Low-frequency detection in ECG signals and joint EEG-Ergospirometric measurements for precautionary diagnosis

HRV (Heart Rate Variability) is an indicator that can be related to different human organs and systems: breathing, heart, brain, pulmonary system, etc. In cardiac clinic, physical exertion can be pre-assessed thanks to HR (Heart Rate) response using appropriate tests to rule out eventual cardiac dysfunction prior to undergo patient to further exams, surgical operations and rehabilitation activities. HR assessment must determine the capability of patient to continue exertion up to a certain level without having angina pain symptoms and brain dysfunctions. The variability of HR is a marker of dynamic load because it is sensitive and responsive to acute stress. Moreover it is also a marker of a cumulative wear and tear because it declines with advancing age. In this paper we propose combined measurements of EEG-Ergospirometry and ECG for patient’s cardio-pulmonary condition assessment for allowing doctors to make a decision on rehabilitation or surgical operation for people suspected of suffering from epilepsy seizures. Measurements assessed using frequency domain parameters have permitted the determination of low and high frequencies that are related to sympathetic and parasympathetic activities respectively.     

Optimization of multilayer cylindrical coils in a wireless localization system to track a capsule-shaped micro-device

A wireless electromagnetic localization method has been presented to track capsule-shaped micro-devices in the gastrointestinal tract. And a prototype for the novel localization system has been developed. In the localization method, cylindrical coils placed on the patient’s abdomen generate alternating electromagnetic fields one by one. The system of equations from the localization model has been established and then transformed into a nonlinear optimization problem. The localization method presents excellent anti-interference ability and high stability. In order to solve the magnetic inverse problem in the localization model, an analytical expression between the magnetic flux density and the position & orientation should be derived by superposition of the fields generated by the coil turns, which causes systematic errors. As a result, the geometry of the cylindrical coils is optimized to reduce the errors. A full factorial experiment with two factors has been carried out. The experiment shows that the optimal L/Dout ratio and Din/Dout ratio are 0.4 and 0.8, respectively. In this case, the mean error and the standard deviation are reduced to 0.89% and 0.77%, respectively, where the distance along the axis of the cylindrical coil from the coil’s center to a measured point is 30 mm. Furthermore, the experimental results also show that the imitation error decreases significantly with increased distance from the coil. The accuracy of the localization model can be further improved using the optimized coil.     

Multi-index optimization design for electrical resistance tomography sensor

A multiple index optimization method for ERT sensors is put forward which combines an orthogonal design and fuzzy analysis. This method first establishes a scientific and proper fuzzy evaluation method using fuzzy mathematics to define ERT index satisfaction (ERTIS) and overall ERT index satisfaction (OERTIS) and to construct their satisfaction functions. It unifies all of ERT sensor indices into a single comparable satisfaction value. Then, the OERTIS analysis is developed which allows a set of multiple index orthogonal experiments to be transferred into a single index orthogonal experiment. Where, the uniformity index and the correlation coefficient index of the ERT sensor are set as the optimization objectives. The experiments are set up based on multi-index orthogonal design. The experimental results indicate that the method can derive an evenly distributed sensitivity field and a better image with the optimized sensors, and improve the OERTIS of the ERT sensors by 13.75%.     

A New Active Tilting-Pad Bearing: Nonlinear Modeling and Feedback Control

This article introduces a new type of active fluid film bearing and its feedback control. In particular, the active adjustment of the angular velocity of the pads of a tilting-pad bearing in response to changes in the operating conditions of the rotating machine is proposed. This is motivated by the observation that there is more control authority in the pad tilting motion than in its radial translation. To this end, a dynamic model for the bearing system is first developed, inclusive of the nonlinear hydrodynamic force for the infinitely short bearing case. A model-based controller is then constructed, based on measurements of the journal position and velocity and pad tilting angles, to ensure that the journal is asymptotically regulated to the bearing center. Numerical simulations illustrate the performance of the active bearing under the proposed control in comparison with the bearing's standard passive mode of operation.     

刀轨环无跳刀尖角垂线过渡连接算法

针对刀轨环如何高效地连接成环切刀轨的问题,提出了刀轨环无跳刀尖角垂线过渡连接算法。首先在基于向量角分线的子域上生成等距环,然后建立刀轨环数组和生成环的多个单向链表,采取顺序取外等距环、逆序取内环的方式生成单根节点刀轨环关系树,提出尖角垂线过渡的连接方式,遍历刀轨环树获得无跳刀刀轨,最后构建加减速数学模型并验证算法的有效性。试验表明,该算法计算效率高,无跳刀,满足实际加工要求。     

壳聚糖的功能化及其作为生物医用高分子材料的研究进展

简要综述了壳聚糖的功能化及其在生物医用高分子材料方面的应用。     

淮北煤两级分次萃取物的红外光谱分析

为了揭示煤中可溶组分的存在方式和溶出行为,分别以石油醚和CS2为溶剂对淮北煤进行了按时间段分次取样的两级索氏萃取,并采用FTIR对萃取物进行了定性和定量分析。结果表明,可萃取组分的溶出具有时序性和阶段性特点;萃取物重要基团FTIR吸收峰随时间变化均呈波型曲线规律;石油醚可萃取组分中存在较多较短链的脂肪族组分和两部分特定链长的-OH(-NH)类物质;CS2可萃取物中则有两种特定链长的脂肪族组分和一种特定链长的-OH(-NH)类物质。     

固体超强酸在增塑剂合成中的应用

增塑剂在塑料的各种助剂中占有重要地位,采用固体超强酸代替浓硫酸催化合成增塑剂克服了传统方法中采用浓硫酸的许多缺点,将有很大的前景,本文对目前已经采用固体超强酸催化合成增塑剂的应用进行了总结.     

新型增塑剂DPHP的应用性能评述

介绍了增塑剂DOP的替代产品邻苯二甲酸二(2-丙基庚)酯(DPHP)的物性、力学性能、加工性、电性能、耐候性等应用性能,并提出国内发展DPHP的建议。     

自洁抗菌陶瓷技术的现状和发展

介绍了自洁抗菌陶瓷的国内外发展现状及抗菌陶瓷的抗菌自洁机理，探讨了自洁抗菌陶瓷制备技术及生产中的技术难点及解决方法，并预测了国内自洁抗菌陶瓷的市场前景。