scholarly journals A Method to Predict Rock Fracture with Infrared Thermography Based on Heat Diffusion Analysis

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Nai-Fu Deng ◽  
Lan Qiao ◽  
Qing-wen Li ◽  
Jia-Wang Hao ◽  
Shan Wu
Keyword(s):  
Temperature Field ◽  
Infrared Radiation ◽  
Direct Detection ◽  
Diffusion Theory ◽  
Rock Fracture ◽  
Heat Diffusion ◽  
Indirect Detection ◽  
Rock Surface ◽  
True Triaxial ◽  
The Real

The forming of micro or mesocracks on rock surfaces is a symptom and precursor of the degradation of deep surrounding rocks under excavation. However, the direct detection or observation of these tiny developed cracks is not practical due to the limitation of current instruments which can only capture and recognize macrocracks. Therefore, many indirect detection ways are proposed to acquire some precautional signals and hereby forestall damage and failure of surrounding rocks. Infrared radiation (IRR) monitoring is one of the frequently used technologies. Current thermography derived from IRR can capture all temperature changes including the surrounding environment; this may influence the on-site judgement due to uncertainty or blur of generated temperature images. This paper proposes the “pseudothermography” under the true triaxial compressive test by combining the infrared radiation data and the heat diffusion theory. Our method evenly selects 25 small regions on the observed rock surface and uses the data obtained from these regions to derive the global temperature field which contains no uncertainty. By comparing our method with the real temperature field, the deduced diffusion model proposed in this paper can relatively reflect the real crack initiation under increasing loading. The experiment result proves that the attempt for the application of heat diffusion law is feasible to indirectly reflect the formation of micro and mesocracks and, ultimately, foresee the failure of the surrounding rock.

scholarly journals Effective field theory analysis of dark matter-standard model interactions with spin one mediators

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Fabiola Fortuna ◽  
Pablo Roig ◽  
José Wudka
Keyword(s):  
Field Theory ◽  
Dark Matter ◽  
Standard Model ◽  
Effective Field Theory ◽  
Gamma Ray ◽  
Direct Detection ◽  
Effective Field ◽  
Indirect Detection ◽  
Theory Analysis ◽  
Invisible Decay

Abstract We analyze interactions between dark matter and standard model particles with spin one mediators in an effective field theory framework. In this paper, we are considering dark particles masses in the range from a few MeV to the mass of the Z boson. We use bounds from different experiments: Z invisible decay width, relic density, direct detection experiments, and indirect detection limits from the search of gamma-ray emissions and positron fluxes. We obtain solutions corresponding to operators with antisymmetric tensor mediators that fulfill all those requirements within our approach.

scholarly journals DARK MATTER DYNAMICS AND INDIRECT DETECTION

2005 ◽  
Vol 20 (14) ◽  
pp. 1021-1036 ◽  
Author(s):  
GIANFRANCO BERTONE ◽  
DAVID MERRITT
Keyword(s):  
Dark Matter ◽  
Total Mass ◽  
Galactic Center ◽  
Direct Detection ◽  
Indirect Detection ◽  
Matter Distribution ◽  
Dark Matter Distribution ◽  
Particle Dark Matter ◽  
The Universe ◽  
Rule Out

Non-baryonic, or "dark", matter is believed to be a major component of the total mass budget of the Universe. We review the candidates for particle dark matter and discuss the prospects for direct detection (via interaction of dark matter particles with laboratory detectors) and indirect detection (via observations of the products of dark matter self-annihilations), focusing in particular on the Galactic center, which is among the most promising targets for indirect detection studies. The gravitational potential at the Galactic center is dominated by stars and by the supermassive black hole, and the dark matter distribution is expected to evolve on sub-parsec scales due to interaction with these components. We discuss the dominant interaction mechanisms and show how they can be used to rule out certain extreme models for the dark matter distribution, thus increasing the information that can be gleaned from indirect detection searches.

scholarly journals Signatures of Majorana dark matter with t-channel mediators

2015 ◽  
Vol 24 (07) ◽  
pp. 1530019 ◽  
Author(s):  
Mathias Garny ◽  
Alejandro Ibarra ◽  
Stefan Vogl
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Direct Detection ◽  
Dark Matter Particle ◽  
Search Strategies ◽  
Indirect Detection ◽  
Majorana Fermion ◽  
The Standard Model ◽  
Full Benefit ◽  
Near Future

Three main strategies are being pursued to search for nongravitational dark matter signals: direct detection, indirect detection and collider searches. Interestingly, experiments have reached sensitivities in these three search strategies which may allow detection in the near future. In order to take full benefit of the wealth of experimental data, and in order to confirm a possible dark matter signal, it is necessary to specify the nature of the dark matter particle and of the mediator to the Standard Model. In this paper, we focus on a simplified model where the dark matter particle is a Majorana fermion that couples to a light Standard Model fermion via a Yukawa coupling with a scalar mediator. We review the observational signatures of this model and we discuss the complementarity among the various search strategies, with emphasis in the well motivated scenario where the dark matter particles are produced in the early universe via thermal freeze-out.

scholarly journals Charged scalar production at the compact linear collider for the $$S_3 \otimes \mathbb {Z}_2$$ model

2020 ◽  
Vol 80 (11) ◽  
Author(s):  
G. De Conto ◽  
A. C. B. Machado ◽  
J. Montaño ◽  
P. Chimenti
Keyword(s):  
Total Cross Section ◽  
Cross Section ◽  
Linear Collider ◽  
Direct Detection ◽  
Indirect Detection ◽  
Tree Level ◽  
Charged Scalar ◽  
Exotic Particles ◽  
Small Influence ◽  
The Masses

AbstractWe present a model with $$S_3 \otimes \mathbb {Z}_2$$ S 3 ⊗ Z 2 model plus a sterile neutrino and its phenomenological expectations for the production of charged scalars at the compact linear collider. At tree level, our model predicts a total cross section in between 0.1 and $$10^{-5}$$ 10 - 5 pb for the $$e^- e^+ \rightarrow H^+ H^-$$ e - e + → H + H - process, considering all possible mass values for the charged scalar in the CLIC experiment. We also show that this prediction holds regardless of the masses of the other exotic particles and their couplings. We also show that an indirect detection from its effects in the $$e \overline{e} \rightarrow e \overline{e}$$ e e ¯ → e e ¯ + missing energy process is possible under specific conditions, or a direct detection under other circumstances. However, one cannot use this process to study the sterile neutrinos present in this model, given that they have a small influence in the total cross-section for the direct detection of the exotic scalar to be possible.

Detection and Enumeration of Salmonella Enteritidis in Homemade Ice Cream Associated with an Outbreak: Comparison of Conventional and Real-Time PCR Methods

2006 ◽  
Vol 69 (3) ◽  
pp. 639-643 ◽  
Author(s):  
K. H. SEO ◽  
I. E. VALENTIN-BON ◽  
R. E. BRACKETT
Keyword(s):  
Real Time ◽  
Quantitative Pcr ◽  
Real Time Pcr ◽  
Salmonella Enteritidis ◽  
Direct Detection ◽  
Ice Cream ◽  
Plate Count ◽  
Pcr Assay ◽  
The Real ◽  
Real Time Quantitative Pcr

Salmonellosis caused by Salmonella Enteritidis (SE) is a significant cause of foodborne illnesses in the United States. Consumption of undercooked eggs and egg-containing products has been the primary risk factor for the disease. The importance of the bacterial enumeration technique has been enormously stressed because of the quantitative risk analysis of SE in shell eggs. Traditional enumeration methods mainly depend on slow and tedious most-probable-number (MPN) methods. Therefore, specific, sensitive, and rapid methods for SE quantitation are needed to collect sufficient data for risk assessment and food safety policy development. We previously developed a real-time quantitative PCR assay for the direct detection and enumeration of SE and, in this study, applied it to naturally contaminated ice cream samples with and without enrichment. The detection limit of the real-time PCR assay was determined with artificially inoculated ice cream. When applied to the direct detection and quantification of SE in ice cream, the real-time PCR assay was as sensitive as the conventional plate count method in frequency of detection. However, populations of SE derived from real-time quantitative PCR were approximately 1 log higher than provided by MPN and CFU values obtained by conventional culture methods. The detection and enumeration of SE in naturally contaminated ice cream can be completed in 3 h by this real-time PCR method, whereas the cultural enrichment method requires 5 to 7 days. A commercial immunoassay for the specific detection of SE was also included in the study. The real-time PCR assay proved to be a valuable tool that may be useful to the food industry in monitoring its processes to improve product quality and safety.

Modeling of Titanium Oxide Layer Growth Produced by Fiber Laser Beam

2013 ◽  
Vol 336 ◽  
pp. 11-18 ◽  
Author(s):  
Farida Hamadi ◽  
El Hachemi Amara ◽  
Djamila Bennaceur-Doumaz ◽  
R. Boutaka ◽  
H. Kellou ◽  
...  
Keyword(s):  
Temperature Field ◽  
Laser Beam ◽  
Film Growth ◽  
Three Dimensional ◽  
Layer Growth ◽  
Heat Diffusion ◽  
Metallic Surface ◽  
Heat Diffusion Equation ◽  
Computational Procedures ◽  
Volume Method

In this paper, we study the oxidation process during the heating of a titanium metallic surface by a Nd-YAG fiber pulsed laser beam under air environment. For this, we adopted an approach that considers a three-dimensional heat diffusion model coupled with an oxidation parabolic law (oxidation kinetics). The heat diffusion equation solved numerically, gives the temperature field. The oxide film growth is simulated by implementing a dynamic mesh technique. We developed computational procedures UDFs (User Defined Function) running interactively with the Fluent fluid dynamics software [ that implements the finite volume method. These UDFs are developed to insert the oxidation law, the temperature field, the specific boundary conditions and the mesh deformation into the calculation.

scholarly journals Research on the Mechanical Characteristics of Cyclic Loading and Unloading of Rock Based on Infrared Thermal Image Analysis

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Lewen Wu ◽  
Keping Zhou ◽  
Feng Gao ◽  
Zhongyuan Gu ◽  
Chun Yang
Keyword(s):  
Temperature Field ◽  
Cyclic Loading ◽  
Infrared Radiation ◽  
Energy Analysis ◽  
Heating Zone ◽  
Characteristic Analysis ◽  
Temperature Zone ◽  
Energy Accumulation ◽  
Cyclic Loading And Unloading ◽  
Loading And Unloading

In the operations of underground rock engineering, such as mining, the formation of goafs is often accompanied by unloading and energy effects. In this study, a cyclic loading and unloading stress test is carried out to analyze the strength characteristics of the loaded samples under different loading and unloading ranges as well as different numbers of cycles. The rock force is accompanied by substantial energy changes. To better fit the energy analysis under cyclic loading and unloading conditions, thermal infrared radiation characteristic analysis is performed during rock loading and unloading. An infrared radiation camera is adopted to detect the infrared characteristics of the rock force process after cyclic loading and unloading. Multiangle detection is implemented on the temperature, temperature field, and frequency histogram. The analysis shows that cyclic loading and unloading first strengthen and then weaken the rock. Moreover, the failure caused by the local stress concentration leads to a sharp increase in the temperature. There are significant temperature fluctuations before and after failure, and the temperature field after failure can be divided into three zones, namely, the normal temperature zone, heating zone, and mutational temperature zone, to comprehensively reflect that rock compression failure which is accompanied by the process of energy accumulation and release. On the basis of infrared energy analysis, the index of the energy release rate is introduced, and the loading and unloading analysis model is constructed. The research results reveal that rock failure is accompanied by the process of energy accumulation and release, which provides evidence for the analysis of the spatial stability of the rock mass under cyclic loading and unloading conditions and engineering excavation.

scholarly journals Phylogenetics analysis of TP53 gene in humans and its use in biosensors for breast cancer diagnosis

2020 ◽  
Author(s):  
Sara da Silva Nascimento ◽  
Pierre Teodósio Félix
Keyword(s):  
Breast Cancer ◽  
Maximum Likelihood ◽  
Cancer Diagnosis ◽  
Direct Detection ◽  
Phylogenetic Signal ◽  
Neighbor Join ◽  
Breast Cancer Diagnosis ◽  
Tp53 Gene ◽  
Indirect Detection ◽  
Human Populations

AbstractBiosensors are small devices that use biological reactions to detect target analytes. Such devices combine a biological component with a physical transducer, which converts bio-recognition processes into measurable signals. Its use brings a number of advantages, as they are highly sensitive and selective, relatively easy in terms of development, as well as accessible and ready to use. Biosensors can be of direct detection, using a non-catalytic ligand, such as cell receptors and antibodies, or indirect detection, in which there is the use of fluorescently marked antibodies or catalytic elements, such as enzymes. They also appear as bio-affinity devices, depending only on the selective binding of the target analyte to the ligative attached to the surface (e.g., oligonucleotide probe). The objectives were to evaluate the levels of genetic diversity existing in fragments of the TP53 gene deposited in molecular databases and to study its viability as a biosensor in the detection of breast cancer. The methodology used was to recover and analyze 301 sequences of a fragment of the TP53 gene of humans from GENBANK, which, after being aligned with the MEGA software version 6.06, were tested for the phylogenetic signal using TREE-PUZZLE 5.2. Trees of maximum likelihood were generated through PAUP version 4.0b10 and the consistency of the branches was verified with the bootstrap test with 1000 pseudo-replications. After aligning, 783 of the 791 sites remained conserved. The maximum likelihood had a slight manifestation since the gamma distribution used 05 categories + G for the evolutionary rates between sites with (0.90 0.96, 1.00, 1.04 and 1.10 substitutions per site). To estimate ML values, a tree topology was automatically computed with a maximum Log of −1058,195 for this calculation. All positions containing missing gaps or data were deleted, leaving a total of 755 sites in the final dataset. The evolutionary history was represented by consensus trees generated by 500 replications, which according to neighbor-join and BioNJ algorithms set up a matrix with minimal distances between haplotypes, corroborating the high degree of conservation for the TP53 gene. GENE TP53 seems to be a strong candidate in the construction of Biosensors for breast cancer diagnosis in human populations.

scholarly journals Hydro-Thermo-Mechanical Analysis of an Existing Gravity Dam Undergoing Alkali–Silica Reaction

2019 ◽  
Vol 4 (3) ◽  
pp. 55 ◽  
Author(s):  
Martina Colombo ◽  
Claudia Comi
Keyword(s):  
Damage Model ◽  
Heat Diffusion ◽  
Monitoring Data ◽  
Gravity Dam ◽  
Alkali Silica Reaction ◽  
Concrete Gravity Dam ◽  
Two Phase ◽  
The Real ◽  
Diffusion Analysis ◽  
Temperature And Humidity

The alkali–silica reaction is a chemical phenomenon that, by inducing expansion and the formation of cracks in concrete, can have a severe impact on the safety and functioning of existing concrete dams. Starting from a phenomenological two-phase isotropic damage model describing the degradation of concrete, the effects of alkali-silica reaction in an existing concrete gravity dam are evaluated and compared with real monitoring data. Considering the real temperature and humidity variations, the influence of both temperature and humidity are considered through two uncoupled diffusion analyses: a heat diffusion analysis and a moisture diffusion analysis. The numerical analyses performed with the two-phase damage model allow for prediction of the structural behaviour, both in terms of reaction extent and increase of crest displacements. The crest displacements are compared with the real monitoring data, where reasonably good agreement is obtained.

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