In the recent years structural health monitoring (SHM) has gathered spectacular attention in civil engineering applications. Application of such composites enable to improve the safety and performance of structures. Recent advances in nanotechnology have led to development of new family of sensors – self-sensing materials. These materials enable to create the so-called “smart concrete” exhibiting self-sensing ability. Application of selfsensing materials in cement-based materials enables to detect their own state of strain or stress reflected as a change in their electrical properties. The variation of strain or stress is associated with the variation in material’s electrical characteristics, such as resistance or impedance. Therefore, it is possible to efficiently detect and localize crack formation and propagation in selected concrete element. This review is devoted to present contemporary developments in application of nanomaterials in self-sensing cement-based composites and future directions in the field of smart structures.
This paper presents an experimental study on influence of input light polarization on the spectral characteristics of a fibre twist sensor based on Tilted Fiber Bragg Grating (TFBG) with simultaneous application of bending to an optical fibre. The application of proposed measurement stand could provide the ability of transforming the bending to a displacement. The twist measurement was performed by tuning of the sensor illuminating light polarization angle. The spectral parameters of selected cladding mode which are sensitive to the rotation of input light polarization angle have been shown. This paper shows the characteristics of transmittivity and wavelength shift for an incident high-order cladding mode measured with different curvatures of fibre. The dependency of selected cladding mode spectral parameters related with the twist measurement on the influence of temporary bending has been shown. The measurements were performed for two positions of sensing structure refractive index perturbations in relation to the bending direction plane. The experimental results show that the direction of TFBG structure bending has a small influence on the stability of spectral parameters characteristic for twist measurement, assuming that the bending direction is fixed while measurement.
A method for frequency-multiplexed multi-sample gas sensing is presented. It enables measuring multiple samples placed simultaneously in the setup, without any optical or mechanical switching. Samples are measured using heterodyne detection and signal from each sensing path is encoded at different carrier frequency. Subsequently, a signal from particular sample is retrieved through heterodyne beatnote demodulation at unique frequency. This technique is particularly suitable for real-time calibration of the sensor through a sequential (or simultaneous) detection of three signals: from unknown sample, reference sample and baseline. Basic setup is demonstrated and proof-of-concept experiments are presented. Very good agreement with spectra measured using standard tunable diode absorption spectroscopy is obtained.
Apart from medical care, medical biological equipment or physical environment biggest impact on our health has our behaviours. According to the Functional Health Model (FMZ) H. Wrony-Polańskiej (2003), pro-health behavior is conditioned by the availability of cognitive and behavioral resources, among which the sense of coherence plays an important role. Aim of the study was assessment of dependence between the sense of coherence and health behaviors of studying students. The study involved 245 second and third year students studying in humanities and science. The study was used the M. Ziarko Health Behavior Questionnaire and the A. Antonovsky SOC-29 Life Guidance Questionnaire. Research analysis has confirmed that there is a statistically significant relationship between health behaviors and the sense of coherence and its components: comprehensibility, manageability and meaningfulness. On the basis of the research conducted and based on the Functional Health Model it can be concluded that an important practical direction is to develop from a young age in healthy children and adolescents a special emphasis on the development of this resource.
Products of Gaussian noises often emerge as the result of non-linear detection techniques or as parasitic effects, and their proper handling is important in many practical applications, including fluctuation-enhanced sensing, indoor air or environmental quality monitoring, etc. We use Rice’s random phase oscillator formalism to calculate the power density spectra variance for the product of two Gaussian band-limited white noises with zero-mean and the same bandwidth W. The ensuing noise spectrum is found to decrease linearly from zero frequency to 2W, and it is zero for frequencies greater than 2W. Analogous calculations performed for the square of a single Gaussian noise confirm earlier results. The spectrum at non-zero frequencies, and the variance of the square of a noise, is amplified by a factor two as a consequence of correlation effects between frequency products. Our analytic results are corroborated by computer simulations.
Image processing techniques (band rationing, color composite, Principal Component Analyses)
are widely used by many researchers to describe various mines and minerals. The primary aim of
this study is to use remote sensing data to identify iron deposits and gossans located in Kaman,
Kırşehir region in the central part of Anatolia, Turkey. Capability of image processing techniques is
proved to be highly useful to detect iron and gossan zones. Landsat ETM+ was used to create remote
sensing images with the purpose of enhancing iron and gossan detection by applying ArcMap image
processing techniques. The methods used for mapping iron and gossan area are 3/1 band rationing,
3/5 : 1/3 : 5/7 color composite, third PC and PC4 : PC3 : PC2 as RG B which obtained result from
Standard Principal Component Analysis and third PC which obtained result from Developed Selected
Principal Component Analyses (Crosta Technique), respectively. Iron-rich or gossan zones were mapped
through classification technique applied to obtained images. Iron and gossan content maps were
designed as final products. These data were confirmed by field observations. It was observed that iron
rich and gossan zones could be detected through remote sensing techniques to a great extent. This
study shows that remote sensing techniques offer significant advantages to detect iron rich and gossan
zones. It is necessary to confirm the iron deposites and gossan zones that have been detected for the
time being through field observations.
The possibilities of remote sensing techniques in the field of the Earth surface monitoring and protection specifically for the problems caused by petroleum contaminations, for the mapping of insufficiently plugged and abandoned old oil wells and for the analysis of onshore oil seeps are described. Explained is the methodology for analyzing and detection of potential hydrocarbon contaminations using the Earth observation in the area of interest in Slovakia (Korňa) and in Czech Republic (Nesyt), mainly building and calibrating the spectral library for oil seeps. The acquisition of the in-situ field data (ASD, Cropscan spectroradiometers) for this purpose, the successful building and verification of hydrocarbon spectral library, the application of hydrocarbon indexes and use of shift in red-edge part of electromagnetic spectra, the spectral analysis of input data are clarified in the paper. Described is approach which could innovate the routine methods for investigating the occurrence of hydrocarbons and can assist during the mapping and locating the potential oil seep sites. Important outcome is the successful establishment of a spectral library (database with calibration data) suitable for further application in data classification for identifying the occurrence of hydrocarbons.
Of late, the science of Remote Sensing has been gaining a lot of interest and attention due to its wide variety of applications. Remotely sensed data can be used in various fields such as medicine, agriculture, engineering, weather forecasting, military tactics, disaster management etc. only to name a few. This article presents a study of the two categories of sensors namely optical and microwave which are used for remotely sensing the occurrence of disasters such as earthquakes, floods, landslides, avalanches, tropical cyclones and suspicious movements. The remotely sensed data acquired either through satellites or through ground based- synthetic aperture radar systems could be used to avert or mitigate a disaster or to perform a post-disaster analysis.
In this paper, we present a synthesis of the parameters of the fiber Bragg grating (FBG) and the reconstruction of the distributed strain affecting the grating, performed by means of its reflection spectrum. For this purpose, we applied the transition matrix method and the Nelder-Mead nonlinear optimization method. Reconstruction results of the strain profile carried out on the basis of a simulated reflection spectrum as well as measured reflection spectrum of the FBG indicate good agreement with the original strain profile; the profile reconstruction errors are within the single digit percentage range. We can conclude that the Nelder-Mead optimization method combined with the transition matrix method can be used for distributed sensing problems.
In this paper, a filtering stage based on employing a Savitzky-Golay (SG) filter is proposed to be used in the spectrum sensing phase of a Cognitive Radio (CR) communication paradigm for Vehicular Dynamic Spectrum Access (VDSA). It is used to smooth the acquired spectra, which constitute the input for a spectrum sensing algorithm. The sensing phase is necessary, since VDSA is based on an opportunistic approach to the spectral resource, and the opportunities are represented by the user-free spectrum zones, to be detected through the sensing phase. Each filter typology presents peculiarities in terms of its computational cost, de-noising ability and signal shape reconstruction. The SG filtering properties are compared with those of the linear Moving Average (MA) filter, widely used in the CR framework. Important improvements are proposed.
We define the need for sense-making as the desire to find reliable connections between the objects, situations, and relationships that people encounter. We have proposed and tested that there are possible individual differences in the need for sense-making and that these individual differences are insightful in characterizing individuals and their behaviors. A correlational study (N = 229) showed that need for sense-making was positively related to self-esteem, extroversion, conscientiousness, openness, and sense of control. Additionally, a higher need for sense-making was associated with greater perception of it as an important part of people’s identity. Thus, need for sense-making is relevant to understanding individual differences and can furthermore comprise a significant element of people’s identity. These results break new ground in the study of individual differences in the need for sense-making and can be of great importance in work and organizational psychology.
Animals kept outside their natural environment often suffer from boredom. They don’t hunt or have a chance to conduct their mating rituals, and their natural tendency for physical activity is limited by space. These deficiencies affect their psychological well-being. But when it comes to dogs, we can help them by exploiting their excellent sense of smell.
Satellite remote sensing provides a synoptic view of the land and a spatial context for measuring drought impacts, which have proved to be a valuable source of spatially continuous data with improved information for monitoring vegetation dynamics. Many studies have focused on detecting drought effects over large areas, given the wide availability of low-resolution images. In this study, however, the objective was to focus on a smaller area (1085 km2) using Landsat ETM+ images (multispectral resolution of 30 m and 15 m panchromatic), and to process very accurate Land Use Land Cover (LULC) classification to determine with great precision the effects of drought in specific classes. The study area was the Tortugas-Tepezata sub watershed (Moctezuma River), located in the state of Hidalgo in central Mexico. The LULC classification was processed using a new method based on available ancillary information plus analysis of three single date satellite images. The newly developed LULC methodology developed produced overall accuracies ranging from 87.88% to 92.42%. Spectral indices for vegetation and soil/vegetation moisture were used to detect anomalies in vegetation development caused by drought; furthermore, the area of water bodies was measured and compared to detect changes in water availability for irrigated crops. The proposed methodology has the potential to be used as a tool to identify, in detail, the effects of drought in rainfed agricultural lands in developing regions, and it can also be used as a mechanism to prevent and provide relief in the event of droughts.
Paper presents the description and floristic and ecologica characteristics of three plant communities on the area of Jasnorzewski Gardens in the region of Arctowski Station (Polish Academy of Sciences) on King George Island. They are: 1) Deschampsio antarctici-Colobanthetum quitensis, 2) Polytrichetum alpini, 3) Calliergidio austro-straminei-Calliergonetum sarmentosi. All communities show a considerable differentiation to several variants. Distribution of plant communities on the studied area is presented on a map based on computer analysis of multispectral air photographs.