Force Density and Dilatation Rate Sources on Surfaces of Homogeneous Isotropic Half-Spaces, Radiation Fields of Piezoelectric Transducers

2012 ◽  
Vol 132 (4) ◽  
pp. 480-486 ◽  
Author(s):  
Masanobu Kakihara ◽  
Toshiyuki Hoshi ◽  
Toru Shikayama ◽  
Motomichi Ohto

2020 ◽  
pp. 17-27
Author(s):  
А.А. Шелухин

In this article, the analysis of the acoustic path during the ultrasonic pulse echo testing of the rail head in production is carried out. The influence of the parameters of the applied piezoelectric transducers on the distribution of sensitivity for the sounding scheme used in the existing installations is estimated and the real sensitivity of detecting defects of the «non-metallic inclusion» type is estimated.


2016 ◽  
Vol 1 (2) ◽  
Author(s):  
Richa Gupta ◽  
Piyush Kumar ◽  
D. P. Singh ◽  
Arvind Kumar Chauhan ◽  
Kamal Sahni

INTRODUCTION: Cervical cancer is the second most frequent cancer among Indian women. Radiotherapy is the cornerstone of treatment in all its stages. Three-dimensional conformal radiotherapy (3DCRT) combines multiple radiation fields to deliver precise dose of radiation to the affected area. Tailoring each of the radiation fields to focus on the tumor delivers a high dose of radiation to the tumor and avoids nearby healthy tissue. The present study is done to compare conventional radiotherapy versus 3DCRT in cancer cervix for compliance, clinical response and toxicity. MATERIAL AND METHODS: Fifty patients were enrolled and randomised into two radiotherapy plans with radical intent - Group A treated by conventional radiotherapy and group B treated by 3DCRT. Concurrent cisplatin was delivered on weekly (35mg/m2) or tri-weekly (75mg/m2) basis during external beam Radiotherapy and was followed by High Dose Radiotherapy Brachytherapy. Clinical response and complication assessment were evaluated.Collected data was analyzed using standard statistical methods and softwares to calculate level of significance using “p” value by chi square test. RESULTS: In this study mean age of the patients was 48 years (26-67 years). The anemia was the most common side effect seen in both groups (96% vs 88%, p=0.29). Neutropenia was more in group B (36% vs 44%, p= 0.56). Lower GI toxicity was seen only in patients in group A (20% vs 0%, p=0.018). In follow up there were no significant early rectal and bladder reactions in both groups and 2 patients in each group had late rectal reactions of grade I and II (p= 0.312). No significant skin, bladder and small intestinal toxicity were seen in both groups. CONCLUSION: Conventional radiotherapy gives equally efficacious response though accompanied by toxicities which were acceptable.


Sensors ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 3512 ◽  
Author(s):  
Corina Covaci ◽  
Aurel Gontean

The goal of this paper is to review current methods of energy harvesting, while focusing on piezoelectric energy harvesting. The piezoelectric energy harvesting technique is based on the materials’ property of generating an electric field when a mechanical force is applied. This phenomenon is known as the direct piezoelectric effect. Piezoelectric transducers can be of different shapes and materials, making them suitable for a multitude of applications. To optimize the use of piezoelectric devices in applications, a model is needed to observe the behavior in the time and frequency domain. In addition to different aspects of piezoelectric modeling, this paper also presents several circuits used to maximize the energy harvested.


2013 ◽  
Vol 416-417 ◽  
pp. 428-432
Author(s):  
Li Shan ◽  
Xiao Wei Cheng ◽  
Yong Fang ◽  
Xiao Hua Bao

This paper investigates the vibration which caused by electromagnetic on the stator end-winding of the large dry submersible motor. Firstly, the electromagnetic field which included transition state and steady state is researched by 3-D FEM. Secondly, the electromagnetic force which lead to vibrations of end-winding is calculated by numerical method, it can be obtained that where endured the largest force density along the slant part of end-winding. Finally, the radial displacement and the axial displacement of the slant part which caused by vibrations is studied, the analysis results show that the axial displacement is larger than the amplitude of radial displacement. It indicates that the slant part of end-winding will be more easily damaged at axial direction than radial direction.


Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 221
Author(s):  
Mariya Aleksandrova ◽  
Ivailo Pandiev

This paper presents impedance measurements of ferroelectric structures involving lead-free oxide and polymer-oxide composite coatings for sensing and energy harvesting applications. Three different ferroelectric materials grown by conventional microfabrication technologies on solid or flexible substrates are investigated for their basic resonant characteristics. Equivalent electrical circuit models are applied to all cases to explain the electrical behavior of the structures, according to the materials type and thickness. The analytical results show good agreement with the experiments carried out on a basic types of excited thin-film piezoelectric transducers. Additionally, temperature and frequency dependences of the dielectric permittivity and losses are measured for the polymer-oxide composite device in relation with the surface morphology before and after introduction of the polymer to the functional film.


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