scholarly journals The accuracy of the determination of terrestrial refraction from reciprocal zenith angles

1979 ◽  
Vol 89 ◽  
pp. 203-212 ◽  
Author(s):  
K. Ramsayer
Keyword(s):  
Mean Difference ◽  
Mean Deviation ◽  
Refraction Coefficient ◽  
Refraction Angle ◽  
Observation Station ◽  
The Mean ◽  
True Values ◽  
Better Than

To investigate the accuracy of the determination of terrestrial refraction from reciprocal zenith angles and astronomical latitudes and longitudes at both ends of a line a test net with lines from 4 km to 23 km was observed and three dimensionally adjusted. As the measurements of the zenith angles were repeated every hour 40 times in an average the adjusted values were taken as a substitute for the true values. It is shown, that the mean refraction coefficient k, which is changing from k = 0.10 at day up to k = 0.34 at night, and the corresponding refraction angle can be determined very accurately, if both angles are measured simultaneously. Observations with day light are better than observations in the night. For observations with day light the mean difference between the true refraction angle at the observation station and the mean refraction angle of the observed line was smaller than ± 1″ independent of the length of the line. That means that the mean deviation of the true effective refraction coefficient in the observation station and the mean refraction coefficient of the observed line was inverse proportional to the distance.

Dosage du Sr-90 dans l'eau des lacs et des rivières du Québec par précipitation avec l'oxine et comptage β

1988 ◽  
Vol 66 (1) ◽  
pp. 174-177 ◽  
Author(s):  
E. Haddad ◽  
L. Zikovsky
Keyword(s):  
Detection Limit ◽  
Surface Waters ◽  
New Method ◽  
The Mean ◽  
Better Than

A new method for the determination of Sr-90 dissolved in surface waters has been developed. It is based on the precipitation of Sr with 8-hydroxyquinoline at pH 11.3 and counting of β particles with energy above 150 keV. The detection limit obtained is 0.5 mBq/L and the mean yield is 28%. The decontamination factors from other β emitters achieved are better than 10 000. This method has been used to measure the Sr-90 in 5 lakes and 5 rivers in Québec and activities ranging from 3 to 15 mBq/L were obtained. This new method is as efficient and reliable as conventional techniques while being less tedious.

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.

Determination of Ibuprofen in Human Plasma and Urine by Gas Chromatography/Mass Spectrometry

2014 ◽  
Vol 97 (2) ◽  
pp. 415-420 ◽  
Author(s):  
Bilal Yilmaz ◽  
Ali Fuat Erdem
Keyword(s):  
Human Plasma ◽  
Internal Standard ◽  
Gas Chromatography Mass Spectrometry ◽  
Oral Tablet ◽  
Liquid Liquid Extraction ◽  
Human Plasma And Urine ◽  
The Mean ◽  
Interday Precision ◽  
Better Than

Abstract This paper describes a GC/MS method for the determination of ibuprofen in human plasma and urine. Ibuprofen and internal standard naproxen were extractedfrom plasma and urine by using a liquid–liquid extraction method. Derivatization was carried outusing N-methyl-N-(trimethylsilyl) trifluoroacetamide. Calibration curves were linear over the concentration range of 0.05–5.0 and 0.1–10.0 μg/mL for plasma and urine, respectively. Intraday and interday precision (RSD) values for ibuprofen in plasma and urine were less than 6.31%, and accuracy (relative error) was better than 12.00%. The mean recovery of ibuprofen was 89.53% for plasma and 93.73% for urine. TheLOD was 0.015 and 0.03 μg/mL and the LOQ was 0.05 and 0.1 μg/mL for plasma and urine, respectively. The method was successfully applied to blood samples from three healthy male volunteers who had been given an oral tablet of 600 mg ibuprofen.

THE MAINTENANCE OF A STANDARD OF ELECTROMOTIVE FORCE: NOTES ON STANDARD WESTON CELLS

1930 ◽  
Vol 3 (5) ◽  
pp. 473-489
Author(s):  
A. Norman Shaw ◽  
H. E. Reilley
Keyword(s):  
Electromotive Force ◽  
Essential Feature ◽  
Mean Deviation ◽  
Entire Group ◽  
Standard Cells ◽  
Characteristics Analysis ◽  
A Cell ◽  
The Mean ◽  
The Difference

A detailed procedure for the maintenance of a standard of voltage to within one or two parts in a million is described.In so far as these investigations have proceeded, neutral saturated cells have been found to be superior to acid cells as independent standards for a period of many years, though the latter are preferable for purposes of ordinary precision or shorter periods. The recommended code of procedure is briefly as follows: a number of cells should be constructed according to standard specifications with the new requirements of uniformity of container and speed of preparation, and observations made upon them every few days for a period of three months. The differences in electromotive force (at constant temperature) should be determined between each cell in the group and any one of them chosen arbitrarily as reference cell, and certain new selection and rejection rules applied. In accordance with these rules a cell should be rejected: (a) if its deviation from the mean electromotive force of the group has increased or decreased by 10 microvolts or more during the preceding two weeks; or (b) if it differs in electromotive force from the mean of the group by more than 10 +d microvolts where d is the mean deviation of the cells of the group. If d exceeds 20 microvolts the entire group should be considered untrustworthy. The selected cells should be observed for three additional months, the rejection rules again applied and if a specified proportion survive elimination, the initial reference mean of the laboratory may be established.At intervals of several months additional groups of cells, neutral and acid, should be constructed and exchanges made with laboratories possessing cells of known characteristics. Analysis of the resulting observations determines: (a) the constants in the aging* equation for the reference batch, and (b) the difference between the initial reference mean of the laboratory and the estimated value of the international reference mean.Examples of the analysis of cell observations are given, illustrating the establishment of the initial reference mean, the recapture of this value when the aging coefficients are known, and the preliminary determination of the aging equation for a given group of cells. The use of the aging equation is found to be the essential feature in the attainment of increased precision.A summary of data on standard cells is included.

Frequency resolution of Fourier and maximum entropy spectral estimates

Geophysics ◽  
1982 ◽  
Vol 47 (9) ◽  
pp. 1303-1307 ◽  
Author(s):  
S. L. Marple
Keyword(s):  
Maximum Entropy ◽  
Signal To Noise Ratio ◽  
Frequency Resolution ◽  
Sampled Data ◽  
Signal To Noise ◽  
Analytic Determination ◽  
Spectral Estimates ◽  
The Mean ◽  
Better Than

An analytic determination of the frequency resolution for maximum entropy and conventional Blackman‐Tukey spectral estimates is made for the case of known autocorrelation. As the signal‐to‐noise ratio decreases, the maximum entropy resolution is no better than that achievable by the Blackman‐Tukey spectral estimate. The mean resolution of an ensemble of spectra constructed from sampled data sequences agrees with the analytic result.

scholarly journals An Advanced Method to Estimate Deep Currents from Profiling Floats

2005 ◽  
Vol 22 (8) ◽  
pp. 1294-1304 ◽  
Author(s):  
Jong Jin Park ◽  
Kuh Kim ◽  
Brian A. King ◽  
Stephen C. Riser
Keyword(s):  
Indian Ocean ◽  
Accurate Determination ◽  
New Method ◽  
Advanced Method ◽  
Subsurface Ocean ◽  
Least Squares Fit ◽  
Geostrophic Shear ◽  
The Mean ◽  
Better Than

Abstract Subsurface ocean currents can be estimated from the positions of drifting profiling floats that are being widely deployed for the international Argo program. The calculation of subsurface velocity depends on how the trajectory of the float while on the surface is treated. The following three aspects of the calculation of drift velocities are addressed: the accurate determination of surfacing and dive times, a new method for extrapolating surface and dive positions from the set of discrete Argos position fixes, and a discussion of the errors in the method. In the new method described herein, the mean drift velocity and the phase and amplitude of inertial motions are derived explicitly from a least squares fit to the set of Argos position fixes for each surface cycle separately. The new method differs from previous methods that include prior assumptions about the statistics of inertial motions. It is concluded that the endpoints of the subsurface trajectory can be estimated with accuracy better than 1.7 km (East Sea/Sea of Japan) and 0.8 km (Indian Ocean). All errors, combined with the error that results from geostrophic shear and extrapolation, should result in individual subsurface velocity estimates with uncertainty of the order of 0.2 cm s−1.

A MICROMETHOD FOR THE DETERMINATION OF SUGARS

1950 ◽  
Vol 28b (11) ◽  
pp. 676-682 ◽  
Author(s):  
J. E. Stone ◽  
M. J. Blundell
Keyword(s):  
Phosphoric Acid ◽  
Steam Distillation ◽  
Mean Deviation ◽  
Paper Strip ◽  
The Mean ◽  
Time Required

Certain pentoses and hexoses were determined by measuring spectrophotometrically the yields of furfural and hydroxymethylfurfural obtained on steam distilling with syrupy phosphoric acid. The yields, based on the theoretical recovery, were increased by increasing the temperature and the rate of steam distillation, and by decreasing the amount of sugar. At a steam rate producing 10 ml. per min. of distillate, at 195 °C. externally applied temperature, and with 2 mgm. sugar, the yields of aldehyde were from xylose 91.0%, ribose 74.9%, arabinose 60.6%, rhamnose 55.9%, galactose 20.0%, and glucose 15.5%. As little as 0.1 mgm. of each could be determined in this way, the mean deviation being usually less than ± 3% and the time required less than 10 min. Mixtures of sugars have been separated on a paper strip chromatogram and the individuals determined, without separate extraction, by steam distilling into phosphoric acid.

scholarly journals Comparison of Two Storage Methods for the Analysis of Cholinesterase Activities in Food Animals

2010 ◽  
Vol 2010 ◽  
pp. 1-11 ◽  
Author(s):  
Kasim Abass Askar ◽  
A. Caleb Kudi ◽  
A. John Moody
Keyword(s):  
Significant Inhibition ◽  
Mean Difference ◽  
Altman Plot ◽  
Choline Esters ◽  
Cholinesterase Activities ◽  
The Mean ◽  
Storage Methods ◽  
Lower Limits ◽  
Hydrolysis Of

Cholinesterases (ChE) are specialized carboxylic ester hydrolases that catalyse the hydrolysis of choline esters. They are classified into either acetylcholinesterase (AChE) or butyrylcholinesterase (BChE). Determination of ChE in the tissues is the appropriate tool for the diagnosis of organophosphorus and carbamate exposures. In general, a significant inhibition was seen in both AChE and BChE activities after 6 months of freezing at −80°C and after 3 months of freezing at −20°C. Linear regression of mean AChE and BChE was observed in all individual samples during the months of the two freezing methods. Bland and Altman plot of the ratios of the two freezing methods have showen the mean difference between the two freezing methods to be 8.8, and SD was 144.7 and −127.6 for upper and lower limits, respectively, for liver, while in muscle the mean difference was 1.5 and SD was 32.5 and −28.9 for upper and lower limits, respectively.

scholarly journals Internet of Things Based Learning Media with Problem Solving Approach: Its Effect on Higher Order Thinking Skills

2020 ◽  
Vol 9 (2) ◽  
pp. 225-239
Author(s):  
Yeni Rima Liana ◽  
Suharto Linuwih ◽  
Sulhadi Sulhadi
Keyword(s):  
Problem Solving ◽  
Field Testing ◽  
Thinking Skills ◽  
Mean Difference ◽  
Control Group ◽  
Research Subjects ◽  
Central Java ◽  
The Mean ◽  
Experimental Group ◽  
Better Than

This research analyzed media feasibility and effectiveness based on IoT with a problem-solving approach that provides real experience to improve students' HOTS on thermodynamics law material. The Borg Gall method's research development simplification had three stages: preliminary study, development, and field testing. The research subjects consisted of four lecturers as expert validators, two physics teachers, and three groups consisting of 108 in science XI grade students of Senior High School in Batang Regency, Central Java. Data collecting techniques were using questionnaires, observation, interviews, and written tests. The results of the validation of media experts and material experts were 3.84 and 3.75, respectively. The results of teacher responses and students' responses were 3.92 and 3.50 in the excellent category. The product's effective contribution to improving HOTS from the Multivariate Test analysis on GLM based on the partial eta squared value was 85.9%. The mean difference (MD) test results were -30.600 for the experimental group, while the control groups were -5.879 and -16.125, respectively. The more negative the Mean Difference (MD) score, the higher the students' HOTS. This shows that there is an experimental group giving improved scores better than the control group. This shows that there is an experimental group giving improved scores better than the control group. IoT is an opportunity for teachers to see technology as part of education because technology is the current millennial generation's cultural artifact.

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