bluuebunny/crossref_metadata_2025 huggingface dataset:
Improving performances of microchannels in microfluidic chip using solidifiable adhesive film
Authors: Wu J. , Guo W. , Wang C. , Li Y. , Chen T. , Yu K.
Published: December 2014

In order to improve surface roughness and hydrophilicity of microchannels in microfluidic chip, then to achieve high fluid speed under small pressure, a technology named as coating solidifiable adhesive film is proposed. In this paper the microfluidic chip is manufactured using CO2 laser. The film is coated on inside wall of microchannels using ultraviolet optic solidifiable adhesive. Two coating methods were used to synthesise the NOA61 film. The surface roughness and water-phase contact angle of the microchannel with and without the NOA61 film are measured. The roughness is reduced from 2 μm to 243·36 nm and the contact angle is reduced from 100 to 72·55°, when NOA61 film is coated with the action of gas blowing and consequent drying by UV light. The roughness is reduced from 2 μm to 60·49 nm and the contact angle is reduced from 100 to 55·35°, when NOA61 film is obtained by gravity flow.
P-Rex and Vav Rac-GEFs in platelets control leukocyte recruitment to sites of inflammation
Authors: Pan Dingxin , Amison Richard T. , Riffo-Vasquez Yanira , Spina Domenico , Cleary Simon J. , Wakelam Michael J. , Page Clive P. , Pitchford Simon C. , Welch Heidi C. E.
Published: December 2014

Key Points

P-Rex and Vav Rac-GEFs cooperate in leukocyte recruitment during inflammation by facilitating leukocyte adhesion to the vascular endothelium. P-Rex/Vav expression in platelets is required for vascular adhesion and recruitment of neutrophils and eosinophils into lung tissue.
Systematic qualitative review of randomised trials conducted in nonsmall cell lung cancer with a noninferiority or equivalence design
Authors: Paesmans Marianne , Grigoriu Bogdan , Ocak Sebahat , Roelandts Martine , Lafitte Jean-Jacques , Holbrechts Stéphane , Berghmans Thierry , Meert Anne-Pascale , Moretti Luigi , Danyi Sophie , Pasleau Françoise , Ameye Lieveke , Van Meerhaeghe Alain , Sculier Jean-Paul
Published: December 2014

The use of noninferiority randomised trials for patients with advanced non-small cell lung cancer has emerged during the past 10–15 years but has raised some issues related to their justification and methodology. The present systematic review aimed to assess trial characteristics and methodological aspects.

All randomised clinical trials with a hypothesis of noninferiority/equivalence, published in English, were identified. Several readers extracteda prioridefined methodological information. A qualitative analysis was then performed.

We identified 20 randomised clinical trials (three phase II and 17 phase III), 11 of them being conducted in strong collaboration with industry. We highlighted some deficiencies in the reports like the lack of justification for both the noninferiority assumption and the definition of the noninferiority margin, as well as inconsistencies between the results and the authors' conclusions. CONSORT guidelines were better followed for general items than for specific items (p<0.001).

Improvement in the reporting of the meth"odology of noninferiority/equivalence trials is needed to avoid misleading interpretation and to allow readers to be fully aware of the assumptions underlying the trial designs. They should be restricted to limited specific situations with a strong justification why a noninferiority hypothesis is acceptable.
A systematic review of socioeconomic position in relation to asthma and allergic diseases
Authors: Uphoff Eleonora , Cabieses Báltica , Pinart Mariona , Valdés Macarena , Antó Josep Maria , Wright John
Published: December 2014

The role of socioeconomic position (SEP) in the development of asthma and allergies is unclear, with some pointing to the risks of low SEP and other research pointing in the direction of higher SEP being associated with higher prevalence rates. The aim of this systematic review is to clarify associations between SEP and the prevalence of asthma and allergies. Out of 4407 records identified, 183 were included in the analysis. Low SEP was associated with a higher prevalence of asthma in 63% of the studies. Research on allergies, however, showed a positive association between higher SEP and illness in 66% of studies. Pooled estimates for the odds ratio of disease for the highest compared with the lowest SEP confirmed these results for asthma (unadjusted OR 1.38, 95% CI 1.37–1.39), allergies in general (OR 0.67, 95% CI 0.62–0.72), atopic dermatitis (unadjusted OR 0.72, 95% CI 0.61–0.83) and allergic rhinoconjunctivitis (unadjusted OR 0.52, 95% CI 0.46–0.59). Sensitivity analyses with a subsample of high-quality studies led to the same conclusion. Evidence from this systematic review suggests that asthma is associated with lower SEP, whereas the prevalence of allergies is associated with higher SEP.
Inhaled corticosteroids in COPD: the clinical evidence
Authors: Ernst Pierre , Saad Nathalie , Suissa Samy
Published: December 2014

In this article, we focus on the scientific evidence from randomised trials supporting treatment with inhaled corticosteroids (ICS) in chronic obstructive pulmonary disease (COPD), including treatment with combinations of long-acting β-agonist (LABA) bronchodilators and ICS. Our emphasis is on the methodological strengths and limitations that guide the conclusions that may be drawn.

The evidence of benefit of ICS and, therefore, of the LABA/ICS combinations in COPD is limited by major methodological problems. From the data reviewed herein, we conclude that there is no survival benefit independent of the effect of long-acting bronchodilation and no effect on FEV1decline, and that the possible benefit on reducing severe exacerbations is unclear. Our interpretation of the data is that there are substantial adverse effects from the use of ICS in patients with COPD, most notably severe pneumonia resulting in excess deaths.

Currently, the most reliable predictor of response to ICS in COPD is the presence of eosinophilic inflammation in the sputum. There is an urgent need for better markers of benefit and risk that can be tested in randomised trials for use in routine specialist practice. Given the overall safety and effectiveness of long-acting bronchodilators in subjects without an asthma component to their COPD, we believe use of such agents without an associated ICS should be favoured.
Two-dimensional shallow soil profiling using time-domain waveform inversion
Authors: Amrouche Mohamed , Yamanaka Hiroaki
Published: December 2014

Near-surface characterization has now gained significance among exploration geophysicists, and many methods are being proposed to retrieve the 2D structures of shallow soils. Because most of these methods are based on the modal inversion of the surface waves, they can only be applied to laterally homogeneous or smoothly heterogeneous soil models. We have developed a time-domain waveform inversion method for 2D near-surface exploration that offers an alternative approach to existing surface-wave techniques for layered soils with a flat surface. Our method directly fits the input Rayleigh waveforms to retrieve the 2D soil structure without need of any modal identification, allowing the inversion of soil models that can be challenging with modal-inversion-based approaches. In our method, the forward problem formulated in the time domain is based on a 2.5D staggered-grid finite-difference scheme to simulate the P-SV wavefield; soil modeling was achieved by dividing soil layers into specific number of blocks with discontinuous interfaces. The inversion strategy depends on attributing suitable values for the interface depth and S-wave velocity for each block to reconstruct a numerical soil model that fit the input waveforms. Because we cannot know the source signature during data acquisition, source deconvolution by a reference station is applied to observed and calculated waveforms to make a waveform inversion free of the source signature. Numerical experiments revealed that our method was able to sufficiently reconstruct soil structures with strong lateral velocity gradient or soils with a blind layer in noisy environments, using a single source and reasonable number of receivers. We also applied this method to real waveform data, and we succeeded in obtaining good correlation between the inverted 2D soil model and the existing borehole data.
Eliminating the azimuth ambiguity in single-well imaging using 3C sonic data
Authors: Gong Hao , Chen Hao , He Xiao , Wang Xiuming
Published: December 2014

The shortcomings of conventional single-well sonic imaging are the inefficiency in eliminating azimuth ambiguity of the reflector outside boreholes. To resolve this problem, we proposed that 3C data of the reflection echoes be migrated simultaneously. The quantitative expressions of the received 3C data were first derived. The direct correlations between the polarity of the 3C data and the reflector azimuth were analyzed. It was revealed that the reflector positions can be fully identified by the associated echoes consisting of the transverse and axial components of wavefields. And an improved single-well imaging procedure using axial displacement component in addition to transverse components was thus developed. Numerical examples were evaluated for validation of the imaging method. According to the numerical results, the image intensity of the reflectors was effectively enhanced whereas the artificial mirrors of the reflectors were greatly weakened. It was suggested that a sonic logging tool with the 3C receivers be necessary for the image of reflectors without azimuth ambiguity.
Mobbing and Bullying As Occupational Stress Factors
Authors: Бухтияров  , Bukhtiyarov Igor , Рубцов  , Rubtsov M.
Published: December 2014

An analysis of foreign and domestic publications related to problems of mobbing and bullying as working environment factors to which it wasn´t been paid attention until recently has been presented in this review. Seven summarized mobbing types which reduce the level and quality of work have been identified: institutional arrangement mobbing, social isolation mobbing, mobbing of attacks to victim’s personal life, victim mood mobbing, physical violence mobbing, verbal aggression and rumors mobbing. Administrative, functional and psychological factors which are the causes of mobbing and bullying as manifestations of destructive behavior at work places have been shown. A comparative analysis of mobbing and bullying occurrence frequency in different countries and among different categories of employees has been carried out. Based on a lot of questionnaires data analysis it has been found that the most frequently mobbing and bullying occurrences in the public sector of economy in comparison with the private one, they are observed in pedagogical and health care systems too. It has been shown that mobbing and bullying are stress factors that can lead to employees’ work capacity deterioration, serious physical and mental health disorders, mainly similar to typical post-traumatic stress disorder. In extreme cases mobbing and bullying can lead to serious diseases, professional unsuitability and early disability, social isolation and even suicide, being thus an important safety assurance factor for modern forms of work. In order to solve the mobbing problem through legislation, some European countries have adopted new laws that prevent the occurrence of these phenomena, protecting and ensuring the safety of employees in their workplaces, including an emotional component of health at work. In Russia it is necessary to develop adequate administrative, psychological and medical measures for prevention and diagnosis of mobbing and bullying at workplaces.
Effects of ICT Service Innovation and Complementary Strategies on Brand Equity and Customer Loyalty in a Consumer Technology Market
Authors: Xu Xin , Thong James Y. L. , Venkatesh Viswanath
Published: December 2014

This paper examines the effects of information and communication technology (ICT) service innovation and its complementary strategies on brand equity and customer loyalty toward ICT service providers. We draw from research on brand equity and customer loyalty, ICT innovation management, and strategy complementarity to propose a model that includes new constructs representing ICT service innovation, i.e., service leadership, and its two complementary strategies, i.e., customization-personalization control and technology leadership, and how their interactions influence customer loyalty through customer-based brand equity. We test our model using data from an online survey of 1,210 customers of mobile data services. The results show that service leadership and customization-personalization control have significant direct impacts on ICT service providers' brand equity. Moreover, when either the level of technology leadership or the level of customization-personalization control is high, the impact of service leadership on brand equity is enhanced. In turn, brand equity has significant impacts on consumers' affective loyalty and conative loyalty, but not on cognitive loyalty. Our study contributes to the literature on service management and service science, and in particular to the management of ICT service innovation in a consumer technology market.
Optimal Management of Digital Content on Tiered Infrastructure Platforms
Authors: Du Anna Ye , Das Sanjukta , Gopal Ram D. , Ramesh Ram
Published: December 2014

Media firms are increasingly using tiered infrastructure to cost-effectively manage heterogeneous resources by strategically allocating digital content across multiple tiers to avoid overcapacitating high-performance, expensive infrastructure tiers. Complex migrations in tiered environments are currently possible in a seamless, nondisruptive manner. We model digital content as a network capturing the inter-item impacts and use this network structure to develop optimal migration policies that partition media content into tiers. Addressing the context of large content providers such as video-on-demand providers that employ infrastructure platforms for content storage and delivery, we develop a bilevel programming model to maximize the profits of a price-setting platform and a tiered allocation-setting content provider. We model two fundamental effects with digital content: a revenue effect emanating from the tiered architecture and a traffic generating effect among media objects. Using a detailed longitudinal simulation study, we demonstrate the effectiveness of the proposed provisioning policy and pricing strategy and illustrate the existence and impact of these effects in media markets. Finally, we show that repeated execution of the model can help providers respond effectively to a changing environment and thus better manage the risk from demand fluctuations.
Advising Financially At-Risk Students: Detecting and Addressing Premature Affluence
Authors: Shaffer Leigh S.
Published: December 2014

Academic advisors likely will encounter financially at-risk (FAR) students who jeopardize their chances of completing a college education and compromise their economic futures by accruing burdensome debt. Students may use loans and credit cards to pay for the necessities of a college education, but many also generate personal debt by financing nonessentials while attending college; that is, they borrow to enjoy an expensive lifestyle that they cannot sustain after graduation while living independently. The article traces the history of premature affluence, articulates the borrowing practices that make FAR students susceptible to dropping out of college, and describes the boomerang generation. It concludes with suggestions for detecting FAR students and ways advisors can help all undergraduates make responsible financial decisions.
Independent insurance
Authors: Lewis Rachel
Published: December 2014

I write regarding the recent RCM ballot of members on indemnity insurance for self-employed midwives. As an independent mid-wife I was delighted to hear that the College were to ballot the membership. However, a great number of NHS midwives are totally astounded at the wording on both the ballot paper and the accompanying information.
Linking Costs to Health Outcomes for Allocating Scarce Public Health
Resources
Authors: Corso Phaedra , Ingles Justin B. , Taylor Nathaniel , Desai Samir
Published: December 2014

Introduction: Resources for public health (PH) are scarce and policymakers face
tough decisions in determining their funding priorities. The difficulty of making these
decisions is compounded by current PH accounting systems, which are ill-equipped to link
fiscal resources to PH outcomes. This paper examines the types of revenues and
expenditures, health services, and health outcomes that are being tracked at the local
and state PH levels. The authors provide recommendations for strengthening the ability
of local and state governments to link expenditures to PH outcomes, both within and
across jurisdictions.Framework and Next Steps: The source of revenue data for most local
jurisdictions is the accounting systems used for the budgeting and auditing of fiscal
activities, and these are primarily linked to specific PH programs. In contrast,
expenditure data are mostly generic and typically span multiple PH programs with no link
to specific PH activities. Many challenges exist to then link PH activities to health
outcomes data, which are often collected through separate reporting systems at the
local, state, and national levels. Policy change at the state level and implementation
strategies that are standardized across local health departments are required to assess
the costs and health outcomes of PH activities.Conclusion: Information linking PH
expenditures to health outcomes of PH services could greatly inform the decision-making
process. This information will allow investments in PH to be better understood and will
provide a strong foundation for the PH services and systems research community to
understand variation and drive improvement. Ultimately, these data could be used to
improve accountability at the local and state PH department levels.
The Future of Public Health Informatics: Alternative Scenarios and Recommended
Strategies
Authors: Edmunds Margo , Thorpe Lorna , Sepulveda Martin , Bezold Clem , Ross David A.
Published: December 2014

Background: In October 2013, the Public Health Informatics Institute (PHII) and
Institute for Alternative Futures (IAF) convened a multidisciplinary group of experts to
evaluate forces shaping public health informatics (PHI) in the United States, with the
aim of identifying upcoming challenges and opportunities. The PHI workshop was funded by
the Robert Wood Johnson Foundation as part of its larger strategic planning process for
public health and primary care.Workshop Context: During the two-day workshop, nine
experts from the public and private sectors analyzed and discussed the implications of
four scenarios regarding the United States economy, health care system, information
technology (IT) sector, and their potential impacts on public health in the next 10
years, by 2023.Workshop participants considered the potential role of the public health
sector in addressing population health challenges in each scenario, and then identified
specific informatics goals and strategies needed for the sector to succeed in this
role.Recommendations and Conclusion: Participants developed recommendations for the
public health informatics field and for public health overall in the coming decade.
These included the need to rely more heavily on intersectoral collaborations across
public and private sectors, to improve data infrastructure and workforce capacity at all
levels of the public health enterprise, to expand the evidence base regarding
effectiveness of informatics-based public health initiatives, and to communicate
strategically with elected officials and other key stakeholders regarding the potential
for informatics-based solutions to have an impact on population health.
Filling the Gaps in Data and Methods for Public Health Services and Systems
Research (PHSSR)
Authors: Holve Erin , Mays Glen
Published: December 2014

Introduction: The goal of aligning the delivery of public health and medical care
services so as to achieve population-wide improvements in health status is not new. Yet
the urgency to achieve greater alignment has increased as the prevalence of costly and
preventable diseases and injuries grows, and as incentives for health care system
redesign take hold through Affordable Care Act implementation. The science of public
health services and systems research (PHSSR) can leverage this opportunity for change by
bringing data together from public health and health care systems to support a holistic
and integrated learning health system that maximizes the value of new data streams.Issue
Overview: This joint issue of eGEMs and Frontiers in PHSSR displays the viewpoints of
diverse authors to enhance the types and sources of data that are available to
understand and improve population health, and to integrate these data where possible.
Four primary themes emerge from the papers: (1) the vision and strategy needed to
support the role of data and methods in advancing population health in the United
States; (2) the need to improve the infrastructure required to understand public health
financing and organization; (3) the importance of making early, meaningful use of health
information technology (IT) to achieve these goals; and (4) the need for new approaches
and partners to improve measurement strategies and assess population health.Next Steps
and Considerations for the Field: eGEMs and Frontiers in PHSSR hope that, over time,
this literature will continue to grow, identifying opportunities for multidisciplinary
teams to work with communities and address common priorities that fill in existing
information gaps such as those identified in the special issue.
Influence of oceanographic seasonality and dredging activities on the fish larvae assemblage in the Port of Aratu, Todos os Santos Bay
Authors: Maltez Lucas Campos , Mafalda Junior Paulo de Oliveira , Leitão Sigrid Neumann
Published: December 2014

O presente trabalho tem como objetivo avaliar o impacto da atividade de dragagem de aprofundamento do Porto de Aratu sobre a estrutura da comunidade ictioplanctônica. As coletas foram realizadas em 6 estações de amostragem, tanto na maré enchente, quanto na vazante, antes, durante e após a dragagem. O ictioplâncton foi coletado utilizando-se rede bongo, malha 500 μm, em arrastos superficiais e os parâmetros da qualidade da água (temperatura, salinidade, pH, oxigênio dissolvido, turbidez, amônia e fósforo total) também foram determinados. Foram verificadas diferenças estatísticas significativa para a variabilidade temporal de todos os parâmetros de qualidade da água, exceto a turbidez, e nos índices estruturais da comunidade ictioplanctônica. O período da dragagem apresentou as menores densidades de ovos e larvas, além de menor riqueza e diversidade de táxons, com posterior recuperação no período da pós-dragagem. A análise multivariada de ordenação demonstrou uma separação bastante clara entre as amostragens, demonstrando haver uma variabilidade temporal na composição e abundância do ictioplâncton na área portuária de Aratu, em resposta as características oceanográficas da massa de água e alterações na qualidade, possivelmente associadas à atividade de dragagem.
Seletividade de armadilhas e atrativos na captura de pequenos peixes e crustáceos em ambientes estuarinos
Authors: Possamai Bianca , Cruz da Rosa Leonardo , Maia Corrêa Marco Fábio
Published: December 2014

In this study we tested capture efficiency of two of plastic bottle traps and four kinds of baits (fresh cow liver, broken corn, meat flavored dog food and commercial bait for amateur fishing) for small crustaceans and fishes at estuarine environments (saltmarshes and tidal creeks). Smaller trap opening sizes mainly limited the capture of organisms with hard exoskeleton such as crabs. There were no significant differences in number of species, abundance and/or biomass of captured organisms among baits. However, a bait/feeding behavior relationship was observed. The traps and baits were efficient in capturing small fishes and crustaceans, and therefore can be applied as a complementary method in ichthyological and crustaceans surveys at estuarine shallow water environments. However, in order to increase capture efficiency we recommend to use mixed baits, which best represent the trophic group diversity present in the study area.
Comparison between bottom-up and top-down approaches in the estimation of measurement uncertainty
Authors: Lee Jun Hyung , Choi Jee-Hye , Youn Jae Saeng , Cha Young Joo , Song Woonheung , Park Ae Ja
Published: December 2014

Measurement uncertainty is a metrological concept to quantify the variability of measurement results. There are two approaches to estimate measurement uncertainty. In this study, we sought to provide practical and detailed examples of the two approaches and compare the bottom-up and top-down approaches to estimating measurement uncertainty.

We estimated measurement uncertainty of the concentration of glucose according to CLSI EP29-A guideline. Two different approaches were used. First, we performed a bottom-up approach. We identified the sources of uncertainty and made an uncertainty budget and assessed the measurement functions. We determined the uncertainties of each element and combined them. Second, we performed a top-down approach using internal quality control (IQC) data for 6 months. Then, we estimated and corrected systematic bias using certified reference material of glucose (NIST SRM 965b).

The expanded uncertainties at the low glucose concentration (5.57 mmol/L) by the bottom-up approach and top-down approaches were ±0.18 mmol/L and ±0.17 mmol/L, respectively (all

We presented practical and detailed examples for estimating measurement uncertainty by the two approaches. The uncertainties by the bottom-up approach were quite similar to those by the top-down approach. Thus, we demonstrated that the two approaches were approximately equivalent and interchangeable and concluded that clinical laboratories could determine measurement uncertainty by the simpler top-down approach.
Preliminary evaluation of 14C and 36Cl
in nuclear waste from Ignalina Nuclear
Power Plant decommissioning
Authors: Mažeika Jonas , Lujanienė Galina , Petrošius Rimantas , Oryšaka Nadežda , Ovčinikov Sergej
Published: December 2014

On a first attempt, the determination of 14C and 36Cl activity concentrations in basic operational waste (spent ion-exchange resins and perlite mixture), in decommissioning waste (construction concrete, sand, stainless steel and serpentinite) and irradiated graphite from the Ignalina NPP has been performed. The samples for measurement of the specific activity of 14C and 36Cl were obtained from the selected places, where the highest values of the dose rate and the activity concentrations of gamma emitters were found. The performed study of the total 14C and 36Cl activity concentrations was based on estimated chemical forms of 14C (inorganic and organic compounds) and 36Cl as Cl- ion. The tested methods used in this study were found to be suitable for estimation of activity concentrations of measured radionuclides.
Immobilization of Amano Lipase A onto Stöber silica surface: process characterization
and kinetic studies
Authors: Zdarta Jakub , Sałek Karina , Kołodziejczak-Radzimska Agnieszka , Siwińska-Stefańska Katarzyna , Szwarc-Rzepka Karolina , Norman Małgorzata , Klapiszewski Łukasz , Bartczak Przemysław , Kaczorek Ewa , Jesionowski Teofil
Published: December 2014

The immobilization of Amano Lipase A from Aspergillus niger by adsorption onto Stöber silica matrix obtained by sol-gel method was studied. The effectiveness of the enzyme immobilization and thus the usefulness of the method was demonstrated by a number of physicochemical analysis techniques including Fourier Transform Infrared Spectroscopy
(FT-IR), elemental analysis (EA), thermogravimetric analysis (TG), porous structure of the support and the products after immobilization from the enzyme solution with various concentration at different times. The analysis of the process’ kinetics allowed the determination of the sorption parameters of the support and optimization of the process. The optimum initial concentration of the enzyme solution was found to be 5 mg mL-1, while the optimum time of the immobilization was 120 minutes. These values of the variable parameters of the process were obtained by as ensuring the immobilization of the largest possible amount of the biocatalyst at
Plasma recycling of chloroorganic wastes
Authors: Jędrzejczyk Tomasz , Kołaciński Zbigniew , Koza Dariusz , Raniszewski Grzegorz , Szymański Łukasz , Wiak Sławomir
Published: December 2014

A high temperature of thermal plasma provides
more efficient decomposition of the wastes in comparison
to traditional combustion. Due to the high temperature
and high density of energy in the plasma, the destruction
rate is high, which determines a high efficiency waste
decomposition. The main products of pyrolysis plasma
chloroorganic compounds are pyrolysis gas and pyrolysis
coke.

In order to reduce carbon soot, the steam supported
reaction was used. Application of plasma at a temperature
range from 1000 to 1750 K enabled destruction of the
chloroorganic compounds with a very good yield. Several
degradation products were received , which were analyzed.
In the research electric arc plasma was used in the process
of pyrolysis chloroorganic waste utilization. The reactor
with a rotating arc was applied. Selected chloroorganic
compounds were selected as the model: chloromethane
(CH3Cl), carbon tetrachloride (CCl4), chlorobenzene
(C6H5Cl) and dichlorobiphenyl (PCB-C12H8Cl2). Based on
the amount of the individual components, chloroorganic
in the exhaust gases, and the amount introduced to the
plasma decomposition, percentage yield was calculated.

Research results indicated that decomposition
efficiency was more than 99,8% with the exception of CCl4
pyrolysis, which in the exhaust had a content of 0.2%
CCl4.
Functional polypropylene composites filled
with ultra-fine magnesium hydroxide
Authors: Pilarska Agnieszka , Bula Karol , Myszka Kamila , Rozmanowski Tomasz , Szwarc-Rzepka Karolina , Pilarski Krzysztof , Chrzanowski Łukasz , Czaczyk Katarzyna , Jesionowski Teofil
Published: December 2014

Magnesium hydroxide was prepared under controlled conditions from aqueous Mg(NO3)2 and NaOH solutions. The small, nanoplate-shaped particle size distribution was monomodal from 164 to 459 nm. Functional polypropylene/Mg(OH)2 and polypropylene/polypropylene 1% maleic anhydride/Mg(OH)2 composites were prepared containing 10% or 30% Mg(OH)2. The composites have a high Young’s modulus (twice that of polypropylene) and comparable tensile strength but less ductility. EDX examination of the fractured composite surfaces suggested a homogeneous Mg(OH)2 distribution for composites produced with the addition of polypropylene grafted with maleic anhydride. The polypropylene/Mg(OH)2 composites showed good antibacterial activity. The polypropylene/polypropylene 1% maleic anhydride/Mg(OH)2 composites were less effective.
Determination of Ag+ and Cu2+ ions in mixture samples obtained in the microwave assisted polyol process by differential pulse anodic stripping voltammetry (DPASV) method
Authors: Markowski Piotr , Dzido Grzegorz , Baranowska Irena , Jarzębski Andrzej B.
Published: December 2014

A simple and selective differential pulse anodic stripping voltammetry (DPASV) method for the determination of Ag+ and Cu2+ ions in mixture samples obtained in the microwave assisted polyol process was developed and validated. Analytical methods for the preparation of the reaction mixture for voltammetric analysis (dilute samples in the supporting electrolyte) were worked out and optimized. All measurements were conducted in three-electrode cell system equipped with glassy carbon electrode (GCE) as a working electrode, silver/silver chloride (Ag|AgCl|KCl(sat.)) as a reference and platinum wire as a auxiliary electrode. The optimal conditions for quantitative determination were obtained in an mixture Britton–Robinson buffer at pH 4.1 / ethylene glycol (100/1; v/v). The calibration curves of analysed compounds are linear within the range of concentration: 0.032 − 0.420 μg mL-1 and 0.075 − 0.960 μg mL-1 for Ag+ and Cu2+, respectively. Good linear behaviour over the investigated concentration ranges were observed with the values of r2 higher than 0.996 for the silver and cooper ions. The accuracy of analytical determinations ranged from 0.4 to 3.6%. The levels of analysed ions in the reaction mixture can be successfully determined using this developed method with no matrix effect.
Physical features of atmospheric pressure microdischarge system with vortex gas flows
Authors: Prysiazhnevych Iryna , Lendel Vasyl , Chernyak Valeriy , Solomenko Oksana , Martysh Eugene , Iukhymenko Vitalii
Published: December 2014

The parameters for microdischarges of plasma medicine in air and argon vortex flows at atmospheric pressure for different shapes of electrodes (outlet nozzle and axis electrode diameters ratio set) have been investigated. The current-voltage characteristics of the designed systems have been analyzed, the parameters of the generated jets plasma have been investigated by means of the optical emission spectroscopy, and the form of plasma jets has been studied by using video camera.
Properties of atmospheric pressure plasma oxidized layers on silicon wafers
Authors: Skácelová Dana , Sládek Petr , Sťahel Pavel , Pawera Lukáš , Haničinec Martin , Meichsner Jürgen , Černák Mirko
Published: December 2014

In this research a new process of plasma oxidation of crystalline silicon at room temperature is studied. The plasma oxidation was carried out using Diffuse Coplanar Surface Barrier Discharge (DCSBD) operating in ambient air and oxygen at atmospheric pressure. The influence of exposition time, plasma parameters and crystallographic orientation of silicon on oxidized layers and their dielectric properties were investigated. Thickness, structure and morphology of these layers were studied by ellipsometry, infrared absorption spectroscopy and scanning electron microscopy. During the treatment time, from 1 to 30 minutes, oxidized layers were obtained with thickness from 1 to 10 nm. Their roughness depends on the crystallographic orientation of silicon surface and exposure time. Electrical parameters of the prepared layers indicate the presence of an intermediate layer between silicon substrate and the oxidized layer.
Crystallographic and structural characterization
of heterometallic platinum clusters Part VIII.
Heteronona- and heterodecanuclear clusters
Authors: Melník Milan , Mikuš Peter , Holloway Clive E.
Published: December 2014

This review classifies and analyses fifty heteronona- and heterodecanuclear Pt clusters of metal composition: Pt4Ru5, Pt3Ru6, Pt20sr PtRh8, PtAu8; Pt6M4, Pt5M5, Pt4M6, Pt3M2, Pt2M8, PtM9, Pt3Ru6M and PtAu8M. There are nine different heterometals: M = Ru, Au, Ag, Cu, Hg, Os, Rh, Ir and Fe, of which Ru and Au are the most frequent. The clusters crystallize mostly into two crystal classes, monoclinic (74%) and triclinic (18%), and their structures are complex. Three triangular layers of nine metal atoms arranged in the form of a face-shared bioctahedron are common in the series of heterononanuclear clusters. In the series of heterodecanuclear clusters distorted skeletal icosahedrons, where a central platinum atom is surrounded by nine metal atoms, and face (edge) shared (fused) bioctahedral cluster of the metal atoms are the most common. The most frequent ligands are CO and PPh3. The shortest metal-metal bond distances are: 2.540(4) Å (Pt-Fe), 2.580(2) Å (Ru-Ru), 2.584 Å (Pt-Pt) and 2.629(4) Å (Cu-Au). Several relationships between the structural parameters were found and are discussed. Some clusters contain two crystallographically independent molecules within the same crystal and are examples of distortion isomerism.
Influence of electrode material on hydrogen peroxide generation by DC pinhole discharge
Authors: Vyhnánková Edita , Kozáková Zdenka , Krčma František , Hrdlička Aleš
Published: December 2014

In this work, several materials were studied as electrodes in a pinhole configuration of a DC plasma discharge to estimate their effect on the efficiency of the discharge, indicated by hydrogen peroxide production. Detection was carried out using a specific titanium reagent. This was combined with ICP-OES analysis of the final solutions to determine the difference between the amount of electrode material released during the discharge operation and electrolysis experiment carried out under the same conditions. It was found that from seven studied electrode materials, graphite gives the best results, while lower cost aluminum and titanium-zinc still work well. The most unsuitable materials were copper and brass; in these cases, no hydrogen peroxide was detected in the cathode part of the reactor. Results obtained by ICP analysis indicate that even in the case of brass, the absence of hydrogen peroxide is due to the presence of copper in the material. It probably affects both directly the phase of discharge creation and propagation and the decomposition reactions.
A comparison of carbon tetrachloride decomposition using spark and barrier discharges
Authors: Ulejczyk Bogdan , Krawczyk Krzysztof , Młotek Michał , Schmidt-Szałowski Krzysztof , Nogal Łukasz , Kuca Bolesław
Published: December 2014

The decomposition of CCl4 in air was investigated at atmospheric pressure in two discharges. Reactors used to generate electrical discharges were powered by the same electric power supply. In both reactors, nearly 90% conversion of CCl4 was obtained. All chlorine was in the form of Cl2 in the process carried out in the barrier discharge, while in the spark discharge, COCl2 was formed. The conversion of CCl4 to COCl2 ranged from 2 to 12%. NO was formed in both discharges but the NO content in the gas leaving the reactors was 1.7–2.7% for the spark discharge and 0.045–0.06% for the barrier discharge.
O3 was produced only in the barrier discharge and its content ranged from 0.1 to 0.2%.
Acetic acid hydroconversion over mono-
and bimetallic indium doped catalysts supported on alumina and silicas of various textures
Authors: Onyestyák György , Harnos Szabolcs , Badari Cecília Andrea , Drotár Eszter , Klébert Szilvia , Kalló Dénes
Published: December 2014

Consecutive hydroconversion of acetic acid (AA) to ethanol was compared over monometallic and novel bimetallic (containing In as guest metal) catalysts on alumina and silica supports (inter alia highly ordered SBA-15) of different porosity and pore structure.
The transformation was studied in a fixed bed, flow-through reactor in the temperature range of 220–380°C using hydrogen flow at 21 bar total pressure. AA hydroconversion activity of Cu and Pt catalysts and the yield of selectively produced alcohol were increased drastically by applying SBA-15 as highly ordered, mesoporous silica support instead of alumina. The most active nickel catalysts do not allow the selective addition of hydrogen to carbon-oxygen bonds independently of supports producing mainly CH4; however, indium doping can completely eliminate the hydrodecarbonylation activity as found in earlier studies. The textural properties of studied silica supports of various textures such as SBA-15, CAB-O-SIL, and Grace Sylobead have a profound impact on the catalytic performance of Ni and Ni2In particles.
Modification of PET surface properties using extremely non-equilibrium oxygen plasma
Authors: Junkar Ita , Modic Martina , Mozeti Miran
Published: December 2014

Polyethylene terephthalate (PET) foils have been exposed to oxygen plasma and its afterglow in order to reveal compositional and structural modifications of the surface layer. Oxygen plasma was created by electrode-less RF discharge in a glass chamber so the O-atom density was close to 1022 m-3 although the density of charged particles was only about 1 × 1016 m-3. Long-living reactive particles created in plasma were leaked into the afterglow chamber using a two-stage rotary pump of pumping speed
4.4 × 10-3 m3 s-1. The density of O-atoms in the afterglow as measured with a catalytic probe was 3 × 1021 m-3, while the density of reactive oxygen molecules was estimated theoretically. The functionalization was accomplished even after a brief exposure to either plasma or afterglow since all samples were saturated with oxygen-rich functional groups as revealed by XPS. The water contact angle measurements, however, showed that only plasma treatment allowed for super-hydrophilicity, explained by rich surface morphology as detected by AFM. The differences in morphological properties between plasma and afterglow treated samples were explained by different interaction mechanisms between low and high energy particles impinging the polymer surface.
Diffuse Coplanar Surface Barrier Discharge
in Artificial Air: Statistical Behaviour
of Microdischarges
Authors: Čech Jan , Hanusová Jana , Sťahel Pavel , Černák Mirko
Published: December 2014

Diffuse Coplanar Surface Barrier Discharge (DCSBD) is a novel type of atmospheric-pressure plasma source developed for high-speed large-area surface plasma treatments. The statistical behavior of microdischarges of DCSBD generated in artificial air atmosphere was studied using time-correlated optical and electrical measurements. Changes in behavior of microdischarges are shown for various electrode gap widths and input voltage amplitudes. They are discussed in the light of correlation of the number of microdischarges and the number of unique microdischarges’ paths per discharge event.

The ‘memory effect’ was observed in the behavior of microdischarges and it manifests itself in a significant number of microdischarges reusing the path of microdischarges from previous half-period. Surprisingly this phenomenon was observed even for microdischarges of the same half-period of the discharge, where mechanisms other than charge deposition have to be involved. The phenomenon of discharge paths reuse is most pronounced for wide electrode
Spark plasma sintering of Si3N4/multilayer graphene composites
Authors: Bódis Eszter , Tapasztó Orsolya , Károly Zoltán , Fazekas Péter , Klébert Szilvia , Keszler Anna Mária , Balázsi Katalin , Szépvölgyi János
Published: December 2014

Mulitlayer graphene reinforced silicon nitride composites were prepared by spark plasma sintering to investigate the effect of the graphene addition on mechanical properties. The composites contained multilayer graphene (MLG) in various (0, 1, 3 and 5 wt%) content. Significantly higher fracture toughness of
8.0 MPa m1/2 was obtained at 1% MLG content, however, on further increasing the graphene content the toughness did not increase, but dropped to the value of the monolithic silicon nitride. The maximum hardness of 18.8 MPa was also obtained at 1% MLG, while at higher MLG contents it gradually decreased.
Polylactic acid surface activation by atmospheric pressure dielectric barrier discharge plasma
Authors: Hergelová Beáta , Zahoranová Anna , Kováčik Dušan , Stupavská Monika , Černák Mirko
Published: December 2014

Polylactic acid (PLA) is suitable for applications in packaging and biomedicine due to its biodegradability. To improve PLA surface adhesion a plasma-chemical treatment using nonthermal plasma generated in ambient air via diffuse coplanar surface barrier discharge (DCSBD) was used. The optimal treatment time and power were investigated. Interaction between active plasma species and the polymer surface, and the resulting surface changes were studied by contact angle measurement, surface energy determination, FTIR, and XPS.
The most hydrophilic surface was obtained after only 3–4 s treatment. Treatment up to 10 s did not damage the polymer but longer treatments (30 and 60 s) caused partial degradation. The plasma broke C-C/C-H bonds and formed more C-O, O-C=O and C-O-C bonds. During storage surface oxygen decreased and a negligible amount of nitrogen was adsorbed. The oxygen-containing functional groups probably sank into the PLA volume after treatment.
Optical emission spectra analysis of thermal plasma treatment of poly(vinyl chloride)
Authors: Fazekas Péter , Keszler Anna Mária , Bódis Eszter , Drotár Eszter , Klébert Szilvia , Károly Zoltán , Szépvölgyi János
Published: December 2014

Decomposition of poly(vinyl chloride) (PVC) was investigated in radiofrequency thermal plasma in neutral, oxidative and reductive conditions. Optical emission spectroscopy (OES) was applied for the characterization of the plasma column. OES was used to identify active plasma components such as excited atoms, ions, radicals and molecules. The spectra were dominated by molecular C2, CN, OH, and CH bands, and atomic H, Ar, C, Cl and O lines. Emission intensities of main species were monitored versus various experimental parameters. The rotational-vibrational temperatures determined from different bimolecular species were considered in the range of 2000–6400 K. Solid soot samples were collected and purified to investigate the possibility of graphene formation as a by-product of the decomposition process.
Time resolved optical emission spectroscopy in power modulated atmospheric pressure plasma jet
Authors: Hnilica Jaroslav , Potočňáková Lucia , Kudrle Vít
Published: December 2014

In this paper, the effects of the power modulation on atmospheric pressure plasma jet, operated in
Ar+2%N2 mixture, are studied. Time resolved optical emission spectroscopy is used for the investigation. From line and band intensities, the excitation, vibration and rotation temperatures are calculated. Their evolution during the modulation period exhibits
a strong dependence on modulation frequency. For higher modulation frequencies, there is significant discrepancy in rotational temperatures calculated from OH spectra and from N2+ spectra, which indicates that thermalisation time can reach milliseconds.
Layer-by-layer assembly of thin organic films on PTFE activated by cold atmospheric plasma
Authors: Tóth András , Szentmihályi Klára , Keresztes Zsófia , Szigyártó Imola , Kováčik Dusan , Černák Mirko , Kutasi Kinga
Published: December 2014

An air diffuse coplanar surface barrier discharge is used to activate the surface of polytetrafluoroethylene (PTFE) samples, which are subsequently coated with polyvinylpyrrolidone (PVP) and tannic acid (TAN) single, bi- and multilayers, respectively, using the dip-coating method. The surfaces are characterized by X-ray Photoelectron Spectroscopy (XPS), Attenuated Total Reflection – Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Atomic Force Microscopy (AFM). The XPS measurements show that with plasma treatment the F/C atomic ratio in the PTFE surface decreases, due to the diminution of the concentration of CF2 moieties, and also oxygen incorporation through formation of new C–O, C=O and O=C–O bonds can be observed. In the case of coated samples, the new bonds indicated by XPS show the bonding between the organic layer and the surface, and thus the stability of layers, while the gradual decrease of the concentration of F atoms with the number of deposited layers proves the creation of PVP/TAN bi- and multi-layers. According to the ATR-FTIR spectra, in the case of PVP/TAN multilayer hydrogen bonding develops between the PVP and TAN, which assures the stability of the multilayer. The AFM lateral friction measurements show that the macromolecular layers homogeneously coat the plasma treated PTFE surface.
An application of fluorescent tracer
to groundwater tracking
Authors: Cidzikienė Vigilija , Jakimavičiūtė-Maselienė Vaidotė , Girgždienė Raselė , Ivanec-Goranina Rūta
Published: December 2014

A well network at a potential new nuclear site in Lithuania examined a semi-confined intertill aquifer 10–19 m deep and an unconfined aquifer 4.5–9 m deep. Tracer results indicate a northwest flow direction and great hydraulic connection between observation and injection wells. Natural conditions affect tracer flow velocities.