Cognitive radio CDMA networking with spectrum sensing

In this paper, the performance of cognitive radio (CR) code division multiple access (CDMA) systems is analyzed. More precisely, CR users belong to a cognitive radio network (CRN), which coexists with a primary radio network (PRN). Both CRN and PRN are CDMA‐based, with colocated base stations. Soft hand off and power control are considered in both the CRN and the PRN. Upon the development of an accurate simulator for a representative three‐cell cellular scenario, we evaluate the performance of the proposed CR system in terms of outage probability, blocking probability and average data rate of secondary users. Three different spectrum sensing techniques are. Two new schemes, based on interference limit, are proposed and compared with an existing adaptive spectrum sensing scheme. Spectrum activity measurements and spectrum sharing decisions have been considered for evaluating the performance of the three schemes. The paper proposes a new CR‐CDMA networking model and a simulation testbed for evaluating performances of secondary users and primary users in terms of outage, blocking, BER and average data rate in the presence of soft hand‐off and power control. For comparison purposes, the analysis in the absence of spectrum sensing is also investigated.Copyright © 2012 John Wiley & Sons, Ltd.     

Near-infrared spectroscopic analysis of macronutrients and energy in homogenized meals

Near-infrared (NIR) reflectance spectroscopy was evaluated as a rapid and environmentally benign technique for the simultaneous determination of macronutrients and energy in commercially available, packaged meals. Reflectance spectra (400–2498 nm) of homogenized meals were obtained with a dispersive NIR spectrometer. Protein and moisture were measured by AOAC reference methods, total fat by a semi-automated acid hydrolysis, solvent extraction, gravimetric method and total carbohydrate calculated. Energy was calculated using Atwater factors. Using multivariate analysis software, PLS models (n = 113–115 products) were developed to relate NIR spectra of homogenized meals to the corresponding reference values. The models predicted components and energy in validation samples (n = 37–38 products), overall, with r² of above 0.96. Ratios of deviation to performance were between 3.6 and 6.6, and indicated adequacy of the models for screening, quality control, or process control. Performance of the models varied substantially when used to predict sub-groups of meals within the validation set.     

Lutein Prevents High Fat Diet‐Induced Atherosclerosis in ApoE‐Deficient Mice by Inhibiting NADPH Oxidase and Increasing PPAR Expression

Epidemiological and experimental studies provide supportive evidence that lutein, a major carotenoid, may act as a chemopreventive agent against atherosclerosis, although the underlying molecular mechanisms are not well understood. The main aim of this study was to investigate the effects of lutein on the alleviation of atherosclerosis and its molecular mechanisms involved in oxidative stress and lipid metabolism. Male apolipoprotein E knockout mice (n = 55) were fed either a normal chow diet or a high fat diet (HFD) supplemented with or without lutein for 24 weeks. The results showed that a HFD induced atherosclerosis formation, lipid metabolism disorders and oxidative stress, but noticeable improvements were observed in the lutein treated group. Additionally, lutein supplementation reversed the decreased protein expression of aortic heme oxygenase‐1 and increased the mRNA and protein expressions of aortic nicotinamide‐adenine dinucleotide phosphate oxidase stimulated by a HFD. Furthermore, the decreased mRNA and protein expression levels of hepatic peroxisome proliferator‐activated receptor‐α, carnitine palmitoyltransferase 1A, acyl CoA oxidase 1, low density lipoprotein receptors and scavenger receptor class B type I observed in mice with atherosclerosis were markedly enhanced after treatment with lutein. Taken together, these data add new evidence supporting the anti‐atherogenic properties of lutein and describing its mechanisms of action in atherosclerosis prevention, including oxidative stress and lipid metabolism improvements.     

添加H_2O_2/O_2的微电解深度处理造纸中段废水

在废水传统微电解处理工艺的基础上,增加了H2O2/O2处理,实验结果表明:在pH值4.5,Fe/C=1:1,反应时间40min,H2O2加入量0.8mg·L-1废水,曝气头1个的条件下,H2O2/O2对传统微电解工艺具有加强作用,出水色度48倍,CODCr为51mg·L-1,达到最新造纸行业废水排放标准。且该工艺较适合作为二级生化前的预处理或后处理工艺。     

Influence of hexagonal to orthorhombic phase transformation on diffusion-controlled dendrite evolution in directionally solidified Sn–Ni peritectic alloy

The hexagonal to orthorhombic (HO) transformation from β-Ni₃Sn₂ (hexagonal) phase to α’-Ni₃Sn₂ (orthorhombic) phase was confirmed in directionally solidified Sn–Ni peritectic alloys. It is shown that the remelting/resolidification process which is caused by both the temperature gradient zone melting (TGZM) and Gibbs?Thomson (G?T) effects can take place on secondary dendrites. Besides, the intersection angle between the primary dendrite stem and secondary branch (θ) is found to increase from π/3 to π/2 as the solidification proceeds. This is the morphological feature of the HO transformation, which can change the diffusion distance of the remelting/ resolidification process. Thus, a diffusion-based analytical model is established to describe this process through the specific surface area (S_V) of dendrites. The theoretical prediction demonstrates that the remelting/resolidification process is restricted when the HO transformation occurs during peritectic solidification. In addition, the slope of the prediction curves is changed, indicating the variation of the local remelting/resolidification rates.     

Regulatory framework and business models for charging plug-in electric vehicles: Infrastructure,agents, and commercial relationships

Electric vehicles (EVs) present efficiency and environmental advantages over conventional transportation. It is expected that in the next decade this technology will progressively penetrate the market. The integration of plug-in electric vehicles in electric power systems poses new challenges in terms of regulation and business models. This paper proposes a conceptual regulatory framework for charging EVs. Two new electricity market agents, the EV charging manager and the EV aggregator, in charge of developing charging infrastructure and providing charging services are introduced. According to that, several charging modes such as EV home charging, public charging on streets, and dedicated charging stations are formulated. Involved market agents and their commercial relationships are analysed in detail. The paper elaborates the opportunities to formulate more sophisticated business models for vehicle-to-grid applications under which the storage capability of EV batteries is used for providing peak power or frequency regulation to support the power system operation. Finally penetration phase dependent policy and regulatory recommendations are given concerning time-of-use pricing, smart meter deployment, stable and simple regulation for reselling energy on private property, roll-out of public charging infrastructure as well as reviewing of grid codes and operational system procedures for interactions between network operators and vehicle aggregators.     

Oxide ionic conductivity and crystallographic properties of tetragonal type Bi2O3-based solid electrolyte doped with Ho2O3

Abstract

In the present work, the authors have investigated the binary system of (Bi₂O₃)_1–x(Ho₂O₃)_x. For the stabilisation of the tetragonal type solid solution, small amounts of Ho₂O₃ were doped into the monoclinic Bi₂O₃ via solid state reactions in the stoichiometric range 0·01≤x≤0·1. The crystal formula of the formed solid solution was determined as Bi(III)_4–4xHo(II)_4xO_6–2xVo_(2+2x) (where Vo is the oxide ion vacancy) according to the XRD and SEM microprobe results. In the crystal formula, stoichiometric values of x were 0·04≤x≤0·08, 0·03≤x≤0·09, 0·02≤x≤0·09 and 0·04≤x≤0·09 for annealing temperatures at 750, 800, 805 (quench) and 760°C (quench) respectively. The four probe electrical conductivity measurements showed that the studied system had an oxide ionic type electrical conductivity behaviour, which is increased with increasing dopant concentration and temperature. The obtained solid electrolyte system has an oxygen non-stoichiometry characteristic, and it contains O^2– vacancies, which have disordered arrangements in its tetragonal crystal structure. The increase in the amount of Ho₂O₃ doping and temperature causes an increasing degree of the disordering of oxygen vacancies and a decrease in the activation energy E_a.     

输尿管开口囊肿、狭窄及膀胱颈部挛缩的HO:YAG激光治疗

目的利用HOYAG激光的软组织切割及止血作用,对输尿管开口囊肿、狭窄及膀胱颈部挛缩的患者行激光治疗,并观察疗效.方法采用HOYAG激光对6例输尿管开口囊肿,15例输尿管开口狭窄(其中3例合并输尿管结石),32例膀胱颈部挛缩进行治疗,观察术中出血、术后并发症、膀胱挛缩患者手术前后Qmax.结果总计53例患者通过HOYAG激光治疗,均获得满意临床疗效,术中几乎无出血,输尿管开口囊肿及狭窄患者,术毕能顺利留置F7双猪尾巴导管.膀胱颈部挛缩患者术后最大尿流率提高了7.6ml/s(7.2～14.8ml/s).结论HO;YAG激光对输尿管开口囊肿、狭窄及膀胱颈部挛缩是一种行之有效的治疗方法,且无出血,易于操作、安全、恢复快.尤其是输尿管结石合并输尿管开口狭窄患者,可通过HOYAG激光一次手术解决.