FDM preparation of bio-compatible UHMWPE polymer for artificial implant

Due to its properties of high wear, creep resistance, high stiffness and strength, Ultra-High Molecular Weight Polyethylene (UHMWPE) was developed to eliminate most metallic wear in artificial implant, which conventionally found in stainless steel, Cobalt Chromium (Co-Cr) and Titanium (Ti) alloys. UHMWPE has an ultra-high viscosity that renders continuous melt-state processes including one of the additive manufacturing processes, Fused Deposition Modeling (FDM) ineffective for making UHMWPE implant. Attempt to overcome this problem and adapting this material to FDM is by blending UHMWPE with other polyethylene including High Density Polyethylene (HDPE) and Polyethylene-Glycol (PEG) which provide adequate mechanical properties for biomedical application along with the improvement in extrudability. It was demonstrated that the inclusion of 60% HDPE fraction has improved the flowability of UHMWPE in MFI test and showing adequate thermal stability in TGA

AC voltage regulation of a bidirectional high-frequency link converter using a deadbeat controller

This paper presents a digital controller for AC voltage regulation of a bidirectional high-frequency link (BHFL) inverter using Deadbeat control. The proposed controller consists of inner current loop, outer voltage loop and a feed-forward controller, which imposes a gain scheduling effect according to the reference signal to compensate the steady-state error of the system. The main property of the proposed controller is that the current- and the voltage-loop controllers have the same structure, and use the same sampling period. This simplifies the design and implementation processes. To improve the overall performance of the system, additional disturbance decoupling networks are employed. This takes into account the model discretization effect. Therefore, accurate disturbance decoupling can be achieved, and the system robustness towards load variations is increased. To avoid transformer saturation due to low frequency voltage envelopes, an equalized pulse width modulation (PWM) technique has been introduced. The proposed controller has been realized using the DS1104 digital signal processor (DSP) from dSPACE. Its performances have been tested on a one kVA prototype inverter. Experimental results showed that the proposed controller has very fast dynamic and good steady-state responses even under highly nonlinear loads

Tracking human movement in office environment using video processing

In this paper, we proposed an approach of multi-person movement tracking in office environment without any identity conflicts. Simple image processing with frame differentiation method is applied to identify multiple human motion. An Expert System is applied to predict next camera occurrence of the tracking human. The main objective of this work is to detect and track multi-human motion using single camera in more than a room in an office

Environmental Literacy Mapping Based on Adiwiyata and Non Adiwiyata at Junior High School in Ponorogo

This research is used to find out the effectiveness of adiwiyata program between national, provincial, district and non-adiwiyata schools on environmental literacy based on age and gender. The research was conducted at junior high school Ponorogo in march-october 2017. Type of research is ex post facto. Sampling technique used is Proportionate stratified random sampling technique. The assessment used the Middle School Environmental Literacy Survey (MSELS) standard supported by observational data. The results of validity and reliability test on MSELI are valid and reliable. The results show that the adiwiyata program in ponorogo as a whole is related to the increase of environmental literacy with the sig value. 0.000. The higher the adiwiyata level, the higher the literacy value of the environment. Ability of environmental literacy among junior high school students between the ages of 13, 14, and 15 years or more is not different, with sig value. 0.308. The literacy ability of junior high school students environment between male and female sex is different, with the sig value. 0.004. For general environmental literacy assessment in ponorogo is still low that more than 51% of respondents did not reach the score at level 3 which is the standard level of environmental literacy. The conclusions of the study were the types of levels of adiwiyata and gender affecting environmental literacy.     Keywords: Environmental Literacy, Environmental Education, Adiwiyat

Statistical Technique in Gas Dispersion Modeling Based on Linear Interpolation

In this paper, we introduced statistical techniques in creating a gas dispersion model in an indoor with a controlled environment. The temperature, air-wind and humidity were constant throughout the experiment. The collected data were then treated as an image; which the pixel size is similar to the total data available for x and y axis. To predict the neighborhood value, linear interpolation technique was implemented. The result of the experiment is significantly applicable in extending the total amount of data if small data is available

Study of Corossion Potential in Subsoil Resistivity

The degradation of a substance or its qualities as a result of a reaction with the environment is known as corrosion. Corrosion is a natural process that can take place in almost any substance, but it is most commonly linked with metal. The resistivity of the soil is the one variable that has the most significant impact on the pace of corrosion. Metal that is buried in soils with a low resistivity will, in most cases, become anodic, whereas metal that is buried in soils with a high resistivity will, in most cases, become cathodic. In order to prevent and protect the corrosion of buried metallic structures by underground soil, a soil resistivity field study carried out at Merauke District. The results of the research and interpretation of soil resistivity data that have been carried out can be said that the subsoil structure of the three measurements was identified as topsoil, silty soils, sandy soils, and clayey soils. Sandy and clayey soils that have low soil resistivity values between 2.22 – 11.3 Ωm have the potential to be highly corroded. Topsoil which has a high soil resistivity of 590.0 Ωm can pose a danger if the existing mud causes the water content of topsoil to increase

A Trip Intensity Model on Shopping Travel to the Traditional Market in Makassar City

The present study aims to analyze the travel behaviors of traditional market’s visitors in Makassar City, Indonesia, such as the visitor characteristics, trip chain, and the travel attributes of the visitors. In further, the present study models the trip intensity of the traditional market visitors using the multiple linear regression approach. The study carried out an interview survey on the visitors of Niaga Daya traditional market, one of the biggest traditional markets in the city. The interview survey based on a questionnaire sheet was conducted during the operation time of the market for two days, one day of weekday and one day of weekend. The analysis results show that the majority of the traditional market’s visitors are women and their profession as housewife. In addition, the trip chain of the visitors is dominated by the home-market-home pattern, and most of the visitors used a motorcycle. Furthermore, the results of the visitor intensity model to the traditional market show that the multiple linear regression model used is enough significant in the acceptance of the model. The model analysis revealed that the occupation, the household income, the travel distance, and the travel cost of the visitors have influenced significantly the visitor’s intensity in conducting the shopping travel to the traditional market. The study results provide an expectation in order to develop the continued travel behavior models such as the arrival time choice and the travel mode choice models of the visitors in further studies

Penyusunan Instrumen Tes Higher Order Thinking Skill pada Materi Ekosistem SMA Kelas X

Penelitian ini bertujuan untuk menyusun instrumen tes Higher Order Thinking Skill pada materi ekosistem yang akan diujikan pada siswa SMA kelas X. Instrumen disusun berdasarkan langkah Riset Pengembangan Borg & Gall. Langkah pertama adalah menganalisis semua bentuk tes yang ada pada Ujian Nasional, Ulangan formatif dan sumatif, dan tes yang ada di dalam buku Biologi SMA dengan sampel SMA di Surakarta. Hasil analisis menunjukkan bahwa sebagian besar tes mencerminkan Kemampuan Berpikir Tingkat Rendah (LOTS). Langkah kedua adalah penyusunan draft Tes HOTS pada materi ekosistem yang terdiri dari 20 butir soal pilihan ganda yang akan dikerjakan dalam waktu 60 menit. Draft tes divalidasi oleh validator berkualifikasi dan guru. Instrumen tes selanjutnya diujikan pada sejumlah kecil siswa dalam Uji Coba Pertama. Hasil uji coba kesatu dianalisis secara kuantitatif menggunakan program MicroCat ITEMAN versi 3.00 yang digunakan untuk menentukan reliabilitas, taraf kesukaran, daya beda serta efektivitas distraktor. Berdasarkan hasil Uji Coba Tahap I diketahui bahwa instrumen tes Higher Order Thinking Skill pada siswa SMA kelas X untuk materi Ekosistem yang menunjukkan 45 % item diterima atau valid, 40% item direvisi dan 15% item ditolak. Proses revisi draft instrumen tes dan Uji Coba Tahap II dalam proses penyelesaian.

Power Consumption Modeling and Analysis of Integrated Optical-Wireless Access Network

The integration of optical and wireless technologies at access networks are considered as a future solution which provide both high bandwidth and high mobility in an efficient way. GPON is a suitable candidate for optical backhaul due to the combination of higher data rates, greater split ratio and support for triple play services hence it offers maximum flexibility and cost advantages. On the other hand, recent developments of new radio access technologies and introduction of femtocell base stations provide the potential of offering broadband services and applications to everyone and everywhere. However, the power consumption of this network demands a particular attention because access networks are the largest contributor the network related electricity consumption. Therefore, in this paper we evaluate the power consumption of integrated optical-wireless access network which is based on independent ONU-BS architecture. We proposed a power consumption model for such network and the assessment has been done under different simulation scenarios. The constructed model will provide insight of the energy performance of the integrated access network so that in the network design process, focus can be done to the most energy saving strategies