Publications by authors named "A K Ould Amar"
Background: Centrifugal compressors are dynamic machines utilizing a rotating impeller, efficiently accelerate incoming gases, transforming kinetic energy into pressure energy for compression. They serve a wide range of industries, including air conditioning, refrigeration, gas turbines, industrial processes, and applications such as air compression, gas transportation, and petrochemicals, demonstrating their versatility. Designing a centrifugal compressor poses challenges related to achieving high aerodynamic efficiency, surge and choke control, material selection, rotor dynamics, cavitation, erosion, and addressing environmental considerations while balancing costs.
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- The study investigates the causes of plumage color variations in black sparrowhawks, focusing on the role of specific genes related to melanin production.
- It finds that adult color differences are linked to how eumelanin is distributed in their feathers, with no significant mutations in key genes (MC1R, ASIP) discovered for adult color morphs.
- For juvenile plumage, variations are attributed to levels of eumelanin and pheomelanin, showcasing a complex relationship with ASIP expression that challenges existing theories on how melanin types are produced.
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- The study examined how specific genetic variations (SNPs) in the CD44 gene affect its protein expression and influence the risk of head and neck squamous cell carcinoma (HNSCC).
- It involved comparing genetic and protein expression data from 85 HNSCC patients and 85 healthy controls, using techniques like immunohistochemistry and DNA sequencing.
- Results showed that the SNP rs13347 was significantly linked to a higher risk of HNSCC, particularly in individuals with the TT genotype, while no connection was found for the SNP rs187115.
Ortner's syndrome or cardiovocal syndrome is a rare condition referring to laryngeal recurrent nerve paralysis due to cardiovascular conditions. We report the case of a 66-year-old man, with a medical history of active smoking, who complained of hoarseness of voice secondary to vocal cord palsy. A neck and thoracic CT scan revealed severe enlargement of pulmonary main artery, which caused compression of the left recurrent laryngeal nerve in the aortopulmonary window The prolonged course of the left laryngeal nerve makes it susceptible to injury from cardiovascular structures in the mediastinum.
View Article and Find Full Text PDFSpectroradiometry, radiometry, and dosimetry are employed for the measurement of ultraviolet radiation (UVR) irradiance and non-ionizing exposure. Different types of UVR dosimeter have been developed for measuring personal and environmental UVR exposures since film dosimetry was pioneered in the 1970s. An important type of dosimeter is the thin film variant, which contains materials that undergo changes in optical absorbance when exposed to UVR.
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