Theoretical analysis of "metabolic indices" of blood buffer system

1983 ◽  
Vol 244 (4) ◽  
pp. R492-R499
Author(s):  
T. Sato ◽  
N. Ikeda ◽  
H. Tsuruta ◽  
M. Shirataka

The well-known base excess (BE) and buffer base (BB) curves of Siggaard-Andersen's nomogram are based on their empirical finding that the blood buffer lines in the pH-log PCO2 coordinates with the same BE (or BB) always pass through a single point irrespective of the hemoglobin concentration. We have analytically derived the BE and BB curves on the assumption of a two-compartmental model of blood buffer system comprised of plasma and red blood cells. These hyperbolic functions of BE and BB curves fitted the Siggaard-Andersen's observation very well. The simple formulas derived from the buffer equation with the parameters obtained on the least-square basis were shown to estimate “metabolic indices” of blood as accurately as the computer reading of the nomographic curves. These results seem to indicate that the buffer equation based on the two-compartmental model describes the acid-base status of blood satisfactorily, and that it can entirely replace the Siggaard-Andersen's nomogram.

2020 ◽  
Vol 165 ◽  
pp. 03009
Author(s):  
Li Yan-yi ◽  
Huang Jin ◽  
Tang Ming-xiu

In order to evaluate the performance of GPS / BDS, RTKLIB, an open-source software of GNSS, is used in this paper. In this paper, the least square method, the weighted least square method and the extended Kalman filter method are respectively applied to BDS / GPS single system for data solution. Then, the BDS system and GPS system are used for fusion positioning and the positioning results of the two systems are compared with that of the single system. Through the comparison of experiments, on the premise of using the extended Kalman filter method for positioning, when the GPS signal is not good, BDS data is introduced for dual-mode positioning, the positioning error in e direction is reduced by 36.97%, the positioning error in U direction is reduced by 22.95%, and the spatial positioning error is reduced by 16.01%, which further reflects the advantages of dual-mode positioning in improving a system robustness and reducing the error.


1961 ◽  
Vol 4 (1) ◽  
pp. 13-21
Author(s):  
R. G. de Buda

On an orientable surface of genus p, a set of 2p fundamental circuits can be selected which all pass through a single point A. After cutting along the 2p circuits, the surface can be unfolded into a flat region bounded by a 4p-gon so that: the set of vertices corresponds to the one point A; and the 2p pairs of edges to the 2p fundamental circuits; and the interior of the polygon to the remainder of the surface. If the edges of the polygon are directed, the 2 edges which correspond to one fundamental circuit will be directed in opposite sense, since the surface is orientable [1]. The sequence and direction of the edges is the same as the sequence of the fundamental circuits.


Author(s):  
Parth Vipul Shah

ABSTRACT Objectives: We study the effect of the coronavirus disease 2019 (COVID-19) in India and model the epidemic to guide those involved in formulating policy and building health-care capacity. Methods: This effect is studied using the Susceptible-Exposed-Infected-Recovered (SEIR) compartmental model. We estimate the infection rate using a least square method with Poisson noise and calculate the reproduction number. Results: The infection rate is estimated to be 0.270 and the reproduction number to be 2.70. The approximate peak of the epidemic will be August 9, 2020. A 25% drop in infection rate will delay the peak by 11 d for a 1-mo intervention period. The total infected individuals in India will be 9% of the total population. Conclusions: The predictions are sensitive to changes in the behavior of people and their practice of social distancing.


2007 ◽  
Vol 364-366 ◽  
pp. 1246-1250
Author(s):  
Jian Jun Du ◽  
Suet To ◽  
Chi Fai Cheung ◽  
Wing Bun Lee ◽  
Xiang Wen Miao

Based on the analysis of characteristics of progressive lens, it can be found that lens uneven change of curvature is an important reason of defect on progressive lens processed by single-point diamond cutting technique. By applying least square fairing method to fair the surface which is fitted and interpolated by Double Cubic B-Spline method, the curvature change of progressive surface becomes even. The processing experiment shows that the method in this paper can eliminate the defect effectively in the ultra-precision processing of progressive lenses.


2022 ◽  
Author(s):  
Weining Li ◽  
Khamis Essa ◽  
Sheng Li

Abstract For heat-assisted single point incremental sheet forming (SPIF) works of Ti-6Al-4V sheets, the use of lubricant has shown significant effects on surface quality and geometric accuracy at higher temperatures. Molybdenum disulphide (MoS2) is a common lubricant widely used in SPIF works, however, it usually indicates ineffective performance at high temperatures. This article has studied different lubricants of MoS2 lubricants and proposed a novel mixture of MoS2 to provide better surface quality and improve geometric accuracy. A forming tool with a ball-roller and water channel was designed to enable the MoS2 mixture to pass through the tool tip, allowing easy application of the lubricant on the localised area and reduce the thermal expansion on the ball-roller. Surface roughness analysis has revealed that the water-cooling MoS2 mixture performed well in reducing friction effects and achieved better geometric accuracy. Forming forces measurements, scanning electron microscope (SEM), energy dispersive X-ray Analysis (EDX) and micro-hardness tests also indicated that a higher strain hardening behaviour was detected for the water-cooling MoS2 mixture.


2020 ◽  
Vol 9 (3) ◽  
pp. 789 ◽  
Author(s):  
Toshikazu Kuniya

The first case of coronavirus disease 2019 (COVID-19) in Japan was reported on 15 January 2020 and the number of reported cases has increased day by day. The purpose of this study is to give a prediction of the epidemic peak for COVID-19 in Japan by using the real-time data from 15 January to 29 February 2020. Taking into account the uncertainty due to the incomplete identification of infective population, we apply the well-known SEIR compartmental model for the prediction. By using a least-square-based method with Poisson noise, we estimate that the basic reproduction number for the epidemic in Japan is R 0 = 2.6 ( 95 % CI, 2.4 – 2.8 ) and the epidemic peak could possibly reach the early-middle summer. In addition, we obtain the following epidemiological insights: (1) the essential epidemic size is less likely to be affected by the rate of identification of the actual infective population; (2) the intervention has a positive effect on the delay of the epidemic peak; (3) intervention over a relatively long period is needed to effectively reduce the final epidemic size.


2019 ◽  
Vol 92 (2) ◽  
pp. 163-171 ◽  
Author(s):  
Kamil Krasuski ◽  
Janusz Cwiklak ◽  
Marek Grzegorzewski

Purpose This paper aims to present the problem of the integration of the global positioning system (GPS)/global navigation satellite system (GLONASS) data for the processing of aircraft position determination. Design/methodology/approach The aircraft coordinates were obtained based on GPS and GLONASS code observations for the single point positioning (SPP) method. The numerical computations were executed in the aircraft positioning software (APS) package. The mathematical scheme of equation observation of the SPP method was solved using least square estimation in stochastic processing. In the research experiment, the raw global navigation satellite system data from the Topcon HiperPro onboard receiver were applied. Findings In the paper, the mean errors of an aircraft position from APS were under 3 m. In addition, the accuracy of aircraft positioning was better than 6 m. The integrity term for horizontal protection level and vertical protection level parameters in the flight test was below 16 m. Research limitations/implications The paper presents only the application of GPS/GLONASS observations in aviation, without satellite data from other navigation systems. Practical implications The presented research method can be used in an aircraft based augmentation system in Polish aviation. Social implications The paper is addressed to persons who work in aviation and air transport. Originality/value The paper presents the SPP method as a satellite technique for the recovery of an aircraft position in an aviation test.


Author(s):  
G. Schatten ◽  
S. Paddock ◽  
P. Cooke ◽  
J. Pawley

Confocal microscopy holds great promise for improved imaging of fluorescent or reflective biomedical specimens. The IMR is actively investigating the advantages and optimal usage of the Medical Research Council's Lasersharp laser - scanning confocal microscope and Tracor/Northern's Tandem Scanning Microscope, which benefits from the principles outlined by Petran et al. and Boyde.Quantitative evaluation of microscopic images has always been complicated by the effect of out-of-focus structures on the final image. These effects can be greatly reduced if the conventional light microscope is replaced by a scanning-confocal light microscope. In such an instrument two conditions are met: 1) only a single point of the sample is illuminated at any time and 2) this point on the sample is then imaged onto the pinhole at the entrance to the photodetector. Because little light from out-of-focus planes will pass through the pinhole, only in-focus data is recorded.


2016 ◽  
Vol 10 (4) ◽  
Author(s):  
Kutubuddin Ansari ◽  
Omar F. Althuwaynee ◽  
Ozsen Corumluoglu

AbstractAlthough Global Positioning System (GPS) primarily provide accurate estimates of position, velocity and time of the receiver, as the signals pass through the atmoshphere carrying its signatures, thus offers opportunities for atmoshpheric applications. Precipitable water vapor (PWV) is a vital component of the atmosphere and significantly influences atmospheric processes like rainfall and atmospheric temperature. The developing networks of continuously operating GPS can be used to efficiently estimate PWV. The Turkish Permanent GPS Network (TPGN) is employed to monitor PWV information in Turkey. This work primarily aims to derive long-term data of PWV by using atmospheric path delays observed through continuously operating TPGN from November 2014 to October 2015. A least square mathematical approach was then applied to establish the relation of the observed PWV to rainfall and temperature. The modeled PWV was correlated with PWV estimated from GPS data, with an average correlation of 67.10 %–88.60 %. The estimated root mean square error (RMSE) varied from 2.840 to 6.380, with an average of 4.697. Finally, data of TPGN, rainfall, and temperature were obtained for less than 2 months (November 2015 to December 2015) and assessed to validate the mathematical model. This study provides a basis for determining PWV by using rainfall and temperature data.


2020 ◽  
Author(s):  
Parth Vipul Shah

AbstractWe study the effect of the coronavirus disease 2019 (COVID-19) in India using the SEIR compartmental model. After it’s outbreak in Wuhan, China, it has been imported to India which is a densely populated country. India is fighting against this disease by ensuring nationwide social distancing. We estimate the infection rate to be 0.258 using a least square method with Poisson noise and estimate the reproduction number to be 2.58. We approximate the peak of the epidemic to be August 11, 2020. We estimate that a 25% drop in infection rate will delay the peak by 38 days for a 1 month intervention period. We estimate that the total individuals infected in India will be approximately 9% of the total population.


Sign in / Sign up

Export Citation Format

Share Document