penetration tests
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2021 ◽  
Vol 24 (3-4) ◽  
pp. 159-167
Author(s):  
Jef DECKERS ◽  
Jasper VERHAEGEN ◽  
Ilse VERGAUWEN

The sandy Zandvliet Member represents a particular, decalcified facies in the top of the Pliocene Lillo Formation in northern Belgium. Based on the correlation with nearby boreholes at the type locality of the Zandvliet Member, we were able to characterize this unit on Cone Penetration Tests. Compared to the underlying Merksem Member, the Zandvliet Member generally shows markedly lower cone resistance values. Since besides the decalcification, the Zandvliet Member is lithologically nearly identical to the underlying Merksem Member, the lower cone resistance values in the Zandvliet Member compared to the Merksem Member can only be the result of the decalcification of the Zandvliet Member. Indeed, the partly decalcified top of the Merksem Member also gives similar cone resistance values as the Zandvliet Member. Decalcification of the Eocene Brussel Sand in central Belgium is also known to have resulted in lower cone resistance values. Our Cone Penetration Test interpretations show that the thickness of the Zandvliet Member strongly varies across short distances (>10 m across 1 km). As the Zandvliet Member thickens, the underlying Merksem Member thins and vice versa. This trend is not in line with that of the under- and overlying strata, i.e. intraformational, nor with the depositional environment of these units. The thickness changes of the Zandvliet Member therefore purely reflect changes in depth of the post-depositional decalcification into the original shell-bearing sand (i.e. original Merksem Member). This confirms the existing hypothesis that the Zandvliet Member actually represents the decalcified part of the Merksem Member. The anomalous heavy mineralogy of the Zandvliet Member compared to the other members of the Lillo Formation cannot be readily explained by the acid chemical weathering which caused the decalcification. This may rather be related to a change in the primary heavy mineral signal of the upper part of the Merksem Member and equivalent Zandvliet Member compared to the underlying sequences of the Lillo Formation. The reason for the post-depositional decalcification could be similar to the Pleistocene changes in soil acidity invoked for decalcification of time-equivalent Red Crag sand in England.


Batteries ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 81
Author(s):  
Yiqun Liu ◽  
Yitian Li ◽  
Y. Gene Liao ◽  
Ming-Chia Lai

The nail penetration test has been widely adopted as a battery safety test for reproducing internal short-circuits. In this paper, the effects of cell initial State-of-Charge (SOC) and penetration location on variations in cell temperature and terminal voltage during penetration tests are investigated. Three different initial SOCs (10%, 50%, and 90%) and three different penetration locations (one is at the center of the cell, the other two are close to the edge of the cell) are used in the tests. Once the steel cone starts to penetrate the cell, the cell terminal voltage starts to drop due to the internal short-circuit. The penetration tests with higher initial cell SOCs have larger cell surface temperature increases during the tests. Also, the penetration location always has the highest temperature increment during all penetration tests, which means the heat source is always at the penetration location. The absolute temperature increment at the penetration location is always higher when the penetration is close to the edge of the cell, compared to when the penetration is at the center of the cell. The heat generated at the edges of the cell is more difficult to dissipate. Additionally, a battery cell internal short-circuit model with different penetration locations is built in ANSYS Fluent, based on the specifications and experimental data of the tested battery cells. The model is validated with an acceptable discrepancy range by using the experimental data. Simulated data shows that the temperature gradually reduces from penetration locations to their surroundings. The gradients of the temperature distributions are much larger closer to the penetration locations. Overall, this paper provides detailed information on the temperature and terminal voltage variations of a lithium-ion polymer battery cell with large capacity and high power under penetration tests. The presented information can be used for assessing the safety of the onboard battery pack of electric vehicles.


Author(s):  
Isabelle Böhm ◽  
Samuel Lolagar

AbstractOpen Source Intelligence (OSINT) has gained importance in more fields of application than just in intelligence agencies. This paper provides an overview of the fundamental methods used to conduct OSINT investigations and presents different use cases where OSINT techniques are applied. Different models of the information cycle applied to OSINT are addressed. Additionally, the terms data, information, and intelligence are explained and correlated with the intelligence cycle. A classification system for entities during OSINT investigations is introduced. By presenting the capabilities of modern search engines, techniques for research within social networks and for penetration tests, the fundamental methods used for information gathering are explained. Furthermore, possible countermeasures to protect one’s privacy against the misuse of openly available information as well as the legal environment in Germany, and the ethical perspective are discussed.


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Yuhao Gao ◽  
Jianzhong Li ◽  
Yuxin Zhang ◽  
Xu Sun ◽  
Leiyong Yang

The effectiveness and improvement mechanism of graphite nanoparticles (GN) in strength properties and microstructure characteristics of regional laterite were analysed in this study. Dry density was also taken into consideration, and the effects of graphite nanoparticle (GN) content and dry density were mainly addressed. Triaxial tests, consolidation tests, and penetration tests were used to analyse the effectiveness of different dry densities and graphite nanoparticle mass ratios on the properties of laterite; microscopic methods such as scanning electron microscopy (SEM) tests were used to analyse the improvement mechanism. The results show that the increase in dry density can make the laterite more compact. The large specific surface area and nanoeffects of the graphite nanoparticles (GN) induce the attraction between soil particles after mixing, both of which make the laterite’s shear strength; compression index and impermeability have been enhanced to varying degrees. The microscopic tests showed that, as the content of graphite nanoparticles (GN) continues to increase, when it exceeds 1.0%, the attraction between soil particles increases and coarse particles are formed, which leads to the increase of the pores of the soil. In addition, the graphite nanoparticles have a certain degree of lubricity, a high amount of graphite nanoparticles enters the laterite soil layer, increasing the distance and gap between the layers, making it easy to separate the coarse particles from the coarse particles, and the strength increase is reduced. However, it is still stronger than that of the plain laterite.


Author(s):  
Ch. Mary Pushpa ◽  
K.V.M Udaya Lakshmi ◽  
S. Hepsibha

This paper will discuss the topic of ethical hacking, which is also called penetration testing. It starts by briefing about the ethical hacking introduction and its key protocols. It will further discuss the varied classifications of hacking and explain the causes for the swift rise in the cyber-crimes and their impact on socio-economic growth. The advantages and limitations of ethical hacking are also listed. It will further discuss the steps involved in ethical hacking, who is allowed to conduct ethical hacking, and its importance in order to reduce the effect of these attacks, penetration tests are highly required, to consider an acceptable solution for this task. Results from the case study shows that there are negative impacts where the society suffers from cybercrimes and why the computer or networking tools are targeted for the crimes. Ethical hacking education can provide the future professionals to combat the future cyber security issues.


2021 ◽  
Vol 24 (1) ◽  
Author(s):  
Mingjing Jiang ◽  
Tao Zhao ◽  
Xingxing Wang

Author(s):  
Noor M. Mohamed Nihaaj ◽  
Takashi Kiyota ◽  
Matthew Gapuz Chua

When disintegrated mudstone due to the slaking, subjected to hydraulic pressure, could lead to internal erosion. To examine the combined effects of slaking and internal erosion of gravelly mudstone in 1D deformation under a constant vertical load, a series of modified oedometer tests and laboratory penetration tests were conducted with drying/wetting and hydraulic pressure cycles. Some loading conditions showed the sever erosion in progressing of the cycle, susceptibility of the internal erosion was evaluated in terms of non-filter and fitter factors coefficient Keywords: Vertical strain, Slaking, Internal-erosion, Particle-breakage.


2021 ◽  
Vol 920 (1) ◽  
pp. 012005
Author(s):  
M Z A M Zahid ◽  
B H A Bakar ◽  
F M Nazri ◽  
H Alasmari ◽  
M F P M Latiff ◽  
...  

Abstract This current study attempts to investigate the mechanical, durability as well as rheology properties of Ultra-High Performance Concrete (UHPC) with low cement content and using coarse aggregate. The cement content used in UHPC mix in current study was 800 kg/m3. The slump flow, compressive strength, splitting tensile strength, modulus of elasticity, water absorption and water penetration tests were conducted to determine the workability, mechanical and durability properties of explored UHPC mixture. The test results show that the above properties were exceptional and comparable with other UHPC mixtures.


Author(s):  
Chun Li ◽  
Xinxing Bian ◽  
Qifeng Dong ◽  
Huining Xu

Abstract Under multi-wheel heavy load, the asphalt mixture is prone to exhibit the deformation superposition effect, which exacerbates the damage of pavement structure. Multi-point penetration tests and numerical simulations by discrete element method (DEM) are performed to investigate the deformation superposition effect and micromechanical characteristics of asphalt mixture. The effect of wheel spacing, wheel group, and the evolution of micromechanical deformation superposition behavior are analyzed. Results indicate that the deformation superposition resistance of the asphalt mixture under the multi-wheel load decreases dramatically with the decrease in wheel spacing and the increase in the number of wheels, specifically the wheel spacing is 54 mm and the number of wheels is 4. The DEM simulations reflect the micromechanical property of asphalt mixture in the multi-point penetration test. The reduction of tensile chains is the internal reason for asphalt mixture deformation superposition, indicating the decrease of the adhesive strength of the material. A remarkably positive correlation is found between the reduction of the tensile chain and the deformation effect coefficient. In the process of superposition, the aggregate skeleton force chains are gradually destroyed and decrease to zero until cracking. The numerical simulation outcome is consistent with the laboratory penetration test outcome.


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