scholarly journals The Effect of Temperature, Light and Calcium Carbonate on Seed Germination and Radicle Growth of the Polycarpic Perennial Galium cracoviense (Rubiaceae), a Narrow Endemic Species From Southern Poland

2015 ◽  
Vol 57 (1) ◽  
pp. 70-81 ◽  
Author(s):  
Jeremi Kołodziejek ◽  
Jacek Patykowski

Abstract Germination responses of Galium cracoviense Ehrend. (Rubiaceae), a narrow endemic species from southern Poland, were tested in light and dark conditions at three constant temperatures (5, 10, or 22°C), before and after cold-wet stratification. Additionally, seeds were germinated under different calcium carbonate (CaCO3) concentrations (1, 5, 10, 15, 20, or 25 mM/L CaCO3) at 22°C in light. The high germination capacity of seeds incubated at different temperatures, shortly after collection, already suggested the absence of dormancy in this species. Thus, the seeds are ready to germinate immediately in the field when water resources are available and the temperature is adequate. Light was a significant factor for G. cracoviense; more seeds germinated in light than in darkness at all temperatures tested. Cold stratification decreased germination especially at higher temperatures. The light requirement for G. cracoviense germination ensures their successful germination on or near the soil surface, and in cracks and crevices in limestone, when temperature and edaphic conditions are favourable. Seeds of this species show temperature enforced dormancy throughout the winter. Germination was significantly affected by calcium carbonate. Non-germinated seeds germinated well after being transferred from higher CaCO3 concentrations to distilled water. The results indicate that the seeds of this species can endure CaCO3 stress without losing their viability and start germination once CaCO3 concentration is reduced. It can be concluded that the seeds of this species require lower Ca2+ ion concentration, moderate temperatures and the presence of light to germinate.

2021 ◽  
Vol 9 (1) ◽  
pp. 248-256
Author(s):  
J.A. dos Santos ◽  
R.C. Tucunduva ◽  
J.R.M. D’Almeida

Polymer pipes are being widely used by many industrial segments. Although not affected by corrosion, the mechanical performance of these pipes can be reduced due to exposure to temperature, UV radiation and by contact with various fluids. Depending on the deterioration process, embrittlement or plasticization may occur, and the service life of the pipe can be severely reduced. In this work, the combined action of temperature and water upon the mechanical performance of polyamide 12 and high-density polyethylene pipes is evaluated. Destructive and non-destructive techniques were used and the performance of both materials was compared. Both polymers were platicized by the effect of water. However, for high density polyethylene the effect of temperature was more relevant than for polyamide. This behavior was attributed to the dependence of the free volume with the markedly different glass transition temperature of the polymers and the temperatures of testing.


2015 ◽  
Vol 814 ◽  
pp. 552-558
Author(s):  
Ya Qing Liang ◽  
Hong Juan Sun ◽  
Tong Jiang Peng

Spherical calcium carbonate (CaCO3) is a potential component in many industrial fields such as high-grade papermaking, high-grade painting, environment, and pesticide. This paper describes a novel approach to synthesize spherical calcium carbonate (CaCO3) particles via passing CO2 bubbles into phosphogypsum salt leaching solution (CaSO4) in the presence of ammonia (NH3) at different temperatures. The influence of the initial solution pH and concentration of calcium ions on the polymorph and morphology of CaCO3 was studied. The physical characteristics of the precipitate were evaluated using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that compared with different calcium sources the phase and morphology of CaCO3 synthesized by phosphogysum leaching solution had some regularity. The grain size of spherical CaCO3 became bigger, surface became smoother, and particle dispersion became better with the increase of calcium ion concentration. The content of vaterite increased and particle grain size changed a little with the increase of pH. The research results had important environmental significance for phosphogysum resource utilization and CO2 fixation.


1935 ◽  
Vol 12 (4) ◽  
pp. 297-305
Author(s):  
DANIEL MERRIMAN

1. The eggs of the cut-throat trout (Salmo clarkii clarkii Richardson) were raised from fertilisation through hatching at constant temperatures of 11.3, 8.25 and 6.35°C. These temperatures are well within the limits of normal development of cut-throat trout. 2. The temperature is not the limiting factor in determining the length of the hatching period, because there are a number of other factors that may cause eggs to hatch either prematurely early or abnormally late, and thus the use of the hatching period as a comparable stage of development for eggs raised at different temperatures may result in error. 3. The average size of cut-throat trout embryos at the moment of hatching was smaller at the higher temperatures and larger at the lower temperatures. 4. The maximum increment of growth in the cut-throat trout occurred about the 41st day at 8.25°C. and about the 28th day at 11.3°C. 5. The percentage of dry weight of the cut-throat trout embryos showed a steady decrease from about 25 to 14 per cent., while that of the yolks showed an increase from about 46 to 55 per cent. 6. Cut-throat trout embryos absorbed water from the yolk and also, at a faster rate, from the environment, both somewhat before and after hatching, so that the percentage of wet weight of the larvae was steadily increasing up to the time the experiment was completed.


2021 ◽  
pp. 096703352098236
Author(s):  
M Gonçalves ◽  
NT Paiva ◽  
JM Ferra ◽  
J Martins ◽  
F Magalhães ◽  
...  

Quality control of amino resins must be based on reproducible and rapid methods. Fourier-transform near infrared spectroscopy (FT-NIR) has been gaining increasing interest in this context. However, it is not always possible to perform the analysis under the same conditions. Temperature and storage time, in particular, are two factors that often vary. However, their influence on the FT-NIR results is not yet well understood. This work describes how temperature and resin ageing affect the near infrared spectra of amino resins. It is shown that a previously calibrated near infrared model to assess the molar ratio of amino resins has a linear response with temperature. To counter-act this effect and improve the speed of analysis, the spectral pre-processing of extended multiplicative scattering correction was used in conjunction with the loadings of water at different temperatures. This procedure was able to diminish the dependency of the model in relation to temperature for two amino resins (an R2 above 95 % of a linear fit went down to below 1%). With respect to the ageing of amino resins, NIR spectra of two resins were examined for a period of 9 days. It was found that the spectra are influenced by the continuation of the condensation reactions and the formation of aggregates, which causes increase in absorbance with resin ageing. This was proven by checking the differences between NIR spectra of amino resins before and after being subjected to ultrasonic treatment to promote deagglomeration.


Author(s):  
D. T. Gauld ◽  
J. E. G. Raymont

The respiratory rates of three species of planktonic copepods, Acartia clausi, Centropages hamatus and Temora longicornis, were measured at four different temperatures.The relationship between respiratory rate and temperature was found to be similar to that previously found for Calanus, although the slope of the curves differed in the different species.The observations on Centropages at 13 and 170 C. can be divided into two groups and it is suggested that the differences are due to the use of copepods from two different generations.The relationship between the respiratory rates and lengths of Acartia and Centropages agreed very well with that previously found for other species. That for Temora was rather different: the difference is probably due to the distinct difference in the shape of the body of Temora from those of the other species.The application of these measurements to estimates of the food requirements of the copepods is discussed.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aiyan Guan ◽  
Inge Van Damme ◽  
Frank Devlieghere ◽  
Sarah Gabriël

AbstractAnisakidae, marine nematodes, are underrecognized fish-borne zoonotic parasites. Studies on factors that could trigger parasites to actively migrate out of the fish are very limited. The objective of this study was to assess the impact of different environmental conditions (temperature, CO2 and O2) on larval motility (in situ movement) and mobility (migration) in vitro. Larvae were collected by candling or enzymatic digestion from infected fish, identified morphologically and confirmed molecularly. Individual larvae were transferred to a semi-solid Phosphate Buffered Saline agar, and subjected to different temperatures (6 ℃, 12 ℃, 22 ℃, 37 ℃) at air conditions. Moreover, different combinations of CO2 and O2 with N2 as filler were tested, at both 6 °C and 12 °C. Video recordings of larvae were translated into scores for larval motility and mobility. Results showed that temperature had significant influence on larval movements, with the highest motility and mobility observed at 22 ℃ for Anisakis spp. larvae and 37 ℃ for Pseudoterranova spp. larvae. During the first 10 min, the median migration of Anisakis spp. larvae was 10 cm at 22 ℃, and the median migration of Pseudoterranova spp. larvae was 3 cm at 37 ℃. Larval mobility was not significantly different under the different CO2 or O2 conditions at 6 °C and 12 ℃. It was concluded that temperature significantly facilitated larval movement with the optimum temperature being different for Anisakis spp. and Pseudoterranova spp., while CO2 and O2 did not on the short term. This should be further validated in parasite-infected/spiked fish fillets.


Toxins ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 134
Author(s):  
Ana Isabel Galván ◽  
Alicia Rodríguez ◽  
Alberto Martín ◽  
Manuel Joaquín Serradilla ◽  
Ana Martínez-Dorado ◽  
...  

Dried fig is susceptible to infection by Aspergillus flavus, the major producer of the carcinogenic mycotoxins. This fruit may be contaminated by the fungus throughout the entire chain production, especially during natural sun-drying, post-harvest, industrial processing, storage, and fruit retailing. Correct management of such critical stages is necessary to prevent mould growth and mycotoxin accumulation, with temperature being one of the main factors associated with these problems. The effect of different temperatures (5, 16, 25, 30, and 37 °C) related to dried-fig processing on growth, one of the regulatory genes of aflatoxin pathway (aflR) and mycotoxin production by A. flavus, was assessed. Firstly, growth and aflatoxin production of 11 A. flavus strains were checked before selecting two strains (M30 and M144) for in-depth studies. Findings showed that there were enormous differences in aflatoxin amounts and related-gene expression between the two selected strains. Based on the results, mild temperatures, and changes in temperature during drying and storage of dried figs should be avoided. Drying should be conducted at temperatures >30 °C and close to 37 °C, while industry processing, storage, and retailing of dried figs are advisable to perform at refrigeration temperatures (<10 °C) to avoid mycotoxin production.


Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Guanghui Jiang ◽  
Jianping Zuo ◽  
Teng Ma ◽  
Xu Wei

Understanding the change of permeability of rocks before and after heating is of great significance for exploitation of hydrocarbon resources and disposal of nuclear waste. The rock permeability under high temperature cannot be measured with most of the existing methods. In this paper, quality, wave velocity, and permeability of granite specimen from Maluanshan tunnel are measured after high temperature processing. Quality and wave velocity of granite decrease and permeability of granite increases with increasing temperature. Using porosity as the medium, a new wave velocity-permeability model is established with modified wave velocity-porosity formula and Kozeny-Carman formula. Under some given wave velocities and corresponding permeabilities through experiment, the permeabilities at different temperatures and wave velocities can be obtained. By comparing the experimental and the theoretical results, the proposed formulas are verified. In addition, a sensitivity analysis is performed to examine the effect of particle size, wave velocities in rock matrix, and pore fluid on permeability: permeability increases with increasing particle size, wave velocities in rock matrix, and pore fluid; the higher the rock wave velocity, the lower the effect of wave velocities in rock matrix and pore fluid on permeability.


2010 ◽  
Vol 96 ◽  
pp. 35-40 ◽  
Author(s):  
Yan Ding ◽  
Jun Ping Meng ◽  
Xu Hong Zhang ◽  
Li Juan Wang ◽  
Qing Guo Tang

Multiple copper-zinc alloy was used to treat water in order to restrict the formation of hard scale during heating process. Trace amounts of metal ions were dissolved from the alloy under the action of tiny battery corrosion, which took part in the crystallization of calcium carbonate crystal. The ion migration rules and its effect on the crystal structure of water scale were studied. The ICP test results show that after immersion in the water for 20 min, the zinc ion concentration increased to 0.35 mg•L-1 compared with contrast group. The simulating experiment of the scale crystal growth demonstrated that the calcium carbonate scale after treated with the alloy showed a transformation from calcite to aragonite, and the ratio of calcite to aragonite changed from 1:0.125 to 1:2.30. Meanwhile, the heat transfer efficiency was increased to 2.19%.


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