Alva Edy Tontowi
Jurusan Teknik Mesin dan Industri, Universitas Gadjah Mada

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Perbandingan Metode Rasional Dengan Kreatif Untuk Mendesain Alat Bantu Pasang Lampu Prakosa, Rudy Firman; Tontowi, Alva Edy
Majalah Forum Teknik UGM Vol 3, No 2 (2010)
Publisher : Majalah Forum Teknik UGM

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (71.575 KB)

Abstract

Abstract This article discusses the result comparison of design process of lamp installation device using rational and creative methods and its usability analysis. The study was conducted through team recruitment, prototype development, prototype selection, and usability testing. The teams recruited involved creative team (K-team) consisting of experienced technical expert and non-exact  students,  and  rational  team  (R-Team)  consisting  of  exact  students  with  knowledge  in product design method. Result of prototype selection using weighted objectives method showedthat  rational prototype  produced  higher  total  weight  compared  to  that  of  creative  prototype. Usability  testing  were  also  conducted  in  terms  of  rational  and  creative  prototype  methods. Usability  testing  involved  learnability,  error,  efficiency  of  use,  and  satisfaction.  Result  of usability testing showed that rational prototype had higher efficiency of use, lower error, and higher  satisfaction  level.  Therefore,  rational  method  becomes  better  design  process  in  lamp installation device.  Keywords: product design, creative method, rational method, usability, device
Determination of Operation Condition and Product Dimension Accuracy Optimization of Filament Deposition Modelling on Layer Manufacturing Application Widyanto, Slamet; Tontowi, Alva Edy; Jamasri, Jamasri; Rochardjo, Heru Santoso Budi
Makara Journal of Technology Vol 10, No 2 (2006)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.7454/mst.v10i2.117

Abstract

Layer manufacturing process has proven as a process that can produce a high complexity mechanical part. Now, Improvement of LM methods continuously conduct that is aimed to increase precessions and efficiency of these processes. Pressure filament deposition modelling is a form of layer manufacturing process that is designed to produce a plastic part with controlling its semisolid phase. In this research, the equipment of filament depositor is designed and tested to make the product filament deposition. With operation condition observation, the optimal temperature and pressure of deposition process was determined. These experiments used PVC as crystalline material and  polypropylene as amorphous material. To optimize this process, the tensile strength and density test were conducted. The shape of tensile test specimens is based on ASTM 638 standard and made in 3 orientations deposition path, namely: in 0 degree, 45 degree and 90 degree from load force axis. To found the most accurate dimension, controlling the time delay, temperature of build part, feeding speed and variation deposition path was conducted. The results of experiments show that the filament deposition method can only be applied for amorphous material in which it has a semisolid phase. From the tensile strength test, the binding strength among filaments is 0.5 kg/mm2, 20% of the tensile strength of filament. And the density of a sample product, which used the filament diameter of 0.8 mm, is 0.7668 g/cm3. Accuracy of product dimension can be increased by: controlling time delay in location where the motion orientation of hopper filament is changed and controlling temperature of build part surface.
THE EFFECT OF 3D PRINTING MACHINE PARAMETERS IN EXTRUSION PROCESS OF BIOCOMPOSITE MATERIALS (PMMA AND HA) ON DIMENSIONAL ACCURACY Almy, Raeshifa Diani; Tontowi, Alva Edy
SINERGI Vol 22, No 2 (2018)
Publisher : Universitas Mercu Buana

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (530.128 KB) | DOI: 10.22441/sinergi.2018.2.003

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Bone implants are medical procedures involving replacement or reconstruction of missing or damaged bones with the patients ones, natural substitutes or artificial substitutes. The widely used bone cement is a polymethylmethacrylate (PMMA) based composite material. To improve bioactivity, PMMA is combined with hydroxyapatite (HA). The manual formation can make bone implants during surgery. However, the method requires a longer operation time and raises the possibility of a higher error. Therefore, 3D printing technology is used to improve the quality of bone implants. One of the machines that can be used is the 3D printing machine, the property of the Product Design and Development Laboratory of Universitas Gadjah Mada. This machine needs to be tested to determine the accuracy of the prints, which is one indicator of product quality. Several machine parameters can be set in this machine setting. This study aims to determine the effect of three parameters, those are perimeter speed or edge print speed (20-40 mm / s), infill speed or inner print speed (50 - 70 mm / s), and fill angle or inner slope of inner printing (45 - 90 ° C). Before printing complex shapes, the machine was tested in advance with a more straightforward specimen design, which is a specimen design of flexural strength test. Response surface experiment design is used to determine the effect of three parameters on the dimensional accuracy which is measured through dimensional error. The results show that these three factors have no significant impact on the dimensional error, but the resulting error is still high. Therefore, it is necessary to adjust the design size before printing.
PROSES SINTESIS DAN KARAKTERISASI FTIR HIDROKSIAPATIT DARI GIPSUM ALAM KULON PROGO Sedyono, Joko; Tontowi, Alva Edy
Media Mesin: Majalah Teknik Mesin Vol 9, No 1 (2008)
Publisher : Universitas Muhammadiyah Surakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (65.998 KB)

Abstract

Hidroksiapatit (HAp) [Ca10(PO4)6(OH)2] telah dipergunakan secara luas dalam bidang kedokteran dan kedokteran gigi sebagai bahan substitusi tulang/gigi, hal ini karena komposisi dan strukturnya sama sebagaimana kandungan tulang/gigi. Tetapi HAp yang ada di Indonesia masih import. Tujuan dari penelitian ini adalah membuat bahan biokeramik hidroksiapatit dari gipsum alam Kulon Progo (KPNG) kemudian mengkarakterisasi dengan pengujian FTIR. Sintesa HAp dilakukan dengan teknik Hydrohermal Microwave dengan mereaksikan antara KPNG (CaSO4.2H2O) dengan diamonium hidrogen fosfat [(NH4)2HPO4]. Kemudian hasil reaksinya dianalisa dengan pengujian FTIR dan dibandingkan dengan HAp 200 Jepang sebagai pembanding. Dari hasil analisa didapat pola-pola FTIR hidroksiapatit hasil reaksi menyerupai HAp 200 Jepang dan HAp SRM 2910.
THE EFFECT OF 3D PRINTING MACHINE PARAMETERS IN EXTRUSION PROCESS OF BIOCOMPOSITE MATERIALS (PMMA AND HA) ON DIMENSIONAL ACCURACY Almy, Raeshifa Diani; Tontowi, Alva Edy
SINERGI Vol 22, No 2 (2018)
Publisher : Universitas Mercu Buana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22441/sinergi.2018.2.003

Abstract

Bone implants are medical procedures involving replacement or reconstruction of missing or damaged bones with the patients ones, natural substitutes or artificial substitutes. The widely used bone cement is a polymethylmethacrylate (PMMA) based composite material. To improve bioactivity, PMMA is combined with hydroxyapatite (HA). The manual formation can make bone implants during surgery. However, the method requires a longer operation time and raises the possibility of a higher error. Therefore, 3D printing technology is used to improve the quality of bone implants. One of the machines that can be used is the 3D printing machine, the property of the Product Design and Development Laboratory of Universitas Gadjah Mada. This machine needs to be tested to determine the accuracy of the prints, which is one indicator of product quality. Several machine parameters can be set in this machine setting. This study aims to determine the effect of three parameters, those are perimeter speed or edge print speed (20-40 mm / s), infill speed or inner print speed (50 - 70 mm / s), and fill angle or inner slope of inner printing (45 - 90 ° C). Before printing complex shapes, the machine was tested in advance with a more straightforward specimen design, which is a specimen design of flexural strength test. Response surface experiment design is used to determine the effect of three parameters on the dimensional accuracy which is measured through dimensional error. The results show that these three factors have no significant impact on the dimensional error, but the resulting error is still high. Therefore, it is necessary to adjust the design size before printing.
Characterization of Semi-Interpenetrated Network Alginate/Gelatin Wound Dressing Crosslinked at Sol Phase Perkasa, Dian Pribadi; Erizal, Erizal; Purwanti, Tri; Tontowi, Alva Edy
Indonesian Journal of Chemistry Vol 18, No 2 (2018)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (414.317 KB) | DOI: 10.22146/ijc.25710

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Gel contraction of alginate during ionic crosslinking at sol phase was reduced by blending with gelatin solution due to intermolecular interaction and chain entanglement. The semi-interpenetrated network (semi-IPN) of wound dressing hydrogels were prepared by overlaid alginate/gelatin blend with 1.0% (w/w) CaCl2 solution under ambient temperature for 2 h. Results showed that gel contraction was significantly reduced with increasing gelatin content i.e. from 40.5 ± 5.8% for pure alginate to as low as 5.8 ± 1.2% for alginate/gelatin of 1:7 (w/w). It seems that gelatin successfully inhibited alginate chains mobility during their network re-arrangement by Ca2+ cation. The FTIR spectra of hydrogels showed combination of characteristic vibration of alginate and gelatin. Increasing gelatin content also significantly improved elasticity and tensile strength at break of dried hydrogels. Swelling kinetics of dried hydrogels were fitted Schott’s second-order power-law model. Increasing gelatin fraction increased the swelling rate while decreased the swelling at equilibrium. Their absorptive capacity were of interval for management of moderate to heavily exudating wound.
THE COMPOSITION OF BIOCOMPOSITE [POLYMETHYLMETHACRYLATE/HYDROXYAPATITE] AS MATERIAL FOR SPECIMEN WITH PORTABEE KIT MACHINE Sekarjati, Kartinasari Ayuhikmatin; Tontowi, Alva Edy
SINERGI Vol 22, No 3 (2018)
Publisher : Universitas Mercu Buana

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (209.007 KB) | DOI: 10.22441/sinergi.2018.3.005

Abstract

The development of science and technology related to bone implant material, researchers want to develop materials that have properties near human bones and improve the quality. This study was conducted to determine the composition of the mixture that can pass nozzle at room temperature. It is expected that in this study, the mixture is able to pass through the small nozzle size so that it can print specimens precisely according to the size of the design to be printed. Output mixture through a nozzle is said well if the output is continuous and homogeneous. The quality of the composition of the mixture, the material output from the nozzle will be printed by ASTM F451-95 and compressive test. This mixture consists of polymethylmethacrylate (PMMA), methylmethacrylate (MMA) and hydroxyapatite (HA) by mixing methods manually. PMMA and MMA used in the type of heat curing, while HA derived from fish scales. Through several experiments, there is composition that can pass nozzle and have a high compressive strength value, that is composition PMMA : MMA instead of 1 : 1 (w/w) with mixture 20% HA and have compressive strength value 31,20 MPa, the second composition PMMA : MMA instead of 2 : 1 (w/v) with mixture 10% HA and have compressive strength value 25,62 MPa. This composition was chosen for further research with the Portabee Kit machine.
Konsep ABG (Academic-Business-Government) dalam Rencana Sistem Industri Berbasis Potensi Daerah Kabupaten Sleman dan Gunung Kidul Bimantio, Muhammad Prasanto; Tontowi, Alva Edy
TEKNIK Vol 38, No 2 (2017): (Desember 2017)
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (71.575 KB) | DOI: 10.14710/teknik.v38i2.15797

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Daerah Istimewa Yogyakarta (DIY) mempunyai potensi industri yang cukup tinggi, baik industri kecil, menengah, maupun besar. Namun daya saing produk industri pengolahan di DIY rendah karena beberapa faktor, yakni masih lemahnya keterkaitan antar industri, keterbatasan produksi barang setengah jadi dan komponen di dalam negeri, keterbatasan industri berteknologi tinggi, kesenjangan kemampuan ekonomi antardaerah, serta ketergantungan ekspor pada beberapa komoditas tertentu. Penelitian ini bertujuan untuk membuat rancangan konsep kawasan industri berbasis potensi daerah (Domestic Based Industry/ DBI) menggunakan pendekatan sinergi Academic-Business-Government (ABG). Pendekatan ini dilakukan dengan fokus pada pemanfaatan bahan baku, sumber daya manusia, dan pemenuhan permintaan pasar lokal. Hasil kajian ini menghasilkan tiga konsep kawasan DBI yang diusulkan: (i) pengolahan produk turunan salak pondoh di Turi Sleman, (ii) pengolahan zeolit di Gedangsari Gunungkidul, dan (iii) pengolahan limbah produk biogas di Cangkringan Sleman. Ketiga konsep kawasan industri pengolahan tersebut saling terkait dan akan membentuk jejaring yang terintegrasi mulai dari bahan baku hingga produk, baik dengan industri rancangan baru maupun dengan industri yang sudah ada.
EVALUASI KOMPLIKASI PLATE EXPOSURE PASCA RESEKSI AMELOBL ASTOMA MANDIBULA DENGAN REKONSTRUKSI PELAT TITANIUM DI RSUP DR. SARDJITO YOGYAKARTA Widiastuti, Maria Goreti; Soesatyo, Marsetyawan HNE; Magetsari, Rahardyan; Tontowi, Alva Edy
Jurnal Teknosains Vol 5, No 2 (2016): June
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/teknosains.24222

Abstract

Resection of the jaw is a primary option of treatment in mandibular ameloblastoma with bone damage. Mandibular resection will cause mandibular stability disturbance due toloss of some part of the bone. Instability of the mandible can cause aesthetic, physiological, and psychological malfunctioning. To restore its stability, installment of mandibular reconstruction plate on the remaining mandibular by using screws. However, it is not uncommon that plate exposure occurs following mandibular reconstruction, caused by inaccurate adaptation of the plates to the mandibular bone. A  3D stereolithography modelcan help provide the best assesment on the bone defect, plan the making of the more easily pre-operative curved plates and provide more accurate faster surgery time. Objective: To evaluate plate exposure after mandibular resection with titanium reconstruction plates in Dr. SardjitoHospital. Case report: A case was reported on mandibular reconstruction after resection of ameloblastoma with titanium plate performed in Dr. Sardjito Hospital that experienced intra-oral plate exposure and oro-cutaneous fistula on the left mandible. The clinical evaluation showed the curved titanium plate did not adapt well with the remaining mandibular bone; therefore, the titanium plate was removed without replacing it with a new plate. Inappropriate adaptationof curved titanium plate is one of the main causes of plate exposure. The use of a 3D stereolithography model is very helpful for the success of mandibular reconstruction.
EFEK APLIKASI SERICIN PADA HIDROKSIAPATIT TERHADAP PERLEKATAN SEL OSTEOBLAS Sunarintyas, Siti; Yustisia, Yeni; Tontowi, Alva Edy
Jurnal Teknosains Vol 1, No 1 (2011): December
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/teknosains.3989

Abstract

Hydroxyapatite (HA) is often used as a human bone graft. Modification of HA surface is developed to increase osseointegration process which is influenced by cells attachment surrounded the tissue. Sericin has polar side groups which accelerate cells attachment. The aim of this research was to determine the effect of sericin application over HA surface on the attachment of osteoblast cells. The research used HA synthesized from gypsum (Kulon Progo, Yogyakarta). Sericin was extracted from silkworm cocoons of Bombyx mori. Sericin of 0.01, 0.05, 0.1% were applied over HA discs surface (10 mm in diameter, 3 mm thick). The discs were inserted into osteoblast cells culture of MC3T3E1 for attachment test. The data were analyzed by ANOVA and LSD. The result showed that the amount of osteoblast cells attached to HA (7.60±0.42) was significantly difference (p<0.05) with HA + sericin 0.01% (10.30±0.52), HA + sericin 0.5% (10.63±0.70), HA + sericin 0.1% (10.67±0.87). Variation of sericin concentrations applied over HA did not influence any significant difference on the amount of cells attachment (p>0.05). In conclusion, sericin application over HA surface increased the amount of osteoblast cells attachment. Concentrations of sericin application over HA (0.01, 0.05, 0.1%) did not influence osteoblast cells attachment.