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This paper studied the impact of using CuO nano-particles of 50nm size in a Vapor Compression Refrigeration System (VCRS), along with Poly-alkylene Glycol (PAG) oil, and R-134a mixed to form a nano refrigerant. In this work, the nanoparticles were performed in three different volume fractions (0.1%, 0.3%, and 0.5%) and mixed with 200ml of the PAG oil. A VCR system was built at the mechanical engineering department laboratory in al-qadisiyah University to study the Coefficient of Performance (COP) and the system's energy consumption with and without the addition of the nanoparticles. The paper resulted in a raise in systems COP by 41.7% when using concentration of 0.5% of CuO/PAG oil/R-134a and a reduction in the power consumption by 24.32% compared to when using a pure R-134a/PAG oil. Also, the nano refrigerant appeared to be safe, harmless, and more efficient for use in vapor compression systems. [ABSTRACT FROM AUTHOR]

Machine maintenance is the means by which mechanical assets in a facility are kept running with their optimal working performance in their lifetime. In order to be able to carry out machine maintenance work properly, an engineering graduate as one of the maintenance staff must understand the concept of machine maintenance correctly. Through machine maintenance and repair learning material, mechanical engineering students were provided with knowledge of the mechanical maintenance concept and it's implementing activities. Since the learning materials of mechanical maintenance concept and its activities are theoretical mostly, most the students have difficulties in learning the topic and they tend to memorize the subjects. That circumstance caused a low understanding of the concept of machine maintenances on students. Based on the literature study and prior research one of the methods that can be used to improve students' understanding of theoretical learning materials is through the application of the most proper learning model suitable to the learning topics. The purpose of this study is to obtain information on students' perceptions of the machine preventive maintenance concept and its activities through the application of a contextual-based collaborative learning model for mechanical engineering students. The Quasi-experimental method with two groups of pre-test and post-test design was adopted for this research. The study involved 65 mechanical engineering students which were divided into two groups, namely the control and the experimental classes. The control class is a group of students who carry out teaching and learning by a teacher-centered learning strategy, while the experimental class is a group of students that receive learning treatments using a contextual-based collaborative learning model. Next, to investigate the learning model effects statistical parametric analysis was carried out at pretest and posttest results of both two classes. The "Normalized gain" analysis result of both two classes was obtained as follows: the control class score was 0. 23 while the experiment class' Gain score was 0.73. Based on these study showed that the gain of the experiment class is higher than the control class. The value 0f 0.73 indicate that the contextual-based collaborative learning model is effective in increasing students' understanding of mechanical maintenance learning materials. [ABSTRACT FROM AUTHOR]

The paper considers the issues of wastewater treatment of mechanical engineering enterprises of the rocket and space industry using immobilized microorganisms. Based on the analysis of the process, its hardware design with subsequent development of bioflotation machine is selected, which can significantly reduce capital and operating costs, as well as areas for the placement of treatment facilities. At the same time, the efficiency of the wastewater treatment plant itself, which has a diverse component composition, can be significantly increased. [ABSTRACT FROM AUTHOR]

The article analyzes the experience of organizing distance education, obtained in 2020-2021 in the context of a temporary transition to distance education by the dean's office of the faculty "Special Mechanical Engineering" (SM) of the Bauman Moscow State Technical University, who prepares students for a wide range of undergraduate programs, specialty in the field of "Rocket and Space Engineering and Technology" in more than 50 different specializations. [ABSTRACT FROM AUTHOR]

The paper analyzes the experience of conducting classes with the help of distance learning technologies, obtained in 2020-2021 in the context of the use of anti-epidemic restrictions by the faculty of Special Mechanical Engineering of Bauman Moscow State Technical University, who prepares students for a wide range of undergraduate, graduate and specialty programs in Rocket and Space Engineering and Technology in more than 20 different specializations. [ABSTRACT FROM AUTHOR]

The article analyzes the experience of monitoring the progress and certification of students using distance educational technologies (DET), obtained in 2020-2021 by teachers of the faculty of Special Mechanical Engineering, Bauman Moscow State Technical University, who trains students in a wide range of undergraduate, graduate and specialty programs in Rocket and Space Engineering and Technology in more than 20 different specializations. [ABSTRACT FROM AUTHOR]

The article describes the state of modern finance in mechanical engineering, lists the subjects of mechanical engineering by region of activity, analyzes stock prices and financial indicators of individual public enterprises in the industry. The need to achieve an optimal balance of financial position and financial results within formation of the register of groups of engineering enterprises, with provision of access to group information, as an indicator of sustainable development, is indicated. It is the optimal ratio of the financial position and financial results of an individual enterprise and the entire group that is a key indicator of the sustainable development of the industry. Continuous monitoring of investments and purchases, reduction of indirect costs, targeted government financing of machine-building enterprises and clusters, while preserving the regions of their activity and increasing the share of machinery and equipment in fixed assets, a sound pricing strategy are the priorities of modern engineering finance. [ABSTRACT FROM AUTHOR]

Technological processes during machining stay one of the most common in a wide variety of mechanical engineering industries. Equally important indicators of the quality of these technological processes are their energy efficiency, which characterizes the consumed electrical energy. The article presents experimental studies of environmental indicators of the technological equipment quality and offers a methodology that allows to minimize the value of their impact on the environment and humans during machining process, by managing the energy consumed. [ABSTRACT FROM AUTHOR]

Outcome based education (OBE) is upcoming system in the fields of education in present era. Assessment in OBE is important task to measure the performance of each course outcome of the course. The Performance indicators and the specific rubrics also plays important role in tracing the exact cause of failure of the outcomes. Reflection on failure course outcome and action item to improve the performance of the students on the respective course outcome by applying the different teaching technique is challenging task. In this research work the performance of the students in mechanical engineering course Machine Design-II (ME 413), Automatic Control (ME 415) and Mechanical Vibrations (ME 317) is assessed. The mechanical vibration is chosen as a sample course to design the process of identifying the failure cause and implement the different teaching techniques to close the action item with improved results of the failed course outcomes. The EvalTool is used to generate the mapping of course outcome, performance indicators and ABET students' outcomes and FCAR (Faculty Course Assessment Report) to identify the failure cause of the performance of course outcomes of students on each course-outcome of the course which is generated electronically. It is observed that the failure course outcome can be easily traced and by implementing the action items (defer action items) the students' performance is improved. The average value of EAMU increased from 2.44 to 3.57 in the term 391 and further 4.52 in.the term 411 and the student's evaluation in the term 391 was 69% and student's evaluation to the self-evaluation is 89.64%. Whereas, in the term 411 student's response rate is 57.14% and self-evaluation to the student's response is 105.55%. The student's evaluation increased around 16% by changing the teaching techniques. [ABSTRACT FROM AUTHOR]

Composite materials are widely used in mechanical engineering, aviation and other fields of technology. Composite materials often work in such conditions where the possibility of shock loading is not excluded. Therefore, it is important to know the dynamic characteristics of composite materials. This article investigates the problem of elastic wave diffraction with respect to a rigidly embedded slot in a fibrous composite material of periodic structure. An analytical solution of the problem is obtained in the framework of the long-wave approximation method. [ABSTRACT FROM AUTHOR]

Hydrophobicity is the property of a material to repel water when in contact. Hydrophobic events occur naturally in some plants and animals that are very interesting to study. To further examine the uniqueness of its hydrophobic properties, it is necessary to investigate its application in the field of mechanical engineering. This study investigated the effect of volume variation and surface slope on three types of leaves: lotus leaf (Nelumbo nucifera), cassava leaf (Manihot esculenta) and kapok banana leaf (Musa paradisiaca L leaf). Water droplets were dripped with a novarapid flexpen and then the contact angle was measured using Hiview software. Droplets were varied in volumes of 1-5 ml and the inclination of the material with angles: 0°, 30° and 45°. The results of this study indicate a decrease in the droplet contact angle with increasing droplet volume. Variations in the slope of the leaf surface cause the contact angle to increase, this is influenced by the unconcentrated gravitational force. The benefit of this research is to investigate the effect of droplet contact angle when interacting with fluid droplets. This research was applied to determine the effect of the slope of the hydrophobic material on the car glass application. [ABSTRACT FROM AUTHOR]

A joint curriculum between two or more universities is a program developed in order to increase the capability of graduates with broadened knowledge in their field, taste an international atmosphere and also increase their networking for the global challenges. As a part of internationalization strategy, this program can be described as the exchanges of teaching/learning process and the new knowledge between the countries. These programs are built on the principle of deep academic collaboration and bring important benefits to students (individuals), institutions, national and regional education systems. Institut Teknologi Nasional Bandung (ITENAS Bandung) – Indonesia and Hungarian University of Agricultural and Life Sciences/Magyar Agrár és Éllettudományi Egyetem (MATE) – Hungary, have been initiated to develop a joint curriculum program, since 2018, when ITENAS Bandung got a competitive RISTEKDIKTI grant (Ministry of Research, Technology and Higher Education of the Republic of Indonesia) to develop a joint curriculum of Mechanical Engineering, for the MSc Program. The prerequisite to establish this program, both universities should have a great relationship, at first. The process was carried out by mapping and harmonizing the curriculum (evaluation of the course subjects each semester) while comparing the learning achievements, arrangement the difference of credit number and definition in both universities. Furtherly, this concept is enabling students from ITENAS and MATE take part the mobility program (reciprocal principle), and possible to get a Joint/Double Degree, with predetermined rules, and in the end of study, the students will get 2 (two) certificates (from ITENAS and MATE). At the implementation level, both universities should ensure that the structure of the joint curriculum program may not cause an extension of the study period of the students. [ABSTRACT FROM AUTHOR]

Various elastic elements are widely used in mechanical engineering structures: springs, shells, membranes, etc. In this case, the most widespread are springs - an elastic element designed to create a concentrated load. The spring can be made of any material with sufficiently high strength and elastic properties (steel, nickel, titanium alloys, bronze, plastic, wood, etc.). The main material for the manufacture of springs is spring steel (steel 70, steel 65G, steel 55S2, steel 50HFA, steel 60S2XA, etc.). The following requirements are imposed on the springs: high strength and elasticity, reliability of operation, high relaxation resistance and cyclic endurance, the ability to maintain their technical characteristics when working in various environments. [ABSTRACT FROM AUTHOR]

This paper presents results of determining the effect of technological deviations on the limit state in mechanical engineering, on example of shell type equipment using digital model. Development of a model that takes into account accurate geometric features, distribution of physical and mechanical characteristics and behaves like real object under influence of operating parameters is one of the most promising areas for reducing production risks. Three cylindrical shells made of steel 09G2S according to the same design scheme were chosen as the object of research. Comparison and analysis of results of loading by internal pressure until destruction of three shell models with ideal model shows that even permissible technological deviations contribute to a significant redistribution of stress and affect limit state. Potential zones of destruction are formed, the internal pressure required for destruction decreases. Destruction of all three models occurred in different places of shell under different conditions. Taking into account peculiarities of shells, timely identification of potential destruction zones and use it during technical examination will reduce the risk of an accident. [ABSTRACT FROM AUTHOR]

Robotic manipulators have long been used in industries due to its capability to perform various tasks that require high precision and repetitive in nature. Besides, robotic manipulations are also ideal for applications in the environment that is not conducive to human. With the emerging of Industry 4.0, robotic manipulators are expected to play more important role in the manufacturing sector as higher productivity is required. For that, many robotic related courses have been offered at the undergraduate level to equip students with knowledge of this technology. To understand the technology, demonstration using an actual robotic manipulator setup is necessary. Nevertheless, acquiring setup of the manipulator is quite expensive and if purchase, the quantity and access to the manipulator will be limited. As a result, sufficient amount of time will not be provided for students to explore and learn how the robotic manipulator is actually working. Alternatively, simulator can be used as a learning tool to understand the robotic manipulator. Besides cost-effective, students have unlimited access at their own convenient time. Utilizing the Project Based Learning (PjBL) approach, this paper is written to provide essential information for the final year undergraduate mechanical engineering students of Universiti Tun Hussein Onn Malaysia to build their own path control robotic simulator. At the end of semester, students will be presenting their simulator in group for evaluation purpose. The best simulator will be selected as a learning tool and subject to further improvise in the upcoming semester. [ABSTRACT FROM AUTHOR]

COVID-19 has affected the lifestyles of entire populations around the world. In the academic sector, the government-mandated instruction has changed the pattern of the teaching and learning landscape. Learning styles have changed completely from face to face to the use of virtual mediums. This situation does greatly affect the level of readiness not only to the lecturers but also the students. Assignments involving individual work may be less challenging compared to assignments involving group projects. Therefore, this study was conducted to understand the difficulties and challenges faced by lecturers and students in the implementation of group projects in this pandemic phase. Informal interviews and data collection via survey have been performed to understand the impact of this new norm towards group project particularly in Mechanical Engineering field. Findings showed that online group project in this pandemic phase is complicated as lack of communication effectiveness. In addition, due to lack of physical presence, some important aspects particularly related to technical issues are difficult to be solved. In conclusion, the balance between the goals set in the project as well as the challenges faced by students and lecturers need to be considered to ensure the smooth implementation of group projects. Empathy is one of the necessary elements that been taken in this study. The setting of communication guidelines between group members and supervisors is recommended for online group project if this similar situation happen again in the future. [ABSTRACT FROM AUTHOR]

Today belt transmissions are popular in different areas of mechanical engineering, due to the lowest cost at high reliability, which are provided by the simplicity of design and high indicators of its parts manufacturability. The belt transmission consists of the following parts: a belt, a drive pulley and a driven pulley (additional parts may also be used). Determination of values, directions and points of interaction forces application of these parts will allow evaluating the efficiency of belt transmission. The analysis of interaction by calculation-graphical method of determination all forces acting in the belt contour plane will simplify their finding. It is necessary to take into account peculiarities of elastic belt operation on rigid pulleys and the way of its preliminary (initial) tensioning. Using of this method will allow accurately estimate parameters of belt transmission operation and simplify its design with the necessary indicators. [ABSTRACT FROM AUTHOR]

This study aims to reveal the competency needs of operators in the field of mechanical engineering expertise in the form of a model framework. The aspect that contains the model framework is integrating knowledge, attitudes, and skills to produce competent operator graduates. This research design uses the research and development of the Richey & Klein model with the stages of study analysis, planning, data collection, and model formation. The sample used was 25 teachers and 120 students in the province of Banten, Indonesia. Collecting data using interviews and analyzed with a qualitative approach. The results of the research show that the operator competency is made a model framework that integrates aspects of knowledge, attitudes, and skills. The competency model framework is the basis for learning that emphasizes mastery of basic machining science, has good self-quality individually and socially, and is able to make products in the field of machining engineering. Teachers and students become comprehensive in the learning process to produce professional operators. [ABSTRACT FROM AUTHOR]

This research aims to determine the differences in student achievement in Manufacturing Drawing Engineering by applying handouts and video learning media. This research approach uses a quasi-experimental method of non-equivalent control group design. The topics in the study were students of class XII in Mechanical Engineering at the Muhammadiyah Prambanan Vocational High School, which were divided into two research groups. The first experimental group applied handout learning media in class XII TPA and the second experimental group applied video learning media in class XII TPC. The data collection technique used was a multiple-choice test before treatment (pre-test) and after treatment (post-test). The results of data analysis showed that the increase in learning outcomes based on the difficulties that had been carried out in the first experimental group was 20.73. As for the increase in learning outcomes in the second experimental group, that is equal to 23.82. This research shows an increase in learning achievement using video learning media which is slightly better than using handout media. [ABSTRACT FROM AUTHOR]

This research aims to produce quality interactive learning modules as a source of learning pneumatic system courses and to know the feasibility level of interactive learning modules as a source of learning pneumatic system courses. The method used is Research and Development (R&D) with ten stages. The researfourth-semester students of Manufacturing Engineering, Department of Mechanical Engineering, Faculty of Engineering, UNY. The data collection technique used is a questionnaire system. E-module products can be used in d digital devices such as laptops. The material presented in the e-module is the Basic Pneumatic System. The material's content is SKKNI C.28LOG18.018.2, along with the syllabus. E-module products obtain a feasibility value that is very feasible to be used as a learning process. The feasibility value can be reviewed from the validation of material expert lecturers of 3.48, categorized as very feasible. Validasi lecturer media experts by 3.6 with the category very feasible. Hasil respondents of learners amounted to 3.56 with very proper categorization. Based on these categories, the presence of e-modules received a positive response from students and lecturers. E-modules can be interesting to read and use today as a medium of learning. [ABSTRACT FROM AUTHOR]

A good understanding regarding occupational Health and Safety needs to be owned by someone to avoid work accidents in carrying out work activities. This study aims to produce an Android-based media containing work accident control material for vocational high school students in Yogyakarta. The type of research used is R&D (Research and Development), referring to the Four-D model (define, design, develop, disseminate). The research subjects were 36 students of class X TP2 of the Mechanical Engineering program at State Vocational High School 3 Yogyakarta in the 2020/2021 academic year. This study shows that the developed Android-based media product has six main menus: instructions, competencies, materials, evaluations, references, and profiles. The assessment results by media experts show that the android-based media produced is in the very decent category. While the results of the assessment by material experts showed that the android-based media produced was in the very decent category. Finally, the assessment carried out in the field trial showed that the android-based media produced was categorized as very decent. [ABSTRACT FROM AUTHOR]

Increasing the competence of graduates of course requires adequate facilities and infrastructure, especially practical tools in accordance with the Law of the Republic of Indonesia Number 20 of 2003 concerning the National Education System. Therefore, the purpose of this study was to measure the feasibility of practicum facilities and the level of competence of class XI students of Mechanical Engineering at SMK Muhammadiyah 1 Bantul. The results can be used as evaluation material by schools or foundations. This study used a descriptive method with a quantitative approach which is then described qualitatively. The subject were teachers of lathe subject, head of the Mechanical Engineering Department. The research objects included: the feasibility of buildings, furnishings, equipment, instructional media, and other devices as well as the level of competence of students' lathes. Data collection used observation, interviews, and documentation technique. The instruments used were observation instrument sheets and interview instruments. The data analysis technique used descriptive statistical analysis technique. Based on the results of the research that has been done, the feasibility of the lathe machining workshop facility at SMK Muhammadiyah 1 Bantul reached 72.5% so that it was included in the feasible category to support the formation of students' lathe competencies. The mean score of participants in the lathe subject was above the Minimum Graduation Criteria (MGC). This means that the competency standard for turning students of class XI Mechanical Engineering at SMK Muhammadiyah 1 Bantul has been achieved. Similar research is needed for other competencies that must be fulfilled by vocational students in the field of Mechanical Engineering so that they can be used as evaluation materials to improve the competence of graduates who are ready to face the Industrial Revolution Era 4.0. [ABSTRACT FROM AUTHOR]

This paper is focused on measuring static characteristics of two coaxial contra rotating propellers (CRP). This particular measuring is a part of the complete design of the UAV VTOL tailsitter aircraft, which is developed at The Institute of Fluid Mechanics and Thermodynamics of the Faculty of Mechanical Engineering of the Czech Technical University. The measurement target is to verify correctness of the numerical design method used for measured propellers and then to find the data necessary for maximalization of the power efficiency of the designed UAV. The specificity of measured CRP is a different diameter of the propellers and a different design point. The bigger 22" propeller is designed to provide sufficient thrust for vertical take-off and landing. The smaller one, 16" propeller, is optimized for a horizontal flight with constant speed, however it contributes to achieve sufficient thrust in a vertical position as well. For the measurement of these propellers, a laboratory measuring device was designed and assembled. This device allows the propellers to be measured separately or together and the propellers can also be measured in an open space as well as integrated in the aircraft. In both cases the propellers take the same position in the space and therefore the same position relatively to each other. The first part of the measurement is focused on measuring static characteristics of each propeller separately. The measured data was compared with the design static characteristics calculated with 3D panel method, thus the accuracy of used numerical design method was determined. In the following part of the measurement, the propellers were integrated in the aircraft and all measurements were repeated. In this configuration it is possible to determine thrust losses caused by the aircraft body. Another important point of measurement is to determinate optimal propeller rpm ratio for the lowest possible power consumption and propeller rpm ratio when the final torque on a propeller axis is zero. This data is essential for subsequent tuning of the autopilot unit. [ABSTRACT FROM AUTHOR]

The vibration study of the cycloidal gear and the prevention of vibrations are important issues in the field of mechanical engineering. Cycloidal gears are used in many different applications, including industrial machinery, industrial robots and medical devices. Vibration tests of the cycloidal gear consist in identifying the sources of vibrations and determining their characteristics. As a result of the conducted research, the sources of vibrations can be identified and strategies for their reduction can be developed. Vibration studies of the cycloidal gear include spectral analysis, time-frequency analysis, vibration analysis, as well as verification of the impact of using other control methods (e.g. microstep control) on the generation of vibrations. A cycloidal gear made in 3D printing technology was used in the research. Ultimately, the gearing is to be used to move the robot's arm. The purpose of the research is to analyze vibrations, which will be used to control the robot to minimize vibrations, which will positively affect its accuracy and life. Ultimately, an active vibration monitoring system will be developed, where an Arduinotype microcontroller will be used. This system will monitor and warn against vibrations of dangerous amplitude. For the correct implementation of this system, tests will be carried out to compare the accuracy of the measurement using the developed system based on Arduino and the professional Digiducer 333d01 sensor. [ABSTRACT FROM AUTHOR]

In the field of mechanical engineering, achieving precise measurements of small-module gears and transmissions is critical. This paper presents an innovative non-contact method for assessing the accuracy of these components, based on optic-electronic signal processing principles. It offers superior precision in evaluating gear geometry, pitch, and profile. With recent advancements in gear manufacturing, there is a growing need for efficient and precise measurement methods to ensure optimal performance and durability. Traditional tactile methods and double-flank inspections have limitations, including potential subjective errors. This paper addresses these challenges by providing a comprehensive solution that not only enhances measurement accuracy but also sheds light on the relationship between production variables and gear precision. This study is significant for delivering high-precision gear assessments, revealing production-precision links, reducing subjective errors, highlighting automation potential, and contributing to the discourse on mechanical precision in gear-dependent industries. Drawing from foundational research in gear measurement, optic-electronic signal processing, and manufacturing automation, its primary aim was to determine if non-contact methods improve smallmodule gear measurement. Through rigorous analysis, this study unequivocally affirms this question, advancing gear and transmission measurement and control. [ABSTRACT FROM AUTHOR]