Applied Mechanics and Materials Vols. 719-720

Abstract: In the present work, the embedded-type TiO₂/magnetic activated carbon (TiO₂/MAC) photocatalysts were prepared. The MAC support was manufactured by one-step method and the TiO₂ coated on the surface of MAC was prepared by sol-gel method. Its crystalline structural properties, morphology, magnetic performances and pore texture were characterized by XRD, SEM, TEM, ultraviolet-visible absorption spectra (Uv-vis), vibrating sample magnetometry (VSM) and N₂ adsorption isotherm. Characterization results showed that TiO₂ was highly dispersed on the surface of MAC support in the form of anatase with a particle size of 10 nm. Obtained TiO₂/MAC photocatalysts were applied to treatment of contaminant phenol in aqueous solution. The phenol removal percentage by TiO₂/MAC photocatalyst is as high as 94% after three cycles. In addition, photocatalytic degradation of phenol in water was examined using TiO₂/MAC photocatalysts. The results show that 4 wt% Fe₃O₄ was suitable to prepare the support of TiO₂/MAC composite. The phenol removal percentage by TiO₂/MAC photocatalyst is as high as 94% after three cycles. However, the adsorption capability of photocatalyst disappears after six cycles, while its phenol removal percentage via photodegradation is still as high as 60%. Meanwhile, the used TiO₂/MAC photocatalyst after six cycles still maintains good magnetic stability because the majority of magnetic particles are embedded into the bulk of carbon matrix. And the embedded structure could still meet the requirement of magnetic separation by an external magnetic field.

Abstract: Sacrificial layer release is the key process step of cavity structure formation of Film Bulk Acoustic Resonator (FBAR), the degree of sacrificial layer release directly determines how good or bad the resonance characteristic of FBAR is. The Constant Diffusion Coefficient (CDC) model numerical iteration of sacrificial layers etching process was simulated with MATLAB, and the etching process was also simulated with Silvaco. According to the simulation results, put forward optimum design of release window. The resonance simulations of FBAR with/without release window have been done by FEA software. The simulation results show that the aperture cavity type FBAR, i.e. the cavity type FBAR with release holes, still has distinct resonant characteristic, but the frequency of impedance zero point and impedance pole of the novel type FBAR are all drifted to higher frequency, and the effective electromechanical coupling coefficient and the quality factor are all reduced.

Abstract: By now the application of Textile Reinforced Concrete (TRC) for facade constructions can be considered as state of the art. Especially ventilated curtain walls made of TRC and sandwich elements made in combination of TRC-layers and foam cores recently are realized in pilot projects, which are predominantly located in Aachen, Germany. Textile reinforced concrete elements for architectural facade applications give new chances for architects and engineers design.

Abstract: Due to environmental and energy matters, importance of future construction trend-Passive House Design is increasing all over the world. In Europe, already recommended values ​​for passive buildings are included in thermal insulation standards and energy regulation directives. There is a wide range of construction materials nowadays. The key point is using proper techniques by harmonizing correct practice and materials. In this regard, smart optimization set-up approach is necessary in order to achieve the most suitable design which has the lowest CO₂ and SO₂ values and appears as the cheapest option. The sample given in this paper is an example of an exterior wall design for residential passive houses (heat transfer coefficient (U) value through the cross section is 0,108 W/m²K). Connected with the aim of the paper, which is showing an multi-objective optimization method for choosing the best thermal insulation design in the case of that more than one projection, results of given example design in the paper is used. Simultaneously, criteria of total thickness, heat transfer coefficient (U) through the cross section, global warming potential (GWP), acid produce (AP), primary energy content (PEI) non renewable and cost in 2013 per m² are included in “Smart optimization set-up approach diagram”.

Abstract: As the external environment of the international construction project has become increasingly complex, risk management is emphasized in the project management. BIM(Building Information Model) has bring change to the Construction Industry in China. It has contributed to the schedule and cost management. However, BIM is not widely used to solve the problem of risk management. This thesis cites the possibility about BIM application to risk management and evaluates the progress it may bring to the process of risk management. Furthermore, a BIM-Risk System is proposed for Chinese international contractors to solve some major risks the international contractors may face. By using this system, the level of the project risk management will significantly improve. Then the barriers and the potential problems of applying BIM to risk management in China are analyzed. The BIM application to risk management has great value to be further researched.

Abstract: The paper discusses strength-time relation of unfired soil-lime bricks in presence of different water content of soil as one of principal materials for the brick making. Two batches of soil-lime bricks were made with a mixture of lime, soil and water with a mass proportion of 1: 5.7: 1. Water contents of the first and second batch of soil are 30% and 40.581% respectively. Both batches of brick underwent compression and three point bending test. Absorption and physical change of bricks were also evaluated. Experimental investigation reveals that for both batches of bricks, up to 90 days compressive strength decreases a little but modulus of rupture rapidly decreases with time. The study shows that unfired soil-lime bricks with lower soil water content resulted in better strength performances compared to those with higher soil water content.

Abstract: It is well known that the mechanical behavior of the natural intact soft clay is usually quite different from that of the reconstituted counterpart. Hence, how to predict the influences of soil structure on the mechanical behavior of natural clays is an important issue in geotechnical engineering.The mechanical behavior of structured soils can usually be quantitatively assessed based on the mechanical behavior obtained from corresponding reconstituted clays. The preparing method for reconstituted soils will affect the quality of reconstituted samples greatly, and therefore, affect their mechanical parameter. To guarantee the quality of reconstituted soil samples, a large diameter oedometer apparatus is developed. Also, an oedomer-based method for preparing reconstituted clay samples is proposed. Typical soft Lianyungang city clay from China is chosen to testify the methods and corresponding procedures. The feasibility of the improved method is confirmed by comparing its results with those of the normal oedometer test.

Abstract: Augmented reality, which has been designed to improve the services in many application domains such as school education, military warfare, military trainings, industrial maintenance, retail and medical, can be defined in the simplest form as augmenting the real world with information from the virtual world. The main aim of this study, which presents an overview of an ongoing project, is to develop an innovative method by making a construction worker, foreman, equipment operator or a site engineer watch a very comprehensive and informative animation which will enable the said staff to perform or supervise all the phases of the activity he or she is in charge for in a more efficient, productive, safer and qualified manner by means of smart glasses using augmented reality systems. Basic trainings about the system will be given to target group, i.e. construction workers, foremen, operators, site engineers and managers working in the construction sites to apply the system on sites after all the system was tested. After the testing, to determine the effectiveness of this system, semi-structured interviews and survey questionnaires will be conducted among the mentioned target group. Therefore, the potential benefits of this system to the construction industry can be determined. There are relatively few studies about the implementations of augmented reality technology in construction. The outputs to be attained in the end of the study have the potential of improvement of time, cost, quality and safety parameters.

Abstract: Space trusses are three-dimensional structures made of steel bars very frequently used at the roof construction. The bars, with tubular section, are linking in the 3D form by connections. There are several types of connections to attach these members. The most economical connection is the staking end-flattened connection, also called typical node. The reduced cost and the fast assemblage of the truss are among their advantages. However, such connections present disadvantages like eccentricities and stiffness weakening of the tubular members. This research presents suggestions of reinforcement and constructive correction in the connection in order to increase its capacity. The base for this is the reduction of the eccentricity in typical node applying the spacer. This spacer was made by polymer composite with sisal fiber. In this work was developed experimental lab tests in prototypes with fifty four meters square of area. The results show an increase of 26% for collapse in the truss load carrying capacity when the suggested changes proposed in this article are used for the staking end-flattened connections.

Abstract: A possible use of natural zeolite originating from a mining area in South Slovakia as a pozzolanic material suitable for the partial cement replacement in composite production is studied. Measurement of chemical composition of natural zeolite is performed using XRF analysis. The particle size distribution of zeolite and dry paste mixtures is accessed on laser diffraction principle. For the tested pastes, basic physical properties and mechanical properties are determined. The obtained results indicate a good potential for the application of natural zeolite in the composite mix design.