Kerusakan permanen pada sendi memerlukan tindakan penggantian dengan sendi buatan (artificial hip... more Kerusakan permanen pada sendi memerlukan tindakan penggantian dengan sendi buatan (artificial hip replacement). Pemilihan sifat material pengganti komponen dan dimensi yang digunakan perlu dilakukan secara cermat untuk mendapatkan kemampuan maskimal sambungan tulang pinggul buatan. Sambungan tulang ini terdiri dari tiga bagian utama, yaitu femoral head, acetabular cup dan cement. Material penyusun yang dipilih berturut-turut adalah Co-Cr, UHMWPE, dan PMMA. Dua material terakhir memiliki sifat viscoelastic. Tujuan penelitian ini adalah mengetahui pengaruh variasi ketebalan acetabular cup terhadap parameter kontak seperti tekanan kontak, dan radius kontak. Perangkat lunak berdasarkan metode elemen hingga digunakan untuk memodelkan berbagai lapisan komponen sambungan yang ada. Berdasarkan studi ini diketahui bahwa ketebalan acetabular cup tidak memiliki pengaruh yang signifikan terhadap parameter kontak, bahkan pada saat waktu pembebanan ditingkatkan. Oleh karena itu untuk efisiensi, k...
The 12-lead EKG is a useful first-line diagnostic tool for detecting cardiovascular diseases, inc... more The 12-lead EKG is a useful first-line diagnostic tool for detecting cardiovascular diseases, including arrhythmias, conduction abnormalities, and myocardial ischemia or infarction. This scoping review aims to discuss the ECG perspective for detecting heart problems. This study was conducted by following the narrative review and development framework. The literature search used ScienceDirect, Scopus, ProQuest, ClinicalKey, and SpringerLink data. The keywords used were "criteria" or "guidelines" and "ECG" or "ECG" or "electrocardiography" or "electrocardiogram" and "detection" and "heart problem" or "heart disease" or "heart problem" or "heart problem." The method uses a narrative review through eight articles spanning 2017–2022. The lighting method uses the PICO analysis framework. The results found four components, namely: 1) automatic diagnosis; 2) 3-D ECG with artificial intelligence (AI) classification; 3) use of the LSTM deep-learning model; and 4) leads using Tpeak-End (Tp-e). In patients with heart problems, the initial examination is an EKG. Thus, the ECG, with the addition of the automatic diagnosis feature, EKG-3D, and the use of a 12-lead ECG with a deep-learning LSTM model, also followed by high sensitivity and specificity, can be used as a tool to perform examinations on patients who require serial ECG examinations. Keywords: Electrocardiogram; nursing care; nursing review; clinical symptoms; nursing assessment
Zenodo (CERN European Organization for Nuclear Research), Jun 21, 2023
Robotic technology has the potential to revolutionize the field of neurology by providing new met... more Robotic technology has the potential to revolutionize the field of neurology by providing new methods for diagnosis, treatment, and rehabilitation of neurological disorders. In recent years, there has been an increasing interest in the development of robotics applications for neurology, driven by advances in sensing, actuation, and control systems. This review paper provides a comprehensive overview of the recent advancements in robotics technology for neurology, with a focus on three main areas: diagnosis, treatment, and rehabilitation. In the area of diagnosis, robotics has been used for developing new imaging techniques and tools for more accurate and non-invasive mapping of brain structures and functions. For treatment, robotics has been used for developing minimally invasive surgical procedures, including stereotactic and endoscopic approaches, as well as for the delivery of therapeutic agents to specific targets in the brain. In rehabilitation, robotics has been used for developing assistive devices and platforms for motor and cognitive training of patients with neurological disorders. The paper also discusses the challenges and limitations of current robotics technology for neurology, including the need for more reliable and precise sensing and actuation systems, the development of better control algorithms, and the ethical implications of robotic interventions in the human brain. Finally, the paper outlines future directions and opportunities for robotics applications in neurology, including the integration of robotics with other emerging technologies, such as neuroprosthetics, artificial intelligence, and virtual reality. Overall, this review highlights the potential of robotics technology to transform the field of neurology and improve the lives of patients with neurological disorders.
Journal Of Biomedical Science And Bioengineering, Nov 15, 2022
This study aims at building a checklist used on each stage of wearable Elbow Exoskeletons develop... more This study aims at building a checklist used on each stage of wearable Elbow Exoskeletons development. The Wearable Elbow Exoskeleton is one of the hand stroke therapy aids which was developed by Diponegoro University. Te product is still in the form of a prototype so that some tests must be carried out before the product is tested on respondents. Test during this far is still focus on functionality test. This study provides a general checklist for ergonomics testing of stroke therapy aid products. Method of checklist is developed based on exploration study and literature review for producing appropriate test related to product characteristics. There are three iteration on development product and each version repair the previous version. The implementation of checklist shows that on third iteration, product is in accordance with objective of development and reach the targeted level of respondents' satisfaction.
One of the limbs that plays an important role for mobility is the leg. However, some persons with... more One of the limbs that plays an important role for mobility is the leg. However, some persons with disabilities, especially losing legs, have physical limitations that cause reduced mobility. Therefore, the development of artificial legs is very helpful for persons with disabilities in carrying out their daily activities. One of the above knee prosthetic products that has been developed by Diponegoro University is an above knee prosthetic with a mechanical joint. However, in the loading analysis process, only 100 kg load is used. So that in this study, a loading analysis was carried out using a ground reaction force. The results of the analysis of ground reaction force loading at the gait cycle 17% resulted in a maximum von Mises stress of 18.47 MPa, a maximum deformation of 0.11 mm and a safety factor of 14.94. While the gait cycle 47% produces a maximum von Mises stress of 20.88 MPa, a maximum deformation of 0.14 mm and a safety factor of 13.21. It can be concluded that the above knee prosthetic can receive the greatest load on the gait cycle 47% which is greater than the gait cycle 17%.
Journal of biomedical research & environmental sciences, May 1, 2022
Journal of Biomedical Research & Environmental Sciences main aim is to enhance the importance of ... more Journal of Biomedical Research & Environmental Sciences main aim is to enhance the importance of science and technology to the scientifi c community and also to provide an equal opportunity to seek and share ideas to all our researchers and scientists without any barriers to develop their career and helping in their development of discovering the world.
Eastern-European Journal of Enterprise Technologies
Multilayered Armor System (MAS) is being extensively studied around the world for its ability to ... more Multilayered Armor System (MAS) is being extensively studied around the world for its ability to retain ceramic fragmentation after a collision occurs. MAS consist of a ceramic layer placed at the front and supported by a composite layer of ramie-fiber-reinforced epoxy resin. Present study utilizes natural fibers of 50 % ramie fibers with epoxy resin as the matrix and Silicon Carbide (SiC) ceramic as the front panel. The ballistic testing in this study used 7.62×51 mm NATO Ball projectile with a firing distance of 15 m from the bullet panel. The velocity of projectile was detected using LIGHT SCREEN B471 type. The aim of the study is to conclude the optimal thickness of ramie fiber-epoxy and SiC ceramics MAS structure based on experiments which can withstand 7.62 NATO ball bullet penetration. To achieve this aim, the following objectives are accomplished: study the effect of SiC ceramic addition to ramie composite on BFS and study the effect of SiC ceramic addition to ramie composi...
The optimum condition for leaching calcined dolomite ore in aqueous hydrochloric acid solutions w... more The optimum condition for leaching calcined dolomite ore in aqueous hydrochloric acid solutions was determined in this study. The process parameters referred to the acid concentration, the temperature and leaching time. The leaching experiments were performed in a spherical glass batch reactor having a capacity of 1000 mL. The experimental results show that the calcined dolomite ore leaching efficiency increases with addition of acid concentration, temperatur and leaching time increases. The optimum results were achieved at 75 °C for 5 h, and the acid concentration of 2 M HCl. The leaching Seminar Nasional Metalurgi dan Material (SENAMM) X 2017
Journal of Biomedical Research & Environmental Sciences
Recent demand and interest in patient health monitoring has driven significant interest toward de... more Recent demand and interest in patient health monitoring has driven significant interest toward developing varies alternative rehabilitation monitoring instrument. Muscle power can be seen from how many power it’s generate from contraction effort that can be sense by its voltage potential in microvolt order. Surface Electromyogram (EMG) is used to take the record acquisition of muscle power data as patient take the rehabilitation program for some period. In this paper the surface EMG designed to get some level amplification to maintain the data readable and filter to minimize noise that always is the problem from instrument to get data. The aim of the research is to design compact surface EMG device that can be record data development of muscle power over time.
Salah satu anggota gerak tubuh yang berperan penting untuk mobilitas adalah kaki. Akan tetapi, be... more Salah satu anggota gerak tubuh yang berperan penting untuk mobilitas adalah kaki. Akan tetapi, beberapa penyandang disabilitas terutama kehilangan kaki memiliki keterbatasan fisik yang menyebabkan mobilitas berkurang. Oleh karena itu, perkembangan kaki tiruan sangat membantu penyandang disabilitas dalam melakukan aktivitas sehari-hari. Salah satu produk kaki tiruan atas lutut yang telah dikembangkan oleh Universitas Diponegoro yaitu kaki tiruan atas lutut dengan sendi mekanik. Akan tetapi dalam proses analisis pembebanan, hanya menggunakan pembebanan 100kg. Sehingga dalam penelitian ini, dilakukan analisis pembebanan menggunakan ground reaction force . Hasil analisis pembebanan ground reaction force pada gait cycle 17% menghasilkan tegangan von Mises maksimal sebesar 18,47 MPa, deformasi maksimal sebesar 0,11 mm dan safety factor sebesar 14,94. Sedangkan pada gait cycle 47% menghasilkan tegangan von Mises maksimal sebesar 20,88 MPa, deformasi maksimal sebesar 0,14 mm dan safety fact...
Roda gigi merupakan salah satu komponen mesin yang kompleks dalam proses perancangan dan pembuata... more Roda gigi merupakan salah satu komponen mesin yang kompleks dalam proses perancangan dan pembuatannya. Hingga saat ini, Usaha Kecil dan Menengah (UKM) produsen komponen otomotif di Jawa Tengah belum mempu memproduksi roda gigi untuk sistem transmisi sepeda motor yang mampu memenuh standar perusahaan otomotif nasional atau mampu menjadi komponen after sales di pasar komponen purna jual. Berdasarkan survey yang dilakukan di pasar purna jual di Semarang terhadap produk roda gigi transmisi sepeda motor, roda gigi transmisi yang dijual merupakan produk Original Equipment Manufacturer (OEM) atau produk impor dari China dan Taiwan. Berdasarkan survey di UKM, roda gigi yang diproduksi UKM lebih mengarah pada pesanan yang spesifik (customized) dan belum menjadi produk massal. Penelitian ini mencoba mendorong UKM untuk memproduksi roda gigi yang dapat diproduksi massal dan memberikan pesasanan secara kontinyu. UKM produsen roda gigi di Kecamatan Juwana, Kab. Pati, diberikan order pembuatan ro...
PROEFSCHRIFT ter verkrijging van de graad van doctor aan de Universiteit Twente, op gezag van de ... more PROEFSCHRIFT ter verkrijging van de graad van doctor aan de Universiteit Twente, op gezag van de rector magnificus, prof.dr. H. Brinksma, volgens besluit van het College voor Promoties in het openbaar te verdedigen op woensdag 6 november 2013 om 14.45 uur door Rifky Ismail geboren op 16 juli 1980 te Semarang, Indonesia Dit proefschrift is goedgekeurd door: de promotor: prof.dr.ir. D.J. Schipper de assistent-promotor: dr.ir. J. Jamari V Running-in of two fresh and unworn surfaces in contact is a transient phase where friction and wear vary considerably in time. During running-in the surface properties of the components are adjusted. If the initial surface roughness of the rubbing surfaces is correctly chosen, the running-in changes into the steady-state phase. At this stage, the rubbing surfaces are in general smoother and their wear rate is low and constant. On the other hand, an inappropriate choice of roughness may lead to a rapid deterioration of the rubbing surfaces. The micro-geometry of the surface is an important factor in determining the life of mechanical components. During the running-in phase, the highest asperities are "flattened", thereby increasing the number of asperities in contact and, as a result, increasing the load-carrying capacity of the surface. Fundamental studies that attempt to consider the details of running-in phenomena are relatively rare. This research is conducted with the aim of exploring the running-in phase for the rolling, sliding and rolling-sliding contact. Finite element simulations are conducted to calculate the stress distributions for the three types of contact motions during the running-in phase. The evolution of the contact pressure for a certain rolling or sliding distance is studied to unravel the running-in phase. During running-in of rolling contacts, the change in the surface topography results in the transformation from a rough surface to a smoother surface: the flattening of the high asperities induces a reduction in surface roughness. This flattening of asperities is due to plastic deformation and causes a higher equivalent residual stress at the surface. The transition of the running-in phase to the steady-state phase of a rolling contact is governed by the transition of plastic to elastic deformation on roughness level.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
The paper presents the development of wearable robot called supernumerary robotic fingers (SRF) t... more The paper presents the development of wearable robot called supernumerary robotic fingers (SRF) that can be integrated with 3D Animation. The robot comprises of two parts, robotic finger (RF) and robotic thumb (RT). RF is located next to little finger, and RT is located next to the thumb. The robot is driven by modified glove sensor. 3D CAD model is exported into SimMechanics for 3D Animation purpose under MATLAB/Simulink environment. Forward kinematics of the robot is studied using SimMechanics and the trajectory of each robotic fingertip will be calculated. Based on the experimental result, the robot and its 3D animation can be operated by a healthy person in real time. The robot can assist in object manipulation with ten-inch tablet using single human hand.
Kerusakan permanen pada sendi memerlukan tindakan penggantian dengan sendi buatan (artificial hip... more Kerusakan permanen pada sendi memerlukan tindakan penggantian dengan sendi buatan (artificial hip replacement). Pemilihan sifat material pengganti komponen dan dimensi yang digunakan perlu dilakukan secara cermat untuk mendapatkan kemampuan maskimal sambungan tulang pinggul buatan. Sambungan tulang ini terdiri dari tiga bagian utama, yaitu femoral head, acetabular cup dan cement. Material penyusun yang dipilih berturut-turut adalah Co-Cr, UHMWPE, dan PMMA. Dua material terakhir memiliki sifat viscoelastic. Tujuan penelitian ini adalah mengetahui pengaruh variasi ketebalan acetabular cup terhadap parameter kontak seperti tekanan kontak, dan radius kontak. Perangkat lunak berdasarkan metode elemen hingga digunakan untuk memodelkan berbagai lapisan komponen sambungan yang ada. Berdasarkan studi ini diketahui bahwa ketebalan acetabular cup tidak memiliki pengaruh yang signifikan terhadap parameter kontak, bahkan pada saat waktu pembebanan ditingkatkan. Oleh karena itu untuk efisiensi, k...
The 12-lead EKG is a useful first-line diagnostic tool for detecting cardiovascular diseases, inc... more The 12-lead EKG is a useful first-line diagnostic tool for detecting cardiovascular diseases, including arrhythmias, conduction abnormalities, and myocardial ischemia or infarction. This scoping review aims to discuss the ECG perspective for detecting heart problems. This study was conducted by following the narrative review and development framework. The literature search used ScienceDirect, Scopus, ProQuest, ClinicalKey, and SpringerLink data. The keywords used were "criteria" or "guidelines" and "ECG" or "ECG" or "electrocardiography" or "electrocardiogram" and "detection" and "heart problem" or "heart disease" or "heart problem" or "heart problem." The method uses a narrative review through eight articles spanning 2017–2022. The lighting method uses the PICO analysis framework. The results found four components, namely: 1) automatic diagnosis; 2) 3-D ECG with artificial intelligence (AI) classification; 3) use of the LSTM deep-learning model; and 4) leads using Tpeak-End (Tp-e). In patients with heart problems, the initial examination is an EKG. Thus, the ECG, with the addition of the automatic diagnosis feature, EKG-3D, and the use of a 12-lead ECG with a deep-learning LSTM model, also followed by high sensitivity and specificity, can be used as a tool to perform examinations on patients who require serial ECG examinations. Keywords: Electrocardiogram; nursing care; nursing review; clinical symptoms; nursing assessment
Zenodo (CERN European Organization for Nuclear Research), Jun 21, 2023
Robotic technology has the potential to revolutionize the field of neurology by providing new met... more Robotic technology has the potential to revolutionize the field of neurology by providing new methods for diagnosis, treatment, and rehabilitation of neurological disorders. In recent years, there has been an increasing interest in the development of robotics applications for neurology, driven by advances in sensing, actuation, and control systems. This review paper provides a comprehensive overview of the recent advancements in robotics technology for neurology, with a focus on three main areas: diagnosis, treatment, and rehabilitation. In the area of diagnosis, robotics has been used for developing new imaging techniques and tools for more accurate and non-invasive mapping of brain structures and functions. For treatment, robotics has been used for developing minimally invasive surgical procedures, including stereotactic and endoscopic approaches, as well as for the delivery of therapeutic agents to specific targets in the brain. In rehabilitation, robotics has been used for developing assistive devices and platforms for motor and cognitive training of patients with neurological disorders. The paper also discusses the challenges and limitations of current robotics technology for neurology, including the need for more reliable and precise sensing and actuation systems, the development of better control algorithms, and the ethical implications of robotic interventions in the human brain. Finally, the paper outlines future directions and opportunities for robotics applications in neurology, including the integration of robotics with other emerging technologies, such as neuroprosthetics, artificial intelligence, and virtual reality. Overall, this review highlights the potential of robotics technology to transform the field of neurology and improve the lives of patients with neurological disorders.
Journal Of Biomedical Science And Bioengineering, Nov 15, 2022
This study aims at building a checklist used on each stage of wearable Elbow Exoskeletons develop... more This study aims at building a checklist used on each stage of wearable Elbow Exoskeletons development. The Wearable Elbow Exoskeleton is one of the hand stroke therapy aids which was developed by Diponegoro University. Te product is still in the form of a prototype so that some tests must be carried out before the product is tested on respondents. Test during this far is still focus on functionality test. This study provides a general checklist for ergonomics testing of stroke therapy aid products. Method of checklist is developed based on exploration study and literature review for producing appropriate test related to product characteristics. There are three iteration on development product and each version repair the previous version. The implementation of checklist shows that on third iteration, product is in accordance with objective of development and reach the targeted level of respondents' satisfaction.
One of the limbs that plays an important role for mobility is the leg. However, some persons with... more One of the limbs that plays an important role for mobility is the leg. However, some persons with disabilities, especially losing legs, have physical limitations that cause reduced mobility. Therefore, the development of artificial legs is very helpful for persons with disabilities in carrying out their daily activities. One of the above knee prosthetic products that has been developed by Diponegoro University is an above knee prosthetic with a mechanical joint. However, in the loading analysis process, only 100 kg load is used. So that in this study, a loading analysis was carried out using a ground reaction force. The results of the analysis of ground reaction force loading at the gait cycle 17% resulted in a maximum von Mises stress of 18.47 MPa, a maximum deformation of 0.11 mm and a safety factor of 14.94. While the gait cycle 47% produces a maximum von Mises stress of 20.88 MPa, a maximum deformation of 0.14 mm and a safety factor of 13.21. It can be concluded that the above knee prosthetic can receive the greatest load on the gait cycle 47% which is greater than the gait cycle 17%.
Journal of biomedical research & environmental sciences, May 1, 2022
Journal of Biomedical Research & Environmental Sciences main aim is to enhance the importance of ... more Journal of Biomedical Research & Environmental Sciences main aim is to enhance the importance of science and technology to the scientifi c community and also to provide an equal opportunity to seek and share ideas to all our researchers and scientists without any barriers to develop their career and helping in their development of discovering the world.
Eastern-European Journal of Enterprise Technologies
Multilayered Armor System (MAS) is being extensively studied around the world for its ability to ... more Multilayered Armor System (MAS) is being extensively studied around the world for its ability to retain ceramic fragmentation after a collision occurs. MAS consist of a ceramic layer placed at the front and supported by a composite layer of ramie-fiber-reinforced epoxy resin. Present study utilizes natural fibers of 50 % ramie fibers with epoxy resin as the matrix and Silicon Carbide (SiC) ceramic as the front panel. The ballistic testing in this study used 7.62×51 mm NATO Ball projectile with a firing distance of 15 m from the bullet panel. The velocity of projectile was detected using LIGHT SCREEN B471 type. The aim of the study is to conclude the optimal thickness of ramie fiber-epoxy and SiC ceramics MAS structure based on experiments which can withstand 7.62 NATO ball bullet penetration. To achieve this aim, the following objectives are accomplished: study the effect of SiC ceramic addition to ramie composite on BFS and study the effect of SiC ceramic addition to ramie composi...
The optimum condition for leaching calcined dolomite ore in aqueous hydrochloric acid solutions w... more The optimum condition for leaching calcined dolomite ore in aqueous hydrochloric acid solutions was determined in this study. The process parameters referred to the acid concentration, the temperature and leaching time. The leaching experiments were performed in a spherical glass batch reactor having a capacity of 1000 mL. The experimental results show that the calcined dolomite ore leaching efficiency increases with addition of acid concentration, temperatur and leaching time increases. The optimum results were achieved at 75 °C for 5 h, and the acid concentration of 2 M HCl. The leaching Seminar Nasional Metalurgi dan Material (SENAMM) X 2017
Journal of Biomedical Research & Environmental Sciences
Recent demand and interest in patient health monitoring has driven significant interest toward de... more Recent demand and interest in patient health monitoring has driven significant interest toward developing varies alternative rehabilitation monitoring instrument. Muscle power can be seen from how many power it’s generate from contraction effort that can be sense by its voltage potential in microvolt order. Surface Electromyogram (EMG) is used to take the record acquisition of muscle power data as patient take the rehabilitation program for some period. In this paper the surface EMG designed to get some level amplification to maintain the data readable and filter to minimize noise that always is the problem from instrument to get data. The aim of the research is to design compact surface EMG device that can be record data development of muscle power over time.
Salah satu anggota gerak tubuh yang berperan penting untuk mobilitas adalah kaki. Akan tetapi, be... more Salah satu anggota gerak tubuh yang berperan penting untuk mobilitas adalah kaki. Akan tetapi, beberapa penyandang disabilitas terutama kehilangan kaki memiliki keterbatasan fisik yang menyebabkan mobilitas berkurang. Oleh karena itu, perkembangan kaki tiruan sangat membantu penyandang disabilitas dalam melakukan aktivitas sehari-hari. Salah satu produk kaki tiruan atas lutut yang telah dikembangkan oleh Universitas Diponegoro yaitu kaki tiruan atas lutut dengan sendi mekanik. Akan tetapi dalam proses analisis pembebanan, hanya menggunakan pembebanan 100kg. Sehingga dalam penelitian ini, dilakukan analisis pembebanan menggunakan ground reaction force . Hasil analisis pembebanan ground reaction force pada gait cycle 17% menghasilkan tegangan von Mises maksimal sebesar 18,47 MPa, deformasi maksimal sebesar 0,11 mm dan safety factor sebesar 14,94. Sedangkan pada gait cycle 47% menghasilkan tegangan von Mises maksimal sebesar 20,88 MPa, deformasi maksimal sebesar 0,14 mm dan safety fact...
Roda gigi merupakan salah satu komponen mesin yang kompleks dalam proses perancangan dan pembuata... more Roda gigi merupakan salah satu komponen mesin yang kompleks dalam proses perancangan dan pembuatannya. Hingga saat ini, Usaha Kecil dan Menengah (UKM) produsen komponen otomotif di Jawa Tengah belum mempu memproduksi roda gigi untuk sistem transmisi sepeda motor yang mampu memenuh standar perusahaan otomotif nasional atau mampu menjadi komponen after sales di pasar komponen purna jual. Berdasarkan survey yang dilakukan di pasar purna jual di Semarang terhadap produk roda gigi transmisi sepeda motor, roda gigi transmisi yang dijual merupakan produk Original Equipment Manufacturer (OEM) atau produk impor dari China dan Taiwan. Berdasarkan survey di UKM, roda gigi yang diproduksi UKM lebih mengarah pada pesanan yang spesifik (customized) dan belum menjadi produk massal. Penelitian ini mencoba mendorong UKM untuk memproduksi roda gigi yang dapat diproduksi massal dan memberikan pesasanan secara kontinyu. UKM produsen roda gigi di Kecamatan Juwana, Kab. Pati, diberikan order pembuatan ro...
PROEFSCHRIFT ter verkrijging van de graad van doctor aan de Universiteit Twente, op gezag van de ... more PROEFSCHRIFT ter verkrijging van de graad van doctor aan de Universiteit Twente, op gezag van de rector magnificus, prof.dr. H. Brinksma, volgens besluit van het College voor Promoties in het openbaar te verdedigen op woensdag 6 november 2013 om 14.45 uur door Rifky Ismail geboren op 16 juli 1980 te Semarang, Indonesia Dit proefschrift is goedgekeurd door: de promotor: prof.dr.ir. D.J. Schipper de assistent-promotor: dr.ir. J. Jamari V Running-in of two fresh and unworn surfaces in contact is a transient phase where friction and wear vary considerably in time. During running-in the surface properties of the components are adjusted. If the initial surface roughness of the rubbing surfaces is correctly chosen, the running-in changes into the steady-state phase. At this stage, the rubbing surfaces are in general smoother and their wear rate is low and constant. On the other hand, an inappropriate choice of roughness may lead to a rapid deterioration of the rubbing surfaces. The micro-geometry of the surface is an important factor in determining the life of mechanical components. During the running-in phase, the highest asperities are "flattened", thereby increasing the number of asperities in contact and, as a result, increasing the load-carrying capacity of the surface. Fundamental studies that attempt to consider the details of running-in phenomena are relatively rare. This research is conducted with the aim of exploring the running-in phase for the rolling, sliding and rolling-sliding contact. Finite element simulations are conducted to calculate the stress distributions for the three types of contact motions during the running-in phase. The evolution of the contact pressure for a certain rolling or sliding distance is studied to unravel the running-in phase. During running-in of rolling contacts, the change in the surface topography results in the transformation from a rough surface to a smoother surface: the flattening of the high asperities induces a reduction in surface roughness. This flattening of asperities is due to plastic deformation and causes a higher equivalent residual stress at the surface. The transition of the running-in phase to the steady-state phase of a rolling contact is governed by the transition of plastic to elastic deformation on roughness level.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
The paper presents the development of wearable robot called supernumerary robotic fingers (SRF) t... more The paper presents the development of wearable robot called supernumerary robotic fingers (SRF) that can be integrated with 3D Animation. The robot comprises of two parts, robotic finger (RF) and robotic thumb (RT). RF is located next to little finger, and RT is located next to the thumb. The robot is driven by modified glove sensor. 3D CAD model is exported into SimMechanics for 3D Animation purpose under MATLAB/Simulink environment. Forward kinematics of the robot is studied using SimMechanics and the trajectory of each robotic fingertip will be calculated. Based on the experimental result, the robot and its 3D animation can be operated by a healthy person in real time. The robot can assist in object manipulation with ten-inch tablet using single human hand.
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