In the anisotropic scintillators the light output and the pulse shape for heavy particles (
p
,
α
, nuclear recoils) depend on the direction with respect to the crystal axes; the response to
γ
/
β
...radiation is isotropic instead. This feature offers the possibility to study the directionality approach, which is applicable in the particular case of those Dark Matter candidate particles inducing just nuclear recoils. Among the anisotropic scintillators, the ZnWO
4
has unique features, which make it an excellent candidate for this type of research, and there is still plenty of room for the improvement of its performances. In this paper the possibility of a low background pioneer experiment (named ADAMO—Anisotropic detectors for DArk Matter Observation) to exploit deep underground the directionality approach by using anisotropic ZnWO
4
scintillators is discussed.
The results obtained in the search for possible diurnal effect in the
single-hit
low energy data collected by DAMA/LIBRA-phase1 (total exposure 1.04 ton
×
year) deep underground at the Gran Sasso ...National Laboratory (LNGS) of the INFN are presented. At the present level of sensitivity the presence of any significant diurnal variation and of diurnal time structures in the data can be excluded for both the cases of solar and sidereal time. In particular, the diurnal modulation amplitude expected, because of the Earth diurnal motion, on the basis of the DAMA dark matter annual modulation results is below the present sensitivity.
Limits and performances of a BaWO4 single crystal Caracciolo, V.; Cappella, F.; Cerulli, R. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2018, Letnik:
901
Journal Article
Recenzirano
A Barium Tungstate single crystal (BaWO4) was produced using the low thermal gradient Czochralski technique. In this paper the results concerning its light emission and radioactive contaminants are ...presented. The aim of this work is to investigate the possibility to realize BaWO4 crystals with suitably features to study the double beta decay of 130Ba and 132Ba isotopes by the “source=detector” approach. The results show the limitations of a BaWO4 crystal as a scintillator and give some idea on how to overcome them in order to take profit from the potentiality of this single crystal.
In the present paper the results obtained in the investigation of possible diurnal effects for low-energy
single-hit
scintillation events of DAMA/LIBRA-phase1 (1.04 ton
×
year exposure) have been ...analysed in terms of an effect expected in case of dark matter (DM) candidates inducing nuclear recoils and having high cross-section with ordinary matter, which implies low DM local density in order to fulfill the DAMA/LIBRA DM annual modulation results. This effect is due to the different Earth depths crossed by those DM candidates during the sidereal day.
Some theoretical and experimental aspects regarding the direct dark matter field are mentioned. In particular some arguments, which play a relevant role in the evaluation of model dependent ...interpretations of experimental results and in comparisons, are shortly addressed.
Several experiments were performed during last years at underground (3600 m w.e.) Laboratori Nazionali del Gran Sasso (LNGS) of the INFN, Italy; to search for resonant 2ϵ0ν captures in 96Ru, 106Cd, ...136Ce, 156Dy, 158Dy, 180W, 184Os, 190Pt with the help of HP Ge semiconductor detectors, and ZnWO4 and 106CdWO4 crystal scintillators. No evidence for r-2ϵ0ν decays was found, and only T1/2 limits were established in the range of 1014 - 1021 yr.
The objective of this study was to verify the impact of various sports on body cell mass (BCM). Ninety-eight male subjects, 17-33 years of age, participated in the study. The sample included athletes ...from three professional Italian football (soccer) teams, representing three different divisions (A, n=16; B, n=14; and C, n=18), judo athletes (J, n=10), and water polo athletes (W, n=14) who all competed at the national level. Twenty-six age-matched individuals served as the control group (CG). Fat-free mass (FFM), fat mass (FM), percent body fat (%BF), and BCM were assessed using bioimpedance spectroscopy (BIS). There were no significant differences in body weight and FFM among the groups. A and B were significantly taller than J and CG. B had a significantly lower body mass index (BMI; kg/m(2)) than CG, while C had a significantly lower BMI than J and CG. CG had a significantly greater FM and %BF than A, B, and C. C had a significantly lower BCM than Aand B. CG had a significantly lower BCM than A, B, J, and W. In conclusion, differences in BCM exist among athletes of different sports, and among athletes within the same sport who compete at different levels.
Acute exacerbations (AECOPD) of negatively influence the natural history of chronic obstructive pulmonary (COPD) and they are related to muscle dysfunction. In this pathway hypogonadism could play a ...pivotal role. Our study wants to evaluate possible relationships among prognostic indexes of AECOPD, represented by Acute Physiology and Chronic Health Evaluation (APACHE) II, inflammation (serum amyloid A, SSA) and anabolic hormones, especially less studied steroids, like dihydrotestosterone (DHT) e free-testosterone (f-T).
Twenty-four patients (17 males; age 75 ± 13 yrs) were studied. On admission and at discharge a blood sample for total testosterone (T), DHT, insulin like grow factor 1 (IGF-1) and Serum Amyloid A (SSA) was obtained. f-T was calculated using Vermeulen's formula.
Descriptive statistical analysis shows reduced of T values (1.85 ± 2.28 ng/mL), f-T (0.028 ± 0.030 ng/mL), DHT (0.18 ± 0.19 ng/mL) and IGF-1 (91.840 ± 74.19 pg/mL). Calculating tertile for Apache II and SSA and using them as cut off point, three categories were made and used in the analysis (SSA< 10 mg/mL; 10-160 mg/mL; > 160 mg/mL); (APACHE II ≤ 10; 11-12; > 12). Using this classification, an inverse correlation between SAA and T (P = 0.01), f-T (0.01), DHT (0.001) and IGF-1 (P = 0.05) was found. Data show the same inverse relationship between APACHE II tertiles on one hand and T (P = 0.01) and f-T (P = 0.02) on the other hand.
Our data confirm systemic effects of AECOPD and the role of endocrinological derangements, suggesting a possible mechanism explaining them.
The results obtained with the total exposure of 1.04 ton x yr collected by DAMA/LIBRA-phase1 deep underground at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N. during 7 annual cycles are ...briefly summarized. The DAMA/LIBRA-phase 1 and the former DAMA/NaI data (cumulative exposure 1.33 ton x yr, corresponding to 14 annual cycles) give evidence at 9.3 sigma C.L. for the presence of Dark Matter (DM) particles in the galactic halo, on the basis of the exploited model independent DM annual modulation signature by using highly radio-pure NaI(Tl) target. The modulation parameters are well in agreement with those expected for DM particles. No systematic or side reaction able to mimic the exploited DM signature has been found or suggested by anyone over more than a decade. Some of the perspectives of the presently running DAMA/LIBRA-phase2 are outlined.
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