A Tunable Metamaterial Joint for Mechanical Shock Applications Inspired by Carbon Nanotubes

The significant developments of additive manufacturing and especially 3D-printing technologies have broadened the application field of metamaterials. The present study aims at establishing the main design parameters of a novel 3D-printed polymer-based joint. The proposed joint can efficiently absorb impact energy, relieving the material components from extensive plastic deformations. The design of the machine element is inspired by the molecular structure of carbon nanotubes and appropriately adjusted in such a way that it has the ability to partially transform translational motion to rotational motion and, thus, provide axial structural protection from compressive shocks. The utilized material is a photosensitive resin that is typically utilized in 3D manufacturing processes. Experiments are utilized to characterize the mechanical performance of the raw material as well as the static compressive behavior of the joint. Finally, finite element simulations are performed to test the developed design under impact loadings characterized by different frequencies. The damping capabilities of the metamaterial-based joint are revealed and discussed.

Fatigue Characteritics of Medium Carbon Steel after Heat Treatment Using Sand as Cooling Media

Stress concentrations cause many machine element failures. Failure will occur more rapidly if the machine elements obtain repeated and fluctuating loading. For this reason, the material for machine elements must have better fatigue life. There are various attempts made to increase material life and other mechanical properties. In this study, the research sample used is AISI 4140 steel. The samples obtain hardening followed by cooling and tempering. The hardening temperature is 8500C with a holding time of 17 minutes. The cooling media in this research are dry sand, semi-wet sand, and wet sand. Wet measurements based on volumetric ratios. Semi-wet sand with a ratio of sand and water 4: 1, sandy sand 4: 2. The final process is tempering treatment, with a temperature of 2500C. The material fatigue test refers to the JIS Z 2274 Standard. From this study, the heat treatment given can reduce the fatigue life of the material, even though the hardness increases. The higher the cooling rate, the hardness of the material increases, but the fatigue life is low.

Heat Treatment Consideration in Structural Simulations of Machine Elements: Analysis of a Starter Clutch Barrel

Consideration of heat treatment in simulations of structural components and its impact on predictions of behaviour during operation is analysed here. An automotive machine element with a complex geometry and dynamic load is analysed rather than a standard laboratory specimen under controlled conditions. The heat treatment analysis of a starter clutch barrel has been performed in DANTE followed by a structural analysis in ANSYS 2019 R3 during operation simulating a load cycle due to the start of an internal combustion engine. The heat treatment simulation consisted of carburisation, quenching and tempering. First, the carbon content and its distribution have been simulated. Next, the hardness of the starter clutch barrel and its distribution have been analysed with respect to the carbon distribution and hardness-dependent material properties of the AISI/SAE 4142 steel. Finally, the stress field after the heat treatment and during the operation of the starter clutch barrel has been thoroughly evaluated and compared to the simulation without the consideration of the heat treatment. Results of the simulation show that the heat treatment introduces favourable compressive stresses at the critical location of the starter clutch barrel and reduces the effective amplitude of the equivalent stress during the operation. Furthermore, the results of the simulation prove that heat treatment should be considered already during the early stages of the R & D process as it can have a decisive effect on the operational behaviour of the structural component. Moreover, a non-consideration of the heat treatment can lead into erroneous conclusions regarding the suitability of machine elements.

THE MANAGEMENT OF MEDICAL REPORT COMPLETENESS FOR THE LEGALITY OF MEDICAL RECORD DOCUMENTS AT RSUD KRMT WONGSONEGORO (RSWN) SEMARANG CITY

ABSTRACTBackground: Quality hospital services is reflected in the achieving of medical records. Improper medical record documentation would negatively affect the quality of service delivered to patients and it would disadvantage the hospital when medical disputes occur.Objective:Analyzing the management of medical record completeness at RSWN to guarantee the legality of medical record documents and its effect in supporting the completeness of medical record documents.Method:In this qualitative research, observation and interviews were conducted to 60 PJRM officers in the Arimbi ward, Banowati, Nakula I and Prabukresna. The obtained data were qualitatively and quantitatively analyzed based on several underlying theories.Results:The results showed that the completeness of some aspects includinghuman, money, method, material and machine elements was proper. The quantitative analysis showed 100%, while the qualitative analysis showed a percentage of 100% with the exception on the informed consent component with the potential for loss of 99%.Conclusions:The human element required periodic outreach to PPA. In the machine element, special computerswere needed for PJRM officers, and the importance of informed consent for patients undergoing hemodialysis to obtain medical records with strong legal force. Key Words :Management, Medical Record Completeness, Legality of Medical Records.

Pelaksanaan Penyimpanan Rekam Medis Berdasarkan Unsur Manjemen 5M di Puskesmas Medan Johor

The implementation of medical records carried out at the puskesmas requires management in managing all existing activities with the aim of creating good health services, in accordance with procedures and guidelines. To achieve the goal of processing medical records, 5 elements of management are needed, namely man, money, material, machine, and method. The purpose of this study was to determine the management elements of man, money, material, machine, and method in the implementation of medical records carried out at the Medan Johor Health Center. This type of research uses qualitative research methods with a phenomenological approach. The study was conducted from May to July 2020. The population was all medical record officers at the Medan Johor Health Center. The research sample amounted to 5 people who were taken by saturated sampling. The research instrument is an interview guide and recorded using an audio recorder and a check list sheet for observation. The results showed that the man element was 5 people and none of them had a medical record background and had never received training, the money element was the funding obtained from JKN and APBD, the material element was that a family folder was used to store all patient forms, while the use of tracers and register books has not been used to control the borrowed files out of the storage rack, and the filling cabinet is used as a tool to store medical record files, the machine element is a primary care application to register patients, the SIMPUS application is used for reporting, the method element is Not all SOPs in medical records exist. The advice given is to provide training to medical record officers so that their officers better understand the importance of medical records.

Fatigue Analysis of Actuators with Teflon Impregnated Coating—Challenges in Numerical Simulation

Actuators are essential components for motion in machines, and warranty service lives are basic specifications of actuators. However, fatigue damage or wear of actuators are very complex and related to many design factors, such as materials properties, surface conditions, loads, and operating temperature. Actuator manufacturers still rely heavily on physical experiments to determine the fatigue lives of actuators. This paper investigates the state-of-the-art of using numerical simulations for fatigue analysis of mechanical actuators. Failure criteria of machine elements are discussed extensively; existing works on using finite element methods for machine element designs are examined to (1) explore the feasibility of using a numerical simulation for fatigue analysis and (2) discuss the technical challenges in practice. Moreover, a systematic procedure is suggested to predict fatigue lives of mechanical actuators with Teflon impregnated hard coatings. A virtual fatigue analysis allows for optimizing a mechanical structure, reducing design verification costs, and shortening the development time of actuators.