Elimination of chlorobenzene vapors from air in a compost‐based biofilter

In this work, the removal of monochlorobenzene (CB) vapors from air was studied, for the first time, in a non‐inoculated, laboratory‐scale, aerobic biofilter. The influence of three parameters on the bioprocess has been evaluated: the rate of nitrogen supplied to the bed, the inlet concentration of CB, and the flow rate. The CB inlet concentration was varied between 0.3 and 3.2 g m^?3, at a constant flow rate of 1.0 m³ h^?1. Removal rates of greater than 90% were achieved for CB inlet concentrations of up to 1.2 g m^?3. Then the flow rate was varied from 0.5 to 3.0 m³ h^?1 with a constant inlet concentration (1.2 g m^?3). Maximum elimination capacities (70 g m^?3 h^?1) were reached for contact times of greater than 60 s. The study of varying flow rates also permitted evaluation of a first order macrokinetic constant (1.1 × 10^?2 s^?1) for the CB biodegradation. Finally, the optimum nitrogen input value was found to lie between 0.3 and 0.4 g N h^?1 and gave rise to elimination capacities as high as 70 g m^?3 h^?1 for an inlet load of near 80 g m^?3 h^?1. Copyright © 2003 Society of Chemical Industry     

融合降噪自编码器与BPSO的特征组合方法及其中医应用

离散二进制粒子群算法（BPSO）在各种离散优化问题中有着诸多优势,但其很容易由于非线性的问题陷入局部最优解,无法得到最佳特征子集。而降噪自编码器可通过多层非线性网络进行映射与重构,对中医药数据有良好的处理效果。因此提出了一种融合降噪自编码器与BPSO的特征组合方法,该方法主要是利用降噪自编码器对特征进行非线性映射形成超完备基,然后在超完备基中通过BPSO进行搜索,从而得到最佳特征子集。分别采用临床糖尿病数据集和UCI数据集进行分析处理,实验结果表明,融合降噪自编码器与BPSO的特征组合方法对中医药临床实验数据有较好的适应性。     

A new method to determine the microbial kinetic parameters in biological air filters

This paper presents a new method to determine kinetic parameters of the biodegradation of various pollutants in a biofilter. Toluene, a readily biodegradable volatile organic compound, and methane, a hydrocarbon and a greenhouse gas, have been chosen as the target pollutants. The new protocol utilized biomass immobilized on bed pellets; these directly sampled from a continuous steady-state biofilter. The comparison of this method with the conventional experimental protocol utilizing micro-organisms suspended in a liquid medium was made using the pollutant toluene. Indeed, with both methods, the kinetic parameters have been evaluated by following the microbial growth in batch, thermostated reactors, using determined amounts of pollutant substrate. This experiment has confirmed the pertinence of the new procedure. The interesting features of the new method are that: (1) it is easy to operate (no preliminary treatment of the bed samples) and (2) it provides reproducible parameters that represent the real biofilter case more adequately than liquid cultures. In addition, modeling of the experimental specific growth rates in the case of toluene has shown that the values obtained with the use of solid extracts can be correlated by a Haldane's formulation, where , , and . The maximum specific growth rate was reached for an initial concentration of toluene near . The determination of the experimental specific growth rates of micro-organisms in the methane biofilter has also been performed. This study allowed highlighting two methane concentrations’ ranges: from 1000 to 14 500 ppmv and from 14 500 to 27 000 ppmv. For the first range, the Monod model proves to be suitable with the kinetic parameters: and . For the second range, neither the Monod nor the Haldane's formulation could directly be used. However, a mathematical adjustment of the Monod model allows to find kinetic parameters and . The biomass yields for the tested methane concentrations have also been determined and showed two different tendencies, depending on the same two ranges. For the first range of methane concentrations, the biomass yield was quite constant with an average value around while for the second range, it could be approached by a polynomial second-order regression. The maximum value of the biomass yield obtained on the second range was at a methane initial concentration of 20 000 ppmv.     

Nutritional quality and antioxidant activity of marama-sorghum composite flours and porridges

Marama bean, an underutilised legume in southern Africa, is a good source of protein, fat and phenolic compounds, the latter known to have potential health benefits. Marama flours, sorghum meal, marama-sorghum composite flours and porridges were analysed for proximate composition, amino acid composition, energy value, fatty acid composition, total phenolic content and antioxidant activity. Compositing sorghum meal (70%) with marama flours (30%) significantly increased the protein and fat contents in flours and porridges. Energy values of marama-sorghum composite porridges were 11-24% higher than sorghum porridge. Lysine content was 3-4 times higher in marama-sorghum porridges than in sorghum porridge. There was an increase in oleic acid as sorghum meal was composited with marama flour. There was a positive correlation between the total phenolic content and antioxidant activity in all samples. Use of marama flour in sorghum composite flours and porridges improved the nutritional quality and antioxidant activity.     

基于扭矩的安全钻进控制

扭矩是钻进过程中的一个重要参数,扭矩太小时破岩效率低而影响机械钻速,扭矩太大又可能会引发钻具事故,因此需要针对不同的钻具组合,探讨井口处钻柱及钻头扭矩计算方法。本文针对提供扭矩的顶驱或者电动钻机,阐述了钻柱井口扭矩值的计算。根据底部钻具组合中是否带螺杆钻具,提出了钻头处扭矩的计算方法。研究结果得出,在电机电压和负载电阻一定的条件下,井口钻柱的扭矩随其转速变化,一旦转速确定,则扭矩就确定。如果底部钻具组合中不带螺杆,则整个钻柱的扭矩值从井口到钻头向下逐渐递减;如果底部钻具组合中带有螺杆,则钻头扭矩就是此压力降下螺杆的输出扭矩值。螺杆的输出扭矩值与其负载压力降大小成正比,钻井液排量一定的情况下,一旦螺杆的负载压力降确定,其输出扭矩值确定。只要井口与钻头处扭矩差值不超过整个钻柱任意一处的抗扭强度,钻柱就不会发生因扭矩导致的事故。研究结果表明,本文提出的方法为科学选择顶驱或转盘转速及电机功率,合理匹配钻头和螺杆钻具等方面提供了理论指导。     

Influence of intrinsic and extrinsic factors on rheology of pectin–calcium gels

Pectin was selectively demethoxylated by use of NaOH or pectinmethylesterase from plant or fungal origin in order to produce a library of pectins with varying degree and pattern of methoxylation. In addition, pectin was chemically depolymerised by a heat treatment. The resulting pectin products were characterised by studying the degree and pattern of methoxylation and the extent of depolymerisation. The pattern of methoxylation was estimated quantitatively by determining the “degree of blockiness” (DB and DB_abs). Pectin–calcium gels were prepared at varying concentrations of both components. Rheological properties of these gels were studied by performing small deformation oscillatory tests. Gel strengths were better explained by the pattern of methoxylation than by the degree of methoxylation. The relation between rheological properties and calcium or pectin concentration depended on the pattern of methoxylation. Depolymerisation had a detrimental effect on gel strength, especially at low calcium concentration.     

云南移动省干100G OTN网目标架构设计思路

针对在LTE时代,省干光传送网(OTN)如何适应业务发展进行网络建设,结合省级干线光传送网的特点和影响省干光传送网建设的各种因素进行分析,提出多环网、少节点、大容量、高安全的目标网架构,为中西部省份的省干光传送网(OTN)的建设提出建设性的意见。     

某湿法炼锌净化钴渣选择性浸出回收锌与钴

采用选择性浸出—酸浸—萃取工艺回收某湿法炼锌企业产生的净化钴渣中的锌、钴。合适的选择性浸出条件为:净化钴渣粒度<0.530mm、浸出过程pH≥3.5、浸出终点pH=4.5、浸出时间3h、浸出液固比4∶1、浸出过程不加热(30℃),在此条件下锌浸出率超过95%、钴浸出率仅为6.24%。选择性浸出后锌主要进入浸出液,可返回至湿法炼锌工序回收利用;钴主要留存在选择性浸出渣中,继续经过酸浸溶出、P204萃取除杂后也可被回收利用。