bluuebunny/crossref_metadata_2025 huggingface dataset:
Reliability of Manganese Dioxide and Conductive Polymer Tantalum Capacitors under Temperature Humidity Bias Testing
Authors: Peter Anto , Azarian Michael H. , Pecht Michael
Published: November 2015

Despite being highly reliable under steady state operating conditions, manganese dioxide (MnO2) tantalum capacitors are prone to catastrophic exothermic failures under surge current conditions. Such failures can be mitigated by the use of conductive polymers in place of MnO2. However, these polymers are more susceptible to failure at elevated humidity levels. In this paper, the electrical performances of both MnO2 and polymer tantalum capacitors are compared by subjecting them to temperature humidity bias testing at 85°C and 85% RH. The test population consists of tantalum capacitors with two voltage ratings (50V and 16V). At each of these voltage ratings, two sets of tantalum capacitors, one each with MnO2 and conductive polymer electrodes, were tested. The voltage levels used to bias the capacitors were periodically increased in multiples of the rated voltage to accelerate degradation. The performance of the capacitors was tracked by monitoring their capacitance, dissipation factors and leakage currents, both in-situ and at room temperature. The degradation trends are discussed in light of the differences in voltage ratings and electrode types. These trends are also mapped to fundamental failure mechanisms within the capacitors.
Ultra Fine Pitch RDL Development in Multi-layer eWLB (embedded Wafer Level BGA) Packages
Authors: Choi Won Kyoung , Na Duk Ju , Aung Kyaw Oo , Yong Andy , Lee Jaesik , Ray Urmi , Radojcic Riko , Adams Bernard , Yoon Seung Wook
Published: November 2015

The market for portable and mobile data access devices connected to a virtual cloud access point is exploding and driving increased functional convergence as well as increased packaging complexity and sophistication. This is creating unprecedented demand for higher input/output (I/O) density, higher bandwidths and low power consumption in smaller package sizes. There are exciting interconnect technologies in wafer level packaging such as eWLB (embedded Wafer Level Ball Grid Array), 2.5D interposers, thin PoP (Package-on-Package) and TSV (Through Silicon Via) interposer solutions to meet these needs.

eWLB technologies with the ability to extend the package size beyond the area of the chip are leading the way to the next level of high density, thin packaging capability. eWLB provides a robust packaging platform supporting very dense interconnection and routing of multiple die in very reliable, low profile, low warpage 2.5D and 3D solutions. The use of these embedded eWLB packages in a side-by-side configuration to replace a stacked package configuration is critical to enable a more cost effective mobile market capability. Combining the analog or memory device with digital logic device in a semiconductor package can provide an optimum solution for achieving the best performance in thin, multiple-die integration aimed at very high performance.

This paper highlights the rapidly moving trend towards eWLB packaging technologies with ultra fine 2/2μm line width and line spacing and multi-layer RDL. A package design study, process development and optimization, and mechanical characterization will be discussed as well as test vehicle preparation. JEDEC component level reliability test results will also be presented.
Porosity Evolution of Ag-Sintering at Die Attach
Authors: Chen Sihai , Fan Guangyu , Yan Xue , Labarbera Chris , Kresge Lee , Lee Ning-Cheng
Published: November 2015

Die-attach for high power devices such as IGBT is facing increasing challenges of service temperature, thermal conductivity, electrical conductivity, and reliability. Conventional high-lead solder materials are reaching their limitation of performance. Recently, sintering of Ag-paste has been advocated as a technology to meet this new challenge. In general, this technology prints the Ag paste on top of a direct bond copper substrate, followed by drying, die placement, and heating under a pressure up to 50 MPa. The high pressure is applied in order to avoid formation of high porosity within the Ag joint. The need for high pressure during sintering requires the acquisition of expensive equipment, and inevitably, results in low through-put. Some Ag pastes incorporate polymeric ingredients to avoid the need for pressure, at a cost of high-Ag porosity and a low tolerance for high service temperatures. In this study, a novel Ag-paste without any polymeric inclusion has been developed for the pressureless sintering die-attach process. The porosity of sintered joints was lower toward center of die, due to the venting route factor. The porosity was also lower with a higher bondline thickness, due to a reduced tension in the joint. Thermal aging time has negligible effect on porosity, presumably due to balanced stress between tension and sintering shrinkage. The maximum service temperature of Ag sintered joint is about 470°C, versus 230°C for high-Pb joints.
Maintaining Low Voiding Solder Die Attach for Power Die While Minimizing Die Tilt
Authors: Hamm Randy , Peterson Ken
Published: November 2015

This paper addresses work to minimize voiding and die tilt in solder attachment of a large power die, measuring 9.0 mm × 6.5 mm × 0.1 mm (0.354″ × 0.256″ × 0.004″), to a heat spreader. As demands for larger high power die continue, minimizing voiding and die tilt is of interest for improved die functionality, yield, manufacturability, and reliability. High-power die generate considerable heat, which is important to dissipate effectively through control of voiding under high thermal load areas of the die while maintaining a consistent bondline (minimizing die tilt). Voiding was measured using acoustic imaging and die tilt was measured using two different optical measurement systems. 80Au-20Sn solder reflow was achieved using a batch vacuum solder system with optimized fixturing. Minimizing die tilt proved to be the more difficult of the two product requirements to meet. Process development variables included tooling, weight and solder preform thickness.
Design of Filled One Step Chip Attach Materials (OSCA) for Conventional Mass Reflow Processing: Rheology Considerations for Jet Dispensing and Die Placement
Authors: Duffy Daniel , Bhavsar Hemal , Xin Lin , Liu Jean , Tolla Bruno
Published: November 2015

One step chip attach materials (OSCA) are dispensable polymeric materials for flip chip assembly, which are designed to flux metallic interconnections and subsequently turn into an underfill upon curing. OSCA materials enable a drastic simplification of the assembly process by combining the reflow, flux residue cleaning and capillary underfilling steps used in traditional die attach processing into a single step. A key challenge when designing filled OSCA materials for conventional mass reflow processing (OSCA-R) is to ensure that the materials have a process-friendly rheological design allowing seamless integration with jet dispensing equipment and allowing for accurate die placement. This paper presents research results and design concepts for OSCA-R materials focused on understanding the impact of filler loading, size, type and surface chemistry on rheology and the relationships with jet dispensing performance, die placement and reliability performance for test vehicles constructed with silicon and organic substrates.
Enhanced optical performance for a reduction stepper to meet the challenges for advanced packaging applications
Authors: Webb James E. , Cochet Philippe
Published: November 2015

Mass production of high density interconnects using 3D and 2.5D technologies requires optimal lithography processing with certain optical properties. This paper discusses the modifications and performance changes made to a step-and-repeat camera that have improved the tool utilization. New options are available that enhance the performance and provide the best match to a wide range of resist requirements to attain optimal fidelity and higher throughput. Changes in illumination power, partial coherence and wavelength bandwidth are discussed. Modeling tools are used to predict the improvement and guide the process. Changed optical parameters that impact the image performance are modeled and compared to resist images evaluated. The illumination power increases are used to calculate the impact these changes have on increased throughput. Examples will show modeled and measured improvements achieved.
Cleaning in Electronics: Understanding Today's Needs
Authors: Duchi P.J. , Laügt Anne-Marie , Levasseur Laurent
Published: November 2015

Because of the phase out of CFC's and HCFC's, standard solder pastes and fluxes evolved from RA and RMA fluxes, to No-Clean, low residue No-Clean, and very low residue No-Clean. Many companies came out with their cleaning solutions, aqueous and semi-aqueous, with each product release being more innovative than the previous one. Unfortunately for most of the suppliers of cleaners, two other trends appeared; lead-free soldering and the progressive miniaturization of electronic devices.

Traditional chemicals like CFC's, HCFC's, brominated solvents, detergents and glycols cannot do a good cleaning job anymore because most flux formulations have changed. Also, assembly processes have been modified due to smaller components and more compact board assemblies. The world is composed of two main things: organics and inorganics. Organics are made of resins and activators, whereas inorganics are made of salts, metallic salts and fillers.

Cleaning performance is affected by three main criteria. The first involves the Hansen Parameters which is a characterization of a contaminant to be dissolved and can be simplified by the solvency power of a product also known as the Kauri Butanol Index (KB Index). The second is surface tension, expressed in mN/m. This parameter must be considered because when the cleaning product cannot make contact with the contaminants under or around components, the contaminants cannot be dissolved.

The third criteria are the physical parameters like temperature, mechanical activities, and the process cyle.

The mastery to manage all of these parameters while facing high-tech miniaturization and environmental regulations, like ROHS, REACH, etc. brings innovation to cleaning in this electronic world.
High Speed, High Density Separable Interconnect - 1000 plus I/O ultra-low profile interfaces
Authors: Rathburn James
Published: November 2015

HSIO Technologies has developed several interconnect technologies that enable very high speed, fine pitch separable interconnect between a semiconductor package, flex cable or printed circuit assembly and a system level printed circuit board. In basic terms, connector technology has been produced that allows of direct socketing of the SoC, PoP, CPU, RF Module or Memory device directly in a mobile platform in an ultra-low profile interface that also extends to a ganged RF capable interface for flex cable and board to board applications. The technology revolves around matching very small metallic contacts with fusion bonded Liquid Crystal Polymer materials to create a high speed interface on very fine pitch. Applications to be detailed are socketing of mobile processors, memory devices, and RF modules directly in a cell phone handset, tablet and notebook computer. Emerging complexity with mobile platforms dictates that traditional methods of validating platform performance is not adequate with significant value in the ability to plug packaged IC devices into the actual consumer platform to validate silicon and performance. The paper will document the package substrate to connector interface as well as introduce very high performance connector and flex cable interconnects on 0.35 mm pitch area array for mobile, desktop, and server applications.
Reliability of silver wedge bonding for power devices
Authors: Wei Xing , Yu Zhou , Xu Wanmeng , Iizuka Tomonori , Tatsumi Kohei
Published: November 2015

Recently there is a trend toward to use SiC instead of Si in power devices since SiC can withstand higher temperature (above 300°C) and higher voltage with less power loss than Si. So there is a great interest to improve interconnection technique for power devices package. In this study, Ag wire with diameter of 200 μm was bonded on Al pad, after annealing at 200°C and 300°C, intermetallic compounds (IMC) were investigated by energy dispersive X-ray spectroscopy (EDS). The results show that, when annealed in air, two kinds of IMC Ag2Al and Ag3 Al formed and no voids or cracks were observed; but when annealed with epoxy molded IC package, voids were observed, and between Ag wire and IMC there was a corrosion layer.
The Christian church’s role in the escalating mob justice system in our black townships – An African pastoral view
Authors: Baloyi Elijah
Published: November 2015

Among the crimes in the South African black townships, mob justice has become a growing concern. Some questions that need to be asked are: Is our police force doing enough to protect the ordinary citizens of this country? If the situation continues, will all suspects be killed in the same manner or will there be a solution to change the situation? What is the impact of mob justice on the families of the victims and the witnesses of the brutal acts? How long are we going to live as a traumatised nation as a result of these violent acts? Is there any hope that our nation will ever have the peace it deserves in the context of democracy? This article intends to investigate the impact of the mob justice system and find out what the role of the Christian church should be in the midst of this escalating violence. This study aims to unveil the negative impact of mob justice on the lives of many township South Africans and giving pastoral-biblical suggestions of the church’s role in the elimination of this kind of brutality.
God-image of Servant King as powerful but vulnerable and serving: Towards transforming African church leadership at an intersection of African kingship and biblical kingship to servant leadership
Authors: Magezi Vhumani
Published: November 2015

Christianity is mediated through culture and people’s cultural practices. One such cultural practice is African kingship. African kingship conveys on the ruler sovereignty, power, authority and supremacy over people under one’s jurisdiction. Intricately linked to respect for elders and those in power, African church leaders are at an intersection of the African kingship leadership style and the biblical kingship leadership style. Consciously or unconsciously, church leaders tend to embrace the African kingship approach to leadership and to a lesser extent biblical servant leadership. In such a situation, what God-image of biblical leadership could be discerned for constructive church leadership? In response, the God-image of Servant King as all powerful God, although vulnerable and serving, provides the framework for a transformative approach to church leadership in Africa.
Ancient Israelite and African proverbs as advice, reproach, warning, encouragement and explanation
Authors: Adamo David T.
Published: November 2015

With few exceptions, the majority of biblical scholars (Euroamericans and Africans) concentrate on comparing ancient Israelite proverbs with the so-called ancient Near Eastern proverbs. Despite the importance of proverbs in Sub-Saharan Africa it is doubly unfortunate that the majority of African biblical scholars did not think it wise to compare proverbs from ancient Israel with Sub-Saharan African proverbs. It is also a double tragedy that young people in Sub-Saharan Africa are ignorant of proverbs because they have refused to learn them because they think them archaic. Proverbs in both ancient Israel and in Africa are similar in function and classification. Thus, they serve as advice, reproach, warning, encouragement and further explanation of some facts. They have great value and importance, such as giving a sense of identity, community, culture, respect for authority and elders, sacredness of everything under the sun and a sense of hospitality and others.
(Un-)shackling the University in the City
Authors: Kistner Ulrike
Published: November 2015

This article examines the relation between the University of Pretoria and the City of Tshwane, outlining seven different kinds of relation as they have taken shape historically. The first type relation between the University and the City presented here, establishes correspondences in public architecture at the height of apartheid modernity, between structures marking and shaping political convergences. The second type of relation is premised on the walling in and fencing off of the University from the City; the Metro musings exhibition inaugurating the ‘Capital Cities’ project looks across the divides thus cemented, from within the confines of the University. The third type of relation is that of ‘Community Engagement’ culminating in the annual Mandela Day activities, impelled by ideas on the Developmental State featuring in the National Development Plan. In the fourth type of relation, corporate models of municipal governance find common cause with the corporate management styles of the University, expressed in corporate partnerships combining a ‘University of Excellence’ with ‘the African City of Excellence’. The strategies envisaged for social intervention emerging from this ‘partnership’ form a sixth type of relation between the University and the City. In the process of pitting property and law against poverty and lawlessness, new civic challenges are emerging for transformative constitutionalism and for the University. In both arenas, this article concludes, what is at stake is a seventh type of relation between the University and the City – outside of the ‘legal’-‘illegal’ distinction. For the University, in particular, this would entail a productive idea of ‘dissensus’.
Article Commentary: Educating Future Environmental Health Professionals
Authors: Knechtges Paul L. , Kelley Timothy R.
Published: November 2015

Future environmental health problems will require a new generation of educated and trained professionals. Efforts to enhance the environmental public health workforce have been promoted by several organizations. While progress has been measured by these organizations, many environmental health academic programs are experiencing budget reductions and lower enrollments. One of the reasons for this trend is the so-called higher education crisis. We argue that training is not equivalent to education in the environmental health sciences, albeit the two terms are often used interchangeably. Organizations involved with the education, training, and credentialing of environmental health professionals must work together to ensure the viability and effectiveness of environmental health academic programs.
A Thompson group for the basilica
Authors: Belk James , Forrest Bradley
Published: November 2015

We describe a Thompson-like group of homeomorphisms of the Basilica Julia set. Each element of this group acts as a piecewise-linear homeomorphism of the unit circle that preserves the invariant lamination for the Basilica. We develop an analogue of tree pair that the group is finitely generated. We also prove that the group is virtually simple.
Embedding surfaces into $S^3$ with maximum symmetry
Authors: Wang Chao , Wang Shicheng , Zhang Yimu , Zimmermann Bruno
Published: November 2015

We restrict our discussion to the orientable category. For

g > 1

, let

\mathrm {OE}_g

be the maximum order of a finite group

G

acting on the closed surface

\Sigma_g

of genus

g

which extends over

(S^3, \Sigma_g)

, for all possible embeddings

\Sigma_g\hookrightarrow S^3

. We will determine

\mathrm {OE}_g

for each

g

, indeed the action realizing

\operatorname{OE}_g

.

In particular, with 23 exceptions,

\operatorname{OE}_g

is

4(g+1)

if

g\ne k^2

or

4(\sqrt{g}+1)^2

if

g=k^2

,and moreover

\operatorname{OE}_g

can be realized by unknotted embeddings for all

g

except for

g=21

and

481

.
Property (T) for groups acting on simplicial complexes through taking an “average” of Laplacian eigenvalues
Authors: Oppenheim Izhar
Published: November 2015

is article generalizes the Żuk’s criterion for property (T) and gives new criteria for property (T) (and for vanishing of higher

L^2

-cohomologies).
Comunicación política en la red social Facebook: segmento rusoparlante
Authors: Pilgun Maria , Gradoselskaya Galina
Published: November 2015

El presente artículo expone el análisis de las características de la comunicación política en el segmento rusoparlante de la red social Facebook a base de grupos políticamente activos y sus actores. Al contrario de lo habitual en los EEUU y otros países, los usuarios de blogs rusos prefieren plataformas que combinan elementos típicos de un blog y los de las redes sociales tipo Facebook. Los datos fueron recogidos en un momento político complicado para Rusia (rebeldía en Ucrania) lo que avivó la actividad de la oposición rusa y los procesos manipuladores en las redes sociales rusas. Objetivos. El objetivo era clasificar los actores políticamente activos de Facebook ruso y analizar su comportamiento sociolingüístico. Metodología. Se efectuó un análisis interdisciplinar de los grupos políticos (N 200) y actores (N 291) durante enero-mayo 2014. Resultados. Según sus opiniones políticas los actores principales fueron clasificados como oficiales-gubernamentales, de oposición y nacionalistas y juzgando por su actividad como proyectores de espacio comunicativo, manipuladores, grafómanos y autores de Clusters locales. Su comportamiento comunicativo y verbal también ha sido analizado donde fueron identificadas identidades virtuales específicas compartidas.  Discusión y conclusiones. Desde que las redes sociales están siendo utilizadas cada vez más con fines políticos el análisis de los procesos sociolingüísticos en las comunidades virtuales activas políticamente ha adquirido mucha importancia tanto en Rusia, como en el resto del mundo. Como la perspectiva del desarrollo futuro del presente estudio se contempla la detección de la relación entre la actividad comunicativa de los actores online y offline dentro de los grupos señalados.
El análisis sobre el estado e impacto de la actividad cultural china en España. El análisis del instituto Confucio de valencia
Authors: Shi Bingqin
Published: November 2015

Este trabajo aborda la actividad cultural china en España. Porque hemos tomado conciencia de que las actividad cultural son claves para desarrollar cultura a exterior. Aunque en España, la cultura china no es la cultura dominante exterior, se ha desarrollado mucho en los últimos 5 años. Después de una fase de crecimiento de la actividad cultural china orientada a su promoción de la cultura en el exterior, parece necesario analizar el estado del desarrollo y su impacto. En ese artículo se analizan las actividades culturales que se han realizado en el Instituto Confucio de la Universitat de Valencia y los problemas y alcance de su impacto.
Les falles com a agents culturals. Estudi de l'activitat cultural de les falles d'Alzira
Authors: Fluixà Pelufo Alba
Published: November 2015

L'objectiu d'aquest estudi ha estat investigar l'activitat cultural de les comissions falleres de la localitat d'Alzira, la seua tipologia i forma de gestió, així com analitzar el seu potencial com a agents culturals. S'ha emprat una combinació d'investigació quantitativa (qüestionaris de resposta tancada) i qualitativa (entrevistes personals en profunditat). Aquesta metodologia ha permès obtenir, per una banda, dades objectives traduïbles a gràfiques i percentatges que radiografien per primera vegada tots els aspectes d'aquest fenomen i, per altra banda, informació no recollida abans sobre les motivacions, el procés de treball o les dificultats amb què s'han trobat els qui l'han dut a terme.
Análisis del impacto de los principales museos de Asia
Authors: HUA SAI
Published: November 2015

Actualmente, las instituciones museísticas han intentado adaptarse al cambio de la sociedad y tecnología, las redes sociales son la forma más adecuada para crear este ambiente. En los últimos años las instituciones museísticas occidentales, cada vez más, se han relacionado con las redes sociales consiguiendo así mayor difusión. Pero en Asia, la implantación de dichas redes sociales, por causa de requisitos políticos, económicos y sociales es imposible. El mundo asiático tiene redes sociales propias, puesto que el sentimiento de incrementar los lazos sociales entre sus habitantes y las instituciones museísticas es el mismo que el europeo. El siguiente trabajo que se desarrolla tiene como objetivo de realizar un estudio analítico del impacto del los principales museos de Asia. Además, lo que se pretende con este análisis es intentar descubrir la influencia que dichos museos tienen en la sociedad a través de mismas redes sociales que difieren entre los museos y países.
An improved method for retrieving nighttime aerosol optical thickness from the VIIRS Day/Night Band
Authors: McHardy T. M. , Zhang J. , Reid J. S. , Miller S. D. , Hyer E. J. , Kuehn R. E.
Published: November 2015

Abstract. Using Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) data, a method, dubbed the "variance method", is developed for retrieving nighttime aerosol optical thickness (τ) values through the examination of the dispersion of radiance values above an artificial light source. Based on the improvement of a previous algorithm, this updated method derives a semi-quantitative indicator of nighttime τ using artificial light sources. Nighttime τ retrievals from the newly developed method are inter-compared with an interpolated value from late afternoon and early morning ground observations from four AErosol RObotic NETwork (AERONET) sites as well as column-integrated τ from one High Spectral Resolution Lidar (HSRL) site at Huntsville, AL, during the NASA Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) campaign, providing full diel coverage. Sensitivity studies are performed to examine the effects of lunar illumination on VIIRS τ retrievals made via the variance method, revealing that lunar contamination may have a smaller impact than previously thought; however, the small sample size of this study limits the conclusiveness thus far. VIIRS τ retrievals yield a coefficient of determination (r2) of 0.60 and a root-mean-squared error (RMSE) of 0.18 when compared against straddling daytime-averaged AERONET τ values. Preliminary results suggest that artificial light sources can be used for estimating regional and global nighttime aerosol distributions in the future.
Retrieving clear-air turbulence information from regular commercial aircraft using Mode-S and ADS-B broadcast
Authors: Kopeć J. M. , Kwiatkowski K. , de Haan S. , Malinowski S. P.
Published: November 2015

Abstract. Navigational information broadcast by commercial aircraft in the form of Mode-S and ADS-B messages can be considered a new and valid source of upper air turbulence measurements. A set of three processing methods is proposed and analysed using a quality record of turbulence encounters made by a research aircraft. The proposed methods are based on processing the vertical acceleration or the background wind into the eddy dissipation rate. All the necessary parameters are conveyed in the Mode-S/ADS-B messages. The comparison of the results of application of the processing against a reference eddy dissipation rate obtained using on-board accelerometer indicate a significant potential of those methods. The advantages and limitation of the presented approaches are discussed.
CO2-flux measurements above the Baltic Sea at two heights: flux gradients in the surface layer?
Authors: Lammert A. , Ament F.
Published: November 2015

Abstract. The estimation of CO2 exchange between the ocean and the atmosphere is essential to understand the global carbon cycle. The eddy-covariance technique offers a very direct approach to observe these fluxes. The turbulent CO2 flux is measured, as well as the sensible and latent heat flux and the momentum flux, a few meters above the ocean in the atmosphere. Assuming a constant-flux layer in the near-surface part of the atmospheric boundary layer, this flux equals the exchange flux between ocean and atmosphere. The purpose of this paper is the comparison of long-term flux measurements at two different heights above the Baltic Sea to investigate this assumption. The results are based on a 1.5-year record of quality-controlled eddy-covariance measurements. Concerning the flux of momentum and of sensible and latent heat, the constant-flux layer theory can be confirmed because flux differences between the two heights are insignificantly small more than 95 % of the time. In contrast, significant differences, which are larger than the measurement error, occur in the CO2 flux about 35 % of the time. Data used for this paper are published at http://doi.pangaea.de/10.1594/PANGAEA.808714.
Two new species of megasporangiate Sigillariostrobus Schimper (Sigillariostrobaceae) fructifications from the British Coal Measures
Authors: Thomas B. A. , Seyfullah L. J.
Published: November 2015

Abstract. The arborescent lycophyte group known as the sigillarians bore pedunculate fructifications, including Sigillariostrobus Schimper, which has a known propensity to disaggregate, making comparisons of cones and in situ spores often difficult if not impossible. Sigillariostrobus is monosporangiate, containing either megaspores or microspores. Two new species of Sigillariostrobus with megaspores are described from the British Coal Measures. Two cones of Sigillariostrobus saltwellensis sp. nov. are described from Langsettian–Duckmantian strata of Great Britain, containing in situ Laevigatisporites glabratus (Zerndt) Potonié and Kremp spores, making this the first British Sigillariostrobus species described containing such spores. Sigillariostrobus barkeri sp. nov. is given here to the previously described cone with in situ Tuberculatisporites brevispiculus (Schopf) Potonié and Kremp spores. This is the first Sigillariostrobus cone with this megaspore species in situ, and thus shows that T. brevispiculus and T. mamillarius (Bartlett) Potonié and Kremp are not conspecific as others have previously suggested.
The Explicit Wake Parametrisation V1.0: a wind farm parametrisation in the mesoscale model WRF
Authors: Volker P. J. H. , Badger J. , Hahmann A. N. , Ott S.
Published: November 2015

Abstract. We describe the theoretical basis, implementation, and validation of a new parametrisation that accounts for the effect of large offshore wind farms on the atmosphere and can be used in mesoscale and large-scale atmospheric models. This new parametrisation, referred to as the Explicit Wake Parametrisation (EWP), uses classical wake theory to describe the unresolved wake expansion. The EWP scheme is validated for a neutral atmospheric boundary layer against filtered in situ measurements from two meteorological masts situated a few kilometres away from the Danish offshore wind farm Horns Rev I. The simulated velocity deficit in the wake of the wind farm compares well to that observed in the measurements, and the velocity profile is qualitatively similar to that simulated with large eddy simulation models and from wind tunnel studies. At the same time, the validation process highlights the challenges in verifying such models with real observations.
Climate response to Amazon forest replacement by heterogeneous crop cover
Authors: Badger A. M. , Dirmeyer P. A.
Published: November 2015

Abstract. Previous modeling studies with atmospheric general circulation models and basic land surface schemes to balance energy and water budgets have shown that by removing the natural vegetation over the Amazon, the region's climate becomes warmer and drier. In this study we use a fully coupled Earth system model and replace tropical forests by a distribution of six common tropical crops with variable planting dates, physiological parameters and irrigation. There is still general agreement with previous studies as areal averages show a warmer (+1.4 K) and drier (−0.35 mm day−1) climate. Using an interactive crop model with a realistic crop distribution shows that regions of vegetation change experience different responses dependent upon the initial tree coverage and whether the replacement vegetation is irrigated, with seasonal changes synchronized to the cropping season. Areas with initial tree coverage greater than 80 % show an increase in coupling with the atmosphere after deforestation, suggesting land use change could heighten sensitivity to climate anomalies, while irrigation acts to dampen coupling with the atmosphere.
Evaluation of numerical models by FerryBox and fixed platform in situ data in the southern North Sea
Authors: Haller M. , Janssen F. , Siddorn J. , Petersen W. , Dick S.
Published: November 2015

Abstract. For understanding and forecasting of hydrodynamics in coastal regions, numerical models have served as an important tool for many years. In order to assess the model performance, we compared simulations to observational data of water temperature and salinity. Observations were available from FerryBox transects in the southern North Sea and, additionally, from a fixed platform of the MARNET network. More detailed analyses have been made at three different stations, located off the English eastern coast, at the Oyster Ground and in the German Bight. FerryBoxes installed on ships of opportunity (SoO) provide high-frequency surface measurements along selected tracks on a regular basis. The results of two operational hydrodynamic models have been evaluated for two different time periods: BSHcmod v4 (January 2009 to April 2012) and FOAM AMM7 NEMO (April 2011 to April 2012). While they adequately simulate temperature, both models underestimate salinity, especially near the coast in the southern North Sea. Statistical errors differ between the two models and between the measured parameters. The root mean square error (RMSE) of water temperatures amounts to 0.72 °C (BSHcmod v4) and 0.44 °C (AMM7), while for salinity the performance of BSHcmod is slightly better (0.68 compared to 1.1). The study results reveal weaknesses in both models, in terms of variability, absolute levels and limited spatial resolution. Simulation of the transition zone between the coasts and the open sea is still a demanding task for operational modelling. Thus, FerryBox data, combined with other observations with differing temporal and spatial scales, can serve as an invaluable tool not only for model evaluation, but also for model optimization by assimilation of such high-frequency observations.
Estudios
Authors: Arredondo Erika
Published: November 2015

Vargas Vila, más allá de la hipérbole
Reseñas
Authors: Arredondo Erika
Published: November 2015

Vargas Vila, más allá de la hipérbole
Stochastic progamming in the mid-term operations planning of an oil refinery
Authors: Nascimento Leonardo , Venceslau Helder , Xavier Adilson , Filho Virgílio Ferreira , Sakalauskas Leonidas , Rocha Roger
Published: November 2015

Oil refining is a series of processes that aim to separate the crude oil into pre-standardized fractions. The way these processes can be combined result in a variety of schemes where each one can be used as a production plan. This work presents a methodology, based upon stochastic programming (SP), that support the decision makers in the mid-term operations planning of an oil refinery. Results generated by running a multi-period two-stage SP model are used to measure the impact on the economic efficiency when not considering the randomness of the demand and the receipt of crude oil.
La antropología y el derecho ante los fenómenos posesorios: entre la comunidad y la propiedad
Authors: Montesinos Llinares Lidia
Published: November 2015

La autora hace un repaso de las metodologías de investigación que ponen en relación Antropología y Derecho a partir de su experiencia investigadora en el ámbito de las relaciones de propiedad. La complementariedad entre estas dos disciplinas contribuye ampliamente a la comprensión de conflictos y realidades posesorias complejas —poniendo en relación propiedad y comunidad—, pero no está exenta de tensiones. Como pone de manifiesto la autora, la Antropología jurídica plantea una relación crítica con el Derecho cuando éste muestra intransigencia ante las singularidades antropológicas; cuando pierde de vista que es sólo un medio, una herramienta con fines sociales y antropológicos, y no un fin en sí mismo; o cuando apela recurrentemente a las ficciones jurídicas para legitimarse.
La propiedad como hecho social. Una contribución etnográfica a la crítica del economicismo
Authors: Márquez Raúl
Published: November 2015

La tesis de que la propiedad supone una relación entre personas (que se distribuyen ciertos poderes, privilegios y deberes respecto a determinadas cosas), y no una relación individual entre el propietario y su bien, ha sido ampliamente defendida desde el Derecho y la Antropología. Con el objetivo de ilustrar empíricamente dicha tesis, apuntar alguna de sus implicaciones y criticar determinados enfoques economicistas, describiremos el funcionamiento de la institución en una ocupación de Salvador de Bahía. Este caso mostrará la relación estrecha que existe entre propiedad y ordenación social, así como la influencia de factores extraeconómicos en su configuración y puesta en práctica, algo obviado por quienes utilizan esquemas basados exclusivamente en la utilidad y la eficiencia.
Mujeres maltratadas en los juzgados: la etnografía como método para entender el derecho “en acción”
Authors: Rodríguez Luna Ricardo , Bodelón González Encarna
Published: November 2015

En este estudio se analiza el desarrollo del derecho de acceso a la justicia de mujeres que denunciaron violencia de su pareja y/o ex pareja y que llevaron adelante el proceso judicial. El acercamiento a este objeto de estudio se realizó a través de una observación etnográfica llevada a cabo en los juzgados especializados de violencia contra las mujeres de la ciudad de Barcelona. Como resultados de la investigación, entre otras cuestiones, se destaca cómo las prácticas jurídicas de los/as operadores/as del sistema penal incidieron negativamente en algunos derechos de las mujeres. Particularmente, se constataron vulneraciones en lo que respecta al derecho a la información, a la formación especializada en violencia de género de los/as profesionales, y también se documentaron “resistencias” a indagar en torno a la violencia habitual. Asímismo, pudo comprobarse que las víctimas están lejos de ser tratadas como protagonistas del proceso penal y que reciben un trato que no protege su dignidad.
Derechos y pueblos indígenas: avances objetivos, debilidades subjetivas
Authors: Aparicio Wilhelmi Marco
Published: November 2015

Tras décadas de invisibilización, los pueblos indígenas han logrado reforzar su protagonismo, aunque con enormes diferencias según los casos, en el escenario político latinoamericano. Dicha emergencia ha ido acompañada de distintos procesos de reconocimiento, tanto internacional como constitucional, de derechos colectivos. Años después de la aprobación de los dos textos que recogen los mayores avances en la cuestión, la Declaración de Naciones Unidas sobre derechos de los pueblos indígenas (2007) y la Constitución Política de Bolivia (2009), nos hallamos ante la necesidad de hacer un balance: tales avances normativos, ¿deben ser vistos desde la esperanza o desde el desencanto? El presente texto trata de aportar elementos que puedan ser útiles en dicho balance. Para ello, se realiza un breve recorrido por los textos citados para, a continuación, centrarse en la significación del derecho a la consulta, previa libre e informada. Finalmente, se aborda una reflexión sobre el sentido mismo de los derechos, pues se considera imprescindible para la comprensión de la relación entre pueblos indígenas, Estado y sociedad dominante.
El Derecho desde la Antropología: Etnografía y Derecho consuetudinario en Madagascar
Authors: Rosés Tubau Mariona
Published: November 2015

Este artículo pretende contribuir a poner de manifiesto la relación entre el Derecho y la Antropología prestando una atención particular al derecho consuetudinario. Tomamos el caso concreto de Madagascar con el propósito de analizar la etnografía como fuente de derecho, incidiendo en su relación con el derecho constitucional malgache, a partir de los conflictos que generan los robos de cebúes en el ámbito local y rural de las comunidades malgaches.
La Antropología desde el Derecho: Derecho consuetudinario Gallego y Etnografía
Authors: Rodríguez Montero Ramón P.
Published: November 2015

Estudio mediante el que se pretenden poner de manifiesto las necesarias interrelaciones que se producen entre la ciencia etnográfica y la jurídica, especialmente a los efectos de la posible determinación, conocimiento y estudio, tanto histórico como actual, de las diversas peculiaridades jurídicas de carácter consuetudinario existentes en el específico caso del ordenamiento jurídico civil gallego.
Del presente a los años 60: representaciones y regulaciones sobre la vida familiar y la educación infantil en Argentina
Authors: Cerletti Laura Beatriz
Published: November 2015

La atención de los niños en sus hogares ha sido objeto de cambiantes preocupaciones y acciones en distintos campos de la vida social, y en particular, en vinculación con la educación infantil. Los modos en que se representan y se buscan regular las responsabilidades y el accionar de los adultos en torno a los niños se han ido transformando como parte de procesos complejos, cuyas huellas se imbrican en la configuración de problemáticas actuales —usualmente vinculadas a representaciones fuertemente naturalizadas, que la investigación antropológica permite evidenciar y problematizar. En este artículo se analizan y se historizan algunos de estos modos de regulación de la vida familiar, según surge de nuestra investigación sobre las relaciones entre las familias y las escuelas en la Ciudad de Buenos Aires, Argentina, realizada desde un enfoque histórico-etnográfico. Específicamente, se analiza una obra paradigmática de la década de 1960: la Escuela Para Padres de Eva Giberti, tomada como analizador significativo para el estudio de esta problemática.
Calendario festivo y actos de culto en Carmona: una reflexión acerca de las fiestas en la modernidad
Authors: Macías Sánchez Clara , Hernández González Salvador , Rodríguez Becerra Salvador
Published: November 2015

El artículo ofrece un recorrido por el ciclo anual festivo de Carmona (Sevilla), con especial énfasis en los actos de culto y en la religiosidad. Los datos, fruto de la observación directa, han sido apoyados con otros de carácter histórico lo que proporciona un panorama diacrónico de las principales fiestas de esta ciudad. Esto posibilitará un análisis general de las transformaciones más recientes del hecho festivo en una población que puede funcionar como modelo para la Baja Andalucía. Buscando este objetivo en el artículo se describen los agentes organizadores y los grados de participación de los diferentes sectores de la comunidad, se detecta la influencia de modelos dominantes y diferentes procesos de revitalización festiva. Finalmente, la información aportada permite una reflexión acerca de las consecuencias de la modernidad en el hecho festivo.
La ironía de ser indígena y la imaginación del tiempo social
Authors: Díaz de Rada Ángel
Published: November 2015

Este ensayo trata de un viejo asunto: la reflexión sobre la noción “indígena” en el contexto de sus usos temporales. La referencia clásica es la obra de Johannes Fabian Time and the Other (1983), y el campo de aplicación, en este caso, los usos de la palabra “indígena” en algunas formas de identificación de nuestros contemporáneos en el norte de Escandinavia. La tesis básica de este ensayo es que la noción “indígena” se inserta habitualmente en un juego de ironías, debido a su orientación de-temporalizada en relación con los agentes en los actos de enunciación. A la luz de esta problemática, este ensayo critica las persistentes fórmulas de exotización de la antropología contemporánea, y subraya de nuevo la radical contemporaneidad de aquéllos cuyas prácticas representamos en nuestros discursos analíticos. Se distingue así la sensibilidad hacia la alteridad de la preferencia por el exotismo, y se retoma la idea de una etnografía irónica (Brown 1999) como un esfuerzo agonístico y colaborativo de dotar de inteligibilidad al mundo contemporáneo.
Liberalizing Russian Gas Markets: An Economic Analysis
Authors: Aune Finn Roar , Golombek Rolf , Moe Arild , Rosendahl Knut Einar , Le Tissier Hilde Hallre
Published: November 2015

The Russian gas market is highly regulated with low user prices of natural gas. In this paper we examine possible impacts of regulatory changes on the demand side of this market. In particular, we consider the effects on Russian energy consumers of increasing the regulated prices of natural gas, and how changes in Russian gas consumption may affect its gas export to Europe. We also examine the importance of Russian pipeline capacity to Europe, as well as impacts of hypothetical changes in Russian gas export behavior. For this purpose we use a detailed numerical model for the energy markets in Europe and Russia—LIBEMOD. Our results suggest that increasing the regulated natural gas prices will have substantial impacts on total consumption of gas in Russia, especially in the electricity sector. The magnitude of gas export to Europe will be significantly affected because more gas becomes available for export. Removal of other market imperfections in the Russian energy markets has smaller impacts on prices and quantities than imposing competitive natural gas prices. More competitive Russian gas export behavior would lead to much higher gas export to Europe, but our results suggest that Russian welfare would drop due to lower gas export prices.
Mineral Depletion and the Rules of Resource Dynamics
Authors: Cairns Robert D. , Davis Graham A.
Published: November 2015

Conditions of exploitation of natural resources under certainty and uncertainty in some canonical natural resource problems are unified as r-percent rules by which the sum of all sources of gain from refraining from an irreversible action is compared to the interest rate. Action is initiated once the gain from action equals the gain from inaction. Morris Adelman’s insights, succinctly presented his 1990 paper on mineral depletion, are highlighted as implicitly recognizing, and even being grounded by, these timing rules.
Co‐occurrences of EDCs/PPCPs in Surface Water Using Chemometrics
Authors: Hagemann Mark , Park Minji , Srinivasan Varun , Reckhow David A. , Lavine Michael , Rosenfeldt Erik , Stanford Benjamin D. , Park Mi‐Hyun
Published: November 2015

This study investigated co‐occurrences of endocrine‐disrupting compounds (EDCs), and pharmaceuticals and personal care products (PPCPs) in order to develop effective monitoring strategies. EDCs/PPCPs were clustered on the basis of similarities in their occurrence in surface waters to reduce analytical complexity. Chemometric approaches were applied to three water bodies with different water systems and climate conditions: Lake Mead in Nevada, the Assabet River in Massachusetts, and the Santa Ana River in California. The results show that site‐specific co‐occurrences among EDCs/PPCPs exist, though these co‐occurrences do not translate well between sites. Therefore, the usefulness of this study is in demonstrating the approach of selecting indicator/surrogate compounds using chemometrics rather than providing a single list of recommended compounds for long‐term monitoring. This study offers a systematic and practical approach to selecting a suite of analytes when implementing a monitoring program for EDCs/PPCPs in surface waters.