Causality and dispersion relations and the role of the S-matrix in the ongoing research

The adaptation of the Kramers-Kronig dispersion relations to the causal localization structure of QFT led to an important project in particle physics, the only one with a successful closure. The same cannot be said about the subsequent attempts to formulate particle physics as a pure S-matrix project. The feasibility of a pure S-matrix approach are critically analyzed and their serious shortcomings are highlighted. Whereas the conceptual/mathematical demands of renormalized perturbation theory are modest and misunderstandings could easily be corrected, the correct understanding about the origin of the crossing property requires the use of the mathematical theory of modular localization and its relation to the thermal KMS condition. These new concepts, which combine localization, vacuum polarization and thermal properties under the roof of modular theory, will be explained and their potential use in a new constructive (nonperturbative) approach to QFT will be indicated. The S-matrix still plays a predominant role but, different from Heisenberg's and Mandelstam's proposals, the new project is not a pure S-matrix approach. The S-matrix plays a new role as a "relative modular invariant"..Comment: 47 pages expansion of arguments and addition of references, corrections of misprints and bad formulation

Consumer evaluation of a hydro-conservation model and its efficiency on improving the collard greens cv. manteiga shelf life (Brassica oleracea, cv. acephala)

[PORT] Neste estudo avaliou-se a aceitação, pelo consumidor, de um equipamento com temperaturas hidrocontroladas e sua eficiência no aumento do tempo de prateleria de couve manteiga (Brassica oleracea, v. acephala). O método de hidroconservação consiste em utilizar uma solução aquosa como meio trocador de calor entre o evaporador e o produto armazenado. O equipamento analisado foi um modelo híbrido onde as câmaras de armazenamento foram parcialmente submersas na solução aquosa. Foram usadas oito câmaras de 7371 cm3 . A aceitação do equipamento foi avaliada através de questionário apresentado próximo do equipamento em um ponto de venda da região central da cidade de São Carlos- SP-BR. A couve manteiga foi escolhida por ser amplamente comercializada no Brasil e apresentar um curto tempo de prateleira. Após higienização e segmentação as amostras foram lacradas em sacos de polietileno de baixa densidade (PEBD) instalados nas câmaras de armazenamento. O tempo de prateleira foi estimado através de teste sensorial e do teor de água das folhas. A análise dos questionários indicou alto índice de aprovação do equipamento (acima de 90%) e índice de rejeição nulo. O teste sensorial mostrou que o consumidor julgou o produto adequado ao consumo por um período de armazenamento superior a 20 dias, três vezes mais que o tempo de prateleira da couve armazenada em geladeira. Neste período a perda de massa foi de 5,8%. Conclui-se que o modelo industrial avaliado mostrou-se viável, tanto do ponto de vista da aprovação pelo público consumidor como pela capacidade de conservação de couve manteiga processada, capacidade esta que pode ser estendida para outros produtos olerícolas. [ENG] This study evaluated the acceptability of an equipment that uses hydrocontroled temperature system, and its efficiency on increasing the shelf life time of collard greens (Brassica oleracea cv. acephala). The hydroconservation method uses a water solution to exchange heat between the evaporator and the stored product. On this paper, however, an hybrid model was evaluated where small storage chambers were parcialy submerged in the solution. There were used eight chambers with 7371 cm3. The acceptability of the equipment was evaluated based on a form fullfiled by the consumers close to the equipment, in a small market at São Carlos-SP-BR. The collard greens was choosen because of its big market in Brazil and its short shelf life time. After satinization and segmentation the samples were inserted in polietilene of low density (PEBD) bags with lock, installed in the storage chambers. The shelf life time was estimated from organoleptic tests and the water content of the leaves. The analysis of the forms showed the high aceptance index (above 90%) of the equipment, and no rejection. The organoleptic tests indicated that the costumer evaluated the equipment positively on storing the collad greens for more than 20 days, three times more than the shelf life when stored in a refrigerator. Along the experiment the mass loss was 5,8%. The conclusions list includes the positive evaluation of the industrial model and its efficency on improving the shelf life time, what can be extended to other vegetables