A study of T = 2 states in ^(12)B, ^(12)C, ^(20)F and ^(28)Al

The lowest T = 2 states have been identified and studied in the nuclei ¹²C, ¹²B, ²⁰F and and ²⁸Al. The first two of these were produced in the reactions ¹⁴C(p,t)¹²C and ¹⁴C (p,³He)¹²B, at 50.5 and 63.4 MeV incident proton energy respectively, at the Oak Ridge National Laboratory. The T = 2 states in ²⁰F and ²⁸Al were observed in (³He,p) reactions at 12-MeV incident energy, with the Caltech Tandem accelerator.

The results for the four nuclei studied are summarized below:

(1) ¹²C: the lowest T = 2 state was located at an excitation energy of 27595 ± 20 keV, and has a width less than 35 keV.

(2) ¹²B: the lowest T = 2 state was found at an excitation energy of 12710 ± 20 keV. The width was determined to be less than 54 keV and the spin and parity were confirmed to be 0⁺. A second ¹²B state (or doublet) was observed at an excitation energy of 14860 ± 30 keV with a width (if the group corresponds to a single state) of 226 ± 30 keV.

(3) ²⁰F: the lowest T = 2 state was observed at an excitation of 6513 ± 5 keV; the spin and parity were confirmed to be 0⁺. A second state, tentatively identified as T = 2 from the level spacing, was located at 8210 ± 6 keV.

(4) ²⁸Al: the lowest T = 2 state was identified at an excitation of 5997 ± 6 keV; the spin and parity were confirmed to be 0⁺. A second state at an excitation energy of 7491 ± 11 keV is tentatively identified as T = 2, with a corresponding (tentative) spin and parity assignment J^π = 2⁺.

The results of the present work and the other known masses of T = 2 states and nuclei for 8 ≤ A ≤ 28 are summarized, and massequation coefficients have been extracted for these multiplets. These coefficients were compared with those from T = 1 multiplets, and then used to predict the mass and stability of each of the unobserved members of the T = 2 multiplets.

Growth of highly sensitive thermoluminescent crystal alpha-Al2O3 : C by the temperature gradient technique

In this work, an alpha-Al2O3:C crystal with highly sensitive thermoluminescence was directly grown by the temperature gradient technique (TGT) using Al2O3 and graphite powders as raw materials. The optical and luminescent properties and the dosimetric characteristics of the crystal were investigated. An as-grown alpha-Al2O3:C crystal shows a single glow peak at 462 K and a blue emission peak at 415 nm. The thermoluminescence (TL) response of the crystal shows a linear-sublinear-saturation characteristic. In the dose range from 5 x 10(-6) to 10Gy, the alpha-Al2O3:C crystal shows excellent linearity, and saturation was observed at about 30Gy. The sensitivity of the crystal decreases as the heating rate increases. (c) 2008 Elsevier B.V. All rights reserved.

Distribution and life history of two diminutive flatfishes, Citharichthys gymnorhinus and C. cornutus (Pleuronectiformes: Paralichthyidae), in the western North Atlantic

Citharichthys cornutus and C. gymnorhinus, diminutive flatfishes inhabiting continental shelves in the western Atlantic Ocean, are infrequently reported and poorly known. We identified 594 C. cornutus in 56 different field collections (68–287 m; most between 101–200 m) off the eastern United States, Bahamas, and eastern Caribbean Sea. Historical records and recently captured specimens document the northern geographic range of adults on the shelf off New Jersey (40°N, 70°W). Citharichthys cornutus measured 17.2–81.3 mm standard length (SL); males (20.0–79.1 mm SL) and females (28.0–81.3 mm SL) attain similar sizes (sex could not be determined for fish <20 mm SL). Males reach nearly 100% maturity at ≥60 mm SL. The smallest mature females are 41.5 mm SL, and by 55.1 mm SL virtually all are mature. Juveniles are found with adults on the outer shelf. Only 214 C. gymnorhinus were located in 42 different field collections (35–201 m, with 90% between 61 and 120 m) off the east coast of the United States, Bahamas, and eastern Caribbean Sea. Adults are found as far north as the shelf off Cape Hatteras, NC (35°N, 75°W). This diminutive species (to 52.4 mm SL) is among the smallest flatfishes but males (n=131; 20.3–52.4 mm SL) attain a slightly larger maximum size than that of females (n=58; 26.2–48.0 mm SL). Males begin to mature between 29 and 35 mm SL and reach 100% maturity by 35–40 mm SL. Some females are mature at 29 mm SL, and all females >35.1 mm SL are mature. Overlooked specimens in museum collections and literature enabled us to correct long-standing inaccuracies in northern distributional limits that appear in contemporary literature and electronic data bases for these species. Associated locality-data for these specimens allow for proper evaluation of distributional information for these species in relation to hypotheses regarding shifts in species ranges due to climate change effects.

Study on the sustainability of FPC produced from Kilka (Clupeonella engrauliformis, C. grimmi and C. cultriventris) in two vacuum packaging and modified atmosphere packaging at different environmental factors

Fish protein concentrate (FPC) is a healthy, sustainable and high nutritive product which sanitized produced from fishes in which, protein and other nutrients are more concentrated than in fresh fishes. The aim of this research is to study on the sustainability of FPC produced from Kilka (Clupeonella engrauliformis , C. grimmi and C. cultriventris) in two Vaccum Packaging and Modified Atmosphere Packaging at different environmental factors during six months. In our study the analysis of FPC protein showed 91.2%, lipid: 0.5%, ash: 3.6%, moisture: 2.3%, Total Volatile Nitrogen: 10 ml/100gr and peroxide: 5meq/kg. Amino acids and fatty acids were also determined. Bacteria and Fungi were lower than 1000 colony. Samples are kept in different condition of temperature (5, 20 and 35 degree centigrade), humidity (25, 40 and 90 percent) and light and dark environment in six month. Lipid rate in FPC after 6 months in VP and MAP (60% C02, 30 % N2 and 10% O2), packages was decreased but was not significant (P>0.05). It was also detected that increase temperature lead to more decrease in lipid content. Protein rate of FPC was decreased from 91.2% to 73.6% during six months at 35°C in VP Package and from 91.2% to 69.4% in MAP package. These changes were significant (P<0.05). TVN and PV rate in FPC after 6 months in VP and MAP packages was increased but was significant (P<0.05). Amino acids and fatty acids were also determined. But more changes in MAP packages was detected.