Paved Paradise: Belowground Parking Structures Sustain Urban Mosquito Populations in Washington, DC

ABSTRACT After notification of mosquitoes within federal buildings in Washington, DC, we surveyed belowground levels of nearby parking structures for mosquitoes and standing water in the summer months of 2018 and 2019. Aedes aegypti, Ae. albopictus, and members of the Culex pipiens Assemblage were found. Genotyping revealed pipiens, molestus, and quinquefasciatus ancestry among Cx. pipiens Assemblage mosquitoes, and allele frequency comparisons indicated a stable, resident population. Winter and spring aboveground temperatures ranged from −11°C to 35°C, while belowground temperatures never dropped below 5°C or exceeded 30°C, and winter temperatures were significantly higher belowground compared with aboveground. Moderated winter conditions suggest that belowground urban structures could act as refugia for warmer-climate species, like Ae. aegypti and Cx. quinquefasciatus, allowing them to overcome assumed thermal barriers. Surveys of parking structures should be incorporated into integrated vector management programs in urban areas.

Jetfire lab: Jetfire at reduced scale

This article addresses the development of a bench-scale test (jetfire lab) mimicking the fire exposure of the large-scale jetfire facility. An experimental approach was addressed to develop direct correlation and to validate the similitude between bench-scale test and large-scale jetfire. Comparisons were made by testing Zaltex passive fire protection material in the form of panels. Novel setups were designed to make the jetfire lab able to measure time/temperature curves similar to those obtained at a large scale. The assembly of the tested samples was also investigated. An experimental protocol was elaborated to consider the junction between parts of the sample at the reduced scale. Direct correlation was found between the large and the bench scale and it was evidenced that jetfire lab can be used for preliminary study and development of new thermal barriers for fire protection.

Mechanical Properties of MAX Phases

MAX Phase Materials are uniquely structured carbide and nitride materials which combine the rigidity, oxidation-resistance and high-temperature strength of ceramic materials with such metallic properties as good machinability, thermal-shock resistance, damage-tolerance and good transport properties. Potential applications include microelectronic layers, coatings for electrical contacts, thermal shock-resistant refractories, high-temperature heating elements, neutron-irradiation resistant nuclear applications, thermal barriers, protective aerospace coatings, and bio-compatible materials. The book reviews theoretical and experimental research up to early 2021 and references 185 original resources with their direct web links for in-depth reading.

Influence of SiC Addition on Mechanical Behavior of Thermal Barriers with the Aid of Acoustic Emission

The improvement of high temperature materials with lower heat transfer coefficients lead to the development of thermal barrier coatings (TBCs). One of the most widely used materials for thermal barrier coatings is Y2O3 stabilized ZrO2 (Y-TZP) because of its excellent shock resistance, low thermal conductivity, and relatively high coefficient of thermal expansion. The aim of this work is to study the TBCs mechanical behavior with the addition of SiC into the suspension of Y-TZP/Al2O3 by acoustic emission (AE). Additionally, a microstructural analysis and a finite elements model were carried out in order to compare results. The coatings were made by suspension plasma spray (SPS) on metal plates of 70 × 12 × 2 mm3. An intermetallic was deposited as a bond coating, followed by a coating of Y-TZP/Al2O3 with and without 15 wt.% SiC, with thicknesses between 87 and 161 μm. The AE becomes a fundamental tool in the study of the mechanical behavior of thermal barriers. The use of wavelet transforms streamlines the study and analysis of recorded sound spectra. The crack generation arises at very low stress levels.

Principles and Applications of Thermal Spray Coatings

The goal of the chapter is to address the fundamental theory of thermal spraying and its modern industrial applications, in particular, those involving flame spray, HVOF, plasma spray, and cold spray processes. During the last 30 years, thousands of manuscripts and various book chapters have been published in the field of thermal spray, displaying the evolution of thermally sprayed coatings in many industrial applications. Thermal spray coatings are currently interesting for different modern applications including prosthesis, thermal barriers, electrochemical catalysis, electrochemical energy conversion devices, biofouling, and self-repairing surfaces. The chapter will explain the fundamental principles of the aforementioned thermal spraying processes and discuss the effect of different controlling parameters on the final properties of the produced coatings. This chapter will also explore current and future industrial applications of thermal spray coatings.