The level of degradation of reinforced concrete bridges was evaluated based on the in-situ measurements performed on five reinforced concrete bridges under service located in the Czech Republic. The combined effect of carbonation and chlorides with respect to the corrosion of steel reinforcement, namely the pH and the amount of water-soluble chlorides, were evaluated on drilled core samples of concrete. Based on these parameters, the ratio between the concentrations of Cl– and OH, which indicates the ability of concrete to protect reinforcement, was calculated. All the data were statistically summarized and the relationships among them were provided. The main goal of this study is to evaluate the non-proportional effect of the amount of chlorides per mass of concrete on the risk of corrosion initiation and to localize the “critical” locations in the bridges that are the most affected by the degradation effects.
Breath analysis has attracted human beings for centuries. It was one of the simplest methods to detect various diseases by using human smell sense only. Advances in technology enable to use more reliable and standardized methods, based on different gas sensing systems. Breath analysis requires the detection of volatile organic compounds (VOCs) of the concentrations below individual ppm (parts per million). Therefore, advanced detection methods have been proposed. Some of these methods use expensive and bulky equipment (e.g. optical sensors, mass spectrometry –MS), and require time-consuming analysis. Less accurate, but much cheaper, are resistive gas sensors. These sensors use porous materials and adsorptiondesorption processes, determining their physical parameters.We consider the problems of applying resistive gas sensors to breath analysis. Recent advances were underlined, showing that these economical gas sensors can be efficiently employed to analyse breath samples. General problems of applying resistive gas sensors are considered and illustrated with examples, predominantly related to commercial sensors and their long-term performance. A setup for collection of breath samples is considered and presented to point out the crucial parts and problematic issues.
This research is focused on the analysis of heat-affected sub-zones in 2 mm thick steel S960MC samples, with the aim of observing and evaluating the mechanical properties after exposure to temperatures corresponding to individual heat-affected sub-zones. Test samples were prepared using a Gleeble 3500 thermo-mechanical simulator. The samples were heated in the range from 550°C to 1350°C and were subsequently quickly cooled. The specimens, together with the base material, were then subjected to tensile testing, impact testing, and micro-hardness measurements in the sample cross-section, as well as evaluation of their microstructure. Fracture surfaces are investigated in samples after impact testing. The heat-affected sub-zones studied indicate high sensitivity to the thermal input of welding. There is a significant decrease in tensile strength and yield strength at temperatures around 550°C.
Accordingly to recommendations set out by standards, degradation curves which will serve as a tool facilitating decision-making regarding renovation works ought to be developed. The article presents the proposal of a model for predicting the aging of a residential building. The proposed PRRD (Prediction of Reliability According to Rayleigh Distribution) model determines the performance characteristics of a building over the full period of its use. PRRD accounts for the life spans of individual building components. Additionally introduced in the model were supplements accounting for the intensity of changes in the building and its surroundings. The developed method of the non-linear degradation process of a building accounts for the role and weights of individual building components as well as the intensity of significant factors influencing the aging process. The presented methodology of the description of changes in the performance characteristics over the course of using a building will be a diagnostic process of predicting the technical state of a building. The proposed predictions can serve as the basis for making the right strategic decisions when planning renovation works in residential buildings.
About 1600 joint fractures were measured in tillites of the Upper Hecla Hoek Formation on the southern shore of Bellsund. Measurements were collected in 12 areas between the Renardbreen and Tjörndalen. Ray diagrams and contour diagrams of joint fractures, and contour diagrams of joint fractures after rotation to pre-folding position were made for each area. The preliminary analysis of diagrams indicates 2 conjugated joint sets: ca. 60°—120° and 0°—30°. This joint system is probably older than folding and was originated under ENE—WSW to NE—SW stress.
The article contains reflections on the role of reflexivity in contemporary education. The most important is to emphasize the importance of a pragmatic reflexivity in constructing the cultural identity of a young man. The majority of the text consists of references to the thoughts of Hans Georg Gadamer in the context of pragmatics of reflexivity. In conclusion, the author proposes a pedagogical definition of reflexivity.
In search for a path of development, some communities face internal factors deeply influencing the choice of development strategy. Such factor would be an environmental protection of the territory, as it may crucially limit industrial activity. Narol community, located in southeastern Poland, near the Ukrainian border (Podkarpackie Voivodeship), has landscape protection of several levels covering 100% of the territory, so the possible development could not consist on industrial investments. On the other hand the concerned region, Roztocze, is a recognized touristic area, but Narol was always rather out of its main tourists trails. Nevertheless its assets (nature reserves, landscape and monuments), would predestine Narol for a touristic destination. But, considering strong competition in the region, the distinguishing feature would be of importance. The municipality had recognized cultural tourism as a way Narol could adopt, and has started several activities aiming to transform Narol into a cultural centre of the region. This paper presents the study case of Narol municipality’s activities in the context of transferring neglected heritage into an activated agent of development – resulting in social and economic growth. Its’ aim is to research (based on the Narol example) a place of local heritage assets in development process: if, and how they can be used to increase community’s sustainable growth.
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