scholarly journals Pressure stress modeling on expanded polystyrene materials using genetic programming

2021 ◽  
Vol 1208 (1) ◽  
pp. 012013
Author(s):  
Ermin Bajramović ◽  
Bahrudin Hrnjica ◽  
Redžo Hasanagić ◽  
Emir Bajramović

Abstract In the production of expanded polystyrene, the standards are very high in terms of thermal, fire, dimensional, and mechanical characteristics, because each of the characteristics is a condition for achieving quality that allows competitiveness in the market. To ensure high-quality products, it is necessary to achieve optimal performance and product quality through carefully adjusted input parameters of production. Since the production of expanded polystyrene is specific in several ways, an experimental study was conducted in which the basic parameters affecting product quality were detected and through which a series of experiments were performed to prove product quality. Experimental research for this work was conducted on three types of expanded polystyrene samples whose purpose is to insulate floors exposed to pressure. The samples were made of the same material of different densities and aging times for which the pressure stress at a deformation of 10% was tested. After the experimental phase, the modeling of the output parameters was performed. Modeling involved the development of a model that describes a given problem and the obtained modeled values were analyzed and compared with the experimental one. The modeling method used genetic programming using the GPdotNET software package. The goal of modeling with the GpdotNET tool is to obtain a realistic model that would give the value of the compression stress at a deformation of 10% as an output variable in materials made of expanded polystyrene.

Author(s):  
V. P. Klimenko ◽  
V. М. Kosolapov ◽  
V. G. Kosolapova ◽  
К. Е. Yurtaeva

The data on assessment the preservative action of new enzymatic multisystem in combination with bacterial silage additive Silzak at alfalfa ensiling are presented in this study. It is known that alfalfa is a nonensiling legume grass because of excess moisture, sugar deficit and high content of crude protein. The experiments on alfalfa ensiling were conducted with application the enzymatic multisystem FM-1 under laboratory and research-and-production conditions. The multisystem was developed by the specialists of science-and-technical centre «Lecbiotech» in cooperation with scientists of Williams Fodder Research Institute. The optimal dose of FM-1 application and its preservative effectiveness in comparison with chemical conservant were determined in technological experiments. Obtained silage was evaluated on basic parameters: nutrients and organic acids content, ammonia, active acidity. The influence of the tested biological additive on the nutrients digestibility and energy value of alfalfa silage was estimated in experiments with hog lambs. Total results have shown the efficiency of the new development. Lucerne silage, prepared with application of mixture FM-1 and Silzak, was characterized by the better parameters of nutrients digestibility and energy value than at using a chemical conservant AIV 3 plus. The optimal dose of enzymatic multisystem application, as 90 gram per ton of fresh plant mass, was determined in the series of experiments.


Genetics ◽  
2000 ◽  
Vol 155 (4) ◽  
pp. 1991-2001 ◽  
Author(s):  
A García-Dorado ◽  
A Caballero

Abstract T. Mukai and co-workers in the late 1960s and O. Ohnishi in the 1970s carried out a series of experiments to obtain direct estimates of the average coefficient of dominance (h¯) of minor viability mutations in Drosophila melanogaster. The results of these experiments, although inconsistent, have been interpreted as indicating slight recessivity of deleterious mutations, with h¯≈0.4. Mukai obtained conflicting results depending on the type of heterozygotes used, some estimates suggesting overdominance and others partial dominance. Ohnishi's estimates, based on the ratio of heterozygous to homozygous viability declines, were more consistent, pointing to the above value. However, we have reanalyzed Ohnishi's data, estimating h¯ by the regression method, and obtained a much smaller estimate of ~0.1. This significant difference can be due partly to the different weighting implicit in the estimates, but we suggest that this is not the only explanation. We propose as a plausible hypothesis that a putative nonmutational decline in viability occurring in the first half of Ohnishi's experiment (affecting both homozygotes and heterozygotes) has biased upward the estimates from the ratio, while it would not bias the regression estimates. This hypothesis also explains the very high h¯≈0.7 observed in Ohnishi's high-viability chromosomes. By constructing a model of spontaneous mutations using parameters in the literature, we investigate the above possibility. The results indicate that a model of few mutations with moderately large effects and h¯≈0.2 is able to explain the observed estimates and the distributions of homozygous and heterozygous viabilities. Accounting for an expression of mutations in genotypes with the balancer chromosome Cy does not alter the conclusions qualitatively.


1881 ◽  
Vol 32 (212-215) ◽  
pp. 407-408

During the progress of the investigations which I have from time to time had the honour of bringing under the notice of the Royal Society, I have again and again noticed the apparent disappearance of gases inclosed in vessels of various materials when the disappearance could not be accounted for upon the assumption of ordinary leakage. After a careful examination of the subject I found that the solids absorbed or dissolved the gases, giving rise to a striking example of the fixation of a gas in a solid without chemical action. In carrying out that most troublesome investigation, the crystalline separation of carbon from its compounds, the tubes used for experiment have been in nine cases out of ten found to be empty on opening them, and in most cases a careful testing by hydraulic press showed no leakage. The gases seemed to go through the solid iron, although it was 2 inches thick. A series of experiments with various linings were tried. The tube was electro-plated with copper, silver, and gold, but with no greater success. Siliceous linings were tried fusible enamels and glass—but still the' tubes refused to hold the contents. Out of thirty-four experiments made since my last results were published, only four contained any liquid or condensed gaseous matter after the furnacing. I became convinced that the solid matter at the very high pressure and temperature used must be pervious to gases.


Author(s):  
Marvin S Godsey ◽  
Dominic Rose ◽  
Kristin L Burkhalter ◽  
Nicole Breuner ◽  
Angela M Bosco-Lauth ◽  
...  

Abstract Following the recent discovery of Bourbon virus (BRBV) as a human pathogen, and the isolation of the virus from Amblyomma americanum (L.) collected near the location of a fatal human case, we undertook a series of experiments to assess the laboratory vector competence of this tick species for BRBV. Larval ticks were infected using an immersion technique, and transstadial transmission of virus to the nymphal and then to the adult stages was demonstrated. Transstadially infected nymphs transmitted virus to adult ticks at very high rates during cofeeding, indicating the presence of infectious virus in the saliva of engorging ticks. Vertical transmission by transstadially infected females to their progeny occurred, but at a low rate. Rabbits fed on by infected ticks of all active life stages developed high titers of antibody to the virus, demonstrating host exposure to BRBV antigens/live virus during tick blood feeding. These results demonstrate that A. americanum is a competent vector of BRBV and indicate that cofeeding could be critical for enzootic maintenance.


2021 ◽  
pp. 1-20
Author(s):  
Zan Zhang ◽  
Guofang Nan ◽  
Minqiang Li ◽  
Yong Tan

When confronted with a new product, consumers often find it difficult to predict how it will perform, and such uncertainty reduces consumers’ willingness to adopt the product. In this paper, we consider a market whereby consumers decide when and which product to buy, given that they know the product quality of the incumbent but are uncertain about that of the entrant. We investigate how consumer uncertainty about product quality affects firms’ behavior-based pricing and customer acquisition and retention dynamics. Using a two-period vertical model, we find that, under high-end encroachment, an increase in consumer uncertainty reduces the entrant’s profit and hurts the incumbent’s profit when the quality differential between the products is relatively small, whereas, under low-end encroachment, increasing uncertainty not only benefits the incumbent but also can favor the entrant. An important implication for entrants is that the marketing activities, which aim to reduce consumer uncertainty about product functionalities, may fail to improve profitability. We also find that the entrant lowers the price for uninformed customers and raises the price for repeat buyers under high-end encroachment but lowers the price for all customers under low-end encroachment. We further examine the subsidy strategy and show that, when the entrant’s product has a significant quality advantage and consumer uncertainty is high but not very high, the optimal strategy for the entrant is to acquire all consumers who do not buy from the incumbent by providing subsidies and to drop the low-valuation customers by means of a high price after their uncertainty is resolved.


2007 ◽  
Vol 44 (12) ◽  
pp. 1462-1473 ◽  
Author(s):  
Mohammad Rezania ◽  
Akbar A. Javadi

In this paper, a new genetic programming (GP) approach for predicting settlement of shallow foundations is presented. The GP model is developed and verified using a large database of standard penetration test (SPT) based case histories that involve measured settlements of shallow foundations. The results of the developed GP model are compared with those of a number of commonly used traditional methods and artificial neural network (ANN) based models. It is shown that the GP model is able to learn, with a very high accuracy, the complex relationship between foundation settlement and its contributing factors, and render this knowledge in the form of a function. The attained function can be used to generalize the learning and apply it to predict settlement of foundations for new cases not used in the development of the model. The advantages of the proposed GP model over the conventional and ANN based models are highlighted.


2012 ◽  
Vol 16 (suppl. 1) ◽  
pp. 237-250 ◽  
Author(s):  
Velimir Congradac ◽  
Bosko Milosavljevic ◽  
Jovan Velickovic ◽  
Bogdan Prebiracevic

The manufacturing, distribution and use of electricity are of fundamental importance for the social life and they have the biggest influence on the environment associated with any human activity. The energy needed for building lighting makes up 20-40% of the total consumption. This paper displays the development of the mathematical model and genetic algorithm for the control of dimmable lighting on problems of regulating the level of internal lighting and increase of energetic efficiency using daylight. A series of experiments using the optimization algorithm on the realized model confirmed very high savings in electricity consumption.


2021 ◽  
Author(s):  
Zijian Zhang ◽  
Zhongshi Zhang ◽  
Zhengtang Guo

<p>The early Eocene is a warm period with a very high atmosphere CO<sub>2</sub> level in the Cenozoic. It  provides a good reference for our future climate under the Representative Concentration Pathway 8.5 scenario. Therefore, the early Eocene climate has received many attentions in  modeling studies, for example, the Deep-Time Model Intercomparison Project (DeepMIP). However, the early Eocene palaeogeographic conditions show remarkable contrasts to the present conditions. Meanwhile, there are a few different reconstructions for the early Eocene palaeogeography, which may cause further model spreads in simulating the early Eocene warm climate. Here, we present a series of experiments carried out with the NorESM1-F, under the framework of DeepMIP. In these experiments, we consider three different palaeogeographic reconstructions for the early Eocene. We also compare our simulations with climate proxy records, to validate which palaeogeographic reconstructions can reproduce simulations that agree better with the climate proxy records.</p>


2020 ◽  
Vol 641 ◽  
pp. A139
Author(s):  
A. Dugaro ◽  
G. C. de Elía ◽  
L. A. Darriba

Aims. We analyze the formation and evolution of terrestrial-like planets around solar-type stars in the absence of gaseous giants. In particular, we focus on the physical and dynamical properties of those that survive in the system’s habitable zone (HZ). This investigation is based on a comparative study between N-body simulations that include fragmentation and others that consider all collisions as perfect mergers. Methods. We use an N-body code, presented in a previous paper, that allows planetary fragmentation. We carry out three sets of 24 simulations for 400 Myr. Two sets are developed adopting a model that includes hit-and-run collisions and planetary fragmentation, each one with different values of the individual minimum mass allowed for the fragments. For the third set, we considered that all collisions lead to perfect mergers. Results. The planetary systems produced in N-body simulations with and without fragmentation are broadly similar, though with some differences. In simulations with fragmentation, the formed planets have lower masses since part of them is distributed among collisional fragments. Additionally, those planets presented lower eccentricities, presumably due to dynamical friction with the generated fragments. Lastly, perfect mergers and hit-and-run collisions are the most common outcome. Regardless of the collisional treatment adopted, most of the planets that survive in the HZ start the simulation beyond the snow line, having very high final water contents. Such planets are called water worlds. The fragments’ contribution to their final mass and water content is negligible. Finally, the individual minimum mass for fragments may play an important role in the planets’ collisional history. Conclusions. Collisional models that incorporate fragmentation and hit-and-run collisions lead to a more detailed description of the physical properties of the terrestrial-like planets formed. We conclude that planetary fragmentation is not a barrier to the formation of water worlds in the HZ. The results shown in this work suggest that further refinement is necessary to have a more realistic model of planetary formation.


2016 ◽  
Vol 48 (1) ◽  
pp. 41-50 ◽  
Author(s):  
Dominika Chądzyńska ◽  
Dariusz Gotlib

Abstract Advanced terrain models are currently commonly used in many video/computers games. Professional GIS technologies, existing spatial datasets and cartographic methodology are more widely used in their development. This allows for achieving a realistic model of the world. On the other hand, the so-called game engines have very high capability of spatial data visualization. Preparing terrain models for the purpose of video games requires knowledge and experience of GIS specialists and cartographers, although it is also accessible for non-professionals. The authors point out commonness and variety of use of terrain models in video games and the existence of a series of ready, advanced tools and procedures of terrain model creating. Finally the authors describe the experiment of performing the process of data modeling for “Condor Soar Simulator”.


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