scholarly journals Long-Term Performance of Aanderaa Optodes and Sea-Bird SBE-43 Dissolved-Oxygen Sensors Bottom Mounted at 32 m in Massachusetts Bay

2007 ◽  
Vol 24 (11) ◽  
pp. 1924-1935 ◽  
Author(s):  
Marinna Martini ◽  
Bradford Butman ◽  
Michael J. Mickelson
Keyword(s):  
Dissolved Oxygen ◽  
Correlation Coefficient ◽  
Field Evaluation ◽  
Mean Difference ◽  
Massachusetts Bay ◽  
The Mean ◽  
The Difference ◽  
Long Term Performance ◽  
Term Performance ◽  
Oxygen Measurements

Abstract A field evaluation of two new dissolved-oxygen sensing technologies, the Aanderaa Instruments AS optode model 3830 and the Sea-Bird Electronics, Inc., model SBE43, was carried out at about 32-m water depth in western Massachusetts Bay. The optode is an optical sensor that measures fluorescence quenching by oxygen molecules, while the SBE43 is a Clark polarographic membrane sensor. Optodes were continuously deployed on bottom tripod frames by exchanging sensors every 4 months over a 19-month period. A Sea-Bird SBE43 was added during one 4-month deployment. These moored observations compared well with oxygen measurements from profiles collected during monthly shipboard surveys conducted by the Massachusetts Water Resources Authority. The mean correlation coefficient between the moored measurements and shipboard survey data was >0.9, the mean difference was 0.06 mL L−1, and the standard deviation of the difference was 0.15 mL L−1. The correlation coefficient between the optode and the SBE43 was >0.9 and the mean difference was 0.07 mL L−1. Optode measurements degraded when fouling was severe enough to block oxygen molecules from entering the sensing foil over a significant portion of the sensing window. Drift observed in two optodes beginning at about 225 and 390 days of deployment is attributed to degradation of the sensing foil. Flushing is necessary to equilibrate the Sea-Bird sensor. Power consumption by the SBE43 and required pump was 19.2 mWh per sample, and the optode consumed 0.9 mWh per sample, both within expected values based on manufacturers’ specifications.

A New Equal Area Method to Calculate and Represent Physiologic, Anatomical, and Alveolar Dead Spaces

2006 ◽  
Vol 104 (4) ◽  
pp. 696-700 ◽  
Author(s):  
Yongquan Tang ◽  
Martin J. Turner ◽  
A Barry Baker
Keyword(s):  
Carbon Dioxide ◽  
Dead Space ◽  
Graphical Method ◽  
Mean Difference ◽  
Equal Area ◽  
Area Method ◽  
Physiologic Dead Space ◽  
Anatomical Dead Space ◽  
The Mean ◽  
The Difference

Background Physiologic dead space is usually estimated by the Bohr-Enghoff equation or the Fletcher method. Alveolar dead space is calculated as the difference between anatomical dead space estimated by the Fowler equal area method and physiologic dead space. This study introduces a graphical method that uses similar principles for measuring and displaying anatomical, physiologic, and alveolar dead spaces. Methods A new graphical equal area method for estimating physiologic dead space is derived. Physiologic dead spaces of 1,200 carbon dioxide expirograms obtained from 10 ventilated patients were calculated by the Bohr-Enghoff equation, the Fletcher area method, and the new graphical equal area method and were compared by Bland-Altman analysis. Dead space was varied by varying tidal volume, end-expiratory pressure, inspiratory-to-expiratory ratio, and inspiratory hold in each patient. Results The new graphical equal area method for calculating physiologic dead space is shown analytically to be identical to the Bohr-Enghoff calculation. The mean difference (limits of agreement) between the physiologic dead spaces calculated by the new equal area method and Bohr-Enghoff equation was -0.07 ml (-1.27 to 1.13 ml). The mean difference between new equal area method and the Fletcher area method was -0.09 ml (-1.52 to 1.34 ml). Conclusions The authors' equal area method for calculating, displaying, and visualizing physiologic dead space is easy to understand and yields the same results as the classic Bohr-Enghoff equation and Fletcher area method. All three dead spaces--physiologic, anatomical, and alveolar--together with their relations to expired volume, can be displayed conveniently on the x-axis of a carbon dioxide expirogram.

scholarly journals Comparison of direct and geodetic mass balances on a multi-annual time scale

2010 ◽  
Vol 4 (3) ◽  
pp. 1151-1194
Author(s):  
A. Fischer
Keyword(s):  
Mass Balance ◽  
Direct Method ◽  
Mean Difference ◽  
Published Data ◽  
Glacier Mass Balance ◽  
Mass Balances ◽  
Direct Data ◽  
The Mean ◽  
The Difference ◽  
Geodetic Mass Balance

Abstract. Glacier mass balance is measured with the direct or the geodetic method. In this study, the geodetic mass balances of six Austrian glaciers in 19 periods between 1953 and 2006 are compared to the direct mass balances in the same periods. The mean annual geodetic mass balance for all periods is −0.5 m w.e./year. The mean difference between the geodetic and the direct data is −0.7 m w.e., the minimum −7.3 m w.e. and the maximum 5.6 m w.e. The accuracy of geodetic mass balance resulting from the accuracy of the DEMs ranges from 2 m w.e. for photogrammetric data to 0.002 m w.e. for LIDAR data. Basal melt, seasonal snow cover and density changes of the surface layer contribute up to 0.7 m w.e. for the period of 10 years to the difference to the direct method. The characteristics of published data of Griesgletscher, Gulkana Glacier, Lemon Creek glacier, South Cascade, Storbreen, Storglaciären, and Zongo Glacier is similar to these Austrian glaciers. For 26 analyzed periods with an average length of 18 years the mean difference between the geodetic and the direct data is −0.4 m w.e., the minimum −7.2 m w.e. and the maximum 3.6 m w.e. Longer periods between the acquisition of the DEMs do not necessarily result in a higher accuracy of the geodetic mass balance. Specific glaciers show specific trends of the difference between the direct and the geodetic data according to their type and state. In conclusion, geodetic and direct mass balance data are complementary, but differ systematically.

scholarly journals Persepsi Petani terhadap Pilihan Menjual Padi Kepada Penebas atau Perpadi (Kasus Subak Benel, Desa Kaliakah, Kecamatan Negara, Kabupaten Jembrana)

2017 ◽  
pp. 563
Author(s):  
I MADE PRASADA ARY WIRAWAN ◽  
I DEWA PUTU OKA SUARDI ◽  
I MADE SARJANA
Keyword(s):  
T Test ◽  
Mean Difference ◽  
P Value ◽  
Food Crops ◽  
Test Program ◽  
Qualitative Descriptive ◽  
The Mean ◽  
The Difference ◽  
The Government ◽  
Better Than

Farmers Perception Of Options To Sell Rice Penebas Or Perpadi(especially in Subak Benel, Kaliakah Village, Negara districts,Jembrana Regency) Various efforts have been implemented by the Provincial Food Crops Agency of Balito stabilize the price of grain, this is done by giving Funds of Rural EconomicEmpowerment Capital to the government for the purchase of rice. Although it hasbeen done from 2003, farmers are still selling it to Penebas with a bondage system.The purpose of this study to determine the perception of farmers to the choice ofselling rice to Perpadi or Penebas seen and differences in farmers' perceptions of thechoice of selling rice to Penebas or Perpadi. The research location is located in SubakBenel, Kaliakah Village, State District, Jembrana District. The analytical methodused is qualitative descriptive that aided with score, to answer the purpose ofresearch by using questionnaire. The results of this study indicate that the perceptionof farmers to the choice of selling rice to Perpadi better than to Penebas. This is seenin the achievement of the farmers' choice of selling paddy to Perpadi is very goodand to Penebas is good. The difference of Perpadi with Penebas is measured throughDifferent Test with SPSS Independent Sample T test program which the result of Sigvalue. Or p value of 0.004 where <0.05 then there is a statistically significantdifference in probability 0.05, the mean difference or mean of both groups is shownin Mean Difference ie .29559.

Large Differences of Temperature between the Ben Nevis and Fort-William Observatories

1910 ◽  
Vol 44 (2) ◽  
pp. 702-705
Author(s):  
R. T. Omond
Keyword(s):  
Preceding Paper ◽  
Mean Difference ◽  
Average Difference ◽  
The Mean ◽  
The Difference

The immediately preceding paper deals with the average difference of temperature between Ben Nevis and Fort-William throughout the year, but the difference often departs widely from these average values. The greatest departures from the average during the time that hourly readings are available at both places, viz. from 1st August 1890 to 30th September 1904, were Ben Nevis 17°·6 warmer than Fort-William at 9 A.M. on 19th February 1895, and Ben Nevis 28°·8 colder than Fort-William at 2 A.M. on 19th December 1890, being respectively 33°·3 below and 13°·1 above the mean difference, which is Ben Nevis 15°·7 colder than Fort-William.

Magnetic resonance imaging versus histological assessment for estimation of lesion volume after experimental spinal cord injury

2008 ◽  
Vol 9 (3) ◽  
pp. 301-306 ◽  
Author(s):  
David S. Ditor ◽  
Sunil John ◽  
Jason Cakiroglu ◽  
Colin Kittmer ◽  
Paula J. Foster ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Mr Imaging ◽  
Mean Difference ◽  
Lesion Volume ◽  
Perfect Agreement ◽  
Experimental Spinal Cord Injury ◽  
Cord Injury ◽  
The Mean ◽  
The Difference

Object The purpose of this study was to compare measures of lesion volume obtained by means of 1.5-T MR imaging to those obtained by the Cavalieri method, 6 weeks after experimental spinal cord injury. Methods Nine male Wistar rats were subjected to spinal cord injury by clip compression (50 g) at the T-4 level. Six weeks postinjury, the rats were sacrificed, and spinal cords were analyzed ex vivo for lesion volume by means of 1.5-T MR imaging and subsequently, by the Cavalieri method. In the latter method, cords were cut longitudinally in 25-μm sections and stained with solochrome cyanin for myelin. The area of the lesion was determined for each serial section, and the distance-weighted sum of all area measures was then calculated to estimate the total lesion volume. Results Bland–Altman analysis showed that the 2 methods had an acceptable level of agreement for lesion volume estimation, but the Cavalieri method was prone to an overestimation bias. The MR imaging estimates of lesion volume were greater than the Cavalieri method estimates in 3 spinal cords, but the difference between measures was within 1 standard deviation of perfect agreement in these 3 lesions, and the mean difference between measures was 18.3%. In contrast, in those lesions in which the Cavalieri method yielded larger lesion volumes (5 lesions), the difference between measures was 2 standard deviations away from perfect agreement for 2 animals and the mean difference between measures was 72.4%. Conclusions The results illustrate that the overestimation bias of the Cavalieri method is due, in part, to artifacts produced during processing of the spinal cord tissue.

Comparisons of Accelerometer and Pedometer Determined Steps in Free Living Samples

2011 ◽  
Vol 8 (3) ◽  
pp. 390-397 ◽  
Author(s):  
Timothy K. Behrens ◽  
Mary K. Dinger
Keyword(s):  
Secondary Analysis ◽  
Mean Difference ◽  
Measurement Bias ◽  
Strong Correlations ◽  
Free Living ◽  
Analytical Strategies ◽  
The Mean ◽  
The Difference

Background:The purpose of this study was to compare steps·d-1 between an accelerometer and pedometer in 2 free-living samples.Methods:Data from 2 separate studies were used for this secondary analysis (Sample 1: N = 99, Male: n = 28, 20.9 ± 1.4 yrs, BMI = 27.2 ± 5.0 kg·m-2, Female: n = 71, 20.9 ± 1.7 yrs, BMI = 22.7 ± 3.0 kg·m-2; Sample 2: N = 74, Male: n = 27, 38.0 ± 9.5 yrs, BMI = 25.7 ± 4.5 kg·m-2, Female: n = 47, 38.7 ± 10.1 yrs, BMI = 24.6 ± 4.0 kg·m-2). Both studies used identical procedures and analytical strategies.Results:The mean difference in steps·d-1 for the week was 1643.4 steps·d-1 in Study 1 and 2199.4 steps·d-1 in Study 2. There were strong correlations between accelerometer- and pedometer-determined steps·d-1 in Study 1 (r = .85, P < .01) and Study 2 (r = 0.87, P < .01). Bland-Altman plots indicated agreement without bias between steps recorded from the devices in Study 1 (r = −0.14, P < .17) and Study 2 (r = −0.09, P < .40). Correlations examining the difference between accelerometer–pedometer steps·d-1 and MVPA resulted in small, inverse correlations (range: r = −0.03 to −0.28).Conclusions:These results indicate agreement between accelerometer- and pedometer-determined steps·d-1; however, measurement bias may still exist because of known sensitivity thresholds between devices.

Inter- and intra-operator variability associated with extracapsular suture tensioning

2012 ◽  
Vol 25 (06) ◽  
pp. 472-477 ◽  
Author(s):  
E. A. Buffa ◽  
A. M. Marchevsky ◽  
J. Heller ◽  
A. P. Moores ◽  
M. Farrell ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Cruciate Ligament ◽  
Mean Difference ◽  
Marked Variation ◽  
Limits Of Agreement ◽  
Cranial Cruciate Ligament ◽  
Suture Tension ◽  
Clinical Consequences ◽  
The Mean ◽  
The Difference

SummaryObjectives: To determine inter- and intra- operator variability associated with extracapsular suture tensioning as performed during lateral fabello-tibial suture placement.Study design: Ex vivo study.Methods: Fifteen Greyhound cadaveric pelvic limbs were prepared by cutting the cranial cruciate ligament and placing an extracapsular fabello-tibial suture. On two occasions, three surgeons tensioned the extracapsular suture of each stifle. Stifles were returned to 135 degrees of flexion and the suture tension was measured using a commercially available suture tensioner with inbuilt tensiometer.Statistical analysis: Intra-operator and inter-operator agreement were assessed using the limits of agreement method. A linear mixed effects model was specified to assess the effect of operator, repeated estimates and stifle order on tension applied.Results: The mean difference within the three operators ranged from 0 to 14.7N. With 95% limits of agreement, on most occasions for all three operators, the difference was between –31.7 and 41.0 N. The mean difference between the three operators ranged from 6.0 to 30.7 N. With 95% limits of agreement, on most occasions the difference between operators was between –25.6 and 62.5 N.Clinical significance: Marked variation exists in the tension applied during fabello- tibial suture application, both within and between surgeons. This variation may lead to inconsistent clinical outcomes. Further studies are required to determine the clinical consequences of this marked variation in extracapsular suture tensioning.

scholarly journals Twenty-four-hour Blood Pressure Monitoring in Central Serous Chorioretinopathy – A Case-control Study

2013 ◽  
Vol 07 (01) ◽  
pp. 42
Author(s):  
Pradeep Venkatesh ◽  
Vikas Jain ◽  
Satpal Garg ◽  
◽  
◽  
...  
Keyword(s):  
Blood Pressure ◽  
Central Serous Chorioretinopathy ◽  
Case Control Study ◽  
Blood Pressure Monitoring ◽  
Case Control ◽  
Mean Difference ◽  
National Committee ◽  
The Mean ◽  
The Difference ◽  
Control Study

Purpose:A case-control study to explore the diurnal variation of blood pressure (BP) in patients with central serous chorioretinopathy (CSCR).Methods:One-hundred patients (50 cases with central serous chorioretinopathy and 50 age- and sex-matched controls) participated in this study. Twenty-four-hour BP was recorded by auscultatory method using manual standard mercury sphygmomanometer by a single, trained observer. Hypertension was categorised according to the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC-VII) classification.Results:Mean systolic BP (SBP) and diastolic BP (DBP) in cases and controls were 123.4 mmHg (range 112.3–134.6), 81.72 mmHg (range 73.0–90.5); 118.33 mmHg (range 108.4–128.2); and 77.50 mmHg (range 71.4–83.6), respectively. The difference in SBP and DBP was statistically significant at p=0.02 for the former and p=0.006 for the latter. The mean difference in maximum and minimum SBP in cases was 18 (±15.81) mmHg versus 9.04 (±3.08) mmHg in controls (p=0.001). Mean difference for DBP in cases was 15.16 (±7.86) mmHg versus 9.16 (±3.68) mmHg in controls (0.001). On the JNC-VII classification scale for hypertension, 66 % of cases were found to be pre-hypertensive (60 %) or hypertensive (6 %). Comparative figures for controls were pre-hypertension (30 %) and hypertension (2 %). The mean SBP and DBP was consistently higher in patients with CSCR compared with controls over the entire 24-hour period. The difference in variation between maximum and minimum SBP and DBP was also found to be statistically significant between the groups.Conclusion:A significant correlation exists between higher values BP and central serous chorioretinopathy. Screening of CSCR patients for pre-hypertension may be useful in decreasing the risk of progression to established hypertension, with its associated risks.

scholarly journals The Effectiveness of Mix Impact Aerobic Gymnastics Exercises With SKJ 2000 On Improvement of Physical Freshness

2021 ◽  
Vol 12 (03) ◽  
pp. 39-44
Author(s):  
Anik Maryani ◽  
Fahmy Fachrezzy ◽  
Ramdan Pelana
Keyword(s):  
Standard Deviation ◽  
Physical Fitness ◽  
Aerobic Exercise ◽  
Standard Error ◽  
Exercise Group ◽  
Mean Value ◽  
Mean Difference ◽  
Final Test ◽  
The Mean ◽  
The Difference

This study aims to determine the effectiveness of the effect of aerobic mix impact and SKJ 2000 version (core exercise) to improve physical fitness in female students. The research was conducted at SMEA YASMA Sudirman Cijantung for 8 weeks with 24 meetings. The method used is an experimental method with a pre and post-test design. The sampling technique was random sampling from a total of 40 grade 1 students and 30 samples were taken. The data collection technique used was a physical fitness test using the Indonesian Physical Fitness Test (TKJI). Hypothesis testing uses the t-test at the significant level (α) 0.05. The results showed that the difference between the mean value of the initial test (x) and the final test (y) in the mixed impact aerobic exercise group was obtained = -6.47; the value of the standard deviation of the difference = 1,2; the standard error value of the mean difference = 0.32; and the value becomes = -20,2. The initial test (x) and the final test (y) in the 2000 version of the Physical Fitness exercise obtained the difference in the mean value is = -5; the value of the standard deviation of the difference = 1.1; the standard error value of the mean difference = 0.29; and the value becomes = -17.24. The final test of the mixed impact aerobic exercise group (x) and the final test of the aerobic exercise group (y) version 2000, obtained the mean value of the variable x = 19.33; variable value y = 17; the standard deviation value x = 1.48; standard deviation of the variable y = 2.31; standard error variable x = 0.4; standard error for the variable y = 0.62; standard error for the mean difference between x and variable = 0.74; Hypothesis test results obtained t observation = 3.15, at 28 degrees of freedom and a significant level (α) 0.05, the value of t table = 2.048 is obtained. The conclusion of the study is that the effect of mix impact aerobic exercise is more effective in improving physical fitness compared to those using the 2000 version of the fitness gymnastics version of aerobic exercise.

Quantification of the Long-Term Performance of Steels T91 and 316L in Oxygen-Containing Flowing Lead-Bismuth Eutectic at 550°C

2010 ◽  
Vol 132 (8) ◽  
Author(s):  
Carsten Schroer ◽  
Juergen Konys
Keyword(s):  
Liquid Metal ◽  
Dissolved Oxygen ◽  
Martensitic Steel ◽  
Metal Flow ◽  
Liquid Metal Flow ◽  
Lead Bismuth Eutectic ◽  
Long Term Performance ◽  
Term Performance

The long-term performance of ferritic/martensitic steel T91 and austenitic 316L in oxygen-containing flowing lead-bismuth eutectic at 550°C was investigated by exposing the materials for up to 15,000 h in the CORRIDA loop. The velocity of the liquid-metal flow was 2 m/s and the concentration of dissolved oxygen averaged 1.6×10−6 mass %. The resulting corrosion processes and products were analyzed and quantified using metallographic methods.

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