Air Removal System Research Articles

A novel system for removing examinee’s exhaled air using an open, lightweight non-sealing facemask-a proof-of-concept study

Patients with respiratory infections (e.g., COVID-19, antimicrobial resistant bacteria) discharge pathogens to the environment, exposing healthcare workers and inpatients to deleterious complications. This study tested the performance of SPEAR-P1 (synchronized personal exhaled air removal system - prototype 1), which actively detects expiration and removes exhaled air using an open, non-sealing lightweight facemask connected to a deep vacuum generating unit (DVGU). Fourteen healthy examinees practiced breathing through facemasks at 30, 25 and 20 breaths per minute; oxygen and nebulized saline were added at later steps. To test the efficacy of removing exhaled air, CO2 was used as a proxy and its level was measured from the outer surface of the open facemask. Compared to the baseline recording, SPEAR-P1 reduced CO2 escaping from the facemask by 66% on average for all study steps and respiratory rates (p<0.001), reaching 85.55% on average at 20 breaths per minute (p<0.001). This study shows that removing exhaled air from examinees using an open, non-sealing lightweight facemask is feasible. Future development of this system will enhance its efficacy and provide a method to remove a patient's contaminating aerosol without the need to "seal" the patient, especially in settings where isolation rooms are not readily available.

Parametric optimization for estimating beta detection efficiency in thin plastic scintillation detector

A condenser air removal system plays a crucial role in radiation monitoring within nuclear power plants, specifically for detecting potential leaks of radioactive material from primary-to-secondary systems. This system assesses the leakage rate (LR) by measuring the emission of β particles from noble gases using a thin plastic scintillation (TPS) detector, which is specifically designed for counting purposes. Among the factors used in LR calculation, the detection efficiency (k) must be experimentally determined in advance. However, this is challenging because of the limitations posed by radiation safety regulations. Moreover, simulation-based calculations are difficult to achieve because only a portion of the β-ray energy is transferred in the TPS detectors, resulting in a lack of prior energy information. To overcome these challenges, this study employed a multi-objective parameter optimization technique to simultaneously calculate the parameters required for the β-ray detection response function and energy calibration equation. Subsequently, k values were calculated using the optimization results. The optimization performance was demonstrated by comparing the measured spectra of the TPS detector with the spectra obtained from the Monte Carlo N-particle simulation. Furthermore, we confirmed that the calculated k values agreed with the reference values.

Application of the Methodology of Energy and Environmental Analysis to Study the Air Removal System of Clean Rooms in Microelectronics

Application of the Methodology of Energy and Environmental Analysis to Study the Air Removal System of Clean Rooms in Microelectronics

Development of an Energy­Efficient Microclimate System for Dairy Herd Loose Keeping

The authors studied the scientific and technical literature regarding the microclimate influence on dairy cattle productivity. It was found out that the building microclimate parameter deviation from certain limit values reduces milk yield by 10-20 percent decrease the live weight gain by 20-30 percent increases the mortality of young animals by 5-40 percent and reduces the number of lactations by 15-20 percent for the herd. (Research purpose) To conduct a survey of modern microclimate systems and their technical implementation for livestock buildings, suggesting the best option while reducing energy costs. (Materials and methods) A classification scheme was provided for microclimate systems. The factors affecting the microclimate of livestock premises were presented in one figure. The main functions of ventilation systems in animal husbandry were identified. The conditions for the use of natural and forced (tunnel) ventilation systems were described. The devices for changing the microclimate on the premises were presented. The possibility of using an overlapped ridge in the area of the roof ridge was considered to catch the airflow and minimize moisture penetration. (Results and discussion) To decrease energy consumption, it was proposed to shift from a supply ventilation system to a natural and hybrid ventilation system, which contains an air removal system, lighting equipment, heating elements, sensors, fans with spray nozzles, sashes. (Conclusions) It was found out that in summer, natural ventilation is unable to prevent heat stress from cows. It was determined that in case of heat stress within 60 days, losses could amount to 4.2 million rubles. To ensure optimal microclimate conditions and reduce costs from heat stress, it was proposed to use an innovative natural and hybrid ventilation system. The calculations showed that a 60-day energy consumption of the proposed system equals 264 thousand rubles.

Применение методологии энергоэкологического анализа для исследования системы удаления воздуха чистых помещений в микроэлектронике

The most part of chemical substances applied in clean rooms are aggressive and toxic, which requires analysis of air removal system not only from functionally related standpoint but also with regard to energy and environment. This study investigates the possibility of applying the methodology of energy and environmental analysis to compare the environmental friendliness of various air removal systems of clean rooms. It was shown that direct air removal, although having a thermodynamic advantage over a system with purification, was less favorable for the environment due to the significant level of the environmental index, which reflected the considerable potential economic damage from emissions to the atmosphere. This investigation has revealed the pollutants dominating in the composition of emissions and determining the validity of the decision on the structure of the air removal system of the clean room, taking into account the environmental, economic and biomedical aspects of its operation.

Air removal capacity of two different minimal invasive ECC systems: an in vitro comparison.

Minimally invasive extracorporeal circulation systems are developed to decrease the deleterious effects of cardiopulmonary bypass. For instance, prime volume and foreign surface area are decreased in these systems. However, because of the lack of a venous reservoir in minimized systems, air handling properties of these minimally invasive extracorporeal circulation systems may be decreased as compared to conventional cardiopulmonary bypass systems. The aim of this in vitro study is to compare the air handling properties of two complete minimized cardiopulmonary bypass systems of two manufacturers, of which one system is provided with the air purge control. In an in vitro study, two minimally invasive extracorporeal circulation systems, Inspire Min.I manufactured by Sorin Group Italia, Mirandola, Italy (LivaNova, London, United Kingdom) and minimized extracorporeal circulation manufactured by Maquet, Rastatt, Germany (Getinge, Germany), were challenged with two types of air challenges; a bolus air challenge and a gaseous microemboli challenge. The air removal characteristics of the venous bubble traps and of the complete minimally invasive extracorporeal circulation systems were assessed by measuring the gaseous microemboli volume and number downstream of the venous bubble traps in the arterial line with a bubble counter. No significant differences were observed in air reduction between the venous bubble traps of Getinge (venous bubble traps) and LivaNova (Inspire venous bubble traps 8 in conjunction with the air purge control). Similarly, no significant differences were observed in volume and number of gaseous microemboli in the arterial line of both complete minimally invasive extracorporeal circulation systems. However, the gaseous microemboli load of the Inspire Min.I system was marginally lower after both the bolus air and the gaseous microemboli challenges. Both minimally invasive extracorporeal circulation systems assessed in this study, the LivaNova Inspire Min.I and the Getinge minimized extracorporeal circulation, showed comparable air removal properties, after both bolus and gaseous microemboli air challenges. Besides, air purge control automatic air removal system provided with the LivaNova Inspire Min.I. system may enhance patient's safety with the use of a minimally invasive extracorporeal circulation system. We consider both systems equally safe for clinical use.

Investigation of the efficiency of the lateral exhaust hood enhanced by aeroacoustic air flow

Abstract This paper presents a novel concept of local push-pull ventilation system used to remove aerosol particles from open surface tanks. Sound waves generated by aerodynamic sound generator are introduced into the push air flow of lateral exhaust hood and used to agglomerate aerosol particles. Results of calculation of parameters of sound generator and aeroacoustic air flow are presented. It is established that 5–10 μm aerosol particles are aggregated better at frequencies below the ultrasonic range (1–5 kHz) and aerosols with a particle size of less than 5 μm are more effectively aggregated at ultrasonic frequencies. It was experimentally established that the relative air humidity measured above open surface tank is decreased up to 1.6 times in presence of acoustic field as compared with humidity obtained for conventional push-pull air removal system. It is also obtained that increase of the temperature of the liquid increases the aerosol removal efficiency of lateral exhaust hood enhanced by aeroacoustic air flow.

QUALITY OF RAW CHICKEN BREAST STORED AT 5C AND PACKAGED UNDER DIFFERENT MODIFIED ATMOSPHERES

ABSTRACTThe objective of this study was to determine the quality of raw chicken breast store at 5C and packaged under different modified atmospheres. The samples of raw chicken breast (20 samples per treatment) were individually wrapped and packed in high‐density plastic bags. Before sealing, the air was removed automatically by an air removal system (vacuum) and then injected into different mixtures of purified natural gas. Physicochemical analysis of texture, pH, thiobarbituric acid (TBA), total volatile bases (TVB), color and microbiological analyses (mesophilic aerobic, Staphylococcus, psychrotrophic, Salmonella and Escherichia coli) were carried out. The cutting strengths and TBA of the control sample after 9 days of storage were 0.94 kgf and 0.601, respectively, there was lower browning, variation in pH, TBA and nitrogen TVB, and a lower growth of psychrotrophic, mesophilic and Staphylococcus was shown; the absence of Salmonella and Escherichia coli is noted. It can be concluded that the best treatment is C after 9 days of storage obtaining a longer shelf life of the chicken breast meat.PRACTICAL APPLICATIONSThe deterioration of foods caused by internal and external factors are responsible for considerable economic loss. Chicken breast meat is easily perishable by microorganisms depending on conditions of supply and production chain. An alternative to try to minimize the losses and increase the shelf life of this product is the use of modified atmospheres. The use of modified atmospheres in this study was effective to retard spoilage and reduce the volatile compounds in chicken breast meat, thus increasing food security without bringing risk to public health.

A Statistical Study of Process Variables to Optimize a High Speed Curtain Coater-Part II

In Part I of this work, we identified four important process, base sheet, and formulation variables that strongly influence the runnability of a curtain coater at high speed, using a Taguchi orthogonal array experimen-tal design approach. The effects identified are base sheet roughness, coating rheology, curtain height, and the amount of steam applied in the boundary layer air removal system (steam substitution system [SSS]). In the second phase of our study, we examine the contribution of these four variables on curtain coating stability in more depth using a D-optimal design of experiment. The results show the set-up of the boundary layer air removal system to be the most critical variable to maintaining the stability of the curtain. We found base sheet roughness, in combination with the parameters of the coating formulation, to also be very important. Coating coverage improved with the smoothness of the base sheet and excellent coating coverage was attainable at low coat weights. A shear thinning coating was found to provide the most favorable coating rheology for curtain stability at high speeds.

A Statistical Study of Process Variables to Optimize a High Speed Curtain Coater: Part I

Using an experimental design approach, researchers altered process parameters and material prop-erties to stabilize the curtain of a pilot curtain coater at high speeds. Part I of this paper identifies the four significant variables that influence curtain stability. The boundary layer air removal system was critical to the stability of the curtain and base sheet roughness was found to be very important. A shear thinning coating rheology and higher curtain heights improved the curtain stability at high speeds. The sizing of the base sheet affected coverage and cur-tain stability because of its effect on base sheet wettability. The role of surfactant was inconclusive. Part II of this paper will report on further optimization of curtain stability with these four variables using a D-optimal partial-facto-rial design.

The use of Minimized Extracorporeal Circulation System has a Beneficial Effect on Hemostasis--A Randomized Clinical Study

Conventional cardiopulmonary bypass (CPB) is associated with increased coagulation and fibrinolytic activity. A closed miniaturized bypass circuit (CorX) features a significantly reduced tubing set, an integrated pump, and an air removal system without a cardiotomy reservoir. In a prospective randomized trial, the effects on hemostasis were investigated while comparing CorX with conventional CPB in patients undergoing coronary artery bypass grafting. Over a period of 1 year, 81 patients were randomly assigned either to the CorX system (n = 39, group A) or standard CPB system (n = 42, group B). Primary endpoints were platelet count, plasmin-antiplasmin complex (PAP), prothrombin fragments 1+2 (F1+F2), D-dimers, and fibrinogen. Secondary end-points were hematocrit, blood loss in the first 12 hours postoperatively, transfused packed red blood cells, and fresh frozen plasma in the first 24 hours postoperatively. In addition, we analyzed partial thromboplastin time, prothrombin time, and antithrombin III. After aortic declamping, PAP complex and prothrombin F1+F2 were significantly lower in group A than in group B. The difference in D-dimers between groups reached significance at 1 hour post-CPB. Hematocrit values at the end of CPB measured 26 +/- 6% in group A versus 22 +/- 4% in group B (P = .01). The rest of the observed parameters did not significantly differ between groups. Postoperative blood loss was not reduced in the present study. However, the use of the CorX system leads to a significant suppression of activation of coagulation and fibrinolytic cascades compared to conventional CPB, suggesting that miniaturized extracorporeal circuits are a step forward toward reduced imbalance of hemostasis in cardiac surgery.

A new minimized extracorporeal circuit reduces inflammatory response in arrested heart coronary artery bypass grafting

Objectives: Conventional cardiopulmonary bypass (CPB) is associated with inflammatory response, deteriorated coagulation and potential systemic organ dysfunction. A new closed extracorporeal circuit (CorX™) is characterized by an integrated pump, air removal system and oxygenator, and no pericardial suction. In a prospective randomized study we compared the CorX™ system with the conventional CPB in arrested heart coronary artery bypass grafting.

A Computational Model of a Power Plant Steam Condenser

A computational model of a power plant steam condenser which incorporates the effects of air in-leakage and removal on the performance of the condenser is reported. The condenser interior space is modeled as a porous medium. A quasi-three-dimensional approach is taken in which the steady-state steady-flow conservation equations for the steam-air mixture mass, momentum, thermal energy, and air mass fraction are solved for a series of two-dimensional grids perpendicular to the circulating water flow direction. The air removal system is explicitly modeled. The computational model is used to calculate the performance of the steam condenser of a 750-MWe unit at 100 percent load. Some of the calculated variables are compared with measurements obtained in the condenser. The effects of changing various operating parameters on the condenser performance at 100 percent load are also studied.

Development of an air removal system for dissolved air flotation

Dissolved Air Flotation (DAF) is often used as a separation step in drinking water treatment. An increasing use of high rate processes has become a trend in chemical treatment. When increasing the loading rate for a flotation process, an increasing head loss built up occurs in the following filter process due to dispersed air carry over. This paper describes the development of an air removal system by using a lamella plate separation system for the dispersed air. Pilot plant experiments showed that the surface load for the combination Lamella Dissolved Air Flotation, the LDAF-unit can be considerably increased in comparison with a conventional DAF-unit.

Development of an air removal system for dissolved air flotation

Development of an air removal system for dissolved air flotation