scholarly journals Temperatura y concentración de fluoruro de sodio en geles fluorados

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 ◽  
Influence Of Temperature ◽  
Neutral Ph ◽  
Influence Of Temperature On ◽  
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 and Oxygen Concentration on the Radiation Induced Oxidation of Phenylalanine

1995 ◽  
Vol 50 (9) ◽  
pp. 864-870 ◽  
Author(s):  
P. Krajnik ◽  
R. M. Quint ◽  
S. Solar ◽  
N. Getoff ◽  
G. Sontag
Keyword(s):  
Oxygen Concentration ◽  
Room Temperature ◽  
Degradation Process ◽  
Storage Conditions ◽  
Food Storage ◽  
Reaction Conditions ◽  
Influence Of Temperature ◽  
Influence Of Temperature On ◽  
Radiation Induced ◽  
Induced Changes

AbstractThe formation of tyrosine isomers by γ-radiolysis of neutral aqueous phenylalanine solutions was found to be strongly dependent on oxygen concentration and temperature. Changing the dose rate did not influence the degradation process. In the presence of 0.25 x 10-3 mol dm-3 oxygen at room temperature the yields of o-tyrosine as well as of m- and p-tyrosine drop from G(o-Tyr) = 0.5 and G(m-Tyr) = G(p-Tyr) = 0.4 at a dose of 0.3 kGy to 0.18 and 0.16 at 2.5 kGy, respectively. In solutions containing 1.25 x 10-3 mol dm-3 oxygen the initial yields remain unchanged but decrease at 2.5 kGy only to G(o-Tyr) = 0.3 and G(m-Tyr) = G(p-Tyr) = 0.20. Under the latter reaction conditions also 3,4-dihydroxyphenylalanine was found.Samples irradiated in frozen state did not show remarkable radiolysis of phenylalanine and tyrosine formation. In the range between 5 and 20°C no essential influence of temperature on the phenylalanine radiolysis and tyrosine yields was observable. The obtained results are important for methods using the tyrosine yields as markers for the detection of irradiated food. Storage conditions and irradiation temperature play an essential role on radiation induced changes of food.

Temperature induced phase transition in fluorescence active zein nanoparticles

2021 ◽  
Vol 99 (1) ◽  
pp. 18-23
Author(s):  
Charlie Joe Croxford ◽  
Rajpreet Kaur ◽  
Kultar Singh ◽  
Mandeep Singh Bakshi
Keyword(s):  
Phase Transition ◽  
Temperature Variation ◽  
Room Temperature ◽  
Colloidal Stability ◽  
Precipitation Method ◽  
Effect Of Temperature ◽  
Influence Of Temperature ◽  
Influence Of Temperature On ◽  
Potential Use ◽  
Controlled Precipitation

Stable colloidal zein nanoparticles (NPs) were synthesized by using controlled precipitation method. They were made fluorescence active by incorporating a small amount of fluorescence quinolinium surfactant. The incorporation of fluorescence surfactant provided both the colloidal stability and the fluorescence ability to determine the phase transition in zein NPs under the effect of temperature variation. Maintaining colloidal stability under the effect of temperature variation is an essential aspect of zein NPs applicability as a source of vegetarian protein supplement in different food suspensions. Different techniques such as fluorescence, DLS size, zeta potential, and FTIR measurements were applied to determine the influence of temperature on the colloidal stability of zein NPs. Zein NPs undergo phase transition well above room temperature while maintaining their size in nanometer range, and the phase transition temperature decreased with the amount of zein used in the synthesis of zein NPs. The results highlighted the potential use of zein NPs as a vegetarian supplement protein in different food products.

Effect of Temperature on Crater Formation and Ejecta Composition in Aluminum Alloy Targets

2012 ◽  
Vol 706-709 ◽  
pp. 768-773
Author(s):  
Masahiro Nishida ◽  
Koichi Hayashi ◽  
Junichi Nakagawa ◽  
Yoshitaka Ito
Keyword(s):  
Aluminum Alloy ◽  
High Temperature ◽  
Low Temperature ◽  
Room Temperature ◽  
Effect Of Temperature ◽  
Crater Formation ◽  
Influence Of Temperature ◽  
Gas Gun ◽  
Influence Of Temperature On ◽  
Increasing Temperature

The influence of temperature on crater formation and ejecta composition in thick aluminum alloy targets were investigated for impact velocities ranging from approximately 1.5 to 3.5 km/s using a two-stage light-gas gun. The diameter and depth of the crater increased with increasing temperature. The ejecta size at low temperature was slightly smaller than that at high temperature and room temperature. Temperature did not affect the size ratio of ejecta. The scatter diameter of the ejecta at high temperature was slightly smaller than those at low and room temperatures.

scholarly journals THE INFLUENCE OF TEMPERATURE ON THE ACTION OF STRYCHNIN IN FROGS

1913 ◽  
Vol 18 (3) ◽  
pp. 300-309 ◽  
Author(s):  
Thomas Stotesbury Githens
Keyword(s):  
Low Temperature ◽  
High Temperatures ◽  
Low Temperatures ◽  
Room Temperature ◽  
Drug Action ◽  
The State ◽  
Great Caution ◽  
Influence Of Temperature ◽  
Influence Of Temperature On

In order to establish the influence of temperature upon the effect of varying doses of strychnin injected into frogs, the animals must be kept under observation for several days and at various definite degrees of temperature. Statements that the animal was kept "cold," "at room temperature," or "warm" are insufficient. With a certain dose tetanus may result constantly at 30° C. yet never appear at 21° C., and either of these temperatures might be described as warm, when compared to a room temperature of 15° C. Furthermore an animal may apparently fail to respond in the cold to an injection of certain doses of strychnin and yet be found in tetanic convulsions the next day. That an animal may have late, long lasting, or strong tetanus while kept at such a low temperature as 5° C. after an injection of a dose of strychnin smaller than 0.01 of a milligram per frog emphasizes the fact that great caution must be exercised in formulating laws as to the influence of temperature on drug action. The main results of this investigation may be summarized as follows: Doses of strychnin amounting to 0.0006 of a milligram per gram of frog will cause tetanus at all temperatures between 5° C. and 30° C., although at low temperatures the tetanus may appear late. A dose of 0.0003 of a milligram per gram of frog will frequently produce tetanus at 5° C. as well as at 30° or 27° C., but may nevertheless fail to produce any reaction at such an intermediary temperature as 21° C. Smaller doses, 0.0002 of a milligram per gram, will cause tetanus in the cold but not at high temperatures. It may be stated in general that in frogs kept at low temperatures the tetanic state sets in later, continues longer, and each tetanic attack is of longer duration, while in the interval between the attacks the state of tonus is higher and the animals are more irritable than when they are kept at higher temperatures.

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

Agromet ◽  
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 ◽  
Influence Of Temperature ◽  
Influence Of Temperature On ◽  
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 (&gt; 600 asl) and the lowlands (&lt; 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>

scholarly journals Pengaruh pH Ekstraksi pada Pewarnaan Batik Sutera Menggunakan Pewarna Alami Kulit Kayu Mahoni (Switenia Mahagoni)

2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Dwi Wiji Lestari ◽  
Vivian Atika ◽  
Isnaini Isnaini ◽  
Agus Haerudin ◽  
Tin Kusuma Arta
Keyword(s):  
Room Temperature ◽  
Natural Dye ◽  
Alkaline Ph ◽  
Influence Of Temperature ◽  
Ph Values ◽  
Influence Of Temperature On ◽  
Good Scale ◽  
Swietenia Mahagoni

The natural dye extracted from Swietenia mahagoni was applied to silk batik. Mahagoni bark is known to contain dyestuff components such as flavonoids and tannins. The dye compound was extracted using water at pH values of 6 (original pH extract), pH 2 (acid), and pH 12 (base) at 100 °C for 1 hour. Variation of extraction pH values was carried out to determine the influence of temperature on the results of the extract. Batik dyeing was carried out at room temperature using dye products. The pre-mordanting and post-mordanting used were alum (Al2(SO4)3.K2SO4.24H2O). The results showed that the dye product extracted in alkaline pH shows a high amount of tannins and flavonoids and the ability to color the silk batik better. The color direction is reddish-brown. The pH values of extraction do not affect the results of the colorfastness to washing test, which is on 4-5 (good) scale. A B S T R A KPewarna alami yang diekstrak dari mahoni (Swietenia mahagoni) diaplikasikan pada kain batik sutra. Kulit kayu mahoni diketahui mengandung komponen zat warna berupa flavonoid dan tanin. Komponen zat warna diekstraksi menggunakan air pada pH 6, pH 2 (asam) dan pH 12 (basa) pada suhu 100 °C selama 1 jam. Variasi pH ekstraksi dilakukan untuk mengetahui pengaruhnya terhadap hasil ekstrak. Pewarnaan dilakukan pada suhu ruang menggunakan pewarna hasil ekstraksi. Mordan awal dan mordan akhir yang digunakan adalah tawas (Al2(SO4)3.K2SO4.24H2O). Ekstraksi pada pH basa terbukti meningkatkan jumlah zat tanin dan flavonoid yang terekstrak dan mampu mewarnai kain batik sutra dengan lebih baik. Arah warna yang dihasilkan adalah cokelat kemerahan. Derajat keasaman (pH) ekstraksi tidak berpengaruh pada hasil uji ketahanan luntur warna terhadap pencucian, yaitu skala 4-5 (baik).

Influence of Temperature on theF‐Center Absorption in Sodium Fluoride

1966 ◽  
Vol 44 (4) ◽  
pp. 1324-1326 ◽  
Author(s):  
Kwasi Amenu‐Kpodo ◽  
Theodore J. Neubert ◽  
Walter Youngblade
Keyword(s):  
Sodium Fluoride ◽  
Influence Of Temperature ◽  
Influence Of Temperature On

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

Tribologia ◽  
2016 ◽  
Vol 269 (5) ◽  
pp. 21-30 ◽  
Author(s):  
Marcin FRYCZ
Keyword(s):  
Magnetic Susceptibility ◽  
Magnetic Particles ◽  
Operating Temperature ◽  
Measurement Data ◽  
Main Subject ◽  
Temperature Changes ◽  
Influence Of Temperature ◽  
Influence Of Temperature On ◽  
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.

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.

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