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A saturated riparian buffer (SRB) is an edge-of-field conservation practice that intercepts tile drainage and reduces nitrate flux to nearby streams by redistributing the flow as shallow groundwater. In this study, a three-dimensional, finite-difference groundwater model representative of SRBs in central Iowa was developed to assess the flow of groundwater and implications for nitrate removal during spring conditions, when flow to the SRB is highest. The model reproduces field observations of water level with Nash-Sutcliffe efficiency of 0.68, which is deemed acceptable for hydrologic models. The modeling shows that groundwater flow is three-dimensional near the distribution pipe and the stream and primarily one-dimensional in the rest of the buffer. The path the water takes in flowing toward the stream depends on where it exits the distribution pipe. When nitrate is not limiting, the potential for nitrate removal depends on the length of the path-and thus travel time-and depth because denitrification potential varies with depth. Travel time T

Introduction: This study investigated the influence of clinical and psychosocial factors on medical students’ quality of life (QOL). Methods: A total of 408 medical students participated in this study. We collected data on participants’ sociodemographic details, symptoms of depression and Internet addiction, self-esteem, social support, and QOL. QOL was assessed using the World Health Organization Quality of Life-Abbreviated form (WHOQOL-BREF), which has four domains (physical health, psychological health, social relationships, and environment). A stepwise multiple linear regression model was constructed to identify factors’ independent impact on QOL. Results: Higher levels of depression and Internet addiction were associated with lower scores in all domains of QOL, whereas higher levels of self-esteem and social support were associated with higher scores. Being in third year versus first-year was associated with higher scores in the physical health and environment domains. Living alone or in dormitories, low or middle socioeconomic status, and insufficient or moderate pocket money were associated with lower scores in the environment domain. Additionally, female students displayed significantly lower scores for physical health, psychological health, and environment than male students, but not for social relationships. There were significant differences in certain domains of QOL due to sociodemographic factors. Discussion: This study demonstrates the clinical and psychosocial factors influencing medical students’ QOL. Educational strategies focusing on strengthening self-esteem and social support as well as preventing depression and Internet addiction may contribute to improving medical students’ QOL.

Construction-related ground-disturbing activities leave exposed land susceptible to soil loss and increase the risk of polluting adjacent waterbodies with sediment-laden discharge. State and federal regulations require stormwater pollution prevention plans to be implemented during construction to mitigate the impact of stormwater runoff. Areas prone to soil loss can be identified early in site planning using soil loss modeling. Identification of these critical areas could influence the design and placement of erosion and sediment control practices. The Revised Universal Soil Loss Equation (RUSLE) can be applied to estimate the soil loss on construction sites in tonnes per Ha per year (tons/acre/year) by considering factors of rainfall erosivity, soil erodibility, length of slope, erosion control, and sediment control. This study integrates geographic information system (GIS) with RUSLE to create soil loss models for residential, commercial, and highway construction scenarios in the contiguous U.S.A. These three construction types were modeled in various locations throughout the country to assess erosive risk. Soil loss outputs were categorized into five risk tiers ranging from very low to very high. Southeastern states had the highest estimated soil loss during residential, commercial, and highway construction, reaching rates of 1,464, 706, and 1,302 tonnes per Ha per year (653, 315, and 581 tons/acre/year), respectively. This study provides a customizable model for any site-specific slope-length factor outside of the three construction scenarios modeled. Integration of GIS provides a unique opportunity to apply RUSLE across a larger landscape. The presented macro-scale data can be used for the design of erosion and sediment control practices.

The effect of gnomonic distortion on orientation indexing of electron backscatter diffraction patterns is explored through simulation of electron diffraction patterns for sample-to-detector geometries associated with transmission Kikuchi diffraction (TKD) and electron backscatter diffraction (EBSD). Simulated data were analysed by computing a similarity index for both Hough transformed data and simulated patterns to determine the sensitivity of each method for detecting subtle differences in the effect of gnomonic distortions on electron diffraction patterns. These results indicate that the increased gnomonic distortions in electron diffraction patterns for a TKD geometry enhance the sensitivity for detecting subtle differences in interband angles. Additionally, the utilisation of a Hough transform-based indexing approach further enhances the sensitivity.

The effects of elemental sulfur on the corrosion of mild steel is a serious problem in the oil & gas industry costing millions of dollars annually in lost production and assets. Mitigating the corrosive effects of elemental sulfur on mild steel in the oil and gas industry is a challenge and finding a viable solution would provide a more cost effective and safer working environment and as well as be environmentally conscious. Currently, there are no highly effective products for elemental sulfur corrosion in the marketplace. More than fifty new chemical formulations were blended and screened by rotating cylinder electrode method (RCE). These formulations were tested in the presence of 0.1% elemental sulfur in mildly sour conditions. The promising candidates were identified and tested again in the presence of elemental sulfur under the same mildly sour conditions. The most promising candidates from the initial screening were then subjected to rotating cage autoclave (RCA) testing for extended periods of time in the presence of 0.1% and 0.15% elemental sulfur. The general corrosion rates were calculated via weight loss and the metal surfaces were examined under a high-power digital microscope for pitting and localized corrosion. A detailed analysis of the above testing yields promising results. The results from the testing show that formulations mitigate pitting in environments containing elemental sulfur. In less harsh conditions, such as low chloride brines or low CO2 environment, formulations seem to provide excellent protection against general corrosion while mitigating pitting due to elemental sulfur. In more extreme environments such as harsh brines with elevated chloride levels, high hydrogen sulfide and CO2 levels, the formulations mitigate pitting but need further development in inhibiting general corrosion The best product currently developed inhibits corrosion and pitting in the presence of elemental sulfur in various conditions and performs well against elemental sulfur in more aggressive sour systems. We are currently improving the performance against elemental sulfur and developing chemistries to mitigate polysulfide induced corrosion in sour systems. This paper describes the development of effective inhibitors for corrosion and pitting in the presence of elemental sulfur under sour conditions. This study focuses more on pitting corrosion due to the corrosive characteristics of elemental sulfur than on uniform general corrosion. The general corrosion with the selected inhibitor was highly mitigated and was less than 3.0 mpy while yielding excellent protection against sulfur induced pitting.

Integrity is considered an important corporate value. Yet recent global events have highlighted the challenges firms face at living up to their stated values, especially when extended supply chain partners are involved. The concept of Supply Chain Integrity (SCI) can help firms shift focus beyond internal corporate integrity, toward supply chain integrity. Researchers and managers will benefit from an understanding of the SCI concept toward implementing SCI to better align supply chain partners with stated corporate values. This research fully develops and empirically grounds the firm-level, inter-firm-oriented SCI concept. The thematic analysis of six firms' archival and website content elaborated empirical descriptions of SCI themes and enabled the development of a process model for SCI, presenting a novel view of the underlying process by which firms can assess, develop, and maintain SCI across their supply chains. We propose the SCI model as an evolutionary process to improve a firm's supply chain sustainability, rather than a dichotomous end state where firms either "have" integrity or they don't. The SCI model could be used as a tool to help leaders create necessary change to better align values and supporting statements with culture, while influencing and affecting stakeholders across the supply chain. This is particularly important in today's world, where business leaders must consider all stakeholders and address important stakeholder-driven issues such as supply chain sustainability, resilience, and security, which are now at the forefront in the ever-changing environment.

In situ high-energy X-ray diffraction (XRD) was performed on lead-zirconate-titanate-based ferroelectric materials with composition near the morphotropic phase boundary (MPB). The utilization of the two-dimensional area detector in in situ field-dependent experiments enables the complete analysis of the material response with respect to all azimuthal angles at each field amplitude. The studies reveal that the field-induced phase transition from tetragonal to rhombohedral is dependent on crystal orientation in Nb-doped PbZr0.53Ti0.47O3 that is in close compositional proximity to the MPB. However, only domain wall motion is activated in Nb-doped PbZr0.50Ti0.50O3, which is further in composition from the MPB. This synchrotron-based XRD characterization approach illustrates the importance in evaluating the orientation-dependence of phase transitions in piezoelectric and ferroelectric polycrystalline materials.

Pandemics are associated with heightened distress among healthcare workers (HCWs). We report qualitative findings from a two-stage survey administered to HCWs at a large acute care hospital in Ontario during the COVID-19 pandemic to identify their concerns and wellness needs. Responses reflected HCWs' desires to be heard, protected, prepared, supported and cared for by the organization. HCWs' concerns were diverse and dynamic, reflecting the specific circumstances of their work and personal lives as well as the shifting landscape of the pandemic. We discuss implications for organizations seeking to promote and protect HCWs' psychological well-being and resilience during pandemics.

In flash sintering experiments, the thermal history of the sample is key to understanding the mechanisms underlying densification rate and final properties. By combining robust temperature measurements with current-ramp-rate control, this study examined the effects of the thermal profile on the flash sintering of yttria-stabilized zirconia, with experiments ranging from a few seconds to several hours. The final density was maximized at slower heating rates, although processes slower than a certain threshold led to grain growth. The amount of grain growth observed was comparable to a similar conventional thermal process. The bulk electrical conductivity correlated with the maximum temperature and cooling rate. The only property that exhibited behavior that could not be attributed to solely the thermal profile was the grain boundary conductivity, which was consistently higher than conventional in flash sintered samples. These results suggest that, during flash sintering, athermal electric field effects are relegated to the grain boundary.

Wildlife research by citizen scientists, involving the capture and handling of animals, provides clear scientific benefits, but also potential risks to animal welfare. We explore debates about how best to regulate such work to ensure that it is undertaken in an ethical manner. We focus on the UK as a case study, drawing on qualitative research and stakeholder engagement events. We show that because trapping and marking of certain species requires minimal licensing, training and justification, some argue for increased formal regulation to minimise risks to animal welfare. However, others have reflected on the already complex regulatory landscape affecting wildlife research, and have expressed concern that introducing additional formal regulations could potentially make citizen science working with wildlife more difficult. Informal regulation could therefore offer a preferable alternative. We set out three steps that could be taken to open up conversations about ethics and regulation of wildlife‐focussed citizen science, in the UK and elsewhere: (a) take stock of wildlife‐focussed citizen science in terms of numbers and harms to animal welfare; (b) assess the state of formal regulations and consider reforms; and (c) consider informal regulations as alternatives or additions to formal regulations. A free Plain Language Summary can be found within the Supporting Information of this article.

Relaxor ferroelectrics, which can exhibit exceptional electromechanical coupling, are some of the most important functional materials, with applications ranging from ultrasound imaging to actuators. Since their discovery, their complex nanoscale chemical and structural heterogeneity has made the origins of their electromechanical properties extremely difficult to understand. Here, we employ aberration-corrected scanning transmission electron microscopy to quantify various types of nanoscale heterogeneities and their connection to local polarization in the prototypical relaxor ferroelectric system Pb(Mg1/3Nb2/3)O3–PbTiO3. We identify three main contributions that each depend on Ti content: chemical order, oxygen octahedral tilt and oxygen octahedral distortion. These heterogeneities are found to be spatially correlated with low-angle polar domain walls, indicating their role in disrupting long-range polarization and leading to nanoscale domain formation and the relaxor response. We further locate nanoscale regions of monoclinic-like distortion that correlate directly with Ti content and electromechanical performance. Through this approach, the connections between chemical heterogeneity, structural heterogeneity and local polarization are revealed, validating models that are needed to develop the next generation of relaxor ferroelectrics. Relaxor ferroelectric systems exhibit exceptional electromechanical coupling that arises from a variety of nanoscale chemical ordering. Here, scanning transmission electron microscopy is used to quantify this structural complexity directly.

The crystallization behavior of amorphous barium titanate (BaTiO3) thin films was studied as a function of annealing temperature from 500 to 1000 °C. Quantitative phase analysis by grazing incidence X-ray diffractometry revealed that the metastable hexagonal phase preferentially nucleates at lower temperatures with a transition to stable cubic nuclei at higher temperatures. The predominance of the metastable hexagonal-phase nucleation at lower temperatures suggests that it has the lowest nucleation barrier, in accordance with the Ostwald’s step rule. To help induce the nucleation of the cubic phase at lower temperatures, we explored the effects of electric fields on the crystallization behavior and found that direct-current fields moderately enhanced the cubic phase fraction in the 500–700 °C temperature range. Although the nucleation barrier of the cubic phase in the presence of an electric should be lowered more significantly with respect to that of the hexagonal phase because of the former’s higher relative permittivity, the effect arising from the change in volume free energy should only become significant at electric field strengths in the range of MV cm−1, an order of magnitude higher than the experimentally accessible fields in the present study. This suggests alternative, perhaps interface-mediated, mechanisms by which the electric field modifies the nucleation behavior of BaTiO3.

In this work, we measure DC and AC conductivity and Hall voltage to determine the origin of electrical insulating properties of Fe-doped β-Ga2O3 single crystals, which are measured perpendicular to the 2¯01 crystallographic plane. We find that electrical conduction is predominantly controlled by free electrons in the temperature range 230–800 °C with the mutual compensation of the impurity donor (Si) and acceptor dopant (Fe), explaining the low concentration of free electrons and Fermi level pinning over a wide range of temperatures. Furthermore, the negative temperature-dependence of the carrier mobility indicates that it is limited by optical phonon scattering. Importantly, we find electrical conductivity to be largely independent of oxygen partial pressure (pO2) from air to 10−4 atm at 600 °C, but it becomes slightly dependent on pO2 at 800 °C, as intrinsic non-stoichiometric point defects begin to influence the charge balance.

The effects of elemental sulfur on the corrosion of mild steel is a serious problem in the oil & gas industry costing millions of dollars annually in lost production and assets. Mitigating the corrosive effects of elemental sulfur on mild steel in the oil and gas industry is a challenge and finding a viable solution would provide a more cost effective and safer working environment and as well as be environmentally conscious. Currently, there are no highly effective products for elemental sulfur corrosion in the marketplace. More than fifty new chemical formulations were blended and screened by rotating cylinder electrode method (RCE). These formulations were tested in the presence of 0.1% elemental sulfur in mildly sour conditions. The promising candidates were identified and tested again in the presence of elemental sulfur under the same mildly sour conditions. The most promising candidates from the initial screening were then subjected to rotating cage autoclave (RCA) testing for extended periods of time in the presence of 0.1% and 0.15% elemental sulfur. The general corrosion rates were calculated via weight loss and the metal surfaces were examined under a high-power digital microscope for pitting and localized corrosion. A detailed analysis of the above testing yields promising results. The results from the testing show that formulations mitigate pitting in environments containing elemental sulfur. In less harsh conditions, such as low chloride brines or low CO2 environment, formulations seem to provide excellent protection against general corrosion while mitigating pitting due to elemental sulfur. In more extreme environments such as harsh brines with elevated chloride levels, high hydrogen sulfide and CO2 levels, the formulations mitigate pitting but need further development in inhibiting general corrosion The best product currently developed inhibits corrosion and pitting in the presence of elemental sulfur in various conditions and performs well against elemental sulfur in more aggressive sour systems. We are currently improving the performance against elemental sulfur and developing chemistries to mitigate polysulfide induced corrosion in sour systems. This paper describes the development of effective inhibitors for corrosion and pitting in the presence of elemental sulfur under sour conditions. This study focuses more on pitting corrosion due to the corrosive characteristics of elemental sulfur than on uniform general corrosion. The general corrosion with the selected inhibitor was highly mitigated and was less than 3.0 mpy while yielding excellent protection against sulfur induced pitting.

The low-frequency dielectric properties of cotton fabrics in the fabric thickness direction are examined in relation to the fabric construction, thread count and solid volume fraction (SVF) at five different relative humidity levels. It is found that the real part of the relative permittivity increases with increase in thread count, and this is due to the associated increase in SVF. On the other hand, the imaginary part of the relative permittivity and loss tangent (dielectric loss) show no clear monotonic tendency to the SVF at highly moist environments. Permittivity is observed to change depending on fabric constructions under the controlled SVF. These observations indicate that, in addition to the SVF, the fabric geometrical parameters, which are influenced by construction methods, also need to be considered in low-frequency dielectric analysis.

The conductivity of ceramic ionic materials is highly influenced by dopant segregation at the grain boundaries or interfaces, which usually induces a depletion of charge carriers by space charge effects. Hence, obtaining interfacial configurations that promote the formation of oxygen vacancies is highly desirable. In this paper we have combined high resolution electron microscopy (HREM), kelvin probe force microscopy (KPFM) and density functional theory (DFT) to elucidate the equilibrium state of CGO–CoO and CGO–NiO eutectic ceramics (CGO: cerium-gadolinium oxide). HREM proves that the interface is sharp, formed by a single common oxygen plane, and that in CGO–CoO the concentration of gadolinium ions at the interface is almost three times greater than in the bulk, while they distribute homogeneously in the CGO–NiO system. Accordingly, KPFM experiments suggest that interfacial ionic conductivity is much higher in CoO–CGO than in NiO–CGO. DFT demonstrates that Gd segregation in the CGO–CoO reduces the interface energy, contributing to its stability. The Gd-oxygen vacancy complexes compensate the interfacial ionic charge density discontinuity. Additionally, the induced local distortions around the defect release the strain associated with the lattice mismatch. Therefore, we show that in CGO-based eutectics the structure and ionicity of the constituent oxides are essential to promote the interface dopant segregation, indicating a new way to produce nanocomposites with enhanced interfacial ionic conductivity., This work was funded through MAT2015-68078-R, MAT2015-66888-C3-1R, MAT2016-80762-R and RTI2018-097895-B-C41 projects by the Spanish Government (Ministerio de Economía y Competitividad) and the Feder Programme of the European Union. Financial support from Xunta de Galicia (Centro singular de investigación de Galicia, accreditation 2016–2019, ED431G/09) is also recognized. F. W. acknowledges the financial support of the China Scholarship Council (CSC) during her stay at the ICMM.

The onset of flash sintering is generally considered to be predominantly a function of the conductivity of a given ceramic, the furnace temperature, and the electric field. However, the evolution of the point defect profiles in ionic conductors such as yttria-stabilized zirconia (YSZ) can complicate the picture of homogeneous Joule heating and thermal runaway during DC flash sintering. Here, 8 mol% YSZ pellets were partially flash sintered under a DC bias using various current densities and hold times. The electrode geometry was varied to modulate the oxygen ion flux available to the cathode to compare the effects on the resulting oxygen vacancy inhomogeneity. The contribution from fundamental and experimental factors to the cathodic reduction reaction is also discussed, such as interface reaction kinetics and sample geometry. Local reduction of the ceramic was inevitably observed under all current densities and the resulting microstructural inhomogeneity was explained as the result of a transient conductivity asymmetry. This asymmetry was the result of the enhanced electronic conductivity in the cathode region to a value significantly greater than the ionic conductivity of near-stoichiometric YSZ. The link between the local conductivity, voltage and Joule heating is mathematically demonstrated to result in an asymmetric heating profile.

The primary purpose of this paper is to report on psychiatry residents’ perceptions of what is important when receiving feedback from evaluators. In January 2018, as part of the Harvard South Shore Psychiatry Residency Training Program’s (HSS) ongoing local quality improvement efforts to enhance the delivery and effectiveness of feedback that residents receive from faculty during training, the authors disseminated a survey to psychiatry residents (n = 31) at HSS. Residents rated the level of importance of 17 statements pertaining to the way feedback is delivered. Two open-ended prompts also allowed respondents to share examples of growth-oriented and unhelpful feedback they have received during residency. Twenty-seven residents responded (87% response rate). Eighty-one percent rated “the evaluator models the same behavior they’re encouraging” as “extremely important” when receiving feedback. Many residents also rated the following survey items as “extremely important”: “confidence in the evaluator’s clinical and interpersonal skills” (63.0%), “amount of time the evaluator observed the resident” (51.9%), “there is a way to fix a performance deficit” (51.8%), and “specific feedback based off the resident’s work” (48.1%). Conversely, only 11.1% of residents rated the feedback sandwich as “extremely important.” Despite a small sample size, this project demonstrated that, when receiving feedback, the majority of psychiatry residents strongly value when evaluators model the targeted behavior. The feedback sandwich was least important to residents. This project underscores the importance of evaluators serving as role models in the context of feedback, and findings can be used in faculty development activities focused on feedback delivery best practices.

Samarium supersensors Piezoelectric materials produce electric charge in response to changes in stress and are thus good sensor materials. One challenge has been growing single-crystal piezoelectrics with uniform properties. As of now, much of the crystal is discarded because of compositional variations. Li et al. synthesized single crystals of samarium-doped Pb(Mg 1/3 Nb 2/3 )O 3 -PbTiO 3 that have uniform and extremely high piezoelectric properties (see the Perspective by Hlinka). These crystals are ideal for a variety of sensing applications and could reduce cost by eliminating waste. Science , this issue p. 264 ; see also p. 228

When and where animals breed can shape the genetic structure and diversity of animal populations. The importance of drivers of genetic diversity is amplified in island populations that tend to have more delineated gene pools compared to continental populations. Studies of relatedness as a function of the spatial distribution of individuals have demonstrated the importance of spatial organisation for individual fitness with outcomes that are conditional on the overall genetic diversity of the population. However, few studies have investigated the impact of breeding timing on genetic structure. We characterise the fine-scale genetic structure of a geographically-isolated population of seabirds. Microsatellite markers provide evidence for largely transient within-breeding season temporal processes and limited spatial processes, affecting genetic structure in an otherwise panmictic population of sooty terns Onychoprion fuscatus. Earliest breeders had significantly different genetic structure from the latest breeders. Limited evidence was found for localised spatial structure, with a small number of individuals being more related to their nearest neighbours than the rest of the population. Therefore, population genetic structure is shaped by heterogeneities in collective movement in time and to a lesser extent space, that result in low levels of spatio-temporal genetic structure and the maintenance of genetic diversity.

Cold sintering of ZnO and MnO with dimethyl sulfoxide (DMSO)-based solutions is demonstrated. For ZnO ceramics, density values approach 99% theoretical when cold-sintered at 180 °C with DMSO-HOAc and DMSO-Zn(OAc)2 solutions. MnO densified with aqueous HOAc solutions produces ceramics of 84% theoretical density that contain significant amounts of Mn(OH)2 secondary phases. In comparison, using DMSO-HOAc solutions produces density values of 94% theoretical at 250 °C with trace quantities of Mn3O4, verified via X-ray diffraction. Scanning electron microscope analysis of sample fracture surfaces containing Mn3O4 reveals numerous crystallites smaller than 100 nm that nucleate on or between the considerably larger starting MnO grains. With increasing temperature, these precipitates appear to coalesce and fill the porosity that remains after initial compaction. These results identify an avenue to cold sinter metal oxides that, in the presence of aqueous media, favor hydroxide formation which inhibits further densification.

Barium Titanate and Ni-based multilayer ceramic capacitors have wide commercial applicability, and interfaces are critical to the overall device behavior as they can help control unwanted leakage currents. Here we make use of photoemission methods to investigate the electrostatic barriers formed at BaTiO3/Ni(O) interfaces to understand the implications for electron injection. We find the interface Fermi level in BaTiO3 to evolve smoothly during Ni deposition with a Schottky barrier height for electrons of 0.68 eV, whereas with NiO the Fermi level evolves rapidly with an electron injection barrier of 1.49 eV. In-situ poling shows the Schottky barrier at the BaTiO3/Ni interface is not significantly altered by ferroelectric polarization, consistent with the good screening of the Ni electrode. This study presents a direct quantitative measurement of the interface barrier heights and highlights the significance of the oxidation state of the electrode.