Studies related with the storage of peach fruits have received great relevance in Egypt. In this study, the effect of pre-harvest sprays of calcium chloride and chitosan, separately and in combination, on quality attributes and storability of peach fruits stored at 0±1 °C was studied. 'Early Swelling' peach trees were sprayed twice with 1% or 2% calcium chloride. The first spraying was at pea stage, while the second one was performed at 10 days before harvesting. Chitosan sprays were performed at 0.5 or 1%, alone or in combination with 1 and 2% calcium chloride, at 10 days before harvesting. Untreated trees served as control. Fruits were harvested at maturity stage, then packaged and stored at 0±1 °C and 85-90% of relative humidity. Fruit physical and chemical properties were evaluated at 7-day intervals. Results showed that pre-harvest application with 2% CaCl 2 +1% chitosan was most effective in minimizing weight loss (%) and decay (%), as well as in maintaining maximum firmness and lengthening shelf life. Fruit color was not affected by any of the treatments, while untreated fruits and calcium chloride treatment alone, at both applied concentrations, maintained higher total soluble solids (TSS, %), total phenolic content, and lower titratable acidity percentage.Index terms: Alternative chemicals; CaCl 2 ; quality attributes. RESUMOEstudos relacionados ao armazenamento de pêssego tem sido considerado de grande relevância no Egito. Neste estudo, o efeito da pulverização pré-colheita com cloereto de calico e quitosano, isoladamente ou em conjunto, na qualidade e na capacidade de armazenamento de frutos de pessegueiro armazenados a 0±1 °C foi avaliada. Frutos da variedade 'Early Swelling' foram tratados com 1,0 ou 2,0% de cloreto de cálcio. O primeiro tratamento foi aplicado num estado precoce de formação do fruto enquanto o segundo foi aplicado 10 dias antes da colheita. Quitosano foi aplicado nas concentrações de 0,5 ou 1,0%, isoladamente ou em combinação com 1,0% ou 2,0% de cloreto de cálcio também 10 dias antes da colheita. Árvores não tratadas serviram como controle. Os frutos foram colhidos quando maduros, empacotados e mantidos a 0±1 °C e sob condições de humidade relativa de 85-90%. Propriedades físicas e químicas dos frutos foram avaliadas em intervalos de 7 dias. Os resultados mostraram que a aplicação de 2% CaCl 2 + 1% quitosano foi a mais eficaz em minimizar a perda de peso (%) e a senescência (%), bem como na manutenção da rigidez e aumento do período de vida em prateleira. A cor dos frutos não foi afectada por nenhum dos tratamentos enquanto frutos não tratados e cloreto de cálcio isoladamente, em ambas as concentrações, mantiveram um elevado teor de sólidos solúveis totais (TSS, %), elevado teor de fenóis e reduzida percentagem de acidez de titulação.Termos para indexação: Químicos alternativos; CaCl 2 ; atributos qualitativos.

No abstract

A b s t r a c t . The cross-section for the reaction e+ + e-+ z1 + V , under a strong magnetic field is calculated. The rate of energy loss is also calculated. These calculations may be of great importance for astrophysical estimations in neutron stars. Lepton-Lepton-Wechselwirkung im starken MagnetfeldI n h a l t s u b e r s i c h t . Es wird der Wirkungsquerschnitt der Reaktion e+ + e--+z1 + Fsowie die Energieverlustrate in einem starken Magnetfeld berechnet. Die Ergebnisse konnen fur astrophysikalische Abschkitzungen in Neutronensternen von groSem Interesse sein.2 1 A < l , --% V --S l .

The present study was carried out on On year trees of mango cultivars Ewais and Sedik during 2005/2006 and 2006/2007 seasons to study the effect of pruning severity after harvest, GA 3 and Ethrel on the total number of panicles, perfect flowers %, average number of flowering shoots, average number of vegetative shoots and yield in the next off year season. Pruning severity were as follows: no pruning, heading back (Removing half of fruiting terminal flush) and removing the intact terminal flushes, GA 3 (0, 50 and 100 ppm) and GA 3 was applied 15-21 days after pruning and Ethrel was sprayed in the first week of November. Results of mango cv. Sedik indicated that heading back and removing the intact terminal flushes have the highest value of total number of panicles, perfect flowers %, the average number of flowering shoots and yield compared to control trees while there was no significant difference among all pruning severity and the number of vegetative shoots. Removing the intact terminal flushes with Ethrel application at 500 ppm resulted in the highest value of total number of panicles, flowering shoots and yield, while using 500 ppm alone recorded the highest average of perfect flowers % but removing the terminal flushes with 100 ppm of GA 3 attained the highest number of vegetative shoots. Results of mango cv. Ewais indicated that removing the intact terminal flushes with 1000 ppm of Ethrel has recorded the highest total number of panicles, flowering shoots and yield while the highest perfect flowers % was accomplished with Ethrel at 500 ppm with heading back. The highest vegetative shoots in heading back was obtained with 100 ppm of GA 3 .

Radiation loss due to pair production by ah intense electromagnetic wave is calculated. The calculations were made in the coulomb field of the ions and in the presence of a constant strong magnetic field aligned along the z-direction. The expression obtained for the radiation loss can be used for the case of nonrelativistic electrons and positrons. These calculations may be of great importarLce for the astrophysical estimations, since the basic mechanism of the energetic losses is mainly due to pair production.

No abstract

The cross-sections for the antineutrino process V + p --f e T are calculated in the theory of weak boson interaction. The dependence of the cross-section on the mass of the intermediate vector boson is explicitly shown. We assume that all form factors have the same analytic form and the same effective mass as that of the isorector part of the nucleon electromagnetic form factor.

The neutrino energy loss rate is calculated due to the photoneutrino process in a hot plasma, under magnetic field.The calculations done for Iow densities and re]atively ]ow temperatures may be used for astrophysical estimations in neutron stars. IntroduetionRecent progress in the production of a strong magnetic field in the laboratory [1] has focussed interest on the study of the effect of magnetic fields on various phenomena [2]. The largest field t h a t can now be produced in the laboratory is of the order of 1 5 G, which is much smaHer than that existing in neutron stars, which ma)" be of the order of 10 ~ G [3].Canonical models for the description of the weak interaction among fermions predicts a direct interaction between electron-neut¡ pairs [4]. The effective Hamiltonian which describes the eleetron neutrino interactions is H,,---ig (~~ ~,~(1 -5 Zs)V',,)(W,, 9'~ (1 --5 y.~)%).(1) 8m',,, Such an interaction follows immediately in conventional theories in which the weak interaction is mediated by a few intermediate vector bosons [5], or when the weak coupling has the forro phenomenologically at least of current-current interaction.A Fierz transformation of the Hamiltonian of Eq. (1) yields the equivalent form Hw = _ i/___~2 [~e Y,, V'e)(~,, }'. (1 + Ys) %) + (~, Y6 Y,, 'P,)(~,, ~'. (1 + Ys) V',,)], 8 m~ (2)which exhibits more explicitly the matrix element for a neut¡241 pair to be radiated by ah electron, by means of a vector or axial rector current. The vector current is analogous to the coupling of an eleetron to a photon and Acla Physica Aeod+miae Sci+n+iar~m lt.ngori+o+ 39, 1975