Ethylene production and quality in 1-Methylcyclopropene treated 'Abbé Fètel'pears after storage in Dynamically Controlled Atmosphere

This research studies the ethylene production rate (EP) and quality in 1-MCP treated ‘Abbé Fètel’ pears after storage in DCA compared to NA and CA. 1-MCP treated (300 ppb) and control fruit were stored at -0.5°C in NA, CA (2 kPa O2 + 0.7 kPa CO2) and DCA (0.7 kPa O2 + 0.3 kPa CO2). After 4 and 6 months storage, fruit were held up to 7 d at 20°C. Skin colour, firmness and EP were measured during shelf life and the incidence of disorders after 7 d. 1-MCP treatment drastically reduced EP, which began to recover after 7 d at 20°C, except for DCA stored pears. In control fruit, NA stored pears showed the highest EP. 1-MCP treated fruit were the greenest at the end of shelf-life, especially after CA and DCA. Control fruit stored in DCA and in CA were greener than NA both at 1 d and 7 d of shelf life. Pears treated with 1-MCP did not soften during shelf life, while in control fruit firmness decreased from about 40 N to about 15-20 N, whatever the storage atmosphere. 1-MCP treatment prevented soft and superficial scald and internal breakdown, independently of storage atmosphere. DCA prevented superficial scald in control fruit, while it increased internal browning and breakdown in control and 1-MCP treated pears. No differences were found for soft scald incidence between control DCA and CA stored fruit. The highest percentage of sound fruit was found in NA stored 1-MCP treated pears, and the lowest in control fruit stored in DC

Influence of cold storage time on the softening prediction in Spring Bright nectarines

With Time-resolved Reflectance Spectroscopy (TRS) the maturity of nectarines at harvest can be assessed by measuring the absorption coefficient at 670 nm (µa 670) in the fruit flesh. A kinetic model has been developed linking the optical properties as measured by TRS with the models of µa 670 and firmness decay in shelf-life at 20°C, making the prediction of the softening time for individual fruit possible. In order to study the influence of cold storage time prior to shelf life on the softening prediction, 540 (year 2003) and 870 (year 2004) ‘Spring Bright’ nectarines were measured at harvest with TRS; then fruit were put in shelf life after various periods of cold storage at 0°C (4 and 10 d, year 2003; 6, 13 and 20 days, year 2004). During the 5-day period of shelf life at 20°C, fruit were analysed for firmness by pressure test after 30, 48, 54, 72, 78, 96, 102 and 120h in 2003 and after 36, 43, 62, 87, 108 and 135h in 2004. For each year and cold storage time, the parameters of the logistic model of softening as a function of µa 670 at harvest were computed. The cold storage up to 13 days did not significantly influence the estimates of the softening rate constant (kf), of the maximum firmness at minus infinite time (Fmax) and of parameter alpha (a) in both years, whereas parameter beta (ß) in 2003 significantly decreased from -1.867 at day 4 to -2.237 at day 10. The further 7 days of cold storage in 2004 significantly affected kf, which decreased from 0.00084 at days 6 and 13 to 0.00069 at day 20, and ß which increased from -2.395 at day 6 to -2.053 at day 20. Our results indicate that the cold storage time significantly influences the softening prediction of nectarines as the longer the cold storage, the lower the softening rat

TRS-measurements as a nondestructive method assessing stage of maturity and ripening in plum (Prunus domestica L.)

n plum fruit with dark red or blue blush colour covering the whole fruit, the change in ground colour from green to yellow during maturation and ripening is masked. Hence, the maturity stage is difficult to judge. Time-resolved reflectance spectroscopy (TRS) has been used as a nondestructive method to assess changes in important internal quality factors in ‘Jubileum’ plums (Prunus domestica L.). Absorption coefficients (µa) and scattering coefficients (µs) were measured at both 670 and 758 nm during 5 days of storage. The changes in soluble solids content, titratable acidity and firmness were as expected. No change in soluble solids content was observed, while the plums became less acid and softer during storage. The TRS-measurements of plums indicated that TRS could give interesting information on internal quality factors in plums as the absorption at 670 nm was closely related to firmness, TA and TSS at the time of picking. Absorption at 758 nm was more closely related to the quality parameters after storage. The study did not indicate that scattering could be used in assessing maturity stage in plum

Hawking Radiation as Tunneling: the D-dimensional rotating case

The tunneling method for the Hawking radiation is revisited and applied to the $D$ dimensional rotating case. Emphasis is given to covariance of results. Certain ambiguities afflicting the procedure are resolved.Comment: Talk delivered at the Seventh International Workshop Quantum Field Theory under the influence of External Conditions, QFEXT'05, september 05,Barcelona, Spain. To appear in Journal of Phys.

Ready to Eat Nectarines - Assuring Quality in the Chain

Time-resolved reflectance spectroscopy, coupled to the modelling of firmness decrease, was used to predict at harvest softening behaviour of nectarines. Selected fruit were used in an export trial from Italy to The Netherlands. Quality assessed after shelf life was in agreement with the predicted firmness for fruit of different stages of maturity, showing that it is possible to select fruit at harvest for different market destinations and prevent transportation of fruit unsuitable for consumption

On the semiclassical treatment of Hawking radiation

In the context of the semiclassical treatment of Hawking radiation we prove the universality of the reduced canonical momentum for the system of a massive shell self gravitating in a spherical gravitational field within the Painlev\'e family of gauges. We show that one can construct modes which are regular on the horizon both by considering as hamiltonian the exterior boundary term and by using as hamiltonian the interior boundary term. The late time expansion is given in both approaches and their time Fourier expansion computed to reproduce the self reaction correction to the Hawking spectrum.Comment: 18 pages, LaTeX, Corrected typo

Multi-match Packet Classification on Memory-Logic Trade-off FPGA-based Architecture

Packet processing is becoming much more challenging as networks evolve towards a multi-service platform. In particular, packet classification demands smaller processing times as data rates increase. To successfully meet this requirement, hardware-based classification architectures have become an area of extensive research. Even if Field Programmable Logic Arrays (FPGAs) have emerged as an interesting technology for implementing these architectures, existing proposals either exploit maximal concurrency with unbounded resource consumption, or base the architecture on distributed RAM memory-based schemes which strongly undervalues FPGA capabilities. Moreover, most of these proposals target best-match classification and are not suited for high-speed updates of classification rulesets. In this paper, we propose a new approach which exploits rich logic resources available in modern FPGAs while reducing memory consumption. Our architecture is conceived for multi-match classification, and its mapping methodology is naturally suited for high-speed, simple updating of the classification ruleset. Analytical evaluation and implementation results of our architecture are promising, demonstrating that it is suitable for line speed processing with balanced resource consumption. With additional optimizations, our proposal has the potential to be integrated into network processing architectures demanding all aforementioned features.http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6602301Fil: Zerbini, Carlos A. Universidad Tecnológica Nacional. Departamento de Ingeniería Electrónica; Argentina.Fil: Finochietto, Jorge M. Universidad Nacional de Córdoba. Consejo Nacional de Investigaciones Científicas y Técnicas. Laboratorio de Comunicaciones Digitales; Argentina.Ingeniería de Sistemas y Comunicacione

The extremal limit of D-dimensional black holes

The extreme limit of a class of D-dimensional black holes is revisited. In the static limit, it is shown that well defined extremal limiting procedure exists and it leads to new solutions of the type AdS2 times constant curvature symmetric spaces.Comment: 8 pages, proceedings of Londrina Conference, April 2000, Londrina, Brazi