tests, the performance of solar dryer designed was quite satisfactory (temperature ranges between 40-60°C). ANOVA and t-tests showed that there were no differences in temperature between each racks in each heat sources. In addition, based on the validation test there were no significant differences between the measurement results of the simulation and prototype tests.

Wearable Instrument Applications for Indonesian’s Worker Clothing

UU No I 1970 tells about the assurance for workers’ health conditions. Current years, there is no monitoring aids that can help supervisors to monitor the workers condition. A standard worker’s clothing can protect from harm situation but it cannot deliver the actual physical condition of workers. If there is something happen dealing with physical condition of the workers it will not only interfere the operation and production line but also lead deathly risk. Monitoring of labor conditions is easily done in a laboratory but doing it directly in the production floor still face many challenge. Therefore, it is necessary to develop a device to monitor physiological conditions that can be used on the site. Wearable instrumentation is a solution to face these problems. This research aims to develop a physiological detector based on wearable instrumentation that able to indicate physical conditions of workers in real time. From these results, it is known that the TMP 36 sensor has a fairly accurate measurement values for different only 0.1–0.2 °C from the actual temperature. This instrumentation system accuracy was verified by observing physiological condition of 30 subjects. Further we are going to attach the system to a worker’s clothing which was specifically designed for simple and comfort usage.

Development and application of humanistic logistics models for optimizing location-allocation problem solutions to volcanic eruption disaster (Case study: Volcanic eruption of Mount Merapi, Indonesia)

Abstract Logistics distribution in the event of natural disasters, such as volcanic eruptions, earthquakes and floods, is an important matter that needs attention of both government and society. The distribution of logistics in many disaster-prone countries, including Indonesia, is poorly planned and managed. Therefore, various problems arise, such as low efficiency and effectiveness of delivery and poor cost-effective flow. This study developed location-allocation models for distribution and evacuation of refugees and logistics. The investigation was conducted by determining the characteristics of the disaster management system of volcanic eruption in Mount Merapi, Indonesia. The mathematical model was built and a set of solution procedure was proposed to solve the problem. The objective of the model is to minimize total costs of the system and determine the optimal solutions at the three alert-levels, which are alert phase, danger phase and post-disaster phase. The results were discussed and models were analyzed to give several managerial insights regarding the model’s optimal solution. Based on the results, the proposed models are proven to give more effective solutions at lower costs. The usage of each evacuation shelter can be utilized to its maximum level. Therefore, it allows minimum waste of capacity as well as costs related to evacuation and distribution.

A Study on Customized Low Degree of Freedom Hydraulics Flexible Material Handling: Alternatives and Limitations

Abstract Inventory plays very important role in a manufacturing system. Compare to conventional forklift vehicle, a robotic arm is more efficient and reliable because it requires no human operator. Unfortunately, a robotic system needs high investment and maintenance cost, commonly due to its control system as a consequence of its high Degree of Freedom (DOF). For medium enterprises it is still difficult to find high capacity but affordable system. Customized system with a hydraulic power pack is a considerable alternative solution since speed and accuracy is not a mandatory. Therefore, this paper provide a preliminary study report for a low DOF hydraulic robotic arm. Basically, this is a conceptual product development study. This research used the first 5 activity stages of Concept Development Phase from Generic Development Process. The first stage was Identifying Customer Needs which involved automation experts from academician. The second stage was Translating Customer Needs into Technical Requirement. The third stage was Generating Concept Alternatives which was more focused on mechanical structure alternatives. The fourth stage was Selecting The Best Concept which was based on valuation with some technical criteria. The final stage was Testing The Best Concept which addressed to evaluate its operational abilities by building a prototype. The development process produce three design alternatives which featured with only three DOF linkage system. A flexible material handling with PRR (Prismatic-Revolute-Revolute) robotic arm then selected as the best concept. The robotic arm was inspired by VANTA MD410ib/300 Palletizing Robot. The arm is actuated with a hydraulic cylinders for each DOF. The system was designed to handle material from or to a graded vertical shelf. A 450 mm sized prototype was build using small plastic hydraulics components. From several trial, we found a critical part on the second link actuator thus an additional counter balance or spring system should take in to consideration.

Inventory decisions in a two-echelon system with remanufacturing, carbon emission, and energy effects

Abstract In this study, we propose an inventory model consisting of a depot and a distributor with environmental and finite remanufacturing generations considerations. Investigation of the environmental effects is done by examining how carbon emissions and energy consumption for both transportation and production affect the model’s optimal solution. In the system, the depot fulfils demand at the distributor through ordering new products from outside supplier and remanufacturing used items that are returned from the market. We build the joint annual inventory cost function and find its minimum value by determining the optimal value of shipment lot size, number of shipments per year, and the number of remanufacturing generations. The results show that the proposed model gives benefit to the depot and the distributor, respectively. Optimizing the inventory related costs and the environmental costs actually provides less remanufacturing generations. In the other hand, higher amount of solid waste disposal and carbon emissions will be generated yet lower amount of energy is consumed. This study also showed that the joint total cost can be reduced by increasing the number of used items collected from the market.

Work climate and work load measurement in production room of Batik Merak Manis Laweyan

The work environment is everything around the labours that can affect them in the exercise of duties and work that is charged. In a work environment, there are workplace climate and workload which affect the labour in force carrying out its work. The working climate is one of the physical factors that could potentially cause health problems towards labour at extreme conditions of hot and cold that exceed the threshold limit value allowed by the standards of health. The climate works closely related to the workload accepted by workers in the performance of their duties. The influence of workload is pretty dominant against the performance of human resources and may cause negative effects to the safety and health of the labours. This study aims to measure the effect of the work climate and the workload against workers productivity. Furthermore, some suggestions to increase the productivity also been recommended. The research conducted in production room of Batik Merak Manis Laweyan. The results showed that the workplace climate and the workload at eight stations in production room of Merak Manis does not agree to the threshold limit value that has been set. Therefore, it is recommended to add more opening windows to add air velocity inside the building thus the humidity and temperature might be reduced.The work environment is everything around the labours that can affect them in the exercise of duties and work that is charged. In a work environment, there are workplace climate and workload which affect the labour in force carrying out its work. The working climate is one of the physical factors that could potentially cause health problems towards labour at extreme conditions of hot and cold that exceed the threshold limit value allowed by the standards of health. The climate works closely related to the workload accepted by workers in the performance of their duties. The influence of workload is pretty dominant against the performance of human resources and may cause negative effects to the safety and health of the labours. This study aims to measure the effect of the work climate and the workload against workers productivity. Furthermore, some suggestions to increase the productivity also been recommended. The research conducted in production room of Batik Merak Manis Laweyan. The results showed that t...