The Double Gut Point: A Novel Sonographic Sign of Pneumoperitoneum

Pneumoperitoneum is a life-threatening condition, caused by hollow organ perforation. The diagnosis is often difficult, and Point-of-care ultrasound can be useful to distinguish from different conditions, and early set the indication of urgent surgery. We report a critically ill patient presented to the Emergency Department with sudden increase in upper abdominal pain and distension with a diagnosis of small bowel obstruction on ultrasound using a curvilinear probe. After repeating the ultrasound using a linear probe, two dynamic points at mesogastrium very similar to the “double lung point” seen in thoracic ultrasound was detected. This “double gut point” due to bowel ischemia and perforation was confirmed on a computed tomography scan. In this case, the finding of an abdominal “double gut point” allowed us to diagnose pneumoperitoneum, being a novel sign not previously described, that could aid to diagnose small amounts of free air in the peritoneal cavity.

Performance of open-path lasers and FTIR spectroscopic systems in agriculture emissions research

The accumulation of gases into our atmosphere is a growing global concern that requires considerable quantification of the emission rates and mitigate the accumulation of gases in the atmosphere, especially the greenhouse gases (GHG). In agriculture there are many sources of GHG that require attention in order to develop practical mitigation strategies. Measuring these GHG sources often rely on highly technical instrumentation originally designed for applications outside of the emissions research in agriculture. Although the open-path laser (OPL) and open-path Fourier transform infrared (OP-FTIR) spectroscopic techniques are used in agricultural research currently, insight into their contributing error to emissions research has not been the focus of these studies. The objective of this study was to assess the applicability and performance (accuracy and precision) of OPL and OP-FTIR spectroscopic techniques for measuring gas concentration from agricultural sources. We measured the mixing ratios of trace gases methane (CH4), nitrous oxide (N2O), and ammonia (NH3), downwind of point and area sources with known release rates. The OP-FTIR provided the best performance regarding stability of drift in stable conditions. The CH4 OPL accurately detected the low background (free-air) level of CH4; however, the NH3 OPL was unable to detect the background values < 10 ppbv.

Weight loss and commodity evaluation of pear fruits during storage depending on the packaging method

Pear fruits have a high biological and nutritional value; however, they are perishable products, storage of which is accompanied by certain difficulties. You can preserve the quality of fresh pears through the use of various packaging methods, among which the use of polyethylene liners is effective. The article presents the results of studies of weight loss and yield of pears during storage, depending on the variety and method of packaging. Conferencia, Noiabrska, and Osnovianska pears of the highest and first commodity varieties were pre-cooled and packed in wooden boxes №3, with a capacity of up to 25 kg (“control” option) and in boxes with a plastic bag liner inserted inside the package 45–50 μm followed by sealing (option “box with a polyethylene liner”). Pear fruits were stored for four months at a temperature of 0 ... + 3 ± 1 ºС and relative humidity of 92% ± 2%. Fruit weight losses were determined by the method of weighing fixed samples, the yield of marketable products - according to DSTU 8326:2015. It was found that during the storage period of pear fruits, their weight loss was 2.3–5%, depending on the variety and method of packaging. In terms of pomological varieties, according to average data, the highest weight loss was pears of the Osnovianska variety – 2.6%. The use of polyethylene liners during the storage of pears helped to reduce losses by 0.5–2.3% depending on the variety and duration of storage. It was found that in the conditions of free air access the share of standard products was 78.6–88.3% with the minimum value in the fruits of Conference and the maximum in the fruits of Noiabrska Moldova. It is proved that packing pear fruits in wooden boxes with polyethylene inserts caused an increase in the yield of marketable products to 90.2–98.4%, a decrease in the share of non-standard products to 1.6–7.0%, and waste to 2.8%. The weight loss of pear fruits of the Noiabrska Moldova variety was 0.3–1.5 lower compared to similar indicators of other varieties. The fruits of the same variety recorded a higher yield of marketable products – 88.3–98.4% depending on the method of storage.

SARS-CoV-2 Aerosol Transmission Indoors: A Closer Look at Viral Load, Infectivity, the Effectiveness of Preventive Measures and a Simple Approach for Practical Recommendations

There is uncertainty about the viral loads of infectious individuals required to transmit COVID-19 via aerosol. In addition, there is a lack of both quantification of the influencing parameters on airborne transmission and simple-to-use models for assessing the risk of infection in practice, which furthermore quantify the influence of non-medical preventive measures. In this study, a dose–response model was adopted to analyze 25 documented outbreaks at infection rates of 4–100%. We show that infection was only possible if the viral load was higher than 108 viral copies/mL. Based on mathematical simplifications of our approach to predict the probable situational attack rate (PARs) of a group of persons in a room, and valid assumptions, we provide simplified equations to calculate, among others, the maximum possible number of persons and the person-related virus-free air supply flow necessary to keep the number of newly infected persons to less than one. A comparison of different preventive measures revealed that testing contributes the most to the joint protective effect, besides wearing masks and increasing ventilation. In addition, we conclude that absolute volume flow rate or person-related volume flow rate are more intuitive parameters for evaluating ventilation for infection prevention than air exchange rate.

Simplified and Detailed Analysis of Data Center Particulate Contamination At Server and Room Level Using CFD

Continuous rise in cloud computing and other web-based services propelled the data center proliferation seen over the past decade. Traditional data centers use vapor-compression-based cooling units that not only reduce energy efficiency but also increase operational and initial investment costs due to involved redundancies. Free air cooling and airside economization can substantially reduce the IT Equipment (ITE) cooling power consumption, which accounts for approximately 40% of energy consumption for a typical air-cooled data center. However, this cooling approach entails an inherent risk of exposing the IT equipment to harmful ultrafine particulate contaminants, thus, potentially reducing the equipment and component reliability. The present investigation attempts to quantify the effects of particulate contamination inside the data center equipment and ITE room using CFD. An analysis of the boundary conditions to be used was done by detailed modeling of IT equipment and the data center white space. Both 2-D and 3-D simulations were done for detailed analysis of particle transport within the server enclosure. An analysis of the effect of the primary pressure loss obstructions like heat sinks and DIMMs inside the server was done to visualize the localized particle concentrations within the server. A room-level simulation was then conducted to identify the most vulnerable locations of particle concentration within the data center space. The results show that parameters such as higher velocities, heat sink cutouts, and higher aspect ratio features within the server tend to increase the particle concentration inside the servers.

Impact of Elevated CO2 and Reducing the Source-Sink Ratio by Partial Defoliation on Rice Grain Quality – A 3-Year Free-Air CO2 Enrichment Study

Evaluating the impact of increasing CO2 on rice quality is becoming a global concern. However, whether adjusting the source-sink ratio will affect the response of rice grain quality to elevated CO2 concentrations remains unknown. In 2016–2018, we conducted a free-air CO2 enrichment experiment using a popular japonica cultivar grown at ambient and elevated CO2 levels (eCO2, increased by 200 ppm), reducing the source-sink ratio via cutting leaves (LC) at the heading stage, to investigate the effects of eCO2 and LC and their interactions on rice processing, appearance, nutrition, and eating quality. Averaged across 3 years, eCO2 significantly decreased brown rice percentage (−0.5%), milled rice percentage (−2.1%), and head rice percentage (−4.2%) but increased chalky grain percentage (+ 22.3%) and chalkiness degree (+ 26.3%). Markedly, eCO2 increased peak viscosity (+ 2.9%) and minimum viscosity (+ 3.8%) but decreased setback (−96.1%) of powder rice and increased the appearance (+ 4.5%), stickiness (+ 3.5%) and balance degree (+ 4.8%) of cooked rice, while decreasing the hardness (−6.7%), resulting in better palatability (+ 4.0%). Further, eCO2 significantly decreased the concentrations of protein, Ca, S, and Cu by 5.3, 4.7, 2.2, and 9.6%, respectively, but increased K concentration by 3.9%. Responses of nutritional quality in different grain positions (brown and milled rice) to eCO2 showed the same trend. Compared with control treatment, LC significantly increased chalky grain percentage, chalkiness degree, protein concentration, mineral element levels (except for B and Mn), and phytic acid concentration. Our results indicate that eCO2 reduced rice processing suitability, appearance, and nutritional quality but improved the eating quality. Rice quality varied significantly among years; however, few CO2 by year, CO2 by LC, or CO2 by grain position interactions were detected, indicating that the effects of eCO2 on rice quality varied little with the growing seasons, the decrease in the source-sink ratios or the different grain positions.

Tracheal Diverticulum in SARS-CoV-2 Patients on Non-Invasive Ventilation A not so “Spontaneous” Cause of Pneumomediastinum? An imaging Pictorial Presentation of Two Cases with Review of Literature

Spontaneous pneumomediastinum is a rare but potentially life-threatening condition, the incidence of which has showed an increase in patients with SARS-CoV-2 pneumonia, especially when they are on positive pressure ventilation. None of the reported cases of covid related pneumomediastinum had an associated tracheal diverticulum. Also, to the best of our knowledge, tracheal diverticulum has not been reported in patients on NIV. We report 2 cases of COVID-19 pneumonia on NIV with pneumomediastinum, which also had associated tracheal diverticulum, one of which developed after NIV. Though the establishment of causality needs further research, early detection of a tracheal diverticulum, which might be a harbinger of pneumomediastinum, can be a timely alarm to prompt titration of the pressure settings and judicious use of NIV. The role of inverted grey scale CT images in mediastinal window is a simple, yet hardly utilised radiological tool to increase detection of ‘mediastinal air’, let it be free air or air within a diverticulum. Through this case report, we would like to highlight the role of conventional and inverted CT imaging of pneumomediastinum and tracheal diverticulum in general and in SARS-CoV-2 pneumonia in particular, and to call for more objective research to throw light on the plausible relationship between pneumomediastinum and tracheal diverticulum.

Findings from Measurements of the Electric Power Demand of Air Compressors

The compressed air electric ratio (CAER) describes the ratio of the real electric power demand to the nominal mechanical power of an air compressor. The CAER is an important indicator as the electric power demand of air compressors varies throughout its operation dependent on compressor technology, pressure ratio, and free air delivery. The nameplate power of the compressor drive motor is not sufficient for evaluating the electric power demand; therefore, the CAER plays an important role in assessing the electric operating power demand. In this paper, results from measurements of fixed speed and variable speed (VFD) compressors are presented with the analysis of key influencing factors of the CAER. The data show that the pressure ratio of operating pressure to the maximum design outlet pressure has the largest impact on the CAER. For VFD compressors, the CAER is represented as a linear function dependent on the respective load. Fixed and variable speed compressors’ CAERs are always dependent on the load condition. In idle condition, the CAER was measured to be 0.2. In full load condition with a pressure ratio of 0.6, the CAER averages at a value of 0.87, meaning a 90 kW compressor at 0.6 pressure ratio draws 78.3 kW electric power.

FORMATION AND MONITORING OF SECONDARY X-RAY RADIATION UNDER PRODUCT PROCESSING WITH ELECTRON BEAM

When conducting an industrial radiation processes at an electron accelerator, a part of the beam energy is trans-formed into bremsstrahlung radiation. In such a way, the mixed e,X-radiation is formed in the area behind an irra-diated object. The intensity of the electron and photon components in the radiation is determined by the energy and power of the primary electron beam, as well as by the parameters of the object and devices located behind it. In paper, the characteristics of the e,X-radiation accompanying the product processing by a scanning electron beam with energy 8…12 MeV at a LU-10 Linac of NSC KIPT are studied. The conditions for obtaining a source of sec-ondary X-rays in the state of electronic equilibrium, as well as its monitoring using an extended free-air ionization chamber are explored. Such an extra-source of radiation can be used for carrying out various non-commercial pro-grams like radiation tests, sanitization of archival materials and cultural heritage objects, etc.