Advanced Materials Research Vol. 740

Abstract: Soft magnetic field samples were placed into the homogenous magnetic field of an imager based on nuclear magnetic resonance. Several samples made of a soft magnetic material (cut from a data disc) were tested. Theoretical computations on a magnetic double layer were performed. For experimental verification an MRI 0.178 Testa ESAOTE Opera imager was used. For our experiments a homogeneous circular holder (reference medium) - a container filled with doped water - was designed. The resultant image corresponds to the magnetic field variations in the vicinity of the samples. For data detection classical gradient-echo and spin-echo imaging methods, susceptible to magnetic field inhomogeneities, were used. Experiments proved that the proposed method is perspective for soft magnetic material testing using magnetic resonance imaging methods (MRI).

Abstract: The main factors that influent the friction coefficient between PTFE and stainless-steel of sliding isolation bearings (SIB) are introduced in this paper. The positive pressure, sliding velocity, air temperature and lubricant all played important roles to the friction coefficient of SIB. By means of experimental investigation, the friction coefficient of SIB is indicated, and according to the test data, estimation formula of friction coefficient is regressed. Furthermore, relationship between friction coefficient, positive pressure and the use of lubricant are preliminarily validated.

Abstract: The motion of impurity ions affects the electrical properties of polymer solid. The ions move through free spaces which exist in the non-crystalline part between polymer crystallites. The free spaces have inhomogeneous size distribution depending on a property of polymers or crystallization conditions. The homogeneity or inhomogeneity of the size of the free space affects the ionic motion, and consequently it also affects the electrical properties of polymer solids. In order to study the electrical properties of polymer solids in relation with such motion of impurity ions, the conductivity relaxation time was calculated for isotactic poly (propylene) (iPP), low density poly (ethylene) (LDPE) and plasticized poly (vinyl chloride) with dioctyl phthalate (p-PVC) from the electric modulus as a function of frequency which was observed by means of the Broadband Dielectric Spectroscopy (BDS). The value of the conductivity relaxation time reflects the non-crystalline structure of these polymers.

Abstract: Based on characteristic of the muddy soil residing in east-south coastal area of China, the effect of cement grade, cement-mixing ration and cement type on mechanical properties of cement-soil was carried out in this paper. The results show that cement-soil increases obviously with increasing of hydration age for different cement types. At early hydration age, strength of cement-soil increases quickly. And at the age of 28d~90d, strength of cement-soil still show quite obvious increasing, but increase rate is slow. Increasing cement-mixing ratio improve strength of cement-soil obviously and 0.15~0.20 cement-mixing ratio is suitable to use. Higher cement grade can bring higher strength of cement-soil. Early strength of cement-soil solidified with P.S32.5 increases slowly, but the middle and late stage strength of cement-soil solidified with P.S32.5 increase quickly. The solidification effect of P.S 32.5 is better than that of AEC32.5 and P.MSR32.5.

Abstract: This paper experimentally investigates light intensity distribution in a paraboloid of thin shell irradiated by a laser. Light intensity distribution needs to be understood for solar energy heat receiver or laser drilling cavity. A novel method is utilized to measure the light intensity distribution in a paraboloid of thin shell irradiated by a laser. The results are explained by simple geometric optics.

Abstract: Based on the motion characteristics of mechanical oscillating parts, a wear test machine is developed with single drive biaxial rotational oscillating, which can effectively simulate multiaxial rotational oscillation of mechanical oscillating parts and take different kinds of friction couplings wear test. Based on this design, the tribological property of easy wearing material in mechanical oscillating parts is studied and corresponding sphere-block test method is established. Pilot test and demonstration are taken to evaluate the sphere-block test method from feasibility, practicality, reliability and economy aspects. The results are meeting test requirements of tribological property under the condition of composite motion.

Abstract: This paper presents 3D reconstruction of fabric surface with the pills, detection of the pills and qualitative evaluation of pilling with the help of spatial data analysis. 3D reconstruction of fabric surface is performed with the help of gradient fields method. The surface pills are extracted from 3D image by techniques of image analysis. Consequently, the tools of spatial data analysis as K function, density and test are used for experiment of qualitative evaluation of pills distribution in the space.

Abstract: Through the practice of tamped cement soil pile in treatment of soft soil foundation in Guan to Shenzhou section of Daqing-Guangzhou Expressway, the author expounds the action mechanism of rammed soil cement pile, composite foundation design points and calculation method of bearing capacity characteristic value.

Abstract: Presented article deals with absorbability and thermal capacity measuring for few basic types of towels. Absorbability is the material ability to absorb water. That is especially for towels the most important property. The thermal capacity behaviour according to the increasing moisture degree was investigated by the Alambeta device. Thermal capacity is the parameter, which characterizes the thermal touch. A task of laboratory experiments was to determine how much water stayed on human body after an ordinary shower. Furthermore, it was obligatory to set chosen property characteristics by the Alambeta device and finally to set towels drying time.

Abstract: The potassium metavanadate samples were digested by hydrochloric acid and diluted with water to a constant volume, then the inductively coupled plasma atomic emission spectrometry (ICP-OES) was used to directly determine the content of 10 to 45% matrix vanadium. The matrix effects, spectral interference, background noise and other interference factors in the high concentration of potassium ions coexistence system were all examined in the paper. The results showed that although the coexisting alkali metal potassium significantly increased the ICP flame, the 1g/L potassium standard solution did not produce peaks in the scanning window of analysis line which substantially coincide with the reagent blank signal line, i.e., the 28% (or 0.28g/L) potassium contained in the potassium metavanadate did not interfere with the determination. Therefore, only the standard solution of vanadium was used to draw a calibration curve without the need of potassium matrix matching. In order to obtain a wide linear range and improve the detection precision and the accuracy of the matrix element vanadium, the sample dilution ratio and ICP spectrometer detection parameters were optimized, and the suitable sensitivity spectral lines and their detection integral and background correction regional were selected, the detection signal intensity of the high concentration vanadium is effectively regulated moderate, the detection range is covered from 10 to 45%, which fully meet the need for determination of vanadium in the potassium metavanadate (qualified products containing 37% vanadium). The results also showed that the background equivalent concentration is less than 5 μg/L, the relative standard deviation (RSD) is less than 1.0%, the detection results consistent with the redox titration method. The method is simple and fast, accurate and reliable, the precision is high. The inspection cycle is 10 to 15 minutes, which is greatly shorter than the chemical titration that takes 2 to 3 hours, so that the method meet the requirements of fast-paced production site of the potassium metavanadate product quality inspection and control.