scholarly journals Water vapor observations up to the lower stratosphere through the Raman lidar during the MAïdo LIdar Calibration Campaign

2014 ◽  
Vol 7 (10) ◽  
pp. 10361-10422
Author(s):  
D. Dionisi ◽  
P. Keckhut ◽  
Y. Courcoux ◽  
A. Hauchecorne ◽  
J. Porteneuve ◽  
...  
Keyword(s):  
Water Vapor ◽  
Calibration Procedure ◽  
Relative Difference ◽  
Lamp Method ◽  
Control Procedure ◽  
Significant Difference ◽  
The Mean ◽  
Set Up ◽  
Lidar Calibration ◽  
Good Agreement

Abstract. A new lidar system devoted to tropospheric and lower stratospheric water vapor measurements has been installed at the Maïdo altitude station facility of La Reunion Island, in the southern subtropics. The main objectives of the MAïdo LIdar Calibration Campaign (MALICCA), performed in April 2013, were to validate the system, to set up a calibration methodology, to compare the acquired water profiles with radiosonde measurements and to evaluate its performances and capabilities with a particular focus on the UTLS measurements. Varying the characteristics of the transmitter and the receiver components, different system configuration scenarios were tested and possible parasite signals (fluorescent contamination, rejection) were investigated. A hybrid calibration methodology has been set up and validated to insure optimal lidar calibration stability with time. In particular, the receiver transmittance is monitored through the calibration lamp method that, at the moment, can detect transmittance variations greater than 10–15%. Calibration coefficients are then calculated through the hourly values of IWV provided by the co-located GPS. The comparison between the constants derived by GPS and Vaisala RS92 radiosondes launched at Maïdo during MALICCA, points out an acceptable agreement in terms of accuracy of the mean calibration value (with a difference of approximately 2–3%), but a significant difference in terms of variability (14 vs. 7–9%, for GPS and RS92 calibration procedures, respectively). We obtained a relatively good agreement between the lidar measurements and 15 co-located and simultaneous RS92 radiosondes. A relative difference below 10% is measured in low and middle troposphere (2–10 km). The upper troposphere (up to 15 km) is characterized by a larger spread (approximately 20%), because of the increasing distance between the two sensors. To measure water vapor in the UTLS region, nighttime and monthly water vapor profiles are presented and compared. The good agreement between the lidar monthly profile and the mean WVMR profile measured by satellite MLS has been used as a quality control procedure of the lidar product, attesting the absence of significant wet biases and validating the calibration procedure. Thanks to its performance and location, the MAIDO H2O lidar is devoted to become a reference instrument in the southern subtropics, allowing to insure the long-term survey of the vertical distribution of water vapor, and to document scientific themes such as stratosphere–troposphere exchange, tropospheric dynamics in the subtropics, links between cirrus clouds and water vapor.

scholarly journals Water vapor observations up to the lower stratosphere through the Raman lidar during the Maïdo Lidar Calibration Campaign

2015 ◽  
Vol 8 (3) ◽  
pp. 1425-1445 ◽  
Author(s):  
D. Dionisi ◽  
P. Keckhut ◽  
Y. Courcoux ◽  
A. Hauchecorne ◽  
J. Porteneuve ◽  
...  
Keyword(s):  
Water Vapor ◽  
Lower Stratosphere ◽  
Calibration Procedure ◽  
Lamp Method ◽  
Control Procedure ◽  
Upper Troposphere ◽  
Significant Difference ◽  
The Mean ◽  
Lidar Calibration ◽  
Good Agreement

Abstract. A new lidar system devoted to tropospheric and lower stratospheric water vapor measurements has been installed at the Maïdo altitude station facility of Réunion island, in the southern subtropics. To evaluate the performances and the capabilities of the new system with a particular focus on UTLS (Upper Troposphere Lower Stratosphere) measurements, the Maïdo Lidar Calibration Campaign (MALICCA) was performed in April 2013. Varying the characteristics of the transmitter and the receiver components, different system configuration scenarios were tested and possible parasite signals (fluorescent contamination, rejection) were investigated. A hybrid calibration methodology has been set up and validated to insure optimal lidar calibration stability with time. In particular, the receiver transmittance is monitored through the calibration lamp method that, at the moment, can detect transmittance variations greater than 10–15%. Calibration coefficients are then calculated through the hourly values of IWV (Integrated Water Vapor) provided by the co-located GPS. The comparison between the constants derived by GPS and Vaisala RS92 radiosondes launched at Maïdo during MALICCA, points out an acceptable agreement in terms of accuracy of the mean calibration value (with a difference of approximately 2–3%), but a significant difference in terms of variability (14% vs. 7–9%, for GPS and RS92 calibration procedures, respectively). We obtained a relatively good agreement between the lidar measurements and 15 co-located and simultaneous RS92 radiosondes. A relative difference below 10% is measured in the low and middle troposphere (2–10 km). The upper troposphere (up to 15 km) is characterized by a larger spread (approximately 20%), because of the increasing distance between the two sensors. To measure water vapor in the UTLS region, nighttime and monthly water vapor profiles are presented and compared. The good agreement between the lidar monthly profile and the mean WVMR profile measured by satellite MLS (Microwave Limb Sounder) has been used as a quality control procedure of the lidar product, attesting the absence of significant wet biases and validating the calibration procedure. Due to its performance and location, the MAIDO H2O lidar will become a reference instrument in the southern subtropics, insuring the long-term survey of the vertical distribution of water vapor. Furthermore, this system allows the investigation of several scientific themes, such as stratosphere–troposphere exchange, tropospheric dynamics in the subtropics, and links between cirrus clouds and water vapor.

scholarly journals Prostate-Specific Antigen Density: A Measurement to Differentiate Benign Hypertrophy of Prostate from Prostate Carcinoma

2020 ◽  
Vol 12 (01) ◽  
pp. 44-48
Author(s):  
Chandan Kumar Nath ◽  
Bhupen Barman ◽  
Pranjal Phukan ◽  
Stephen L. Sailo ◽  
Biswajit Dey ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Prostate Specific Antigen ◽  
Sensitivity And Specificity ◽  
Prostate Volume ◽  
Specific Antigen ◽  
Prostate Specific Antigen Density ◽  
Significant Difference ◽  
The Mean ◽  
Set Up ◽  
The Individual

Abstract Background Determination of isolated prostate-specific antigen (PSA) in asymptomatic individuals has not demonstrated sufficient sensitivity and specificity to be useful in the routine evaluation of prostate disease. To enhance the accuracy of serum PSA we have used a proportion of serum PSA and prostate volume, which we refer to as prostate-specific antigen density (PSAD). Prostate volume in this study was calculated using transrectal ultrasonography (TRUS). Materials and Methods A total of 106 patients with prostatic disease clinically confined to the prostate glands were evaluated. Results and Observation The mean PSAD for prostate cancer was 0.15 ± 0.01 while that for benign hypertrophy of the prostate (BPH) was 0.11 ± 0.02 (p < 0.05). Significant difference (p < 0.05) was noted in the prostate volume in these two groups with the mean prostate volume measured by TRUS in the BPH to be 53.85 ± 9.71 mL compared with 58.14 ± 7.48 mL in the carcinoma. PSA density of 0.13 ng/mL can be used as a cutoff for the individual in our set-up who should go for prostate biopsy with sensitivity and specificity of over 90%. Conclusion These results suggest that PSAD may be useful in distinguishing BPH and prostate cancer.

The crystal and molecular structure of thioformaldehyde trimer

1967 ◽  
Vol 45 (4) ◽  
pp. 353-357 ◽  
Author(s):  
J. E. Fleming ◽  
H. Lynton
Keyword(s):  
Crystal And Molecular Structure ◽  
Three Dimensional ◽  
Bond Distance ◽  
Orthorhombic Space Group ◽  
Significant Difference ◽  
The Mean ◽  
Temperature Factors ◽  
No Absorption ◽  
Good Agreement ◽  
Atomic Parameters

Crystals of thioformaldehyde trimer, (CH2S)3 are orthorhombic, space group Pmn21 with a = 7.697 Å [Formula: see text], b = 7.067 Å [Formula: see text], c = 5.323 Å [Formula: see text]. There are two molecules in the unit cell with sulfur and carbon atoms in positions (4b) and (2a). The atomic parameters for sulfur and carbon have been determined from a three-dimensional analysis using observed and calculated differential syntheses with isotropic temperature factors. No absorption corrections were applied to the intensity data and no attempt has been made to establish the hydrogen positions. The final discrepancy index is R = 0.093. The molecule has the chair configuration and shows no significant difference between the lengths of any S—C bonds. The mean S—C bond distance is 1.818 Å and the standard deviation of the mean is 0.003 Å. This value is in good agreement with the commonly accepted value of 1.817 ± 0.005 Å for the S—C paraffinic bond.

scholarly journals Validation of HNO<sub>3</sub>, ClONO<sub>2</sub>, and N<sub>2</sub>O<sub>5</sub> from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS)

2008 ◽  
Vol 8 (13) ◽  
pp. 3529-3562 ◽  
Author(s):  
M. A. Wolff ◽  
T. Kerzenmacher ◽  
K. Strong ◽  
K. A. Walker ◽  
M. Toohey ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Atmospheric Chemistry ◽  
Relative Difference ◽  
Fourier Transform Spectrometer ◽  
Infrared Wavelength ◽  
Key Species ◽  
The Mean ◽  
Chemistry Experiment ◽  
Good Agreement

Abstract. The Atmospheric Chemistry Experiment (ACE) satellite was launched on 12 August 2003. Its two instruments measure vertical profiles of over 30 atmospheric trace gases by analyzing solar occultation spectra in the ultraviolet/visible and infrared wavelength regions. The reservoir gases HNO3, ClONO2, and N2O5 are three of the key species provided by the primary instrument, the ACE Fourier Transform Spectrometer (ACE-FTS). This paper describes the ACE-FTS version 2.2 data products, including the N2O5 update, for the three species and presents validation comparisons with available observations. We have compared volume mixing ratio (VMR) profiles of HNO3, ClONO2, and N2O5 with measurements by other satellite instruments (SMR, MLS, MIPAS), aircraft measurements (ASUR), and single balloon-flights (SPIRALE, FIRS-2). Partial columns of HNO3 and ClONO2 were also compared with measurements by ground-based Fourier Transform Infrared (FTIR) spectrometers. Overall the quality of the ACE-FTS v2.2 HNO3 VMR profiles is good from 18 to 35 km. For the statistical satellite comparisons, the mean absolute differences are generally within ±1 ppbv ±20%) from 18 to 35 km. For MIPAS and MLS comparisons only, mean relative differences lie within±10% between 10 and 36 km. ACE-FTS HNO3 partial columns (~15–30 km) show a slight negative bias of −1.3% relative to the ground-based FTIRs at latitudes ranging from 77.8° S–76.5° N. Good agreement between ACE-FTS ClONO2 and MIPAS, using the Institut für Meteorologie und Klimaforschung and Instituto de Astrofísica de Andalucía (IMK-IAA) data processor is seen. Mean absolute differences are typically within ±0.01 ppbv between 16 and 27 km and less than +0.09 ppbv between 27 and 34 km. The ClONO2 partial column comparisons show varying degrees of agreement, depending on the location and the quality of the FTIR measurements. Good agreement was found for the comparisons with the midlatitude Jungfraujoch partial columns for which the mean relative difference is 4.7%. ACE-FTS N2O5 has a low bias relative to MIPAS IMK-IAA, reaching −0.25 ppbv at the altitude of the N2O5 maximum (around 30 km). Mean absolute differences at lower altitudes (16–27 km) are typically −0.05 ppbv for MIPAS nighttime and ±0.02 ppbv for MIPAS daytime measurements.

scholarly journals Validation of HNO<sub>3</sub>, ClONO<sub>2</sub>, and N<sub>2</sub>O<sub>5</sub> from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS)

2008 ◽  
Vol 8 (1) ◽  
pp. 2429-2512 ◽  
Author(s):  
M. A. Wolff ◽  
T. Kerzenmacher ◽  
K. Strong ◽  
K. A. Walker ◽  
M. Toohey ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Atmospheric Chemistry ◽  
Relative Difference ◽  
Fourier Transform Spectrometer ◽  
Infrared Wavelength ◽  
Key Species ◽  
The Mean ◽  
Chemistry Experiment ◽  
Good Agreement

Abstract. The Atmospheric Chemistry Experiment (ACE) satellite was launched on 12 August 2003. Its two instruments measure vertical profiles of over 30 atmospheric trace gases by analyzing solar occultation spectra in the ultraviolet/visible and infrared wavelength regions. The reservoir gases HNO3, ClONO2, and N2O5 are three of the key species provided by the primary instrument, the ACE Fourier Transform Spectrometer (ACE-FTS). This paper describes the ACE-FTS version 2.2 data products, including the N2O5 update, for the three species and presents validation comparisons with available observations. We have compared volume mixing ratio (VMR) profiles of HNO3, ClONO2, and N2O5 with measurements by other satellite instruments (SMR, MLS, MIPAS), aircraft measurements (ASUR), and single balloon-flights (SPIRALE, FIRS-2). Partial columns of HNO3 and ClONO2 were also compared with measurements by ground-based Fourier Transform Infrared (FTIR) spectrometers. Overall the quality of the ACE-FTS v2.2 HNO3 VMR profiles is good from 18 to 35 km. For the statistical satellite comparisons, the mean absolute differences are generally within ±1 ppbv (±20%) from 18 to 35 km. For MIPAS and MLS comparisons only, mean relative differences lie within ±10% between 10 and 36 km. ACE-FTS HNO3 partial columns (~15–30 km) show a slight negative bias of −1.3% relative to the ground-based FTIRs at latitudes ranging from 77.8° S–76.5° N. Good agreement between ACE-FTS ClONO2 and MIPAS, using the Institut für Meteorologie und Klimaforschung and Instituto de Astrofísica de Andalucía (IMK-IAA) data processor is seen. Mean absolute differences are typically within ±0.01 ppbv between 16 and 27 km and less than +0.09 ppbv between 27 and 34 km. The ClONO2 partial column comparisons show varying degrees of agreement, depending on the location and the quality of the FTIR measurements. Good agreement was found for the comparisons with the midlatitude Jungfraujoch partial columns for which the mean relative difference is 4.7%. ACE-FTS N2O5 has a low bias relative to MIPAS IMK-IAA, reaching −0.25 ppbv at the altitude of the N2O5 maximum (around 30 km). Mean absolute differences at lower altitudes (16–27 km) are typically −0.05 ppbv for MIPAS nighttime and ±0.02 ppbv for MIPAS daytime measurements.

Computed Tomographic Evaluation of the Position of the Leg for Mortise Radiographs

2001 ◽  
Vol 22 (10) ◽  
pp. 828-831 ◽  
Author(s):  
Masato Takao ◽  
Mitsuo Ochi ◽  
Kohei Naito ◽  
Atsushi Iwata ◽  
Yuji Uchio ◽  
...  
Keyword(s):  
Internal Rotation ◽  
Rotation Angle ◽  
Average Height ◽  
Computed Tomographic ◽  
Foot Length ◽  
Significant Difference ◽  
Tibiofibular Joint ◽  
Internal Rotation Angle ◽  
The Mean ◽  
Set Up

We investigated the most advantageous internal rotation angle of the leg for mortise radiographs. One hundred and twenty-eight feet of 64 healthy volunteers with no histories of ankle or foot pathology (72 feet of 36 males, 56 feet of 28 females) were examined. The subjects had an average age of 29 years (range, 19 to 51 years), average height of 167 cm (range, 157 to 181 cm), and average foot length of 25 cm (range, 23 to 27 cm). We obtained a plain axial view at the level of the central patella and 5 mm proximal to the tibial plafond using computed tomography, and investigated the inclination angle of the distal tibiofibular joint to a horizontal plane, regarding it as a mortise angle. The mean mortise angle was 19.1 + 5.0°. However, two peaks were observed at around 15° and 20°. This indicated that the mean mortise angle of the males was 21.2 + 4.6°, and the mean mortise angle of the females was 16.4 + 4.1°, with a significant difference between the males and the females' mortise angle (P < 0.0001). There was no correlation between the mortise angle and the height (P = 0.899 in the males, and P = 0.871 in the females), nor between the mortise angle and the foot length (P = 0.359 in the males, and P = 0.512 in the females). Therefore, we concluded that the internal rotation angle of the leg for mortise radiography should be generally set up at about 20° on males and 15° on females.

Pattern of Hypothyroidism with Liver Cirrhosis among Indian population

2015 ◽  
Vol 4 (5) ◽  
pp. 247-251
Author(s):  
Ekta Chitkara ◽  
Abdikarem Abdulahi ◽  
Anania Arjuna
Keyword(s):  
Liver Disease ◽  
Inorganic Ions ◽  
Vital Role ◽  
The Body ◽  
Chronic Liver ◽  
P Value ◽  
Nonalcoholic Fatty Liver ◽  
Significant Difference ◽  
The Mean ◽  
Set Up

  The thyroid plays a vital role in the overall body function during all stages of life. Although relatively small, it produces hormones that regulate the body’s overall metabolism ,the rate at which the body produces energy from nutri-ents. Thyroid hormones influence growth and development, oxygen con-sumption and heat production, nerve function and metabolism of lipids , carbohydrates ,proteins, nucleic acids ,vitamins and inorganic ions. Cirrhosis and chronic liver failure are leading causes of morbidity and mortality in the whole the world-with the majority of preventable cases attributed to exces-sive alcohol consumption, viral hepatitis or nonalcoholic fatty liver disease. The main objective of the study is to assess the relationship and interconnec-tion between hypothyroidism and chronic liver disease specially cirrhosis patients. All patients selected for this study were diagnosed as type of cir-rhosis in the line with the criteria set up by WHO. The study is comparative study containing two groups (1) cases and (2) controls. The result showed that TSH increased, T3 slightly decreased and T4 seems normal where the P value is 0.039,0.014 and 0.245 respectively. The mean of TSH levels of cir-rhotic patients is higher than the mean of non cirrhotic subjects and show significant difference. And also there are significant difference for T4 and T3 between two groups.

A Circuit Approach to the Calculation of Lightning Transients in Cage-like Multiconductor Systems

2010 ◽  
Vol 47 (2) ◽  
pp. 213-222 ◽  
Author(s):  
Xiaoqing Zhang
Keyword(s):  
Fourier Transform ◽  
Efficient Algorithm ◽  
Potential Method ◽  
Equivalent Network ◽  
Transient Responses ◽  
The Mean ◽  
Impedance Parameters ◽  
Set Up ◽  
Good Agreement

An efficient algorithm is proposed for calculating lightning transients in cage-like multiconductor systems. Capacitance and impedance parameters of the conducting branches are evaluated by the mean potential method and Neumann's formula, respectively. The equivalent network is formed for the multiconductor systems by a series of coupled π-type circuits. The lightning transient responses in the multiconductor systems are then obtained using Fourier transform. When the algorithm was tested using an experimental set-up, good agreement was found between the calculated and measured results.

scholarly journals CT-Dose Measurement of the Spinal Cord Region Using XR-QA2 Radiochromic Films and TLD 100H Dosimeters

Instruments ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 19
Author(s):  
Martina Pace ◽  
Giuseppe Stella ◽  
Letizia Barone Tonghi ◽  
Stefania Mazzaglia ◽  
Anna Maria Gueli
Keyword(s):  
Spinal Cord ◽  
Calibration Procedure ◽  
Current Output ◽  
Radiochromic Films ◽  
Ct Dose ◽  
Medical Exposure ◽  
The Mean ◽  
Ct System ◽  
Dose Measurements ◽  
Good Agreement

The European Directive 2013/59/Euratom focuses on the radiation protection and patient dosimetry. In particular, the dose absorbed by serial organs such as the spinal cord due to diagnostic exams plays a crucial role in the appraisal of medical exposure. In this work, a comparison between dose measurements performed with GafchromicTM XR-QA2 and TLD 100H is presented. The dosimeters—after a calibration procedure through an X-ray tube—were placed within the thorax region of an anthropomorphic phantom corresponding to the spinal cord area exposed to a thoracic CT procedure. The mean-dose value was measured with GafchromicTM first, and it was then compared to the dose value obtained with TLDs, resulting in a good agreement between the two dosimetric methodologies. Additionally, the results showed that—due to the usage of the automatic exposure control (EC) system—the discrepancy between the two methods is proportional to the current output of the CT system.

scholarly journals Automatic Lidar Calibration and Processing Program for Multiwavelength Raman Polarization Lidar

2020 ◽  
Vol 237 ◽  
pp. 08007
Author(s):  
Zhenping Yin ◽  
Holger Baars ◽  
Patric Seifert ◽  
Ronny Engelmann
Keyword(s):  
Water Vapor ◽  
Mixing Ratio ◽  
Extinction Coefficients ◽  
Good Consistency ◽  
Processing Program ◽  
Lidar Ratio ◽  
Water Vapor Mixing Ratio ◽  
Lidar Calibration ◽  
Aerosol Backscatter ◽  
Good Agreement

A new version of automatic lidar calibration and processing program was developed to process the data from multiwavelength Raman polarization lidar. The absolute lidar calibration and water vapor calibration algorithms were applied. The program can provide plentiful products, like aerosol backscatter and extinction coefficients, lidar ratio, Ångström exponent, volume and particle depolarization ratios, water vapor mixing ratio and aerosol target classification. Good agreement was found in the comparison with manual quality-assured profiles or radiosonde measurement. Lidar calibration based on the aerosol optical properties retrieved with Raman method, Klett method and AOD-Constrained method were implemented. Good consistency was found.

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