Ultra Mobile Broadband Technology Overview and Competitive Advantages

To efficiently meet the increasing demands for mobile broadband, Ultra Mobile Broadband (UMB) is designed to complement 3G deployments. It is equipped with all the necessary features for optimal support of real-time and best-effort traffic with seamless mobility. This article overviews the UMB technology, and discusses its competitive advantages, which are fast time to market, flexible deployment options, inherently designed for real-time services and flexible IP-based network architecture. Moreover, the article analyzes key UMB design features, including Orthogonal Frequency Division Multiple Access (OFDMA), advanced antenna techniques, Reverse Link (RL) sector capacity optimization, adaptive interference management mechanisms, efficient RL control design, low-overhead signaling, fast seamless handoffs, multi-carrier support and beacons, enhanced terminal battery life, and flexible IP-based network architecture. UMB is well suited to be at the center of the future that melds broadband applications with faster, more capable mobile multimedia devices. UMB’s competitive advantages provide operators with continuous differentiation today and tomorrow.     

Order selection and scheduling with leadtime flexibility

In this paper, we study integrated order selection and scheduling decisions, where the manufacturer has the flexibility to choose leadtimes. Our main goal is to provide a mechanism for coordinating order selection, leadtime and scheduling decisions and to determine under what conditions leadtime flexibility is most useful for increasing the manufacturer's profits. Through numerical analyses, we compare and contrast the benefits of leadtime flexibility and the flexibility to partially fulfill orders in different demand environments defined by the congestion level (or demand load), seasonality of the demand and order size. We consider both the cases where the manufacturer has and does not have the flexibility to produce orders early before they are committed.     

Strongly amphiphilic wetting behavior for polyurethanes with polyoxetane soft blocks having –CF2H terminated side chains

Two novel polyoxetanes with –CF₂CF₂H (4F) or –(CF₂)₃CF₂H (8F) terminated side chains were synthesized and characterized by ¹H NMR spectroscopy, DSC and GPC. 4F and 8F diols were incorporated in polyurethanes IPDI-BD(40)/4F-8.2 (U-4F-8.2) and IPDI-BD(40)/8F-5.8 (U-8F-5.8), where isophorone diisocyanate (IPDI) and 1,4-butane diol (BD) comprise the hard block (40 wt%) and 4F-8.2 or 8F-5.8 are soft blocks with M_n in kDa. Surface characteristics were evaluated using TM-AFM, XPS and dynamic contact angle (DCA) measurements. In contrast to U-4F-8.2, TM-AFM reveals an interesting phase separated surface morphology for U-8F-5.8 apparently driven by higher F side chain content. A model is proposed to account for contact angle measurements that show reversible, strongly amphiphilic wetting with θ_adv > 100° and θ_rec < 40°. Resistance to surface phase separation and related studies suggest the –CF₂CF₂H moiety is an important candidate for expanding the range of functional groups employed in surface modifiers.     

Comments on “Analytical expression for electrical efficiency of PV/T hybrid air collector” by S. Dubey,G.S. Sandhu,and G.N. Tiwari

In this short communication, a theoretical attempt has been made and the analytical expression developed by Dubey, Sandhu, and Tiwari [2009. “Analytical Expression for Electrical Efficiency of PV/T Hybrid air Collector.” Applied Energy 86: 697–705.] for temperature-dependent electrical efficiency of air type PV/T collector has been corrected. The analyses have indicated that their efficiency expression only considers the effects of solar intensity. However, it is unequivocal from the governing equations that the ambient temperature is another variable that should be in the efficiency expression as an initial condition of the energy balance equation of flowing air. Although they asserted that the electrical efficiency of the system has been evaluated with respect to the variations in solar intensity and ambient temperature for a typical day in the month of April 2008 for New Delhi condition, the results clearly show that the ambient temperature has not been taken into account in their study. Their expression not including a term for ambient temperature proves our statement. In the present work, the corrected version of the efficiency expression is given.     

Towards faster liquid crystals at lower driving voltages

Abstract— Response times and switching voltages of positive‐ and negative‐type nematic liquid‐crystal mixtures are improved by the addition of small amounts of diaryl‐ether derivatives. The effect of such doping is directly seen as a reduction in the rotational viscosities of the mixtures. Despite their non‐planar nature, the dopant molecules do not cause any detrimental changes to the black levels and the contrast ratios of the displays filled with the doped LC mixtures.     

Clickable,versatile poly(2,5-dithienylpyrrole) derivatives

In this study a novel, clickable, azide containing conducting polymers based on 1-(2-azido-ethyl)-2,5-dithiophene-2-yl-1H-pyrrole (SNS-N₃) were synthesized and characterized. Optical and electronic properties of homopolymer (PSNS-N₃) were investigated and colorimetric studies were performed. The homopolymer has a band gap of 2.49 eV and it displays yellow to blue coloration upon doping. Electrochemically prepared copolymers of SNS-N₃ and 3,4-ethylenedioxythiophene (EDOT) formed multichromic, color tunable electrochromic materials with continuous color gradient from cinnamon, mustard, lime green, blue and dark blue. Spectroelectrochemical analyses revealed that the neutral copolymers possess two absorption maxima (～320 and 450 nm) where the relative intensity and position of the two depends on polymerization potential. Copolymer films could be fully switched between their neutral and oxidized forms in ～1.2 s with a percent transmittance of ～65% at 950 nm. Moreover, a PSNS-N₃ coated ITO electrode was subjected to click reaction using ethynylferrocene. CV and FTIR studies revealed that ferrocene could easily be attached onto the electrode surface without loss of electroactivity of both ferrocene and PSNS backbone. Our results suggest that electrochemically prepared PSNS-N₃ films offer a novel and multipurpose platform for simple, effective post-functionalization of poly(2,5-dithienylpyrrole)s under mild conditions.     

Prevalence,characterization and antibiotic resistance of enterococci from traditional cheeses in Turkey

The aim of the present work is to provide information about Enterococcus strains isolated from traditional Turkish cheese samples in Ankara (Turkey), focusing on their prevalence, phenotypic and genotypic characteristics, and antibiotic resistance. A total of 213 probable enterococcal isolates isolated from 215 samples were identified by phenotypic and genotypic methods. As a result of 16S rDNA sequence analysis, 88 of the 213 enterococci strains were identified as Enterococcus faecium and 125 as Enterococcus faecalis. The E. faecalis strains (58.7%) were identified as the dominant species isolated from cheese samples in Turkey. The 213 Enterococcus strains were tested for susceptibility to 12 different antimicrobial agents. The resistance phenotype were as follow: nalidixic acid (100%), kanamycin (98.6%), rifampicin (78.4%), ampicillin (48.8%), ciprofloxacin (45.5%), erythromycin (18.8%), tetracycline (11.7%), penicillin G (5.6%), chloramphenicol (4.2%), gentamycin (3.8%) and streptomycin (1.4%). None of the strains was resistant to vancomycin. E. faecium strains showed more resistant phenotypes than E. faecalis strains as shown by the antibiotic resistance levels. It was also observed that the resistance of E. faecium and E. faecalis strains against the antibiotics was statistically significant (p ? 0.05). In total, 100% of E. faecium and 88.8% of E. faecalis strains were resistant to multiple drugs.     

Inhibition of lipid oxidation in anchovy oil (Engraulis encrasicholus) enriched emulsions during refrigerated storage

The aim of this study was to produce a functional emulsion product enriched with anchovy (Engraulis encrasicholus) oil. Tomato and garlic extracts were added to perform oxidative stability. Tomato and garlic extracts were added to avoid oxidative degradation in such a product. The plant extracts delayed the formation of primary and secondary oxidation products. The value of conjugated diens (3.07 ± 0.15) was markedly low in the emulsions containing garlic extract at the end of the storage period. The p–Av values of the emulsions treated with the extracts were significantly (P < 0.01) lower than untreated samples. TBARS formation increased slightly, therewithal statistical difference was not observed in the samples treated with garlic extract during the storage. Strong odour and flavour of the garlic suppressed the odour of fish oil. The panellists preferred the flavour, odour and aroma characteristics of the samples treated with the extracts.