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Hydrate complexes of magnesium aspartate, magnesium aspartate glycinate, magnesium aspartate arginate have been synthesized and characterized by the elemental and spectral analysis. The formulae of the magnesium complexes were Mg(C4H6O4N) • 4H2O, Mg(C6H10O5N2) • 5H2O, and Mg(C10H19O5N5) • 7H2O. The main thermal process: dehydration of the complexes, was studied using the thermoanalytical methods: differential thermal analysis (DTA), thermogravimetric analysis (TG), and differential scanning calorimemtry (DSC) measurements. The influence of additional ligands (glycinate or arginate) introduced to the structure of magnesium aspartate on the physicochemical properties of the newly synthesized compounds was analysed.
The concrete with compact structure on the basis of Portland cement modified by the dispersion of multilayer carbon nanotubes GraphistrengthTM by Arkema is investigated. The change in the structure of cement stone in the process of concrete setting and hardening when introducing carbon nanotubes into the concrete composition is observed.
The aim of the study was to analyze the kinetic parameters (activation energy Ea, pre-exponential coefficient A, rate constant k) of thermolysis in torrefied and raw willow wood (Salix viminalis L.), as well as to determine the effect of thermal modification conditions on the kinetics of this process. Samples of raw and torrefied willow wood in a steam atmosphere were analysed. The samples were subjected to thermogravimetric analysis under isothermal conditions. Analyses were conducted in an atmosphere of helium at 270–330°C. TG and DTG curves were recorded. The thermal characteristics of the samples were based on thermogravimetric analysis under dynamic conditions at a temperature of up to 600°C. On the basis of the data obtained from the TGA analyses, the kinetic parameters were calculated and statistical and mathematical analyses of the results were performed.
An analysis of thermal decomposition in oxidative conditions of model wood-based materials glued with amino resin. The presented work includes the results of thermal analysis of model samples of particleboards glued with urea-formaldehyde resin with varying degree of sealing (5 ÷ 30%), which is a measurable factor changing the elemental nitrogen content in the samples. Changes of the kinetic parameters of the thermo-destruction reactions occurring in the air were observed as well.
An experimental study on Carica papaya leaves was carried out in Thermo gravimetric analyzer (TGA), Differential Thermal Analyzer (DTA) and Differential Scanning Calorimetric (DSC) analyzer to investigate the effects of reaction atmosphere on thermal chemical characteristics. Experimental results show that In DSC curve, Endothermic peak at 101 °C is attributed to dehydration/Water loss from surface and pores of the powder sample. Step at 215 °C is associated with second order phase transition such as Glass Transition and it should be further confirmed in second heating (During heat- cool- heat cycle). Endothermic peak at 336 °C is associated protease thermal decomposition /Beta Cyclodextrin breakdown. In the TGA Curve, The initial 4 % weight loss is due to water loss from surface/pores of powder sample. Second weight loss between 200-450 °C is associated to degradation of cellulose and hemicellulose.
Starch from kudzu roots (Pueraria lobata) was isolated, characterized and compared with commercial available starch products such as potato, corn and wheat. The yield of starch from kudzu roots ranged from 65 to 162 g starch/kg depending on the age of the root. The examined diameters of kudzu starch granules showed that about 80% had an average diameter less than 32 µm. The fat and protein contents of the starch were about 0.15 and 0.08%, respectively. The HPLC analysis of enzymatic hydrolysate (alpha-amylase) of the starch showed that it contained low amount of reducing sugars, and the predominate carbohydrate was dextrin (Gn=45.6%). The viscosity obtained was 412 BU, being two-fold lower than the viscosity of both potato and corn starches, and somewhat closer to the viscosity of wheat starch. In addition, kudzu starch showed different physico-chemical properties compared to starches from other sources. These features could offer a novel application of this starch in carbohydrate processing industries.
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