We demonstrate an efficient and versatile spectral microthermography technique for identifying hot and cold spots in the active layer of a biased integrated circuit. Hot (cold) spots are regions where heat accumulates more rapidly (slowly) than the average rate of the entire active layer. Knowledge of the hot and cold spot locations is crucial in assessing the thermal integrity of a layer structure because hot spots are locations were defects are more likely to develop. The active layer is uniformly illuminated with light from a tungsten lamp and its reflectance image r(x, y) is scanned across (x-direction) the entrance slit of a grating-prism pair (GRISM) spectrometer to produce a spectral map R(lambda; x, y) where lambda is the wavelength [450 = lambda (nm) = 650]. For a particular slit position x = x(1), the GRISM spectrometer outputs a one-dimensional spectral map R (lambda; x(1), y). A pair of maps R(ub) (lambda; x, y) and R(b)(lambda; x, y) are obtained from the active layer in the absence and presence of voltage bias, respectively. A reflectance gradient map R(lambda; x, y) = R(b)(lambda; x, y) - R(ub)(lambda; x, y), is derived and used to locate possible hot and cold spots because R(lambda; x, y) is proportional to the temperature gradient T(lambda; x, y). We use the technique to generate gradient maps of a photodiode array and the emitting surface of a biased light emitting diode. Two different semiconductor materials could be distinguished easily from their dissimilar reflectance spectra.
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http://dx.doi.org/10.1364/oe.14.001021 | DOI Listing |
Gut Liver
January 2025
Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Background/aims: We investigated the clinical practice patterns of Korean endoscopists for the endoscopic resection of colorectal polyps.
Methods: From September to November 2021, an online survey was conducted regarding the preferred resection methods for colorectal polyps, and responses were compared with the international guidelines.
Results: Among 246 respondents, those with <4 years, 4-9 years, and ≥10 years of experience in colonoscopy practices accounted for 25.
Sci Rep
January 2025
Department of Health Informatics, Institute of Public Health, College of Medicine & Health Sciences, University of Gondar, Gondar, Ethiopia.
United Nations is standing for Sustainable Development Goal (SDG) 6 sets the agenda to address worldwide inequality in accessing safe water and improved sanitation facilities for all by 2030. However, governments in Africa seem unable to address the issue water and of sanitation facilities, since there are problems like increasing costs of sustaining existing water sources and the requirement to deliver new facilities ahead of time. Hence, this study aimed to investigate unimproved water sources and sanitation facilities geographical variation in Ethiopia using EDHS 2019 datasets.
View Article and Find Full Text PDFActa Gastroenterol Belg
January 2025
Department of Gastroenterology and Hepatology, Ghent University Hospital, Ghent, Belgium.
Colorectal cancer (CRC) is the second and third leading cause of cancer death in men and women respectively worldwide. Colonoscopy is the gold standard screening test to detect premalignant lesions with endoscopic polypectomy preventing evolution to CRC. Endoscopic polypectomy is effective with a higher safety profile and is less costly as compared to surgery.
View Article and Find Full Text PDFEnviron Int
December 2024
School of the Environment, Yale University, 195 Prospect St, New Haven, CT 06511, USA; Interdisciplinary Program in Precision Public Health, Department of Public Health Sciences, Graduate School of Korea University, Seoul, 145 Anam-ro, Anam-dong 3-ga, Seongbuk-gu, Seoul 02841, South Korea.
Biological and psychological theories suggest complex impacts of heat on aggression and violence. Most previous studies considered temporal intervals of months to years and assumed linear associations. Evidence is needed on daily impacts of temperature on crime, applying non-linear models across different locations.
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December 2024
School of Safety Engineering, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China.
Hot dry rock (HDR) is a novel green, low-carbon energy. Its development requires the creation of fracture channels in deep thermal reservoirs. Traditional methods such as hydraulic fracturing have limited effectiveness in reservoir stimulation, so a method of liquid nitrogen cold shock was proposed.
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