示差熱分析

WordNet

an investigation of the component parts of a whole and their relations in making up the whole
the abstract separation of a whole into its constituent parts in order to study the parts and their relations (同)analytic thinking
a branch of mathematics involving calculus and the theory of limits; sequences and series and integration and differentiation
a form of literary criticism in which the structure of a piece of writing is analyzed
the use of closed-class words instead of inflections: e.g., `the father of the bride instead of `the brides father
relating to or showing a difference; "differential treatment"
a quality that differentiates between similar things
involving or containing one or more derivatives; "differential equation"
of or relating to a hot spring; "thermal water"
rising current of warm air
relating to or associated with heat; "thermal movements of molecules"; "thermal capacity"; "thermic energy"; "the caloric effect of sunlight" (同)thermic, caloric
caused by or designed to retain heat; "a thermal burn"; "thermal underwear"
distinguishing characteristics (especially in different species of a genus)
a unit of heat equal to 100,000 British thermal units

PrepTutorEJDIC

(内容・状況などの)『分析』,分解;(詳細な)検討 / (化学・物理で)分析;《米》(心理学で)[精神]分析;(数学で)解析
『差別的な』 / 微分の / 差動の / 〈C〉差別額,運賃差 / 〈U〉微分 / 〈C〉〈U〉(また『differential gear』)差動歯車,差動装置
熱の,熱による / 熱い / (暖まった)上昇気流
(論理学で)種差(ある種が同じ属の他の種と区別される属性);本質的な相違点

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/06/09 07:25:19」(JST)

wiki en

Differential thermal analysis (or DTA) is a thermoanalytic technique, similar to differential scanning calorimetry. In DTA, the material under study and an inert reference are made to undergo identical thermal cycles, while recording any temperature difference between sample and reference.^[1] This differential temperature is then plotted against time, or against temperature (DTA curve, or thermogram). Changes in the sample, either exothermic or endothermic, can be detected relative to the inert reference. Thus, a DTA curve provides data on the transformations that have occurred, such as glass transitions, crystallization, melting and sublimation. The area under a DTA peak is the enthalpy change and is not affected by the heat capacity of the sample.

Apparatus

A DTA consists of a sample holder comprising thermocouples, sample containers and a ceramic or metallic block; a furnace; a temperature programmer; and a recording system. The key feature is the existence of two thermocouples connected to a voltmeter. One thermocouple is placed in an inert material such as Al₂O₃, while the other is placed in a sample of the material under study. As the temperature is increased, there will be a brief deflection of the voltmeter if the sample is undergoing a phase transition. This occurs because the input of heat will raise the temperature of the inert substance, but be incorporated as latent heat in the material changing phase.^[2]

Today's Instruments

In today’s market most manufacturers no longer make true DTA systems but rather have incorporated this technology into thermogravimetric analysis (TGA) systems, which provide both mass loss and thermal information. With today’s advancements in software, even these instruments are being replaced by true TGA-DSC instruments that can provide the temperature and heat flow of the sample, simultaneously with mass loss. These instruments are normally called SDT (simultaneous DSC/TGA).

Applications

A DTA curve can be used only as a finger print for identification purposes but usually the applications of this method are the determination of phase diagrams, heat change measurements and decomposition in various atmospheres.

DTA is widely used in the pharmaceutical^[3] and food industries.^[4]^[5]^[6]^[7]

DTA may be used in cement chemistry,^[8] mineralogical research^[9] and in environmental studies.^[10]

DTA curves may also be used to date bone remains^[11] or to study archaeological materials.^[12]^[13]

References

^ Bhadeshia H.K.D.H. “Thermal analyses techniques. Differential thermal analysis”. University of Cambridge, Material Science and Metallurgy. www.msm.cam.ac.uk/phase-trans/2002/Thermal1.pdf
^ Robert Bud, Deborah Jean Warner. Instruments of Science. pp. 170–171.
^ Ferrer S., Borrás J., Martín Gil J. and Martín Gil F.J. "Thermal studies on sulphonamide derivative complexes”. Thermochim. Acta, 1989, 147, 321 330; 1989, 153, 205 220; 1991, 185, 315 333.
^ Berger K.G., Akehurst E.E. “Some applications of differential thermal analysis to oils and fats”. International Journal of Food Science & Technology, 1966, 1, 237–247.
^ Ramos Sánchez M.C., Rey F.J., Rodríguez M.L., Martín Gil F.J. and Martín Gil J. "DTG and DTA studies on typical sugars". Thermochim. Acta, 1988, 134, 55 60.
^ F.J. Rey, M.C. Ramos-Sánchez, M.L.Rodríguez, J. Martín-Gil, F.J. Martín-Gil. "DTG and DTA studies on sugar derivatives". Thermochim. Acta, 1988, 134, 67 72.
^ Rodríguez Méndez M.L., Rey F.J., Martín Gil J. and Martín Gil F.J. "DTG and DTA studies on amino acids". Thermochim. Acta, 1988, 134, 73 78.
^ Ramachandran V.S. “Applications of differential thermal analysis in cement chemistry”. Chap. V, Chemical Publishing Co., Inc., New York (1969), 92.
^ Smykatz-Kloss W. “Application of differential thermal analysis in mineralogy”. J. Therm. Anal. Cal., 1982, 23, 15-44.
^ Smykatz-Kloss W., Heil A, Kaeding L. and Roller E. “Thermal analysis in environmental studies”. In: Thermal analysis in Geosciences. Springer Berlin / Heidelberg, 1991.
^ Villanueva, PrE, Girela F. y Castellanos M. “The application of differential thermal analysis and thermogravimetric analysis to dating bone remains”. Journal of Forensic Sciences, 1976, 21,
^ Misiego-Tejeda J.C., Marcos-Contreras G.J., Sarabia Herrero F.J., Martín Gil J. and Martín Gil F.J. "Un horno doméstico de la primera Edad del Hierro de "El Soto de Medinilla" (Valladolid) y su análisis por ATD". BSAA (University of Valladolid) 1993, LIX, 89 111.
^ Kingery W.D. “A note on the differential thermal analysis of archaeological ceramics”. Archaeometry, 1974, 16, 109–112.

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. 骨転移を有する成人患者の疫学、臨床所見、診断、およびマネージメントの概要 overview of the epidemiology clinical presentation diagnosis and management of adult patients with bone metastasis
2. 成人における神経性食思不振症：臨床的特徴、評価、および診断 anorexia nervosa in adults clinical features assessment and diagnosis
3. 成人における間欠性爆発性障害：疫学、臨床的特徴、評価、および診断 intermittent explosive disorder in adults epidemiology clinical features assessment and diagnosis
4. 心気症：疫学、臨床症状、評価、および診断 hypochondriasis epidemiology clinical presentation assessment and diagnosis
5. 糸球体疾患の鑑別診断および評価 differential diagnosis and evaluation of glomerular disease

English Journal

INFLUENCE OF pH AND TEMPERATURE ON THE ACTIVITY OF SnO2-BOUND α-AMYLASE: A GENOTOXICITY ASSESSMENT OF SnO2 NANOPARTICLES.

Khan MJ1, Husain Q.Author information 1a Department of Biochemistry , Faculty of Life Sciences, Aligarh Muslim University , Aligarh , India.AbstractImmobilization of biologically important molecules on a myriad of nanosized materials has attracted great attention due to their small size, biocompatibility, higher surface-to-volume ratio, and lower toxicity. These properties make nanoparticles (NPs) a superior matrix over bulk material for the immobilization of enzymes and proteins. In the present study, Bacillus amyloliquefaciens α-amylase was immobilized on SnO2 nanoparticles by a simple adsorption mechanism. Nanoparticle-adsorbed enzyme retained 90% of the original enzyme activity. Thermal stability of nanosupport was investigated by thermogravimetric and differential thermal analysis. Scanning electron microscopic studies showed that NPs have porous structure for the high-yield immobilization of α-amylase. The genotoxicity of SnO2-NPs was analyzed by pUC(19) plasmid nicking and comet assay and revealed that no remarkable DNA damage occurred in lymphocytes. The pH-optima was found to be the same for both free and SnO2-NPs bound enzyme, while the temperature-optimum for NPs-adsorbed α-amylase was 5°C higher than its free counterpart. Immobilized enzyme retained more than 70% enzyme activity even after its eight repeated uses.
Preparative biochemistry & biotechnology.Prep Biochem Biotechnol.2014 Aug 18;44(6):558-71. doi: 10.1080/10826068.2013.835732.
Immobilization of biologically important molecules on a myriad of nanosized materials has attracted great attention due to their small size, biocompatibility, higher surface-to-volume ratio, and lower toxicity. These properties make nanoparticles (NPs) a superior matrix over bulk material for the im
PMID 24499361

Novel delivery approach for ketotifen fumarate: dissofilms formulation using 3² experimental design: in vitro/in vivo evaluation.

Fahmy RH1, Badr-Eldin SM.Author information 1Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Cairo University , Cairo , Egypt.AbstractOrally dissolving films (dissofilms) have gained increasing popularity and attention due to their ease of administration and avoidance of first pass metabolism. Ketotifen fumarate (KF) bioavailability is reported to be only ~ 50% due to hepatic first-pass metabolism. Aiming to surmount this drawback and improve patients' compliance, a 3(2) full factorial design was applied to formulate KF Orodispersible films, and to investigate the effects and interactions of the concentrations of the novel film former; Lycoat NG73® and the film modifier; maltodextrin (MDX) on the characteristics of the films prepared using solvent casting technique. The dissofilms were thoroughly evaluated regarding their weight uniformity, content uniformity, moisture uptake, in vivo mouth dissolving time (MDT) and their thermal behavior via differential scanning calorimetry. Statistical analysis revealed the significant influence of Lycoat NG73® concentration on percent elongation, percent KF dissolved after 5 min, and in vivo MDT, while MDX concentration had significant effect only on percent elongation. Further, storage of the optimal selected formula (15% Lycoat NG73 and 0% MDX) at 40 °C/75% relative humidity for 12 weeks caused no significant change in appearance, KF content or drug dissolution profile. Pharmacokinetic study revealed that the orally dissolving films showed significantly higher absorption extent than the reference marketed product, while no significant difference was observed for Cmax.
Pharmaceutical development and technology.Pharm Dev Technol.2014 Aug;19(5):521-30. doi: 10.3109/10837450.2013.800108. Epub 2013 May 28.
Orally dissolving films (dissofilms) have gained increasing popularity and attention due to their ease of administration and avoidance of first pass metabolism. Ketotifen fumarate (KF) bioavailability is reported to be only ~ 50% due to hepatic first-pass metabolism. Aiming to surmount this drawback
PMID 23713715

Evaluation of different methods for determination of the iron saturation level in bovine lactoferrin.

Bokkhim H1, Tran T2, Bansal N3, Grøndahl L4, Bhandari B5.Author information 1The University of Queensland, School of Agriculture and Food Sciences, Brisbane, QLD 4072, Australia. Electronic address: h.rai@uq.edu.au.2The University of Queensland, School of Agriculture and Food Sciences, Brisbane, QLD 4072, Australia. Electronic address: trannguyenhatrang@yahoo.com.3The University of Queensland, School of Agriculture and Food Sciences, Brisbane, QLD 4072, Australia. Electronic address: n.bansal@uq.edu.au.4The University of Queensland, School of Chemistry and Molecular Biosciences, Brisbane, QLD 4072, Australia. Electronic address: l.grondahl@uq.edu.au.5The University of Queensland, School of Agriculture and Food Sciences, Brisbane, QLD 4072, Australia. Electronic address: b.bhandari@uq.edu.au.AbstractLactoferrin (Lf) samples with ca. 25%, 50%, 75%, 85% and 100% iron saturation were prepared for the purpose of evaluating Chromametry, Differential Scanning Calorimetry (DSC) and Circular Dichroism (CD) spectropolarimetry for their suitability in determining the iron saturation level. Numerical values for colour from Chromametry, enthalpy change of denaturation (ΔHcal) from DSC and molar ellipticities from CD were statistically analysed to evaluate their correlation with the level of iron saturation in Lf. Linear regression analysis of colour coordinates Chroma (C(∗)) and hue (h°) angle on percentage iron saturation level of Lf showed that the values can be used to estimate the iron saturation level. The ΔHcal for the iron saturated peak and the CD ellipticities in the 310-340 nm region provided reliable data for the estimation of iron saturation level of Lf up to 75%. Mono- and di-saturated Lf displayed the same thermal stability and very similar tertiary structures.
Food chemistry.Food Chem.2014 Jun 1;152:121-7. doi: 10.1016/j.foodchem.2013.11.132. Epub 2013 Nov 28.
Lactoferrin (Lf) samples with ca. 25%, 50%, 75%, 85% and 100% iron saturation were prepared for the purpose of evaluating Chromametry, Differential Scanning Calorimetry (DSC) and Circular Dichroism (CD) spectropolarimetry for their suitability in determining the iron saturation level. Numerical valu
PMID 24444915

Japanese Journal

Analysis on partial thermal resistances of packaged SiC schottky barrier diodes at elevated temperatures

Jpn. J. Appl. Phys. 55(4S), 04ER18, 2016-03-22
NAID 150000112094

Preparation and characterization of monolithic Al2O3–SiO2 aerogel

Journal of the Ceramic Society of Japan 124(4), 442-447, 2016
NAID 130005142397

Crystallization mechanism and properties of high basicity steel slag-derived glass-ceramics

Journal of the Ceramic Society of Japan 124(3), 247-250, 2016
NAID 130005132944

Related Pictures

★リンクテーブル★

リンク元	「示差熱分析」
関連記事	「analysis」「differential」「thermal」

「示差熱分析」

Differential Thermal Analysis
Acronym	DTA
Classification	Thermal analysis
Other techniques
Related	Differential scanning calorimetry; Isothermal microcalorimetry; Dynamic mechanical analysis; Thermomechanical analysis; Thermogravimetric analysis; Dielectric thermal analysis