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A great deal of attention has been applied recently to machine learning (ML) algorithms to solve difficult engineering problems in the field of structural engineering. Using borrowed features of ML algorithms (implemented), a solution to one of the most troublesome problems in concrete structures--namely, shear--is proposed. The understanding of shear failure in reinforced concrete (RC) structures has led to numerous laboratory investigations and analytical studies over the last century. Due to decades of efforts afforded by researchers, significant experimental shear test results have been created and archived. This data provides an opportune environment to implement ML techniques and evaluate model efficiency and accuracy. The focus of this paper is on ML modeling of the shear-transfer mechanism for slender RC beams without transverse reinforcement. Test results for 1149 RC beams were incorporated in the ML analysis for training (80%) and testing (20%) purposes. Prior to the ML analysis, a correlation coefficient analysis was conducted to determine if given design parameters affected shear strength. When compared to the data used, code-based shear equations provided with large safety margins gave reasonable predictions. Exponential-based Gaussian process regression (GPR) ML models yielded comparable predictions. Of the 19 ML models employed, most were considered as an effective strength predictive tools. These ML model predictions were compared to each other and with design provision shear equations. [ABSTRACT FROM AUTHOR]

This study presents the use of V-M interaction diagrams to estimate the ultimate shear and moment demands of reinforced concrete (RC) beams. The method of analysis presented can be beneficial for both design and analysis as it provides a visual aid for gaining clearer insight into the determination of the maximum load-carrying capacity of a considered section, as well as its failure mode. To simplify the construction of such V-M interaction diagrams and remove the often-needed iterative procedure, the current American Association of State Highway and Transportation Officials (AASHTO) shear sectional design model based on the Modified Compression Field Theory (MCFT) was modified. As a result, the simplified process uses the strains of flexural reinforcement and moment demands at three events, which can be obtained by a simple elastic analysis. The maximum shear strengths were predicted for 1012 RC beams without transverse reinforcement using two current AASHTO shear design methods and the proposed simplified method. Overall predictions at failure from the V-M interaction diagram approach for all three methods showed great agreement with the test results with a reasonable coefficient of variation. Further investigation of the experimental variables revealed an overly conservative trend in beams with smaller effective depth and a/d ratio due to insufficient consideration of size effect and arch action. The noticeable trend by a/d ratio was somewhat moderated in the proposed method. Although the proposed method showed the most accurate predictions compared to the two AASHTO methods, an unconservative aspect existed for many cases so that a strength reduction factor of 0.75 was suggested. Also, the current strength reduction factor of 0.9 in AASHTO for shear was evaluated and considered appropriate. Given the satisfactory performance in estimating the maximum shear capacity, the proposed simplified AASHTO method using the V-M interaction diagram can serve as an alternative shear strength design and analysis method for slender RC beams. [ABSTRACT FROM AUTHOR]

Gas hydrates have recently attracted attention due to their potential applications in important not only gas separation/recovery but also the related transportation/storage technologies. In this study, hydrate-based gas separation from CH4/C3H8 gas mixture investigated and evaluated. The phase equilibrium condition of which was predicted using the CSMGem software. Hydrate formation from CH4/C3H8 gas mixture 9.5 % C3H8 at 3.7 MPa and 275.15 K was also investigated to determine the separation efficiency of CH4. During hydrate formation, the vapor phase was analyzed by in situ Raman spectroscopy and double-checked by gas chromatography. The Raman data also revealed the structure of the gas hydrate and the time-dependent encapsulation of guest molecules. The experimental results demonstrated that highly concentrated CH4 can be effectively separated from natural gas hydrates; they will be very useful for methane separation/recovery from natural gas. [ABSTRACT FROM AUTHOR]

The problem of clathrate hydrate plugging in flow pipes has been the most important issue in the off-shore exploitation since hydrates were found in transport facilities. In recent years, low dosage hydrate inhibitors have attracted much interest among researchers in place of thermodynamic hydrate inhibitors such as methanol and mono ethylene glycol (MEG). Poly-vinyl caprolactam and poly-isopropylacrylamide (PNIPAM) are among the hydrate inhibitors that are typically used for polymers containing amide groups. Furthermore, various kinds of polymer inhibitors containing amide group including tetrabutylphosphonium bromide(TBPB), which is a quaternary salt, were synthesized and studied in a methane gas hydrate environment. In this experiment, the injection of 0.1 wt% inhibitor at 276 K and 5 MPa was followed by stirring the water to induce nucleation. From the result, when PNIPAM alone was used as a single KHI, PNIPAM exhibited worst performance among the KHIs tested in this study. But the mixing of TBPB with PNIPAM further extended the induction time and reduced the CH4 hydrate growth rate. The real-time in situ Raman system used to understand the inhibition principle was recorded during CH4 hydrate formation, as a result, PNIPAM showed that the large hydrate cage affected, while TBPB prevented the CH4 molecule from occupying the small cage. TBPB was excellent synergist in blends with PNIPAM for kinetic hydrate inhibition of structure I forming CH4 hydrate. [ABSTRACT FROM AUTHOR]

Freshwater scarcity has been troubling the high-quality development of many countries and regions, and water purification process is a vital source of freshwater. The traditional water purification processes such as distillation (multi-stage flash) and membrane processes (reverse osmosis) have been evaluated to be reliable and established processes. The desalination or water treatment technologies are mature enough to be a reliable source for fresh water but there is still a need to develop innovative technologies that can reduce energy costs. The water purifying by gas hydrate (hydrate-based) process is based on a liquid to solid phase change coupled with a physical process to separate the solids from the remaining liquid. In this study, we investigated the water purification by hydrate process for seawater and wastewater samples. In a single stage of hydrate process without any pre-treatment, dissociated water from the extracted hydrate pellets show that the removal efficiency of each ionic compound in seawater was 89 % (average). In the case of wastewater test from leachate sample, 77-95 % of dissolved contaminants and nutrients were excluded. Therefore, the experimental proposal and results of this study are of great significance to the development of water purification technology. [ABSTRACT FROM AUTHOR]

Given the increasing use of shear bands for slab-column connections as an alternative to stirrups and other types of shear reinforcement, punching and lateral cyclic behavior of reinforced concrete (RC) slab-column connections with shear bands was experimentally investigated. A total of six half-scale specimens of RC interior slab-column connection subassemblies were constructed on the same day. Of six specimens, three were tested under monotonically increased gravity loads and three under the combined effects of constant gravity and reversed cyclic lateral loads. Control specimens had no shear reinforcement, while closed stirrups and modular shear bands without punched holes were used for the shear-reinforced specimens. The slabs were heavily reinforced to limit the degree of flexural yielding prior to punching failure, and associated with gravity shear ratios of approximately 0.5 when subjected to lateral loads. The test results and comparison with current design codes indicate that the performance of the shear bands was equivalent to or better than that of the closed stirrups and that the code provisions for stirrups are applicable to shear bands, with the exception of provisions for anchorage requirement. [ABSTRACT FROM AUTHOR]

The phosphatase of regenerating liver (PRL) family, including PRL-1, PRL-2, and PRL-3, comprises protein tyrosine phosphatases whose deregulation is associated with the tumorigenesis and metastasis of many types of cancer. However, the underlying mechanism is poorly understood. In this study, aiming to increase understanding of the molecular mechanisms underlying the functions of PRL-1 and PRL-3, a yeast two-hybrid system was employed to screen for their interacting proteins. Alignment with the NCBI BLAST database revealed 12 interactive proteins: Synaptic nuclear envelope protein 2, emerin, mannose 6-phosphate receptor-binding protein 1, low-density lipoprotein receptor-related protein 10, Rab acceptor 1, tumor protein D52-like 2, selectin P ligand (SELPLG), guanylate binding protein 1, transmembrane and ubiquitin-like domain-containing 2, NADH:ubiquinone oxidoreductase subunit B8, syndecan 4 and FK506-binding protein 8 (FKBP8). These proteins are associated with cell proliferation, apoptosis, immune response, cell fate specification and metabolic process in biological process categories, and involved in various signaling pathways, including Alzheimer's disease, Parkinson's disease, Huntington's disease, hypertrophic cardiomyopathy and cell adhesion molecules. Interactions of PRL-1 with the prey proteins SELPLG and FKBP8 were confirmed by immunoprecipitation or immunostaining. Furthermore, SELPLG and FKBP8 suppressed PRL-1- or PRL-3-mediated p53 activity. Identification of the proteins interacting with PRL family proteins may provide valuable information to better understand the mechanism of PRL-mediated signal transduction in cancer and other diverse diseases. [ABSTRACT FROM AUTHOR]

A post-tensioned (PT) concrete member can be reinforced with either bonded or unbonded prestressing tendons. The bond condition of tendons may influence the flexural and shear performance of various types of PT concrete members. The main purpose of this study is to provide a direct comparison between members with the two different tendon systems and assess their structural performance in depth. To accomplish this, previously tested PT beams, one-way slabs, and slab-column connections are reexamined, and detailed nonlinear finite element analyses are conducted using the developed modeling techniques. A series of test results verifies that the developed model is reliable for both bonded and unbonded PT members. The results of the prior experimental and current numerical studies are used for better understanding the behavior of bonded and unbonded PT members. [ABSTRACT FROM AUTHOR]