139 research outputs found

    A multiscale deep learning model for elastic properties of woven composites

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    Time-consuming and costly computational analysis expresses the need for new methods for generalizing multiscale analysis of composite materials. Combining neural networks and multiscale modeling is favorable for bypassing expensive lower-scale material modeling, and accelerating coupled multi-scale analyses (FE2). In this work, neural networks are used to replace the time-consuming micromechanical finite element analysis of unidirectional composites, representing the local material properties of yarns in woven fabric composites in a multiscale framework. Leveraging the fast multiscale data generation procedure, we presented a second neural networks model to estimate the elastic engineering coefficients of a particular weave architecture based on a broad range of dry resin and fiber properties and yarn fiber volume fraction. As an outcome, this paper provides the user with a generalized, neural network-based approach to tackle the balance of computational efficiency and accuracy in the multiscale analysis of elastic woven composites

    The occurrence of riddled basins and blowout bifurcations in a parametric nonlinear system

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    In this paper, a two parameters family Fβ1,β2F_{\beta_1,\beta_2} of maps of the plane living two different subspaces invariant is studied. We observe that, our model exhibits two chaotic attractors AiA_i, i=0,1i=0,1, lying in these invariant subspaces and identify the parameters at which AiA_i has a locally riddled basin of attraction or becomes a chaotic saddle. Then, the occurrence of riddled basin in the global sense is investigated in an open region of β1β2\beta_1\beta_2-plane. We semi-conjugate our system to a random walk model and define a fractal boundary which separates the basins of attraction of the two chaotic attractors, then we describe riddled basin in detail. We show that the model undergos a sequence of bifurcations: "a blowout bifurcation", "a bifurcation to normal repulsion" and "a bifurcation by creating a new chaotic attractor with an intermingled basin". Numerical simulations are presented graphically to confirm the validity of our results.Comment: 26 pages, 15 figure

    Kokcidioza koza: učinci pokusne infekcije na određene krvne pokazatelje.

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    The objective of this experiment was to elucidate the aspects of differential circulatory cell responses during experimental coccidiosis in goat. A total of twenty newborn kids were selected; ten of them were infected with sporulated oocysts of the most pathogenic species of Eimeria and the remainder served as control. Blood samples were taken at 0 (before inoculation), 3, 7, 14, 17, 21, 24, 28 and 35 days post infection (dpi) and some hematological and fecal related parameters were measured. According to our data, except for a significant decrease at 24 dpi, packed cell volume (PCV) and hemoglobin (Hb) concentrations evidenced no substantial changes in the infected kids compared to controls. The percentage of the circulatory neutrophils showed remarkable increases from 7 to 24 dpi. Unlike neutrophils, the level of lymphocytes represented marked decreases from 7 to 24 dpi. In addition, circulatory eosinophils evidenced no statistical changes during the infection; however monocytes revealed a significant elevation only at 17 and 24 dpi. Substantial activations of neutrophils and lymphocytes indicate that these cells have key roles in either preventing or establishing primary infections with Eimeria in goats.Cilj pokusa bio je rasvijetliti različite odgovore stanica u krvnom optjecaju tijekom pokusno uzrokovane kokcidioze u koza. U pokus je bilo uključeno 20 novoojarene jaradi od čega je 10 bilo zaraženo sporuliranim oocistama najpatogenije vrste roda Eimeria, a ostalih 10 su poslužili za kontrolu. Uzorci njihove krvi bili su uzeti 0. (prije zaražavanja), 3., 7., 14., 17., 21., 24., 28. i 35. dana nakon zaražavanja te su bili pretraženi na neke hematološke pokazatelje. Parazitološki su bili pretraženi i uzorci izmeta. Vrijednosti hematokrita i koncentracije hemoglobina nisu pokazivale bitne promjene u zaraženih u odnosu na kontrolne životinje, osim značajnog smanjenja 24. dana nakon infekcije. Postotak optjecajnih neutrofila bio je značajno povećan od 7. do 24. dana nakon infekcije. Za razliku od neutrofila, razina limfocita bila je znantno smanjena od 7. do 24. dana poslije infekcije. Povrh toga, statistički značajne promjene ustanovljene su u broju optjecajnih eozinofila dok je broj monocita bio značajno povišen 17. i 24. dana nakon infekcije. Znatna aktivacija neutrofila i limfocita upućuju na zaključak da te stanice imaju ključnu ulogu u sprječavanju primarne infekcije kokcidijama roda Eimeria u koza

    Limnological survey on the most important rivers in the Iranian southern soasts of the Caspian Sea in the Guilan Province with emphasize on the pollutants (Hevigh, Karkanrud and Shafarud rivers)

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    In order to create a reliable ecological database for Guilans running waters(north Iran near the Caspian sea), at the first step 3 important rivers containing Hevigh, Karkanrud and Shafarud, were selected and limnological survey, during autumn 1380 and summer1381 were seasonally carried out for them. Results showed that the key physico-chemical parameters such as dissolved O2, BOD5, pH, Phosphate, Nitrate, Nitrite, ammonium and in all of the three rivers water were in their normal range suggesting good water quality. Chrysophyta, Chlorophyta, Cyanophyta and Euglenophyta were respectively the most prevalent phytoplankton taxa and Zooplankton fauna of the rivers were fixed and sessile species belong to Protozoa and Rotatoria. 42 benthic macroinvertebrates taxa(Hevigh:36,Karkanrud:22 and Shafarud:30) were identified in these 3 rivers which individuals belong to order Diptera compromise the most divers and frequent one. Regarding macroinvertebrates diversity and indicator groups, it seems that Hevigh river has relatively better water quality than the two other. 23 fish species belong to 9 family,7 order and 2 class , were identified in these rivers during the study period which cyprinid were the most diverse and prevalent of them. Albornoides sp., Capoeta capoeta and Neogobios sp. were the most widespread and frequent species of the identified fishes in all of them. Bacteriological survey including Coliform and E.Colie count showed that the lower parts of the rivers near the estuaries were more infected and the bottom sediments had more bacterial count during the all sampling period. However the total coliform count never exceed of 200 colonies per 100cc , suggesting no risk for direct contact (swimming and washing), according to EPA standards. Chromium, Cadmium and Mercury had very low concentrations in the rivers water but Cupper had relatively high concentration (up to 1.788 mg/l in Hevigh river) amongst the studied heavy metals. The maximum and minimum concentrations of detergent materials or surfactant (LAS) were respectively observed in Shafarud (0.047 mg/l) and Hevigh (0.014 mg/l). According to the results of the study even though all the three rivers water had an overall reasonable quality, but some signs of destructions and degradations such as sedimentation, relatively increase of nutrient, increased concentrations of some pollutants, which all results in the low diversity of macroinvertebrates and prevents migration of anadromous fishes, calls for a continuing monitoring program and precise control for these regions

    The study and feasibility of Cheshmeh-Ali River and downstream area of Shahid Shah-Charaghy dam in Damghan for aquaculture development

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    To reveal the fisheries productivity and to get the maximum possible exploitations of the running water resources, existing potentials for aquaculture in Shit and Kordabad rivers in Tarom of Zanjan province were surveyed in a one year round study. In this way 4 and 3 sampling site were respectively selected in Shit and Kordabad rivers and benthic macroinvertebrates and water samples were collected and analyzed at least two times a season and fish fauna were also sampled and studied only two times during the period. All the measured water quality characteristics(such as O_2, water temperature, pH, nutrients, NH_3, BOD_5 and . . . ) were within the normal range suggested for the cold water fish culture. In both rivers no significant differences (p≤95%) were detected for physicochemical parameters within the study sites except for electrical conductivity and total hardness which differed in the firs and last station. Depletion of Agricultural run off and residual from the adjacent farmlands and municipal drainages into the water body of the rivers, were certainly effective in these changes However none of water quality parameters exceed the maximum permitted level for aquaculture. According to the benthic macroinvertebrates study 38 family of 12 taxa and 26 family of the 11 taxa were identified in Shit and Kordabad rivers respectively, most of them belonged to the aquatic insect larvae of the sensitive groups. Community structure indices and Hilsenhof family level biotic index proved a "very good" to "good" water quality criteria for the study sites in both rivers .One fish species in Shit and five species (4 of them were endemic) were identified in Kordabad river. Despite acceptable water quality in Shit river, some inhibiting factors such as adjacent farmlands and dense agricultural land use, high slope of river valley in most region which cause rare suitable lands for locating aquaculture sites, very limited access to road and electricity supply and lack of acceptability to manipulate or divert river water for fish farms, by the local people, are the major constrains for constructing trout farms in Shit river. However constructing a 15 mt capacity rainbow trout farm is possible at first 2 kilometers of the upstream where the water quality and quantity are relatively better and there are some lands with low slope and access to road and electricity supply. Kordabad river has a similar criteria and water quality and quantity at upstream is desirable for rainbow trout culture. The first 2 kilometer of this river is capable of constructing trout farms in some non cultivated lands. Moreover the Kordabad natural dam reservoir is available to conduct its water for further demands. In addition a total of 75mt rainbow trout production in the form of 2 or 3 separate site is possible in this river. Even though the local climate particularly in Kordabad river is acceptable for carp fishes, however land limitations, soil texture and the high volume of water demands, make warm water fishes commercial production impossible

    Assessment of explanatory models of mental illness: effects of patient and interviewer characteristics

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    Background: Explanatory models (EMs) refer to patients’ causal attributions of illness and have been shown to affect treatment preference and outcome. Reliable and valid assessment of EMs may be hindered by interviewer and respondent disparities on certain demographic characteristics, such as ethnicity. The present study examined (a) whether ethnic minority patients reported different EMs to ethnically similar interviewers in comparison with those with a different ethnicity, and (b) whether this effect was related to respondents’ social desirability, the perceived rapport with the interviewer and level of uncertainty toward their EMs. Methods: A total of 55 patients of Turkish and Moroccan origins with mood and anxiety disorders were randomly assigned to ethnically similar or dissimilar interviewers. EMs were assessed, using a semi-structured interview, across 11 different categories of causes. Results: Participants who were interviewed by an ethnically similar interviewer perceived interpersonal, victimization and religious/mystical causes as more important, whereas interviews by ethnically dissimilar interviewers generated higher scores on medical causes. These effects were not mediated by the perceived rapport with the interviewer, and social desirability had a modest impact on the results. Higher uncertainty among participants toward medical and religious/mystical causes seemed to be associated with greater adjustment in the report of these EMs. Conclusion: The findings have significant implications for interviewer selection in epidemiological research and clinical practice
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