Innovative Testing Investigations on the Influence of Particle Morphology and Oil Contamination on the Geotechnical Properties of Sand

Shear strength and the permeability in a soil mass are two prime parameters that characterize the geotechnical behaviour of the soil. These parameters (c', Ø’, k) help assess the bearing capacity and settlement characteristics of foundations, stability of slopes, lateral earth pressure on retaining walls and fluid infiltration. Geo environmental contamination resulting from chemicals and oil spills are becoming very common news and these  alter the inter-particle behaviour of the soil, making it to lose its strength and deformability considerably and also become less permeable. This study focuses on the effects of contamination of sands with different grading size and particle shapes on its shear strength and its coefficient of permeability. Well graded and gap graded sand samples were used in the research. A simple statistical approach was used to define not only the particle size but also its shape distribution. Comparison of the shear strength of these sand samples were tested in an automated motorised direct shear apparatus under both dry and fully saturated conditions (with water and also with oil). The coefficient of permeability of the two sands under clean and contaminated conditions was obtained using a modified falling head permeability test. It was observed that the well graded sand which was submerged in oil apparently had the lowest peak shear strength values. However, a higher order of cohesion was apparent when the soil was contaminated with oil. Permeability was also an issue, as by virtue of its viscosity, the oil hindered the water seepage through the sand samples when compared with clean sands. However, it appeared that with more viscous liquid contaminants, the rate of water infiltration was notably higher. Permeability was also affected by the particle grading and shape distribution. The significant loss in strength and the tortuosity of water flow in the soils can cause major problems such as unwarranted floods and potential failures in civil engineering works. Therefore, the extent of the problem that is caused by oil contamination needs to be truly understood to minimize unwarranted construction risk.&nbsp

SALINAS - An implicit finite element structural dynamics code developed for massively parallel platforms

As computational needs for structural finite element analysis increase, a robust implicit structural dynamics code is needed which can handle millions of degrees of freedom in the model and produce results with quick turn around time. A parallel code is needed to avoid limitations of serial platforms. Salinas is an implicit structural dynamics code specifically designed for massively parallel platforms. It computes the structural response of very large complex structures and provides solutions faster than any existing serial machine. This paper gives a current status of Salinas and uses demonstration problems to show Salinas' performance

The Public\u27s Perception of an Earthquake Early Warning System: A Study on Factors Influencing Continuance Intention

This paper investigates the perceptions of the New Zealand public towards the Android Earthquake Alert (AEA) system, a public-facing earthquake early warning system. Specifically, it examines the public’s continuance intention towards the AEA system and the influencing factors of satisfaction, confirmation, perceived usefulness, and perceived trust. To gather insights into the public’s perceptions regarding the AEA system, this study distributed online surveys following two separate earthquake alert events on 12 October and 22 October 2021. A total of 524 and 671 participants responded to the two events’ surveys, providing valuable data for analysis and exploration. Structural Equation Modelling of the two datasets revealed that the continuance model fit the data to some extent, especially on the significance of perceived usefulness and perceived trust to continuance intention. However, the results also showed varying results for satisfaction’s relationship with perceived trust and continuance intention. These findings underscore the need for further investigation into the role of satisfaction and perceived trust, considering the evolving nature of EEW technologies and users’ familiarity over time. The descriptive and inferential analysis results raised concerns about potential confusion around the alerts’ source and highlighted the question of responsibility and liability for EEW. Overall, this study contributes to understanding continuance intention in the EEW context and provides insights into the public’s perception of the AEA system in New Zealand. The findings have implications more broadly for EEW systems’ design, implementation, and communication strategies

Scattering by coupled resonating elements in air

Scattering by (a) a single composite scatterer consisting of a concentric arrangement of an outer N-slit rigid cylinder and an inner cylinder which is either rigid or in the form of a thin elastic shell and (b) by a finite periodic array of these scatterers in air has been investigated analytically and through laboratory experiments. The composite scatterer forms a system of coupled resonators and gives rise to multiple low-frequency resonances. The corresponding analytical model employs polar angle dependent boundary conditions on the surface of the N-slit cylinder. The solution inside the slits assumes plane waves. It is shown also that in the low-frequency range the N-slit rigid cylinder can be replaced by an equivalent fluid layer. Further approximations suggest a simple square root dependence of the resonant frequencies on the number of slits and this is confirmed by data. The observed resonant phenomena are associated with Helmholtz-like behaviour of the resonator for which the radius and width of the openings are much smaller than the wavelength. The problem of scattering by a finite periodic array of such coupled resonators in air is solved using multiple scattering techniques. The resulting model predicts band-gap effects resulting from the resonances of the individual composite scatterers below the first Bragg frequency. Predictions and data confirm that use of coupled resonators results in substantial insertion loss peaks related to the resonances within the concentric configuration. In addition, for both scattering problems experimental data, predictions of the analytical approach and predictions of the equivalent fluid layer approximations are compared in the low-frequency interval

Conservation Status of the Southern Appalachian Herpetofauna

Seventy one species of amphibians (55 salamanders, 16 anurans) and 46 species of reptiles (15 turtles, 8 lizards, 23 snakes) inhabit a five state area (Kentucky, North Carolina, Tennessee, Virginia, West Virginia) in the southern Appalachian region bordered by the Potomac River, the Blue Ridge Mountains, and the western margin of the Appalachian Plateau. Of these, 47.9 % of the amphibian fauna and 52.2 % of the reptilian fauna are listed as being of conservation concern by federal, state, and Natural Heritage programs in all or a portion of their ranges of this region. The Shenandoah salamander (Plethodon Shenandoah) is listed as Endangered and the Cheat Mountain salamander (Plethodon Shenandoah) is listed as Endangered and the Cheat Mountain salamander (Plethodon nettingi) is listed as Threatened under the U.S. Endangered Species Act. Nine others are classified as federal species at risk. State endangered species number 1-3 (per state), threatened 1-4, and special concern or declining 6-19. Three to 6 species per state are additionally listed as natural heritage S1 and 2-13 as S2. We review the existing and potential threats to species and populations (e.g., timbering, urbanization, collection for the wildlife trade, acid precipitation, introduced species) and provide an assessment of the conservation status of the southern Appalachian herpetofauna based on land ownership

Corrosion Inhibition of Sodium Silicate with Nanosilica as Coating in Pre-Corroded Steel

This study was conducted to investigate the potential of using sodium silicate with nanosilica as a treatment to inhibit the progress of corrosion in steel specimens that are already corroded. Steel specimens measuring 16 mm in diameter and 4 mm in thickness were prepared and subjected to pre-corrosion by immersion to 3.5% NaCl solution. Two sets of specimens were then dip-coated with sodium silicate containing nanosilica. One set was coated with 1% nanosilica, and the other was coated with 2.5% nanosilica. The coated specimens were then subjected to Complex Impedance Spectroscopy (CIS) at 20 Hz to 20 MHz frequency range. Compared with the sodium silicate coating with 1% nanosilica, the sodium silicate coating with 2.5% nanosilica had a larger semi-circle curve in the Nyquist plot. Similarly, the sodium silicate coating with 2.5% nanosilica also showed larger magnitudes of impedance at the low-frequency region and larger phase angles at the high-frequency regions in the Bode plot. These results imply that the sodium silicate coating with 2.5% nanosilica coating demonstrated better capacitive behavior. In addition, equivalent circuit modelling results also showed that the sodium silicate coating with 2.5% nanosilica had higher coating resistance and lower coating capacitance as compared to the sodium silicate coating with 1% nanosilica. Doi: 10.28991/cej-2021-03091761 Full Text: PD

Induced pseudoscalar coupling of the proton weak interaction

The induced pseudoscalar coupling $g_p$ is the least well known of the weak coupling constants of the proton's charged--current interaction. Its size is dictated by chiral symmetry arguments, and its measurement represents an important test of quantum chromodynamics at low energies. During the past decade a large body of new data relevant to the coupling $g_p$ has been accumulated. This data includes measurements of radiative and non radiative muon capture on targets ranging from hydrogen and few--nucleon systems to complex nuclei. Herein the authors review the theoretical underpinnings of $g_p$, the experimental studies of $g_p$, and the procedures and uncertainties in extracting the coupling from data. Current puzzles are highlighted and future opportunities are discussed.Comment: 58 pages, Latex, Revtex4, prepared for Reviews of Modern Physic

Expression of SMARCD1 interacts with age in association with asthma control on inhaled corticosteroid therapy.

BackgroundGlobal gene expression levels are known to be highly dependent upon gross demographic features including age, yet identification of age-related genomic indicators has yet to be comprehensively undertaken in a disease and treatment-specific context.MethodsWe used gene expression data from CD4+ lymphocytes in the Asthma BioRepository for Integrative Genomic Exploration (Asthma BRIDGE), an open-access collection of subjects participating in genetic studies of asthma with available gene expression data. Replication population participants were Puerto Rico islanders recruited as part of the ongoing Genes environments & Admixture in Latino Americans (GALA II), who provided nasal brushings for transcript sequencing. The main outcome measure was chronic asthma control as derived by questionnaires. Genomic associations were performed using regression of chronic asthma control score on gene expression with age in years as a covariate, including a multiplicative interaction term for gene expression times age.ResultsThe SMARCD1 gene (SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily D member 1) interacted with age to influence chronic asthma control on inhaled corticosteroids, with a doubling of expression leading to an increase of 1.3 units of chronic asthma control per year (95% CI [0.86, 1.74], p = 6 × 10- 9), suggesting worsening asthma control with increasing age. This result replicated in GALA II (p = 3.8 × 10- 8). Cellular assays confirmed the role of SMARCD1 in glucocorticoid response in airway epithelial cells.ConclusionFocusing on age-dependent factors may help identify novel indicators of asthma medication response. Age appears to modulate the effect of SMARCD1 on asthma control with inhaled corticosteroids

Rubber-Tree Leaf Diseases Mapping Using Close Range Remote Sensing Images

 Currently, close-range remote sensing method using drone-based platform which payload compact sensor has been used for monitoring and mapping in the agriculture sector at large area. Thus, this study is deployed drone with a compact sensor to identify the rubber tree leaf diseases based on two groups of a spectral wavelength which are visible (RGB: 0.4 µm – 0.7 µm) and near infrared (NIR: 0.7µm – 2.0 µm), respectively. Spectral obtained from drone-based platform will be validated using ground observation handheld spectroradiometer. Eight types of rubber tree clones leaf at three different conditions (healthy, unhealthy and severe) were randomly selected within the 9.4-hectare Experimental Rubber Plot, Rubber Research Institute of Malaysia (RRIM), Kota Tinggi, Johor whereby consist RRIM 2000 series, RRIM 3000 series, and PB series, respectively. Based on the result, quantitative analysis shows that the f-value is smaller than Critical-one tail for healthy, unhealthy while for severe the f-value is larger than Critical-one tail. The f-value is 2.887 < 4.283 (healthy), 0.002 < 0.264 (unhealthy) and 1.008 > 0.0526, respectively. Thus, this can be concluded that spectral and estimate is equal at the 0.05 significant levels. For qualitative analysis, it shows that each rubber clone tree diseases can be distinguished at the near infrared band for healthy, unhealthy and severe respectively

Rubber-Tree Leaf Diseases Mapping Using Close Range Remote Sensing Images

 Currently, close-range remote sensing method using drone-based platform which payload compact sensor has been used for monitoring and mapping in the agriculture sector at large area. Thus, this study is deployed drone with a compact sensor to identify the rubber tree leaf diseases based on two groups of a spectral wavelength which are visible (RGB: 0.4 µm – 0.7 µm) and near infrared (NIR: 0.7µm – 2.0 µm), respectively. Spectral obtained from drone-based platform will be validated using ground observation handheld spectroradiometer. Eight types of rubber tree clones leaf at three different conditions (healthy, unhealthy and severe) were randomly selected within the 9.4-hectare Experimental Rubber Plot, Rubber Research Institute of Malaysia (RRIM), Kota Tinggi, Johor whereby consist RRIM 2000 series, RRIM 3000 series, and PB series, respectively. Based on the result, quantitative analysis shows that the f-value is smaller than Critical-one tail for healthy, unhealthy while for severe the f-value is larger than Critical-one tail. The f-value is 2.887 < 4.283 (healthy), 0.002 < 0.264 (unhealthy) and 1.008 > 0.0526, respectively. Thus, this can be concluded that spectral and estimate is equal at the 0.05 significant levels. For qualitative analysis, it shows that each rubber clone tree diseases can be distinguished at the near infrared band for healthy, unhealthy and severe respectively