Rini Dharmastiti
Jurusan Teknik Mesin, Fakultas Teknik, Universitas Gadjah Mada

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ANALISIS PENGARUH JUMLAH RESPONDEN PADA EVALUASI USABILITAS APLIKASI EDUKASI ANAK-ANAK Puspitasari, Melita; Dharmastiti, Rini
Forum Teknik Vol 36, No 1 (2015)
Publisher : Faculty of Engineering, Universitas Gadjah Mada

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Abstract

     The development in technology for children is now increasing. In order to make the design and appearance of a software/application is easy to operate, run, and understood by children, an usability test is needed. One method that popular in usability testing is thinking aloud that takes at least 3-5 samples so the optimal problem can be found during test. This study aims to determine whether the needs of the number of respondents in the thinking aloud method is still relevant today, especially when applied to children, and to determine the effect of number of children involved in the test on usability problems found.This study involved 10 children assubjects with a mean age of 10,6 years to play educational application that run on Apple Ipad 2 named Candy Factory. However, the number of respondents in usability test on children's educational application has the effect that the more the number of respondents, the more problems found but only up to 4 respondents. More than 4 respondents, the usability problems that found is decreasing because the children keep revealing the same problem. One respondentwas able to found 45,45% usability problems, and 85% usability problems found by only 4 respondents. While 100 % usability problems can be found by 9 respondents. Moreover, the result of usability test analysis and recommendations for improvement of Candy Factory are explained.Keywords: usability, number of respondent, thinking aloud, educational game, children
Effect of Bombyx mori silk-fiber volume on flexural strength of fiber-reinforced composite Fransiska, Aria; Sunarintyas, Siti; Dharmastiti, Rini
Majalah Kedokteran Gigi Indonesia Vol 4, No 2 (2018): August
Publisher : Faculty of Dentistry, Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (489.826 KB) | DOI: 10.22146/majkedgiind.25186

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Dental glass fiber is one of dental synthetic fibers that are widely used in dentistry as a dental resin reinforcement, such as in dentin replacement material. The availability of glass fiber is limited in Indonesia because it must be imported and relatively expensive. Bombyx mori silk-fiber is one of the strongest natural fiber derived from silkworm cocoon processing. Silk-fiber is used in medical applications as a post-surgical sutures, scaffolds for tissue engineering and drug delivery. The purpose of this study was to evaluate the effect of Bombyx mori silk-fiber volume on the flexural strength of fiber-reinforced composite (FRC). We used Bombyx mori silk-fiber (Perhutani Pati, Central Java, Indonesia) and flowable composite (Charmfil flow, Denkist, Korea) in this study. The FRC samples were divided into 4 groups consisting of fiber volumes of 0%, 5%, 10% and 15% (n = 4). Tests of flexural strength were performed according to ISO 4049. The results were analyzed using one way ANOVA (p<0.05). The study showed that the means of the flexural strength (MPa) of Bombyx mori silk-fiber FRC for volume of 0%, 5%, 10% and 15% were 149.2 ± 5.5; 127.6 ± 3.8; 110.9 ± 3.5; 71.2 ± 4.2. One-way ANOVA test showed that the means of FRC flexural strength on the four groups’ silk-fiber Bombyx mori volumetric were significantly different (p<0.05). This study concluded that Bombyx mori silk-fiber volumetric influences the flexural strength of fiber- reinforced composite. An increase in Bombyx mori silk-fiber volume decreases the flexural strength of FRC because there is a small gap due to the weak interfacial bonds between dental flowable composite and Bombyx mori silk-silk-fiber.
Evaluasi Canting Elektrik (Cantrik Lama) Sebagai Dasar Perbaikan Dalam Pengembangan Canting Elektrik (Cantrik) Studi Kasus di Balai Besar Kerajinan dan Batik Lestariningsih, Siti; Dharmastiti, Rini; Moyoretno, Bambang
Dinamika Kerajinan dan Batik: Majalah Ilmiah Vol 30, No 1 (2013): Dinamika Kerajinan dan Batik
Publisher : Balai Besar Kerajinan dan Batik

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (786.13 KB) | DOI: 10.22322/dkb.v30i1.952

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AbstrakBeberapa kekurangan yang terjadi dalam penggunaan canting tradisional menjadi dasar Balai Besar Kerajinan dan Batik melakukan penelitian tentang rekayasa canting listrik (cantrik), mengingat begitu pentingnya alat tersebut dalam pembuatan batik khususnya batik tulis. Penelitian ini bertujuan untuk mengevaluasi cantrik lama sebagai dasar perbaikan dalam pengembangan cantrik supaya diperoleh cantrik yang sesuai dengan keinginan pengguna. Penelitian dilakukan di Balai Besar Kerajinan dan Batik, pengambilan data tentang evaluasi cantrik lama dengan kuesioner I, data kebutuhan dan keinginan pengguna diketahui dari kuesioner II yang diolah berdasarkan metode Kano dan QFD. Hasil evaluasi dari cantrik lama adalah tidak ergonomis, untuk memperoleh cantrik yang sesuai keinginan, faktor teknik yang perlu diperbaiki dalam pengembangan cantrik yaitu: mekanisme, model sesuai dengan pekerjaan, kualitas bahan, ukuran sesuai dengan antropometri, keringanan bahan, dan kekuatan bahan. Kata Kunci: Canting elektrik, evaluasi, faktor teknis AbstractSome disadvantages which are found in utilization of traditional canting, are the main reasons for Balai Besar Kerajinan dan Batik in conducting research to develop an electrical canting  (Cantrik), given the importance of these tools in batik making process, specifically written batik. This research aims to evaluate old cantrik, as a basic to develop it into a cantrik which fulfill the needs of batik makers.This research is conducted at Balai Besar Kerajinan dan Batik. The data about old cantrik evaluation are collected using questionnaire I, while data of users’ requirements are obtained using questionnaire II, which then are proceeded using Kano method and QFD. The evaluation results of old cantrik show that it does not meet ergonomic requirements. To obtain appropriate cantrik, it needs some technical factor improvements, namely: mechanism, suitable model for work, quality of materials, sizes according to Anthropometry, Materials light weight, and strength. Keywords: Electrical canting, evaluation, technical factor
Pengaruh posisi dan fraksi volumetrik fiber polyethylene terhadap kekuatan fleksural fiber reinforced composite (The effect of position and volumetric fraction polyethylene fiber on the flexural strength of fiber reinforced composite) Septommy, Catur; Widjijono, Widjijono; Dharmastiti, Rini
Dental Journal (Majalah Kedokteran Gigi) Vol 47, No 1 (2014): (March 2014)
Publisher : Faculty of Dental Medicine, Universitas Airlangga

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (433.54 KB) | DOI: 10.20473/j.djmkg.v47.i1.p52-56

Abstract

Background: Composite resin is a combination of filler and matrix. The additional of fiber in the composite resin has a function as load-bearing in mastication. Polyethylene fiber has been used as a reinforced to receive the forces on the fixed denture fiber reinforced composite (FRC). Purpose: The purpose of this study was to determine effect of position and olumetric fraction of fibers on the flexural strength and modulus polyethylene FRC. Methods: This study used 7 groups with variations in the position and the volume of fiber. Group I, position compression volume 1 sheet; group II, 2 volume compression sheet position; group III, volume 1 sheet neutral position; group IV, neutral position volume 2 sheets; group V, position tension volume 1 sheet; group VI position tension volume 2 sheets; and group VII without fiber. Each group consisted of 6 samples and FRC rod-shaped samples with size (25 x2 x 2) mm. Samples were tested by three-point bending test with a universal testing machine. The data were analyzed by two-way Anova and LSD test continued (α = 0,05). Results: Group VI had the highest mean flexural strength than others (360.74 MPa) and group IV had the highest flexural modulus than others (3.56 GPa). The flexural strength and modulus with the variation of position or volume showed a significant differences (p<0.05), while the interaction between position and volume showed no significant difference (p>0.05). Conclusions: The position fiber on tension and additional two strips on volumetric fiber affected the increasing flexural strength and modulus of FRC.Latar belakang: Komposit merupakan gabungan filler dan matriks. Penambahan fiber pada komposit berfungsi sebagai penahan beban pengunyahan. Polyethylene fiber telah digunakan sebagai penguat dalam menerima gaya-gaya pada gigi tiruan cekat fiber reinforced composite (FRC). Tujuan: Penelitian ini bertujuan untuk mengetahui pengaruh posisi dan fraksi volumetrik fiber pada kekuatan fleksural polyethylene FRC. Metode: Penelitian ini membuat 7 kelompok sampel polyethylene FRC dengan variasi posisi dan volume fiber. Kelompok I, posisi compression volume 1 lembar; kelompok II, posisi compression volume 2 lembar; kelompok III, posisi netral volume 1 lembar; kelompok IV, posisi netral volume 2 lembar; kelompok V, posisi tension volume 1 lembar; kelompok VI, posisi tension volume 2 lembar; dan kelompok VII, tanpa fiber. Setiap kelompok terdiri atas 6 sampel dan sampel berbentuk batang FRC dengan ukuran (25x2x2) mm. Sampel diuji dengan three-point bending test dengan universal testing machine. Data dianalisis dengan two-way anova dan dilanjutkan uji LSD (α=0.05). Hasil: Rerata kekuatan fleksural kelompok VI paling tinggi (360.74 MPa) dan kelompok IV memiliki modulus fleksural tertinggi (3.56 GPa). Kekuatan dan modulus fleksural dengan variasi posisi atau volume menunjukkan perbedaan bermakna (p<0.05) sedangkan interaksi antara posisi dan volume menunjukkan perbedaan tidak bermakna (p>0.05). Simpulan: Posisi fiber pada sisi tension FRC dan penambahan volume 2 lembar fiber akan meningkatkan kekuatan fleksural FRC.
Perbandingan Sifat Keausan UHMWPE Terhadap Commercially Pure Titanium (CP-Ti) Dan Stainless Steel 316L Untuk Aplikasi Sendi Lutut Buatan Prayoga, Benidiktus Tulung; Dharmastiti, Rini; Suyitno, Suyitno; Fadilah, Arfan
Jurnal Material dan Teknologi Proses Vol 1, No 1 (2015)
Publisher : Departemen Teknik Mesin, Sekolah Vokasi, Universitas Gadjah Mada.

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Abstract

Titanium dan stainless steel 316L telah banyak dipakai sebagai material implan karena sifat tahan korosi, kekuatan dan biokompabilitas yang baik. Permasalahan utama pada implan persendian adalah keausan dari implan tersebut. Penelitian ini bertujuan untuk mengetahui sifat keausan UHMWPEterhadap dan commerciall pure titanium (CP-Ti) dan stainless steel 316L untuk aplikasi sendi lutut buatan.Pada penelitian ini uji keausan yang digunakan adalah metode reciprocating pin on flat (RPOF) sesuai dengan ASTM F732-00. Pin UHMWPE digesekkan pada plat yang bergerak bolak-balik di bawah pin. Durasi pengujian selama  20 x 105 siklus dan pengambilan data kehilangan aus diambil pada durasi setiap 250.000 siklus menggunakan timbangan dengan ketelitian 0,001 gram.Hasil penelitian ini menyatakan bahwa kekerasan 316 L lebih tinggi dibandingkan material CP-Ti. Bahan 316 L lebih tahan goresan dibandingkan material CP-Ti. Material UHMWPE yang berpasangan dengan stainless steel 316L memiliki ketahanan aus yang lebih baik dibandingkan dengan material UHMWPE yang berpasangan dengan CP-Ti. Lapisan oksida pada CP-Ti mudah terlepas sehingga keausan meningkat. Mekanisme keausan yang terjadi adalah keausan adesif dan abrasif.
PENGARUH KEDALAMAN AIR TERHADAP SHORT TERM MEMORY DAN KONSUMSI ENERGI PADA PENYELAM Dharmastiti, Rini; Harisa, Dhirga
J@ti Undip : Jurnal Teknik Industri Volume 5, No.2, Mei 2010
Publisher : Departemen Teknik Industri, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (209.151 KB) | DOI: 10.12777/jati.5.2.135-142

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Penelitian ini akan melihat pengaruh kedalaman air terhadap short term memory dan konsumsi energi penyelam. Penelitian ini mengambil sampel 10 mahasiswa pria dan 5 wanita. Pengukuran performansi short term memory dilakukan dengan cara setiap obyek diperlihatkan deretan 7 angka acak yang diberikan selama 5 detik dan setelah 15 detik kemudian dilakukan pemanggilan kembali informasi yang baru saja diberikan. Setiap obyek diuji sebangak 30 kali untuk setiap kedalaman (1 m; 2,5 m; dan 4 m). Pengukuran konsumsi energi dilakukan dengan menghitung denyut jantung menggunakan metode palpasi. Hasil penelitian menunjukkan bahwa semakin meningkat kedalaman air, maka performasi short term memory penyelam tersebut semakin menurun.  Penurunan ini berlaku untuk pria dan wanita. Penambahan kedalaman ini juga meningkatkan konsumsi energi baik pada pria maupun wanita. Perbedaan jenis kelamin mempengaruhi performansi short term memory secara signifikan. Pria memiliki performansi rata-rata short term memory sebesar 91,67% pada kedalaman 1 m, 90,67% pada kedalaman 2,5 m, dan 86,33% pada kedalaman 4 m. Sedangkan wanita memiliki performansi rata-rata sebesar 86% pada kedalaman 1 m, 84% pada kedalaman 2,5 m, dan 80,67% pada kedalaman 4 m. Rata-rata konsumsi energi pria adalah 3,19 kkal, 3,34 kkal, dan 3,65 kkal pada kedalaman 1 m; 2,5 m; dan 4 m berturut-turut. Sedangkan rata-rata konsumsi energi wanita adalah 3,81 kkal, 4,07 kkal, dan 4,54 kkal pada kedalaman yang sama dengan pria.     Kata kunci : tekanan, kedalaman air, performansi short term memory, konsumsi energi.       This research is to observe water depth effects on short term memory and energy expenditure of diver. This research objects are 10 male and 5 female students. Short term memory performance measurement held by every object has been shown 7 random numerics (as information) for 5 seconds and after 15 seconds later they write down the information on a paper. Every object got 30 tests for every depth ( 1 m; 2.5 m, and 4 m). Energy expenditure measurement held by counting heart rate using palpasi method. The results are as deep as the diver dive, short term memory performance will be decreasing and energy expenditure will be increasing for male and female. Gender differences influencing the results significantly. Male has short term memory performance average 91.67% at 1 m, 90,67% at 2.5 m, and 86,33% at 4 m. Female has average performance 86% at 1 m, 84% at 2.5%, and 80,67% at 4 m. Energy expenditure average for male are 3.19 kcal, 3,34 kcal, and 3,65 kcal at 1 m, 2.5 m, and 4 m respectively. Energy expenditure for female are 3.81 kcal, 4,07 kcal, and 4,54 kcal at same depth like male. Keywords: pressure, water depth, short term memory performance, energy expenditure.
Analisis Aktivitas Otot Dengan Perbedaan Jenis Kelamin Pada Postur Tangan Menggunakan Surface Electromyography Pratiwi, Indah; Purnomo, Purnomo; Dharmastiti, Rini; Setyawati, Lientje
Jurnal Ilmiah Teknik Industri Vol. 16, No. 2, Desember 2017
Publisher : Universitas Muhammadiyah Surakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23917/jiti.v16i2.5207

Abstract

This study aims to analyze the muscle activity in the upper body of the hand posture. Measurements are made when the workers perform the activities of making pottery in a sitting position. Measurements use surface electromyography and differentiate sex between men and women. The research steps were: (1) worker capture resulted in ten postures, (2) determination of muscle influences, namely: extensor carpi radialis muscle, extensor carpi ulnar muscle, extensor of the wrist muscle, biceps brachii muscle, flexor carpi radialis muscle, and (5) calculate using root mean square (RMS) and RMS value index RMS value and deviation index RMS value of male - higher than women in each muscle and in every posture.
OPTIMIZATION OF TISSUE DECELLULARIZATION METHOD BASED ON MACROSCOPIC AND MICROSCOPIC OBSERVATION IN THE SHEEP PERIPHERAL NERVES Permata, Fajar Shodiq; Susilowati, Rina; Dharmastiti, Rini; Sirat, Muhammad Mirandy Pratama Sirat Mirandy Pratama; Kartikasari, Pipin Dwi
Jurnal Sain Veteriner Vol 30, No 2 (2012): DESEMBER
Publisher : Fakultas Kedokteran Hewan Universitas Gadjah Mada bekerjasama dengan PB PDHI

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (13252.092 KB) | DOI: 10.22146/jsv.2606

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Animal graft tissue  (xenograft) was developed  to replace the limited supply of human graft tissue (allograft). Peripheral nerve graft tissue  is needed to replace  the damage. Swine is the most developed source of tissue donor for the preparation of acellular tissue because a lot of livestocks population and its extracellular matrix components similar to human collagen. Swine xenograft development would be an obstacle in Indonesia because of socio-cultural so that sheep used as swine donor replacement. Sheep cartilage tissue acellular induced less human inflammatory mediators than swine. Xenograft is necessary to decellularizebefore implantation into human that results in only extracellular matrix. However, decellularization process varies depending on the species and methods so that it is needed a preliminary study to get the best decellularization method for sheep peripheral nerve specimens. Five samples of sheep Ischiadicus  nerves were conducted decellularization various processes and one sample of fresh nerve (control). Decellularization methods were 24 hours shaking, tissue soaking and perfusion for both 14 days and 17 days, respectively. Decellularization solution was 0.1% SDS-EDTAin PBS. Post decellularization, samples were observed macroscopically, fixed, HE staining of histopathologic examination for microscopic examination. The data were analyzed descriptively. At the macroscopic observation of post decellularization tissue showed white, and samples of soaking method showed softer consistency than that of shaking and perfusion. Microscopic examination showed that samples were not being completed decellularization at shaking method. There was destruction of collagen fibers of perineurium and endoneurium in 17 days of soaking and perfusion methods, while 14 days soaking and perfusion methods showed that samples were being completed decellularization and both perineurium and endoneurium collagen were still good. Conclusion of this study is that 14 days soaking and perfusion decellularization methods are better than that of 24 hours shaking method and 17 days of soaking and perfusion methods for sheep decellularization peripheral nerve.  
PENGEMBANGAN ALAT UKUR EVALUASI DAN PERANCANGAN PRODUK KURSI RODA Jatmiko, Hapsoro Agung; Dharmastiti, Rini
Jurnal Teknosains Vol 7, No 2 (2018): June
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1089.261 KB) | DOI: 10.22146/teknosains.28222

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A wheelchair is one of the mobility aids for people with disabilities. Availability of wheelchair type is very decisive for users based on the limitations they have. The problem felt by users in Indonesia today, especially in Yogyakarta, is that users have not got the right kind of wheelchairs with the needs, with certain limitations. This study aims to develop a wheelchair evaluation and to know the users expectation of the wheelchair design. This study shows that there are problems due to the users not getting a wheelchair that suits their needs. The wheelchair design that the users want are the wheelchair with 3 wheels and have new feature.
ROLE OF REDUCING CELL LEAKAGE IN CELL CULTURE USING LARGE PORE SIZE PERMEABLE MEMBRANE Kaliwantoro, Nur; Soesatyo, Marsetyawan HNE; Indarto, Indarto; Juffrie, Mohammad; Dharmastiti, Rini; Suprihatin, Suprihatin
Jurnal Teknosains Vol 6, No 1 (2016): December
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3008.233 KB) | DOI: 10.22146/teknosains.27192

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Permeable membranes are widely used in many in vitro studies using cell culture. Some cell leakage are often occurs when using permeable membrane with large pore size. Unfortunately the use of permeable membrane with smaller pore size in permeability studies faces some difficulties due to its small pore size and pore density. Recent study provides the protocol in using permeable membrane with large pore size with smaller cell leakage. Vero cell line (CCL-81, ATCC) was used and culture on polyester permeable membrane with 3 µm pore size. Visualization using inverted microscope was used to analized the cell leakage on the permeable membrane. Parallel plate flow chamber was used to analized the permeability performance of the Vero cell cultured on the permeable membrane. The result showed that the current technique is significant in reducing cell leakage of the cell cultured on large pore size of permeable membrane. The same results were found in using polyester and polycarbonate permeable membrane.