Stabilizing High Expansion Foam Using Zirconium Phosphate

Natural gas has been a fast developing industry for its advantages over other energy sources such as coal. Natural gas is usually stored as Liquefied Natural Gas (LNG). In the case of a leak of LNG, a potential risk for a fire hazard, a cryogenic vapor cloud, that is at a higher density than air, forms that travels downwind near ground level and could ignite upon contact with an ignition source. As a recommendation from The National Fire Protection Agency (NFPA) as well as the American Gas Association (AGA), high expansion foam is used to diminish the risk due to this vapor cloud by forming a “blanket” over the leaked LNG. This project intends to study the role of Zirconium Phosphate (ZrP) nanoplates in stabilizing high expansion foam. Experiments were performed with and without ZrP nanoplates to investigate nanoplate stabilization effects on foam stability. Experiments were also carried out in the presence of a cryogenic liquid (Liquid Nitrogen) spill along with the ZrP stabilized foam to examine ZrP effectiveness in mitigating the LNG vapor risk. Forced convection and thermal radiation were found to have significant effects on foam breakage. Adding the ZrP greatly enhanced the foams stabilization effect in reducing the foam breakage rate under forced convection and radiation. On the other hand, ZrP nanoplates have also reduced the liquid drainage rate under forced convection and thermal radiation which would, in turn, allow for extended time to transfer heat from the foam to as they make their way upwards through the foam layers; hence, a lower boil-off effect reducing the fire hazard of the leaked LNG

Modeling the blanketing and warming effect of high expansion foam used for LNG vapor risk mitigation

PresentationNatural Gas is a cleaner energy when compared to other sources like oil or coal. Its consumption has been drastically increasing over the past few years and is projected to increase further. Liquefying natural gas is an effective way of easily storing and transporting it because of the high ratio of liquid to vapor densities. However, a leak of liquefied natural gas (LNG) can result in the formation of a huge vapor cloud, which poses a potential risk. This cryogenic vapor cloud has the potential to ignite and can migrate downwind near ground level because of a density greater than air. NFPA recommends the use of high expansion foam to mitigate the vapor hazard due to LNG. The primary objective of this paper is to study the effects of heat transfer mechanisms like convection and radiation on foam breakage to be able to accurately quantify the amount of foam required to mitigate the vapor risk of LNG spills

Micromechanical Properties of Injection-Molded Starch–Wood Particle Composites

The micromechanical properties of injection molded starch–wood particle composites were investigated as a function of particle content and humidity conditions. The composite materials were characterized by scanning electron microscopy and X-ray diffraction methods. The microhardness of the composites was shown to increase notably with the concentration of the wood particles. In addition,creep behavior under the indenter and temperature dependence were evaluated in terms of the independent contribution of the starch matrix and the wood microparticles to the hardness value. The influence of drying time on the density and weight uptake of the injection-molded composites was highlighted. The results revealed the role of the mechanism of water evaporation, showing that the dependence of water uptake and temperature was greater for the starch–wood composites than for the pure starch sample. Experiments performed during the drying process at 70°C indicated that the wood in the starch composites did not prevent water loss from the samples.Peer reviewe

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

An experimental and analytical investigation of reinforced concrete beam-column joints strengthened with a range of CFRP schemes applied only to the beam

This paper investigates the experimental and analytical behaviour of beam-column joints that are subjected to a combination of torque, flexural and direct shear forces, where different Carbon Fibre Polymer (CFRP) strengthening wraps have been applied only to the beam. These wrapping schemes have previously been determined by the research community as an effective method of enhancing the torsional capacities of simply supported reinforced concrete beams. In this investigation, four 3/4-scale exterior beam-column joints were subjected to combined monotonic loading; three different beam wrapping schemes were employed to strengthen the beam region of the joint. The paper suggests a series of rational formulae, based on the space truss mechanism, which can be used to evaluate the joint shear demand of the beams wrapped in these various ways. Further, an iterative model, based on the average stress-strain method, has been introduced to predict joint strength. The proposed analytical approaches show good agreement with the experimental results. The experimental outcomes along with the adopted analytical methods reflect the consistent influence of the wrapping ratio, the interaction between the combined forces, the concrete strut capacity and the fibre orientation on the joint forces, the failure mode and the distortion levels. A large rise in the strut force resulting from shear stresses generated from this combination of forces is demonstrated and leads to a sudden-brittle failure. Likewise, increases in the beams’ main steel rebar strains are identified at the column face, again influenced by the load interactions and the wrapping systems used

Barbarians at the British Museum: Anglo-Saxon Art, Race and Religion

A critical historiographical overview of art historical approaches to early medieval material culture, with a focus on the British Museum collections and their connections to religion

The effect of moisture, depth of planting, and compaction on seedling emergence of winterfat and crested wheatgrass

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Stabilizing High Expansion Foam Using Zirconium Phosphate

Natural gas has been a fast developing industry for its advantages over other energy sources such as coal. Natural gas is usually stored as Liquefied Natural Gas (LNG). In the case of a leak of LNG, a potential risk for a fire hazard, a cryogenic vapor cloud, that is at a higher density than air, forms that travels downwind near ground level and could ignite upon contact with an ignition source. As a recommendation from The National Fire Protection Agency (NFPA) as well as the American Gas Association (AGA), high expansion foam is used to diminish the risk due to this vapor cloud by forming a “blanket” over the leaked LNG. This project intends to study the role of Zirconium Phosphate (ZrP) nanoplates in stabilizing high expansion foam. Experiments were performed with and without ZrP nanoplates to investigate nanoplate stabilization effects on foam stability. Experiments were also carried out in the presence of a cryogenic liquid (Liquid Nitrogen) spill along with the ZrP stabilized foam to examine ZrP effectiveness in mitigating the LNG vapor risk. Forced convection and thermal radiation were found to have significant effects on foam breakage. Adding the ZrP greatly enhanced the foams stabilization effect in reducing the foam breakage rate under forced convection and radiation. On the other hand, ZrP nanoplates have also reduced the liquid drainage rate under forced convection and thermal radiation which would, in turn, allow for extended time to transfer heat from the foam to as they make their way upwards through the foam layers; hence, a lower boil-off effect reducing the fire hazard of the leaked LNG