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Using National Agricultural Workers Survey (NAWS) data, we examine which farmworkers are unionized and whether their status differs systematically from non‐unionized farmworkers. Logit results indicate farmworkers are less likely to be unionized if they are Black, unauthorized to work in the U.S., less educated, have English proficiency, work for farm labor contractors (versus growers), and cultivate field (vs. horticulture) crops. Blinder‐Oaxaca decomposition reveals that union members earn $0.87 more in hourly wages, are 4.8% points more likely to receive a bonus, and are 15.6% points more likely to have employer‐provided health insurance than comparable non‐unionized farmworkers. [ABSTRACT FROM AUTHOR]

Successful farms—in the public imagination, agricultural policy, and more—tend to be highly profitable and operate at extremely large scales. Research has shown that women are less likely to operate these types of farms, possibly due to their preferences and lifestyle choices. There is evidence, however, that these gaps are additionally the result of differences in access to resources due to gender discrimination. Patterns of inequity in land inheritance and other resources limit women's farm size and choice of crops, and thus their opportunities to farm at larger, more profitable scales. Nonetheless, women farmers also employ creative strategies to make farming work for them. Our study uses 2017 Census of Agriculture data to compare women and men farmers at 7 different farm scales, revealing gendered strategies and comparing men and women farmers on equal footing. This presents a more nuanced picture of women's participation in farming at various scales. Overall, we find that within farm scales, women are often doing just as well as men—usually with fewer or different resources and approaches. Women's unbalanced representation at each farm scale, however, helps to explain why women are not always envisioned as "real farmers" in the popular conscience. [ABSTRACT FROM AUTHOR]

Successful farms—in the public imagination, agricultural policy, and more—tend to be highly profitable and operate at extremely large scales. Research has shown that women are less likely to operate these types of farms, possibly due to their preferences and lifestyle choices. There is evidence, however, that these gaps are additionally the result of differences in access to resources due to gender discrimination. Patterns of inequity in land inheritance and other resources limit women's farm size and choice of crops, and thus their opportunities to farm at larger, more profitable scales. Nonetheless, women farmers also employ creative strategies to make farming work for them. Our study uses 2017 Census of Agriculture data to compare women and men farmers at 7 different farm scales, revealing gendered strategies and comparing men and women farmers on equal footing. This presents a more nuanced picture of women's participation in farming at various scales. Overall, we find that within farm scales, women are often doing just as well as men—usually with fewer or different resources and approaches. Women's unbalanced representation at each farm scale, however, helps to explain why women are not always envisioned as "real farmers" in the popular conscience. [ABSTRACT FROM AUTHOR]

Using Census of Agriculture (2017) data, we investigate the association between the principal operator's sexual orientation and farm profitability. Farms run by a male principal operator married to another male (MMM) have higher profits than farms run by a male principal operator married to a woman (MMW), a woman married to a man (WMM), and a woman married to another woman (WMW). Having two men on farm confers profit advantages. Compared with other marital combinations studied, MMM operate large‐scale farms, are more experienced farmers, and are more likely to engage in commodity agriculture. Findings suggest gender, not sexual orientation, is driving the observed profit gaps. [ABSTRACT FROM AUTHOR]

Farm operation is among the most gender‐unequal occupations in the U.S. Data from the 2017 U.S. Census of Agriculture reveals that average net farm income was 151% higher on farms with a male versus a female principal operator. Decomposition analysis indicates the gender gap is almost entirely explained by differences in endowments. Female farmers have lower farm profitability than their male counterparts because their operations use far less capital (land, machinery, and labor), they have less farming experience, and they engage in the production of commodities that are less profitable. [ABSTRACT FROM AUTHOR]

We use nationally representative data from the National Agricultural Workers Survey to assess gender‐based differences in wages and benefits of hired farmworkers. Decomposition and matching results indicate that, compared to men, women make 5% to 6% less in hourly wages and are less likely to receive a bonus or have health insurance paid by their employer. These gender gaps are partly explained by differences between female and male farmworkers in farming experience, hours worked, farm tasks, and crops cultivated. Sizable proportions of the gender gaps are unexplained and the result of discrimination, unmeasured differences between women and men, or both. [ABSTRACT FROM AUTHOR]

Rotor blades of large, modern wind turbines are susceptible to lightning strikes. In order to produce a design that resists lightning strikes, it is crucial to simulate lightning current propagation in the blade components. Since the current in the blade is generated by the superposition of potential and induced electric fields, a coupling exists between electric and magnetic fields which need to be calculated by an imposed integral constraint at each time step. Commercial software packages can deal with such constraints, but it results in time‐consuming computations. Therefore, this work aims to develop a numerical methodology able to compute the voltage which drives the lightning current through the structure. In this way, the problem is reformulated as a voltage‐driven one which in turn allows a simple subsequent coupling of electrical and magnetic problems. The computation of the voltage waveform was accomplished using the fast Fourier transform and the finite element method (FEM) to compute the structure impedance in the frequency domain. The developed procedure showed high efficiency for a blade subjected to different lightning impulses. It allows a description of the time‐dependent lightning current to be given, as well as the distribution of current within the blade conductors. [ABSTRACT FROM AUTHOR]

In this study, three different moieties containing amino‐groups were incorporated into graphene oxide (GO) in order to modify interfacial interactions within an epoxy matrix. The GO was functionalized with two bifunctional molecules of different molar masses (d230 and d4000) and a trifunctional (t440). The resulting functionalized GO (fGO) systems were characterized by Raman spectroscopy, thermogravimetric analysis (TGA) and X‐ray photoelectron spectroscopy (XPS), which demonstrated the presence of the functionalizer groups. Analysis of nanocomposites including the above three fGOs by microscopy and differential scanning calorimetry (DSC) demonstrated that the presence of the functionalizer moieties served to improve the platelet distribution within the matrix and to affect the local fGO/matrix interfacial interactions perturbing the epoxy curing reactions; we suggest that these changes stem from the fGO surface structure and the introduction of additional reactive amine nitrogen. X‐ray diffraction revealed reduced graphitic stacking with increased functionalizer molar mass. The electrical conductivity of the fGO‐filled epoxy was enhanced with increasing functionalizer molecular weight, an effect we relate to the influence of this on platelet stacking. The thermal conductivity was, however, adversely affected by all reagents at low fGO contents. [ABSTRACT FROM AUTHOR]

The AC and DC dielectric properties of hydrofluoroethers (HFE) [C3F7OCH3] and fluorinated ketone (FK) [C2F5C(O)CF(CF3)2] have been characterised by dielectric spectroscopy and DC conductivity at different temperatures. Results show that DC conductivity and imaginary permittivity of both fluids are positively correlated with increasing temperature. However, the real permittivity decreases with increasing temperature. The breakdown voltages of HFE and FK at 295 K are ∼10 kV mm−1. Reducing temperature is an effective method to increase the breakdown voltage of the FK coolant, but the breakdown voltage of HFE is less temperature dependent. Finally, as expected repeated breakdown had no significant effect on the AC dielectric strength of both liquids. [ABSTRACT FROM AUTHOR]

Regional economic resilience can be defined as an economy's ability to withstand and recover quickly from shocks. The ability to measure resilience is necessary to developing our understanding of what influences resilience. In this paper, we develop a new, two‐dimensional quantitative measure of resilience using observed differences between expected and actual employment in a region following a shock and distinguish the response to the shock from random variation. We demonstrate one application of this metric to US county‐level employment data to compare county responses to the 2007–2009 national recession and discuss how different regions of the United States responded to the shock of the Great Recession in terms of resilience. [ABSTRACT FROM AUTHOR]

With an increasing number of offshore high-voltage direct current wind farm projects planned, submarine cable crossings become inevitable. It is important to accurately rate these circuits, because if high temperatures occur at crossing points, the cable may age prematurely. At present, the IEC60287-3-3 crossing rating method is inapplicable to such crossings due to a failure of the 'Image' theory, and it is challenging to carry out other analytical studies due to the difficulties in modelling the subsea thermal environment. As a solution, this study presents a new finite element analysis approach to study the thermal performance of submarine crossings under various continuous rating combinations and rock protection layer conditions, to provide guidelines for crossing operation. With focus on the free thermal convection mechanism within the rock layer, the significance of this mechanism is highlighted in a quantitative manner. It shows that when the free convection is preserved, the upper circuit can operate safely with its stand-alone rating regardless of the crossing; while the lower circuit may require a de-rating if its stand-alone rating is thermally limited. [ABSTRACT FROM AUTHOR]

With an increasing number of offshore high‐voltage direct current wind farm projects planned, submarine cable crossings become inevitable. It is important to accurately rate these circuits, because if high temperatures occur at crossing points, the cable may age prematurely. At present, the IEC60287‐3‐3 crossing rating method is inapplicable to such crossings due to a failure of the 'Image' theory, and it is challenging to carry out other analytical studies due to the difficulties in modelling the subsea thermal environment. As a solution, this study presents a new finite element analysis approach to study the thermal performance of submarine crossings under various continuous rating combinations and rock protection layer conditions, to provide guidelines for crossing operation. With focus on the free thermal convection mechanism within the rock layer, the significance of this mechanism is highlighted in a quantitative manner. It shows that when the free convection is preserved, the upper circuit can operate safely with its stand‐alone rating regardless of the crossing; while the lower circuit may require a de‐rating if its stand‐alone rating is thermally limited. [ABSTRACT FROM AUTHOR]

The maximum current rating of high‐voltage power cables is limited by the allowable conductor temperature, in order to prevent damage to the adjacent dielectric material. Cross‐linked polyethylene dielectrics are generally subject to a thermal limit of 90°C in the UK. The use of novel new dielectric materials may allow the temperature limit to be raised considerably. This study examines the possible thermal rating benefits available from 400 kV cable systems capable of conductor temperatures of up to 150°C in a number of common deployment scenarios, including direct burial and installation in ventilated tunnels. The results of the analysis show a divide between modest improvements in continuous rating and much more utilisable gains in short‐term emergency ratings, which could offer the possibilities of single‐cable circuits being able to match the current carrying capacity of overhead lines over 24‐h period. [ABSTRACT FROM AUTHOR]

SUMMARY Previous work has shown that the structure of repetitive control (RC) and that of iterative learning control (ILC) differ only in the location of an internal model of the disturbance. In this paper, it is shown how this common setting permits derivation of controllers in one domain based on an existing controller in the other. This is illustrated using the following case studies: 1) an RC scheme using a state feedback structure is derived based on an existing ILC scheme, which also uses state feedback (the underlying structure is first extended to comprise both current-error feedback and previous-error feedforward implementations); and 2) an ILC scheme using an output injection structure is developed based on an existing RC scheme, which uses state feedback, but differs from 1) by containing only a single internal model representation. All controllers are shown to have similar equivalent representations, with parameters derived by using linear quadratic regulator analysis. This correspondence enables comparison of the effect of the structure (ILC or RC, state feedback or output injection), number of internal models, and use of error (feedback or feedforward) on subsequent performance. This is undertaken using experimental results obtained using a gantry robot. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This article uses nationally representative data from Malawi's 2004/05 Integrated Household Survey (IHS2) to examine whether rainfall conditions influence a rural worker's decision to make a long-term move to an urban or another rural area. Results of a Full Information Maximum Likelihood regression model reveal that (1) rainfall shocks have a negative association with rural out-migration, (2) migrants choose to move to communities where rainfall variability and drought probability are lower, and (3) rainfall shocks have larger negative effects on the consumption of recent migrants than on the consumption of long-time residents. [ABSTRACT FROM AUTHOR]

The successful operation of buried infrastructure within urban environments is fundamental to the conservation of modern living standards. Open-cut methods are predominantly used, in preference to trenchless technology, to effect a repair, replace or install a new section of the network. This is, in part, due to the inability to determine the position of all utilities below the carriageway, making open-cut methods desirable in terms of dealing with uncertainty since the buried infrastructure is progressively exposed during excavation. However, open-cut methods damage the carriageway and disrupt society's functions. This paper describes the progress of a research project that aims to develop amulti-sensor geophysical platform that can improve the probability of complete detection of the infrastructure buried beneath the carriageway. The multi-sensor platform is being developed in conjunction with a knowledge-based system that aims to provide information on how the properties of the ground might affect the sensing technologies being deployed. The fusion of data sources (sensor data and utilities record data) is also being researched to maximize the probability of location. This paper describes the outcome of the initial phase of testing along with the development of the knowledge-based system and the fusing of data to produce utility maps. [ABSTRACT FROM AUTHOR]