scholarly journals Computer Vision in Analyzing the Propagation of a Gas–Gunpowder Jet

Sensors ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 6
Author(s):  
Irina G. Palchikova ◽  
Igor V. Latyshov ◽  
Evgenii S. Smirnov ◽  
Vasilii A. Vasiliev ◽  
Alexander V. Kondakov ◽  
...  
Keyword(s):  
Cross Section ◽  
Optical Density ◽  
Experimental Validation ◽  
Digital Images ◽  
Radial Dependence ◽  
Angular Distributions ◽  
Target Image ◽  
Different Types ◽  
Soot Distribution ◽  
Mathematical Justification

A method of mathematically processing the digital images of targets is developed. The theoretical and mathematical justification and the experimental validation of the possibility of estimating the amount of gunshot residue (GSR) and determining the GSR distribution over the target on the basis of its digital image is provided. The analysis of the optical density in selected concentric rings in the images reveals the radial dependence of soot distribution in the cross section of a gas–gunpowder jet. The analysis of the optical density in selected sectors of the circle reveals the angular dependence of the soot distribution in the gas–gunpowder jet cross section. It is shown that the integral optical density averaged over a selected area in the target image characterizes the mass of GSP deposited on it. It is possible to quantify the differences in the radial and angular distributions of the thickness of the GSR layer on various targets obtained both with the help of weapons of different types at the same distances and with the help of weapons of the same type at different distances, by calculating the distribution of optical density on their digital images.

scholarly journals Outlier Detection at the Parcel-Level in Wheat and Rapeseed Crops Using Multispectral and SAR Time Series

2021 ◽  
Vol 13 (5) ◽  
pp. 956
Author(s):  
Florian Mouret ◽  
Mohanad Albughdadi ◽  
Sylvie Duthoit ◽  
Denis Kouamé ◽  
Guillaume Rieu ◽  
...  
Keyword(s):  
Outlier Detection ◽  
Experimental Validation ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Multispectral Images ◽  
Vegetation Indexes ◽  
Crop Development ◽  
Different Types ◽  
Selection Of ◽  
Sentinel 2

This paper studies the detection of anomalous crop development at the parcel-level based on an unsupervised outlier detection technique. The experimental validation is conducted on rapeseed and wheat parcels located in Beauce (France). The proposed methodology consists of four sequential steps: (1) preprocessing of synthetic aperture radar (SAR) and multispectral images acquired using Sentinel-1 and Sentinel-2 satellites, (2) extraction of SAR and multispectral pixel-level features, (3) computation of parcel-level features using zonal statistics and (4) outlier detection. The different types of anomalies that can affect the studied crops are analyzed and described. The different factors that can influence the outlier detection results are investigated with a particular attention devoted to the synergy between Sentinel-1 and Sentinel-2 data. Overall, the best performance is obtained when using jointly a selection of Sentinel-1 and Sentinel-2 features with the isolation forest algorithm. The selected features are co-polarized (VV) and cross-polarized (VH) backscattering coefficients for Sentinel-1 and five Vegetation Indexes for Sentinel-2 (among us, the Normalized Difference Vegetation Index and two variants of the Normalized Difference Water). When using these features with an outlier ratio of 10%, the percentage of detected true positives (i.e., crop anomalies) is equal to 94.1% for rapeseed parcels and 95.5% for wheat parcels.

Efficacy of Inverted Digital Luminescence Radiography in Evaluating Chest Neoplasms

1991 ◽  
Vol 32 (6) ◽  
pp. 442-448 ◽  
Author(s):  
M. Kehler ◽  
U. Albrechtsson ◽  
A. Andrésdóttir ◽  
P. Hochbergs ◽  
H. Lárusdóttir ◽  
...  
Keyword(s):  
Statistical Difference ◽  
Digital Images ◽  
Left Lung ◽  
Roc Curves ◽  
Lung Tumors ◽  
Chest Radiographs ◽  
Contrast Enhanced ◽  
Different Types ◽  
Digital Chest ◽  
Digital Luminescence Radiography

Inverted (positive) digital chest radiographs of patients with lung tumors were compared with commonly used (negative) digital images, consisting of one simulated normal and one contrast enhanced image. The first part of the material consisted of 80 patients of whom 40 had tumors and 40 were normal. Five radiologists with different experience reviewed the examinations. From their answers, ROC curves were constructed. The second part of the material consisted of 100 chest phantom examinations with a simulated tumor in the mediastinum (45 examinations) and/or the left lung (46 examinations). In 31 exposures there was no abnormality. These were reviewed by 3 observers and performed as an ROC study as well. There was no statistical difference between the different types of images or between the observers in the 2 studies.

The study of neutron capture processes in AlN nanoparticles

2021 ◽  
pp. 2150127
Author(s):  
T. G. Naghiyev
Keyword(s):  
Computer Modeling ◽  
Cross Section ◽  
Neutron Capture ◽  
Absorption Cross Section ◽  
Effective Cross Section ◽  
Absorption Cross ◽  
Effective Absorption ◽  
Different Types ◽  
N Isotopes

The neutron capture processes in the AlN nanoparticles were investigated by computer modeling. Neutrons absorption were separately investigated for aluminum (Al) and nitrogen (N) atoms in the AlN nanoparticles. The modeling was performed separately for each stable Al and N isotopes, because the effective absorption cross-section of different types of isotopes of Al and N atoms is different. Moreover, effective cross-section spectra of neutron capture for aluminum and nitrogen atoms were comparatively investigated.

scholarly journals Preliminary results for the 19F(ρ,α)16O reaction cross section measured at INFN-LNS

2020 ◽  
Vol 227 ◽  
pp. 02009
Author(s):  
T Petruse ◽  
G. L. Guardo ◽  
M. La Cognata ◽  
D. Lattuada ◽  
C. Spitalieri ◽  
...  
Keyword(s):  
Nuclear Reaction ◽  
Cross Section ◽  
Theoretical Models ◽  
Calibration Procedure ◽  
Reaction Rates ◽  
Reaction Cross ◽  
Asymptotic Giant Branch ◽  
Angular Distributions ◽  
Agb Stars ◽  
Indirect Measurements

The 19F(ρ,α)16O reaction is an important fluorine destruction chan- nel in the proton-rich outer layers of asymptotic giant branch (AGB) stars and it might also play a role in hydrogen-deficient post-AGB star nucleosynthesis. At present, theoretical models overproduce F abundances in AGB stars with re-spect to the observed values, thus calling for further investigation of the nuclear reaction rates involved in the production and destruction of fluorine. In the last years, new direct and indirect measurements improved significantly the knowl- edge of 19F(ρ,α)16O cross section at deeply sub-Coulomb energies (below 0.8 MeV). However, those data are larger by a factor of 1.4 with respect the previ- ous data reported in the NACRE compilation in the energy region 0.6-0.8 MeV. Using the Large High resolution Array of Silicons for Astrophysics (LHASA), we performed a new direct measurement of the 19F(ρ,α)16O. The goal of this experiment is to reduce the uncertainties in the nuclear reaction rate of the 19F(ρ,α)16O reaction. Here, experimental details, the calibration procedure and angular distributions are presented.

scholarly journals Bhabha scattering in very special relativity at finite temperature

2020 ◽  
Vol 80 (8) ◽  
Author(s):  
Alesandro Ferreira dos Santos ◽  
Faqir C. Khanna
Keyword(s):  
Differential Cross Section ◽  
Special Relativity ◽  
Cross Section ◽  
Differential Cross ◽  
Local Form ◽  
Bhabha Scattering ◽  
Thermo Field Dynamics ◽  
Different Types ◽  
Non Local ◽  
Very Special Relativity

Abstract In this paper the differential cross section for Bhabha scattering in the very special relativity (VSR) framework is calculated. The main characteristic of the VSR is to modify the gauge invariance. This leads to different types of interactions appearing in a non-local form. In addition, using the Thermo Field Dynamics formalism, thermal corrections for the differential cross section of Bhabha scattering in VSR framework are obtained.

scholarly journals Prevalence of Gastrointestinal Helminth Infections in Indigenous Chickens of Selected Areas of Barisal District, Bangladesh

2014 ◽  
Vol 12 (2) ◽  
pp. 135-139 ◽  
Author(s):  
MN Alam ◽  
M Mostofa ◽  
MAHNA Khan ◽  
MA Alim ◽  
AKMA Rahman ◽  
...  
Keyword(s):  
Cross Section ◽  
Helminth Parasites ◽  
Ascaridia Galli ◽  
Routine Examination ◽  
Pathological Lesions ◽  
Heterakis Gallinarum ◽  
Indigenous Chickens ◽  
Gastrointestinal Helminth ◽  
Helminth Infections ◽  
Different Types

The prevalence of gastrointestinal helminth infections and the gross pathological lesions produced by them were studied from February 2012 to January 2013 in the Department of Pharmacology of Bangladesh Agricultural University, Mymensingh. In this study, a total of 320 indigenous chickens aged ranging from 2 to 4 months were examined to identify the different types of gastrointestinal helminth infections in indigenous chickens. During routine examination, six species of helminth parasites were recorded, of which five species of nematodes such as Ascaridia galli, Heterakis gallinarum, Capillaria spp, Acuaria hamulosa and Dispharynx spiralis; and one species was cestode called Raillietina tetragona. The highest prevalence was observed for Ascaridia galli (41.56%) followed in descending order by Raillietina tetragona (19.68%), Heterakis gallinarum (15.62%), Acuaria hamulosa (8.75%), Capillaria spp. (4.68% ) and Disopharinx spiralis (1.56%). The gross pathological lesions were observed in case of Acuaria hamulosa and Heterakis gallinarum infection. In case of Acuaria hamulosa infection keratinization of gizzard mucosa and cross section of adult Acuaria hamulosa were seen along with marked infiltration of neutrophils. The results of this study suggest that both nematodes and cestodes are highly prevalent in indigenous chickens in the studied area.DOI: http://dx.doi.org/10.3329/bjvm.v12i2.21275 Bangl. J. Vet. Med. (2014). 12 (2): 135-139 

scholarly journals Effects of Using Channelling Devices to Increase Efficiency of Hydrokinetic Devices

2015 ◽  
Vol 52 (2) ◽  
pp. 3-12
Author(s):  
A. Kalnacs ◽  
J. Kalnacs ◽  
A. Mutule ◽  
V. Entins
Keyword(s):  
Flow Control ◽  
Flow Velocity ◽  
Cross Section ◽  
Power Output ◽  
High Importance ◽  
Different Types ◽  
The Cross ◽  
Increase Efficiency ◽  
Flow Velocities

Abstract In the rivers of Latvia and of many other countries the flow velocity in the places that are most suitable for installation of hydrokinetic devices is 0.4 to 0.9 m/s. In a stream or a river the hydrokinetic devices can reach full efficiency starting from about twice higher flow velocities. It is advisable to at least double this velocity thus increasing the efficiency and power output of the hydrokinetic devices installed in such places. Since Latvia has abundance of slow rivers and almost none are fast, research in this field is of high importance. Diversified technical methods are known that allow increasing substantially the efficiency of hydrokinetic devices. These methods include the use of diffusers, concentrators, different types of other channelling devices and means of flow control. Desirable effects are achieved through changing the cross-section and/or direction of a flow, its pressure, minimizing the turbulence, etc. This work substantiates the use of such devices for increasing the efficiency of hydrokinetic devices. A method is proposed for evaluation of the effects on power output gained owing to the use of channelling devices. Results show that the efficiency of hydrokinetic devices can be increased by at least 110%.

scholarly journals Thermal Stresses in the Wall Connections of Cast Grate Structures

2016 ◽  
Vol 16 (4) ◽  
pp. 11-16 ◽  
Author(s):  
A. Bajwoluk ◽  
P. Gutowski
Keyword(s):  
Heat Treatment ◽  
Cross Section ◽  
Hot Spots ◽  
Thermal Stresses ◽  
Cooling Process ◽  
Temperature Variations ◽  
Temperature Changes ◽  
Different Types ◽  
The Difference ◽  
The Impact

Abstract The purpose of this study was to establish a relationship between the type of wall connection used in the cast grates, which are part of the equipment operating in furnaces for heat treatment and thermal-chemical treatment, and stresses generated in these grates during the process of rapid cooling. The places where the grate walls are connected to each other are usually characterized by the thickness larger than the remaining parts of walls. Temperature variations in those places are responsible for the formation of hot spots, and in the hot spots temperature changes much more slowly. The type of wall connection shapes the temperature gradient in the joint cross-section, and hence also the value of thermal stresses generated during cooling. In this study, five different designs of the grates were compared; the difference in them was the type of the designed wall connection. The following design variants were adopted in the studies: X connections with and without holes, T connections with and without technological recesses, and R (ring) connection. Numerical analysis was performed to examine how the distribution of temperature changes in the initial phases of the cooling process. The obtained results served next as a tool in studies of the stress distribution in individual structures. The analysis were carried out by FEM in Midas NFX 2014 software. Based on the results obtained, the conclusions were drawn about the impact of different types of wall connections on the formation of thermal stresses in cast grates.

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