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Work In The Sea
Published in Robert A. Ragotzkie, J. Robert Moore, Man and the Marine Environment, 2018
Where it is feasible to build them, pipelines afford the best means of moving crude oil. These are connected to the separator complex and pumping facility and are laid on the sea floor following the most feasible route. As it is laid the steel pipe is coated first with a polymer or tar based “dope” and then encased in a reinforced concrete protective shell two or three inches thick. The pipe may or may not be buried, depending mostly on whether the area is used for bottom fishing and how much influence the fisherman have. Burying adds to the expense of building and sometimes of maintaining a pipeline but it considerably reduces the chances of damage.
Recent Progress on High Temperature and High Pressure Heat Exchangers for Supercritical CO2 Power Generation and Conversion Systems
Published in Heat Transfer Engineering, 2023
Investment casting produces patterns using rapid prototyping processes rather than molded wax. The pattern is encased in refractory material, and then burned out to form a mold cavity in the shape of the pattern, and then the mold cavity is filled with molten metal to create the metal part with the similar geometric shapes and size of the patterns [72, 73]. The mold surface can have low roughness and the refractory material can offer ample refractory strength and chemical inertness. The technique can make metal components with complex geometry and accurate dimensions, compared to those manufactured with sand casting. Tolerances as low as 76 μm have been claimed and metal components with sections as narrow as 0.4 mm have been manufactured [74, 75]. The technique can also make metal parts from various metal alloys including carbon and low alloy steels, stainless steels, tool steels, nickel and cobalt alloys, and aluminum and copper alloys, [76]. It has been used for the production of quality components for many applications in the aerospace, power generation, automotive, gas and oil, and energy industries [74, 77].
Characterization of Fly Ash Cenosphere – Capric acid composite as phase change material for thermal energy storage in buildings
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2022
Sivasubramani Perumal Arulselvan, Srisanthi Vellalapalayam Gurusamy
Incorporation of Phase Change Materials (PCM) into construction materials is an upcoming technique to improve the energy efficiency of the building by reducing the fluctuation of indoor temperature in order to enhance thermal comfort (Mahdaoui et al. 2021; Srinivasaraonaik et al. 2021). PCM possess the unique property of latent heat storage and latent heat release. When the environmental temperature rises, PCM undergoes a transition of its phase from solid to liquid, absorbing heat energy. Analogically when the surrounding temperature lowers, PCM solidifies back, releasing the absorbed heat energy (Abhat 1983). Among various classes of PCM, fatty acids exhibit excellent thermal and physical properties, suitable for application in buildings as thermal energy storage (TES) material and furthermore, it is easily obtainable (Sari and Kaygusuz 2002). Capric Acid is a PCM classified under organic fatty acid. It has a transition temperature ranging from 29°C to 33°C, which is close to the thermal comfort range of 20°C to 28°C (Pasupathy, Velraj, and Seeniraj 2008), and is innocuous, making it ideal for improving the thermal performance of a structure (Saikia, Azad, and Rakshit 2018). PCM leakage in a liquid state can damage the properties of building materials (Xu et al. 2022). Therefore, PCMs have been encased and stabilized using techniques such as micro-encapsulation, nano-encapsulation, macro-encapsulation, and form stabilization (Su, Darkwa, and Kokogiannakis 2015). Some of the studies on capric acid composite PCM are explored more below.
Pyrolytic Carbon Coating Effects on Oxide and Carbide Kernels Intended for Nuclear Fuel Applications
Published in Nuclear Technology, 2020
Miles F. Beaux, Douglas R. Vodnik, Reuben J. Peterson, Bryan L. Bennett, Kevin M. Hubbard, Brian M. Patterson, Jeffrey D. Goettee, James D. Jurney, Graham M. King, Alice I. Smith, Eric L. Tegtmeier, Erik P. Luther, Venkateswara R. Dasari, David J. Devlin, Igor O. Usov
Due to the challenges of working with radiological materials, a variety of nonuranium surrogate oxide and carbide kernel materials were utilized in this study in addition to uranium carbide kernels. Specifically, yttria-stabilized zirconia (YSZ) kernels were purchased from Microspheres-Nanospheres (a Corpuscular company, Cold Springs, New York), hafnia kernels were purchased from BRACE GmbH (Karlstein, Germany), tungsten carbide kernels were supplied by Tekna (Sherbrooke, Québec, Canada), and uranium carbide kernels were purchased from General Atomics (San Diego, California). Scanning electron microscopy (SEM) was performed on intact kernels prior to PyC coating as well as cross sections of polished kernels encased in epoxy to determine the mean diameters and quality (i.e., sphericity and porosity) of kernels (Fig. 2). SEM images were collected using a Thermo Fischer Inspect F field emission gun SEM (FEGSEM) and a Thermo Fischer Apreo FEGSEM (Waltham, Massachusetts). A Zygo NewView 7300 optical profilometer (Zygo Corporation, Middlefield, Connecticut) was also utilized to measure the root-mean-square (rms) roughness of the nonradiological kernels by imaging a 70 × 50-µm area on top of the kernels and subtracting a spherical background from the surface image. X-ray powder diffraction (XRD) patterns were collected using Cu Kα radiation (λ = 1.5406 Å) on either a Rigaku Ultima III or Scintag XDS 2000 diffractometer at ambient conditions.43,44 Each one of these XRD measurements was collected from several hundred kernels, such that any variation among individual kernels would be averaged out in the final XRD patterns. Rietveld refinements were carried out on these patterns using the GSAS program suite.45 Characterization results for mean kernel diameters, surface roughness, composition, and crystallographic phase are given in Table I.