Advanced Materials Research Vol. 1083

Abstract: The mono-(6-p-toluenesulfonyl)-β-cyclodextrin was firstly synthesized fast and efficiently by adopting ultrasound assisted method in alkaline water solution. The reaction time was only 40 min but with the yield of 31.1% under ultrasound condition. Compared with the conventional synthetic methods, the proposed novel method could shorten the reaction time and improve the yield. It is a simple, rapid and efficient method.

Abstract: The crystalline structure of the hexagonal Ba (Ti_0.95Fe_0.05)O_3−δ (BTF) ceramic were directly measured using a temperature-dependent XRD technique. Different from the traditional structural transitions of rhombohedral-orthorhombic (−90 °C), orthorhombic-tetragonal (−10 °C), and tetragonal-cubic (i.e., the Curie temperature T_C = 130 °C) for BaTiO₃, the phase transition from hexagonal to any phase above for BTF cannot occur at T_C even up to 300 °C. Increasing temperature cannot give rise to the occupation of oxygen vacancies by environmental oxygen absorbed. The lattice electro-neutrality maintained by Fe³⁺-V_O-Fe³⁺ defect complexes is predominant in BTF. This experiment clarifies the phase stability of the hexagonal perovskite structure above T_C up to 300 °C.

Abstract: According to different melting point of paraffin type of PCM, has carried out some experimental research and analysis, through the visualization experiment method, the PCM phase change expansion coefficient is determined. At the same time, under the same conditions, for 30 #, 40 #, 50 # PCM storage heat release experiments, contrast analysis of the regenerative heat release, total heat release, and storage time on average water temperature difference factors. In addition, carried out more than melting point PCM cascade configuration related experimental heat storage properties, expect to achieve energy utilization efficiency.

Abstract: Beside being used as alternative fuel, Jatropha curcas can also be use as dielectric fluid in the Electric Discharge Machining (EDM/EDC). The use of Jatropha curcas as dielectric fluid is starting to grow due to its green characteristic. This paper discusses the effects of using Jatropha curcas combined with rectangular cross section layered electrode for cutting SKD 61 steel. It is then compared to the cutting result of EDM process using combination of kerosene dielectric fluid with solid electrode. The outcomes reveal that cutting process using Jatropha curcas as dielectric fluid in lower current produces higher surface roughness and combination of dielectric fluid with electrode type will determine surface roughness, hardness, and white layer thicknesses.

Abstract: We analyze previously not studied issue on the value, nature and manifestation f a demagnetizing factor of effective channels-magnets formed in magnetized granular media by the chains of contacting granules. We provide the factor values for conditionally defined quasi-solid cores of the channels varying in length and diameter, as well as a corresponding consolidating expression which turned out to be exponential with such an argument as the radical of the core relative size. We emphasize full agreement of this expression with the one for a granular medium, i.e. the medium consisting, basically, of the effective channels bundle according to the developed theory of channel-by-channel (selective) magnetization of granular ferro-magnetic media used, e.g. as operating elements in versatile magnetic separators.

Abstract: This paper establishes the HPLC method of determining three nitrophenol isomers in municipal sewage, surface water and tap water. After the sample is filtered and distilled, conduct the monitoring analysis on the distillate with HPLC-DAD and quantify it in external standard method. In the municipal sewage treated in bioanalysis method one type of target object o-nitrophenol is found, whose content is 0.11mg·L^-1, no target object is found in all the other samples. This method has the adventages of high separation efficiency and high analysis rate. The experiment result shows that the linear correlation coefficient is above 0.983, the recovery rate lies between 78.6% and 105.2%, the minimum detection limit is 0.05mg·L^-1(S/N=3.0).

Abstract: A new simple and efficient RP-HPLC-UV method was developed for the simultaneous analysis of isoflavonoids in Huangqi Gegen and its marketed formulations. Effective chromatographic separation of ten active components was achieved on a Kromasil C₁₈ column (4.6×250 mm, i.d.; 5 μm) with gradient elution of methanol and 0.2% formic acid aqueous solution at a flow rate of 1.0 mL/min in 60 min. Detection was performed at 250nm. The validation of the method included tests of linearity, sensitivity, precision, repeatability, stability and accuracy. All calibration curves showed good linear regression (r>0.999) within test ranges. The established method showed good precision and accuracy with overall intra-day and inter-day variations of 0.77-1.81 % and 1.38-2.47 %, and overall recoveries of 96.64-103.96 % for the compounds analyzed. The developed method was successfully applied for the quantitative analysis of constituents in Huangqi gegen and its marketed formulations.

Abstract: In order to obtain GFRP reinforcement bars it is necessary to undertake tests regulated code which require important mechanical tools. This paper presents a method which allows for determining GFRP rebars tensile strength value from their flexural strength value which has been obtained with a simple, inexpensive and reliable test. This method results will be verified by applying it to values obtained in a series of bending tests and comparing these results with values obtained in tensile tests. Values concordance for small diameter GFRP rebars is very good.

Abstract: A SVM calibration model combined with new information processing method of support vector machine and infrared spectroscopy is established. For the problem of model parameters affecting the analysis results, the optimization of the model parameters is studied through the experiment. The mixed gas containing hydrocarbon is used as an example, spectra data preprocessing, spectra analysis band, spectrometer scanning interval, types of kernel function for SVM calibration model, penalty factor C, and other parameters that affect the measurement results are optimized. The experimental results show that the accuracy of the analysis results can be improved in the case of the SVM calibration model optimized and the model has a practical application value.

Abstract: When aircrafts have hypersonic flights in the atmosphere, high-temperature IR windows become the main factor of complicated aero-thermo-radiation effects, which reduce the performance of IR detection systems, or even make these detection systems fail. Consequently, measuring thermo-radiation characteristics of IR window material is essential for the assessment of aero-thermo-radiation effect. By analyzing thermal radiation transfer in IR windows, a method is proposed to measure thermo-radiation characteristics of IR window materials, and an experimental platform is established. Based on the platform, thermo-radiation characteristics of a sapphire IR window of a MWIR detection system in a hypersonic vehicle are measured. The results indicate that, the thermo-radiation characteristics of the sapphire IR window material in 3.7μm-4.8μm have an approximate cubic relationship with temperature at 100~350. With the rise of temperature, the transmittance of the sapphire material decreases, while the self-radiation increases. Subsequently, the self-radiation can drive detector into saturation easily, of which the influence on the MWIR detection system is bigger than that of the transmittance. And, with thickness increasing, transmittance decreases exponentially, and self-radiation increases, but the increment decreases exponentially. Consequently, as IR windows’ thickness or temperature increases, SNR of the MWIR detection system declines, saturation of IR detectors occurs easily.