Search results

Center for Technology and Sciences - Institute of Chemistry.
Biuret (Figure 1) is the name given to a chemical structure formed from the process of decomposition of urea, at temperatures slightly above their melting point (132°C).
Chemical structure of biuret.

In Fig. 2(a), TEM micrograph of HAp powder, synthesized hydrothermally, shows that the diameter and length of rod-shaped HAp particles having hexagonal structure are about 30 and 100 nm, respectively.
Elliot: Structure and Chemistry of Apatites and Other Calcium Orthophosphates (Elsevier Science Publishers, Amsterdam 1994) [6] P.W.

In this paper, the propene gas sensing performance of Pt-thin Ga2O3-SiC MOS structures is investigated.
A micro heater was placed beneath the structure to control the temperature of the device.
Atkins, Physical Chemistry 6th Edition (Freeman, USA 1999).

Therefore, the 1CBr2 + 3O2 reaction plays a significant role in atmospheric chemistry.
The geometric structures and vibrational frequencies for all stationary points are obtained at the B3LYP/6-311++G(d,p) level.
Optimized geometric structures of the reactants, intermediates, transition states and products involved in the 1CBr2 + 3O2 reaction.

Microwave Hydrothermal Synthesis of GaN Nanorods Dong Li1,a, Fen Wang,Jianfeng Zhu,Dawei Liu, Xiaofeng Wang, Liuyi xiang 1Key Laboratory of Auxiliary Chemistry & Technology for Chemical Industry, Ministry of Education, Shaanxi University of Science & Technology, Xi'an, 710021, China aE-mail: lidong-qycl@163.com Keywords: Microwave; GaN; nanorods Abstract: The GaOOH Nanocrystal rods were successfully synthesized by microwave-hydrothermal method using Ga2O3 ,HNO3 and NH3·H2O as raw materials.
When the reaction temperature reached 1000 ℃, the diffraction pattern exhibits a stronger (002) peak compared to the (100) and (101) peaks due to the fact that the rods structure were made of highly oriented GaN nanocrystals.
The SEM and TEM images indicated that the obtained GaN particles had a rod-like crystal structure with length to width ratio about 5∶1.

Several method have been used for the synthesis of commercial hydroxyapatite which include solid state reaction [3], wet chemistry [4,5] and sol gel synthesis [6,7,8].
Hydroxyapatite powder manufactured from bovine bones has the advantage of inheriting some properties of the raw materials such as its chemical composition and structure, and also cost effectiveness.
The crystal structure analysis of dried and calcined samples phase was monitored by using x-ray diffractometer (PW3040/60 X’pert Pro) using CuKa radiation, 40 kV and 30 mA in 2 theta range of 5-80 degrees.

Sulfuric acid attack on various types of fine grained concrete Martin Vyšvařil1, a and Markéta Rovnaníková1, b 1 Brno University of Technology, Faculty of Civil Engineering, Institute of Chemistry, Žižkova 17, 602 00 Brno, Czech Republic avysvaril.m@fce.vutbr.cz, bchroma.m@fce.vutbr.cz Keywords: sulfuric acid, sulfates, pH, ettringite, gypsum, concrete.
The concrete pipes, walls and others structures can be affected by sulfate directly from wastewater (in the bottom part of pipelines) or produced by microbiological activity (on the sewer crown).
The pore structures of the samples included determination of total porosity (Pt; Table 2) and pore size distribution were studied by high pressure mercury intrusion porosimetry using a Micromeritics PoreSizer 9310.

Since it's related to surface composition, structure, crystalline orientation, adsorption, etc., a measurement of work function can indicate the surface condition [1,2].
Due to this, the work function has been widely studied in surface chemistry, addressing corrosion, the use of adsorption for gas sensors, application to semiconductor devices, and potential uses of micro and nano materials [5-8].
The half film and half substrate structure creates a bimetal interface.

The use of such structural promoters does not modify the specific catalytic properties of iron and enables the a stable nanocrystalline structure to be formed.
To achieve this outcome it is necessary to inhibit the carburisation reaction rate by an increase of the reverse reaction rate; i.e decarburisation due to the increase of the hydrogen partial pressure in the reaction mixture; or by changes in the surface structure of the carburised sample.
Mellor: A comprehensive treatise on inorganic and theoretical chemistry, vol.

First, solution data must be expressed in gene mode and string structure data.
The medium is fine particle, biotitic, and plagioclase granite, with massive structure and good homogeneousness.
Levitt: Physics and Chemistry of the Earth.