Development of a Carbon Dioxide-Based Field Deployable Environmental Control Unit to Replace HCFC-22 or HFC-134a Units

2002 ◽  
Author(s):  
Joo S. Baek ◽  
Eckhard A. Groll ◽  
Patrick B. Lawless
Keyword(s):  
Carbon Dioxide ◽  
Environmental Control ◽  
Control Unit ◽  
Hfc 134A

scholarly journals A Paradigm Shift in Critical Care Infrastructure in Complex Settings: Evaluating an Ultraportable Operating Room to Improve Field Surgical Safety

2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 295-299
Author(s):  
Debbie L Teodorescu ◽  
Stephen Okajima ◽  
Asad Moten ◽  
Mike H M Teodorescu ◽  
Majed El Hechi ◽  
...  
Keyword(s):  
Operating Room ◽  
In Silico ◽  
Environmental Control ◽  
External Environment ◽  
Control Unit ◽  
Mortality And Morbidity ◽  
Particle Count ◽  
Surgical Safety ◽  
Surgical Field ◽  
Complex Settings

ABSTRACT Introduction Scarcity of operating rooms and personal protective equipment in far-forward field settings make surgical infections a potential concern for combat mortality and morbidity. Surgical and transport personnel also face infectious risks from bodily fluid exposures. Our study aimed to describe the serial, proof-of-concept testing of the SurgiBox technology: an inflatable sterile environment that addresses the aforementioned problems, fits on gurneys and backpacks, and drapes over incisions. Materials and Methods The SurgiBox environmental control unit and inflatable enclosure were optimized over five generations based on iterative feedback from stakeholders experienced in surgery in austere settings. The airflow system was developed by analytic modeling, verified through in silico modeling in SOLIDWORKS, and confirmed with prototype smoke-trail checking. Particulate counts evaluated the enclosure’s ability to control and mitigate users’ exposures to potentially infectious contaminants from the surgical field in various settings. SurgiBox enclosures were setup over a mannequin’s torso, in a configuration and position for either thoracic or abdominal surgery. A particle counter was serially positioned in sternotomy and laparotomy positions, as well as bilateral flank positions. This setup was repeated with open ports exposing the enclosure to the external environment. To simulate stress scenarios, sampling was repeated with enclosure measurements during an increase in external particulate concentration. Results The airflow technology effectively kept contaminants away from the incision and maintained a pressure differential to reduce particle entry. Benchtop testing demonstrated that even when ports were opened or the external environment had high contaminant burden, the enclosed surgical field consistently registered 0 particle count in all positions. Time from kit opening to incision averaged 54.5 seconds, with the rate-limiting step being connecting the environmental control unit to the enclosure. The portable kit weighted 5.9 lbs. Conclusions Analytic, in silico, and mechanical airflow modeling and benchtop testing have helped to quantify the SurgiBox system’s reliability in creating and maintaining an operating room-quality surgical field within the enclosure as well as protecting the surgical team outside the enclosure. More recent and ongoing work has focused on specifying optimal use settings in the casualty chain of care, expanding support for circumferential procedures, automating airflow control, and accelerating system setup. SurgiBox’s ultimate goal is to take timely, safe surgery to patients in even the most austere of settings.

THERMOELECTRIC ENVIRONMENTAL CONTROL UNIT

1965 ◽  
Author(s):  
R. E. Stillwagon
Keyword(s):  
Environmental Control ◽  
Control Unit

scholarly journals Design of gas concentration measurement and monitoring system for biogas power plant

2021 ◽  
Vol 22 (2) ◽  
pp. 726
Author(s):  
Iswanto Iswanto ◽  
Alfian Ma’arif ◽  
Bilah Kebenaran ◽  
Prisma Megantoro
Keyword(s):  
Carbon Dioxide ◽  
Monitoring System ◽  
Liquid Crystal Display ◽  
Control Unit ◽  
Methanogenic Bacteria ◽  
Concentration Data ◽  
Gas Concentration ◽  
Type K ◽  
Calculation Results ◽  
Biogas Reactor

Biogas is a gas obtained from the breakdown of organic matter (such as animal waste, human waste, and plants) by methanogenic bacteria in an oxygen-free (anaerobic) state. The biogas produced mainly consists of 50-70% methane, 30-40% carbon dioxide, and other gases in small amounts. The gas produced has a different composition depending on the type of animal that produces it. It is challenging to obtain biogas concentration data because the monitoring equipment is currently minimal. Therefore, this research discusses how to make a monitoring system for biogas reactors. Sensors are installed in the digester tank and storage tank. The installed sensors are the MQ-4 sensor to detect methane gas (CH<sub>4</sub>), MG-811 sensor to detect carbon dioxide (CO<sub>2</sub>) gas, MQ-136 sensor to detect sulfide acid gas (H<sub>2</sub>S), and Thermocouple Type-K to detect temperature. The sensor will send a signal to the control unit in Arduino Mega 2560, then processed and displayed on the liquid crystal display (LCD). The sensor calculation results' accuracy is not much different from the reference based on the sensor readings. The sensor deviation standard is below 5.0, indicating that the sensor is in precision. The sensor's linearity of MQ-4 is 0.7%, the MG-811 is 0.17%, the MQ-136 is 0.29%, and the Type-K Thermocouple is 1.19%. The installed sensor can be used to monitor gas concentration and temperature in a biogas reactor.

Third Generation of Working Fluids for Advanced Refrigeration Heating and Power Generation Technologies

2020 ◽  
Vol 839 ◽  
pp. 51-56
Author(s):  
Oleg B. Tsvetkov ◽  
Igor V. Baranov ◽  
Yuriy A. Laptev ◽  
Alexander V. Sharkov ◽  
Vladimir V. Mitropov ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Power Generation ◽  
Global Warming ◽  
Chemical Industry ◽  
Montreal Protocol ◽  
Third Generation ◽  
Atmospheric Lifetime ◽  
Working Fluids ◽  
Hfc 134A ◽  
Organic Rankine Cycles

Since the 1987 Montreal Protocol, chlorinated refrigerants (CFCs and HCFCs) have been pointed out as responsible for the destruction of the ozone layer. The chemical industry has realized suitable replacement for CFC-12 and for HCFC-22 e.g. HFC-134a, HFC-404A, HFC-410A, HFC-507. This generation of refrigerants developed by the chemical industry can be characterized by the no ozone depleting potential and long atmospheric lifetime resulting in global warming potential. The contribution of the HFCs to the global warming brings up to discussion whether the HFCs should be considered as a transitional substance. Historically the use of natural and ecologically safe refrigerants was a strategy to eliminate environmental problems and avoid uncertainties with synthetic replacement fluids. Since ammonia is toxic, carbon dioxide provide high pressure, and the hydrocarbons are flammable, the general conclusion is often drawn that natural fluids gave safety problems. This paper will describe the possibilities of application as working fluids in low-temperature engineering refrigeration, heat pumping and organic Rankine cycles of the hydrofluoroolefins (HFOs) as third generation of synthetic working fluids.

Exploring environmental control unit use in the age group 10-20 years

2006 ◽  
Vol 13 (11) ◽  
pp. 511-516 ◽  
Author(s):  
SN Paul ◽  
AO Frank ◽  
RS Hanspal ◽  
R Groves
Keyword(s):  
Environmental Control ◽  
Control Unit ◽  
Age Group ◽  
Group 10

Carbon Dioxide Fluxes and Their Environmental Control in a Reclaimed Coastal Wetland in the Yangtze Estuary

2015 ◽  
Vol 39 (2) ◽  
pp. 344-362 ◽  
Author(s):  
Qicheng Zhong ◽  
Kaiyun Wang ◽  
Qifang Lai ◽  
Chao Zhang ◽  
Liang Zheng ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Coastal Wetland ◽  
Environmental Control ◽  
Yangtze Estuary ◽  
The Yangtze Estuary ◽  
Carbon Dioxide Fluxes
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