Thermomechanical Analysis of (Cu0.5Tl0.5)-1223 Substituted by Pr and La

The thermomechanical analysis (TMA) of Cu 0.5 Tl 0.5 Ba 2 Ca 2 x R x Cu 3 O 10 δ,where R=Pr and La,with 0.0≤x≤0.15,was carried out in temperature range from 450 to 1145 K.The samples were prepared by singlestep solid state reaction technique.The prepared samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).The superconductivity of the prepared samples was investigated by electrical resistivity measurement.The results showed that low substitution content enhanced the (Cu 0.5 Tl 0.5)1223 phase formation,while the higher substitution content degraded this phase.The higher superconducting transition temperatures T c were found to be 114 K and 109 K at x= 0.025 for Pr-and La-substitutions,respectively.The average linear thermal expansion coefficient increased as x increased,while the shrinkage temperature decreased as x increased.Those results were emphasized by porosity and Vickers microhardness calculations.Debye temperature θ D was calculated from the linear thermal expansion coefficient data and correlated to T c to estimate the electron-phonon coupling λ ep.     

Optimization of the restructuring cost of an urban drainage network

Urban drainage networks are subjected to increased runoff caused by urbanization and climate change. Wear and tear, coupled with a lack of network maintenance, reduces the hydraulic capacity of these networks and results in surcharged flows, discharges and overflows calling for the need to institute effective restructuring strategies. The purpose of this study was to develop an optimization model for the optimal selection and placement of structural best management practices (BMPs). In this research, four types of structural BMPs were being considered (i.e., retention pond, green roofs, infiltration trenches and vegetated depressions). The objective function was to minimize the total cost of BMPs, within the constraints of (1) draining infrequent heavy rainfall without surcharging the conduits and (2) driving frequent small rainfall into the water-treatment plant without overflows. The model was tested on a case study in the Greater Montreal Area and the results obtained from the model effectively demonstrated its capacity to improve the hydraulic and environmental performances by adopting optimal BMPs placement strategies.     

Hybrid fiber-to-the-x and free space optics for high bandwidth access networks

The authors demonstrate an implementation of hybrid fiber-to-the-x (FTTx) and free space optical (FSO) technologies as another alternative solution to bring light-speed performance to the residential users. A simulation experiment was performed with a 20 km single-mode fiber spanning from the Central Office to 1:32 splitter, before the signal propagated through the air to FSO receivers which were individually equipped with an Optical Network Unit (ONU). A downstream performance of the video signal transmitted at 1550 nm wavelength with a bit rate of 1 Gbps was studied under different weather conditions. The results show that for an acceptable bit error rate of 10⁻⁹, 32 ONUs are supportable at a combined FSO: FTTx distance ratio of 20:4.8, 20:2, and 20:1.4 km during clear weather, average and heavy rain, respectively.     

Sensory Evaluation of Flavored Soy Milk-Based Yogurt： A Comparison between Jordanian and Malaysian Consumers

Soy yogurt has gained significant popularity due to its nutritional health benefits. The objectives of this study were to develop flavored yogurt from soybean milk with reduced soy aftertaste by the addition of 30% （wt/wt） strawberry or orange jam in conjunction with a lactic acid fermentation. Soy milk-based yogurt products were assessed for microbial quality and for acceptability by a panel of Jordanian and Malaysian consumers. Sixty-one individuals, of whom 75.4% （n = 46） were Jordanian and 24.6% （n = 15） were Malaysian, evaluated the plain and flavored soy milk-based yogurt. The overall acceptability of orange and strawberry soy yogurt was rated significantly higher than plain soy yogurt. In general, the orange and strawberry soy yogurt received higher sensory ratings from Malaysian than Jordanian consumers. In addition, formulations with orange jam received higher scores than those flavored with strawberry. Shelf life tests showed that soy yogurt was acceptable for at least 8 d without perceptible spoilage. Therefore, the approach used yielded flavored products with better acceptability and improved sensory attributes, including decreased intensity of off flavor, with suitable shelf life at 4 ℃.     

Temperature-Sensitive Microcapsules Containing Lactoferrin and Their Action Against Carnobacterium viridans on Bologna

ABSTRACT:  Lactoferrin (LF) was encapsulated in 2 types of emulsion to protect it from contact with agents like divalent cations, which interfere with its antimicrobial activity. First, paste-like microcapsules were prepared as water-in-oil (W₁/O) emulsions from mixtures of 20% w/v LF in distilled water, 20% w/v LF in 3% w/v sodium lactate or in 20 mM sodium bicarbonate, which were emulsified with an oil mixture of 22% butter fat plus 78% corn oil and 0.1% polyglycerol polyricinoleate. Second, freeze-dried double emulsion (W₁/O/W₂), powdered microcapsules were produced following emulsification of paste-like microcapsules in an external aqueous phase (W₂) consisting of a denatured whey protein isolate (WPI) solution. The release of LF from the W₁/O microcapsules was dependent on temperature and NaCl concentration. LF was not released from the W₁/O emulsion at <5.5 °C. Its release was greater from W₁/O microcapsules when suspended in 5% aqueous NaCl than in water at ≥10 °C, whereas LF release from freeze-dried microcapsules was not controlled by temperature change. Paste-like microcapsules were incorporated in edible WPI packaging film to test the antimicrobial activity of LF against a meat spoilage organism Carnobacterium viridans . The film was applied to the surface of bologna after its inoculation with the organism and stored under vacuum at 4 or 10 °C for 28 d. The growth of C. viridans was delayed at both temperatures and microencapsulated LF had greater antimicrobial activity than when unencapsulated. The temperature-sensitive property of the W₁/O microcapsules was reduced when they were incorporated into a WPI film.     

Impact of environmental stress desiccation, acidity, alkalinity, heat or cold on antibiotic susceptibility of Cronobacter sakazakii

Cronobacter sakazakii is an emerging foodborne pathogen that has been implicated in severe forms of meningitis, septicemia or necrotizing colitis in pre-term neonates. Although illness outbreaks (primarily associated with powdered infant formula, PIF) caused by this pathogen are rare, the case-fatality rate may reach 50%. Successful treatment of C. sakazakii infection is reliant upon clinical use of antibiotics (AB) such as ampicillin. Recent reports showed increased resistance of C. sakazakii to broad-spectrum antibiotics. The objective of this study was to evaluate the effect of extreme pH (3.5 for 30 min or 11.25 for 5 min), cold (4 °C for 24 h), heat (55 °C for 5 min), and desiccation (cells were dried at 40 °C for 2 h and held at 21 °C for 4 d) stresses on susceptibility of five isolated strains of C. sakazakii to streptomycin, gentamicin, kanamycin, neomycin, tetracycline, doxycycline, tilmicosin, florfenicol, ampicillin, amoxicillin, vancomycin, ciprofloxacin and enrofloxacin. All unstressed strains of C. sakazakii were sensitive to streptomycin, gentamycin, kanamycin, ciprofloxacin, enrofloxacin, ampicillin and amoxicillin, but were moderately resistant or resistant to the rest. Exposing cells to alkaline or acidic stress did not change their sensitivity toward streptomycin, gentamycin, kanamycin or ciprofloxacin, but their resistance toward the other AB was increased. Cells stressed by desiccation showed increased sensitivity toward streptomycin, gentamicin, kanamycin, ciprofloxacin, enrofloxacin, ampicillin and doxycycline, but showed resistance toward the others. Cold-stressed cells were more sensitive to streptomycin, gentamicin, kanamycin, and ciprofloxacin compared with heat-stressed cells, but both heat and cold-stressed cells showed increased resistance toward all the other AB. Results obtained will help in understanding the effect of environmental stresses during processing on C. sakazakii susceptibility to AB.     

Performance Analysis of Amplify-and-Forward Relay Systems with Interference-Limited Destination in Various Rician Fading Channels

In this paper, we investigate the performance of a dual-hop fixed-gain amplify-and-forward relay system in the presence of co-channel interference at the destination node. Different fading scenarios for the desired user and interferers’ channels are assumed in this study. We consider the Rician/Nakagami- \(m\) , the Rician/Rician, and the Nakagami- \(m\) /Rician fading environments. In our analysis, we derive accurate approximations for the outage probability and symbol error probability (SEP) of the considered scenarios. The generic independent non-identically distributed (i.n.d.) case of interferers’ channels is considered for the Rician/Nakagami- \(m\) scenario; whereas, the independent identically distributed (i.i.d.) case is studied for the Rician/Rician and the Nakagami- \(m\) /Rician environments. Furthermore, to get more insights on the considered systems, high signal-to-noise ratio (SNR) asymptotic analysis of the outage probability and SEP is derived for special cases of the considered fading scenarios. Monte-Carlo simulations and numerical examples are presented in order to validate the analytical and asymptotic results and to illustrate the effect of interference and other system parameters on the system performance. Results show that the different fading models of interferers’ channels have the same diversity order and that the interference degrades the system performance by only reducing the coding gain. Furthermore, findings show that the case where the fading parameter of the desired user first hop channel is better than that of the second hop gives better performance compared to the vise versa case, especially, at low SNR values; whereas, both cases almost behave the same at high SNR values where the performance of the system is dominated by the interference affecting the worst link. Finally, results show the big gap in system performance due to approximating the Rician fading distribution with the Nakagami- \(m\) distribution which is an indication on the inaccuracy of making such approximations in systems like the considered.     

Design and modeling of high-resolution multibit log-domain \Delta \Sigma modulators

Log-domain Delta-Sigma ( $\Delta \Sigma$ ) modulators are attractive for implementing analog-to-digital (A/D) converters (ADCs) targeting low-power low-voltage applications. Previously reported log-domain $\Delta \Sigma$ modulators were limited to 1-bit quantization and, hence, could not benefit from the advantages associated with multibit quantization (namely, reduced in-band quantization noise, and increased modulator stability). Unlike classical $\Delta \Sigma$ modulators, directly extending a log-domain $\Delta \Sigma$ modulator with a 1-bit quantizer to a log-domain $\Delta \Sigma$ modulator with a multibit quantizer is challenging, in terms of CMOS circuit implementation. Additionally, the realization of log-domain $\Delta \Sigma$ modulators targeting high-resolution applications necessitates minimization of distortion and noise in the log-domain loop-filter. This paper discusses the challenges of multibit quantization and digital-to-analog (D/A) conversion in the log-domain, and presents a novel multibit log-domain $\Delta \Sigma$ modulator, practical for CMOS implementation. SIMULINK models of log-domain $\Delta \Sigma$ modulator circuits are proposed, and the effects of various circuit non-idealities are investigated, including the effects of log-domain compression–expansion mismatch. Furthermore, this paper proposes novel low-distortion log-domain analog blocks suitable for high-resolution analog-to-digital (A/D) conversion applications. Circuit simulation results of a proposed third-order 3-bit class AB log-domain $\Delta \Sigma$ loop-filter demonstrate 10.4-bit signal-to-noise-and-distortion-ratio (SNDR) over a 10 kHz bandwidth with a $0.84\,V_{pp}$ differential signal input, while operating from a 0.8 V supply and consuming a total power of $35.5\,\upmu \hbox {W}.$      

Social acceptance of location-based mobile government services for emergency management

Location-based services deployed by governments can be used to assist people manage emergencies via their mobile handsets. Research delineating the acceptance of public services in the domain of emergency management has been scantly investigated in information systems. The main aim of this study is to assess the viability of location-based mobile emergency services by: (i) exploring the issues related to location-based services and their nationwide utilisation for emergency management; (ii) investigating the attitudinal and behavioural implications of the services; and (iii) examining the social acceptance or rejection of the services and identify the determinants of this acceptance or rejection. The results reveal that both attitude and perceived usefulness demonstrate a good prediction power of behavioural intention. Although perceived ease of use was found not to be a predictor of attitude, the results affirm its influence on perceived usefulness. The results also demonstrate the role of trust as the most influential determinant of individual perception of the usefulness of the services. Further, the results indicate that only the collection of personal location information, as a perceived privacy concern, had a significant negative impact on trust. Implications and future research are also discussed.     

Dynamic forecasting of travel demand,residential location and land development

TheChicago Area Transportation/Land-Use Analysis System (CATLAS) is a large scale urban simulation model which synthesizes location rent analysis from urban economics with travel demand analysis from transportation planning. This paper describes the theoretical formulation, empirical estimation and policy application of CATLAS to the evaluation of CBD-oriented rapid transit projects in Chicago.