Temperature Coefficient of Vulcanization on a Litharge Compound

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.

Proceedings of the Royal Society of London. Series B, Containing Papers of a Biological Character ◽

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

10.1098/rspb.1912.0082 ◽

1912 ◽

Vol 85 (582) ◽

pp. 546-553 ◽

Cited By ~ 20

Keyword(s):

Hordeum Vulgare ◽

Aqueous Solutions ◽

Temperature Coefficient ◽

Chemical Change ◽

Experimental Conditions ◽

Suitable Medium ◽

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.

Influence of Temperature on the Determination of Enzyme Activities in Human Serum

Enzyme and Protein ◽

10.1159/000458792 ◽

1977 ◽

pp. 213-218

Author(s):

K. Jung ◽

W. Liese

Keyword(s):

Human Serum ◽

Enzyme Activities ◽

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

Sensors ◽

10.3390/s19102223 ◽

2019 ◽

Vol 19 (10) ◽

pp. 2223 ◽

Cited By ~ 5

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 ◽

Temperature Characteristics ◽

Device Resistance ◽

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.

Pengaruh Ketinggian Tempat dan Curah Hujan Pada Penyakit Diare (Studi Kasus: Kabupaten Bogor)

Agromet ◽

10.29244/j.agromet.28.1.33-39 ◽

2018 ◽

Vol 28 (1) ◽

pp. 33

Author(s):

Muhammad Syafei ◽

Rini Hidayati

Keyword(s):

Sea Level ◽

Negative Influence ◽

Positive Influence ◽

The Other ◽

Threshold Values ◽

Climate Classification ◽

Very High

<em>This study aimed to determine the effect of altitude and rainfall on the incidence of disease ( IR ) diarrhea, and to obtain threshold values of rainfall that often cause diarrhea. Determination category of normal rate of diarrhea IR is based on diarrhea IR by DINKES Bogor in the amount of 20-25/1000 population per year, while the determination of precipitation category is based on consideration of Oldeman climate classification. The results showed that there were two districts with very high levels of vulnerability i.e. Cisarua and Cijeruk, while the other regions only at a moderate level. The negative influence of altitude (or positive influence of temperature) on the IR will be evident if the analysis is separated between in the highlands (> 600 asl) and the lowlands (< 600 asl). This influence is significant, especially at altitudes above 600 meters above sea level. The correlation of the precipitation is significant negative linear to the incidence of diarrhea in the district Cisarua, Cibinong, Jonggol, and Jasinga. In districts Cibinong, Jonggol, and Jasinga, precipitation should be anticipated in the range of 100-200 mm/month, where moderate IR often occurs, while in the district Cisarua, is in the range of precipitation 300-400 mm/month, where high IR often occurs.</em>

THE INFLUENCE OF TEMPERATURE ON COEFFICIENT OF MAGNETIC SUSCEPTIBILITY χ OF FERRO-OILS WITH DIFFERENT CONCENTRATIONS OF MAGNETIC PARTICLES

Tribologia ◽

10.5604/01.3001.0010.6579 ◽

2016 ◽

Vol 269 (5) ◽

pp. 21-30 ◽

Cited By ~ 2

Author(s):

Marcin FRYCZ

Keyword(s):

Magnetic Susceptibility ◽

Magnetic Particles ◽

Operating Temperature ◽

Measurement Data ◽

Main Subject ◽

Temperature Changes ◽

Physicochemical Features

In this paper, the authors presented research concerning the determination of the relation between magnetic susceptibility coefficient χ of ferro-oil and temperature changes. The tests were conducted on the ferro-oil samples of various, chosen magnetic particles concentrations: 1%, 2%, 4%, 6%, and 8%. In accordance with the conclusions resulting from Curie-Weiss equation, the values of magnetic susceptibility χ depend on the physicochemical features of considered material, including the magnitude and amount (concentration) of magnetic particles and physical properties of its environment, i.e. the kind and direction of magnetic field and also on the operating temperature, which is the main subject of conducted tests in this paper. This article presents the structure of the bench used for experimental designation of magnetic susceptibility coefficient in relation to temperature changes of tested ferro-oil. Moreover, the authors demonstrated a method enabling the determination of these values from obtained measurement data, conducted the analysis of obtained results and presented the conclusions.

Temperatura y concentración de fluoruro de sodio en geles fluorados

Yachay - Revista Científico Cultural ◽

10.36881/yachay.v7i01.76 ◽

2019 ◽

Vol 7 (01) ◽

pp. 294-301

Author(s):

Vianne Diana Huamán Baca ◽

Alejandro pablo Pletickosich ◽

Teófila Baca Carbajal

Keyword(s):

Sodium Fluoride ◽

Room Temperature ◽

Acidic Ph ◽

Neutral Ph ◽

Para Determinar

ResumenEl objetivo de esta investigación fue determinar la influencia de la temperatura en la concentración de fluoruro de sodio; la muestra estuvo conformada por 60 geles fluorados de un mismo lote y la validez de dos marcas: ‘Fluofar®’ en sus dos presentaciones (pH neutro y acidulado) y el ‘Fluorgel Maquira®’ en sus dos presentaciones (pH neutro y acidulado). De cada gel fluorado se obtuvieron cuatro muestras: para comprobar el pH, para determinar la concentración de fluoruro de sodio a temperatura ambiente, para fijar la concentración de fluoruro de sodio después de haber sido sometido a una temperatura de 8 °C durante tres meses, y para, determinar la concentración de fluoruro de sodio después de haber sido sometido a una temperatura de 20 °C durante tres meses.La determinación de concentración de fluoruro de sodio, se realizó mediante la técnica de destilación y titulación. Por los resultados obtenidos se concluyó: que el incremento de la temperatura influye en la disminución de la concentración de fluoruro de sodio —siendo estadísticamente significativa en los geles fluorados con pH ácido (geles acidulados) y, en los geles fluorados con pH neutro mantiene su concentración—, aún se incrementó la temperatura. La concentración de fluoruro de sodio, indicado por el fabricante, disminuyó significativamente al comparar con la concentración de fluoruro de sodio encontrado en el laboratorio.Palabras claves; Geles fluorados, concentración de fluoruro de sodio, temperatura, pHAbstractThe objective of this investigation was to determine the influence of temperature on the concentration of sodium fluoride; the sample consisted of 60 fluorinated gels from the same batch and validity of two brands: Fluofar ® in its two presentations (neutral and acidulated pH) and Fluorgel Maquira ® and its two presentations (neutral pH and acidulated). From each fluorinated gel four samples were obtained: to determine the pH, to determine the concentration of sodium fluoride at room temperature, to determine the concentration of sodium fluoride after having been subjected to temperature of 8 °C for three months, and to determine the concentration of sodium fluoride after having been subjected to temperature of 20 °C for three months.The determination of concentration of Sodium Fluoride was carried out by means of the distillation and titration. From the results obtained, it was concluded that the increase in temperature influences the decrease in the concentration of sodium fluoride -being statistically significant in fluorinated gels with acidic pH (acidified gels) and, in fluorinated gels with neutral pH, it maintains its concentration-, the temperature was still increased. The concentration of sodium fluoride, indicated by the manufacturer, decreased significantly when compared to the concentration of sodium fluoride found in the laboratory.

Influence of Temperature on the Electrochemical Characteristics of Ti-6Al-4V

Materials Science Forum ◽

10.4028/www.scientific.net/msf.811.77 ◽

2014 ◽

Vol 811 ◽

pp. 77-82

Author(s):

Martina Ivašková ◽

Martin Lovíšek ◽

Peter Jančovič ◽

Lenka Bukovinová

Keyword(s):

Activation Energy ◽

Polished Surface ◽

Electrochemical Characteristics ◽

Medical Implants ◽

Arrhenius Relation ◽

Military Aviation ◽

Different Temperatures ◽

Titanium is not only the most widely used biomaterial for medical implants, but with its very good mechanical properties, corrosion resistance and low density is also applicated in many sectors of industry (aerospace, military, aviation, machinery, energetics, chemicals, etc.). In this paper it is described the influence of temperature on the electrochemical characteristics of Ti-6Al-4V alloy. The surface was mechanically grinded and polished by chemical-mechanical process. Basic electrochemical characteristics were determined by potentiodynamic tests in 0.1M NaCl solution at different temperatures. The obtained results were analysed by the Tafel-extrapolation method. Finally, a modified Arrhenius relation was used for determination of activation energy. The activation energy of grinded and chemical-mechanical polished surface is nearly three times higher than activation energy of only grinded surface.

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

Canadian Journal of Zoology ◽

10.1139/z90-309 ◽

1990 ◽

Vol 68 (10) ◽

pp. 2221-2229 ◽

Cited By ~ 7

Author(s):

A. Bellido

Keyword(s):

Strong Influence ◽

Postembryonic Development ◽

Egg Laying ◽

Adult Survival ◽

Immature Stages ◽

Small Species ◽

Natural Conditions ◽

Experimental Conditions ◽

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)

Canadian Journal of Chemistry ◽

10.1139/v92-291 ◽

1992 ◽

Vol 70 (8) ◽

pp. 2310-2313 ◽

Cited By ~ 2

Author(s):

Horacio N. Sólimo ◽

José L. Zurita

Keyword(s):

Experimental Data ◽

Conjugate Points ◽

Liquid Equilibrium ◽

Experimental Conditions ◽

Equilibrium Data ◽

Tie Lines ◽

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.

VI. On the Influence of temperature on the musical pitch of harmonium reeds

Proceedings of the Royal Society of London ◽

10.1098/rspl.1880.0055 ◽

1881 ◽

Vol 31 (206-211) ◽

pp. 413-415

Keyword(s):

Musical Pitch ◽

Tuning Forks ◽

In my “Notes of Observations on Musical Beats,” I stated (“Proc. Roy. Soc.,” vol. 30, p. 532) that the influence of temperature on harmonium reeds was, so far as I was aware, unknown. Since then I have made some observations which at least approximately determine it, but there are so m any sources of small errors (stated below) that still more uncertainty must attach to the results, than to the determination of the influence of temperature on the pitch of tuning-forks ( ibid ., p. 523). Roughly we may say that the pitch of harmonium reeds is affected in the same direction as that of tuning-forks (heat flattening and cold sharpening), and very nearly to twice the amount, that is, by about 1 in 10,000 vibrations for each degree Fahrenheit.