Tertiary fatty amides as diesel fuel substitutes

This paper presents experimental results regarding the impact of adding different tertiary amides of fatty acids to mineral diesel fuel; an assessment of the behaviour of these compounds as possible diesel fuel extenders is also included. Measurements of cetane number, cold flow properties (cloud point, pour point and CFPP), density, kinematic viscosity, flash point and distillation temperatures are reported, while initial experiments concerning the effects on particulate emissions are also described. Most of the examined tertiary fatty amides esters have very good performance and they can be easily prepared from fatty acids (biomass). Such compounds or their blends could be used as mineral diesel fuel or even fatty acid methylesters (FAME, biodiesel) substitutes or extenders. Copyright © 2000 John Wiley & Sons, Ltd.     

Microbial spoilage analysis and its effect on chemical changes and shelf‐life of Norway lobster (Nephrops norvegicus) stored in air at various temperatures

Microbial activity and spoilage of Norway lobster (Nephrops norvegicus) from Greek temperate waters, stored in air at 20, 5 and 0 °C was assessed. Microbial spoilage population, Total Volatile‐Base Nitrogen (TVB‐N), Trimethylamine‐Nitrogen (TMA‐N), pH and organoleptic changes were determined. Shelf‐life of Norway lobster stored at 20, 5 and 0 °C was 24, 72 and 96 h respectively. The product was spoiled due to the development of TVB‐N and melanosis of the carapace, as TVB‐N was apparent from the early stages of storage and correlated very well with microbial growth and shelf‐life. Pseudomonas sp. was the predominant spoilage bacterium. Product rejection coincided with TVB‐N levels of 330–400 mg kg^?1 and Pseudomonas sp. population level of about 5 × 10⁵ cfu g^?1. Pseudomonas sp. and TVB‐N are presumably the Specific Spoilage Organism and the Chemical Spoilage Index of the product.     

Pure copper processed by extrusion preceded equal channel angular pressing

High purity copper (99.99%) was severely plastically deformed by miniaturized extrusion preceded ECAP at 200 °C. A partially recrystallized microstructure was detected by TEM observations due to the relative high processing temperature. Isochronal annealing was performed to investigate the material's behavior by measuring the development of Vickers microhardness. As copper is a metal with a relative low stacking fault energy, recovery does not occur readily and only recrystallization takes place.     

Evidence for Novel Action at the Cell‐Binding Site of Human Angiogenin Revealed by Heteronuclear NMR Spectroscopy,in silico and in vivo Studies

A member of the ribonuclease A superfamily, human angiogenin (hAng) is a potent angiogenic factor. Heteronuclear NMR spectroscopy combined with induced‐fit docking revealed a dual binding mode for the most antiangiogenic compound of a series of ribofuranosyl pyrimidine nucleosides that strongly inhibit hAng's angiogenic activity in vivo. While modeling suggests the potential for simultaneous binding of the inhibitors at the active and cell‐binding sites, NMR studies indicate greater affinity for the cell‐binding site than for the active site. Additionally, molecular dynamics simulations at 100 ns confirmed the stability of binding at the cell‐binding site with the predicted protein–ligand interactions, in excellent agreement with the NMR data. This is the first time that a nucleoside inhibitor is reported to completely inhibit the angiogenic activity of hAng in vivo by exerting dual inhibitory activity on hAng, blocking both the entrance of hAng into the cell and its ribonucleolytic activity.     

CD28null and Regulatory T Cells Are Substantially Disrupted in Patients with End-Stage Renal Disease Due to Diabetes Mellitus

Background: End-stage renal disease (ESRD) is associated with alterations in T-cell immunity, including increased CD28null and reduced regulatory T cells (Tregs). However, whether immune disturbances are due to ESRD or primary disease is not yet clear. As diabetes mellitus is the leading cause of ESRD, we evaluated its impact on the immune profile of ESRD patients. Methods: CD28null, Tregs, and natural killer cells were initially analyzed by flow cytometry in 30 predialysis ESRD patients due to diabetes (DM), 30 non-DM (NDM), and 25 healthy controls. Measurements were repeated after 6 months on hemodialysis (HD) or peritoneal dialysis (CAPD). Results: The percentage of CD4 + CD28null cells, CD8 + CD28null cells, and Tregs showed significant differences in DM, NDM, and controls; mean rank 33.71 vs. 25.68 vs. 18.88, p = 0.006, 37.79 vs. 28.82 vs. 17.08, p = 0.008, and 20.79 vs. 26.12 vs. 41.33, p = 0.001, respectively. DM vs. NDM had increased CD4 + CD28null and CD8 + CD28null cells, 11.5% (1.5%–24%) vs. 4.1% (0–42.3%), p = 0.02 and 61.3% (24%–76%) vs. 43% (5.7%–85%), p = 0.04, respectively. After 6 months on HD but not CAPD, DM showed a significant further increase in CD4 + CD28null cells, from 30 (14–100) to 52.7 (15–203), p = 0.02; and CD8 + CD28null cells, from 137 (56–275) to 266 (103–456), p = 0.01. Conclusions: Diabetes mellitus affects T-cell subtypes even at predialysis stage, though changes become more prominent after commencement on HD.     

Performance evaluation study for QoS-aware triple play services over entry-level xDSL connections

Nowadays IT and telecom worlds and specifically all network, service, and content providers show special interest in multiservice delivery. The concurrent provision of video or TV content, voice, and fast Internet via the same network and user equipment, known as “triple play service”, constitutes one of the major concerns in modern telecommunications due to the latest developments in the areas of video and audio encoding which strain the capacity of content delivery systems. The combination of the above technologies has raised significant quality of service related issues. Problems such as full exploitation of available bandwidth, providing adequate quality of service to subscribers and meeting the requirements of all three supported services (video, voice, and data), must be addressed. Based on this framework, the paper examines the performance of the most common packet scheduling techniques (PQ, WFQ, WFQ-LL) used in IP triple play architecture, considering also two different packetization schemes applied to single-layer video. The performance of these scheduling algorithms is assessed, in order to propose the most appropriate solution, supporting the triple play bundle. The evaluation of schedulers is based on simulations designed taking into account existing triple play networks, while trace files are used for the simulation of video flows.     

Critical review of the e-loyalty literature: a purchase-centred framework

Over the last few years, the concept of online loyalty has been examined extensively in the literature, and it remains a topic of constant inquiry for both academics and marketing managers. The tremendous development of the Internet for both marketing and e-commerce settings, in conjunction with the growing desire of consumers to purchase online, has promoted two main outcomes: (a) increasing numbers of Business-to-Customer companies running businesses online and (b) the development of a variety of different e-loyalty research models. However, current research lacks a systematic review of the literature that provides a general conceptual framework on e-loyalty, which would help managers understand their customers better, take advantage of industry-related factors, and improve their service quality. The present study is an attempt to critically synthesize results from multiple empirical studies on e-loyalty. Our findings illustrate that 62 instruments for measuring e-loyalty–with two or more items—are currently in use, influenced predominantly by Zeithaml et al. (J. Marketing 60(2):31–46, 1996) and Oliver (Satisfaction: a behavioral perspective on the consumer. New York: McGraw Hill, 1997). Additionally, we propose a new general conceptual framework, which leads to e-loyalty dividing antecedents into prepurchase, during-purchase and after-purchase factors, based on the act of purchase. To conclude, a number of managerial implementations are suggested in order to help marketing managers increase their customers’ e-loyalty by making crucial changes in each purchase stage.     

Shelf-life extension of refrigerated Mediterranean mullet (Mullus surmuletus) using modified atmosphere packaging

The present work evaluated the quality and freshness characteristics and the effect of modified atmosphere packaging (MAP) on the shelf-life extension of refrigerated Mediterranean mullet using microbiological, biochemical, and sensory analyses. Fresh open sea red mullet (Mullus surmuletus) were packaged in four different atmospheres: M1, 10%/20%/70% (O2/ CO2/N2); M2, 10%/40%/50% (O2/CO2/N2); M3, 10%/60%/30% (O2/CO2/N2); identical fish samples were packaged in air. All fish were kept under refrigeration (4 +/- 0.5 degrees C) for 14 days. Of the three gas atmospheres, the 10%/40%/50% (M2) and 10%/ 60%/30% (M3) gas mixtures were the most effective for inhibiting growth of aerobic microflora in mullet samples until day 10 of refrigerated storage. H2S-producing bacteria and pseudomonads were part of the mullet microflora and their growth was partly inhibited under MAP conditions. Between these two bacterial groups, H2S-producing bacteria (including Shewanella putrefaciens) were dominant toward the end of the storage period, regardless of the packaging conditions. Brochothrix thermosphacta and lactic acid bacteria were found to be members of the final microbial flora of MAP and air-packaged mullet, whereas the Enterobacteriaceae population was lower than other bacterial groups. Of the chemical freshness indices determined, thiobarbituric acid values were variable in mullet samples irrespective of packaging conditions indicative of no specific oxidative rancidity trend. Based on sensorial data and aerobic plate count, trimethylamine nitrogen and total volatile basic nitrogen limit values in the range of ca. 15 to 23 and 52 to 60 mg N/100 g of fish muscle were obtained, respectively, for mullet packaged under modified atmosphere and air. Sensory analyses (odor and taste attributes) showed that the limit of sensorial acceptability was reached after ca. 6 days for the samples packaged in air, 8 days for the M1 and M3 samples, and after 10 days for the M2 samples. Respective shelf-life extension for fresh whole mullet was ca. 2 days (M1 and M3 gas mixtures), and 4 days (M2 gas mixture).