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International Journal of Astronomy and Astrophysics 2016年第4期6卷 393-409页

作者： Alexandre S. Shcherbakov Miguel Chavez Dagostino adan omar arellanes Eduardo Tepichin National Institute for Astrophysics Optics and Electronics Puebla Mexico

We present an advanced schematic arrangement of the radio-wave spectrometer with a few parallel optical arms for processing the data flow. This arrangement includes two principal novelties. First of them consists in the proposed design, where each individual optical arm exhibits its original performances providing parallel multi-band observations within a few different scales simultaneously. These optical arms have the beam shapers providing both the needed incident light polarization and apodization to increase the dynamic range. After parallel acousto-optical processing, data flows of all the optical arms are united by the joint CCD matrix on the stage of the combined electronic data processing. The second novelty is in usage of unique wide-aperture bastron-based acousto-optical cell providing one of the best performances at the middle-frequencies (about 500 MHz) in comparison with the other available crystalline materials in this range. Such multi-band capabilities have a number of applications in astrophysical scenarios at different scales: from objects in the distant universe to planetary atmospheres in the Solar system. Thus one yields the united versatile instrument, which provides comprehensive studies of astrophysical objects simultaneously with precise synchronization in various frequency ranges.

关键词： Precise Acousto-Optical Spectrum Analysis Frequency Bandwidth and Resolution Wide-Aperture Crystalline Cell Astronomical Instrumentation

High-Resolution Broadband Millimeter-Wave Astrophysical Spectrometer with Triple Product Acousto-Optical Processor

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International Journal of Astronomy and Astrophysics 2013年第4期3卷 421-430页

作者： Miguel Chavez Dagostino Alexandre S. Shcherbakov adan omar arellanes Vahram Chavushyan National Institute for Astrophysics Optics & Electronics (INAOE) Puebla Mexico

An advanced conceptual design of a high-bit-rate triple product acousto-optical processor is presented that can be applied in a number of astrophysical problems. We briefly describe the Large Millimeter Telescope as one of the potential observational infrastructures where the acousto-optical spectrometer can be successfully used. A summary on the study of molecular gas in relatively old (age > 10 Myr) disks around main sequence stars is provided. We have identified this as one of the science cases in which the proposed processor can have a big impact. Then we put forward triple product acousto-optical processor is able to realize algorithm of the space-and-time integrating, which is desirable for a wideband spectrum analysis of radio-wave signals with an improved resolution providing the resolution power of about 105 - 106. It includes 1D-acousto-optic cells as the input devices for a 2D-optical data processing. The importance of this algorithm is based on exploiting the chirp Z-transform technique providing a 2D-Fourier transform of the input signals. The system produces the folded spectrum, accumulating advantages of both space and time integrating. Its frequency bandwidth is practically equal to the bandwidth of transducers inherent in acousto-optical cells. Then, similar processor is able to provide really high frequency resolution, which is practically equal to the reciprocal of the CCD-matrix photo-detector integration time. Here, the current state of developing the triple product acousto-optical processor in frames of the astrophysical instrumentation is shortly discussed.

关键词： Astrophysical Instrumentation Radio-Astronomy Millimeter-Wave Spectrometer Space-and-Time Integrating Acousto-Optical Devices Optical Processing System

Optical Spectrometer with Acousto-Optical Dynamic Grating for Guillermo Haro Astrophysical Observatory

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International Journal of Astronomy and Astrophysics 2013年第4期3卷 376-384页

作者： Alexandre S. Shcherbakov Adán omar arellanes Vahram Chavushyan National Institute for Astrophysics Optics & Electronics (INAOE) Puebla Mexico

Optical spectrometer of the Guillermo Haro astrophysical observatory (Mexico) realizes investigations in the visible and near-infrared range 350 - 800 nm and exploits mechanically removable traditional static diffraction gratings as dispersive elements. There is a set of the static gratings with slit-densities 150 - 600 lines/mm and optical apertures 9 cm × 9 cm that provide the first order spectral resolution from 0.8 to 3.2 A/pixel, respectively. However, the needed mechanical manipulations, namely, replacing the static diffraction gratings with various resolutions and following recalibration of spectrometer within studying even the same object are practically inconvenient and lead to wasting rather expensive observation time. We suggest exploiting an acousto-optical cell, i.e. the dynamic diffraction grating tunable electronically, as dispersive element in that spectrometer. Involving the acousto-optical technique, which can potentially provide electronic control over the spectral resolution and the range of observations, leads to eliminating the abovementioned demerits and improving the efficiency of analysis.

关键词： Optical Spectrometer Acousto-Optical Cell Dynamic Diffraction Grating Acousto-Optical Material Schematic Arrangement Spectral Resolution Efficiency of Spectrum Analysis

Gall Bladder Stone in a Tertiary Care Teaching Hospital in Mogadishu-Three Year Retrospective Study

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Surgical Science 2022年第9期13卷 435-442页

作者： Abdirahman Ahmed Mohamud Nasteho Mohamad Sheikh omar Nur Adam Mohamed Lıban Muse Mohamed Abdıhakım Artan Abdı Fuduma Nur adan Salim İdris Keleşoğlu Jafar Abdulahi omar Department of General Surgey Mogadishu Somali Turkey Training and Research Hospital Mogadishu Somali Department of Emergency Medicine Mogadishu Somali Turkey Training and Research Hospital Mogadishu Somali Department of Psychiatric Mogadishu Somali Turkey Training and Research Hospital Mogadishu Somali Department of Public Health Mogadishu Somali Turkey Training and Research Hospital Mogadishu Somali Department of ENT Mogadishu Somali Turkey Training and Research Hospital Mogadishu Somali Department of Infectious Disease Mogadishu Somali Turkey Training and Research Hospital Mogadishu Somali Aden Adde International University Mogadishu Somalia

Introduction: Gallstone disease, also known as gallbladder stones or GBS, is almost always asymptomatic but can result in a number of problems, including ascending cholangitis and obstructive jaundice. The frequency of gallbladder stones among patients who were sent for abdominal ultrasound at Mogadishu Somali Turkey Training and Research Hospital, Mogadishu, Somalia, during the period between January 2018 and June 2022 was assessed in this study. Methods: This is a record-based study that was carried out at the radiology department of Mogadishu Somali Turkey Training and Research Hospital on patients who were chosen for abdominal ultrasounds during the months of January 2018 and January 2022. The study focused on cases that occurred within those periods. Reports of abdominal ultrasounds served as the source of the collected data. Results: Records from 2352 patients are included in this study. They were divided into 451 (19.1%) males and 1901 (80.8%) females. Patients with GBS were present in 76.4 percent of cases. 73.2 percent of patients had big stones larger than 5 mm, while 53.4 percent of patients had several stones. GBS 1474 (77.5%) was substantially more common in females than in males (71.6%: 323/451) (P 0.008). The presence of small stones (less than 5 mm) was also shown to be significantly different between males and females (P = 0.015). Furthermore, compared with men, females had a considerably higher frequency of big GBS (5 mm) (P 0.015). Conclusion: In this study, it was discovered that females were significantly more likely than males to have GBS. Small stones were found much more frequently in the males. When compared to men, females had a considerably higher frequency of large GBS.

关键词： Gall Stone Abdominal Ultrasound Gall Bladder Cholangitis Gall Bladder Stone (GBS)