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Selected AbstractsSimultaneous assessment of DNA ploidy and biomarker expression in paraffin-embedded tissue sectionsHISTOPATHOLOGY, Issue 1 2010Stijn J H M Fleskens Fleskens S J H M, Takes R P, Otte-Höller I, van Doesburg L, Smeets A, Speel E-J M, Slootweg P J & van der Laak J A W M (2010) Histopathology,57, 14,26 Simultaneous assessment of DNA ploidy and biomarker expression in paraffin-embedded tissue sections Aims:, Aneuploidy is a potential biomarker for predicting progression of premalignancies. Ploidy assessment is mostly performed on nuclei isolated from tissue sections. Ploidy assessment in situ in tissue sections may be a large improvement, enabling selective sampling of nuclei, thus allowing the correlation between ploidy and histology. Existing ploidy analysis methods in sections suffer from limited sensitivity. The aim was to reliably assess ploidy in sections, combined with simultaneous assessment of other markers at the individual cell level. Methods and results:, Ploidy was measured in 22 paraffin-embedded oral premalignancies. The DNA stoichiometric Feulgen procedure was used on isolated nuclei, as well as fluoresence in situ hybridization analysis. In tissue sections, Feulgen was combined with immunohistochemistry for Ki67 proliferation marker, enabling distinction between cycling euploid and aneuploid cells. Aneuploidy was reliably detected in tissue sections (sensitivity 100%, specificity 92%). One section in which aneuploidy was detected was misclassified in isolated nuclei analysis. Sections were also successfully analysed using our model combined with DNA double strand break marker ,-H2AX in fluorescence microscopy, underlining the power of biomarker evaluation on single cells in tissue sections. Conclusions:, The analysis model proposed in this study enables the combined analysis of histology, genotypic and phenotypic information. [source] A model of equilibrium bed topography for meander bends with erodible banksEARTH SURFACE PROCESSES AND LANDFORMS, Issue 10 2002Stephen E. Darby Abstract Channel curvature produces secondary currents and a transverse sloping channel bed, along which the depth increases towards the outer bank. As a result deep pools tend to form adjacent to the outer bank, promoting bank collapse. The interaction of sediment grains with the primary and secondary flow and the transverse sloping bed also causes meanders to move different grain sizes in different proportions and directions, resulting in a consistent sorting pattern. Several models have been developed to describe this process, but they all have the potential to over-predict pool depth because they cannot account for the influence of erodible banks. In reality, bank collapse might lead to the development of a wider, shallower cross-section and any resulting flow depth discrepancy can bias associated predictions of flow, sediment transport, and grain-size sorting. While bed topography, sediment transport and grain sorting in bends will partly be controlled by the sedimentary characteristics of the bank materials, the magnitude of this effect has not previously been explored. This paper reports the development of a model of flow, sediment transport, grain-size sorting, and bed topography for river bends with erodible banks. The model is tested via intercomparison of predicted and observed bed topography in one low-energy (5·3 W m,2 specific stream power) and one high-energy (43·4 W m,2) study reach, namely the River South Esk in Scotland and Goodwin Creek in Mississippi, respectively. Model predictions of bed topography are found to be satisfactory, at least close to the apices of bends. Finally, the model is used in sensitivity analyses that provide insight into the influence of bank erodibility on equilibrium meander morphology and associated patterns of grain-size sorting. The sensitivity of meander response to bank cohesion is found to increase as a function of the available stream power within the two study bends. Copyright © 2002 John Wiley & Sons, Ltd. [source] Relationship between thermal conductivity and water content of soils using numerical modellingEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 3 2003P. Cosenza Summary There is no simple and general relationship between the thermal conductivity of a soil, ,, and its volumetric water content, ,, because the porosity, n, and the thermal conductivity of the solid fraction, ,s, play a major part. Experimental data including measurements of all the variables are scarce. Using a numerical modelling approach, we have shown that the microscopic arrangement of water influences the relation between , and ,. Simulated values for n ranging from 0.4 to 0.6, ,s ranging from 2 to 5 W m,1 K,1 and , from 0.1 to 0.4 can be fitted by a simple linear formula that takes into account n, ,s and ,. The results given by this formula and by the quadratic parallel (QP) model widely used in physical property studies are in satisfactory agreement with published data both for saturated rocks and for unsaturated soils. Consequently, the linear formula and the QP model can be used as practical and efficient tools to investigate the effects of water content and porosity on the thermal conductivity of the soil and hence to optimize the design of thermal in situ techniques for monitoring water content. [source] On the climate and weather of mountain and sub-arctic lakes in Europe and their susceptibility to future climate changeFRESHWATER BIOLOGY, Issue 12 2009R. THOMPSON Summary 1.,The complex terrain and heterogeneous nature of the mountain environment coupled with remoteness from major centres of human activity makes mountains challenging locations for meteorological investigations. Mountainous areas tend to have more varied and more extreme weather than lowlands. 2.,The EMERGE program has the primary aim of assessing the status of remote mountain and sub-arctic lakes throughout Europe for the first time. In this study, we describe the main features of the climate, ice-cover durations and recent temperature trends of these areas. The main weather characteristics of European mountain and sub-arctic lakes are their cold temperatures and year-round precipitation. Mean annual temperatures are generally close to 0 °C, and maximum summer temperatures reasonably close to 10 °C. 3.,Maritime versus continental settings determine the main differences in annual-temperature range among lake districts (10.5 °C in Scotland to 26.7 °C in Northern Finland), and a similar factor for ice-cover duration. Radiation ranges from low (120 W m,2) in the high latitude sub-arctic and high (237 W m,2) in the southern ranges of the Pyrenees and Rila. Similarly, precipitation is high in the main Alpine chain (250 cm year,1 in the Central Southern Alps) and low in the continental sub-arctic (65 cm year,1 in Northern Finland). 4.,The main temporal patterns in air temperature follow those of the adjacent lowlands. All the lake districts warmed during the last century. Spring temperature trends were highest in Finland; summer trends were weak everywhere; autumn trends were strongest in the west, in the Pyrenees and western Alps; while winter trends varied markedly, being high in the Pyrenees and Alps, low in Scotland and Norway and negative in Finland. 5.,Two new, limnological case studies on Lake Redon, in the Pyrenees, highlight the sensitivity of remote lakes to projected changes in the global climate. These two case studies involve close linkages between extreme chemical-precipitation events and synoptic wind-patterns, and between thermocline behaviour and features of the large-scale circulation. 6.,Individual lakes can be ultra-responsive to climate change. Even modest changes in future air temperatures will lead to major changes in lake temperatures and ice-cover duration and hence probably affect their ecological status. [source] Pan Evaporation Trends and the Terrestrial Water Balance.GEOGRAPHY COMPASS (ELECTRONIC), Issue 2 2009Pan evaporation is just that , it is the evaporation rate of water from a small dish located at the ground-surface. Pan evaporation is a measure of the evaporative demand over terrestrial surfaces. Declines in pan evaporation have now been reported in many regions of the world. The trends vary from one pan to the next, but when averaged over many pans, they are typically in the range of ,1 to ,4 mm a,2 (mm per annum per annum). In energetic terms, a trend of ,2 mm a,2 is equivalent to ,0.16 W m,2 a,1 and over 30 years this is a change of ,4.8 W m,2. For comparison, the top-of-atmosphere forcing due to doubled CO2 is estimated by the Intergovernmental Panel on Climate Change (IPCC) to be ~3.7 W m,2. Hence, the magnitude of the pan evaporation trend is large. What is of even greater interest is the direction , a decline , given the well-established warming of the last 30,50 years. In this article, the first in a two part series, we describe the underlying principles in using and interpreting pan evaporation data and then summarise the reported observations from different countries. In the second article, we describe the interpretation of the trends in terms of changes in the terrestrial water balance. [source] Heat-Transport Mechanisms in SuperlatticesADVANCED FUNCTIONAL MATERIALS, Issue 4 2009Yee Kan Koh Abstract The heat transport mechanisms in superlattices are identified from the cross-plane thermal conductivity , of (AlN)x,(GaN)y superlattices measured by time-domain thermoreflectance. For (AlN)4.1 nm,(GaN)55,nm superlattices grown under different conditions, , varies by a factor of two; this is attributed to differences in the roughness of the AlN/GaN interfaces. Under the growth condition that gives the lowest ,, , of (AlN)4 nm,(GaN)y superlattices decreases monotonically as y decreases, ,,=,6.35,W m,1 K,1 at y,=,2.2,nm, 35 times smaller than , of bulk GaN. For long-period superlattices (y,>,40,nm), the mean thermal conductance G of AlN/GaN interfaces is independent of y, G,,,620 MW m,2 K,1. For y,<,40,nm, the apparent value of G increases with decreasing y, reaching G,,,2 GW m,2 K,1 at y,<,3,nm. MeV ion bombardment is used to help determine which phonons are responsible for heat transport in short period superlattices. The thermal conductivity of an (AlN)4.1 nm,(GaN)4.9,nm superlattice irradiated by 2.3 MeV Ar ions to a dose of 2,×,1014 ions cm,2 is reduced by <35%, suggesting that heat transport in these short-period superlattices is dominated by long-wavelength acoustic phonons. Calculations using a Debye-Callaway model and the assumption of a boundary scattering rate that varies with phonon-wavelength successfully capture the temperature, period, and ion-dose dependence of ,. [source] Effects of topography on the spatial distribution of evapotranspiration over a complex terrain using two-source energy balance model with ASTER dataHYDROLOGICAL PROCESSES, Issue 16 2009H. K. Kafle Abstract Spatial distribution of evapotranspiration (ET) over a complex terrain is estimated using a new approach of the conventional two-source energy balance (TSEB) model by considering the effect of topography (difference in slope and aspect). We name this approach topography considered two-source energy balance (T2SEB) model. The novelty of this model is the estimation of incoming shortwave solar radiation considering slope, aspect, altitude, latitude, longitude, and the day of calculation in the TSEB model, so that the new model should have wider applicability than existing models over topographically complex areas. In this study, high spatial resolution Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data and meteorological data are used. ET over a complex terrain of Nagoya, Japan, on three different dates, 4 November 2005, 25 May 2004 and 30 October 2003, is estimated using both TSEB and T2SEB models. To validate both models, estimated results are compared with ground observation data at the flux tower site. Moreover, estimated results from TSEB and T2SEB models are compared in five different locations of different topography within the study area. Variation of net radiation absorbed by the surface (Rn) with topographical variables is also studied with the help of scatter plots. Estimated results for all three dates agreed within ±75 W m,2 with calculated values from both models at the flux tower site. TSEB underestimated/overestimated ET in sunlit/shaded areas in hilly areas. The T2SEB model estimated ET in hilly areas better than the TSEB model. Copyright © 2009 John Wiley & Sons, Ltd. [source] Energy budget above a temperate mixed forest in northeastern ChinaHYDROLOGICAL PROCESSES, Issue 18 2007Jiabing Wu Abstract Components of the energy budget were measured continuously above a 300-year-old temperate mixed forest at the Changbaishan site, northeastern China, from 1 January to 31 December 2003, as a part of the ChinaFlux programme. The albedo values above the canopy were lower than most temperate forests, and the values for snow-covered canopy were over 50% higher than for the snow-free canopy. In winter, net radiation Rn was generally less than 5% of the summer value due to high albedo and low incoming solar radiation. The annual mean latent heat LE was 37·5 W m,2, accounting for 52% of Rn. The maximum daily evaporation was about 4·6 mm day,1 in summer. Over the year, the accumulated precipitation was 578 mm; this compares with 493 mm of evapotranspiration, which shows that more than 85% of water was returned to the atmosphere through evapotranspiration. The LE was strongly affected by the transpiration activity and increased quickly as the broadleaved trees began to foliate. The sensible heat H dropped at that time, although Rn increased. Consequently, the seasonal variation in the Bowen ratio , was clearly U-shaped, and the minimum value (0·1) occurred on a sunny day just after rain, when most of the available energy was used for evapotranspiration. Negative , values occurred occasionally in the non-growing season as a result of intensive radiative cooling and the presence of water on the surface. The , was very high (up to 13·0) in snow-covered winter, when evapotranspiration was small due to low surface temperature and available soil water. Vegetation phenology and soil moisture were the key variables controlling the available energy partitioning between H and LE. Energy budget closure averaged better than 86% on a half-hourly basis, with slightly greater closure on a daily basis. The degree of closure showed a dependence on friction velocity u*. Copyright © 2006 John Wiley & Sons, Ltd. [source] Hydrodynamics and geomorphic work of jökulhlaups (glacial outburst floods) from Kverkfjöll volcano, IcelandHYDROLOGICAL PROCESSES, Issue 6 2007Jonathan L. Carrivick Abstract Jökulhlaups (glacial outburst floods) occur frequently within most glaciated regions of the world and cause rapid landscape change, infrastructure damage, and human disturbance. The largest jökulhlaups known to have occurred during the Holocene within Iceland drained from the northern margin of Vatnajökull and along the Jökulsá á Fjöllum. Some of these jökulhlaups originated from Kverkfjöll volcano and were routed through anastomosing, high gradient and hydraulically rough channels. Landforms and sediments preserved within these channels permit palaeoflow reconstructions. Kverkfjöll jökulhlaups were reconstructed using palaeocompetence (point measurements), slope,area (one-dimensional), and depth-averaged two-dimensional (2D) hydrodynamic modelling techniques. The increasing complexity of 2D modelling required a range of assumptions, but produced information on both spatial and temporal variations in jökulhlaup characteristics. The jökulhlaups were volcanically triggered, had a linear-rise hydrograph and a peak discharge of 50 000,100 000 m3 s,1, which attenuated by 50,75% within 25 km. Frontal flow velocities were ,2 m s,1; but, as stage increased, velocities reached 5,15m s,1. Peak instantaneous shear stress and stream power reached 1 × 104 N m,2 and 1 × 105 W m,2 respectively. Hydraulic parameters can be related to landform groups. A hierarchy of landforms is proposed, ranging from the highest energy zones (erosional gorges, scoured bedrock, cataracts, and spillways) to the lowest energy zones (of valley fills, bars, and slackwater deposits). Fluvial erosion of bedrock occurred in Kverkfjallarani above ,3 m flow depth, ,7m s,1 flow velocity, ,1 × 102 N m,2 shear stress, and 3 × 102 W m,2 stream power. Fluvial deposition occurred in Kverkfjallarani below ,8 m flow depth, 11 m s,1 flow velocity, 5 × 102 N m,2 shear stress, and 3 × 103 W m,2 stream power. Hence, erosional and depositional ,envelopes' have considerable overlap, probably due to transitional flow phenomena and the influence of upstream effects, such as hydraulic ponding and topographic constrictions, for example. Holocene Kverkfjöll jökulhlaups achieved geomorphic work comparable to that of other late Pleistocene ,megafloods'. This work was a result of steep channel gradients, topographic channel constrictions, and high hydraulic roughness, rather than to extreme peak discharges. The Kverkfjöll jökulhlaups have implications for landscape evolution in north-central Iceland, for water-sediment inputs into the North Atlantic, and for recognizing jökulhlaups in the rock record. 2D hydrodynamic modelling is likely to be important for hazard mitigation in similar landscapes and upon other glaciated volcanoes, because it only requires an input hydrograph and a digital elevation model to run a model, rather than suites of geomorphological evidence and field-surveyed valley cross-sections, for example. Copyright © 2006 John Wiley & Sons, Ltd. [source] Snow disappearance in Eastern Siberia and its relationship to atmospheric influencesINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 2 2007Yoshihiro Iijima Abstract In the present study, we examine the climatological features and interannual variations in snow disappearance within the Lena River Basin, Eastern Siberia, during a recent 15-year period (1986,2000), and the relationship of snow disappearance to atmospheric conditions. According to the climatology of the day of the year on which snow disappears, the boundary of snow disappearance within the Lena River Basin migrates rapidly northward from mid-April until early June, with minimum interannual variation occurring in the middle part of the basin. In addition, the preceding snow disappearance is apparent in the central Lena River Basin. Melting of snow within the Lena River Basin commonly occurs within 30 days of complete snow disappearance under certain atmospheric conditions: daily mean air temperature in excess of , 10 °C, greater than 2 hPa of water vapor pressure, and, hence, more than 170 W m,2 of downward longwave radiation under clear sky conditions. Composite analysis using a reanalysis dataset demonstrates that the increase in air temperature and water vapor that accompanies snow melting is due to wet (and warm) air advection in conjunction with enhanced water vapor convergence over the central Lena River Basin during the 30-day period prior to snow disappearance. Copyright © 2006 Royal Meteorological Society. [source] Europe's 2003 heat wave: a satellite view of impacts and land,atmosphere feedbacksINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 6 2006Benjamin F. Zaitchik Abstract A combination of satellite imagery, meteorological station data, and the NCEP/NCAR reanalysis has been used to explore the spatial and temporal evolution of the 2003 heat wave in France, with focus on understanding the impacts and feedbacks at the land surface. Vegetation was severely affected across the study area, especially in a swath across central France that corresponds to the Western European Broadleaf (WEB) Forests ecological zone. The remotely sensed surface temperature anomaly was also greatest in this zone, peaking at +15.4 °C in August. On a finer spatial scale, both the vegetation and surface temperature anomalies were greater for crops and pastures than for forested lands. The heat wave was also associated with an anomalous surface forcing of air temperature. Relative to other years in record, satellite-derived estimates of surface-sensible heat flux indicate an enhancement of 48,61% (24.0,30.5 W m,2) in WEB during the August heat wave maximum. Longwave radiative heating of the planetary boundary layer (PBL) was enhanced by 10.5 W m,2 in WEB for the same period. The magnitude and spatial structure of this local heating is consistent with models of the late twenty-first century climate in France, which predict a transitional climate zone that will become increasingly affected by summertime drought. Models of future climate also suggest that a soil-moisture feedback on the surface energy balance might exacerbate summertime drought, and these proposed feedback mechanisms were tested using satellite-derived heat budgets. Copyright © 2006 Royal Meteorological Society. [source] Solar radiation climate change over southern Africa and an assessment of the radiative impact of volcanic eruptionsINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 3 2005H. C. Power Abstract Spatial and temporal variability in global, diffuse, and horizontal direct irradiance and sunshine duration has been evaluated at eight stations in South Africa and two stations in Namibia where the time series range between 21 and 41 years. Global and direct irradiance and sunshine duration decrease from northwest to southeast; diffuse irradiance increases toward the east. Annually averaged global irradiance Ga decreased between 1.3% (2.8 W m,2) and 1.7% (4.4 W m,2) per decade at Bloemfontein, Cape Town, Durban, Pretoria, and Upington. Annually averaged diffuse irradiance Da decreased 5.2% (3.0 W m,2) per decade at Grootfontein and 4.2% (3.1 W m,2) per decade at Port Elizabeth. Annual direct irradiance Ba decreased 2.1% (3.5 W m,2) per decade at Cape Town and 2.8% (5.7 W m,2) per decade at Alexander Bay. A simultaneous decrease in annually averaged daily sunshine duration Sa may have contributed to the decrease in Ba at Alexander Bay and the decrease in Ga at Pretoria. Increases in aerosols may have contributed to the observed decrease in Ga at Cape Town and Durban, and the decrease in Da at Grootfontein may be due to a decrease in aerosols. On average, variability in Sa explains 89.0%, 50.4%, and 89.5% of the variance in Ga, Da, and Ba respectively. The radiative response to changes in sunshine duration is greater for direct irradiance than for global and diffuse. In the 2 years following the 1963 Mount Agung eruption in Indonesia, changes in global irradiance over southern Africa were small and inconsistent. At eight stations, diffuse irradiance increased 21.9% (13.3 W m,2) on average and direct irradiance decreased 8.7% (15.5 W m,2). After the 1982 El Chichón eruption in Mexico, global irradiance increased at two stations and decreased at seven stations. Eight stations witnessed an increase in diffuse irradiance averaging 7.2% (4.0 W m,2) and a decrease in direct irradiance of 5.0% (9.0 W m,2). The contribution of changes in cloud cover to the observed changes in irradiances appears to be small. Following the 1991 Mount Pinatubo eruption in the Philippines, diffuse irradiance increased an average of 18.8% (10.0 W m,2) at three stations and direct irradiance decreased by 7.2% (13.0 W m,2). Copyright © 2005 Royal Meteorological Society [source] Comparison of different earth radiation budget experiment data sets over tropical oceansINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 3 2002Chang-Hoi Ho Abstract We compare radiation budgets derived from different Earth Radiation Budget Experiment (ERBE) archives over the tropical oceans (30S and 30N) from 1985 to 1989. Two ERBE data sets are used. One is taken from the Earth Radiation Budget Satellite (ERBS), and the other from the combined ERBS, National Oceanic and Atmospheric Administration (NOAA) 9, and NOAA 10 satellites. The domain-mean all-sky outgoing longwave radiation (OLR) derived from the combined data set shows a notable change in early 1987 when NOAA 10 replaced NOAA 9. This change is also found in longwave (LW) cloud radiative forcing (CRF), all-sky shortwave (SW) radiation, and SWCRF. The ERBS, however, does not show such changes. We also examine the sensitivity of cloud,radiation interaction to the sea surface temperature (SST) of the tropical oceans. In general, each component of radiative feedbacks derived from the two ERBE data have the same sign, although they show a certain degree of discrepancy in the magnitude. The discrepancy is more notable for averaged quantities over the entire tropical oceans, particularly over the subtropics where convective activities are relatively weak. The combined data show a larger sensitivity of LWCRF and SWCRF to SST than those of the ERBS, consistent with the above results. The response of clouds to an increase in SST has a net cooling effect when using the combined data but has a net heating effect when using the ERBS data (,0.80 W m,2 K,1 versus 0.48 W m,2 K,1). Most of the discrepancies of the net CRF between the two ERBE data sets can be accounted for by the difference in the sensitivity of all-sky OLR (4.52 W m,2 K,1 versus 1.73 W m,2 K,1). Copyright © 2002 Royal Meteorological Society. [source] Numerical analysis of the single electrode heat effect in molten carbonate fuel cells: temperature analysis of the electrolyte plate by applying irreversible thermodynamicsINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 15 2004Fumihiko Yoshiba Abstract A temperature analysis model of a molten carbonate fuel cells (MCFC) stack is used to calculate the single electrode heat effects. The magnitude of heat which evolves from the cathode and absorbed at the anode is large, and in similar value to the electrical output of a MCFC. This suggests that the heat evolution of a single electrode causes a temperature difference between the electrodes. The temperature distribution in the electrolyte plate is evaluated to establish more accurate results concerning the temperature analysis model of the stack. The temperature distribution in the electrolyte plate is studied by applying irreversible thermodynamics. When the operating current density is less than 3000 A m,2 and the thermal conductivity of the electrolyte is more than 2 W m,1 K,1, the temperature difference between cathode and anode is estimated to be less than approximately 1 K. This result proves that the temperature difference between the electrodes can be supposed constant in constructing the temperature analysis model of the MCFC stack. This results also allows us to construct a two-dimensional heat production distribution in the cell plane and discrete heat production distribution in the stacking direction for the practical use of the temperature analysis model. Copyright © 2004 John Wiley & Sons, Ltd. [source] Computational energy analysis of an innovative isothermal chamber for testing of the special equipment used in the transport of perishable productsINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 10 2004S. K. Chatzidakis Abstract This paper describes an improved numerical simulation study of an isothermal chamber recently constructed at Zografou Campus of the National Technical University of Athens (NTUA) for the testing of special equipment used for transporting perishable foodstuffs in accordance with the United Nations ATP agreement. Using a transient finite difference model, a simulation is developed for a modern ATP test chamber and a typical specimen refrigerated vehicle to be tested. The simulation results are compared to experimental measurements taken under real conditions by a data acquisition system and a refrigerated semi-trailer as specimen. Proportional,integral control is employed for the regulation of the cooling and heating system. The impact of various parameters on the time required to reach the set-point temperature (tset) is investigated and the energy consumption is simulated for a period of 22 h. In particular, the impact of specimen insulation thickness and the thickness of the chamber insulation floor are considered in detail. The total energy consumption increases by approximately 16% when the concrete floor layer thickness is increased from 8 to 16 cm for typical initial conditions and desired chamber and specimen temperatures of 32.5 and 7.5°C, respectively. Using a floor insulation of 6 cm extruded heavy strain-resistant polystyrene reduces the energy consumption by at least 13%. Specimen insulation thickness increase from U -value of 0.35 W m,2 K to 0.75 W m,2 K result to an increase in energy consumption by a percentage of 28%. Thermal capacity, temperature of car body and specimen dimensions are also treated as variables that affect the total duration of an ATP test and its total energy consumption. Copyright © 2004 John Wiley & Sons, Ltd. [source] Prediction of cooling time in injection molding by means of a simplified semianalytical equationADVANCES IN POLYMER TECHNOLOGY, Issue 3 2003D. M. Zarkadas Abstract A simplified semianalytical equation, used successfully in food freezing/chilling time prediction, is proposed as a potential simple alternative for cooling time prediction in injection molding of polymer parts, amorphous or semicrystalline. This equation is based on a convective boundary condition for the mold-part interface and requires information on the thermal contact resistance (TCR) or thermal contact conductance (TCC) at this interface, as well as information on the initial and final product temperatures, the mold surface temperature, and the thermal properties of the part. Eighty-five data points for four polymers, Polystyrene (PS), Polycarbonate (PC), Polypropylene (PP), and Polyethylene (PE) were generated with C-MOLDÔ, a commercial injection molding design software, and the performance of the proposed equation was tested. The % mean error and its standard deviation (SD) in cooling time prediction were, respectively, ,11.61 and 2.27 for PS, ,6.04 and 2.13 for PC, ,7.27 and 6.55 for PP, and ,8.88 and 2.93 for PE. It was also shown that the accuracy of the proposed equation is not affected significantly by the exact knowledge of the TCC, provided that the latter is not smaller than 1000,2000 W m,2 K,1. Since in this comparison all necessary temperatures were obtained from C-MOLDÔ, methods of using the proposed equation independently were tested. The use of the inlet melt temperature as the initial product temperature increased the % mean error by mostly 1.5% while its SD remained practically the same. By incorporating a literature based heat balance method in the proposed equation, it was possible to use it as a stand-alone predictor of polymer cooling time. The % mean error and its SD calculated this way were, respectively, ,9.44 and 0.97 for PS, ,9.44 and 0.83 for PC, ,14.22 and 5 for PP, and ,20.12 and 1.38 for PE. The proposed equation, at least in a preliminary stage, can be used successfully to predict the cooling time of the selected semicrystalline or amorphous polymers with the accuracy being higher for amorphous polymers. © 2003 Wiley Periodicals, Inc. Adv Polym Techn 22: 188,208, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.10048 [source] Evaluation of applied cathode potential to enhance biocathode in microbial fuel cellsJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 5 2009Peng Liang Abstract BACKGROUND: The biocathode is proving to be a promising feature for development of the microbial fuel cell (MFC), although much work remains to be done to increase its power generation. This study aimed to enhance the performance of a biocathode by applying selected cathode potential. RESULTS: When five two-chambered MFCs were operated at selected cathode potentials of 142, 242, 342, 442, or 542 mV (vs standard hydrogen electrode), those MFCs with selected potentials lower than 342 mV could start up, and the highest power density of 0.11 W m,3 was obtained at a selected potential of 242 mV. An inner-biocathode MFC was then constructed and operated at a start-up cathode potential of 242 mV for 30 days. The open circuit cathode potential increased from 477 ± 9 mV to 572 ± 8 mV compared with the potential of the initially abiotic cathode, resulting in an increase in the maximum power density (4.25 ± 0.16 W m,3) of 106%. In addition, tests of continuous operation showed that a loading rate of 135 mg COD L,1 d,1 was optimal for obtaining maximum power generation in the system developed for this study. CONCLUSION: The results indicated that an optimal cathode potential of 242 mV enhanced the performance of a biocathode using oxygen as the electron acceptor. Copyright © 2009 Society of Chemical Industry [source] Effects of ultrasound on culture of Aspergillus terreusJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 5 2008Nuria Sainz Herrán Abstract BACKGROUND: Fermentations of Aspergillus terreus are commercially used to produce lovastatin. How ultrasound might influence this fermentation is unknown. While high-intensity ultrasound is effective in disrupting microbial cells, ultrasound of low intensity is known to improve productivity of some fermentation processes without damaging cells. Mechanisms behind productivity improvements have not been clearly identified in earlier studies. This work reports on the effects of ultrasound on A. terreus fermentation for low (957 W m,3), medium (2870 W m,3) and high (4783 W m,3) values of sonication power input in a slurry bubble column sonobioreactor. RESULTS: Sonication at any power level did not affect biomass growth profiles in comparison with negative controls. In contrast, medium- and high-intensity sonication greatly reduced production of lovastatin and substantially altered the growth morphology. At medium and high intensity, ultrasound disrupted fungal pellets and caused the biomass to grow mainly as dispersed hyphae. Sonication affected broth rheology because rheology depends on the morphology of the suspended biomass. CONCLUSION: Sonication can be used to modify growth morphology and broth rheology without affecting growth of filamentous fungi. Sonication appears to influence the primary growth metabolism and secondary metabolism differently in different situations. Copyright © 2008 Society of Chemical Industry [source] The role of viscous heating in Barrovian metamorphism of collisional orogens: thermomechanical models and application to the Lepontine Dome in the Central AlpsJOURNAL OF METAMORPHIC GEOLOGY, Issue 2 2005J.-P. BURG Abstract Thermal models for Barrovian metamorphism driven by doubling the thickness of the radiogenic crust typically meet difficulty in accounting for the observed peak metamorphic temperature conditions. This difficulty suggests that there is an additional component in the thermal budget of many collisional orogens. Theoretical and geological considerations suggest that viscous heating is a cumulative process that may explain the heat deficit in collision orogens. The results of 2D numerical modelling of continental collision involving subduction of the lithospheric mantle demonstrate that geologically plausible stresses and strain rates may result in orogen-scale viscous heat production of 0.1 to >1 ,W m,3, which is comparable to or even exceeds bulk radiogenic heat production within the crust. Thermally induced buoyancy is responsible for crustal upwelling in large domes with metamorphic temperatures up to 200 °C higher than regional background temperatures. Heat is mostly generated within the uppermost mantle, because of large stresses in the highly viscous rocks deforming there. This thermal energy may be transferred to the overlying crust either in the form of enhanced heat flow, or through magmatism that brings heat into the crust advectively. The amplitude of orogenic heating varies with time, with both the amplitude and time-span depending strongly on the coupling between heat production, viscosity and collision strain rate. It is argued that geologically relevant figures are applicable to metamorphic domes such as the Lepontine Dome in the Central Alps. We conclude that deformation-generated viscous dissipation is an important heat source during collisional orogeny and that high metamorphic temperatures as in Barrovian type metamorphism are inherent to deforming crustal regions. [source] Interaction of metamorphism, deformation and exhumation in large convergent orogensJOURNAL OF METAMORPHIC GEOLOGY, Issue 1 2002R. A. Jamieson Abstract Coupled thermal-mechanical models are used to investigate interactions between metamorphism, deformation and exhumation in large convergent orogens, and the implications of coupling and feedback between these processes for observed structural and metamorphic styles. The models involve subduction of suborogenic mantle lithosphere, large amounts of convergence (, 450 km) at 1 cm yr,1, and a slope-dependent erosion rate. The model crust is layered with respect to thermal and rheological properties , the upper crust (0,20 km) follows a wet quartzite flow law, with heat production of 2.0 ,W m,3, and the lower crust (20,35 km) follows a modified dry diabase flow law, with heat production of 0.75 ,W m,3. After 45 Myr, the model orogens develop crustal thicknesses of the order of 60 km, with lower crustal temperatures in excess of 700 °C. In some models, an additional increment of weakening is introduced so that the effective viscosity decreases to 1019 Pa.s at 700 °C in the upper crust and 900 °C in the lower crust. In these models, a narrow zone of outward channel flow develops at the base of the weak upper crustal layer where T,600 °C. The channel flow zone is characterised by a reversal in velocity direction on the pro-side of the system, and is driven by a depth-dependent pressure gradient that is facilitated by the development of a temperature-dependent low viscosity horizon in the mid-crust. Different exhumation styles produce contrasting effects on models with channel flow zones. Post-convergent crustal extension leads to thinning in the orogenic core and a corresponding zone of shortening and thrust-related exhumation on the flanks. Velocities in the pro-side channel flow zone are enhanced but the channel itself is not exhumed. In contrast, exhumation resulting from erosion that is focused on the pro-side flank of the plateau leads to ,ductile extrusion' of the channel flow zone. The exhumed channel displays apparent normal-sense offset at its upper boundary, reverse-sense offset at its lower boundary, and an ,inverted' metamorphic sequence across the zone. The different styles of exhumation produce contrasting peak grade profiles across the model surfaces. However, P,T,t paths in both cases are loops where Pmax precedes Tmax, typical of regional metamorphism; individual paths are not diagnostic of either the thickening or the exhumation mechanism. Possible natural examples of the channel flow zones produced in these models include the Main Central Thrust zone of the Himalayas and the Muskoka domain of the western Grenville orogen. [source] Comparison of plastic films with different optical properties for soil covering in horticulture: test under simulated environmental conditionsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 4 2005Adolf Heißner Abstract Covering the soil with plastic film is an important method to modify soil temperature and improve the conditions for plant growth. For the optimal use of films in horticulture, it is necessary to quantify this effect, which depends particularly on the optical properties of the film. Five films, used mainly for soil covering in asparagus cultivation, were tested by measuring the soil temperature as well as the transmittance and reflectance in the short- and long-wavelength bands: ,Taschenfolie schwarz/weiß', a film with black and white surfaces and pockets for fastening; ,Antitaufolie', a film with anti-condensation coating, ,Solartherm plus Folie', a film with black top and transparent sides; ,MaterBi Folie', a biodegradable film; and ,Thermoplus Folie', a black polyethylene with transparent sides. All films were produced in Germany. The temperature measurements were carried out under controlled irradiation (short-wavelength band) and ambient temperature conditions in the laboratory: first, 182 W m,2 and 11 °C at a depth of 0.4 m, and second, 340 W m,2 at 20 °C. A significant relationship between the temperature increase or decrease by covering the soil with the film and the calculated apparent quantities of the reflectance in the short and long-wavelength band was derived (r2 = 0.85, n = 12). Furthermore, first tests with a physical model were carried out to obtain basic information, which should be used in the development of strategies for film management in the field. Copyright © 2004 Society of Chemical Industry [source] The accuracy of downward short- and long-wave radiation at the earth's surface calculated using simple modelsMETEOROLOGICAL APPLICATIONS, Issue 1 2004J. W. Finch Estimates of the downward global solar and long-wave radiations are commonly made using simple models. We have tested the estimates produced by a number of these simple models against the values predicted by the radiative transfer model used in a climate model in order to determine their suitability for global applications. For clear sky, two simple models were comparable, but under cloudy conditions a combination of a clear-sky model based on the Angstrom-Prescott equation (which deals with the downwelling solar radiation) with a cloud transmissivity utilising total cloud fraction proved best. The lowest root mean square errors were 27 W m,2 for clear-sky global solar radiation and 90 W m,2 for cloudy conditions. For downward long-wave radiation in clear-sky conditions, the model of Garratt (1992) performed best with a root mean square error of 24 W m,2. However, in cloudy conditions the model of Idso & Jackson (1969) performed best with a root mean square error of 22 W m,2, and, as it performs nearly as well as that of Garratt (1992) in clear-sky conditions, it is probably the best choice. Copyright © 2004 Royal Meteorological Society. [source] Action Spectrum Conversion Factors that Change Erythemally Weighted to Previtamin D3 -weighted UV Doses,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 5 2008Stanley J. Pope Many solar UV measurements, either terrestrial or personal, weight the raw data by the erythemal action spectrum. However, a problem arises when one tries to estimate the benefit of vitamin D3 production based on erythemally weighted outdoor doses, like those measured by calibrated R-B meters or polysulphone badges, because the differences between action spectra give dissimilar values. While both action spectra peak in the UVB region, the erythemal action spectrum continues throughout the UVA region while the previtamin D3 action spectrum stops near that boundary. When one uses the previtamin D3 action spectrum to weight the solar spectra (Deff), one gets a different contribution in W m,2 than what the erythemally weighted data predicts (Eeff). Thus, to do proper benefit assessments, one must incorporate action spectrum conversion factors (ASCF) into the calculations to change erythemally weighted to previtamin D3 -weighted doses. To date, all benefit assessments for vitamin D3 production in human skin from outdoor exposures are overestimates because they did not account for the different contributions of each action spectrum with changing solar zenith angle and ozone and they did not account for body geometry. Here we describe how to normalize the ratios of the effective irradiances (Deff/Eeff) to get ASCF that change erythemally weighted to previtamin D3 -weighted doses. We also give the ASCF for each season of the year in the northern hemisphere every 5° from 30°N to 60°N, based on ozone values. These ASCF, along with geometry conversion factors and other information, can give better vitamin D3 estimates from erythemally weighted outdoor doses. [source] PAR and UV Effects on Vertical Migration and Photosynthesis in Euglena gracilis,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 4 2007Peter Richter Recently it was shown that the unicellular flagellate Euglena gracilis changes the sign of gravitaxis from negative to positive upon excessive radiation. This sign change persists in a cell culture for hours even if subsequently transferred to dim light. To test the ecological relevance of this behavior, a vertical column experiment was performed (max. depth 65 cm) to test distribution, photosynthetic efficiency and motility in different horizons of the column (surface, 20, 40 and 65 cm). One column was covered with a UV cut-off filter, which transmits photosynthetically active radiation (PAR) only, the other with a filter which transmits PAR and UV. The columns were irradiated with a solar simulator (PAR 162 W m,2, UV-A 32.6 W m,2, UV-B 1.9 W m,2). The experiment was conducted for 10 days, normally with a light/dim light cycle of 12 h:12 h, but in some cases the light regime was changed (dim light instead of full radiation). Under irradiation the largest fraction of cells was found at the bottom of the column. The cell density decreased toward the surface. Photosynthetic efficiency, determined with a pulse amplitude modulated fluorometer, was negligible at the surface and increased toward the bottom. While the cell suspension showed a positive gravitaxis at the bottom, the cells in the 40 cm horizon were bimodally oriented (about the same percentage of cells swimming upward and downward, respectively). At 20 cm and at the surface the cells showed negative gravitaxis. Positive gravitaxis was more pronounced in the UV + PAR samples. At the surface and in the 20 and 40 cm horizons photosynthetic efficiency was better in the PAR-only samples than in the PAR + UV samples. At the bottom photosynthetic efficiency was similar in both light treatments. The data suggest that high light reverses gravitaxis of the cells, so that they move downward in the water column. At the bottom the light intensity is lower (attenuation of the water column and self shading of the cells) and the cells recover. After recovery the cells swim upward again until the negative gravitaxis is reversed again. [source] Influence of UV Radiation on Four Freshwater Invertebrates,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 5 2000Alina Cywinska ABSTRACT Laboratory tests confirmed a negative and variable response of the following four species to artificial UV radiation: Cypridopsis vidua, an ostracode; Chironomus riparius, a midge larvae; Hyalella azteca, an amphipod; and Daphnia magna, a daphnid. Severe damage occurred at UV-B irradiance ranging from 50 to 80% of incident summer values. Under constant exposure to UV and photosynthetically active radiation (PAR) the acute lethal response was recorded at 0.3, 0.8, 0.8 and 4.9 W m,2 UV-B for D. magna, H. azteca, C. riparius and C. vidua, respectively. Sublethal UV-B damage to invertebrates included impaired movement, partial paralysis, changes in pigmentation and altered water balance (bloating). A series of UV-B, UV-A and PAR treatments, applied separately and in combination, revealed a positive role for both UV-A and PAR in slowing down UV-B damage. Mean lethal concentration values of the species typically more tolerant to UV and PAR (Cypridopsis, Chironomus) decreased conspicuously when both UV-A and PAR were eliminated. For UV-B,sensitive species (Hyalella, Daphnia) these differences were notably smaller. We suggest that this gradation of sensitivity among the tested species demonstrates potential differences in repairing mechanisms which seem to work more efficiently for ostracodes and chironomids than for amphipods and daphnids. Manipulations with a cellulose acetate filter showed that lower range UV-B (280,290 nm), produced by FS-40 lamps, may cause excessive UV damage to invertebrates. [source] Preparation and thermoelectric properties of polycrystalline nonstoichiometric Yb14MnSb11 Zintl compoundsPHYSICA STATUS SOLIDI - RAPID RESEARCH LETTERS, Issue 8-9 2010C. Yu Abstract Polycrystalline nonstoichiometric Yb14MnSb11 compounds have been successfully prepared by modified induction melting and spark plasma sintering. The carrier concentration was finely tuned by changing the elemental ratio of Mn to Sb. Excess Mn decreases the electrical conductivity and increases the Seebeck coefficient. The thermal conductivity of all samples was less than 1.0 W m,1 K,1. The maximum ZT value is 0.35 K at 673 K for Yb14Mn1.05Sb11, significantly higher than that of the stoichiometric Yb14MnSb11 polycrystalline sample. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Determination of in-plane thermal conductivity of Nax Co2O4 single crystals via a parallel thermal conductance (PTC) techniquePHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 5 2008Xiaofeng Tang Abstract A novel parallel thermal conductance ("PTC") system was specifically developed to conduct the steady state thermal conductivity measurement on small size samples such as single crystals of Nax Co2O4 as reported here. The accuracy and reproducibility of the PTC system has been confirmed by measuring several standard reference materials. The in-plane thermal conductivity , of Nax Co2O4 single crystals grown by a NaCl flux method was measured from 10 K to 300 K and , was found to be ,5 W m,1 K,1 at 300 K. The phonon mean free path (MFP) is estimated to be lph , 9 Å at 300 K, which is comparable to the lattice constant but much smaller than the reported MFP of conducting carriers. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] The effect of gravity on surface temperatures of plant leavesPLANT CELL & ENVIRONMENT, Issue 4 2003Y. KITAYA ABSTRACT A fundamental study was conducted to develop a facility having an adequate air circulation system for growing healthy plants over a long-term under microgravity conditions in space. To clarify the effects of gravity on heat exchange between plant leaves and the ambient air, surface temperatures of sweet potato and barley leaves and replica leaves made of wet paper and copper were evaluated at gravity levels of 0.01, 1.0, 1.5 and 2.0 g for 20 s each during parabolic aeroplane flights. Thermal images were captured using infrared thermography at an air temperature of 26 °C, a relative humidity of 18% and an irradiance of 260 W m,2. Mean leaf temperatures increased by 0.9,1.0 °C with decreasing gravity levels from 1.0 to 0.01 g and decreased by 0.5 °C with increasing gravity levels from 1.0 to 2.0 g. The increase in leaf temperatures was at most 1.9 °C for sweet potato leaves over 20 s as gravity decreased from 1.0 to 0.01 g. The boundary layer conductance to sensible heat exchange decreased by 5% when the gravity decreased from 1.0 to 0.01 g at the air velocity of 0.2 m s,1. The decrease in the boundary layer conductance with decrease in the gravity levels was more significant in a lower air velocity. Heat exchange between leaves and the ambient air was more retarded at lower gravity levels because of less sensible and latent heat transfers with less heat convection. [source] DNA damage and photosynthesis in Antarctic and Arctic Sanionia uncinata (Hedw.) Loeske under ambient and enhanced levels of UV-B radiationPLANT CELL & ENVIRONMENT, Issue 12 2002D. LUD Abstract The response of the bipolar moss Sanionia uncinata (Hedw.) Loeske to ambient and enhanced UV-B radiation was investigated at an Antarctic (Léonie Island, 67°35, S, 68°20, W) and an Arctic (Ny-Alesund, 78°55, N, 11°56, E) site, which differed in ambient UV-B radiation (UV-BR: 280,320 nm) levels. The UV-BR effects on DNA damage and photosynthesis were investigated in two types of outdoor experiments. First of all, sections of turf of S. uncinata were collected in an Arctic and Antarctic field site and exposed outdoors to ambient and enhanced UV-BR for 2 d using UV-B Mini-lamps. During these experiments, chlorophyll a fluorescence, chlorophyll concentration and cyclobutyl pyrimidine dimer (CPD) formation were measured. Secondly, at the Antarctic site, a long-term filter experiment was conducted to study the effect of ambient UV-BR on growth and biomass production. Additionally, sections of moss turf collected at both the Antarctic and the Arctic site were exposed to UV-BR in a growth chamber to study induction and repair of CPDs under controlled conditions. At the Antarctic site, a summer midday maximum of 2·1 W m,2 of UV-BR did not significantly affect effective quantum yield (,F/Fm,) and the ratio of variable to maximal fluorescence (Fv/Fm). The same was found for samples of S. uncinata exposed at the Arctic site, where summer midday maxima of UV-BR were about 50% lower than at the Antarctic site. Exposure to natural UV-BR in summer did not increase CPD values significantly at both sites. Although the photosynthetic activity remained largely unaffected by UV-B enhancement, DNA damage clearly increased as a result of UV-B enhancement at both sites. However, DNA damage induced during the day by UV-B enhancement was repaired overnight at both sites. Results from the long-term filter experiment at the Antarctic site indicated that branching of S. uncinata was reduced by reduction of ambient summer levels of UV-BR, whereas biomass production was not affected. Exposure of specimens collected from both sites to UV-BR in a growth chamber indicated that Antarctic and Arctic S. uncinata did not differ in UV-BR-induced DNA damage. It was concluded that S. uncinata from both the Antarctic and the Arctic site is well adapted to ambient levels of UV-BR. [source] Albedo, atmospheric solar absorption and heating rate measurements with stacked UAVsTHE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 629 2007M. V. Ramana Abstract This paper reports unique measurements of albedo, atmospheric solar absorption, and heating rates in the visible (0.4 to 0.7 µm) and broadband (0.3 to 2.8 µm) spectral regions using vertically stacked multiple lightweight autonomous unmanned aerial vehicles (UAVs). The most significant finding of this study is that when absorbing aerosols and water vapour concentrations are measured accurately and accounted for in models, and when heating rates are measured directly with stacked aircraft, the simulated clear sky heating rates are consistent with the observed broadband heating rates within experimental errors (about 15%). We conclude that there is no need to invoke anomalous or excess absorption or unknown physics in clear skies. Aerosol,radiation,cloud measurements were made over the tropical Indian Ocean within the lowest 3 km of the atmosphere during the Maldives Autonomous UAV Campaign (MAC). The UAVs and ground-based remote sensing instruments determined most of the parameters required for calculating the albedo and vertical distribution of solar fluxes. The paper provides a refined analytical procedure to reduce errors and biases due to the offset errors arising from mounting of the radiometers on the aircraft and due to the aircraft attitude. Measured fluxes have been compared with those derived from a Monte-Carlo radiative transfer algorithm which can incorporate both gaseous and aerosol components. Under cloud-free conditions the calculated and measured incoming fluxes agree within 2,10 W m,2 (<1%) depending upon the altitudes. Similarly, the measured and calculated reflected fluxes agreed within 2,5 W m,2 (<5%). The analysis focuses on a cloud-free day when the air was polluted due to long-range transport from India, and the mean aerosol optical depth (AOD) was 0.31 and mean single scattering albedo was 0.92. The UAV-measured absorption AOD was 0.019 which agreed within 20% of the value of 0.024 reported by a ground-based instrument. The observed and simulated solar absorption agreed within 5% above 1.0 km and aerosol absorption accounted for 30% to 50% of the absorption depending upon the altitude and solar zenith angle. Thus there was no need to invoke spurious or anomalous absorption, provided we accounted for aerosol black carbon. The diurnal mean absorption values for altitudes between 0.5 and 3.0 km above mean sea level were observed to be 41 ± 3 W m,2 (1.5 K/day) in the broadband region and 8 ± 2 W m,2 (0.3 K/day) in the visible region. The contribution of absorbing aerosols to the heating rate was an order of magnitude larger than the contribution of CO2 and one-third that of the water vapour. In the lowest 3 km of the tropical atmosphere, aerosols accounted for more than 80% of the atmospheric absorption in the visible region. Copyright © 2007 Royal Meteorological Society [source] | |||||||||||||||||||||||||