Reasonable Degree Of Agreement Research Articles

PULM7: Toward Automatic Control Of Arterial Blood Paco2 Using Artificial Lung Exhaust Gas CO2 As A Surrogate

Purpose: Current clinical Extra Corporeal CO2 removal systems rely on human intervention to adjust to changes in patient activity. Previous studies have investigated the use of capnography for measurement of arterial blood carbon dioxide tension (PaCO2) using artificial lungs (AL). The presented work demonstrates an initial implementation of a controller that directly monitors and regulates PaCO2 using exhaust gas CO2 (EGCO2) measurements. Method: The system operates through two cycles, namely measurement and control. First, the sweep gas flow through the AL is temporarily (~60s) reduced to ~400 mL/min to allow the CO2 concentration on the blood and gas phase of the AL to equilibrate. This allows for EGCO2 (measured via a CO2Meter GC-0017) values to be used as an estimate of PaCO2. The control cycle is based on Proportional-Integral-Derivative (PID) principle wherein the system automatically modulates sweep gas flows through the AL to minimize the difference between the desired PaCO2 and the estimated PaCO2 (i.e., measured EGCO2). Blood samples were intermittently collected at the inlet of the AL to monitor actual PaCO2 (measured via a Radiometer ABL800 Flex blood gas analyzer). The in vitro study setup (Fig. 1) consists of a Novalung iLA oxygenator (main AL) and a Capiox RX25 oxygenator (conditioning AL) connected in parallel to model a typical ECMO circuit. The blood reservoir mimics the blood volume (7 L) while the centrifugal pump simulates cardiac output (fixed at ~5 L/min) of a patient. Blood flow through the main AL (AV shunt) was regulated at ~1 L/min using a Hoffman clamp. CO2 concentration in the sweep gas through the conditioning AL was modulated to simulate metabolic activity. The baseline CO2 concentration measured at the outlet of the conditioning AL that projects reservoir PaCO2 level when the main AL is not operational. The baseline blood concentration was varied between 45 and 90 mmHg representing all levels of normocapnia and hypercapnia. Results: Prior to the controller testing, a feasibility study was performed to determine the accuracy of capnography technique in calculating the PaCO2 using the AL. A total of forty-two blood samples were collected at blood flow rates of 0.5, 0.6 and 1.0 L/min. The results show a good correlation between PaCO2 and EGCO2 (r2=0.824, P<0.001). There was a reasonable degree of agreement between the PaCO2 and EGCO2 with accuracy (bias or mean difference between PaCO2 and EGCO2) of 6.04 mmHg with a precision (95% limits of agreement) of ± 9.62 mmHg (Fig. 2). Despite the limitation of the AL in estimating PaCO2 using EGCO2, the PID controller implementation demonstrated that average reservoir CO2 concentration can be maintained at 44.23 ± 8.7 mmHg for a target PaCO2 of 40 mmHg (Fig. 3),against baseline blood reservoir PaCO2 of 60.76 ± 13.81 mmHg.Figure 1. Image showing in vitro test setup. The bovine blood in the test circuit was anticoagulated (ACT > 1200s) with heparin and maintained at 37°C.Figure 2. a) The regression curve generated between PaCO2 samples and measured EGCO2 b) Agreement between PaCO2 samples and measured EGCO2.Figure 3. a) In vitro test results showing changes in all PaCO2 concentrations in the circuit b) Result summary comparing average reservoir PaCO2 level with target PaCO2

Circular slotted patch with defected grounded monopole patch antenna for microwave-based head imaging applications

Medical microwave imaging (MWI) research has gained more attention in recent decades, particularly with regard to the early detection of brain tumors. It offers numerous benefits over existing imaging technologies, including magnetic resonance imaging (MRI) and computed tomography (CT) scans. Antennas represent a key element of MWI systems, so optimizing their performance is critical. A new, simple patch antenna for MWI is presented in this article. The radiating patch has a circular slot and a tiny triangular cut at the top right corner, and it is designed and manufactured with a low-cost FR4-epoxy substrate with a loss tangent of 0.02 and a dielectric constant of 4.4. The overall dimensions are 0.28λ × 0.22λ × 0.005λ (where λ is the wavelength of a lower frequency of 1.22 GHz). A total impedance bandwidth (<-10 dB) of 2.23 GHz (1.22–3.45 GHz) is achieved with a very decent gain of above 5 dBi (measured) and above 85 % efficiency over the functional range. Time-domain assessment of the antenna confirms minimum signal distortion and shows a better response in terms of group delay (GD) and fidelity factor (FF, 92 %). Measurements confirm the results from simulations (CST and HFSS) with a reasonable degree of agreement. Finally, the 3D-electromagnetic CST simulator was utilized to analyze the behavior of a nine-antenna array placed around a 3D-realistic Hugo-head model; it yielded satisfactory results and proved the practical utility of the proposed antenna in the intended MWI application.

Evaluation of a Double-Entry Turbine Model Coupled With a One-Dimensional Calibrated Engine Model at Engine Full Load Curves

Turbocharging is one of the foremost ways of engine downsizing and represents the leading technology for reducing the engine CO2emission standards in gasoline engine application. Turbocharger turbine always faces high unsteadiness of flow coming from the reciprocating internal combustion engines. Besides, increasing levels of engine downsizing include rising degrees of pulse charging. Utilization of pulse energy in the engine exhaust and reducing the interferences between the cylinders using the double-entry turbines is a vital element in solving the low-end-torque targets and improving rated power in highly boosted four-cylinder engines. The present paper describes a model of double-entry turbines. The model’ aim is to accommodate an efficient boundary condition to turbocharged engine models with zero and one-dimensional gas dynamic codes. The model is based on the simple procedure of testing and systematizing the performance maps of these turbines with different flow admission conditions. However, the described model in the present paper is capable of extrapolating operating conditions that differ from those included in the turbine maps because a turbocharger turbine with an engine usually works instantaneously and away from the narrow range of data that are measured in the gas stand. The described model has been implemented in a one-dimensional gas dynamic code and has been used to calculate unsteady operating conditions coming from the engine. The results obtained from the whole engine simulation show that the model can produce all the full load engine variables such as air mass flow and brake torque in a reasonable degree of agreement with the experimental data that are obtained from the engine test bench.

Validação do Questionário de Avaliação da Atividade Física em Crianças

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Design, Analysis and Optimization of a Solar Dish/Stirling System

In this paper, a mathematical model by which the thermal and physical behavior of a solar dish/Stirling system was investigated, then the system was designed, analysed and optimized. In this regard, all of heat losses in a dish/Stirling system were calculated, then, the output net-work of the Stirling engine was computed, and accordingly, the system efficiency was worked out. These heat losses include convection and conduction heat losses, radiation heat losses by emission in the cavity receiver, reflection heat losses of solar energy in the parabolic dish, internal and external conduction heat losses, energy dissipation by pressure drops, and energy losses by shuttle effect in displacer piston in the Stirling engine. All of these heat losses in the parabolic dish, cavity receiver and Stirling engine were calculated using mathematical modeling in MatlabTM software. For validation of the proposed model, a 10 kW solar dish/Stirling system was designed and the simulation results were compared with the Eurodish system data with a reasonable degree of agreement. This model is used to investigate the effect of geometric and thermodynamic parameters including the aperture diameter of the parabolic dish and the cavity receiver, and the pressure of the compression space of the Stirling engine, on the system performance. By using the PSO method, which is an intelligent optimization technique, the total design was optimized and the optimal values of decision-making parameters were determined. The optimization has been done in two scenarios. In the first scenario, the optimal value of each designed parameter has been changed when the other parameters are equal to the designed case study parameters. In the second scenario, all of parameters were assumed in their optimal values. By optimization of the modeled dish/Stirling system, the total efficiency of the system improved to 0.60% in the first scenario and it increased from 21.69% to 22.62% in the second scenario of the optimization, while the system variables changed slightly. Article History: Received Sept 28, 2015; Received in revised form January 08, 2016; Accepted February 15, 2016; Available online How to Cite This Article: Nazemi, S. D. and Boroushaki, M. (2016) Design, Analysis and Optimization of a Solar Dish/Stirling System. Int. Journal of Renewable Energy Development, 5(1), 33-42. http://dx.doi.org/10.14710/ijred.5.1.33-42

Structural parameters, elastic properties and piezoelectric constants of wurtzite ZnS and ZnSe under pressure

The results of first-principles plane-wave-based pseudopotential method calculations of the structural, elastic and piezoelectric parameters are reported for wurtzite mono-chalcogenides ZnS and ZnSe. The elastic constants are calculated from a method based on total energy as a function of strain, whereas the piezoelectric constants are determined from the second mixed derivatives of total energy versus electric field and strain. Generally, a reasonable degree of agreement is obtained between our results and data available in the literature. The pressure dependence of the features of interest has been examined and discussed.

Pressure-dependent dynamical properties of Zn-based II–VI semiconductors

The effect of pressure on optical phonons and polaron properties in ZnS, ZnSe, and ZnTe II–VI compound semiconductors has been investigated. The calculations are performed in the framework of ab initio pseudopotential approach based on the density functional perturbation theory . At zero pressure, a reasonable degree of agreement is generally found between our results and data available in the literature. It is found that when pressure is increased the phonon modes at Г in the Brillouin zone are shifted towards high energies. The pressure dependence of features such as Fröhlich coupling parameter, the Debye temperature of the longitudinal optical phonon frequency and the polaron effective mass showed that the polaron properties are sensitive to the pressure effect.

CHILDREN'S AND PARENTS’ PERCEPTIONS ON CHILDREN'S PARTICIPATION IN DECISION MAKING AFTER PARENTAL SEPARATION AND DIVORCE*

This article outlines the views of children and parents involved in family law disputes, about the need for and appropriateness of children's participation in decisions regarding residence and contact arrangements. Ninety parents and 47 children (ranging in age from 6 to 18 years) who had been through parental separation, were interviewed. Both parents and children had a range of views about the general appropriateness and fairness of children being involved, but the great majority, particularly of parents, thought that children should have a say in these matters. Core findings of the study include the considerable influence that older children had over the arrangements either in the aftermath of the separation or in making further changes over time, and the higher stated need of children who had experienced violence, abuse, or high levels of conflict to be heard than those in less problematic and noncontested matters. Parents involved in contested proceedings supported the participation of children at a younger age than those who were not. There was a reasonable degree of agreement between parents and children about the need for children to be acknowledged and the value of their views being heard in the decision‐making process. Parents, however, expressed concern about the pressure and manipulation that children can face and exert in this process, whereas children were generally more concerned about the fairness of the outcomes, and maintaining their relationships with their parents and siblings.

Emission factors from wheat and Kentucky bluegrass stubble burning: Comparison of field and simulated burn experiments

Emission factors (EFs) of PM 2.5, CO, elemental carbon (EC), particulate organic carbon (OC), polycyclic aromatic hydrocarbons (PAHs) and methoxyphenols (MPs) from post-harvest burning of wheat and Kentucky bluegrass (KBG) stubble were evaluated in a series of field burns. Integrated smoke samples were collected at ground level, upwind and downwind of the fires, and EFs were determined with the carbon balance method (validated during previous chamber experiments). These EFs were compared against EFs evaluated from previously conducted chamber burns, to determine how well the latter represent field scenarios. In general, when combustion efficiency (CE) differences were taken into account, a reasonable degree of agreement was observed between emission factors measured in the field and in the chamber, except for EC and solid+vapor phase PAHs, both from wheat burns. EC and PAHs from wheat burns were seen in higher amounts in the chamber, although the PAH data are in agreement at CEs>90%. EC overestimates might be due to a misassigned EC–OC split in the heavily loaded quartz filters from chamber burns. Poor EC and OC EF–CE correlations in KBG chamber data make the comparison with field data difficult. The particulate organic matter/OC ratios (2.1±1.3 for wheat and 1.9 for KBG) were higher than those observed during chamber experiments (1.5 for both wheat and KBG). Overestimates of EC in the chamber and possibly the condensation of oxygenated species in the field may be responsible for this difference. Though CO and CH4 EFs evaluated from ground-based samples differed from those collected on board a light aircraft, EF–CE relationships were similar. This underscores the importance of determining both the CEs and EFs simultaneously.

Journal Reviewer Ratings: Issues of Particularistic Bias, Agreement, and Predictive Validity Within the Manuscript Review Process

Reviewer evaluations and recommendations for 853 manuscript submissions, over a span of 4 years, are analyzed for evidence of particularistic bias, reviewer agreement, and predictive validity for forecasting a published manuscript's citation impact. Attributes of the submitters, their affiliated institutions, and the reviewers have little consistent association with reviewers' recommendations or editorial decision outcomes. Furthermore, reviewers' recommendations demonstrate a reasonable degree of agreement. However, neither reviewers' evaluative ratings across five dimensions nor publication recommendations can predict the number of citations that a published article subsequently receives. Strengths and limitations of various features of the manuscript review process, as well as the importance of monitoring the process for particularistic biases and evidence of predictive validity, are discussed.

Membrane Oxygenator Exhaust Capnography for Continuously Estimating Arterial Carbon Dioxide Tension During Cardiopulmonary Bypass

Typically, the standard practice for measuring the arterial blood carbon dioxide tension (PaCO2) during cardiopulmonary bypass (CPB) is to take intermittent blood samples for analysis by a bench blood gas analyzer. Continuous inline blood gas monitors are available but are expensive. A potential solution is the capnograph, which was evaluated by determining how accurately the carbon dioxide tension in the oxygenator exhaust gases (PECO2) predicts PaCO2. A standard capnograph monitoring line was attached to the exhaust port of the membrane oxygenator. During CPB, the capnograph reading and arterial blood temperature were recorded at the same time as routine arterial blood gases were taken. One hundred fifty-seven blood samples were collected from 78 patients. A good correlation was found between the PECO2 and the temperature corrected PaCO2 (r2 = 0.833, P &lt; .001). There was also a reasonable degree of agreement between the PECO2 and the temperature corrected PaCO2 during all phases of CPB: accuracy (bias or mean difference between PaCO2 and PECO2) of −1.2 mmHg; precision (95% limits of agreement) of ± 4.7 mmHg. These results suggest that oxygenator exhaust capnography may be a simple and inexpensive adjunct to the bench blood gas analyzer in continuously estimating PaCO2 of a clinically useful degree of accuracy during CPB.

Analysis of short fatigue crack growth in cast aluminum alloys

An analysis of the rate growth of short, surface fatigue cracks in both a coarse-grained and a fine-grained cast 319 aluminum alloy and squeeze-cast aluminum alloy has been carried out using a modified linear elastic approach. The modified LEFM approach includes consideration of elastic–plastic behavior, the development of crack closure, and the relation between the threshold for fatigue crack growth and the endurance limit. A reasonable degree of agreement has been achieved between the predicted behavior and experimental result.

Reliability of dermatology teleconsultations with the use of teleconferencing technology

Background: Recent advances in telecommunications technology allow physicians to consult on patients at a distance via an interactive video format. Few data exist as to the reliability of this form of consultation. Objective: Our purpose was to measure the degree of concordance between a dermatologist seeing a patient in a clinic and another dermatologist seeing the same patient over a commercially available videoconferencing system. Methods: Patients referred to a general dermatology clinic were seen by both a “live” dermatologist and a “teledermatologist” via a T1 connection. Diagnosis and recommendations were recorded by both physicians and compared. The physicians were also asked to rate the degree of confidence they had in their diagnosis. Results: Seventy-nine diagnoses were made on 60 patients. The two physicians were in absolute agreement on 61 of the diagnoses (77.2%). Race or sex of the patient, nature of the skin problems, or which of the two physicians was the teledermatologist did not statistically correlate with the concordance of the two physicians. Conclusion: There was a reasonable degree of agreement between the two examining physicians. Despite the relatively high degree of concordance the teledermatologist had a significantly lower degree of confidence in his diagnoses. (J Am Acad Dermatol 1997;37:398-402.)

Reliability of dermatology teleconsultations with the use of teleconferencing technology

<h2>Background</h2> Recent advances in telecommunications technology allow physicians to consult on patients at a distance via an interactive video format. Few data exist as to the reliability of this form of consultation. <h3>Objective</h3> Our purpose was to measure the degree of concordance between a dermatologist seeing a patient in a clinic and another dermatologist seeing the same patient over a commercially available videoconferencing system. <h3>Methods</h3> Patients referred to a general dermatology clinic were seen by both a "live" dermatologist and a "teledermatologist" via a T1 connection. Diagnosis and recommendations were recorded by both physicians and compared. The physicians were also asked to rate the degree of confidence they had in their diagnosis. <h3>Results</h3> Seventy-nine diagnoses were made on 60 patients. The two physicians were in absolute agreement on 61 of the diagnoses (77.2%). Race or sex of the patient, nature of the skin problems, or which of the two physicians was the teledermatologist did not statistically correlate with the concordance of the two physicians. <h3>Conclusion</h3> There was a reasonable degree of agreement between the two examining physicians. Despite the relatively high degree of concordance the teledermatologist had a significantly lower degree of confidence in his diagnoses.

Artificial Intelligence in Pediatrics: Important Clinical Signs in Newborn Syndromes

New methods are warranted in the field of syndromology. This study is an exploration into whether an artificial intelligence method (ID3) could provide a new angle for approaching syndromes. Diagnosing syndromes in the newborn is difficult. The accepted approach is to look for individual clinical signs that add up to a syndrome diagnosis. Of all possible clinical signs, one would want to extract the signs with the strongest predictive power. I used the ID3 algorithm to extract predictive clinical signs from a catalogue of syndromes (Birth Defects Encyclopedia Online;BDEO). Using information from BDEO, files of randomly generated “patients” were created. The signs consistently high in the identification tree were long philtrum, short palpebral fissures, low-set ears, and hepatosplenomegaly. The program used featured a crude “expert system” based on the ID3 algorithm. When using one-half of the data set as a training set and the other half as a testbed, a correct classification rate of 92.1–98.1% was attained. When the ID3 expert system was tested against cases from a clinical database (Pictures of Standard Syndromes and Undiagnosed Malformations), the correct classification rate was less than 20%. This may not necessarily reflect faults with the ID3 approach, but possibly biases in the clinical database. In syndromology no “criterion standards” exist that can confirm a diagnosis. The statistical method of cluster analysis does not require prior knowledge of diagnoses and will make a tree of syndromes based upon clinical signs. A cluster analysis was performed as a validity check to provide a tree for comparison with the ID3 tree. There was a reasonable degree of agreement between the two. Applying artificial intelligence methods to this field highlights problems with basic assumptions and philosophical aspects of syndrome diagnosis.

An analytic study of boiling heat transfer from a fin

Analytic expressions for the one-dimensional temperature distribution in a pin fin or a straight fin of rectangular profile are derived if various types of boiling occur simultaneously at adjacent locations on such a fin's surface. The heat transfer coefficients for the transition and nucleate boiling are taken as being the power functions of the wall superheat and that for film boiling as being constant. The number of cases analysed is 66. Some of the results obtained are compared with those of experiments carried out elsewhere. A quite reasonable degree of agreement is found between the theory and the experiment carried out in practice.

Contact angle determinations on pharmaceutical powders: A comparison of two methods

Contact angle determinations have been carried out on pharmaceutical powders by two methods, the h—e technique (Kossen and Heertjes, 1965) and the direct measurement of the angle formed by a drop of liquid on the compacted powder. Despite the assumptions and variables involved, a reasonable degree of agreement between the two techniques is possible.

Heat transfer from a buoyant smoke layer beneath a ceiling to a sprinkler spray. 2—an experiment

AbstractAn experiment is described which measures the heat transferred from a hot, flowing, buoyant gas layer in a mall, to a sprinkler spray. Interpolation techniques are described which allow for the large heat losses occurring within the apparatus (a large‐scale model mall). The results are compared with predictions based on the method developed in Part 1 and found to be consistently 150% of the predicted heat transfer rates. Given the assumptions required by the predictive calculations this is thought to be reasonable degree of agreement. The largest heat transfer rate to the one sprinkler spray in this experiment was 157 kW ± 38 kW.

Deposition of particles on rough surfaces during turbulent gas-flow in a pipe

The importance of surface roughness on the deposition of particles from a flowing gas stream is well known but there has been little theoretical work that helps predictions to be made. The theory presented here follows the general approach of Davies (1966) who considered deposition on smooth surfaces. To take account of surface roughness extra distances have been added to the particle-capture distance and, by shifting the position of the origin of the velocity profile, it has been possible to use the same equation for the radial velocity fluctuations. The effect of surface roughness on the friction velocity is dealt with by empirical equations. Details of the analysis are given together with a computer solution procedure. Results of calculations are compared with the experimental results of other workers and a reasonable degree of agreement is shown. The effect of small changes in surface roughness on deposition velocity are shown to be so large that there is difficulty in making precise predictions of deposition rates and results from apparently similar experiments may vary widely.