Simple computer measurement of pulmonary VCO2 per breath

1992 ◽  
Vol 72 (5) ◽  
pp. 2029-2035 ◽  
Author(s):  
P. H. Breen ◽  
S. A. Isserles ◽  
B. A. Harrison ◽  
M. F. Roizen
Keyword(s):  
Co2 Concentration ◽  
Computer Algorithms ◽  
Positive End Expiratory Pressure ◽  
Transport Delay ◽  
A Value ◽  
Wide Range ◽  
Airway Opening ◽  
Anesthetized Dogs ◽  
On Line ◽  
End Tidal

Measurements of the volume of CO2 exhaled per breath (VCO2/br) are preferable to end-tidal PCO2, when the exhaled flow and CO2 waveforms may be changing during unsteady states, such as during alterations in positive end-expiratory pressure or alterations in cardiac output. We describe computer algorithms that determine VCO2/br from digital measurements of exhaled flow (including discontinuous signals common in anesthesia circuits) and CO2 concentration at the airway opening. Fractional concentration of CO2 is normally corrected for dynamic response and transport delay (TD), measured in a separate procedure. Instead, we determine an on-line adjusted TD during baseline ventilation. In six anesthetized dogs, we compared the determination of VCO2/br with a value measured in a simultaneous collection of expired gas. Over a wide range of tidal volume (180–700 ml), respiratory rate (3–30 min-1), and positive end-expiratory pressure (0–14 cmH2O), VCO2/br was more accurate with use of the adjusted TD than the measured TD (P less than 0.05).

Recent Progress and Plans in Computer-Controlled High Resolution Electron Microscopy

1990 ◽  
Vol 48 (1) ◽  
pp. 154-155
Author(s):  
W.J. de Ruijter ◽  
Peter Rez ◽  
David J. Smith
Keyword(s):  
Electron Microscopy ◽  
Digital Processing ◽  
High Resolution Electron Microscopy ◽  
Objective Lens ◽  
Linear Filter ◽  
Contrast Transfer Function ◽  
Image Displacement ◽  
Spatially Resolved ◽  
Wide Range ◽  
On Line

Digital computers are becoming widely recognized as standard accessories for electron microscopy. Due to instrumental innovations the emphasis in digital processing is shifting from off-line manipulation of electron micrographs to on-line image acquisition, analysis and microscope control. An on-line computer leads to better utilization of the instrument and, moreover, the flexibility of software control creates the possibility of a wide range of novel experiments, for example, based on temporal and spatially resolved acquisition of images or microdiffraction patterns. The instrumental resolution in electron microscopy is often restricted by a combination of specimen movement, radiation damage and improper microscope adjustment (where the settings of focus, objective lens stigmatism and especially beam alignment are most critical). We are investigating the possibility of proper microscope alignment based on computer induced tilt of the electron beam. Image details corresponding to specimen spacings larger than ∼20Å are produced mainly through amplitude contrast; an analysis based on geometric optics indicates that beam tilt causes a simple image displacement. Higher resolution detail is characterized by wave propagation through the optical system of the microscope and we find that beam tilt results in a dispersive image displacement, i.e. the displacement varies with spacing. This approach is valid for weak phase objects (such as amorphous thin films), where transfer is simply described by a linear filter (phase contrast transfer function) and for crystalline materials, where imaging is described in terms of dynamical scattering and non-linear imaging theory. In both cases beam tilt introduces image artefacts.

A Wide Range Ge Gamma-Ray Spectrometer for on-Line Measurements of Reactor Cooling Water Activity

1977 ◽  
Vol 24 (1) ◽  
pp. 673-677 ◽  
Author(s):  
J. J. Lipsett ◽  
I. L. Fowler ◽  
R. J. Dinger ◽  
H. L. Malm
Keyword(s):  
Water Activity ◽  
Gamma Ray ◽  
Cooling Water ◽  
Gamma Ray Spectrometer ◽  
Wide Range ◽  
On Line

Path Integral Calculations of Particle Self-Energy and Effective Mass in Coulomb Systems

1997 ◽  
Vol 11 (04) ◽  
pp. 129-138 ◽  
Author(s):  
V. Sa-Yakanit ◽  
V. D. Lakhno ◽  
Klaus Haß
Keyword(s):  
Effective Mass ◽  
Path Integral ◽  
State Energy ◽  
Coulomb Systems ◽  
Integral Approach ◽  
Coupling Region ◽  
Self Energy ◽  
Consistent Approximation ◽  
A Value ◽  
Wide Range

The generalized path integral approach is applied to calculate the ground state energy and the effective mass of an electron-plasmon interacting system for a wide range of densities. It is shown that in the self-consistent approximation an abrupt transition between the weak coupling and the strong coupling region of interaction exists. The transition occurs at low electron densities according to a value of 418 for rs, when Wigner crystallization is possible. For densities of real metals, the electron bandwidth is calculated and a comparison with experimental results is given.

Estimation of the Thermodynamic Properties of Branched Hydrocarbons

2000 ◽  
Vol 122 (3) ◽  
pp. 147-152 ◽  
Author(s):  
Hui He ◽  
Mohamad Metghalchi ◽  
James C. Keck
Keyword(s):  
Thermodynamic Properties ◽  
Degrees Of Freedom ◽  
Statistical Thermodynamic ◽  
Motion Modes ◽  
Branched Alkanes ◽  
Branched Hydrocarbons ◽  
Wide Range ◽  
On Line ◽  
Kinetic Calculations ◽  
Good Agreement

A simple model has been developed to estimate the sensible thermodynamic properties such as Gibbs free energy, enthalpy, heat capacity, and entropy of hydrocarbons over a wide range of temperatures with special attention to the branched molecules. The model is based on statistical thermodynamic expressions incorporating translational, rotational and vibrational motions of the atoms. A method to determine the number of degrees of freedom for different motion modes (bending and torsion) has been established. Branched rotational groups, such as CH3 and OH, have been considered. A modification of the characteristic temperatures for different motion mode has been made which improves the agreement with the exact values for simple cases. The properties of branched alkanes up to 2,3,4,-trimthylpentane have been calculated and the results are in good agreement with the experimental data. A relatively small number of parameters are needed in this model to estimate the sensible thermodynamic properties of a wide range of species. The model may also be used to estimate the properties of molecules and their isomers, which have not been measured, and is simple enough to be easily programmed as a subroutine for on-line kinetic calculations. [S0195-0738(00)00902-X]

Health care Online

2000 ◽  
Vol 1 (2) ◽  
pp. 24-25
Keyword(s):  
Health Care ◽  
Health Care Policy ◽  
Central Government ◽  
Medical Profession ◽  
Medical Opinion ◽  
Proactive Approach ◽  
The United Kingdom ◽  
Wide Range ◽  
On Line ◽  
The Subject

The BMJ has always been recognised as a leading medical journal for a wide range of subjects, and has always been useful for nurses to access for up to date and current medical opinion. Recently the BMJ has diversified to take on a more political nature, with its content reflecting a more proactive approach to influencing health care policy in the United Kingdom by the medical profession. As such the BMJ has become extremely useful for identifying opinions of current ‘hot topics’ for nurses that are headline news such as nurse consultants, hospital administration and central government policy. However, one problem remains, trying to find the original copy in the library will remain difficult. After spending the best part of an hour to suddenly realise that ‘how silly you are for not realising that BMJ March 1997 is filed in the British Journal of Nursing section 1998!!’ is often a frustrating and demoralising experience - particularly if after finding the article you find it has nothing to do with the subject that you are researching. This problem is to be banished forever with the BMJ website. The full BMJ is available free on line. The excellent search engine is particularly useful and is accurate when matching target articles. All articles are available for ‘full text’ downloads free of charge.

scholarly journals Framing the Values of Vernacular Architecture for a Value-Based Conservation: A Conceptual Framework

2021 ◽  
Vol 13 (9) ◽  
pp. 4974
Author(s):  
Obafemi A. P. Olukoya
Keyword(s):  
Vernacular Architecture ◽  
Conservation Strategy ◽  
Participatory Process ◽  
Value Assessment ◽  
A Value ◽  
Wide Range ◽  
Flexible Framework ◽  
Value Model ◽  
Contextual Values ◽  
Range Of Values

While a growing number of researchers have provided series of tough critiques of the typology-led heritage value assessment over the recent years, the impacts have been constrained by the continued obsession with expanding the list of the predetermined value typologies rather than escaping its limitations. While these sustained debates have provided important insights, this article argues that operationalizing these predetermined ‘one-size-fits-all’ value typologies is symptomatic of a number of shortcomings, especially in the context of capturing the pluralities of values in contextualized heritage such as vernacular architecture. It also often undermines inclusivity and participation in the valuing processes. However, rather than simply rejecting the values-based paradigm, this article proposes a conceptual value assessment framework that is informed by the theorization of vernacular architecture as a contextualized heritage. The proposed Vernacular Value Model (VVM) puts forward the ‘when(s)’ and ‘how(s)’ of amalgamating both technical and normative processes to capture the range of contextual values present in built vernacular heritage. To this end, this article posits that by drawing on such a proposed flexible framework, the conservation strategy for built vernacular heritage can be propagated as an inclusive and participatory process which captures the wide range of values for a more sustainable practices for conservation.

Artificial Neural Network and the Taguchi Method Application for Robust Wheatstone Bridge Design

1994 ◽  
Author(s):  
Jung-eui Hong ◽  
Cihan H. Dagli ◽  
Kenneth M. Ragsdell
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Wheatstone Bridge ◽  
Parameter Design ◽  
System Response ◽  
Measurement Circuit ◽  
Wide Range ◽  
Reduce Measurement Error ◽  
On Line ◽  
Artificial Neural

Abstract The primary function of the Wheatstone bridge is to measure an unknown resistance. The elements of this well-known measurement circuit will take on different values depending upon the range and accuracy required for a particular application. The Taguchi approach to parameter design is used to select values for the measurement circuit elements so as to reduce measurement error. Next we introduce the use of an artificial neural network to extrapolate limited experimental results to predict system response over a wide range of applications. This approach can be employed for on-line quality control of the manufacture of such device.

Prescreening in large populations as a tool for identifying elevated CO2-responsive genotypes in plants

2019 ◽  
Vol 46 (1) ◽  
pp. 1 ◽  
Author(s):  
Hiroyuki Shimono ◽  
Graham Farquhar ◽  
Matthew Brookhouse ◽  
Florian A. Busch ◽  
Anthony O'Grady ◽  
...  
Keyword(s):  
Genetic Selection ◽  
Co2 Concentration ◽  
Elevated Atmospheric Co2 ◽  
High Performing ◽  
Active Selection ◽  
Wide Range ◽  
Large Populations ◽  
Increase Productivity ◽  
The Cost ◽  
Selection Of

Elevated atmospheric CO2 concentration (e[CO2]) can stimulate the photosynthesis and productivity of C3 species including food and forest crops. Intraspecific variation in responsiveness to e[CO2] can be exploited to increase productivity under e[CO2]. However, active selection of genotypes to increase productivity under e[CO2] is rarely performed across a wide range of germplasm, because of constraints of space and the cost of CO2 fumigation facilities. If we are to capitalise on recent advances in whole genome sequencing, approaches are required to help overcome these issues of space and cost. Here, we discuss the advantage of applying prescreening as a tool in large genome×e[CO2] experiments, where a surrogate for e[CO2] was used to select cultivars for more detailed analysis under e[CO2] conditions. We discuss why phenotypic prescreening in population-wide screening for e[CO2] responsiveness is necessary, what approaches could be used for prescreening for e[CO2] responsiveness, and how the data can be used to improve genetic selection of high-performing cultivars. We do this within the framework of understanding the strengths and limitations of genotype–phenotype mapping.

On-line NIR sensing of CO2 concentration for polymer extrusion foaming processes

2000 ◽  
Vol 40 (8) ◽  
pp. 1843-1849 ◽  
Author(s):  
Takefumi Nagata ◽  
Masataka Tanigaki ◽  
Masahiro Ohshima
Keyword(s):  
Co2 Concentration ◽  
Polymer Extrusion ◽  
Extrusion Foaming ◽  
On Line

Gas exchange in nonperfused dog lungs

1981 ◽  
Vol 51 (5) ◽  
pp. 1261-1267 ◽  
Author(s):  
J. W. Shepard ◽  
V. D. Minh ◽  
G. F. Dolan
Keyword(s):  
Gas Exchange ◽  
Minute Ventilation ◽  
Left Lung ◽  
Co2 Concentration ◽  
Gas Transfer ◽  
O2 Uptake ◽  
Tissue Metabolism ◽  
End Tidal

Gas exchange was studied under conditions of zero perfusion both in situ and in vitro. Six dogs, anesthetized with pentobarbital sodium, underwent surgical interruption of both pulmonary and bronchial circulations to the left lung. Despite the absence of perfusion, O2 uptake for the left lung ranged from 0.76 to 0.98 ml/min, whereas CO2 elimination greatly exceeded O2 uptake ranging from 1.68 to 4.34 ml/min. In addition, CO2 output was observed to vary directly with the level of minute ventilation (VE) and inversely with end-tidal CO2 concentration. To investigate the mechanisms responsible for these findings we studied 20 excised, ventilated, but nonperfused dog lungs to evaluate the relative roles of tissue metabolism and transpleural diffusion to gas exchange. The results obtained with these excised lungs under conditions of varying VE and extrapleural gas concentrations indicate that the high respiratory exchange ratios observed in situ can be explained by the greater rate with which CO2 diffuses through the pleura, and that reduced ventilation decreases total gas transfer by decreasing the transpleural partial pressure driving gradient. Our data further document that the concentration of CO2 in alveolar gas may differ significantly from that present in inspired gas under conditions of ventilation-perfusion ratio equal to infinity, and that tissue metabolism as well as transpleural diffusion contribute to gas exchange in nonperfused lung.

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