bluuebunny/crossref_metadata_2025 huggingface dataset:
SMART Platform for Structural Health Monitoring of Sensorised Stiffened Composite Panels
Authors: Sharif-Khodaei Z. , Ghajari M. , Aliabadi M.H. , Apicella A.
Published: November 2012

A SMART Platform is developed based on sensor readings for Structural Health Monitoring of a stiffened composite panel. The platforms main function is divided into three categories: Passive sensing, Active sensing and Optimal sensor positioning. The platform has self-diagnostic capabilities, i.e. prior to its application the health of the sensors and their connection will be checked to avoid any false alarm. Passive sensing results in impact location and force magnitude detection. Active sensing is performed for damage detection. It results in detecting the damage location and severity. Finally the optimal sensor location can be provided given the number of sensors and probability of detection value. This platform is the first step in applying the developed SHM methodologies to real size structures in service load conditions.
The Analysis of Abrasive Wear of the Helical Grooved Journal Bearing
Authors: Sep Jarosław , Pawlus Pawel , Dzierwa Andrzej
Published: November 2012

The paper presents results of the tests concerning slide bearings having modified journal with helical groove. Such a bearing is more wear-resistant than the classical bearing in case of hard particles presence in oil. Investigations show that above mentioned modification results in over twofold decrease in wear intensity in case of suitable helical groove parameters. Differences in worn journals surface topography for investigated variants have also been stated.
Tribological Behavior of Bronze Alloys with Solid Lubricants
Authors: Kallio Marke , Vuorinen Petri , Fuentes Elena , Maraña Oscar , Ruusila Viivi , Nyyssönen Tuomo , Kuokkala Veli Tapani , Lehtovaara Arto
Published: November 2012

Lead containing bronzes are widely used as bearings, bushings and sliding plates. Lead is a heavy metal and known to be harmful to people and environment, but currently no feasible substitute material exists in many engineering applications. The ecological considerations in recent years have led to restrictions by the European Commission on the use of lead for example in the bearings used in cars (The Directive on the end-of-life of vehicles). However, due to the lack of substitutes for lead in many application areas, the ban has been given an exemption. The aim of the ECOBEARINGS project was to evaluate, whether any metallic or composite bearing material has similar tribological and mechanical properties as the currently used standard lead bronzes. In heavy machine engineering, lead bronze alloys containing up to 10-20 % of Pb are commonly used as sliding bearings such as thrust and journal bearings. In lead bronzes, lead has a function of a solid lubricant especially during the start of the operation of the bearing. Additionally, lead bronzes form a soft sliding surface where small contamination particles can be embedded in the material without causing an abrasive effect. A variety of different lead-free bearing solutions are already commercially available, but there are many applications where the emergency lubricating properties of lead cannot be substituted yet. It has been proposed that other solid lubricants such as graphite or bismuth could possibly have similar tribological characteristics as lead in bronze bearing materials. In this work, bronze alloys containing solid lubricants such as bismuth and graphite were produced by casting and spray forming. The alloys were characterized and tribologically tested in boundary lubricated and dry sliding conditions. The results were compared with the testing results of lead bronze. On the basis of the results, it was noted that different solid lubricants have very special tribological characteristics. This information can be used in the further development of ecologically sound bearing materials.
Friction of Thin Electroless NiP and NiP-SiO2 Coatings on Aluminium Alloy Substrate
Authors: Myshkin Nikolai K. , Grigoriev Andrei Ya. , Gutsev Dzmitry M.
Published: November 2012

Thin NiP and NiP+SiO2 coatings were deposited by electroless techniques on aluminum alloy plates. Dry sliding tests against Al2O3 counterbody with the ball on plate contact geometry and reciprocal moving were carried out. The results of tribological tests showed that the friction coefficient of the modified coating at loads above 500 mN by 3-4 times, and wear 1.4-2 times lower than for original NiP coatings. It was found that during friction of NiP and NiP+SiO2 coatings different tribochemical processes are realized. These processes lead to the formation of different by chemical composition of P, Ni and O of secondary structures on the friction surfaces and as result to different tribological properties of the investigated coatings.
Theory of Phase Transformations in the Mechanics of Solids and its Applications for Description of Fracture, Formation of Nanostructures and Thin Semiconductor Films Growth
Authors: Kukushkin S.A. , Osipov A.V.
Published: November 2012

The brief review of the current state of the theory of first-order phase transitions is given. The basic processes of nucleation and evolution of nanostructure ensembles on crystal surfaces are considered. The general equations describing nanoparticle size distribution, evolution of their average radius and density are deduced. The influence of mechanical pressure on nucleation and property of quantum dots and nanopores is considered. The equations describing new phase nucleation under condition of mechanical pressure caused by distinction in density of an old and new phase are resulted. The kinetic theory of micropore nucleation in solids under loading is described. The kinetic criterion is received of nucleation of micropores and microcracks in fragile solids under the influence of stretching pressure.
Effect of Different Parameters on the Stability of Femur Neck Fixing
Authors: Bagi István
Published: November 2012

In our country the most prevalent procedure to treat displaced fractured neck of the femur is the method of double canulated femoral neck screw developed by Professor Jenő Manninger and coworkers. The aim while elaborating this method was to synthesize displaced fractured neck of the femur and to ensure the highest possible stability with the minimal operative strain.
An essential condition of successful recovery is the enhancement of the stability of the fixation of fractures. However, at old age the layer of spongiosa becomes so porous that the threads of screws used for the treatment of the fracture of the neck of the femur virtually fulfil their fixing function only in the subchondral region less and less in the inner layer of the spongiosa. But, in the subchondral region, the outer layer of 4 to 5 mm remains relatively dense. To increase stability, we modified the traditionally shaped canulated screws, used for the neck of the femur to date, and developed duplex-threaded screws for the neck of the femur. One of the basic criteria of the success of the operation is the positioning of the screws related to anatomical landmarks and to each other.
We examined both traditional and duplex screws with altered thread profile in several conditions applying finite element calculations. Normal pull-out force was applied in order to compare the results in case of both traditional and duplex screws. It showed that the duplex screw increase the pull-out force by 65 % compared to the traditional screws. In case of 5° positioning error we found that the power needed for pulling the screw out was decreased by at least 10-17 %, depending on the direction of the positioning error but it was less (6-9 %) in case of duplex screws. The loading capacity of the models with spongiosa bone matter differs from that of the subchondral bone layer models by at least 12-20 % depending, on the shape of the screw and the material law.
X-Ray Diffraction Measurements of Residual Stress Induced by Surface Compressing Methods
Authors: Cseh Dávid , Mertinger Valéria
Published: November 2012

Residual stresses have a fundamental effect on the operational behaviour and lifetime of industrial products. The fatigue resistance of machine parts can be increased by introducing residual compressive stresses into the surface region. For certain machine parts especially in the vehicle industry the residual stress is strongly demanded by the quality control. For this reason, measuring the stress accurately is becoming increasingly important. The Almen test, which only gives a qualitative result, is widely used in the industry. Shot peening and rolling are methods which are suitable for creating elastic residual stresses.
This paper examines the technologies used by Rába Futómű Nyrt. to increase the lifetime by means of residual stress. We performed analysis of the residual stress of samples shot peened the same way but under different heat treatment states. We compared the residual stress values of burnished and hardened shaft joints, and the residual stress states of gear made of hardened alloy, comparing the carbonized ones to ones which were shot peened under small intensity.
The Influence of Impurity Content on Thermal Stability of Low Stacking Fault Energy Silver Processed by Severe Plastic Deformation
Authors: Hegedűs Zoltán , Gubicza Jenő , Kawasaki Megumi , Chinh N.Q. , Fogarassy Z. , Langdon Terence
Published: November 2012

The effect of the impurity content on the evolution of the ultrafine-grained (UFG) microstructure in low stacking fault energy Ag and its stability at room and elevated temperatures were investigated. Samples of silver having high (99.995%) and somewhat lower (99.99%) purity levels were processed by equal-channel angular pressing (ECAP) at room temperature (RT) up to 16 passes. Although, the minimum grain size achieved by ECAP was ~200 nm for both series, the lattice defect structure was strongly influenced by the impurity content. In the samples processed by 4-16 passes of ECAP a self-annealing occurred during storage RT that was promoted by the higher twin boundary frequency. Both room-and high-temperature thermal stability of 99.99% purity Ag were much better due to the pinning effect of impurities. It was found that a large number of dislocation loops remained in the microstructure even after recrystallization at high temperatures.
Single, Binary and Ternary Ion Exchanged Zeolite as an Effective Bioactive Filler for Biomedical Polymer Composites
Authors: Kaali Péter , Czél György
Published: November 2012

The preparation and modelling of single, binary and ternary ion exchanged zeolites that express antimicrobial efficiency is discussed. As experimental material A type zeolite was used and different variations of Ag, Cu and Zn ions were incorporated into the crystal structure. Antimicrobial efficiency is based on the ion concentration and ion release of the zeolite, therefore the maximum cation-exchange capacities (CEC) were determined for each of the single ions. After the determination of CEC the preparation of binary and ternary ion-exchanged zeolite samples were prepared by the mixture of silver, copper and zinc nitrate solutions and the composition of the samples was determined by atomic absorption spectroscopy (AAS). To verify the bioactive effect, the minimum inhibitory concentration (MIC) of single, binary and ternary ion-exchanged zeolite A was determined for bacteria strains.
Analysis of Applicability of the Hollow Carbon Fibres for Self-Repairing Composites
Authors: Kling Sándor , Czigány Tibor
Published: November 2012

The geometry and mechanical properties of solid and hollow carbon fibres were investigated by light-and scanning electron microscopy, and by single fibre tensile tests. The hollowness factor of fibres was determined by their external and internal diameter. The tensile strength was determined by single fibre tensile break tests. It was shown that the bigger the diameter of the fibres the lower the mechanical properties is. It was found that the hollow carbon fibres are suitable for preparation of a self-repairing composite with the advantage over other solutions because of their geometrical and mechanical properties.
Microstructure and Phase Analysis by TEM in Cu-Hf-Ti Alloys
Authors: Rontó Viktória , Sólyom Jenő , Kovács Á. , Pekker P. , Dódony I.
Published: November 2012

There are no data about the equilibrium phases in the Cu-Hf-Ti system, in the Cu-rich corner which is a glass former region. Phases and solidifying microstructures were examined in the master alloy (cooling rate: ~150 K/s) and in slowly cooled (5 K/min) samples in case of different compositions. Unknown ternary phases were found by SEM and XRD analysis and one of them with the highest Ti content could be identified by TEM study.
Investigation of Mechanical Properties and Crack Propagation Behaviour of Hybrid Composites with Epoxy Resin Matrix
Authors: Tamás P. , Czigány T.
Published: November 2012

Mechanical properties, micro structure and crack propagation behaviour of different fabric reinforced mono and hybrid composites for materials of wind turbines have been investigated. Mechanical properties of different fabrics (glass, basalt and carbon) reinforced mono and hybrid composites with epoxy resin matrix have been compared. For characterization of materials tensile, three-point bending and single-edge notched tensile (SEN-T) tests with acoustic emission study were used and scanning electron microscope (SEM) pictures have been taken of the fracture surfaces of composite specimens. Similar behaviour of glass and basalt fibre reinforced composites was revealed by tensile and three-point bending tests. The satisfactory adhesion between fibre and matrix was shown by scanning electron microscope. The fibre-break was proven by the taken pictures to be the main failure mechanism. Results of mechanical tests were also confirmed by acoustic emission study. The crack propagation method of glass and basalt fabric reinforced composites is similar.
Modelling Possibilities of the Medieval Bloomery Process under Laboratory Conditions
Authors: Thiele Adam , Dévényi László
Published: November 2012

Two different models have been developed under laboratory conditions based on the experiences of smelting experiments carried out in bloomery furnaces patterned on some excavated 10-12th century ones. Using Rudabánya iron ore, experiments were conducted in a closed pot and in a small open shaft furnace. During the experiments the air supply, the temperature and the weight of the iron ore and the charcoal were measured. SEM-EDX analyses were performed on bloom pieces obtained from the experiments. The results of the modelling may be correlated with the results of the previous smelting experiments. The model is sufficient for investigating some adequate parameters of the medieval bloomery technology, e.g. the iron yield.
Mechanical Behavior of Bioactive TiC Nanocomposite Thin Films
Authors: Balázsi Katalin , Vandrovcová Marta , Bačáková Lucie , Balázsi Csaba , Bertóti Imre , Davin François , Radnóczi György Z.
Published: November 2012

Carbon-based nanocomposite thin films have large application potential because they possess unique mechanical properties, especially high hardness, high elasticity, and a low widely adjustable friction coefficient.
In this work, relatively easy preparation of the nanocomposite Ti and C system with good mechanical properties and bioactivity was showed. Formation of physical and mechanical processes, relationship between the evolving structure and other properties of TiC films were studied. The films were deposited on oxidized silicon substrates by dc magnetron sputtering of Ti and C targets in argon and nitrogen at different temperatures between 25°C and 800°C. The composite films consisted of metallic nanocrystalls embedded in a carbon matrix. Highest hardness ~ 18 GPa and reduced modulus of elasticity ~ 205 GPa were obtained when the crystalline nanoparticles were separated by 2-3 nm thin carbon matrix consisting of amorphous and graphite-like carbon phases. In these films the H/E ratio in the both cases is ~ 0,1. Bioactivity studies were carried out on human osteoblast-like cell line MG-63. The number of initially adhering cells on day 7 after seeding was significantly higher on the TiC surface than on the control culture dishes. Good biocompatibility and bioadhesion of these surfaces are attained by a favourable combination of surface roughness and chemistry.
Analysis of the Creep Behavior of Polypropylene and Glass Fiber Reinforced Polypropylene Composites
Authors: Bakonyi Péter , Vas László Mihály
Published: November 2012

In this paper tensile and creep tests were performed on polypropylene (PP) and its glass fiber reinforced composites. The tensile tests were carried out on 6 different glass fiber content reinforced PP composites (0, 5, 10, 20, 30 and 40%) while the creep tests were performed on the unreinforced and 30% and 40% fiber reinforced ones of industrial importance. 50 N/s constant force rate was used until the specimen failed (tensile test) or the preset load level was reached (creep test). The applied load levels for the creep experiments were determined as given ratios of the average breaking force. The tensile breaking strain and tensile strength versus fiber content relationship were analyzed and described by empirical formulas based on the correction and averaging procedure developed.
On the Relation between Stress Relaxation and Constant Strain Rate Tensile Behavior for Linear Viscoelastic Materials; An Engineering Approach
Authors: Bódai Gábor , Goda Tibor
Published: November 2012

The present paper, as a first step summarizes briefly the master curve construction methods applying the stress relaxation and DMTA based approach. Then, authors make recommendation to increase the covered time (frequency) domain of relaxation modulus master curve coming from standard tensile tests-performed at wide temperature range-by utilizing the time-temperature superposition principle. The proposed approach is used for natural rubber, whose tensile tests, for the sake of simplicity, are replaced by calculated engineering stress-strain curves. All in all, the proposed method gives fast and reliable way for engineers to identify the parameters of spring-dashpot models.
The Role of the Displacement Reaction in the Production of Surface Composite Layer
Authors: Janó Viktória , Buza Gábor
Published: November 2012

Composites of ceramic particle reinforcement (such as alumina) have potential for high temperature structural applications. In contrast to conventional processing methods (e.g. mechanical alloying), in situ processing techniques can be inexpensive and can also lead to unique microstructures, such as very fine dispersions of the reinforcements or interconnecting phases. The feasibility of processing Fe/Al2O3 composites layer by an in situ displacement reaction between Fe2O3 and Al by using laser beam pre-experiments were carried out and the results are presented in this paper.
Impedance Analysis of Silicone Rubber Filled by Electrically Conductive Nanoparticles
Authors: Bojtos Attila , Huba Antal
Published: November 2012

During the research, scanning electron microscopy, compression, tensile and frequency analysis were performed on silicone rubbers filled with conductive particles , in order to understand the electrical conduction mechanism. The distribution of the conductive nanoparticles and its relationship with the substrate was examined with scanning electron microscopy (SEM). During the SEM studies, the conductive elastomers were investigated in their deformed and original state too. The connection between the deformation and the resistivity was examined with compression and tensile tests. The impedance of the material was examined on a wide range of frequency. The correctness of the lumped parameter model that is mentioned in the literature , was examined and its parameters were determined. The dependence of the resistivity on the aspect ratio of the specimens was also investigated. The aim of this research is to make this construction material intelligent, and to use it to produce hyperelastic mechanical sensors (for strain, force, torque, ect. measuring).
Effect of Organic Additives on Friction Properties of Clay Based Compounds
Authors: Kocserha István , Gömze László A. , Kristály Ferenc , Geber Robert , Győrffy Bálint
Published: November 2012

In the traditional heavy-clay industry, compounds are usually prepared by the addition of organic waste material. These additives originate mainly from the wood, food or paper industries. The purpose of this study is to present the results of the examination of friction contact between the wall of the forming die and the clay compounds containing organic additives. Saw dust and ground sunflower seed shell were mixed to clay in 0 wt%, 3 wt% and 5 wt%. The water content of compounds was also varied. The clay and the additives were described by morphology, XRD, bulk density and equivalent diameter. Friction tests were carried out on a special tribometer up to plastic deformation of the sample. The coefficient of friction decreased when normal stress was increased for all the ten compounds. Average results showed that the tendency of change in the value of the coefficient of friction could be divided into three sections: a decreasing, a quasi constant and a shearing section. It follows from this that the coefficient of friction can be characterized with a number only inside the quasi constant section, i.e. between two definable normal stress values. Averaged coefficient of friction was between 0.17 and 0.21 for saw dust and between 0.19 and 0.21 for the compounds with ground sunflower seed shell.
Accurate Calculation of the Non-Variant Points of Equilibrium Phase Diagrams by Using the ESTPHAD Method
Authors: Mende Tamás , Roósz András
Published: November 2012

Certain phase transitions take place at a given temperature in the equilibrium phase diagrams, the values of their temperatures can exactly be measured so it is an essential task to calculate these values by a high accuracy. New parameters were introduced into the ESTPHAD equation for calculating the so-called non-variant points. By using the ESTPHAD method, the accuracy of calculations are compared to the data used for the calculations so the exact calculation of the temperatures of non-variant points are defined as compared to the data used for the calculations.
Recrystallization of Pure Copper Investigated by Calorimetry and EBSD
Authors: Mucsi András
Published: November 2012

This paper deals with the recrystallization of high purity copper. Cold rolled specimens heat treated in the DSC apparatus by constant heating rate to chosen temperatures, after that water quenched producing partially recrystallized microstructure. Microstructure of samples investigated by EDSB.
Technological Investigation of Plated Aluminium Sheets
Authors: Szabó Gábor , Mertinger Valéria
Published: November 2012

In this study the aluminium sheet bonding properties is investigated. The bonding was performed between 1050 and 3003 Al alloys using mechanical press (eccentric press) or hot rolling (VON ROLL experimental duo mill). The experimental temperatures were 400, 450, 500°C. The goodness of bonding was tested by tensile test and T-peel test. The optimal parameters were developed for the T-peel test. The results obtained from these tests give a good description about the quality of bonding. Structure analysis was also performed by LM and SEM to detect the typical bonding faults.
Application of Specimen Reconstitution to Evaluate the Ageing of Nuclear Pressure Vessels
Authors: Székely Richárd , Horváth Ákos
Published: November 2012

Determining the effect of irradiation on the mechanical properties of reactor pressure vessel during the operational lifetime of a nuclear power plant is crucial from the safe operation point of view. That information is derived from the investigations of specimens made of the same material as the pressure vessel. One of the most commonly used methods is the Charpy test. In order to better use the limited volume of the available space for specimens in the reactor, and further investigate the radiation ageing of used samples, the probe reconstitution by welding is applied. The reconstituted specimen can be investigated three times thus improving the amount of data gained and reducing the radioactive waste. In the presented paper the stud welding technology was investigated, the effect of different stud geometries and weld protection on the quality of the final product will be discussed.
Examination of Crystallization of Low Melting Point Alloys for Miniature Casting
Authors: Vlaszák Mihály , Takács Katalin T. , Marosi László , Barkóczy Péter , Kállai Kinga
Published: November 2012

Our company started an alloy development project with the aim of developing an alloy to miniature casting, which meets customer requirements the most. Besides solders and alloys for nuclear usage, the manufacturing of alloys to miniature casting is also a significant business. The development was started based on the requirements of the customers. Model metals are mainly alloys of lead-tin-bismuth and antimony. Adequately, the research concentrated on this alloy system. In the first step, besides the thermal characteristics, the crystallization of dissimilar alloys in the system and crystallized microstrtucture was examined. The thermal features of the crystallization of alloys were examined by calorimetry, while microstructural constituents were examined by metallographic and SEM-EDX examinations.
Hydrogen Storage, Microstructure and Mechanical Properties of Strained Mg65Ni20Cu5Y10 Metallic Glass
Authors: Revesz Adam , Kis-Tóth Ágnes , Szommer Péter , Spassov Tony
Published: November 2012

Melt-spun amorphous Mg65Ni20Cu5Y10 metallic glass compacts were subjected to severe shear deformation by high-pressure torsion. High-resolution X-ray diffraction analysis and scanning electron microscopy revealed that high-pressure torsion resulted in a deformation dependent microstructure. Nanoindentation measurements indicated that the heavy shear deformation yields an increase in hardness. High-pressure calorimetry measurements revealed that hydrogen uptake in the fully amorphous alloy occurs at a significantly lower temperature compared to the fully crystallized state, while the amount of absorbed hydrogen increased considerably after shear strain due to the formation of Mg2Ni crystals.
New plant records for Tankwa Karoo National Park, South Africa
Authors: Bester Stoffel P. , Klopper Ronell R. , Steyn Hester M. , Bezuidenhout Hugo
Published: November 2012

The Tankwa Karoo National Park has been enlarged from 27 064 ha to 143 600 ha. This whole area is severely under-collected for plants in general and therefore it was an obvious target for the South African National Parks (SANParks) Programme, a component of the Pretoria National Herbarium (PRE) Plant Collecting Programme. This programme not only aims to survey national parks that have been poorly surveyed, but also inadequately known taxa, unique habitats, remote and inaccessible areas and plant species flowering at irregular times, especially after events such as fire or unusual timing of, or high, rainfall. General collecting in the Tankwa Karoo National Park has already led to the description of two new taxa, from two families. It furthermore resulted in new distribution records for the park and for the Northern Cape Province. These are reported on here.Conservation implications: Although the Tankwa Karoo National Park falls within the Succulent Karoo Biome (a biodiversity hotspot of international importance), information on its plant diversity is insufficient because it is an under-collected area. Results of this study will guide conservation and supply occurrence and distribution data required to compile management plans for the park.
Standard Operating Procedure for In-house Preparation of 131 I-rituximab for Radioimmunotherapy of Non-Hodgkin′s Lymphoma
Authors: Pickford Matthew , Turner J.
Published: November 2012

A Standard Operating Procedure (SOP) has been formulated for in-house preparation, quality control, dispensing and administration of 131 I-rituximab appropriate for the safe, effective, radioimmunotherapy of non-Hodgkin lymphoma. A decade of experience of semi-automated radioiodination of rituximab in our hospital radiopharmaceutical laboratory was analysed. The methodology was then refined for safe, practical, affordable application to radioimmunotherapy of lymphoma in departments of nuclear medicine in developing countries. This SOP has the potential to be incorporated into good laboratory practice conditions appropriate for local regulatory agency requirements.
Role of tissue engineering in dental pulp regeneration
Authors: Sial Shruti , Jurel Sunit Kumar , Singh Raghuwar D. , Gupta Durga S. , Singh Mayank
Published: November 2012

Stem cells constitute the source of differentiated cells for the generation of tissues during development, and for regeneration of tissues that are diseased or injured postnatally. In recent years, stem cell research has grown exponentially owing to the recognition that stem cell-based therapies have the potential to improve the life of patients with conditions that span from Alzheimer′s disease to cardiac ischemia to bone or tooth loss. Growing evidence demonstrates that stem cells are primarily found in niches and that certain tissues contain more stem cells than others. Among these tissues, the dental pulp is considered a rich source of mesenchymal stem cells that are suitable for tissue engineering applications. It is known that dental pulp stem cells have the potential to differentiate into several cell types, including odontoblasts, neural progenitors, osteoblasts, chondrocytes, and adipocytes. The dental pulp stem cells are highly proliferative. Collectively, the multipotency, high proliferation rates, and accessibility make the dental pulp an attractive source of mesenchymal stem cells for tissue regeneration. This review discusses fundamental concepts of stem cell biology and tissue engineering within the context of regenerative dentistry.
Effect of sodium bicarbonate air abrasive polishing on resistance to sliding during tooth alignment and leveling: An in vitro study
Authors: Filho Jorge C. B. L. , Consolmagno Andressa V. , de Araújo Cristiano M. , Brunet Marcel D. , Rosa Edvaldo A. R. , Tanaka Orlando M.
Published: November 2012

Objective: The aim of this in vitro study was to evaluate the Resistance to Sliding (RS) provided by metallic brackets and 3 types of orthodontic wires (TMA, SS and NiTi), before and after the use of sodium bicarbonate airborne particle abrasion, in an experimental model with 3 non leveled brackets. Materials and Methods: The bicarbonate airborne abrasion was applied perpendicularly to the bracket slots at a distance of 2 mm, for 5 seconds (T2) and 10 seconds (T3) on each bracket slot. In a universal testing machine, the wires were pulled through a set of 3 non leveled brackets at a cross head speed of 50 mm/min for a distance of 10 mm, and static and kinetic friction readings were registered at T1 (no airborne abrasion), T2 and T3. Results: For all tested wires, a significant RS increase between T1 and T3 (P<0.001) was seen. For SS and TMA wires, there was a statistically significant RS increase between T1 and T2 (P<0.001). Between T2 and T3, RS increase was significant for TMA (P<0.001) and NiTiwires (P<0.05). Conclusions: Sodium bicarbonate air abrasive polishing during orthodontic treatment is not recommended, once this procedure promoted a significant RS increase between the metallic brackets and all the three types of wires tested.
Qualitative research on family businesses: The relevance and usefulness of the interpretive approach
Authors: Nordqvist Mattias , Hall Annika , Melin Leif
Published: November 2012

Family business research has grown over the last decade and there are increasing requests for deeper insights into the nature and workings of these organizations. Currently, family business research is dominated by quantitative research methods. In this article, we argue that these studies should be complemented by a research approach that is more apt to capture the specific complexity and dynamics unique to family businesses. We suggest that the interpretive approach within the broader umbrella of qualitative methods has this potential. The article discusses issues, choices, requirements and implications for family business scholars engaged in interpretive research. We also offer suggestions for how editors and reviewers can assess interpretative research.
Family business leadership transition: How an adaptation of executive coaching may help
Authors: Härtel Charmine EJ , Bozer Gil , Levin Leon
Published: November 2012

Within the traditional business organizational climate in which an executive coach operates, the identity of ‘the coached’ (coachee) can be quite clearly differentiated from the business identity. This is not the case within the world of family business, where the incumbent family business leader, the successor, the business and the family culture, are interwoven. This unique feature of family business means that, for executive coaching to be effective within the family business environment, a radically different approach to that used in traditional business environments must be adopted – namely, the consideration of what generally are thought of as noneconomic variables. This article represents a first attempt to effectively address the key and unique variables executive coaches need to know to work within the family business environment.
Technical Note: The application of an improved gas and aerosol collector for ambient air pollutants in China
Authors: Dong H.-B. , Zeng L.-M. , Hu M. , Wu Y.-S. , Zhang Y.-H. , Slanina J. , Zheng M. , Wang Z.-F. , Jansen R.
Published: November 2012

Abstract. An improved Gas and Aerosol Collector (GAC) equipped with a newly designed aerosol collector and a set of dull-polished wet annular denuder (WAD) was developed based on a Steam Jet Aerosol Collector (SJAC) sampler. Combined with Ion Chromatography (IC) the new sampler performed well in laboratory tests with high collection efficiencies for SO2 (above 98%) and particulate sulfate (as high as 99.5%). An inter-comparison between the GAC-IC system and the filter-pack method was performed and the results indicated that the GAC-IC system could supply reliable particulate sulfate, nitrate, chloride, and ammonium data in field measurement with a much wider range of ambient concentrations. When applied in two major field campaigns (rural and coastal sites) in China, the GAC-IC system provided high-quality data in ambient conditions even under high loadings of pollutants. Its measurements were highly correlated with data by other commercial instruments such as the SO2 analyzer (43c, Thermo-Fisher, USA; R2 as 0.96), the HONO analyzer (LOPAP, Germany; R2 as 0.91 for samples from 15:00 to 07:00), a filter sampler (Tianhong, China; R2 as 0.86 for SO42−), and Aerosol Mass Spectrometer (AMS, Aerodyne, USA; R2 above 0.77 for major species) over a wide range of concentrations. Through the application of the GAC-IC system, it was identified that 70% of chloride and nitrate by the filter method could be lost during daytime sampling due to high temperature in the rural site of Kaiping. In Changdao field campaign (coastal site), though a particle dryer was applied, its drying efficiency was not well considered for the collection efficiency of AMS seemed still interfered a bit by local high relative humidity. If the inter-comparison was done with relative humidity below 50%, the correlations ranged from 0.81 to 0.94 for major species. Through laboratory and field studies, this instrument is proved particularly useful in future intensive campaigns or long-term monitoring stations to study various environmental issues such as secondary aerosol and haze formation, as well as climate change.
Effect of air composition (N2, O2, Ar, and H2O) on CO2 and CH4 measurement by wavelength-scanned cavity ring-down spectroscopy: calibration and measurement strategy
Authors: Nara H. , Tanimoto H. , Tohjima Y. , Mukai H. , Nojiri Y. , Katsumata K. , Rella C. W.
Published: November 2012

Abstract. We examined potential interferences from water vapor and atmospheric background gases (N2, O2, and Ar), and biases by isotopologues of target species, on accurate measurement of atmospheric CO2 and CH4 by means of wavelength-scanned cavity ring-down spectroscopy (WS-CRDS). Changes of the background gas mole fractions in the sample air substantially impacted the CO2 and CH4 measurements: variation of CO2 and CH4 due to relative increase of each background gas increased as Ar < O2 < N2, suggesting similar relation for the pressure-broadening effects (PBEs) among the background gas. The pressure-broadening coefficients due to variations in O2 and Ar for CO2 and CH4 are empirically determined from these experimental results. Calculated PBEs using the pressure-broadening coefficients are linearly correlated with the differences between the mole fractions of O2 and Ar and their ambient abundances. Although the PBEs calculation showed that impact of natural variation of O2 is negligible on the CO2 and CH4 measurements, significant bias was inferred for the measurement of synthetic standard gases. For gas standards balanced with purified air, the PBEs were estimated to be marginal (up to 0.05 ppm for CO2 and 0.01 ppb for CH4) although the PBEs were substantial (up to 0.87 ppm for CO2 and 1.4 ppb for CH4) for standards balanced with synthetic air. For isotopic biases on CO2 measurements, we compared experimental results and theoretical calculations, which showed excellent agreement within their uncertainty. We derived instrument-specific water correction functions empirically for three WS-CRDS instruments (Picarro EnviroSense 3000i, G-1301, and G-2301), and evaluated the transferability of the water correction function from G-1301 among these instruments. Although the transferability was not proven, no significant difference was found in the water vapor correction function for the investigated WS-CRDS instruments as well as the instruments reported in the past studies within the typical analytical precision at sufficiently low water concentrations (<0.7% for CO2 and <0.6% for CH4). For accurate measurements of CO2 and CH4 in ambient air, we concluded that WS-CRDS measurements should be performed under complete dehumidification of air samples, or moderate dehumidification followed by application of a water vapor correction function, along with calibration by natural air-based standard gases or purified air-balanced synthetic standard gases with the isotopic correction.
Flash flood forecasting in poorly gauged basins using neural networks: case study of the Gardon de Mialet basin (southern France)
Authors: Artigue G. , Johannet A. , Borrell V. , Pistre S.
Published: November 2012

Abstract. In southern France, flash flood episodes frequently cause fatalities and severe damage. In order to inform and warn populations, the French flood forecasting service (SCHAPI, Service Central d'Hydrométéorologie et d'Appui à la Prévision des Inondations) initiated the BVNE (Bassin Versant Numérique Expérimental, or Experimental Digital Basin) project in an effort to enhance flash flood predictability. The target area for this study is the Gardon d'Anduze basin, located in the heart of the Cévennes range. In this Mediterranean mountainous setting, rainfall intensity can be very high, resulting in flash flooding. Discharge and rainfall gauges are often exposed to extreme weather conditions, which undermines measurement accuracy and continuity. Moreover, the processes governing rainfall-discharge relations are not well understood for these steeply-sloped and heterogeneous basins. In this context of inadequate information on both the forcing variables and process knowledge, neural networks are investigated due to their universal approximation and parsimony properties. We demonstrate herein that thanks to a rigorous variable and complexity selection, efficient forecasting of up to two-hour durations, without requiring rainfall forecasting as input, can be derived using the measured discharges available from a feedforward model. In the case of discharge gauge malfunction, in degraded mode, forecasting may result using a recurrent neural network model. We also observe that neural network models exhibit low sensitivity to uncertainty in rainfall measurements since producing ensemble forecasting does not significantly affect forecasting quality. In providing good results, this study suggests close consideration of our main purpose: generating forecasting on ungauged basins.
Assymmetric eddy populations in adjacent basins – a high resolution numerical study of the Tyrrhenian and Ligurian Seas
Authors: Caldeira R. M. A. , Couvelard X. , Casella E. , Vetrano A.
Published: November 2012

Abstract. A high-resolution ocean circulation modelling system forced with a high-resolution numerical wind product was used to study the mesoscale and sub-mesoscale eddy population of the North-Western Mediterranean Sea, contrasting eddy-activity between the Tyrrhenian and Ligurian sub-basins. Numerical solutions reproduced some of the known regional dynamics, namely the occurrence and oceanic implications of Mistral events, the convective cell leeward of the Gulf of Lion, as well as the Balearic frontal system. Calculated transport across the Corsica Channel followed a similar trend, when compared to the transport computed from a moored current meter. The analysis of the results showed that surface eddy activity is mostly confined to the boundary-currents, whereas in the deeper layers most eddies are concentrated on the central-deeper part of the basins. The Liguro-Provençal basin shows a much higher concentration of intermediate and deep-water eddies, when compared to the Tyrrhenian basin. Sub-mesoscale surface eddies tend to merge and migrate vertically onto intermediate waters. Intense eddy activity in the boundary-current surrounding the Liguro-Provençal Gyre, concentrate high-productivity, manifested by higher concentrations of mean sea surface chlorophyll, in the central part of the gyre, defined herein as the Ligurian Productive Pool (LPP). On average, the Tyrrhenian was mostly oligotrophic except for a small productive vortice in the south-eastern (leeward) side of Corsica. The transport in the Tyrrhenian Gyre, and across the basin is one order of magnitude higher than the transport calculated for the Liguro-Provençal basin. A high concentration of eddies in the passage between the Balearic Archipelago and Sardinia suggests retention and longer residence times of nutrient rich water in the "Ligurian pool", compared to a "fast draining" Tyrrhenian basin. Previous studies support the cyclonic gyre circulation generated in the Liguro-Provençal basin but more studies are needed to address the surface and deep mesoscale activity of the Tyrrhenian basin.
What You Are Depends on Where You're Standing: How Expanding Refugee Protections to the Internally Displaced through the Refugee Act of 1980 Violates International Law
Authors: Pace Matthew T. Clyde
Published: November 2012

None
EFFECT OF THERMAL TREATMENT ON THE BENTONITE PROPERTIES
Authors: Orolínová Zuzana , Mockovčiaková Annamária , Dolinská Silvia , Briančin Jaroslav
Published: November 2012

The main objective of this study is to investigate the changes in structure, surface area and porosity of monomineral fraction of the local bentonite upon heating at 300, 500 and 650 °C. IR spectroscopy, DTA, XRD and N2 adsorption method were employed for the analyses. The non-heated montmorillonite was characterized by a basal spacing of 1.50 nm, after thermal treatment of 0.98 nm. This decrease was attributed to the loss of interlamellar water, finally a phase transformation occured. Changes of the crystal structure related with the decrease of the value of specific surface area and total pore volume.
Long-Term Prospective Outcomes of Intensity Modulated Radiotherapy for Locally Advanced Lung Cancer
Authors: Chun Stephen G. , Hu Chen , Komaki Ritsuko U. , Timmerman Robert D. , Schild Steven E. , Bogart Jeffrey A. , Dobelbower Michael C. , Bosch Walter , Kavadi Vivek S. , Narayan Samir , Iyengar Puneeth , Robinson Clifford , Rothman Jan , Raben Adam , Augspurger Mark E. , MacRae Robert M. , Paulus Rebecca , Bradley Jeffrey D.
Published: June 2024

Importance

The optimal radiotherapy technique for unresectable locally advanced non–small cell lung cancer (NSCLC) is controversial, so evaluating long-term prospective outcomes of intensity-modulated radiotherapy (IMRT) is important.

Objective

To compare long-term prospective outcomes of patients receiving IMRT and 3-dimensional conformal radiotherapy (3D-CRT) with concurrent carboplatin/paclitaxel for locally advanced NSCLC.

Design, Setting, and Participants

A secondary analysis of a prospective phase 3 randomized clinical trial NRG Oncology–RTOG 0617 assessed 483 patients receiving chemoradiotherapy (3D-CRT vs IMRT) for locally advanced NSCLC based on stratification.

Main Outcomes and Measures

Long-term outcomes were analyzed, including overall survival (OS), progression-free survival (PFS), time to local failure, development of second cancers, and severe grade 3 or higher adverse events (AEs) per Common Terminology Criteria for Adverse Events, version 3. The percentage of an organ volume (V) receiving a specified amount of radiation in units of Gy is reported as V(radiation dose).

Results

Of 483 patients (median [IQR] age, 64 [57-70] years; 194 [40.2%] female), 228 (47.2%) received IMRT, and 255 (52.8%) received 3D-CRT (median [IQR] follow-up, 5.2 [4.8-6.0] years). IMRT was associated with a 2-fold reduction in grade 3 or higher pneumonitis AEs compared with 3D-CRT (8 [3.5%] vs 21 [8.2%]; P = .03). On univariate analysis, heart V20, V40, and V60 were associated with worse OS (hazard ratios, 1.06 [95% CI, 1.04-1.09]; 1.09 [95% CI, 1.05-1.13]; 1.16 [95% CI, 1.09-1.24], respectively; all P < .001). IMRT significantly reduced heart V40 compared to 3D-CRT (16.5% vs 20.5%; P < .001). Heart V40 (<20%) had better OS than V40 (≥20%) (median [IQR], 2.5 [2.1-3.1] years vs 1.7 [1.5-2.0] years; P < .001). On multivariable analysis, heart V40 (≥20%), was associated with worse OS (hazard ratio, 1.34 [95% CI, 1.06-1.70]; P = .01), whereas lung V5 and age had no association with OS. Patients receiving IMRT and 3D-CRT had similar rates of developing secondary cancers (15 [6.6%] vs 14 [5.5%]) with long-term follow-up.

Conclusions and Relevance

These findings support the standard use of IMRT for locally advanced NSCLC. IMRT should aim to minimize lung V20 and heart V20 to V60, rather than constraining low-dose radiation bath. Lung V5 and age were not associated with survival and should not be considered a contraindication for chemoradiotherapy.

Trial Registration

ClinicalTrials.gov Identifier: NCT00533949
Dosing vs Assessment Intervals With Faricimab and Aflibercept
Authors: Freund K. Bailey , Bijon Jacques , Ramtohul Prithvi
Published: June 2024

This Viewpoint highlights the discrepancy between dosing and patient assessment schedules in clinical trials for 2 new intravitreal agents, faricimab, 6 mg, and aflibercept, 8 mg, to treat neovascular age-related macular degeneration.
Antibiotic Treatment and Health Care Use in Children and Adolescents With Conjunctivitis
Authors: Shapiro Daniel J. , Geanacopoulos Alexandra T. , Subramanian S. V. , Wu Ann Chen , Bardach Naomi S. , Oke Isdin
Published: June 2024

This cohort study examines ambulatory care revisits and same-day topical antibiotic prescription in insured patients with acute infectious conjunctivitis.