bluuebunny/crossref_metadata_2025_split huggingface dataset:
Short‐term forecasts of biologically effective UV radiation: Comparison between modelled and measured irradiation
Authors: Feister Uwe 
Published: June 2010

AbstractUltraviolet (UV) radiation from the sun affects the biosphere and chemical processes of atmospheric trace gases. The amount of atmospheric ozone as well as the amount of clouds and atmospheric aerosols determine the UV radiation reaching the earth's surface at a definite place and time. Using numerically forecast meteorological parameters such as temperature and relative vorticity at different pressure levels, a short‐term forecast of atmospheric ozone was calculated. This ozone value and the numerically forecast cloud cover were fed into a UV forecasting model to determine a short‐term forecast of biologically effective UV radiation. UV radiation forecasts were calculated for three stations in the northern, central and southern part of Germany. Comparisons between ozone forecasts and ground‐based as well as satellite‐based ozone measurements for the summer months of 1994 showed the uncertainty of ozone forecasts to be within ±3% and ±6%. Values of the modelled biologically effective UV radiation were compared with measured UV radiation data taken with UV filter instruments and with a spectro‐radidmeter at Potsdam in the period September 1993 to September 1994. It turned out that for a cloud cover of less than 4/8 to 5/8, the model calculations overestimated the measured irradiation by about 10 to 15%. The main reason for the discrepancy between model calculations and measurements may be the cloud parameterization in the model. Also, the method of estimating the aerosol load as well as uncertainties in the measured UV radiation may have contributed to the differences.
Assessment of the benefits of an enhanced weather information service for the cotton industry in Australia
Authors: Anaman Kwabena A , Lellyett Stephen C 
Published: June 2010

AbstractThe benefits derived from using an enhanced weather information service, the Cottonfielcis Weather Service, produced by the Australian Bureau of Meteorology were determined via a survey of producers of the Namoi Cotton Co‐operative. The economic benefits were estimated using two methods: (a) the change in aggregate gross producer benefits (producers' surplus) due to reduction of unit costs of production from use of the service, and (b) the maximum amounts of money users would be willing to pay (WTP) for use of the service. Results indicated that the average annual WTP for the service was about 223 Australian dollars (A$). The WTP value was modestly higher than the average annual phone facsimile charges of A$190. The change in aggregate gross producer benefits derived were based on the estimated average 1 % cost reduction in the production of raw cotton from using the service based on elicited survey data. The annual aggregate gross benefits were about A$397 150 for cotton production only. The total annual costs incurred by cotton producers for use of the service were A$31 590. Hence the benefit‐cost ratio (for cotton production only) was about 12.6. Reported indirect benefits included time savings for producers and use of the service to plan household and social activities.
Estimations of Probable Maximum Precipitation (PMP) for the Evinos catchment in Greece using a Storm Model approach
Authors: Hardaker P J 
Published: June 2010

AbstractA Storm Model is used to estimate Probable Maximum Precipitation (PMP) for the Evinos catchment in Greece. The model determines the maximum dew‐point temperature from the effects of solar heating, orographic lifting and convergence, in terms of the change in temperature of a rising parcel of air. From this the model estimates the maximum precipitable water over the catchment and together with storm efficiency calculates PMP. For the Evinos catchment the 12‐hour PMP is estimated to be 478 mm and the 24‐hour PMP is 494 mm, occurring in late July. Further, the total water from a maximum rainfall event taken together with a rare snowmelt is unlikely to exceed the amount of water produced by a maximum rainfall in late July; hence, the latter is taken as the catchment PMP.
Exploring the effects of different types of model initialisation: Simulation of a severe air‐pollution episode in Athens, Greece
Authors: Lagouvardos K , Kotroni V , Kallos G 
Published: June 2010

AbstractA combined modelling system consisting of a meteorological model (Colorado State University/ Regional Atmospheric Modelling System) and a transport package (Hybrid Particle and Concentration Transport Model) is used. The simulations were performed using two types of model initialisation: the first with ECMWF gridded analysis data and the second with one sounding profile. The modelling system has been used to simulate an important air‐pollution episode in the Athens urban area. This area is characterised by complex and variable topographic features, and the associated local atmospheric circulations play a significant role in defining the transport and dispersion conditions over the area. The advantages and shortcomings of both types of initialisation, and more specifically the capability of the model to represent and reproduce the local‐scale conditions and the dispersion of air pollutants, are discussed.
Prediction of near‐surface gusts generated by deep convection
Authors: Nakamura K , Kershaw R , Gait N 
Published: June 2010

AbstractAn equation for the prediction of near‐surface gusts generated by convection is tested against observations and against simulations made with a model which resolves convectve clouds, in order to investigate the phenomenon, and to validate the equation in a range of convective regimes. These include two types of severe weather which affect the UK: mid‐latitude depressions and thunderstorms. The prediction equation works well in both convective regimes. Two processes are shown to be important. The first is the production of horizontal momentum by pressure gradient forces, as convective downdraughts are blocked by the surface and distorted to spread out horizontally. The second is the downward transport of horizontal momentum by the convective downdraughts, in the presence of vertical shear. The equation should be tested by forecasters, especially when deep convection occurs in conjunction with strong geostrophic winds. It could also be applied in Numerical Weather Prediction models to automate the prediction of convective gusts.
Test of indices for classification of winter climate
Authors: Gustavsson Torbjörn 
Published: June 2010

AbstractThree types of index were tested which classified winter climates in relation to winter road maintenance activities. The indices were tested with data from December 1994, from one open, well‐exposed station which forms part of the Swedish Road Weather Information System. All three types of index gave different results when applied to the test period. The selection of the weather parameters in the index, as well as the definition of weather types, are considered important, since they control the number of severe weather conditions which are summed over a period of time. Another important controlling factor was found to be the character of the summation, i.e. whether it was on a daily basis or whether the summation was over severe weather situations.
Dropsondes with GPS windfinding
Authors: Cogan J , Greenling T , Luces S A , Thomas J 
Published: June 2010

AbstractDetailed, quantitative, atmospheric data are essential for accurate analysis and forecasting of mesoscale phenomena for both military and civilian applications. Small manned or unmanned aircraft can carry small sensors and dropsondes into remote or hazardous regions, at little or no risk to personnel and at a very low cost. This paper describes two prototype dropsondes that used the Global Positioning System (GPS) for measuring wind velocity. Flight tests using a helicopter produced results that gave an accuracy in wind velocity about the same as coincident rawinsondes. The test data suggest that it may be possible to delineate zones of significantly different wind velocity that are less than 200 metres thick, although further tests are needed to evaluate this possibility thoroughly.
Modelling evapotranspiration in semi‐arid terrains: Comparison of two schemes
Authors: Fernández C , Nieto G , Prego J A 
Published: June 2010

AbstractThe importance of choosing a relatively detailed parameterisation for plant transpiration in semi‐arid terrains is evidenced by comparison of model results and observations from a European field experiment recently performed in La Mancha (Spain). In severe drought periods the contribution of the vegetation cover to the total latent heat flux is greater, since the evaporation from the bare soil fraction is small. Also, the observed heterogeneity of vegetation types in semi‐arid regions, such as the Iberian peninsula, is an additional argument to recommend the inclusion of somewhat sophisticated parameterisations in mesoscale models. A set of sensitivity tests and different formulations for the stomatal resistance illustrates fairly well the importance of the vegetation properties in regions where plants are scarce.
Analysis of the operational calibration of the Meteosat infrared‐window channel
Authors: Gube Marianne , Gärtner Volker , Schmetz Johannes 
Published: June 2010

AbstractThe operational procedure for the calibration of the Meteosat infrared (IR: 10.5‐12.5 m̈m) channel is studied. Since no adequate onboard calibration is available, calibration techniques have been developed which use conventional meteorological data together with model calculations. The operational calibration technique for the IR channel relies on radiation model calculations for clear‐sky which take independent data on the atmospheric and surface temperature as model input. Satellite observations (radiometric counts) over the ocean are correlated with radiances calculated from independent sea‐surface temperature analyses and short‐term forecast fields of temperature and humidity. The sensitivity of the radiation calculations to humidity profiles and to different parameterisations of the water vapour continuum is studied. The operational calibration coefficients are based on averaging over previous calibration calculations. This method is reviewed and a new approach, based on daytime satellite observations only, is proposed. The new method reduces calibration coefficients by about 1%, which yields better agreement with a previous cross‐calibration study.
Medium range weather forecasts in India during Monsoon 1994
Authors: Rao P Sanjeeva , Saseendran S A , Rathore L S , Bahadur J 
Published: June 2010

AbstractAiming to enhance and sustain farm production in India, an Agromet Advisory Service has been started. Numerical weather prediction output from a spectral model (T80L18) is fine‐tuned by employing statistical and synoptic methods to prepare 24 h, 48 h and 72 h weather forecasts for 20 locations during the principal crop growing period of 1994. Also, weekly rainfall forecasts for 35 meteorological sub‐divisions during monsoon period are produced. The accuracy of location‐specific rain/no‐rain event forecasts was found to be 70%. However, the root mean square error for the quantitative rainfall forecast was 17 mm; hence, there is a need for further improvement. The accuracy of maximum temperature (at 10 locations) and minimum temperature (at 18 locations) was 2 °C. The forecasts of rainfall event, temperature, cloud cover and wind speed showed considerable skill over random forecasts. The performance of trends and temporal variability in weekly sub‐divisional rainfall forecasts were evaluated.
Meteorology and forest fires: Some case studies
Authors: Palmieri Sabino , Inghilesi Roberto , Siani Anna Maria 
Published: June 2010

AbstractThe role of the physical and meteorological factors involved in forest fires is outlined. The index used by the Meteorology Group of Rome University is then described. The methodology is based on the computation of an aridity factor which is a non‐linear function of precipitation and evapotranspiration in the last 40 days. The aridity is then coupled with an exponential function which takes into account actual or predicted meteorological conditions (temperature, wind, relative humidity and rainfall) to give the fire‐risk index. The results of applying the index to cases of fires in Liguria and Tuscany are given. It is suggested that the development of fine‐mesh non‐hydrostatic meteorological models coupled with fire spread and burn rate models is a promising approach for scientific progress in this field.
Fetal tricuspid valve Doppler at 11–13 weeks and 6 days: reference values and reproducibility
Authors: Ninno Milena Almeida Prado , Liao Adolfo Wenjaw , Lamberty Clarissa Oliveira , Miguelez Javier , Zugaib Marcelo 
Published: June 2010

AbstractObjectiveTo determine normal blood flow velocities across the fetal tricuspid valve (TV) at 11–13 weeks and 6 days of gestation and to examine the reproducibility of these measurements.MethodsA prospective study involving 166 normal singleton pregnancies examined at 11–13 weeks and 6 days was carried out. Descriptive analysis of E‐ and A‐waves' maximum velocities, E/A ratio, duration of the cardiac cycle (C) and diastole (D) and D/C ratio were calculated. Intraobserver and interobserver agreement analysis was performed in a subgroup of 12 cases.ResultsAverage ( ± SD) flow velocities were: E‐wave, 25.0 ( ± 4.6) cm/s; A‐wave, 42.9 ( ± 5.9) cm/s; E/A, 0.58 ( ± 0.07); cardiac cycle, 390 ( ± 21.1) ms; diastole, 147 ( ± 18) ms and D/C, 0.38 ( ± 0.04). Significant correlation was observed between all parameters (except A‐wave) and gestational age but not with nuchal translucency (NT). Intraclass correlation coefficients (interobserver, intraobsever examiner 1 and intraobserver examiner 2) were: E‐wave, 0.53, 0.53 and 0.64; A‐wave, 0.45, 0.46 and 0.49; cardiac cycle, 0.70, 0.79 and 0.84 and diastole, 0.63, 0.85 and 0.82, respectively.ConclusionsThe present study establishes normal Doppler parameters for blood flow across the TV at 11–13 weeks and 6 days and demonstrates that these parameters do not correlate with NT measurement and have good/moderate reproducibility. Copyright © 2010 John Wiley & Sons, Ltd.
Two‐ or three‐dimensional ultrasonography: which is the best predictor of pulmonary hypoplasia?
Authors: Vergani Patrizia , Andreani Marianna , Greco Massimiliano , Farina Giuliano , Fedeli Tiziana , Cuttin Serena 
Published: June 2010

AbstractObjectiveThe aim of our study is to compare the three‐dimensional (3D) ultrasound fetal lung volume measurements with two‐dimensional (2D) ultrasound biometric parameters in predicting pulmonary hypoplasia (PH).MethodsFrom June 2006 to November 2008, we identified 35 fetuses at high risk for developing PH, including premature preterm rupture of membranes (17), fetal skeletal malformations (7), hydrothorax (7), and bilateral renal dysplasia (4). 3D lung volumes adjusted for gestational age (GA) or estimated fetal weight (EFW), thoracic circumference adjusted for GA or femur length, thoracic/abdominal circumference ratio, and thoracic/heart area ratio were measured.ResultsThree infants were excluded because no clinical or histological information regarding lung hypoplasia was available. Of the 32 remaining infants, 13 (41%) were diagnosed with PH at postmortem examination or by clinical and radiological examination. 3D lung volume measurements had a better diagnostic accuracy for predicting PH either when adjusted for GA [sensitivity, 12/13 (92%); specificity, 16/19 (84%); positive predictive value 12/15 (80%); negative predictive value, 16/17(94%)] or EFW [sensitivity, 11/13 (85%); specificity, 18/19 (94%); positive predictive value 11/12(92%); negative predictive value, 18/20(90%)] compared to the 2D biometric measurement.Conclusion3D lung volume measurements seem to be useful in the prenatal prediction of PH. Copyright © 2010 John Wiley & Sons, Ltd.
An IR molding system for direct shaping of thermoplastics
Authors: Quadrini Fabrizio , Santo Loredana , Tagliaferri Vincenzo , Trovalusci Federica 
Published: June 2010

AbstractA new molding technique is proposed to directly mold small parts from thermoplastic pellets. A small molding machine was designed and fabricated: the mold consisted of a transparent glass and a metallic frame; an infrared (IR) lamp provided the heat for the pellet melting. Molding tests were carried out by using three commercial thermoplastics and two metallic molds. Molding time and IR lamp power were changed to extract a moldability window for each combination of material and metallic mold. In the best process conditions, a high quality of the samples was obtained in terms of mold filling and surface aesthetics. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers
Effect of microfiber reinforcement on the morphology, electrical, and mechanical properties of the polyethylene/poly(ethylene terephthalate)/carbon nanotube composites
Authors: Yesil Sertan , Koysuren Ozcan , Bayram Goknur 
Published: June 2010

AbstractIn situ microfiber reinforced conductive polymer composites consisting of high‐density polyethylene (HDPE), poly(ethylene terephthalate) (PET), and multiwalled carbon nanotube (CNT) were prepared in a twin screw extruder followed by hot stretching of PET/CNT phase in HDPE matrix. For comparison purposes, the HDPE/PET blends and HDPE/PET/CNT composites were also produced without hot stretching. Extrusion process parameters, hot‐stretching speed, and CNT amount in the composites were kept constant during the experiments. Effects of PET content and molding temperature on the morphology, electrical, and mechanical properties of the composites were investigated. Morphological observations showed that PET/CNT microfibers were successfully formed in HDPE phase. Electrical conductivities of the microfibrillar composites were in semi‐conductor range at 0.5 wt% CNT content. Microfiber reinforcement improved the tensile strength of the microfibrillar HDPE/PET/CNT composites in comparison to that of HDPE/PET blends and HDPE/PET/CNT composites prepared without hot stretching. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers
Creep behavior of high density polyethylene after aging in contact with different oil derivates
Authors: Habas‐Ulloa Amelia , D'Almeida Jose‐Roberto Moraes , Habas Jean‐Pierre 
Published: June 2010

AbstractThe creep behavior of a high density polyethylene (HDPE), currently used as raw material for pipe manufacture, was evaluated before and after exposure to oil derivates using transient rheometry. The creep behavior of the original HDPE was satisfactorily described using a generalized Kelvin‐Voigt model based on two retardation times. The values of these critical times were quite different from each other, indicating a large distribution of macromolecular weight. The aging procedure was performed by immersing the polymer in two model fluids chosen to discriminate and understand the action of aromatic and paraffinic fractions of fuel derivatives (white oil, gas‐oil). The batch operation was also carried out at two different temperatures to investigate the thermal activation of plausible degrading mechanisms. In the case of the aging performed in the paraffinic fluid, the polymer compliance continuously increased with the immersion duration. This behavior was attributed to a plasticization induced by the diffusion of the liquid in the polymer matrix. The same phenomenon was observed in the early stage of the HDPE aging carried out with the aromatic fluid. However, for longer aging times, the extraction of low molecular weight species produced the stiffening of the thermoplastic. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers
The effect of compatibilizer on the co‐continuity and nanoclay dispersion level of tpe nanocomposites based on PP/EPDM
Authors: Mirzadeh Amin , Lafleur Pierre G. , Kamal Musa R. , Dubois Charles 
Published: June 2010

AbstractThe effects of different polypropylene (PP)‐g‐maleic anhydride polymers, used as compatibilizers, on the degree of exfoliation and co‐continuity of PP/ethylene‐propylene‐diene terpolymer (EPDM) thermoplastic elastomer (TPE)/clay nanocomposites were investigated. X‐ray diffraction and transmission electron microscopic micrographs showed that nanocomposites ranged from intercalated structure to a coexistence of intercalated tactoids and exfoliated layers. The observed significant increase in crystallization temperature (∼20°C) could be beneficial for molding applications, because it means faster solidification and shorter cycle time. The rheological characteristic relaxation time of the compatibilizer correlated with the dispersion level in the nanocomposites. Solvent extraction and gravimetry measurements of continuity showed that compatibilizer affects the co‐continuity composition range through its effect on the dispersion level of nanoclays. At high EPDM concentration, the continuity of the thermoplastic phase for semi‐exfoliated TPE nanocomposites was higher than in the corresponding TPEs. Considering that TPE formation is the first step for thermoplastic vulcanizate production, where the thermoplastic phase should have a certain level of continuity, these results suggest that higher levels of EPDM could be incorporated into the semi‐exfoliated system before losing matrix continuity. It was also observed that there is a direct relation between the magnitude of the normalized stress growth viscosity overshoot and the continuity of TPE nanocomposites. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers
Facile synthesis and characterization of hyperbranched poly(aryl ether ketone)s obtained via an A2 + BB′2 approach
Authors: Li Xiujie , Zhang Shuling , Wang Hui , Pang Jinhui , Sun Dong , Mu Jianxin , Wang Guibin , Jiang Zhenhua 
Published: June 2010

AbstractA fast and highly efficient approach for the synthesis of hyperbranched poly(aryl ether ketone)s (HPAEKs) via the polycondensation of A2 and BB′2 monomers is described. Commercially available hydroquinone (HQ, A2 monomer) and easily synthesized 2,4′,6‐trifluorobenzophenone (TF, BB′2 monomer) were thermally polycondensed to prepared fluoro‐ or phenolic‐terminated HPAEKs with K2CO3 and Na2CO3 as catalysts. During the reaction, the fluorine at the 4′‐position of TF reacts rapidly with the phenolic group of HQ, forming predominantly dimers and some other species. The dimer can be considered as a new AB′2 monomer. Further reactions among molecules AB′2 and AB′2 with some other species result in the formation of HPAEKs. Fourier transform infrared and 1H NMR spectra revealed the structures of the resultant polymers. The degree of branching (DB) of the fluoro‐terminated hyperbranched polymers was determined to be in the range 50–57% from 1H NMR spectra, whereas the DB of the phenolic‐terminated hyperbranched polymers was determined to be 100%. These hyperbranched polymers exhibit excellent solubility in general organic solvents and possess moderate molecular weights with broad distributions determined using gel permeation chromatography. Moreover, the structure and performance of the HPAEKs can be conveniently regulated by adjusting the type and feed ratio of the two monomers. Copyright © 2010 Society of Chemical Industry