Ultrasonic-assisted catalytic transfer hydrogenation for upgrading pyrolysis-oil

Recent interest in biomass-based fuel blendstocks and chemical compounds has stimulated research efforts on conversion and upgrading pathways, which are considered as critical commercialization drivers. Existing pre-/post-conversion pathways are energy intense (e.g., pyrolysis and hydrogenation) and economically unsustainable, thus, more efficient process solutions can result in supporting the renewable fuels and green chemicals industry. This study proposes a process, including biomass conversion and bio-oil upgrading, using mixed fast and slow pyrolysis conversion pathway, as well as sono-catalytic transfer hydrogenation (SCTH) treatment process. The proposed SCTH treatment employs ammonium formate as a hydrogen transfer additive and palladium supported on carbon as the catalyst. Utilizing SCTH, bio-oil molecular bonds were broken and restructured via the phenomena of cavitation, rarefaction, and hydrogenation, with the resulting product composition, investigated using ultimate analysis and spectroscopy. Additionally, an in-line characterization approach is proposed, using near-infrared spectroscopy, calibrated by multivariate analysis and modeling. The results indicate the potentiality of ultrasonic cavitation, catalytic transfer hydrogenation, and SCTH for incorporating hydrogen into the organic phase of bio-oil. It is concluded that the integration of pyrolysis with SCTH can improve bio-oil for enabling the production of fuel blendstocks and chemical compounds from lignocellulosic biomass.     

Testing for forbidden order patterns in an array

A sequence contains a pattern , that is, a permutations of [k], iff there are indices i₁ < … < i_k, such that f(i_x) > f(i_y) whenever π(x) > π(y). Otherwise, f is π‐free. We study the property testing problem of distinguishing, for a fixed π, between π‐free sequences and the sequences which differ from any π‐free sequence in more than ? n places. Our main findings are as follows: (1) For monotone patterns, that is, π = (k,k ? 1,…,1) and π = (1,2,…,k), there exists a nonadaptive one‐sided error ?‐test of query complexity. For any other π, any nonadaptive one‐sided error test requires queries. The latter lower‐bound is tight for π = (1,3,2). For specific it can be strengthened to Ω(n^{1 ? 2/(k + 1)}). The general case upper‐bound is O(?^?1/kn^{1 ? 1/k}). (2) For adaptive testing the situation is quite different. In particular, for any there exists an adaptive ?‐tester of query complexity.     

On the assessment of electrocatalysts for nitrate reduction

The electrochemical reduction of nitrate is attracting attention in the context of producing ammonia, besides the traditional removal to harmless N₂. To make progress in this complex reaction and facilitate the search for active and selective catalysts, we need to establish generalized testing protocols which will enable to compare and complement data from different laboratories. The purpose of this article is to raise awareness on the importance of (i) solution processes that involve products of the electrode reaction, (ii) determination of products with appropriate, product-specific quantitative methods, (iii) the strong sensitivity of the reaction on experimental parameters, (iv) the cell design for the separation of anode from cathode processes, and (v) the increase in the interfacial and solution pH that occurs during the electrolysis at high current densities.     

Prediction of trafficability for tracked vehicle on broken soil: real size tests

Full-scale tests were carried out within the broader framework of a study of an operational mechanical mine clearance system. This system is made up of a tracked machine pushing a mine clearance plow that scarifies the soil to approximately 30 cm depth. This study examines the capacity of the tractor to move on a disturbed soil. This paper presents motion resistance tests and drawbar pull tests on four types of soil. The soils have been chosen to be scientifically representative of the broad distribution on our planet: a sand (frictional soil), a silt (cohesive soil), a silty gravel (coarse-grained soil), and a silty sand (cohesive soil). The tests are performed in two configurations: on compacted soils and on soils scarified with an experimental plow. The results of each test condition are described. The effects of the soil type, its state, and the speed of the tested vehicle are presented. Using these results and, in addition, full-scale tests of scarification, we present an operational analysis determining the mobility of a tracked vehicle on broken soil. This method makes it possible to calculate the maximum speed of a mechanical mine clearance system for the whole range of soils tested.     

Characterization of shock accelerometers using Davies bar and laser interferometer

In this paper, we propose a novel method for evaluating the frequency response of shock accelerometers using Davies bar and interferometry. The method adopts elastic wave pulses propagating in a thin circular bar for the generation of high accelerations. The accelerometer to be examined is attached to one end of the bar and experiences high accelerations of the order of 10³∼10⁵ m/s². A laser interferometer system is newly designed for the absolute measurement of the bar end motion. It can measure the motion of a diffuse surface specimen at a speed of 10⁻³ ∼10⁰ m/s. Uncertainty of the velocity measurement is estimated to be±6×10⁻⁴ m/s, proving a high potential for use in the primary calibration of shock accelerometers. Frequency characteristics of the accelerometer are determined by comparing the accelerometer's output with velocity data of the interferometry in the frequency domain. Two piezoelectric-type accelerometers are tested in the experiment, and their frequency characteristics are obtained over a wide frequency range up to several ten kilohertz. It is also shown that the results obtained using strain gages are consistent with those by this new method. Paper was presented at the 1992 SEM Spring Conference on Experimental Mechanics held in Las Vegas, NV on June 8–11.     

Electroelastic field concentrations ahead of electrodes in multilayer piezoelectric actuators: experiment and finite element simulation

The effects of applied voltage on the electroelastic field concentrations ahead of electrodes in multilayer piezoelectric actuators were examined in a combined experimental and numerical investigation. Experiments were performed to measure the strain near internal and surface electrodes at various electrical loading conditions. The finite element method was also used to solve the coupled electro-elastic boundary value problem. The strain, stress and electric displacement concentrations were calculated and a non-linear behavior induced by localized polarization switching was discussed. A comparison of strain concentration was made between experiment and simulation.     

红外幅射应力定量分析方法及其在断裂力学上的应用研究

本文研究了用红外热象系统做热幅射应力定量分析的方法、技术及应用.阐述了其物理基础、实施条件、系统结构及应用软件功能.建立了用以确定Ⅰ型裂纹应力强度因子及远场应力的基本方程。用紧凑拉伸试件实测的 K_Ⅰ值具有较好精度,并同时获得裂尖前沿各特征区的界限及范围大小,为断裂力学研究提供了一种有效的实验分析方法。     

Defect detection and evaluation of ultrasonic infrared thermography for aerospace CFRP composites

The ultrasonic infrared thermography Non-destructive Testing is introduced for detecting the impact damage of a CFRP specimen for Unmanned Aerial Vehicles. The characteristics of thermal images with damage are particularly analyzed. A Local Binary Fitting (LBF) model based on a non-Gaussian kernel function is used to segment the defect edge. In view of the discontinuity of defect in thermal images due to multilayered structure of composite materials, defect merging algorithms are proposed including time domain and space domain methods by using a few thermal images, and the defect geometric distortion during camera imaging is also compensated. The defect in the composite material can be quantitatively analyzed after the defect reconstruction. The experimental result has shown that the proposed algorithm can effectively detect and evaluate the impact damage of thermal images and the accuracy of quantitative assessment is correspondingly increased.     

基于PID控制的空调器性能测试装置研制

介绍了PID控制技术在空调器性能测试室内温湿度控制中的应用,设计了一个空调器性能测试系统,并基于VB编程技术,在Win2000/WinXP操作系统上,开发了系统数据采集,显示数据处理功能的测控系统。试验证明,该系统稳定、可靠,能满足国家标准的规定。     

Test methods for measuring pure mode III delamination toughness of composite

This paper focuses on the characterization of pure mode III delamination behavior of composite materials. The development for pure mode III delamination testing methods is reviewed. Two testing methods for mode III experiments were evaluated: a novel test proposed in our previous study, termed Edge Ring Crack Torsion (ERCT) test, and the widely used Edge Crack Torsion (ECT) test. The two methods were compared by experiment and finite element analysis. The results demonstrate the advantage of ERCT. The limitations of the ECT test are discussed.