Evaluating increasing block tariff pricing policies when applied to multiple household connections

This paper develops a model for evaluating the consequences of increasing block tariff pricing policies when multiple households share a connection and applies it to a sample from Kumasi, Ghana. Results show that for any given consumption, a household's average share of total monthly water bill for shared connections can either be higher or lower than its single-household equivalent. Significant differences between the average and single-household equivalent bills were found in these cases, although this difference is under-estimated if the sample is not disaggregated by payment group.     

Development of allergic responses related to microorganisms exposure in early life

The prevalence of allergic disorders may stem from reduced microbial exposure during childhood. Allergic disorders (rhinitis, asthma, atopic dermatitis) result from a systemic inflammatory reaction triggered by Th2-cell-mediated immune responses against ‘innocuous’ environmental antigens. Initial interpretations proposed an immune deviation of allergen-specific responses from a Th1 to a Th2 profile resulting from reduced production of interleukin-12 and interferons by natural immune cells stimulated by bacterial products. Both stereotypical and selective responses of innate host cells are invoked by different microorganisms. Early in an infection, pathogens can therefore imprint their ‘signatures’ on antigen-presenting cells and subsequent immune responses. This interaction between microorganisms and enterocytes is important for the controlled production of cytokines and chemokines. Some probiotic microorganisms can modulate the in vitro expression of pro- and anti-inflammatory cytokines in a strain-dependent manner, probably skew the immune response towards Th1 phenotype and play an important role in allergy prevention.     

A perturbation technique to model InGaAs/InP and GaAs FETs for millimeter-wave integrated circuits

A perturbation method is described to analytically model the electrical behavior of submicron FETs for millimeter-wave circuit applications. The approach includes the determination of the two-dimensional potential distribution in a non-rectangular depletion region. The result is used to derive analytical expressions for the threshold voltage and transconductance of FETs.     

Semiconductor cylinder fibers

We report on the fabrication and test of semiconductor cylinder fibers (SCFs). To date, we have used two semiconductors CdTe and CdS. Characterization indicates that the semiconductors survive the fabrication process. A number of fibers of each kind were fabricated with reproducible results     

Demonstration of a Self-Synchronized Polyphase Sampling and Demultiplexing Scheme for Radio-Frequency Analog Signals

A novel self-synchronizing optoelectronics polyphase scheme for sampling and demultiplexing radio-frequency (RF) signals is demonstrated. One unique feature of this approach is that the optically sampled RF signal always remains in the electrical domain and thus eliminates the need for electrical-to-optical and back to electrical conversions. Furthermore, the simplicity and ease of construction of the scheme readily allows it to be scaled to obtain high sampling rates. As a proof of concept, a 100-MHz RF electrical signal sampled at the rate of 1.28 GS/s and then demultiplexed into four 320-MHz signals was experimentally demonstrated.     

消费者属性对产品造型相似度认知的影响

目的 研究消费者属性对产品造型相似度认知的影响,为优化产品造型空间,提高人们对其认知的一致性提供依据。方法 首先,采用传统的方法,筛选出四十三个家用加湿器样本,构建产品造型空间,邀请七十三位被试,根据造型相似度将其进行多层分类,获取样本间造型相似度数据及被试属性数据;其次,基于轮廓分析法,依次分析不同属性下各组被试对各样本造型相似度认知的一致性;最后,根据异常样本的分布情况,分析各属性对产品造型相似度认知的影响程度。结论 生活形态属性对被试产品造型相似度认知的影响显著,异常率达20%以上,并且强于人口综合特征的影响;学历、性别、专业背景则基本无影响。应引入生活形态因素,检验人们对产品样本造型认知的一致性,进一步优化产品造型空间。     

Immunomodulatory properties of selectively processed prawn protein fractions assessed using human peripheral blood mononuclear cells

Prawn muscles were treated with acetic acid and high-pressure processing (600 MPa) separately to analyse their antigenicity and immunogenicity. The protein fractions were separated and isolated using preparative HPLC, and their antigenicity was analysed using Immunoglobulin G (IgG) ELISA kit. Out of thirty-nine protein fractions, only four (A10, A11, B10 and C9) were detected with antigenic potentials. The immunogenicity of these protein fractions was analysed using human PBMCs, and supernatants were collected at multiple times from 0 to 144 h. The treated fractions (B10 and C9) analysed using Immunoglobulin E (IgE) ELISA kit showed significantly (P < 0.05) lower pro- and anti-inflammatory cytokine production compared with control (A10). The allergenic fractions were characterised using an LC/MS/MS, which identified nine proteins. Among these, six proteins (tropomyosin, arginine kinase, haemocyanin, enolase, vitellogenin and 14-3-3 zeta) have been established as allergenic in prawn muscle and ovaries. Other three proteins (beta-1,3-glucan-binding protein, translationally controlled tumour protein and farnesoic acid O-methyltransferase short isoform protein) identified in this study need further investigation for their immunogenic properties.     

Frequency spurious aversion by minimal reverse bias selection of a high-speed optically triggered sampling circuit based on a positive-intrinsic-negative photodiode

In this paper we present a procedure for the selection of the minimal dc reverse bias voltage of a high-speed optically triggered sampling circuit. The optically triggered sampling circuit is based on a PIN photodiode. A set of expressions that includes the optical power dependence of the current passing through the PIN photodiode is derived. Theoretical results of the procedure are experimentally verified with practical measurements obtained from a 3 giga samples per second (GS/s) and a 20 GS/s sampling circuit implemented with commercial PIN photodiodes. Reductions in the signal-to-noise and distortion ratio of 37.28 and 6.9?dBs, as well as increments in the spurious free dynamic range of 31 and 19?dBs in the sampled signals, are respectively averted by the selection of the minimal reverse bias.     

Effect of waste matrix for the optimization of moisture content and calorific value of biodried material using Taguchi DOE

In this study, Taguchi approach was used to determine the influence of waste composition for the optimization of moisture content (MC) and calorific value (CV) of food waste via bio-drying process. The objective was to reduce MC and increase CV of the bio-dried material. The effect of three different levels of four factors including food (FW), paper (Pa), plastic (Pl) waste, and bulking agent (BA) were studied and optimized. The moisture content of the bio-dried material varied between 8.59 and 50.93%, whereas that of the calorific value was 11–25?MJ/kg. The results revealed optimum configurations for MC and CV as FW₁Pa₃Pl₃BA₃ and FW₁Pa₁Pl₃BA₁, respectively. Regression analysis revealed MC as a positive function of FW and BA with plastic positively correlated with calorific value. ANOVA analysis indicated that FW had more prominent effect on both MC and CV. The predicted and measured values were very close to each other. Additionally, the results realized in the confirmatory experiments at optimized conditions of CV was found to be higher than the test runs of Taguchi design, suggesting that Taguchi method was very successful in the optimization of bio-drying factors for MC and CV.     

Experimental multiuser quantum key distribution network using a wavelength-addressed bus architecture

A six-user quantum key distribution network implemented on a bus topology is experimentally demonstrated. The network employs the BB84 protocol to transmit cryptographic keys encoded unto the phase states of highly attenuated laser light to distances of up to 31 km in a standard telecommunication-grade fiber. Each user on the network is assigned a unique wavelength for communication with the network server at a time. The measured quantum bit error rate and sifted key rate compare favorably with theoretical results.