120 research outputs found
Effect of thickness of polyethylene packaging and temperature on quality of solar-dried oyster mushroom (Pleurotus sajor-caju)
Pleurotus sajor-caju is evaluated as an edible fungi with high nutritional and medicinal value, but fresh mushrooms are easily damaged after harvest due to many reasons. Drying methods can be taken to maintain mushroom quality, reduce losses and prolong postharvest storage time. The objective of this study was to evaluate the effects of polyethylene (PE) packaging thickness (91.70 µm; 81.30 µm and 53.50 µm), temperature (28 oC-30 oC and 3 oC-5 oC) (with air humidity of 60-62% and 76-78% respectively), to the quality of oyster mushrooms dried by solar energy, during storage. During the storage period, the total sugar and protein contents of all treatments decreased. Besides, the colour (through the difference in lightness and darkness (?L) value) and firmness of the solar-dried oyster mushrooms also decreased, so, oyster mushrooms were darkened and softened. After 6 months, the lowest protein, total sugar and lipid loss was found in PE packaging of 91.70 µm thickness at storage temperature of 3 oC-5 oC. In addition, the water activity of dried mushrooms was lower (less than 0.7), so it ensures microbiological safety
Magnetic and Magnetotransport Properties of La0.7ca0.3mn1-x(zn,cu)xo3
Magnetic and magnetotransport properties of two perovskite manganite samples of La0.7Ca0.3Mn0.9Zn0.1O3 and La0.7Ca0.3Mn0.95Cu0.05O3 prepared by conventional solid-state reaction have been studied in detail. Experimental results revealed that the temperature dependences of magnetization and resistance varied strongly around the phase-transition temperature. Maximum magnetoresistance (MR) values of La0.7Ca0.3Mn0.9Zn0.1O3 and La0.7Ca0.3Mn0.95Cu0.05O3 under an applied field of 400 Oe were about 21.4 % and 11.0 %, respectively. The maximum magnetic-entropy change (ΔSM) was 2.73 J/kg.K for La0.7Ca0.3Mn0.9Zn0.1O3, and 3.34 J/kg.K for La0.7Ca0.3Mn0.95Cu0.05O3 when the applied field was 45 kOe. Both the MR and ΔSM values obtained from two samples were smaller than those of the parent compound La0.7Ca0.3MnO3. This was due to the change in the Mn3+/Mn4+ ratio caused by Zn and Cu dopants, which led to a change in the type of the ferromagneticparamagnetic phase transition
Pulse Shape Discrimination of CsI(Tl) with a Photomultiplier Tube and MPPCs
In this study, we evaluate and compare the pulse shape discrimination (PSD)
performance of multipixel photon counters (MPPCs, also known as silicon
photomultiphers - SiPMs) with that of a typical photomultiplier tube (PMT) when
testing using CsI(Tl) scintillators. We use the charge comparison method,
whereby we discriminate different types of particles by the ratio of charges
integrated within two time-gates (the delayed part and the entire digitized
waveform). For a satisfactory PSD performance, a setup should generate many
photoelectrons (p.e.) and collect their charges efficiently. The PMT setup
generates more p.e. than the MPPC setup does. With the same digitizer and the
same long time-gate (the entire digitized waveform), the PMT setup is also
better in charge collection. Therefore, the PMT setup demonstrates better PSD
performance. We subsequently test the MPPC setup using a new data acquisition
(DAQ) system. Using this new DAQ, the long time-gate is extended by nearly four
times the length when using the previous digitizer. With this longer time-gate,
we collect more p.e. at the tail part of the pulse and almost all the charges
of the total collected p.e. Thus, the PSD performance of the MPPC setup is
improved significantly. This study also provides an estimation of the short
time-gate (the delayed part of the digitized waveform) that can give a
satisfactory PSD performance without an extensive analysis to optimize this
gate
Prototyping of DSSDs for Particle Tracking and Spectroscopy within the EXL Project at Fair
Prototype double-sided silicon strip detectors (DSSD) of 300 m thickness produced at PTI St. Petersburg (Russia) were tested for the use as position sensitive, and E detectors for tracking and particle identification in the EXL (EXotic nuclei studied in Light-ion induced reactions at the NESR storage ring) setup at the FAIR (Facility for Antiproton and Ion Research) project at GSI. We describe the characteristics of detectors with and strips, respectively. The response of these detectors for Am particles injected either from the p or n side was examined. The test measurements were performed partially at GSI and the University of Edinburgh. A first in-beam test with a proton beam of 50 MeV with the latter two DSSDs and two 6.5 mm thick Si(Li) detectors was also done at KVI Groningen, the Netherlands. The results reveal good spectroscopic properties of these detectors
Low-energy electric dipole response in 120Sn
The electric dipole strength in 120Sn has been extracted from proton
inelastic scattering experiments at E_p = 295 MeV and at forward angles
including 0 degree. Below neutron threshoild it differs from the results of a
120Sn(gamma,gamma') experiment and peaks at an excitation energy of 8.3 MeV.
The total strength corresponds to 2.3(2)% of the energy-weighted sum rule and
is more than three times larger than what is observed with the (gamma,gamma')
reaction. This implies a strong fragmentation of the E1 strength and/or small
ground state branching ratios of the excited 1- states.Comment: 7 pages, 6 figure
Dipole polarizability of 120Sn and nuclear energy density functionals
The electric dipole strength distribution in 120Sn between 5 and 22 MeV has
been determined at RCNP Osaka from a polarization transfer analysis of proton
inelastic scattering at E_0 = 295 MeV and forward angles including 0{\deg}.
Combined with photoabsorption data an electric dipole polarizability
\alpha_D(120Sn) = 8.93(36) fm^3 is extracted. The dipole polarizability as
isovector observable par excellence carries direct information on the nuclear
symmetry energy and its density dependence. The correlation of the new value
with the well established \alpha_D(208Pb) serves as a test of its prediction by
nuclear energy density functionals (EDFs). Models based on modern Skyrme
interactions describe the data fairly well while most calculations based on
relativistic Hamiltonians cannot.Comment: 6 pages, 4 figure
A school-based intervention program in promoting leisure-time physical activity: Trial protocol
Background: Regular participation in moderate-to-vigorous physical activity (MVPA) is important to manage obesity. Physical education (PE) is considered to play an important role in promoting lifelong participation in physical activity (PA) because it provides an existing network where cost-effective interventions can be implemented to produce sustainable change in health behavior. However, the association between compulsory school PA (e.g., PE lessons) and body composition levels has received mixed support in the literature. Therefore, the present study aimed to investigate whether a school-based intervention targeting salient PA benefits and barriers grounded on the theory of planned behavior would promote young people's participation in MVPA during leisure time and reduce body mass index (BMI) of overweight students. Methods/design: A total of 171 students from 3 secondary schools in Singapore underwent the control condition followed by the intervention condition. Both the conditions consisted of PE lessons twice per week over 4 weeks. In the control condition, PE teachers encouraged students to participate in PA during leisure time without providing persuasive message. While in the intervention condition, PE teachers delivered persuasive messages that targeted the salient benefits and barriers associated with PA to the students at the last 5 to 10 min of each PE lesson. PA levels over a week were measured objectively with wrist-mounted GENEActiv Original accelerometers and subjectively with self-reporting questionnaires three times (Baseline, Post 1, and Post 2) in each condition. Student's self-reported PA level was measured using the Leisure-Time Physical Activity Participation Questionnaire and the International Physical Activity Questionnaire, and their attitudes, intentions, subjective norms and perceived behavior control towards leisure-time PA were measured with a questionnaire based on the theory of planned behavior. Furthermore, students' intention, determination and willingness to engage in leisure-time PA were compared with the other activity (e.g., doing homework, shopping). Discussion: This study will provide the evidence on the effectiveness of a cost-effective school-based intervention on reducing BMI of overweight students through promoting sustained participation in leisure-time PA. It will also address methodological issues on the gaps between objective and subjective measures of PA. Trial registration: This trial is registered with the ISRCTN registry (ISRCTN73786157, 26/10/2017, retrospectively registered)
Status of 48Ca double beta decay search and its future prospect in CANDLES
CANDLES(CAlcium fluoride for the study of Neutrinos and Dark matters by Low Energy Spectrometer) is the experiment to search for the neutrino-less double beta decay(0vββ) of 48Ca with CaF2 scintillator. 48Ca has the highest Qββ-value (4.3 MeV) among all isotope candidates for 0vββ. It enables us to measure signals with very low background condition. After rejection analysis with 131 days × 86 kg data for background events from radioactive contaminations in the CaF2 scintillators, no events are observed in the Qββ-value region. As a result, the 0vββ half-life of 48Ca is greater than 6.2 × 1022 yr (90% confidence level). For further high sensitive measurement of 48Ca 0vββ search, we have been developing the 48Ca enrichment and CaF2 scintillating bolometer techniques. In this paper, the latest result for CANDLES and the status of scintillating bolometer development are described
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