Search

In this paper 3D FEM analysis of process parameters and its influence in rotary piercing mill is presented. The FEM analyze of the rotary piercing process was made under the conditions of 3D state of strain with taking into consideration the thermal phenomena. The calculations were made with application of different rolls' skew angles and different plug designs. In the result, progression of shapes, temperature and distributions of stress and strain were characterized. The numerical results of calculations were compared with results of stand test with use of 100Cr6 steel. The comparisons of numerical and experimental tests confirm good agreement between obtained results. [ABSTRACT FROM AUTHOR]

As a part of EMEP, MSC-W in Oslo has the task to compute atmospherictransport and deposition of sulfur and nitrogen species over Europe.To perform this task, a three-dimensional Eulerian multilayer model was developed at MSC-W. This model has a 50 km horizontal resolution with 20 vertical layers, of which 10 are below 2 km level. Meteorological input, from a dedicated weather prediction model, is updated at 6-hour intervals. Emission inventories for NOx (NO+NO2), NH3 (and SO2), submitted officially by the individual countries, are used as input data. In the model, NOx may be converted to PAN by the CH3COO2 radical, or to nitrate (as HNO3 in the gas phase and ammonium nitrate as particulate matter). The oxidation of NOx is assumed to proceed either by the OH radical in the gas phase, or as a night-time reaction via N2O5 on deliquescent particles. Both OH and CH3COO2 are prescribed as a function of solar zenith angle and cloud cover. Furthermore,ammonium sulfate is formed by NH3 and sulfate. Excess NH3 may react with HNO3, forming ammonium nitrate in an equilibrium reaction. Nitrogen is removed from the atmosphere by dry and wet deposition. A description of the model, as well as the model results, are presented and discussed. We also present a comparison of calculated concentrations and deposition fields for nitrogen with available measurements of concentrations and wet deposition for 1992. [ABSTRACT FROM AUTHOR]

The paper presents chosen aspects of the skew rolling process of hollow stepped products with the use of a skew rolling mill designed and manufactured at the Lublin University of Technology. This machine is characterized by the numerical control of spacing between the working rolls and the sequence of the gripper axial movement, which allows for the individual programming of the obtained shapes of parts such as stepped axles and shafts. The length of these zones and the values of possibly realizable cross-section reduction and obtained outlines are the subject of this research paper. The chosen results regarding the influence of the technological parameters used on the course of the process are shown in the present study. Numerical modelling using the finite element method in Simufact Forming, as well as the results of experimental tests performed in a skew rolling mill, were applied in the conducted research. The work takes into account the influence of cross-section reduction of the hollow parts and the feed rate per rotation on the metal flow mechanisms in the skew rolling process. The presented results concern the obtained dimensional deviations and changes in the wall thickness determining the proper choice of technological parameters for hollow parts formed by the skew rolling method. Knowledge about the cause of the occurrence of these limitations is very important for the development of this technology and the choice of the process parameters.

Predictions of the atmospheric dispersion of radionuclides accidentally released from a nuclear power plant are influenced by two large sources of uncertainty: one associated with the meteorological data employed, and one with the source term, i.e. the temporal evolution of the amount and physical and chemical properties of the release. A methodology is presented for quantitative estimation of the variability of the prediction of atmospheric dispersion resulting from both sources of uncertainty. The methodology, which allows for efficient calculation, and thus is well suited for real-time assessment, is applied to a hypothetical accidental release of radionuclides., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

This article presents the results of theoretical-experimental testing of the process of rotational compression of hollow stepped shafts. The advantages of the technology and the potential area of its application were discussed. Further on, the limits of the rotational compression technology, preventing the manufacturing of high-quality products, were presented. The research was conducted on the basis of numerical modelling using the finite element method in Simufact Forming, as well as the results of experimental tests performed in a forging machine for rotational compression. On the basis of the results obtained, it can be stated that the process of rotational compression of hollow stepped shafts can be hindered by the following phenomena: uncontrolled slip, deformation of the semi-finished product wall, twisting of the formed steps, material cracking, and deformation of the cross-section of the formed steps. The possibility of those hindrances occurring depends heavily on the assumed technological parameters of the process. For this reason, knowledge of the cause of occurrence of those limitations is vital for the development of the technology and the choice of the process parameters.

The article presents the issue of material fracture during the process of cross-wedge rolling (CWR). The object of the research was the process of forming a harrow tooth preform. In the conducted analysis nine damage criteria were applied. The critical value of damage was determined with a new calibrating test, basing on rotational compression of a sample in a channel. The results of calculations were compared to the results of experimental testing performed in laboratory conditions in Lublin University of Technology. On the basis of the obtained results an assessment of the applied damage criteria and their applicability in the analysis of CWR processes was conducted.

Waste tanks at the nuclear facility located at Sellafield, UK, represent a nuclear source which could release radionuclides to the atmosphere. A model chain which combines atmospheric transport, deposition as well as riverine transport to sea has been developed to predict the riverine activity concentrations of 137 Cs. The source term was estimated to be 9 × 10 4  TBq of 137 Cs, or 1% of the assumed total 137 Cs inventory of the HAL (Highly Active Liquid) storage tanks. Air dispersion modelling predicted 137 Cs deposition reaching 127 kBq m -2 at the Vikedal catchment in Western Norway. Thus, the riverine transport model predicted that the activity concentration of 137 Cs in water at the river outlet could reach 9000 Bq m -3 in the aqueous phase and 1000 Bq kg -1 in solid phase at peak level. The lake and river reaches showed different transport patterns due to the buffering effects caused by dilution and slowing down of water velocity.

Background: Pelvic floor muscle (PFM) training is recommended to increase their strength and endurance. Muscles which act synergistically with PFM are taken into consideration in the therapeutic management of weakened PFM., Research Question: how does electromyography activity of the synergists muscle to PFM change concerning pelvis position and does the greater bioelectric activity of synergist muscles affect PFM function?, Methods: A prospective, observational study evaluating the surface electromyography (sEMG) activity of selected synergist muscles of the PFM depending on the orientation of the pelvis. One hundred thirty-one menopausal women registered for the study were screened for inclusion and exclusion criteria, and by the results, eighty-two participants were enrolled for measurements. The comparisons of results between the values obtained in different positions of the pelvis (anterior pelvic tilt - P1, posterior pelvic tilt - P2 and neutral pelvic tilt - P3) were performed using Kruskal-Wallis test. A multivariate linear regression analysis was used to assess relationships between the bioelectrical activity of PFM and activity of all tested muscles - rectus abdominis (RA), gluteus maximus (GM), and adductor magnus (AM)., Results: Higher RA, GM, AM bioelectrical activity was observed in the P2 as compared to P3 (during resting and functional PFM activity)(p < 0.05). Multivariate linear regression did not find the association between the bioelectrical activity of PFM and the activity of all synergist muscles in each position., Significance: sEMG activity of selected muscles acting synergistically with PFM differ depending on the pelvis position and is the highest in the posterior pelvic tilt. Greater activity of the synergists, resulting from the pelvic position, does not affect the myoelectric activity of PFM. It seems that muscles that act synergistically with PFM may not play such a significant role in the therapeutic management of PFM., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Pregnancy is a special time in the life of a woman, which induces many changes not only in the biological, but also in the biopsychosocial dimension., Objectives: The aim of the study was to evaluate the factors affecting the sense of coherence (SOC) among women during pregnancy. It was hypothesized that a high SOC will depend on a high level of received support, lack of the risk of mental disorders in the perinatal period and physiological course of pregnancy., Material and Methods: Factographic material was collected by a diagnostic survey method. As a 1st research tool, the Polish adaptation of the Sense of Coherence - Orientation to Life Questionnaire (SOC-29) was used. Another research tool was the Edinburgh Postnatal Depression Scale (EPDS), used here for pregnant women and therefore called Edinburgh Depression Scale (EDS)., Results: We analyzed the data of all 200 women with physiological pregnancies and 200 women with complicated pregnancies from whom a complete valid responses were obtained. All women were aged between 18 and 36 years. Significant predictors of low SOC results in the model were: age (odd ratio [OR] = 0.929, 95% confidence interval [CI] 0.870-0.992, p = 0.0280), being multipara (OR = 1.996, 95% CI 1.271-3.135, p = 0.0027), having never/occasionally husband/partner support (OR = 1.978, 95% CI 1.070-3.656, p = 0.0295), and EDS results (OR = 1.312, 95% CI 1.169-1.472, p = 0.0000)., Conclusions: Predisposing factors for the occurrence of a low rate of SOC in pregnant women are: lower age, multiparity, lack of social support, especially from the husband/partner, and the risk of depression during pregnancy. This may result from the fact that a strong SOC develops in the process of socialization, and with age we acquire the ability to accurately assess reality.

Poland is the second most important emission source after Germany in contributing atmospheric nitrogen deposition to the Baltic Sea basin. The main sectors contributing to reactive nitrogen emissions from Polish sources, in the period 1995-2014, are combustion and transportation, responsible together for over 97% of nitrogen oxide emissions, and agriculture responsible for over 98% of ammonia emissions. The EMEP MSC-W model with 50-km resolution was used for estimating the contribution of nitrogen emission sources from Poland to nitrogen deposition into the Baltic Sea basin and its sub-basins, in the period 1995-2014. Polish contribution in this period is mainly visible in annual wet deposition of reduced nitrogen with the range 13-18% and in wet deposition of oxidized nitrogen: 9-15%. Concerning sub-basins, a major contribution for Polish sources to total nitrogen deposition can be noticed for Baltic Proper with the range 13-19%, followed by northern sub-basins (7-18%) and finally by three western sub-basins (5-7%). Polish contribution to the Baltic Sea Basin in the year 2013 was analyzed in more detail using two models, the EMEP MSC-W model with 50-km resolution and model developed at the Institute of Meteorology and Water Management in Warsaw with 14-km resolution (IMWM Model). Both models give similar results concerning the deposition of oxidized nitrogen from Polish sources, but results show that the deposition of reduced nitrogen calculated with IMWM model is lower. The most likely reasons for the differences are different parameterizations of the deposition processes and chemical reactions in both models.

Background: Menopausal women often experience the prolapse of the uterus, bladder and rectum resulting from the failure and weakening of the pelvic floor muscles (PFM). Strengthening of the PFM through the standard exercises is recognized as an effective way of preventive measures and conservative treatment of the symptoms listed above, but still need to be improved., Aim: The goal was the objective assessment of resting and functional bioelectrical activity of PFM in women during menopause and its comparison in three different positions of the pelvis: anterior pelvic tilt - position 1 (P1), posterior pelvic tilt - position 2 (P2), and neutral pelvic tilt - position 3 (P3)., Design: Prospective, cross-sectional observational study., Setting: Department and Clinic of Urology of a University Hospital., Population: The target group of this study included women in the menopausal period (inpatient and outpatient)., Methods: The study evaluating resting and functional activity of the PFM depending on the orientation of pelvis. Bioelectric activity was assessed with an electromyographic instrument (sEMG) and endovaginal electrodes. The inclination angle was measured with an inclinometer. The comparisons of results between the values obtained in P1, P2, and P3 were performed using one-way Analysis of Variance (ANOVA)., Results: One hundred thirty-one registered for the study were screened for inclusion and exclusion criteria and on the basis of the results 82 participants were enrolled for analysis. The highest mean resting activity of sEMG PFM (µV) was observed in P2 and it amounted to 11.6 µV (SD=5.5 µV) in P1 the value equaled 9.8 µV (SD=4.8 µV) and P3-9.0 µV (SD=4.2 µV). The results revealed a significant statistical difference (main effect: P=0.0007). Considering the functional sEMG activity of PFM (µV), the highest mean value was recorded in P2., Conclusions: Posterior pelvic tilt position determines higher resting and functional bioelectric activity of PFM. Additionally, electromyographic activity of PFM increases during the pelvic movement backwards., Clinical Rehabilitation Impact: These positions should be implemented in therapy in order to improve the effectiveness of the effect on the pelvic floor.

The Russian nuclear submarine K-27 suffered a loss of coolant accident in 1968 and with nuclear fuel in both reactors it was scuttled in 1981 in the outer part of Stepovogo Bay located on the eastern coast of Novaya Zemlya. The inventory of spent nuclear fuel on board the submarine is of concern because it represents a potential source of radioactive contamination of the Kara Sea and a criticality accident with potential for long-range atmospheric transport of radioactive particles cannot be ruled out. To address these concerns and to provide a better basis for evaluating possible radiological impacts of potential releases in case a salvage operation is initiated, we assessed the atmospheric transport of radionuclides and deposition in Norway from a hypothetical criticality accident on board the K-27. To achieve this, a long term (33 years) meteorological database has been prepared and used for selection of the worst case meteorological scenarios for each of three selected locations of the potential accident. Next, the dispersion model SNAP was run with the source term for the worst-case accident scenario and selected meteorological scenarios. The results showed predictions to be very sensitive to the estimation of the source term for the worst-case accident and especially to the sizes and densities of released radioactive particles. The results indicated that a large area of Norway could be affected, but that the deposition in Northern Norway would be considerably higher than in other areas of the country. The simulations showed that deposition from the worst-case scenario of a hypothetical K-27 accident would be at least two orders of magnitude lower than the deposition observed in Norway following the Chernobyl accident., (Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objectives: Evaluation of resting and functional bioelectrical activity of the pelvic floor muscles (PFM) and the synergistic muscles, depending on the orientation of the pelvis, in anterior (P1) and posterior (P2) pelvic tilt., Design: Preliminary, prospective observational study., Setting: Department and Clinic of Urology, University Hospital in Wroclaw, Poland., Participants: Thirty-two menopausal and postmenopausal women with stress urinary incontinence were recruited. Based on inclusion and exclusion criteria, sixteen women aged 55 to 70 years were enrolled in the study., Primary Outcome Measures: Evaluation of resting and functional bioelectrical activity of the pelvic floor muscles by electromyography (sEMG) and vaginal probe., Secondary Outcome Measures: Evaluation of activity of the synergistic muscles by sEMG and surface electrodes., Results: No significant differences between orientations P1 and P2 were found in functional and resting sEMG activity of the PFM. During resting and functional PFM activity, higher electrical activity in P2 than in P1 has been recorded in some of the synergistic muscles., Conclusions: This preliminary study does not provide initial evidence that pelvic tilt influences PFM activation. Although different activity of synergistic muscles occurs in various orientations of the pelvic tilt, it does not have to affect the sEMG activity of the PFM.

A combination of state-of-the-art isotopic fingerprinting techniques and atmospheric transport modelling using real-time historical meteorological data has been used to demonstrate direct tropospheric transport of radioactive debris from specific nuclear detonations at the Semipalatinsk test site in Kazakhstan to Norway via large areas of Europe. A selection of archived air filters collected at ground level at 9 stations in Norway during the most intensive atmospheric nuclear weapon testing periods (1957-1958 and 1961-1962) has been screened for radioactive particles and analysed with respect to the concentrations and atom ratios of plutonium (Pu) and uranium (U) using accelerator mass spectrometry (AMS). Digital autoradiography screening demonstrated the presence of radioactive particles in the filters. Concentrations of (236)U (0.17-23nBqm(-3)) and (239+240)Pu (1.3-782μBqm(-3)) as well as the atom ratios (240)Pu/(239)Pu (0.0517-0.237) and (236)U/(239)Pu (0.0188-0.7) varied widely indicating several different sources. Filter samples from autumn and winter tended to have lower atom ratios than those sampled in spring and summer, and this likely reflects a tropospheric influence in months with little stratospheric fallout. Very high (236)U, (239+240)Pu and gross beta activity concentrations as well as low (240)Pu/(239)Pu (0.0517-0.077), (241)Pu/(239)Pu (0.00025-0.00062) and (236)U/(239)Pu (0.0188-0.046) atom ratios, characteristic of close-in and tropospheric fallout, were observed in filters collected at all stations in Nov 1962, 7-12days after three low-yield detonations at Semipalatinsk (Kazakhstan). Atmospheric transport modelling (NOAA HYSPLIT&#95;4) using real-time meteorological data confirmed that long range transport of radionuclides, and possibly radioactive particles, from Semipalatinsk to Norway during this period was plausible. The present work shows that direct tropospheric transport of fallout from atmospheric nuclear detonations periodically may have had much larger influence on radionuclide air concentrations and deposition than previously anticipated., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Salmonella apapa is transmitted by reptiles, e.g., bearded dragons. To date only few cases of S. apapa-related human infections have been reported. Because the bacteria are transmitted through the feces of animals or direct contact with low infection doses, infection in early infancy is possible. We report an 18-day-old newborn with sepsis caused by Salmonella apapa. Salmonella apapa was isolated from the feces of a bearded dragon living along with the family., (© Georg Thieme Verlag KG Stuttgart · New York.)

The aim of this review was to present recent information about the fetal condition in cases of intrahepatic cholestasis of pregnancy. A relatively mild course of maternal disease does not predict fetal well-being accurately. Increased risk of sudden intrauterine death was emphasized, implicating the need for more stringent obstetric monitoring of fetal condition in this disorder. A pathogenetic mechanism leading to sudden deterioration of fetal wellbeing was proposed and discussed. Current recommendations regarding medical management of intrahepatic cholestasis of pregnancy were also presented.

The aim of this review was to present the latest developments regarding maternal condition in cases of intrahepatic cholestasis of pregnancy. The changing clinical picture and altered hormonal milieu were related to the underlying cellular and molecular pathomechanisms. Intrahepatic cholestasis of pregnancy may be considered as an obstetric endocrinopathy. The relatively mild course of maternal disease masks the multisystemic nature of the disorder.

Objective: The purpose of this study was to evaluate the association of vaginal fetal fibronectin expression to risk of preterm delivery and delivery of very-low-birth-weight infants., Study Design: Vaginal secretions were obtained from women between 22 and 35 weeks' pregnant with minimal cervical dilation (< or = 2 cm) and threatened preterm delivery. The secretions were analyzed for the presence of fetal fibronectin. Other clinical information including cervical dimensions, uterine activity, serum C-reactive protein concentration, vaginal pH, evidence of vaginal or systemic infection, and vaginal bleeding were also obtained., Results: Of the 112 patients recruited, 40 (35.7%) were delivered prematurely (<37 weeks). For prediction of preterm delivery, the fetal fibronectin test result had a sensitivity, specificity, and positive and negative predictive values of 67.5, 90.3, 79.4, and 83.3%, respectively (odds ratio 19.3, p < 0.0001). Women with a positive fetal fibronectin test had a nearly 13-fold increased probability of being delivered of an infant weighing <1500 gm than did women with a negative fetal fibronectin test (32.4% vs 2.5%, p<0.0001). Categoric analysis and multiple logistic regression demonstrated that fetal fibronectin was an independent risk factor for prediction of preterm delivery and birth weight <1500 gm., Conclusion: Vaginal fetal fibronectin expression is an independent risk factor for preterm delivery and birth of very-low-birth-weight infants in symptomatic women with intact amniotic membranes and minimal cervical dilatation.

In a retrospective study on 86 twins born between 1971 and 1990, the clinical and acidity status of small for gestational age twins in cases of uncomplicated labor was analysed and compared with the status of appropriate for gestational age twins. No difference was observed in Apgar score and umbilical blood pH between growth retarded and normal twins. The single fact of growth retardation without other factors of risk during labor has no influence on clinical status of small for gestational age twins.

Thirty-one pregnant women divided into three groups (AGA prepartum, SGA prepartum without distress, AGA in labor) were examined using Doppler ultrasonography before, during and after oxygen administration to mothers via a face mask. The aim of the study was to find out if there was any effect on the blood flow values in the fetal aorta, the umbilical artery, the fetal common carotid artery and the uterine arcuate arteries. The resistance index (RI) did not change in those vessels during maternal hyperoxygenation with one exception: in the group of SGA fetuses the RI in the fetal aorta increased significantly. Blood flow velocity and volume blood flow remained unchanged in the fetal aorta during oxygen administration.