bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects on the Bending Strength of Metal-Bonded Diamond Segments in DEM Simulation
Authors: Chen Xiu Yu , Yu Yi Qing , Xu Xi Peng
Published: July 2011

An attempt was taken to simulate the bending strength of diamond impregnated segments in three point bending tests by using a discrete element method (DEM). The influences of main bond matrix components (Fe and Cu), the porosity in the matrix, the coefficient of friction among the matrix particles, and the connection strength between abrasive particles and matrix particles on the bending strength were investigated through simulation. It is found that the bending strength increases with the proportion of Fe but decreases with the increase of porosity. An increase in both the friction coefficient of the matrix particles and the bonding strength between the diamond grains and metal matrix particles can also lead to the increase of bending strength.
Microstructural Property of Silicon Thin Films Deposited on Nanodiamonds Related to QALD Growth Condition
Authors: Lu Jing , Wang Yan Hui
Published: July 2011

Quasi atomic layer deposition method has been successfully used to coat detonation nanodiamonds with ultrathin silicon film from decomposition of gaseous monosilane. Transmission electron microscopy observation indicates a continuous silicon coating could be obtained on every individual particle of nanodiamonds. The changes in the microstructural property of silicon thin films deposited at the temperatures of 400, 450, 500, 550, and 600 °C have been characterized by Raman spectroscopy, X-ray diffraction and Energy dispersive spectroscopy techniques. The results show the phase transition of as-deposited silicon from a crystalline to an amorphous then to a crystalline phase with the temperature increase.
Fabrication and Applications of Ultra-Smooth Composite Diamond Coated WC-Co Drawing Dies
Authors: Shen Bin , Sun Fang Hong , Zhang Zhi Ming , Shen He Sheng , Guo Song Shou
Published: July 2011

Micro/nano-crystalline multilayered ultra-smooth diamond (USCD) films are deposited on the interior-hole surface of conventional WC-Co drawing dies with a combined process consisting of the hot filament chemical vapor deposition (HFCVD) method and polishing technique. Scanning electron microscopy (SEM), surface profilemeter, Raman spectroscopy and X-ray diffraction (XRD) are employed to provide a characterization of as-deposited USCD films. The results exhibit that as-deposited USCD films present an ultra-smooth surface, its surface roughness values (Ra) in the entry zone, drawing zone and bearing zone are measured as 25.7 nm, 23.3 nm and 25.5 nm respectively. Furthermore, the working lifetime and performance of as-fabricated USCD coated drawing dies are examined in producing copper tubes with hollow sinking, fixed plug and floating plug. The results show that the lifetime of USCD coated drawing is as more than 30 times as that of WC-Co drawing dies in the drawing process with hollow sinking, 7 times in the fixed plug drawing and 10 times in the floating drawing.
Study on Fabrication and Cutting Performance of CVD Diamond Coated Drills in Machining the Carbon Fiber Reinforced Plastics
Authors: Zhang Jian Guo , Shen Bin , Sun Fang Hong
Published: July 2011

Carbon fiber reinforced plastics (CFRP) have been widely used for manufacturing spacecraft, aircraft and automobile structural parts in aerospace and automotive industries. However, CFRP is a kind of hard machining materials and conventional tungsten carbide drills always experience severe tool wear, and thus short lifetime in the CFRP drilling process. In this paper, the CVD diamond films are deposited on the surface of cobalt cemented tungsten carbide (WC–Co) drills using hot filament chemical vapor deposition (HFCVD) method. Scanning electron microscope (SEM) is adopted to investigate the surface morphology of as-fabricated CVD diamond coated drills, additional analysis using Raman spectrum also indicates the high purity of sp3 phase of as-deposited diamond film. Furthermore, the machining performance of as-fabricated CVD diamond coated drills is examined in drilling the CFRP, comparing with the uncoated WC-Co drills. The chisel edge and primary cutting edge wear of drills are studied using the tool microscope. The results show that as-fabricated CVD diamond coated drills exhibit a much elongated lifetime than that of uncoated WC-Co drills, and also smoother surface finish of machined holes, which is supposed to be attributed to the excellent wear resistance and satisfied adhesive strength between the as-deposited diamond films and drills.
The Study of Electrochemical Polishing HVOF Spraying Coating
Authors: Li Wei Hua , Zhang Yong Jun , Song Xiao Zhong
Published: July 2011

HVOF WC-Co spraying coating can enhance greatly the anti-wear performance of workpiece, but it is just the high hardness of spraying coatings that makes the polishing of workpiece very difficult, the application of HVOF was limited. In this paper, we discuss the feasibility of apply ECP(electrochemical polishing) to spraying coatings, include the study of electrolyte, the optimization of machining parameters et al., the experiment results show that it is not only feasible that apply ECP to machining spraying coatings, but also high machining efficiency, high quality surface can be obtained. The surface roughness can be reduced from Ra=4.0μm to Ra=0.7μm with suitable machining parameters during a very short time.
Hardness Improvement of Welded Joint by Laser Weld Technology
Authors: Liu Gui Jie , Wang Xin , Li An Jin
Published: July 2011

In offshore jacket platforms, the structural steels are widely used and usually welded connected. This paper presents the welding of 45# steel plate by LER-3 YAG Pulse Laser. Experiments are carried out to investigate the performance of the welded joint under different process parameters and working conditions. In details, microstructure and macro-morphology in the laser-affected area are analyzed and the micro hardness of the specimens is tested. The results show that: (a) the performance of the welded joint can be improved by the optimization of process parameters, (b) the welding area has the closest grained, the heat affected zone is isometric crystal, (c) the martensite can be reduced by increasing the heat, (d) the grain can be greatly refined by properly increasing the scan speed and decreasing the laser power supply, and that (e) the mean value of the hardness (420HV) in the welded area is obviously higher than that of the substrate (205.12HV) and the highest hardness (492.32HV) appears in the heat affected area.
CFRP Drilling with Brazed Diamond Core Drill
Authors: Mu Juan , Xu Jiu Hua , Chen Yan , Fu Yu Can
Published: July 2011

Despite the facts that carbon fiber reinforced plastics (CFRP) components are mostly produced near net shape, machining, especially drilling is often required in order to bring the component into dimensional requirements and prepare it for assembly. Rapid drill wear and serious machining defects are the key problems in CFRP drilling, and employing proper drill is an effective way to solve these problems. In this paper, tests of the brazed diamond core drill are presented and the related issues, such as the thrust force, the drilling quality and the drill wear are studied.
Predicting Surface White Layer in Precision Hard Turning
Authors: Chen Tao , Zhang Ming Jun , Liu Xian Li
Published: July 2011

With the advantage of neural network in dealing with non-linear problem, this paper has established a BP artificial neural network model of non-linear mapping for tool parameters, cutting parameters and white layer depth value in precision hard turning. Results indicate that the model is of high accuracy and of extensive ability to deal with problem, and can accurately predict surface whiter layer in precision hard turning. This research will provide essential help for selection of cutting parameter and tool parameter.
Development Evaluation of Mechanical Properties of Brazed Diamond Wire
Authors: Li Yong Peng , Huang Hui , Xu Xi Peng
Published: July 2011

Fixed-abrasive wire saw, with its ability to cut hard brittle material, such as silicon ingots, crystals and quartz, has emerged as a leading technology for production in semiconductor and photovoltaic industry. There are some defects in conventional fixed-abrasive wire saw such as significant low holding abrasive ability, low machining efficiency, high running costs, etc. A new fixed-abrasive wire, namely brazed diamond wires have been developed to overcome these problems. In this paper, brazed diamond wire were carried out to braze two different size diamond grits onto two different thin steel wires by using a nickel-based powder as brazing alloy. The mechanical properties of brazed diamond wire were evaluated by tensile and breaking twist experiment. The experimental results showed that the heating in the brazing process has litter influence on the wire mechanical properties. The addition of brazed alloy and diamond grits sharply decreased the wire mechanical properties significantly, both in the tensile strength and breaking twist angle. Bigger diamond grit would make the accumulation of brazed alloy which leaded to the deterioration of diameter consistency of wires.
Measurement of Forces in Shearing Brazed Diamonds
Authors: Su Zhen Fa , Huang Guo Qin , Huang Hui , Guo Hua , Xu Xi Peng
Published: July 2011

In order to assess the bonding of brazing alloys to diamonds, an investigation was conducted to measure the forces while shearing brazed diamonds. A device was designed to shear diamonds and shearing forces were recorded under different brazing parameters. The morphologies of diamonds were followed before and after shearing. It is found that the shearing force reduces with the increase of grit protrusion height. For specific grit protrusion, shearing forces decrease with the increase of holding time in brazing.
A Comparative Study: Tool Life and Wear of Thin-Walled Monolayer Brazed Diamond Core Drill Fabricated with Ni-Cr and Ag-Cu-Ti Alloy
Authors: Su Hong Hua , Fu Yu Can , Chen Yan , Xu Jiu Hua , Ding Wen Feng
Published: July 2011

Monolayer brazed diamond tools, which are high bonding strength at the interface between brazing alloy and grits, are becoming the active field in which improvements in processing and advanced products can be anticipated. Some researchers proposed brazing diamond methods with Ni-Cr and Ag-Cu-Ti alloy, but there is a shortage of the comparative study of the characteristics of the brazed diamond tools fabricated with the different brazing alloy. In this paper, machining performance experiments have been carried out, including contrast tests about tool life and machining efficiency for thin-walled monolayer brazed diamond core drills fabricated with Ni-Cr and Ag-Cu-Ti alloy. The results show that the Ag-Cu-Ti alloy can improve the machining performance. Wear mechanism of diamond grits was studied in those drilling processes. The results show that the low ratio of grit breakdown of the core drill using Ag-Cu-Ti alloy is the key factor of its longer life. Furthermore, based on the experimental results, the areas of the grits wear flat increase the feed force, and decrease the machining efficiency.
Analysis of Grit Cut Depth in Fixed-Abrasive Diamond Wire Saw Slicing Single Crystal Silicon
Authors: Gao Yu Fei , Ge Pei Qi
Published: July 2011

A mathematical model to calculate the grit average cut depth in wire sawing single crystal silicon was founded. So the grit average cut depths were calculated theoretically by choosing different process parameters, and influences of process parameters on grit cut depths of slicing silicon crystal were analyzed. Analysis results indicate that the grit average cut depth relates to the silicon mechanical properties, grit shape and size, wire speed and ingot feed speed, etc. And there is a monotone increasing non-linear correlation between grit average cut depth and the ratio i value of ingot feed speed and wire speed, when the i value is lower, the average grit cut depth is lower.
Research on the Mechanical Properties of CaF2 Crystal for Ultra-Precision Machining
Authors: Chen Ming Jun , Jiang Wen Bin , Cheng Jian , Chu Xin
Published: July 2011

Indentations on the main crystallographic plane (111) of CaF2 were analyzed. Appropriate material parameters were obtained by experiments. The process of CaF2 indentations had been investigated by the finite element approach in order to obtain the initial shear yield strength. The results show a value of 110 MPa for the initial shear yield strength. Vickers hardness of plane (111) was also investigated. The results show the dependence on the orientation of the CaF2 crystal. The hardness is small at the angular direction 0° and 120°, and at the angular direction 60°, the hardness of the largest value is 1.67GPa. The Young’s Modulus and Fracture Toughness are also obtained. These properties are valuable to the ultra-precise machining of CaF2 crystal.
Material Removal Distribution of Chemical Mechanical Polishing by the Bionic Polishing Pad with Phyllotactic Pattern
Authors: Lu Yu Shan , Wang Jun , Li Nan , Zhang Tian , Duan Min , Xing Xue Ling
Published: July 2011

In order to make the material removal distribution on polishing silicon surface more non-uniform during the chemical mechanical polishing (CMP), a kind of the bionic polishing pad with phyllotactic pattern has been designed based on phyllotaxis theory, and by polishing experiment, the effects of the phyllotaxis parameters on material removal distributions on silicon wafer surfaces are investigated. The research results show that the material removal distribution of polishing silicon surface more uniform and the edge rounding of polishing wafer can be decreased when the phyllotaxis parameters of the polishing pad are reasonably selected.
The Effects of the Geometric Parameters of Segmented Sawblades on the Fluctuated Temperatures in Sawing
Authors: Fang Cong Fu , Huang Hui , Xu Xi Peng
Published: July 2011

The effects of the geometric parameters of a sawblade on the sawing fluctuated temperatures were analyzed based on a fluctuated temperature model advanced in my recent paper. The results show that the sawing temperatures are fluctuated only near the workpiece surface in the sawing zone, the blade segment ratio, the number of segments and the contact angle have great influence on the sawing temperatures, which has the guiding significance for optimal design of the sawblade structure.
Weldability of the MSRB Magnesium Alloy
Authors: Adamiec Janusz
Published: July 2011

This work, in combination with industrial tests of casting welding, shows that the causes of high-temperature brittleness are the partial tears of the structure and the hot cracks of both the castings, as well as the welded and padded joints. Such phenomena should be treated as irreversible failures caused by the process of crystallization that is in the area of co-existence of the solid and liquid structural constituent. Nil-strength temperature (NST), nil-ductility temperature (NDT) and ductility recovery temperature (DRT) were determined using Gleeble 3800. Obtained results enabled the defining of brittle temperature range of MSR-B magnesium alloy. The assessment of the resistance to hot fractures was conducted on the basis of the transvarestriant trial. The transvarestriant trial involves changing of strain during welding. It was stated that the range of the high-temperature brittleness is very broad, which significantly limits the application of the welding techniques to join or repair elements made of the MSRB alloy. brittleness is caused mainly by metallurgical factors, i.e. precipitation of intermetallic phases from the solid solution.
Bayern`s Method of Al2O3 Production – Possibilities of Red Mud Disposal and Utilization
Authors: Saternus Mariola
Published: July 2011

Bayern`s method is the first stage of obtaining primary aluminium. The product of this process is alumina. The paper presents how much alumina was produced in the last couple of years and who were its leading producers. As the main ore for alumina production is bauxite; it was necessary to describe its characteristics: chemical composition and types of bauxites. Short description of the method (digestion, precipitation and calcination) was presented. During this process a lot of pollution is usually emitted to the atmosphere, but mostly a lot of red mud is generated. This is the main waste of the process, which at the same time is very harmful to the environment. The ways red mud is disposed or utilized were reviewed. Two kinds of red mud disposal are known: wet and dry disposal. Both were characterized and their advantages and disadvantages were outlined. The possibilities of red mud utilization were shown. The focus was put on iron recovery or recovery of compounds such as Al2O3 or TiO2. The use of red mud in building materials was discussed. Radioactivity of such materials was also analyzed. Possibility of red mud utilization as a pigment and radiopaque material was also mentioned.
Deformation of Ti-6Al-4V Alloy with Carbon
Authors: Szkliniarz Agnieszka
Published: July 2011

This paper presents the results from investigations on the effect of temperature and strain rate on the shape of the stress-strain curves, the peak flow stress and microstructure of Ti-6Al-4V alloy with carbon (0.7–0.8 wt%) that were axisymmetrically compressed on a thermo-mechanical simulator Gleeble 3800. Conditions under which the alloy deformation proceeded without cracking were determined. The obtained results were verified by industrial open die forging tests.
Microstructure and Mechanical Properties of Aluminum Processed by Multi-Axial Compression
Authors: Rodak Kinga , Radwański Krzysztof , Molak Rafal M.
Published: July 2011

. In this study, commercial Al was subjected to plastic deformation by multi-axial compression. The microstructure and mechanical properties in dependence on effective strain were studied. Aluminum was processed to effective strain f = 9.6. The misorientation distribution and subgrain/grain size were analyzed by using a scanning electron microscopy (SEM) equipment with electron back scattered diffraction (EBSD) facility. The dislocation microstructure was investigated by a scanning transmission electron microscope (STEM). The mechanical properties as: yield strength (YS), ultimate tensile strength (UTS), uniform and total elongation were performed on MTS QTest/10 machine equipped with digital image correlation method (DIC). Deformation of Al by the multi-axial compression leads to grain refinement to ultra-fine grains (UFGs) and improvement in strength properties. Material exhibits the following strength parameters: UTS: 129 MPa, YS: 124 MPa after deformation at f = 9.6. These values are about two times higher compared with initial state.
Microstructure and Properties of Sand Casting Magnesium Alloys for Elevated Temperature Applications
Authors: Kiełbus Andrzej
Published: July 2011

It is required of sand casting magnesium used for aircraft industry to be, among others, increasingly creep-resisting. This paper describes microstructure and properties of chosen magnesium sand casting alloys, intended for usage at ambient and elevated temperature. The first part describes the most popular magnesium alloy Mg-9Al-1Zn (AZ91), which, due to the presence of Mg17Al12 phase in its structure, can be used only up to the temperature of ~120°C. The second part describes Mg-5Y-4RE-Zr (WE54) alloy, which can be used at the temperature of up to ~250°C. Unfortunately, its usage is very limited due to high price. The third part characterizes Mg-3Nd-1Gd-Zr (EV31A) alloy, which has properties similar to Mg-5Y-4RE-Zr alloy, but lower price. This paper also discusses the potential applications of these alloys.
Ancillary Studies in Determining Human Papillomavirus Status of Squamous Cell Carcinoma of the Oropharynx: A Review
Authors: Cantley Richard L. , Gabrielli Eleonora , Montebelli Francesco , Cimbaluk David , Gattuso Paolo , Petruzzelli Guy
Published: July 2011

Squamous cell carcinoma (SCC) of the oral cavity and pharynx represents the sixth most common form of malignancy worldwide. A significant proportion of these cases are related to human papillomavirus (HPV) infection. In general, HPV-associated SCC is more commonly nonkeratinizing and poorly differentiated, whereas non-HPV-associated SCC is typically keratinizing and moderately differentiated. Nevertheless, significant overlap in morphology is seen between these two forms of SCC. The purpose of this paper is to highlight the utility of ancillary studies in the establishment of HPV status of oropharyngeal SCC, including p16 immunohistochemistry, high-risk HPV in situ hybridization, polymerase chain reaction, and newer HPV detection modalities.
Persistent Penumbra in a Rabbit Stroke Model: Incidence and Histologic Characteristics
Authors: Hennings Leah J. , Flores Rene , Roberson Paula K. , Brown Aliza , Lowery John , Borrelli Michael , Culp William C.
Published: July 2011

Duration and extent of penumbra determine the window and brain volume in which interventions may save injured tissue after stroke. Understanding the penumbra in animals is necessary in order to design models that translate to effective clinical therapies. New Zealand white rabbits were embolized with aged autologous clot (n=23) or insoluble microspheres (n=21). To examine effects of treatment on penumbra, sphere-stroked animals were treated with 3 μm microbubbles plus ultrasound (n=19). Rabbits were euthanized at 4 or 24 hr. Infarct volume was measured following triphenyltetrazolium chloride (TTC) staining of brain sections. Penumbra was visualized using immunostaining of pimonidazole injected fifteen minutes prior to euthanasia. Potentially reversible penumbra was present in 14.3% stroked rabbits at 4 hours and 15.7% at 24 hours after embolic stroke and represented up to 35% of total lost tissue. Intervention at up to 24 hours may benefit a significant patient population.
Review of Tolvaptan in the Treatment of Hyponatremia
Authors: Garcha Amarinder S. , Khanna Apurv
Published: July 2011

Hyponatremia is a very common electrolyte disorder and is a significant independent predictor of medical prognosis and costs. Tolvaptan is a vasopressin receptor antagonist developed for the treatment of hyponatremia. It has its principal application in the treatment of euvolemic and hypervolemic hyponatremia. Its major role is in the treatment of heart failure (HF), cirrhosis and the syndrome of inappropriate antidiuretic hormone secretion (SIADH). While at present tolvaptan has not demonstrated long term survival benefit with its use, it clearly has proven short term efficacy in the management of hyponatremia by demonstrating improvement in serum sodium levels at an acceptable rate without evidence of over-correction.
Tadpoles and commutative spectral triples
Authors: Iochum Bruno , Levy Cyril
Published: July 2011

Using the Chamseddine–Connes approach of the noncommutative action on spectral triples, we show that there are no tadpoles of any order for compact spin manifolds without boundary, and also consider a case of a chiral boundary condition. Using pseudodifferential techniques, we study noncommutative integrals in commutative geometries.
Hopf action and Rankin–Cohen brackets on an Archimedean complex
Authors: Banerjee Abhishek
Published: July 2011

The Hopf algebra

\mathcal H_1

of “codimension 1 foliations”, generated by operators

X

,

Y

and

\delta_n

,

n\geq 1

, satisfying certain conditions, was introduced by Connes and Moscovici in [1]. In [2], it was shown that, for any congruence subgroup

\Gamma

of SL

_2(\mathbb Z)

, the action of

\mathcal H_1

on the “modular Hecke algebra”

\mathcal A(\Gamma)

captures classical operators on modular forms. In this paper, we show that the action of

\mathcal H_1

captures the monodromy and Frobenius actions on a certain module

\mathbb B^*(\Gamma)

that arises from the Archimedean complex of Consani [4]. The object

\mathbb B^*(\Gamma)

replaces the modular Hecke algebra

\mathcal A(\Gamma)

in our theory. We also introduce a “restricted” version

\mathbb B^*_r(\Gamma)

of the module

\mathbb B^*(\Gamma)

on which the operators

\delta_n

,

n\geq 1

, of the Hopf algebra

\mathcal H_1

act as zero. Thereafter, we construct Rankin–Cohen brackets of all orders on

\mathbb B^*_r(\Gamma)

.
Symmetries of the Generalized Variational Functional of Herglotz for Several Independent Variables
Authors: Georgieva Bogdana
Published: July 2011

This paper provides a method for calculating the symmetry groups of the functional defined by the generalized variational principle of Herglotz in the case of several independent variables. Examples of calculating variational symmetry groups are given, including those for the non-conservative nonlinear Klein-Gordon equation, and for the equations describing the propagation of electromagnetic fields in a conductive medium.
On Compactness of Minimizing Sequences Subject to a Linear Differential Constraint
Authors: Krömer Stefan
Published: July 2011

For

\Omega\subset \mathbb R^N

open, we consider integral functionals of the form

F(u):=\int_\Omega f(x,u)\,dx,

defined on the subspace of

L^p

consisting of those vector fields

u

which satisfy the system

\mathcal{A} u=0

on

\Omega

in the sense of distributions. Here,

\mathcal{A}

may be any linear differential operator of first order with constant coefficients satisfying Murat's condition of constant rank. The main results provide sharp conditions for the compactness of minimizing sequences with respect to the strong topology in

L^p

. Although our results hold for bounded domains as well, our main focus is on domains with infinite measure, especially exterior domains.
An Approximation Result in Generalized Anisotropic Sobolev Spaces and Applications
Authors: Bendahmane Mostafa , Chrif Moussa , El Manouni Said
Published: July 2011

In this paper, we give an approximation result in some anisotropic Sobolev space. We also describe the action of some distributions in the dual and we mention two applications to some strongly nonlinear anisotropic elliptic boundary value problems.
Occupational Therapy Students' Choice of Client Activities: Does Patients' Gender Matter?
Authors: Liedberg Gunilla , Hensing Gunnel
Published: July 2011

Aim:

In order to achieve a fairer system of health care, it is important that the research and education of health professionals, as well as the organisation of health care, takes into account the gender perspective. The gender order influences women's and men's lifestyles and living conditions and, through this, their health, quality of life and daily activities. The aim of the present study was to explore the perceptions of gender in occupational therapy students in their choice of activities: do students choose activities according to traditional roles?

Method:

The method was a fictional case study containing 16 activities. Each student was given a copy of one of the versions of the case, Eric or Erica. The students were told to underline the three activities regarded as being of most benefit for the actual patient. Eight male and 99 female students participated.

Results:

The most chosen activities were cooking, visits to cafeterias and gardening, and the least chosen were spinning, laundry and computer work. The results showed that the students made choices based on traditional gender roles.

Conclusion:

Extended knowledge is needed about how gender is constructed in occupational therapy, and about whether gendered choices contribute to a prolonged period of treatment or rehabilitation, or the opposite.
Convergent Validity of Two Visual Motor Integration Tests
Authors: Brown Ted , Chinner Alex , Stagnitti Karen
Published: July 2011

Background:

Occupational therapists often assess visual motor integration (VMI) skills. It is, therefore, imperative that therapists use VMI tests with robust measurement properties.

Objective:

This study examined the convergent validity of two VMI tests used to assess children, adolescents and adults.

Method:

Three groups of healthy participants (n = 153) completed the Beery-Buktenica Developmental Test of Visual-Motor Integration (DTVMI) and the Full Range Test of Visual Motor Integration (FRTVMI). Seventy-three children aged 5–10 years (37 males and 36 females; mean age 7.5 years, SD = 2.20), 19 adolescents aged 11–17 years (8 males and 11 females; 13.1 years, SD = 2.16), and 61 adults (18 males and 43 females; mean age 31.82 years, SD = 11.20) completed the DTVMI and the FRTVMI. Spearman rho correlation coefficients were used to investigate whether each pair of the VMI test scores for each of the three participant age groups were associated.

Results:

The Spearman rho correlation coefficients between all three versions of the DTVMI and FRTVMI were statistically significant. For the child group, the correlation coefficient was rho = 0.70 (p<0.000), while the correlation between the VMI scores obtained by the adolescent group on the two tests was rho = 0.77 (p<0.000). For the adult participant group, the correlation coefficient between the DTVMI and the FRTVMI was rho = 0.70 (p<0.000).

Conclusion:

The VMI scores obtained by the three participant age groups on the DTVMI and the FRTVMI were all significantly correlated with each other. Overall, the DTVMI and the FRTVMI exhibited large levels of convergent validity with each other, indicating that the two tests appear to measure similar visual-motor integration constructs.
Large ancient organic matter contributions to Arctic marine sediments (Svalbard)
Authors: Kim J.-H. , Peterse F. , Willmott V. , Kristensen D. Klitgaard , Baas M. , Schouten S. , Sinninghe Damsté J. S.
Published: July 2011

Soils, fine‐grained ice‐rafted detritus (IRD), coals, and marine surface sediments in the Arctic realm (Svalbard) were collected in 2007 and 2008 to characterize organic matter (OM) sources in Arctic marine sediments. Bulk geochemical (C : N ratio and stable carbon isotopic composition) parameters suggest a predominant marine contribution to sedimentary OM. The branched and isoprenoid tetraether index (a proxy of soil OM input) indicates that soil OM contribution to the marine sediments is minor. However, the presence of retene (used as an indicator for coal‐derived OM), the low carbon preference index and the average chain length of n‐alkanes, and the depleted bulk radiocarbon content (Δ14C value) suggest that ancient OM of both coal‐derived and mature IRD‐derived OM is being buried in the Kongsfjord–Krossfjord system of Svalbard in the high Arctic. The relatively low retene concentrations in the marine surface sediments other than those in close vicinity of Ny Ålesund, previously a coal‐mining town, indicated that input of IRD‐derived OM was predominantly responsible for the generally low Δ14C value. We applied three‐end‐member models based on Δ14C and retene and n‐alkane concentration data to disentangle relative coal‐derived, IRD‐derived, and marine OM proportions to sedimentary OM. Sediments were comprised on average 2% ± 4% of coal‐derived OM, 37% ± 17% of IRD‐derived OM, and 61% ± 18% of marine OM with higher IRD‐derived OM deposit in the Kongsvegen glacier front. Our results highlight the important role of ancient OM on carbon dynamics in Arctic environments, in particular for benthic food webs.
Carbon and nitrogen dynamics in shallow photic systems: Interactions between macroalgae, microalgae, and bacteria
Authors: Hardison A. K. , Anderson I. C. , Canuel E. A. , Tobias C. R. , Veuger B.
Published: July 2011

We tracked carbon (C) and nitrogen (N) uptake into sediments in the presence and absence of benthic macroalgae using dual stable isotope tracers in combination with compound‐specific isotope analyses of hydrolyzable amino acids and phospholipid‐linked fatty acids to quantify the uptake and retention of C and N within bulk sediments, benthic microalgae (BMA), and heterotrophic bacteria. Stable isotope tracers (as 15NH+4 and H13CO−3) were added to mesocosms either via the surface water or pore water for the first 14 d of the 42‐d experiment. Macroalgae and sediments exposed to ambient light and dark cycles rapidly took up label from both sources and retained label for at least 4 weeks after isotope additions ended. BMA dominated sediment uptake of 13C and 15N, initially accounting for 100% of total uptake. Over time, heterotrophic bacterial uptake became relatively more important, increasing from 0% on day 1 to 20–50% on day 42, indicating a close coupling between BMA and bacterial production. In treatments with macroalgae, sediment 13C and 15N uptake was ∼ 40% lower than treatments without macroalgae, likely because of shading of the sediment surface by macroalgae, which decreased BMA production, which in turn decreased bacterial production. Overall, sediments served as a sink for C and N through uptake and retention by the microbial community, but retention was lower in the presence of macroalgae.
Active prey rejection in the filter‐feeding appendicularian Oikopleura dioica
Authors: Lombard F. , Selander E. , Kiørboe T.
Published: July 2011

We describe different modes of prey rejection in a filter‐feeding appendicularian, Oikopleura dioica. Nonselective prey rejection occurs by intermittent rejection through reversal of the feeding current of all particles when the pharyngeal filter is overloaded, and by accidental loss through the spiracles of all particles that have entered the house when the pharyngeal filter occasionally breaks. In addition, selective prey rejection of individual particles may occur in the mouth by reversal of the ciliary current in the spiracle: the unwanted particle is expelled with a small amount of water. Up to four rejections of individual particles may occur per second. This active rejection is based on both the size and the chemical characteristics of the individual particle. A significantly higher rejection rate was found for toxic dinoflagelate (68%) compared to similar sized nontoxic ones (34%); exponentially growing algae were less rejected than senescent ones; and nutrient‐depleted algae were more rejected than nutrient‐replete cells. For nontoxic particles, prey size relative to the size of the appendicularian was the main prey selection criterion and the optimal prey size (> 80% acceptance) for O. dioica is between 0.4% and 2% of their own size, whereas the minimum and maximum particle sizes that they can ingest range from 0.04% to 20% of their own size. This prey size spectrum is much broader than that found in most other planktivorous organisms and demonstrates that appendicularians are simultaneous microphageous and macrophageous planktonic grazers.
Model of Broadcasting as a Model for Local Media: Distinctiveness with Market Orientation
Authors: Žilič Fišer Suzana , Medina Mercedes
Published: July 2011

The idea of satisfying cultural and economic dimensions of a society is the crucial issue of modern media in local environment. Management of local media organizations has become a very complex process. It is inevitable to anticipate different interests, technological changes, changes in regulation, political changes and different societal trends. The paper explores the issue of confrontation between public interest, and economic success of media organisation, and management approaches to fulfil the economic success and social responsibility at the same time. The case of Channel 4, public service broadcaster in UK, explains why it is important to attract a broader range of viewers with its programmes while still catering for minorities with new digital services. The idea of Channel 4 will be examined as a possible broadcasting model for a local media environment.
Development and characterization of a single particle laser ablation mass spectrometer (SPLAM) for organic aerosol studies
Authors: Gaie-Levrel F. , Perrier S. , Perraudin E. , Stoll C. , Grand N. , Schwell M.
Published: July 2011

Abstract. A single particle instrument has been developed for real-time analysis of organic aerosols. This instrument, named Single Particle Laser Ablation Mass Spectrometry (SPLAM), samples particles using an aerodynamic lens system for which the theoretical performances were calculated. At the outlet of this system, particle detection and sizing are realized using two continuous diode lasers operating at λ = 403 nm. Polystyrene Latex (PSL), sodium chloride (NaCl) and dioctylphtalate (DOP) particles were used to characterize and calibrate optical detection of SPLAM. The optical detection limit (DL) and detection efficiency (DE) were determined using size-selected DOP particles. The DE is ranging from 0.1 to 90 % for 100 and 350 nm DOP particles respectively and the SPLAM instrument is able to detect and size-resolve particles as small as 110–120 nm. Scattered light is detected by two photomultipliers and the detected signals are used to trigger a UV excimer laser (λ = 248 nm) used for laser desorption ionization (LDI) of individual aerosol particles. The formed ions are analyzed by a 1 m linear time-of-flight mass spectrometer in order to access to the chemical composition of individual particles. The TOF-MS detection limit for gaseous aromatic compounds was determined to be 0.85 attograms. DOP particles were also used to test the overall functioning of the instrument. The analysis of a secondary organic aerosol, formed in a smog chamber by the ozonolysis of indene, is presented as a first scientific application of the instrument. Single particle mass spectra are obtained with a global hit rate of 10 %. They are found to be very different from one particle to another, reflecting chemical differences of the analyzed particles, and most of the detected mass peaks are attributed to oxidized products of indene.
The choice of the concept of magnetic field lines or of electric current lines: Alfvén medal lecture
Authors: Akasofu S.-I.
Published: July 2011

Abstract. In 1967, at the Birkeland Symposium in Sandefjord, Norway, Professor Hannes Alfvén stated that the second approach (in solving unsolved problems by the standard MHD theory) to cosmic electrodynamics is to "thaw" the "frozen-in" magnetic field lines. "We can illustrate essential properties of the electromagnetic state of space either by depicting the magnetic field lines or by depicting electric current lines," he said. There has been much progress in space physics since the Birkeland Symposium more than 40 years ago, but unfortunately our scientific community has not really succeeded in thawing the frozen-in field lines. Instead, it has pursued magnetic reconnection, a concept that Alfvén had been critical of. It is shown here that we have to study many unsolved problems and problems thought to be solved in terms of both the magnetic field line concept and the current system concept. In taking Alfvén's approach, we must consider the whole system, including the power supply (dynamo process) and its transmission and distribution (electric currents) and observed phenomena (power dissipation processes). Such a consideration can provide physical insight into many of our unsolved problems and problems thought to be solved. In this paper, we consider substorm onset processes, the substorm current system, sunspots, solar flares, coronal mass ejections, the interplanetary current sheet, and the magnetic field configuration of the heliosphere in terms of the current system concept. In particular, it is shown that a study of the current system is essential in substorm studies, more than changes of the magnetic field configuration in the magnetotail.
Pure SILS Floppy Nissen Fundoplication with Hiatal Repair: A Case Report
Authors: Barbaros Umut , Demirel Tugrul , Sumer Aziz , Deveci Ugur , Tukenmez Mustafa , Cansunar Mehmet Ibrahim , Kalayci Murat , Dınccag Ahmet , Seven Ridvan , Mercan Selcuk
Published: July 2011

Background. Single-incision laparoscopic surgery has recently became popular on behalf of inventing less invasive procedures. In this paper, we present a case of Pure SILS Nissen Fundoplication. Patient and Methods. In February 2010 a 29-year old male patient with a 4 cm sliding hiatus hernia presenting with reflux symptoms had undergone a standard floppy Nissen Fundoplication with a hiatus repair via single 2 cm incision in umbilicus. Results. The procedure had obeyed the standard natural orifice surgery rules, and no needlescopic assistance for any stage of the operation was used so to be a pure single-incision procedure. The operation lasted for 120 minutes without any need of conversion, and the patient was discharged the following day of operation. Conclusion. In the recent time, hybrid single incision laparoscopy techniques have been defined with the use of extra-abdominal supplements for retraction of liver or stomach for Nissen procedure. In addition the main issue in single-incision upper GI and/or hiatus surgery is still the retraction of liver. We succeeded to retract the left lobe of liver through the incision and completed the operation without any need for supplemental access besides the umbilical incision till the end. SILS Hiatus Surgery can be safely and effectively done but the issue needs further clinical studies to state the efficacy when compared to standard laparoscopy.
Aerosol‐Spraying Synthesis of Periodic Mesoporous Organometalsilica Spheres with Chamber Cavities as Active and Reusable Catalysts in Aqueous Organic Reactions
Authors: Zhang Fang , Kang Chunmei , Wei Yongyi , Li Hexing
Published: July 2011

Organometal‐bridged periodic mesoporous catalysts with uniform spheres containing cavities in chambers were synthesized by rapid aerosol‐spray assisted co‐condensation between organometallic silane and tetraethoxysilane (TEOS) in the presence of cetyltrimethyl ammonium bromide (CTAB) and NaCl double templates. The as‐prepared M‐PPh2‐PMO(H) catalysts (M = Pd2+, Rh+ and Ru2+) were used in various water‐medium organic reactions with the aim of diminishing environmental pollution from organic solvents. These catalysts exhibited high catalytic activities and selectivities owing to the high surface area, the uniform distribution of active sites, the ordered mesoporous channels and especially, the cavities as microreactors which facilitated the diffusion and adsorption of organic reactants. Meanwhile, they also displayed strong durability and could be used repeatedly owing to the organometals incorporated into silica walls and the presence of chamber cavities which could effectively protect the ordered mesoporous structure from damage and also inhibit the leaching of active sites.
Vibrationally Assisted Polariton‐Relaxation Processes in Strongly Coupled Organic‐Semiconductor Microcavities
Authors: Coles David M. , Michetti Paolo , Clark Caspar , Tsoi Wing Chung , Adawi Ali M. , Kim Ji‐Seon , Lidzey David G.
Published: July 2011

If a semiconductor with an electronic transition that approximates a two‐level system is placed within an optical cavity, strong coupling can occur between the confined photons and the semiconductor excitons. This coupling can result in the formation of cavity polariton states that are a coherent superposition of light and matter. If the material in the cavity is an organic semiconductor, it has been predicted that interactions between Frenkel excitons, polaritons, and molecular vibrational modes will have a profound role in defining the overall relaxation dynamics of the system. Here, using temperature‐dependent spectroscopy on a microcavity containing a J‐ aggregated cyanine dye, it is shown that a spectrum of localized vibrational modes (identified by Raman scattering) enhances the population of certain polaritonic modes by acting as an energy‐loss channel to the excitons as they undergo scattering. Our work demonstrates that simultaneous control of the optical properties of a cavity and the vibrational structure of a molecular dye could promote the efficient population of k = 0 polariton states, from which lasing and other cooperative phenomena may occur.
Qualitätssicherung für Rissfüllungen: ein neuer Ansatz mit bildgebenden Ultraschallverfahren
Authors: Friese Martin , Vogdt Frank U. , Wiggenhauser Herbert
Published: July 2011

Werden Risse in Betonbauteilen durch Verfüllen saniert, so lassen sich drei Kriterien zur Beurteilung des Erfolgs festlegen: die Kraftschlüssigkeit, die Wasserundurchlässigkeit und die Vollständigkeit der Füllung. Kraftschlüssigkeit und Wasserundurchlässigkeit lassen sich relativ einfach am sanierten Bauteil überprüfen, die Prüfung auf Vollständigkeit der Füllung kann derzeit nur zerstörend durch Entnahme von Bohrkernen erfolgen. Mit fortgeschrittenen, bildgebenden Ultraschallverfahren lassen sich für Füllgüter auf Zementbasis (Zementleim, Zementsuspension) sowie Epoxidharz signifikante Unterschiede zwischen offenen, teilweise verfüllten und vollständig verfüllten Rissen feststellen.

Quality control for crack repair: a new approach using ultrasonic imaging

If cracks in concrete elements are repaired by filling them with epoxy, polyurethane or a cement based filler, there are three criteria for the repair quality: there should be a non‐positive connection between the crack's edges, the repaired crack should be watertight, and it should be completely filled. While the first two criteria can easily be verified, to date the only way to get information about the completeness of the filling has been to drill cores. By applying advanced ultrasonic imaging techniques, significant differences between empty, partially filled and completely filled cracks can be observed for epoxy or cement based fillers.
Randomized clinical trial of combined preincisional infiltration and intraperitoneal instillation of levobupivacaine for postoperative pain after laparoscopic cholecystectomy (Br J Surg 2011; 98: 784–789)
Authors: Futier E , Petit A , Pezet D
Published: July 2011

The Editors welcome topical correspondence from readers relating to articles published in the Journal. Responses should be sent electronically via the BJS website (http://www.bjs.co.uk). All letters will be reviewed and, if approved, appear on the website. A selection of these will be edited and published in the Journal. Letters must be no more than 250 words in length.
Design and Synthesis of Sphingomyelin–Cholesterol Conjugates and Their Formation of Ordered Membranes
Authors: Matsumori Nobuaki , Tanada Norio , Nozu Kohei , Okazaki Hiroki , Oishi Tohru , Murata Michio
Published: July 2011

A lipid raft is a cholesterol (Chol)‐rich microdomain floating in a sea of lipid bilayers. Although Chol is thought to interact preferentially with sphingolipids such as sphingomyelin (SM), rather than with glycerophospholipids, the origin of the specific interaction has remained unresolved, primarily because of the high mobility of lipid molecules and weak intermolecular interactions. In this study, we synthesized SM–Chol conjugates with functionally designed linker portions to restrain Chol mobility and examined their formation of ordered membranes by a detergent insolubility assay, fluorescence anisotropy experiments, and fluorescence‐quenching assay. In all of the tests, membranes prepared from the conjugates showed properties of ordered domains comparable to a SM–Chol (1:1) membrane. To gain insight into the structure of bilayers composed from the conjugates, we performed molecular dynamics simulations with 64 molecules of the conjugates, which suggested that the conjugates form a stable bilayer structure by bending at the linker portion and, mostly, reproduce the hydrogen bonds between the SM and Chol portions. These results imply that the molecular recognition between SM and Chol in an ordered domain is essentially reproduced by the conjugated molecules and, thus, demonstrates that these conjugate molecules could potentially serve as molecular probes for understanding molecular recognition in lipid rafts.
A Carbon Material as a Strong Protonic Acid for Efficient Synthesis of 4(3H)‐Quinazolinones
Authors: Tavakoli‐Hoseini Niloofar , Davoodnia Abolghasem
Published: July 2011

Carbon‐based solid acid catalyst has been applied to catalyzing the synthesis of 4(3H)‐quinazolinones from the cyclization reaction of 2‐aminobenzamide with aroyl chlorides. The results showed that the catalyst was very efficient with the average yield over 85%. This carbon material with strong protonic acid sites as heterogeneous catalyst has some advantages such as high activity, strikingly simple work‐up procedure, non‐pollution, and reusability, which will contribute to the green process greatly.