Theoretical and practical methodology for recognizing the road surface structure

A recognition indicator of the possibility of further use of the road during transferring transport loads are changes in the condition of the road surface. If the surface condition indicates incorrect parameters of its equality, rutting, or cracks, the road durability is qualitatively assessed. In this case, the actual load capacity rating and possible reconstruction of the structure begins. Values of dynamic defl ections can be used to recognize the modulus of elasticity and thus the possibility of assessing the durability of a structure. The mechanistic method is used to dimensioning the structure due to the movement planned. It allows a fl exible approach to further construction, giving the opportunity to assess whether part or all of it should be left or apply an additional layer to meet future requirements. The elastic modulus needed for this pavement structure design method for existing layers has been recognized by identifi cation as backcalculation methodology that have been used for many years

The influence of the police on vehicle speed in built-up areas

In many cases, the effects of road accidents have significant impact on human health. This translates directly into society, in both material and emotional terms. The severity of the injury in a road event depends largely on the speed of the vehicles. Excessive vehicle speed is of particular concern in incidents involving vulnerable road users. As confirmed by literature analysis and research, in most cases drivers do not respect the speed limits introduced by the road signs. Existing solutions allow to introduce permanent or temporary speed control. This paper investigates speeding and driver behaviour in built-up areas near schools and pedestriancrossings. The aim of the research described in the paper is to determine the influence of the effectiveness of police actions on speed reduction and improvement of road safety

Theoretical and practical methodology for recognizing the road surface structure

A recognition indicator of the possibility of further use of the road during transferring transport loads are changes in the condition of the road surface. If the surface condition indicates incorrect parameters of its equality, rutting, or cracks, the road durability is qualitatively assessed. In this case, the actual load capacity rating and possible reconstruction of the structure begins. Values of dynamic defl ections can be used to recognize the modulus of elasticity and thus the possibility of assessing the durability of a structure. The mechanistic method is used to dimensioning the structure due to the movement planned. It allows a fl exible approach to further construction, giving the opportunity to assess whether part or all of it should be left or apply an additional layer to meet future requirements. The elastic modulus needed for this pavement structure design method for existing layers has been recognized by identifi cation as backcalculation methodology that have been used for many years

Mieszanki mineralno-cementowo-emulsyjne (MMCE) modyfikowane miałem gumowym

MCE mixtures fortified with fine rubber were the subject of research in laboratory tests in Lublin University of Technology. As a basic literature review shows, an amount of fine rubber in mixtures with cement in MCEM should be 2%, 4% and 6% of the aggregate. The mixtures were designed planned and prepared as samples for tests assessing the fulfillment of the requirements contained in the Manual [9]. Analysis of the results allows to assess the usefulness of fine rubber in MCE mixtures and is a basis for further detailed studies that are aimed at setting new quantitative requirements, going beyond the requirements included in the Manual.Mieszanki MMCE z dodatkiem miału gumowego były przedmiotem rozpoznawczych badań laboratoryjnych przeprowadzonych w Politechnice Lubelskiej. Ustalono wstępnie na podstawie przeglądu literatury, dotyczącej stosowania miału gumowego do mieszanek związanych cementem, jego dodatek w ilości 2%, 4% i 6% w stosunku do kruszywa. Zaprojektowano mieszanki a następnie wykonano próbki i przebadano je pod kątem spełnienia wymagań w zawartych w Instrukcji [9]. Analiza uzyskanych wyników pozwala stwierdzić przydatność miału gumowego w mieszankach MCE i stanowi postawę do opracowana dalszych szczegółowych prac w celu ustalenia nowych wymagań ilościowych wykraczających poza wymagania zawarte w Instrukcji

The Effect of Microalloying (Nb, V) and Interstitial (C, N) Elements on Mechanical Properties of Microalloyed Steels

The microalloying elements such as Nb, V are added to control the microstructure and mechanical properties of microalloyed (HSLA) steels. High chemical affinity of these elements for interstitials (N, C) results in precipitation of binary compound, nitrides and carbides and products of their mutual solubility – carbonitrides. The chemical composition of austenite, as well as the content and geometric parameters of undissolved precipitates inhibiting the growth of austenite grains is important for predicting the microstructure, and thus the mechanical properties of the material. Proper selection of the chemical composition of the steel makes it possible to achieve the required properties of the steel at the lowest possible manufacturing cost. The developed numerical model of carbonitrides precipitation process was used to simulate and predict the mechanical properties of HSLA steels. The effect of Nb and V content to change the yield strength of these steels was described. Some comparison with literature was done

Stereoscopic visualization for model of deformation of steels with mushy zone

The paper deals with visualization of results for simulation of a deformation process of a sample with a mushy zone. The numerical model consists of three basic subsystems: the mechanical, thermal and density changes parts. These describe both solid and semisolid deformation states. Taking into consideration their specific distribution graphical visualization is very helpful for understanding the course of the process. Moreover, a three-dimensional presentation is applied in various fields, ranging from medical imaging systems to technological processes assistance to scientific visualizations and entertainment. The stereoscopic imaging technique is still being developed. It is based on the idea of showing each eye the same scene from a bit different perspective. As an effect the illusion of depth is created due to the way the two images are interpreted by the human brain. Stereoscopy is not a new concept, but in the past few years a significant increase in the interest in this method of visualization could be observed. It is caused by computer and audio-visual technology development. In the paper several techniques of creating stereoscopic images are presented together with their physical bases and devices providing such functionality. The use of projection equipment and possibilities of its application to visualization of semi-solid steel deformation is discussed. Apart from that a description of an implementation of OpenGL specification for stereoscopic presentation of computer simulation results is provided

Zawał serca u 44-letniego chorego spowodowany jednoczesnym zamknięciem dwóch tętnic wieńcowych

Simultaneous thrombosis of multiple epicardial coronary arteries is an uncommon clinical finding in ST-segment elevationmyocardial infarction (STEMI). We describe a 44 year-old male present with STEMI who was found to have simultaneouslyoccluded two epicardial arteries. There is many clinical states that can lead to multiple thrombosis i.e. essential trombocytosis,hiperhomocysteinaemia, depletion of antitrombin III, cocaine abuse etc. In this particular case L-arginin supplementation andassociation with thrombosis or atherosclerosis progression is discussed

Early results of the ongoing polish registry on valve thrombosis after transcatheter aortic valve implantation (ZAK-POL TAVI)

Background: Conflicting data exist regarding the risk factors for transcatheter heart valve thrombosis (THVT). In addition, no optimal pharmacological strategy to treat THVT has been established so far. Aims: The aim of this study was to assess the incidence, risk factors, diagnostic workup, and treatment of THVT in Poland. Methods: Data were collected retrospectively in themulticenter registry of patients with THVT (ZAK‑POLTAVI) between November 2008 and November 2018. Transcatheter heart valve thrombosis was defined as an increased mean transvalvular gradient accompanied by a decreased effective orifice area or severe aortic regurgitation, reversible after treatment. Baseline characteristics and procedural data were compared between patients with THVT and those without THVT (matched by age, sex, and diabetic status). Results: In a group of 2307 patients undergoing transcatheter aortic valve implantation (TAVI), 26 patients with THVT were identified (incidence, 1.14%). In half of the patients, THVT was diagnosed within 6 months after TAVI. As compared with the control group, patients with THVT more frequently had chronic obstructive pulmonary disease (P = 0.035), a smaller aortic valve area (P = 0.007), a higher mean postprocedural transvalvular gradient (P = 0.037), and a lower platelet count (P = 0.029) at the time of the diagnosis. A total of 24 patients (84.6%) received anticoagulation therapy for THVT, and complete resolution of THVT was noted in 12 individuals (46.1%). We observed thromboembolic complications in 2 patients (7.7%). Conclusions: Transcatheter heart valve thrombosis is a rare complication of TAVI. However, a higher risk of THVT may be expected in patients with chronic obstructive pulmonary disease, a smaller aortic valve area, a higher mean postprocedural transvalvular gradient, and a lower platelet count. Anticoagulation alone or combined with antiplatelet therapy seems to be the optimal pharmacological treatment in this population

Heart failure due to chronic hypoparathyroidism in patient with acute coronary syndrome

Severe heart failure can be a rare symptom of hypocalcemia. We report a case of a 58 year-old male admitted with a diagnosisof acute coronary syndrome. The ECG showed prolonged QTc interval with severly impared left ventricular ejection fractionrecognised in echocardiography. During the hospitalisation hypocalcemia due to primary hypoparathyreoidism was revealedto be the cause of those symptoms

Early and Long-Term Results of Unprotected Left Main Coronary Artery Stenting The LE MANS (Left Main Coronary Artery Stenting) Registry

ObjectivesThe aim of the study was to evaluate early and late outcomes after percutaneous coronary intervention (PCI) of unprotected left main coronary artery disease (ULMCA) and to compare bare-metal stent (BMS) and drug-eluting stent (DES) subgroups.BackgroundPCI is an increasingly utilized method of revascularization in patients with ULMCA.MethodsThis multicenter prospective registry included 252 patients after ULMCA stenting enrolled between March 1997 and February 2008. Non–ST-segment elevation acute coronary syndrome was diagnosed in 58% of patients; ST-segment elevation myocardial infarction cases were excluded. Drug-eluting stents were implanted in 36.2% of patients.ResultsMajor adverse cardiovascular and cerebral events (MACCE) occurred in 12 (4.8%) patients during the 30-day period, which included 4 (1.5%) deaths. After 12 months there were 17 (12.1%) angiographically confirmed cases of restenosis. During long-term follow-up (1 to 11 years, mean 3.8 years) there were 64 (25.4%) MACCE and 35 (13.9%) deaths. The 5- and 10-year survival rates were 78.1% and 68.9%, respectively. Despite differences in demographical and clinical data in favor of BMS patients, unmatched analysis showed a significantly lower MACCE rate in DES patients (25.9% vs. 14.9%, p = 0.039). This difference was strengthened after propensity score matching. The DES lowered both mortality and MACCE for distal ULMCA lesions when compared with BMS. Ejection fraction <50% was the only independent risk factor influencing long-term survival.ConclusionsStenting of ULMCA is feasible and offers good long-term outcome. Implantation of DES for ULMCA decreased the risk of long-term MACCE, and particularly improved survival in patients with distal ULMCA disease