16,083 research outputs found
Neutral heavy lepton production at next high energy linear colliders
The discovery potential for detecting new heavy Majorana and Dirac neutrinos
at some recently proposed high energy colliders is discussed. These
new particles are suggested by grand unified theories and superstring-inspired
models. For these models the production of a single heavy neutrino is shown to
be more relevant than pair production when comparing cross sections and
neutrino mass ranges.
The process is calculated
including on-shell and off-shell heavy neutrino effects.
We present a detailed study of cross sections and distributions that shows a
clear separation between the signal and standard model contributions, even
after including hadronization effects.Comment: 4 pages including 15 figures, 1 table. RevTex. Accepted in Physical
Review
Alternate islands of multiple isochronous chains in wave-particle interactions
We analyze the dynamics of a relativistic particle moving in a uniform
magnetic field and perturbed by a standing electrostatic wave. We show that a
pulsed wave produces an infinite number of perturbative terms with the same
winding number, which may generate islands in the same region of phase space.
As a consequence, the number of isochronous island chains varies as a function
of the wave parameters. We observe that in all the resonances, the number of
chains is related to the amplitude of the various resonant terms. We determine
analytically the position of the periodic points and the number of island
chains as a function of the wave number and wave period. Such information is
very important when one is concerned with regular particle acceleration, since
it is necessary to adjust the initial conditions of the particle to obtain the
maximum acceleration.Comment: Submitte
CONTAINER FOR THE TRANSPORTATION AND CONSERVATION OF IMMUNOBIOLOGICALS
A container was developed for the transport and conservation of immunological products under low temperatures of between 2 and 8 º C, within a time span of 8 hours. The container is practical, simple and userfriendly, and can be used in places without electric power, and all these advantages are added of low operational costs. The container proposed aims at meeeting the demand of the Programa Nacional de Imunizações (PNI- the National Immunization Program), through Cold Chain, which sets the standards for all the procedures concerning conservation, handling, distribution and transport of the vaccine from the laboratory that produces it to the moment of inoculation.Innitially, the container was specifically developed for Vaccine for Inactive Influenza Virus against flu, which, according to a survey conducted with laboratories, is the most widely consumed, and whose conservation time span is also applicable to other immunobiologicals After the design and construction of the prototype, the container was exhaustively tested under different weather conditions. The results of the experiment are being exposed and discussed in this paper and the prototype lived up to the expectations of the reserachers in terms of the time spans and temperatures foreseen for the conservation of the vaccine selected
Divergências morfológicas e de caracteristicas qualitativas nas variedades de uva Itália e Italia melhorada no Submédio São Francisco.
As variedades de uva Italia e Italia Melhorada são amplamente difundidas no Vale do Submédio São Francisco. Porém, não se sabe a origem da Italia Melhorada. O presente trabalho teve como objetivo comparar morfologicamente as variedades Italia e Italia Melhorada, a fim de constatar as semelhanças e divergências entre elas. Os trabalhos foram realizados na coleção de videira da Embrapa Semi-Árido, localizada na Estação Experimental de Mandacaru, Juazeiro-BA. As avaliações levaram em consideração caracteres morfológicos de folhas e frutos. Para as características de folhas, foram coletadas amostras de quatro plantas das regiões apical, mediana e basal, medindo-se os comprimentos das nervuras denominadas nervura mediana (L1); lateral superior (L2); lateral inferior (L3) e nervura peciolada (L4). Avaliaram-se também as características qualitativas tais como pilosidade, cor, forma do limbo e dos ?dentes?, e número de lóbulos. Em relação às características de frutos, avaliaram-se o comprimento e o diâmetro dos cachos e das bagas, em 10 frutos/planta, coletados em cinco plantas de vinhedos comerciais. Para análise estatística, utilizou-se o delineamento de blocos inteiramente casualizados, onde as plantas foram consideradas repetições. Realizaram-se a análise de variância e a comparação de médias pelo teste de Tukey ao nível de 5% de probabilidade. Os resultados revelaram diferenças significativas apenas em relação aos comprimentos das nervuras L1 nas folhas medianas e L4 nas folhas basais, em que a Italia Melhorada apresentou médias superiores (9,8 e 3,4 cm, respectivamente) às da Italia (7,6 e 2,7 cm, respectivamente). Para a morfologia do cacho, houve diferença significativa em relação ao comprimento do cacho, largura e comprimento das bagas em que a Italia Melhorada apresentou médias superiores (24,7; 30,43 e 25,54 cm, respectivamente) às da Italia (16,1; 26,38 e 23 cm, respectivamente). Nas avaliações referentes aos caracteres qualitativos, não foram observadas diferenças entre as duas variedades
How much of nitrogen from fertilizer is absorbed by palisadegrass when intercropped with corn?
The study evaluates the influence of Palisadegrass in the use of N fertilizer, according to forms of implantation of Palisadegrass intercropped with corn in Brazil
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