NS Values Research Articles

Hole mobility in the ultra-thin-body junctionless germanium-on-insulator p-channel metal-oxide-semiconductor field-effect transistors

Junctionless Germanium-on-insulator (GOI) p-channel metal-oxide-semiconductor field-effect transistors (MOSFETs) have been realized with an ultra-thin-body (UTB) channel of down to 6 nm. The hole mobility of 166 cm2/V s has been realized at an Ns value of 1013 cm−2 attributable to the reduction of carrier scattering by interface traps under a bulk transport behavior for the devices. The back bias dependence of the hole mobility in junctionless UTB GOI pMOSFETs was examined; it is found that the hole mobility in the devices is dominated by the surface roughness scattering at the MOS interface.

Improving hydrological simulation in the Upper Mississippi River Basin through enhanced freeze-thaw cycle representation

Freeze-thaw cycles are important processes relevant to terrestrial hydrological cycling. However, the representation of freeze-thaw cycles has been often simplified in large scale watershed models. The Soil and Water Assessment Tool (SWAT), which has been widely used to understand and assess hydrologic budgets and water resources management, employs a simplified empirical approach to estimate soil temperature and determine the freezing and thawing status of soils. Here, we compared the performance of a physically-based soil temperature module and the built-in empirical approach in SWAT against field measurements at surface and 5, 10, 20, 50, and 100 cm depths at six stations of the U.S. Climate Reference Network (USCRN) within the Upper Mississippi River Basin (UMRB). In general, SWAT consistently underestimated winter soil temperatures and overestimated frozen days at all soil depths, while the modified version of SWAT (equipped with the physically-based soil temperature model; referred to as TSWAT) pronouncedly reduced the bias in estimated winter soil temperatures and frozen days compared with SWAT. Model performance assessment is conducted with three statistical coefficients, i.e., Bias (°C), the coefficient of determination (R2), and Nash-Sutcliffe coefficient (NS). Statistical analyses show that TSWAT accurately simulated surface and soil temperatures at the five depths with R2 and NS values greater than 0.82 at most sites, and Bias values were generally within the range of −1 to 1 °C during winter and ranged between −2.09 and 2.58 °C in non-winter seasons. The differences in freeze-thaw cycle representation between SWAT and TSWAT translate into noticeable discrepancies in simulated key hydrologic variables, such as surface runoff, percolation, and baseflow. Compared against long-term observed streamflow (1980–2015), TSWAT outperformed SWAT in capturing variations in monthly streamflow in both winter and non-winter seasons. These results and analyses highlight the value of improving freeze-thaw cycle representation for enhanced hydrologic modeling in large watersheds that are subject to freeze-thaw cycles.

Reheating and dark radiation after fibre inflation

We study perturbative reheating at the end of fibre inflation where the inflaton is a closed string modulus with a Starobinsky-like potential. We first derive the spectral index ns and the tensor-to-scalar ratio r as a function of the number of efoldings and the parameter R which controls slow-roll breaking corrections. We then compute the inflaton couplings and decay rates into ultra-light bulk axions and visible sector fields on D7-branes wrapping the inflaton divisor. This leads to a reheating temperature of order 1010 GeV which requires 52 efoldings. Ultra-light axions contribute to dark radiation even if Δ Neff is almost negligible in the generic case where the visible sector D7-stack supports a non-zero gauge flux. If the parameter R is chosen to be small enough, ns≃ 0.965 is then in perfect agreement with current observations while r turns out to be of order r≃ 0.007. If instead the flux on the inflaton divisor is turned off, Δ Neff≲ 0.6 which, when used as a prior for Planck data, requires ns≃ 0.99. After R is fixed to obtain such a value of ns, primordial gravity waves are larger since r≃ 0.01.

Evaluation of Hydrological Application of CMADS in Jinhua River Basin, China

Evaluating the hydrological application of reanalysis datasets is of practical importance for the design of water resources management and flood controlling facilities in regions with sparse meteorological data. This paper compared a new reanalysis dataset named CMADS with gauge observations and investigated the performance of the hydrological application of CMADS on daily streamflow, evapotranspiration, and soil moisture content simulations. The results show that: CMADS can represent meteorological elements including precipitation, temperature, relative humidity, and wind speed reasonably for both daily and monthly temporal scales while underestimates precipitation compared with gauge observations slightly (<15%). The hydrological model using CMADS dataset as meteorological inputs can capture the daily streamflow chracteristics well overall (with a NS value of 0.56 during calibration period and 0.61 during validation period) but underestimates streamflow obviously (with a BIAS of − 42.42 % during calibration period and a BIAS of − 33.29 % during validation period). The underestimation of streamflow simulated with CMADS dataset is more seriously in dry seasons ( − 48.40 %) than that in wet seasons ( − 39.41 %) for calibration period. The model driven by CMADS estimates evapotranspiration and soil moisture content well compared with the model driven by gauge observations.

Planck 2018 and brane inflation revisited

We revisit phenomenological as well as string-theoretical aspects of D-brane inflation cosmological models. Phenomenologically these models stand out on par with α-attractors, as models with Planck-compatible values of ns, moving down to the sweet spot in the data with decreasing value of r. On the formal side we present a new supersymmetric version of these models in the context of de Sitter supergravity with a nilpotent multiplet and volume modulus stabilization. The geometry of the nilpotent multiplet is evaluated in the framework of string theory.

Evaluating infiltration models and pedotransfer functions: Implications for hydrologic modeling

Soil is a critical medium that governs hydrological processes in a landscape; however, soil data quality and resolution are not given much emphasis during watershed modeling and developing practical management practices, especially in data scarce regions such as in the Ethiopian highlands. This is primarily because measuring most soil parameters is costly, laborious, and at times impractical. Infiltration models and Pedotransfer functions (PTFs) may bridge this gap by estimating such complex soil parameters from easily measurable ones. However, most infiltration models and PTFs were developed for temperate regions and there is no comprehensive experimental or modeling work done to evaluate the robustness of such approaches in the Ethiopian highlands. Therefore, this study aims to i) evaluate the performance of three infiltration models, namely Horton, Koistakov, and Philip in simulating soil infiltration rates and ii) test the reliability of nine PTFs in estimating saturated hydraulic conductivity and soil moisture contents at field capacity and permanent wilting point in a case study in the Anjeni watershed. Soils in the Anjeni watershed on average contain higher percentages of clay and silt with 42 and 34%, respectively; and have acidic pH and low organic matter. Steady infiltration rate (fs) and saturated hydraulic conductivity (Ks) ranged between 0.19 and 30.6 mm h−1 and 0.19 and 3.3 mm h−1, respectively. All the three infiltration models fitted observed data very well with R2 and Nash-Sutcliffe efficiency (NS) values between 0.95 and 0.97 each. While the Horton and Koistakov models had the same R2 and NS values, the Horton provided smaller Mean Absolute Error (MAE) and Root Mean Square Error (RMSE) values. Some of the tested PTFs showed promising results in estimating saturated hydraulic conductivity and soil moisture content; however, all PTFs showed limitations which warrant further evaluation using observed data. This study showed that soil hydrologic parameters vary significantly even within a small area, and widely available soil datasets (e.g., Africa Soil Information Service (AfSIS) and FAO Harmonized World Soil Database) fail to reflect actual field conditions. This suggests that emphasis should be given to soil data quality and resolution during watershed modeling, and land and water management planning.

Statistical modeling of a scale network of nanosatellites

Statistical modeling of nanosatellite networks having no motion control of the center of mass and therefore randomly distributed in an intended service area of the interturn ground track interval is considered. This modeling is conducted on square structured matrices as service area models by methods of percolation theory. The concept of programmable service area percolation has been introduced implementing in two phases. Numerically, using the results of statistical modeling of two-phase operations, the concentration value of NS of the stochastic base has been obtained ensuring the minimum of aggregate expenditures.

Ice-nucleating ability of aerosol particles and possible sources at three coastal marine sites

Abstract. Despite the importance of ice-nucleating particles (INPs) for climate and precipitation, our understanding of these particles is far from complete. Here, we investigated INPs at three coastal marine sites in Canada, two at mid-latitude (Amphitrite Point and Labrador Sea) and one in the Arctic (Lancaster Sound). For Amphitrite Point, 23 sets of samples were analyzed, and for Labrador Sea and Lancaster Sound, one set of samples was analyzed for each location. At all three sites, the ice-nucleating ability on a per number basis (expressed as the fraction of aerosol particles acting as an INP) was strongly dependent on the particle size. For example, at diameters of around 0.2 µm, approximately 1 in 106 particles acted as an INP at −25 ∘C, while at diameters of around 8 µm, approximately 1 in 10 particles acted as an INP at −25 ∘C. The ice-nucleating ability on a per surface-area basis (expressed as the surface active site density, ns) was also dependent on the particle size, with larger particles being more efficient at nucleating ice. The ns values of supermicron particles at Amphitrite Point and Labrador Sea were larger than previously measured ns values of sea spray aerosols, suggesting that sea spray aerosols were not a major contributor to the supermicron INP population at these two sites. Consistent with this observation, a global model of INP concentrations under-predicted the INP concentrations when assuming only marine organics as INPs. On the other hand, assuming only K-feldspar as INPs, the same model was able to reproduce the measurements at a freezing temperature of −25 ∘C, but under-predicted INP concentrations at −15 ∘C, suggesting that the model is missing a source of INPs active at a freezing temperature of −15 ∘C.

Soil moisture and discharge modeling in a representative watershed in northeastern Brazil using SWAT

Soil moisture and discharge are interrelated variables which play a major role on water availability, environmental conservation and ecohydrological functioning of a watershed. In order to investigate their spatio-temporal dynamics, hydrological models are valuable tools. However, to minimize uncertainties of the modeled estimates, good quality distributed observational data sets are required for realist predictions. The aim of this study is to apply the Soil and Water Assessment Tool (SWAT) in a representative watershed of the northeastern Brazil, and to evaluate the effects of using both discharge and soil moisture datasets on the model uncertainties and predictions. The study area is located in the Mundaú River Basin (4090.39km2). For streamflow, the values of the Nash–Sutcliffe model efficiency (NS) among gauge stations ranged from 0.71 to 0.92 in the calibration phase for the annual time step, and between 0.55 and 0.78 in the monthly time step. In the validation phase, NS values ranged from 0.53 to 0.76 for the annual time step, and between 0.62 and 0.72 for the monthly time step. Calibration and validation against daily soil moisture data resulted in a NS values of 0.53 and 0.52, and PBIAS of 0.4% and −1.1%, respectively. These results represent “satisfactory” and “very good” performances for discharge and soil moisture. Although there is still some amount of uncertainty, the use of complementary data, such as soil moisture, to calibrate and validate the SWAT model is useful, especially when discharge data are scarce, as for some watersheds in the semiarid zone.

Influence of particle-size segregation on the impact of dry granular flow

Even though dry granular flow can cause well-known impact hazards to retaining structures, studies rarely have been conducted to determine the influence of particle-size segregation on the impact of dry granular flow. Based on the existing experiments concerning the impact of dry granular flow, we calibrated a code of the Discrete Element Method and designed three numerical simulations. Two types of degree of particle-size segregation Ns and Nl were defined to show the extent of particle-size segregation in the depth and flow directions. The results of the simulation indicated that a dry granular flow initiated with different degrees of particle-size segregation (Ns) could develop into very distinctive conditions in terms of the relative positions of different groups of particles in the depth and flow directions. The initial deposition with a higher Ns could make it easier for the coarser particles to be located in the front and top of a dry granular flow, with the finer particles being in the tail and bottom of the flow. In the impact process, the greater the values of Ns and Nl are, the more the coarser particles impact the retaining wall at a higher position at an earlier time during the impact. However, a higher degree of segregation of the particle sizes does not necessarily correspond to a higher impact force and action point. It is more rational to use the change of Ns with respect to its initial value as the index to show the influence of particle-size segregation, and a greater change in Ns corresponds to a higher impact force and a higher action point. The greater change of Ns corresponds to a lower energy dissipation, which is accounted for by the friction among the particles in the flow process, i.e.,less contacts among the particles correspond to the less dissipation of energy, which means that more energy can be converted into impact force.

Procalcitonin kinetics after burn injury and burn surgery in septic and non-septic patients \u2013 a retrospective observational study

BackgroundEarly sepsis diagnosis is crucial for the correct management of burn patients, and it clearly influences outcomes. The systemic inflammatory response triggered by burns mimics sepsis presentation and complicates early sepsis diagnosis. Biomarkers were advocated to aid the diagnosis of early sepsis. Serum procalcitonin (PCT) exhibits fair accuracy and good correlation with sepsis severity, being used in diverse clinical settings. However, few studies have evaluated perioperative changes in PCT levels in burn patients. The present study evaluated PCT kinetics during the first days after burn injury and subsequent surgical interventions to assess PCT utility in distinguishing septic from non-septic inflammatory responses.MethodsThis study was a retrospective observational study of all burn patients admitted to the Coimbra Burns Unit (Portugal) between January 2011 and December 2014 who presented with a total burn surface area ≥ 15% and who underwent subsequent surgery. PCT kinetics were investigated a) during the first five days after burn injury and b) preoperatively during the five days after surgery in three subsets of patients, including those with no preoperative and no postoperative sepsis (NN), no preoperative but postoperative sepsis (NS), and preoperative and postoperative sepsis (SS). A total of 145 patients met the selection criteria and were included in the analysis.ResultsPCT levels in the first five days after burn injury were significantly higher in patients who developed at least one sepsis episode (n = 85) compared with patients who did not develop sepsis (n = 60). PCT values > 1.00 ng/mL were clearly associated with sepsis. Study participants (n = 145) underwent a total of 283 surgical interventions. Their distribution by preoperative/postoperative sepsis status was 142 (50.2%) in NN; 62 (21.9%) in NS; and 79 (27.9%) in SS. PCT values exhibited a parallel course in the three groups that peaked on the second postoperative day and returned to preoperative levels on the third day or later. The lowest PCT values were found in NN, and the highest values were observed in SS; the NS values were intermediate.ConclusionsPCT kinetics coupled with a clinical examination may be helpful for sepsis diagnosis during the first days after burn injury and burn surgery.

Design and evaluation of SVR, MARS and M5Tree models for 1, 2 and 3-day lead time forecasting of river flow data in a semiarid mountainous catchment

Accurate and reliable river flow forecasts attained with data-intelligent models can provide significant information about future water resources management. In this study we employed a 50-model ensemble of three data-driven predictive models, namely the support vector regression (SVR), multivariate adaptive regression spline (MARS) and M5 model tree (M5Tree) to forecast river flow data in a semiarid and ecologically significant mountainous region of Pailugou catchment in northwestern China. To attain stable and accurate forecast results, 50 different models were trained by randomly sampling the entire river flow data into 80% for training and 20% for testing subsets. To attain a complete evaluation of the ensemble-model based results, the global mean of six quantitative statistical performance evaluation measures: the coefficient of correlation (R), mean absolute relative error (MAE), root mean squared error (RMSE), Nash–Sutcliffe efficiency coefficient (NS), relative RMSE, and the Willmott’s Index (WI), and Taylor diagrams, including skill scores relative to a persistence model, were selected to assess the performances of the developed predictive models. The results indicated that all of the averaged R value attained was higher than 0.900 and all of the averaged NS values were higher than 0.800, representing good performance of the SVR, MARS and M5Tree models applied in the 1-, 2- and 3-day ahead modeling horizon, and this also accorded with the deductions made through an assessment of the Willmott’s Index. However, the M5Tree model outperformed both the SVR and MARS models (with NS = 0.917 vs. 0.904 and 0.901 for 1-day, 0.893 vs. 0.854 and 0.845 for 2-day, and 0.850 vs. 0.828 and 0.810 for 3-day forecasting horizons, respectively), which was in concurrence with the high value of WI. Therefore, based on the ensemble of 50 models, the performance of the M5Tree can be considered as superior to the SVR and MARS models when applied in a problem of river flow forecasting at multiple forecast horizon. A detailed comparison of the overall performance of all three models evaluated through Taylor diagrams and boxplots indicated that the 1-day ahead forecasting results were more accurate for all of the predictive models compared to the 2- and 3-day ahead forecasting horizons. Data-intelligent models designed in this study indicate that the M5Tree method could successfully be explored for short-term river flow forecasting in semiarid mountainous regions, which may have useful implications in water resources management, ecological sustainability and assessment of river systems.

Small field models with gravitational wave signature supported by CMB data.

We study scale dependence of the cosmic microwave background (CMB) power spectrum in a class of small, single-field models of inflation which lead to a high value of the tensor to scalar ratio. The inflaton potentials that we consider are degree 5 polynomials, for which we precisely calculate the power spectrum, and extract the cosmological parameters: the scalar index ns, the running of the scalar index nrun and the tensor to scalar ratio r. We find that for non-vanishing nrun and for r as small as r = 0.001, the precisely calculated values of ns and nrun deviate significantly from what the standard analytic treatment predicts. We study in detail, and discuss the probable reasons for such deviations. As such, all previously considered models (of this kind) are based upon inaccurate assumptions. We scan the possible values of potential parameters for which the cosmological parameters are within the allowed range by observations. The 5 parameter class is able to reproduce all of the allowed values of ns and nrun for values of r that are as high as 0.001. Subsequently this study at once refutes previous such models built using the analytical Stewart-Lyth term, and revives the small field brand, by building models that do yield an appreciable r while conforming to known CMB observables.

Surface Plasmon Resonance Biosensor in Healthcare Application Using Kretschsmann & Otto Configuration

In this study, a planar D-shape optical fiber sensor based on Surface Plasmon Resonance phenomenon using two different excitation methods has been demonstrated. The proposed bio-sensor uses Amplitude-Wavelength hybrid detection technique to determine the change in urine refractive index that depends on resonance parameters. The analysis employs finite element method to investigate the optical properties of the proposed sensor. From the results it can be evident that Otto configuration offers greater amount of reflected light intensity dip for a particular urine refractive index in comparison with Kretschmann configuration. For an example, for Otto configuration the dip of reflected light intensity measured in terms of reflectance which attains a value 0.5 for ns (urine refractive index) of 1.489 while Kretschmann configuration provides a dip of 0.65 for the same value of ns. Results also show that the sharpness of reflectance is comparatively higher for the sensor using Otto configuration in comparison with Kretschmann configuration in case of wavelength interrogation. Thus, Otto configuration offers better performance in comparison with Kretschmann configuration.

Water quality assessment and catchment-scale nutrient flux modeling in the Ramganga River Basin in north India: An application of INCA model

The present study analyzes the water quality characteristics of the Ramganga (a major tributary of the Ganga river) using long-term (1991–2009) monthly data and applies the Integrated Catchment Model of Nitrogen (INCA-N) and Phosphorus (INCA-P) to the catchment. The models were calibrated and validated using discharge (1993–2011), phosphate (1993–2010) and nitrate (2007–2010) concentrations. The model results were assessed based on Pearson's correlation, Nash-Sutcliffe and Percentage bias statistics along with a visual inspection of the outputs. The seasonal variation study shows high nutrient concentrations in the pre-monsoon season compared to the other seasons. High nutrient concentrations in the low flows period pose a serious threat to aquatic life of the river although the concentrations are lowered during high flows because of the dilution effect. The hydrological model is satisfactorily calibrated with R2 and NS values ranging between 0.6–0.8 and 0.4–0.8, respectively. INCA-N and INCA-P successfully capture the seasonal trend of nutrient concentrations with R2>0.5 and PBIAS within ±17% for the monthly averages. Although, high concentrations are detected in the low flows period, around 50% of the nutrient load is transported by the monsoonal high flows. The downstream catchments are characterized by high nutrient transport through high flows where additional nutrient supply from industries and agricultural practices also prevail. The seasonal nitrate (R2: 0.88–0.94) and phosphate (R2: 0.62–0.95) loads in the catchment are calculated using model results and ratio estimator load calculation technique. On average, around 548tonnes of phosphorus (as phosphate) and 77,051tonnes of nitrogen (as nitrate) are estimated to be exported annually from the Ramganga River to the Ganga. Overall, the model has been able to successfully reproduce the catchment dynamics in terms of seasonal variation and broad-scale spatial variability of nutrient fluxes in the Ramganga catchment.

Evaluation and hydrological application of satellite-based precipitation datasets in driving hydrological models over the Huifa river basin in Northeast China

Satellite-based precipitation estimates with high spatial and temporal resolution and large areal coverage have provided hydrologists a potential alternative source for hydrological applications since the last few years, especially for ungauged regions. This study evaluates five satellite-based precipitation datasets, namely, Fengyun, TRMM 3B42, TRMM 3B42RT, CMORPH_BLD and CMORPH_RAW, against gauge observations for streamflow simulation with a distributed hydrological model (SWAT) over the Huifa river basin, Northeast China. Results show that, by comparing the statistical indices (MA, M5P, STDE, ME, BIAS and CC) and inter-annual precipitation, it is demonstrated that Fengyun TRMM 3B42 and CMORPH_BLD show better agreement with gauge precipitation data than CMORPH_RAW and TRMM 3B42RT. When the SWAT model for each dataset calibrated and validated individually, satisfactory model performances (defined as: NS > 0.5) are achieved at daily scale for Fengyun, TRMM 3B42 and gauge-driven model, and very good performances (defined as: NS > 0.75) are achieved at monthly scale for Fengyun and gauge-driven model, respectively. The CMORPH_BLD forced daily simulations also yield higher values of NS and R2 than CMORPH_RAW and TRMM 3B42RT at daily and monthly step. From the uncertainty results, variations of P-factor values and frequency distribution curves of NS suggest that the simulation uncertainty increase when operating the Fengyun, 3B42RT, CMORPH_BLD and CMORPH_RAW-driven model with best fitted parameters for rain gauge SWAT model. The results also indicate that the influence of parameter uncertainty on model simulation results may be greater than the effect of input data accuracy. It is noted that uncertainty analysis is necessary to evaluate the hydrological applications of satellite-based precipitation datasets.

Atmospheric Ice‐Nucleating Particles in the Dusty Tropical Atlantic

AbstractDesert dust is one of the most important atmospheric ice‐nucleating aerosol species around the globe. However, there have been very few measurements of ice‐nucleating particle (INP) concentrations in dusty air close to desert sources. In this study we report the concentration of INPs in dust laden air over the tropical Atlantic within a few days' transport of one of the world's most important atmospheric sources of desert dust, the Sahara. These measurements were performed as part of the Ice in Clouds Experiment‐Dust campaign based in Cape Verde, during August 2015. INP concentrations active in the immersion mode, determined using a droplet‐on‐filter technique, ranged from around 102 m−3 at −12°C to around 105 m−3 at −23°C. There is about 2 orders of magnitude variability in INP concentration for a particular temperature, which is determined largely by the variability in atmospheric dust loading. These measurements were made at altitudes from 30 to 3,500 m in air containing a range of dust loadings. The ice active site density (ns) for desert dust dominated aerosol derived from our measurements agrees with several laboratory‐based parameterizations for ice nucleation by desert dust within 1 to 2 orders of magnitude. The small variability in ns values determined from our measurements (within about 1 order of magnitude) is striking given that the back trajectory analysis suggests that the sources of dust were geographically diverse. This is consistent with previous work, which indicates that desert dust's ice‐nucleating activity is only weakly dependent on source.

Towards the development of a modeling framework to track nitrogen export from lowland artificial watersheds (polders)

Excess nitrogen (N) export from lowland artificial watersheds (polders) is often assumed to be a major contributor to the cultural eutrophication of downstream aquatic ecosystems. However, the complex transport processes characterizing lowland areas pose significant challenges in accurately quantifying their actual role. In this study, we developed a dynamic model to track N sources and transport pathways in lowland polders. The model is able to accommodate all the unique characteristics of polder dynamics, including artificial drainage, and interactions among surface water, groundwater and soil water. Our model was calibrated and validated against water level data and nitrogen concentrations measured in a lowland polder (Polder Jian) in China during the 2014–2016 period. Model performance was satisfactory with an R2 value of 0.55 and an NS value of 0.53 for total N concentrations. The characterization of the various components of water budget and N cycle derived by the model was on par with local empirical estimates. N export from Polder Jian was approximately 57 kg ha−1 yr−1 and was distinctly higher than values reported from nearby non-polder areas. The largest fraction of N export stemmed from seepage. To our knowledge, this is the first dynamic model to quantify N export from a watershed with artificial drainage network and can be used to design remedial measures of ecosystem degradation.

Relativistic and nonrelativistic effective nuclear charges for atoms from 1H to 103Lr

This work examines the relativistic and nonrelativistic effective charges (values of Zeff) for valence-shell electrons from 1H to 103Lr. Differences between relativistic and nonrelativistic Zeff values are investigated in detail. Except for 46Pd (4d)10 (5s)0, all atoms have ns or np spinors/orbitals as their outermost shell. Apart from 24Cr (3d)5 (4s)1, 41Nb (4d)4 (5s)1, and 42Mo (4d)5 (5s)1, the relativistic ns+Zeff values are always larger than the corresponding nonrelativistic ns values. For all atoms having np+ spinors as their outermost shell, in contrast, the np+Zeff values are smaller than the corresponding np Zeff values. In the valence nd and nf shells of transition metal atoms, the lanthanoid and actinoid atoms, the relativistic Zeff values are always smaller than the corresponding nonrelativistic nd and nf Zeff values except for 46Pd (4d)10 (5s)0. There are considerable differences between values of Zeff for the two series, but the relativistic Zeff values plotted against the atomic number (Z) recognizably retain the shape of the nonrelativistic Zeff versus Z curve. This fact implies that the nonrelativistic equation of motion for electrons largely determines the electronic configurations of atoms.

Hydrological simulation in a tropical humid basin in the Cerrado biome using the SWAT model

Abstract A Soil and Water Assessment Tool (SWAT) model was used to model streamflow in a tropical humid basin in the Cerrado biome, southeastern Brazil. This study was undertaken in the Upper São Francisco River basin, because this basin requires effective management of water resources in drought and high-flow periods. The SWAT model was calibrated for the period of 1978–1998 and validated for 1999–2007. To assess the model calibration and uncertainty, four indices were used: (a) coefficient of determination (R2); (b) Nash–Sutcliffe efficiency (NS); (c) p-factor, the percentage of data bracketed by the 95% prediction uncertainty (95PPU); and (d) r-factor, the ratio of average thickness of the 95PPU band to the standard deviation of the corresponding measured variable. In this paper, average monthly streamflow from three gauges (Porto das Andorinhas, Pari and Ponte da Taquara) were used. The results indicated that the R2 values were 0.73, 0.80 and 0.76 and that the NS values were 0.68, 0.79 and 0.73, respectively, during the calibration. The validation also indicated an acceptable performance with R2 = 0.80, 0.76, 0.60 and NS = 0.61, 0.64 and 0.58, respectively. This study demonstrates that the SWAT model provides a satisfactory tool to assess basin streamflow and management in Brazil.