267 research outputs found
System for measuring spatial distribution of ejected droplets, a concept
System measures the spatial distribution of high-velocity droplets ejected from a nozzle or spray gun. The system employs an electrically resistive grid as the sensing screen, electrical leads, and a signal scanner such as a cathode ray tube
Laminar flow enhancement Patent
Laminar flow of liquid coolants in rocket engine
Propellent mass distribution metering apparatus Patent
Electronic recording system for spatial mass distribution of liquid rocket propellant droplets or vapors ejected from high velocity nozzle
Contribuição das atividades de relações públicas para a qualidade de vida no trabalho
Orientador: Jair Antonio de OliveiraTrabalho de Conclusão de Curso (graduação) - Universidade Federal do Paraná. Setor de Artes, Comunicação e Design. Curso de Graduação em Relações Pública
Sub-picosecond compression by velocity bunching in a photo-injector
We present an experimental evidence of a bunch compression scheme that uses a
traveling wave accelerating structure as a compressor. The bunch length issued
from a laser-driven radio-frequency electron source was compressed by a factor
>3 using an S-band traveling wave structure located immediately downstream from
the electron source. Experimental data are found to be in good agreement with
particle tracking simulations.Comment: 19 pages, 9 figures, submitted to Phys. Rev. Spec. Topics A&
On bio-inspired induced drag reduction techniques
The current study was aimed at identifying wing planform
geometries which favours low induced drag. The
geometries were defined by mathematical functions and
following a subsequent parametric study, with a focus
on sweep angle and taper ratio, inspired by birds wings
and aquatic animals flukes or caudal fins planforms. The
parametric studies were carried out using a vortex lattice
method (VLM) which was validated with experimental
data from literature. The main finding is a confirmation
of the fact that the maximum Oswald efficiency factor, e
is not exclusive to an elliptical wing planform. Despite
its apparent simplicity, in fact a swept-back-tapered wing
with a linear chord distribution can reach e = 1, the limit
or minimum induced drag established from elliptical lift
distribution. Moreover, the crescent wing geometry, such
as the one displayed by the swift, can even surpass this
limit
Directly Measured Denitrification Reveals Oyster Aquaculture and Restored Oyster Reefs Remove Nitrogen at Comparable High Rates
Coastal systems are increasingly impacted by over-enrichment of nutrients, which has cascading effects for ecosystem functioning. Oyster restoration and aquaculture are both hypothesized to mitigate excessive nitrogen (N) loads via benthic denitrification. The degree to which these management activities perform similar functions for removing N, however, has not been extensively examined in New England, a place where nutrient runoff is high and increasing oyster (Crassostrea virginica) restoration and aquaculture activity is taking place. Here, we use a novel in situ methodology to directly measure net N2 and O2 fluxes across the sediment-water interface in a shallow (~1 m) coastal pond in southern Rhode Island. We collected data seasonally during 2013 and 2014 at restored oyster reefs, oyster aquaculture, oyster cultch (shell), and bare sediment. Restored oyster reefs and aquaculture had the highest mean (±SE) denitrification rates, 581.9 (±164.2) and 346 (±168.6) μmol N2−N m−2 h−1, respectively, and are among the highest recorded for oyster-dominated environments. Denitrification rates at sites with oyster cultch were 60.9 (±44.3) μmol N2−N m−2 h−1, which is substantially less than the sites with active oysters but still more than 50% higher than denitrification rates measured in bare sediment (24.4 ± 10.1 μmol N2–N m−2 h−1). The increase in denitrification rates at treatments, however, varied by season and the greatest rates for restored reefs were in the fall. Overall, the greatest aggregate denitrification rates occurred in the fall. Sediment oxygen demand (SOD) followed similar patterns but with greater overall rates in the summer, and displayed a strong linear relationship with denitrification (R2 = 0.93). Our results demonstrate that habitats associated with live oysters have higher net denitrification rates and that oyster reef restoration and oyster aquaculture may provide similar benefits to the ecosystem in terms of N removal. However, gas fluxes may also be affected where three-dimensional structure is introduced via oyster shell cultch and this appears to be seasonally-dependent. These data will be important for managers as they incorporate oysters into nutrient reduction strategies and consider system-level trade-offs in services provided by oyster reef restoration and aquaculture activities
Synaptic expression of TAR-DNA-binding protein 43 in the mouse spinal cord determined using super-resolution microscopy
Funding: This work was supported by Motor Neurone Disease (MND) Association UK (Miles/Apr18/863-791), Chief Scientist Office, RS Macdonald Charitable Trust, ALS CURE Project, the European Research Council (ERC) under the European Union’s Horizon 2020 Research and Innovation Programme (695568 SYNNOVATE), Simons Foundation Autism Research Initiative (529085), and the Wellcome Trust (Technology Development grant 202932).Amyotrophic Lateral Sclerosis (ALS) is characterised by a loss of motor neurons in the brain and spinal cord that is preceded by early-stage changes in synapses that may be associated with TAR-DNA-Binding Protein 43 (TDP-43) pathology. Cellular inclusions of hyperphosphorylated TDP-43 (pTDP-43) are a key hallmark of neurodegenerative diseases such ALS. However, there has been little characterisation of the synaptic expression of TDP-43 inside subpopulations of spinal cord synapses. This study utilises a range of high-resolution and super-resolution microscopy techniques with immunolabelling, as well as an aptamer-based TDP-43 labelling strategy visualised with single-molecule localisation microscopy, to characterise and quantify the presence of pTDP-43 in populations of excitatory synapses near where motor neurons reside in the lateral ventral horn of the mouse lumbar spinal cord. We observe that TDP-43 is expressed in approximately half of spinal cord synapses as nanoscale clusters. Synaptic TDP-43 clusters are found most abundantly at synapses associated with VGLUT1-positive presynaptic terminals, compared to VGLUT2-associated synapses. Our nanoscopy techniques showed no difference in the subsynaptic expression of pTDP-43 in the ALS mouse model, SOD1G93a, compared to healthy controls, despite prominent structural deficits in VGLUT1-associated synapses in SOD1G93a mice. This research characterizes the basic synaptic expression of TDP-43 with nanoscale precision and provides a framework with which to investigate the potential relationship between TDP-43 pathology and synaptic pathology in neurodegenerative diseases.Publisher PDFPeer reviewe
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