Organic matter and nitrogen removal by an on site sewage treatment and disposal system

The performance of an on site sewage treatment and disposal system consisting of a septic tank, a gravel filter, a sand filter and soil absorption trenches operated alternatively, was studied in relation to organic matter and nitrogen removal efficiency. The system was simulated with the aid of a laboratory scale model. BOD₅ and SS removal efficiencies averaged 92.9 and 93.4% respectively. Substantial removal of nitrogen (up to 70%) was achieved due to nitrification followed by denitrification. Removal efficiencies were found to depend on the compaction characteristics of the filter media and the soil, the hydraulic loading applied and the flow conditions (saturated/unsaturated). The results indicate that the system under consideration is a feasible alternative for on site treatment and disposal of domestic sewage.     

Evaluating the transfer of technology between application domains: a critical evaluation of the human component in the system

Technology can take many forms from the development of sophisticated electronics to the application of basic procedural principles. Technology transfer can also take several forms, however, in this case, it is the transfer of technological principles between application domains that is of primary interest. This paper presents a framework (the Five ‘M’s framework) that can be used to consider the likely success of technology transfer. The framework is based upon a sociotechnical system approach. The framework is illustrated with an evaluation of the introduction of intelligent cruise control into motor vehicles. It is argued that this is a technological concept first developed as an aerospace application in the form of the autopilot. In this case, it is argued that the transfer of this technology in its current form may potentially compromise safety.     

Fast microwave detection system for coherent synchrotron radiation study at KEK: Accelerator test facility

A fast room temperature microwave detection system based on the Schottky Barrier-diode detector was created at the KEK ATF (Accelerator Test Facility). It was tested using Coherent Synchrotron Radiation (CSR) generated by the 1.28 GeV electron beam in the damping ring. The speed performance of the detection system was checked by observing the CSR from a multi-bunch (2.8 ns bunch separation time) beam. The theoretical estimations of CSR power yield from an edge of bending magnet as well as new injection tuning method are presented. A very high sensitivity of CSR power yield to the longitudinal electron distribution in a bunch is discussed.     

The Gas-to-Particle Heat Transfer and Hydrodynamics in Spouted Bed Drying of Sawdust

This article presents experimental results for spouted bed drying of sawdust, carried out in a full-scale as well as in a laboratory-scale dryer using air as well as steam as drying media. The aim is to present design parameters for a spouted-bed sawdust dryer that can be used by the industry in designing full-scale dryers. A hydrodynamically stable spouted jet spouted bed was obtained. The heat transfer characteristics of the bed were represented in terms of a volumetric heat transfer coefficient (VHC). When sawdust is dried in a spouted bed, the mean VHC is increasing up to fiber saturation level (20-25% wb) from 40 to 110 W/m³ K. The VHC decreases with the residence time and with an increased static bed height. Gas temperature profiles are also presented for the bottom part of the drying chamber.     

一种基于判决反馈的OFDM系统载波频率跟踪算法

研究了多径信道下OFDM系统的一种新的载波频率跟踪算法，这种算法以判决反馈和接收端的时域信号重构为基础。推导了估计结果的精确解，比较了使用原估计结果和新的估计结果进行频偏补偿时系统跟踪性能的不同。通过对算法的仔细分析，发现除了通常的加性噪声外，信道估计误差、子载波数目和子载波的调制方式也影响频偏的估计结果和跟踪范围，而且子载波的数目和调制方式是决定性的因素。这种频率跟踪方法的优点是即使在很低的信噪比下仍然能获得高的跟踪精度，且实现相对简单。     

离散事件系统状态反馈控制的几何理论的进一步拓广

本文研究了定义在状态-事件序列上的谓词的离散事件系统的状态反馈控制问题。离散事件系统的数学模型是自动机。状态反馈与闭环过程的关系及许多基本的几何性质得到了详细的阐明;在这些几何背景下,解决了离散事件系统状态反馈控制的拓广问题,包括关于简单谓词与一般谓词的问题。     

Representation of shift-invariant operators onL 2 byH ∞ transfer functions: An elementary proof,a generalization toL p,and a counterexample forL ∞

We give an elementary proof of the well-known fact that shift-invariant operators onL ²[0, ∞) are represented by transfer functions which are bounded and analytic on the right open half-plane. We prove a generalization to Banach space-valuedL ^p -functions, where 1≤p<∞. We show that the result no longer holds forp=∞. This research was supported partially by the Weizmann Fellowship, and partially by the Air Force Office of Scientific Research under Contract F49620-86-C-0111.     

Observer design for autonomous discrete-time nonlinear systems

We obtain a necessary and sufficient condition for a discrete-time nonlinear system to be locally state equivalent to the nonlinear observer form. The result looks similar to the continuous counterpart except for the fact that Ad-operation is utilized instead of ad-operation.