The request of minimally processed vegetable is continuously increasing, and there is a growing interest for new fresh cut products. Cauliflower, as other cabbages, is highly appreciated for its ...nutritional value due to the good content of vitamins, antioxidants and anti-carcinogenic compounds. It is suitable to be used as a minimally processed vegetable, but harvesting and the following processing can cause a severe stress determining the appearance of accelerated senescence symptoms. The aim of the present work was to investigate the effect of hot air treatment and cold storage on minimally processed green cauliflower. Fresh-cut cauliflower florets put in sealed PE bags were treated at 48°C for 180 min and then stored at 4°C for 21 days. During the storage period, weight loss, colour, firmness, soluble solids, titratable acidity and overall quality were evaluated. Non treated fresh-cut cauliflower maintained soluble solid content, good firmness and showed low weight loss, but marketability was limited to 14 days, mainly due to the browning occurring in the cut zones. The hot air treatment increased weight loss during storage, but strongly reduced colour changes of minimally processed cauliflower. This lead to prolonged shelf life up to 3 weeks.
The thermal noise coupling with the displacement of the mirrors of a gravitational wave interferometric detector is a limit to its sensitivity in a range of frequencies from about 10
Hz to few ...hundreds of Hz; fused silica proved to be a very suitable material to reduce this source of noise for the first generation of detectors. The future advanced detectors are planning to make use of fused silica mirrors and suspending elements in a monolithic arrangement: in these conditions, the main contribution to the thermal noise will come from the amorphous multilayered coating deposited on the mirrors. This paper is focused on the multiple advantages provided by the use of fused silica material in a present day interferometric detector; a new suspension for measurements of the acoustic attenuation in fused silica is presented together with the loss angle dependance on frequency and aspect ratio. Furthermore we report on the status of the art of the research activity on fused silica wires production and characterization and coating thermal noise accomplished by the Firenze–Urbino Virgo group.
The ban of methyl bromide and the need for low environmental impact of agriculture has recently increased the interest in the biofumigant effects of Brassica species on soil-borne pathogens. Many ...researches have tested the toxic effects of Brassica green manures on several soil-borne pathogens in vitro, but field studies have not assessed definitely the efficiency of biofumigation at the field scale and the effect on crop development and production quality. The aim of this research was to evaluate the effect of a winter-spring cover crop of Brassica juncea compared to bare soil on a mono-succession of melon. The biomass of the B. juncea plants or of the weeds eventually developed in bare soil, used as control, were managed as follows:(i) shredded and left on the soil as organic mulching; (ii) shredded and incorporated into the soil; (iii) shredded and incorporated into the soil under PE mulching along melon crop rows. Marketable and unmarketable production, fruit weight and fruit quality (thickness of the epicarp and pulp, percentage of edible part, soluble solid content, firmness, etc.) were evaluated on melon fruits. The use of Brassica juncea as a cover crop positively influenced melon yield and quality compared to bare soil when the biomass was incorporated into the soil, while no difference was found when PE mulching was used.
Collard greens (Brassica oleracea var. acephala) are a group of plants cultivated for its thick, slightly bitter, edible leaves. As other Brassicaceae, have a good nutritional value as they are a ...good sources of vitamin C and soluble fiber, and contain various compounds with potent anticancer properties. In order to enhance collard cultivation in Sicily, different planting dates were tested. The research was carried out during 2009-2010 in the experimental field of SAgA Department - University of Palermo. Plants of a Sicilian local cultivar, with high vigor, good emission of side shoots, large and moderately curly leaves and long and strong petiole, were planted in three different periods: end of November, end on January, end of March. The harvest of the main shoot was made when they had tender and non-fibrous leaves and petioles. Secondary shoots, eventually originated from axillary buds left on the plant, were also harvested. Data were recorded on: number of leaves plant-1, stem diameter, fresh weight, dry weight, length and number of harvested shoots. The plants of the earliest transplant were harvested in March (main shoot), April and May (secondary shoots), while only the main shoot was harvested in the other plants (on May and June respectively for the second and the third transplant). This determined an higher yield for the first transplant against the other planting dates. Early transplant influenced also the quality of the main shoots that had more leaves, higher percentage of edible part and less dry matter than those from the other transplant. Secondary shoots had worst quality than the main shoot.
The use of floating cover directly applied on top of the crop is rapidly increasing on leafy vegetables like lettuce as a simple, inexpensive and effective technique to induce earliness. Two lettuce ...types, ‘Iceberg’ and ‘Romaine’, under two different crop management systems (black plastic mulch and black plastic mulch combined with floating cover) were tested in Sicily in 2007. Plug type transplants were planted at the end of January on double rows. The nonwoven floating cover was applied after transplanting. Maximum and minimum air temperatures below the floating cover during the growing period were in the average 5 and 1.5°C higher than those without cover. Lettuces mulched and protected with floating cover reached their commercial fresh weight ten days before those without floating cover. Regardless of the cultivar tested, total yield was significantly higher in the plots where black mulch was combined with floating cover as compared to that obtained with black plastic mulch alone. Regardless of the direct covering, ‘Romaine’ was more productive than ‘Iceberg’.
In order to reduce the suspension thermal noise, the second generation GW interferometric detectors will employ monolithic suspensions in fused silica to hold the mirrors. The fibres are produced by ...melting and pulling apart a fused silica rod, obtaining a long thin wire with two thicker heads. The dynamics of such a fibre is in principle different from that of a cylindrical, regular fibre, because most of the deformation energy is stored in the neck region where the diameter is variable. This is an advantage, since adjusting the neck tapering, a thermoelastic noise cancellation effect can be obtained. Therefore, a careful study of the suspensions behavior is necessary to estimate the overall noise and to optimize the control strategy. To simplify the control design, a simple three segment model for the silica fibres has been developed, fully equivalent to the beam equation at low frequencies. The model, analytically proved for a regular cylindrical fibre, can be extended to a fibre with tapered necks, provided that the equivalent bending length is suitably measured. We developed a tool to measure the position of the bending point for each fibre, thus allowing to experimentally check the validity of the model. A numerical code has been written to solve the beam equation for wires with varying diameter. This code confirms the validity of the three segment model. Moreover, it is possible to extend the solution to higher frequencies thus computing the transfer function and the energy distribution of the suspension system and estimating the thermal noise contribution.
PDF
