bluuebunny/crossref_metadata_2025 huggingface dataset:
Two-Terminal Non-Volatile Memory Devices Using Silicon Nanowires as the Storage Medium
Authors: Saranti Konstantina , Paul Shashi
Published: October 2014

In the recent years a notable progress in the miniaturisation of electronic devices has been achieved in which the main component that has shown great interest is electronic memory. However, miniaturisation is reaching its limit. Alternative materials, manufacturing equipment and architectures for the storage devices are considered. In this work, an investigation on the suitability of silicon nanowires as the charge storage medium in two-terminal non-volatile memory devices is presented. Silicon nanostructures have attracted attention due to their small size, interesting properties and their potential integration into electronic devices. The two-terminal memory devices presented in this work, have a simple structure of silicon nanowires sandwiched between dielectric layers (silicon nitride) on glass substrate with thermally evaporated aluminium bottom and top contacts. The silicon nanostructures and the dielectric layer were deposited by Plasma Enhanced Chemical Vapour Deposition (PECVD) technique. The electrical behaviour of the memory cell was examined by Current-Voltage (I-V), data retention time (Current-time) and write-read-erase-read measurements. Metal-Insulator-Semiconductor (MIS) structures were also prepared for further analysis. The same silicon nanowires were embedded into the MIS capacitors and Capacitance-Voltage (C-V) analysis was conducted. Strong I-V and C-V hysteresis as well as an electrical bistability were detected. The memory effect is observed by this electrical bistability of the device that was able to switch between high and low conductivity states.
Power Management for Vibrational Energy Harvesters
Authors: Stanzione Stefano , van Liempd Chris , van Hoof Chris
Published: October 2014

As known, wireless sensing applications can be enabled by using ultra-low-power electronics for sensing, processing and transmitting information, in order to extend the battery lifetime. Battery size is also a limiting factor constrained by the application requirements. In this scenario, energy harvesting is a fascinating solution, which can attenuate the trade-off between battery size, power consumption of the load circuits and battery lifetime. In some particular applications, characterized by long times in which no energy is available in any form, the battery could completely deplete because of the standby current of the load circuits. For that reason, battery-less applications become more and more relevant. In this paper the available circuit techniques for interfacing vibrational energy harvesters are presented and compared.
Origin of the Current Transport Anisotropy in Epitaxial Graphene Grown on Vicinal 4H-SiC (0001) Surfaces
Authors: Giannazzo Filippo , Deretzis Ioannis , La Magna Antonino , Nicotra Giuseppe , Spinella Corrado , Fisichella Gabriele , Fiorenza Patrick , Yakimova Rositza , Roccaforte Fabrizio
Published: October 2014

In this paper, the electronic transport in epitaxial graphene (EG) grown on the Si face of 8° off-axis 4H-SiC has been investigated, using both electrical characterization of macroscopic devices and conductive atomic force microscopy (CAFM). In particular, current measurements on linear transmission line model (TLM) structures with different orientations showed a current transport anisotropy related to steps orientation, with the resistance of EG in the direction orthogonal to the steps ~2× higher than in the parallel direction. Two dimensional morphology and current maps in EG over the stepped SiC surface were obtained by CAFM and revealed a local resistance increase of EG over the (11-2n) facets with respect to the (0001) basal planes. This effect allows to account for the observed macroscopic current transport anisotropy and can be explained in terms of a different interface nature between EG and SiC on the two faces, leading to a locally different substrate induced doping of EG.
10 MeV Proton Irradiation Effect on 4H-SiC nMOSFET Electrical Parameters
Authors: Florentin Matthieu , Alexandru Mihaela , Constant Aurore , Schmidt Bernd , Godignon Philippe
Published: October 2014

This work presents the 10 MeV protons irradiation effects on 4H-SiC MOSFETs at different fluences. MOSFETs main electrical parameters, such as the channel mobility (µEFF), threshold voltage (VTH), transconductance (gm) and subthreshold current, were analyzed using the time bias stress instability (BSI) technique. Applying this method allowed us to study the effect of carriers interaction with generated interface traps, whether in the bulk or at the interface. Improvements, such as VTH stabilization in time and a significant increase of the µEFF at high fluencies, have been noticed. We assume that this behavior is connected with the atomic diffusion from the SiO2/SiC interface, towards the epilayer during proton irradiation. These atoms, in majority Nitrogen, may create other bonds by occupying various vacancies coming from Silicon and Carbon’s dangling bond. Therefore, by enhancing the passivated Carbon atoms number, we show that high irradiation proton could be a way to improve the SiO2/SiC interface quality.
Probing at Nanoscale Underneath the Gate Oxides in 4H-SiC MOS-Based Devices Annealed in N2O and POCl3
Authors: Fiorenza Patrick , Vivona Marilena , Swanson L.K. , Giannazzo Filippo , Bongiorno C. , Di Franco S. , Lorenti S. , Frazzetto A. , Chassagne Thierry , Roccaforte Fabrizio
Published: October 2014

In this paper a comparative study of the impact of N2O and POCl3 annealing on the SiO2/SiC system is presented, combining nanoscale electrical characterization of SiC surface doping by scanning spreading resistance microscopy (SSRM) and scanning capacitance microscopy (SCM) to the conventional capacitance-voltage (C-V) and current-voltage (I-V) measurements on MOS-based devices. A significant reduction of the interface states density (from 1.8×1012 to 5.7×1011 cm-2eV-1) and, correspondingly, an increase in the carrier mobility (from 19 to 108 cm2V-1s-1) was found moving from N2O to POCl3 annealing. Furthermore, SSRM measurements on bare p+-type SiC regions selectively exposed to N2O and POCl3 at high temperature provided the direct demonstration of the incorporation of N or P-related donors in the SiC surface, leading to a partial compensation of substrate acceptors during N2O treatment and to an overcompensation during POCl3 annealing. Finally, cross-sectional SCM profiles performed on epitaxial n-doped 4H-SiC with 45 nm SiO2 (subjected to post deposition annealing in the two ambients) allowed to quantify the active donors concentrations associated to P or N incorporation under the gate oxide, showing almost a factor of ten higher doping (4.5×1018cm-3 vs 5×1017cm-3) in the case of P related donors.
The Impact of Oxygen Flow Rate on the Oxide Thickness and Interface Trap Density in 4H-SiC MOS Capacitors
Authors: Thomas Stephen M. , Jennings Michael R. , Sharma Y.K. , Fisher C.A. , Mawby P.A.
Published: October 2014

Silicon carbide based devices have the potential to surpass silicon technology in high power, high frequency and high temperature applications. 4H-SiC MOS transistors currently suffer from a low channel mobility due to a high density of traps near the oxide/SiC interface. In this work, oxides have been grown on the Si face of 4H-SiC using oxygen flow rates ranging from 2.5 l/min to 0.05 l/min. Capacitance-voltage measurements on MOS capacitors revealed approximately a fourfold reduction in the interface trap density and a 25% increase in oxide thickness by reducing the flow rate from 2.5 l/min to 0.05 l/min.
Buffer Layer Optimization for the Growth of State of the Art 3C-SiC/Si
Authors: Bosi Matteo , Attolini Giovanni , Negri Marco , Frigeri Cesare , Buffagni Elisa , Ferrari Claudio , Rimoldi Tiziano , Cristofolini Luigi , Aversa L. , Tatti Roberta , Verucchi R.
Published: October 2014

We describe a procedure for the optimization of a 3C-SiC buffer layer for the deposition of 3C-SiC on (001) Si substrates. A 100 – 150 nm thick SiC buffer was deposited after a standard carbonization at 1125 °C, while increasing the temperature from 1125 °C to 1380 °C. Ramp time influenced the quality and the crystallinity of the buffer layer and the presence of voids at the SiC/Si interface. After the optimization of the buffer, to demonstrate its effectiveness, a high-quality 3C-SiC was grown, with excellent surface morphology, crystallinity and low stress.
3C-SiC: New Interest for MEMS Devices
Authors: Michaud Jean François , Portail Marc , Chassagne Thierry , Zielinski Marcin , Alquier Daniel
Published: October 2014

The aim of this paper is to review the recent developments conducted by our groups for the achievement of 3C-SiC based heterostructures compatible for MEMS applications. It deals with different aspects, from the influence of the defects generated at the 3C-SiC/Si interface on the mechanical properties to the elaboration of new multilayered structures, required for specific applications like, for example, Atomic Force Microscopy.
Heteroepitaxy of P-Doped 3C-SiC on Diamond by VLS Transport
Authors: Vo-Ha Arthur , Rebaud Mickaël , Lazar Mihai , Tallaire Alexandre , Soulière Véronique , Ferro Gabriel , Carole Davy
Published: October 2014

This work deals with the selective heteroepitaxial growth of silicon carbide on (100) diamond substrates using the Vapour-Liquid-Solid (VLS) transport. The morphology, the structure and doping were determined using various characterization techniques. In order to achieve succesful heteroepitaxy, the diamond surface was silicided by solid-state reaction between a silicon layer and the substrate at 1350 °C. This allowed forming a SiC buffer layer on which p-doped 3C-SiC(100) islands elongated in the <110> directions were obtained after VLS growth. The influence of the experimental parameters on the epitaxial growth is discussed.
Investigation of Aluminum Incorporation in 4H-SiC Epitaxial Layers
Authors: Arvinte Roxana , Zielinski Marcin , Chassagne Thierry , Portail Marc , Michon Adrien , Kwasnicki Pawel , Juillaguet Sandrine , Peyre Hervé
Published: October 2014

In the present contribution, the trends in voluntary incorporation of aluminum in 4H-SiC homoepitaxial films are investigated. The films were grown on Si-and C-face 4H-SiC 8°off substrates by chemical vapor deposition (CVD) in a horizontal, hot wall CVD reactor. Secondary Ion Mass Spectrometry (SIMS) and capacitance-voltage (C-V) measurements were used to determine the Al incorporation in the samples. The influence of Trimethylaluminum (TMA) flow rate, growth temperature, growth pressure and C/Si ratio on the dopant incorporation was studied.
Potentialities of AlGaN/GaN Heterostructures Grown on 2°-Off 4H-SiC Substrates
Authors: Leszczynski Mike , Prystawko Pawel , Kruszewski Piotr , Sarzynski Marcin , Plesiewicz Jerzy , Domagala Jarek , Gkanatsiou Alexandra , Lioutas Christos , Frangis Nicolaos , Polychroniadis Efstathios K.
Published: October 2014

So far, most of the SiC homoepitaxy has been realized on 8-deg-off and 4-deg-off substrates, whereas GaN heteroepitaxy is done on SiC on-axis (up to 0.3 deg off). As 6-inch SiC wafers are being introduced into the market, a decrease of the substrate off-cut to 2 deg for SiC homoepitaxy is desirable to reduce the manufacturing costs. If both, GaN heteroepitaxy and SiC homoepitaxy are successful on 2-deg-off SiC substrates, this would pave the way to monolithic integration of both kinds of devices, as well as to obtain cheap insulating SiC substrates for AlGaN/GaN microwave and THz devices. In this work, we present our present status of AlGaN/GaN growth on SiC 2-deg off. Comparing to the on-axis situation, we obtained similar structural (XRD and TEM data) and electrical characteristics, but not morphological ones. Therefore, we propose two ways of a decrease of AlGaN surface roughness when grown on SiC 2 deg-off: i) by planarization, ii) by lateral patterning.
High Quality Graphene Formation on 3C-SiC/4H-AlN/Si Heterostructure
Authors: Jiao Sai , Murakami Yuya , Nagasawa Hiroyoki , Fukidome Hirokazu , Makabe Isao , Tateno Yasunori , Nakabayashi Takashi , Suemitsu Maki
Published: October 2014

The growth of graphene on 3C-SiC/Si heterostructure is a promising approach, which provides low production cost, high scalability and easiness of nanoelectromechanical system fabrication. However, the quality of graphene is still insufficient for device applications due to mediocre morphological and structural quality of the 3C-SiC epilayers compared to bulk SiC crystals and to excessive Si out-diffusion from the Si substrate. Here, we propose a solution of inserting a 4H-AlN layer between 3C-SiC and Si, which allows us to polish the 3C-SiC film without worrying about enhancement of the Si out-diffusion despite the thinning after the polishing. With this insertion, a considerable quality improvement is achieved in our graphene on silicon.
Handleiding vir eksegete en ander studente van Klassieke en Nuwe-Testamentise Grieks
Authors: Jordaan Pierre
Published: October 2014

No abstract available.
Understanding Deleuze, Understanding Modernism
Authors: Ardoin Paul , Ardoin Paul , Gontarski S. E. , Mattison Laci , Gontarski S. E. , Mattison Laci
Published: October 2014

Understanding Deleuze, Understanding Modernism explores the multi-faceted and formative impact of Gilles Deleuze on the development and our understanding of modernist thought in its philosophical, literary, and more broadly cultural manifestations.

Gilles Deleuze himself rethought philosophical history with a series of books and essays on individual philosophers such as Kant, Spinoza, Leibniz, Nietzsche, and Bergson and authors such as Proust, Kafka, Beckett and Woolf, on the one hand, and Bacon, Messiaen, and Pollock, among others, in other arts. This volume acknowledges Deleuze's profound impact on a century of art and thought and the origin of that impact in his own understanding of modernism.

Understanding Deleuze, Understanding Modernism begins by “conceptualizing” Deleuze by offering close readings of some of his most important works. The contributors offer new readings that illuminate the context of Deleuze's work, either by reading one of Deleuze's texts against or in the context of his entire body of work or by challenging Deleuze's readings of other philosophers. A central section on Deleuze and his aesthetics maps the relationships between Deleuze's thought and modernist literature. The volume's final section features an extended glossary of Deleuze's key terms, with each definition having its own expert contributor.
Measuring acetic and formic acid by proton transfer reaction-mass spectrometry: sensitivity, humidity dependence, and quantifying interferences
Authors: Baasandorj M. , Millet D. B. , Hu L. , Mitroo D. , Williams B. J.
Published: October 2014

Abstract. We present a detailed investigation of the factors governing the quantification of formic acid (FA), acetic acid (AA) and their relevant mass analogues by proton transfer reaction-mass spectrometry (PTR-MS), assess the underlying fragmentation pathways and humidity dependencies, and present a new method for separating FA and AA from their main isobaric interferences. PTR-MS sensitivities towards glycolaldehyde, ethyl acetate and peroxyacetic acid at m/z 61 are comparable to that for AA; when present, these species will interfere with ambient AA measurements by PTR-MS. Likewise, when it is present, dimethyl ether can interfere with FA measurements. On the other hand, for E/N = 125 Townsend (Td), the PTR-MS sensitivity towards ethanol at m/z 47 is 5–20× lower than for FA; ethanol will then only be an important interference when present in much higher abundance than FA. Sensitivity towards 2-propanol is <1% of that for AA, so that propanols will not in general represent a significant interference for AA. Hydrated product ions of AA, glycoaldehyde, and propanols occur at m/z 79, which is also commonly used to measure benzene. However, the resulting interference for benzene is only significant when E/N is low (
Aerosol black carbon characteristics over a high-altitude Western Ghats location in Southern India
Authors: Udayasoorian C. , Jayabalakrishnan R. M. , Suguna A. R. , Gogoi Mukunda M. , Suresh Babu S.
Published: October 2014

Abstract. Aerosol black carbon (BC) mass concentrations were continuously monitored over a period of 2 years (April 2010 to May 2012) from a high-altitude location Ooty in the Nilgiris Mountain range in southern India to characterize the distinct nature of absorbing aerosols and their seasonality. Despite being remote and sparsely inhabited, BC concentrations showed significant seasonality with higher values (~ 0.96 ± 0.35 μg m−3) in summer (March to May), attributed to increased vertical transport of effluents in the upwind valley regions, which might have been confined to the surrounding valley regions within the very shallow winter boundary layer. The local atmospheric boundary layer (ABL) influence in summer was further modulated by the long-range transported aerosols from the eastern locations of Ooty. During monsoon (June–August), the concentrations were far reduced (~ 0.23 ± 0.06 μg m−3) due to intense precipitation. Diurnal variations were found conspicuous mainly during summer season associated with local ABL. The spectral absorption coefficients (αabs) depicted, in general, flatter distribution (mostly < 1.0 for more than 85% of daily mean values), suggesting the relative dominance of fossil fuel combustion, though showed marginal seasonal change with higher values of αabs in summer.
Reducing structural uncertainty in conceptual hydrological modeling in the semi-arid Andes
Authors: Hublart P. , Ruelland D. , Dezetter A. , Jourde H.
Published: October 2014

Abstract. The use of lumped, conceptual models in hydrological impact studies requires placing more emphasis on the uncertainty arising from deficiencies and/or ambiguities in the model structure. This study provides an opportunity to combine a multiple-hypothesis framework with a multi-criteria assessment scheme to reduce structural uncertainty in the conceptual modeling of a meso-scale Andean catchment (1515 km2) over a 30 year period (1982–2011). The modeling process was decomposed into six model-building decisions related to the following aspects of the system behavior: snow accumulation and melt, runoff generation, redistribution and delay of water fluxes, and natural storage effects. Each of these decisions was provided with a set of alternative modeling options, resulting in a total of 72 competing model structures. These structures were calibrated using the concept of Pareto optimality with three criteria pertaining to streamflow simulations and one to the seasonal dynamics of snow processes. The results were analyzed in the four-dimensional space of performance measures using a fuzzy c-means clustering technique and a differential split sample test, leading to identify 14 equally acceptable model hypotheses. A filtering approach was then applied to these best-performing structures in order to minimize the overall uncertainty envelope while maximizing the number of enclosed observations. This led to retain 8 model hypotheses as a representation of the minimum structural uncertainty that could be obtained with this modeling framework. Future work to better consider model predictive uncertainty should include a proper assessment of parameter equifinality and data errors, as well as the testing of new or refined hypotheses to allow for the use of additional auxiliary observations.
Extracorporeal Membrane Oxygenation Treatment for H1N1-Induced Acute Respiratory Distress Syndrome (ARDS): Results of the Croatian Referral Center for Respiratory ECMO
Authors: Kutleša Marko , Novokmet Anđa , Mraović Renata Josipović , Filar Boris , Mardešić Petar , Baršić Bruno
Published: October 2014

Introduction

Extracorporeal membrane oxygenation (ECMO) has been effective in the treatment of H1N1-induced ARDS across the globe. However, the evidence supporting the use of ECMO in ARDS is still being collected. The intention of this study was to add a piece of puzzle to the growing body of evidence on the use of ECMO in ARDS patients.

Methods

The study included adult patients with H1N1-induced ARDS treated with ECMO at the University Hospital for Infectious Diseases in Zagreb, Croatia between October 2009 and December 2013.

Results

17 patients with H1N1-induced ARDS treated with ECMO were included in the study. The patient cohort of the study was young with a median age of 43 years (range 23–74). The hospital mortality was 35%. Possible variables associated with mortality were analyzed and only hemolysis was found to be significant.

Conclusions

Our results confirm the usefulness of ECMO treatment in patients with H1N1-induced ARDS.
The Science of Folklore: Aurelio Espinosa on Spain and the American Southwest
Authors: Limón Renata
Published: October 2014

Aurelio Espinosa (1880-1958) studied folklore in the American Southwest and Spain. Espinosa was one of the first academic folklorists to work with American materials and the first scholar to write about Mexican American culture. This paper is an attempt to re-insert this forgotten figure into the history of folklore studies. At the same time, drawing on new archival sources, this study will show that Espinosa’s active support of Franco in Spain contributed to his theory of cultural transmission in the American Southwest.
Selecting populations for gene conservation purposes in forestry: a study case with Alnus acuminata in Costa Rica and Panama
Authors: Murillo O.
Published: October 2014

In forest gene conservation programs there is a continuous discussion on criteria for population elections. Before actions are initiated, it is necessary to define what is a gene resource and which of the particular populations (entries) deserve highest priority. Most gene conservation programs are oriented to 1) yield potential: genetic potential for expressions of desirable phenotypic characters; (2) genetic adaptability: the ability of populations to survive and reproduce even in a changed environment; (3) conservation of as much variation as possible. This work presents the study case of Alnus acuminata in Costa Rica and Panama and an extensive discussion on different criteria for population selection. Variables evenness deviation, proposed in this study {ed = Σpi – p-/[2(n – 1)/n]} and genetic diversity [v = ( p2i )-1], both as culling levels, showed the best criteria for populations selection. At least there was found one good candidate population in each of the three most important geographical region (breeding region), suitable for gene conservation purposes: Vara Blanca (Region Poás II), San Gerardo (Region Talamanca) and Boquete (Region Panama). Possibilities of in situ gene conservation in natural protected areas are also discussed.
Post-fire regeneration of P. pinaster Ait. in Sierra de Guadarrama (Central Spain): modelling of initial density and survival
Authors: Madrigal J. , Hernando C. , Martinez E. , Guijarro M. , Diez C.
Published: October 2014

Natural regeneration of Pinus pinater after wildfire is quite irregular and depends on several unwellknown factors. The objective of this research work is to analyze said process in the forest fire which took place in summer 1999, affecting a total surface of 450 ha, in the Monte Abantos (Sierra de Guadarrama), located in the region of Madrid (Central Spain). This study was carried out in 50 permanent plots, 3 × 3 m size, over the following four years after the fire, collecting data about density, height, slenderness and mortality of the P. pinaster natural regeneration. The final results show that there are a large number of factors which affect seedlings emergency and mortality. A linear pattern that reveals the importance of germination layer physical properties (litter, outcrops and erosion), physiography and interspecific competition, has been obtained. According with the logistical pattern generated, interspecific competition is the most important factor to determine seedlings survival, although physiography, potential forest productivity, basal area, and erosion are also determinant.
Influence of chemical prunning on biomass and root system development in Pinus pinaster Ait. and Pinus radiata D. Don
Authors: Cabal A. , Kidelman A. , Ortega U. , Duñabeitia M. , Majada J.
Published: October 2014

In relation to the stability problems found in many plantations, this work studies the effect in the nursery of different cultural practices, with the purpose of improving seedling quality. Two of the most commonly used species for afforestation purposes in the Cantabrian cornice in the last years were grown in the nursery: Pinus pinaster Ait. and Pinus radiata D. Don, using three different containers (Forest Pot 250, Cetap 54-Universal and Planfor) and covering the walls of the first two ones with CuCO3 in different concentrations (0, 1.5, 3, 4.5 %). Both species showed different response to copper treatment depending on the container, beeing P. pinaster the less sensitive species as regards to allometric modification. In general, copper treatment in P. radiata produced higher diameter, height and shoot biomass. We found statistically significant differences in the height to diameter ratio, for both species. All these circumstances produced finally a root system architecture modification in copper treated plants. Chemical prunning has demonstrated to be an effective method for rectifying some limitations derived from root system deformations, which are a consequence of using closed-walls containers for plant production.
Stand basal area growth functions for Pinus sylvestris L. plantations in Galicia
Authors: Diéguez-Aranda U. , Castedo Dorado F. , Álvarez González J. G.
Published: October 2014

A compatible basal area growth system was developed for single-species, even-aged Scots pine (Pinus sylvestris L.) stands in Galicia (northwestern Spain). The data used to develop the system were obtained from an inventory of 155 plots located in unthinned or lightly thinning stands and from a second inventory of 68 of these plots. The system consists of a function for predicting initial stand basal area and another for projecting stand basal area. The former is a growth function obtained by integration of a differential equation; the latter was obtained from the initialization function expressed as an algebraic difference equation. Compatibility between the two equations was ensured by estimating the projection function parameters separately, substituting their values into the initialization function, and then fitting this function to obtain the estimate of the remaining parameter. This method of proceeding gives priority to the projection function, and was selected because it was considered that the model projection would be used most frequently to estimate stand basal area from any given initial stand conditions obtained from a forest inventory. The model that provided the best results was based on the Korf ’s function (with b1 as free parameter), which explained 93.5% of the variability of the stand basal area projected by the algebraic difference equation. This model estimates future stand basal area using initial basal area and initial and final ages as independent variables. The corresponding initialization equation explained 71.9% of the variability of the stand basal area at any point in time. In this case, the free parameter was expressed as a multiplicative inverse function of site index.
Palaeophytogeographical contributions to the Iberian vegetal landscape interpretation: state of the art and new prospects for research
Authors: Alcalde C. , García-Amorena I. , García Álvarez S. , García Calvo D. , García García R. , Génova M. , Gil Borrell P. , Gómez Manzaneque F. , Maldonado J. , Morla C. , Del Nido J. , Postigo J. M. , Regato P. , Río S. , Roig S. , Rubiales J. M. , Sánchez Hernando L. J.
Published: October 2014

The palaeobotanical studies that have been accomplished in the Iberian Peninsula during the last two decades have provided a great amount of data that can be applied in geobotanical knowledge. In most of the cases, those results have contributed to solve classical scientific debates regarding vegetal landscapes interpretations. One of the most relevant discussions is related to the aloctonous or non-aloctonous origin of much of the Iberian pine forests, on diverse Iberian habitats. The main contributions of Palaeobotany to the processes that explain the present distribution of plants are reviewed in a spatial and temporal framework, from old geological periods (Mesozoic, Tertiary) to the recent ones (Pleistocene, Holocene). Linked to the history of our vegetal landscapes, Pleistocene and Holocene epochs have been treated from two different points of view: firstly the problems within extensive territorial environments and, secondly, the problems related to the interpretation of the evolution and/or behaviour of taxa. In the last part, some new investigation trends related to palaeophytogeography are exposed, focusing on the high potential interest on being applied to Iberian ecosystems.
Selection of an instrument to evaluate the organizational environment of nurses working in intensive care: an integrative review
Authors: Abbenbroek Brett , Duffield Christine , Elliott Doug
Published: October 2014

Objective: To determine an appropriate survey instrument to evaluate the impact of organizational structures on the work environment of intensive care nurses. Background: Internationally the demand for intensive care is increasing. Solely increasing bed capacity is not sustainable. Large capacity multi-specialty Intensive Care Units are emerging as the preferred organizational model with benefits resulting from optimizing operational synergies and economies of scale. The impact of this organizational transition on intensive care nurses is not well understood. An appropriate survey instrument for intensive care nurses is required. Design: Integrative literature review. Data Sources: CINAHL, PubMed, EMBASE and OVID Nursing databases searched for studies published between 2005 and 2013. Review methods: An integrative review and quality assessment of the studies was undertaken to select nurse outcome measures associated with organizational structures across a range of acute and critical care settings. Congruence between nurse outcome measures and nurse survey instruments tested in the literature was assessed to select instruments for further psychometric evaluation. Results: Thirty-one cross sectional quantitative studies, from fourteen countries, were reviewed. Twenty one nurse outcome measures associated with organizational factors were identified and a total of twenty five survey instruments used in the studies reviewed. Assessment of congruence and psychometric properties determined that a combination of two instruments is required to comprehensively assess the organizational environment of nurses working in intensive care units. Conclusion: The environment of nurses working in intensive care is effectively evaluated with an instrument that combines subscales from the Practice Environment Scale-Nurse Work Index and Maslach’s Burnout Inventory.
Mathematical Modelling of Non-Isothermal Moisture Transfer and Rheological Behavior in Cappilary-Porous Materials with Fractal Structure During Drying
Authors: Sokolowskyi Yaroslav , Shymanskyi Volodymyr
Published: October 2014

The mathematical model of non-isothermal moisture transfer and rheological behavior of wood during drying with taking into account the fractal structure of this material is regarded in the article. The mathematical tools of integration and differentiation of fractional order for description the mathematical model of this process was used. For finding the numerical solution of this problem the finite-difference method predictor-corrector was used. Results show the practicability of using the mathematical tools of integration and differentiation of fractional order to calculate the temperature and humidity fields and the stress-strain state during drying timber.
Ontology Based Data Mining Approach on Web Documents
Authors: Hajiabadi Hamideh
Published: October 2014

Internet which is included plenty of huge data source is now rapidly increasing in all domains. It is considered as valuable data sources if the data can be processed that results in information. Data mining techniques are widely utilized in web documents in order to extract information. In this paper a data mining approach based on Ontology is proposed to classify web documents in order to facilitate applications based on classified text documents like search engines. The proposed approach is implemented and applied on several web documents. The experimental results show considerable progress.
An Efficient Traffic-Load and Link-Interference Aware Routing Metric for Multi Radio Multi Channel Wireless Mesh Networks Based on Link’s Effective Capacity Estimation
Authors: Islam Maheen , Rahman M. Lutfar , Rashid Mamun-Or-
Published: October 2014

Routing metrics proposed for Wireless Mesh Networks (WMNs) has various concerns like hop count, packet transmission delay, power consumption, congestion control, load balance and message collision. The routing metric of expected effective capacity (EEC) proposed in this paper guarantees to a select a path providing maximum throughput and minimum delay. A forwarding link constituting routing path is characterized by its quality, capacity, traffic demand and the degree of intervention experienced due to inter-flow and intra-flow interference. Thus the bandwidth actually attainable on a link for a flow is affected by those link properties. Our proposed metric computes the attainable bandwidth for a flow over a path which actually reflects congestion, node delay and traffic pressure on the desired path. Experiments conducted on ns-2 simulations demonstrate that our proposed routing metric can achieve significant improvements in overall network throughput, minimize end-to-end delay and able to distribute network load.
Reviewer Acknowledgements for Computer and Information Science, Vol. 7, No. 4
Authors: Lee Chris
Published: October 2014

Reviewer Acknowledgements for Computer and Information Science, Vol. 7, No. 4, 2014
Geographic Information System for Detecting Spatial Connectivity Brown Planthopper Endemic Areas Using a Combination of Triple Exponential Smoothing - Getis Ord
Authors: Yulianto J. P. Sri , Widyawati Nugraheni , D. H. Kristoko , Hasiholan S. Bistok
Published: October 2014

This study aims to develop a GIS application to detect the possible formation of brown planthoppers (BPH) (Nilaparvata lugens.Stal) endemic areas based on spatial trend, hierarchical effects and risks areas caused of spatial connectivity in a particular area. The study was conducted through five stages: (1) the collection and preprocessing of research data, (2) database development, (3) the creation of the component class Exponential Smoothing, Weight Metrics and Getis Ord, (4) development of a Early Warning class and GIS applications, and (5) information visualization in the form of graphs, maps and tables. The results show that the software component in this study; the class prediction engine; Getis Ord class and class early detection function optimally generate predictive, endemic regions and early warning information on the period ahead.
A Novel Encryption Scheme for Digital Image - Based on One Dimensional Logistic Map
Authors: Al-hazaimeh Obaida M.
Published: October 2014

In this paper, an implementation of digital image encryption scheme based on one dimensional logistic map is proposed. The chaotic cryptography technique concentrates in general on the symmetric key cryptographic technique. In the proposed algorithm, a random key table lookup criterion was combined with a one-dimensional chaotic map were used for high degree 2-stage security image encryption while maintaining acceptable overhead delay time. The proposed algorithm is based on image row shuffling and pixel-wise XOR encryption. To increase the security of row shuffling variable rotation and inversion were applied to each shuffled row, based on the difference between old and new row location. The experimental results showed that the proposed algorithm is effective and applicable. The combination of logistic map and key table lookup shows advantages of large random key space and high-level of security. The resulting cipher image is suitable for practical use in secure image storing and transmission.
Prototyping Data Warehouse System for Ministry of Higher Education in Saudi Arabia
Authors: A Alenazi Saleh Rehiel , Gholamdin Abd Ghani , Alanzi Ayed Rheal A. , Al-Matari Ebrahim Mohammed
Published: October 2014

One of the major issues confronting the ministry of higher education in the kingdom of Saudi Arabia is the procedures for taking managerial decision making on their institutions of higher learning. Thus, there has not been empirical study on the integration of institutions of higher learning’s repository to the ministry of higher education as the stakeholder. Since data warehouse is described as a system that capable of storing and exploring large amount of information from various data sources, this paper design a prototyping data warehouse for the ministry of higher institution of learning so as to facilitate searching and decision making on concerned institution. The XAMPP web server was used to design the data warehouse due to its embedded PHP and MySQL functions. Hence, the result presents a prototype that integrates the repositories of some higher learning institutions with the ministry of higher institution of learning in Saudi Arabia Kingdom.
Discounts on Discounts
Authors: Brown Scott A. , Avila Cheryl L.
Published: October 2014

Practical concerns about advertised discounts are raised. In a 1947 movie, the demographics of a small town are perfectly matched to the nation.
The Algebra Artist
Authors: Beigie Darin
Published: October 2014

Students create drawings with online software and are inspired to think holistically about graphing algebraic equations and inequalities.
Curiosity & Connections
Authors: Lim Kien H.
Published: October 2014

Counterintuitive results based on Simpson's paradox generate rich discussions about scoring and weighted averages.
Impromptu Investigations in Proof
Authors: Izydorczak Mark E.
Published: October 2014

An unexpected departure from an intended calculus lesson-maximizing the area of a rectangular enclosure containing interior fences-gives students insight in an exciting way.
Interesting Functions
Authors: Macks Judith
Published: October 2014

Contexts from the fields of geography and history emphasize functions as situations in which each input has exactly one output.
Heat and mass transport during a groundwater replenishment trial in a highly heterogeneous aquifer
Authors: Seibert Simone , Prommer Henning , Siade Adam , Harris Brett , Trefry Mike , Martin Michael
Published: October 2014

Changes in subsurface temperature distribution resulting from the injection of fluids into aquifers may impact physiochemical and microbial processes as well as basin resource management strategies. We have completed a 2 year field trial in a hydrogeologically and geochemically heterogeneous aquifer below Perth, Western Australia in which highly treated wastewater was injected for large‐scale groundwater replenishment. During the trial, chloride and temperature data were collected from conventional monitoring wells and by time‐lapse temperature logging. We used a joint inversion of these solute tracer and temperature data to parameterize a numerical flow and multispecies transport model and to analyze the solute and heat propagation characteristics that prevailed during the trial. The simulation results illustrate that while solute transport is largely confined to the most permeable lithological units, heat transport was also affected by heat exchange with lithological units that have a much lower hydraulic conductivity. Heat transfer by heat conduction was found to significantly influence the complex temporal and spatial temperature distribution, especially with growing radial distance and in aquifer sequences with a heterogeneous hydraulic conductivity distribution. We attempted to estimate spatially varying thermal transport parameters during the data inversion to illustrate the anticipated correlations of these parameters with lithological heterogeneities, but estimates could not be uniquely determined on the basis of the collected data.
Cloud feedbacks on greenhouse warming in the superparameterized climate model SP‐CCSM4
Authors: Bretherton Christopher S. , Blossey Peter N. , Stan Cristiana
Published: October 2014

Cloud feedbacks on greenhouse warming are studied in a superparameterized version of the Community Climate System Model (SP‐CCSM4) in an atmospheric component SP‐CAM4 that explicitly simulates cumulus convection. A 150 year simulation in an abrupt quadrupling of CO2 is branched from a control run. It develops moderate positive global cloud feedback and an implied climate sensitivity of 2.8 K comparable to the conventionally parameterized CCSM4 and the median of other modern climate models. All of SP‐CCSM4's positive shortwave cloud feedback is due to a striking decrease in low cloud over land, which is much more pronounced than in most other climate models, including CCSM4. Four other cloud responses – decreased midlevel cloud, more Arctic water and ice cloud, a slight poleward shift of midlatitude storm track cloud, and an upward shift of high clouds – are also typical of conventional global climate models. SP‐CCSM4 does not simulate the large warming‐induced decrease in Southern Ocean cloud found in CCSM4. Two companion uncoupled SP‐CAM4 simulations, one with a uniform 4 K sea‐surface temperature increase and one with quadrupled CO2 but fixed SST, suggest that SP‐CCSM4's global‐scale cloud changes are primarily mediated by the warming, rather than by rapid adjustments to increased CO2. SP‐CAM4 show spatial patterns of cloud response qualitatively similar to the previous‐generation superparameterized SP‐CAM3, but with systematically more positive low cloud feedbacks over low‐latitude land and ocean.
A two‐zone model for fluid catalytic cracking riser with multiple feed injectors
Authors: He Pengfei , Zhu Chao , Ho Teh C.
Published: October 2014

Developments in modeling of the fluid catalytic cracking (FCC) process have progressed along two lines. One emphasizes composition‐based kinetic models based on molecular characterization of feedstocks and reaction products. The other relies on computational fluid dynamics. The aim is to develop an FCC model that strikes a balance between the two approaches. Specifically, we present an FCC riser model consisting of an entrance‐zone and a fully developed zone. The former has four overlapping, fan‐shaped oil sprays. The model predicts the plant data of Derouin et al. and reveals an inherent two‐zone character of the FCC riser. Inside the entrance zone, cracking intensity is highest and changes rapidly, resulting in a steep rise in oil conversion. Outside the entrance zone, cracking intensity is low and varies slowly, leading to a sluggish increase in conversion. The two‐zone model provides a computationally efficient modeling approach for FCC online control, optimization, and molecular management. © 2014 American Institute of Chemical Engineers AIChE J, 61: 610–619, 2015
Brain organization of gorillas reflects species differences in ecology
Authors: Barks Sarah K. , Calhoun Michael E. , Hopkins William D. , Cranfield Michael R. , Mudakikwa Antoine , Stoinski Tara S. , Patterson Francine G. , Erwin Joseph M. , Hecht Erin E. , Hof Patrick R. , Sherwood Chet C.
Published: October 2014

Gorillas include separate eastern (Gorilla beringei) and western (Gorilla gorilla) African species that diverged from each other approximately 2 million years ago. Although anatomical, genetic, behavioral, and socioecological differences have been noted among gorilla populations, little is known about variation in their brain structure. This study examines neuroanatomical variation between gorilla species using structural neuroimaging. Postmortem magnetic resonance images were obtained of brains from 18 captive western lowland gorillas (Gorilla gorilla gorilla), 15 wild mountain gorillas (Gorilla beringei beringei), and 3 Grauer's gorillas (Gorilla beringei graueri) (both wild and captive). Stereologic methods were used to measure volumes of brain structures, including left and right frontal lobe gray and white matter, temporal lobe gray and white matter, parietal and occipital lobes gray and white matter, insular gray matter, hippocampus, striatum, thalamus, each hemisphere and the vermis of the cerebellum, and the external and extreme capsules together with the claustrum. Among the species differences, the volumes of the hippocampus and cerebellum were significantly larger in G. gorilla than G. beringei. These anatomical differences may relate to divergent ecological adaptations of the two species. Specifically, G. gorilla engages in more arboreal locomotion and thus may rely more on cerebellar circuits. In addition, they tend to eat more fruit and have larger home ranges and consequently might depend more on spatial mapping functions of the hippocampus. Am J Phys Anthropol 156:252–262, 2015. © 2014 Wiley Periodicals, Inc.
Squeezing‐enhanced measurement sensitivity in a cavity optomechanical system
Authors: Kerdoncuff Hugo , Hoff Ulrich B. , Harris Glen I. , Bowen Warwick P. , Andersen Ulrik L.
Published: October 2014

We determine the theoretical limits to squeezing‐enhanced measurement sensitivity of mechanical motion in a cavity optomechanical system. The motion of a mechanical resonator is transduced onto quadrature fluctuations of a cavity optical field and a measurement is performed on the optical field exiting the cavity. We compare measurement sensitivities obtained with coherent probing and quantum‐enhanced probing of the mechanical motion, i.e. the coherent probe field carries vacuum states and quadrature squeezed vacuum states at sideband frequencies, respectively. We find that quantum‐enhanced probing provides little to no improvement in motion sensing for resonators in the unresolved sideband regime but may significantly increase measurement sensitivities for resonators in the resolved sideband regime.
Palladium‐katalysierte Anti‐Markownikoff‐Oxidation endständiger Alkene
Authors: Dong Jia Jia , Browne Wesley R. , Feringa Ben L.
Published: November 2014

Die Palladium‐katalysierte Oxidation von Alkenen, die Wacker‐Tsuji‐Reaktion, ist zweifellos ein Klassiker der organischen Synthese und bietet unter milden Bedingungen einen zuverlässigen Zugang zu Methylketonen aus endständigen Alkenen. Methoden, die die Selektivität der Reaktion umkehren und zum Aldehyd führen, sind wünschenwert, da sie Zugang zu einer wertvollen funktionellen Gruppe bieten, sind aber auch schwer zu verwirklichen. In diesem Kurzaufsatz geben wir einen Überblick über die beiden Methoden, die vor kurzem entwickelt wurden, um eine solche Selektivität zu erreichen. Außerdem diskutieren wir Gemeinsamkeiten und mechanistische Details, die im Hinblick auf das Ziel, eine allgemeine Methode für die Anti‐Markownikoff‐selektive Olefinoxidation zu entwickeln, vielversprechend sind.
Palladium‐Catalyzed anti‐Markovnikov Oxidation of Terminal Alkenes
Authors: Dong Jia Jia , Browne Wesley R. , Feringa Ben L.
Published: November 2014

The palladium‐catalyzed oxidation of alkenes, the Wacker–Tsuji reaction, is undoubtedly a classic in organic synthesis and provides reliable access to methyl ketones from terminal alkenes under mild reaction conditions. Methods that switch the selectivity of the reaction to provide the aldehyde product are desirable because of the access they provide to a valuable functional group, however such methods are elusive. Herein we survey both the methods which have been developed recently in achieving such selectivity and discuss common features and mechanistic insight which offers promise in achieving the goal of a general method for anti‐Markovnikov‐selective olefin oxidations.