Effects of Thermal Interface Materials on Thermal Conductivity Measurement Using a Modified ASTM D5470 Thermal Resistance Tester

In this paper, we have investigated the effect of thermal interface materials (TIMs) on the accuracy and uncertainty of thermal conductivity measurements. A modified ASTM D5470 thermal resistance tester (TRT) is developed to measure the out-of-plane thermal conductivity of pyrolytic graphite (PG) and grade 2 titanium (TiG2) with and without TIMs. Compared to the ASTM D5470 standard, this modified design uses three thermocouples per side to support regressive analysis and explores the use of TIMs.s Nine PG samples and four TiG2 samples of varying thickness have been tested to obtain thermal resistance as a function of sample thickness. The steady-state temperature profiles were used for heat flux and thermal resistance calculation. The results reveal that TIMs significantly reduce measurement uncertainty for both samples, i.e., 42.85% for TiG2 and 48.81% for PG. The effect of TIMs on the measurement accuracy diverges, with a far more pronounced effect on TiG2 than PG. This is owing to the higher out-of-plane thermal conductivity of TiG2 (~ 17 W/mK) than PG (~ 2 W/mK). For materials with higher thermal conductivity, the percentage of the contact resistance between the sample and sample holder in the total resistance is very high. Thus, good control of the contact resistance by using TIMs is helpful in improving the measurement accuracy. For lower conductivity materials, the weight of contact resistance is lower and the effect of TIMs is thus less pronounced

Effects of Thermal Interface Materials on Thermal Conductivity Measurement Using a Modified ASTM D5470 Thermal Resistance Tester

In this paper, we have investigated the effect of thermal interface materials (TIMs) on the accuracy and uncertainty of thermal conductivity measurements. A modified ASTM D5470 thermal resistance tester (TRT) is developed to measure the out-of-plane thermal conductivity of pyrolytic graphite (PG) and grade 2 titanium (TiG2) with and without TIMs. Compared to the ASTM D5470 standard, this modified design uses three thermocouples per side to support regressive analysis and explores the use of TIMs.s Nine PG samples and four TiG2 samples of varying thickness have been tested to obtain thermal resistance as a function of sample thickness. The steady-state temperature profiles were used for heat flux and thermal resistance calculation. The results reveal that TIMs significantly reduce measurement uncertainty for both samples, i.e., 42.85% for TiG2 and 48.81% for PG. The effect of TIMs on the measurement accuracy diverges, with a far more pronounced effect on TiG2 than PG. This is owing to the higher out-of-plane thermal conductivity of TiG2 (~ 17 W/mK) than PG (~ 2 W/mK). For materials with higher thermal conductivity, the percentage of the contact resistance between the sample and sample holder in the total resistance is very high. Thus, good control of the contact resistance by using TIMs is helpful in improving the measurement accuracy. For lower conductivity materials, the weight of contact resistance is lower and the effect of TIMs is thus less pronounced

Femto-photography: capturing and visualizing the propagation of light

We present femto-photography, a novel imaging technique to capture and visualize the propagation of light. With an effective exposure time of 1.85 picoseconds (ps) per frame, we reconstruct movies of ultrafast events at an equivalent resolution of about one half trillion frames per second. Because cameras with this shutter speed do not exist, we re-purpose modern imaging hardware to record an ensemble average of repeatable events that are synchronized to a streak sensor, in which the time of arrival of light from the scene is coded in one of the sensor's spatial dimensions. We introduce reconstruction methods that allow us to visualize the propagation of femtosecond light pulses through macroscopic scenes; at such fast resolution, we must consider the notion of time-unwarping between the camera's and the world's space-time coordinate systems to take into account effects associated with the finite speed of light. We apply our femto-photography technique to visualizations of very different scenes, which allow us to observe the rich dynamics of time-resolved light transport effects, including scattering, specular reflections, diffuse interreflections, diffraction, caustics, and subsurface scattering. Our work has potential applications in artistic, educational, and scientific visualizations; industrial imaging to analyze material properties; and medical imaging to reconstruct subsurface elements. In addition, our time-resolved technique may motivate new forms of computational photography.MIT Media Lab ConsortiumLincoln LaboratoryMassachusetts Institute of Technology. Institute for Soldier NanotechnologiesAlfred P. Sloan Foundation (Research Fellowship)United States. Defense Advanced Research Projects Agency (Young Faculty Award

Primary Pleomorphic Adenoma of Minor Salivary Gland in the Parapharyngeal Space

ABSTRACTParapharyngeal space (PPS) lesions account for only 0.5% head and neck tumors and the majority of the minor salivary gland tumors are malignant. We report a case of pleomorphic adenoma of minor salivary gland in PPS as this is of a very rare occurrence. High index of suspicion and an adequate clearance of the tumor with a cuff of surrounding dispensable normal tissues are the key to successful treatment of such tumors.How to cite this articleRay CS, Joshi A. Primary Pleomorphic Adenoma of Minor Salivary Gland in the Parapharyngeal Space. Int J Otorhinolaryngol Clin 2016;8(3):125-127.</jats:sec

Disseminated Cutaneous Rhinosporidiosis: A Rare Case Report

ABSTRACTRhinosporidiosis is a chronic granulomatous disorder caused byRhinosporidium seeberi. It usually presents as a soft polypoidal pedunculated or sessile mass. Nose and nasopharynx are the commonly affected sites, but other sites, such as conjunctiva, the lips, palate, uvula, maxillary antrum, epiglottis, larynx, trachea, bronchus, ear, scalp, vulva, vagina, penis, and rectum, have been reported. However, cutaneous manifestation is rare. We report such a case of a 50-year-old male patient from rural south Odisha presenting to the ENT Department of SCB Medical College and Hospital, Cuttack, with multiple granulomatous growths of different sizes all over the body, along with a nasal mass, of 2½-year duration. He also gives history of a surgery on his nose 3 year back. Histopathology of the excised cutaneous and nasal lesions confirmed our diagnosis as rhinosporidiosis. On the basis of these clinical and histopathological findings, a diagnosis of nasal rhinosporidiosis with disseminated cutaneous spread was made.How to cite this articleRay CS, Joshi A, Khatua RK. Disseminated Cutaneous Rhinosporidiosis: A Rare Case Report. Int J Otorhinolaryngol Clin 2016;8(2):72-74.</jats:sec

First Hexa-Combo Logging-While-Drilling Run in Kuwait: A Case Study

Directional wells through the 6-in. production-hole sections in the Marrat Reservoir of the Jurassic formations have traditionally required several wireline-logging and hole-conditioning runs for comprehensive petrophysical interpretation and completion design. As the planned well inclinations increase to maximize reservoir exposure and sweep efficiency, wireline deployment poses significant challenges due to the increased risk of losing the bottomhole assembly (BHA) in the hole. Over time, logging-while-drilling (LWD) tools have become preferable for the asset team, where the tools are run either in the drilling BHA or during a dedicated wiper trip after the section has been drilled to total depth (TD). Using LWD tools in this application also reduces well delivery times and costs. A comprehensive logging solution was required to drill the 6-in. reservoir section of a study well. The complex LWD string, consisting of gamma ray, resistivity, neutron porosity, azimuthal density, azimuthal sonic, and nuclear magnetic resonance (NMR) tools, was deployed on a motorized rotary steerable system (MRSS) BHA. In addition, a prototype high-resolution acoustic imaging and caliper tool, designed to be run in both water-based mud (WBM) and oil-based mud (OBM), was also included. The acquired logging data were used for enhanced formation evaluation. Fracture and borehole breakout interpretation from the image data played a key role in the successful completion design. This ultimately led to Kuwait’s first successful “hexa-combo” LWD drilling run and the country’s first LWD ultrasonic imaging tool run in OBM in this hole size, with 13.3 ppg OBM with a maximum downhole temperature of 275°F.</jats:p