Anthracnose is the main postharvest disease in papaya fruit. Today, there is considerable interest on alternative methods of control to promote resistance against pathogens and supplement or replace ...the use of fungicides. The goal of this work was to evaluate the effects of gamma and UV-C irradiation on
Colletotrichum gloeosporioides, the causal agent of anthracnose. Mycelial growth, sporulation, and conidial germination were evaluated
in vitro after fungal exposition to different irradiation doses. In the
in vivo assays, ‘Golden’ papaya fruit were inoculated through subcuticular injections of a conidial suspension or mycelium discs. Next, fruit were submitted to different irradiation doses (0, 0.12, 0.25, 0.5, 0.75, and 1
kGy), using Co
60 as source, or UV-C (0, 0.2, 0.4, 0.84, 1.3, and 2.4
kJ
m
−2). To check the possibility of resistance induction by irradiation, papayas were also inoculated 24, 48, or 72
h after the treatments. The fruit were stored at 25
°C/80% RH for 7 days and evaluated for incidence and rot severity. The results showed that the 0.75 and 1
kGy doses inhibited conidial germination and mycelial growth
in vitro. All doses increased fungal sporulation. The 0.75 and 1
kGy doses reduced anthracnose incidence and severity, but did not reduce them when the fruit were inoculated after irradiation. All UV-C doses inhibited conidial germination and those higher than 0.84
kJ
m
−2 inhibited mycelial growth. The 0.4, 0.84, and 1.3
kJ
m
−2 UV-C doses reduced fungal sporulation
in vitro. There was no effect of UV-C doses and time intervals between treatment and inoculation on anthracnose control and fungal sporulation in fruit lesions. Moreover, all UV-C doses caused scald on the fruit. Thus, gamma irradiation can contribute for the reduction of postharvest losses caused by anthracnose and reduce the use or doses of fungicides on disease control.
•The thermal stability of cyclopentane, in an organic Rankine cycle unit, is analysed numerically.•The case study is the Draugen offshore oil and gas platform in the Norwegian Sea.•A transient ...analysis is performed to identify hot spots during load variations.•Guidelines for safe and reliable operation of organic Rankine cycle units are suggested.
This paper is devoted to the investigation of critical dynamic events causing thermochemical decomposition of the working fluid in organic Rankine cycle power systems. The case study is the plant of an oil and gas platform where one of the three gas turbines is combined with an organic Rankine cycle unit to increase the overall energy conversion efficiency.
The dynamic model of the plant is coupled with a one-dimensional model of the once-through boiler fed by the exhaust thermal power of the gas turbine. The heat exchanger model uses a distributed cross-flow physical topology and local correlations for single- and two-phase heat transfer coefficients.
The results indicate that severe load changes (0.4–1.0MWs−1) can lead to exceedance of the temperature limit of fluid decomposition for a period of 10min. Ramp rates lower than 0.3MWs−1 are acceptable considering the stability of the electric grid and fluid decomposition. It is demonstrated that the use of a spray attemperator can mitigate the problems of local overheating of the organic compound.
As a practical consequence, this paper provides guidelines for safe and reliable operation of organic Rankine cycle power modules on offshore installations.
Gray mold caused by Botrytis cinerea is considered the major disease of greenhouse grown flowers. The goal of this study was to evaluate the effects of gibberellic acid (GA3), ozone, and 1-MCP, ...applied on postharvest, on the gray mold control in ‘Avant Garde’ rose. Rose flowers were artificially inoculated with B. cinerea (10(4) conidia ml-1) and non-inoculated. After treatments, roses were stored under room conditions (20±2°C/80±5% RH) and checked for gray mold incidence and severity. Spraying of GA3 at 25, 50, and 75 mg L-1 on non-inoculated roses reduced the area under the disease progress curve (AUDPC) of gray mold incidence in 41, 40 and 54%, respectively. Continuous application of ozone at 2.7 ppm reduced 14-folds B. cinerea sporulation. On the other hand, 1-MCP did not control gray mould in rose. These results showed that GA3 sprays and ozone contribute to postharvest control of gray mold in cut rose and can be utilized on integrated disease management.
In this paper, for the first time the threshold voltage instability of 100 V rated p-GaN power HEMTs is investigated by combined pulsed-IV measurements and capture and emission time (CET) maps, by ...investigating a remarkable time window of 9 decades, from 1 μs to 1000 s. After a statistical analysis to demonstrate the repeatability of the experimental results, pulsed IV characterization revealed the existence of a non-monotonic ΔVTH shift, as a function of the (positive) gate stress bias. To gain further insight on the positive threshold shift, CET map analysis has been carried out at different temperatures: the results provide relevant insight on the physical properties of the population of traps responsible for the VTH shift, most likely located at the AlGaN/GaN interface. In addition, the related capture and emission time-constant as a function of temperature are investigated, thus allowing to extract the activation energies for the trapping and de-trapping processes, and to propose a model for the trapping mechanisms.
•Power GaN HEMTs•Capture and Emission Time Map•Threshold voltage Shift•DCTS
The CRESST-III experiment aims at the direct detection of dark matter particles via their elastic scattering off nuclei in a scintillating CaWO
_4
4
target crystal. For many years CaWO
_4
4
crystals ...have successfully been produced in-house at Technische Universität München with a focus on high radiopurity. To further improve the CaWO
_4
4
crystals, an extensive chemical purification of the raw materials has been performed and the crystal TUM93 was produced from this powder. We present results from an
\alpha
α
-decay rate analysis performed on 344 days of data collected in the ongoing CRESST-III data-taking campaign. The
\alpha
α
-decay rate could significantly be reduced.
The CRESST experiment observes an unexplained excess of events at low energies. In the current CRESST-III data-taking campaign we are operating detector modules with different designs to narrow down ...the possible explanations. In this work, we show first observations of the ongoing measurement, focusing on the comparison of time, energy and temperature dependence of the excess in several detectors. These exclude dark matter, radioactive backgrounds and intrinsic sources related to the crystal bulk as a major contribution.
O manuseio inadequado e excessivo de frutas e de hortaliças causa alta incidência de danos físicos e, consequentemente, perdas pós-colheita. O objetivo deste trabalho foi avaliar a magnitude de ...impacto em linhas de beneficiamento e classificação para caqui "Rama Forte" e determinar, em laboratório, seus limites de impactos. Para a avaliação dos pontos críticos, foi utilizada uma esfera instrumentada de 76 mm de diâmetro (Techmark, Inc., Lansing, EUA), que registrou a magnitude dos impactos em sete equipamentos distintos de quatro unidades de beneficiamento. A determinação de danos físicos foi feita em testes laboratoriais, nos quais a queda dos frutos foi relacionada com a magnitude de impacto, incidência de danos físicos e perdas na qualidade do fruto. Nas linhas de beneficiamento, os valores de impactos encontrados variaram de 21 a 87 G nos pontos de transferência, e a maioria dos impactos registrados (acima de 94%) durante a passagem pela linha foram de valores de até 50 G. Alturas de queda a partir de 20 cm causaram aumento na perda de massa do caqui no sexto dia de armazenamento, em temperatura ambiente. As quedas de 20 e 30 cm causaram maior escurecimento da casca (menores valores de L), associada à redução da intensidade da cor (chroma). O impacto não causou efeito nas características químicas da polpa do fruto.Excessive and inadequate handling of fruits and vegetables provides high incidences of physical damage, consequently, post harvest losses. The main goal of this work was to evaluate the impact magnitude in persimmon packing lines, "Rama Forte", and to determine, at the laboratory, its impact limits. For evaluating the critical points it was used an instrumented sphere of 76 mm of diameter (Technmark, Inc, Lansing, USA), which registered the impact magnitude in seven distinctive impact lines located in four packing houses. For determining physical damages, tests were carried out at the laboratory, where fruit drop was related to impact magnitude, physical damage incidence and fruit post harvest losses. At the packing lines, the values found varied from 21 to 87 G on the transfer points and the majority of registered impacts (over 94%) were down 50G. Drops from 20 cm caused an increase in weight losses after six days of storage at room temperature. Drops from 20 and 30 cm caused skin darkness (low L values), associated to a decrease in color intensity (chroma). Impact drop did not affect pulp fruit chemical features.
Black spot, caused by Guignardia citricarpa, is one of the main diseases affecting citrus fruits. UV-C irradiation is known to have potential to be used as an alternative method to supplement or ...replace the use of fungicides, especially because it promotes resistance against pathogens. The aim of this work was to evaluate the in vitro effects of UV-C irradiation on G. citricarpa development and on the control of black spot in postharvest orange. Additionally, changes in skin color of the fruit as a result of UV-C treatment were evaluated. Mycelial growth, conidial germination and appressoria formation were evaluated in vitro after fungal exposure to different irradiation doses. Also, 'Valência' oranges naturally infected were submitted to different irradiation doses to check the possibility of in vivo control. Fruit were stored at 25ºC/80% RH and evaluated 3, 7, 10 and 14 days after treatment and area under the disease progress curve was calculated. UV-C irradiation affected conidial germination of G. citricarpa and apressorium formation. UV-C irradiation was not able to control citrus black spot on fruit at a satisfactory level; however, incidence of quiescent black spot lesions was lower on postharvest 'Valência' orange treated with 7.28 and 15.66 kJ m-2. Low UV-C doses did not affect the visual aspect of fruit. Thus, UV-C irradiation can contribute for the reduction of postharvest losses caused by citrus black spot and reduce the use or doses of fungicides on disease control.
Uso da cor da casca como indicador de qualidade do maracujá amarelo (Passiflora edulis Sims. f. flavicarpa Deg.) destinado à industrialização DE MARCHI, Renata(Universidade Estadual Paulista Faculdade de Ciências Farmacêuticas Departamento de Alimentos e Nutrição); MONTEIRO, Magali(Universidade Estadual Paulista Faculdade de Ciências Farmacêuticas Departamento de Alimentos e Nutrição); BENATO, Eliane A.(Instituto de Tecnologia de Alimentos Centro de Tecnologia de Hortifrutícolas) ...
Ciência e tecnologia de alimentos,
12/2000, Letnik:
20, Številka:
3
Journal Article
Recenzirano
Odprti dostop
As características físico-químicas do maracujá amarelo em três estádios de cor de casca (1/3 amarelo, 2/3 amarelo e inteiro amarelo), em quatro épocas da safra/99 foram avaliadas, visando estabelecer ...o ponto de colheita de melhor qualidade da fruta para a industrialização. Foram determinados o tamanho dos frutos, a cor da casca e da polpa, o rendimento de extração da polpa, o teor de sólidos solúveis totais, o pH, a acidez total, o ratio e o teor de vitamina C. Foi empregado o delineamento experimental inteiramente casualizado, com 8 repetições, 5 frutos por parcela e 3 tratamentos. Os resultados mostraram que o rendimento de polpa não apresentou diferença significativa entre os tratamentos e entre as colheitas. Com relação à cor da polpa, houve diferença significativa entre os três estádios apenas na 1ª colheita. Os frutos de casca 1/3 amarela apresentaram teor de sólidos solúveis significativamente inferior aos demais apenas na 3ª e 4ª colheitas, mas o maior valor médio ocorreu na 4ª colheita. O teor de acidez total dos frutos de casca inteira amarela foi significativamente inferior àqueles das colheitas 2, 3 e 4. Os valores mais elevados de vitamina C foram obtidos na 1ª colheita e, os frutos de casca 1/3 amarela apresentaram teores significativamente inferiores nas colheitas 1 e 2. De maneira geral, os resultados indicaram que, embora tenham ocorrido algumas diferenças nas características físico-químicas dos frutos nos diferentes estádios de cor de casca, frutos colhidos em todos os estádios de cor de casca estudados apresentaram-se adequados à industrialização.
Physico-chemical characteristics of yellow passion fruit, in three stages of peel color (1/3 yellow, 2/3 yellow and full yellow) were studied at four harvest times in 1999 to determine the optimum stage of peel color to industrialize the fruits. Fruit size, peel and pulp color, pulp yield, pH, total soluble solids and total acidity, ratio and vitamin C contents were determined. A completely randomized experimental design was used, with 8 repetitions, 5 fruit samples and 3 treatments. The pulp yield showed no statistical differences among stages or between crops. The pulp color showed statistical difference between the peel color stages only in the first crop. The 1/3 yellow-peel fruits showed lower total soluble solids than the other stages in the third and fourth crops, but the highest mean value was obtained in the fourth crop. The full yellow peel fruits’s total acidity was statistically lower than for the other stages in the second, third and fourth crops. Highest levels for vitamin C were obtained in the first crop, and the 1/3 yellow peel fruits showed lower vitamin C contents in the first and second crops. The results indicated that, although some physico-chemical differences have been observed during the harvest, fruits from all the stages and crops were considered suitable to be industrialized.
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