scholarly journals The influence of temperature on the absorption of water by seeds of hordeum vulgare in relation to the temperature coefficient of chemical change

1912 ◽  
Vol 85 (582) ◽  
pp. 546-553 ◽  
Keyword(s):  
Hordeum Vulgare ◽  
Aqueous Solutions ◽  
Temperature Coefficient ◽  
Chemical Change ◽  
Experimental Conditions ◽  
Influence Of Temperature ◽  
Suitable Medium ◽  
Influence Of Temperature On

Attention has previously been directed by one of us to the existence of a differential septum enclosing the seeds of Hordeum (barley). When the seeds are immersed in aqueous solutions of most electrolytes, and of many non-electrolytes, this covering behaves as a very efficient differential septum, water alone entering the seeds under the attractive influence of the finely granulated contents. The rate at which the water enters is considerably affected if substances are dissolved in it, being increased by some and diminished by others; it is also markedly dependent on the temperature of the water or solution in which the seeds are immersed. Variations of the rate at which water enters with alterations of the experimental conditions are presumably due mainly to changes in the water, and the seeds of Hordeum would thus appear to be a very suitable medium for the investigation of the nature of the changes produced in water by the presence of dissolved substances or by alterations of temperature.

Temperature Coefficient of Vulcanization on a Litharge Compound

1929 ◽  
Vol 2 (4) ◽  
pp. 505-516
Author(s):  
J. R. Sheppard
Keyword(s):  
Temperature Coefficient ◽  
Experimental Conditions ◽  
Influence Of Temperature ◽  
Influence Of Temperature On ◽  
Exact Relationship

Abstract THE influence of temperature on vulcanization is too well known to require emphasis—it has been generally recognized for quite a number of years that the relation between temperature and time for ordinary curing ranges was logarithmic although there has been no unanimity as to the exact relationship. This doubtless is in part due to the varying experimental conditions employed by the investigators and possibly in some cases to less precise measurements. Table I, a partial bibliography, shows some values for the temperature coefficient which have been obtained and the conditions used. It will be seen that values ranging from 8 to 25 have been reported for the coefficient (in terms of degrees Fahrenheit required to double the rate of cure). It is the purpose of this paper to recount the writer's determination of the temperature coefficient for a given litharge stock in press cures—it is not safe perhaps to infer from the present results what might hold under certain other conditions.

Flow Behaviors of High Acyl Gellan Aqueous Solutions as Affected by Temperature, and Calcium and Gellan Concentrations

2008 ◽  
Vol 4 (5) ◽  
Author(s):  
Yiqun Huang ◽  
Pawan Singh Takhar ◽  
Juming Tang ◽  
Barry G Swanson
Keyword(s):  
Shear Rate ◽  
Aqueous Solutions ◽  
Apparent Viscosity ◽  
Flow Resistance ◽  
Effect Of Temperature ◽  
Temperature Changes ◽  
Influence Of Temperature ◽  
Rheological Behaviors ◽  
Low Concentrations ◽  
Influence Of Temperature On

Rheological behaviors of high acyl (HA) gellan are not well understood partially because of its relatively late commercialization compared to low acyl gellan. The objective of this study was to investigate the effect of temperature (5-30 °C), calcium (0, 1 and 10 mM) and gellan concentrations (0.0044-0.1000% w/v) on the flow behaviors of high acyl gellan aqueous solutions using rheological tests. Gellan solutions with 0 or 1 mM added Ca++ exhibited shear thinning behavior at gellan concentrations above 0.0125%. The influence of temperature on apparent viscosity (shear rate, 100 s-1) of gellan solutions can be described with an Arrhenius relationship. The apparent viscosity of gellan solution at low concentrations was more sensitive to temperature changes. The addition of Ca++ led to a decrease in flow resistance for a dilute gellan solution (<0.0125%), but an increased resistance for a relatively concentrated gellan solution (>0.0125%).

scholarly journals Temperature Characteristics of a Pressure Sensor Based on BN/Graphene/BN Heterostructure

Sensors ◽  
2019 ◽  
Vol 19 (10) ◽  
pp. 2223 ◽  
Author(s):  
Mengwei Li ◽  
Teng Zhang ◽  
Pengcheng Wang ◽  
Minghao Li ◽  
Junqiang Wang ◽  
...  
Keyword(s):  
Temperature Coefficient ◽  
Pressure Sensor ◽  
High Performance ◽  
Pressure Sensors ◽  
Resistance Change ◽  
Change Rate ◽  
Influence Of Temperature ◽  
Temperature Characteristics ◽  
Device Resistance ◽  
Influence Of Temperature On

Temperature is a significant factor in the application of graphene-based pressure sensors. The influence of temperature on graphene pressure sensors is twofold: an increase in temperature causes the substrates of graphene pressure sensors to thermally expand, and thus, the graphene membrane is stretched, leading to an increase in the device resistance; an increase in temperature also causes a change in the graphene electrophonon coupling, resulting in a decrease in device resistance. To investigate which effect dominates the influence of temperature on the pressure sensor based on the graphene–boron nitride (BN) heterostructure proposed in our previous work, the temperature characteristics of two BN/graphene/BN heterostructures with and without a microcavity beneath them were analyzed in the temperature range 30–150 °C. Experimental results showed that the resistance of the BN/graphene/BN heterostructure with a microcavity increased with the increase in temperature, and the temperature coefficient was up to 0.25%°C−1, indicating the considerable influence of thermal expansion in such devices. In contrast, with an increase in temperature, the resistance of the BN/graphene/BN heterostructure without a microcavity decreased with a temperature coefficient of −0.16%°C−1. The linearity of the resistance change rate (ΔR/R)–temperature curve of the BN/graphene/BN heterostructure without a microcavity was better than that of the BN/graphene/BN heterostructure with a microcavity. These results indicate that the influence of temperature on the pressure sensors based on BN/graphene/BN heterostructures should be considered, especially for devices with pressure microcavities. BN/graphene/BN heterostructures without microcavities can be used as high-performance temperature sensors.

Caractéristiques biodémographiques d'un acarien oribate (Carabodes willmanni) des pelouses xérophiles

1990 ◽  
Vol 68 (10) ◽  
pp. 2221-2229 ◽  
Author(s):  
A. Bellido
Keyword(s):  
Strong Influence ◽  
Postembryonic Development ◽  
Egg Laying ◽  
Adult Survival ◽  
Immature Stages ◽  
Small Species ◽  
Natural Conditions ◽  
Experimental Conditions ◽  
Influence Of Temperature ◽  
Influence Of Temperature On

An analysis of biodemographic characteristics was undertaken under experimental conditions in Carabodes willmanni, the first study of its kind in the superfamily Carabodoidea. The species dominates the microarthropod fauna of dry Cladonia cover. Immature stages have a very soft integument and live within the decomposing lichen layer. The population is characterized by the following: (i) low fecundity, strongly density dependent; (ii) relatively long postembryonic development for such a small species, lasting 117 days at 20 °C; (iii) extended premoulting stage (pupation), lasting 28% of postembryonic development; (iv) high but very variable longevity, with values varying from 200 to 600 days between egg laying and death of the adult; (v) strong influence of temperature on fecundity, adult survival, and duration of embryonic and postembryonic developments: development is inhibited at 10 °C. Based on previously acquired information on the phenology of the population, a model for the life cycle under natural conditions is proposed. Periods favorable to development being greatly shortened by environmental factors, the duration of the cycle is lengthened and probably takes as much as 1 year under the harshest conditions. The success of C. willmanni in such an environment can be explained by the capacity of the immature stages to take advantage of the lichen substrate both as a source of food and as a means of protection against desiccation.[Journal translation]

Influence of temperature on the liquid-to-liquid extraction of ethanol from (water + ethanol + 1,2-dichloroethane)

1992 ◽  
Vol 70 (8) ◽  
pp. 2310-2313 ◽  
Author(s):  
Horacio N. Sólimo ◽  
José L. Zurita
Keyword(s):  
Experimental Data ◽  
Conjugate Points ◽  
Liquid Equilibrium ◽  
Experimental Conditions ◽  
Influence Of Temperature ◽  
Equilibrium Data ◽  
Tie Lines ◽  
Influence Of Temperature On ◽  
Tie Line ◽  
System Water

To evaluate the influence of temperature on the extraction of ethanol from aqueous solutions with 1,2-dichloroethane, liquid–liquid equilibrium data for the system water + ethanol + 1,2-dichloroethane were obtained at 298.15, 308.15, and 318.15 K. The binodal curves were determined by the cloud-point method, and conjugate points on the tie-lines were obtained by correlating the refractive index of these curves as a function of composition. The tie-line data at each temperature were satisfactorily correlated using the method of Othmer and Tobias, and the plait-point coordinates were estimated. The experimental data were also compared to values calculated by the UNIFAC group contribution method for the activity coefficients using the isoactivity conditions as restraint equations, and with the NRTL and UNIQUAC models. The UNIFAC method proved to be more accurate than the NRTL and UNIQUAC equations fitted to the experimental data. Under the experimental conditions used, ethanol extraction by 1,2-dichloroethane appears to be independent of the temperature.

Influence of temperature on the liquid-to-liquid extraction of 1-propanol from aqueous solutions containing nitromethane

2002 ◽  
Vol 198 (2) ◽  
pp. 267-279
Author(s):  
René A. Clará ◽  
Mónica Gramajo de Doz ◽  
Norma Barnes ◽  
Horacio N. Sólimo
Keyword(s):  
Aqueous Solutions ◽  
Liquid Extraction ◽  
Influence Of Temperature ◽  
Influence Of Temperature On

Influence of temperature on the synthesis of thiol-stabilized CdTe nanoparticles in aqueous solutions

2010 ◽  
Vol 207 (2) ◽  
pp. 370-374 ◽  
Author(s):  
Y. Khalavka ◽  
B. Mingler ◽  
G. Friedbacher ◽  
G. Okrepka ◽  
L. Shcherbak ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Influence Of Temperature ◽  
Cdte Nanoparticles ◽  
Influence Of Temperature On
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