1,566 research outputs found

    Waste Edible Oil Fluid Catalytic Cracking in a Downer Reactor

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    The waste edible oil fluid catalytic cracking process (FCC), an environment friendly process to produce clean fuel (such as gasoline, diesel) and high-value chemical materials (such as propylene), was studied in an small hot model of downer reactor under the temperature 500 ℃, the pressure 1.1×105Pa , the resident time 1 second, the ratio of catalyst to oil 12 , and MA-83 as the catalyst. Compared with other processes, the waste edible oil FCC process can realize the waster utilizing and adjust the product distribution according to the market demand, while with a convenient pretreatment to the raw materials. The experimental results showed that the waste edible oil and cottonseed oil fluid catalytic cracking process have the similar product distribution: liquefied petroleum gas (LPG) 10.3wt%, gasoline 36.4wt%, diesel oil wt23%. And the desired product the gasoline and diesel with trace content of sulfur, nitrogen and heavy metals, have the similar molecular weight and chemical structure to the gasoline and diesel from petroleum-based fuel. Therefore, the waste edible oil fluid catalytic cracking is a promising process, with both economic and environmental benefit

    Research on the Algorithm of Extracting Weak Signals from Radar Images under the Double-layer Rebars Shielding

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    AbstractBasement floor is a component of building structure, which is mainly made of reinforced concrete. The defects threaten the safety of building structures and the use of underground buildings all the time. The main defects in the process of construction are that the pouring thickness of floor can’t reach the design demand or the loose of the base. The thickness of the basement floor, which is made of a double-layer rebars structure and often detected by high frequency radar antennae, is usually 0.4 meters. Steel mesh is highly reflective to radar waves, and is shielded from reflection information of the bottom interface of floor, so that it is too hard to reach the goal of interpreting anomalies of images using conventional approaches. Studies have shown that the modern spectrum has a higher resolution than classical spectrum, so that the algorithm of the expectation value of the modern spectrum. Which constructs profile images of radar modern spectrum by short time-window, has been presented. The spectrum profiles made characters of weak shielded signals prominent, proved the algorithm of modern spectrum profiles, by means of procession, interpretation and application of the double-layer rebar reinforced concrete structure and defects, and also demonstrated the effectiveness of the technology of modern spectrum profiles


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    This study is aimed to explore the balance of participants between arms-free and arms-control conditions with the Star Excursion Balance Test (SEBT) and Romberg\u27s Test. Twenty healthy young males volunteered to participate in the test. Optitrack Optoelectronic system was utilized to capture the spatiotemporal parameters and the three-dimensional coordinates of the lower extremities. Besides, DIERS formetric 4D system was used to analyse the motion amplitude of spine and pelvis. Arms-control could reduce the dynamic balance based on the results of SEBT, and it would increase the static balance in the instability static condition from Romberg’s Test. Results of this study have provided information on clinical evaluation using arm position during dynamic and static balance from a biomechanical perspective

    A new error analysis for parabolic Dirichlet boundary control problems

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    In this paper, we consider the finite element approximation to a parabolic Dirichlet boundary control problem and establish new a priori error estimates. In the temporal semi-discretization we apply the DG(0) method for the state and the variational discretization for the control, and obtain the convergence rates O(k14)O(k^{\frac{1}{4}}) and O(k34ε)O(k^{\frac{3}{4}-\varepsilon}) (ε>0)(\varepsilon>0) for the control for problems posed on polytopes with y0L2(Ω)y_0\in L^2(\Omega), ydL2(I;L2(Ω))y_d\in L^2(I;L^2(\Omega)) and smooth domains with y0H12(Ω)y_0\in H^{\frac{1}{2}}(\Omega), ydL2(I;H1(Ω))H12(I;L2(Ω))y_d\in L^2(I;H^1(\Omega))\cap H^{\frac{1}{2}}(I;L^2(\Omega)), respectively. In the fully discretization of the optimal control problem posed on polytopal domains, we apply the DG(0)-CG(1) method for the state and the variational discretization approach for the control, and derive the convergence order O(k14+h12)O(k^{\frac{1}{4}} +h^{\frac{1}{2}}), which improves the known results by removing the mesh size condition k=O(h2)k=O(h^2) between the space mesh size hh and the time step kk. As a byproduct, we obtain a priori error estimate O(h+k12)O(h+k^{1\over 2}) for the fully discretization of parabolic equations with inhomogeneous Dirichlet data posed on polytopes, which also improves the known error estimate by removing the above mesh size condition

    Shaking Table Tests of Seismic Pile-Soil-Pier Structure Interaction

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    The limited strong earthquake database on structure and pile performance obstructs obtaining further progress in soil-pile structure interaction problem. Model test in laboratory is one of the best ways to expand the database of structure and pile performance during earthquake. In this paper, the problem of pile-soil-pier-structure interaction is investigated by shake table test approach, and on the development of the sandy box for SPSSI test is firstly introduced. Through free field test, the validation of the model container was evaluated by comparisons of soil acceleration records with those numerically calculated by SHAKE91. Secondly, four specimen to simulate friction pile response were employed: single column pile pier, one column pier model with 2x2 piles, two-column piers model with 2x2 piles and two-column piers model with 3x2 piles. The characteristic behaviors of single pier and two piers were comparatively experimented and analyzed under the same condition of pile groups and input motion

    Anisotropic mechanical behavior of thermally bonded nonwoven fabric

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    Anisotropic properties of thermally bonded nonwoven fabric (polypropylene) have been investigated. Firstly, the orientation distribution function of fibre is obtained by applying Hough transform technique to scanning electron microscopy of nonwoven fabric. Secondly, the influence of specimen width on mechanical behavior of nonwoven fabric has been studied, and the relationships between tensile strength of nonwoven fabric and specimen width are acquired by applying nonlinear fitting. Finally, the anisotropic creep behavior of nonwoven is investigated at different stress levels, different directions of nonwoven and different durations by applying nonlinear fitting, and the empirical model for calculating creep elongation is deduced. The results show that the tensile and creep behaviors of nonwoven fabric are influenced significantly by the fibre distribution. The creep elongation of nonwoven fabric is proportional to the level of loading and time. The creep elongation of nonwoven fabrics follows exponential relationships with time and this is true for all the directions of load and for all the levels of loading