scholarly journals Linking bedrock discontinuities to glacial quarrying

2019 ◽  
Vol 60 (80) ◽  
pp. 66-72 ◽  
Author(s):  
J. B. Woodard ◽  
L. K. Zoet ◽  
N. R. Iverson ◽  
C. Helanow
Keyword(s):  
Finite Element ◽  
Alternative Explanation ◽  
Relative Effectiveness ◽  
Fracture Propagation ◽  
Element Model ◽  
Bedding Planes ◽  
Significant Difference ◽  
Strong Control ◽  
Difference Test ◽  
Honest Significant Difference Test

AbstractQuarrying and abrasion are the two principal processes responsible for glacial erosion of bedrock. The morphologies of glacier hard beds depend on the relative effectiveness of these two processes, as abrasion tends to smooth bedrock surfaces and quarrying tends to roughen them. Here we analyze concentrations of bedrock discontinuities in the Tsanfleuron forefield, Switzerland, to help determine the geologic conditions that favor glacial quarrying over abrasion. Aerial discontinuity concentrations are measured from scaled drone-based photos where fractures and bedding planes in the bedrock are manually mapped. A Tukey honest significant difference test indicates that aerial concentration of bed-normal bedrock discontinuities is not significantly different between quarried and non-quarried areas of the forefield. Thus, an alternative explanation is needed to account for the spatial variability of quarried areas. To investigate the role that bed-parallel discontinuities might play in quarrying, we use a finite element model to simulate bed-normal fracture propagation within a stepped bed with different step heights. Results indicate that higher steps (larger spacing of bed-parallel discontinuities) propagate bed-normal fractures more readily than smaller steps. Thus, the spacing of bed-parallel discontinuities could exert strong control on quarrying by determining the rate that blocks can be loosened from the host rock.

Physical bushfire preparation over time in Victoria, Australia

2017 ◽  
Vol 26 (2) ◽  
pp. 241-251 ◽  
Author(s):  
Carlyn Muir ◽  
John Gilbert ◽  
Rebecca O’Hara ◽  
Lesley Day ◽  
Stuart Newstead
Keyword(s):  
High Risk ◽  
Principal Components ◽  
Content Type ◽  
Significant Difference ◽  
Components Analysis ◽  
Difference Test ◽  
Honest Significant Difference Test ◽  
Preparation Variable ◽  
Physical Preparation ◽  
Over Time

Purpose The purpose of this paper is to examine the level of physical preparation for bushfire among Victorian residents in established high risk bushfire locations, and to assess whether these levels of preparation changed over time. Design/methodology/approach Data were analysed from a telephone survey among Victorian residents (n=614-629) living in high risk bushfire locations over a three-year period (2012-2014). The survey measured residents’ bushfire awareness, knowledge, planning, preparation and engagement with bushfire services. This paper focusses on the extent to which respondents undertook physical preparatory bushfire activities over the three-year period using: first, principal components analysis to generate a single preparation variable by identifying a smaller number of uncorrelated variables (or principal components) from a larger set of data, second, analysis of variance to assess differences in preparation scores between years, and third, Tukey’s honest significant difference test to confirm where the differences occurred between groups. Findings Results indicated only moderate levels of physical preparation for bushfires amongst respondents. The activities that respondents rated the lowest were: “having protective covers for windows” and “having firefighting equipment to protect the house”. A significant difference in total preparation scores over time was observed, F(2, 1,715)=6.159, p<0.005, with lower scores in 2012 compared with 2013 and 2014 scores. Social implications This study found some marginal improvements in levels of physical bushfire preparation from 2012 to 2014. However, the results indicate only moderate levels of preparation overall, despite respondents living in established high risk locations. Originality/value This study provides evidence for the current levels of preparedness in high risk bushfire communities, and emphasises the need for future initiatives to focus on specific bushfire preparation activities but also to consider the broader range of interventions that are likely to contribute to desired safety outcomes.

scholarly journals DEKOLORISASI LIMBAH BATIK MENGGUNAKAN LIMBAH MEDIUM TANAM Pleurotus ostreatus PADA WAKTU INKUBASI YANG BERBEDA

2014 ◽  
Vol 1 (1) ◽  
pp. 73
Author(s):  
Fitriya Yuni Wulandari ◽  
Nuniek Ina Ratnaningtyas ◽  
Ratna Stia Dewi
Keyword(s):  
Incubation Time ◽  
Confidence Level ◽  
Pleurotus Ostreatus ◽  
Waste Treatment ◽  
Time Treatment ◽  
Randomized Design ◽  
Significant Difference ◽  
Treatment Technologies ◽  
Difference Test ◽  
Honest Significant Difference Test

The batik waste industry is one source of water pollution. It must undergo treatment before discharge into the environment. Batik waste treatment technologies can be done biologically, chemically, physically, or combination of three processes. This research applied a combination of biology and physic technologies, namely used spent mushroom of Pleurotus ostreatus as the decolorization agent. Mycelium of P. ostreatus was used as biological agent, and cellulose from spent mushroom was used as physical agent. The aims of this research were to determine the effect of spent mushroom with variation incubation time on batik waste decolorization, and to know the optimum incubation time with highest decolorization batik waste percentage using spent mushroom of P. ostreatus. This research used experimental method with completely randomized design (CRD). The data obtained were statistically analyzed using Varian Test (ANOVA) on confidence level of 95% and 99% and continued with Honest Significant Difference Test (BNJ) with 95% confidence level. The result showed that variation incubation time treatment of batik waste decolorization used spent mushroom of P. ostreatus provide a highly signification effect on batik waste decolorization. The optimum incubation time was 60 hour (LW5), with decolorization percentage was 85,64%.

Experimental Investigation and Elastic-Plastic Analysis on Connection Strength of Zirconium Tube-Tubesheet Joints

2008 ◽  
Vol 44-46 ◽  
pp. 529-536
Author(s):  
Biao Yuan ◽  
Y.Z. Wang ◽  
X. Ma ◽  
Yang Yan Zheng ◽  
Shan Tung Tu
Keyword(s):  
Finite Element ◽  
Heat Exchanger ◽  
Element Model ◽  
Connection Strength ◽  
Element Analysis ◽  
Petrochemical Process ◽  
Expansion Joints ◽  
Pull Out ◽  
Significant Difference ◽  
Zirconium Tube

Zirconium tube is widely used in heat exchanger equipments in petrochemical process for significant corrosion resistance. The connection joint of tube-tubesheet is the weakest parts in a heat exchanger. The experiment and numerical analysis of different materials (zirconium tubes, titanium tubes and 16MnR tubesheets, 316L tubesheet) joints were performed in this paper. The expansion joints specimens were prepared at the pressure ranging from 28MPa to 38MPa. And pulling out test was performed from 20°C to 300°C. The finite element model of tube-tubesheet joint was established. The effect of expansion pressure, temperature and groove on the pulling out strength of joints was analyzed. Both the experiments and the finite element analysis show that the pull-out strength increases with the increasing expansion pressures. Working temperature also has a great effect on the connection strength of tube-to-tubesheet joints, especially for the zirconium and 316L joints, which have the most significant difference of thermal expansion coefficient between tube and tubesheet. The residual contacting pressure on the contact surface between tubes and the tubesheet is not uniformly distributed and two tightness bands are found near the surfaces of the tubesheet or at the two brinks of the groove on the tubesheet hole. Compared with the ungrooved joint, the residual contacting pressure on the tightness bands for the grooved joint is much higher, indicating a grooved joint has better tightness.

scholarly journals Biomechanical Evaluation of Cortical Bone Trajectory Fixation with Traditional Pedicle Screw in the Lumbar Spine: A Finite Element Study

2021 ◽  
Vol 11 (22) ◽  
pp. 10583
Author(s):  
Kuo-Chih Su ◽  
Kun-Hui Chen ◽  
Chien-Chou Pan ◽  
Cheng-Hung Lee
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Cortical Bone ◽  
Pedicle Screw ◽  
Spinal Surgery ◽  
Pedicle Screws ◽  
Element Model ◽  
Cortical Bone Trajectory ◽  
Significant Difference ◽  
Flexion Extension

Cortical bone trajectory (CBT) is increasingly used in spinal surgery. Although there are many biomechanical studies, the biomechanical effect of CBT in combination with traditional pedicle screws is not detailed. Therefore, the purpose of this study was to investigate the effects of the traditional pedicle screw and CBT screw implantation on the lumbar spine using finite element methods. Based on the combination of the traditional pedicle screw and the CBT system implanted into the lumbar spine, four finite element spinal lumbar models were established. The models were given four different load conditions (flexion, extension, lateral bending, and axial rotation), and the deformation and stress distribution on the finite element model were observed. The results show that there was no significant difference in the structural stability of the lumbar spine model between the traditional pedicle screw system and the CBT system. In addition, CBT may reduce stress on the endplate. Different movements performed by the model may have significant biomechanical effects on the spine and screw system. Clinical spinal surgeons may also consider using the CBT system in revision spinal surgery, which may contribute to smaller wounds.

scholarly journals SURVIVAL AND SEEDLING GROWTH OF MOON-EYED SNAIL (Turbo chrysostumus L.) ON DIFFERENT TEMPERATURE CONDITIONS

2015 ◽  
Vol 7 (1) ◽  
Author(s):  
M. S. Hamzah
Keyword(s):  
Optimum Temperature ◽  
High Food ◽  
Shell Weight ◽  
Control Temperature ◽  
Relationship Analysis ◽  
Significant Difference ◽  
Survival And Growth ◽  
The Relationship ◽  
Difference Test ◽  
Honest Significant Difference Test

Turbo chrysostumus is commonly known by fishermen community as moon-eyed snail and has common names of yellow-mouth turban or gold-mouth turban. These biota live in rocky beach and coral reefs surface filled with alga. They are also easily collected and used for high nutritive food for coastal villagers. The study of survival and growth of turbo youngsters in relation with different temperature is very limited. This study was done in January 5 – May 4, 2015 in the laboratory with the objective of observing the effect of optimum temperature range on their survival and growth. Based on ANOVA statistical analyses, the temperature had significsant effect on the survival of the turbo youngsters (p<0.05). “Honest Significant Difference” test revealed that control temperature (P1), 26±0.5°C (P2), and 28±0.5°C (P3) produced a significantly different effect on the survival compared with that in 30±0.5°C (P4). Higher growth rate was recorded in  26±0.5°C balanced with high food consumability. The relationship analysis of height shell-weight of wet body in all treatments indicated similar pattern of minor allometric (b<3). Keywords: survival, growth, moon-eyed snail (Turbo chrysostumus L.), temperature

scholarly journals Growth Response of Soybean Varieties to Trichoderma Application on Acid Soils

2021 ◽  
Vol 316 ◽  
pp. 03007
Author(s):  
Sutarman ◽  
A. Miftahurrohmat
Keyword(s):  
Growth Response ◽  
Acid Soils ◽  
Dry Weight ◽  
Randomized Design ◽  
Affected Plant ◽  
Significant Difference ◽  
Wet Weight ◽  
Completely Randomized Design ◽  
Difference Test ◽  
Honest Significant Difference Test

This study aims to determine the growth response of the vegetative stadia of three soybean varieties which are widely used in East Java on acid soils that have been given biological fertilizers from various Trichoderma isolates. The experiment was arranged factorially using a completely randomized design. The first factor was the variety consisting of Detam 3, Detam 4, Gema, Dering 1, and Burangrang. The second factor was Trichoderma isolates formulated as bio fertilizers, consisting of Tc-Jjr-02, Tc-Pjn-01, and Tc-Jro-01. Overall this experiment has 60 experimental units. Data were analyzed by variance analysis (ANOVA) followed by an honest significant difference test at the level of 5%. The results showed that there was no interaction between soybean varieties and Trichoderma isolates formulated in bio fertilizer. Soybean varieties significantly affected plant height, wet weight, and dry weight of roots and stover at 21 days after planting. The Burangrang variety shows the best growing ability in acid soils. There was no interaction between soybean varieties and Trichoderma bio fertilizers. Trichoderma isolate Tc-Jjr-02 increased the wet weight and dry weight of the roots and roots by 48.2 and 54.5%, respectively, and 38.9 and 48.2% compared to without Trichoderma. Trichoderma application maintains soil acidity between pH 4.50-4.67.

scholarly journals Ethanol Extract of Pseudo-stem Lemongrass (Cymbopogon citrates) and Basil Leaves (Ocimum sanctum) Increase Bactrocera (Diptera: Tephritidae) Fruit Fly Catches

2020 ◽  
Vol 20 (3) ◽  
pp. 369
Author(s):  
Angelina Putri Ayu Lestari ◽  
I Putu Artayasa ◽  
Prapti Sedijani
Keyword(s):  
Block Design ◽  
Ethanol Extract ◽  
Fruit Fly ◽  
Fruit Flies ◽  
Ocimum Sanctum ◽  
Randomized Block Design ◽  
Significant Difference ◽  
The Difference ◽  
Difference Test ◽  
Honest Significant Difference Test

The tropical climate in Indonesia supports the presence of many types of plants that have the potential to produce abundant vegetables and fruit, however the presence of fruit flies is an obstacle to fruit and vegetable productivity. Lemongrass and basil have been studied to contain several compounds that have the potential to control fruit fly attacks. This study aims to determine the effect of the ethanol extract of lemongrass pseudo stem (Cymbopogon citrates) and basil (Ocimum sanctum) leaves on the catch of Bactrocera fruit flies and to determine the concentration of the extract that has the highest number of catches. The method used in sampling was factorial randomized block design (RBD). The ethanol extract of the pseudo-lemongrass, the extract of basil leaves or the mixture of both extract (1:1) that was given at concentrations of 15%, 30% and 45% was dropped onto a piece of cotton and for then be put within a trap before placing on the tree. The cathes obtained from each extract at each concentration were observed if they show a significant difference in the number of fruit fly. Data were tested using analysis of variance (F test) at α = 0.05, followed by the Honest Significant Difference test (HSD). The results showed that the catch obtained from ethanol extract of lemongrass pseudo stem or from basil leaf ectract as well as  from their mixture had a significantly higher number of Bactrocera fruit flies than without using these extracts. The difference in extract concentration did not cause a difference in the ability to attract fruit flies. The conclusion of this study is that there is an effect of the  pseudo stem ethanol extract of lemongrass or basil leaf ectract as well as their mixture on the catch of Bactrocera fruit flies and these extract are recommended as non-synthetic pesticidesalternatives.

Full Fluid–Solid Cohesive Finite-Element Model to Simulate Near Wellbore Fractures

2014 ◽  
Vol 137 (1) ◽  
Author(s):  
Saeed Salehi ◽  
Runar Nygaard
Keyword(s):  
Finite Element ◽  
Hoop Stress ◽  
Fracture Propagation ◽  
Fracture Initiation ◽  
Element Model ◽  
Cohesive Elements ◽  
Element Simulation ◽  
Initiation And Propagation ◽  
Fracture Sealing ◽  
Wellbore Strengthening

This paper presents finite-element simulation for hydraulic fracture's initiation, propagation, and sealing in the near wellbore region. A full fluid solid coupling module is developed by using pore pressure cohesive elements. The main objective of this study is to investigate the hypothesis of wellbore hoop stress increase by fracture sealing. Anisotropic stress state has been used with assignment of individual criteria for fracture initiation and propagation. Our results demonstrate that fracture sealing in “wellbore strengthening” cannot increase the wellbore hoop stress beyond its upper limit when no fractures exist. However, this will help to restore part or all of the wellbore hoop stress lost during fracture propagation.

A finite element study on intra-operative corrective forces and evaluation of screw density in scoliosis surgeries

2018 ◽  
Vol 232 (12) ◽  
pp. 1245-1254 ◽  
Author(s):  
Ameneh Musapoor ◽  
Mohammad Nikkhoo ◽  
Mohammad Haghpanahi
Keyword(s):  
Finite Element ◽  
Pedicle Screws ◽  
Element Model ◽  
Applied Force ◽  
Patient Specific ◽  
Scoliosis Surgery ◽  
Element Analysis ◽  
Clinical Images ◽  
Significant Difference ◽  
Screw Density

Scoliosis is an abnormal sideways curvature of the spine and rib cage, which may need surgical treatments. Most of the corrective maneuvers in scoliosis surgeries are based on surgeon’s experience; hence, there is great interest of understanding how the correction ratio can be influenced by the magnitude of forces and moments. Therefore, the objective of this study was to develop and validate a detailed finite element model of the thoracolumbar which can be used to simulate the scoliosis surgeries based on patient-specific clinical images. The validated models of five patients were carefully developed, and the surgery procedures were simulated and the corrective forces were estimated using inverse finite element analysis during the surgery. Furthermore, parametric studies including the influences of the corrective force magnitude and screw density were evaluated. The results showed that the maximum estimated correction force and moment were 173 (±55.43) N and 10.67 (±2.02) N m, respectively, which were aligned with measured clinical observations. The sensitivity analysis on the magnitude of applied force to the screws showed that correction ratio was slightly increased in level 1 (i.e. FB = 1.3 ×  F) but decreased in level 2 (i.e. FB = 1.6 ×  F). In addition, the parametric study on increasing the number of pedicle screws showed that there was no significant difference between lower and higher screw density. However, the stress distribution was significantly greater using higher screw density during correction maneuvers. In conclusion, this study shows a direct relationship between the applied force/moment and screw density and the correction ratio up to a border line which should be defined accurately. This detailed computational modeling can be used in clinic in hope of achieving the optimum outcome of scoliosis surgery using individual patient-specific characterization.

Effect of joint stiffness on torsional stiffness of open lattice composite structures

2019 ◽  
pp. 152808371988181
Author(s):  
Yang Shen ◽  
David Branscomb ◽  
Sabit Adanur
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Composite Structures ◽  
Experimental Testing ◽  
Joint Stiffness ◽  
Element Model ◽  
Torsional Stiffness ◽  
Open Architecture ◽  
Theoretical Limit ◽  
Significant Difference

In open lattice composite structures, the lattice components are chemically bonded, which affects the overall properties of the structure. This study examines the effects of chemically bonded joints on the torsional stiffness of tubular lattice composite structures. Tubular open lattice structures, known as the open-architecture composite structures, are manufactured by braiding the impregnated carbon fiber tows. Samples were prepared with no chemically bonded and with epoxy joints using braid angles of 35°, 45°, and 67.5°. A finite element model of the open-architecture composite structures is developed to examine the mechanical behavior under torsion. It is shown that there is a significant difference between the samples with no-bonding joints and samples with epoxy joints in terms of torsional stiffness. Torsional stiffness of the structure is retained at 97%, 96%, and 93% of the theoretical limit for 35°, 45°, and 67.5° braid angles, respectively, when joint stiffness is ten times the component stiffness. Torsional stiffness is only 32%, 22%, and 13% of the theoretical limit for 35°, 45°, and 67.5° braid angles, respectively, when joint stiffness is one-10th of the component stiffness. The epoxy bonding at the intersection achieves 72% of the theoretical torsional stiffness of the “perfect joint” for 45° braid angle when joint stiffness is equal to the component stiffness. The finite element model is validated by experimental results. It can be concluded from the finite element analysis and experimental testing that the stiffness of the bonding joints has significant impact on the overall torsional stiffness of the biaxial composite lattice.

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