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Post-weld slag and weld metal analyses were used to interpret the effects of different commercial flux compositions on element transfer between molten flux (slag) and weld metal in Submerged Arc Welding (SAW). Selected fluoride based flux compositions cover a wide range of basicity index (BI) values of 0.5–3.0. Thermochemical modelling in FactSage software is used to simulate the welding process in terms of gas-slag-metal equilibria. The importance of the gas phase in SAW element transfer is illustrated. The model provides improved accuracy in predicted weld metal oxygen values (ppm O) compared to the generally used empirical relationship of weld metal ppm O vs. flux BI. Model predicted oxygen values are within 150 ppm of the analysed values, compared to the empirical relationship values which are within 240 ppm from the analysed values. The model provides resolution in ppm O values at BI > 1.8. This information is lacking in the empirical relationship with constant ppm O of 250 ppm at BI > 1.8. The measured ppm O values follow the Fe–FeO equilibrium trend with a positive offset. The relative level of oxygen to deoxidation elements (Ti, Al, Mn, Si) in the weld metal is an important factor in oxide inclusion engineering. This model will aid in the specification of flux formulations to attain specific weld metal compositions for maximum acicular ferrite formation. In this way the weld metal mechanical properties can be improved. This model will reduce the number of welding tests required to develop new flux formulations.

In this chapter, we examine the empirical relationship between slow- and fast-onset natural disasters with economic growth at the subnational level using a panel data of 25 selected Indian states. The period under observation is 1990–2015. Using the augmented panel vector autoregression models, we estimate the growth effects of droughts and floods separately on the growth of the state-level gross domestic product (SGDP). The results indicate that while both slow- and fast-onset disasters adversely affect the SGDP growth, the impact is stronger in the case of the former with a larger magnitude of the estimated coefficients and persistence of the negative impact in the medium (up to 5 years) to long term (up to 10 years) following the disaster event. Further, the severity of the negative impact on SGDP growth increases with both excess and deficiency in the average annual rainfall.

The presented article provides an experimental classification for South Pars marls (SPM), southwest of Iran, using the Schmidt hammer rebound index, marl geological classes, and SPM geo-engineering characteristics. In this regard, 45 samples of marls (rock) are selected on the studied site and tested by geotechnical in-situ and laboratory tests such as Schmidt hammer, uniaxial compressive strength (UCS), laboratory direct-shear (LDS) to estimate the geo-engineering characteristics of SPM. These specimens are categorised by Pettijohn's marl classification in 3 main groups (concluded argillaceous lime, calcareous marl, and marlstone) and established the geologic class and geo-engineering properties as well as Schmidt hammer rebound index. In the meantime, the geologic classes and the Schmidt index show the logic classification. Thus, this work attempted to prepare the experimental classification based on Pettijohn's marl classification and Schmidt rebound index for SPM. According to geotechnical experiments results, the Schmidt index shows 3 main group variations like Pettijohn's marl classification. • This method can be used to prepare the geologic status based on the Schmidt rebound index. • This method can be useful for detailed decryption of geo-engineering characteristics of different type of marls in the studied area. • This method can be used as a quick link for marl geologic status and geo-engineering features., Graphical abstract Image, graphical abstract

In this paper, the specific primary production required (SPPR expressed as kg-NPP/kg-fish in wet weight) of more than 1700 marine species were calculated directly from 96 published food web models using the newly developed SPPR calculation framework. The relationship between SPPR and other ecological factors were then statistically analyzed. Among- and within-species variability of SPPR were found to be both explained by trophic level (TL), suggesting similar mechanisms underpinning both sources of variability. Among species, we found that harvesting species at higher mean trophic levels (MTL) increases the mean SPPR by a factor of 19 per 1 unit increase in MTL. Based on our empirical relationship, the mean SPPR of more than 9000 marine species were predicted and subsequently used to assess the primary production required (PPR) to support fisheries in five major fishing countries in Europe. The results indicated that conventional approach to estimating PPR, which neglects food web ecology, can underestimate PPR by up to a factor of 5. Within species, we found that harvesting populations occupying a higher TL leads to a higher SPPR. For example, the SPPR of Atlantic cod in the Celtic Sea (TL = 4.75) was 5 times higher than in the Gilbert Bay (TL = 3.3). Our results, which are based on large amounts of field data, highlight the importance of properly accounting for ecological factors during the impact assessment of fisheries.

Study focus: Future climate impacts on streamflow are of critical concern due to its importance for water and energy supplies. However, rigorous studies of such impacts involve complicated modeling chains that can be time-consuming and costly to implement. We examine an alternative approach by developing a method to predict the 21st century peak March-May (MAM) streamflow response to warming from historical data alone, specifically, past observations of the Snow-to-Precipitation ratio divided by basin Area (SPA). Study region: Using the Colorado River Basin (CRB) as a proving ground, we test this empirical relationship over 23 basins ranging in size from 9728 to 639,806 km2 within the CRB. Data was derived from hydrology model simulations forced by a suite of climate models, run under two emissions scenarios. New hydrological insights: Our proof-of-concept study revealed useful predictive capability (r2 = 0.58) and additionally identified three response types: rain- (basin SPA 3 × 10−3 km-2). The most dramatic changes occurred in snow-dominant basins where streamflow increased up to 320 % in MAM, but decreased by up to 60 % in the critical high demand months of July-September (JAS). By quantifying the relationship between historical data and future streamflow projections, our findings suggest this empirical relationship is useful to quickly and cheaply determine where and when large changes in hydrology will occur from future warming. Keywords: Streamflow forecasting, Snow, Climate variability, Modeling, Water resources management

Summary: The relationship between different physical parameters of various polymers (e.g., CR-39, Lexan, and PET) used as Nuclear Track Detectors (NTDs) and their intrinsic detection thresholds were investigated. A strong correlation was found between the electrical resistivity and detection thresholds of the NTDs and from that an empirical relationship between the two established. The predicted value of the detection threshold for Perspex® obtained from that empirical formula is in good agreement with its experimentally determined value. Keywords: NTD, Detection threshold, Electrical resistivity

An experimentally validated finite element model of filling pressures in rectangular silos with flexible walls is used to predict the stress regime in the stored solid in squat and intermediate aspect ratio silos. The model predicts the state of stress in the stored solid and the pressures imposed on the flexible walls of the silo. The non-uniform horizontal pressure distributions at each depth at the end of filling are explored. It is known that an empirical relation for the horizontal pressure variation on each straight wall derived from experimental observations in an earlier study closely matches the computational predictions. The coefficients of this relation are found to vary with depth below the stored solid surface, and depend on the relative stiffness of stored solid and the silo wall. Following many calculations involving different solids, an empirical relationship is derived that is suitable for practical design for a range of different stored solids for which relevant properties are known. The resulting expression is well suited to the practical determination of filling pressures in rectangular silos, and provides a silo design pressure proposal that is based on theoretical, rather than empirical findings.

Available online: 12 September 2019 This paper investigates the empirical relationship between countries’ expressed concerns with fairness and the ambition levels in their pledged contributions (NDCs) to the Paris Agreement, asking the following questions: 1) Are the NDCs of countries who express the most concern with fairness more or less ambitious than those of other countries? 2) Does the relationship between fairness and ambition vary across the three fairness principles: Responsibility, Capability, and Rights (needs)? and 3) Is there a tendency for countries to support the fairness principle that implies the largest emissions share for themselves if that principle were used to allocate emissions across countries? The analysis reveals considerable variation in both fairness concerns and assessed NDC ambitions, but no clear relationship between the two. Countries’ expressed support for fairness principles does not correlate with the ambition levels of their NDCs, whether principles are aggregated or disaggregated. The analysis also finds no evidence that countries strategically advocate the fairness principle that allocates them the largest “fair” emissions share.

The ages of carbonate rocks can be determined by comparing their 87Sr/86Sr ratios with the well-established seawater 87Sr/86Sr curve. Current models and databases provide no explicit solution to the problem of accurately assigning uncertainties to derived ages when the 87Sr/86Sr ratios of carbonate rocks contain analytical uncertainties. This is particularly concerning as significant amount of 87Sr/86Sr ratios are being measured by multi-collector inductively-coupled-plasma mass-spectrometry (MC-ICP-MS) which typically has a lower precision (1σ is typically several tens of ppm) compared with thermo-ionization mass-spectrometry (TIMs, 1σ can be as low as several ppm) used for calibrating the seawater 87Sr/86Sr curve. Deriving ages from carbonate 87Sr/86Sr ratios with large analytical uncertainties could introduce significant, sometimes asymmetric uncertainties in age estimates following a non-Gaussian distribution. More importantly, uncertainties in age estimates around the local maximum/minimum and saddle points on the Phanerozoic seawater 87Sr/86Sr curve are difficult to examine using conventional methods. In this study, we developed a rigorous mathematical framework (including perturbation and probability density methods) to estimate the 95% confidence interval (or any confidence interval of interest) of the derived age with any given analytical uncertainty. We applied this method to estimating uncertainties in derived ages for one version of the Phanerozoic seawater 87Sr/86Sr curve, assessing their sources and amplitudes. Our results indicates this method has the potential to be widely applied to estimating the uncertainties in ages derived from inversions using an empirical relationship. A Matlab program is presented that can calculate the age of carbonate rocks (based on their 87Sr/86Sr ratios and analytical uncertainties), the duration of intervals between ages, and the confidence interval of choice over the last 509 Ma (Version1 is available from zwang1@ccny.cuny.edu upon request).

This paper demonstrated the benefits of statistical methods when investigating the climatic and non-climatic drivers responsible for variations in groundwater recharge with a series of up to 43 years of annual recharge for 426 bores in South-East South Australia. We identified the factors influencing groundwater recharge based on 71 climatic metrics and 17 non-climatic metrics (including groundwater abstraction). The results showed: (1) Rainfall during April to October was the most important variable influencing recharge temporal variation, with its decline identified as the most significant factor related to recharge reduction; (2) In contrast, a negative correlation between rainfall during December to February (DJF) and annual groundwater recharge was found. This suggests that a seasonal shift in rainfall (such as decreasing rainfall during April to October and an increase during DJF) can result in a decline in recharge even when the annual rainfall remains unchanged; (3) The length of wet spells (consecutive rain days) and increasing potential evapotranspiration (PET) were additional significant predictors for recharge temporal variation. It demonstrated that a simple empirical relationship (such as recharge as a fixed percentage of rainfall) is not a reliable estimation of renewable groundwater resources under changing climatic conditions; (4) There is a statistically significant correlation between mean groundwater depth and recharge, which implies that if groundwater level fall due to rainfall declines then a positive feedback loop can lead to further recharge declines; (5) Spatially the most statistically significant factors influencing groundwater recharge were soil types and land attributes. The findings of this study can identify which stressors should be included when investigating the impact of climate change on groundwater recharge.

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. Whilst the ongoing banking regulatory reforms towards a comprehensive Basel III framework emphasise bank transparency, disclosure and a competitive banking market environment, very little is known about the empirical relationship between bank opacity and banking competition. We investigate the impact of competition, as measured by the individual bank's pricing power in the banking market, on bank opacity using a large sample of US bank holding companies over the 1986–2015 period. We uncover new evidence, on the competition-bank opacity nexus, which suggests that banks with higher market power and operating in less competitive banking markets have lower analysts' forecast errors and dispersions and may thus be less opaque. This effect is more pronounced for the 2007–09 global financial crisis period. Our evidence is robust to controlling for analysts' characteristics, bank fixed-effects and endogeneity problems.

Factors associated with the burden of influenza among vulnerable populations have mainly been identified using statistical methodologies. Complex simulation models provide mechanistic explanations, in terms of spatial heterogeneity and contact rates, while controlling other factors and may be used to better understand statistical patterns and, ultimately, design optimal population-level interventions. We extended a sophisticated simulation model, which was applied to forecast epidemics and validated for predictive ability, to identify mechanisms for the empirical relationship between social deprivation and the burden of influenza. Our modeled scenarios and associated epidemic metrics systematically assessed whether neighborhood composition and/or spatial arrangement could qualitatively replicate this empirical relationship. We further used the model to determine consequences of local-scale heterogeneities on larger scale disease spread. Our findings indicated that both neighborhood composition and spatial arrangement were critical to qualitatively match the empirical relationship of interest. Also, when social deprivation was fully included in the model, we observed lower age-based attack rates and greater delay in epidemic peak week in the most socially deprived neighborhoods. Insights from simulation models complement current understandings from statistical-based association studies. Additional insights from our study are: (1) heterogeneous spatial arrangement of neighborhoods is a necessary condition for simulating observed disparities in the burden of influenza and (2) unmeasured factors may lead to a better quantitative match between simulated and observed rate ratio in the burden of influenza between the most and least socially deprived populations.

Albedo (or solar reflectivity) plays an important role in the thermal behavior of pavements and other ground surfaces and their resultant impacts on humans and the environment. This chapter develops a new albedo measurement system with a dual-pyranometer and automatic data acquisition system, and it is used to conduct field measurements of albedo on various pavement materials and for long-term monitoring of albedo. Nine 4 by 4-m experimental sections were designed and constructed at Davis, California, and used for albedo and other field measurements presented in this book. The albedo values were obtained for commonly used pavement and land-cover materials. The seasonal effects of albedo on pavement thermal performance were examined through experimental measurements. An empirical relationship between the cooling effect of increased albedo on a pavement’s high temperature and solar radiation was developed. The cooling effect has a positive correlation with the peak solar radiation intensity.

Gully erosion represents one of the most significant types of land degradation in the Mediterranean areas, giving place to important on- and off-site effects. In this paper, a second-order gully located in SW Spain is analyzed. Along the gully, 28 cross-sections were established and measured with a Leica TCRM1102 laser total station, approximately every 6 months from 2001 to 2007. The sections were located at variable distance, placing them in areas where active erosion was evident. In total, 13 field measurements were carried out, and the geometric characteristics of 28 cross-sections were obtained. Morphometric analyses were carried out in both the main gully and a tributary reach by applying an empirical relationship between channel length and eroded volume. Morphometric variables of the gully sections were combined into two dimensionless groups, and a morphological similarity between different linear erosion landforms (rills, ephemeral and permanent gullies) was obtained. Then, the coefficient of variation of the calculated volumes was used to compare the instability between the main gully and the tributary reach. Finally, the hydraulic geometry of the gully was assessed by calibrating three empirical power equations, which relate bankfull discharge with mean flow velocity, cross-sectional depth and width. The hydraulic characterization of the main gully and the tributary reach was investigated for each field survey and a different behavior was detected. The hydraulic analysis also demonstrated that higher values of discharge provide better predictions of flow velocity; the size of the main and tributary gullies affects the discharge–width relationship; and that gully depth is the variable which can be predicted with the highest accuracy.

This article reviews what is known about the relationship between education and health or health behaviors. Current research on the empirical relationship between education and health documents large heterogeneity in this relationship. Possible reasons for the disparate findings are discussed, with particular emphasis to whether this heterogeneity can be explained theoretically. Directions for future research are discussed.

A method of calculation has been developed for determining the average voltage-time (V-T) characteristics of quasi-uniform field gaps subjected to high impulse voltages. The method consists of evaluating the test voltage which will produce a critical electron avalanche in the gas gap, the size of which is a function of the time to breakdown. An empirical relationship determined from experimental data obtained at IREQ defines the critical avalanche size which would cause breakdown of the gap at a time Tf, the measured time to flashover. Comparison of the calculated average V-T curves with experimental data for various gap configurations shows reasonable agreement. The error margin was found to be about 10–15% over the range of times to breakdown from 0.2 to 2.0 μs and for gas pressures up to 1.065 MPa.

Leaf area index (LAI), the total one-sided green leaf area per unit of ground surface, is an important structural property of vegetation. Because leaf surfaces are the primary sites of energy and mass exchange, important processes such as canopy interception, evapotranspiration, and gross photosynthesis are directly proportional to LAI. This article discusses how to obtain LAI, the global LAI characteristics, and how LAI is applied in ecological models. The current state of the art in obtaining LAI can be broken into the ground-based methods and the remote-sensing methods. In the field, LAI can be obtained directly or indirectly: direct methods measure LAI through litterfall or destructive sampling; indirect methods estimate LAI via relationship with other more easily measurable parameters, such as canopy transmittance. Current methods for estimating LAI from optical remote sensing are classified into three categories through: (1) the empirical relationship between LAI and vegetation indices; (2) inversion of canopy reflectance models; and (3) a hybrid inversion method. Following this, some notable satellite sensors that provide LAI products will be introduced. The spatial and temporal properties of global LAI products are analyzed. Finally, how the LAI is applied in various ecological models is discussed.

Cap rocks do not hold infinite amounts of oil/gas so there must be a physical limitation of the column height of oil/gas that a trap can hold. The sealing capacity of a trap is one of the most important conditions that needs to be evaluated quantitatively. In this paper, we review the basic phenomenon of hydrocarbon trapping by capillary pressure. By evaluating the observed hydrocarbon column height from a field, we can quantify the sealing capacity in terms of pore throat radius. The pore throat radius, however, is not a convenient parameter for geologists, so we convert it into grain size (assuming that the sediments consist of equal-sized spheres). In this conversion, we use a theoretical relation of COEF (ratio of pore throat to grain size) as a function of porosity. We improve this relationship by conducting a physical experiment where we measure the capillary pressure for an artificial seal to derive an empirical relationship between COEF and porosity. Thus we can evaluate top seal capacity in terms of imaginary grain size (this is named ‘equivalent grain size method’). Then we propose a ‘practical’ flow chart for evaluating sealing capacity in a quantitative way. One of the biggest problems for seal evaluation is that it was usually based on the structural and stratigraphical interpretations. For the effective seal evaluation, we propose an integrated approach such as doing all the interpretations at the same time. This ‘multi-disciplinary’ approach would solve the debatable phenomena on the sealing/non-sealing problems to give us a deeper understanding of the petroleum systems.

20 pages, 11 figures, 4 tables, The primary productivity of the NW Iberian margin has been determined by a combination of 14C incorporation experiments on natural phytoplankton assemblages and satellite remote sensing with the ocean colour sensor, SeaWiFS. The approach to the field determination of phytoplankton production was Eulerian, involving measurements on a fixed grid of stations covering the region from 41°30′N to 43°00′N and 09°00′W to 10°30′W. Three different laboratories made primary production measurements over a 3-year period. Each group used variations of the 14C method—in situ incubations and two modelling approaches based on P–E parameter derivation. An intercalibration experiment showed acceptable agreement between the three estimates. Measurements by the three groups on eight cruises have been merged to provide estimates of regional productivity. However, the temporal coverage of the data was too limited to provide robust seasonal estimates since few experiments were done in the autumn and winter months. A second approach to the estimation of primary production utilised surface pigment concentrations derived from satellite remote sensing. Two models were used. Firstly, an empirical relationship was found between depth-integrated primary production and surface chlorophyll concentration, which explained 78% of the variance in the production estimates. The second approach used a semi-analytical model which incorporates irradiance and temperature as well as chlorophyll-derived parameters. Both models have been applied to SeaWiFS-derived, surface chlorophyll concentrations to estimate primary production during 1998, 1999 and 2000 for three regions—the shelf, the slope and the open ocean of the region of study. Using the semi-analytical model, the mean primary production for the 3 years is estimated to be 319 g C m−2 year−1 for the shelf, 280 g C m−2 year−1 for the slope and 217 g C m−2 year−1 for the adjacent open ocean. Interannual variation in production on the shelf ranged from 334 g C m−2 year−1 in 1998 to 301 g C m−2 year−1 in 2000. It is estimated that upwelling increased primary production, relative to that in the open ocean, by ∼50%. Satellite-derived estimates of the ratio of new production to primary production were 0.37, 0.28 and 0.40 for the shelf region during the upwelling seasons of 1998, 1999 and 2000, This work was supported by the European Commission in the framework of the Mast 3 Programme, contract number MAS3-CT97-0076. (OMEX project): by the Framework 5 PROOF project (EVK3-1999-00103): by the DYME and MDB Projects of the Plymouth Marine Laboratory, a component of the Natural Environment Research Council: by the Belgian Federal Office for Scientific, Technical and Cultural Affairs in the framework of the Global Change and Sustainable Development Programme, contract no. CG/DD/11C: and by the Spanish Comisión Interministerial de Ciencia y Tecnologı́a grant No. MAR1997-2068-CE

An empirical relationship has been found between the critical strain energy release rate, GIC, of WC-6%Co and parameters obtainable by means of Vickers hardness tests. These results provide a simple method to determine relative values of GIC.

Publisher Summary The chapter presents some basic facts on retirement patterns and examines some reasons for the changes in behavior over time and differences across groups. Retirement is an important phenomenon in life-cycle labor supply. Not only does it mean a complete withdrawal from the labor force, but it also turns on a number of institutional facets such as social security and private pensions. The chapter explores a number of theoretical models and discusses empirical results. The chapter presents a close look at pensions and social security and concludes by analyzing life-cycle savings behavior and looking at the status of retirees. The goal of the chapter is to lay out the important issues in retirement behavior, rather than to draw definitive conclusions on the state of knowledge. A quick look at the data reveals that the most important trend among older workers in the United States is the decline in age of retirement. Because there has been a simultaneous increase in the real income of the population, an obvious conjecture is that most of this reflects an income effect that induces workers to take more leisure. The discussion of pensions focuses on one empirical relationship and a number of theoretical ones. The most important empirical point is that the actuarial value of private pensions first rises, but then declines once the worker continues to work beyond a certain point.

The aggregate fertility model for the relationship between the proximate determinants and a set of aggregate fertility measures including total fertility rate (TFR) and total marital fertility (TM) can be used to gain insights into a variety of theoretical and practical issues concerning the relationship between fertility and the proximate determinants. In the 1st application estimates are made of the trends in the principal proximate determinants during a "synthetic" transition from the fertility behavior found in contemporary developing countries. The 2nd application describes a decomposition procedure that allows the quantification of the contribution made by each proximate determinant to an observed fertility change between 2 points in time. This procedure is used in the 3rd application to demonstrate how socioeconomic differentials in the proximate determinants can explain unexpected differentials in marital fertility. The 4th application presents an age specific elaboration of the aggregate fertility model. The 5th application presents an analysis of the empirical relationship between contraceptive prevalence levels and different fertility measures. In the 6th application future levels of the total fertility rate are projected based on estimated trends in contraceptive practice. The 7th application includes a brief description of an equation for estimating the levels of contraceptive prevalence and use effectiveness required to reach a prescribed fertility target.