A Procedure to Calibrate a Multi-Modular Telescope

A procedure has been developed for the charge, mass and energy calibration of ions produced in nuclear heavy ion reactions. The charge and mass identification are based on a $\Delta$E-E technique. A computer code determines the conversion from ADC channels into energy values, atomic number and mass of the detected fragments by comparing with energy loss calculations through a minimization routine. The procedure does not need prior measurements with beams of known energy and charge. An application of this technique to the calibration of the MULTICS apparatus is described.Comment: 9 pages, Tex file, 3 postscript figures available upon request from [email protected]; to appear in Nucl. Inst. Met

Mutual use of trail-following chemical cues by a termite host and its inquiline

Termite nests are often secondarily inhabited by other termite species ( = inquilines) that cohabit with the host. To understand this association, we studied the trail-following behaviour in two Neotropical species, Constrictotermes cyphergaster (Termitidae: Nasutitermitinae) and its obligatory inquiline, Inquilinitermes microcerus (Termitidae: Termitinae). Using behavioural experiments and chemical analyses, we determined that the trail-following pheromone of C. cyphergaster is made of neocembrene and (3Z,6Z,8E)-dodeca-3,6,8-trien-1-ol. Although no specific compound was identified in I. microcerus, workers were able to follow the above compounds in behavioural bioassays. Interestingly, in choice tests, C. cyphergaster prefers conspecific over heterospecific trails while I. microcerus shows the converse behaviour. In no-choice tests with whole body extracts, C. cyphergaster showed no preference for, while I. microcerus clearly avoided heterospecific trails. This seems to agree with the hypothesis that trail-following pheromones may shape the cohabitation of C. cyphergaster and I. microcerus and reinforce the idea that their cohabitation is based on conflict-avoiding strategies

Multiple-photon Peak Generation Near The 10 M Range In Quantum Dot Infrared Photodetectors

We present results from simulations of the photocurrent observed in recently fabricated InAs quantum dot infrared photodetectors that respond with strong resonance peaks in the ∼ 10 m wavelength range. The results are in good agreement with experimental data generated earlier. Multiphoton scattering of electrons localized in the quantum dots are not only in accordance with the observed patterns, but are also necessary to explain the photocurrent spectrum obtained in the calculations. © 2011 American Institute of Physics.1096Martyniuk, P., Rogalski, A., (2008) Prog. Quantum Electron., 32, p. 89. , For a recent review, see, 10.1016/j.pquantelec.2008.07.001Chakrabarti, S., Stiff-Roberts, A.D., Su, X.H., Bhattacharya, P., Ariyawansa, G., Perera, A.G.U., High-performance mid-infrared quantum dot infrared photodetectors (2005) Journal of Physics D: Applied Physics, 38 (13), pp. 2135-2141. , DOI 10.1088/0022-3727/38/13/009, PII S002237270592069XLim, H., Zhang, W., Tsao, S., Sills, T., Szafraniec, J., Mi, K., Movaghar, B., Razeghi, M., Quantum dot infrared photodetectors: Comparison of experiment and theory (2005) Physical Review B - Condensed Matter and Materials Physics, 72 (8), p. 085332. , http://oai.aps.org/oai/?verb=ListRecords&metadataPrefix= oai_apsmeta_2&set=journal:PRB:72, DOI 10.1103/PhysRevB.72.085332Razeghi, M., Lim, H., Tsao, S., Szafraniec, J., Zhang, W., Mi, K., Movaghar, B., Transport and photodetection in self-assembled semiconductor quantum dots (2005) Nanotechnology, 16 (2), pp. 219-229. , DOI 10.1088/0957-4484/16/2/007Pal, D., Towe, E., (2006) Appl. Phys. Lett., 88, p. 153109. , 10.1063/1.2193466Bhattacharya, P., Su, X.H., Chakrabarti, S., Ariyawansa, G., Perera, A.G.U., Characteristics of a tunneling quantum-dot infrared photodetector operating at room temperature (2005) Applied Physics Letters, 86 (19), pp. 1-3. , DOI 10.1063/1.1923766, 191106Dupont, E., Corkum, P., Liu, H.C., Wilson, P.H., Buchanan, M., Wasilewski, Z.R., (1994) Appl. Phys. Lett., 65, p. 1560. , 10.1063/1.113004Maier, T., Schneider, H., Walther, M., Koidl, P., Liu, H.C., (2004) Appl. Phys. Lett., 84, p. 5162. , 10.1063/1.1763978Jiang, J., Fu, Y., Li, N., Chen, X.S., Zhen, H.L., Lu, W., Wang, M.K., Li, Y.G., (2004) Appl. Phys. Lett., 85, p. 3614. , 10.1063/1.1781732Aivaliotis, P., Zibik, E.A., Wilson, L.R., Cockburn, J.W., Hopkinson, M., Vinh, N.Q., (2008) Appl. Phys. Lett., 92, p. 023501. , 10.1063/1.2833691Sirtori, C., Capasso, F., Sivco, D.L., Cho, A.Y., (1992) Appl. Phys. Lett., 60, p. 2678. , 10.1063/1.106893Souza, P.L., Lopes, A.J., Gebhard, T., Unterrainer, K., Pires, M.P., Villas-Boas, J.M., Vieira, G.S., Studart, N., Quantum dot structures grown on Al containing quaternary material for infrared photodetection beyond 10 μm (2007) Applied Physics Letters, 90 (17), p. 173510. , DOI 10.1063/1.2733603Gebhard, T., Alvarenga, D., Souza, P.L., Guimares, P.S.S., Unterrainer, K., Pires, M.P., Vieira, G.S., Villas-Boas, J.M., (2008) Applied Phys. Lett., 93, p. 052103. , 10.1063/1.2965804Pryor, C.E., Pistol, M.-E., Band-edge diagrams for strained III-V semiconductor quantum wells, wires, and dots (2005) Physical Review B - Condensed Matter and Materials Physics, 72 (20), pp. 1-11. , http://oai.aps.org/oai/?verb=ListRecords&metadataPrefix= oai_apsmeta_2&set=journal:PRB:72, DOI 10.1103/PhysRevB.72.205311, 205311Degani, M.H., Maialle, M.Z., (2010) J. Comput. Theor. Nanosci., 7, p. 454. , 10.1166/jctn.2010.1380Feit, M.D., Fleck Jr., J.A., Steiger, A., (1982) J. Comput. Phys., 47, p. 412. , 10.1016/0021-9991(82)90091-2Degani, M.H., (1991) Appl. Phys. Lett., 59, p. 57(2002) Phys. Rev. B, 66, p. 23306. , 10.1063/1.105521Maialle, M.Z., Degani, M.H., Madureira, J.R., Farinas, P.F., (2009) J. Appl. Phys., 106, p. 123703. , 10.1063/1.3270263Fano, U., Cooper, J.W., (1968) Rev. Mod. Phys., 40, p. 441. , 10.1103/RevModPhys.40.441Tsolakidis, A., Snchez-Portal, D., Martin, R.M., (2002) Phys. Rev. B, 66, p. 235416. , 10.1103/PhysRevB.66.23541

Fragment Production in Non-central Collisions of Intermediate Energy Heavy Ions

The defining characteristics of fragment emission resulting from the non-central collision of 114Cd ions with 92Mo target nuclei at E/A = 50 MeV are presented. Charge correlations and average relative velocities for mid-velocity fragment emission exhibit significant differences when compared to standard statistical decay. These differences associated with similar velocity dissipation are indicative of the influence of the entrance channel dynamics on the fragment production process

Isotopic composition of fragments in multifragmentation of very large nuclear systems: effects of the chemical equilibrium

Studies on the isospin of fragments resulting from the disassembly of highly excited large thermal-like nuclear emitting sources, formed in the ^{197}Au + ^{197}Au reaction at 35 MeV/nucleon beam energy, are presented. Two different decay systems (the quasiprojectile formed in midperipheral reactions and the unique source coming from the incomplete fusion of projectile and target in the most central collisions) were considered; these emitting sources have the same initial N/Z ratio and excitation energy (E^* ~= 5--6 MeV/nucleon), but different size. Their charge yields and isotopic content of the fragments show different distributions. It is observed that the neutron content of intermediate mass fragments increases with the size of the source. These evidences are consistent with chemical equilibrium reached in the systems. This fact is confirmed by the analysis with the statistical multifragmentation model.Comment: 9 pages, 4 ps figure

CORRELAÇÃO GENÉTICA, FENOTÍPICA E AMBIENTAL EM CARACTERÍSTICAS DE CRESCIMENTO DE BOVINOS DA RAÇA NELORE VARIEDADE MOCHA

The objective of this work was estimate the genetic correlations, environmental and phenotypic on the birth weight (WB) and on the 205 (W205), 365 (W365) and 550 (W550) days of age, in animals of the polled nellore breed from Bahia state. The analyses were carried out by software MTDFREML. The genetic correlations were 0.08 (WB and W205), 0.00 (WB and W365), - 0.14 (WB and W550), 0.90 (W205 and W365), 0.81 (W205 and W550) and 0.97 (W205 and W550). The environmental correlations were 0.12 (WB and W205), 0.11 (WB and W365) and 0.16 (WB and W550), 0.35 (W205 and W365), 0.13 (W205 and W550) and 0.54 (W365 and W550). The phenotypic correlations were 0.09 (WB and W205), 0.05 (WB and W365), 0.00 (WB and W550), 0.75 (W205 and W365), 0.65 (W205 and W550) and 0.87 (W365 and W550). The birth weight presented weak genetic, environmental, and phenotypic associations with the others weighting. On the other hand, the values gotten for the genetic correlations between the other weighting, indicates that the selection for weight in young ages will promote changes on the future weights of the animal.O objetivo deste trabalho foi estimar as correlações genéticas, fenotípicas e ambientais sobre os pesos ao nascimento (PN) e aos 205 (P205), 365 (P365) e 550 (P550) dias de idade, em animais da raça Nelore Mocha, criados no estado da Bahia. As análises bi-características foram realizadas através do programa MTDFREML. As correlações genéticas foram iguais a 0,08 (PN e P205), 0,00 (PN e P365), - 0,14 (PN e P550), 0,90 (P205 e P365), 0,81, (P205 e P550) e 0,97 (P365 e P550). As correlações ambientais foram 0,12 (PN e P205), 0,11 (PN e P365), 0,16 (PN e P550), 0,35 (P205 e P365), 0,13 (P205 e P550) e 0,54 (P365 e P550). Os valores obtidos para as correlações fenotípicas foram 0,09 (PN e P205), 0,05 (PN e P365), 0,00 (PN e P550), 0,75 (P205 e P365) 0,65 (P205 e P550) e 0,87 (P365 e P550). O peso ao nascimento apresentou ausência de associações genéticas, ambientais e fenotípicas com as demais pesagens. Por outro lado, os valores obtidos para as correlações genéticas entre as outras pesagens, indicam que a seleção para peso em idades jovens deverá promover mudanças nos pesos posteriores dos animais