bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of L1 Adaptive Control to a High Maneuverability Aircraft
Authors: Ene Costin , Stoica Adrian Mihail
Published: July 2015

The L1 Adaptive control technique is applied to the F-18 HARV (High Alpha Research Vehicle) aircraft. This control architecture compensates for both the matched and the unmatched uncertainties of the full nonlinear aircraft dynamics. This paper describes the L1 control architecture used to control the nonlinear dynamics of the aircraft and the final part presents the detailed simulation results for the lateral channel
Design and Kinematic Analysis of Gull Inspired Flapping Wing Model
Authors: Goyal Tigmanshu , Kumar David , Kumar Vemuri Shyam , Mohite P.M. , Kamle S.
Published: July 2015

A flapping wing mimicking the Black Headed Gull was developed and tested for its kinematics. All the individual joints in the gull wing, namely the shoulder, elbow and wrist joint were mimicked with their corresponding functionalities. The shoulder joint is designed to control the flapping frequency, flapping amplitude, flapping plane and the speed of the upstroke-downstroke. Similarly, the elbow and wrist joints control the upstroke span reduction and twisting of the wing, respectively. Geometry, inertia, mass and frequency data of the gull were used to model the wing. A control input program was designed for the independent control of all the 6 joints (3 per wing). The motion of the manufactured wing system was verified using LASER Displacement Sensor.
Bend Testing on Components Manufactured by Rapid Prototyping Technology in Combination with other Materials
Authors: Lipina Jan , Krys Václav , Marek Jiří
Published: July 2015

The knowledge of the mechanical properties of the material used is a necessary prerequisite for the quality design of any structural unit. It applies to components manufactured using Rapid Prototyping technology (hereinafter only RP) multiple times, because it is not enough to only know the mechanical properties of a material from which the components are printed. Other factors affect the component printing, such as the orientation of the printed component, the selection of the component's internal structure, possibility of connection with other materials, etc. The article follows from the previous research of the experimental determination of the bend strength of parts printed by RP technology from polycarbonate, which focuses on bend-testing of samples printed with various internal structures. This article expands on the original research by experimental determination of the bend strength of printed components, which form a unit with another material. The obtained information can be utilised in the design of components manufactured with RP technology using professional printers.
Flow Control Using Air-Jet to Improve the Aerodynamic Performance of a Multi-Element Airfoil
Authors: Akbar Hassan , Jiao Yu Qin , Bakar Abu
Published: July 2015

This paper describes the application of active flow control for the NLR7301 supercritical airfoil/flap configuration at Re = 2.51x106. A parametric analysis is conducted to investigate the effects of jet parameters (jet direction, jet location and momentum coefficient) on the aerodynamic performance of a multi-element airfoil. The results indicate that flow separation is delayed and efficiency of jet can be improved with specific momentum coefficient (the best lift-drag ratio at Cμ=0.16) and jet angle (16°) when the jet is located near the separation point of the airfoil.
A Fuzzy Logic to Solve the Robotic Inverse Kinematic Problem
Authors: Aggogeri Francesco , Borboni Alberto , Adamini Riccardo , Faglia Rodolfo
Published: July 2015

This study aims at introducing a numerical algorithm based on fuzzy logic to solve the robotic inverse kinematic problem. The increase of robot complexity requires fast and robust algorithms able to improve the convergence problem in the whole workspace. Classical numerical methods are usually difficult and computationally expensive and they do not always converge. The proposed approach is based on a fuzzy scheme, it converges in all the tested simulations on a serial manipulator.
Experimental Research on Magnetic Treatment of Fuel Fluids before Burner for Increasing Thermal Efficiency and Reducing Emissions Resulting from the Burning Process
Authors: Ciobanu Robert , Repetto Maurizio , Donţu Octavian , Besnea Daniel , Spanu Alina
Published: July 2015

Through magnetic treatment of fuel before burner, the main factors influencing the burning process like fuel quality and spray quality undergoes changes, and the burning process is substantially improved. Acting on the fuel fluid with certain successive alternating polarity magnetic waves generated by permanent magnets, which is one of the innovative features of the system proposed in this paper, there is an intensification of the process of changing the stereochemistry of molecules, appearing fractionation, leading to increasing its magnetic moment and to their stronger ionization. These changes result in increased affinity of fuel molecules to other molecules and ions from close proximity, thus implicitly to oxygen molecules who have a strong paramagnetic behavior and the combustion of the fuel will take place in the upper parameters. In this paper is proposed, tested and validated by a series of experimental burning tests an innovative system used for magnetic treatment of combustible fluids before burner.
Preparation and Characterization of Nickel and Copper Oxide/Hydroxide Films on Stainless Steels Substrates for Use as Cathodes in Alkaline Water Electrolysis
Authors: Cardoso David S.P.P. , Brito Paulo S.D. , Rodrigues Luiz F.F.T.T.G.
Published: July 2015

The production high purity hydrogen by water electrolysis based renewable sources as a mean to store energy, has gained some attention in the last years due to the high specific energy of hydrogen, the potentially neutral carbon and zero emission of the usage of H2as fuel. However, it remains certainly necessary to develop efficient and lower cost electrolyzers. Such a situation requires the search for and the development of inexpensive and stable electrode materials, showing low polarization to hydrogen evolution reduction (HER). In this work copper and nickel oxides were studied for use as electrodes for the reduction of hydrogen in alkaline water electrolysis. The nickel and copper oxide composites coatings were deposited electrochemically as oxides/hydroxides on a stainless steel (SS) electrode and characterized using electrochemical methods such as cyclic voltammetry (CV), cathodic polarization and Tafel slops. The HER was studied using as electrolytic cathodes unmodified AISI 304 stainless steel (SS), nickel coated stainless steel (SS/Ni), copper coated stainless steel (SS/Cu), and nickel (under layer) and copper (top layer) coated stainless steel (SS/Ni/Cu) in 5 M KOH solution. It was found that, the SS/Ni/Cu electrode presents good electrocatalytic activity and stability toward the HER, compared to the SS electrodes modified by single nickel oxide layer. This behavior seems be explained by the synergistic interaction of Ni and Cu with Fe present in the stainless steel.
Numerical Study on Impeller Performance of Mini Hydro Turbine
Authors: Kim Kyu Han , Cahyono Joni
Published: July 2015

The aim of this paper is to numerically explore the feasibility of designing a Mini-Hydro turbine. The interest for this kind of horizontal axis turbine relies on its versatility. In the present study, the numerical solution of the discredited three-dimensional, incompressible Navier-Stokes equations over an unstructured grid is accomplished with an ANSYS program. In this study, a mini hydro turbine (3kW) has been considered for utilization of horizontal axis impeller. The turbine performance and flow behavior have been evaluated by means of numerical simulations. Moreover, the performance of the impeller varied in the pressure distribution, torque, rotational speed and power generated by the different number of blades and angles. The results trends are similar between the highest pressure distributions at the impeller also produced highest power outputs on 6 numbers of blades at impeller. The model has been validated, comparing numerical results with available experimental data.
Design of a Gorlov Turbine for Marine Current Energy Extraction
Authors: Chettiar Niranjwan , Narayan Sumesh , Goundar Jai Nendran , Deo Ashneel
Published: July 2015

As fossil fuels near depletion and their detrimental side effects become prominent on ecosystems, the world searches renewable sources of energy. Marine current energy is an emerging and promising renewable energy resource. Marine current energy can be alternative energy source for electricity production. Many marine current converters are designed to tap marine current energy; however, Gorlov turbine proves to have minimum manufacturing and maintenance cost, hence giving desired power output. A 0.3m diameter and 0.6m long 3 bladed Gorlov turbine was designed, fabricated and test to analyse its performance. The turbine produces average power 15 W and proves to be quite efficient for marine current energy extraction.
Design of a Ducted Cross Flow Turbine for Fiji
Authors: Goundar Jai Nendran , Chettiar Niranjwan , Narayan Sumesh , Deo Ashneel , Prasad Deepak
Published: July 2015

Marine current energy is clean and reliable energy source. It can be alternative energy source to produce electricity if tapped with a suitable marine current energy converter. Pacific Island countries (PIC) like Fiji can reduce the amount of Fossil fuel used. However for most energy converters designed perform well at marine current velocities above 2m/s and it needs to be installed at depths of 20 – 40m also installation and the maintenance cost of such devise will be quite high if it needs to be installed in Fiji. Therefore a ducted cross flow turbine was designed, which can give desired output at minimum installation and maintenance cost. A dusted cross flow turbine has been design taking into account for its operating condition. The turbine was modelled and analyzed in commercial; Computational Fluid dynamic (CFD) code ANSYS-CFX. The code was first validated and with experiment results and finally performance analysis of full scale turbine was carried out. The designed turbine can have maximum efficiency of 56% producing rated power of 21kW; it produces 0.77kW at cut in speed of 0.65m/s.
Intravascular Stent Motor
Authors: Nishizawa Uichi , Toyama Shigeki
Published: July 2015

We have developed a movable stent motor in the blood vessel by applying the technique of the ultrasonic motor. We have also designed a stent motor which consists of two parts; a stator part and receiver part. The receiver unit obtains the ultrasonic wave from outside and the stator generates a driving force. The stator is the coil shape and it can move smoothly in intravascular. Adding that, we have designed the horn to provide ultrasonic energy to it from outside of human body. We have made experiments by the horn and the stent motor and we have succeeded in driving the stent motor in the water back and forth.
Concerning on a Lower Limb Joint Affections Rehabilitation Equipment Command
Authors: Petre Ioana Mădălina , Deaconescu Tudor , Deaconescu Andrea
Published: July 2015

The aim of the article is to analyze the command of a rehabilitation equipment. The presented rehabilitation equipment allows lower limb joints movements, in order to recover their functionality. The rehabilitation movements are known as continuous passive motion, term used in kinetotherapy.The command used is composed by of a pneumatic muscle supplied with air from a pressure proportional regulator and controlled by a reference module. The reference module, by means of rotary potentiometers, can generate up to six different values of ​​reference voltage which are transmitted as signals to the proportional controller. If no appeal to any of these benchmarks, the transmitted signal to the pressure regulator is a voltage that can be modified by an external potentiometer. The results of experiments shows that proportional pressure regulator allows easy modification of the pressure slope, with better results on rehabilitation movements.
Design and Motion Analysis of a Powered Wheelchair
Authors: Geonea Ionut , Dumitru Nicolae , Dumitru Violeta
Published: July 2015

This paper presents researches developed by authors to design a motorized robotic wheelchair for disabled people. These devices enable disabled people perform many activities of daily living thus improving their quality of life. Proposed solution uses for traction one DC motor with steps adjustable angular speed, and for steering one smaller motor. It is presented the kinematic scheme of the proposed transmission and kinematic analysis. It is developed a CAD model of the transmission, mounted on a wheelchair. They are made simulation in Adams, in order to verify the functionality of the proposed transmission. The obtained results validate proposed transmission model and enable success implementation of this transmission to a wheelchair experimental model.
Molecular Dynamics Simulations of Thermal Conductivity of Germanene Nanoribbons (GeNR) with Armchair and Zigzag Chirality
Authors: Balatero Marissa A. , Paylaga Giovanni J. , Paylaga Naomi T. , Bantaculo Rolando V.
Published: July 2015

Germanene, an allotrope of germanium which is a two dimensional material withsp2hybridization, has almost the same properties with graphene except for its buckled structure. In this study, germanium nanoribbon (GeNR) is use for it is still a new material for nanoscale level of research. In this paper, we investigate the effect of chirality on the thermal conductivity of zigzag GeNR (ZGeNR) and armchair GeNR (AGeNR) chiralities using equilibrium molecular dynamics with varied lengths at fixed temperature and varied temperatures at fixed length. The simulations were carried out in Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) using Tersoff potential for the Ge-Ge interactions. The thermal conductivity is calculated using Green-Kubo method. It is found that the chirality can affect the thermal conductivity of GeNR. Our results show that thermal conductivity of AGeNR is higher than ZGeNR in both increasing temperatures and lengths similar to the thermal conductivity behavior obtained in silicene nanoribbons [Int. J. Mech. Mater. Des. 9 (2013) 105].
Tool Wear of Aluminum/Chromium/Tungsten-Based-Coated Cemented Carbide in Cutting Hardened Sintered Steel
Authors: Wada Tadahiro , Hanyu Hiroyuki
Published: July 2015

In order to improve both the scratch strength and the micro-hardness of (Al,Cr)N coating film, the cathode material of an aluminum/chromium/tungsten target was used in adding the tungsten (W) to the cathode material of the aluminum/chromium target. In this study, hardened sintered steel was turned with (Al60,Cr25,W15)N, (Al60,Cr25,W15)(C,N), (Al64,Cr28,W8)(C,N), (Al,Cr)N and (Ti,Al)N coated cemented carbide tools. The tool wear of the coated cemented carbide tool was experimentally investigated. The following results were obtained: (1) In cutting hardened sintered steel at the cutting speed of 0.42 m/s using the (Al60,Cr25,W15)N, the (Al60,Cr25,W15)(C,N), the (Al64,Cr28,W8)(C,N), the (Ti,Al)N and (Al,Cr)N coated tools, the wear progress of the (Al64,Cr28,W8)(C,N) coated tool became slowest among that of the five coated tools. (2) The wear progress of the (Al60,Cr25,W15)(C,N) coated tool was almost equivalent to that of the (Al64,Cr28,W8)(C,N) coated tool. However, at a high cutting speed of 1.67 m/s, the wear progress of the (Al60,Cr25,W16)(C,N) coated tool was faster than that of the (Al64,Cr28,W8)(C,N) coated tool.
Analysis of the Deformation Mode and Determination of the Energy Dissipated by the Resistance Structure of the Vehicles
Authors: Soica Adrian , Tarulescu Stelian
Published: July 2015

The increasingly tougher international regulations force motor vehicle designers and manufacturers to find complex solutions that should increase the protection of motor vehicle occupants. In this paper the author carries out an analysis on the energy absorption by a front strut-type structure of a motor vehicle involved in head-on collision with a rigid barrier inclined at various angles. Small overlap collisions open new challenges for car manufacturers with a view to developing structures able to absorb the impact and provide safety to the motor vehicle occupants.
The Vehicle’s Frontal Impact Influence on Driver in out of Position
Authors: Oţăt Oana Victoria , Dumitru Nicolae
Published: July 2015

The present paper underpins a contrastive study of the driver’s behavior and the injuries suffered in frontal vehicle collision, with a focus on the analysis of head-specific injuries. Four different simulation cases have been performed by means of the LS-DYNA software, where a seated belted and/or unbelted Hybrid III 50th percentile male dummy was in turns normally-positioned and out of position. Accordingly, both the analyses as well as the numerical simulation have been completed by applying a five-component model that encompasses: the dummy, the seat, the seatbelt, the steering wheel and the airbag. The assembly’s prescribed motion has been defined following a frontal Virtual Crash software-based impact simulation of a mid-size sedan at a velocity of 50 km/h against a rigid wall. The results analysis aimed at identifying the longitudinal variation laws over time in head displacements and accelerations as well as lateral motion. Admittedly, the results analysis certified that a more controlled-oriented approach to the selection of the driver’s normal positioning is a prerequisite in compliance with typical driving particularities.
Factors preceding CRM readiness in small- and medium-sized tourism enterprises
Authors: Vallabh Dinesh , Radder Laetitia , Venter Danie
Published: July 2015

Orientation: Customer relationship management (CRM) is important to organisations striving for competitive advantage through building relationships with their customers.Research purpose: This study identified the factors preceding CRM and assessed selected South African small- and medium-sized tourism enterprises’ (SMTEs) readiness for CRM.Motivation: CRM is likely to enhance SMTEs’ competitiveness. However, successful adoption and implementation of CRM is unlikely unless the organisation is ready for it.Research design, approach and method: A quantitative research approach and survey questionnaire yielded primary data from 332 respondent organisations selected by systematic sampling. Exploratory factor analysis was used to identify the latent factors preceding CRM readiness. Organisational CRM readiness was assessed based on CRM maturity in terms of data collection, use and sharing throughout the organisation.Main findings: Respondent-organisations performed well on the four factors preceding CRM readiness − business strategy, customer strategy, touch points and competencies, skills and technology and also on data collections and use, but not on data sharing.Practical/Managerial implications: CRM practice is believed to assist organisations in tailoring products and services to customers’ needs, providing customer satisfaction, enhancing customer retention and ultimately improving the organisation’s competitiveness and profitability. CRM might fail if SMTEs do not have CRM-enabling conditions in place and a CRM readiness audit should therefore be performed.Contribution: The study contributes to a largely under-researched area concerning CRM in SMTEs by providing an improved understanding of the factors that will enable SMTEs to engage in CRM activities.
Antimicrobial resistance of bacterial isolates from respiratory secretions of ventilated patients in a multi-specialty hospital
Authors: Ahmed Nishat Hussain , Hussain Tabish , Biswal Indu
Published: July 2015

Context: Ventilator-associated pneumonia (VAP) is a common nosocomial infection occurring in intensive care unit (ICU) settings. VAP occurs due to interplay of three factors - impaired host defense, access of large numbers of pathogenic bacteria to the lower respiratory tract and the virulence of the organism. Knowledge of colonizing microbial flora and their antibiogram in ventilated patients is of great importance in timely institution of empirical therapy, so that mortality and morbidity due to VAP can be reduced. Subjects and Methods: A prospective study was performed over a period of 6 months in a multi-specialty hospital to determine the various pathogens in respiratory secretions and to determine the prevalence of multidrug resistance (MDR). Results: Pseudomonas aeruginosa (26%), Acinetobacter (26%), Klebsiella pneumoniae (26%), followed by Escherichia coli (15%), Staphylococcus aureus (6%) and Citrobacter spp. (1.5%) were the common pathogens isolated in our study. In all, 72.73% (48/66) bacterial isolates were isolated from medical ICU, while 25.76% (17/66) were isolated from surgical ICU. Only one strain (Acinetobacter) was isolated from pediatric ICU. Fifty-seven (86.36%) of the 66 pathogens in our study were MDR. Conclusion: There is increasing colonization of pathogenic bacteria in ventilated patients admitted in ICUs, which are predominantly MDR. These colonizers may cause infection resulting in VAP. Judicious use of antibiotics, guided by local antibiotic resistance profile coupled with strict infection control practices alongside application of VAP bundle are important measures to prevent these pathogens from causing VAP in ICU patients.
Brainstem auditory evoked potential in clinical hypothyroidism
Authors: Sharma Kirti , Kumar Naresh , Behera Joshil Kumar , Sood Sushma , Das Sibadatta , Madan Harnam Singh
Published: July 2015

Objectives: The association of hypothyroidism with impairment of hearing is known to occur. It may be of any kind i. e., conductive, sensorineural or mixed. The aim of this study is to assess auditory pathway by brainstem auditory evoked potential (BAEP) in newly diagnosed patients of clinical hypothyroidism and healthy sex- and age-matched controls. Materials and Methods: The study included 25 healthy age- and sex-matched controls (Group I) and 25 patients of newly diagnosed clinical hypothyroidism (Group II). The recording was taken by using RMS EMG EP MK2 equipment. Statistical Analysis Used: Unpaired Student′s t test. Results: There was a significant increase in wave IV (5.16 ± 0.85 ms) and wave V (6.17 ± 0.89 ms) latencies of right ear BAEP of Group II in comparison to wave IV (4.66 ± 0.39 ms) and wave V (5.49 ± 0.26 ms) of Group I. Wave V of left ear BAEP of Group II was also prolonged (6 ± 0.61 ms) in comparison to Group I (5.47 ± 0.35 ms). There was a significant difference in inter-peak latencies IPL I -V (4.44 ± 0.66 ms) and IPL III -V (2.2 ± 0.5 ms) of right ear BAEP of Group II in comparison to IPL I -V (3.94 ± 0.31 ms) and IPL III -V (1.84 ± 0.34 ms) of Group I. A significant prolongation was also found of IPL I -V (4.36 ± 0.59 ms) and IPL III -V (2.2 ± 0.42 ms) of left ear BAEP of Group II in comparison to IPL I -V (3.89 ± 0.3 ms) and IPL III -V (1.85 ± 0.3 ms) of Group I. Conclusion: Prolongation of wave IV and V along with inter-peak latencies in BAEP of both ears suggests that central auditory pathway is affected significantly in clinical hypothyroid patients.
De Novo Transcriptome Assembly and Development of Novel Microsatellite Markers for the Traditional Chinese Medicinal Herb, Veratrilla baillonii Franch (Gentianaceae)
Authors: Wang Lei , Wang Zhengkun , Chen Jianbing , Liu Chunyan , Zhu Wanlong , Wang Liuyang , Meng Lihua
Published: July 2015

Veratrilla baillonii Franch is an important Chinese medicinal herb for treating liver-related diseases, which has been over-collected in the recent decades. However, the effective conservation and related population genetic study has been hindered because of the lack of genome sequences and genetic markers in the natural population. We have conducted RNA-seq on V. baillonii. We performed de novo assembly of these data to characterize the V. baillonii transcriptome, resulting in 133,019 contigs with size >200 bp. These contigs were annotated using the NCBI nonredundant database and Gene Ontology (GO) terms. From these contigs, we developed novel microsatellite simple sequence repeat (SSR) markers, identifying a total of 40,885 SSRs. SSRs with repeat motifs of 1–4 bp (mono-, di-, tri-, and tetranucleotides) accounted for 99.8% of all SSRs, with mononucleotide repeats most common, followed by dinucleotide (16.2%) and trinucleotide repeats (14.7%). We selected 151 SSRs for experimental validation, of which 74 were confirmed by polymerase chain reaction. Fourteen SSRs were determined to be polymorphic by screening 40 individuals from six distant populations. The number of alleles per locus ranged from two to four, and the expected heterozygosity varied from 0.2637 to 0.8571, suggesting that these SSR markers are highly polymorphic and effective for further genetic analysis in the nature population. In addition, we explored the genetic structure of V. baillonii using five SSRs in four geographic populations and found that the identified genotypes were clustered into two phylogenetic clades: the Mekong River clade and Jinsha River clade. This result indicates that these two regions may harbor highly divergent genetic lineages and enriched genetic diversity. The de novo transcriptome sequences and new SSR markers discovered by this study provide an initial step for understanding the population genetics of V. baillonii, and a valuable resource for effective conservation management.
The Origin of Land Plants: A Phylogenomic Perspective
Authors: Zhong Bojian , Sun Linhua , Penny David
Published: July 2015

Land plants are a natural group, and Charophyte algae are the closest lineages of land plants and have six morphologically diverged groups. The conjugating green algae (Zygnematales) are now suggested to be the extant sister group to land plants, providing the novel understanding for character evolution and early multicellular innovations in land plants. We review recent molecular phylogenetic work on the origin of land plants and discuss some future directions in phylogenomic analyses.
Variational-Hemivariational Approach to a Quasistatic Viscoelastic Problem with Normal Compliance, Friction and Material Damage
Authors: Gasiński Leszek , Ochal Anna , Shillor Meir
Published: July 2015

This work studies a model for quasistatic frictional contact between a viscoelastic body and a reactive foundation. The constitutive law is assumed to be nonlinear and contains damage effects modeled by a parabolic differential inclusion. Contact is described by the normal compliance condition and a subdifferential frictional condition. A variational-hemivariational formulation of the problem is provided and the existence and uniqueness of its solution is proved. The proof is based on a surjectivity result for pseudomonotone coercive operators and a fixed point argument.
A Regularity Criterion for the Density-Dependent Hall-Magnetohydrodynamics
Authors: Fan Jishan , Alsaedi Ahmed , Fukumoto Yasuhide , Hayat Tasawar , Zhou Yong
Published: July 2015

This paper proves a regularity criterion for the density-dependent Hall-magnetohydrodynamics with positive density.
A Linearized Model for Compressible Flow past a Rotating Obstacle: Analysis via Modified Bochner–Riesz Multipliers
Authors: Farwig Reinhard , Pokorný Milan
Published: July 2015

Consider the flow of a compressible Newtonian fluid around or past a rotating rigid obstacle in

{\mathbb R}^3.

After a coordinate transform to get a problem in a time-independent domain we assume the new system to be stationary, then linearize and - in this paper dealing with the whole space case only - use Fourier transform to prove the existence of solutions

u

in

L^q

-spaces. However, the solution is constructed first of all in terms of

g=\mathrm {div}\, u

, explicit in Fourier space, and is in contrast to the incompressible case not based on the heat kernel, but requires the analysis of new multiplier functions related to Bochner-Riesz multipliers and leading to the restriction

\frac{6}{5}<q<6

.
Multiplicity of Nontrivial Solutions of a Class of Fractional $p$-Laplacian Problem
Authors: Abdeljabbar Ghanmi
Published: July 2015

In this paper, we deal with existence of nontrivial solutions to the fractional

p

-Laplacian problem of the type

\left\{
\begin{array}{rll}
(-\vartriangle)^{\alpha}_{p} u \! \!&= \ \frac{1}{r}\frac{\partial F(x,u)}{\partial u} + \lambda a(x)|u|^{q-2}u &\text{ in} \ \Omega, \\
u \! \!&= \ 0 &\text{ in}\ \mathbb{R}^{n}\setminus\Omega, \end{array} \right.

where

\Omega

is a bounded domain in

\mathbb{R}^{n}

with smooth boundary

\partial \Omega

,

a\in C(\Omega)

,

p\geq 2

,

\alpha \in (0,1)

such that

p \alpha < n

,

1 < q < p < r < \frac{np}{n-\alpha p}

, and

F \in C^{1}(\overline{\Omega} \times \mathbb{R}, \mathbb{R})

. Using the decomposition of the Nehari manifold, we prove that the non-local elliptic problem has at least two nontrivial solutions.
A Characterization of Absolute Continuity by means of Mellin Integral Operators
Authors: Angeloni Laura , Vinti Gianluca
Published: July 2015

In the case of classical convolution operators, an important characterization of absolute continuity is given in terms of convergence in variation. In this paper we will study this problem for Mellin integral operators, proving analogous characterizations in the frame of the classical

BV

-spaces, both in the one-dimensional and in the multidimensional setting.
Density Results for Energy Spaces on some Fractafolds
Authors: Lancia Maria Rosaria , Durante Valerio Regis , Vernole Paola
Published: July 2015

In this paper we prove density results for the domains of energy forms defined on a scale irregular fractal surface

S^{(\xi)}

, as well as on the corresponding three-dimensional bounded cylindrical domain

Q^{(\xi)}

, whose lateral boundary is

S^{(\xi)}

.
On the reversibility of transitions between closed and open cellular convection
Authors: Feingold G. , Koren I. , Yamaguchi T. , Kazil J.
Published: July 2015

Abstract. The two-way transition between closed and open cellular convection is addressed in an idealized cloud-resolving modeling framework. A series of cloud-resolving simulations shows that the transition between closed and open cellular states is asymmetrical and characterized by a rapid ("runaway") transition from the closed- to the open-cell state but slower recovery to the closed-cell state. Given that precipitation initiates the closed–open cell transition and that the recovery requires a suppression of the precipitation, we apply an ad hoc time-varying drop concentration to initiate and suppress precipitation. We show that the asymmetry in the two-way transition occurs even for very rapid drop concentration replenishment. The primary barrier to recovery is the loss in turbulence kinetic energy (TKE) associated with the loss in cloud water (and associated radiative cooling) and the vertical stratification of the boundary layer during the open-cell period. In transitioning from the open to the closed state, the system faces the task of replenishing cloud water fast enough to counter precipitation losses, such that it can generate radiative cooling and TKE. It is hampered by a stable layer below cloud base that has to be overcome before water vapor can be transported more efficiently into the cloud layer. Recovery to the closed-cell state is slower when radiative cooling is inefficient such as in the presence of free tropospheric clouds or after sunrise, when it is hampered by the absorption of shortwave radiation. Tests suggest that recovery to the closed-cell state is faster when the drizzle is smaller in amount and of shorter duration, i.e., when the precipitation causes less boundary layer stratification. Cloud-resolving model results on recovery rates are supported by simulations with a simple predator–prey dynamical system analogue. It is suggested that the observed closing of open cells by ship effluent likely occurs when aerosol intrusions are large, when contact comes prior to the heaviest drizzle in the early morning hours, and when the free troposphere is cloud free.
Efficient photochemical generation of peroxycarboxylic nitric anhydrides with ultraviolet light-emitting diodes
Authors: Rider N. D. , Taha Y. M. , Odame-Ankrah C. A. , Huo J. A. , Tokarek T. W. , Cairns E. , Moussa S. G. , Liggio J. , Osthoff H. D.
Published: July 2015

Abstract. Photochemical sources of peroxycarboxylic nitric anhydrides (PANs) are utilized in many atmospheric measurement techniques for calibration or to deliver an internal standard. Conventionally, such sources rely on phosphor-coated low-pressure mercury (Hg) lamps to generate the UV light necessary to photo-dissociate a dialkyl ketone (usually acetone) in the presence of a calibrated amount of nitric oxide (NO) and oxygen (O2). In this manuscript, a photochemical PAN source in which the Hg lamp has been replaced by arrays of ultraviolet light-emitting diodes (UV-LEDs) is described. The output of the UV-LED source was analyzed by gas chromatography (PAN-GC) and thermal dissociation cavity ring-down spectroscopy (TD-CRDS). Using acetone, diethyl ketone (DIEK), diisopropyl ketone (DIPK), or di-n-propyl ketone (DNPK), respectively, the source produces peroxyacetic (PAN), peroxypropionic (PPN), peroxyisobutanoic (PiBN), or peroxy-n-butanoic nitric anhydride (PnBN) from NO in high yield (> 90 %). Box model simulations with a subset of the Master Chemical Mechanism (MCM) were carried out to rationalize product yields and to identify side products. The present work demonstrates that UV-LED arrays are a viable alternative to current Hg lamp setups.
Estimating along-track plasma drift speed from electron density measurements by the three Swarm satellites
Authors: Park J. , Lühr H. , Stolle C. , Malhotra G. , Baker J. B. H. , Buchert S. , Gill R.
Published: July 2015

Abstract. Plasma convection in the high-latitude ionosphere provides important information about magnetosphere–ionosphere–thermosphere coupling. In this study we estimate the along-track component of plasma convection within and around the polar cap, using electron density profiles measured by the three Swarm satellites. The velocity values estimated from the two different satellite pairs agree with each other. In both hemispheres the estimated velocity is generally anti-sunward, especially for higher speeds. The obtained velocity is in qualitative agreement with Super Dual Auroral Radar Network data. Our method can supplement currently available instruments for ionospheric plasma velocity measurements, especially in cases where these traditional instruments suffer from their inherent limitations. Also, the method can be generalized to other satellite constellations carrying electron density probes.
Inferring climate variability from nonlinear proxies: application to paleo-ENSO studies
Authors: Emile-Geay J. , Tingley M. P.
Published: July 2015

Abstract. Inferring climate from paleodata frequently assumes a direct, linear relationship between the two, which is seldom met in practice. Here we simulate an idealized proxy characterized by a nonlinear, thresholded relationship with surface temperature, and demonstrate the pitfalls of ignoring nonlinearities in the proxy–climate relationship. We explore three approaches to using this idealized proxy to infer past climate: (i) methods commonly used in the paleoclimate literature, without consideration of nonlinearities, (ii) the same methods, after empirically transforming the data to normality to account for nonlinearities, (iii) using a Bayesian model to invert the mechanistic relationship between the climate and the proxy. We find that neglecting nonlinearity often exaggerates changes in climate variability between different time intervals, and leads to reconstructions with poorly quantified uncertainties. In contrast, explicit recognition of the nonlinear relationship, using either a mechanistic model or an empirical transform, yields significantly better estimates of past climate variations, with more accurate uncertainty quantification. We apply these insights to two paleoclimate settings. Accounting for nonlinearities in the classical sedimentary record from Laguna Pallcacocha leads to quantitative departures from the results of the original study, and markedly affects the detection of variance changes over time. A comparison with the Lake Challa record, also a nonlinear proxy for El Niño–Southern Oscillation, illustrates how inter-proxy comparisons may be altered when accounting for nonlinearity. The results hold implications for how nonlinear recorders of normally distributed climate variables are interpreted, compared to other proxy records, and incorporated into multiproxy reconstructions.
Google chemtrails: A methodology to analyze topic representation in search engine results
Authors: Ballatore Andrea
Published: July 2015

Search engine results influence the visibility of different viewpoints in political, cultural, and scientific debates. Treating search engines as editorial products with intrinsic biases can help understand the structure of information flows in new media. This paper outlines an empirical methodology to analyze the representation of topics in search engines, reducing the spatial and temporal biases in the results. As a case study, the methodology is applied to 15 popular conspiracy theories, examining type of content and ideological bias, demonstrating how this approach can inform debates in this field, specifically in relation to the representation of non-mainstream positions, the suppression of controversies and relativism.
The Twitter Archive at the Library of Congress: Challenges for information practice and information policy
Authors: Zimmer Michael
Published: July 2015

In April 2010, the U.S. Library of Congress and the popular micro-blogging company Twitter announced that every public tweet, since Twitter’s inception in March 2006, will be archived digitally at the Library and made available to researchers. The Library of Congress’ planned digital archive of all public tweets holds great promise for the research community, yet, over five years since its announcement, the archive remains unavailable. This paper explores the challenges faced by the Library that have prevented the timely realization of this valuable archive, divided into two categories: challenges involving practice, such as how to organize the tweets, how to provide useful means of retrieval, how to physically store them; and challenges involving policy, such as the creation of access controls to the archive, whether any information should be censored or restricted, and the broader ethical considerations of the very existence of such an archive, especially privacy and user control.
Richard Schacht's Nietzsche
Authors: Clark Maudemarie
Published: July 2015

In this article, written for a panel presentation celebrating the thirtieth anniversary of the publication of Richard Schacht's Nietzsche, I examine the perspective from which Schacht wrote his 1983 book. That perspective, I argue, accounts for many virtues of the book, including Schacht's convincing treatment of Nietzsche as a philosopher who deserved to be taken seriously and, in its amazing thoroughness, his demonstration that Nietzsche's thought could be organized using the sort of framework one would use for other great philosophers. But it also accounts for certain commitments that differ substantially from mine; in particular, in its extensive reliance on Nietzsche's unpublished material, and in its neglect of the genealogy of Nietzsche's views and questions of his style, which I take to be more central.
América Latina y África. Entre la solidaridad sur-sur y los propios intereses
Authors: Lechini Gladys
Published: July 2015

Este trabajo analiza las relaciones entre América Latina y África en el marco de la cooperación Sur-Sur a partir de tres casos particulares que muestran diferentes estrategias de inserción en el contexto de una política por impulsos. Brasil utilizó una diplomacia cultural y desarrolló una política acumulativa que dio sus frutos con la gestión de Lula, Argentina inició el acercamiento más temprano pero tuvo impulsos intermitentes y Venezuela, un actor tardío desplegó su petro-diplomacia con un discurso ideológico.
Hacia una perspectiva constructivista y crítica del análisis de política exterior
Authors: Álvarez Fuentes Gonzalo
Published: July 2015

En el siguiente artículo se discuten las corrientes teóricas de las relaciones internacionales junto al Análisis de Política Exterior. Se sostiene que para la comprensión del comportamiento de los estados en materia internacional, es necesario realizar estudios que vayan más allá del análisis separado de los factores externos-internos e intereses objetivos-subjetivos que explican su accionar. Para ello, se propone una aproximación a la política exterior que incorpora las teorías constructivistas y críticas de las relaciones internacionales, como forma de obtener una visión amplia pero parsimoniosa del comportamiento externo del Estado.
Argentina con China: el riesgo de la bonanza
Authors: Miranda Roberto
Published: July 2015

El objetivo de este trabajo es analizar las características del bilateralismo de Argentina con China, a fin de determinar la perspectiva de este bilateralismo como relación interdependiente. En este sentido, hipotetizamos que si bien Argentina obtuvo importantes «ganancias relativas», fue China quien amplió la asimetría preexistente en el marco de los extraordinarios niveles de interacción alcanzados entre ambos países. Esto significó, para Argentina, el riesgo de ingresar a una situación de

dependencia con el país asiático. Precisamente en este análisis, más allá de haber realizado el recorrido de las relaciones bilaterales durante la primera década del presente siglo, identificamos los motivos y las condiciones que determinaron el mencionado riesgo.
Evolução da política federal de desenvolvimento territorial no Brasil
Authors: Sabourin Eric Pierre
Published: July 2015

Numa perspectiva de análise da institucionalização da política de agricultura familiar no Brasil, esse artigo propõe introduzir alguns elementos de uma leitura sócio histórica do Programa de Desenvolvimento Sustentável dos Territórios Rurais - PRONAT, implementado pelo Ministério de Desenvolvimento Agrário-MDA que nasceu da vertente infraestrutura municipal do Programa Nacional de Fortalecimento da Agricultura família-PRONAF. A primeira parte do texto apresenta o referencial teórico da análise de políticas públicas e em particular da sócio-história da ação pública. A segunda parte aplica esse referencial ao caso do PRONAT e trata das origens e da trajetória mais recente da política de desenvolvimento territorial rural do Ministério do Desenvolvimento Agrário. A terceira parte é dedicada à discussão e ensinamentos. A conclusão formula algumas perspectivas e propostas de trabalho para a pesquisa.
Da reinterpretação de sistemas tradicionais de uso da terra à construção social de mercados com os agricultores familiares da roça de toco de Biguaçu-SC
Authors: Uller-Gómez Cíntia , Dorow Reney , Stern Ivonete Lenir , Bauer Eliane
Published: July 2015

Apresentamos a importância do sistema de agricultura de roça de toco para a conservação da biodiversidade e para a segurança alimentar. Com base em trabalhos desenvolvidos com agricultores de Biguaçu, no Sul do Brasil, apresentamos como os produtos oriundos desses sistemas podem alcançar mercados diferenciados, gerando melhoria de renda e autoestima. Analisamos o acesso dos produtos ao mercado, antes e depois do desenvolvimento de um processo participativo de planejamento, que resultou em inovações organizacionais, de gestão e de produto. Destacamos os procedimentos adotados através da cooperação entre organizações de pesquisa, de ensino, de extensão e de meio ambiente que permitiram a regularização ambiental do sistema, a saída dos agricultores da clandestinidade e a criação de uma marca coletiva denominada “Valor da Roça”. Aponta-se para os desafios ainda presentes relativos ao aprimoramento do processo de comunicação com os consumidores e demais integrantes do mercado, como os órgãos ambientais.
Desigualdade, exclusão e conflitos nos espaços rurais - Dossiê do VI Encontro da Rede de Estudos Rurais
Authors: Gomes Ramonildes A. , Bergamasco Sônia
Published: July 2015

A tradição de publicar um dossiê com artigos indicados pelos Grupos de Trabalho que fizeram parte da programação do VI Encontro da Rede de Estudos Rurais, é uma grande satisfação, ao mesmo tempo é uma espécie de recompensa, de chegada ao podium após a maratona que envolve a organização de cada encontro. O investimento feito na preparação do dossiê pós-encontro representa um esforço de reunir experiências empíricas e reflexões consistentes sobre temas importantes que, sob olhares, inter, multidisciplinares e intergeracionais, colocam na mesa questões que dialogam com atores, espaços e arranjos institucionais, com o Estado, com o mercado, com a sociedade civil e com um universo de políticas públicas.
Bêtes de terrain
Authors: Bondaz Julien
Published: July 2015

L’invention de l’ethnozoologie en Afrique de l’Ouest entre 1928 et 1960, à une période où l’ethnologie française se professionnalise et où de nouvelles méthodologies d’enquête de terrain sont mises en place, donne à voir la construction de savoirs inédits, à la croisée de l’ethnologie et de la zoologie. Les ethnologues africanistes de l’époque, et Marcel Griaule en premier lieu, entretiennent des relations variées et souvent privilégiées avec les animaux. Une certaine fascination pour la faune africaine joue à coup sûr un rôle dans l’intérêt scientifique que ces ethnologues développent pour les savoirs zoologiques locaux. Décrire les manières de faire de l’ethnozoologie oblige ainsi à tenir compte des manières dont les ethnologues sont affectés par les animaux concernés, à travers le goût qu’ils entretiennent pour la chasse, leurs pratiques de collecte et de capture, ou encore leurs gestes d’attachement.
Bellina
Authors: Cros Michèle
Published: July 2015

Nous sommes au Burkina, en pays lobi, lors d’un grand rituel de fécondité. L’ethnologue effectue une mission de terrain avec son jeune fils. On nous apprend que notre chienne (Bellina) est atteinte d’un mal foudroyant. On pourrait alléger sa souffrance à l’aide de soins palliatifs. L’enfant pleure celle qu’il considère comme une sorte de petite soeur. Les Lobi, mis au courant de cette situation, recommandent au contraire de tuer au plus vite Bellina afin d’en faire une bonne soupe, cynophagie oblige. Deux modes de représentations, d’affects et de comportements se retrouvent soudain mis en écho, discutés et commentés. Ils seront ici analysés à l’aide de narrations graphiques, de brèves de terrain recueillies dans le hors-champ de l’enquête et de récits aux allures de mythe. Mis en dialogues, ces éléments discursifs accentuent autant la violence de ces déliaisons croisées qu’ils mettent en évidence des liaisons vitales inattendues unissant l’homme au chien, en France comme au Burkina.
L’animal dans une société sans miroir
Authors: Brunois-Pasina Florence
Published: July 2015

L’article décrit les expériences éprouvées par les enfants kasua de Nouvelle-Guinée dès leur naissance et en l’absence d’une image réfléchie entière du soi humain. Cette description permet de mettre en valeur la manière dont la société kasua structure schématiquement les expériences au monde et les oriente vers un relationnement de type animiste.