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This work is part of the interlaboratory collaboration to study the stability of organic solar cells containing PCDTBT polymer as a donor material. The varieties of the OPV devices with different device architectures, electrode materials, encapsulation, and device dimensions were prepared by seven research laboratories. Sets of identical devices were aged according to four different protocols: shelf lifetime, laboratory weathering under simulated illumination at ambient temperature, laboratory weathering under simulated illumination, and elevated temperature (65 °C) and daylight outdoor weathering under sunlight. The results generated in this study allow us to outline several general conclusions related to PCDTBT-based bulk heterojunction (BHJ) solar cells. The results herein reported can be considered as practical guidance for the realization of stabilization approaches in BHJ solar cells containing PCDTBT.
By applying a display ecology to the Deeper, Wider, Faster proactive, simultaneous telescope observing campaign, we have shown a dramatic reduction in the time taken to inspect DECam CCD images for potential transient candidates and to produce time-critical triggers to standby telescopes. We also show how facilitating rapid corroboration of potential candidates and the exclusion of non-candidates improves the accuracy of detection; and establish that a practical and enjoyable workspace can improve the experience of an otherwise taxing task for astronomers. We provide a critical road test of two advanced displays in a research context—a rare opportunity to demonstrate how they can be used rather than simply discuss how they might be used to accelerate discovery.
Preliminary studies report no negative and a possible positive impact of deep brain stimulation (DBS) on cognition of patients with treatment-resistant depression (TRD). However, these studies neither controlled for practice effects nor compared active with sham stimulation.
To address these limitations, we compared 25 TRD patients, who underwent DBS of the ventral anterior limb of the internal capsule (vALIC), with 21 healthy controls (HCs) matched on gender, age and education level. Both groups did subtests of the Cambridge Neuropsychological Test Automated Battery assessing verbal and visuospatial memory, attention, cognitive flexibility, psychomotor functioning, planning and object naming. TRD patients were tested 3 weeks prior to DBS surgery (baseline), 3 weeks following surgery (T1) and following 52 weeks of DBS optimization (T2). HCs were tested at baseline, 6 weeks following baseline (T1) and 20–24 weeks following baseline (T2). Subsequently, TRD patients entered a randomized, double-blind crossover phase, in which they were tested in an active and a sham stimulation phase.
TRD patients did not improve on a test of immediate verbal recognition from baseline to T1, whereas HCs did (group x time: p = 0.001). Both TRD patients and HCs improved over sessions on tests measuring delayed verbal recall, visuospatial memory, planning and object naming (all p < 0.01). Active and sham stimulation did not have an impact on any of the tests differentially.
vALIC DBS neither has a lasting positive nor negative impact on cognition in TRD patients. DBS surgery might have a temporary negative effect on verbal memory.
Heart failure (HF) affects up to 20 per cent of residents in long-term care (LTC) and is associated with substantial morbidity, mortality, and health service utilization. Our study objective was to formulate recommendations on implementing HF care processes in LTC. A three-phase and iterative stakeholder consultation process, guided by expert panel input, was employed to develop recommendations on implementing care processes for HF in LTC. This article presents the results of the third phase, which consisted of a series of interdisciplinary workshops. We developed 17 recommendations. Key elements of these recommendations focus on improving interprofessional communication and improving HF-related knowledge among all LTC stakeholders. Engaging frontline staff, including personal support workers, was stated as an essential component of all recommendations. System-level recommendations include improving communication between LTC homes and acute care and other external health service providers, and developing facility-wide interventions to reduce dietary sodium intake and increase physical activity.
A small fraction of Tidal Disruption Events (TDE) produce relativistic jets, evidenced by their non-thermal X-ray spectra and transient radio emission. Here we present milliarcsecond-resolution imaging results on TDE J1644+5734 with the European VLBI Network (EVN). These provide a strong astrometric constraint on the average apparent jet velocity βapp < 0.27, that constrains the intrinsic jet velocity for a given viewing angle.
The concept of ‘sustainability’ or ‘sustainable development’ is multi-dimensional, encompassing economic, environmental, social, and institutional governance aspects. The theoretical framework for this article on sustainability in poultry production is built on this multi-dimensional understanding of the concept, acknowledging that it is complex and contested. It is challenging to analyse or discuss the sustainability of one single sector within agriculture, because this sector is part of a global food system, and a systems approach is necessary. This article gives examples of elements which link to one or more of the four aspects, e.g., pollution and antibiotic use, biodiversity (environmental aspects), conditions for farm workers and animal welfare (social aspects), governance of the food chain (institutional aspects), and the development of poultry from a valuable food to a cheap staple food throughout major parts of the world (economic aspects). There are numerous potential pathways for sustainable development of poultry production. Poultry are living, sentient animals that can be well integrated into many different types of urban and rural farming systems, where they benefit from and contribute to such systems and to the livelihood of households around the globe, with special emphasis on women. Furthermore, local production provides potential for production with minimum transport and, concomitantly, minimum usage of fossil fuels. Among the terrestrial animals, poultry has the best conversion rate of feed to human food and the smallest environmental footprint in terms of energy and water use per kg meat or eggs produced.
The Evolutionary Map of the Universe (EMU) is a proposed radio continuum survey
of the Southern Hemisphere up to declination + 30°, with the Australian
Square Kilometre Array Pathfinder (ASKAP). EMU will use an automated source
identification and measurement approach that is demonstrably optimal, to
maximise the reliability and robustness of the resulting radio source
catalogues. As a step toward this goal we conducted a “Data
Challenge” to test a variety of source finders on simulated images. The
aim is to quantify the accuracy and limitations of existing automated source
finding and measurement approaches. The Challenge initiators also tested the
current ASKAPsoft source-finding tool to establish how it could benefit from
incorporating successful features of the other tools. As expected, most finders
show completeness around 100% at ≈ 10σ dropping to about 10% by
≈ 5σ. Reliability is typically close to 100% at ≈
10σ, with performance to lower sensitivities varying between finders. All
finders show the expected trade-off, where a high completeness at low
signal-to-noise gives a corresponding reduction in reliability, and vice versa.
We conclude with a series of recommendations for improving the performance of
the ASKAPsoft source-finding tool.
Foodshed analysis provides a way to assess the capacity of regions to feed themselves. While dozens of foodshed analyses have been completed across North America, they have not been systematically analyzed. This paper reviews 22 foodshed analyses completed in the USA and Canada between 2000 and 2013. The criteria used to evaluate the foodshed studies are authorship/type of publication, spatial extent, goals and questions, methods and data sources for assessing consumption and production, analysis of pathways from production to consumption and findings. Similarities and differences, along with strengths and weaknesses, are identified. Together, the foodshed studies indicate significant opportunity for food system relocalization across North America. Foodshed studies are a potentially powerful tool for policy analysis and planning. A future research agenda for foodshed studies is identified, including addressing data gaps and establishing more standardized models for evaluating production, consumption and pathways.
Due to an increasing demand for natural products to control coccidiosis in broilers, we investigated the effects of supplementing a combination of ethanolic extracts of Artemisia annua and Curcuma longa in drinking water. Three different dosages of this herbal mixture were compared with a negative control (uninfected), a positive control (infected and untreated), chemical coccidiostats (nicarbazin+narazin and, later, salinomycin), vaccination, and a product based on oregano. Differences in performance (weight gain, feed intake, and feed conversion rate), mortality, gross intestinal lesions and oocyst excretion were investigated. Broilers given chemical coccidiostats performed better than all other groups. Broilers given the two highest dosages of the herbal mixture had intermediate lesion scores caused by Eimeria acervulina, which was higher than in broilers given coccidiostats, but less than in broilers given vaccination, oregano and in negative controls. There was a trend for lower mortality (P = 0·08) in the later stage of the growing period (23–43 days) in broilers given the highest dosage of herbal mixture compared with broilers given chemical coccidiostats. In conclusion, the delivery strategy of the herbal extracts is easy to implement at farm level, but further studies on dose levels and modes of action are needed.
Fulfilling the need for reproducible Quantum Dots (QDs) with certain spectroscopic features, high stability and luminescence we have established synthetic routes for the production of CdSe core as well as CdSe/shell particles in a continuous flow (cf) system. Our method features the deviation between nucleation and growth in two different parts of the system to mimic the well-known and often-used hot injection method for the synthesis of nanoparticles in organic solvents.
Experimental research in behavioural nutrition is often limited by practical applicability. In the present study, we assess the reproducibility and validity of a new experimental method using food replicas. A total of fifty-seven people were invited on two separate occasions with an interval of 2 weeks to serve themselves a meal from a fake food buffet (FFB) containing replica carrots, beans, pasta and chicken. The external validity of the FFB was assessed in a second study by comparing meals served from replica foods (beans, pasta, chicken) with meals served from a corresponding real food buffet (RFB). For the second study, forty-eight participants were invited on two separate occasions; first to serve themselves a meal from the FFB or an RFB and 2 weeks later from the other buffet. The amounts of food items served and (theoretical) energy content were compared. Correlation coefficients between the amounts of fake foods served were 0·77 (95 % CI 0·68, 0·86) for chicken, 0·79 (95 % CI 0·68, 0·87) for carrots, 0·81 (95 % CI 0·69, 0·89) for beans and 0·89 (95 % CI 0·82, 0·93) for pasta. For the FFB meal and the RFB meal, the correlations ranged between 0·76 (95 % CI 0·73, 0·91) for chicken and 0·87 (95 % CI 0·77, 0·92) for beans. The theoretical energy of the fake meal was 132 kJ (32 kcal) lower compared to the energy of the real meal. Results suggest that the FFB can be a valuable tool for the experimental assessment of relative effects of environmental influences on portion sizes and food choice under well-controlled conditions.
Electronic properties of thin epitaxial silicon films deposited at temperatures below 650°C by means of ion-assisted deposition strongly depend on substrate orientation as well as on deposition temperature: In (100)-oriented epitaxial films we find a low density of structural defects, and the minority carrier diffusion length is only limited by the presence of point defects or point defect complexes. These investigations also show an improvement of the electronic quality with increasing deposition temperature. Epitaxy on non-(100)-oriented substrates results in a significantly higher density of structural defects. The electronic properties of films deposited on stable flat surfaces, such as (111)- and (113)-oriented substrates are inferior as compared to (100)-oriented films, but are still superior to those of films deposited on faceted surfaces, as shown by light beam induced current and electron back-scattering diffraction measurements of polycrystalline thin films.
Nanoparticles of indium oxide, tin oxide and indium oxide doped with tin oxide (ITO) have been prepared by Chemical Vapor Synthesis, CVS (a modified CVD process), starting with In- (tmhd)3 as precursor. A modification of the CVS process using a novel radio-frequency reaction zone has been developed in order to avoid the rapid decomposition of the nanocrystalline indium oxide particles at high temperatures. These oxides are candidates for applications as transparent conducting oxides, catalysts and gas sensors. Structural characterization by high resolution scanning and transmission electron microscopy and X-ray-diffraction has been used to determine the phase, grain size, grain size distribution and crystallinity of the nanoparticles. The specific surface area, and particle or agglomerate size of the powders have been measured by nitrogen sorption. Agglomerate sizes in aqueous dispersions have been determined by photon correlation spectroscopy. Zeta-potentials were measured. As well CVS powders exhibit a narrow size distribution with an average size of about 5 nm.
CdS nanoclusters ranging in diameter between 1 and 4 nm were prepared in aqueous solution using aliphatic mercaptoalcohols as ligands. The photon energies of the Is Is absorption and the respective oscillator strengths are in accordance with size quantization theory. Some clusters crystallize as macroscopic 3-D superlattices which were investigated by single crystal x-ray analysis. The neutral Cd17S4(RS)26 clusters are covalently linked in the superlattice the structure of which exhibits self similarity to the interior structure of the clusters.
Onion-shell-like composite particles from CdS and HgS were prepared by successive substitution and re-precipitation processes. Particles with a core radius of 2 nm, a shell of up to 1 nm HgS followed by a final shell of up to 1.5 nm CdS were obtained. Electrons and holes were localized in the HgS shell giving rise to excitonic fluorescence.
Studies of microstructure evolution as a function of sintering parameters are necessary to better control the microstructure of nanophase ceramic compacts during processing. Small-angle scattering provides a comprehensive probe of the statistically-representative microstructures present in nanophase ceramics. A complete characterization includes complementary density, electron microscopy, nitrogen desorption and x-ray diffraction measurements. Small-angleneutron and ultra-small-angle x-ray scattering have been used to determine the effects of different sintering temperatures, pressures and additives during sintering of nanophase zirconia compacts. The samples were of sufficient size and uniformity to permit absolute calibration of the scattering data, making it possible to confirm that scattering from the pore/grain interface dominates the total scattering cross-section. A quantitative microstructural model was developed for this system, resulting in the determination of specific pore surface area, total pore volume fraction, pore number size distribution and grain size as a function of sintering parameters.
The atomic structure of thin epitaxial erbium suicides on Si(111) substrates has been studied in situ by means of surface X-ray diffraction and medium-energy ion scattering. In the sub-monolayer range, a two-dimensional (2D) suicide is formed within a 1 × 1 unit cell, with the Er atoms occupying T4 sites and a Si bilayer on top which is 180° rotated with respect to the bulk (5-type). Suicide layers with a thickness of 3 monolayers exhibit a regular network of Si vacancies which release the compressive strain of the graphite-like Si layers between adjacent Er layers. This results in a √3 × √3 R 30° unit cell, in which 3 out of 5 Si atoms are displaced towards the vacancy, and in which 3 Er atoms relax away from the vacancy.
Tracer diffusion experiments were carried out in synthetic air at 1573 K in SrTiO3(100) and (110) single crystals, which were either undoped or doped with up to 1 at.% La, respectively. Tracer sources of 139La and 142Nd were applied by ion implantation. The resulting depth profiles were measured by SIMS. The reconstruction of the surface was monitored ex-situ using microscopic and spectroscopic methods including SEM, EPMA, and AFM. The measured tracer diffusivities show no dependency on orientation. The tracer diffusion takes place via cation vacancies. Under oxidizing conditions the dopant is compensated by Sr vacancies. Hence the diffusion is increasing strongly with La concentration. The observed time dependency of the diffusivities may be related to a space charge layer postulated by the current defect chemistry model for donor doped SrTiO3. At high dopant concentrations annealing leads to segregation of bulk La to the surface. La is not significantly incorporated into the secondary crystallites at the surface which consist almost entirely of Sr and O.