Search

This article from Architectural Record discusses the importance of fenestration systems in creating effective barriers for buildings. Building science has advanced to the point where manufacturers offer a range of exterior barrier products that can meet specific performance needs, such as limiting airflow, resisting water, and controlling thermal properties. Fenestration systems, including entrances and movable glass walls, can play a crucial role in meeting these barrier objectives when specified correctly. The choice of which products to use is determined by the architect or designer of a project. The article also provides learning objectives for readers, including recognizing the safety and performance characteristics of fenestration systems and assessing their contributions to green and sustainable design. [Extracted from the article]

In collaboration with Isao Noda, I have been using Raman spectroscopy to study the properties of the bioplastic polyhydroxybutyrate hexanoate (PHBHx), which depend on the percentage of hexanoate (which produces propyl side branches to the polymer chain). The percentages of hexanoate determine the maximum crystallinity that the polymer can experience, and that determines its physical and chemical properties, which include its optical clarity, dyability, flexibility, and thermal properties (melting and glass transition temperature). It is useful to have an easy way to determine the composition; in this column, we describe how Raman spectroscopy was used to show that this is feasible at an accuracy greater than expected. [ABSTRACT FROM AUTHOR]

The article discusses a regression model developed by researchers at Seco Tools AB to predict the thermal properties of cemented carbides, emphasizing reliable and easily measurable material characteristics such as chemical composition and coercivity.

Metal-organic frameworks (MOFs) are self-assembled combinations of metals and inorganic ligands that result in a relatively young class of highly ordered, porous materials. Because of the number of structural and chemical possibilities, high surface area, controlled pore volume, and favorable thermal properties, MOFs are being investigated in several fields, including chromatography. Because of the enormous interest in a 2018 "Column Watch" article on the subject and the high level of research in the field, this article explores recent (2019-present) activity specifically toward the application of MOFs for liquid chromatography (LC). [ABSTRACT FROM AUTHOR]

The article explores the history of castable refractory development, highlighting the improvements in refractories. These improvements include alumina-chromia refractory development, addition of zirconia for thermal shock resistance, and steel ladle refractories. Topics include the breakthroughs in castable development from 1950 to 1960, the accelerated progress in castable development through 1985, and research and development in the 1990s.

The article focuses on the ensilication technology which helps the storage and transportation of life-saving vaccines without refrigeration. Topics discussed include lack of public health protection system due to issues of vaccine availability and distribution in under developed countries, disarding of vaccines due to refrigeration failure, and challenges of determining the proper scale and bridging the social and communication gaps between chemists.

The article examines the connection capabilities of the three variable refrigerant flow (VRF) manufacturers and the magnitude of difference in their controls platforms. Topics discussed include the building management system (BMS) and buiilding automation system (BAS), the standard connection of packaged equipment, and the technological innovation on the VRF system.

The article discusses how the thermal properties of cermet fuel may be used in future nuclear thermal propulsion (NTP) systems. It states that researchers from Missouri University of Science and Technology and NASA Marshall Space Flight Center, Alabama, including the American Ceramic Society archives (ACerS) Fellows Bill Fahrenholtz and Greg Hilmas, used a surrogate material to explore the thermal properties of a cermet fuel.

Raman spectroscopy can be used to determine the temperature of a material when other more direct means are either impractical or not possible. The material's temperature can affect the peak position of Raman bands. When a Raman band shifts significantly with temperature, the monitoring of the peak position can be the most straightforward manner of determining temperature provided the Raman spectrometer has sufficient spectral resolution. Another method is to determine the temperature from the ratio of the Stokes and anti-Stokes signal strengths of a given Raman band. The latter method requires the ability to detect light at wavelengths longer and shorter than that of the laser and an accurate measurement of the wavelength-dependent instrument response function. [ABSTRACT FROM AUTHOR]

The article discusses the review of the U.S. Chemical Safety Board (CSB) report regarding the fire incident at Tesoro refinery in Anacortes, Washington on April 2, 2010. Topics mentioned include the rupture of the heat exchanger shell in the naphtha hydrotreating unit that caused the fire, the highlight on the difficulties of detecting high temperature hydrogen attack (HTHA), and the lack of the understanding on the operation of the commercial hydrotreating unit.

The article discusses how aluminum nitride coatings enhances thermal performance of light-emitting diode arrays. It mentions the technique of electrostatic spraying in this respect. It also mentions thermal conductance of the aluminum nitride crystal structure. It also mentions that commercial heat sink exhibited luminous flux.

The article presents a case study wherein a crude vacuum tower overhead system's troubleshoot operation was corrected. The system comprises of 12 steam ejectors and 12 condensers. The vacuum tower pressure became unstable due to the onset of summer and higher cooling water temperature. The importance of offgas analysis, the need to analyze both ejectors and condensers to identify the source of the malfunction, and the impact of motive steam conditions on vacuum column operation are discussed.

The article reports that heat transfer compound (HTC) is a viscous mastic designed to fill small air gaps between the tracing element and the object to be heated and is effective at transferring heat than static air, but it has relatively poor thermal conductivity compared to the other components in a steam tracing system. It mentions information on high-performance steam tracing technologies were tested which includes fluid tracing system (FTS) and carbon steel tracing (CST).

The article focuses on the importance of coatings to protect gas turbines from extreme heat. Ramesh Subramanian of Siemens Energy advises power plants to always reduce the thermal conductivity of coating materials. Another challenge facing plants is that different parts of gas turbines require different coating materials that need different application processes. Plants need to ensure that the coating system they select can expand and contract to avoid it from cracking or falling off.

The article discusses the importance of drying hygroscopic resins to prevent possible loss of essential performance properties of polymers. It offers tips on how to determine the dryness of a resin before processing. It also provides information on resins that do not need drying and some polymers that are not susceptible to hydrolysis but may need drying.

The article discusses the components of a printed circuit board (PCB) materials. It states that the materials are insulators that provide electrical isolation between transmission lines, components, and semiconductor devices. It mentions that the thermal properties of PCB defines the limit of the power-handling capabilities.

The article discusses the semiconductor devices that operate at high junction temperatures for long period and its impact on the operating performance. It cites that designers should understand the thermal properties of a printed circuit board (PCB) design for a given Monolithic Microwave Integrated Circuit (MMIC) device to minimize thermal resistance and temperature rise. It also discusses the method for computing thermal resistance between a MMIC amplifier and the ambient environment.

The article focuses on the analog sensors developed by instrument companies Analog Devices Inc. and Texas Instruments based on the different of two transistors operated with different densities. It provides the formula and equation of the sensors and discusses their interesting refinement. It also mentions the refinement of the analog and digital sensors to perform and support accurate wide-range temperature sensing.

The article discusses factors that should be considered for selection of ceramics and steel bearings. It states the differences between ceramics and metal bearings along with advantages and disadvantages, load resistance, and surface finish. Also mentioned the mechanical and thermal properties of ceramics, the importance of lubrication for steel bearings, and costs of manufacturing steel bearings.

The article reports on the move of the U.S. Joint Space Operations Center to track debris after the explosion of weather satellite launched by the Air Force in 1995. The Air Force Space Command officials say that the incident occurred after operators of the National Oceanic and Atmospheric Administration detected a thermal spike in the satellite. According to the Air Force Space Command, a decision was made of rendering the vehicle safe after a spike in temperature found by satellite operators.

The article reports on how power amplifiers have now become feasible with gallium-nitride (GaN) technology because of its thermal behavior.