scholarly journals Microdosimetry Performance of The First Multi-Arrays of 3D-Cylindrical Microdetectors

2021 ◽  
Author(s):  
Diana Bachiller-Perea ◽  
Mingming Zhang ◽  
Celeste Fleta ◽  
David Quirion ◽  
Daniela Bassignana ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Radiation Detectors ◽  
Particle Accelerators ◽  
Energy Distributions ◽  
Detection Systems ◽  
Lineal Energy ◽  
New Type ◽  
Silicon Based ◽  
Beam Monitoring ◽  
Good Agreement

Abstract Purpose: The present work reports on the microdosimetry measurements performed with the two first multi-arrays of microdosimeters with the highest radiation sensitive surface covered so far. The sensors are based on new silicon-based radiation detectors with a novel 3D cylindrical architecture. Methodology: Each system consists of arrays of independent microdetectors covering 2 mm×2 mm and 0.4 mm×12 cm radiation sensitive areas, the sensor distributions are arranged in layouts of 11×11 microdetectors and 3×3 multi-arrays, respectively. We have performed proton irradiations at several energies to compare the microdosimetry performance of the two systems, which have different spatial resolution and detection surface. The unit-cell of both arrays is a new type of 3D cylindrical diode with a 25 µm diameter and a 20 µm depth that results in a well-defined and isolated radiation sensitive micro-volume etched inside a silicon wafer. Measurements were carried out at the Accélérateur Linéaire et Tandem à Orsay (ALTO) facility by irradiating the two detection systems with monoenergetic proton beams from 6 to 18 MeV at clinical-equivalent fluence rates. Results: The microdosimetry quantities were obtained with a spatial resolution of 200 µm and 600 µm for the 11×11 system and for the 3×3 multi-array system, respectively. Experimental results were compared with Monte Carlo simulations and an overall good agreement was found. Conclusion: We have studied the microdosimetry response under clinical equivalent fluence rate of the first multi-arrays of 3D cylindrical microdetectors covering several centimeters of sensitive area. The good performance of both microdetector arrays demonstrates that this architecture and both configurations can be used clinically as microdosimeters for measuring the lineal energy distributions and, thus, for RBE optimization of hadron therapy treatments. Likewise, the results have shown that the devices can be also employed as a multipurpose device for beam monitoring in particle accelerators.

Automatic analysis of Kikuchi diffraction patterns

1994 ◽  
Vol 52 ◽  
pp. 900-901
Author(s):  
H. Weiland ◽  
D. P. Field
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Spatial Resolution ◽  
Relevant Information ◽  
Crystalline Materials ◽  
Large Size ◽  
Transmission Electron ◽  
New Type ◽  
Diffraction Patterns ◽  
Orientation Determination

Recent advances in the automatic indexing of backscatter Kikuchi diffraction patterns on the scanning electron microscope (SEM) has resulted in the development of a new type of microscopy. The ability to obtain statistically relevant information on the spatial distribution of crystallite orientations is giving rise to new insight into polycrystalline microstructures and their relation to materials properties. A limitation of the technique in the SEM is that the spatial resolution of the measurement is restricted by the relatively large size of the electron beam in relation to various microstructural features. Typically the spatial resolution in the SEM is limited to about half a micron or greater. Heavily worked structures exhibit microstructural features much finer than this and require resolution on the order of nanometers for accurate characterization. Transmission electron microscope (TEM) techniques offer sufficient resolution to investigate heavily worked crystalline materials.Crystal lattice orientation determination from Kikuchi diffraction patterns in the TEM (Figure 1) requires knowledge of the relative positions of at least three non-parallel Kikuchi line pairs in relation to the crystallite and the electron beam.

Theoretical and experimental research on slip and uplift of the timber-concrete composite beam

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 7079-7099
Author(s):  
Jianying Chen ◽  
Guojing He ◽  
Xiaodong (Alice) Wang ◽  
Jiejun Wang ◽  
Jin Yi ◽  
...  
Keyword(s):  
Differential Equations ◽  
Deformation Theory ◽  
Concrete Slab ◽  
Theoretical Calculations ◽  
Structural Element ◽  
Structural Efficiency ◽  
Theoretical Investigations ◽  
New Type ◽  
Interlayer Slip ◽  
Good Agreement

Timber-concrete composite beams are a new type of structural element that is environmentally friendly. The structural efficiency of this kind of beam highly depends on the stiffness of the interlayer connection. The structural efficiency of the composite was evaluated by experimental and theoretical investigations performed on the relative horizontal slip and vertical uplift along the interlayer between composite’s timber and concrete slab. Differential equations were established based on a theoretical analysis of combination effects of interlayer slip and vertical uplift, by using deformation theory of elastics. Subsequently, the differential equations were solved and the magnitude of uplift force at the interlayer was obtained. It was concluded that the theoretical calculations were in good agreement with the results of experimentation.

Optical Vibration and Acceleration Sensor With a Silicon Cantilever

1999 ◽  
Author(s):  
Mitsuteru Kimura ◽  
Katsuhisa Toshima ◽  
Harunobu Satoh
Keyword(s):  
Simple Model ◽  
Optical Fiber ◽  
Resonance Frequency ◽  
Acceleration Sensor ◽  
Frequency Range ◽  
Silicon Cantilever ◽  
All Optical ◽  
New Type ◽  
Good Agreement ◽  
Optical Vibration

Abstract A new type all optical vibration and acceleration sensor using the combination of micromachined Si cantilever and optical fiber is proposed, and its fundamental characteristics are demonstrated. The light emitted from bulb-lens set into the V-groove is reflected at the reflector formed on the Si cantilever and then recoupled into the bulb-lens. Several sensors with different length (0.64–6.0 mm long) of the Si cantilever are fabricated to compare the theoretical resonance frequency fr obtained from the simple model and experimental ones. They had good agreement. From the sensing principle the sensing frequency range of the vibration is suitable below the fr of the Si cantilever of the sensor.

Dynamic Modeling and Validation of a Lorentz, Self-Bearing Motor Test Rig

2002 ◽  
Vol 125 (1) ◽  
pp. 156-166 ◽  
Author(s):  
L. S. Stephens ◽  
D.-G. Kim
Keyword(s):  
Dynamic Model ◽  
Permanent Magnets ◽  
Transfer Functions ◽  
System Model ◽  
Test Rig ◽  
Motor Test ◽  
Three Phase ◽  
New Type ◽  
Bearing Force ◽  
Good Agreement

A new type of self-bearing motor that uses Lorentz-type forces to generate both bearing force and motoring torque has been developed. The motor stator is of slotless construction with four three-phase windings. The motor rotor is constructed of 16 surface mounted permanent magnets (PM’s). The main advantage of the design is that it eliminates the tradeoff between motoring torque and bearing force with PM thickness as found in previous designs. This paper presents the dynamic model for the self-bearing motor and illustrates how the model is integrated into the overall system model of the motor test rig. The dynamic model is validated against experimentally measured transfer functions with good agreement between the two.

Fusion of Feature Selection and Random Forest for an Anomaly-Based Intrusion Detection System

2019 ◽  
Vol 16 (8) ◽  
pp. 3603-3607 ◽  
Author(s):  
Shraddha Khonde ◽  
V. Ulagamuthalvi
Keyword(s):  
Feature Selection ◽  
Random Forest ◽  
Intrusion Detection ◽  
Real Time ◽  
Intrusion Detection System ◽  
New Technologies ◽  
Detection System ◽  
Sensitive Data ◽  
Detection Systems ◽  
New Type

Considering current network scenario hackers and intruders has become a big threat today. As new technologies are emerging fast, extensive use of these technologies and computers, what plays an important role is security. Most of the computers in network can be easily compromised with attacks. Big issue of concern is increase in new type of attack these days. Security to the sensitive data is very big threat to deal with, it need to consider as high priority issue which should be addressed immediately. Highly efficient Intrusion Detection Systems (IDS) are available now a days which detects various types of attacks on network. But we require the IDS which is intelligent enough to detect and analyze all type of new threats on the network. Maximum accuracy is expected by any of this intelligent intrusion detection system. An Intrusion Detection System can be hardware or software that analyze and monitors all activities of network to detect malicious activities happened inside the network. It also informs and helps administrator to deal with malicious packets, which if enters in network can harm more number of computers connected together. In our work we have implemented an intellectual IDS which helps administrator to analyze real time network traffic. IDS does it by classifying packets entering into the system as normal or malicious. This paper mainly focus on techniques used for feature selection to reduce number of features from KDD-99 dataset. This paper also explains algorithm used for classification i.e., Random Forest which works with forest of trees to classify real time packet as normal or malicious. Random forest makes use of ensembling techniques to give final output which is derived by combining output from number of trees used to create forest. Dataset which is used while performing experiments is KDD-99. This dataset is used to train all trees to get more accuracy with help of random forest. From results achieved we can observe that random forest algorithm gives more accuracy in distributed network with reduced false alarm rate.

Modular 64×64 CdZnTe Arrays With Multiplexer Readout for High-Resolution Nuclear Medicine Imaging

1997 ◽  
Vol 487 ◽  
Author(s):  
J. M. Woolfenden ◽  
H. B. Barber ◽  
H. H. Barrett ◽  
E. L. Dereniak ◽  
J. D. Eskin ◽  
...  
Keyword(s):  
Nuclear Medicine ◽  
High Resolution ◽  
Spatial Resolution ◽  
Personal Computer ◽  
Imaging System ◽  
Radiation Detectors ◽  
Readout Circuit ◽  
Nuclear Medicine Imaging ◽  
Pixel Pitch

AbstractWe are developing modular arrays of CdZnTe radiation detectors for high-resolution nuclear medicine imaging. Each detector is delineated into a 64×64 array of pixels; the pixel pitch is 380 jim. Each pixel is connected to a corresponding pad on a multiplexer readout circuit. The imaging system is controlled by a personal computer. We obtained images of standard nuclear medicine phantoms in which the spatial resolution of approximately 1.5 mm was limited by the collimator that was used. Significant improvements in spatial resolution should be possible with different collimator designs. These results are promising for high-resolution nuclear medicine imaging.

The Influence of Ion Energy Distribution for Multiple Frequencies Driven

2013 ◽  
Vol 664 ◽  
pp. 947-953
Author(s):  
Zhu Wen Zhou ◽  
Yuan Sheng Wang ◽  
Bo Kong
Keyword(s):  
Integrated Circuit ◽  
Dual Frequency ◽  
Energy Distributions ◽  
Low Frequencies ◽  
Ion Energy ◽  
Ion Energy Distribution ◽  
Multiple Frequencies ◽  
Ion Energy Distributions ◽  
Capacitive Discharges ◽  
Good Agreement

The voltages, resonant waves and frequencies how to influence on the ion energy distributions (IEDs) from multiple frequencies driven in capacitive discharges, it is important to analyze these phenomenon and mechanism in order to control the microelectronic processes of integrated circuit and develop the base theories of plasma physics. We focused on the function of the ion energy distributions under high and low frequencies (dual frequency) drive in capacitive discharges, we derived a model of computation of the multiple frequencies driven IEDs from analyzing theories. The model can analyze and predict the IEDs under different high and low frequencies driven, the results from the model are in good agreement with these important data from public publish.

Sensor Characteristics of Carbon Fiber Mat

2006 ◽  
Vol 326-328 ◽  
pp. 1451-1454 ◽  
Author(s):  
Xiao Yu Zhang ◽  
Zhuo Qiu Li ◽  
Xian Hui Song ◽  
Yong Lv
Keyword(s):  
Carbon Fiber ◽  
Concrete Structure ◽  
Fiber Reinforced Concrete ◽  
Static Characteristics ◽  
Gage Factor ◽  
Thin Carbon ◽  
On Line ◽  
New Type ◽  
New Skin ◽  
Good Agreement

Structural health monitoring (SHM) is becoming a popular topic. Carbon fiber reinforced concrete (CFRC) is an intrinsically smart material that can sense strain. The resistivity increases reversibly under tension and decreases under compression. A new skin-like sensor —cement-based smart layer had been put forward, which can serve as whole field strain sensor. The smart layer is satisfactorily consistent with concrete structure. The smart layer is a thin carbon fiber mat cementbased composite material layer with finite electrodes. It can cover the surface of concrete structure, and provide on-line reliable information about the deformation of whole concrete structure. The static characteristics of the new-type sensor had been researched. Its gage factor is 20-25 under tension and 25-30 under compression within the elastic deformation range. Furthermore the smart layer has satisfactory linearity and repeatability. In this paper, the sensor characteristics of the bare carbon fiber mat have been reached. The resistivity of carbon fiber mat has good agreement with strain under uniaxial tension. The gage factor can be up to 375, and the sensor limit can be up to 10000 microstrain. The strain and the fractional change in electrical resistance .R/R0 are totally reversible and reproducible under cyclic loading and amplitude-variable cyclic tensile loading.

scholarly journals A NEW TYPE OF BREAKWATER UTILIZING AIR COMPRESSIBILITY

1988 ◽  
Vol 1 (21) ◽  
pp. 172 ◽  
Author(s):  
Masaaki Ikeno ◽  
Naokatsu Shimoda ◽  
Koichiro Iwata
Keyword(s):  
Energy Dissipation ◽  
Wave Energy ◽  
Theoretical Models ◽  
Pressure Variation ◽  
Wave Energy Dissipation ◽  
Air Chamber ◽  
New Type ◽  
Experimental Values ◽  
Better Than ◽  
Good Agreement

This paper is to investigate both theoretically and experimentally the wave energy dissipation and air-pressure variation of a new type of breakwater having a pressurized air-chamber and two buoyancy tanks. The theoretical models are developed in this paper and they are shown to be in good agreement with experimental values. The new type of breakwater proposed in this paper is pointed out to attenuate the transmitted wave much better than the rectangular-shaped and concave-shaped breakwaters without the air-chamber.

scholarly journals Mobile monitoring of traffic-related air pollution for a prospective cohort study in the greater Seattle area

2021 ◽  
Author(s):  
Magali N. Blanco ◽  
Amanda Gassett ◽  
Timothy Gould ◽  
Annie Doubleday ◽  
David L. Slager ◽  
...  
Keyword(s):  
Air Pollution ◽  
Spatial Resolution ◽  
Mobile Monitoring ◽  
Annual Average ◽  
Monitoring Campaign ◽  
Adverse Health Effects ◽  
Exposure Levels ◽  
One Year ◽  
Particulate Matter 2.5 ◽  
Good Agreement

AbstractGrowing evidence links traffic-related air pollution (TRAP) to adverse health effects. Previous air pollution studies focused on a few commonly measured pollutants with poor spatial resolution. Well-designed mobile monitoring studies may address this limitation. We designed an extensive mobile monitoring campaign to characterize TRAP exposure levels for a Seattle-based cohort, the Adult Changes in Thought (ACT) study. The campaign measured particulate matter ≤ 2.5 µm in diameter (PM2.5), ultrafine particulates (UFP), black carbon (BC), nitrogen dioxide (NO2) and carbon dioxide (CO2) at 309 stop locations representative of the cohort. We collected about 29 two-minute measures at each location during all seasons, days of the week, and most times of day for a one-year period. Annual average concentrations of UFPs had similar degrees of spatial variability as BC and NO2 but higher degrees of variability as CO2 and PM2.5. UFPs had less temporal variability than other pollutants. Validation showed good agreement between our BC, NO2, and PM2.5 measurements and regulatory monitoring sites. The results from this campaign will be used to assess TRAP exposure in the ACT cohort.SynopsisWe assessed annual-average traffic-pollutant levels with high spatial resolution at locations representative of participant residences using a temporally balanced short-term mobile monitoring campaign.Abstract Figure

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