scholarly journals Design of Travelling-Wave Rotating Ultrasonic Motor under High Overload Environments: Impact Dynamics Simulation and Experimental Validation

2019 ◽  
Vol 9 (24) ◽  
pp. 5309 ◽  
Author(s):  
Jiaojiao Zhang ◽  
Lin Yang ◽  
Haisong Chen ◽  
Chengcheng Ma ◽  
Xinmin Shen ◽  
...  
Keyword(s):  
Performance Test ◽  
Impact Test ◽  
Variable Structure ◽  
Travelling Wave ◽  
High Impact ◽  
Dynamics Simulation ◽  
Ultrasonic Motors ◽  
And Performance ◽  
The Impact ◽  
Disc Spring

Nowadays, piezoelectric actuators are widely used, but are rarely applied in high overload environments due to th difficulty implementing them. Traveling wave rotary ultrasonic motors (TRUMs) have the characteristics of variable structure and are insensitive to overload, endowing them with the potential ability of high overload resistance. In this study, four TRUMs with different rotor structures are designed to work under the high-impact acceleration of 10,000 g through modifying the rotors with a designed slotted disc spring. The dynamics model is established, the impact process is simulated, and the results are analyzed successively. The high-impact test, deformation measurement and performance test of the motors are carried out to verify the modification. The results show that performance of the TRUMs with a disc spring declines much less than those without a disc spring after the high-impact test. The TRUM-4 with the modified rotor and disc spring has the best performance, the speed of which decreased only 1.6% at the torque of 0.15 N m, and it is considered to be capable of withstanding the high acceleration of 10,000 g. This work is significance for guiding the ultrasonic motors’ optimization to expand their application in high-overload environments.

scholarly journals The Impact of Applied Research: Student Research as a High Impact Practice in Freshman Environmental Science

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Billy Morris
Keyword(s):  
Applied Research ◽  
Environmental Science ◽  
Research Question ◽  
High Impact ◽  
Stem Majors ◽  
Research Questions ◽  
And Performance ◽  
Science Major ◽  
High Impact Practice ◽  
The Impact

Abstract: Non-STEM-majors in a freshman elective Science course, Environmental Science 1, were given the opportunity to identify a research question using the course objectives as a guideline. Their research questions and investigations served to fulfill the lab component of the course in lieu of a lab manual. Students were asked to choose a question of interest that could be researched on campus. Student partnerships were encouraged, and a class of 17 students produced 11 research projects. Frequent interactions with the Instructor and peers resulted in lively discussions, new questions, and high levels of student engagement and performance. This approach to laboratory work in a non-science major course can be duplicated when access to resources and instructor/student ratio allows.

On the Development and Performance Test of Combined Packing Integrated Device for Treating Domestic Sewage Aboard Ships

2011 ◽  
Vol 66-68 ◽  
pp. 2153-2157
Author(s):  
Zhi Li Chen ◽  
Kai Sheng Xiong ◽  
Wan Tu Zhang ◽  
Wen Biao Wang ◽  
Wen Ping Chen ◽  
...  
Keyword(s):  
High Speed ◽  
Performance Test ◽  
Simulation Experiment ◽  
Sewage Treatment ◽  
High Specific Surface Area ◽  
Domestic Sewage ◽  
Raw Water ◽  
And Performance ◽  
Integrated Device ◽  
The Impact

This paper elaborates on the development of elastic combined packing and an integrated device for treating domestic sewage aboard ships, analyzes the growth of combined packing microorganisms, the speed of membrane forming as well as the impact of raw water quality on membrane forming, and conducts a simulation experiment of treating domestic sewage by membrane bio-reactors. Researches show that elastic combined packing features high specific surface area and high speed of membrane forming and that this integrated domestic sewage treatment device performs well and can be widely applied.

Design and tests of a non-contact Bernoulli gripper for rough-surfaced and fragile objects gripping

2020 ◽  
Vol 40 (5) ◽  
pp. 735-743
Author(s):  
Dong Liu ◽  
Minghao Wang ◽  
Naiyu Fang ◽  
Ming Cong ◽  
Yu Du
Keyword(s):  
Negative Pressure ◽  
Simulation Analysis ◽  
Structural Parameters ◽  
Mathematic Model ◽  
Parameters Optimization ◽  
Dynamics Simulation ◽  
Content Type ◽  
Design And Optimization ◽  
And Performance ◽  
The Impact

Purpose Varied shapes and sizes of different products with irregular rough surface and fragile properties give a challenge to traditional contact gripping. Single Bernoulli grippers are not suited to handle fragile objects as the impact of center negative pressure force could result in large deformation and stress which damage the materials, and they are also have some limitations for gripping objects with different large and small shapes. Thus, this paper aims to design a non-contact gripper for soft, rough-surfaced and fragile objects gripping with multi Bernoulli heads, which have optimal structures and parameters. Design/methodology/approach The compressed air is ejected into four Bernoulli heads through radial and long flow channels, then passes through four strip-shaped narrow gaps after fully developing in the annular cavity to provide negative pressure. Based on the mathematic model and the computational model, the key structural parameters affecting the gripping performance are selected, and parameters optimization of the gripper is performed by computational fluid dynamics simulation analysis and performance evaluation. The orthogonal method is used and L16 orthogonal array is selected for experimental design and optimization. The characteristics of the designed gripper are tested from the aspects of pressure distribution and lifting force. Findings From the applications in gripping different objects, the designed non-contact gripper can grip varied shapes and sizes of soft, rough-surfaced, fragile and sliced objects with little effect of torque. Originality/value In this paper, a non-contact gripper is designed for handling soft, rough-surfaced and fragile objects based on the Bernoulli principle. A systematic approach, which consists of modeling, simulation, optimization and measurement is provided for the non-contact gripper design and tests.

The impact of ultraviolet light exposure on the performance of polybenzidimazole and polyaramid fabrics: Prediction of end-of-life performance

2017 ◽  
Vol 48 (1) ◽  
pp. 77-86 ◽  
Author(s):  
Shadi Houshyar ◽  
Rajiv Padhye ◽  
Sandip Ranjan ◽  
Steve Tew ◽  
Rajkishore Nayak
Keyword(s):  
End Of Life ◽  
Residual Strength ◽  
Ultraviolet Irradiation ◽  
Protective Clothing ◽  
Performance Test ◽  
Light Exposure ◽  
Test Results ◽  
And Performance ◽  
The Impact ◽  
Frequent Exposure

This study evaluated the deterioration in thermo-mechanical and performance properties of the polyaramid and polybenzidimazole fabric used in firefighters’ protective clothing after exposure to ultraviolet irradiation, and the effect of weathering. The performance of firefighters’ protective clothing plays an important role in protection against heat and physical threats to firefighters. However, frequent exposure to heat and ultraviolet irradiation can deteriorate performance. Test results demonstrated a 79% drop in the residual strength of polybenzidimazole/Kevlar® fabric and a 51% drop in the residual strength of polyaramid (Nomex® IIIA). The results confirmed that heat accelerates the degradation of PBI, resulting in lower performance, an important consideration for firefighters’ protective clothing. In this study, a new ‘UVPro-Tex’ sensor was developed, with the capability to record the amount of ultraviolet irradiation absorbed by the fabric. When the amount of the absorbed ultraviolet irradiation reaches a critical value, the sensor warns the wearer of the end-of-life of the garment.

Research on Structure Design and Performance Test of Electromagnetic Shielding Clothes

2011 ◽  
Vol 383-390 ◽  
pp. 6508-6513
Author(s):  
Yan Li ◽  
Wen Bin Zhang
Keyword(s):  
Performance Test ◽  
Orthogonal Experiment ◽  
Variable Structure ◽  
Structure Design ◽  
Electromagnetic Shielding ◽  
Woven Fabric ◽  
Structure Parameters ◽  
Steel Core ◽  
Spun Yarns ◽  
And Performance

Based on the theory analysis of electromagnetic shielding mechanism and structure design, a woven fabric with stainless steel core-spun yarns is selected. Several sets of shielding clothes with variable structure parameters are designed and manufactured through orthogonal experiment method. An experimental platform has been set up to measure the shielding efficiency of the shielding clothes in key parts. With direct and variance analysis identify the significant structure parameters which influence the shielding performance, so as to provide a theory basis for the optimization structure design of electromagnetic shielding clothes.

scholarly journals Impact of Flipped Classroom on Mathematics Learning Outcome of Senior Secondary School Students in Lagos, Nigeria

2020 ◽  
Vol 9 (2) ◽  
pp. 23-42
Author(s):  
Semiu Olawale Makinde
Keyword(s):  
Secondary School ◽  
Flipped Classroom ◽  
Secondary School Students ◽  
Performance Test ◽  
Learning Outcome ◽  
School Students ◽  
Senior Secondary School ◽  
And Performance ◽  
Senior Secondary ◽  
The Impact

This study examined the impact of the flipped classroom on the learning outcome of secondary school students in mathematics in Lagos, Nigeria. It examined the impact of a flipped classroom package (FCP) on post-test performance (PP) and retention performance (RP) of students in Mathematics; it also sought to determine the influence of gender on PP and RP of students towards learning mathematics in the flipped classroom (FC). This is in response to the search for means to reverse the poor performance of students in mathematics O’level West African Secondary School Certificate Examinations. The flipped classroom, an innovative teaching technique, was introduced as a possible corrective that could produce effective student learning engagement and performance. A Quasi-experimental design was adopted and 275 Senior secondary school (SSS) 2 Students, 147experimental and 128 as control (conventional) intact classes, constituted the purposive sampled population for the study. Three research instruments: Flipped Classroom Package, Lesson Note and Performance Test were validated by expects and used for the study. The instruments were also checked for reliability; and the inter-rater reliability coefficient of a developed FC package was 0.79; lesson note, 0.83; and test instrument 0.85. Four hypotheses were raised and tested after 6 weeks of the experiment. The results of the findings indicated that the flipped classroom encourages good performance in mathematics and should, thus, be encouraged in schools for being a student centred learning approach. The study concluses among others that teachers should be encouraged to attend seminars and workshops on the use of the approach for effective performance of the learners.   

Benchmarking Indian ceramic enterprises based on green supply chain management pressures, practices and performance

2018 ◽  
Vol 25 (9) ◽  
pp. 3628-3653 ◽  
Author(s):  
Kailash Choudhary ◽  
Kuldip Singh Sangwan
Keyword(s):  
High Impact ◽  
Green Supply Chain ◽  
Medium Size ◽  
Small Enterprises ◽  
Content Type ◽  
Export Activity ◽  
Implementation Level ◽  
And Performance ◽  
The Impact ◽  
Enterprise Size

Purpose The purpose of this paper is to identify and analyze the impact of green supply chain management (GSCM) pressures, implementation level of GSCM practices and improvement in performance of the Indian ceramic enterprises. The paper also aims at benchmarking the Indian ceramic enterprises based on enterprise size and market orientation (export activity). Design/methodology/approach The research is based on the empirical study of Indian ceramic industry. Propositions are developed to study: the impact of GSCM pressures, implementation level of GSCM practices, improvement in GSCM performance, and the effect of GSCM pressures on implementation of practices, and impact of GSCM practices on GSCM performance. Data are collected from Indian ceramic enterprises of different sizes. Exploratory factor analysis is performed to segregate the pressures, practices and performance variables into constructs. Two-step algorithm, with log-likelihood measures of distance and Bayesian information criterion, is used to decide the optimal number of clusters. These clusters are compared and benchmarked according to the enterprise size and export activity. Findings This study finds that the implementation level of GSCM practices is higher in large- and medium-size enterprises as compared to small-size enterprises. Large- and medium-size enterprises have high impact of mimetic and informative pressures and small enterprises have high impact of coercive pressure (CP). Although the CP is high on small enterprises but due to the limited resources, these enterprises cannot afford to implement GSCM practices. The implementation of GSCM practices results into the improvement of environmental and operational performance but decrease in economic performance. Practical implications The findings of this study will suggest the policy maker to encourage the diffusion mechanism through a collaborative partnership with larger enterprises to enhance the implementation level of GSCM practices in small-size enterprises. Originality/value The novelty of the paper are: it analyzes and benchmarks GSCM pressures, practice and performance for Indian ceramic enterprises by considering enterprises size and export activities as control variables, and it finds the effect of GSCM pressures on the implementation level of GSCM practices and improvement in enterprise performance for Indian ceramic enterprises.

scholarly journals PENGARUH PERUBAHAN SUHU TERHADAP UJI IMPAK LAPISAN NIKEL-KROM PADA SUBSTRAT TEMBAGA

2015 ◽  
Vol 3 (2) ◽  
pp. 304
Author(s):  
Sukainil Ahzan ◽  
Ahmadi Ahmadi
Keyword(s):  
Impact Strength ◽  
Impact Energy ◽  
Impact Test ◽  
High Impact ◽  
Optimal Flow ◽  
Energy Impact ◽  
Operating Current ◽  
High Impact Strength ◽  
The Impact

It has been done plating a copper with process electroplating technique using a solution of nickel and chrome. The purpose of this study to find the best strength of the layer with the optimal flow. The strength of the material in the test with the impact test on a sample of coated copper at different work flows (1A, 1.5 A, 2.0 A, and 2.5 A). The results of the impact energy impact test obtained for each flow which is 2.1566 J / mm2; 2.3017 J / mm2; 1.9319 J / mm2; 1.9205 J / mm2. From the analysis concluded layer with high impact strength at an operating current of 1.5 A

Development of Easy-Removable Underwater Manipulator Unit with Built-in Controller

2013 ◽  
Vol 25 (5) ◽  
pp. 778-784 ◽  
Author(s):  
Fumiaki Takemura ◽  
◽  
Reyes Tatsuru Shiroku ◽  
Kuniaki Kawabata ◽  
Shinichi Sagara ◽  
...  
Keyword(s):  
Performance Test ◽  
Coral Cover ◽  
High Water ◽  
Underwater Robots ◽  
Runoff Water ◽  
Robot Hands ◽  
Underwater Manipulator ◽  
Manipulator Design ◽  
And Performance ◽  
The Impact

In recent years, coral cover has been decreased by the impact of bleaching due to high water temperature, red-soil runoff, water pollution, and coral-eating starfish outbreak. It is necessary to appropriately measure, observe, and sample seawater. To succeed in these tasks, underwater robots should have a function of responds flexibly in solving problems. Underwater tasks are summarized as follows: (1) acquiring images and environmental information using cameras and sensors, (2) collecting objects and other necessary work using robot hands. Manipulator should be attached quickly to underwater robots as needed. So we have been developing “an easy-removable underwater manipulator.” The manipulators is easy to maintain because all electric components – DC motors, motor controllers, etc. – are in a pressure-resistant vessel, the manipulator has only one cable, and the manipulator is easy to attach and detach. In this paper, we illustrate the manipulator design and performance test results.

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