Surface modification of nano-TiO2 with lanthanide-acetylacetonate complexes

The surface modification of nano-TiO2 was carried out with lanthanide-acetylacetonate complexes by adsorption method. The effects of lanthanide complexes content, lanthanide element type, adsorption temperature, solvent dosage, adsorption time and other conditions on the photodegradation activity of methyl orange by the modified catalyst were studied, and suitable modification conditions were obtained. The results show that the photocatalytic activity of the modified nano-TiO2 is much higher than that of the unmodified pure TiO2, and the lanthanide-acetylacetonate complexes is an excellent surface modifier.

Distribution of load effects and reliability of reinforced concrete frames: intact and with columns removed

abstract: The design of reinforced concrete (RC) frames is made on a member-by-member basis. Similarly, in the literature, the reliability of RC beams and columns is often studied in isolation from the rest of the structure. Yet, in the construction of regular frames, symmetry and regularity are often exploited, resulting in the same design for each element type. This is despite of different load effects on different parts of the structure, which leads to significant variations in the failure probability of the elements. Hence, in this paper, we investigate the reliability of members and the distribution of load effects in regular RC frame buildings, considering intact and column loss cases, where symmetry is lost. Results show that the ratios of normal-to-bending loads change significantly along building height, and this has a significant impact on reliability of individual columns.

Maximal Type Elements for Families

In this paper, we present a variety of existence theorems for maximal type elements in a general setting. We consider multivalued maps with continuous selections and multivalued maps which are admissible with respect to Gorniewicz and our existence theory is based on the author’s old and new coincidence theory. Particularly, for the second section we present presents a collectively coincidence coercive type result for different classes of maps. In the third section we consider considers majorized maps and presents a variety of new maximal element type results. Coincidence theory is motivated from real-world physical models where symmetry and asymmetry play a major role.

Development of Line-to-Line Contact Formulation for Continuum Beams

A line-to-line beam contact formulation in the framework of the absolute nodal coordinate formulation (ANCF) is introduced in this paper. Higher- and lower-order ANCF beam elements employ the introduced beam contact formulation. The higher- and lower-order ANCF beam elements are compared in terms of their accuracy and performance in a large deformation contact problem. Efficiency of numerical integration of contact energy variation contribution to the system’s equations of motion is studied. The contacting elements’ surfaces of the ANCF beam elements are parameterized by segmentation of integration over the contact patch. Numerical results investigate the accuracy, robustness and efficiency of the developed line-to-line contact formulation by comparing against a solid element type using commercial finite element code. According to the numerical results, the higher-order ANCF beam element’s solution is closer than the lower-order ANCF beam element’s in accordance with the reference solution provided by a solid element type using commercial finite element code ABAQUS. Furthermore, the higher-order beam element is found to be more efficient than the lower-order beam with respect to the numerical integration of the contact energy variation. Expectedly, the higher-order ANCF beam element is able to capture the cross-section deformation in a large deformation contact problem, while the lower-order element fails to exhibit such cross-sectional deformation.

Analytical modeling of the shear behavior of reinfored concrete exterior beam-column joints

In reinforced concrete structures, failure of beam-column joint was observed as one of the major causes of damage of those structures during earthquakes. Non-ductile detailing of reinforcement in the joint in terms of inadequate shear reinforcement in the joint panel or insufficient anchorage of the beam bars within the joint region are the main causes of deficiency in the performance of joints during an earthquake. The objectives of this study are to compare different aspects of modeling the nonlinear behavior of exterior beam-column joints and also to propose a new model for the shear behavior of exterior joints. Two well-known computer programs for nonlinear dynamic analysis of the structures DRAIN-2DX (element type 15) and IDARC2D are used. The advantages of using each one for the beam-column joints in the reinforced concrete structures, and the effect of modeling features on the response of beam-column joints are discussed.

Analytical modeling of the shear behavior of reinfored concrete exterior beam-column joints

In reinforced concrete structures, failure of beam-column joint was observed as one of the major causes of damage of those structures during earthquakes. Non-ductile detailing of reinforcement in the joint in terms of inadequate shear reinforcement in the joint panel or insufficient anchorage of the beam bars within the joint region are the main causes of deficiency in the performance of joints during an earthquake. The objectives of this study are to compare different aspects of modeling the nonlinear behavior of exterior beam-column joints and also to propose a new model for the shear behavior of exterior joints. Two well-known computer programs for nonlinear dynamic analysis of the structures DRAIN-2DX (element type 15) and IDARC2D are used. The advantages of using each one for the beam-column joints in the reinforced concrete structures, and the effect of modeling features on the response of beam-column joints are discussed.

The ductile/brittle transition of polycrystalline aggregates in terms of their single crystal cubic properties

The Kröner solution is used to determine the shear modulus of any polycrystalline aggregate composed of cubic crystals. This solution from the self-consistent method takes the form of a cubic equation specified by the three elastic properties of the crystal. The ductile/brittle transition for homogeneous and isotropic materials in uniaxial tension is specified by terms of the shear modulus and the bulk modulus of the aggregate. These two basic results are then combined to specify the ductile/brittle transition of the polycrystalline aggregate in terms of its cubic crystal symmetry elastic properties. The various forms that the combined results take are developed and interpreted. Examples and detailed results are given for carbon-diamond, copper, tungsten, iron, silicon, lithium and platinum element type polycrystal materials. The tungsten and iron cases very closely bracket the ductile/brittle transition for all of the solids forming elements of the Periodic Table, one from the brittle side and the other from the ductile side.

Unique Neural Activity Patterns Among Lower Order Cortices and Shared Patterns Among Higher Order Cortices During Processing of Similar Shapes With Different Stimulus Types

We investigated the neural mechanism of the processing of three-dimensional (3D) shapes defined by disparity and perspective. We measured blood oxygenation level-dependent signals as participants viewed and classified 3D images of convex–concave shapes. According to the cue (disparity or perspective) and element type (random dots or black and white dotted lines), three types of stimuli were used: random dot stereogram, black and white dotted lines with perspective, and black and white dotted lines with binocular disparity. The blood oxygenation level-dependent images were then classified by multivoxel pattern analysis. To identify areas selective to shape, we assessed convex–concave classification accuracy with classifiers trained and tested using signals evoked by the same stimulus type (same cue and element type). To identify cortical regions with similar neural activity patterns regardless of stimulus type, we assessed the convex–concave classification accuracy of transfer classification in which classifiers were trained and tested using different stimulus types (different cues or element types). Classification accuracy using the same stimulus type was high in the early visual areas and subregions of the intraparietal sulcus (IPS), whereas transfer classification accuracy was high in the dorsal subregions of the IPS. These results indicate that the early visual areas process the specific features of stimuli, whereas the IPS regions perform more generalized processing of 3D shapes, independent of a specific stimulus type.

Research progress of wearable electric heating elements

The research progress of electric heating elements is summarized in terms of heating element type and thermal performance evaluation. Their shortcomings are summarized, and the development trend is pointed out to provide help and direction guidance for the research of electric heating element.