scholarly journals A Novel Method for Obtaining Diffuse Field Measurements for Microphone Calibration

2020 ◽  
Author(s):  
Noman Akbar ◽  
Glenn Dickins ◽  
Mark R. P. Thomas ◽  
Prasanga Samarasinghe ◽  
Thushara Abhayapala
Keyword(s):  
Field Measurements ◽  
Novel Method

Light source based on a 100 mm-long monolithic undulator magnet with a very short 4 mm-period length

2019 ◽  
Vol 26 (6) ◽  
pp. 1902-1910 ◽  
Author(s):  
Shigeru Yamamoto ◽  
Shigeru Kashiwagi ◽  
Shinichi Masuda ◽  
Nobuhiko Nakanii ◽  
Tomonao Hosokai ◽  
...  
Keyword(s):  
Light Source ◽  
Field Measurements ◽  
Period Length ◽  
Calculated Spectrum ◽  
Fundamental Radiation ◽  
Novel Method ◽  
Electron Photon ◽  
Photon Science

A novel method to fabricate undulator magnets of a-few-millimetre-period length is being explored. Plate-type magnets, 100 mm-long with 4 mm-period length, have been successfully fabricated. They produce an undulator field of approximately 3 kG at a gap of 1.6 mm. Prototype undulators based on this technology have been constructed. Field measurements and characterization show that the quality of the undulator field of these plate magnets is sufficient for an undulator light source, and the calculated spectrum shows that the fundamental radiation emitted from this field is quite satisfactory. Test experiments for light generation using a real electron beam have been carried out at a test accelerator at the Research Center for Electron Photon Science (ELPH), Tohoku University, Japan, which is able to realize optics conditions to accept a very short gap of ∼1.6 mm. First observation and characterization of blue light was successfully accomplished.

Modal Identification from Non-Stationary Responses of High-Rise Buildings by Variational Mode Decomposition and Direct Interpolation Techniques

2020 ◽  
Vol 20 (11) ◽  
pp. 2050115
Author(s):  
Meng-Meng Sun ◽  
Qiu-Sheng Li ◽  
Kang Zhou ◽  
Ying-Hou He ◽  
Lun-Hai Zhi
Keyword(s):  
Field Measurements ◽  
Modal Identification ◽  
Frame Structure ◽  
The Novel ◽  
Variational Mode Decomposition ◽  
High Rise ◽  
Mode Decomposition ◽  
Structural Responses ◽  
Novel Method ◽  
High Level

For high-rise buildings subjected to ambient excitations such as typhoons and earthquake actions, their structural responses may include non-stationary features. Under such conditions, traditional modal identification methods may not be applicable due to the violation of the stationary assumption of the response signals. To deal with this issue, a novel modal identification method is presented in this paper based on combination of the variational mode decomposition (VMD) and direct interpolation (DI) techniques. Through numerical simulation study of a three-story frame structure, the effectiveness and accuracy of the combined VMD-DI method for modal identification of the structure are validated for the case of the structural responses containing non-stationary properties and high-level noise. Moreover, the novel method is further applied to the field measurements of acceleration responses of a 600[Formula: see text]m high skyscraper during a typhoon. The identified results verify the applicability and accuracy of the combined VMD-DI method in field measurements. This paper aims to provide an effective tool for modal identification from non-stationary structural responses of high-rise buildings.

scholarly journals Static form-finding of normal and defective catenaries based on the analytical exact solution of the tensile Euler–Bernoulli beam

2018 ◽  
Vol 233 (7) ◽  
pp. 691-700 ◽  
Author(s):  
Farzad Vesali ◽  
Mohammad Ali Rezvani ◽  
Habibolah Molatefi ◽  
Markus Hecht
Keyword(s):  
Exact Solution ◽  
Equilibrium Configuration ◽  
Field Measurements ◽  
Steady State Solution ◽  
Contact Wire ◽  
Proposed Model ◽  
Before And After ◽  
Novel Method ◽  
Static Form ◽  
Euler Bernoulli Beam

The aim of this research is to propose and develop an analytical exact solution for finding the static equilibrium configuration of a catenary before and after incurring defects such as tension loss or a broken dropper. The procedure includes considering the steady-state solution of the dynamic motion equation of the contact wire and the messenger cable. The wire and the cable are considered as tensile Euler–Bernoulli beams. The stiffness matrix of the beam is configured and is used to calculate the dropper's dead load. Progressively, a novel method is proposed to find the equilibrium configuration of the same catenary after the defect. The results prove that the tension loss in the messenger cable is more precarious than the tension loss in the contact wire. The broken dropper causes a significant sag in the sub-span and increases the static forces of the adjacent droppers. A comparison with field measurements justifies the accuracy of the results of the proposed model.

A novel method for effective field measurements in electrical field-flow fractionation

2012 ◽  
Vol 33 (6) ◽  
pp. 1040-1047 ◽  
Author(s):  
Srinivas Merugu ◽  
Himanshu J. Sant ◽  
Bruce K. Gale
Keyword(s):  
Field Measurements ◽  
Effective Field ◽  
Field Flow Fractionation ◽  
Electrical Field ◽  
Novel Method ◽  
Flow Fractionation

Novel method of sound barrier measurement of porous and nonporous materials

2013 ◽  
Vol 10 (4) ◽  
pp. 353-358 ◽  
Author(s):  
Vijay Baheti ◽  
V. Kothari
Keyword(s):  
Composite Structures ◽  
Simple Technique ◽  
Field Measurements ◽  
Woven Fabric ◽  
Sound Waves ◽  
Sound Barrier ◽  
Actual Field ◽  
Novel Method ◽  
Larger Sample ◽  
Random Scatter

Noise is an unwanted sound which creates the pollution and adverse effects on individual. One of the simple ways to reduce the noise is to place the acoustic material in the path between the source and the receiver so that sound waves get either absorbed or blocked while reaching towards the receiver. There are various techniques available to measure sound absorption or sound barrier (blocking) caused by the acoustic material. However these techniques are also associated with certain limitations. Our objective was to design and fabricate simple technique to measure sound barrier which overcomes these limitations and allows larger sample size and random scatter of sound wave to accurately predict actual field measurements. A sound source (i.e. a speaker) and a microphone, placed in different pipes separated by sample in between, were used for the measurement of sound barrier property of porous materials (nonwovens, woven fabric, and foam), nonporous materials (rubber, cardboard) and their composite structures at four different frequencies 250 Hz, 500 Hz, 1,000 Hz, and 2000 Hz. Different set of readings were taken in absence and presence of the sample by measuring the transmitted sound across the sample.

scholarly journals A Publicly Available Dataset of Out-of-Field Dose Profiles of a 6 MV Linear Accelerator

2021 ◽  
Author(s):  
Samuel Peet ◽  
Naasiha Cassim ◽  
Tanya Kairn ◽  
Jamie V Trapp ◽  
Scott B Crowe
Keyword(s):  
Linear Accelerator ◽  
Feature Matching ◽  
Field Measurements ◽  
Analytical Models ◽  
Water Tank ◽  
Large Dataset ◽  
Beam Incident ◽  
Recent Developments ◽  
Novel Method ◽  
Development And Validation

Abstract An increase in radiotherapy-induced secondary malignancies has led to recent developments in analytical modelling of out-of-field dose. These models must be validated against measurements, but currently available datasets are outdated or limited in scope. This study aimed to address these shortcomings by producing a large dataset of out-of-field dose profiles measured with modern equipment. A novel method was developed with the intention of allowing physicists in all clinics to perform these measurements themselves using commonly available dosimetry equipment. A standard 3D scanning water tank was used to collect 36 extended profiles. Each profile was measured in two sections, with the inner section measured with the beam directly incident on the tank, and the outer section with the beam incident on a water-equivalent phantom abutted next to the tank. The two sections were then stitched using a novel feature-matching approach. The profiles were compared against linac commissioning data and manually inspected for discontinuities in the overlap region. The dataset is presented as a publicly accessible comma separated variable file containing off-axis ratios at a range of off-axis distances. This dataset may be applied to the development and validation of analytical models of out-of-field dose. Additionally, it may be used to inform dose estimates to radiosensitive implants and anatomy. Physicists are encouraged to perform these out-of-field measurements in their own clinics and share their results with the community.

The removal and morphology of intact biofilms from implanted venous access devices

1995 ◽  
Vol 53 ◽  
pp. 1020-1021
Author(s):  
M.A. Gregory ◽  
G.P. Hadley
Keyword(s):  
Patient Selection ◽  
Surgical Oncology ◽  
Venous Access ◽  
Common Procedure ◽  
Indwelling Catheters ◽  
Careful Patient ◽  
Novel Method ◽  
The Subject ◽  
Vascular Catheters ◽  
Venous Access Devices

The insertion of implanted venous access systems for children undergoing prolonged courses of chemotherapy has become a common procedure in pediatric surgical oncology. While not permanently implanted, the devices are expected to remain functional until cure of the primary disease is assured. Despite careful patient selection and standardised insertion and access techniques, some devices fail. The most commonly encountered problems are colonisation of the device with bacteria and catheter occlusion. Both of these difficulties relate to the development of a biofilm within the port and catheter. The morphology and evolution of biofilms in indwelling vascular catheters is the subject of ongoing investigation. To date, however, such investigations have been confined to the examination of fragments of biofilm scraped or sonicated from sections of catheter. This report describes a novel method for the extraction of intact biofilms from indwelling catheters.15 children with Wilm’s tumour and who had received venous implants were studied. Catheters were removed because of infection (n=6) or electively at the end of chemotherapy.

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