Packaged fresh market strawberries and grapes were subjected to vibration conditions which simulate truck transportation. Frequencies ranged from 2 to 30 Hz. Fruit quality was evaluated by several methods before vibration, after vibration, and after a one-week storage period. Effects of vibration frequency and box position in a 9 or a 15 high stack on fruit damage were investigated. The frequency range of 5.0 to 10 Hz caused the maximum damage to both commodities and the top box in this range was the worst for the strawberries. KEYWORDS.

Fresh fruits and vegetables experience losses enroute to market that are caused by mechanical injuries. Past studies have indicated that transit vibration contributes to this loss, and may be more important than impacts as a source of damage. In crosscountry tests of cherries, nectarines, and pears in semi-trailers equipped with steel-spring suspension systems, highest Power Spectral Density (PSD) levels were found at about 3.5 Hz. In this study, PSD is used to mean acceleration spectral density. Other frequencies with high PSD levels were 9,18, and 25 Hz, Similar results were found in tests with fresh tomatoes. However, in trailers equipped with an air-ride suspension and loaded with tomatoes, the PSD levels were attenuated at 3.5 Hz, and were reduced at other frequencies. The highest PSD levels were found at the rear of the trailer, with resonance in the loaded boxes occurring at some frequencies. Horizontal acceleration was much less than the vertical acceleration. Understanding acceleration levels and frequencies that occur during shipment of perishables in refrigerated trailers will help to determine methods that will dampen the vibration energy and reduce the present losses in produce quality.

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While exchange controls under prior French law in general, 7 and their application to American investment in particular, 8 have 2. Law No. 66-1008 of Dec. 28, 1966, [1966) J.O. 11621. 3. Article 34 of the Constitution of 1958 explicitly limits the legislative powers of parliament, while art. 37 reserves to the government areas that are outside of parliamentary competence. The practice of the Fifth Republic has been to make maximum use of this constitutional fact to increase government powers.

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