A study on swelling behavior of poly(p‐chloro styrene) networks in some aromatic hydrocarbons and linear poly(p‐chloro styrene) solutions

Crosslinked networks (NPPCS) and linear polymers (LPPCS) of poly (p‐chloro styrene) were synthesized by free‐radical polymerization of p‐chloro styrene. NPPCS networks were swollen in four different molecular weights of LPPCS solutions in toluene at three different concentrations. The equilibrium swelling results were evaluated by means of Flory‐Rehner theory to obtain network–linear polymer interaction parameter, χ′₂₃ between NPPCS and LPPCS. It was concluded that the parameter χ′₂₃ decreased with molecular weight but increased with concentration of LPPCS in outer solution. The solvent independent interaction parameter between NPPCS and PPCS was estimated as 0.7 by extrapolation of the values of χ′₂₃ to zero value of the fraction ratio of solvent to linear polymer, ν₁/ν₃ inside the network. As well as, the binary interaction parameters, χ₁₂ of NPPCS with benzene, ethyl benzene, n‐propyl benzene and isopropyl benzene were obtained by means of Flory‐Rehner theory at temperatures between 25 and 55°C. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Extended kalman filtering for the modeling and analysis of ICG pharmacokinetics in cancerous tumors using NIR optical methods

Compartmental modeling of indocyanine green (ICG) pharmacokinetics, as measured by near infrared (NIR) techniques, has the potential to provide diagnostic information for tumor differentiation. In this paper, we present three different compartmental models to model the pharmacokinetics of ICG in cancerous tumors. We introduce a systematic and robust approach to model and analyze ICG pharmacokinetics based on the extended Kalman filtering (EKF) framework. The proposed EKF framework effectively models multiple-compartment and multiple-measurement systems in the presence of measurement noise and uncertainties in model dynamics. It provides simultaneous estimation of pharmacokinetic parameters and ICG concentrations in each compartment. Moreover, the recursive nature of the Kalman filter estimator potentially allows real-time monitoring of time varying pharmacokinetic rates and concentration changes in different compartments. Additionally, we introduce an information theoretic criteria for the best compartmental model order selection, and residual analysis for the statistical validation of the estimates. We tested our approach using the ICG concentration data acquired from four Fischer rats carrying adenocarcinoma tumor cells. Our study indicates that, in addition to the pharmacokinetic rates, the EKF model may provide parameters that may be useful for tumor differentiation.     

Effect of whey pH at drainage on physicochemical, biochemical, microbiological, and sensory properties of Mozzarella cheese made from buffalo milk during refrigerated storage

The objective of this research was to determine the effect of drainage pH on physicochemical, biochemical, microbiological and sensory properties of Mozzarella cheese made from buffalo milk during refrigerated storage. Four vats of cheese were made at 4 different whey drainage pH (6.2, 5.9, 5.6, and 5.2). Lower drainage pH caused higher pH 4.4-soluble N and pH 4.4-soluble N:total N. Interaction of drainage pH at d 1 and 30 of storage on all soluble nitrogen fractions was significant. Degradation of caseins in samples made at a drainage pH of 6.2 was lower than that of other cheese samples. The decreasing whey drainage pH significantly increased counts of thermophilic and mesophilic lactobacilli of the samples during refrigerated storage. No coliforms or Escherichia coli were detected in the cheeses. The average sensory property scores of all cheese samples were very close, and, as expected, storage time had a negative effect on all sensory scores.     

Person?×?Situation interactionism in self-encoding (Iam…when…): Implications for affect regulation and social information processing.

Although Person?×?Situation (P?×?S) interactionism is central in current social-cognitive conceptions of personality organization, its implications for the encoding of the self remain unexplored. Two studies examined the causal role of P?×?S interactionism in self-encoding on affect regulation and discriminative social perception. Following failure (Studies 1 and 2) and success (Study 2) ideation, participants were prompted to encode the self either in P?×?S interactionist terms (I am…when…) or in traitlike unconditional terms (I am…). Interactionist (compared with unconditional) self-encoding led to less affective extremity, suggesting that such encoding may prevent individuals from generalizing specific success and failure experiences to the self as a whole. Study 2 also found that interactionist self-encoding attenuated the endorsement of global stereotypes, suggesting that such encoding may enhance fine-grained social perception as well. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A cross-layer fault tolerance management module for wireless sensor networks

It is a well-established fact that wireless sensor networks (WSNs) are very power constraint networks, but besides this, they are inherently more fault-prone than any other type of wireless network and their protocol design is very application specific. Major reasons for the faults are the unpredictable wireless communication channel, battery depletion, as well as fragility and mobility of the nodes. Furthermore, as traditional protocol design methods have proved inadequate, the cross-layer design (CLD) approach, which allows for interactions between different layers, providing more flexible and energy-efficient functionality, has emerged as a viable solution for WSNs. In this study we define a fault tolerance management module suitable to the requirements, limitations, and specifics of WSNs, encompassing methods for fault detection, fault prevention, fault management, and recovery. The suggested solution is in line with the CLD approach, which is an important factor in increasing the network performance. Through simulations the functionality of the network is evaluated, based on packet loss, delay, and energy consumption, and is compared with a similar solution not including fault management. The results achieved support the idea that the introduction of a unified approach to fault management improves the network performance as a whole.     

Comparison of acid and enzymatic hydrolysis of tobacco stalk xylan for preparation of xylooligosaccharides

Tobacco stalk (TS), a major agricultural waste in the Black Sea region of Turkey, was used for the production of xylooligosaccharides (XOs). It contains about 22 g/100 g xylan whose composition was determined as 93.5 g/100 g xylose, 6.54 g/100 g glucose and 11.2 g/100 g uronic acid after complete acid hydrolysis. XO production was performed by enzymatic and acid hydrolysis of xylan which was obtained by alkali extraction from tobacco stalk. In enzyme hydrolysis, xylan was hydrolyzed using a xylanase preparation and the effects of pH, temperature, hydrolysis period, substrate and enzyme concentrations on the xylooligosaccharide yield and degree of polymerization were investigated. For enzymatic hydrolysis under optimum conditions XO yield with respect to tobacco stalk xylan (TSX) was 8.2 g/100 g after 8 h and 11.4 g/100 g after 24 h reaction period. In the acid hydrolysis, sulfuric acid was used and the hydrolyzate contained different amount of oligosaccharides and monosaccharides. For acid hydrolysis under optimum conditions, XO yield with respect to TSX was 13.0 g/100 g. Enzymatically obtained oligosaccharides were purified via ultrafiltration by using 10 and 3 kDa membranes. After a two-step membrane processing, the permeate containing mostly oligosaccharides was obtained.     

Hydrogen and fuel cell activities at UNIDO-ICHET

To place hydrogen energy usage into proper perspective, International Center for Hydrogen Energy Technologies (ICHET) has been implementing measures to demonstrate potential benefits of the “hydrogen and fuel cell systems” in developing countries. Demonstration of technologies is the most important aspect of ICHET vision for the formation of an industry in the developing world. ICHET has embarked on a series of educational and laboratory activities designed to increase the knowledge and awareness of students and advanced researchers concerning hydrogen energy technologies. The state of the art fuel cell laboratory is available for joint technology development and demonstration activities. Internship activities facilitate knowledge transfer, exchange of information at regional, national and international levels and involve academics, researchers, experts and service providers. Collaboration is a key part of the organizational strategy for joint projects, funding and trainings in the field of hydrogen and fuel cells.     

A comparative analysis of the effects of computer and paper-based personalization on student achievement

The aim of this study is to investigate whether personalization of mathematical word problems affects student achievement; and if it does, to find out whether the outcomes vary depending on computer and class environment in the teaching of mathematics. The sample of the research, conducted in the 2006–2007 fall semester, consists of 90 seventh grade in four sub-groups. During the application in the classroom, paper-based personalized and paper-based non-personalized problems were given. As to the computer environment, web-based personalized and web-based non-personalized problems were presented. After the application, an achievement test was performed as an achievement post-test parallel to the pre-test. The results show no significant difference between the scores of the groups who used personalized materials and the groups who used non-personalized materials. The results also indicate that no significant difference exists between those who studied in the computer-based environment and those in the paper-based environment.     

Polyphenol oxidase properties,anti-urease,and anti-acetylcholinesterase activity of Diospyros lotus L. (Plum Persimmon)

Diospyros lotus fruit polyphenol oxidase was purified using affinity chromatography, resulting in a 15-fold enrichment in specific activity. The purified enzyme, having 16.5 kDa molecular weight on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, exhibited the highest activity toward 4-methylcatechol. Maximum diphenolase activity was reached at pH 7.0 and 60°C in the presence of 4-methylcatechol. K_m and V_max values were calculated as 3.8 mM and 1250 U/mg protein, respectively. Ascorbic acid was a promising inhibitor with an IC₅₀ value of 0.121 µM. The activity of the purified enzyme was stimulated by Fe²⁺, Sr²⁺, Zn²⁺, and K⁺ and deeply inhibited by Hg²⁺, at 1 mM final concentration. Aqueous extract of Diospyros lotus L. fruit showed strong substantial urease and acetylcholinesterase inhibition, with IC₅₀ values of 1.55 ± 0.05 and 16.75 ± 0.11 mg/mL, respectively.     

The importance of economies of scale,transport costs and demand patterns in optimising hydrogen fuelling infrastructure: An exploration with SHIPMod (Spatial hydrogen infrastructure planning model)

Hydrogen is widely recognised as an important option for future road transportation, but a widespread infrastructure must be developed if the potential for hydrogen is to be achieved. This paper and related appendices which can be downloaded as Supplementary material present a mixed-integer linear programming model (called SHIPMod) that optimises a hydrogen supply chains for scenarios of hydrogen fuel demand in the UK, including the spatial arrangement of carbon capture and storage infrastructure. In addition to presenting a number of improvements on past practice in the literature, the paper focuses attention on the importance of assumptions regarding hydrogen demand. The paper draws on socio-economic data to develop a spatially detailed scenario of possible hydrogen demand. The paper then shows that assumptions about the level and spatial dispersion of hydrogen demand have a significant impact on costs and on the choice of hydrogen production technologies and distribution mechanisms.