Progression in Design and Technology Learning

2020 ◽  
Vol 21 (6) ◽  
pp. 619
Author(s):  
Kostandin Gjika ◽  
Antoine Costeux ◽  
Gerry LaRue ◽  
John Wilson

Today's modern internal combustion engines are increasingly focused on downsizing, high fuel efficiency and low emissions, which requires appropriate design and technology of turbocharger bearing systems. Automotive turbochargers operate faster and with strong engine excitation; vibration management is becoming a challenge and manufacturers are increasingly focusing on the design of low vibration and high-performance balancing technology. This paper discusses the synchronous vibration management of the ball bearing cartridge turbocharger on high-speed balancer and it is a continuation of papers [1–3]. In a first step, the synchronous rotordynamics behavior is identified. A prediction code is developed to calculate the static and dynamic performance of “ball bearing cartridge-squeeze film damper”. The dynamic behavior of balls is modeled by a spring with stiffness calculated from Tedric Harris formulas and the damping is considered null. The squeeze film damper model is derived from the Osborne Reynolds equation for incompressible and synchronous fluid loading; the stiffness and damping coefficients are calculated assuming that the bearing is infinitely short, and the oil film pressure is modeled as a cavitated π film model. The stiffness and damping coefficients are integrated on a rotordynamics code and the bearing loads are calculated by converging with the bearing eccentricity ratio. In a second step, a finite element structural dynamics model is built for the system “turbocharger housing-high speed balancer fixture” and validated by experimental frequency response functions. In the last step, the rotating dynamic bearing loads on the squeeze film damper are coupled with transfer functions and the vibration on the housings is predicted. The vibration response under single and multi-plane unbalances correlates very well with test data from turbocharger unbalance masters. The prediction model allows a thorough understanding of ball bearing turbocharger vibration on a high speed balancer, thus optimizing the dynamic behavior of the “turbocharger-high speed balancer” structural system for better rotordynamics performance identification and selection of the appropriate balancing process at the development stage of the turbocharger.


2018 ◽  
Vol 4 (1) ◽  
pp. 67-84
Author(s):  
Wahyudin Noor

Abstract Pesantren are often associated with backwardness and traditionalism in everything: facilities, technology, learning methods, and even the curriculum. For now, it seems like the traditional term for pesantren is no longer relevant enough. The pace of movement in the era of renewal marked by the rapid development of technology has demanded pesantren to make adjustments. However, on the one hand, when viewed from the direction of change, the reform efforts pursued by pesantren are not to erase the old tradition, but merely to add something new so that the old tradition and conditions can be maintained while accepting the presence of a new one. On the other hand, the reform efforts undertaken by pesantren have implications for the fact that the typical values of the pesantren are fading away. Abstrak  Pesantren seringkali diasosiasikan dengan keterbelakangan dan tradisional dalam segala hal: fasilitas, teknologi, metode pembelajaran, dan bahkan kurikulumnya. Untuk saat ini, sepertinya istilah tradisional untuk pesantren, sudah tidak lagi cukup relevan. Laju gerak pembaharuan zaman yang ditandai dengan pesatnya perkembangan teknologi telah menuntut pesantren untuk melakukan penyesuaian diri. Kendatipun demikian, di satu sisi, jika dilihat dari arah perubahan, upaya pembaharuan yang ditempuh pesantren tidaklah untuk menghapus tradisi yang lama, tetapi sekadar menambah dengan sesuatu yang baru sehingga tradisi maupun kondisi yang lama bisa dipertahankan sambil menerima kehadiran yang baru. Di sisi yang lain, upaya pembaharuan yang dilakukan pesantren ternyata berimplikasi pada kenyataan akan semakin pudarnya nilai-nilai khas yang dimiliki oleh pesantren.


2014 ◽  
Vol 15 (1) ◽  
pp. 22-30
Author(s):  
R. Dicky Agus Purnama ◽  
Benny Agus Pribadi

This article will elaborate the use of performance assessment to measure students competencies in learning science. What type of performance assessment appropriate to assess students learning outcome of science? The answer of this question is necessary for the teachers to determine the best assessment technique in science. Basically science can be considered as the root of knowledge and technology. Learning activities in science should be designed in order to facilitate students learning. It is a constructive process which requires students to study concepts inductively. Learning activities in science should be based on constructivism learning theory which encourages students to build their own knowledge and to apply it in the real world. Learning science should involve several essentials activities such as student involvement (engagement); extracting knowledge (exploration); presenting the findings (explanation); understanding knowledge (elaboration); and achievement learning competencies (assessment). It is necessary to implement performance assessment to measure the students learning outcome in science. Penulisan artikel ini bertujuan untuk mengelaborasi implementasi penilaian performa siswa untuk mengukur kemampuan siswa dalam mempelajari isi atau mata pelajaran sains. Bentuk penilaian seperti apa yang diperlukan untuk mengetahui kompetensi siswa setelah mempelajari mata pelajaran sains? Jawaban terhadap pertanyaan ini sangat diperlukan untuk dapat merancang dan mengembangkan sistem penilaian untuk mengukur kemampuan siswa dalam mata pelajaran sains. Sains atau science pada hakekatnya merupakan akar perkembangan ilmu pengetahuan dan teknologi (iptek). Pembelajaran sains pada semua jenjang pendidikan perlu dirancang agar menarik dan bermakna bagi siswa. Aktivitas dalam pembelajaran sains harus memanfaatkan pendekatan dan teori belajar konstruktivistik yang mendorong siswa dapat membangun pengetahuan dan mengaplikasikannya dalam dunia nyata. Pembelajaran sains berbasis teori belajar konstruktivistik bercirikan belajar seperti: Keterlibatan siswa (engagement); penggalian pengetahuan (exploration); penjelasan (explanation); penjabaran (elaboration); dan penilaian (assessment). Dalam aktivitas pebelajaran sains berbasis teori belajar konstruktivistik penilaian hasil belajar menekankan pada performa siswa dalam mengintegrasikan pengetahuan-fenomena alam. Artikel ini akan mengupas implementasi konsep penilaian performa atau performance assessmentdalam pembelajaran sains berbasis teori belajar konstruktivistik.


2010 ◽  
Vol 6 (2) ◽  
pp. 71 ◽  
Author(s):  
Lindsay A Smith ◽  
Amit Bhan ◽  
Mark J Monaghan ◽  
◽  
◽  
...  

Echocardiography provides excellent realtime imaging of the heart, making it the imaging modality of choice immediately before, during and after cardiac interventional procedures. It helps to guide case selection and execution of the intervention, evaluates the effects of the intervention and enables early detection of complications. Advances in the design and technology of medical devices and delivery systems, coupled with demand for alternative non-surgical therapies for common medical problems, have led to an increase in the volume, variety and complexity of non-coronary cardiac interventional procedures performed. Many of these procedures require a multidisciplinary team approach and demand optimal imaging to ensure successful outcomes. The aim of this article is to review the expanding role of echocardiography in non-coronary interventional cardiology in adults.


2000 ◽  
Author(s):  
Krishna Shenai ◽  
Philip Neudeck ◽  
Gene Schwarze

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