建材の反射指向特性を考慮した室内の輝度分布計算

In this report we describe an optical scattering measurement instrument developed for the design of machine vision illumination. The instrument can measure the radiance of surfaces as a function of the illumination and viewing angles and it can be used to measure relative bidirectional reflectance (BRDF) characteristics of materials. The constructions used were the traditional mechanically scanned single detector based solution and a new video camera based solution. The benefits of the video camera based solution are the rapid measurement of a large scattering angle range and the possibility of viewing scattering patterns on a monitor in real time. The experimental results of the BRDF measurements on copper and galvanized steel are modeled by using reflectance models based on geometrical optics and wave theory.

3D Ultrasound Computer Tomography (3D USCT) promises reproducible high-resolution images for early detection of breast tumors. For reflectivity reconstruction a 3D synthetic aperture focusing technique (SAFT) is used which calculates one reflectivity value for each voxel from about 10 million A-scans. In this work the standard SAFT algorithm is extended to calculate reflectivity characteristics for each voxel in the volume using a directional vector derived from the transducer positions. The reflectivity characteristic is evaluated with in-vivo data and enables new information about the reflecting tissues, e.g. local normals. The contrast of SAFT images of an example breast could be increased by 32% and the data shows potential for tissue classification by comparing reflectivity characteristics. Regardless of calculating twelve-times more data for the simplest case, a performance of 46% of the standard SAFT algorithm on GPU could be reached.

Old Mosul is characterized by the presence of many buildings and heritage monuments of high architectural value which represents the identity and culture of the Mosul community. As a result of the improvisation of reconstruction work after 2017, and the lack of experience in dealing with traditional building materials and their technical, sensory, and intangible characteristics, the main research problem emerged, which is losing of sustainability of urban identity, and losing the spirituality of the place as a result of using modern building materials that do not express their sensual and intangible characteristics with the traditional heritage of the old city. The research aims to explore the reconstruction of heritage residential buildings in old Mosul according to levels of international standers conservation, regarding the role of building materials and their properties order to reach indicators that contribute to the reconstruction of heritage residential buildings to ensure the sustainability of urban identity. In addition, to identify the most important characteristics of the building materials associated with the traditional heritage of the old city in Mosul. The research is based on the field survey method, which depends on collecting data of the heritage residential buildings after their reconstruction or rehabilitation. The characteristics of the building materials and their role in the sustainability of the urban heritage are then described and analyzed, finally, they are compared with the levels and standards of international conservation. The results of the study showed the effect of the characteristics of sensory and intangible building materials on the construction of residential buildings and the sustainability of their architectural identity.

The paper presents experimental results of reflectivity and transmissivity measurements for two types of building materials at 62.4 GHz. A theoretical model, based on successive internal reflections inside the material has been developed and used to estimate the dielectric parameters by comparing measured and predicted results. Theoretical and experimental results obtained for different thickness plasterboard are in good qualitative and reasonably good quantitative agreement. The values of the dielectric parameters obtained based on either transmissivity or reflectivity measurements are similar. However, some variations from this are found particularly for plywood. Theoretical predictions do not describe experimental results accurately. The estimated values vary depending on the type of measurement being used. The model gives a close match for a material which can be described as homogeneous such as plasterboard. However, for other materials such as plywood, the agreement between experimental and theoretical results is relatively poorer.

Reflection and Transmission Properties of Common Construction Materials at 2.4 GHz Frequency

A study of indoor propagation factors at 17 and 60 GHz is described. A dual narrowband sounder is described, aimed at evaluating the coverage and frequency reuse potential of these bands. A number of different indoor environments are under investigation from office type buildings containing a large number of small rooms, to a large open plan environment containing no internal walls. Also under investigation are the reflection and transmission characteristics of several construction materials at the same frequencies.

The problem of assessing the possible relative errors of the technical characteristics of building materials when testing samples of the correct geometric shape has been solved. The work is based on the theory of errors and on the method of linearization of functions of random variables. The technical characteristics of the materials are determined by the equations of indirect measurements through the input parameters, directly measured during the tests with known level of accuracy. Linearization of the equations of indirect measurement allowed to obtain dependences for determining the standard and probable relative errors of determining the average density, humidity, water absorption and compressive strength of building materials. Samples of the correct geometric shape of the following types are considered: cube, parallelepiped, circular cylinder. The input values of the obtained formulas are the size and weight of the samples, as well as the destructive force during compression. The accuracy of direct measurement of these values is determined by the values of division of the corresponding measuring instruments. The obtained formulas give possible relative errors of indirect measurements of the analyzed technical characteristics corresponding to the given two-way security level. The use of the obtained formulas allows you to reasonably choose the means for measuring the input parameters that provide the necessary accuracy of the results of determining the technical characteristics with the maximum ease of performing the measurements. The method for assessing the accuracy and the choice of measuring instruments for measuring the size and mass of samples is illustrated by an example of determining the average density of a mortar based on the results of testing cubic samples of different sizes. The results of the study can be used in the experimental determination of the analyzed technical characteristics of building materials of other types, as well as extended to assess the accuracy of other technical characteristics, which are determined by indirect methods.

Radon permeability and radon exhalation of building materials

Application and development of the LCA methodology to the context of the building sector makes several building specific considerations necessary, as some key characteristics of products in the building sector differ considerably from those of other industrial sectors. The largest difference is that the service life of a building can stretch over centuries, rather than decades or years as seen for consumer products. The result of the long service life is that it is difficult to obtain accurate data and to make relevant assumptions about future conditions regarding, for example, recycling. These problems have implications on the issue of allocation in the building sector, in the way that several allocation procedures ascribe environmental loads to users of recycled or reused products and materials in the future which are unknown today. The long service life for buildings, building materials and building components, is associated with the introduced concept of a virtual parallel time perspective proposed here, which basically substitutes historical and future processes and values with current data. Further, the production and refining of raw material as a parallel to upgrading of recycled material, normally contains several intermediate products. A suggestion is given for how to determine the comparability of intermediate materials. The suggested method for allocation presented is based on three basic assumptions: (1) If environmental loads are to be allocated to a succeeding product life cycle, the studied actual life cycle has to take responsibility for upgrading of the residual material into secondary resources. (2) Material characteristics and design of products are important factors to estimate the recyclable amount of the material. Therefore, a design factor is suggested using information for inherent material properties combined with information of the product context at the building level. (3) The quality reduction between the materials in two following product life cycles is indicated as the ratio between the market value for the material in the products. The presented method can be a good alternative for handling the problem of open-loop recycling allocation in the context of the building sector if a consensus for the use of the fictive parallel time perspective and the use of the design factor can be established. This as the use of the time perspective and design factor is crucial to be able to deal with the problem of long service lives for buildings and building materials and the specific characteristics of the same building materials and components built into different building contexts.

Moisture in porous building materials plays an important role in almost all durability problems. The sorption characteristics of building materials exhibit hysteresis in the way the equilibrium curves develop between adsorption and desorption. The sorption curves are also somewhat temperature-dependent. These facts are most often neglected in models for combined heat and moisture transport in materials. This study provides the sorption isotherm and its hysteresis of different porous building materials. The paper seeks to contribute to the knowledge base about such sorption characteristic by presenting some new measurements of hysteresis and temperature dependency of the moisture sorption characteristics of different porous building materials: concrete, porous concrete, cement plaster, limes cement plaster, brick, and spruce. Scanning curves are measured for all materials where periods with adsorption and desorption interrupt each other intermittently between 0% and 97% of relative humidity.

A review of the literature on scientific approaches in the development of composite materials and building structures made of composites is carried out. When creating and manufacturing traditional and new composite materials, for example, by additive manufacturing, and when creating structures and structures in engineering calculations, new techniques, finite element computational software systems, and neural network technologies are used, which are used in the creation of modern metal and composite materials, analysis of mechanical characteristics of materials, forecasting loads on the structure, optimization of structures and calculation of their construction characteristics. The distinctive features of modern composite materials are shown. The main types of composite materials are considered: talc, diatomite, calcium carbonate, gibbsite, barium sulfate, feldspar, nepheline, aragonite, calcium carbonate, wool, silk, cotton, linen, jute, wood pulp, asbestos, fiberglass, metal fibers, quartz fibers, basalt fibers, polyamide fibers, polyester fibers, polyvinyl alcohol fibers, carbon fibers, viscose fibers. The physical and mechanical characteristics of composite materials (based on epoxy, aluminum, carbon, magnesium, and nickel matrices) and traditional (steel, aluminum, brick, concrete) building materials are presented. The disadvantages of such composite materials as carbon fiber, fiberglass, organoplastics, textolite, carbon concrete, and polystyrene concrete are presented. Deformation diagrams of some types of fibers for composite materials are considered: high-modulus carbon fibers, high-strength carbon fibers, aramid fibers, glass fibers, and basalt fibers. The advantages of the system of external reinforcement of building structures with composite materials are described. Examples of reinforcement of building structures are considered: reinforced concrete reinforcement; reinforcement of floor slabs; reinforcement of columns; and reinforcement of brick walls.

The specific features of reducing the radar observability of aircraft by applying radar-absorbent materials are studied. A method for determining the reflective characteristics of different types of materials based on the Fresnel equations is considered. A good agreement between the radiophysical characteristics of multilayered materials calculated using this method and those obtained based on analytical solutions is demonstrated.

A detailed description of the application and performance characteristics of new energy-saving building materials, including the use of new wall material, thermal insulation material, waterproof sealing material. New building materials is different from the traditional brick, gray sand and gravel and other building materials, building materials of new varieties, instead of supporting a variety of various auxiliary materials and chemical materials. RFID tags by coupling components and chips, each tag has a unique electronic coding, attached to the object target object. The paper presents Development of Novel Building Materials and Mining system based on improved radio frequency identification technology. Experimental results show that the proposed method has high efficiency.

Nowadays, it is necessary to develop new building materials, which are in accordance to the principles of the following provisions of the Roads Act: The design of road is a subject that follows national technical standards, technical regulations and objectively established results of research and development for road infrastructure. Foam concrete, as a type of lightweight concrete, offers advantages such as low bulk density, thermal insulation and disadvantages that will be reduced by future development. The contribution focuses on identifying the major material characteristics of foam concrete named Poroflow 17-5, in order to replace cement-bound granular mixtures. The experimental measurements performed on test specimens were the subject of diploma thesis in 2015 and continuously of the dissertation thesis and grant research project. At the beginning of the contribution, an overview of the current use of foam concrete abroad is elaborated. Moreover, it aims to determine the flexural strength of test specimens Poroflow 17-5 in combination with various basis weights of the underlying geotextile. Another part of the article is devoted to back-calculation of indicative design modulus of Poroflow based layers based on the results of static plate load tests provided at in situ experimental stand of Faculty of Civil Engineering, University of Žilina (FCE Uniza). Testing stand has been created in order to solve problems related to research of road and railway structures. Concern to building construction presents a physical homomorphic model that is identical with the corresponding theory in all structural features. Based on the achieved material characteristics, the tensile strength in bending of previously used road construction materials was compared with innovative alternative of foam concrete and the suitability for the base layers of pavement roads was determined.

The pore system characterization of an Ultra High Performance Fibre Reinforced Concrete (UHPFRC) exposed to the elevated temperatures is presented in the paper. The porosity and pore size distribution of building materials are of the particular importance because of their clear effect on durability and service life of structural elements and buildings. Material characteristics as mechanical, thermal and hygric properties are strongly dependent on pore system. For porosity measurement, several techniques having specific advantages or disadvantages with respect to the pore size are available. In building materials research, usage of Mercury Intrusion Porosimetry (MIP) with range of the detected pores up to 100 µm is the most common. Nevertheless, in practical measurements, the differences between the porosity values determined by helium pycnometry and MIP are usually observed. It can be attributed to the presence of pores bigger than 100 µm. Based on the literature analysis it is evident that the porosity i...