scholarly journals Temperature influences water sorptivity of soil aggregates

2013 ◽  
Vol 61 (1) ◽  
pp. 84-87 ◽  
Author(s):  
Henryk Czachor ◽  
Ľubomír Lichner

Abstract The aim of this study was to determine the potential development of water sorptivity of soil aggregates by heating. Soil aggregates were sampled from arable layer of 5 Polish soils: Haplic Luvisol 1 from Czesławice, Haplic Luvisol 2 from Wierzchucinek, Haplic Cambisol from Felin, Gleyic Mollic Cambisol from Chylice, and Haplic Phaeozem from Grabiec. Three aggregates of each soil type with minimum diameter between 4 and 10 mm were heated in the oven for at least 3 hours at temperatures 20, 100, 200, 250, and 360ºC. After each temperature treatment the soil aggregates were conditioned at the room temperature for 16 hours. Laboratory measurements of water sorptivity of soil aggregates were performed under a negative tension h0 = -2 cm using tension infiltrometer. It was found that the exposure to temperatures between 100 and 200°C tends to decrease water sorptivity of aggregates from all the studied soils but one (Haplic Luvisol 1), followed by about two- to four-fold increase in water sorptivity for exposure to temperatures of 250°C (in Haplic Luvisol 1, Haplic Luvisol 2, and Haplic Phaeozem) or 360°C (in Haplic Cambisol and Gleyic Mollic Cambisol).

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1084
Author(s):  
Ivan N. Ivanov ◽  
Vilém Zachleder ◽  
Milada Vítová ◽  
Maria J. Barbosa ◽  
Kateřina Bišová

An increase in temperature can have a profound effect on the cell cycle and cell division in green algae, whereas growth and the synthesis of energy storage compounds are less influenced. In Chlamydomonas reinhardtii, laboratory experiments have shown that exposure to a supraoptimal temperature (39 °C) causes a complete block of nuclear and cellular division accompanied by an increased accumulation of starch. In this work we explore the potential of supraoptimal temperature as a method to promote starch production in C. reinhardtii in a pilot-scale photobioreactor. The method was successfully applied and resulted in an almost 3-fold increase in the starch content of C. reinhardtii dry matter. Moreover, a maximum starch content at the supraoptimal temperature was reached within 1–2 days, compared with 5 days for the control culture at the optimal temperature (30 °C). Therefore, supraoptimal temperature treatment promotes rapid starch accumulation and suggests a viable alternative to other starch-inducing methods, such as nutrient depletion. Nevertheless, technical challenges, such as bioreactor design and light availability within the culture, still need to be dealt with.


2003 ◽  
Vol 10 (01) ◽  
pp. 55-63 ◽  
Author(s):  
M. DIANI ◽  
J. DIOURI ◽  
L. KUBLER ◽  
L. SIMON ◽  
D. AUBEL ◽  
...  

In 6H- or 4H-SiC(0001) surface technology, a Si-rich 3 × 3 reconstruction is usually first prepared by heating at 800°C under Si flux, and two other most stable [Formula: see text] or [Formula: see text] reconstructions are obtained by further extensive annealing at higher temperatures ranging between 900 and 1250°C. The 3 × 3 Si excess is thus progressively depleted up to a graphitized C-rich surface. By crystallographic (LEED) and chemical surface characterizations (XPS and UPS), we show that all these reconstructions can be obtained at a unique, low formation temperature of 800°C if the Si richness is controlled before annealing. This control is achieved by exposing the 3 × 3 surface to atomic hydrogen at room temperature. This procedure allows one to etch or partially deplete the (3 × 3)-associated Si excess, and make it more comparable to the final Si coverages, required to form the less Si-rich [Formula: see text] or [Formula: see text] reconstructions. After annealing at 800°C, the latter reconstructions are no longer determined by the heating time or temperature but only by the initial Si coverage set by the H doses inducing the low temperature etching. The high temperature treatment, required to remove by sublimation a significant Si amount associated with the Si-rich 3 × 3 reconstruction, is thus avoided. Such a methodology could be applied to other binary systems in the formation of reconstructions that depends on surface richness.


Author(s):  
Siti Hajar Ariffin ◽  
Rosnah Shamsudin ◽  
I. S. M. A. Tawakkal

Dabai (Canarium odontophyllum) or also known as ‘Sarawak olive’ is one of the potential indigenous seasonal fruits commonly found in Sarawak. Due to its high nutritional contents, it has wide potential to be marketed locally and exported internationally. Dabai is very delicate and highly perishable. The shelf life of dabai is usually 3 days when stored in room temperature (27°C). Improper storage and handling lead to the reduction of quality and shelf life of the fruit throughout storage. There is still limitation on the information of postharvest, storage and handling, quality and shelf life of dabai. Studies on quality and shelf life affected by storage treatment and packaging are necessary in optimising shelf life and minimising quality loss of the fruit. This could ensure further potential development of the fruit locally and internationally.


2011 ◽  
Vol 418-420 ◽  
pp. 222-227
Author(s):  
Zhi Jian Zhang ◽  
Nai Chao Si ◽  
Guang Lei Liu ◽  
Song Hai Si

The TiNiV shape memory alloy wire that was cold pressed under 9Mpa at the room temperature had good superelasticity. On this basis, a tensile test was made after a series of medium-temperature treatment. Then the effect of superelasticity and microstructure of TiNiV shape memory alloy by medium-temperature treatment were studied. The results indicate that the experimental wires assume thorough non-linear superelasticity after holding 30 min at 430°C. The superelasticity of the wire enhances firstly, then declines with the ascent of the temperature and extension of the time of the holding. A kind of potentiation phase-Ti3Ni4 precipites out of the wire under different medium-temperature treatment.


2011 ◽  
Vol 5 (2) ◽  
pp. 69-72 ◽  
Author(s):  
Branko Matovic ◽  
Jelena Pantic ◽  
Jelena Lukovic ◽  
Svetlana Ilic ◽  
Nadezda Stankovic ◽  
...  

Nanometric size (Ba, Yb) doped ceria powders with fluorite-type structure were obtained by applying selfpropagating room temperature methods. Tailored composition was: Ce0.95-xBa0.05YbxO2-? with fixed amount of Ba - 0.05 and varying Yb content 'x' from 0.05 to 0.2. Powder properties such as crystallite and particle size and lattice parameters have been studied. R?ntgen diffraction analyses (XRD) were used to characterize the samples at room temperature. Also, high temperature treatment (up to 1550?C) was used to follow stability of solid solutions. The mean diameters of the nanocrystals are determined from the full width at half maxima (FWHM) of the XRD peaks. It was found that average diameter of crystallites is less than 3 nm. Williamson- Hall plots were used to separate the effect of the size and strain in the nanocrystals.


2021 ◽  
pp. 131-137
Author(s):  
Akshaya Sarangharaajan ◽  
Saibaba Jagadeesan ◽  
Kalpana Palani ◽  
Ramasubramaniyan Ramanathan Melmangalam

The present study was undertaken to develop an alternative idli from proso millet with horse gram and fenugreek seeds. Two types of wet batters (Batter A & Batter B) were prepared by soaking     the ingredients proso millet, horse gram and fenugreek separately (in the ratio by weight 7:2:1) in excess water for 8 hours at room temperature (25±2ºC). In method A, the ingredients were soaked in excess water and whereas in method B, fenugreek was soaked in buttermilk. The soaked ingredients were ground separately with adequate amount of water using a grinder and mixed with the addition of 1% salt. The resulting batter was fermented for 10 hours at room temperature. The batter was analyzed for its microbial load (Total Plate Count, Lactobacillus and Yeast and Mold) and physico-chemical properties (height rise, pH and titratable acidity) by drawing aliquots at fixed intervals. Microbial analysis revealed maximum load at 6th hour of fermentation for TPC, LAB and Yeast growth. Suppressing activity of the organisms was seen after this stage and there was                  a sharp decline in microbial growth (LAB and Yeast). The pH and total titratable acidity ranged between 4.88-6.20 and 0.19–0.51% respectively. The nutritional analysis and sensorial acceptance of the idli formulated with both the batters were also studied. Both the idlis were found to have                   a two-fold increase in protein content and a 50% reduction in carbohydrate content when compared with the traditional rice idli. The sensory analysis was conducted with 100 untrained panelists and the results revealed that idli prepared from Batter A was preferred. A dry ready to cook idli mix was also formulated and was studied for the above said properties. The study highlights that proso millet, horse gram and fenugreek can be used as an effective alternative for preparation of idli.


1984 ◽  
Vol 246 (5) ◽  
pp. R747-R752
Author(s):  
S. J. Wickler ◽  
B. A. Horwitz ◽  
S. F. Flaim ◽  
K. F. LaNoue

Blood flow was measured with labeled microspheres in cold (6 degrees C)- and room-temperature-acclimated rats at rest and during infusion of the beta-agonist, isoproterenol. Isoproterenol elicited decreased mass-specific blood flows (ml . g-1 . min-1) to liver (55% of control), kidney (48%), and white fat (64%) in room-temperature-acclimated (RT) rats. Blood flow was similarly decreased in liver (51%), kidney (37%), and white fat (70%) in cold-acclimated (CA) rats. In contrast, isoproterenol increased blood flows to brown fat and cardiac and skeletal muscles. The blood flows to cardiac muscle during isoproterenol infusion were comparable in both RT (12.7 ml . g-1 . min-1) and CA (11.7 ml . g-1 . min-1) animals, representing increases of 2.9- and 2.6-fold above control values, respectively. Blood flow to skeletal muscle was also similarly elevated in RT and CA animals, representing increases 5.9 and 5.6 times those of their respective control values. In contrast, although isoproterenol greatly stimulated (ca. 8-fold) blood flow to brown fat (interscapular plus cervical depots) in RT animals, it had a greater effect on these two depots in the CA rats (18-fold increase). These data emphasize the importance of brown fat as a major effector of nonshivering thermogenesis as well as the importance of beta-adrenergic receptors in mediating the metabolic response of nonshivering thermogenesis.


1977 ◽  
Vol 164 (1) ◽  
pp. 131-137 ◽  
Author(s):  
Michael Newman ◽  
Henry McIlwain

1. Adenosine was determined in rapidly frozen rat and guinea-pig brain and in guinea-pig cerebral tissues after incubation in vitro. Adenosine concentrations were approx. 2nmol/g wet wt. in frozen tissue, diminished at room temperature, and returned to 2nmol/g on incubation in oxygenated glucose/salines. 2. Superfusion with noradrenaline then increased the tissue's adenosine concentration 2.5-fold, and hypoxia caused an 8-fold increase. 3. Electrical stimulation alone or in the presence of noradrenaline or histamine increased the tissue's adenosine and cyclic AMP, but adenosine concentrations reached their peak later and were maintained for longer than those of cyclic AMP. 4. Superfusion with l-glutamate with and without electrical excitation raised adenosine concentrations to 15–34nmol/g. The increases in cyclic AMP on electrical stimulation, superfusion with glutamate or a combination of these treatments were diminished by addition of adenosine deaminase or theophylline. 5. It is concluded that adenosine can be produced endogenously in cerebral systems, in sufficient concentrations to accelerate an adenosine-activated adenylate cyclase, and by this route can contribute to the cerebral actions of electrical stimulation and of the neurohumoral agents. In certain instances cyclic AMP as substrate contributes to an increase in adenosine.


1973 ◽  
Vol 105 (12) ◽  
pp. 1489-1494 ◽  
Author(s):  
D. P. Peschken ◽  
R. W. Beecher

AbstractCeutorhynchus litura (F.) laid an average of 123 eggs per female. Development from egg to adult took about 6 weeks at room temperature, followed by an obligatory diapause of 3–4 months. In laboratory rearings a maximum of only an 8-fold increase over the original breeding stock was achieved in one generation. The weevil was released against the weed Canada thistle (Cirsium arvense (L.) Scop.) near Belleville, Ont., in 1967. Near the centre of the release site on about 400 m2, thistle shoots have decreased to 4% of their former density of about 3–7 shoots per 0.25 m2. Circumstantial evidence indicates that the weevil aided in the spread of thistle rust Puccinia punctiformis (Str.) Rohl.


Sign in / Sign up

Export Citation Format

Share Document