Capacity of OSB Skin Structural Insulated Panels with Strengthening to Resist Windborne Debris Impact

Strong wind may damage building structures. Impact by debris propelled by strong wind on building envelope may induce localized damage. Opening on building envelop by windborne debris impact leads to increase in internal pressure, which may result in roof lifting up and wall collapse. This study investigates the capacity of OSB skin Structural Insulated Panel (SIP) in resisting windborne debris impact and the effectiveness of strengthening techniques in improving its impact resistance capacity

Lipid and glucose metabolism in senescence

Senescence is an inevitable biological process. Disturbances in glucose and lipid metabolism are essential features of cellular senescence. Given the important roles of these types of metabolism, we review the evidence for how key metabolic enzymes influence senescence and how senescence-related secretory phenotypes, autophagy, apoptosis, insulin signaling pathways, and environmental factors modulate glucose and lipid homeostasis. We also discuss the metabolic alterations in abnormal senescence diseases and anti-cancer therapies that target senescence through metabolic interventions. Our work offers insights for developing pharmacological strategies to combat senescence and cancer

Role of Electronic Excited State in Kinetics of the CH2OO + SO2 ! HCHO + SO3 Reaction

In this work, kinetics of the CH2OO + SO2 ! HCHO + SO3 reaction was studied by ring-polymer molecular dynamics (RPMD). To perform RPMD calculations, multi-reference configuration interaction (MRCI) was first carried out to compute data for constructing potential energy surface (PES) through a kernel regression method. On the basis of the present MRCI calculations, the statics multi-state mechanism involving the lowest-lying singlet excited state (denoted by S 1) was proposed, which is di?erent from the previously proposed mechanism with the lowest-lying triplet state (denoted by T1). Moreover, the present RPMD calculations predicted the rate coe?cient of 3:95?1011cm3 molecule1s1 at the room temperature (namely 298 K), agreeing with the previously reported experimental values. Finally, based on the present calculations, a probable dynamics mechanism was discussed, where the produced HCHO molecule was proposed to be in a vibrationally excited state. This needs further experimental and theoretical observation in the future.<br /

Vulnerability Analyses of Structural Insulated Panels with OSB Skins Strengthened by Basalt Fiber Cloth Subjected to Windborne Debris Impact

© 2018 World Scientific Publishing Company. In this study, numerical simulations are conducted with a verified model to develop damage threshold curves for structural insulated panels (SIPs) with OSB skins strengthened by basalt fiber cloth subjected to windborne debris impact. Numerical models of the SIP with OSB skins strengthened by basalt fibre cloth at the front or back side are developed by using LS-DYNA. The accuracy of the numerical model is verified by comparing numerical results with laboratory testing data. Using the verified numerical model, intensive simulations are conducted to examine the influence of various parameters, including thickness of basalt fiber, location of basalt fiber layer, bonding strength between the basalt fiber cloth and the OSB skin, on the dynamic responses of the SIP. The debris penetration or fracture of the strengthened SIP that creates an opening is defined as failure of the panel in this study. Empirical formulae are derived on the basis of the numerical results to predict the thresholds of penetration velocity and projectile mass that lead to failure of the SIP. The empirical formulae can be straightforwardly used to assess the performance of the SIP with OSB skins strengthened by basalt fiber cloth subjected to windborne debris impact

Numerical and experimental study of steel wire mesh and basalt fibre mesh strengthened structural insulated panel against projectile impact

Extreme wind events caused damages and losses around the world every year. Windborne debris impact might create opening on building envelop, which would lead to the increase in internal pressure and result in roof being lift up and wall collapse. Some standards including Australia Wind Loading Code (AS/NZS 1170:2:2011, 2011) put forward design criteria to protect structures against windborne debris impacts. Structural insulated panel with Oriented Strand Board skin and expanded polystyrene core has been increasingly used in the building industry. Its capacity was found insufficient to resist the windborne debris impact in cyclonic areas defined in the Australian Wind Loading Code. Therefore, such panels need be strengthened for their applications in construction in cyclonic areas. In this study, impact resistance capacities of seven structural insulated panels strengthened with steel wire mesh and basalt fibre mesh were experimentally and numerically investigated. The impact resistance capacities were identified by comparing the damage mode, residual velocity and unpenetrated length of projectile after impact. Experimental results clearly demonstrated the enhancement of the impact resistance capacities of panels strengthened with steel wire mesh and basalt fibre mesh. Finite element model was developed in LS-DYNA to simulate the dynamic response of the structural insulated panels under windborne debris impact. The accuracy of the numerical model was validated with the testing data

An in vitro study evaluating the effect of ferrule design on the fracture resistance of endodontically treated mandibular premolars after simulated crown lengthening or forced eruption methods

Abstract Background The purpose of this study was to evaluate the effect of ferrule design on the fracture resistance of endodontically treated mandibular first premolars after simulated crown lengthening and orthodontic forced eruption methods restored with a fiber post-and-core system. Methods Forty extracted and endodontically treated mandibular first premolars were decoronated to create lingual-to-buccal oblique residual root models, with a 2.0 mm height of the lingual dentine wall coronal to the cemento-enamel junction, and the height of buccal surface at the cemento-enamel junction. The roots were divided randomly into five equal groups. The control group had undergone incomplete ferrule preparation in the cervical root, with 0.0 mm buccal and 2.0 mm lingual ferrule lengths (Group F0). Simulated surgical crown lengthening method provided ferrule preparation of 1.0 mm (Group CL/F1) and 2.0 mm (Group CL/F2) on the buccal surface, with ferrule lengths of 3.0 mm and 4.0 mm on the lingual surface, respectively. Simulated orthodontic forced eruption method provided ferrule preparation of 1.0 mm (Group OE/F1) and 2.0 mm (Group OE/F2) on the buccal surface and ferrule lengths of 3.0 mm and 4.0 mm on the lingual surface, respectively. After restoration with a glass fiber post-and-core system and a cast Co-Cr alloy crown, each specimen was embedded in an acrylic resin block to a height on the root 2.0 mm from the apical surface of the crown margin and loaded to fracture at a 135° angle to its long axis in a universal testing machine. Data were analyzed statistically using two-way ANOVA with Tukey HSD tests and Fisher’s test, with α = 0.05. Results Mean fracture loads (kN) for groups F0, CL/F1, CL/F2, OE/F1 and OE/F2 were as follows: 1.01 (S.D. = 0.26), 0.91 (0.29), 0.73 (0.19), 0.96 (0.25) and 0.76 (0.20), respectively. Two-way ANOVA revealed significant differences for the effect of ferrule lengths (P = 0.012) but no differences for the effect of cervical treatment methods (P = 0.699). The teeth with no buccal ferrule preparation in control group F0 had the highest fracture resistance. In contrast, the mean fracture loads for group CL/F2 with a 2.0-mm buccal and 4.0-mm lingual ferrule created by simulated crown lengthening method were lowest (P = 0.036). Conclusions Increased apically complete ferrule preparation resulted in decreased fracture resistance of endodontically treated mandibular first premolars, regardless of whether surgical crown lengthening or orthodontic forced eruption methods been used

Review on the Developments of Structure, Construction Automation, and Monitoring of Intelligent Construction

The building and construction industry is a traditional industry that features high-capacity investment, long return period, high environment impact, and low technology demand in the past decades. With the fast development of technology and the demand for environmental sustainability, it is inevitable for the building and construction industry to embrace the revolution of technology. Intelligent construction is developed in light of advanced technologies including advanced computing technology, 3D design and manufacturing, automation and control, sensing, unmanned aircraft, and autonomous intelligence. It is also closely integrated with using perceived, analytical, decision-making coordination for building construction with perceived intelligent execution technology in the processes. Currently, there is no consensus definition on “intelligent construction” despite its rapid development. This paper reviews existing and current development in intelligent construction focusing on the following three aspects: (a) new structural forms, which are innovative and with potential or are being applied to automated and mass manufacturing/construction; (b) automated and intelligent construction system; and (c) advanced structure sensing and monitoring technology. These three components do not compromise the entire aspects for intelligent construction, but they have no doubt are the core elements for intelligent construction towards future building systems

An investigation of impact resistance capacity of polypropylene (PP) added plasterboard subjected to soft-body impact

Plasterboard is one of the most-commonly used construction materials because of its low cost and easy installation characteristics. Although the low strength and fragility make plasterboard functioned as non-load-bearing components. Plasterboard walls are always required to satisfy impact resistance against impact from accidental body strike, hard-body impact from wheelchair, etc. during its usage. This study investigates the impact resistance capacity of plasterboards being subjected to soft-body impact load. Laboratory sandbag impact tests are conducted to examine the responses of plasterboard and PP fibre strengthened plasterboard system at different velocities. Detailed numerical models of plasterboards are also generated to assist the analysis. Different damage and failure modes are observed on the plasterboards when subjected to impactor strike at different velocities. It is found that the coupled deformation of plasterboard and sandbag leads to different impact load time histories from sandbag soft impact, which results in the different failure modes. The PP fibre strengthened board exhibits better impact resistance than conventional plasterboard. Parametric study is then conducted to quantify the peak central deflections under different strength and thickness variances on plasterboard. An empirical formula is then derived based on the parametric results for preliminary assessment of the plasterboard impact resistance capacity

Multilayer Multiconfiguration Time-Dependent Hartree Study on the Mode-/Bond-Specific Quantum Dynamics of Water Dissociation on Cu(111)

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