A global inventory of photovoltaic solar energy generating units.

Photovoltaic (PV) solar energy generating capacity has grown by 41 per cent per year since 20091. Energy system projections that mitigate climate change and aid universal energy access show a nearly ten-fold increase in PV solar energy generating capacity by 20402,3. Geospatial data describing the energy system are required to manage generation intermittency, mitigate climate change risks, and identify trade-offs with biodiversity, conservation and land protection priorities caused by the land-use and land-cover change necessary for PV deployment. Currently available inventories of solar generating capacity cannot fully address these needs1-9. Here we provide a global inventory of commercial-, industrial- and utility-scale PV installations (that is, PV generating stations in excess of 10 kilowatts nameplate capacity) by using a longitudinal corpus of remote sensing imagery, machine learning and a large cloud computation infrastructure. We locate and verify 68,661 facilities, an increase of 432 per cent (in number of facilities) on previously available asset-level data. With the help of a hand-labelled test set, we estimate global installed generating capacity to be 423 gigawatts (-75/+77 gigawatts) at the end of 2018. Enrichment of our dataset with estimates of facility installation date, historic land-cover classification and proximity to vulnerable areas allows us to show that most of the PV solar energy facilities are sited on cropland, followed by aridlands and grassland. Our inventory could aid PV delivery aligned with the Sustainable Development Goals.

Characterization of full-scale carbon contactors for siloxane removal from biogas using online Fourier transform infrared spectroscopy.

In this study, online Fourier transform infrared (FTIR) spectroscopy has been used to generate the first comprehensive characterization of full-scale carbon contactors for siloxane removal from biogas. Using FTIR, two clear operational regions within the exhaustion cycle were evidenced: an initial period of pseudo-steady state where the outlet siloxane concentration was consistently below the proposed siloxane limits; and a second period characterized by a progressive rise in outlet siloxane concentration during and after breakthrough. Due to the sharp breakthrough front identified, existing detection methods (which comprise field sampling coupled with laboratory-based chromatographic determination) are insufficiently responsive to define breakthrough, thus carbon contactors currently remain in service while providing limited protection to the combined heat and power engine. Integration of the exhaustion cycle to breakthrough identified average specific media capacities of 8.5-21.5 gsiloxane kg(-1)GAC, which are lower than that has been reported for vapour phase granular activated carbon (GAC). Further speciation of the biogas phase identified co-separation of organic compounds (alkanes and aromatics), which will inevitably reduce siloxane capacity. However, comparison of the five full-scale contactors identified that greater media capacity was accessible through operating contactors at velocities sufficient to diminish axial dispersion effects. In addition to enabling significant insight into gas phase GAC contactors, the use of FTIR for online control of GAC for siloxane removal is also presented.

Nurses' engagement in AIDS policy development.

BACKGROUND: A multidisciplinary team of 20 researchers and research users from six countries - Canada, Jamaica, Barbados, Kenya, Uganda and South Africa - are collaborating on a 5-year (2007-12) program of research and capacity building project. This program of research situates nurses as leaders in building capacity and promotes collaborative action with other health professionals and decision-makers to improve health systems for human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) nursing care. One of the projects within this program of research focused on the influence of workplace policies on nursing care for individuals and families living with HIV. Nurses are at the forefront of HIV prevention and AIDS care in these countries but have limited involvement in related policy decisions and development. In this paper, we present findings related to the barriers and facilitators for nurses' engagement in policymaking. METHODS: A participatory action research design guided the program of research. Purposive sampling was used to recruit 51 nurses (unit managers, clinic and healthcare managers, and senior nurse officers) for interviews. FINDINGS: Participants expressed the urgent need to develop policies related to AIDS care. The need to raise awareness and to 'protect' not only the workers but also the patients were critical reason to develop policies. Nurses in all of the participating countries commented on their lack of involvement in policy development. Lack of communication from the top down and lack of information sharing were mentioned as barriers to participation in policy development. Resources were often not available to implement the policy requirement. Strong support from the management team is necessary to facilitate nurses involvement in policy development. CONCLUSIONS: The findings of this study clearly express the need for nurses and all other stakeholders to mobilize nurses' involvement in policy development. Long-term and sustained actions are needed to address gaps on the education, research and practice level.

Magnetocrystalline and magnetoelastic constants determined by magnetization dynamics under static strain.

We consider here the magnetization dynamics induced in a ferromagnet by magnetoelastic coupling, after application of a step like strain. We derive the time evolution of the magnetization vector. We show that the material micromagnetic parameters (and specifically magnetic anisotropy and magnetoelastic coupling) can be derived from measurable quantities, i.e. the precession frequency, relaxation time and phase lag between the precession angles. Such measurements can be performed by state of the art time resolved Kerr experiments.

Straight motion of half-integer topological defects in thin Fe-N magnetic films with stripe domains.

In thin magnetic films with perpendicular magnetic anisotropy, a periodic "up-down" stripe-domain structure can be originated at remanence, on a mesoscopic scale (~100 nm) comparable with film thickness, by the competition between short-range exchange coupling and long-range dipolar interaction. However, translational order is perturbed because magnetic edge dislocations are spontaneously nucleated. Such topological defects play an important role in magnetic films since they promote the in-plane magnetization reversal of stripes and, in superconductor/ferromagnet hybrids, the creation of superconducting vortex clusters. Combining magnetic force microscopy experiments and micromagnetic simulations, we investigated the motion of two classes of magnetic edge dislocations, randomly distributed in an [Formula: see text]-implanted Fe film. They were found to move in opposite directions along straight trajectories parallel to the stripes axis, when driven by a moderate dc magnetic field. Using the approximate Thiele equation, analytical expressions for the forces acting on such magnetic defects and a microscopic explanation for the direction of their motion could be obtained. Straight trajectories are related to the presence of a periodic stripe domain pattern, which imposes the gyrotropic force to vanish even if a nonzero, half-integer topological charge is carried by the defects in some layers across the film thickness.

Development of on-line FTIR spectroscopy for siloxane detection in biogas to enhance carbon contactor management.

Activated carbon filters are used to limit engine damage by siloxanes when biogas is utilised to provide electricity. However, carbon filter siloxane removal performance is poorly understood as until recently, it had not been possible to measure siloxanes on-line. In this study, on-line Fourier Transform Infrared (FTIR) spectroscopy was developed to measure siloxane concentration in real biogas both upstream (86.1-157.5mg m(-3)) and downstream (2.2-4.3mg m(-3)) of activated carbon filters. The FTIR provided reasonable precision upstream of the carbon vessel with a root mean square error of 10% using partial least squares analysis. However, positive interference from volatile organic carbons was observed in downstream gas measurements limiting precision at the outlet to an RMSE of 1.5mg m(-3) (47.8%). Importantly, a limit of detection of 3.2mg m(-3) was identified which is below the recommended siloxane limit and evidences the applicability of on-line FTIR for this application.

Effects of parents' job insecurity on children's work beliefs and attitudes.

The authors hypothesized that children's perceptions of their parents' job insecurity mediate the effects of parental job insecurity and layoffs on children's work beliefs and work attitudes. Male and female undergraduate students (N = 134; M age = 18.9 years), as well as their mothers (M age = 47.0 years) and fathers (M age = 49.1 years), participated voluntarily. With structural equation modeling as implemented by LISREL VIII, support for the proposed model was obtained, whereas no support was obtained for a competing model. Moreover, identification with fathers moderated the influence of perceived paternal job insecurity on children's humanistic work beliefs, but no comparable effect emerged for mothers.

Parents' job insecurity affects children's academic performance through cognitive difficulties.

The authors developed and tested a model in which children who perceive their parents to be insecure about their jobs are distracted cognitively, which in turn affects their academic performance negatively. Participants were 102 female and 18 male undergraduates (mean age = 18 years), their fathers (mean age = 49 years), and their mothers (mean age = 47 years). Students completed questionnaires measuring perceived parental job insecurity, identification with parents, and cognitive difficulties; 3 months later, they also reported their midyear grades. Fathers and mothers each completed questionnaires assessing their job insecurity. Support for the model was obtained using LISREL 8, and as predicted, children's identification with their mothers and fathers moderated the relationship between their perceptions of their mothers' and fathers' job insecurity and their own cognitive difficulties.

Eldercare responsibilities, interrole conflict, and employee absence: a daily study.

A model was developed specifying that the number of hours employees spend providing care to or interacting with elderly parents predicts conflict between the roles of employee and caregiver. Interrole conflict was subsequently expected to predict partial absence from work (e.g., arriving late). Seventeen employed eldercare providers completed a daily questionnaire for 20 work days. The data were standardized and pooled, and the proposed model was tested by using structural equation modeling. The proposed model provided a good fit to the data. A competing model that added the direct effects of hours of interacting with and hours of providing care to parents on partial absence provided a significantly better fit. The potential impact of the findings on employees and organizations is discussed.

Stooped postures are modified by pretask walking in a simulated weed-pulling task.

Seasonal agricultural workers are hired in some sectors for intermittent manual weed removal, a stoop and grasp harvesting task likely similar to those associated with the high prevalence of musculoskeletal disorders in agriculture. Evaluation of this task in an experimental situation would be useful for identifying and controlling musculoskeletal injury risks, presuming a valid experimental model of the task can be created. The purpose of the present study was to examine how a relevant work-related task, namely prolonged walking, altered the biomechanics of manual weed removal in a laboratory setting. Preliminary field assessments informed the development and analysis of a simulated manual weed removal with two separate conditions: not primed, where 11 participants (4 female, mean age 21.6 years) manually removed a simulated weed six times, and primed, where 23 participants (13 female, mean age 22.1 years) walked 1600 m prior to manually removing the same simulated weed six successive times. Segment end point markers and experimental motion capture were used to determine hip, knee, and ankle angles, as well as toe-target proximity, during weed removal. Significant differences between primed and not primed participants were found for angular displacement at the ankle (t(32) = 5.08, P < .001) and toe-target proximity (t(32) = 2.78, P = .008), where primed participants had increased ankle flexion and a greater distance to the weed, leading to decreased trunk flexion during the harvesting task. These findings suggest that priming can positively influence whole-body postures for manual weed removal.

Early employer response to workplace injury: what injured workers perceive as fair and why these perceptions matter.

The authors examined whether early employer response to workplace injury affects injured workers' subsequent attitudes and mental health. At 1 month and 6 months postinjury, telephone surveys were conducted with 344 workers from Ontario, Canada, who had experienced a musculoskeletal lost-time workplace injury. One-month reports of initial supervisor reaction to the injury and the use of workplace-based return-to-work strategies (early contact with worker, ergonomic assessment, presence of designated coordinator, accommodation offer) were hypothesized to predict reports of fairness, affective commitment, and depressive symptoms measured at 6 months postinjury. Structural equation modeling supported a model wherein fairness perceptions fully mediated the relationship between early responses and injured workers' attitudes and mental health. Early contact and supervisor reactions were significant predictors of fairness perceptions. The implications for early employer response are discussed.

Dancing the two-step: Collaborating with intermediary organizations as research partners to help implement workplace health and safety interventions.

OBJECTIVE: To evaluate the effect of the involvement of intermediaries who were research partners on three intervention studies. The projects crossed four sectors: manufacturing, transportation, service sector, and electrical-utilities sectors. The interventions were participative ergonomic programs. The study attempts to further our understanding of collaborative workplace-based research between researchers and intermediary organizations; to analyze this collaboration in terms of knowledge transfer; and to further our understanding of the successes and challenges with such a process. PARTICIPANTS: The intermediary organizations were provincial health and safety associations (HSAs). They have workplaces as their clients and acted as direct links between the researchers and workplaces. METHODS: Data was collected from observations, emails, research-meeting minutes, and 36 qualitative interviews. Interviewees were managers, and consultants from the collaborating associations, 17 company representatives and seven researchers. RESULTS: The article describes how the collaborations were created, the structure of the partnerships, the difficulties, the benefits, and challenges to both the researchers and intermediaries. The evidence of knowledge utilization between the researchers and HSAs was tracked as a proxy-measure of impact of this collaborative method, also called Mode 2 research. CONCLUSION: Despite the difficulties, both the researchers and the health and safety specialists agreed that the results of the research made the process worthwhile.

The Readiness for Return-To-Work (RRTW) scale: development and validation of a self-report staging scale in lost-time claimants with musculoskeletal disorders.

INTRODUCTION: We report on the development and validation of a 22-item scale assessing stage of readiness for return-to-work, the Readiness for Return-to-Work (RRTW) scale. METHODS: Lost-time claimants (n = 632) completed a telephone survey one month after a work-related musculoskeletal injury. Exploratory and confirmatory factor analyses of readiness items were conducted with two separate samples, and concurrent validity was examined. RESULTS: For workers not working, 60% of the variance was explained by four factors--(1) Precontemplation, (2) Contemplation (3) Prepared for Action-Self-evaluative and (4) Prepared for Action-Behavioral. For those working, 58% of the variance was explained by two factors--(1) Uncertain Maintenance and (2) Proactive Maintenance. Confirmatory factor analyses had satisfactory fit indices to confirm the initial model. Concurrent validity of the scale was supported: relationships of readiness with depressive symptoms, fear-avoidance, pain, and general health, were generally in the hypothesized direction. CONCLUSIONS: Psychometric properties of the newly developed instrument suggest that the application of the Readiness for Change model to return-to-work is relevant to work disability research. The instrument may facilitate the offer of stage-specific services tailored to injured workers' needs, and be used for evaluation of return-to-work interventions.

Placental steroid deficiency: association with arylsulfatase A deficiency.

A family with an obstetric history consistent with placental sulfatase deficiency has X-linked ichthyosis. Steroid sulfatase deficiency was confirmed in placenta, leukocytes, and cultured skin fibroblasts of affected males; arylsulfatase A diminution was also observed in these tissues of both affected males and 2 generations of related females. No symptoms of metachromatic leukodystrophy are present in any family members. In this family, placental sulfatase deficiency, and arylsulfatase A pseudodeficiency are nonallelic.