scholarly journals Anthropocene rockfalls travel farther than prehistoric predecessors

2016 ◽  
Vol 2 (9) ◽  
pp. e1600969 ◽  
Author(s):  
Josh Walter Borella ◽  
Mark Quigley ◽  
Louise Vick
Keyword(s):  
Numerical Models ◽  
Three Dimensional ◽  
Anthropogenic Activity ◽  
Native Forest ◽  
Rockfall Hazard ◽  
Geologic Hazards ◽  
Human Modification ◽  
Before And After ◽  
European Colonization ◽  
And Behavior

Human modification of natural landscapes has influenced surface processes in many settings on Earth. Quantitative data comparing the distribution and behavior of geologic phenomena before and after human arrival are sparse but urgently required to evaluate possible anthropogenic influences on geologic hazards. We conduct field and imagery-based mapping, statistical analysis, and numerical modeling of rockfall boulders triggered by the fatal 2011 Christchurch earthquakes (n= 285) and newly identified prehistoric (Holocene and Pleistocene) boulders (n= 1049). Prehistoric and modern boulders are lithologically equivalent, derived from the same source cliff, and yield consistent power-law frequency-volume distributions. However, a significant population of modern boulders (n= 26) traveled farther downslope (>150 m) than their most-traveled prehistoric counterparts, causing extensive damage to residential dwellings at the foot of the hillslope. Replication of prehistoric boulder distributions using three-dimensional rigid-body numerical models that incorporate lidar-derived digital topography and realistic boulder trajectories and volumes requires the application of a drag coefficient, attributed to moderate to dense slope vegetation, to account for their spatial distribution. Incorporating a spatially variable native forest into the models successfully predicts prehistoric rockfall distributions. Radiocarbon dating provides evidence for 17th to early 20th century deforestation at the study site during Polynesian and European colonization and after emplacement of prehistoric rockfall. Anthropocene deforestation enabled modern rockfalls to exceed the limits of their prehistoric predecessors, highlighting a shift in the geologic expression of rockfalls due to anthropogenic activity. Reforestation of hillslopes by mature native vegetation could help reduce future rockfall hazard.

Numerical Study on Self-Consistency Centering Process of Periodic Symmetric Struts Support

2011 ◽  
Vol 462-463 ◽  
pp. 1373-1378
Author(s):  
Ji Zhe Hai ◽  
Mamtimin Gheni ◽  
Wei Bing Liu ◽  
Wei Chen ◽  
Lie Yu
Keyword(s):  
Thermal Deformation ◽  
Transfer Problem ◽  
Numerical Study ◽  
Numerical Models ◽  
Three Dimensional ◽  
Internal Flow ◽  
Three Dimensional Model ◽  
Temperature State ◽  
Before And After ◽  
The Impact

In this paper，the simplified three-dimensional model of Periodic Symmetric Struts Support (PSSS) was established, which is applied to a certain type of gas turbine. The software of computational fluid Dynamics (CFD) and the standard k-ε turbulence model are used in the numerical simulation．To simulate the coupling problems of fluid and solid，the numerical models by considering the heat transfer problem coupling with the solid and fluid have been developed．The internal flow field in PSSS was numerically simulated by an effective method for solving integrated coupling problems. The temperature field and thermal deformation rule of the PSSS was obtained. Through comparison coordinate values of the checked points before and after thermal deformation, the impact of thermal deformation on bearing center level height under temperature load was studied. The centering process of the PSSS at high temperature state was verified.

Analysis of Two Oil Spills in the Southern Brazilian Shelf, in the Years of 2012 and 2014

2017 ◽  
Vol 372 ◽  
pp. 70-80 ◽  
Author(s):  
Caroline Barbosa Monteiro ◽  
Eduardo de Paula Kirinus ◽  
Wiliam Correa Marques ◽  
Phelype Haron Oleinik ◽  
Juliana Costi
Keyword(s):  
Oil Spills ◽  
Numerical Models ◽  
Three Dimensional ◽  
Weather Conditions ◽  
Biological Processes ◽  
Physical Chemical ◽  
Simulation Strategy ◽  
And Behavior ◽  
Local Wind Forcing ◽  
Oil Particles

Numerical models have been widely used to simulate and predict the behavior and transport of oil spills in marine environments. Their behavior is governed by physical, chemical and biological processes which are related to the hydrocarbon properties, hydrodynamic and weather conditions, and other environmental variables. The transport and interactions of oil particles were evaluated in simulations reproducing two oil spills recorded in the northern part of the Southern Brazilian Shelf (SBS). The numerical simulations were performed using the ECOS (Easy Coupling Oil System) model coupled to the three-dimensional hydrodynamic module TELEMAC3D. The hydrodynamic model provides the variables needed by oil spill model to calculate and infer the properties and behavior of the oil slick. The results indicate that the local wind forcing is the most important factor in determining the oil fate, followed by the intensities and directions of coastal currents. Regarding the events, in 2012 the oil reached the coast after 10 hours of the leak while in 2014 it was transported towards the ocean. The simulation strategy used in this article did not prove to be appropriate for estimates of the oil risk in the region, due to the distinct susceptibility responses between the events simulated.

scholarly journals Prediction and minimization of the heat treatment induced distortion in 8620H steel gear – Simulation and experimental verification

2020 ◽  
Author(s):  
Wen Shao ◽  
Mohan Yi ◽  
Jinyuan Tang ◽  
Siyuan Sun
Keyword(s):  
Heat Treatment ◽  
Numerical Models ◽  
Three Dimensional ◽  
Dimensional Accuracy ◽  
Treatment Method ◽  
Field Coupling ◽  
Web Structure ◽  
Novel Approach ◽  
Before And After ◽  
Novel Method

Abstract The considerable heat treatment induced runout value in the end face of the automobile main reducer gear is always dimensionally out of tolerance. It directly affects the dimensional accuracy, the grade of carburized and hardened gears, and the post-quenching manufacturing costs. In this study, three dimensional numerical models were developed to simulate the carburizing-quenching process of gear based on the multi-field coupling theory using DEFORM software. The results indicated that the ununiform cooling rate of the gear caused by the asymmetry of the web structure was the determinant of severe deformation of the gear. Therefore, a novel method was proposed to minimize the heat treatment induced runout value. It was found that the heat treatment induced runout value could be effectively controlled by the addition of a compensation ring and the support of a rod structure. Further experiments showed that the average runout value of the gear end face before and after the proposed heat treatment method were about 0.023 mm and 0.059 mm respectively, which was in good agreement with the simulated results. The novel approach proposed in this study led to a reduction of the gear runout value by 70.0%-76.9% compared to that of the original heat treatment process, which may serve as a practical and economical way to predict and minimize the heat treatment induced distortion in drive gear.

The Influence of Attitudes, Subjective, Norms, and Behavior Controls on Intention to Choose Islamic Banks With Islamic Religiosity as a Moderating Variable (Case Study at Bri Syariah Purwokerto Customers)

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Akhmad Khoyrun Najakh ◽  
Dwiwiyati Astogini ◽  
Sri Martini
Keyword(s):  
Behavioral Control ◽  
Sampling Technique ◽  
Subjective Norm ◽  
Subjective Norms ◽  
Islamic Banks ◽  
Control Behavior ◽  
Before And After ◽  
And Behavior ◽  
Number Of Customers

The purpose of this study was to analyze the influence of attitudes on the intention to choose Islamic banks, to analyze the effect of subjective norm on the intention to choose Islamic banks. to analyze the effect of the control behavior of the intention to choose the Islamic banks, to analyze the moderating influence of religiosity on the relationship attitudes, subjective norms and behavioral control of the intention to choose the Islamic banks . The method used is a survey with a sampling technique used purposive sampling with a sample size of this study was 100 respondents . Further analysis tools used in this study is multiple regression analysis using SPSS 16.0 software . Based on this study it can be concluded that the attitude does not affect to the intention of choose Bank BRISyariah. Subjective norm positive effect on intention choose Bank BRISyariah. Control behavior does not affect to the intention choose Bank BRISyariah. Relationship between Attitudes, Subjective Norms and Behavior Control with the intention to select Bank BRISyariah not moderated by religiosity.Based on these conclusions can be said that the Bank BRISyariah should improve understanding related to the subjective norm in order to increase the number of customers who use the services of Islamic Banking . Further research is recommended in order to follow up and develop this research to further explore the independent and dependent variables continued before and after behavioral intention or intention to perform a specific action .

Anti-Tobacco Education in Vacation Bible School in Mississippi: The Morality of Tobacco Prevention

2003 ◽  
Vol 21 (4) ◽  
pp. 355-368
Author(s):  
Bonita Reinert ◽  
Vivien Carver ◽  
Lillian M. Range
Keyword(s):  
African American Youth ◽  
Negative Influence ◽  
Tobacco Prevention ◽  
Summer Vacation ◽  
Tobacco Policies ◽  
Before And After ◽  
Tobacco Education ◽  
And Behavior ◽  
Bible School ◽  
Vacation Bible School

Knowledge, attitudes, and behavior regarding the morality of tobacco use of 355 mostly African-American youth in Mississippi, were measured before and after tobacco prevention lessons in summer vacation Bible school. Knowledge and behavioral intentions were strong initially and did not change. Two attitudes improved: youth favored anti-tobacco policy and activism even more after the lessons compared to before. One attitude deteriorated: youth favored banning young people from tobacco less strongly after the lessons compared to before. Educational implications for introducing tobacco prevention, which may seem to be a secular topic, into a religious setting such as summertime Bible school, include covering important topics such as the perniciousness of tobacco companies, the negative influence of tobacco advertisements, the benefits of anti-tobacco policies, and ways to increase young people's personal comfort with anti-tobacco activism.

scholarly journals Three-dimensional analysis of the root canal preparation with Reciproc Blue®, WaveOne Gold® and XP EndoShaper®: a new method in vivo

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Javier Caviedes-Bucheli ◽  
Nestor Rios-Osorio ◽  
Diana Usme ◽  
Cristian Jimenez ◽  
Adriana Pinzon ◽  
...  
Keyword(s):  
3D Reconstruction ◽  
Root Canal ◽  
Paired Comparison ◽  
Three Dimensional ◽  
New Method ◽  
Root Canal Preparation ◽  
Paired Data ◽  
Before And After ◽  
Student’S T

Abstract Background The purpose of this study was to evaluate the changes in canal volume after root canal preparation in vivo with 3 different single-file techniques (Reciproc-Blue®, WaveOne-Gold® and XP-EndoShaper®), with a new method using CBCT and 3D reconstruction. Methods In this prospective study, thirty human lower premolars from healthy patients were used, in which extraction was indicated for orthodontic reasons. All the teeth used were caries- and restoration-free with complete root development, without signs of periodontal disease or traumatic occlusion, and with only one straight canal (up to 25º curvature). Teeth were randomly divided into three different groups: Reciproc-Blue, WaveOne-Gold and XP-EndoShaper. CBCT scans before root canal preparation were used to create a 3D reconstruction with RHINOCEROS 5.0 software to assess the initial canal volume, and then compared with 3D reconstructions after canal preparation to measure the increase in canal volume. Student’s t test for paired data were used to determine statistically significant differences between the before and after canal volumes. Anova test was used to determine statistically significant differences in the percentage of canal volume increase between the groups and Tukey's post-hoc test were used to paired comparison. Results Reciproc-Blue showed the higher increase in canal volume, followed by WaveOne-Gold and XP-EndoShaper (p = 0.003). XP-EndoShaper did not show a statistically significant increase in canal volume after root canal preparation (p = 0.06). Conclusion With this model, Reciproc-Blue showed higher increase in root canal volume, followed by WaveOne-Gold, while XP-EndoShaper did not significantly increase root canal volume during preparation.

scholarly journals Experimental and Numerical Investigation of 3D Dam-Break Wave Propagation in an Enclosed Domain with Dry and Wet Bottom

2021 ◽  
Vol 11 (12) ◽  
pp. 5638
Author(s):  
Selahattin Kocaman ◽  
Stefania Evangelista ◽  
Hasan Guzel ◽  
Kaan Dal ◽  
Ada Yilmaz ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Numerical Models ◽  
Three Dimensional ◽  
Dam Break ◽  
Dam Failure ◽  
Navier Stokes ◽  
Negative Wave ◽  
Through Flow ◽  
Instantaneous Removal ◽  
Surface Patterns

Dam-break flood waves represent a severe threat to people and properties located in downstream regions. Although dam failure has been among the main subjects investigated in academia, little effort has been made toward investigating wave propagation under the influence of tailwater depth. This work presents three-dimensional (3D) numerical simulations of laboratory experiments of dam-breaks with tailwater performed at the Laboratory of Hydraulics of Iskenderun Technical University, Turkey. The dam-break wave was generated by the instantaneous removal of a sluice gate positioned at the center of a transversal wall forming the reservoir. Specifically, in order to understand the influence of tailwater level on wave propagation, three tests were conducted under the conditions of dry and wet downstream bottom with two different tailwater depths, respectively. The present research analyzes the propagation of the positive and negative wave originated by the dam-break, as well as the wave reflection against the channel’s downstream closed boundary. Digital image processing was used to track water surface patterns, and ultrasonic sensors were positioned at five different locations along the channel in order to obtain water stage hydrographs. Laboratory measurements were compared against the numerical results obtained through FLOW-3D commercial software, solving the 3D Reynolds-Averaged Navier–Stokes (RANS) with the k-ε turbulence model for closure, and Shallow Water Equations (SWEs). The comparison achieved a reasonable agreement with both numerical models, although the RANS showed in general, as expected, a better performance.

scholarly journals Scientific validation of three-dimensional stereophotogrammetry compared to the IGAIS clinical scale for assessing wrinkles and scars after laser treatment

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Barbara Helena Barcaro Machado ◽  
Ivy Dantas De Melo E. Silva ◽  
Walter Marou Pautrat ◽  
James Frame ◽  
Mohammad Najlah
Keyword(s):  
Laser Treatment ◽  
Three Dimensional ◽  
Skin Surface ◽  
Clinical Scale ◽  
3D Images ◽  
Laser Resurfacing ◽  
Before And After ◽  
Measuring Outcomes ◽  
Skin Scar ◽  
Scientific Validation

AbstractMeasuring outcomes from treatments to the skin is either reliant upon patient’s subjective feedback or scale-based peer assessments. Three-Dimensional stereophotogrammetry intend to accurately quantify skin microtopography before and after treatments. The objective of this study is comparing the accuracy of stereophotogrammetry with a scale-based peer evaluation in assessing topographical changes to skin surface following laser treatment. A 3D stereophotogrammetry system photographed skin surface of 48 patients with facial wrinkles or scars before and three months after laser resurfacing, followed immediately by topical application of vitamin C. The software measured changes in skin roughness, wrinkle depth and scar volume. Images were presented to three observers, each independently scoring cutaneous improvement according to Investigator Global Aesthetic Improvement Scale (IGAIS). As for the results, a trend reflecting skin/scar improvement was reported by 3D SPM measurements and raters. The percentage of topographical change given by the raters matched 3D SPM findings. Agreement was highest when observers analysed 3D images. However, observers overestimated skin improvement in a nontreatment control whilst 3D SPM was precise in detecting absence of intervention. This study confirmed a direct correlation between the IGAIS clinical scale and 3D SPM and confirmed the efficacy and accuracy of the latter when assessing cutaneous microtopography alterations as a response to laser treatment.

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