scholarly journals Influence of the calibration on experimental UV index at a midlatitude site, Granada (Spain)

2010 ◽  
Vol 3 (6) ◽  
pp. 5645-5670
Author(s):  
M. Antón ◽  
J. E. Gil ◽  
A. Cazorla ◽  
J. M. Vilaplana ◽  
F. J. Olmo ◽  
...  
Keyword(s):  
Calibration Method ◽  
Conversion Factors ◽  
Uv Index ◽  
Calibration Methods ◽  
One Step ◽  
The Difference ◽  
Mean Differences ◽  
Experimental Values ◽  
The One

Abstract. The ultraviolet (UV) index is the variable most commonly used to inform the general public about the levels and potential harmful effects of UV radiation incident at Earth's surface. This variable is derived from the output signal of the UV radiometers applying conversion factors obtained by calibration methods. This paper focused on the influence of the use of two of these methods (called one-step and two-steps methods) on the resulting experimental UV Index (UVI) as measured by a YES UVB-1 radiometer located in a midlatitude station, Granada (Spain) for the period 2006–2009. In addition, it is also analyzed the difference with the UVI values obtained when the calibration factors provided by the manufacturer are used. For this goal, the detailed characterization of the UVB-1 radiometer obtained in the first Spanish calibration campaign of broadband UV radiometers at the "El Arenosillo" INTA station in 2007 is used. In addition, modeled UVI data derived from the LibRadtran/UVSPEC radiative transfer code are compared with the experimental values recorded at Granada for cloud-free conditions. The absolute mean differences between the measured and modeled UVI data at Granada are around 5% using the one-step and two-steps calibration methods. This result indicates the excellent performance of these two techniques for obtaining UVI data from the UVB-1 radiometer. In contrast, the application of the calibration factor supplied by the manufacturer produces a high overestimation (~14%) of the UVI values. This fact generates unreliable alarming high UVI data in summer when the manufacturer's factor is used. Thus, days with an extreme erythemal risk (UVI higher than 10) increase up to 46% of all cases measured between May and September at Granada when the manufacturer's factor is applied. This percentage is reduced to a more reliable value of 3% when the conversion factors obtained with the two-steps calibration method are used. All these results report about the need of a sound calibration of the broadband UV instruments in order to obtain reliable measurements.

scholarly journals Influence of the calibration on experimental UV index at a midlatitude site, Granada (Spain)

2011 ◽  
Vol 4 (3) ◽  
pp. 499-507 ◽  
Author(s):  
M. Antón ◽  
J. E. Gil ◽  
A. Cazorla ◽  
J. Fernández-Gálvez ◽  
J. M. Vilaplana ◽  
...  
Keyword(s):  
Harmful Effect ◽  
Calibration Method ◽  
Conversion Factors ◽  
Uv Index ◽  
Calibration Methods ◽  
One Step ◽  
Mean Differences ◽  
Experimental Values ◽  
The One

Abstract. The ultraviolet index (UVI) is the most commonly used variable to inform about the level and potential harmful effect of ultraviolet (UV) radiation reaching the Earth's surface. This variable is derived from the output signal of UV radiometers applying conversion factors from calibration methods. This paper focused on the influence of the use of two of these methods (called one-step and two-steps methods) on the experimental UVI measured by a YES UVB-1 radiometer located in a midlatitude station, Granada (Spain) for the period 2006–2009. In addition, it also analyzes the deviation from the UVI values obtained when the manufacturer's calibration factors are applied. For this goal, a detailed characterization of the UVB-1 radiometer from the first Spanish calibration campaign of broadband UV radiometers at the "El Arenosillo" INTA station in 2007 was used. In addition, modeled UVI data derived from the LibRadtran/UVSPEC radiative transfer code are compared with the experimental values recorded at Granada for cloud-free conditions. Absolute mean differences between measured and modeled UVI data at Granada were around 5% using the one-step and two-steps calibration methods, indicating an excellent performance of these two techniques for obtaining UVI data from the UVB-1 radiometer. Conversely, the application of the manufacture's calibration factor produced a large overestimation (~14%) of the UVI values, generating unreliable alarming high UVI data in summer. Thus, the number of days with an extreme erythemal risk (UVI higher than 10) increased up to 46% between May and September at Granada. This percentage reduced to a more reliable value of 3% when the conversion factors obtained with the two-steps calibration method are used. These results evidence the need for a sound calibration of the broadband UV instruments in order to obtain reliable measurements.

Fabrication and mechanical characterization of glass fibre reinforced triaxially braided composites

2020 ◽  
pp. 002199832094893
Author(s):  
Gayatri Vineela Marrivada ◽  
Phaneendra Kiran Chaganti ◽  
Ravindran Sujith
Keyword(s):  
Glass Fibre ◽  
Mechanical Characterization ◽  
Research Work ◽  
Braided Composites ◽  
Short Beam ◽  
Beam Shear ◽  
Glass Fibre Reinforced ◽  
The Difference ◽  
Experimental Values

The aim of this research work is to study the mechanical behaviour of dry triaxially braided glass fibre sleeves and its composites experimentally and analytically. The braided glass fibre sleeves for three angles 30°, 45° and 60° were fabricated on a modified maypole vertical braider following a regular braid architecture. Tensile, flexural, short beam shear and impact tests were performed to evaluate the mechanical properties of the composites. A numerical model was developed, which can be used to find the elastic properties and mechanical strength values of the dry braided fabric and its composites. It was observed that the tensile, flexural and interlaminar properties of 30° specimens were more compared to 45° and 60°. The difference between the estimated and experimental values were found to be an average of 8% for tensile moduli and 24% for the tensile strength.

scholarly journals Characterization of highly active 2-keto-3-deoxy-L-arabinonate and 2-keto-3-deoxy-D-xylonate dehydratases in terms of the biotransformation of hemicellulose sugars to chemicals

2020 ◽  
Vol 104 (16) ◽  
pp. 7023-7035
Author(s):  
Samuel Sutiono ◽  
Bettina Siebers ◽  
Volker Sieber
Keyword(s):  
Racemic Mixture ◽  
Highly Active ◽  
Key Points ◽  
Deoxy Sugar ◽  
Weimberg Pathway ◽  
One Step ◽  
The One ◽  
Increased Activity ◽  
Enzyme Class

Abstract2-keto-3-L-arabinonate dehydratase (L-KdpD) and 2-keto-3-D-xylonate dehydratase (D-KdpD) are the third enzymes in the Weimberg pathway catalyzing the dehydration of respective 2-keto-3-deoxy sugar acids (KDP) to α-ketoglutaric semialdehyde (KGSA). The Weimberg pathway has been explored recently with respect to the synthesis of chemicals from L-arabinose and D-xylose. However, only limited work has been done toward characterizing these two enzymes. In this work, several new L-KdpDs and D-KdpDs were cloned and heterologously expressed in Escherichia coli. Following kinetic characterizations and kinetic stability studies, the L-KdpD from Cupriavidus necator (CnL-KdpD) and D-KdpD from Pseudomonas putida (PpD-KdpD) appeared to be the most promising variants from each enzyme class. Magnesium had no effect on CnL-KdpD, whereas increased activity and stability were observed for PpD-KdpD in the presence of Mg2+. Furthermore, CnL-KdpD was not inhibited in the presence of L-arabinose and L-arabinonate, whereas PpD-KdpD was inhibited with D-xylonate (I50 of 75 mM), but not with D-xylose. Both enzymes were shown to be highly active in the one-step conversions of L-KDP and D-KDP. CnL-KdpD converted > 95% of 500 mM L-KDP to KGSA in the first 2 h while PpD-KdpD converted > 90% of 500 mM D-KDP after 4 h. Both enzymes in combination were able to convert 83% of a racemic mixture of D,L-KDP (500 mM) after 4 h, with both enzymes being specific toward the respective stereoisomer. Key points• L-KdpDs and D-KdpDs are specific toward L- and D-KDP, respectively.• Mg2+affected activity and stabilities of D-KdpDs, but not of L-KdpDs.• CnL-KdpD and PpD-KdpD converted 0.5 M of each KDP isomer reaching 95 and 90% yield.• Both enzymes in combination converted 0.5 M racemic D,L-KDP reaching 83% yield.

The optimal value of markov stopping problems with one-step look ahead policy

1988 ◽  
Vol 25 (3) ◽  
pp. 544-552 ◽  
Author(s):  
Masami Yasuda
Keyword(s):  
Random Number ◽  
Secretary Problem ◽  
Choice Problem ◽  
Best Choice Problem ◽  
Look Ahead ◽  
Optimal Value ◽  
One Step ◽  
The Difference ◽  
The One ◽  
A Charge

This paper treats stopping problems on Markov chains in which the OLA (one-step look ahead) policy is optimal. Its associated optimal value can be explicitly expressed by a potential for a charge function of the difference between the immediate reward and the one-step-after reward. As an application to the best choice problem, we shall obtain the value of three problems: the classical secretary problem, a problem with a refusal probability and a problem with a random number of objects.

The Reliability Analysis of Mechanical Leg (2UPS+UP) Based on a Discrete Time Repairable Markov Model

2015 ◽  
Vol 713-715 ◽  
pp. 760-763
Author(s):  
Jia Lei Zhang ◽  
Zhen Lin Jin ◽  
Dong Mei Zhao
Keyword(s):  
Steady State ◽  
Discrete Time ◽  
Transition Probability ◽  
Continuous Model ◽  
Transition Probability Matrix ◽  
State Equations ◽  
One Step ◽  
The Difference ◽  
Step Transition ◽  
The One

We have analyzed some reliability problems of the 2UPS+UP mechanism using continuous Markov repairable model in our previous work. According to the check and repair of the robot is periodic, the discrete time Markov repairable model should be more appropriate. Firstly we built up the discrete time repairable model and got the one step transition probability matrix. Secondly solved the steady state equations and got the steady state availability of the mechanical leg, by the solution of the difference equations the reliability and the mean time to first failure were obtained. In the end we compared the reliability indexes with the continuous model.

Characterization Of The Active Site Of Urokinase With A Series Of Potent Inhibitory Amidines

1981 ◽  
Author(s):  
J D Geratz ◽  
S R Shaver ◽  
R R Tidwell
Keyword(s):  
Active Site ◽  
Factor Xa ◽  
Selective Inhibition ◽  
The Other ◽  
Plasminogen Activation ◽  
Steric Factors ◽  
The Difference ◽  
The One ◽  
Striking Contrast

Twenty amidine-substituted indole-like heterocycles were synthesized and examined for their blocking effect against human urokinase and a number of related arginine- or lysine- directed proteases. Kinetic analyses were carried out with the help of peptide anilide substrates and revealed a reversible competitive inhibitory pattern with each compound. The Ki values were therefore interpreted to reflect binding conditions at the active site of the enzymes.A highly potent inhibitor of urokinase was discovered in 5-amidino-l-(4-amidinobenzyl)indole which proved to be 18 times more effective on a molar basis than p-aminobenzamidine and 150 times more effective than benzamidine. The Ki value at 37°C and pH 8.3 was determined as 3.2 × 10-6 M. In striking contrast to the findings with the other proteases studied, urokinase was very sensitive to inhibition by 6-amidinoindoline (Ki 1.8 × 10-5 M), yet was much less susceptible to inhibition by the fully unsaturated analog 6-amidinoindole. Steric factors resulting from the difference in planarity between the two compounds are held responsible for this observation. In plasminogen activation assays the antiurokinase effect of the heterocycles mirrored their potency in the assays employing the synthetic urokinase substrate.The significant differences in the inhibitory activities of amidines against urokinase, on the one hand, and plasmin, thrombin and factor Xa, on the other hand, will be useful for experiments where selective inhibition of plasminogen activation is to be achieved. The compounds will also be of help in characterizing other tissue activators with respect to urokinase.

Framework for Multivariate Selectivity Analysis, Part I: Theoretical and Practical Merits

2005 ◽  
Vol 59 (6) ◽  
pp. 787-803 ◽  
Author(s):  
Christopher D. Brown ◽  
Trent D. Ridder
Keyword(s):  
Near Infrared ◽  
Clinical Laboratory ◽  
Simulated Data ◽  
Calibration Method ◽  
National Committee ◽  
Data Sets ◽  
Calibration Methods ◽  
Inverse Calibration ◽  
The One ◽  
Definition Of

A number of definitions of multivariate selectivity have been proposed in the literature. Arguably, the one that enjoys the greatest chemometric attention has been the net analyte signal (NAS) based definitions of Lorber and Zinn. Recent works have suggested that similar inference can be made for inverse least-squares calibration methods (e.g., principal components regression). However, the properties of inverse calibration methods are markedly different than classical methods, so in many practical cases involving inverse models classically derived figures of merit cannot be transparently interpreted. In Part I of this work, we discuss a selectivity framework that is theoretically consistent regardless of the calibration method. Importantly, it is also experimentally measurable, either through controlled selectivity experiments, or through analysis on opportunistically acquired sample measurements. It is statistically advantageous to use the former if such control is achievable. Selectivity is defined to be a function of the change in predicted analyte concentration that will result from a change in the concentration of an interferant, an approach consistent with traditional definitions of analytical selectivity and National Committee for Clinical Laboratory Standards recommendations for interference testing. Unlike the NAS-based definition of selectivity, the definition discussed herein is relevant to only a particular analyte–interferant pair. The theoretical and experimental aspects of this approach are illustrated with simulated data herein and in Part II of this paper, which investigates several experimental near-infrared data sets.

scholarly journals Chitosan-Capped Au Nanoparticles for Laser Photothermal Ablation Therapy: UV-Vis Characterization and Optothermal Performances

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Giancarlo Margheri ◽  
Silvana Trigari ◽  
Mariabeatrice Berti ◽  
Maurizio Muniz Miranda ◽  
Rita Traversi
Keyword(s):  
Near Infrared ◽  
Au Nanoparticles ◽  
Ablation Therapy ◽  
Synthesis Conditions ◽  
Photothermal Ablation ◽  
Nir Absorption ◽  
One Step ◽  
The One ◽  
Refined Version

We have reported on the synthesis and characterization of near-infrared- (NIR-) absorbing colloidal nanoparticles prepared by exploiting the one-step reaction of HAuCl4 and Na2S2O3, followed by their stabilization with chitosan. This reaction also produces a big amount of unwanted nanoparticles detuned with respect to the NIR spectral region. For this reason, it is usually assumed that the product has to be filtered and enriched to enhance its NIR absorption, and the possible exploitation of the simpler raw product has never been worthy to be considered. Aiming to investigate this missing aspect, we chose to avoid the purification steps and rather focused on the preparation of the unrefined colloid, identifying the synthesis conditions that maximize its NIR absorbance and, subsequently, testing it as an optothermal transducer by measuring its molar heating rate (MHR). As expected, we found that the performances of the raw colloid are indeed lower than those of its refined version, but only to a limited extent. Moreover, MHR is unexpectedly higher than that deducible for other classical NIR-absorbing nanoparticles, like Au nanorods or Au nanostars. Thus, the product of the simpler preparation protocol appears as a competitive trade-off solution between easy manufacturing and optothermal performances.

The One-Dimensional Optimum Hydrodynamic Gas Slider Bearing

1968 ◽  
Vol 90 (1) ◽  
pp. 281-284 ◽  
Author(s):  
C. J. Maday
Keyword(s):  
Film Thickness ◽  
Load Capacity ◽  
Maximum Load ◽  
Slider Bearing ◽  
Compression Process ◽  
One Dimensional ◽  
One Step ◽  
The Difference ◽  
The One ◽  
Bearing Number

Bounded variable methods of the calculus of variations are used to determine the optimum or maximum load capacity hydrodynamic one-dimensional gas slider bearing. A lower bound is placed on the minimum film thickness in order to keep the load finite, and also to satisfy the boundary conditions. Using the Weierstrass-Erdmann corner conditions and the Weierstrass E-function it is found that the optimum gas slider bearing is stepped with a convergent leading section and a uniform thickness trailing section. The step location and the leading section film thickness depend upon the bearing number and compression process considered. It is also shown that the bearing contains one and only one step. The difference in the load capacity and maximum film pressure between the isothermal and adiabatic cases increases with increasing bearing number.

A New Binocular Camera Calibration Method Based on an Improved Genetic Algorithm

2011 ◽  
Vol 411 ◽  
pp. 602-608 ◽  
Author(s):  
Xiang Kui Jiang
Keyword(s):  
Genetic Algorithm ◽  
Camera Calibration ◽  
Calibration Method ◽  
Improved Genetic Algorithm ◽  
Linear Calibration ◽  
Calibration Methods ◽  
Calibration Accuracy ◽  
Encoding Method ◽  
The One ◽  
Crossover And Mutation

In this paper,an improved genetic algorithm was proposed,which is applicable to binocular camera calibration. On the one hand, conventional encoding method is improved so that variable search interval can be adjusted adaptively. On the other hand, crossover and mutation probability is varied by using superiority inheritance principle to avoid premature question. Experimental results show that the proposed method has a higher calibration accuracy and better robustness, compared to those of non-linear calibration methods. The proposed method is able to improve the performance of global optimization effectively.

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