Structural and thermal efficiency of precast concrete sandwich panel systems

Precast concrete sandwich panels (PCSP) are structurally and thermally efficient elements used for exterior walls in multi-unit residential, commercial, and warehouse buildings throughout the world. A typical PCSP consists of two precast reinforced concrete layers (called wythes) separated by a layer of insulation and connected with connectors which penetrate the insulation layer. The connectors used in the majority of available PCSP systems consist of concrete webs or blocks, steel elements, or a combination thereof. Because of their low thermal resistance, steel and concrete connectors can cause significant reduction in the effective thermal resistance of the panel through thermal bridging. The objective of this research is to develop a connecting system capable of improving the thermal and structural performance of PCSPs. This dissertation first presents a review of existing PCSP systems. Next, evaluation of selected fiber reinforced plastic (FRP) connectors is summarized. The structural performance of a few FRP connectors is evaluated through a series of pure-shear (push-out) tests performed on small scale specimens. The initial evaluation and the first phase of testing led to the selection of a FRP bent-bar connector. The bar is fabricated in a deformed spiral shape through which a pair of prestressing strands or reinforcing bars can be threaded to provide anchorage in the concrete wythes. Phase two (pure shear tests) and phase three (flexural tests) were performed on small scale specimens to evaluate the structural performance of the bent-bar connector. In addition, the structural performance of the connector was analytically evaluated by developing finite element models for panel behavior in testing phases two and three. Experimental and analytical results from finite element and differential equation analysis are in good correlation. This dissertation also includes a brief study of stresses and deformation due to differential volume changes. Volume changes often contribute a large portion of the stress or out-of-plane deflection of PCSPs. The finite element model, calibrated with the results of testing phase three, is used to evaluate the effectiveness of the differential equations for computing deflections due to differential volume changes. Both methods are compared with a practical design method for evaluating stresses and out-of-plane deflection due to differential volume changes

SANAD: Single-Label Arabic News Articles Dataset for Automatic Text Categorization

SANAD Dataset is a large collection of Arabic news articles that can be used in different Arabic NLP tasks such as Text Classification and Word Embedding. The articles were collected using Python scripts written specifically for three popular news websites: AlKhaleej, AlArabiya and Akhbarona. All datasets have seven categories [Culture, Finance, Medical, Politics, Religion, Sports and Tech], except AlArabiya which doesn’t have [Religion]. SANAD contains a total number of 190k+ articles. How to use it: ___________ 1. Unzip compressed resources. 2. Each folder contains 6-7 sub-folders which are labeled by the category's name. 3. Each sub-folder contains a set of article files corresponding to its category. SANAD_SUBSET is a balanced benchmark dataset (from SANAD) that is used in our research work. It contains the training (90%) and testing (10%) sets. How to use it: ___________ 1. Unzip the compressed file. 2. There are 3 main folders containing the 3 datasets: Akhbarona, Khaleej, and Arabiya. 3. Each dataset-folder contains 2 sub-folders: training and testing. 4. The training and testing folders include the balanced categories sub-folders

SANAD: Single-Label Arabic News Articles Dataset for Automatic Text Categorization

SANAD Dataset is a large collection of Arabic news articles that can be used in different Arabic NLP tasks such as Text Classification and Word Embedding. The articles were collected using Python scripts written specifically for three popular news websites: AlKhaleej, AlArabiya and Akhbarona. All datasets have seven categories [Culture, Finance, Medical, Politics, Religion, Sports and Tech], except AlArabiya which doesn’t have [Religion]. SANAD contains a total number of 190k+ articles. How to use it: ___________ 1. Unzip compressed resources. 2. Each folder contains 6-7 sub-folders which are labeled by the category's name. 3. Each sub-folder contains a set of article files corresponding to its category. SANAD_SUBSET is a balanced benchmark dataset (from SANAD) that is used in our research work. It contains the training (90%) and testing (10%) sets. How to use it: ___________ 1. Unzip the compressed file. 2. There are 3 main folders containing the 3 datasets: Akhbarona, Khaleej, and Arabiya. 3. Each dataset-folder contains 2 sub-folders: training and testing. 4. The training and testing folders include the balanced categories sub-folders

SANAD: Single-Label Arabic News Articles Dataset for Automatic Text Categorization

SANAD Dataset is a large collection of Arabic news articles that can be used in different Arabic NLP tasks such as Text Classification and Word Embedding. The articles were collected using Python scripts written specifically for three popular news websites: AlKhaleej, AlArabiya and Akhbarona. All datasets have seven categories [Culture, Finance, Medical, Politics, Religion, Sports and Tech], except AlArabiya which doesn’t have [Religion]. SANAD contains a total number of 194'797 articles. How to use it: ___________ 1. Unzip compressed resources. 2. Each folder contains 6-7 sub-folders which are labeled by the category's name. 3. Each sub-folder contains a set of article files corresponding to its category

Dynamic characteristics of streched-membrane heliostats

Stretched-membrane heliostats provide efficient two-axis tracking mirrors for use in solar thermal applications. The solution of the two-dimensional wave equation for a circular stretched membrane provided lower and upper bounds of the natural frequencies of the heliostat. The effects of the boundary condition on the mode shapes of the membrane were shown in the finite element analysis as well as in the vibration tests. Different natural modes were excited depending upon the number of supports around the circumference of the membrane. Damping in the heliostat was small. Damping ratios estimated from vibration decay curves were less than 3% of critical when the membrane was not stretched and less than 1% when stretched. The bending stiffness of the membrane became significant when the membrane tension was low. The anisotropic effect causing non-uniform membrane tension due to the weldments was negligible