Neutrinos were assumed to be massless particles until the discovery of the neutrino oscillation process. This phenomenon indicates that the neutrinos have non-zero masses and the mass eigenstates ...(ν1, ν2, ν3) are mixtures of their flavour eigenstates (νe, νμ, ντ). The oscillations between different flavour eigenstates are described by three mixing angles (θ12, θ23, θ13), two differences of the squared neutrino masses of the ν2/ν1 and ν3/ν1 pairs and a charge conjugation parity symmetry violating phase δCP. The Double Chooz experiment, located near the Chooz Electricité de France reactors, measures the oscillation parameter θ13 using reactor neutrinos. Here, the Double Chooz collaboration reports the measurement of the mixing angle θ13 with the new total neutron capture detection technique from the full data set, yielding sin2(2θ13) = 0.105 ± 0.014. This measurement exploits the multidetector configuration, the isoflux baseline and data recorded when the reactors were switched off. In addition to the neutrino mixing angle measurement, Double Chooz provides a precise measurement of the reactor neutrino flux, given by the mean cross-section per fission 〈σf〉 = (5.71 ± 0.06) × 10−43 cm2 per fission, and reports an empirical model of the distortion in the reactor neutrino spectrum.The Double Chooz collaboration reports the neutrino oscillation parameter θ13 from a measurement of the disappearance of reactor anti-electron neutrinos with the total neutron capture technique.
Adapted from powder injection molding (PIM), the micro-PIM technology satisfies the increasing demands for functionalization and miniaturization of micro-parts. Research works in this area have been ...carried out through micro injection molding tests issued from mixtures consisting in 316L stainless steel fine powders with D50=3.4μm and different thermoplastic polymeric binders. The well appropriate polymer–powder formulations are composed with different binders. The binders have been adapted to micro-injection and tested to find out an optimum feedstock. The rheological characterization of the elaborated feedstock has been carried out according to the selected stainless steel powders and polymers. The critical powder volume loading has been determinated and fixed in the range of 68–70%, and the optimal powder volume loading has been chosen around 66% for 316L stainless steel feedstock (D50=3.4μm). This choice has been confirmed by processing of the micro-components with the retained feedstock loaded up to 66%.
We present a search for signatures of neutrino mixing of electron anti-neutrinos with additional hypothetical sterile neutrino flavors using the Double Chooz experiment. The search is based on data ...from 5 years of operation of Double Chooz, including 2 years in the two-detector configuration. The analysis is based on a profile likelihood, i.e. comparing the data to the model prediction of disappearance in a data-to-data comparison of the two respective detectors. The analysis is optimized for a model of three active and one sterile neutrino. It is sensitive in the typical mass range
5
×
10
-
3
eV
2
≲
Δ
m
41
2
≲
3
×
10
-
1
eV
2
for mixing angles down to
sin
2
2
θ
14
≳
0.02
. No significant disappearance additionally to the conventional disappearance related to
θ
13
is observed and correspondingly exclusion bounds on the sterile mixing parameter
θ
14
as a function of
Δ
m
41
2
are obtained.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Preclinical imaging studies offer a unique access to the rat brain, allowing investigations that go beyond what is possible in human studies. Unfortunately, these techniques still suffer from a lack ...of dedicated and standardized neuroimaging tools, namely brain templates and descriptive atlases. Here, we present two rat brain MRI templates and their associated gray matter, white matter and cerebrospinal fluid probability maps, generated from ex vivo Formula: see text-weighted images (90 µm isotropic resolution) and in vivo T
-weighted images (150 µm isotropic resolution). In association with these templates, we also provide both anatomical and functional 3D brain atlases, respectively derived from the merging of the Waxholm and Tohoku atlases, and analysis of resting-state functional MRI data. Finally, we propose a complete set of preclinical MRI reference resources, compatible with common neuroimaging software, for the investigation of rat brain structures and functions.
For the past 2 years, interest in manufacturing technologies based on micro-fluidic systems has been continuously increasing. Today, micro-fluidic systems are used in numerous biomedical and ...pharmaceutical applications. Micro-fluidics cannot be thought about separately without advances in micro- and nano-fabrication. Investigations based on experiments, finite element modelling and simulations of powder hot embossing process (PHE) were performed to optimise the sintering step and processing parameters of micro-fluidic components. The model pertaining to thermo-elasto-viscoplastic behaviour was identified for 316L stainless steel powders. In this regard, different material properties such as sintering stress, bulk, and shearing viscosities were identified by inverse analysis from present dilatometer measurements using beam-bending and free sintering tests. The identification of materials was performed for various powder volume loadings and kinetic rates for different 316L elaborated feedstock, and the parameters were obtained as functions of relative density. The initial inhomogeneity due to the PHE process has been taken into account in the sintering simulation, as it affects the final shrinkage of the sintered components. The solid-state sintering simulations were investigated for various final sintering temperatures and kinetic rates to obtain high and homogeneous relative density distributions, achieve isotropic shrinkage and optimise the sintering process parameters. The numerical simulations were realised based on the identified parameters on a 3D micro-structured specimen with an associated rectangular plate support elaborated by PHE; this allowed a comparison between the numerical predictions and the experimental results for the sintering stage. The finite element simulation results of the sintering stage with a micro-fluidic structured component at a high final temperature (1360 °C) are in excellent agreement with the results of the experiments. The comparison of the simulation and experimental results validated the identified and implemented physical model and proposed methodologies.
A
bstract
The Double Chooz experiment presents improved measurements of the neutrino mixing angle
θ
13
using the data collected in 467.90 live days from a detector positioned at an average distance ...of 1050 m from two reactor cores at the Chooz nuclear power plant. Several novel techniques have been developed to achieve significant reductions of the backgrounds and systematic uncertainties with respect to previous publications, whereas the efficiency of the
ν
¯
e
signal has increased. The value of
θ
13
is measured to be sin
2
2
θ
13
= 0.090
− 0.029
+ 0.032
from a fit to the observed energy spectrum. Deviations from the reactor
ν
¯
e
prediction observed above a prompt signal energy of 4 MeV and possible explanations are also reported. A consistent value of
θ
13
is obtained from a fit to the observed rate as a function of the reactor power independently of the spectrum shape and background estimation, demonstrating the robustness of the
θ
13
measurement despite the observed distortion.
Elastomer injection moulding is a process whereby an elastomer mix is injected into a closed mould where the material is shaped to the desired geometry. Once completely filled, the silicone elastomer ...mix is vulcanised. Vulcanisation is the process whereby a viscous flow of silicone is converted into an elastic material through the incorporation of chemical cross-links between the material chains. To correctly use simulation tools to predict the filling of die mould cavities, it is necessary to characterise the material in terms of their rheological properties and kinetic behaviour during curing. The aim of this study was to develop mathematical models for the thermo-kinetic parameters of elastomers that can properly predict the filling of the die mould cavity. In this work, a rotational rheometer was used to determine changing viscosity and vulcanisation characteristics of a silicone compound. The rheokinetic properties of different silicone fluid samples were measured over a broad temperature range from 25 to 100 °C and are reported in this paper. Good agreement was obtained between the experimental results and the model predictions. The methods proposed could well represent the overall experimental data for different silicone elastomers; thus, it could be readily employed for simulation of the elastomer injection moulding process.
The paper is concerned with the way to prepare feedstocks for powder injection moulding of fine stainless steel powders. The way to prepare adequate feedstocks is described, and injection moulding ...experiments are determined. The effects of powder volume loading, as well as mixing conditions are investigated and the results indicate that powder loading, injection moulding conditions and sintering kinetics largely influence the resulting shrinkage after sintering. Finally, the modelling and associated numerical simulations are used the help process design.
The paper concerns the preparation of feedstocks (powder/binder) with fine stainless steel powders for subsequent powder injection moulding (PIM) process. The way to realize micro-components is described, the effects of powder volume loading and the mixing conditions are investigated, as well as, the injection moulding conditions and the sintering stage parameters. The modelling of sintering stage and associated numerical simulations are also used to the help process design (mould cavities). The used model associated to a thermo-elasto-viscoplastic constitutive law is described, as well as the identification methodology for physical parameters.
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•Promising and cost-effective method for the continuous duplication of flexible devices.•Influence of process parameters on replication quality with micro-scaled feature sizes.•Process reliability ...and potentialities of replicating surface with complex topography.
The replication of micro-fluidic devices is increasingly utilised in various industrial fields, such as medicine and cell biology research, and in many applications: drug screening, sugar testers, chemical microreactors, microprocessor cooling (just reward) and micro fuel cells. The roll embossing process (R2R) is an efficient and economical method for fabricating micro/meso-features on the large-area surface of the polymer parts. In this work, we describe a roll embossing process for manufacturing micro-fluidic devices in different commercially available thermoplastic polymer using a micro-structured elastomeric pattern with low roughness (Ra<50nm) as a roller stamping tool. This work investigates the effect of processing parameters on material performance for manufacturing the micro-fluidic devices via a roll embossing process. They describes observations and surface topography analyses made to compare the replication quality of polymeric replicas obtained by filling micro-cavities using the roll embossing process.
The results indicate that the variation in flow behaviour of polymer surface during roll embossing process is highly dependent on the forming temperature and rheological of polymer. In addition, the features of the elastomeric mould were replicated with good fidelity, retaining the original dimensions. By careful adjustment of process parameters, a micro-fluidic circuit with details in the range of μm was successfully transferred onto different polymeric films.
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