scholarly journals UV aerosol indices from SCIAMACHY: introducing the SCattering Index (SCI)

2009 ◽  
Vol 9 (3) ◽  
pp. 13569-13592 ◽  
Author(s):  
M. Penning de Vries ◽  
S. Beirle ◽  
T. Wagner
Keyword(s):  
Aerosol Absorption ◽  
Southeast Usa ◽  
Sulphate Aerosols ◽  
Correct Determination ◽  
High Production ◽  
Absorbing Aerosols ◽  
Scattering Index ◽  
Aerosol Index ◽  
Good Agreement

Abstract. The Absorbing Aerosol Index (AAI) is a useful tool for detecting aerosols that absorb UV radiation – especially in cases where other aerosol retrievals fail, such as over bright surfaces (e.g. desert) and in the presence of clouds. The AAI does not, however, consider contributions from "scattering" (hardly absorbing) aerosols and clouds: they cause negative AAI values and are usually discarded. In this paper, we demonstrate the use of the AAI's negative counterpart, the SCattering Index (SCI) to detect "scattering" aerosols. Maps of seasonally averaged SCI show significantly enhanced values in summer in Southeast USA and Southeast Asia, pointing to high production of "scattering" aerosols (presumably mainly sulphate aerosols and organic aerosols) in this season. The application of a cloud filter makes the presence of "scattering" aerosols even more clear. In a comparison of AOT from AERONET and our Aerosol Indices from SCIAMACHY, good agreement was found for two AERONET stations in Southeast USA, and two stations in Africa. This fact confirms the suitability of SCI as a tool to detect "scattering" aerosols. The combination of the UV Aerosol Indices AAI and SCI provides the unique possibility to characterise absorbing properties of aerosols from space. Accurate knowledge about aerosol absorption is crucial for the correct determination of the contribution of aerosols to the radiative budget.

scholarly journals UV Aerosol Indices from SCIAMACHY: introducing the SCattering Index (SCI)

2009 ◽  
Vol 9 (24) ◽  
pp. 9555-9567 ◽  
Author(s):  
M. J. M. Penning de Vries ◽  
S. Beirle ◽  
T. Wagner
Keyword(s):  
Southeast Asia ◽  
Cloud Parameters ◽  
Aerosol Absorption ◽  
Southeast Usa ◽  
Special Cases ◽  
Quantitative Manner ◽  
Absorbing Aerosols ◽  
Aerosol Parameters ◽  
Scattering Index ◽  
Aerosol Index

Abstract. The Absorbing Aerosol Index (AAI) is a useful tool for detecting aerosols that absorb UV radiation – especially in cases where other aerosol retrievals fail, such as over bright surfaces (e.g. desert) and in the presence of clouds. The AAI does not, however, consider contributions from scattering (hardly absorbing) aerosols and clouds: they cause negative AAI values and are usually disregarded. In this paper, we demonstrate the use of the AAI's negative counterpart, the SCattering Index (SCI) to detect scattering aerosols. Consideration of the full UV Aerosol Index scale is of importance if the Aerosol Index is to be used for the quantification of aerosol absorption in the future. Maps of seasonally averaged SCI show significantly enhanced values in summer in Southeast USA and Southeast Asia, pointing to a high production of scattering aerosols (presumably mainly sulphate aerosols and secondary organic aerosols) in this season. The application of a cloud filter makes the presence of scattering aerosols even more clear. Radiative transfer calculations were performed to investigate the sensitivity of AAI and SCI to cloud parameters, and it is demonstrated that clouds cause significant SCI, in some special cases even small AAI values. The results from cloud modelling imply that cloud effects need to be taken into account when AAI and SCI are used in a quantitative manner. The paper concludes with a comparison of aerosol parameters from AERONET and our Aerosol Indices (AAI and SCI) from SCIAMACHY, where reasonable agreement was found for six AERONET stations in Southeast USA, Southeast Asia, and Africa. These findings corroborate the suitability of SCI as a tool to detect scattering aerosols.

Evaluating Modelled Aerosol Absorption by Simulating the UV Aerosol Index using Machine Learning

2020 ◽  
Author(s):  
Jiyunting Sun ◽  
J.Pepijn Veefkind ◽  
Peter van Velthoven ◽  
Pieternel.F Levelt
Keyword(s):  
Machine Learning ◽  
Radiative Forcing ◽  
Training Data ◽  
Transfer Model ◽  
Data Set ◽  
Aerosol Absorption ◽  
Model Aerosol ◽  
Absorbing Aerosols ◽  
Aerosol Index ◽  
Aerosol Properties

<p>The environmental effects of absorbing aerosols are complex: they warm the surface and the atmosphere on a large scale, while locally they cool the surface. Absorbing aerosols also affect precipitation and cloud formation. A comprehensive understanding of aerosol absorption is important to reduce the uncertainties in aerosol radiative forcing assessments. The ultraviolet aerosol index (UVAI) is a qualitative measure of aerosol absorption provided by multiple satellite missions since 1978. UVAI is directly calculated by the difference between the measured spectral contrast and the simulated ones in the near-UV channel, without assumptions on aerosol properties. This long-term global daily data set is advantageous for many applications. In previous work, we have attempted to derive the single scattering albedo (SSA) from UVAI. In this work, we evaluate the UVAI derived from a chemistry transport model (CTM) with satellite observations. Conventionally, UVAI from a model aerosol fields at a satellite footprint is simulated using a radiative transfer model. In order to do this, one has to make assumptions on the spectral dependence of the aerosol optical properties. The lack of measurements and our poor knowledge of these properties may lead to large uncertainties in the simulated UVAI, and these uncertainties are difficult to quantify. In this work, we propose an alternative method, that is to simulate the UVAI based on Machine Learning (ML) approaches. A training data set is constructed by independent measurements and/or model simulations with strict quality controls. We simulate the UVAI using modelled aerosol properties, the Sun-satellite geometry and the surface parameters. The discrepancy between the retrieved UVAI and the ML predictions can help us to identify the unrealistic inputs of aerosol absorption in the model.</p>

scholarly journals Electron fluence determination per Monitor Unit of a linear accelerator used for radiation therapy

2019 ◽  
Vol 18 ◽  
pp. 204
Author(s):  
A. Makridou ◽  
C. Tziaka ◽  
M. Fragopoulou ◽  
S. Stoulos ◽  
M. Zamani
Keyword(s):  
Linear Accelerator ◽  
Ionization Chamber ◽  
Electron Flux ◽  
Electron Beams ◽  
Monitor Unit ◽  
Proper Treatment ◽  
Activation Detector ◽  
Correct Determination ◽  
Good Agreement

About 20% of patients in Greece undergoing radiotherapy were irradiated by electron beams with energies ranged between 4 to 20 MeV. The correct determination of electron beam, leads to the proper treatment planning. In this study electron fluence at the isocenter was determined for a linear accelerator ELECTA SL 20 for nominal electron energy of 20 MeV. Two methods have been applied using (a) an ionization chamber in the frame of monthly quality assurance and activation detector (238U). The experimental estimated electron flux, which was in good agreement with the applied calculations using the data of irradiation procedure, ranged between 3.5 up to 4.3 x 108 electrons per cm 2 per sec or 6.1 ±0.7 x 10^7 e.cm-2 per MU.

COMPARATIVE ACTION OF VARIOUS OESTROGENIC COMPOUNDS ON MOUSE VAGINAL SIALIC ACIDS (II)

1969 ◽  
Vol 62 (4) ◽  
pp. 663-670 ◽  
Author(s):  
Lars Carlborg
Keyword(s):  
Sialic Acid ◽  
Response Curve ◽  
Sialic Acids ◽  
Clear Cut ◽  
Suitable Parameter ◽  
Sufficient Degree ◽  
Comparative Action ◽  
Relative Potencies ◽  
Good Agreement

ABSTRACT Oestrogens administered in lower doses than necessary to induce full cornification of the mouse vagina induce mucification. It was shown previously that the degree of mucification could be estimated by quantitative determination of sialic acids. A suitable parameter for oestrogen assay was the measurement of vaginal sialic acid concentration which exhibited a clear cut dose response curve. Eleven assays of various oestrogens were performed with this method. Their estimated relative potencies were in good agreement with other routine oestrogen assays. A statistically sufficient degree of precision was found. The sensitivity was of the same order, or slightly higher, than the Allen-Doisy test.

An Automated Method for the Determination of Serum Calcium with Glyoxal Bis (2-Hydroxyanil)

1967 ◽  
Vol 13 (6) ◽  
pp. 515-520 ◽  
Author(s):  
Genevieve Farese ◽  
Janice L Schmidt ◽  
Milton Mager
Keyword(s):  
Serum Calcium ◽  
Automated Analysis ◽  
Automated Method ◽  
Good Agreement

Abstract A completely automated analysis is described for the determination of serum calcium with glyoxal bis (2-hydroxyanil) solution (GBHA). The method is simple and precise, and the data obtained are in good agreement with results obtained by the manual GBHA procedure.

Numerical evaluation of hydrodynamic characteristics of planing hulls by using a hybrid method

2021 ◽  
pp. 147509022199024
Author(s):  
Emre Kahramanoglu ◽  
Silvia Pennino ◽  
Huseyin Yilmaz
Keyword(s):  
Experimental Data ◽  
Hybrid Method ◽  
Design Stage ◽  
Hydrodynamic Characteristics ◽  
Calm Water ◽  
Preliminary Design Stage ◽  
Reduction Function ◽  
Hull Forms ◽  
Good Agreement

The hydrodynamic characteristics of the planing hulls in particular at the planing regime are completely different from the conventional hull forms and the determination of these characteristics is more complicated. In the present study, calm water hydrodynamic characteristics of planing hulls are investigated using a hybrid method. The hybrid method combines the dynamic trim and sinkage from the Zarnick approach with the Savitsky method in order to calculate the total resistance of the planing hull. Since the obtained dynamic trim and sinkage values by using the original Zarnick approach are not in good agreement with experimental data, an improvement is applied to the hybrid method using a reduction function proposed by Garme. The numerical results obtained by the hybrid and improved hybrid method are compared with each other and available experimental data. The results indicate that the improved hybrid method gives better results compared to the hybrid method, especially for the dynamic trim and resistance. Although the results have some discrepancies with experimental data in terms of resistance, trim and sinkage, the improved hybrid method becomes appealing particularly for the preliminary design stage of the planing hulls.

scholarly journals An SPRi Biosensor for Determination of the Ovarian Cancer Marker HE4 in Human Plasma

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3567
Author(s):  
Beata Szymanska ◽  
Zenon Lukaszewski ◽  
Beata Zelazowska-Rutkowska ◽  
Kinga Hermanowicz-Szamatowicz ◽  
Ewa Gorodkiewicz
Keyword(s):  
Ovarian Cancer ◽  
Cancer Patients ◽  
Tumor Resection ◽  
Analytical Signal ◽  
Cancer Marker ◽  
Human Epididymis Protein 4 ◽  
Pearson Coefficient ◽  
Rabbit Polyclonal Antibody ◽  
Good Agreement

Human epididymis protein 4 (HE4) is an ovarian cancer marker. Various cut-off values of the marker in blood are recommended, depending on the method used for its determination. An alternative biosensor for HE4 determination in blood plasma has been developed. It consists of rabbit polyclonal antibody against HE4, covalently attached to a gold chip via cysteamine linker. The biosensor is used with the non-fluidic array SPRi technique. The linear range of the analytical signal response was found to be 2–120 pM, and the biosensor can be used for the determination of the HE4 marker in the plasma of both healthy subjects and ovarian cancer patients after suitable dilution with a PBS buffer. Precision (6–10%) and recovery (101.8–103.5%) were found to be acceptable, and the LOD was equal to 2 pM. The biosensor was validated by the parallel determination of a series of plasma samples from ovarian cancer patients using the Elecsys HE4 test and the developed biosensor, with a good agreement of the results (a Pearson coefficient of 0.989). An example of the diagnostic application of the developed biosensor is given—the influence of ovarian tumor resection on the level of HE4 in blood serum.

scholarly journals Manufacturing PLA/PCL Blends by Ultrasonic Molding Technology

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2412
Author(s):  
Inés Ferrer ◽  
Ariadna Manresa ◽  
José Alberto Méndez ◽  
Marc Delgado-Aguilar ◽  
Maria Luisa Garcia-Romeu
Keyword(s):  
Molecular Weight ◽  
Crystallization Rate ◽  
Raw Material ◽  
Small Particle Size ◽  
Polymer Mixtures ◽  
Crystallinity Degree ◽  
Correct Determination ◽  
Production Stages ◽  
Process Speed

Ultrasonic molding (USM) is a good candidate for studying the plasticization of polymer mixtures or other composite materials due to either the little amount of material needed for processing, low waste or the needed low pressure and residence time of the mold. Thus, the novelty of this research is the capability of USM technology to process PLA/PCL blends and their corresponding neat materials, encompassing all the production stages, from raw material to the final specimen. The major findings of the work revealed that the thermal properties of the blends were not affected by the USM process, although the crystallinity degree experienced variations, decreasing for PLA and increasing for PCL, which was attributed to the crystallization rate of each polymer, the high process speed, the short cooling time and the small particle size. The employed ultrasonic energy increased the molecular weight with low variations through the specimen. However, the degradation results aligned with the expected trend of these material blends. Moreover, this study also showed the effect pellet shape and dimensions have over the process parameters, as well as the effect of the blend composition. It can be concluded that USM is a technology suitable to successfully process PLA/PCL blends with the correct determination of process parameter windows.

Evaluation of methods for detection of β-lactamase production in MSSA

2021 ◽  
Author(s):  
Robert Skov ◽  
David R Lonsway ◽  
Jesper Larsen ◽  
Anders Rhod Larsen ◽  
Jurgita Samulioniené ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Confirmatory Test ◽  
Disc Diffusion ◽  
Broth Microdilution ◽  
Confirmatory Tests ◽  
Correct Determination ◽  
Primary Test ◽  
Zone Edge ◽  
Evaluation Of Methods

Abstract Objectives Correct determination of penicillin susceptibility is pivotal for using penicillin in the treatment of Staphylococcus aureus infections. This study examines the performance of MIC determination, disc diffusion and a range of confirmatory tests for detection of penicillin susceptibility in S. aureus. Methods A total of 286 consecutive penicillin-susceptible S. aureus blood culture isolates as well as a challenge set of 62 MSSA isolates were investigated for the presence of the blaZ gene by PCR and subjected to penicillin-susceptibility testing using broth microdilution MIC determination, disc diffusion including reading of the zone edge, two nitrocefin tests and the cloverleaf test. Results Using PCR-based detection of blaZ as the gold standard, both broth microdilution MIC testing and disc diffusion testing resulted in a relatively low accuracy (82%–93%) with a sensitivity ranging from 49%–93%. Among the confirmatory tests, the cloverleaf test performed with 100% accuracy, while zone edge interpretation and nitrocefin-based tests increased the sensitivity of β-lactamase detection to 96%–98% and 82%–96% when using MIC determination or disc diffusion as primary test, respectively. Conclusions This investigation showed that reliable and accurate detection of β-lactamase production in S. aureus can be obtained by MIC determination or penicillin disc diffusion followed by interpretation of the zone edge as a confirmatory test for apparently penicillin-susceptible isolates. The more cumbersome cloverleaf test can also be used. Nitrocefin-based tests should not be used as the only test for confirmation of a presumptive β-lactamase-negative isolate.

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