Microstructural evolution during friction stir welding of AlSi1MgMn alloy

This paper provides the research of the infl uence of geometric and kinematic parameters on the microstructure and mechanical properties of welded joint of aluminum alloy AlSi1MgMn (6082-T6) obtained through the Friction Stir Welding (FSW) process. The experiment parameters were welding speed, rotation speed, angle of pin slope, pin diameter and shoulder diameter. On the obtained welded workpieces the dynamic testing on the impact toughness, and determination of microstructural zones were carried out

Mikrostrukturni razvitak AlSi1MgMn slitine tijekom zavarivanja trenjem

This paper provides the research of the influence of geometric and kinematic parameters on the microstructure and mechanical properties of welded joint of aluminum alloy AlSi1MgMn (6082-T6) obtained through the Friction Stir Welding (FSW) process. The experiment parameters were welding speed, rotation speed, angle of pin slope, pin diameter and shoulder diameter. On the obtained welded workpieces the dynamic testing on the impact toughness, and determination of microstructural zones were carried out.U radu se istražuje uticaj geometrijskih i kinematskih parametara na mikrostrukturu i mehanička svojstva zavarenog spoja od aluminijske slitine AlSi-1MgMn (6082-T6) dobivene postupkom zavarivanja trenjem (ZT). Parametri provedenih pokusa su brzina zavarivanja, kutna brzina okretanja alata, kut nagiba trna, promjer trna i promjer čela alata. Kod dobivenih zavarenih uzoraka izvedena su dinamička ispitivanja na udarnu žilavosti i određene su mikrostrukturne zone

Release of Fermentable Sugars from Corn Silage – The Effect of Biological Pretreatment

Lignocellulose biomass, as a renewable and biodegradable carbon source, provides a wide range of valuable bioproducts. Their utilization requires an efficient conversion process to break down the complex and variable chemical structure of lignocellulose. In this work, a solid-state fermentation-based pretreatment method for the release of fermentable sugars from corn silage was investigated. The optimal process conditions for water-soluble sugar extraction were initially explored by response surface methodology with the aim to achieve the maximum sugar concentration in the extracts. The optimal extraction conditions were determined: t = 30 min; the liquid-solid ratio L/S = 25 mL g–1; n = 170 rpm; and T = 30 °C. The changes in the content of water-soluble sugars (glucose, fructose, sucrose, maltose, maltotriose) were analyzed during seven days of fungal treatment

Specific igm antibodies as parameters of toxoplasma infection in pregnancy

The aim of this investigation was to determine the time of toxoplasma infection more precisely by using an indirect fluorescent antibody test and indirect hemagglutination test in 51 pregnant women whose Sabin-Feldman test and immunosorbent agglutination assay were positive. Analysis of the results of sera tested with the two additional serological assays showed that the infection was acquired during pregnancy in 19 cases, while the other pregnant women had become infected before conception

Toksoplazmoza u trudnoći sa posebnim osvrtom na laboratorijsku dijagnostiku

On the occasion of the thirty-five years of systematic research of toxoplasmosis, a review of the present knowledge of the role of toxoplasmosis in pregnancy is presented. Diagnostic procedures and the interpretation of the results of laboratory examinations are particularly stressed. The main conclusion is that in a population exposed to the infection in the way as was in the cases studied, the prevention of congenital toxoplasmosis can be achieved through a serologic follow-up of all pregnant women starting from the moment when pregnancy is established. The purpose of such screening is to identify those pregnant women who are not immunized (who are then advised to follow certain hygienic and dietetic measures) and those who are primoinfected in pregnancy. As the latter are at risk for transmitting the infection to their fetuses, they receive specific therapy and their fetuses are carefully controlled by ultrasound and other methods for the antenatal diagnosis of intrauterine infection

Risk factors for Toxoplasma infection in a reproductive age female population in the area of Belgrade, Yugoslavia

The contribution to Toxoplasma infection of known transmission risk factors such as consumption of undercooked meat, contact with soil, and contact with cats, as well as that of age, degree of education, residence in central vs, suburban city communities, and year of entry into the study, has been investigated in a group of 1157 female residents (age range 15 to 45 years) of a defined geographic area (Belgrade) during a 4-years period (1988-1991). The rate of infection increased with age, ranging from 57 % to 93 %, with an overall mean of 77 %. However, it decreased significantly over the study period (p lt 0.01). Of the potential risk factors examined, regression analysis showed that the following: age (relative risk (RR): 1.18, 95% confidence interval (CI): 1.02-1.37, p = 0.022), undercooked meat consumption (RR: 2.22, 95% CI: 1.2-2.86, p = 0.001), and the year of entry into the study (RR: 0.69, 95% CI: 0.6-0.8, p = 0.000) were significantly associated with infection. However, while the consumption of undercooked meat contributed to the frequency of infection in the whole group, its significance increased with the degree of education but decreased with age, and was greater in women residing in the suburbs. In addition, in women below age 20, exposure to soil (farming, gardening) was significantly associated with infection (RR: 1.38, 95% CI: 1.12-1.97, p = 0.037). Since cats are the single source of toxoplasma oocysts, the above finding indicates that cats are an epidemiologically significant source of environmental contamination in Belgrade. However, cat ownership itself as a criterion of contact with cats was not associated with infection (p = 0.326). In the absence of a general screening in pregnancy program in Yugoslavia, these data point out the groups of pregnant women at the highest risk of infection and provide a basis for a region-appropriate educational program to prevent congenital toxoplasmosis

ARC: An open-source library for calculating properties of alkali Rydberg atoms

We present an object-oriented Python library for computation of properties of highly-excited Rydberg states of alkali atoms. These include single-body effects such as dipole matrix elements, excited-state lifetimes (radiative and black-body limited) and Stark maps of atoms in external electric fields, as well as two-atom interaction potentials accounting for dipole and quadrupole coupling effects valid at both long and short range for arbitrary placement of the atomic dipoles. The package is cross-referenced to precise measurements of atomic energy levels and features extensive documentation to facilitate rapid upgrade or expansion by users. This library has direct application in the field of quantum information and quantum optics which exploit the strong Rydberg dipolar interactions for two-qubit gates, robust atom-light interfaces and simulating quantum many-body physics, as well as the field of metrology using Rydberg atoms as precise microwave electrometers