Analysis of leaf and needle litter decomposition by differential scanning calorimetry and differential thermogravimetry

1990 ◽  
Vol 9 (2) ◽  
pp. 188-191 ◽  
Author(s):  
U. Reh ◽  
W. Kratz ◽  
G. Kraepelin ◽  
C. Angehrn-Bettinazzi
Keyword(s):  
Differential Scanning Calorimetry ◽  
Litter Decomposition ◽  
Scanning Calorimetry ◽  
Needle Litter ◽  
Differential Thermogravimetry

scholarly journals Structural, Luminescent and Thermal Properties of Heteronuclear PdII–LnIII–PdII Complexes of Hexadentate N2O4 Schiff Base Ligand

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2423 ◽  
Author(s):  
Barbara Miroslaw ◽  
Beata Cristóvão ◽  
Zbigniew Hnatejko
Keyword(s):  
Differential Scanning Calorimetry ◽  
Schiff Base ◽  
Thermal Properties ◽  
Schiff Base Ligand ◽  
Intramolecular Energy Transfer ◽  
Scanning Calorimetry ◽  
Lanthanide Oxides ◽  
Schiff Base Ligands ◽  
Low Efficiency ◽  
Differential Thermogravimetry

New PdII–LnIII–PdII complexes of hexadentate N2O4 Schiff base ligand (H4L: N,N′-bis(2,3-dihydroxybenzylidene)-1,3-diamino-2,2-dimethylpropane) with Eu (1), Tb (2), Er (3) and Yb (4) ([Pd2Eu(H2L)2NO3](NO3)2∙2H2O∙2CH3OH 1, [Pd2Ln(H2L)2H2O](NO3)3∙3H2O, where Ln = Tb 2, Er 3, [Pd2Yb(H2L)2H2O](NO3)3∙5.5H2O 4) were synthesized and characterized structurally and physicochemically by thermogravimetry (TG), differential thermogravimetry (DTG), differential scanning calorimetry (DSC) and luminescence measurements. The compounds 1–4 are built of cationic heterometallic PdII–LnIII–PdII trinuclear units. The palladium(II) centers adopt a planar square geometry occupying the smaller N2O2 cavity of the Schiff base ligand. The lanthanide(III) is surrounded by two Schiff base ligands (eight oxygen atoms) and its coordination sphere is supplemented by a chelating bidentate nitrate ion in 1 or by a water molecule in 2–4. The complexes have a bent conformation along the PdII–LnIII–PdII line with valence angles in the ranges of 162–171°. The decomposition process of the complexes results in mixtures of: PdO, Pd and respective lanthanide oxides Eu2O3, Tb2O3, Tb4O7, Er2O3, Yb2O3. The luminescent measurements show low efficiency intramolecular energy transfer only in the complex of terbium(III) (2).

Synthesis, Characterization and Properties of Rare Earth Complexes with Caprolactam

2014 ◽  
Vol 707 ◽  
pp. 73-76
Author(s):  
Hui Fang Yang ◽  
Shu Xia Ren ◽  
Lei Sun ◽  
Huang Li
Keyword(s):  
Differential Scanning Calorimetry ◽  
Rare Earth ◽  
Fluorescence Spectra ◽  
Rare Earth Ions ◽  
Rare Earth Complexes ◽  
Scanning Calorimetry ◽  
Solid State Method ◽  
State Method ◽  
Differential Thermogravimetry ◽  
The Eu

Three rare earth complexes of (Eu (C6H11NO)8, La0.6Eu0.4(C6H11NO)6, Tb0.5Eu0.5(C6H11NO)6(H2O)) were synthesized by solid-state method. The as-prepared complexes were characterized by elemental analysis, thermogravimetry-differential thermogravimetry-differential scanning calorimetry (TG-DTG-DSC), infrared (IR) spectra and fluorescence spectra. The results showed that complexed were prepared by the rare earth ions directly bonded to oxygen atoms of caprolactam ligand and emitted a characteristic fluorescence of the Eu3 +or Tb3+ions.

Thermal Stability of N-Heterocycle-Stabilized Iodanes – A Systematic Investigation

2019 ◽  
Author(s):  
Andreas Boelke ◽  
Yulia A. Vlasenko ◽  
Mekhman S. Yusubov ◽  
Boris Nachtsheim ◽  
Pavel Postnikov
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Systematic Investigation ◽  
Scanning Calorimetry ◽  
Thermal Stability Of

<p>The thermal stability of pseudocyclic and cyclic <i>N</i>-heterocycle-stabilized (hydroxy)aryl- and mesityl(aryl)-l<sup>3</sup>-iodanes (NHIs) through thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) is investigated. NHIs bearing <i>N</i>-heterocycles with a high N/C-ratio such as triazoles show among the lowest descomposition temperatures and the highest decomposition energies. A comparison of NHIs with known (pseudo)cyclic benziodoxolones is made and we further correlated their thermal stability with reactivity in a model oxygenation. </p>

Optimasi Proses Pembuatan dan Karakterisasi Fisik Niosom Sinkonin

2019 ◽  
Vol 16 (2) ◽  
pp. 178
Author(s):  
Hariyanti Hariyanti ◽  
Sophi Damayanti ◽  
Sasanti Tarini
Keyword(s):  
Differential Scanning Calorimetry ◽  
Particle Size ◽  
Hair Follicle ◽  
Scanning Calorimetry ◽  
Span 60

Sinkonin praktis tidak larut dalam air, sedikit larut dalam kloroform dan alkohol. Hal ini berdampak pada rendahnya penetrasi transfollicular sinkonin, karena hanya bahan aktif hidrofilik yang mampu melewati hair follicle. Dengan demikian dibutuhkan satu sistem penghantaran yang mampu menurunkan hidrofobisitas sinkonin untuk meningkatkan penetrasi sinkonin ke follicle. Niosom merupakan vesikel ampifilik dengan struktur lapisan rangkap yang terbentuk dari hidrasi kombinasi surfaktan nonionik dan kolesterol yang mampu menurunkan hidrofobisitas sinkonin. Penelitian ini bertujuan untuk menentukan proses pembuatan niosom sinkonin yang optimum. Pembuatan niosom sinkonin diawali dengan menentukan temperatur gelasi (Tg) dari span 60 dengan Differential Scanning Calorimetry (DSC), kemudian dilanjutkan dengan optimasi proses meliputi: optimasi kecepatan rotavapor pembentukan film lapis tipis, temperatur hidrasi, kecepatan rotavapor hidrasi, waktu hidrasi, dan waktu sonikasi. Karakteristik vesikel niosom yang optimal meliputi: ukuran partikel dan indeks polidispersitas dengan menggunakan Particle Size Analized (PSA) serta efisiensi penjeratan sinkonin dengan menggunakan KCKT. Temperatur gelasi (Tg) span 60 45±2 oC, kecepatan rotavapor pembentukan film lapis tipis niosom 210 rpm, temperatur hidrasi 55±2 oC, kecepatan rotavapor hidrasi 210 rpm, waktu hidrasi 20 menit, waktu sonikasi suspensi niosom 1 menit. Ukuran vesikel yang diperoleh adalah 100–200 nm, indeks polidispersitas 0,2–0,4 dan efisiensi penjeratan niosom sinkonin 84,49±0,0025%. Proses pembuatan niosom sinkonin memiliki pengaruh besar terhadap hasil ukuran vesikel dan efisiensi penjeratan niosom sinkonin.

Improving Wire Sweep Performance by Measuring Degree of Cure of Epoxy Mold Compounds

2011 ◽  
Author(s):  
Sheila Liza B. Dal
Keyword(s):  
Differential Scanning Calorimetry ◽  
Shelf Life ◽  
Trial And Error ◽  
Active Components ◽  
Scanning Calorimetry ◽  
Degree Of Cure ◽  
Electronic Package ◽  
Viscosity Changes ◽  
Epoxy Mold Compounds

Abstract The choice of epoxy mold compound (EMC) for an electronic package is based mostly on how much protection it provides to the active components in the package. But the choice is not a straightforward process. Rather it is mostly trial and error using different assembly parameters to find the most robust material while assembly defects are monitored. One such defect associated to EMC processing is wire sweep, and many studies have shown that it is mainly caused by viscosity changes in the EMC. In this study, samples of EMC in various stages of shelf life and staging times were analyzed for degree of cure using a method called differential scanning calorimetry (DSC). Samples are then processed at assembly for wire sweep measurement. It was found out that degree of cure increases with staging time at different rates for each shelf life. It was also found out that wire sweep did not only increase with degree of cure but it was also found to be predictable with respect to the latter. Using this information, the age and staging limit for each material was identified that would not cause wire sweep issues.

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