A future heavy-ion program at J-PARC has been discussed. The QCD phase structure in high baryon density regime will be explored with heavy ions at the beam momenta of around 10 A GeV/c at the beam ...rate of 1010–1011 Hz. For this quest, a large acceptance spectrometer is designed to measure electrons and muons, and rare probes such as multi-strangeness and charmed hadrons/nuclei. A heavy-ion acceleration scheme is under study with a new heavy-ion linac and a new booster ring, which accelerate and inject beams into the existing Rapid-Cycling Synchrotron and Main Ring synchrotron. An overview of the heavy-ion program and an accelerator design, as well as physics goals and a conceptual design of the heavy-ion experiment are discussed.
Diphenylacetylenes having various silyl groups PhC&z.tbd;CC
6
H
4
-R; R =
p
-SiMe
3
(TMSDPA),
p
-SiEt
3
(TESDPA),
p
-SiMe
2
-
n
-C
8
H
17
(DMOSDPA), and
p
-SiPh
3
(TPSDPA) were copolymerized with ...diphenylacetylene having a
tert
-butyl group (PhC&z.tbd;CC
6
H
4
-
tert
Bu; TBDPA) using a TaCl
5
-
n
-Bu
4
Sn catalyst in various monomer feed ratios to provide high-molecular-weight copolymers in high yields. The free-standing membranes were fabricated by solution-casting, except poly(TPSDPA-
co
-TBDPA). Interestingly, the gas permeability of poly(TMSDPA-
co
-TBDPA) was higher than those of the homopolymers, poly(TMSDPA) and poly(TBDPA). The permeability of the copolymers became lower as the silyl groups became bulkier. The desilylation of membranes was carried out using a mixture of trifluoroacetic acid/hexane. When bulkier silyl groups were removed, the oxygen permeability increased to larger extents. The oxygen permeability coefficients of the copolymers and desilylated copolymers increased with increasing composition ratio of TBDPA. The gas diffusivity and gas solubility were also increased upon desilylation.
The gas permeability of poly(TMSDPA-
co
-TBDPA) was higher than those of homopolymers, poly(TMSDPA) and poly(TBDPA). The gas permeability of copolymers and desilylated copolymers increased with increasing of the composition ratio of TBDPA.
A Hadron Blind Detector (HBD) has been developed, constructed and successfully operated within the PHENIX detector at RHIC. The HBD is a Cherenkov detector operated with pure
CF
4
. It has a 50
cm ...long radiator directly coupled in a windowless configuration to a readout element consisting of a triple GEM stack, with a CsI photocathode evaporated on the top surface of the top GEM and pad readout at the bottom of the stack. This paper gives a comprehensive account of the construction, operation and in-beam performance of the detector.
Dislocation densities and dislocation structure arrangements in cold compressed polycrystalline commercial M2052 (Mn–20Cu–5Ni–2Fe) high damping alloy with various strains were determined in scanning ...mode by X-ray peak profile analysis and electron backscatter diffraction (EBSD). The results indicate that the Mn–Cu–Ni–Fe alloy has an evolution behavior quite similar to the dislocation structure in copper. The dislocation arrangement parameter shows a local minimum in the transition range between stages III and IV that can be related to the transformation of the dislocation arrangement in the cell walls from a polarized dipole wall (PDW) into a polarized tile wall (PTW) structure. This evolution is further confirmed by the results of local misorientation determined by EBSD. In addition, during deformation, the multiplication of dislocation densities in the MnCu alloy is significantly slower than that in copper, and the transition of the dislocation structure is strongly retarded in the MnCu alloy compared with copper. These results can be explained by the mechanism of elastic anisotropy on the dislocation dynamics, as the elastic anisotropy in the MnCu alloy is larger than that in copper, which can strongly retard the multiplication of the dislocation population and the transformation of the dislocation structure. These results are important for research into the plastic working behavior of Mn–Cu–Ni–Fe high damping alloy.
In J-PARC heavy-ion project, we aim at studies of QCD phase structures and hadron properties in high baryon density close to the neutron star core. We have developed a heavy-ion acceleration scheme ...with a new linac and a new booster with existing two synchrotrons with the goal beam rate of about 1011 Hz. We have also designed a large acceptance spectrometer based on a toroidal magnet. We have evaluated the spectrometer performance, and demonstrated reconstructing dielectron and dimuon spectra with full detector simulations. Finally, we designed a hypernuclear spectrometer which can utilize the full intensity ion beams.
We propose a general and practical planning framework for generating 3-D collision-free motions that take complex robot dynamics into account. The framework consists of two stages that are applied ...iteratively. In the first stage, a collision-free path is obtained through efficient geometric and kinematic sampling-based motion planning. In the second stage, the path is transformed into dynamically executable robot trajectories by dedicated dynamic motion generators. In the proposed iterative method, those dynamic trajectories are sent back again to the first stage to check for collisions. Depending on the application, temporal or spatial reshaping methods are used to treat detected collisions. Temporal reshaping adjusts the velocity, whereas spatial reshaping deforms the path itself. We demonstrate the effectiveness of the proposed method through examples of a space manipulator with highly nonlinear dynamics and a humanoid robot executing dynamic manipulation and locomotion at the same time.
The sPHENIX Micromegas Outer Tracker Aune, S.; Azmoun, B.; Bonenfant, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2024, Letnik:
1066, Številka:
C
Journal Article
Recenzirano
Odprti dostop
The sPHENIX Time Projection Chamber Outer Tracker (TPOT) is a Micromegas based detector. It is a part of the sPHENIX experiment that aims to facilitate the calibration of the Time Projection Chamber, ...in particular the correction of the time-averaged and beam-induced distortions of the electron drift. This paper describes the detector mission, setup, construction, installation, commissioning and performance during the first year of sPHENIX data taking.
Sequential living cationic copolymerizations of vinyl ethers having oxyethylene side chains (MOEO
2
VE and MOEO
3
VE) with vinyl ether having a crosslinkable group (VEEM) provided the ABA-typed ...triblock copolymers poly(VEEM)-
b
-poly(MOEO
2
VE)-
b
-poly(VEEM)s and poly(VEEM)-
b
-poly(MOEO
3
VE)-
b
-poly(VEEM)s. All triblock copolymers are sticky liquids at room temperature, and the
T
g
s were −77 to −73 °C. Heating the triblock copolymers afforded membranes by thermal crosslinking
via
mathacrylate groups at the outer segments in the polymers. All the membranes showed high CO
2
permselectivity (
P
CO
2
/
P
N
2
= 40-51) due to the high CO
2
solubility selectivity (
S
CO
2
/
S
N
2
= 44-61). The CO
2
permeability of the triblock copolymers was higher than that of the random copolymers with the same composition ratios. This indicates that the inner segment (MOEO
2
VE and MOEO
3
VE) effectively enhanced the gas diffusivity in the polymer matrix because the crosslinking points are present only in the outer segments.
Triblock copolymers exhibited high gas permeability than the random copolymers. The triblock copolymers have the crosslinking only at the end segments, which makes the polymer chains more flexible than the random copolymers.
Severe atherosclerosis of the ascending aorta frequently causes difficulties during heart operations, hindering surgical maneuvers and potentially leading to systemic embolism. There have been ...several methods to solve these problems but the best way to treat patients requiring aortic valve replacement (AVR) has not been established yet. Surgical techniques for AVR in these patients include AVR under deep hypothermic circulatory arrest with or without endarterectomy of the ascending aorta or replacement of the ascending aorta. Endovascular clamping using a balloon is another approach but requires manipulation of the heavily calcified aorta that may result in a certain risk for stroke. Another option to avoid the ascending aorta and cross-clamping is the apicoaortic conduit. Recently introduced trans-catheter AVR (TAVR), especially trans-apical AVR, has been shown to be feasible in such patients. Larger studies and longer follow-up will be required to scientifically prove the superiority of trans-apical AVR over conventional surgical strategies in patients with porcelain aorta requiring AVR.
Heat‐resistant fungi occur sporadically and are a continuing problem for the food and beverage industry. The genus Talaromyces, as a typical fungus, is capable of producing the heat‐resistant ...ascospores responsible for the spoilage of processed food products. Isocitrate lyase, a signature enzyme of the glyoxylate cycle, is required for the metabolism of non‐fermentable carbon compounds, like acetate and ethanol. Here, species‐specific primer sets for detection and identification of DNA derived from Talaromyces macrosporus and Talaromyces trachyspermus were designed based on the nucleotide sequences of their isocitrate lyase genes. Polymerase chain reaction (PCR) using a species‐specific primer set amplified products specific to T. macrosporus and T. trachyspermus. Other fungal species, such as Byssochlamys fulva and Hamigera striata, which cause food spoilage, were not detected using the Talaromyces‐specific primer sets. The detection limit for each species‐specific primer set was determined as being 50 pg of template DNA, without using a nested PCR method. The specificity of each species‐specific primer set was maintained in the presence of 1,000‐fold amounts of genomic DNA from other fungi. The method also detected fungal DNA extracted from blueberry inoculated with T. macrosporus. This PCR method provides a quick, simple, powerful and reliable way to detect T. macrosporus and T. trachyspermus.
Significance and Impact of the Study
Polymerase chain reaction (PCR)‐based detection is rapid, convenient and sensitive compared with traditional methods of detecting heat‐resistant fungi. In this study, a PCR‐based method was developed for the detection and identification of amplification products from Talaromyces macrosporus and Talaromyces trachyspermus using primer sets that target the isocitrate lyase gene. This method could be used for the on‐site detection of T. macrosporus and T. trachyspermus in the near future, and will be helpful in the safety control of raw materials and in food and beverage production.
Significance and Impact of the Study: Polymerase chain reaction (PCR)‐based detection is rapid, convenient and sensitive compared with traditional methods of detecting heat‐resistant fungi. In this study, a PCR‐based method was developed for the detection and identification of amplification products from Talaromyces macrosporus and Talaromyces trachyspermus using primer sets that target the isocitrate lyase gene. This method could be used for the on‐site detection of T. macrosporus and T. trachyspermus in the near future, and will be helpful in the safety control of raw materials and in food and beverage production.
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