Fizikalno modeliranje naprezanja tijekom kontinuiranog lijevanja čelika St3S

In this work the results of physical and numerical modeling of stresses in metal during continuous casting were shown. The numerical research for St3S ingot were realized. Computer program based on Finite Element Method (FEM) was used to simulation. Investigated conditions were based on actual data received from one of polish steel plant. The simulation of continuous casting process was made on GLEEBLE 3800 simulator. The results of thermal load and also stages of bending and straightening of the bloom and stress relaxation phenomenon were shown. Mechanical properties of a solid metal are described by the theory of dislocation that allows taking into account history of changes of stress and strain in the material.Fizikalno modeliranje naprezanja tijekom kontinuiranog lijevanja čelika St3S. U radu su prikazani rezultati fizikalnog i numeričkog modeliranja naprezanja u metalu tijekom kontinuiranog lijevanja. Provedeno je numeričko istraživanje ingota St3S. Za simulaciju je rabljen računalni program utemeljen na Metodi konačnih elemenata (MKE). Istraživani uvjeti temelje se na stvarnim podacima dobijenim u jednoj poljskoj čeličani. Simulacija procesa kontinuiranog lijevanja provedena je na simulatoru GLEEBLE 3800. Prikazani su rezultati toplinskog opterećenja a također stadiji savijanja i izravnavanja bluma te fenomen relaksacije naprezanja. Mehanička svojstva krutog metala opisana su uz pomoć teorije dislokacija koja omogućuje uzimanje u obzir prethodne promjene naprezanja i deformacije u metalu

3D freeform surfaces from planar sketches using neural networks

A novel intelligent approach into 3D freeform surface reconstruction from planar sketches is proposed. A multilayer perceptron (MLP) neural network is employed to induce 3D freeform surfaces from planar freehand curves. Planar curves were used to represent the boundaries of a freeform surface patch. The curves were varied iteratively and sampled to produce training data to train and test the neural network. The obtained results demonstrate that the network successfully learned the inverse-projection map and correctly inferred the respective surfaces from fresh curves

Fizikalno modeliranje naprezanja tijekom kontinuiranog lijevanja čelika St3S

In this work the results of physical and numerical modeling of stresses in metal during continuous casting were shown. The numerical research for St3S ingot were realized. Computer program based on Finite Element Method (FEM) was used to simulation. Investigated conditions were based on actual data received from one of polish steel plant. The simulation of continuous casting process was made on GLEEBLE 3800 simulator. The results of thermal load and also stages of bending and straightening of the bloom and stress relaxation phenomenon were shown. Mechanical properties of a solid metal are described by the theory of dislocation that allows taking into account history of changes of stress and strain in the material.Fizikalno modeliranje naprezanja tijekom kontinuiranog lijevanja čelika St3S. U radu su prikazani rezultati fizikalnog i numeričkog modeliranja naprezanja u metalu tijekom kontinuiranog lijevanja. Provedeno je numeričko istraživanje ingota St3S. Za simulaciju je rabljen računalni program utemeljen na Metodi konačnih elemenata (MKE). Istraživani uvjeti temelje se na stvarnim podacima dobijenim u jednoj poljskoj čeličani. Simulacija procesa kontinuiranog lijevanja provedena je na simulatoru GLEEBLE 3800. Prikazani su rezultati toplinskog opterećenja a također stadiji savijanja i izravnavanja bluma te fenomen relaksacije naprezanja. Mehanička svojstva krutog metala opisana su uz pomoć teorije dislokacija koja omogućuje uzimanje u obzir prethodne promjene naprezanja i deformacije u metalu

Complex genital system of a haplogyne spider (Arachnida, Araneae, Tetrablemmidae) indicates internal fertilization and full female control over transferred sperm.

The female genital organs of the tetrablemmid Indicoblemma lannaianum are astonishingly complex. The copulatory orifice lies anterior to the opening of the uterus externus and leads into a narrow insertion duct that ends in a genital cavity. The genital cavity continues laterally in paired tube-like copulatory ducts, which lead into paired, large, sac-like receptacula. Each receptaculum has a sclerotized pore plate with associated gland cells. Paired small fertilization ducts originate in the receptacula and take their curved course inside the copulatory ducts. The fertilization ducts end in slit-like openings in the sclerotized posterior walls of the copulatory ducts. Huge masses of secretions forming large balls are detectable in the female receptacula. An important function of these secretory balls seems to be the encapsulation of spermatozoa in discrete packages in order to avoid the mixing of sperm from different males. In this way, sperm competition may be completely prevented or at least severely limited. Females seem to have full control over transferred sperm and be able to express preference for spermatozoa of certain males. The lumen of the sperm containing secretory balls is connected with the fertilization duct. Activated spermatozoa are only found in the uterus internus of females, which is an indication of internal fertilization. The sperm cells in the uterus internus are characterized by an extensive cytoplasm and an elongated, cone-shaped nucleus. The male genital system of I. lannaianum consists of thick testes and thin convoluted vasa deferentia that open into the wide ductus ejaculatorius. The voluminous globular palpal bulb is filled with seminal fluid consisting of a globular secretion in which only a few spermatozoa are embedded. The spermatozoa are encapsulated by a sheath produced in the genital system. The secretions in females may at least partly consist of male secretions that could be involved in the building of the secretory balls or play a role in sperm activation. The male secretions could also afford nutriments to the spermatozoa

Chemical Short-Range Order in Selenide and Telluride Glasses

International audienc

Midday Meals Do Not Impair Mouse Memory

Nocturnal mice fed in the middle of the light period exhibit food anticipatory rhythms of behavior and physiology under control of food-entrainable circadian clocks in the brain and body. This is presumed to be adaptive by aligning behavior and physiology with predictable mealtimes. This assumption is challenged by a report that daytime feeding schedules impair cognitive processes important for survival, including object memory and contextual fear conditioning assessed at two times of day. To further evaluate these effects, mice were restricted to a 6 h daily meal in the middle of the light or dark period and object memory was tested at four times of day. Object memory was not impaired by daytime feeding, and did not exhibit circadian variation in either group. To determine whether impairment might depend on methodology, experimental procedures used previously to detect impairment were followed. Daytime feeding induced food anticipatory rhythms and shifted hippocampal clock genes, but again did not impair object memory. Spontaneous alternation and contextual fear conditioning were also not impaired. Hippocampal memory function appears more robust to time of day and daytime feeding schedules than previously reported; day-fed mice can remember what they have seen, where they have been, and where it is dangerous

Peroxisome proliferator-activated receptor β/δ activation inhibits hypertrophy in neonatal rat cardiomyocytes

Objective: Peroxisome proliferator-activated receptor β/δ (PPARβ/δ) is the predominant PPAR subtype in cardiac cells and plays a prominent role in the regulation of cardiac lipid metabolism. However, the role of PPARβ/δ activators in cardiac hypertrophy is not yet known. Methods and Results: In cultured neonatal rat cardiomyocytes, the selective PPARβ/δ activator L-165041 (10 μmol/L) inhibited phenylephrine (PE)-induced protein synthesis ([3H]leucine uptake), induction of the fetal-type gene atrial natriuretic factor (ANF) and cardiac myocyte size. Induction of cardiac hypertrophy by PE stimulation also led to a reduction in the transcript levels of both muscle-type carnitine palmitoyltransferase (50%, P<0.05) and pyruvatedehydrogenase kinase 4 (30%, P<0.05), and these changes were reversed in the presence of the PPARβ/δ agonist L-165041. Stimulation of neonatal rat cardiomyocytes with PE and embryonic rat heart-derived H9c2 cells with lipopolysaccharide (LPS) enhanced the expression of the nuclear factor (NF)-κB-target gene monocyte chemoattractant protein 1 (MCP-1). The induction of MCP-1 was reduced in the presence of L-165041, suggesting that this compound prevented NF-κB activation. Electrophoretic mobility shift assay (EMSA) revealed that L-165041 significantly decreased LPS-stimulated NF-κB binding activity in H9c2 myotubes. Finally, coimmunoprecipitation studies showed that L-165041 strongly enhanced the physical interaction between PPARβ/δ and the p65 subunit of NF-κB, suggesting that increased association between these two proteins is the mechanism responsible for antagonizing NF-κB activation by PPARβ/δ activators. Conclusion: These results suggest that PPARβ/δ activation inhibits PE-induced cardiac hypertrophy and LPS-induced NF-κB activatio

2-[2-Benzoyl-3,3-bis­(methyl­sulfan­yl)prop-2-enyl­idene]malononitrile

The title compound, C15H12N2OS2, is an example of a push–pull butadiene in which the electron-releasing methyl­sulfanyl groups and electron-withdrawing nitrile groups on either end of the butadiene chain enhance the conjugation in the system. Short intra­molecular C—H⋯S inter­actions are observed. In the crystal structure, an O⋯C short contact of 2.917 (3) Å is observed