bluuebunny/crossref_metadata_2025 huggingface dataset:
High Temperature Flow Behaviour of Semi-Solid Steel Alloys
Authors: Pouyafar Vahid , Sadough S.A. , Hosseini Farzad , Jabbari Amin
Published: October 2012

Semi-solid processing is an attractive and an effective near-net-shape forming process to produce components with complex geometry and in fewer forming steps. Its key is the spheroidal solid particles suspended in a liquid matrix which in turn eventuate in a complex thixotropic behaviour of semi-solids. However, the consequences of such behaviour on the flow during semi- solid forming processes is still neither completely characterized and nor fully understood, especially for high melting point alloys like steels. Many attempts have been made for understanding the time- dependent flow behaviour of semisolid materials which is essential for the simulation of semi-solid processes. During processing, the structure of a semi-solid material changes with the processing history due to agglomeration and dissagglomeration of particles or particle–particle interactions. This kind of processing condition can be experimented using rotary rheometers. In the case of steel alloys, conventional rheometers cannot be directly used because of their high temperature processing conditions. For this purpose, a self-developed rotary rheometer has been employed to study the rheology of steels up to 1500 oC. Steel samples are melted in an Alumina cup and sheared with an Alumina rod in a resistance furnace under isothermal condition and also under argon controlled atmosphere. The torque and rotary speed signals are used to calculate the viscosity and shear rate data. For rheology investigations, shear rate jump experiments and rest experiments have been carried out using the rheometer for different steel alloys. The flow of SSM is modelled using the Herschel–Bulkley fluid model. The viscosity and the power-law index are assumed to be functions of the solid volume fraction and a structural parameter that changes with the processing history. The evolution of the structural parameter is described by a first-order kinetic differential equation. The model is in a good agreement with the experimental results which can then be used for simulation purposes.
Preparation of AlSi9Mg Alloy Semi-Solid Slurry by Electromagnetic Stirring Combined with Mechanical Vibration
Authors: Dao Van Luu , Zhao Sheng Dun , Lin Wen Jie , Zhang Chen Yang
Published: October 2012

The electromagnetic stirring combined with mechanical stirring (EMSCMV) method was developed for preparing the AlSi9Mg alloy semi-solid slurry. The experimental results demonstrate that, the preparation of semi-solid slurry by EMSCMV is sufficient to obtain fine microstructure of billet. The primary -Al particles are small, spherical and uniform throughout the microstructure. When increasing the stirring power and the vibrating power, the size of primary -Al particles decreases while the shape factor increases, and its distribution is more uniform. The fine microstructure of billet prepared by EMSCMV was obtained at the stirring power of 2.0~2.4 kW and vibrating power of 0.8 kW.
Preparation and Rheo-Die Casting of Semi-Solid A356 Aluminum Alloy Slurry through a Serpentine Pouring Channel
Authors: Mao W.M. , Chen Z.Z. , Liu H.W. , Li Y.G.
Published: October 2012

The semi-solid slurry of A356 aluminum alloy was prepared through a serpentine pouring channel, which is a new method proposed recently for semi-solid forming process, and the effect of pouring temperature and bend number in the channel on the slurry microstructure was investigated and the slurry was finally rheo-die cast. The results show that when the pouring temperatures are between 640oC and 680oC, the slurry of A356 aluminum alloy with spherical primary a-Al grains can be prepared under the given conditions. The more the bend numbers in the channel are, the better the slurry is, i.e. the primary a-Al grains are more spherical and finer. The results also show that the as-cast ultimate strength and elongation of the rheo-die castings can reach 250MPa and 8.613.2% respectively. After T6 heat treatment, the ultimate strength and elongation of the rheo-die castings can reach 320MPa and 8.011.3% respectively. The work undertaken demonstrates eventually that the serpentine pouring channel process is a good method for semi-solid rheo-die casting or rheo-forming of metallic materials, the process is simple and the slurry cost is not expensive.
Development of Generation Technology of High Quality Semi-Solid Slurry by Double-Axis-Electromagnetic Stirrer Combined with Properly Designed Cup
Authors: Itamura Masayuki , Anzai Koichi , Hirata Naoya , Shimaski Shinichi , Maeda Takuma
Published: October 2012

For the semi-solid casting process it is very important to make high quality slurry with high speed and low cost. Recently the double-axis-electromagnetic stirrer is developed as the slurry-making tool. This stirrer has rotating magnetic field (RMF) and linear traveling magnetic field (TMF). This new technology shows several advantages in the quality of slurry. The cup design is also important to make uniform quality slurry. In this paper the new stirrer and its advantages from test report and technology of cup design is introduced.
Development of Aluminum Die Casting Products with High Accuracy as Well as Superior Die-to-Casting Transcriptional Capability by Using Semi-Solid Method
Authors: Itamura Masayuki , Anzai Koichi , Hirata Naoya , Akahoshi Naoki , Maeda Takuma , Tanazawa Hiroyuki , Furuya Yoichi , Fukuoka Singoro , Yamamoto Naomichi
Published: October 2012

Despite the lightweight demands, precision die casting products with high dimensional/ die-transcriptional accuracy is still made by zinc die-casting, because the conventional aluminum die-casting cannot satisfy the requirement. While light weight precision die casting demand for electric devices /automobile parts has been encouraging the material replacement from zinc to aluminum, it cannot be realized yet. We applied the Semi-Solid die casting technique to the precision casting, and verified possibility of replacement of the material from zinc to aluminum
Study on the Semi-Solid Thixo-Diecasting Process of Aluminum Alloys and Die Design
Authors: Shang Shu Zhen , Wang Jiao Jiao , Lu Gui Min , Tang Xiao Ling
Published: October 2012

The constitutive equation of semi-solid 6061 alloy was established according to the thermal simulation compression tests of semi-solid billet of 6061 alloy prepared by near-liquids semi-continuous casting method. Parameters of Bingham model, such as apparent viscosity, had been investigated based on the constitutive equation of semi-solid 6061 alloy. The software ANYCASTING was applied to simulate and analyze the semi-solid die-casting processes of semi-solid 6061 alloy. A well-designed runner and gating system of automobile aluminum alloy part were presented and the casting defect were investigated here utilizing these parameters by simulation. The results show that a well-designed runner and gating system is very important to secure good quality die castings through providing a homogenous mould filling pattern. Most defects of semi-solid casting products can be founded in the final solidification of the parts of casting.
Rheo-Extrusion of AZ91D
Authors: Xia Ming Xu , Huang Yan , Cassinath Zen , Fan Zhong Yun
Published: October 2012

The process of a novel rheo-extrusion was investigated by the combination of theoretical analysis and experimental verification based on a prototype counter rotating twin screw extruder. The investigation on the viscosity variation of AZ91D slurry and heat exchange of the system during extrusion shows both extrusion temperature and speed can affect the temperature and viscosity of the slurry. Thus, a continuous mass flow can be established by setting proper processing parameters to prevent bridging phenomenon in the extrusion according to the analysis. A thermal strategy for continuous output was setup at the highest extrusion speed of the extruder after investigation. The feasibility of the process and thermal strategy was then demonstrated by extruding an AZ91D rod using rheo-extrusion method.
Experimental Study on Rheoforming of Quality Magnesium Alloys
Authors: Liu Guo Jun , Xu Jun , Yang Liu Qing
Published: October 2012

Adopting the rheoforming technology, namely rheo-diecasting (RDC) and rheo-twin-roll casting (RTRC) processes were investigated for preparing of AZ91D and AZ31 magnesium alloy products, and their structure characterization and property evaluation were presented. The trials instruct that both semi-solid and melt-intensive-homogenized rheoforming processes, in which a metal-slurry is treated near liquidus by subjecting a forced homogenization are applicable in fabrication of quality magnesium alloys. The experimental results show that the rheoformed alloys obtain more finely and homogeneously dispersed structures, and superior mechanical properties. The average grain size of the α-Mg was 20-40 μm, and the tensile strength was 250 MPa for RDC AZ91D magnesium alloy sample; The RTRC strips consist of equiaxed grains with a mean size of 50–80 μm, correspond to the tensile strength of 213 MPa and 215 MPa plus the elongation of 5.5% and 8.0% for AZ91D and AZ31 alloy strips respectively. Finally, the AZ31 magnesium alloy sheets with thickness of 1.6 mm were prepared by hot and cold rolling from the initial thickness of 6.5mm RTRC strips.
On the Rheocasting of High Integrity Hollow Shape Components for Automotive Applications Using 357 Aluminum Alloy
Authors: Samuel Ehab , Zheng Chang Qing , Côté Pascal
Published: October 2012

Recent studies regarding semi-solid casting as a viable alternative to conventional liquid metal casting have been met with considerable interest. The dual nature of semi-solid materials results in a marked decrease in internal defects otherwise associated with conventional casting methods. In recent years, the National Research Council Canada - Aluminum Technology Centre (NRC-ATC) has dedicated itself to better understanding the behaviour of semi-solid aluminum alloys, notably 357, using the SEED (Swirled Enthalpy Equilibration Device) rheocasting method. SEED is a novel process which relies on the mechanical agitation and cooling of molten aluminum to produce a semi-solid billet. This billet is then injected into a die to yield the desired cast shape. The current work focuses on the rheocasting of a 357 aluminum alloy support bracket, consisting of four rings. Material flow around a ring is known to result in a welding of the two metal fronts. Traces of porosity and oxides can sometimes be found at the weld, unless preventative measures are taken. These include the use of overflows attached to the ring via a web as well as a careful control of the casting parameters. At NRC-ATC, several parts were rheocast and then subjected to both destructive and non-destructive testing, in an effort to better understand the material flow behaviour around these rings. The results obtained are presented herein.
Production of A356/TiB2 Nanocomposite Feedstock for Thixoforming by an Ultrasonic Method
Authors: Kandemir Sinan , Weston David P. , Atkinson Helen V.
Published: October 2012

Metal matrix nanocomposites (MMNCs) are promising materials to produce engineering components for the automotive and aerospace industry. This study aims to determine the feasibility of Al/TiB2 nanocomposite fabrication by the combination of the ultrasonic method and flux-assisted particle incorporation for the production of thixoforming feedstock material. Flux assistance has been invoked to attempt to overcome challenges with the presence of oxide on the surface of the foil in the aluminium foil capsulate method. A356 alloy has been reinforced with 0.25 wt.% TiB2 nanoparticles using different methods; 1. Flux-assisted casting, 2. Flux-assisted casting with ultrasonic cavitation, and 3. The Al foil capsulate method for particle feeding with ultrasonic cavitation. The composite fabricated by the ultrasonic method with the use of flux agent provided a non-dendritic microstructure which is the requirement for thixoforming. It was found that the flux-assisted casting method is not appropriate for achieving nanoparticle entry into the melt in MMNC fabrication due to the buoyancy forces of nanoparticles, unlike micron-sized particles.
Continuous Production of Metal Matrix Composites from the Semisolid State
Authors: de Pádua Lima Filho Antonio , Shoiti Ikeda Rafael
Published: October 2012

Continuous strip metal matrix composite (MMC) casting of 0.3 mm diameter hard-drawn stainless steel (316L) wire in a quasi-eutectic SnPb (64Sn36Pb) matrix was performed by a two-roll melt drag processing (TRMDping) method, with the wire being dragged through a semisolid puddle with a fibre contact time of approximately 0.2 s. A slag weir placed at the nozzle contained two wire guide holes: one located near the upper roll, and the other located between the rolls. A successful continuous composite strip casting with good fibre alignment was achieved by inserting and embedding the wire into the matrix using the guide hole between the rolls. Degeneration of eutectic/dendrite structures led to the formation of globular structures. The occurrence and formation mechanisms of cracks, de-lamination and voids in the matrix were discussed. TRMDping is economically viable and has significant benefits over other MMC fabrication methods.
Pictorial pattern generalisation: Tension between local and global visualisation
Authors: Samson Duncan
Published: October 2012

This article engages with the notion of local and global visualisation within the context of figural pattern generalisation. The study centred on an analysis of pupils’ lived experience whilst engaged in the generalisation of linear sequences presented in a pictorial context. The study was anchored within the interpretive paradigm of qualitative research and made use of the complementary theoretical perspectives of enactivism and knowledge objectification. A crucial aspect of the analytical framework used was the sensitivity it showed to the visual, phenomenological and semiotic aspects of figural pattern generalisation. A microanalysis of a vignette is presented to illustrate the subtle underlying tensions that can exist as pupils engage with pictorial pattern generalisation tasks. It is the central thesis of this article that the process of objectifying and articulating an appropriate algebraic expression for the general term of a pictorial sequence is complicated when tension exists between local and global visualisation.
Service improvement in the English National health service: Complexities and tensions
Authors: Burgess Nicola , Radnor Zoe
Published: October 2012

The English National Health Service (NHS) is a public sector organisation with a longstanding objective to deliver high quality healthcare that is free at the point of use. In order to achieve this, the NHS has endured an evocative and controversial theme of reform across many decades. Despite such high levels of reform, the recent Operating Efficiency Framework declared that the NHS is about to enter its toughest ever financial climate. This paper will illustrate the complexities and tensions of implementing service improvement in the NHS in a climate of persistent policy reform, reduced budgets and tough regulation. The paper reports findings of three case studies of hospital trusts in the UK in relation to the implementation of Lean improvement methodologies, highlighting key complexities of a hospital context and the corresponding tension with service improvement activity.
The challenges acute care nurse unit managers face and the strategies they use to address them: Perceptions of directors of nursing and nurse unit managers
Authors: Gaskin Cadeyrn J , Ockerby Cherene M , Smith Tammy R , Russell Vibeke , O'Connell Bev
Published: October 2012

The aim of this study was to investigate the challenges that nurse unit managers (NUMs) face while working in acute care settings, the strategies they use to deal with these challenges, and the effectiveness of these strategies from the perspectives of NUMs and their supervisors. NUMs (N = 22) and directors of nursing (N = 3) were interviewed for this study. Thematic analysis revealed 14 challenges relating primarily to NUMs interactions with others, both within and outside of their wards/units. These challenges related to the managerial, but not clinical, aspects of their roles; 16 strategies for managing these challenges were identified, the effectiveness of which seemed dependent on how well they were executed. The strategies are: seeking assistance and support; trial and error; satisficing; taking responsibility for own professional development; scheduling of time; working longer hours; delegation; adaptive staffing and rostering; being a visible presence on the ward; team development; facilitating professional development for staff; being available for staff; negotiation and collaboration; communication; working with the processes of a large organisation; and complying with the demands of others, The findings make a strong case for NUMs to be supported in undertaking comprehensive management education.
The impact of supervisor-nurse relationships, patient role clarity, and autonomy upon job satisfaction: Public and private sector nurses
Authors: Shacklock Kate , Brunetto Yvonne , Farr-Wharton Rod
Published: October 2012

In the Australian healthcare sector, many changes in the public sector have affected nurse management and thereby, nurses. Yet it is unclear whether such efficiency measures, based on private sector business models, have impacted private sector nurses in similar ways. This paper examines four important issues for nurses: supervisor–subordinate relationships; perceptions of autonomy; role clarity in relation to patients; and job satisfaction. The paper uses an embedded mixed methods research design to examine the four issues and then compares similarities and differences between public and private sector nurses. The findings suggest supervisor–subordinate relationships, patient role clarity and autonomy significantly predict job satisfaction. The private sector nurses reported more satisfaction than public sector nurses with their supervisor–subordinate relationships, plus higher perceptions of patient role clarity and autonomy, and hence, higher levels of job satisfaction. The findings raise questions about whether present management practices (especially public sector) optimise service delivery productivity.
Exploring the antecedents and consequences of mentoring relationship effectiveness in the healthcare environment
Authors: Huang Ching-Yuan , Weng Rhay-Hung
Published: October 2012

The study focused on mentoring relationship effectiveness (RE) from the perspective of protégé in the healthcare environment. The purpose tried to examine the effects of interpersonal attraction, self-efficacy and transformational leadership (TL) on RE respectively, to test mentoring function as a mediator, and to verify the effect of RE on protégé work outcomes. Self-administered questionnaires were employed and 306 questionnaires from hospital nurses were collected in total. Structural equation model was used to test the research model. The results indicated that interpersonal attraction and TL do have positive effects on RE while self-efficacy was not; RE also showed a significant effect on job satisfaction and organizational commitment, which verified that the formal mentoring among nurses was good for improving relationship quality and relationship learning between mentors and protégés. Accordingly, to strengthen the antecedent variables would be helpful for mentoring RE, and also the protégé's work outcomes.
Promoting employee wellbeing and quality service outcomes: The role of HRM practices
Authors: Clarke Marilyn Alexandra , Hill Sally Rao
Published: October 2012

As a transformative service, aged care has the capacity to create uplifting changes and improvements to the quality of life for individuals and communities. Recent studies have, however, highlighted the pressures faced by aged care workers and the impact that these pressures have on employee wellbeing and quality of care. This paper explores the relationship between employee wellbeing and service quality. We present a model for the aged care sector which suggests that by identifying and implementing appropriate HRM strategies both employee wellbeing and service quality will be enhanced thus ensuring that this transformative service meets the needs of its many stakeholders. Essentially, we argue that employee wellbeing is directly linked to service delivery outcomes and overall business performance and that HR practices that address issues such as learning and development, employee voice and involvement and workplace health and safety play a significant role in enhancing and maintaining employee wellbeing.
Using biodata as a predictor of errors, tardiness, policy violations, overall job performance, and turnover among nurses
Authors: Becton J Bret , Matthews Michael C , Hartley David L , Whitaker L Douglas
Published: October 2012

The current study examined the use of biographical data to predict errors, tardiness, policy violations, overall job performance, and turnover among nurses. The results of the study indicate that biodata measures are valid selection devices for nurses and effective at predicting nurse errors, tardiness, policy violations, and overall job performance, but the instrument was not an effective predictor of turnover, voluntary or involuntary. Additionally, examination of group differences revealed that White subjects scored significantly higher on the biodata instrument compared to Black subjects but produced group differences considerably smaller than typically found with measures of cognitive ability. Future research directions and implications for practice are discussed.
A compressed super-parameterization: test of NAM-SCA under single-column GCM configurations
Authors: Yano J.-I. , Cheedela S. K. , Roff G. L.
Published: October 2012

Abstract. The NAM-SCA (nonhydrostatic anelastic model with segmentally-constant approximation) is a type of cloud-resolving model (CRM) with a highly-inhomogeneous distribution of finite volumes of varying sizes in a horizontal direction under a two-dimensional geometrical configuration. These finite-volume positions and sizes are dynamically adapted to achieve best performance with a limited number of finite volumes. The concept can be compared with "compression" techniques used for digital images. The physics are also limited only to a minimum microphysics. The present paper reports on a successful implementation of NAM-SCA into single column versions of two global atmospheric models as a compressed super-parameterization. ECHAM1 and ACCESS2 are chosen as the host models. A stand-alone single-column model (SCM) is also developed, in which the other physics are prescribed by observations. A simple radiation scheme is added as required. Overall, it is found that, under this configuration, the lowest-resolution (Δ x = 16 km) NAM-SCA with the smallest domain size (L = 32 km) often works the best in terms of the errors for the precipitation rate, apparent heat source and moisture sink. Neither increase of resolution nor domain size leads to better performance in these respects until both cross the thresholds (Δ x ≤ 1km and L ≥ 256 km). These results suggest that even a simple parameterization (with a small degree of freedom) can perform in a reliable way as long as it is constructed in a physically consistent manner. On the other hand, the prediction errors tend to be smaller for higher resolutions and larger domains. This tendency is clearer for the GATE3 case than the TWP-ICE4case. 1ECMWF (European Centre for Medium Range Weather Forecasts) Hamburg version Atmospheric Model. 2Australian Community Climate and Earth-System Simulator. 3The Global Atmospheric Research Program’s (GARP) Atlantic Tropical Experiment. 4Tropical Warm Pool-International Cloud Experiment.
On-orbit radiometric calibration of SWIR bands of TANSO-FTS onboard GOSAT
Authors: Yoshida Y. , Kikuchi N. , Yokota T.
Published: October 2012

Abstract. The Greenhouse gases Observing SATellite (GOSAT) was launched on 23 January 2009 to monitor global distributions of carbon dioxide and methane. The Thermal And Near-infrared Sensor for carbon Observation-Fourier Transform Spectrometer (TANSO-FTS) onboard GOSAT measures the short-wavelength infrared (SWIR) spectra. Radiometric accuracy directly influences the accuracy of the retrieved greenhouse gas concentrations. From a 2.5-yr retrieval analysis of GOSAT data, we found that the minimum of the mean-squared value of the residuals (the difference between observed and fitted spectra) and the radiance adjustment factor (one of the ancillary parameters to be retrieved with the gas concentrations for adjusting the radiance level between the bands) changed with time, possibly due to inaccurate degradation correction. In this study, the radiometric degradation of TANSO-FTS was evaluated from the on-orbit solar calibration data and modeled as a function of time and wavenumber for each spectral band. The radiometric degradation of TANSO-FTS Band 1 (centered at 0.76 μm) after the launch was found to be about 4 to 6%, varying with wavenumber, whereas the other two bands (Band 2: 1.6 μm and Band 3: 2.0 μm) showed about 1% degradation and small wavenumber dependency. When we applied the new degradation model in the retrieval analysis, the above-mentioned issues disappeared.
A centrifugal ice microtome for measurements of atmospheric CO2 on air trapped in polar ice cores
Authors: Bereiter B. , Stocker T. F. , Fischer H.
Published: October 2012

Abstract. For atmospheric CO2 reconstructions using ice cores, the technique to release the trapped air from the ice samples is crucial for the precision and accuracy of the measurements. We present here a new dry extraction technique in combination with a new gas analytical system that together show significant improvements with respect to current systems. Ice samples (3–15 g) are pulverized using a novel Centrifugal Ice Microtome (CIM) by shaving the ice in a cooled vacuum chamber (−27 °C) in which no friction occurs due to the use of magnetic bearings. Both, the shaving principle of the CIM and the use of magnetic bearings have not been applied so far in this field. Shaving the ice samples produces finer ice powder and releases a minimum of 90% of the trapped air compared to 50%–70% when needle crushing is employed. In addition, the friction-free motion with an optimized design to reduce contaminations of the inner surfaces of the device result in a reduced system offset of about 2.0 ppmv compared to 4.9ppmv. The gas analytical part shows a factor two higher precision than our corresponding part of the previous system and all processes except the loading and cleaning of the CIM now run automatically. Compared to our previous system the new system shows a 3 times better measurement reproducibility of about 1.1 ppmv (1σ) which is similar to the best reproducibility of other systems applied in this field. With this high reproducibility, replicate measurements are not required anymore for most prospective measurement campaigns resulting in a possible output of 12–20 measurements per day compared to a maximum of 6 with other systems.
Theoretical and practical limitations of the acetylene inhibition technique to determine total denitrification losses
Authors: Felber R. , Conen F. , Flechard C. R. , Neftel A.
Published: October 2012

Abstract. The loss of N2 from intensively managed agro-ecosystems is an important part of the N budget. Flux monitoring of N2 emissions at the field scale, e.g., by eddy correlation or aerodynamic gradient method, is impossible due to the large atmospheric N2 background (78%). The acetylene (C2H2) inhibition technique (AIT) is a rather simple and frequently used, albeit imperfect, method to determine N2 losses from intact soil cores. In principle, AIT allows an estimation of total denitrification at high temporal resolution and on small spatial scales, with limited workload and costs involved. To investigate its potential and limitations, a laboratory system with two different detection systems (photoacoustic IR spectroscopy and gas chromatography) is presented, which allowed simultaneous measurements of up to 7 intact soil cores in air-tight glass tubes in a temperature controlled cabinet (adjusted to field conditions) with automated C2H2 injection. A survey of total denitrification losses (N2 + N2O) over 1.5 yr in soil cores from an intensively managed, cut grassland system in central Switzerland supports previous reports on severe limitations of the AIT, which precluded reliable estimates of total denitrification losses. Further, the unavoidable sampling and transfer of soil samples to the laboratory causes unpredictable deviations from the denitrification activity in the field.
Reconstruction of high resolution atmospheric fields for Northern Europe using analog-upscaling
Authors: Schenk F. , Zorita E.
Published: October 2012

Abstract. The analog method (AM) has found application to reconstruct gridded climate fields from the information provided by proxy data and climate model simulations. Here, we test the skill of different setups of the AM, in a controlled but realistic situation, by analysing several statistical properties of reconstructed daily high-resolution atmospheric fields for Northern Europe for a 50-yr period. In this application, station observations of sea-level pressure and air temperature are combined with atmospheric fields from a 50-yr high-resolution regional climate simulation. This reconstruction aims at providing homogeneous and physically consistent atmospheric fields with daily resolution suitable to drive high resolution ocean and ecosystem models. Different settings of the AM are evaluated in this study for the period 1958–2007 to estimate the robustness of the reconstruction and its ability to replicate high and low-frequency variability, realistic probability distributions and extremes of different meteorological variables. It is shown that the AM can realistically reconstruct variables with a strong physical link to daily sea-level pressure on both a daily and monthly scale. However, to reconstruct low-frequency decadal and longer temperature variations, additional monthly mean station temperature as predictor is required. Our results suggest that the AM is a suitable upscaling tool to predict daily fields taken from regional climate simulations based on sparse historical station data.
Analysing inter-relationships among water, governance, human development variables in developing countries
Authors: Dondeynaz C. , Carmona Moreno C. , Céspedes Lorente J. J.
Published: October 2012

Abstract. The "Integrated Water Resources Management" principle was formally laid down at the International Conference on Water and Sustainable development in Dublin 1992. One of the main results of this conference is that improving Water and Sanitation Services (WSS), being a complex and interdisciplinary issue, passes through collaboration and coordination of different sectors (environment, health, economic activities, governance, and international cooperation). These sectors influence or are influenced by the access to WSS. The understanding of these interrelations appears as crucial for decision makers in the water sector. In this framework, the Joint Research Centre (JRC) of the European Commission (EC) has developed a new database (WatSan4Dev database) containing 42 indicators (called variables in this paper) from environmental, socio-economic, governance and financial aid flows data in developing countries. This paper describes the development of the WatSan4Dev dataset, the statistical processes needed to improve the data quality, and finally, the analysis to verify the database coherence is presented. Based on 25 relevant variables, the relationships between variables are described and organised into five factors (HDP – Human Development against Poverty, AP – Human Activity Pressure on water resources, WR – Water Resources, ODA – Official Development Aid, CEC – Country Environmental Concern). Linear regression methods are used to identify key variables having influence on water supply and sanitation. First analysis indicates that the informal urbanisation development is an important factor negatively influencing the percentage of the population having access to WSS. Health, and in particular children's health, benefits from the improvement of WSS. Irrigation is also enhancing Water Supply service thanks to multi-purpose infrastructure. Five country profiles are also created to deeper understand and synthetize the amount of information gathered. This new classification of countries is useful in identifying countries with a less advanced position and weaknesses to be tackled. The relevance of indicators gathered to represent environmental and water resources state is questioned in the discussion section. The paper concludes with the necessity to increase the reliability of current indicators and calls for further research on specific indicators, in particular on water quality at national scale, in order to better include environmental state in analysis to WSS.
Propagation of soil moisture memory to runoff and evapotranspiration
Authors: Orth R. , Seneviratne S. I.
Published: October 2012

Abstract. As a key variable of the land-climate system soil moisture is a main driver of runoff and evapotranspiration under certain conditions. Soil moisture furthermore exhibits outstanding memory (persistence) characteristics. Also for runoff many studies report distinct low frequency variations that represent a memory. Using data from over 100 near-natural catchments located across Europe we investigate in this study the connection between soil moisture memory and the respective memory of runoff and evapotranspiration on different time scales. For this purpose we use a simple water balance model in which dependencies of runoff (normalized by precipitation) and evapotranspiration (normalized by radiation) on soil moisture are fitted using runoff observations. The model therefore allows to compute memory of soil moisture, runoff and evapotranspiration on catchment scale. We find considerable memory in soil moisture and runoff in many parts of the continent, and evapotranspiration also displays some memory on a monthly time scale in some catchments. We show that the memory of runoff and evapotranspiration jointly depend on soil moisture memory and on the strength of the coupling of runoff and evapotranspiration to soil moisture. Furthermore we find that the coupling strengths of runoff and evapotranspiration to soil moisture depend on the shape of the fitted dependencies and on the variance of the meteorological forcing. To better interpret the magnitude of the respective memories across Europe we finally provide a new perspective on hydrological memory by relating it to the mean duration required to recover from anomalies exceeding a certain threshold.
Peripapillary Retinal Nerve Fiber Layer Thickness in Children with Iron Deficiency Anemia
Authors: Türkyilmaz Kemal , Öner Veysi , Özkasap Serdar , Şekeryapan Berrak , Dereci Selim , Durmuş Mustafa
Published: October 2012

Purpose.

To evaluate peripapillary retinal nerve fiber layer (RNFL) thickness in children with iron deficiency anemia (IDA) in comparison with healthy controls and to investigate the correlation between peripapillary RNFL thicknesses and the hematologic parameters in these subjects.

Methods.

Forty eyes of 40 children with a diagnosis of IDA (anemic group) and 40 eyes of 40 age- and sex-matched healthy children (control group) were enrolled in this study. Peripapillary RNFL thickness measurements were performed using Cirrus HD optical coherence tomography (OCT).

Results.

Mean age of each group was 11.3±2.7 years. Average RNFL and RNFLs of superior and inferior quadrants were significantly thinner in the anemic group than in the control group (p=0.006, p=0.005, and p=0.005, respectively). In addition, average peripapillary RNFL thickness and RNFL thicknesses of superior, inferior, and temporal quadrants were correlated with hemoglobin levels (r1=0.734, p1<0.001, r2=0.456, p2=0.005, r3=0.598, p3<0.001, r4=0.349, p4=0.037, respectively) in anemic group.

Conclusions.

We found that children with IDA had different peripapillary RNFL profile measured by Cirrus HD spectral-domain OCT. We caution ophthalmologists when they measure RNFL thickness in children to diagnose glaucoma or other neuro-ophthalmic disorders.
Effect of Breed of Sire on Carcass Traits and Meat Quality of Katahdin Lambs
Authors: Partida José A. , Vázquez Edith , Rubio María S. , Méndez Danilo
Published: October 2012

Crossbred lambs (n = 40) of 137 ± 3 days of age from Katahdin ewes with either Charollais (KCh), Dorper (KD), Suffolk (KS) and Texel (KT) sires were used in this study. The effect of sire breeds on carcass traits, chemical composition of muscle, meat quality and consumer acceptability was determined. Regarding carcass traits, KCh animals had the highest fat thickness. KT lambs had the smallest M. Longissimusdorsi (MLD) area compared tothat of KCh, KD and KS (17.0, 15.9, 15.5 and 13.9 cm2; respectively). Breed of sire had no effect (P>0.05) on the chemical composition, pH or Warner-Bratzler shear force (WBSF) of lamb; however, it did affect meat color. KS lambs had lower L*, a*, b* and Ch* values compared to the other crossbreeds (P<0.05). Consumer acceptability of lamb was similar (P>0.05) across genotypes.
 
Effect of Kale Cultivation Conditions on Biosynthesis of Xanthophylls
Authors: Ligor Magdalena , Buszewski Boguslaw
Published: October 2012

Conditions of plant cultivation directly influence the chlorophyll and carotenoid pigments concentrations. The aim of investigations was the determination of lutein in kale (Brassica oleracea L. var. acephala) upon various cultivation conditions including: low and high temperature (overnight and daytime in the greenhouse the temperature was 12 ± 2C and in the laboratory the temperature was 22 ± 2C), lack of water (some plants were watered only one time weekly), saline stress (5% of sodium chloride added to irrigation water; watering two times weekly was applied), as well as UV radiation of plants by means of UV lamp (lambda = 254 nm; suitable to UVC solar radiation; duration 4 h per day). Three months old cuttings were taken and next mentioned cultivation conditions were applied during one month. Moreover, the outdoor cultivation of kale cuttings was performed. Qualitative and quantitative analyses of plant extracts were made by use of HPLC-UV-VIS-MS technique. Mean values for lutein accumulation as a function of dry mass (mg/g) in leaves of kale have been presented. Obtained results show maximum xantophylls (lutein) concentration occur in fully developed plant leaves of kale for red kale 2.04 ± 0.15 and green kale 1.10 ± 0.09 mg/g respectively.
Foggy perception slows us down
Authors: Pretto Paolo , Bresciani Jean-Pierre , Rainer Gregor , Bülthoff Heinrich H
Published: October 2012

Visual speed is believed to be underestimated at low contrast, which has been proposed as an explanation of excessive driving speed in fog. Combining psychophysics measurements and driving simulation, we confirm that speed is underestimated when contrast is reduced uniformly for all objects of the visual scene independently of their distance from the viewer. However, we show that when contrast is reduced more for distant objects, as is the case in real fog, visual speed is actually overestimated, prompting drivers to decelerate. Using an artificial anti-fog—that is, fog characterized by better visibility for distant than for close objects, we demonstrate for the first time that perceived speed depends on the spatial distribution of contrast over the visual scene rather than the global level of contrast per se. Our results cast new light on how reduced visibility conditions affect perceived speed, providing important insight into the human visual system.
Immunogenicity, Safety, and Efficacy of Abatacept Administered Subcutaneously With or Without Background Methotrexate in Patients With Rheumatoid Arthritis: Results From a Phase III, International, Multicenter, Parallel‐Arm, Open‐Label Study
Authors: Nash Peter , Nayiager Sauithree , Genovese Mark C. , Kivitz Alan J. , Oelke Kurt , Ludivico Charles , Palmer William , Rodriguez Cristian , Delaet Ingrid , Elegbe Ayanbola , Corbo Michael
Published: October 2012

Objective

To evaluate the impact of concomitant methotrexate (MTX) on subcutaneous (SC) abatacept immunogenicity, and to assess safety and efficacy.

Methods

This phase III, open‐label study had a 4‐month short‐term (ST) period and an ongoing long‐term extension (LTE) period. Rheumatoid arthritis patients were stratified to receive SC abatacept (125 mg/week) with (combination) or without MTX (monotherapy), with no intravenous loading dose; patients receiving monotherapy could add MTX in the LTE period. Immunogenicity (percentage of anti‐abatacept antibody–positive patients) was assessed. ST and LTE period data are reported, including efficacy through LTE month 14 and safety through LTE month 20.

Results

Ninety‐six of 100 enrolled patients completed the ST period; 3.9% (combination) and 4.1% of patients (monotherapy) developed transient immunogenicity, and no patients were antibody positive at month 4. Serious adverse events (SAEs) were reported in 3.9% (combination) and 6.1% of patients (monotherapy); 5.9% (combination) and 8.2% of patients (monotherapy) experienced SC injection reactions, and all were mild in intensity. Mean 28‐joint Disease Activity Score (DAS28) changes were −1.67 (95% confidence interval [95% CI] −2.06, −1.28; combination) and −1.94 (95% CI −2.46, −1.42; monotherapy) at month 4. Ninety patients entered and were treated in the LTE period; 83.3% (75 of 90) remained ongoing at month 24. One LTE‐treated patient (1.1%) developed immunogenicity, 14.4% of patients experienced SAEs, and no SC injection reactions were reported. For patients entering the LTE period, mean DAS28 changes from baseline were −1.84 (95% CI −2.23, −1.34; combination) and −2.86 (95% CI −3.46, −2.27; monotherapy) at month 18.

Conclusion

SC abatacept did not elicit immunogenicity associated with loss of safety or efficacy, either with or without MTX.
Top‐Down Fabrication of High Quality III–V Nanostructures by Monolayer Controlled Sculpting and Simultaneous Passivation
Authors: Naureen Shagufta , Shahid Naeem , Sanatinia Reza , Anand Srinivasan
Published: October 2012

In the fabrication of III–V semiconductor nanostructures for electronic and optoelectronic devices, techniques that are capable of removing material with monolayer precision are as important as material growth to achieve best device performances. A robust chemical treatment is demonstrated using sulfur (S)‐oleylamine (OA) solution, which etches layer by layer in an inverse epitaxial fashion and simultaneously passivates the surface. The application of this process to push the limits of top‐down nanofabrication is demonstrated by the realization of InP‐based high optical quality nanowire arrays, with aspect ratios more than 50, and nanostructures with new topologies. The findings are relevant for other III–V semiconductors and have potential applications in III–V device technologies.
A Stiff Injectable Biodegradable Elastomer
Authors: Mizrahi Boaz , Shankarappa Sahadev A. , Hickey Julia M. , Dohlman Jenny C. , Timko Brian P. , Whitehead Kathryn A. , Lee Jung‐Jae , Langer Robert , Anderson Daniel G. , Kohane Daniel S.
Published: October 2012

Injectable materials often have shortcomings in mechanical and drug‐eluting properties that are attributable to their high water contents. A water‐free, liquid four‐armed PEG modified with dopamine end groups is described which changes from liquid to elastic solid by reaction with a small volume of Fe3+solution. The elastic modulus and degradation times increase with increasing Fe3+concentrations. Both the free base and the water‐soluble form of lidocaine can be dissolved in the PEG4‐dopamine and released in a sustained manner from the cross‐linked matrix. PEG4‐dopamine is retained in the subcutaneous space in vivo for up to 3 weeks with minimal inflammation. This material's tailorable mechanical properties, biocompatibility, ability to incorporate hydrophilic and hydrophobic drugs and release them slowly are desirable traits for drug delivery and other biomedical applications.
Virus‐Tethered Magnetic Gold Microspheres with Biomimetic Architectures for Enhanced Immunoassays
Authors: Jeon Chang Su , Hwang Inseong , Chung Taek Dong
Published: October 2012

In immunoassays, non‐specific bindings to biosensing surfaces can be effectively prevented by formation of biocompatible and hydrophilic self‐assembled monolayer (SAM) on the surfaces. A thin gold (Au) layer on magnetic microspheres, 15 μm in diameter, enables facile SAM formation and thereby accepts second layer of filamentous virus scaffolds for the immobilization of functional proteins. The merger of the virus and SAM‐Au protected microspheres not only provides exceptionlly dense antibody loading, but also resembles biological cellular structures that enhance ligand‐receptor interactions. Site‐specific biotinylation of filamenous viruses allows formation of free‐standing virus threads (>1.0 × 1010) on streptavidin‐modified SAM‐Au microspheres. The augmented yield of antibody loading, due to the increased surface to volume ratio, on virus‐modified Au microspheres is confirmed by measuring fluorescence intensities. The bead‐based immunoassays for the detection of cardiac marker proteins exhibit increased sensitivity of virus‐Au microspheres, as low as 20 pg mL−1 of cardiac troponin I in serum, and extremely low non‐specific adsorption when compared with bare polymer beads. This increased sensitivity due to filamentous morphology and SAM‐Au layer demonstrates the feasibility of merging viruses with non‐biological materials to yield biomimetic tools for the enhanced bead‐based immunoassays.
Preparation, characterization, and polymerization of chromium complexes‐grafted Al/SBA‐15 and Ti/SBA‐15 nanosupports
Authors: Ahmadi Ebrahim , Mohamadnia Zahra , Mashhadi‐Malekzadeh Asemeh , Hamdi Zahra , Saghatchi Fatemeh
Published: October 2012

Ethylene polymerization catalysts have been prepared by grafting chromium (III) nitrate onto Al/SBA‐15 and Ti/SBA‐15 mesoporous materials. A combination of XRD, nitrogen adsorption, TEM, and inductively coupled plasma‐atomic emission spectroscopy (ICP‐AES), were used to characterize the catalysts. Polymerization activity of Cr/SBA‐15 catalyst is significantly improved by Al or Ti insertion to the supports. Particularly, the chromium catalyst prepared with Ti/SBA‐15 support is more active than Al/SBA‐15 catalyst. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013