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ANALISIS MANAJEMEN PEMENUHAN PELANGGAN PADA INDUSTRI KECIL MENENGAH PEMBUATAN TAS DAN BORDIR MENGGUNAKAN PEMODELAN SYSTEM DYNAMICS (STUDI KASUS PADA CV. KURNIA JAYA – YOGYAKARTA) Rahmanto, Nurdin; Hartono, Budi; Tontowi, Alva Edy
Jurnal Manajemen dan Organisasi Vol. 2 No. 3 (2011): Jurnal Manajemen dan Organisasi
Publisher : IPB University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (582.816 KB) | DOI: 10.29244/jmo.v2i3.14212

Abstract

Small Medium Enterprise (SME) plays a strategic role in developing countries economy. Each of SMEs has unique strategy of order fulfillment management. This is influenced by factor dynamics influencing the system. The system characteristic becomes the inspiration to be studied furthermore continues especially using system dynamics modeling approach. System dynamics modeling approach used because this method used to know and learn the system behavior. This paper represents of order fulfillment management analysis with case study at CV. Kurnia Jaya ? Yogyakarta. The developed model has 4 sub models: customer order sub model, order fulfillment sub model, raw material management sub model and labor sub model. Next step is calibrating the developed model with boundary adequacy test, extreme conditions test and behavior reproduction test. After passing all these steps, the developed model to be ran with policy design (different scenario of order such as: constant order, step order, impulse order and actual order). Finally 3 alternative recommendations proposed for increasing the production rate so the order backlog and delivery delay decrease.
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 : Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (383.297 KB) | DOI: 10.14710/teknik.v38i2.15797

Abstract

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.
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 | Full PDF (269.348 KB) | 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

Abstract

Bone implants are medical procedures involving replacement or reconstruction of missing or damaged bones with the patient's 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.
ANALISIS UKURAN PORI BIOKOMPOSIT (SERICIN-BIOPLASTIK) PADA BERBAGAI SUHU PEMBEKUAN AWAL DENGAN METODE TAGUCHI Putra, Gaustama; Tontowi, Alva Edy
JURNAL TEKNIK INDUSTRI Vol 9, No 3 (2019): Volume 9 No 3 November 2019
Publisher : Jurusan Teknik Industri, Fakultas Teknologi Indusri Universitas Trisakti

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25105/jti.v9i3.6571

Abstract

Intisari? Kebutuhan Biomaterial bidang medis dalam berbagai keperluan terus meningkat. Produk biomaterial di Indonesia kebanyakan adalah produk impor, harganya mahal dan membutuhkan waktu lama saat dibutuhkan. Berdasarkan hal ini, penelitian di bidang biokomposit makin meningkat. Sericin adalah protein yang biokompatibel, biodegradable dan sifat penting lainnya. Sericin banyak digunakan dalam aplikasi biomedis dan merupakan bahan alami yang menjanjikan sebagai bahan medis alternatif. Tujuan penelitian adalah menganalisis diameter pori yang terbentuk dan campuran optimal biokomposit sericin-bioplastik dengan menggunakan metode Taguchi. SEM dan FTIR untuk melihat diameter pori dan struktur biokomposit. Bahan yang digunakan pati tapioka 16g, 14g dan 10g, aquades 80 ml dan gliserin 6 ml, sericin 0,03, 0,1, dan 0,3%. Biokomposit mengalami proses freeze drying dan pembekuan pada -25°C, -45°C dan -80°C. Hasil penelitian untuk respon rata-rata dan SNR, maksimum pada 16g tepung tapioka, 0,03% sericin dan pembekuan -25°C. SEM menunjukkan pembekuan -25°C biokomposit C: 41,94 ?m, F: 33,416 ?m, dan I: 2,743 ?m memenuhi syarat regenerasi jaringan kulit. Nilai prediksi dan interval kepercayaan rata-rata besar 11,656 ?m dan kecil 54,602 ?m, SNR besar 31,940 ?m dan kecil 33,642 ?m. Nilai konfirmasi secara eksperimental kondisi optimal diameter pori besar untuk rata-rata lebih besar dari 32.342 ?m dan lebih kecil dari 34.206 ?m, SNR lebih besar dari 32.342 ?m dan kecil 34.206 ?m. pembekuan I biokomposit -80 C muncul gugus fungsi C=O yang tidak ada dalam sampel lain. Abstract? The need for Biomaterials in the medical field for various purposes continues to increase. Most of biomaterial products available in Indonesia are imported products. They are expensive and take a long time to provide. Due to these reasons, research in the field of biocomposites is increasing. Sericin is a protein that is biocompatible, biodegradable and has other important properties. Sericin is widely used in biomedical applications and is a promising natural material as an alternative medical material. The aim of the study was to analyze the pore diameter formed and the optimal mixture of sericin-bioplastics biocomposite using the Taguchi method. SEM and FTIR were also employed to see the pore diameter and biocomposite structure. The materials used were 16g, 14g and 10g of tapioca starch, 80 ml of aquades and 6 ml of glycerin, as well as 0.03, 0.1 and 0.3% sericin. Biocomposite underwent a freeze drying and freezing process at -25°C, -45°C and -80°C. The results showed that the maximum mean and SNR responses were at 16g tapioca starch, 0.03% sericin and freezing temperature of -25°C. SEM showed that freezing at -25°C for biocomposite C: 41.94 ?m, biocomposite F: 33.416 ?m, and biocomposite I: 2.743 ?m fulfilled the requirements for skin tissue regeneration. Predicted mean values and confidence intervals for large and small pore sizes were 11.656 ?m and 54.602 ?m, SNR values for large and small pore sizes were 31.940 ?m and 33.642 ?m. The mean experimental confirmation values of optimal conditions for pores with large diameters were greater than 32.342 ?m and smaller than 34.206 ?m, SNRs were greater than 32.342 ?m and smaller than 34.206 ?m. The freezing of biocomposite I at -80 C yielded C=O functional group which was not present in other samples.
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

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

Abstract

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 | 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.
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 | Full PDF (412.199 KB) | 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.