The Utilization of Fischer Tropsch And its Pentanol Blends in an Aviation Compression Ignition Engine (preprint)

The aviation industry is recovering from COVID-19 to regain rapid growth at an increasing rate of over 5% annually. Aviation compression ignition (CI) engines attributed to their economic fuel consumption and adorable reliability, have been widely utilized in the general aviation (GA) industry. This research mainly focuses on characterizing the combustion performance and particle matter (PM) emissions of an aviation CI engine by utilizing Fischer Tropsch (FT) alternative fuel and its pentanol (FT80P20 - 80% FT + 20% pentanol) in comparison with baseline diesel/pentanol-diesel blends (D80P20 - 80% diesel + 20% pentanol). It was found that FT80P20 significantly increases the indicated thermal efficiency (ITE) by 6.5%, and remarkably decreases the indicated specific fuel consumption (ISFC) by 12% in contrast to neat diesel at high load (8.5 bar IMEP), which is due to better homogeneous charge that alternates heterogeneous combustion. Moreover, the PM size-resolved number distributions of emissions were characterized. It was observed that the integrated PM emissions from diesel were predominant (> 1.2×1014 #/kg∙fuel), while those from FT80P20 were significantly reduced (< 0.3×1014 #/kg∙fuel). This is due to the different dominant combustion modes. The results confirm that “main premixed combustion” was dominant when FT80P20 was adopted (Long ignition delay: 19 - 20 ℃A, Short combustion duration: 14.5 - 16.5 ℃A) while the “main diffusion combustion” was found to be dominant for diesel (Short ignition delay: 9 - 11℃A, Long combustion duration: 20 - 27℃A). This is owing to the physical improvement of atomization and evaporation, and chemical promotion of combustion when FT alternative fuel blended with pentanol is used.

[Meralgia paraesthetica as complication of patient positioning : A not fully controllable risk]. / Meralgia paraesthetica als Lagerungsschaden : Kein voll beherrschbares Risiko.

Meralgia paraesthetica (MP) is the consequence of an entrapment or stretch injury of the lateral femoral cutaneous nerve at the crossing region with the inguinal ligament where the nerve exits the pelvis. It results in temporary or permanent sensory loss, paraesthesia and pain in the anterolateral region of the thigh. Idiopathic forms are known for example as seat belt syndrome or jeans syndrome. An MP can also occur as a complication of surgical or intensive care patient positioning. In focus are the lithotomy position, prone position and beach chair position.We analyzed 21 complaints about MP occurring for the first time postoperatively, which had been submitted to the expert committee for medical treatment errors at the North Rhine Medical Association over the past 10 years. Among these, six cases could be identified as positioning damage after a lithotomy position. In three cases MP occurred after supine positioning but the etiology could not be clarified with certainty. In 12 cases MP was recognized as a direct surgical complication.The pathophysiology, incidence and course as well as legal implications of position-related MP are discussed. Pressure damage to the nerve at its intersection with the inguinal ligament is assumed to be the main pathomechanism. Although all the cases presented here occurred after lithotomy positioning, the complication also appears to occur with other types of positioning according to the literature data, the most common being prone positioning. This also explains the increasingly published case reports of MP after prone positioning in COVID-19 patients for respiratory treatment. Safe avoidance of the positioning-related complication does not appear to be possible due to the anatomical variability of the course of the nerve and the unclear pathomechanisms.

Childhood focal compressive mononeuropathies during the COVID-19 pandemic in Buenos Aires, Argentina.

INTRODUCTION/AIMS: Focal peripheral neuropathies are infrequently seen in pediatric patients. The COVID-19 pandemic has disrupted normal life for many people, including complete lockdowns and school closing for long periods of time in many countries, which prompted children to stay at home. Our aim is to assess whether there has been an increased incidence of focal compressive peripheral neuropathies in the pediatric population during COVID-19-associated lockdown. METHODS: Clinical, electrophysiological, and imaging characteristics were reviewed for patients referred to the electrodiagnostic (EDx) laboratory with suspicion of a focal neuropathy. The incidence of focal compressive peripheral neuropathies seen during the period of March to September 2020 was compared with the same time period in 2019. RESULTS: An increased incidence of focal neuropathies was seen in 2020 (31%) compared with 2019 (6.8%). During 2020, 7 fibular (peroneal) mononeuropathies and 2 ulnar neuropathies were diagnosed. Most patients with focal neuropathies were underweight and acknowledged prolonged screen time periods. Electrophysiological findings consisted of mostly demyelinating lesions with an overall good clinical outcome. DISCUSSION: In this study we raise awareness about a possible increased incidence of focal compressive peripheral neuropathies in children during COVID-19-associated lockdown, which may be prevented with changing positions during sedentary activities.

Nerve Compression Injuries After Prolonged Prone Position Ventilation in Patients With SARS-CoV-2: A Case Series.

BACKGROUND: Prone positioning improves oxygenation in adult respiratory distress syndrome. This procedure has been widely used during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. However, this procedure can also be responsible for nerve damage and plexopathy. METHODS: We retrospectively reviewed a series of 7 infectious patients with coronavirus disease 2019 who underwent prone positioning ventilation at the San Raffaele Hospital of Milan, Italy, during the SARS-CoV-2 pandemic. RESULTS: Clinical and neurophysiological data of 7 patients with nerve compression injuries have been reported. CONCLUSIONS: Health care workers should take into consideration the risk factors for prone positioning-related plexopathy and nerve damage, especially in patients with coronavirus disease 2019, to prevent this type of complication.

COVID-CLNet: COVID-19 Detection with Compressive Deep Learning Approaches (preprint)

One of the most serious global health threat is COVID-19 pandemic. The emphasis on improving diagnosis and increasing the diagnostic capability helps stopping its spread significantly. Therefore, to assist the radiologist or other medical professional to detect and identify the COVID-19 cases in the shortest possible time, we propose a computer-aided detection (CADe) system that uses the computed tomography (CT) scan images. This proposed boosted deep learning network (CLNet) is based on the implementation of Deep Learning (DL) networks as a complementary to the Compressive Learning (CL). We utilize our inception feature extraction technique in the measurement domain using CL to represent the data features into a new space with less dimensionality before accessing the Convolutional Neural Network. All original features have been contributed equally in the new space using a sensing matrix. Experiments performed on different compressed methods show promising results for COVID-19 detection. In addition, our novel weighted method based on different sensing matrices that used to capture boosted features demonstrates an improvement in the performance of the proposed method.