scholarly journals TEMPERATURE AND THE MECHANISM OF LOCOMOTION IN PARAMECIUM

1925 ◽  
Vol 9 (1) ◽  
pp. 115-121 ◽  
Author(s):  
Otto Glaser
Keyword(s):  
Biological Process ◽  
Absolute Temperature ◽  
Theoretical Interpretation ◽  
Logarithmic Scale ◽  
Unit Distance ◽  
Different Temperatures ◽  
Time Required ◽  
Percentage Basis ◽  
Straight Lines ◽  
Frequency Polygons

1. Frequency polygons in which the number of observations at each temperature is reduced to a percentage basis while the time factor is represented on a logarithmic scale, indicate that the time required by Paramecium to swim a unit distance at different temperatures varies within definite limits which are constant above 15°. Below 15° the range of variability very possibly is not the same, though probably likewise constant. 2. Logarithmic velocities deduced from mean, maximal, minimal, and modal time classes, when plotted against reciprocals of the absolute temperature, fall respectively on straight lines. These lines are parallel and give µ values of 8,000 above 15° and probably 16,000 below. 3. This implies that the mechanism of locomotion in Paramecium remains essentially unaltered by a rise in temperature from 15° to 30°, and probably remains in a similar sense constant from 6° to 15°. 4. The theoretical interpretation of this result is possible in terms of a catenary series 0 → A → E in which the passages 0 → A and A → E are controlled by two catalysts differing respectively in concentration in different individuals and perhaps at different times in the same individual, but depending for their effective concentration on reactions having temperature coefficients identical with those which at each temperature characterize the biological process under consideration.

scholarly journals The Thermal Dependence of the Rates of Glycogen and Triglyceride Synthesis in the Mosquito

1966 ◽  
Vol 44 (3) ◽  
pp. 523-528
Author(s):  
EMILE VAN HANDEL
Keyword(s):  
Glycogen Synthesis ◽  
Neurosecretory Cells ◽  
Absolute Temperature ◽  
Limiting Factors ◽  
Thermal Dependence ◽  
Triglyceride Synthesis ◽  
Sugar Absorption ◽  
Different Temperatures ◽  
Time Required ◽  
Rate Limiting

1. Net synthesis of glycogen and triglycerides produced from 1 mg. of sugar by the female mosquito A. sollicitans was determined at different temperatures. 2. At each temperature 0·2 mg. of glycogen and 0·13-0·14 mg. of triglycerides was synthesized from 1 mg. of sugar. 3. The logarithm of the rate constant (the time required to synthesize 75 % of the maximum) was proportional with the reciprocal of the absolute temperature. 4. For triglyceride synthesis the Q10 = 3 from 10 to 30° C.; for glycogen synthesis the Q10 = 5 from 10 to 22·5°C., but from 22·5 to 35° C. the rate of glycogen synthesis was independent of the temperature (Q10 = 0). 5. Crop emptying and sugar absorption are not rate-limiting factors. 6. Medial neurosecretory cells, which limit the maximum amount of glycogen that can be synthesized from sugar, do not affect the rate of synthesis.

scholarly journals THE EFFECTS ON BIOLOGICAL MATERIALS OF FREEZING AND DRYING BY VACUUM SUBLIMATION

1954 ◽  
Vol 100 (1) ◽  
pp. 81-88 ◽  
Author(s):  
Donald Greiff ◽  
Henry Pinkerton
Keyword(s):  
Influenza Virus ◽  
Biological Materials ◽  
Continuous Operation ◽  
Virus Suspension ◽  
Vacuum Sublimation ◽  
End Point ◽  
Different Temperatures ◽  
Time Required

A vacuum sublimation apparatus is described which will permit, (a) the removal of water from virus suspensions at temperatures ranging down to –80°C., (b) continuous operation with a minimum of attention from the investigator, (c) sealing off of samples at operating pressures (10–5 mm. Hg), (d) simultaneous lyophilization of aliquot samples at different temperatures, (e) isolation of a portion of the apparatus without disturbing the remainder of the system, and (f) determination of the end-point of sublimation without disturbing the samples. The time required for drying 0.1 ml. of influenza virus suspension was shown to increase markedly with decrease of temperature, 8 days being required for dehydration at –80°C. in contrast to 2 days at –30°C. and 1 day at 0°C.

scholarly journals The estimation of electric moment in solution by the temperature coefficient method. Part I.—Experimental method and the electric moments of some benzyl compounds

1933 ◽  
Vol 142 (846) ◽  
pp. 173-197 ◽  
Keyword(s):  
Single Molecule ◽  
Polar Solvent ◽  
Fundamental Equation ◽  
Absolute Temperature ◽  
Electric Moment ◽  
Avogadro’S Number ◽  
Boltzmann Gas ◽  
Different Temperatures ◽  
The Moment ◽  
Coefficient Method

The theory of the estimation of the electric moment of molecules dissolved in a non-polar solvent is now well known. The fundamental equation is P 2∞ = 4 π /3 N (α 0 + μ 2 /3 k T) (1) in which the symbols have the following significance: P 2∞ the total polarizability of the solute per grain molecule at infinite dilution, N Avogadro’s number, α 0 the moment induced in a single molecule by unit electric field, k the Boltzmann gas constant, T the absolute temperature, and μ the permanent electric moment of the molecule. This equation is of the form P 2∞ = A + B/T, (2) where A = 4 π /3 Nα 0 and B = 4 π /9 . N μ 2 / k , from which it follows that if A and B are constant, i. e ., independent of temperature, then each may be evaluated from a series of measurements of P 2∞ at different temperatures or alternatively B (and hence μ ) may be obtained from one value of P 2∞ at one temperature, provided that A can be obtained by some independent method.

Rheological Properties of Tomato Concentrate

2008 ◽  
Vol 4 (7) ◽  
Author(s):  
Manish Dak ◽  
Radha Charan Verma ◽  
S N A Jaaffrey
Keyword(s):  
Rheological Properties ◽  
Absolute Temperature ◽  
Power Law Model ◽  
Arrhenius Model ◽  
Rotational Viscometer ◽  
Consistency Coefficient ◽  
Flow Behaviour Index ◽  
Different Temperatures ◽  
Wide Gap ◽  
Good Agreement

Rheological properties of tomato concentrate were evaluated using a wide-gap rotational viscometer (Brookfield Engineering Laboratories: Model LVDV-II) at different temperatures of 20, 30, 40, 50, and 60oC, at concentration of 18, 12.18 and 8.04 % total solids, and at appropriate shear rate(1-100 RPM). The power law model was fitted to the experimental results. The values of flow behaviour index (n) were found less than unity (0.23 to 0.82) at all the temperature and the concentration indicating shear-thinning (pseudoplasticity) behaviour of the concentrate. The correlation between the observed consistency coefficient ranging from 0.09 to 65.87 Pa.sn and the inverse absolute temperature has been exhibited by Arrhenius model. Consistency coefficient increased exponentially with increase in the concentration. Statistical model was used for prediction of the consistency coefficient as a function of temperature and concentration which showed a good agreement (r2=0.99) between experimental and theoretical values. The magnitude of activation energy were found to be in the range of 8.6 to 14.08 kJ/mol.K.

scholarly journals Optical and Electrical Properties of Thin Films of CuS Nanodisks Ensembles Annealed in a Vacuum and Their Photocatalytic Activity

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
J. Santos Cruz ◽  
S. A. Mayén Hernández ◽  
F. Paraguay Delgado ◽  
O. Zelaya Angel ◽  
R. Castanedo Pérez ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Hydrogen Peroxide ◽  
Photocatalytic Activity ◽  
Electrical Properties ◽  
Absolute Temperature ◽  
Glass Substrates ◽  
Transmission Electron ◽  
Different Temperatures ◽  
Blue Solution

Effects on the optical, electrical, and photocatalytic properties of undoped CuS thin films nanodisks vacuum annealed at different temperatures were investigated. The chemical bath prepared CuS thin films were obtained at 40°C on glass substrates. The grain size of13.5±3.5 nm was computed directly from high-resolution transmission electron microscopy (HRTEM) images. The electrical properties were measured by means of both Hall effect at room temperature and dark resistivity as a function of the absolute temperature 100–330 K. The activation energy values were calculated as 0.007, 0.013, and 0.013 eV for 100, 150, and 200°C, respectively. The energy band gap of the films varied in the range of 1.98 up to 2.34 eV. The photocatalytic activity of the CuS thin film was evaluated by employing the degradation of aqueous methylene blue solution in the presence of hydrogen peroxide. The CuS sample thin film annealed in vacuum at 150°C exhibited the highest photocatalytic activity in presence of hydrogen peroxide.

Conductivity, Electrodeposition and Magnetic Property of Cobalt(II) and Dysprosium Chloride in Zinc Chloride-1-Ethyl-3-Methylimidazolium Chloride Room Temperature Molten Salt

2003 ◽  
Vol 58 (1) ◽  
pp. 139-146 ◽  
Author(s):  
Hsin-Yi Hsu ◽  
Chao-Chen Yang
Keyword(s):  
Zinc Chloride ◽  
Room Temperature ◽  
Deposition Potential ◽  
Nucleation Density ◽  
Alloy Electrodeposition ◽  
Viscosity Increase ◽  
Different Temperatures ◽  
Time Required ◽  
Computerized System ◽  
Zn Alloy

Abstract Electric conductivity of the molten zinc chloride-1-ethyl-3-methylimidazolium chloride phases has been measured by a computerized system using the d.c. four-probes method. The sequence of the conductivities for the different component melts is ZnCl2-EMIC > ZnCl2-EMIC-CoCl2 > ZnCl2- EMIC-DyCl3 > ZnCl2-EMIC-CoCl2-DyCl3. The results may be explained in terms of the viscosity increase due to the complex formation. The electrochemistry and the nucleation mechanism of cobalt(II) or/and dysprosium chloride in acidic ZnCl2-EMIC melts have been investigated by cyclic voltammetry and chronoamperometry at different temperatures, respectively. The results of the SEM and VSM analyses reveal that reduction of Dy3+ to Dy2+ may have occurred, while reduction of Dy3+ to Dy(0) is conjectured to play no role. Moreover, the results of chronoamperometry experiments show that nucleation in the alloy electrodeposition is instantaneous, and that, as the applied deposition potential becomes more negative, the nucleation density increases, which rapidly shortens the time required for the diffusion zones to overlap. Electrodeposition of a Dy-Co-Zn alloy on a Ni or Cu sheet from the 50-50 mol% ZnCl2-EMIC melt containing 1.687 mol% CoCl2 and 1.114 mol% DyCl3 has been accomplished, and the morphology and the composition have been analyzed by SEM and EDS, respectively. The magnetism of the deposited layer is discussed based on the results of the VSM analysis.

scholarly journals EFFECTS OF ADMIXTURES ON THE CRYSTALLISATION RATE OF GYPSUM A BATCH CRYSTALLISATION STUDY

REAKTOR ◽  
2017 ◽  
Vol 8 (2) ◽  
pp. 85
Author(s):  
S. Muryanto ◽  
H. M. Ang
Keyword(s):  
Equilibrium Concentration ◽  
Crystallization Rate ◽  
Supersaturated Solution ◽  
Different Types ◽  
Different Temperatures ◽  
Copper Zinc ◽  
Time Required ◽  
Crystallisation Rate ◽  
Zinc Concentrate ◽  
Concentrate Production

This paper descripbes a study on the effects of admixtures on the crystallization rate of gypsum. Two different types of biodegradable admixtures commonly used as flotation agent in copper/zinc concentrate production, namely, sodium isopropyl xanthate (=SIPX) and isopropyl thionocarbamate were investigated in this study. A laboratory batch crystallizer was used in this study, and the experiments were run using seeded method. The rate of desupersaturation or the time required to reach the equilibrium concentration was  compared for varying admixture oncentrations. It was discovered that the added seed crystals started growing imediately upon addition into the supersaturated solution, i.e. there  was no induction time.Results of this batch crystallizationstudy suggest that addition of admixtures individually or in combination, significantly affects the crystallization kinetics and in particular, reduces the rate of crystallization of gypsum. Activation energies were determined using three different temperatures, and the values obtained  mostly agreed with other published values, i.e. 60.00 ± 3.00, 57.39 ± 2.87, and 37.65 ±1.88 kj/mol, for pure gypsum, isopropyl yhionocarbamate, and SIPX, respectively.Keywords : activation energy; admixtures; CaSO4.2H2O; crystallization, gypsum; reaction rate

Reduction of Campylobacter jejuni on Poultry by Low-Temperature Treatment

2003 ◽  
Vol 66 (4) ◽  
pp. 652-655 ◽  
Author(s):  
TONG ZHAO ◽  
GABRIEL O. I. EZEIKE ◽  
MICHAEL P. DOYLE ◽  
YEN-CON HUNG ◽  
RHONDA S. HOWELL
Keyword(s):  
Liquid Nitrogen ◽  
Campylobacter Jejuni ◽  
The United States ◽  
Temperature Treatment ◽  
Epidemiologic Studies ◽  
Human Infection ◽  
Internal Temperature ◽  
Low Temperature Treatment ◽  
Different Temperatures ◽  
Time Required

Campylobacter jejuni is a leading cause of acute bacterial gastroenteritis in the United States, with epidemiologic studies identifying poultry as a leading vehicle in human infection. Studies were conducted to determine rates of C. jejuni inactivation on poultry exposed to different cooling and freezing temperatures. A mixture of three strains of C. jejuni originally isolated from poultry was inoculated onto chicken wings at ca. 107 CFU/g. The results of the study revealed that the storage of wings at −20 and −30°C for 72 h reduced the population of C. jejuni on wings by 1.3 and 1.8 log10 CFU/g, respectively. The results with regard to long-term freezing for 52 weeks revealed C. jejuni reductions of ca. 4 and 0.5 log10 CFU/g on wings held at −20 and −86°C, respectively. Protocols were developed to superchill wings in Whirl-Pak bags with liquid nitrogen at −80, −120, −160, and −196°C such that the internal portion of each wing quickly reached −3.3°C but did not freeze. The results with regard to the superchilling of wings at different temperatures for 20 to 330 s (the time required for the wings to reach an internal temperature of −3.3°C) revealed C. jejuni reductions of 0.5 log10 CFU/g for wings held at −80°C, 0.8 log10 CFU/g for wings held at −120°C, 0.6 log10 CFU/g for wings held at −160°C, and 2.4 log10 CFU/g for wings held at −196°C. The superchilling of wings to quickly cool meat to −3.3°C (internal temperature) can substantially reduce C. jejuni populations at −196°C when the wings are submerged in liquid nitrogen, but not at −80 to −160°C when the wings are treated with vapor-state liquid nitrogen. The results of this study indicate that freezing conditions, including temperature and holding time, greatly influence the rate of inactivation of C. jejuni on poultry. The conditions used in the poultry industry to superchill poultry to a nonfrozen-state internal temperature are not likely to substantially reduce Campylobacter populations on fresh products.

Kinetic Analysis on SiC Prepared by Carbothermic Method

2012 ◽  
Vol 550-553 ◽  
pp. 2745-2748
Author(s):  
Bin Hao ◽  
Jin Qiang Liu ◽  
Fu Wang
Keyword(s):  
Silicon Carbide ◽  
Reaction Time ◽  
Dynamic Analysis ◽  
Kinetic Analysis ◽  
Kinetic Parameters ◽  
Particle Diameter ◽  
Thermal Reduction ◽  
Different Temperatures ◽  
Time Required

Kinetic analysis of silicon carbide prepared by carbon-thermal reduction is introduced in this paper. Through the dynamic analysis, kinetic parameters of Si-C are calculated, and it is estimated that the time required reaction materials of different diameter completely converted to SiC at different temperatures. Reaction time is nearly 1 hour long when the reaction particle diameter is 1μm around 1900K.

Effect of temperature on embryonic development of Melanotaenia boesemani (Allen and Cross, 1982)

Zygote ◽  
2015 ◽  
Vol 24 (2) ◽  
pp. 301-309 ◽  
Author(s):  
Marcella Costa Radael ◽  
Leonardo Demier Cardoso ◽  
Dalcio Ricardo de Andrade ◽  
André Veloso Ferreira ◽  
Douglas da Cruz Mattos ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Effect Of Temperature ◽  
Hatching Rate ◽  
Oil Droplets ◽  
Development Stages ◽  
Different Temperatures ◽  
Effects Of Temperature ◽  
The Moment ◽  
Time Required ◽  
Faster Development

SummaryThe present study aimed to provide data on the time required for Melanotaenia boesemani to complete embryonic development, and to investigate the influence that incubation at different temperatures caused in this species. The effects of temperature on the time and hatching rate are presented, as well as information related to embryonic development stages. After fertilization, the eggs were kept in incubators at 23, 26, 29 or 32°C and observed at predetermined times until the moment of hatching. Stages of development were identified and classified according to morphological and physiological characteristics. Oil droplets were visualized inside the eggs as well as filament adhesion present at the chorion. Embryonic development was similar to that observed in other species of the genus Melanotaenia with hatching and faster development in higher temperatures.

Sign in / Sign up

Export Citation Format

Share Document