Adsorption of Bismark Brown dye on activated carbons prepared from rubberwood sawdust (Hevea brasiliensis) using different activation methods

Hevea brasiliensis or rubberwood tree, as it is commonly known finds limited use once the latex has been tapped. The sawdust of this tree is chosen to ascertain it viability as a precursor for activation. The carbons thus obtained were characterized in terms of iodine, methylene blue number and surface area. The best carbon in each method was utilized to study the adsorption of Bismark Brown, a dye used in the leather industry. Adsorption equilibrium studies were carried out with the synthetic solutions of the dye, at room temperature (298 K). Equilibrium data are fitted with the Langmuir and the Freundlich isotherms models for the system. The effects of contact time, adsorbent dosage and initial dye concentrations on sorption capacity were carried out. Excellent adsorption capacities of 2000 and 1111 mg g(-1) were obtained for steam and chemical followed by steam-activated carbons, respectively. Pilot-plant experimental studies have been performed using packed-bed column with different feed concentrations, flow rates and bed heights, to evaluate sorption of Bismark Brown on steam-activated carbon. Bed depth service time (BDST) design model have been used to analyze the data.     

Technologies used in agricultural machinery engines that contribute to the reduction of atmospheric emissions: A patent analysis in Brazil

Greenhouse gas emissions are directly associated with climate change issues. Part of the emissions originates from the burning of fossil fuels such as coal, natural gas, and oil used as an energy source for the performance of agricultural machinery's internal combustion engines. However, discussions relevant to the topic are under development in Brazil, and there is a lack of research in the academic field on the intellectual property of agricultural technologies. The purpose of the article is to analyze patent filings in Brazil on technologies that seek to mitigate pollutant emissions from agricultural machinery engines. As a complement, a survey is carried out on the profile of manufacturers in the Brazilian market for technologies for agricultural machinery engines and countries that stand out to develop technologies related to reducing pollutant emissions. The Questel Orbit Platform was used to collect patent data between 2006 and 2017. The research represents innovation and extension of pollutant emissions by non-road engines and patent analysis, a field of research considered in continuous evolution by different researchers and under construction.     

微孔结构与表面改性对活性炭吸附储氢能力的影响

研究了椰壳基活性炭微孔结构和化学改性对其储氢能力的影响。结果表明,物理活化的椰壳基活性炭用HF或NH3.H2O处理后可提高活性炭的吸氢能力,用HNO3处理后吸氢能力几乎没有什么变化,而用H3PO4处理后吸氢能力却有明显的下降。活性炭的比表面积、孔径分布和表面性质都会影响其吸附氢气的能力,其中,比表面积是最主要的影响因素。     

Comments on drugs difficult to compound and the quality of chemicals to be used in compounding

These comments are minor modifications to the material submitted by the author to the docket for the FDA Pharmacy Compounding Committee that met on October 15 and 16, 1998.     

应用于机车车辆横向减振控制中的计算机测控系统

本文在分析了铁路机车车辆横向减振控制系统发展现状的基础上 ,系统地介绍了该系统所采用的计算机测控系统硬、软件设计和系统构成。试验表明 :以该计算机测控系统为核心的铁路机车车辆横向减振控制系统具有明显的减振效果 ,完全可以应用在实际机车车辆中。     

The effect of megavoltage radiation on polymeric materials to be used in biomedical devices

For a number of biomedical applications, including the development of phantoms for quality control of radiotherapy treatments and dose determination, it is important to study the radiation response of the used materials, in order to distinguish the relevant dose distribution modifications from the artifacts caused by the phantom material when subjected to high dose irradiation. Beside the radiation response, those materials should have certain physical and chemical properties in order to be able to be used for the purposes described above, i.e., mechanical hardness and inelasticity, chemically stability and nonreactive, among others. In this work, a wide range of polymeric materials were irradiated under megavoltage radiation using a radiotherapy linear accelerator. The irradiated materials were imaged using transmission X-ray tomography to determine if some radiation induced electronic density change could result in altered Hounsfield units. Furthermore, Raman Spectroscopy and X-ray Diffraction (XRD) techniques were used before and after irradiation in order to study any structural modification induced by the radiation. In addition, a special phantom simulating a breast treatment with two tangential beams has been fabricated and tested.     

一种挠性航天器的自适应姿态控制与振动控制

挠性航天器三轴姿态控制与振动控制需要处理复杂的姿态运动学耦合、动力学力矩耦合、挠性模态与刚体的动力学耦合,以及在轨航天器挠性附件的参数不确定等问题。基于频带分离方法分别设计了姿态控制器和振动控制器,其中的挠性附件振动对姿态的影响以时变干扰模型进行考虑。利用奇异摄动理论,设计了姿态控制器。该控制器由快速角速度环和慢速角度环两回路组成,采用具有较强抗干扰能力的积分型SDRE（State-Dependent Riccati Equation）控制器进行姿态指令跟踪。对于挠性振动,设计了独立模态控制的正位置反馈（PPF）控制器,通过对一阶控制器参数进行调节,使系统当存在结构不确定或参数变化的情况时仍能较好地收敛,保证了系统的鲁棒性。最后仿真表明了在干扰力矩下姿态的稳定性和振动的快速抑制。     

Processing and characterization of chitosan microspheres to be used as templates for layer-by-layer assembly

Chitosan (Ch) microspheres have been developed by precipitation method, cross-linked with glutaraldehyde and used as a template for layer-by-layer (LBL) deposition of two natural polyelectrolytes. Using a LBL methodology, Ch microspheres were alternately coated with hyaluronic acid (HA) and Ch under mild conditions. The roughness of the Ch-based crosslinked microspheres was characterized by atomic force microscopy (AFM). Morphological characterization was performed by environmental scanning electron microscopy (ESEM), scanning electron microscopy (SEM) and stereolight microscopy. The swelling behaviour of the microspheres demonstrated that the ones with more bilayers presented the highest water uptake and the uncoated cross-linked Ch microspheres showed the lowest uptake capability. Microspheres presented spherical shape with sizes ranging from 510 to 840 μm. ESEM demonstrated that a rougher surface with voids is formed in multilayered microspheres caused by the irregular stacking of the layers. A short term mechanical stability assay was also performed, showing that the LBL procedure with more than five bilayers of HA/Ch over Ch cross-linked microspheres provide higher mechanical stability.     

Characterisation of a new bioadhesive system based on polysaccharides with the potential to be used as bone glue

Although gluing bone is in theory a very attractive alternative to classical fracture treatment, this method is not yet clinically established due to the lack of an adhesive which would meet all the necessary requirements. We therefore developed a novel two-component bioadhesive system with the potential to be used as a bone adhesive based on biocompatible and degradable biopolymers (chitosan, oxidised dextran or starch). After mixing in water, the two components covalently cross-link by forming a Schiff’s base. By the same mechanism, the glue binds to any other exposed amino group such as for example those exposed in fractured bone, even in the presence of water. Modified chitosan was synthesised from commercially available chitosan by deacetylation and was then reduced in molecular weight by heating in acid. The amount of free amino groups was analysed by IR. The molecular weight was determined by viscosimetry. Starch or dextran were oxidised with periodic acid to generate aldehyde groups, which were quantified by titration. l-Dopa was conjugated to oxidised dextran or starch in analogy to the gluing mechanism of mussels. Biomechanical studies revealed that the new glue is superior to fibrin glue, but has less adhesive strength than cyanoacrylates. In vitro cell testing demonstrated excellent biocompatibility, rendering this glue a potential candidate for clinical use.     

Methods used to assess the safety and reliability of a nuclear reactor rod control system

This paper describes the reliability techniques used to estimate the risk of fission product release from accidents caused by faults in the rod control system of a pressurized water reactor.These techniques include: a three-level reliability assessment using a functional event tree and two levels of fault tree to assess functional and system's reliability, an operator response model using event trees and a method of using the structure function of a reliability model to investigate possible common mode failure interactions.     

结构噪声主动控制原理及方法

本文以矩形的板－箱系统作为研究模型，探讨了在外界声源激励下，弹性薄板受激励振动，辐射入箱内噪声的形成机理，并分析了选用压电片作为激励器，进行箱内噪声主动控制的原理，在此基础上，对３种控制方案进行了分析比较，得出最优方案。     

Comment on "Holographic characteristics of a 1-mm-thick photopolymer to be used in holographic memories."

We believe there is an error in the calculation of the M/# in a previous paper [Appl. Opt. 42, 7008 (2003)]. From the data provided, we calculate an M/# of 3.8 rather than the reported value of 38 for the 1-mm sample tested.     

Clarifications to the paper "Holographic characteristics of a 1-mm-thick photopolymer to be used in holographic memories"

We have corrected typing errors related to the characterization of the dynamic range of the acrylamide photopolymer described in an earlier study [Appl. Opt. 42, 7008 (2003)]. The M number is expressed as M/# instead of M# as appears in the text. The value calculated from the experimental results that are included in the article is M/# = 3.8 instead of 38 as appears in the text.     

论似与不似与标志的形和意

从"天人合一"、"中庸之道"哲学思想入手,论述了中国传统绘画"似与不似"造型原则的本质内涵,阐明了中国文化对艺术的影响,结合标志设计中的"形"和"意",提出图形设计中"具象"与"抽象"、"象征"与"隐喻"是对"似与不似之妙"的追求和表达。认为研究本土审美哲学,从传统艺术形式的内容和表现手段中汲取精髓,是传承中国传统文化创新设计理念,实现真正意义上的设计"本土语言"的必由之路。     

基于自适应滤波的电主轴-刀具系统不平衡振动的主动控制

为了有效抑制由质量不平衡引起的电主轴-刀具系统的不平衡振动,本文提出了一种基于最小方差的分块(FBLMS)自适应滤波的电主轴-刀具系统不平衡振动的主动控制方案,该控制方案中用来抑制振动的力源于无轴承电机径向磁悬浮力产生的原理。本文首先研究了双绕组感应型电主轴的结构及工作原理和径向控制力的模型,借助有限元法建立了感应型柔性电主轴-电主轴-刀具系统的动力学模型以及研究了FBLMS自适应滤波控制算法,设计了感应型柔性电主轴-电主轴-刀具系统不平衡振动的主动控制系统,通过有限元法来确定径向控制力的系数以及单边磁拉力的系数,研究了经典PID控制器以及FBLMS自适应滤波控制器对刀具端的不平衡振动的控制效果,结果表明采用FBLMS自适应滤波控制器对抑制电主轴-刀具系统端不平衡振动具有更佳控制效果。     

基于i_p-i_q法和滞环控制的新型有源滤波器设计研究

由于电网非线性负荷及各种时变电力电子装置的大规模应用,解决由此引起的谐波电流注入电网的问题已成为电力系统研究中的热点问题。该文分析有源滤波器的基本原理,基于ip-iq检测法和滞环控制,用PSCAD仿真软件建立一种新型有源滤波器模型,并应用该滤波器对谐波源所产生的谐波电流进行滤除仿真及实验分析。仿真及实验的结果表明:该有源滤波器对谐波电流有较为理想的滤除作用。     

The influences of the structure and activity of biologically active compounds on the assessment of inventive step

The assessment of inventive step for (biologically) active organic chemical compounds is discussed in the light of the application of well-established structure–activity-relationship theory as an important part of the common general knowledge. Applying the problem–solution approach (PSA), several relevant decisions of the Technical Boards of Appeal of the European Patent Office are discussed and the relevance of the PSA in this particular technical field is documented.     

Effect of Moisture on Solid Dosage forms. can the Arrhenius Equation be used as a Predictor?

Abstract

It is shown that for pure (organic) solids, the Arrhenius equation is valid, except it may be difficult to elucidate the rate controlling parameter andor the predominant mechanism. The two most predominant mechanisms are Prout-Tompkins and Bawn kinetics.

One aspects of kinetic investigations is to extrapolate so-called accelerated data (e.g. elevated temperature data), to other temperatures (e.g. room temperature). In such cases the Arrhenius equation is usually resorted to, but it is necessary, always, to establish the correct mechanism, extract from it the pertinent, rate-controlling parameters, and extrapolate these to room temperature. At times it is possible to obtain phenomenological parameters which can be extrapolated.

In cases where solids are stored in the presence of moisture there are several subdivisions (a) cases where the moisture is in excess (plain Leeson-Mattocks model of non-ionizing substance) (b) cases where some of the moisture present is “bound”, i.e. not free to react, (c) the case of less than molar ratios of moisture to drug, (d) the case of adsorbed moisture, (e) the case of drug hydrates/anhydrate pairs.     

窄带噪声主动控制中的波形综合法研究

文本讨论了在窄带噪声主动控制技术中采用的波形综合法的特性，通过窄带主动噪声控制ＦＸＬＭＳ算法的步长μ，滤波器长度Ｌ，以及由于二次通道的存在而导致的滞事等因素对该方法传递特性的影响研究，进一步探讨窄带噪声控制技术为工程实际的应用研究奠定了基础。