Fire, a phenomenon occurs in most parts of the world and causes severe financial losses, even, irreparable damages. Many parameters are involved in the occurrence of a fire; some of which are constant over time (at least in a fire cycle), but the others are dynamic and vary over time. Unlike the earthquake, the disturbance of fire depends on a set of physical, chemical, and biological relations. Monitoring the changes to predict the occurrence of fire is efficient in forest management. Method: In this research, the Persian and English databases were structurally searched using the keywords of fire risk modeling, fire risk, fire risk prediction, remote sensing and the reviewed papers that predicted the fire risk in the field of remote sensing and geographic information system were retrieved. Then, the modeling and zoning data of fire risk prediction were extracted and analyzed in a descriptive manner. Accordingly, the study was conducted in 1995-2017. Findings: Fuzzy analytic hierarchy process (AHP) zoning method was more practical among the applied methods and the plant moisture stress measurement was the most efficient among the remote sensing indices. Discussion and Conclusion: The findings indicate that RS and GIS are effective tools in the study of fire risk prediction.
In the present study, friction damper, an energy dissipating passive device is explored to reduce the response of open ground storey building under lateral loading due to earthquake. This damper is installed in the selected bays of open ground storey so that the response is reduced. The masonry infill wall is macro-modeled in the form of compression only diagonal members. Three different types of bracing system were installed along with Pall friction damper – single diagonal tension – compression brace with friction damper, tension only cross brace with friction damper and chevron brace with friction damper were modeled using Wen’s plastic link element in SAP2000. G+4 storey buildings were analyzed using nonlinear time history analysis. The storey displacement and inter-storey drift for all the cases were compared in the study.
In this paper silver nanoparticles (NPs) which are synthesized by a simple plasma arc discharge method, that is a kind of electrochemical methods, are examined. The method is very simple and silver NPs are obtained very fast by means of two polished silver plates and electrochemical cell. The effects of changing some terms of the experiment including using Hydrogen peroxide (H2O2), temperature and the medium of experiment on oxygen percent and crystalline structure of silver NPs have been studied by transmission electron microscopy, UV-visible spectrophotometery, and X-ray diffraction. Water medium gets larger nanoparticles with less oxygen content compare to air medium. The size of synthesized nanoparticles become smaller and they also become more spherical by using H2O2 in air medium. In water medium, the size and concentration of the silver crystallite increase by temperature growth and adding H2O2 respectively.
In this study, the influence of sewage sludge ash (SSA) waste particle contents on the mechanical properties and interlaminar fracture toughness for mode I and mode II delamination of S-glass fiber-reinforced epoxy composites was investigated. Composite laminate specimens for tensile, flexural double-cantilever beam (DCB), and end-notched fracture (ENF) tests were prepared and tested according to ASTM standards with 5, 10, 15, and 20 wt% SSA-filled S-glass/epoxy composites. Property improvement reasons were explained based on optical and scanning electron microscopy. The highest improvement in tensile and flexural strength was obtained with a 10 wt% content of SSA. The highest mode I and mode II interlaminar fracture toughness’s were obtained with 15 wt% content of SSA. The mode I and mode II interlaminar fracture toughness improved by 33% and 63.6%, respectively, compared to the composite without SSA.
The effect of isocyanate trimer on the flame retardancy mechanism of polyisocyanurate (PIR) foam was studied in three aspects, including the mechanism of thermal decomposition in the condensed phase, the barrier mechanism of carbon layer formation on the surface in the condensed phase, and the mechanism in the gaseous phase, by using infrared spectroscopy, scanning electron microscopy, thermal analysis, a cone calorimeter, and high-temperature pyrolysis gas chromatography mass spectrometry. The results show that the trimmer can improve the thermal stability of the PIR foam and is not easily decomposed in the combustion. The trimmer can increase the carbon content of the PIR foam to 29.9% of that of the polyurethane (PU) foam. The carbon layer formed is denser, and it can retard heat and oxygen and thus improve the flame retardant properties; trimer can reduce the release of flammable polyol gas, decompose into more carbon dioxide, which is an inert gas, and it has certain flame retardant effects in the gaseous phase.
Investment growth in many emerging market and developing economies (EMDEs) has slowed sharply since 2010. Investment growth performance has varied significantly across different regions, however. This paper examines the evolution of investment growth in six EMDE regions, documents remaining investment needs, especially for infrastructure, and presents a set of region-specific policy responses to address these needs. It reports three main findings. First, investment growth has been particularly weak in EMDE regions hosting a large number of commodity exporters. In regions with a substantial number of commodity-importing economies, investment growth has been somewhat resilient but has also declined steadily since 2010. Second, sizable investment needs remain in most EMDE regions to make room for expanding economic activity and rapid urbanization. A large portion of these investment needs is in infrastructure and human capital. Finally, while specific policy priorities vary across regions, several policy options to address remaining investment needs apply universally. These include more, and more efficient, public investment and measures to improve overall growth prospects and the business climate. Improved project selection and monitoring, as well as better governance, may enhance the efficiency and benefits from public investment.
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