scholarly journals Qualification of the Carbon Dioxide Measurement System to Supervise and Improve the Process of Obtaining Breathing Gas for Oxygen Hyperbaric Conditions

2019 ◽  
Vol 69 (4) ◽  
pp. 7-32
Author(s):  
Arkadiusz Woźniak

AbstractMaintaining a stable carbon dioxide content below the established CTQ1 requirements in the process of obtaining breathing gas for hyperbaric oxygen conditions is essential for the safety of underwater work. This article discusses the subject of validation of a selected measuring system for on-line control of the breathing gas production process and describes the application of multidimensional sensory systems to control critical parameters of the production process in production systems intended for intensive use away from supply facilities. In this case, the on-line contamination measurement option should be considered2. Monitoring of the analysed process from the point of view of its ability to minimise its variability should be oriented towards measuring the input or process values in such a way as to prevent the occurrence of potential defects already at the production stage. The assessment of the CCS - Carbon Dioxide Control System3 selected for testing, designed to control the carbon dioxide content, was performed in DUWT PNA4 for the DGKN - 120 complex compressed air supply system5. The system evaluation was conducted using MSA6 procedures and methods of SPC7.

1996 ◽  
Vol 2 (3) ◽  
pp. 233-276 ◽  
Author(s):  
C.-T. Kuo ◽  
J.-T. Lim ◽  
S. M. Meerkov

In this work, a new definition of production systems bottlenecks is formulated and analyzed. Specifically, a machine is defined as the bottleneck if the sensitivity of the system's performance index to this machine's production rate in isolation is the largest. Although appealing from the systems point of view, this definition suffers a deficiency due to the fact that the sensitivities involved cannot be either measured on-line or efficiently calculated off-line. To avoid this, the paper develops a method based on indirect but real-time data. From this point of view, the main result of the work is as follows: The bottleneck machine in a serial production line can be identified by analyzing relationships between the so-called manufacturing blockage and manufacturing starvation of each machine. This leads to a simple rule for bottleneck identification. The rule requires neither the calculation of the production rate sensitivities nor the production rate itself. When the probabilities of manufacturing blockages and starvations are not available from on-line measurements, the paper presents their analytical estimates which, under certain conditions, can be used for bottleneck identification. Finally, a case study at an automotive component plant is described.


1976 ◽  
Vol 15 (01) ◽  
pp. 36-42 ◽  
Author(s):  
J. Schlörer

From a statistical data bank containing only anonymous records, the records sometimes may be identified and then retrieved, as personal records, by on line dialogue. The risk mainly applies to statistical data sets representing populations, or samples with a high ratio n/N. On the other hand, access controls are unsatisfactory as a general means of protection for statistical data banks, which should be open to large user communities. A threat monitoring scheme is proposed, which will largely block the techniques for retrieval of complete records. If combined with additional measures (e.g., slight modifications of output), it may be expected to render, from a cost-benefit point of view, intrusion attempts by dialogue valueless, if not absolutely impossible. The bona fide user has to pay by some loss of information, but considerable flexibility in evaluation is retained. The proposal of controlled classification included in the scheme may also be useful for off line dialogue systems.


1991 ◽  
Vol 24 (7) ◽  
pp. 277-284 ◽  
Author(s):  
E. Gomólka ◽  
B. Gomólka

Whenever possible, neutralization of alkaline wastewater should involve low-cost acid. It is conventional to make use of carbonic acid produced via the reaction of carbon dioxide (contained in flue gases) with water according to the following equation: Carbon dioxide content in the flue gas stream varies from 10% to 15%. The flue gas stream may either be passed to the wastewater contained in the recarbonizers, or. enter the scrubbers (which are continually sprayed with wastewater) from the bottom in oountercurrent. The reactors, in which recarbonation occurs, have the ability to expand the contact surface between gaseous and liquid phase. This can be achieved by gas phase dispersion in the liquid phase (bubbling), by liquid phase dispersion in the gas phase (spraying), or by bubbling and spraying, and mixing. These concurrent operations are carried out during motion of the disk aerator (which is a patent claim). The authors describe the functioning of the disk aerator, the composition of the wastewater produced during wet gasification of carbide, the chemistry of recarbonation and decarbonation, and the concept of applying the disk aerator so as to make the wastewater fit for reuse (after suitable neutralization) as feeding water in acetylene generators.


1997 ◽  
Vol 36 (4) ◽  
pp. 127-134 ◽  
Author(s):  
J. C. Liu ◽  
M. D. Wu

A fuzzy logic controller (FLC) incorporating the streaming current detector (SDC) was utilized in the automatic control of the coagulation reaction. Kaolinite was used to prepare synthetic raw water, and ferric chloride was used as the coagulant. The control set point was decided at a streaming current (SC) of −0.05 and pH of 8.0 from jar tests, zeta potential and streaming current measurements. A bench-scale water treatment plant with rapid mix, flocculation, and sedimentation units, operated in a continuous-flow mode, was utilized to simulate the reaction. Two critical parameters affecting the coagulation reaction, i.e., pH and streaming current, were chosen as process outputs; while coagulant dose and base dose were chosen as control process inputs. They were on-line monitored and transduced through a FLC. With raw water of initial turbidity of 110 NTU, residual turbidity of lower than 10 NTU before filtration was obtained. Results show that this combination functions satisfactorily for coagulation control.


Human Ecology ◽  
2021 ◽  
Author(s):  
Michael Schnegg ◽  
Coral Iris O’Brian ◽  
Inga Janina Sievert

AbstractInternational surveys suggest people increasingly agree the climate is changing and humans are the cause. One reading of this is that people have adopted the scientific point of view. Based on a sample of 28 ethnographic cases we argue that this conclusion might be premature. Communities merge scientific explanations with local knowledge in hybrid ways. This is possible because both discourses blame humans as the cause of the changes they observe. However, the specific factors or agents blamed differ in each case. Whereas scientists identify carbon dioxide producers in particular world regions, indigenous communities often blame themselves, since, in many lay ontologies, the weather is typically perceived as a local phenomenon, which rewards and punishes people for their actions. Thus, while survey results show approval of the scientific view, this agreement is often understood differently and leads to diverging ways of allocating meaning about humans and the weather.


Physchem ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 176-188
Author(s):  
Gregor Lipinski ◽  
Markus Richter

Efficient and environmentally responsible use of resources requires the development and optimization of gas separation processes. A promising approach is the use of liquids that are designed for specific tasks, e.g., the capture of carbon dioxide or other greenhouse gases. This requires an accurate determination of gas solubilities for a broad range of temperatures and pressures. However, state of the art measurement techniques are often very time consuming or exhibit other pitfalls that prevent their use as efficient screening tools. Here, we show that the application of Raman spectroscopy through a compact measuring system can simplify data acquisition for the determination of gas solubilities in liquids. To demonstrate that this approach is expedient, we determined gas solubilities of carbon dioxide in water for three isotherms T = (288.15, 293.15, 298.15) K over a pressure range from p = (0.5–5) MPa and in three imidazolium-based ionic liquids for one isotherm T = 298.15 K at pressures from p = (0.1–5) MPa. When compared to data in the literature, all results are within the reported uncertainties of the measurement techniques involved. The developed analysis method eliminates the need for a lengthy volume or mass calibration of the sample prior to the measurements and, therefore, allows for fast screening of samples, which can help to advance gas separation processes in scientific and industrial applications.


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