Modeling - Science topic

While doing micro-modelling of Brick masonry in ABAQUS, I am using Dynamic Explicit step for the analysis. What will the best option for the time period while using the same?

Hello everyone, I have some question to discuss with you, looking forward your help!

1, As we can use phase modelling method to estimate the melt vol% of a rock by its bulk composition, can we use the estimated result to link the real sample' melt content?

2, Do you have any methods to estimate the melt vol% in the migmatite through petrographic observation, hand sample or even the field observation?

Hello everyone. Please tell me how to make sure that when the curvature changes, the length of the segment remains constant? I'm modeling a patch antenna that I wrap around a cylinder. The antenna length (285 mm) is correct if there is no bend, but the dimensions change when bending (360 mm).

If you are interested in learning system modelling and how it is an important tool for tackling environmental challenges you can join my course here:

last day for registration April 15, 2024.

Regards

Can we stop global climate change? Does human scientific power reach the world's climate change? How do researchers respond?

As you know, humans are very intelligent and can predict the future climate of the world with hydrology, climatology and paleontology. But don't countries, especially industrialized countries, that produce the most harmful gases in the earth's atmosphere and think about the future of the earth's atmosphere? Do they listen to the research of climatologists? What would have to happen to force them to listen to climate scientists?

Miloud Chakit added a reply

Climate change is an important and complex global challenge, and scientific theories about it are based on extensive research and evidence. The future path of the world depends on various factors including human actions, political decisions and international cooperation.

Efforts to mitigate and adapt to climate change continue. While complete reversal may be challenging, important steps can be taken to slow progression and lessen its effects. This requires global cooperation, sustainable practices and the development and implementation of clean energy technologies.

Human scientific abilities play an important role, but dealing with climate change also requires social, economic and political changes. The goal is to limit global warming and its associated impacts, and collective action at the local, national, and international levels is essential for a more sustainable future.

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Osama Bahnas added a reply

It is impossible to stop global climate change. The human scientific power can not reach the world's climate change.

Borys Kapochkin added a reply

Mathematical models of increasing planetary temperature as a function of the argument - anthropogenic influence - are erroneous.

Alastair Bain McDonald added a reply

We could stop climate change but we won't! We have the scientific knowldge but not the political will. One could blame Russia and China from refusing to cooperate but half the population of the USA (Republicans) deny climate change is a problem and prefer their profligate life styles reply:

All climate change has been loaded on the CO2 responsible for the greenhouse effect. Therefore, there must be scientific experiments from several independent scientific institutes worldwide to find out what the greenhouse impact is on various CO2 concentrations. Then, there must be a conference from a reliable, professional organization with the participation of all independent scientific institutions to establish standards on CO2 concentrations and propose political actions accordingly.

The second action that can be done is to plant as many trees and plants as possible to breathe the CO2 and free the oxygen. Stop any deforestation and plant trees immediately in any bunt areas.

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Effect of Injecting Hydrogen Peroxide into Heavy Clay Loam Soil on Plant Water Status, NET CO2 Assimilation, Biomass, and Vascular Anatomy of Avocado Trees

In Chile, avocado (Persea americana Mill.) orchards are often located in poorly drained, low-oxygen soils, situation which limits fruit production and quality. The objective of this study was to evaluate the effect of injecting soil with hydrogen peroxide (H2O2) as a source of molecular oxygen, on plant water status, net CO2 assimilation, biomass and anatomy of avocado trees set in clay loam soil with water content maintained at field capacity. Three-year-old ‘Hass’ avocado trees were planted outdoors in containers filled with heavy loam clay soil with moisture content sustained at field capacity. Plants were divided into two treatments, (a) H2O2 injected into the soil through subsurface drip irrigation and (b) soil with no H2O2 added (control). Stem and root vascular anatomical characteristics were determined for plants in each treatment in addition to physical soil characteristics, net CO2 assimilation (A), transpiration (T), stomatal conductance (gs), stem water potential (SWP), shoot and root biomass, water use efficiency (plant biomass per water applied [WUEb]). Injecting H2O2 into the soil significantly increased the biomass of the aerial portions of the plant and WUEb, but had no significant effect on measured A, T, gs, or SWP. Xylem vessel diameter and xylem/phloem ratio tended to be greater for trees in soil injected with H2O2 than for controls. The increased biomass of the aerial portions of plants in treated soil indicates that injecting H2O2 into heavy loam clay soils may be a useful management tool in poorly aerated soil.

Shade trees reduce building energy use and CO2 emissions from power plants

Urban shade trees offer significant benefits in reducing building air-conditioning demand and improving urban air quality by reducing smog. The savings associated with these benefits vary by climate region and can be up to $200 per tree. The cost of planting trees and maintaining them can vary from $10 to $500 per tree. Tree-planting programs can be designed to have lower costs so that they offer potential savings to communities that plant trees. Our calculations suggest that urban trees play a major role in sequestering CO2 and thereby delay global warming. We estimate that a tree planted in Los Angeles avoids the combustion of 18 kg of carbon annually, even though it sequesters only 4.5-11 kg (as it would if growing in a forest). In this sense, one shade tree in Los Angeles is equivalent to three to five forest trees. In a recent analysis for Baton Rouge, Sacramento, and Salt Lake City, we estimated that planting an average of four shade trees per house (each with a top view cross section of 50 m2) would lead to an annual reduction in carbon emissions from power plants of 16,000, 41,000, and 9000 t, respectively (the per-tree reduction in carbon emissions is about 10-11 kg per year). These reductions only account for the direct reduction in the net cooling- and heating-energy use of buildings. Once the impact of the community cooling is included, these savings are increased by at least 25%.

Can Moisture-Indicating Understory Plants Be Used to Predict Survivorship of Large Lodgepole Pine Trees During Severe Outbreaks of Mountain Pine Beetle?

Why do some mature lodgepole pines survive mountain pine beetle outbreaks while most are killed? Here we test the hypothesis that mature trees growing in sites with vascular plant indicators of high relative soil moisture are more likely to survive mountain pine beetle outbreaks than mature trees associated with indicators of lower relative soil moisture. Working in the Clearwater Valley of south central British Columbia, we inventoried understory plants growing near large-diameter and small-diameter survivors and nonsurvivors of a mountain pine beetle outbreak in the mid-2000s. When key understory species were ranked according to their accepted soil moisture indicator value, a significant positive correlation was found between survivorship in large-diameter pine and inferred relative high soil moisture status—a finding consistent with the well-documented importance of soil moisture in the mobilization of defense compounds in lodgepole pine. We suggest that indicators of soil moisture may be useful in predicting the survival of large pine trees in future pine beetle outbreaks. Study Implications: A recent outbreak of the mountain pine beetle resulted in unprecedented levels of lodgepole pine mortality across southern inland British Columbia. Here, we use moisture-dependent understory plants to show that large lodgepole pine trees growing in sites with high relative moisture are more likely than similar trees in drier sites to survive severe outbreaks of mountain pine beetle—a finding that may be related to a superior ability to mobilize chemical defense compounds compared with drought-stressed trees.

Can Functional Traits Explain Plant Coexistence? A Case Study with Tropical Lianas and Trees

Organisms are adapted to their environment through a suite of anatomical, morphological, and physiological traits. These functional traits are commonly thought to determine an organism’s tolerance to environmental conditions. However, the differences in functional traits among co-occurring species, and whether trait differences mediate competition and coexistence is still poorly understood. Here we review studies comparing functional traits in two co-occurring tropical woody plant guilds, lianas and trees, to understand whether competing plant guilds differ in functional traits and how these differences may help to explain tropical woody plant coexistence. We examined 36 separate studies that compared a total of 140 different functional traits of co-occurring lianas and trees. We conducted a meta-analysis for ten of these functional traits, those that were present in at least five studies. We found that the mean trait value between lianas and trees differed significantly in four of the ten functional traits. Lianas differed from trees mainly in functional traits related to a faster resource acquisition life history strategy. However, the lack of difference in the remaining six functional traits indicates that lianas are not restricted to the fast end of the plant life–history continuum. Differences in functional traits between lianas and trees suggest these plant guilds may coexist in tropical forests by specializing in different life–history strategies, but there is still a significant overlap in the life–history strategies between these two competing guilds.

The use of operator action event trees to improve plant-specific emergency operating procedures

Even with plant standardization and generic emergency procedure guidelines (EPGs), there are sufficient dissimilarities in nuclear power plants that implementation of the guidelines at each plant must be performed in a manner that ensures consideration of plant-specific design features and operating characteristics. The use of operator action event tress (OAETs) results in identification of key features unique to each plant and yields insights into accident prevention and mitigation that can be factored into plant-specific emergency procedures. Operator action event trees were developed as a logical extension of the event trees developed during probabilistic risk analyses. The dominant accident sequences developed from a plant-specific probabilistic risk assessment represent the utility's best understanding of the most likely combination of events that must occur to create a situation in which core cooling is threatened or significant releases occur. It is desirable that emergency operating procedures (EOPs) provide adequate guidance leading to appropriate operator actions for these sequences. The OAETs provide a structured approach for assuring that the EOPs address these situations.

Plant and Wood Area Index of Solitary Trees for Urban Contexts in Nordic Cities

Background: We present the plant area index (PAI) measurements taken for 63 deciduous broadleaved tree species and 1 deciduous conifer tree species suitable for urban areas in Nordic cities. The aim was to evaluate PAI and wood area index (WAI) of solitary-grown broadleaved tree species and cultivars of the same age in order to present a data resource of individual tree characteristics viewed in summer (PAI) and in winter (WAI). Methods: All trees were planted as individuals in 2001 at the Hørsholm Arboretum in Denmark. The field method included a Digital Plant Canopy Imager where each scan and contrast values were set to consistent values. Results: The results illustrate that solitary trees differ widely in their WAI and PAI and reflect the integrated effects of leaf material and the woody component of tree crowns. The indications also show highly significant (P < 0.001) differences between species and genotypes. The WAI had an overall mean of 0.91 (± 0.03), ranging from Tilia platyphyllos ‘Orebro’ with a WAI of 0.32 (± 0.04) to Carpinus betulus ‘Fastigiata’ with a WAI of 1.94 (± 0.09). The lowest mean PAI in the dataset was Fraxinus angustifolia ‘Raywood’ with a PAI of 1.93 (± 0.05), whereas Acer campestre ‘Kuglennar’ represents the cultivar with the largest PAI of 8.15 (± 0.14). Conclusions: Understanding how this variation in crown architectural structure changes over the year can be applied to climate responsive design and microclimate modeling where plant and wood area index of solitary-grown trees in urban contexts are of interest.

Do Exotic Trees Threaten Southern Arid Areas of Tunisia? A Case Study Indian Journal of Ecology (2020) 00(0): 000-000 Plant-plant interactions

an afforested steppe planted This study was conducted in with aims to compare the effects of exotic and native Stipa tenacissima trees (and , respectively) on the understory vegetation and soil properties. For each tree species, two sub-Acacia salicina Pinus halepensis habitats were distinguished: the canopied sub-habitat (under the tree crown) and the un-canopied sub-habitat (open grassland). Soil moisture was measured in both sub-habitats at 10 cm depth. In parallel to soil moisture, investigated the effect of tree species on soil fertility. Soil samples were collected from the upper 10 cm soil, excluding litter and stones. The nutrient status of soil (organic matter, total N, extractable P) was significantly higher under compared to and open areas. This tendency remained constant with the soil water A. salicina P. halepensis content which was significantly higher under trees compared to open sub-habitats. For water content, there were no significant differences between studied trees. Total plant cover, species richness and the density of perennial species were significantly higher under the exotic species compared to other sub-habitats. Among the two tree species, had the strongest positive effect on the understory Acacia salicina vegetation. It seems to be more useful as a restoration tool in arid areas and more suitable to create islands of resources and foster succession than the other investigated tree species.

Effects of Elevated Atmospheric CO2 on Microbial Community Structure at the Plant-Soil Interface of Young Beech Trees (Fagus sylvatica L.) Grown at Two Sites with Contrasting Climatic Conditions

Soil microbial community responses to elevated atmospheric CO2 concentrations (eCO2) occur mainly indirectly via CO2-induced plant growth stimulation leading to quantitative as well as qualitative changes in rhizodeposition and plant litter. In order to gain insight into short-term, site-specific effects of eCO2 on the microbial community structure at the plant-soil interface, young beech trees (Fagus sylvatica L.) from two opposing mountainous slopes with contrasting climatic conditions were incubated under ambient (360 ppm) CO2 concentrations in a greenhouse. One week before harvest, half of the trees were incubated for 2 days under eCO2 (1,100 ppm) conditions. Shifts in the microbial community structure in the adhering soil as well as in the root rhizosphere complex (RRC) were investigated via TRFLP and 454 pyrosequencing based on 16S ribosomal RNA (rRNA) genes. Multivariate analysis of the community profiles showed clear changes of microbial community structure between plants grown under ambient and elevated CO2 mainly in RRC. Both TRFLP and 454 pyrosequencing showed a significant decrease in the microbial diversity and evenness as a response of CO2 enrichment. While Alphaproteobacteria dominated by Rhizobiales decreased at eCO2, Betaproteobacteria, mainly Burkholderiales, remained unaffected. In contrast, Gammaproteobacteria and Deltaproteobacteria, predominated by Pseudomonadales and Myxococcales, respectively, increased at eCO2. Members of the order Actinomycetales increased, whereas within the phylum Acidobacteria subgroup Gp1 decreased, and the subgroups Gp4 and Gp6 increased under atmospheric CO2 enrichment. Moreover, Planctomycetes and Firmicutes, mainly members of Bacilli, increased under eCO2. Overall, the effect intensity of eCO2 on soil microbial communities was dependent on the distance to the roots. This effect was consistent for all trees under investigation; a site-specific effect of eCO2 in response to the origin of the trees was not observed.

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Michael Senteza added a reply:

We have to separate science from business and politics in the first place , before we can adequately discuss the resolution of this global challenge .

The considerations to global warming can be logically broken down in the following

1. What are the factors that have affected the earths climate over the last million years ? 100,000 years , 10,000 years and 1,000 years .

2. Observations , the climatic changes , formations , and archaeological data to support the changes

3. The actualities of the earth dynamics , for example we know that approx 2/3 of the earth is water and we also know that of the 1/3 we have approximately 60% un inhabitable , and the 40% habitable has approximately 10% who contribute to the alleged pollution , where for example as of 2022 (https://www.whichcar.com.au/news/how-many-cars-are-there-in-the-world) The US had 290 Million cars compared to Africa (50+ Countries ) 26 Million cars the EU (33 + countries ) 413 million cars then Asia pacific with 543 Million cars ( with a population of close to 2 billion ) . We estimate that as of may there are 1.45 billion cars . this means that North America , Western Europe and Asia pacific combined have approx 1.3 billion cars , and yet close to 70% of vegetation cover and forest space is concentrated in africa , south america , northern europe and canada. we need to analyse this

4. We need to also analyse the actualities of the cause separating factors outside our reach , for example global worming as opposed to climate change . We know that climate change which has been geologically and scientifically observed to have been the reason things like Oil came into place , species became extinct and other formations created . We need to realise that a fair share of changes in climate (which some times may be confused with global worming ) have been due to changes in the earth's rotation , axis and orbit around the sun . These are factors that greatly affect the distribution of the sun's radiation on to the surface of the earth and the atmospheric impact , them make consideration of how much we produce , the dispersion rate , natural chemical balances and volumetric analysis of concentration , assimilation and alteration of elements .

5. The extent to which non scientific factors are contributing to attenuating strength of scientific argument . It is not uncommon to have politicians alter the rhetoric to serve their agenda , however it's even worse when the sponsors of the scientific research are intent on achieving specific goals and not facts .

In conclusion humans are intelligent enough to either end of mitigation the impact of global worming if it can be detached from capitalism and politics . Science can and will provide answers

Sunil Deshpande added a reply:

World‘s scientific power is doing its best to stop the global climate change. For example , alternatives to Petrol, cement, plastic are already identified and once they are consumed by many, it will have a positive impact to stop the climate change. However, to my mind, its not sufficient unless citizen of every country also contribute in his own way to stop climate change such as stopping the use of plastic, use of electric car against Petrol, stopping the engine of car at traffic signal. It should become a global movement to protect the climate.

I am learning microstructure modeling and also looking for some resources and opensource software to start with.

I'm currently doing my thesis which uses structural equation modeling for longitudinal data. Is it normal for a model to have 0 RMSEA, Test Statistic, Degrees of Freedom, and p-value? What does that represents in sem.

The value of the average RMSE in my study is 0.523 for training data and 0.514 for testing. I have used 90% data for training and 10% for testing. However I am getting higher RMSE average, is this acceptable? and any study available to cite RMSE average optimum limit?

I have done a stress-strain test and it looks like the picture attached. However, in here, I only have upper and lower plateau stresses.

In Auricchio's model for the superelastic behavior of nitinol material, four parameters and constant are required to model the behavior. How can I extract these parameters from my test?

What I have from my test: upper plateau stress, lower plateau stress, elongation, residual elongation

What I need for the modeling: Sigma_s and Sigma_f for both forward and reverse phase transformations (four constants as shown in the attached picture), residual strain.

Hello everyone,

I am facing an issue with Abaqus and parallel computing. I am using VUHARD subroutine with COMMON block and VEXTERNALDB. But I am using different results using different number of cores. I am starting each analysis with same microstructure and same subroutine just with different number of cores. The results seem to show triangles where calculations seems to be happening. For example, in the attached document, I start with an initial microstructure with 10,000 elements and I run it with cpus=4, 8, 12. I get different results. Could someone please explain what could be going on? And how can I achieve analysis of the full model?

Thanks,

Akanksha

In an area or region where there are inadequate Continuously Operating Reference Stations (CORS), how can one use GIS based techniques such as Multi - Criteria Decision modelling to analyze site suitability for the establishment of more CORS within the region so as to achieve optimal CORS network coverage? Thank you.

Hello

I'm learning camsol. I studied the mathematical particle tracking method used for modeling in turbomolecular pumps, and I can model a single-stage rotor, but I can not model a single-stage rotor and stator.

Can you guide me, please?

thanks

maryam

ICMTIM 2024 will be held once a year, aiming to bring scholars, experts, researchers and technicians in the academic fields of "mechatronics" and "intelligent manufacturing" together into an academic exchange platform, and provide a platform to share scientific research results, cutting-edge technologies, understand academic development trends, broaden research ideas, and strengthen academic research and discussion.

The topics of interest for submission include, but are not limited to:

TRACK 1: Mechatronics Technology

· Mechatronics Control

· Sensors and Actuators

· 3D Printing Technologies

· Intelligent control

· Motion Control

......

TRACK 2:Intelligent Manufacturing

· Modeling and Design

· Intelligent Systems

· Intelligent mechatronics

· Micro-Machining Technology

· Sustainable Production

......

All papers, both invited and contributed, the accepted papers, will be published and submitted for inclusion into IEEE Xplore subject to meeting IEEE Xplore’s scope and quality requirements, and also submitted to EI Compendex and Scopus for indexing. All conference proceedings paper can not be less than 4 pages.

Full Paper Submission Date: February 10, 2024

Registration Deadline: March 10, 2024

Final Paper Submission Date: March 25, 2024

Conference Dates: April 26-28, 2024

Hi, I am looking into modeling of polymer dynamics using a combination of Rouse and spring-dashpot modeling. Is it possible? If yes, can anyone refer me to some good repository?

2024 5th International Conference on Artificial Intelligence and Electromechanical Automation (AIEA 2024) will be held in Shenzhen, China, from June 14 to 16, 2024.

The topics of interest for submission include, but are not limited to:

(1) Artificial Intelligence

- Intelligent Control

- Machine learning

- Modeling and identification

......

(2) Sensor

- Sensor/Actuator Systems

- Wireless Sensors and Sensor Networks

- Intelligent Sensor and Soft Sensor

......

(3) Control Theory And Application

- Control System Modeling

- Intelligent Optimization Algorithm and Application

- Man-Machine Interactions

......

(4) Material science and Technology in Manufacturing

- Artificial Material

- Forming and Joining

- Novel Material Fabrication

......

(5) Mechanic Manufacturing System and Automation

- Manufacturing Process Simulation

- CIMS and Manufacturing System

- Mechanical and Liquid Flow Dynamic

......

All accepted papers will be published in the Conference Proceedings, which will be submitted for indexing by EI Compendex, Scopus.

Full Paper Submission Date: April 1, 2024

Registration Deadline: May 31, 2024

Final Paper Submission Date: May 14, 2024

Conference Dates: June 14-16, 2024

*Using the invitation code on submission system/registration can get priority review and feedback

I begin scientific inquiry by somewhat philosophizing. Science approximately derives from philosophy. Engineering is roughly derived from science.

Please, if you could recommend any books or journals on TBC modeling to me, that would be greatly appreciated.

To a non-mathematicia.

i am trying to make a GUI interface for my modelings but a syntax error are emerged.

how can i solve this error?

GUI codes are attached...

Most of the researchers concerned with analytical study or numerical study use ANSYS for the FE Modeling. The awareness about NASTRAN is low. What may be the reason and Why?

Modelling a phenomena has been a great interest for researchers. The question came to me, how can we model a floc growth during coagulation-flocculation process. Many studies reported floc growth using the approach of population balance model and fractal dimension, such as recent study by Moruzzi et al ( ). However, I haven't seen any other approach such as modelling floc as a growing sphere. Can anyone share their thoughts and expertise regarding this matter?

I am investigating the impact of pretension effect around circular tunnels. How can I do my own modeling?

1- I want to excavate a tunnel.

2- I want to put a rock bolt or cable bolt in the hole

3- Apply grout or resin to the end of reinforcement element

4- After that, I put the element under pre-tension force and pull it out

Please write the software commands that are needed for this modeling

I'm modeling the habitat suitability of a species. I know that you can project the model to future scenarios when setting up the modeling, but can you project your maxent model to future scenarios after the modeling is complete?

I am modeling an underground structure with fixed support conditions around the exterior walls. I would like to apply different ground acceleration time history data into specific nodes (joints) of the structure. Is this possible in SAP 2000? I would appreciate any guidelines. Thank you very much!

RUSLE and USLE are the prevalent soil erosion models widely used especially for catchments, watersheds, and basins. these zones are hilly or sloppy can this model be used in a nearly flat environment for soil modeling

I am modeling a heat pump on the EES program and for the heat exchanger, I am using the NTU method to solve which requires iterations and I am unsure how to use it. If somebody explains it to me through an example then I will be thankful

While Modelling infillwall, why does after failure the line drops in a straight pattern rather than moving along the displacement as seen from experimental results?

Kaiser H (1979) The dynamics of populations as result of the properties of individual animals. FORTSCHR. D. ZOOL.25: 109-136.

This a visionary article about the rationale of individual-based modelling of populations.

I have a model for 48 pulse NPC built it, and conncted it to a grid, I am controlleing the active and reactive power, so basically my control finds the requied reference vd and vq that will enter the converter so I can at the end of the converter I ger the desired reference voltage. Now, this model runs on continuous mode in matlab, I need to make it run in phasor mode, how can I do that?

or in other words, what I need to change to adabt the phasoe running mode ?

Can someone guide during numercial modelling using FEA software DIANA FEA, in cyclic loading i dont see the pinching effcet. what is the reason that might be

Is there any free software which is helpful to do dispersion modelling of the pollutants emitted from the line sources like vehicular source and also suitable for hilly region?

Dear experts

I'm modeling a structure in ETABS through MATLAB using the CSI OAPI. I want to define a response spectrum function from a file or as user-defined, but I can't find any method that is designed for this purpose.

Is there any method that can define a spectrum?

Your suggestions are appreciated.

N.Djafar

I am currently conducting a meta-analysis of animal studies using R, however, to model the optimum dosage of the treatment, I am faced with the challenge of how the data should be structured in excel and the R script to run.

I am modeling the Kirchhoff plate through FEM. I have already used the Q4 element.

However, I want to use the Q8 element. Is this possible? If yes, how many items should be in the approximate polynomial to derive the shape functions according to Pascal triangle?

I modeled the 2D frame with OpenSeesPy in a way that the concrete class is variable, there is a distributed load on the beams and horizontal load on only 2 nodes, I analyzed the statics in this way, but I am getting an error in the analysis part.

My modeling steps are very similar to the OpenSeesPy 2D Portal Frame example:

However, while I was doing the analysis using eigen in the example, I did not use eigen. I would like your comments.

import time

import sys

import os

import openseespy.opensees as ops

import numpy as np

import matplotlib.pyplot as plt

m = 1.0

s = 1.0

cm = m/100

mm = m/1000

m2=m*m

cm2=cm*cm

mm2 = mm*mm

kN = 1.0

N = kN/1000

MPa = N/(mm**2)

pi = 3.14

g = 9.81

GPa = 1000*MPa

ton = kN*(s**2)/m

matTag=1

for i in range(0,8):

# remove existing model

ops.wipe()

# set modelbuilder

ops.model('basic', '-ndm', 2, '-ndf', 3)

L_x = 3.0*m # Span

L_y = 3.0*m # Story Height

b=0.3*m

h=0.3*m

# Node Coordinates Matrix (size : nn x 2)

node_coords = np.array([[0, 0], [L_x, 0],

[0, L_y], [L_x, L_y],

[0, 2*L_y], [L_x, 2*L_y],

[0, L_y], [L_x, L_y],

[0, 2*L_y], [L_x, 2*L_y]])

# Element Connectivity Matrix (size: nel x 2)

connectivity = [[1,3], [2,4],

[3,5], [4,6],

[7,8], [9,10],

[7,3], [8,4],

[9,5], [10,6]

]

# Get Number of elements

nel = len(connectivity)

# Distinguish beams, columns & hinges by their element tag ID

all_the_beams = [5, 6]

all_the_cols = [1, 2, 3, 4]

[ops.node(n+1,*node_coords[n])

for n in range(len(node_coords))];

# Boundary Conditions

## Fixing the Base Nodes

[ops.fix(n, 1, 1, 1)

for n in [1, 2]];

fpc = [30,33,36,39,42,45,48,50]

epsc0 = [0.002,0.002,0.002,0.002,0.002,0.002,0.002,0.002]

fpcu = [33,36,39,42,45,48,51,54]

epsU = [0.008,0.0078,0.0075,0.0073,0.0070,0.0068,0.0065,0.0063]

Ec=(3250*(fpc[i]**0.5)+14000)

A=b*h

I=(b*h**3)/12

ops.uniaxialMaterial('Concrete01', matTag, fpc[i], epsc0[i], fpcu[i], epsU[i])

sections = {'Column':{'b':b, 'h':h,'A':A, 'I':I},

'Beam':{'b':300, 'h':500, 'A':300*300,'I':(300*(300**3)/12) }}

# Transformations

ops.geomTransf('Linear', 1)

# Beams

[ops.element('elasticBeamColumn', e, *connectivity[e-1], sections['Beam']['A'], Ec, sections['Beam']['I'], 1)

for e in all_the_beams];

# Columns

[ops.element('elasticBeamColumn', e, *connectivity[e-1], sections['Column']['A'], Ec, sections['Column']['I'], 1)

for e in all_the_cols];

D_L = 0.27*(kN/m) # Distributed load

C_L = 0.27*(kN) # Concentrated load

# Now, loads & lumped masses will be added to the domain.

loaded_nodes = [3,5]

loaded_elems = [5,6]

ops.timeSeries('Linear',1,'-factor',1.0)

ops.pattern('Plain', 1, 1)

[ops.load(n, *[0,-C_L,0]) for n in loaded_nodes];

ops.eleLoad('-ele', *loaded_elems,'-type', '-beamUniform',-D_L)

# create SOE

ops.system("BandSPD")

# create DOF number

ops.numberer("RCM")

# create constraint handler

ops.constraints("Plain")

# create integrator

ops.integrator("LoadControl", 1.0)

# create algorithm

ops.algorithm("Linear")

# create analysis object

ops.analysis("Static")

# perform the analysis

ops.analyze(1)

# get node displacements

ux = ops.nodeDisp(5, 1)

uy = ops.nodeDisp(3, 1)

print(ux,uy)

print('Model built successfully!')

Hello everyone,

I want to model Wire and arc additive manufacturing in abaqus.I have written down Dflux subroutine in which the ellipsoidal heat flux is modeled. Parameters are travel speed, Heat input and efficiency. How to add wire feed rate parameter in model whether to be included in subroutine or not?

Pls, I need a reviwer contact, to submit to a journal. Topic: Control, Energy saving, Robotics, Modeling and Simulation.

Is there any program to convert ssDNA sequences to possible three-dimensional conformation for MD simulations?

Edit: It is an aptamer generated against specific target

Hello towards the above topic, I successfully loop-modeled a transmembrane heptamer protein (426-residues per monomer) exhibiting 7-extracellular loops each missing 11-residues via MODELLER via constraining the already known structural residues (I had input the entire heptamer despite possible interface of multiple subunit problems due to failing to loop-model it as a monomer which would preclude loop-to-loop modeling interference).

My inquiry, does AlphaFold have the ability to similarly loop model constraining the known residues via structural input(s) and if so would there be two modeling options to input the monomer and also the heptamer as I did via MODELLER for comparison or if one is best which i.e. Alphafold2 of Alphafold Multimer? (Can Alphafold Multimer model 426 residues times 7 monomers or is this capacity too large?)

(Maybe in this case the only option would be to use Alphafold Multimer via sequence input and then extract the modeled loops.) Thanks if you know:), Joel 🚀

While working on the modeling of Internal Short Circuits (ISC) in batteries, I have encountered some challenges.

Hello everyone!

I am trying to match an upwards drift in I(t) data (at the same bias the photo=current slighly increases at the same bias) by using Stress-induced leakage current (SILC) trap model, which in turn is governed by assistant tunneling model. In this model (see appended pdf, derivation is in Appendix) the current J=P1(1-exp(-P2*t), where J- is a current at the same bias, t is a time and P1 and P2 are coefficients. It is explained (in the same appended paper) that PI can be interpreted, in the depletion of precursor model, as the SILC component that is related (proportional) to the density of a certain type of precursor sites and P2 the rate constant of the trap generation from these precursors.

While the meaning of P2 is somehow clear-it is connected to a trap density, but I do not understand what is " the depletion of precursor model in explanation of P1 coef" and how this coefficient is connected to a trap density. For me P1 is connected to a current offset, when the trap concentration can be considered to be zero, but I might be completely wrong.

Am I missing somethin?

Thansk again!

In his very helpful online book on structural equation modeling, Jon Lefcheck writes the following concerning d-separation tests for SEMs:

"Once the model is fit, statistical independence is assessed with a t-, F-, or other test. If the resulting P-value is >0.05, then we fail to reject the null hypothesis that the two variables are conditionally independent. In this case, a high P-value is a good thing: it indicates that we were justified in excluding that relationship from our path diagram in the first place, because the data don’t support a strong linkage between those variables within some tolerance for error."

My understanding is that this is a standard procedure in SEM and more broadly in DAG-data consistency checks, not a quirk of Lefcheck's workflow. My question is, doesn't this amount to an attempt to use p-values to control type II error rate?

Setting aside the inherent limitations of p-values even when used correctly, the fundamental problem is that p-values simply don't control type II error rate --- they control type I error rate.

The language in the documentation of the R package bnlearn, a suite of Bayesian causal discovery tools, is even more explicit in equating the failure to reject the null hypothesis of zero correlation with the acceptance of the null hypothesis, i.e. the conclusion that correlation is "in fact" zero:

"Now, let’s check whether the global Markov property is satisfied in this example. We will use the survey data to check the Null hypothesis that S is independent of T given O and R. In R, we can use ci.test function from bnlearn to find conditional dependence. [...] As you can see, the p-value is greater than 0.05 threshold, hence we do not reject the Null hypothesis and conclude that in fact, S is independent of T given O and R."

As a convert to causal inference and Bayesian logic from the cult of cause-blind null-hypothesis statistical testing, I find it frustrating that when it comes time to validate our causal graphs --- after all our effort to construct principled causal models and estimate parameters informatively --- we fall back on p-values, and a dubious use of p-values at that.

Am I missing something? I hope to be corrected.

Hello everybody !

I am working on a medium size organic molecule (around 40 atoms) and I try to check the presence of a conical intersection between S1 and S0. I used DFT and TD-DFT to compute the PES of S0 and S1 in my molecule along different modes and motions but for now no conical intersection was identified.

Do you think it would be a possible and interesting approach to use TD-DFT/MD simulation to start from the S1 optimized geometry and apply temperature to check the evolution of the geometry in the S1 state of the molecule in time ? Will it go back to the S0 optimized geometry in the case of an easy accessible conical intersection ?

Thank you for any help you may provide and for your interesting comments about it.

At the level of resource allocation modelling can't see any difference:(

Greetings to the world geophysical community

During my master's degree, I worked in the field of earthquake engineering and risk analysis, and recently I have been thinking about the future of this issue and its importance for the world, whether it is important at all or not.

I am consulting with Iranian professors so that I can work in the field of oil and exploration. But unfortunately, in Iran, we lack data and facilities in the field of oil and exploration.

I am currently studying in the field of (time reverse modeling) and if you are interested in doing this in the future, please let me know. and share your idea for me.

Thanks

I modelling seepage analysis using SEEP/w and the result is XY gradient contour out of the phreatic line? And i think it's not make sense, so how i compute SF for boiling if the exit gradient computed by SEEP/w is wrong?

Every answer would be appreciated. Thanks before.

I want to weld two tubular members in Abaqus(see figure). How can I do it. I am using the cut merge option. Will this option be considered welding? If not, then what do I need to do? Can you please guide me? Thanks

Are there any difference between causal model and model testing?

AIMD simulation requires a reasonable initial structure, so how should it be modeled? That is, is POSCAR a structure file after preliminary optimization by MS or other modeling software?

I want to use vasp to perform a first-principles molecular dynamics simulation of more than two hundred atoms (9 elements). It is a rock model containing multiple minerals, and the lattice parameters can’t be searchable. I need to build a cubic unit cell with a side length of 15 Å and a unit cell parameter of 1. The question now is how to set the atomic coordinates?

How can I get my POSCAR? Is it to write an initial POSCAR randomly to relax the structure? But the structure obtained in this way is probably not the global minimum.

Or if I can use MS software to model and optimize the structure, and then output the optimized structure as a POSCAR file. Next import it into VASP for AIMD simulation?

If anyone can give me some suggestions, I would be very glad! Thaks for your attention!

How can we apply structural causal modeling in the analysis or modeling of complex systems? What are its fundamental principles? Is it purely a mathematical approach, or does it involve computational methods as well?"

Traffic models are very useful for various purposes. First, they can help in the design and operations of traffic systems since they can predict traffic operational conditions at some time in the future under various sets of design, traffic, and control characteristics. Traffic engineers and designers can make decisions regarding facility modifications or traffic management improvements based on the expected impact of those improvements in the transportation system. Second, they can help in the evaluation of existing systems and in the development of priorities for improvement. Mathematical models are those that describe a physical system mathematically. Such models describe specific r​e​l​a​t​i​o​n​s​h​i​p​s​”

Hello everyone,

I work with polymer materials and I am attempting to model optical parameters (refractive index) and dielectric parameters (dielectric permittivity). Since I am not very familiar with this type of modeling, I am reaching out to you to inquire about possible approaches for creating mathematical models to estimate these parameters in the frequency range of Giga and Terahertz.

Best regards,

I would like to add some questions that made me stuck for sometimes. So i have an issue in imbalance segmentation data for landslide modelling using U-Net (my landslide data is way less than my non-landslide data). So my questions are:

1. Should i try to find a proper loss function for the imbalance problem? or should i focus on balancing data to improve my model?

2. Some suggest to use SMOTE (oversampling), but since my data are images (3D) i have found out that it is not suitable to use SMOTE for my data. So, any other suggestions?

Thank you,

Your suggestions will be appreciated.

Hello dear all,

We want to set-up a CFD -Discrete Particle Modelling case for a bubble column where liquid is eulerian and gas bubbles and solid particles are discrete phases (three-phases total holdup <10 %) as given in attached diagram. In this case only gas bubbles are flowing with velocity UG <1 cm/s while liquid and solid particles have no initial velocity (means batch mode). Boundary condition (DPM) for gas phase at outlet is pretty straight forward "escape" but we want to retain second discrete phase "particles" with in column volume. However, Boundary condition panel in Ansys Fluent do not show "escape" or "wall" or "reflect" for an individual DPM (injection) phase but one for all DPMs.

We want to model the effect of gas bubble induced flow behavior (in one-way coupling) on liquid and solid phases, so we need to keep liquid in batch mode and solid phase (one-time injection). Any suggestion on how to set-up DPM-BC for two discrete phases (two different injections) separately in Ansys Fluent?

For gastroplus modeling - can I determine the D90 from the specified D50 and SD/bins from the particle entry section? I've modeled several scenarios using a specified D50 and SD and # bins, but I'd like to know what my D90 is. Is this possible to determine?

I am looking for someone who is an expert in dynamic Bayesian Network (DBN) analysis and modeling. I have the data, so we can do the research together. Or if she or he is possible, give me a workshop in DBN analysis and modeling.

I have a large data set of lead isotopic ratios and I need to determine the unique points where there is (are) distinct changes in those values with respect to time.

How can I do this by applying the above modelling?

How to apply design thinking into guitar build modeling?

What is functional modeling?

I want to model plastic hinge in opensees navigator

Can any one help me with this?

On the above mentioned modelling methods, which one is suitable for protein structure prediction for protein/gene families? Suggest some highly reliable modelling methods and software used for it.

I have two different PEEC models of two different circuits, is there any way I can combine them into one model?

This is an observation that has been made from first priciples studies and i have the same observation from my TCAD modeling results.

Need some guide how to simulate the stone column model of manuscript "Simplified Plane-Strain Modeling of Stone-Column Reinforced Ground - DOI: 10.1061/(ASCE)1090-0241(2008)134:2(185)" with PLAXIS 2D or 3D software.

I'm intermediate PLAXIS software user.

I would appreciate it if you could share useful articles.

Which authentication schemes would perform better than improved Feige–Fiat–Shamir (IFFS) for modeling a secure IoT-integrated WBAN framework for e-healthcare?

NEED SOME SAMPLES

What is Bayesian structural equation modeling?