Effects of high temperature on the growth and composition of sugarcane internodes

2006 ◽  
Vol 57 (10) ◽  
pp. 1087 ◽  
Author(s):  
G. D. Bonnett ◽  
M. L. Hewitt ◽  
D. Glassop
Keyword(s):  
High Temperature ◽  
Soluble Sugars ◽  
Dry Mass ◽  
Temperature Treatment ◽  
Sucrose Content ◽  
Insoluble Fibre ◽  
Higher Temperature ◽  
Lower Temperature ◽  
Leaf Appearance ◽  
Possible Cause

Sugarcane grown in the Ord River district of Western Australia has lower sucrose content than expected from earlier trials and experience in other irrigated districts. High temperatures have been hypothesised as a possible cause. The effects of high temperature (above 32°C) on growth and carbon partitioning were investigated. A temperature regime of (25–38°C) was compared with (23–33°C). In one experiment, 7-month-old plants of cvv. Q117 and Q158 were subjected to the treatments for 2 months. In another experiment, the plants were allowed to regrow (ratoon) for 6 months. In both experiments, the higher temperature resulted in more, shorter internodes and higher moisture content. Most internodes from plants in the higher temperature treatment had lower sucrose content than internodes from the lower temperature. On a dry mass basis the internodes from the plants in the higher temperature had proportionately more fibre and hexoses but lower sucrose. Combined with an increased number of nodes in a stem of similar or shorter length this would result in higher stalk fibre and lower sucrose content. The data provided evidence that sugarcane partitions less carbon to stored sucrose when grown under high compared with low temperatures. The two cultivars partitioned carbon between soluble (sugars) and insoluble (fibre) fractions to different degrees. These experiments also indicate that the current models describing leaf appearance and perhaps sugarcane growth at temperatures above 32°C, in general, need revision.

Evidence for inhibitor involvement in thermodormancy of Grand Rapids lettuce seeds

1991 ◽  
Vol 1 (4) ◽  
pp. 263-267 ◽  
Author(s):  
J. G. Chris Small ◽  
Yitzchak Gutterman
Keyword(s):  
High Temperature ◽  
Temperature Treatment ◽  
Small Extent ◽  
High Temperature Treatment ◽  
Ultraviolet Region ◽  
Distilled Water ◽  
Osmotic Effect ◽  
Lettuce Seeds ◽  
Grand Rapids ◽  
Lower Temperature

AbstractProlonged imbibition and incubation of lettuce seeds at a supraoptimal temperature induces secondary dormancy. Such seeds no longer germinate when returned to conditions optimal for germination of non-dormant seeds. The possibility that inhibitors are involved in the induction of thermodormancy was investigated.Washing of thermodormant seeds restored germination to a small extent. However, continuous leaching of seeds during high-temperature treatment with distilled water, largely prevented the induction of thermodormancy. Such seeds were qualitatively similar to nondormant seeds, i.e. they required only light to germinate at a lower temperature and germinated in the dark if given GA3. The germination water from thermodormant seeds inhibited the germination of non-dormant lettuce seeds. The inhibition was not an osmotic effect. Absorbance in the ultraviolet region was higher in germination water from thermodormant seeds than that of non-dormant seeds. It is concluded that inhibitors are involved in the induction of thermodormancy of lettuce seeds.

Study of mechanical properties and subsurface damage of quartz glass at high temperature based on MD simulation

2019 ◽  
Vol 04 (02) ◽  
pp. 1950003 ◽  
Author(s):  
Xiaoguang Guo ◽  
Chong Chen ◽  
Renke Kang ◽  
Zhuji Jin
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
High Temperature ◽  
Quartz Glass ◽  
Subsurface Damage ◽  
Simulation Based ◽  
Glass Model ◽  
Crystal Model ◽  
Higher Temperature ◽  
Lower Temperature

The mechanical properties (hardness, elastic modulus) and subsurface damage of quartz glass at high temperature are studied by nanoindentation simulation based on molecular dynamics (MD). By heating the quartz crystal model to 3000[Formula: see text]K and annealing to 300[Formula: see text]K twice, the quartz glass model is prepared. According to the nanoindentation simulation results, the hardness of quartz glass decreases by 53.6% and the elastic modulus increases by 10.9% at 1500[Formula: see text]K compared to those at 300[Formula: see text]K. When the temperature rises from 300[Formula: see text]K to 1500[Formula: see text]K, the critical grinding depth of quartz glass increases from nanoscale to micron-scale. The investigation of subsurface damage shows that the damaged layer thickness decreases slightly with the increase of temperature. The damaged layer extends downward under the indenter at lower temperature and extends along the indenter at higher temperature.

Crystallisation of amorphous Mg-Fe silicates produced from microwave-dried sol-gels

2019 ◽  
Vol 15 (S350) ◽  
pp. 408-409
Author(s):  
Stephen P. Thompson ◽  
Anna Herlihy ◽  
Claire A. Murray ◽  
Annabelle R. Baker ◽  
Sarah J. Day
Keyword(s):  
High Temperature ◽  
Powder Diffraction ◽  
Protoplanetary Disks ◽  
Activation Energies ◽  
X Ray ◽  
Higher Temperature ◽  
Lower Temperature

AbstractAmorphous Mg-Fe silicates are produced from microwave-dried sol-gels and their thermal crystallisation is studied via in situ synchrotron X-ray powder diffraction. Mg-pyroxene crystallised to forsterite, enstatite and cristobalite. The inclusion of 10% Fe formed only forsterite at much higher temperature, while pure Mg-olivine crystallised at a lower temperature than Mg-pyroxene. Cristobalite is observed as a high-temperature crystallite in the pure-Mg compositions. Crystallisation activation energies are derived and discussed in relation to protoplanetary disks.

scholarly journals Effect of high temperature stress on the performance of twelve sweet pepper genotypes

1970 ◽  
Vol 35 (3) ◽  
pp. 525-534 ◽  
Author(s):  
SR Saha ◽  
MM Hossain ◽  
MM Rahman ◽  
CG Kuo ◽  
S Abdullah
Keyword(s):  
High Temperature ◽  
Temperature Stress ◽  
Reproductive Behaviour ◽  
Sweet Pepper ◽  
High Temperature Stress ◽  
Fruit Weight ◽  
Temperature Regimes ◽  
Higher Temperature ◽  
Heat Tolerant ◽  
Lower Temperature

A study on heat tolerance in sweet pepper was conducted at the Asian Vegetable Research and Development Centre (AVRDC), Taiwan from December 1999 to May 2000. Experiments were carried out to investigate the influence of 29/23°C and 24/18°C stress on 12 sweet pepper genotypes on growth, development, reproductive behaviour and yield potentialities and to verify the results of the phytotron study. Performance of 12 sweet pepper genotypes was evaluated under two different temperature regimes of 24/18° C and 29/23° C in the phytotron. Plant height was found higher at 29/23° C compared to 24/18° C. High temperature reduced percent fruit set as well as size of fruits. Individual fruit weight was higher (7.44-125.00 g) when grown at 24/18°C and lower (5.35-103.80 g) at 29/23°C. Out of 12 genotypes, SP00l, SP002, SP004, and SP012 performed poor in respect of per plant yield at higher temperature compared to the lower temperature. So, these four genotypes were considered to be heat sensitive than the others. Leaf proline content of the sensitive genotypes decreased under the high temperature conditions and the heat tolerant lines produced higher amount of proline indicating the role of proline in expressing the heat tolerant capability of sweet pepper genotypes concerned. Keywords: High temperature stress; performance; sweet pepper. DOI: 10.3329/bjar.v35i3.6459Bangladesh J. Agril. Res. 35(3) : 525-534

scholarly journals The Coupled Effect of Temperature and Carbonation on the Corrosion of Rebars in the Simulated Concrete Pore Solutions

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Jiezhen Hu ◽  
Xuequn Cheng ◽  
Xiaogang Li ◽  
Peichang Deng ◽  
Gui Wang
Keyword(s):  
High Temperature ◽  
Electrochemical Impedance ◽  
Ph Value ◽  
Concrete Structures ◽  
Open Circuit ◽  
Effect Of Temperature ◽  
Coupled Effect ◽  
Latitude Region ◽  
Higher Temperature ◽  
Lower Temperature

The reinforced concrete structures have to survive high temperature and carbonation at low latitude region. The research on the effect of temperature and the effect of carbonation are vital to the corrosion of the rebars in concrete structures. The coupled effect of temperature and carbonation on the corrosion of rebars was researched by using the open circuit potential (OCP), the electrochemical impedance spectroscopy (EIS), and the potentiodynamic polarization (PP) measurement in the simulated concrete pore solutions (SPSs). The high temperature environment is conducive to the formation of passivated surface of rebars in SPSs, but the dissolution velocity of passivated surface is higher. The rebars have the greater capacity of passivity at lower temperature. The corrosion rate of rebars at higher temperature is smaller in moderate pH value (10.6) SPSs. The rebars suffer from serious corrosion in the pH = 9.6 SPSs at 318 K temperature.

Effects of filtration temperature, humic acid level and alum dose on cryptosporidium sized particle breakthrough

2006 ◽  
Vol 54 (11-12) ◽  
pp. 353-361
Author(s):  
G.R. Xu ◽  
C.S.B. Fitzpatrick ◽  
L.Y. Deng
Keyword(s):  
High Temperature ◽  
Humic Acid ◽  
Acid Level ◽  
Low Dose ◽  
Optimal Dose ◽  
Influence Of Temperature ◽  
Ζ Potential ◽  
Before And After ◽  
Higher Temperature ◽  
Lower Temperature

Recent Cryptosporidium outbreaks have highlighted concerns about filter efficiency and especially particle breakthrough. Understanding the causes of breakthrough is essential, as the parasite cannot be destroyed by conventional disinfection with chlorine. Particle breakthrough depends on many factors. This research aims to investigate the influence of temperature, humic acid (HA) level and chemical dosing on particle breakthrough in filtration. A series of temperatures were set at 5 °C, 15 °C and 25 °C; humic acid level was 5 mg L−1. Each was combined with a series of Al doses. A laser particle counter was used to assess the particle breakthrough online. Turbidity, ζ potential, and UV254 absorption were measured before and after filtration. The results showed that particle breakthrough was influenced significantly by temperature, humic acid and dosing. Particle breakthrough occurred earlier at lower temperature, while at higher temperature it was reduced at the same coagulant dose. With coagulants, even at low dose, particle breakthrough was significantly reduced. With HA 5 mg L−1, particle breakthrough was earlier and the amount was much larger than without HA even at high temperature. There was an optimal dose in filtration and it was well correlated with ζ potential.

scholarly journals Abiotic factors, not herbivorous pressure, are primarily responsible for the performance of an invasive aquatic plant

2018 ◽  
Vol 54 ◽  
pp. 12 ◽  
Author(s):  
Márcio José Silveira ◽  
Simon Chollet ◽  
Gabrielle Thiébaut ◽  
Sidinei Magela Thomaz
Keyword(s):  
Aquatic Plant ◽  
Abiotic Factors ◽  
Dry Mass ◽  
Superior Performance ◽  
Exotic Plant ◽  
Biotic Factors ◽  
Introduced Range ◽  
Invasive Aquatic Plant ◽  
Higher Temperature ◽  
Lower Temperature

Morphological performance of invasive plants can be determined by abiotic factors (e.g. water temperature) and biotic factors (e.g. herbivory). This study investigates the performance of an exotic plant in its native and introduced environments. The questions of study are: Is the performance of Egeria densa in both its native and introduced areas associated with abiotic and/or biotic factors? Is the performance of this plant better in the native or in the introduced area? In order to answer these questions, E. densa individuals collected in France (introduced range) were compared with individuals collected in Brazil (native range). The results demonstrate that E. densa populations sampled in its native areas included a higher percentage of plants grazed than in the introduced range populations, but they also exhibited a superior performance in terms of length and dry mass. In both regions, the performance of the plants was associated mainly with abiotic factors. Whereas the higher temperature in its native area may have promoted greater growth in terms of length and dry mass, a lower temperature and high levels of ammonium in French waters might have reduced the development of this plant in its introduced range. The lower performance of E. densa in France should not be associated with abiotic factors alone, since other factors can also be involved, as limited resources or low clonal adaptation. Thus, future studies concerning E. densa performance in France should consider these factors in order to assist in understanding the nature of the plant’s invasiveness in this region.

scholarly journals Back-reacted saponite in Jurassic mudstones and limestones intruded by a Tertiary sill, Isle of Skye

Clay Minerals ◽  
2005 ◽  
Vol 40 (3) ◽  
pp. 263-282 ◽  
Author(s):  
S. J. Kemp ◽  
C. A. Rochelle ◽  
R. J. Merriman
Keyword(s):  
High Temperature ◽  
Thermal Effects ◽  
Mineral Assemblage ◽  
Fracture System ◽  
Detailed Understanding ◽  
Higher Temperature ◽  
Lower Temperature ◽  
Host Rocks ◽  
Grossular Garnet ◽  
Isle Of Skye

AbstractThe Lòn Ostatoin stream section, Trotternish Peninsula, Isle of Skye, exposes a sequence of Middle Jurassic mudstones and limestones which have been locally metasomatized by a transgressive sill of Tertiary age. Limestones in the sequence, including some previously reported as bentonite, have been altered to an unusual assemblage of grossular garnet and saponite clay. The mudstones also contain large proportions of saponite together with pyroxene and zeolites. Saponite also occurs within the basalt intrusion. Grossular and pyroxene represent artifacts of relatively high-temperature assemblages that formed during an early phase of alteration. As the intrusion and adjacent altered country rocks cooled, lower-temperature fluids flowed through a late set of contraction (micro)fractures. Back-reacted saponite, analcime and clinoptilolite were formed, possibly as alteration products of the unstable higher-temperature minerals. The lower-temperature mineral assemblage eventually sealed the late fracture system.This paper highlights an important concept for the study of analogue sites used to investigate thermal effects on engineered liners or barrier host rocks for the landfill and radioactive-waste industries. This is that the original thermally altered mineral assemblage may be overprinted by later, lower-temperature back-reactions. A detailed understanding of both processes is necessary in order to construct a sensible model for the thermal and mineralogical evolution of the site.

scholarly journals Exogenous spermidine enhances the photosynthetic and antioxidant capacity of rice under heat stress during early grain-filling period

2018 ◽  
Vol 45 (9) ◽  
pp. 911 ◽  
Author(s):  
She Tang ◽  
Haixiang Zhang ◽  
Ling Li ◽  
Xia Liu ◽  
Lin Chen ◽  
...  
Keyword(s):  
High Temperature ◽  
Antioxidant Capacity ◽  
Temperature Stress ◽  
Soluble Sugars ◽  
High Temperature Stress ◽  
Temperature Treatment ◽  
High Temperature Treatment ◽  
Japonica Rice ◽  
Rice Varieties ◽  
Fluorescence Maximum

High temperature has adverse effects on rice growth by inhibiting the flag leaf photosynthetic and antioxidant capacity, which can be alleviated by various exogenous chemicals such as spermidine (Spd). However, the role of Spd in conferring heat tolerance in rice is not well documented. Conventional japonica rice varieties Wuyunjing 24 and Ningjing 3 were treated with high temperatures at 37.5/27.0°C (day/night) and foliar sprayed with 1 mmol L−1 Spd after flowering. Results showed activities of superoxide dismutase (SOD) and peroxidase (POD) activities were deceased during high temperature treatment and eventually lead to the malondialdehyde (MDA) accumulation. Exogenous Spd significantly increased both SOD and POD activities at the later stage of high-temperature treatment, and reduced MDA accumulation were identified in both rice varieties. Application of Spd further increased the amount of soluble sugars during high temperature stress and that maintained the osmotic equilibrium of rice leaves. Spd significantly increased photosystem II (ΦPSII), photosynthetic electron transport rate (ETR), variable fluorescence/maximum fluorescence ratio (Fvʹ/Fmʹ), stomatal conductance and the photochemical reaction of light energy ratio (Pr), and ultimately improved the photosynthetic and transpiration rate during high temperature stress. In conclusion, exogenous Spd can effectively alleviate the adverse consequences of high temperature and could be further applied to provide strategies in mitigating the challenges of global warming-induced yield loss and other possible relevant issues.

Effect of Thermal Treatment on the EPR Spectrum and on Catalytic Properties of Pure Co3O4

1996 ◽  
Vol 50 (11) ◽  
pp. 1395-1398 ◽  
Author(s):  
C. Oliva ◽  
L. Forni ◽  
L. Formaro
Keyword(s):  
Thermal Treatment ◽  
Specific Activity ◽  
Temperature Treatment ◽  
Epr Spectrum ◽  
Exchange Effect ◽  
Paramagnetic Resonance ◽  
Oxygen Excess ◽  
Higher Temperature ◽  
Lower Temperature ◽  
Electron Paramagnetic

Thermal treatment of Co3O4 decreases the number of cationic vacancies by reducing the oxygen excess in the “as prepared” sample. Correspondingly, a narrower Lorentzian-shaped EPR line is detectable after higher temperature treatment, because of a more efficient Co–O–Co super-exchange effect, favored by the Co2+ enrichment of the sample. Furthermore, the linewidth increases linearly with electron paramagnetic resonance (EPR) recording temperature. We attribute this effect to the onset of antisymmetric exchange in layer-like structures. Catalytic activity tests have been carried out at 323, 373, and 423 K on oxidation of CO by air oxygen as a probe reaction. Samples calcined at 536 and 773 K were tested. Both the catalysts proved to be practically inactive at 323 K. However, at 423 K the specific activity of the catalyst calcined at higher temperature was approximately twice as high as that shown by the sample calcined at lower temperature. Also, this effect has been attributed to the enrichment in Co2+ ions, which would act as catalytic centers when located at the solid surface.

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