bluuebunny/crossref_metadata_2025 huggingface dataset:
Lignocellulosic biomass feedstock transportation alternatives, logistics, equipment configurations, and modeling
Authors: Miao Zewei , Shastri Yogendra , Grift Tony E. , Hansen Alan C. , Ting K.C.
Published: February 2012

Lignocellulosic biomass feedstock transportation bridges biomass production, transformation, and conversion into a complete bioenergy system. Transportation and associated logistics account for a major portion of the total feedstock supply cost and energy consumption, and therefore improvements in transportation can substantially improve the cost‐competitiveness of the bioenergy sector as a whole. The biomass form, intended end use, supply and demand locations, and equipment and facility availability further affect the performance of the transportation system. The sustainability of the delivery system thus requires optimized logistic chains, cost‐effective transportation alternatives, standardized facility design and equipment configurations, efficient regulations, and environmental impact analysis. These issues have been studied rigorously in the last decade. It is therefore prudent to comprehensively review the existing literature, which can then support systematic design of a feedstock transportation system. The paper reviews the major transportation alternatives and logistics and the implementation of those for various types of energy crops such as energy grasses, short‐rotation woody coppices, and agricultural residue. It emphasizes the importance of performance‐based equipment configuration, standard regulations, and rules for calculating transport cost of delivery systems. Finally, the principles, approaches, and further direction of lignocellulosic feedstock transportation modeling are reviewed and analyzed. © 2012 Society of Chemical Industry and John Wiley & Sons, Ltd
Provider volume and long-term outcome after elective abdominal aortic aneurysm repair
Authors: Holt P J E , Karthikesalingam A , Hofman D , Poloniecki J D , Hinchliffe R J , Loftus I M , Thompson M M
Published: February 2012

Background

Robust risk-adjusted analyses have demonstrated that a reduction in perioperative mortality is associated with the repair of an abdominal aortic aneurysm (AAA) in centres with a high operative caseload (volume). However, the long-term impact of this volume-related effect on mortality remains unknown.

Methods

Demographic and clinical data were extracted from UK Hospital Episodes Statistics for patients undergoing elective repair of an infrarenal AAA from 1 April 2000 to 31 March 2005. The long-term mortality of this cohort was investigated through linkage to the UK Office for National Statistics (ONS) registry. Risk-adjusted survival was analysed using Cox proportional hazards modelling to identify the effect of hospital volume on long-term mortality.

Results

A total of 14 396 patients with mean age of 72 years, of whom 85·7 per cent were men, underwent elective repair of an infrarenal AAA in England. They were linked to follow-up using ONS data. Risk-adjusted analysis of all-cause mortality by Cox proportional hazards modelling demonstrated a significant effect of hospital volume across all quintiles up to 2 years (P = 0·013). Remodelling the data after excluding in-hospital mortality still demonstrated the significant effect of hospital volume on late outcome.

Conclusion

There is a long-term benefit to patients who undergo elective AAA repair in a high-volume hospital.
Reversible Synthesis of Sub‐10 nm Spherical and Icosahedral Gold Nanoparticles from a Covalent Au(CN)2− Precursor and Recycling of Cyanide to form Ferric Ferrocyanide for Cell Staining
Authors: Huang Chih‐Chia , Lai Wei‐Cheng , Tsai Chia‐Yi , Yang Chih‐Hui , Yeh Chen‐Sheng
Published: February 2012

A solution approach based on Au(CN)2− chemistry is reported for the formation of nanoparticles. The covalent character of the Au(CN)2− precursor was exploited in the formation of sub‐10 nm nanospheres (≈2.4 nm) and highly monodisperse icosahedral Au nanoparticles (≈8 nm) at room temperature in a one‐pot aqueous synthesis. The respective spherical and icosahedral Au morphologies can be controlled by either the absence or presence of the polymer polyvinylpyrrolidone (PVP). Using Au(CN)2− as a metal ion source, our findings suggest that the addition of citrate ions is necessary to enhance the particle formation rate as well as to generate a more homogeneous colloidal dispersion. Because of the presence of oxygen and the operation of a CN− etching process associated with Au(CN)2− complex formation, an interesting reversible formation–dissolution process was observed, which allowed us to repeatedly prepare spherical and icosahedral Au nanoparticles. Time‐dependent TEM images and UV/Vis spectra were carefully acquired to study the reversibility of this formation–dissolution process. In view of the accompanying generation of toxic cyanide anions, we have developed a protocol to recycle cyanide in the presence of citrate ions through ferric ferrocyanide formation. After completion of particle formation, the residual solutions containing citrate ions and cyanide ions were processed to stain iron oxide nanoparticles endocytosized in cells. Additionally, the as‐prepared 8 nm Au icosahedra could be isolated and grown to larger 57 nm‐sized icosahedra using the seed‐mediated growth approach.
Relay feedback‐based time domain modelling of off‐diagonal elements of linear 2‐by‐2 MIMO systems
Authors: Sujatha V. , Panda Rames C.
Published: February 2012

A novel approach to model the off‐diagonal closed‐loop transfer function of 2‐by‐2 multi input multi output (MIMO) system in time domain using ideal as well as biased relay feedback tests are presented. Analytical expressions are derived, for transfer function models of 2‐by‐2 MIMO system having individual transfer function elements of first‐order plus dead time (FOPDT) nature, using ideal and biased relay feedback tests in time domain and have been validated on 2‐by‐2 multivariable distillation column examples from the literature as well as on coupled tanks liquid level experimental set‐up. The results show that the derived expression matches with the original undesired relay response even without approximation of time delay in the denominator of closed‐loop transfer function of 2‐by‐2 MIMO system. These analytical expressions are useful to identify unknown system parameters. © 2012 Canadian Society for Chemical Engineering
Electrical properties of dye‐doped colour tunable organic light emitting diode
Authors: Khantham Sirintra , Tunhoo Benchapol , Onlaor Korakot , Thiwawong Thutiyaporn , Nukeaw Jiti
Published: February 2012

In this work, we report on the electrical properties of dye‐doped colour tunable organic light‐emitting diode (OLED). The device structure is glass substrate/indium tin oxide/N,N′‐di(naphthalen‐1‐yl)‐N,N′‐diphenyl‐benzidine (NPB) 30 nm/Alq3:DCM 50 nm/Aluminum (Al) 150 nm where NPB is the hole transport layer. Alq3:DCM is the emitting layer which made of tris(8‐hydroxyquinoline) aluminium (Alq3) doped with 4‐(Dicyanomethylene)‐2‐methyl‐6‐(4‐dimethyl‐aminostyryl)‐4H‐pyran (DCM) organic dye. The influence of doping concentration has been investigated by current density–voltage measurement, luminance intensity–voltage characteristic, electroluminescence (EL) and impedance spectroscopy, respectively. The EL spectrum exhibits the shifted of peak position from green to red region. The threshold voltage of the device decreased at the low DCM doping concentration (1 wt.%), in contrast, when the increase in the doping concentrations then the threshold voltage will be increased. The highest luminance intensity and lowest turn‐on voltage of OLED can be observed at doping concentration about of 1 wt.% of DCM. The impedance characteristics of the dye‐doped OLED can be modelled by simply adopting the conventional equivalent circuit with the simple combination of resistors and capacitors network. © 2012 Canadian Society for Chemical Engineering
Non‐equilibrium molecular dynamics simulation of the thermocapillary effect
Authors: Maier Holger A. , Bopp Philippe A. , Hampe Manfred J.
Published: February 2012

We report on extended computer simulations of the thermocapillary effect in a model liquid biphasic mixture by employing a nonequilibrium molecular dynamics (NEMD) technique. It maintains a constant temperature gradient in the simulated system. We discuss the methodology used and report, after a careful analysis of the uncertainties inherent to such simulations, first results. The main feature is a stable roll cell convection with flows from hot to cold in the vicinity of the interfaces. This basic pattern persists in systematic variations of the temperature gradients, the size of the simulated systems and several other parameters. We thus assume to be dealing with Marangoni flows (thermocapillary effect) at the microscopic level. © 2012 Canadian Society for Chemical Engineering
Redox‐Active, Dinuclear Sandwich Compounds [Cp*Fe(μ‐L)FeCp*] (L = Naphthalene and Anthracene)
Authors: Schnöckelborg Eva‐Maria , Hartl František , Langer Thorsten , Pöttgen Rainer , Wolf Robert
Published: February 2012

Although there has been much interest in the chemistry of bimetallic transition metal complexes, compounds with naphthalene or anthracene as bridging ligands are still rare. In this article, we describe the synthesis of the homodinuclear iron complexes [Cp*Fe(μ‐η4:η4‐L)FeCp*] (1: L = C10H8, 2: L = C14H10; Cp* = η5‐C5Me5). The complexes were characterized by 1H and 13C{1H} NMR, UV/Vis, and 57Fe Mössbauer spectroscopy, and their molecular structures were determined by X‐ray crystallography. Both complexes are diamagnetic as a result of the strong magnetic coupling of the 17e FeI centers mediated by the polyarene bridge. An analysisof the redox behavior of 1 and 2 by cyclic voltammetry andUV/Vis spectroelectrochemistry shows that the complexes can be oxidized reversibly in two well‐separated one‐electron steps to the monocation [Cp*Fe(μ‐L)FeCp*]+ and the dication [Cp*Fe(μ‐L)FeCp*]2+. The reduction to the monoanion [Cp*Fe(μ‐L)FeCp*]– was also observed.
Copper‐Mediated One‐Pot Access to Benzo[b][1,4]thiazines from 2‐N‐Sulfonylaminoaryl Disulfides
Authors: Viglianisi Caterina , Bonaccorsi Paola , Simone Lavinia , Nassini Lucia , Menichetti Stefano
Published: February 2012

2‐N‐Sulfonylaminoaryl disulfides can be converted into the corresponding benzo[b][1,4]thiazines in one pot when reacted with an electron‐rich alkene in the presence of a base and a substoichiometric amount of a copper salt. Depending upon the reaction conditions, and in particular the copper salt used, we observed the concurrent formation of variable amounts of the corresponding benzo[b][1,4]thiazine S‐oxides that are not the result of a post‐oxidation reaction. The overall procedure can provide simple access to benzo[b]thiazines or thiazine S,S‐dioxides by sequential reduction or oxidation of the crude reaction mixtures.
Oxidation of 6‐Benzylaminopurine‐Copper(I) Complex on Pencil Graphite Electrode
Authors: Serrano Núria , Alberich Arístides , Trnkova Libuse
Published: February 2012

A voltammetric study of the 6‐benzylaminopurine (BAP)/Cu(I) system is performed. BAP is an adenine‐type cytokinin that elicits cell division in plants and presents antitumor activity when forming complexes with different transition metal ions as copper(I). In the frame of this research field, an analysis of linear sweep voltammetry (LSV), adsorptive stripping voltammetry (AdSV), and elimination voltammetry with linear scan (EVLS) data obtained with a pencil graphite electrode (PeGE), allows us to propose the stoichiometry of the possible complexes formed and the mechanism for total electrode reactions of the BAP/Cu(I) system.
Estimation of detention time and effluent concentration in treatment process reactors
Authors: Bahadori Alireza
Published: February 2012

In this article, an attempt has been made to formulate a simple‐to‐use method for accurate and rapid estimation of detention time, effluent, and influent concentration ratios in plug flow reactors. This tool is useful to facilitate the design of treatment processes such as stabilization ponds. The average absolute deviations between the reported data and the proposed correlations are found to be less than 1.8% demonstrating the excellent performance of proposed method. The tool developed in this study can be of immense practical value for engineers and scientists to have a quick check on the percent remaining in plug flow reactors at various conditions. In particular, process engineers would find the predictive tool to be user‐friendly with transparent calculations involving no complex expressions. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 223‐228, 2013
Acid‐catalyzed esterification of naphthenic acids
Authors: Dastjerdi Zahra , Dubé Marc A.
Published: February 2012

The reclamation of mining operation tailings water is of major concern to the oil sands industry. Naphthenic acids (NAs) are recognized as a major toxic component in tailings water. The acid‐catalyzed esterification of commercially prepared NAs to biodiesel was performed as a test case for the utilization of these toxic compounds. In a series of batch acid‐catalyzed esterification reactions, the influence of reaction temperature, catalyst type, catalyst concentration, and methanol to oil ratio on the esterification was investigated. The NA esterification reactions were found to be positively dependent on temperature and catalyst concentration while large methanol to oil ratios had a negative effect on the esterification. Finally, sulfuric acid was identified as a preferred catalyst for the esterification compared to p‐toluene sulfonic acid. The esterification was completed successfully at the relatively mild conditions used in commercial biodiesel production. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 406‐410, 2013
How can DG solar be made viable more quickly?
Authors: Stevens Graham
Published: February 2012

Currently distributed generation (DG) solar power is more expensive than fossil fuel sources. Nevertheless, its use has been mandated through renewable portfolio standards (RPS) programs at many utilities; other portions of RPS programs mandate large utility‐scale ground mount solar fields. This article considers the technical and economic drivers and barriers to large‐scale implementation of distributed photovoltaics (PV), and presents some suggestions of how the viability of DG solar power can be accelerated. Combined with current developments and trajectories, these cost‐reduction strategies have the potential to reduce solar costs to be competitive with coal and possibly natural gas over the next 5–10 years.
Electric transmission: Aging infrastructure a misunderstood conundrum for the power industry
Authors: Lee Willis H.
Published: February 2012

America's electric utility systems are growing older. Every year, most power systems across the nation grow nearly a year older.
Regulatory economics: Is heating assistance heating up?
Authors: Barclay Richard A.
Published: February 2012

Is there a state economic regulatory issue lurking under your radar? Take another look after state regulators confabulate at their National Association of Regulatory Utility Commissioners Winter Committee meetings in February.
Energy and the environment: Pipeline petulance
Authors: Lesser Jonathan A.
Published: February 2012

The president's decision in January to “defer” (i.e., cancel) the Keystone Pipeline project pending yet more environmental review is perhaps the best known of the administration's politically driven environmental policy decisions.
Electric regulation: Future of the electric vehicle charging stations
Authors: Bowden Nicholas S.
Published: February 2012

In my January 2012 column, “Future of the Electric Vehicle,” I asserted that a lack of strong consumer demand, whether for the sake of preference or due to lack of information, is the most serious of several barriers to the substitution of electric for internal combustion automobiles. The argument focused on the historical development of automobile transportation in the United States with focus on technology and political economy. The lack of charging infrastructure was mentioned as another primary barrier to the electric vehicle's ability to compete.
Dynamic changes of ICA‐derived EEG functional connectivity in the resting state
Authors: Chen Jean‐Lon , Ros Tomas , Gruzelier John H.
Published: February 2012

An emerging issue in neuroscience is how to identify baseline state(s) and accompanying networks termed “resting state networks” (RSNs). Although independent component analysis (ICA) in fMRI studies has elucidated synchronous spatiotemporal patterns during cognitive tasks, less is known about the changes in EEG functional connectivity between eyes closed (EC) and eyes open (EO) states, two traditionally used baseline indices. Here we investigated healthy subjects (n = 27) in EC and EO employing a four‐step analytic approach to the EEG: (1) group ICA to extract independent components (ICs), (2) standardized low‐resolution tomography analysis (sLORETA) for cortical source localization of IC network nodes, followed by (3) graph theory for functional connectivity estimation of epochwise IC band‐power, and (4) circumscribing IC similarity measures via hierarchical cluster analysis and multidimensional scaling (MDS). Our proof‐of‐concept results on alpha‐band power demonstrate five statistically clustered groups with frontal, central, parietal, occipitotemporal, and occipital sources. Importantly, during EO compared with EC, graph analyses revealed two salient functional networks with frontoparietal connectivity: a more medial network with nodes in the mPFC/precuneus which overlaps with the “default‐mode network” (DMN), and a more lateralized network comprising the middle frontal gyrus and inferior parietal lobule, coinciding with the “dorsal attention network” (DAN). Furthermore, a separate MDS analysis of ICs supported the emergence of a pattern of increased proximity (shared information) between frontal and parietal clusters specifically for the EO state. We propose that the disclosed component groups and their source‐derived EEG functional connectivity maps may be a valuable method for elucidating direct neuronal (electrophysiological) RSNs in healthy people and those suffering from brain disorders. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.
Nutrient export via overland flow from a cultivated field of an Ultisol in southern China
Authors: Wei Linhong , Cheng Xunqiang , Cai Yuanfeng
Published: February 2012

Understanding the influence of complex interactions among hydrological factors, soil characteristics and biogeochemical functions on nutrient dynamics in overland flow is important for efficiently managing agricultural nonpoint pollution. Experiments were conducted to assess nutrient export from Ultisol soils in the Sunjia catchment, Jiangxi province, southern China, between 2003 and 2005. Four plots were divided into two groups: two peanut plots and two agroforestry (peanut intercropped with citrus) plots. During the study period, we collected water samples for chemical analyses after each rainfall event that generated overland flow to assess nutrient export dynamics.

The concentrations of potassium (K) and nitrate‐N (NO3––N) in overland flow were higher during the wetting season (winter and early spring). This reflects the solubility of K and NO3––N, the accumulation of NO3––N during the dry season and an increase in desorption processes and mixing with pre‐event water caused by prolonged contact with soil in areas with long‐duration, low‐intensity rainfall. In contrast, concentrations of total nitrogen (TN) and total phosphorus (TP) were higher during the wet season (late March to early July) and during the dry season (mid‐July to the end of September or early October). This was due to the interaction between specific hydrological regimes, the properties of the Ultisol and particulate transport processes. Variations in nutrient concentrations during storm events further identified that event water was the dominant source of total nitrogen and total phosphorus, and pre‐event water was the dominant source of NO3––N. In addition, the results obtained for the different land uses suggest that agroforestry practices reduce nutrient loss via overland flow. Copyright © 2012 John Wiley & Sons, Ltd.
Accurate Computation of Structures and Strain Energies of Cyclophanes with Modern DFT Methods
Authors: Grimme Stefan , Mück‐Lichtenfeld Christian
Published: February 2012

Four contemporary density functionals of meta‐GGA, hybrid‐GGA, meta‐GGA‐hybrid, and double‐hybrid type connected with two versions of our recent dispersion correction (DFT‐D3) are tested for the description of the geometric and electronic structures of typical cyclophanes. Strain energies (SE) as well as aromatic interaction energies (AIE) are considered. The systems [2.2]para‐ and [2.2]metacyclophane, [2.2.2.2.2.2]cyclophane, [2.2]paracyclonaphthane, [2.2](9,10)anthracenophane, and [2.2](1,4)anthracenophane are investigated. Computed structures are compared to experimental X‐ray data. For the three smallest cyclophanes, accurate CCSD(T)/CBS reference SE and AIE values are computed to assess the accuracy of the DFT methods. It is found that medium‐range dispersion (correlation) effects are important for all cyclophanes. Dispersion corrections in the Becke–Johnson damping (BJ) variant of the DFT‐D3 method provide the most accurate results. The best density functionals yield relative (strain) energies accurate to within about 5–10 %. Inter‐ring distances can be computed very accurately with errors less than about 0.003 Å while, for example, uncorrected B3LYP yields large average errors of almost 0.1 Å for this property. The PW6B95‐D3(BJ) and TPSS‐D3(BJ) general purpose quantum chemical methods overall perform best and can be recommended also for studies of cyclophanes. The strain energies are partitioned to chemically meaningful components and the effect of the crystal environment is discussed.
Differences in suprathreshold heat pain responses and self‐reported sleep quality between patients with temporomandibular joint disorder and healthy controls
Authors: Ribeiro‐Dasilva M.C. , Goodin B.R. , Fillingim R.B.
Published: February 2012

The purpose of this study was to examine differences in heat pain threshold (HPTh) and heat pain tolerance (HPTo) between temporomandibular joint disorder (TMJD) patients and healthy controls. Using suprathreshold heat pain, this study also examined between‐group (i.e. TMJD vs. healthy controls) differences in hyperalgesia and temporal summation (TS) of heat pain. Lastly, whether between‐group differences in these heat pain outcomes were mediated by self‐reported sleep quality was also tested. A total of 119 participants (41% TMJD) completed the current study. HPTh and HPTo responses were assessed at the ventral forearm with an ascending method of limits, while hyperalgesia and TS responses were assessed at the dorsal forearm at temperatures of 46, 48 and 50 °C. Prior to completion of heat pain procedures, participants completed the Pittsburgh Sleep Quality Index. Significant between‐group differences in HPTh and HPTo were not observed. TMJD patients demonstrated significantly greater hyperalgesia than healthy controls at 46 °C only, but there were no differences for TS. Furthermore, TMJD patients reported significantly poorer sleep quality compared with healthy controls. Data analysis revealed a significant simple mediation effect whereby the presence of TMJD was strongly associated with poorer self‐reported sleep quality, which, in turn, was related to enhanced hyperalgesia at 46 °C. These findings support the hypothesis that the thermal hyperalgesia demonstrated by TMJD patients may be related to poor quality of their self‐reported sleep. The ability of interventions that improve sleep quality to also affect pain sensitivity is currently the topic of ongoing investigation.
A density functional theory investigation on the mechanism and kinetics of dimethyl carbonate formation on Cu2O catalyst
Authors: Zhang Riguang , Song Luzhi , Wang Baojun , Li Zhong
Published: February 2012

A theoretical analysis about the mechanism and kinetics of dimethyl carbonate (DMC) formation via oxidative carbonylation of methanol on Cu2O catalyst is explored using periodic density functional calculations, both in gas phase and in solvent. The effect of solvent is taken into account using the conductor‐like screening model. The calculated results show that CO insertion to methoxide species to produce monomethyl carbonate species is the rate‐determining step, the corresponding activation barrier is 161.9 kJ mol−1. Then, monomethyl carbonate species reacts with additional methoxide to form DMC with an activation barrier of 98.8 kJ mol−1, above reaction pathway mainly contributes to the formation of DMC. CO insertion to dimethoxide species to form DMC is also considered and analyzed, the corresponding activation barrier is 308.5 kJ mol−1, suggesting that CO insertion to dimethoxide species is not competitive in dynamics in comparison with CO insertion to methoxide species. The solvent effects on CO insertion to methoxide species involving the activation barriers suggest that the rate‐determining step can be significantly affected by the solvent, 70.2 kJ mol−1 in methanol and 63.9 kJ mol−1 in water, which means that solvent effect can reduce the activation barrier of CO insertion to methoxide species and make the reaction of CO insertion to methoxide in solvents much easier than that in gas phase. Above calculated results can provide good theoretical guidance for the mechanism and kinetics of DMC formation and suggest that solvent effect can well improve the performance of DMC formation on Cu2O catalyst in a liquid‐phase slurry. © 2012 Wiley Periodicals, Inc.
A theoretical investigation of the interaction between substituted carbonyl derivatives and water: Open or cyclic complexes?
Authors: Chandra Asit K. , Zeegers‐Huyskens Thérèse
Published: February 2012

The structures and binding energies of complexes between substituted carbonyl bases and water are the B3LYP/6‐311++G(d,p) computational level. The calculations also include the proton affinity (PA) of the O of the CO group, the deprotonation enthalpies (DPE) of the CH bonds along a natural bond orbital analysis. The calculations reveal that stable open CO···HwOwas well as cyclic CH···OwHw···OC complexes are formed. The binding energies for the open complexes are linearly related to the PAs, whereas the binding energies for the cyclic complexes depend on both the PA and DPE. Different indicators of hydrogen bonds strength such as electron charge density, intramolecular and intermolecular hyperconjugation energy, occupation of orbitals, and charge transfer show significant differences between open and cyclic complexes. The contraction of the CH bond of the formyl group and the corresponding blue shift of the ν(CH) vibration are explained by the classicaltranslone pair effect. In contrast, the elongation or contraction of the CH3group involved in the interaction with water results from the variation of the orbital interaction energies from the σ(CH) bonding orbital to the σ* and π* antibonding orbitals of the CO group. The resulting blue or red shifts of the ν(CH3) vibrations are calculated in the partially deuterated isotopomers. © 2012 Wiley Periodicals, Inc.
Comparative study of statistical and artificial neural network's methodologies for deriving global solar radiation from NOAA satellite images
Authors: Rahimikhoob A. , Behbahani S. M. R. , Banihabib M. E.
Published: February 2012

The use of satellite data to estimate global solar radiation (G) at ground level has become an effective way for a large area with high spatial and temporal resolution. The statistical approach is a widely applied procedure for this task. The first objective of this study was to examine the potential of this approach for deriving instantaneous G from NOAA–AVHRR satellite data for the atmosphere of semi‐arid environment of Iran. The second objective was to apply artificial neural network (ANN) to the estimation of G from advanced very high resolution radiometer (AVHRR) images. A Comparison between these two methods was the last objective of this study. A total of 661 images of NOAA–AVHRR level 1b, covering the area of this study were collected from the Satellite Active Archive of NOAA. The results demonstrated that the use of ANN model gave better estimates than the statistical technique. Root mean square error and R2 for the comparison between observed and estimated G for the tested data using the proposed ANN model are 56.95 W m−2 and 0.90, respectively. For the statistical approach method these values are 68.33 W m−2 and 0.86. Copyright © 2012 Royal Meteorological Society
Influence of large‐scale climate modes on daily synoptic weather types over New Zealand
Authors: Jiang Ningbo , Griffiths Georgina , Lorrey Andrew
Published: February 2012

This article examines the influence of El Niño Southern Oscillation (ENSO), Southern Annular Mode (SAM) and Interdecadal Pacific Oscillation (IPO) on the synoptic weather types over New Zealand. The effects of ENSO (indicated by the Southern Oscillation Index, SOI), SAM and IPO on the occurrence of synoptic types are estimated in a holistic framework using the maximum likelihood method via applications of generalized linear models, both annually and by seasons. The average within‐class variations in the intensity and air‐mass characteristics (as expressed in the Auckland Airport meteorological variables) of synoptic systems were examined for individual types at the annual level. The results show that ENSO, SAM and IPO have significant effects on the probability of occurrence and to lesser degree the intensity and air‐mass characteristics of some synoptic types. The effects vary considerably with seasons, synoptic types and phases of SOI, SAM and IPO and it is the confounding effects of different large‐scale modes that lead to the observed changes in the type frequencies. The findings, with respect to ENSO and SAM in all cases and for IPO at the seasonal level, are in good agreement with the literature. However, the annual changes in type frequencies associated with the 1976/1977 IPO phase shift do not support the observed changes in the strength of anomalous southwesterly windflows over New Zealand, and the influence of the recent negative IPO phase also appears different from what we expect based on the existing research. It appears that the interaction between IPO and ENSO is important for understanding the observed climatic effects of IPO on New Zealand's weather and climate. This aspect deserves further attention in future studies. The findings from this work have important methodological and practical implications for New Zealand climate research. Copyright © 2012 Royal Meteorological Society
How to sustain entrepreneurial performance during the current financial crisis
Authors: Kianfar Michael , Smith Helen Lawton , Milana Carlo
Published: February 2012

The extra money obtained from immediate sales of idle or low‐productive government properties can boost economic growth if lent to innovative entrepreneurial firms.
Managing privatizations in the telecommunications sector: case study of the Hellenic Telecommunication Organization
Authors: Karamanis Kostas
Published: February 2012

A well‐designed privatization program can be a good response to the economic crisis that many countries, such as Greece, are facing.
Co‐creation for impact investment in microfinance
Authors: Ashta Arvind
Published: February 2012

The poor are requiring not only microcredit, but also micropayments and micro‐insurance as well as health check‐ups.
Imaging predictors of the response to transarterial chemoembolization in patients with hepatocellular carcinoma: A radiological-pathological correlation
Authors: Kwan Sharon W. , Fidelman Nicholas , Ma Elizabeth , Kerlan Robert K. , Yao Francis Y.
Published: February 2012

Transarterial chemoembolization (TACE) is one of the standard therapies for bridging patients with hepatocellular carcinoma (HCC) to transplantation. This study was designed to determine which features on pre- and post-TACE imaging are associated with tumor necrosis in pathological specimens. Records of 105 patients with 132 HCC lesions who underwent liver transplantation after TACE were retrospectively reviewed. In 70% of the nodules, >90% necrosis was achieved. The development of >90% lesion necrosis upon pathological analysis was associated with avid lesion enhancement (P = 0.03) and the presence of a feeding vessel larger than 0.9 mm in diameter on the pre-TACE visceral angiogram (P = 0.01). Near-complete lesion necrosis was also associated with an extensive accumulation of ethiodized oil within a lesion during TACE administration (P = 0.04). On post-TACE computed tomography imaging, a lack of residual contrast enhancement (P < 0.0001), a decrease in the lesion size (P = 0.04), a high lesion density due to an accumulation of ethiodized oil (P = 0.03), and a diffuse distribution of ethiodized oil throughout the lesion (P = 0.0001) were also correlated with near-complete lesion necrosis upon pathological analysis. In conclusion, this study found multiple pre- and post-TACE imaging characteristics of HCC that were associated with near-complete tumor necrosis upon histopathological analysis after TACE. These findings may help to guide the selection of an optimal treatment strategy for bridging patients with HCC to liver transplantation.
Mesenchymal stem cells administered after liver transplantation prevent acute graft-versus-host disease in rats
Authors: Xia Xuefeng , Chen Wei , Ma Tao , Xu Guodong , Liu Hao , Liang Chao , Bai Xueli , Zhang Yun , He Yong , Liang Tingbo
Published: February 2012

Acute graft-versus-host disease is a serious and life-threatening complication of liver transplantation (LT) that occurs in 1% to 2% of liver allograft recipients. It is associated with a high mortality rate, and effective therapies are lacking. In our established rat model, a relative decrease in regulatory T cells (Tregs) was previously shown to be associated with acute graft-versus-host disease after liver transplantation (LT-aGVHD). Mesenchymal stem cells (MSCs) have been used to treat graft-versus-host disease after allogeneic hematopoietic stem cell transplantation, and they have been shown to induce Tregs, which have immunomodulatory effects. In this study, when a treatment with donor- or recipient-derived MSCs was administered from day 8 to day 14 after the typical symptoms of LT-aGVHD started, the recipients were not cured, and their survival time was not prolonged. However, when MSCs of different origins were administered from day 0 to day 6 after LT, the recipients survived significantly longer than the control group, and the surviving MSC-treated rats did not show typical LT-aGVHD symptoms. In vivo tracings of carboxyfluorescein diacetate succinimidyl ester–stained MSCs did not show significant accumulations in the target organs after administration. Flow cytometry analysis showed that the Treg ratios in peripheral blood were more higher for the MSC-treated groups versus the control group. More immunohistochemically stained forkhead box P3–positive cells were also found in the intestines of the MSC-treated groups versus the control group. Further investigations of the function of MSCs showed that they could increase the Treg ratio in a mixed lymphocyte reaction (MLR) and lead to a greater reduction in MLR proliferation in vitro. In conclusion, the post-LT administration of MSCs of either donor or recipient origin could prevent the onset of LT-aGVHD in our rat model.
Conductive Hydrogels: Mechanically Robust Hybrids for Use as Biomaterials
Authors: Green Rylie A. , Hassarati Rachelle T. , Goding Josef A. , Baek Sungchul , Lovell Nigel H. , Martens Penny J. , Poole‐Warren Laura A.
Published: February 2012

A hybrid system for producing conducting polymers within a doping hydrogel mesh is presented. These conductive hydrogels demonstrate comparable electroactivity to conventional conducting polymers without requiring the need for mobile doping ions which are typically used in literature. These hybrids have superior mechanical stability and a modulus significantly closer to neural tissue than materials which are commonly used for medical electrodes. Additionally they are shown to support the attachment and differentiation of neural like cells, with improved interaction when compared to homogeneous hydrogels. The system provides flexibility such that biologic incorporation can be tailored for application.

magnified image
Homologous Copolymerization Route to Functional and Biocompatible Polyvinylpyrrolidone
Authors: Tardajos Myriam G. , Nash Maria , Rochev Yury , Reinecke Helmut , Elvira Carlos , Gallardo Alberto
Published: February 2012

Linear multifunctional polyvinylpyrrolidone (PVP) chains bearing carboxylate (COO−) or/and sulfonate (SO3−) groups are prepared by standard radical copolymerization of homologous vinylpyrrolidone (VP) and the VP derivatives 3‐carboxyvinylpyrrolidone (VPC) and 3‐sulfoalkylvinylpyrrolidone (VPS). Functional PVP networks with homogeneous crosslinking density are also prepared using a new homologous water‐compatible VP‐R‐VP crosslinker. This homologous approach for the preparation of functionalized PVP systems is compared theoretically with the preparation of VP with commercial acrylic comonomers bearing similar functionalities. All the linear chains and networks are tested under basic in vitro cell cultures.
Molecular Weight Distribution of Linear Chains in Step‐Growth Polymerization Under the Influence of Cyclization Reactions
Authors: Wutz Christoph , Kricheldorf Hans R.
Published: February 2012

Two different equations are presented describing the frequency distribution (fl) of linear chains in step‐growth (SG) polymerizations. Two related equations for the weight distribution (wl) are formulated as well. All equations contain either an exponent α that represents the reaction rates (or probabilities) of chain growth versus cyclization reactions or they contain a cyclization factor β′. Plots of fl and wl versus conversion or degree of polymerization are presented and discussed. Distribution curves of individual oligomers versus conversion and versus β′ are described. Furthermore, the consequences for hyperbranched polymers resulting from polycondensations of abn monomers are discussed. Analogous to Flory's theory all equations concern kinetically controlled SG polymerizations.

magnified image
Complete systems of recursive integrals and Taylor series for solutions of Sturm–Liouville equations
Authors: Kravchenko Vladislav V. , Morelos Samy , Tremblay Sébastien
Published: February 2012

Given a regular nonvanishing complex valued solution y0 of the equation , x ∈ (a,b), assume that it is n times differentiable at a point x0 ∈ [a,b]. We present explicit formulas for calculating the first n derivatives at x0 for any solution of the equation . That is, a map transforming the Taylor expansion of y0 into the Taylor expansion of u is constructed. The result is obtained with the aid of the representation for solutions of the Sturm‐Liouville equation in terms of spectral parameter power series. Copyright © 2012 John Wiley & Sons, Ltd.
Exploiting packet‐sampling measurements for traffic characterization and classification
Authors: Tammaro Davide , Valenti Silvio , Rossi Dario , Pescapé Antonio
Published: February 2012

The use of packet sampling for traffic measurement has become mandatory for network operators to cope with the huge amount of data transmitted in today's networks, powered by increasingly faster transmission technologies. Therefore, many networking tasks must already deal with such reduced data, more available but less rich in information. In this work we assess the impact of packet sampling on various network monitoring‐activities, with a particular focus on traffic characterization and classification. We process an extremely heterogeneous dataset composed of four packet‐level traces (representative of different access technologies and operational environments) with a traffic monitor able to apply different sampling policies and rates to the traffic and extract several features both in aggregated and per‐flow fashion, providing empirical evidences of the impact of packet sampling on both traffic measurement and traffic classification. First, we analyze feature distortion, quantified by means of two statistical metrics: most features appear already deteriorated under low sampling step, no matter the sampling policy, while only a few remain consistent under harsh sampling conditions, which may even cause some artifacts, undermining the correctness of measurements. Second, we evaluate the performance of traffic classification under sampling. The information content of features, even though deteriorated, still allows a good classification accuracy, provided that the classifier is trained with data obtained at the same sampling rate of the target data. The accuracy is also due to a thoughtful choice of a smart sampling policy which biases the sampling towards packets carrying the most useful information. Copyright © 2012 John Wiley & Sons, Ltd.
High Cytotoxic Activity of Phosphonium Salts and Their Complementary Selectivity towards HeLa and K562 Cancer Cells: Identification of Tri‐n‐butyl‐n‐hexadecylphosphonium bromide as a Highly Potent Anti‐HeLa Phosphonium Salt
Authors: Bachowska Barbara , Kazmierczak‐Baranska Julia , Cieslak Marcin , Nawrot Barbara , Szczęsna Dorota , Skalik Joanna , Bałczewski Piotr
Published: February 2012

Quaternary ammonium and phosphonium salts have been screened for their toxic effect on HeLa and K562 cancer cell lines, as well as on normal HUVEC cells. Tri‐n‐butyl‐n‐hexadecylphosphonium bromide, the first phosphonium salt with a halogen anion tested against HeLa cells, was 12 times more potent (IC50 <5 μM after 24 and 48 h) than the clinically used reference compound cisplatin and 17 times more potent than tri‐n‐hexyltetradecylphosphonium bis(trifluoromethylsulfonyl)imide, which, to the best of our knowledge, is the first phosphonium salt to be evaluated in HeLa cells. However, it was inactive against K562 cells (24 and 48 h). According to a caspase‐3/7 assay, its toxicity has not been connected with the induction of apoptosis. In contrast, triphenylalkylphosphonium iodides with shorter C1–5 alkyl chains were inactive against HeLa cells but very active against K562 cells (IC50=6–10 μM after 48 h). Phosphonium cations with halide counterions proved to be more potent than those with (CF3SO2)2N− as the anion, as in the anticancer agent NSC 747251, or other anions in molecules with similar alkyl chain lengths. On the other hand, a series of ammonium salts containing a short methylthiomethyl or methoxymethyl side chain revealed low cytotoxicity (IC50 >500 μM after 24 and 48 h) against both HeLa and K562 cancer cell lines as well as normal HUVEC cells, showing that the nontoxic N+CH2YMe (Y=S, O) structural motif in ammonium salts could be suitable for further optimization and development, especially in transfection experiments.
Hot‐embossing experiments of polymethyl methacrylate across the glass transition temperature with variation in temperature and hold times
Authors: Singh Kamakshi , Dupaix Rebecca B.
Published: February 2012

Hot‐embossing (HE) experiments were conducted on polymethyl methacrylate (PMMA) across its glass transition temperature from 92 to 142°C. The glass transition temperature (Tg) of the PMMA used in this study was ∼ 102°C. The polymer samples were embossed to a depth of 0.8 mm (800 μm). The experiments were carried out at various temperatures for different hold times of 30, 90, and 180 sec during the embossing process. A few additional experiments were conducted at 142°C with cooling of the samples as well. The force required for embossing and the final depth of the embossed features were analyzed. Polymers, including PMMA, show significantly different material behavior around and above Tg. The same was seen in the aforementioned tests; the trends observed for the force as well as the final depth changed considerably around 122°C (Tg + 20). These findings will be used in developing material models for use in simulating the hot‐embossing process. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Experimental investigation on the role of PVA in eliminating inhibition phenomenon of carbon black during the synthesis of polystyrene/carbon black composite particles
Authors: Yan Juntao , Wang Chunlei , Gao Yan , Zheng Zaihang , Cheng Zhiqiang , Cui Xuejun , Wang Hongyan
Published: February 2012

In this study, the role of polyvinyl alcohol (PVA) in eliminating the inhibition phenomenon of modified light‐weight carbon black (CB) during the synthesis of polystyrene/modified light‐weight carbon black (PS/MLCB) composite particles was examined. It was interesting to note that the polymerization time was largely shortened in the presence of a certain PVA. And the effect of PVA dosage on the polymerization time and the macromorphology of obtained PS/MLCB composite particles were systematically investigated, as well as the correlation between PVA dosage, polymerization time, and MLCB content. In addition, the potential mechanism about the role of PVA in eliminating the inhibition phenomenon of MLCB during the suspension polymerization of styrene was also proposed and analyzed in detail. The PS/MLCB composites particles were studied in terms of surface morphology, thermal stability, and molecular weight. Scanning electron microscopy images of the resulting PS/MLCB composite particles demonstrated that CB was well dispersed in the PS matrix. And the thermal stability of obtained PS/MLCB composite particles was significantly enhanced with the incorporation of MLCB, and increased with the increasing content of MLCB. This synthesis technique brought about a promising future in the large‐scale production of black expandable polystyrene. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Nanocomposites of poly(m‐xylene diamide) with polyhedral oligomeric silsesquioxane, montmorillonite, and their combination: Structure and properties
Authors: Magniez K. , Fox Bronwyn L. , Looney Mark G.
Published: February 2012

In this work, nanocomposites of poly (m‐xylene diamide) (MXD6) with dodecaphenyl polyhedral oligomeric silsesquioxane (POSS), montmorillonite (MMT) and their combination (MMT‐POSS) were produced by melt‐compounding and their structure–property relationships were established. The montmorillonite was found to be homogeneously dispersed affording intercalated disordered structures whilst the distribution and dispersion of the POSS was rather skewed with the presence of phase separated crystalline aggregates of up to several hundred nanometers. Significant differences in properties were observed depending on the type of nanoscale filler present in the nanocomposites. The montmorillonite provided some improvements in stiffness and dynamic response of MXD6. POSS on the other hand improved the ductility of MXD6 and had a plasticizing effect. It has been suggested that there might be a lubricating action at the interface inducing better molecular motion between polymer chains of MXD6. By combining MMT and POSS, the properties of the corresponding nanocomposites were found to be intermediate. The thermal stability of MXD6 was enhanced in the nanocomposites although a negative deviation from the theoretical model was observed when POSS was present in the nanocomposites. This observation underlies some antagonistic effects which have been attributed to the presence of catalytic benzene radicals during thermal degradation. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers