scholarly journals Fotoblastismo e temperaturas na germinação de sementes de celosias

2018 ◽  
Vol 24 (4) ◽  
pp. 408-414
Author(s):  
Janine Farias Menegaes ◽  
Geovana Facco Barbieri ◽  
Rogério Antônio Bellé ◽  
Ubirajara Russi Nunes
Keyword(s):  
Moisture Content ◽  
Environmental Conditions ◽  
Laboratory Tests ◽  
Average Moisture Content ◽  
Limiting Factor ◽  
Thermal Range ◽  
Celosia Argentea ◽  
Different Temperatures ◽  
Presence And Absence ◽  
Cold Chamber

Germination is the result of the triggering of various processes occurred in the seed, which are influenced by the environmental conditions, especially light and temperature. In this way, the objective of the present study was to evaluate the influence of different temperatures and photoblastic on the germination of cockscomb seeds. The experiment was carried out in a completely randomizeddesign, with a 2 x 5 factorial scheme (two lighting regimes and five temperatures), with four replicates of 50 seeds, for two species of cockscomb (Celosia argentea L. and C. cristata L.). The lighting regimes were with absence (dark continuous) and the presence of light (photoperiod of 24 h), and temperatures were constant at 15, 20, 25, 30 and 35 ºC. The seed lots of the two species of cockscomb were cultivated in 2012 and stored in a cold chamber (15 ºC and 40% RH), with an average moisture content of 11% and a mean germination of 98%. The results of the laboratory tests indicated that the two species of cockscomb presented fast germination in average 2.5 and 4.5 days for the regimes with presence and absence of illumination, respectively, characterizing as neutral photoblastic species. However, it was observed that the temperature is a limiting factor for the germination of the two species of cockscomb, having its optimal thermal range between 20 and 30 ºC.

scholarly journals Qualidade fisiológica e sanitária de sementes de celosias armazenadas por diferentes períodos

2019 ◽  
Vol 25 (1) ◽  
pp. 34-41
Author(s):  
Janine Farias Menegaes ◽  
Geovana Facco Barbieri ◽  
Rogério Antônio Bellé ◽  
Ubirajara Russi Nunes
Keyword(s):  
Moisture Content ◽  
Relative Frequency ◽  
Average Moisture Content ◽  
Kraft Paper ◽  
Randomized Design ◽  
Celosia Argentea ◽  
Celosia Cristata ◽  
Completely Randomized Design ◽  
Cold Chamber

The objective was to evaluate the physiological and sanitary quality of cockscomb seeds stored for different periods. The experiment was conducted in a completely randomized design, with a 2x5 factorial scheme (two species of cockscomb: Celosia argentea L. and Celosia cristata L., and five seed lots with different storage periods: 0, 4, 8, 12 and 16 years, from the date of harvest) with four replicates. After harvesting each batch of seeds, in their respective years, they were stored with an average moisture content of 11% and average germination of 98% in cold chamber in packages of Kraft paper (15 ºC and 40% RH). It was observed that the average vigor (first count of germination) of the seeds of the two species of cockscomb was 88%, and the average germination of normal seedlings was 89 and 96% for the C. argentea and C. cristata species, respectively, with mean germination of 2.9 days for all storage periods. The relative frequency demonstrated homogeneity in the germination of the two species of cockscomb maintaining germinative viability in all periods of storage. It is concluded that the physiological potential and sanitary quality of the seeds of the C. argentea and C. cristata were preserved for periods ranging from zero to sixteen years of storage.

scholarly journals Envelhecimento acelerado de sementes de Celosia argentea e Celosia cristata

2018 ◽  
Vol 24 (4) ◽  
pp. 459-465
Author(s):  
Janine Farias Menegaes ◽  
Geovana Facco Barbieri ◽  
Rogério Antônio Bellé ◽  
Ubirajara Russi Nunes ◽  
Tiéle Stucker Fernandes ◽  
...  
Keyword(s):  
Heat Exposure ◽  
Accelerated Aging ◽  
Average Moisture Content ◽  
Randomized Design ◽  
Accelerated Aging Test ◽  
Aging Test ◽  
Celosia Argentea ◽  
Celosia Cristata ◽  
Two Temperatures ◽  
Cold Chamber

Celosia argentea L. and Celosia cristata L. are plants that are differentiated by the intensity and color of their flowering, and can be used as garden or cut-flower, with characteristic propagation by seeds produced in large quantities. The present study aimed to evaluate the physiological and sanitary quality of Celosia argentea and Celosia cristata seeds subjected to the accelerated aging test. The experiment was carried out in October 2016, using a completely randomized design, in a 2 × 6 factorial scheme (two temperatures: 41 and 45 oC and six periods of heat exposure: 0 (control), 24, 48, 72, 96 and 120 h), with four replicates of 50 seeds, for the two species of cockscomb (C. argentea and C. cristata). The seed lots of the two species of celosia are from the crops in the year 2012 and were stored in a cold chamber (15 oC and 40% RH), with an average moisture content of 11% and a mean germination of 98%. After the accelerated aging test, the physiological and sanitary qualities of the seeds of the two species of celosia were evaluated. We conclude that the accelerated aging proved to be effective for the evaluation of vigor, germination and emergence in the species field, when submitted to temperatures of 41 and 45 oC up to 120 h.

Drying of Oblate Spheroidal Solids via Model Based on the Non-Equilibrium Thermodynamics

2020 ◽  
Vol 25 ◽  
pp. 83-98 ◽  
Author(s):  
J.C. Soares de Melo ◽  
R. Soares Gomez ◽  
J.B. Silva Júnior ◽  
A.X. Mesquita de Queiroga ◽  
R. Lima Dantas ◽  
...  
Keyword(s):  
Moisture Content ◽  
Complex Geometry ◽  
Transport Coefficients ◽  
Irreversible Processes ◽  
Average Moisture Content ◽  
Vapor Flux ◽  
Model Based ◽  
Oblate Spheroidal ◽  
Different Temperatures ◽  
Temperature Liquid

Food drying is one of the most used methods of preservation. To accurately describe moisture migration within biological products (grains, fruits, vegetables, etc.) during drying and explain the effects of this process on the quality of the material, have been proposed several mathematical models, but few incorporate the phenomena of simultaneous heat and mass transport applied to complex geometry. In this sense, this paper aims to present a mathematical model, based on the thermodynamics of irreversible processes to describe the heat and mass transfer (liquid and vapor) during the drying of bodies with oblate spheroidal geometry. This model was applied to describe drying of lentil, considering the variables transport coefficients and equilibrium conditions at the surface of the solid. Results of the average moisture content, average temperature, liquid flux, vapor flux, and moisture content and temperature distributions inside a lentil kernel during drying process, at different temperatures (40 and 60 oC) were presented and analyzed.

Water Absorption in Caroá-Fiber Reinforced Polymer Composite at Different Temperatures: A Theoretical Investigation

2017 ◽  
Vol 10 ◽  
pp. 16-27 ◽  
Author(s):  
C.J. Silva ◽  
A.G. Barbosa de Lima ◽  
E. Gomes da Silva ◽  
T.H.F. de Andrade ◽  
R.Q. da Costa Melo
Keyword(s):  
Moisture Content ◽  
Water Absorption ◽  
Water Uptake ◽  
Unsaturated Polyester ◽  
Average Moisture Content ◽  
Internal Stresses ◽  
Ansys Cfx ◽  
Different Temperatures ◽  
Higher Temperature ◽  
Uptake Studies

Water uptake studies of composite materials reinforced with vegetable fibers shows that they are highly sensitive to environmental influences such as water and temperature. The presence of moisture leads to impregnation and imperfect interfacial fiber-matrix adhesion, which generate internal stresses porosity and premature system failure. Accordingly, the aim of this work is to study theoretically water absorption in unsaturated polyester composites reinforced with caroá fiber (Neoglaziovia Variegata) at 25, 50 and 70°C by using a transient 3D mathematical model via ANSYS CFX® Software. The samples has composition 30% caroá fiber/70% unsaturated polyester resin and dimensions 6 x 20 x 20 mm3. Results of the average moisture content and moisture content distribution during the water uptake are presented and analyzed. Comparison between numerical and experimental data of the average moisture content showed good agreement. It can be concluded that the water absorption rate is faster in the vertex region of the composites, and mainly at higher temperature.

scholarly journals Cherry Tomato Drying: Sun versus Convective Oven

Horticulturae ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 40
Author(s):  
Vincenzo Alfeo ◽  
Diego Planeta ◽  
Salvatore Velotto ◽  
Rosa Palmeri ◽  
Aldo Todaro
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
Drying Process ◽  
Drying Time ◽  
Oven Drying ◽  
Sun Drying ◽  
Different Temperatures ◽  
Final Water Content ◽  
Drying Curves ◽  
Drying Conditions

Solar drying and convective oven drying of cherry tomatoes (Solanum lycopersicum) were compared. The changes in the chemical parameters of tomatoes and principal drying parameters were recorded during the drying process. Drying curves were fitted to several mathematical models, and the effects of air temperature during drying were evaluated by multiple regression analyses, comparing to previously reported models. Models for drying conditions indicated a final water content of 30% (semidry products) and 15% (dry products) was achieved, comparing sun-drying and convective oven drying at three different temperatures. After 26–28 h of sun drying, the tomato tissue had reached a moisture content of 15%. However, less drying time, about 10–11 h, was needed when starting with an initial moisture content of 92%. The tomato tissue had high ORAC and polyphenol content values after convective oven drying at 60 °C. The dried tomato samples had a satisfactory taste, color and antioxidant values.

scholarly journals Influence of Temperature and Moisture Content on Thermal Performance of Green Roof Media

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2421
Author(s):  
Bohan Shao ◽  
Caterina Valeo ◽  
Phalguni Mukhopadhyaya ◽  
Jianxun He
Keyword(s):  
Thermal Conductivity ◽  
Moisture Content ◽  
Green Roof ◽  
Green Roofs ◽  
Power Functions ◽  
Thick Substrate ◽  
Different Temperatures ◽  
Test Cells ◽  
Substrate Moisture ◽  
Phase Transition Zone

The influence of moisture content on substrate thermal conductivity at different temperatures was investigated for four different commercially available substrates for green roofs. In the unfrozen state, as moisture content increased, thermal conductivity increased linearly. In the phase transition zone between +5 and −10 °C, as temperature decreased, thermal conductivity increased sharply during the transition from water to ice. When the substrate was frozen, thermal conductivity varied exponentially with substrate moisture content prior to freezing. Power functions were found between thermal conductivity and temperature. Two equally sized, green roof test cells were constructed and tested to compare various roof configurations including a bare roof, varying media thickness for a green roof, and vegetation. The results show that compared with the bare roof, there is a 75% reduction in the interior temperature’s amplitude for the green roof with 150 mm thick substrate. When a sedum mat was added, there was a 20% reduction in the amplitude of the inner temperature as compared with the cell without a sedum mat.

Heat and Mass Diffusion Including Shrinkage and Hygrothermal Stress during Drying of Holed Ceramics Bricks

2011 ◽  
Vol 312-315 ◽  
pp. 971-976 ◽  
Author(s):  
J. Barbosa da Silva ◽  
G. Silva Almeida ◽  
W.C.P. Barbosa de Lima ◽  
Gelmires Araújo Neves ◽  
Antônio Gilson Barbosa de Lima
Keyword(s):  
Moisture Content ◽  
Three Dimensional ◽  
Average Moisture Content ◽  
Stress Distributions ◽  
Drying Process ◽  
Convective Boundary ◽  
Volume Method ◽  
Hygrothermal Stress ◽  
Thermo Physical Properties ◽  
Good Agreement

The Aim of this Work Is to Present a Three-Dimensional Mathematical Modelling to Predict Heat and Mass Transport inside the Industrial Brick with Rectangular Holes during the Drying Including Shrinkage and Hygrothermalelastic Stress Analysis. the Numerical Solution of the Diffusion Equation, Being Used the Finite-Volume Method, Considering Constant Thermo-Physical Properties and Convective Boundary Conditions at the Surface of the Solid, it Is Presented and Analyzed. Results of the Temperature, Moisture Content and Stress Distributions, and Drying and Heating Kinetics Are Shown and Analyzed. Results of the Average Moisture Content and Surface Temperature of the Brick along the Drying Process Are Compared with Experimental Data (T = 80.0oC and RH = 4.6 %) and Good Agreement Was Obtained. it Was Verified that the Largest Temperature, Moisture Content and Stress Gradients Are Located in the Intern and External Vertexes of the Brick.

scholarly journals Investigations on the Effects of Seasonal Temperature Changes on the Electrical Resistance of Living Trees

Forests ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 550 ◽  
Author(s):  
Xiaoquan Yue ◽  
Lihai Wang ◽  
Xiaolong Shi ◽  
Mingxian Xu ◽  
Zhiming Zhu
Keyword(s):  
Moisture Content ◽  
Regression Model ◽  
Cross Sections ◽  
Electrical Resistance ◽  
Freezing Point ◽  
Seasonal Temperature ◽  
Populus Simonii ◽  
Standing Trees ◽  
Different Temperatures ◽  
The Cross

In order to use the electrical resistance method to accurately and timely detect and evaluate the internal decay defects of living trees, the effects of the seasonal temperature and moisture content on the electrical resistance of standing trees were investigated. At the Northeast Forestry University Experimental Forest Farm, Harbin, Heilongjiang Province of China, Populus simonii Populus simonii Carr. and Larix gmelinii (Rupr.) Rupr. were selected as the objects and the electrical resistance of standing trees was tested through different seasons from December 2016 to December 2017. Meanwhile, the effects of changes in the seasonal temperatures (−20 to −10 °C, −10 to −5 °C, −5 to 0 °C, 0 to 5 °C, 5 to 10 °C, 10 to 15 °C, 15 to 25 °C) as well as changes in the moisture content (MC) (Populus simonii, MC ≥ 103%; Larix gmelinii, MC ≥ 77.5%) on the electrical resistance in the cross-sections of living trees were studied. The influence of temperature at different moisture contents, the moisture content at different temperatures, and their combined effects on electrical resistance were analyzed, following which a regression model was also established. The obtained results indicated that ambient temperature had a significant effect on the average value of electrical resistance in the cross-section of living trees when temperatures were below the freezing point. There was a sudden discontinuity near the freezing point, and logR (logarithm value of electrical resistance) in the cross-sections of sound trees and decayed trees changed in a similar trend with variations in the temperature. While the effect of moisture content on logR in the cross-sections of threes was insignificant at different temperatures because of the moisture content above FSP (fiber saturation point). It indicated that the temperature and moisture content had interactive effects on logR in the cross-sections. The binary linear regression model between moisture content, temperature, and logR was highly fitted with a correlation coefficient (R2) higher than 0.8. The outcome of this investigation indicates that when non-destructive testing is performed on living trees using electrical resistance at different seasonal temperatures, the measured results need to consider both the temperature and moisture content. For practical work, it is not recommended to consider testing living trees near the freezing point temperature using the electrical resistive tomography. Below the freezing point, the electrical resistance changes with temperature greatly relative to the normal temperature. Therefore, when performing the detection of electrical resistance, it is necessary to calibrate the effects of temperature

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