The effects of pH on phosphate removal from wastewater by electrocoagulation with iron plate electrodes

In this study, the effect of pH on phosphate removal from wastewater by electrocoagulation with iron plate electrodes has been investigated. For this aim, experiments have been carried out controlled initial pH values within the range of 3-9. Effects of initial pH have been analyzed on efficiencies of phosphate removal and energy consumptions. From obtained results, it was found that optimal initial pH is 3. Besides, experiments have been carried out controlled system pH. Effects of system variables have been analyzed on constant pH. From obtained results in these experiments, it was found that optimal system pH is 7.     

Diagnostics of fast processes by charged particle beams at TWAC-ITEP accelerator-accumulator facility

A new setup for the experimental investigation of rapid dynamic processes using proton radiography techniques has been created at the TWAC-ITEP terawatt accelerator-accumulator facility. A set of equipment for conducting shock-wave experiments has been designed, constructed, and tested, and an instrumentation-software complex has been developed for the automation of experiments. The first series of experiments with dynamic targets representing high explosives have been carried out, in which the density distribution in detonation waves initiated in these explosives has been measured.

     

Size-shape determination of nonspherical particles in suspension by means of full and depolarized static light scattering

Full and depolarized static light-scattering (LS) experiments have been carried out to characterize the size and shape of colloidal suspensions. Results have been compared with theoretical predictions following the extended-boundary-condition method (T-matrix) formalism for scattering by nonspherical particles. Theory-to-experiment data fitting has yielded size-shape data that compare well with electron-microscopy determinations. Depolarized light-scattering has been found to be an especially useful tool to use to find the correct geometrical parameters of the suspended particles. Size (though not shape) is also correctly fitted through full LS experiments.     

Comparison of bursting pressure results of LPG tank using experimental and finite element method

In this study, the resistance of liquefied-petroleum gas (LPG) tanks produced from carbon steel sheet metal of different thicknesses has been investigated by bursting pressure experiments and non-linear Finite Element Method (FEM) method by increasing internal pressure values. The designs of LPG tanks produced from sheet metal to be used at the study have been realized by analytical calculations made taking into consideration of related standards. Bursting pressure tests have been performed that were inclined to decreasing the sheet thickness of LPG tanks used in industry. It has been shown that the LPG tanks can be produced in compliance with the standards when the sheet thickness is lowered from 3 to 2.8mm. The FEM results have displayed close values with the bursting results obtained from the experiments.     

Direct digital control of a superconducting magnet

A microcomputer-based controller and its input/output interfaces have been developed for an inductor-converter unit (IC unit) which consists of a six-pulse Graetz-type converter and a solenoidal superconducting magnet (SM). The SM current is feedback-controlled through the following operations: detection of the SM current, comparison with the reference input for generation of the error signal, determination of the firing angle by the digital operation of compensation, and generation of the trigger pulses. The algorithms for digital compensation have been studied by experiments as well as computer simulations. Proportional-integral-derivative (PID), first-order exponential response with transport delay (Dahlin algorithm), and finite time settling control (FTSC) algorithms have been simulated and experimented by using the IC unit. Accurate agreements between the results of simulations and experiments have been obtained for the PID and Dahlin algorithms. The FTSC algorithm has shown the best response of the three methods.     

Study of phase transformations in silicon by scanning tunneling spectroscopy and nanoindentation

The results have been reported of the experiments on nanoscratching and nanoindentation of the surface of silicon using scanning tunneling microscope equipped with diamond semiconducting probe. Physical phenomena in silicon occurring at various contact pressures have been discussed.     

A unified model of stress relaxation and creep applied to oriented polyethylene

The stress relaxation behaviour of high-modulus oriented polyethylene fibre has been studied with regard to the response to successive small strain increments imposed on an initial relatively large strain deformation. For isotropic polymers, the results of such experiments have previously been interpreted in terms of a single thermally activated process modified by strain hardening. It has been found that, although this approach can describe satisfactorily some of the stress relaxation experiments on the oriented polyethylene fibres, it is unsatisfactory once the strain increments have exceeded a certain size, and that it is at variance with stress recovery experiments. It is shown that both the present stress relaxation and stress recovery experiments can be interpreted in terms of a model comprising two thermally activated processes acting in parallel. Furthermore, the parameters obtained for the stress relaxation data are consistent with those required to fit creep data obtained in a comparable stress range. The essential feature of the mechanical behaviour which was previously attributed to strain hardening can now be seen to arise from the transfer of stress between the two thermally activated processes in the two-process model.     

低温供气条件下新型切向小孔气体轴承动特性的实验研究

针对一种新型切向小孔供气轴承进行了低温供气下的动特性实验，实验中得出了轴承的温降曲线，测定了轴承温度由常温降至低温时轴承间隙的变化，比较了常，低温供气时轴承稳定性的差别。     

Gas Adsorption in Novel Environments, Including Effects of Pore Relaxation

Adsorption experiments have been interpreted frequently with simplified model geometries, such as ideally flat surfaces and slit or cylindrical pores. Recent explorations of unusual environments, such as fullerenes and metal-organic-framework materials, have led to a broadened scope of experimental, theoretical and simulation investigations. This paper reviews a number of such studies undertaken by our group. Among the topics receiving emphasis are these: universality of gas uptake in pores, relaxation of a porous absorbent due to gas uptake, and the novel phases of gases on a single nanotube, all of which studies have been motivated by recent experiments.     

用电磁场减轻Al-Pb合金比重偏析的实验研究

本文对正交电磁场作用下的Al-Pb合金凝固进行了实验研究。结果表明,当选取的电磁场参数合适时,可减少合金的比重偏析。文中对该类合金的分解过程进行了探讨,分析了电磁场的作用和用它来模拟微重力条件的可行性。     

用动态全积分法提高圆分度精度

论述了动态全积分法的基本原理和误差分析，比较了几种基本结构和信号处理方法的优缺点，对实现方法的关键技术进行了讨论。组合装配成原理实验装置，并作了三个对比实验，取得了较好的初步结果。实验表明动态全积分法能很好地消除光栅刻划误差及偏心的影响，提高了圆分度精度。此法适用于高精度测量系统。     

Dynamic deformation and fracture of mullite (3Al2O3·2SiO2) ceramics under hypervelocity impact

Shock-recovery experiments have been performed on mullite ceramics to clarify the effect of a phase transition on the microstructural change and deformation mechanism under shock loading. The recovered samples have been examined using the X-ray diffraction method and transmission electron microscope observation. In the samples shocked above the phase-transition pressure, an amorphization of mullite occurs. Mullite nano-crystals with grain sizes less than 10 nm are dispersed in the amorphous phase, indicating that the relatively large starting mullite crystals become nano-crystals accompanied with the amorphization. Mullite bumper-shield experiments have also been performed to examine the influence of shock-induced microstructural changes to ultimate fracture under hypervelocity impact. The results suggest that the phase transition of mullite has an effect on protection against high-velocity impact.     

Detailed Study of Charged Stripes in La1.6−xNd0.4SrxCuO4

Hard x-ray diffraction experiments at the wiggler beamline BW5 at the synchrotron radiation laboratory HASYLAB in Hamburg have been very suc-cesful in studying the charge stripe ordering of holes in the CuO₂ plane of La_1.48Nd_0.4Sr_0.12CuO₄. This compound has been previously studied with neutron diffraction, leading to the idea of charged stripes as antiphase domain boundaries for antiferromagnetic ordering of the Cu spins. In our x-ray experiments we have shown that correlation between the stripes exists also perpendicular to the CuO₂ planes. The modulation of the intensities along the l-direction have been measured at several positions in reciprocal space. We have been succesful in observing stripe peaks also in samples with Sr doping levels of x = 0.15 and x = 0.10, whereas no stripe signal has been observed in a sample with x = 0.20.     

Multispectral method for skin imaging: development and validation

A visible wide field multispectral system for comprehensive imaging of skin chromophores and blood vessels has been implemented, and an inhomogeneous Monte Carlo model of photon migration with randomly distributed blood vessels embedded in dermis has been developed. Predetermined nonlinear transforms have been obtained to address the nonlinear interdependent relationship among diffusive reflectance spectra, skin physiology properties, and geometry. For validation, in addition to real skin experiments and phantoms experiments, two alternative methods for blood vessel imaging have been used on the same set of subjects to compensate for the lack of ground truth for skin subsurface imaging.     

Heat and mass transfer in vertical tubular bubble absorbers for ammonia-water absorption refrigeration systems

A model is developed for calculation of simultaneous heat and mass transfer processes in vertical bubble absorbers as used for ammonia-water absorption refrigeration systems. Some preliminary experiments have been performed in an absorber without heat removal. The results from these experiments are compared with the literature and give a first indication about the methods for prediction of the absorption process. Experiments have also been performed with simultaneous heat removal. The internal diameters of the absorbers tested were 10.0, 15.3, and 20.5 mm. The mass transfer coefficients resulting from these experiments are correlated by a modified Sherwood relation. An interative procedure is presented which allows design of vertical tubular bubble absorbers for ammonia-water absorption refrigeration systems.     

Design for Stamping: Identifying Pedagogically Effective Components in Multimedia Tutors and the Classroom

Multimedia tutors have been developed for a number of different areas in manufacturing—including forging, die casting, and injection molding. Typically, students using these tutors perform better than students receiving traditional classroom instruction. However, the strengths and weaknesses of the tutors have not been isolated in any of the reports to date. This paper presents the results of experiments designed to isolate the most effective components used to teach design for stamping. The experiments compared classroom instruction with software tutorials. The results of these experiments indicate that the use of software tutorials when combined with feedback on graded homework assignments is as effective as traditional lectures that also make use of graded homework assignments     

Advantages and limitations of nuclear physics experiments at an ISIS-class spallation neutron source

Nuclear physics experiments have a long history of being conducted on spallation neutron sources. Like other experiments, these measurements take advantage of the identification of the incident neutron energy by the time-of-flight (ToF) technique. However, in some ways these experiments are often in direct conflict with other experiments. Especially in large (ISIS or SNS class) facilities, the design of the source often reflects a compromise between different experimental needs and requirements. It has been a long standing question for nuclear physics experiments how limiting these compromises are and how they can be dealt with. We have therefore calculated the incident neutron energy spectrum, along with the gamma background spectrum, for flight path (FP) 5 at the Los Alamos Neutron Science Center (LANSCE) Manuel Lujan Jr. Neutron Scattering Center (Lujan Center) including a detailed evaluation of the signal shape. We will discuss the advantages and limitations of the nuclear physics experiments at FP-5 in the light of our results.     

纳米分子筛/聚丙烯酰胺复合材料的制备

采用溶液共混法制备纳米分子筛/聚丙烯酰胺复合材料,做了条件实验(如:温度,pH值,配比,浓度,合成时间,添加偶联剂等),测试了纳米分子筛/聚丙烯酰胺复合材料的吸水性,吸油性.结果表明,随着分子筛含量增加,纳米分子筛/聚丙烯酰胺复合材料吸水率和吸油率都有很大的增加,随着共混温度升高复合材料吸水率和吸油率增大,确定了复合材料最佳吸水率和吸油率制备条件.     

Tribological failure analysis of journal bearings used in sugar mills

In present paper the premature failure of journal bearings encountered in sugar mills has been analyzed. The causes of bearing failure are identified by simulating the operating conditions and conducting controlled experiments on a fully automated Journal Bearing Test Rig with provisions for varied combination (i.e. load, speed, and lubricating oil) of operating conditions. The results of performance behavior (i.e. coefficient of friction, change in surface roughness and weight loss) of the bearings as observed in these experiments have been reported. The theoretical and experimental results indicate the existence of boundary lubrication conditions in sugar mill journal bearings. To mitigate the problem of relatively high wear, lubricating oil with boundary additives have been tried and results are reported.     

Measurement of cylindrical particles with phase Doppler anemometry

Light scattering from cylindrical particles has been described with geometric optics. The feasibility of determining the particle diameter with a planar phase Doppler anemometer has been examined by simulations and experiments. In particular, the influence of particle orientation on measurability and measurement accuracy has been investigated. Some recommendations for realizing a practical-measurement instrument have been presented.