bluuebunny/crossref_metadata_2025 huggingface dataset:
Energy and Eco-Sustainability using Pressure-less Silver Sintering for RF Power Electronics
Authors: Hueners Evan A. , Hueners Richard D. , O' Sullivan Anthony D. F. , Zin M. Redzuan
Published: December 2019

Energy & Eco-Sustainability using Pressureless Silver Sintering for RF Power Electronics

A virtually void free die attach was successfully achieved using a fixed but critical volume of Ag sinter paste by a process of pressureless sintering on a multi-axis cartesian style bonder, retro-fitted with with a high-speed jetting dispenser. While this process potentially offered an ideal combination of cost-effectiveness, control and speed, it required the development of additional software protocols to secure the level of performance demanded of the dispenser to meet exacting technical requirements. This proprietary adaptation we term “Fixed BLT” software, and over five test pieces we were consistently able to deliver a fixed height bond-line of circa 70% of bond height, translating as 50 um before sinter and 30 um after. In each case the result was a virtually bond free void secured in a timely, repeatable, commercially effective manner. The absence of voids was verified through industry standard non-destructive analysis utilizing confocal scanning acoustic microscopy (CSAM).
High Temperature and High Reliability Performance of Electrically Conductive Film Adhesives for RF Grounding Applications
Authors: Zhao Yuan , Katze Doug , Wood John , Tolla Bruno , Yun Howard
Published: December 2019

Over the past decade, electronic parts have become smaller, more complex and higher functioning. This is well-understood for many products within the consumer and handheld markets. Miniaturization, however, is also impacting sectors such as aerospace and automotive, pushing the limits of already harsh environments. As more power is driven through active devices, the integrity of materials used to provide the electrically conductive interfaces is becoming increasingly critical. For many applications, adhesive films have been the preferred material because they offer a variety of performance and operational advantages such high electrical and thermal conductivity, uniform bondlines, superior adhesion and low processing temperatures. Today, though, as miniaturization pushes power-density limits and devices are also being exposed to high operating temperatures, even traditionally robust adhesive films are challenged to cope with these conditions. In sectors such as aerospace where high reliability is essential, material capability must evolve to deliver on fail-safe performance expectations. This paper will compare the performance of an established and widely used electrically conductive film adhesive with that of a newly developed film designed to provide improved mechanical performance over a higher elevated temperature range.
Can Electrolytic Capacitors Meet the Demands of High Reliability Applications?
Authors: Caswell Greg
Published: December 2019

Electrolytic capacitors have long been identified as a weak link for long term high reliability applications. However, capacitor manufacturers have made significant improvements to the materials and manufacturing processes to enhance their reliability. This paper will discuss those changes, provide insight into the various failure mechanisms for electrolytic capacitors and describe appropriate accelerated tests to validate performance.

We will take a deeper dive into the methodologies utilized to improve capacitor performance, e.g. foil purity and electrolyte volume. We will also discuss, from a reliability perspective, the impact of changing to a higher temperature electrolyte (from ethylene glycol to DMF, DMA and GBL) and also changes in the bung material (from butyl to EPDM).

There are several environmental factors involved in the aging of electrolytic capacitors. Electrolyte loss due to drying out and leakage current due to oxide degradation are thermally related as is the self-heating associated with ripple current. The impact of the applied voltage level is also a driver as it can cause leakage current increases as well. All of these issues result in a capacitance decrease, an increase in ESR, and a change to the dissipation factor. Many other failure mechanisms associated with manufacturing will also be discussed.
Laser Etching of Gold Conductors for RF Applications
Authors: Edwards Stephanie , Persons Ryan , Feltham Steve , Howerton Jeff , Lott Geoffrey , Macko Daniel
Published: December 2019

Thick film customers who require fine line resolution for their circuitry typically utilize wet chemical etching as a means to reduce conductor's lines and spaces when fine line definition cannot be reliably attained with screen printing alone. Wet chemical etching typically has the means to reduce conductor line widths from a printed definition of 3 mil (75 μm) to as low as 1 mil (25 μm) lines and spaces. The process of performing this chemical etching is time consuming and costly when factoring in the necessary process limitations.

With the issues presented by wet chemical etching, thick film customers are presented with a high process cost, yield loss due to the imaging process, and costly wastewater/environmental treatment regulations. Therefore, laser etching will be presented as an alternative method to wet chemical etching for various thick film conductor products.

For many years, specialized gold formulations have been etched using typical wet chemical etching processes. Standard and less costly conductor alloys that typically would not be suitable for wet chemical etching will be explored, possibly opening the doors for a wide variety of different applications which would benefit from utilizing this laser etching method. By being able to utilize different conductor alloys (Ag, Cu, etc.), laser etching offers alternative solutions for some of these applications with the added benefit of improved cost and increased throughput. As an example, wet chemical processing of silver conductors has proven to be very challenging in some cases due to the metal form-factor and specialized glasses required. By having the option of laser ablating the silver, a potentially advantageous and cost-effective option would now be possible.

Taking into account that laser etching of thick film conductors on ceramic is a relatively new method, this paper will concentrate on some of the opportunities/advantages it can offer. It will illustrate the boundaries of laser etching and how it compares to wet chemical etching while determining/comparing the impact on several properties including adhesion, signal propagation, line definition, and other important defining characteristics of the fired film in the final application.
Laser Sintering of Aerosol Jet Printed Interconnects on Flexible Substrate
Authors: Alhendi Mohammed , Cestarollo Ludovico , Khinda Gurvinder S. , Weerawarne Darshana L. , Poliks Mark D.
Published: December 2019

Laser sintering of interconnects printed on flexible substrate with silver nanoparticle ink is studied as an alternative to convection oven sintering. Interconnects of 80 μm and 250 μm line width are printed using an aerosol jet printer and sintered using an 830 nm continuous wave laser. A conductivity that is 4.5× higher than that of an oven sintered interconnect is achieved at optimal laser power and sintering speed set using a full factorial statistical design.
Package Voltage Regulators: The Answer for Power Management Challenges
Authors: Meyer Joseph , Moghimi Reza , Sturcken Noah
Published: December 2019

The generational scaling of CMOS device geometries, as predicted by Moore's law, has significantly outpaced advances in CMOS package and power electronics technology. The conduction of power to a high-performance integrated circuit (IC) die typically requires close to 50% of package and IC I/O and is increasing with trends towards lower supply voltages and higher power density that occur in advanced CMOS nodes. The disparity in scaling of logic, package, and I/O technology has created a significant bottleneck that has become a dominant constraint on computational performance. By performing power conversion and voltage regulation in-package, this limitation can be mitigated. Integration of thin-film ferromagnetic inductors with CMOS technology enables single-chip power converters to be co-packaged with processors, high bandwidth memory (HBM), and/or other modules. This paper highlights the advantages of fully integrated package voltage regulators (PVRs), which include: reducing package I/O allocated for power, eliminating the need for upstream power-conversion stages, and improving transient response. These benefits substantially reduce the size, weight, and power of modern electronic systems.
COMBINING ADVANTAGES OF RHEOMETRY AND INLINE VISCOMETRY FOR IMPROVED VISCOSITY MODELING
Authors: Strobelt Jonas , Bauer Joerg , Dreissigacker Marc , Hoelck Ole , Braun Tanja , Becker Karl-Friedrich , Schneider-Ramelow Martin , Lang Klaus-Dieter
Published: December 2019

In microelectronic packaging, encapsulation by compression and transfer molding is a crucial process block to ensure device reliability. Material properties of encapsulants, highly filled systems of reactive epoxy molding compounds (EMC), strongly depend on process conditions in a complex manner and vary over time. Shear-thinning behavior, as well as time- and temperature-dependent conversion strongly impact the viscosity of the polymer melt. In all fields of application, such as automotive or IoT, demands towards miniaturization, lifetime and environmental conditions increase. Thus, detailed understanding of the complex material behavior is of vital importance.

Typically, shear-thinning behavior of polymer melts is characterized using a conventional rheometer in oscillation mode under varying shear-rates and temperatures. Limitations of this approach are, that measurements at process temperature typically cannot be performed due to the high reactivity of the encapsulant at these temperatures (e.g. 175 °C for transfer molding). Therefore extrapolation to the correct temperature range is required. Furthermore, measurements in oscillation mode cannot necessarily be transferred to real process conditions, where a continuous flow is present.

To overcome these limitations the inline viscometer can be used, a specially designed measurement tool for a transfer molding machine developed by Fico/Besi. The polymer melt is pressed through a narrow slit under known volumetric flow at process temperature. By measuring the pressure difference before and after the slit, the viscosity can be calculated.

In order to better understand and also predict material behavior, inline viscosimetry is combined with rheometer measurements. This allows to maintain the advantages of conventional rheometry regarding material consumption and large shear-rate measuring range. At the same time, the inline approach provides relevant data under process conditions. The synthesis of both approaches yields a correction of the rheometer measurements, ultimately improving viscosity modeling and being an improved basis for process simulation.
Thin-film based passive RFID sensor tag for detection of packaged food volatiles
Authors: Karuppuswami Saranraj , Mondal Saikat , Kumar Deepak , Kaur Amanpreet , Chahal Premjeet
Published: December 2019

In this paper, a near-field wireless thin-film coated RFID compatible sensor tag is presented for profiling packaged food volatiles at room temperature. The sensor tag consists of a thin-film coated interdigitated capacitor interrogated in two different configurations: (i) direct-wired configuration, and (ii) wireless configuration. Polyaniline (PANi) is chosen as the thin film to be coated on the interdigitated capacitor due to its specificity towards packaged food, detection of Ammonia. The sensitivity of the sensor is characterized at room temperature and at atmospheric pressure. In the direct-wired configuration, different concentration of Ammonia gas is introduced into an enclosed chamber and the conductivity across the film is measured. In the wireless configuration, an inductor is soldered across the interdigitated capacitor to form an inductor-capacitor (LC) resonant tank. The resonance frequency is wirelessly interrogated using an external pick-up coil (reader coil) and the frequency shift is monitored. The proposed sensor can detect as low as 3 ppm of Ammonia making it a highly sensitive sensor, and it can be easily adapted to monitor packaged food quality across the supply chain.
Reliability analysis of bonding wire based on stacked substrate packaging structure
Authors: Zhang Chi , Tan Yifan , Huang Zhizhao , Chen Cai , Kang Yong
Published: December 2019

The stacked substrate packaging technology is a new 3D power loop structure utilizing multiple layer DBC to achieve ultra-low parasitic for the fast switching SiC device. This structure has a different geometry on interconnection between chips and substrate contrasting to the conventional module design, which needs optimization on the interconnection for the reliability consideration of this new structure. Analytical models of different bonding wire shapes and DBC structures were developed to calculate the von-mise stress on each model under thermal cycling simulation. The simulation results show that the stress on bonding wire reaches minimum when welding point located at the center of the top DBC substrate and the stress decreases when DBC top copper layer thickness increases or ceramic layer thickness decreases. Moreover, bonding wires with smaller diameter, certain peak height and width show lower stress and strain. Furthermore, thermal cycling tests were done on samples with same geometries of analytical models, and the wire pull test results showed consistency with the stress calculation results which verifying the optimum wire shape and DBC structure for the stacked substrate packaging.
An evaluation of medication appropriateness in pregnant women with coexisting illness in a tertiary care hospital
Authors: Moe Htet Wai , Sharma Sushil , Sharma A. K.
Published: December 2019

Aim:

Prescribing drugs during pregnancy needs careful consideration of benefit to the mother and risk to the fetus. Therefore, this study was conducted to evaluate the appropriateness of medications among pregnant women with coexisting illness in a tertiary care hospital, Western India.

Materials and Methods:

It was a hospital-based cross-sectional study conducted in the obstetrics and gynecology department of a tertiary care hospital. The study was conducted over a period of 12 months wherein data from 800 pregnant women suffering from any co-existing illness and being prescribed any medication apart from routine supplementation were analyzed. The Medication Appropriateness Index (MAI) was used to assess the appropriateness of medications. Higher MAI scores indicate more inappropriate prescribing.

Results:

Drugs which were most inappropriately prescribed with the highest average MAI scores were albendazole, itraconazole, injection amikacin, oxcarbazepine, warfarin, domperidone, propylthiouracil, and combiflam (ibuprofen + paracetamol). Diseases with the highest average MAI scores were anemia, Grave's disease, umbilical hernia, urinary tract infection, urticaria, allergic rhinitis, and preeclampsia. The MAI criteria which had the highest percentage of inappropriately prescribed medications were “cost of drugs,” “duration of therapy,” and “indication.”

Conclusion:

Potentially inappropriate prescribing was seen in the study with some of the common coexisting illness being treated with drugs which fared poorly on the MAI. The study has also highlighted areas in drug prescribing where scope for improvement exists. Further, it can act as a benchmark for comparison of future studies to evaluate medication appropriateness in pregnant women.
An evaluation of trigger tool method for adverse drug reaction monitoring at a tertiary care teaching hospital
Authors: Menat Urmila , Desai Chetna K. , Panchal Jigar R. , Shah Asha N.
Published: December 2019

Objectives:

The objective of this study is to evaluate the trigger tool method (TTM) in detection, monitoring, and reporting of adverse drug reactions (ADRs) at Civil Hospital Ahmedabad, India.

Materials and Methods:

A prospective, single-center, observational cum intervention study was conducted in two phases in the Department of Medicine over 15 months. In phase I, preliminary trigger tool list (PTTL) comprising 55 triggers was evaluated by pharmacologist in terms of detection of ADR in 400 patients and then, modified trigger tool list (MTTL) was prepared. In Phase II, the TTM using MTTL was compared with the spontaneous method of ADR monitoring after educational interventions in resident doctors of the two units of medicine department.

Results:

Of the 55 triggers in PTTL, 34 triggers were observed in 327 patients, of which 19 triggers lead to the detection of 66 ADRs. The rate of ADEs was 16.5%/100 patients. Positive predictive value (PPV) of each trigger ranged from 0% to 100%. PPV for drug trigger, laboratory trigger, and PT was 14.4%, 4.5%, and 23.3%, respectively. Overall, PPV of PTTL was 19.27%. Sensitivity and specificity were 100% and 21.66%, respectively. MTTL consists of these 19 triggers. In Phase II, resident doctors reported 16 ADRs, using spontaneous method and 23 ADRs using MTTL. The rate of ADEs per 100 patients was 1.63 and 2.13, respectively, with these methods. A total of 105 ADRs were reported during both phases.

Conclusion:

TTM is an effective method of ADR reporting if it is utilized by a trained person. This method could be used as add-on method to spontaneous method to improve ADR reporting.
Development and validation of patient information leaflet for coronary heart disease patients
Authors: Vinay B. C. , Shastry C. S. , Kodangala Subramanyam , Mateti Uday Venkat , Bhat Krishna
Published: December 2019

Background:

Patient information leaflets (PILs) are effectively used to improve the patient's knowledge about medications, disease, diet, and lifestyle modifications.

Aim:

This study aims to develop and evaluate PILs for coronary heart disease patients.

Materials and Methods:

Primary, secondary, and tertiary resources were used to develop PILs. The developed PILs were validated by four doctors, four academic pharmacists, and one dietician. PILs design and layout was prepared using barker able leaflet design (BALD) criteria. PILs readability was assessed using the Flesch Reading Ease test (FRE), Flesch–Kincaid Grade Level (FKGL), and user readability methods. User opinion on PILs content and design was obtained from patients.

Results:

The FRE and FKGL readability scores were 61.5 and 7.4, respectively. The BALD criteria scores for English, Kannada, and Malayalam PILs were 28, 27, and 26, respectively. The overall user testing readability means scores had significantly improved from 45 to 79.30. Nearly 82.55% of patients rated the PILs as good design and content.

Conclusion:

The developed leaflet met the standard criteria for easy reading and comprehension. The majority of the patients gave good opinion on the content and design of the PILs.
Mini-Workshop: Asymptotic Invariants of Homogeneous Ideals
Authors: Bauer Thomas , Cooper Susan , Harbourne Brian , Szpond Justyna
Published: December 2019

Recent decades have witnessed a shift in interest from isolated objects to families of objects and their limit behavior, both in algebraic geometry and in commutative algebra. A series of various invariants have been introduced in order to measure and capture asymptotic properties of various algebraic objects motivated by geometrical ideas. The major goals of this workshop were to refine these asymptotic ideas, to articulate unifying themes, and to identify the most promising new directions for study in the near future. We expect the ideas discussed and originated during this workshop to be poised to have a broad impact beyond the areas of algebraic geometry and commutative algebra.
Emergence of Structures in Particle Systems: Mechanics, Analysis and Computation
Authors: Braides Andrea , Schmidt Bernd , Stefanelli Ulisse , Theil Florian
Published: December 2019

The meeting focused on the last advances in particle systems. The talks covered a broad range of topics, ranging from questions in crystallization and atomistic systems to mesoscopic models of defects to machine learning approaches and computational aspects.
Complexity Theory
Authors: Bürgisser Peter , Dinur Irit , Goldreich Oded , Vadhan Salil
Published: December 2019

Computational Complexity Theory is the mathematical study of the intrinsic power and limitations of computational resources like time, space, or randomness. The current workshop focused on recent developments in various sub-areas including arithmetic complexity, Boolean complexity, communication complexity, cryptography, probabilistic proof systems, pseudorandomness, and quantum computation. Many of the developments are related to diverse mathematical fields such as algebraic geometry, combinatorial number theory, probability theory, representation theory, and the theory of error-correcting codes.
Mini-Workshop: Mathematical and Numerical Analysis of Maxwell’s Equations
Authors: Dauge Monique , Langer Ulrich , Monk Peter , Pauly Dirk
Published: December 2019

In this mini-workshop 17 leading mathematicians from Europe and United States met at the MFO to discuss and present new developments in the mathematical and numerical analysis of Maxwell’s equations and related systems of partial differential equations. The report at hand offers the extended abstracts of their talks.
Replicar la arquitectura moderna: 4 viviendas de A. Bonet en el Poblado Hifrensa (España)
Authors: Ródenas García Juan Fernando , Domingo Magaña José Ramón
Published: December 2019

Las viviendas diseñadas por Antonio Bonet Castellana (1913-1989) en 1967 para el poblado Hifrensa, L’Hospitalet de l’Infant, Tarragona, constituyen un ejemplo de sistematización de estructuras urbanas. Bonet ensayó operaciones de transformación de un módulo elemental para desarrollar múltiples opciones con una idea de ciudad. En respuesta a la necesidad actual de crecimiento del poblado, se ha planteado replicar el módulo de viviendas propuesto por Bonet para peritos en Hifrensa, adaptándolo a la normativa vigente. El nuevo módulo, formado por cuatro viviendas, permite contemplar nuevamente elementos perdidos del proyecto original: formas, proporciones, materiales y acabados, dado el precario estado de conservación y de mantenimiento de las viviendas originales. El texto explica abundantes detalles constructivos de su proceso de diseño y construcción, revela las dicultades y las soluciones técnicas adoptadas durante el proceso y también advierte sobre la vulnerabilidad del patrimonio de la arquitectura moderna.
La intervención en el tejido residencial histórico del shikumen de Shanghái: Xintiandi como paradigma
Authors: González Martínez Plácido
Published: December 2019

Tras décadas de degradación y demoliciones extensivas, la tipología residencial del shikumen experimenta un proceso de renacimiento en Shanghái. Sin embargo, sus métodos de conservación se revelan tan controvertidos para deniciones occidentales de patrimonio urbano como desinhibidos desde el punto de vista de la práctica del diseño arquitectónico. Este artículo plantea de manera crítica la posibilidad de la producción de nuevos modelos de conservación urbana a partir de un acuerdo entre ambas, en el marco de gobernanza empresarial que impera en Shanghái como ciudad patrimonial.
The Practical Building Conservation series: evolution & content
Authors: Stewart John
Published: December 2019

Practical Building Conservation es una serie de diez volúmenes que ofrece una guía completa para la restauración de un amplio rango de materiales, desde el vidrio, madera y metales, hasta el hormigón. Los dos volúmenes de fundamentos proporcionan el marco de base a los libros sobre materiales de construcción. ConservationBasics describelahistoriadelarestauración, la práctica legal actual y la metodología. Building Environment define los factores medioambientales que afectan a los sistemas de construcción y hasta qué punto una buena restauración es sostenible. Este artículo explora la génesis de la serie, desde los cinco pequeños libros publicados en 1988, hasta la serie actual con más de 5.000 páginas. El nuevo trabajo muestra la evolución de la restauración arquitectónica de las últimas décadas, promoviendo intervenciones holísticas basadas en la valoración del significado, las condiciones y el riesgo. La serie hace referencia a la práctica de la restauración en Inglaterra. Sin embargo, la mayoría de la información proporcionada es de naturaleza genérica, por lo que es aplicable en otros contextos.
El enigma de la continuidad. La integración como instrumento de la conservación
Authors: Di Resta Sara
Published: December 2019

La amenaza de la desaparición de sitios monumentales a causa de guerras, terrorismo, catástrofes naturales o abandono, representa una de las emergencias de este nuevo siglo. Para reaccionar ante este fenómeno, la atención internacional se está centrando en cuestiones como la reconstrucción, réplica, clonación de nuestro patrimonio: las tecnologías de escaneado digital y de reproducción por control numérico apoyan estas operaciones que abarcan la arquitectura, la arqueología y el arte. La investigación, dedicada al tema de la integración como instrumento de la conservación, es un enfoque que parte de fundamentos opuestos. Los resultados de dichas operaciones perlan un espacio de reexión y de experimentación dedicado al lenguaje de la arquitectura contemporánea para la conservación.
The Limits of Modal Knowledge
Authors: Visser Rehan P.
Published: December 2019

Modal agnosticism is the view that we must be agnostic about whether things could have turned out differently. I argue that claims about unrealised possibilities (what I term ‘merely metaphysical modal claims’) are not justified by our modal intuitions, nor are they justified by any of the means proposed by philosophers. It follows that we do not have merely metaphysical modal knowledge, and that we must adopt modal agnosticism.
Partidos políticos importam na definição de carreiras políticas no Brasil?
Authors: Freitas Vitor Eduardo Veras de Sandes , Costa Diarlison Lucas Silva da
Published: December 2019

Este artigo tem como objetivo verificar se os partidos políticos são importantes na definição da escolha de carreira política dos deputados federais brasileiros. Para tanto, este trabalho parte das contribuições sobre carreira política que têm demonstrado que o principal padrão de carreira apresentado pelos deputados federais é o estático, ou seja, a busca por reeleição (PEREIRA; RENNÓ, 2013). A explicação apontada é a de que essa escolha é a mais segura eleitoralmente, independentemente dos partidos aos quais eles são filiados. Entretanto, outros autores têm chamado a atenção para a necessidade de se verificar a importância de fatores que diferenciem os deputados para uma análise mais desagregada das carreiras políticas como a participação na coalizão de governo ou nos grupos de oposição (BORGES; SANCHES FILHO, 2016), assim como as diferenças apresentadas dentro dos distritos (COSTA, 2018; CORRÊA, 2016). Além disso, a variável partidária pode ser um fator importante para definição das carreiras, devido às diferenças ideológicas dos partidos (MARENCO; SERNA, 2007) e aos interesses estratégicos dos partidos nas disputas para Prefeito nas grandes cidades (GRAÇA; SOUZA, 2014). Assim sendo, este artigo visa testar se a variável partidária importa para a escolha de carreira de deputados federais, assim com as demais variáveis retratadas pela literatura. Os resultados encontrados mostram que os deputados de partidos de esquerda e da coalizão de governo têm maior probabilidade de concorrer a reeleição e a prefeituras que os de direita e de centro.
Experiência parlamentar e trajetórias dos deputados federais eleitos por PSDB e PT em 1994 e 2002: quebrando mitos
Authors: Ribeiro Guilherme Leite , D'Araujo Maria Celina Soares
Published: December 2019

Analisam-se as bancadas eleitas pelo Partido da Social Democracia Brasileira (PSDB) e pelo Partido dos Trabalhadores (PT) em 1994 e 2002 a partir de critérios sociais, políticos e econômicos. Na pesquisa, confirmam-se teses correntes de que os parlamentares petistas possuíam vínculos mais próximos a movimentos sindicais, eram menos educados e tinham ocupações mais variadas. Por outro lado, ao contrário do que usualmente se supõe, revela-se que grande parte dos deputados federais do PT, eleitos nesses dois anos, trazia em seu histórico maior experiência no Legislativo, contrariando a concepção de outsider do sistema político. Com isso, contradiz-se a tese de que o PT seria um outsider do sistema político. Comparando a bancada dessas agremiações nas duas eleições estudadas, e supondo que experiência faz diferença, defende-se a hipótese de que em 1994 essa expertise foi fundamental para o papel do PT como oposição ao governo Fernando Henrique, e em 2003 como sustentação do governo Lula da Silva.
Conhecendo o vazio: congruência ideológica e partidos políticos no Brasil
Authors: Bolognesi Bruno , Babireski Flávia Roberta , Maciel Ana Paula
Published: December 2019

As classificações ideológicas dos partidos políticos brasileiros são periodicamente atualizadas a fim de captar mudanças e tendências. Contudo, usualmente apenas grandes partidos nacionais são escolhidos em detrimento do sistema partidário como um todo. Tal escolha reduz a compreensão que temos sobre a representação política no país, na medida que cada dia mais a fragmentação partidária se eleva e partidos pequenos passam a ocupar posições antes reservadas aos grandes. Assim, nosso objetivo aqui é mensurar e validar a medida em relação a um conjunto de partidos que é frequentemente ignorado pela literatura. Para tanto selecionamos oito agremiações menos classificadas pelos cientistas políticos no eixo esquerda-direita. A classificação foi realizada utilizando web based survey com a comunidade de experts brasileiros e brasilianistas. A fim de testar a validade mensuramos a congruência com estudos anteriores e com os programas e manifestos partidáros destes oito desconhecidos. Nossa hipótese é que estes partidos são pouco classificados porque possuem posições ideológicas latentes e não salientes. Os resultados apontam no sentido da confirmação da hipótese, ainda que fatores contextuais e sistêmicos tenham peso na dificuldade da comunidade científica em classificar nossas legendas partidárias.
The role of spring dry zonal advection in summer drought onset over the US Great Plains
Authors: Erfanian Amir , Fu Rong
Published: December 2019

Abstract. This study addresses the role of the atmospheric moisture budget in determining
the onset and development of summer droughts over the North American Great
Plains (GP) using two state-of-the-art reanalysis datasets. We identified
zonal moisture advection as the main cause of severe tropospheric drying
during the extreme droughts in the southern GP in 2011 and northern GP in 2012. For
both events, the eastward advection of anomalously dry and warm air in the
free troposphere in spring set the stage for summer drought. This led to a
sharp drop in relative humidity above the boundary layer, enhancing dry
entrainment and suppressing deep convection. Further breakdown of the zonal
advection into dynamic (caused by circulation anomalies) and thermodynamic
(caused by moisture anomalies) contributions reveals dominance of
thermodynamic advection in the tropospheric drying observed during the onset
of both 2011 and 2012 droughts. The dependence of thermodynamic advection on
the moisture gradient links springtime precipitation in the Rockies and
southwestern US, the source region of the anomalous dry advection, to the GP
summer precipitation (with correlations > 0.4 using gauge-based
data). Identifying this previously overlooked precursor of the GP summer
droughts improves our predictive understanding of drought onset mechanisms
over the region.
Craig-Gordon model validation using observed meteorological parameters and measured stable isotope ratios in water vapor over the Southern Ocean
Authors: Dar Shaakir Shabir , Ghosh Prosenjit , Swaraj Ankit , Kumar Anil
Published: December 2019

Abstract. The stable isotopic composition of water vapor over the ocean is governed by the isotopic composition of surface water, ambient vapor isotopic composition, exchange and mixing processes at the water-air interface as well as the local meteorological conditions. In this study we present water vapor and surface water isotope ratios in samples collected across the latitudinal transect from Mauritius to Prydz Bay in the Antarctic coast. The samples were collected on-board the ocean research vessel SA Agulhas during the 9th (Jan-2017) and 10th (Dec-2017 to Jan-2018) Southern Ocean expeditions. The inter annual variability of the meteorological factors governing water vapor isotopic composition is explained. The parameters governing the isotopic composition of evaporation flux from the oceans can be considered separately or simultaneously in the Craig-Gordon (CG) models. The Traditional Craig-Gordon (TCG) (Craig and Gordon, 1965) and the Unified Craig-Gordon (UCG) (Gonfiantini et al., 2018) models were used to evaluate the isotopic composition of evaporation flux for the molecular diffusivity ratios suggested by Merlivat (1978) (MJ), Cappa et al. (2003) (CD) and Pfahl and Wernli (2009) (PW) and for different ocean surface conditions. We found that the UCG model with CD molecular diffusivity ratios where equal contribution from molecular and turbulent diffusion is the best match for our observations. By assigning the representative end member isotopic compositions and solving the two-component mixing model, a relative contribution from locally generated and advected moisture was calculated along the transect. Our results suggest varying contribution of advected westerly component with an increasing trend upto 65° S. Beyond 65° S, the proportion of Antarctic moisture was found to be increasing linearly towards the coast.
Review article: Natural hazard risk assessments at the global scale
Authors: Ward Philip J. , Blauhut Veit , Bloemendaal Nadia , Daniell James E. , de Ruiter Marleen C. , Duncan Melanie , Emberson Robert , Jenkins Susanna F. , Kirschbaum Dalia , Kunz Michael , Mohr Susanna , Muis Sanne , Riddell Graeme , Schäfer Andreas , Stanley Thomas , Veldkamp Ted I. E. , Winsemius Hessel C.
Published: December 2019

Abstract. Since 1990, natural hazards have led to over 1.6 million fatalities globally, and economic losses are estimated at an average of around $260–310 billion per year. The scientific and policy community recognise the need to reduce these risks. As a result, the last decade has seen a rapid development of global models for assessing risk from natural hazards at the global scale. In this paper, we review the scientific literature on natural hazard risk assessments at the global scale, and specifically examine whether and how they have examined future projections of hazard, exposure, and/or vulnerability. In doing so, we examine similarities and differences between the approaches taken across the different hazards, and identify potential ways in which different hazard communities can learn from each other. For example, we show that global risk studies focusing on hydrological, climatological, and meteorological hazards, have included future projections and disaster risk reduction measures (in the case of floods), whilst these are missing in global studies related to geological hazards. The methods used for projecting future exposure in the former could be applied to the geological studies. On the other hand, studies of earthquake and tsunami risk are now using stochastic modelling approaches to allow for a fully probabilistic assessment of risk, which could benefit the modelling of risk from other hazards. Finally, we discuss opportunities for learning from methods and approaches being developed and applied to assess natural hazard risks at more continental or regional scales. Through this paper, we hope to encourage dialogue on knowledge sharing between scientists and communities working on different hazards and at different spatial scales.
Vertical profiles of wind gust statistics from a regional reanalysis using multivariate extreme value theory
Authors: Steinheuer Julian , Friederichs Petra
Published: December 2019

Abstract. Many applications require wind gust estimates at very different atmospheric height levels. For example, the renewable energy sector is interested in wind and gust predictions at the hub height of a wind power plant. However, numerical weather prediction models typically derive estimates for wind gusts at the standard measurement height of 10 m above the land surface only. Here, we present a statistical post-processing to derive a conditional distribution for hourly peak wind speed as a function of height. The conditioning variables are taken from the regional reanalysis COSMO-REA6. The post-processing is trained using peak wind speed observations at five vertical levels between 10 m and 250 m of the Hamburg Weather Mast. The statistical post-processing is based on a censored generalized extreme value (cGEV) distribution with non-stationary parameters. We use a least absolute shrinkage and selection operator to select the most informative variables. Vertical variations of the cGEV parameters are approximated using Legendre polynomials, such that predictions may be derived at any desired vertical height. Further, the Pickands dependence function is used to assess dependencies between gusts at different heights. The most important predictors are the 10 m gust diagnostic, the barotropic and the baroclinic mode of absolute horizontal wind speed, the mean absolute horizontal wind in 700 hPa, the surface pressure tendency, and the lifted index. Proper scores show improvements with respect to climatology of up to 60 % especially at higher vertical levels. The post-processing model with a Legendre approximation is able to provide reliable predictions of gusts statistics at non-observed intermediate levels. The strength of dependency between gusts at different levels is non-stationary and strongly modulated by the vertical stability of the atmosphere.
Subseasonal Midlatitude Prediction Skill Following QBO-MJO Activity
Authors: Mayer Kirsten J. , Barnes Elizabeth A.
Published: December 2019

Abstract. The Madden-Julian Oscillation (MJO) is known to force extratropical weather days-to-weeks following an MJO event through excitation of stationary Rossby waves, tropical-extratropical teleconnections. Prior research has demonstrated that this tropically forced midlatitude response leads to increased prediction skill on subseasonal to seasonal (S2S) timescales. Furthermore, the Quasi-Biennial Oscillation (QBO) has been shown to possibly alter these teleconnections through modulation of the MJO itself and the atmospheric basic state upon which the Rossby waves propagate. This implies that the MJO-QBO relationship may affect midlatitude circulation prediction skill on S2S timescales. In this study, we quantify midlatitude circulation sensitivity and prediction skill following active MJOs and QBOs across the Northern Hemisphere on S2S timescales through an examination of the 500 hPa geopotential height field. First, a comparison of the spatial distribution of Northern Hemisphere sensitivity to the MJO during different QBO phases is performed for ERA-Interim reanalysis and ECMWF and NCEP hindcasts. Secondly, differences in prediction skill in ECMWF and NCEP hindcasts are quantified following MJO-QBO activity. We find that regions across the Pacific, North America and the Atlantic exhibit increased prediction skill following MJO-QBO activity, but these regions are not always collocated with the locations most sensitive to the MJO under a particular QBO state. Both hindcast systems demonstrate enhanced prediction skill 7–14 days following active MJO events during strong QBO periods compared to MJO events during neutral QBO periods.
Analysing wind and biomass electricity potential in rural Germany considering local demand in 15-minute intervals
Authors: Stößel Laura , Kohl Esther , Roscher Björn , Schelenz Ralf , Jacobs Georg
Published: December 2019

Abstract. Uncoordinated extension of renewable energy sources (RES) disregarding local demand structures leads to increased loads on the transmission grid and overall economic losses. One approach to solve this problem is to support the local power consumption by local power generation without making use of the transmission network. Therefore, the actual physical coverage of local demand with local supply is to be investigated instead of a yearly net power balance. Rural municipalities are an ideal starting point to establish such self-sufficient power supply systems on the basis of RES as they have a high RES potential in combination with low demand loads. Fluctuating feed-in of wind and solar power and peaks in demand loads can be balanced by bioenergy as flexible power generation capacity. In contrast to highly resource dependent wind and solar power, biomass can be stored and power generation from biomass can be controlled flexibly. To assess the potential of electricity from biomass, this study analyses the agricultural structure of the rural municipalities. The objective of this study is to assess what kind of agricultural structure might be advantageous for flexible power generation from bioenergy, hence balancing fluctuation RES feed-in and power demand. The results from this structural assessment of rural municipalities can help for analysing further municipalities to identify potentials at first sight without costly individual analysis. Heat and fuel sectors are neglected. A methodology is introduced to model time series of wind, PV and biomass power with a 15-minute resolution. It is evaluated to which degree it is possible to cover the local demand in power supply with bioenergy as flexible power generation capacity in the identified clusters. The results indicate that bioenergy is generally suitable to cover the gap between local power demand and supply. Waste products from animal farming are far more effective for biomass power production than from agricultural farming. Low population densities raise the potential for self-sufficiency in the power sector because of low demand loads. Further improvement of the model is needed concerning the clustering approach and for the approximation of installed wind and PV power capacities.
The Five Cs of Positive Youth Development in an Aotearoa/New Zealand Program Context
Authors: Mercier Jayne , Powell Catherine , Langdon-Pole Georgina , Finau Daleki (Fole) , Hicks Karen , Bourchier Louise , Hampton Jacqui
Published: December 2019

This study took a qualitative look at an Aotearoa/New Zealand-based positive youth development outdoor-education program in schools using the 5 Cs model of positive youth development. The viewpoints of young people, parents, and teachers were gathered, providing an opportunity to explore additional perspectives of the 5 Cs. All 5 Cs were seen to be present in the program and the 6th C of contribution was also observed. The Cs of competence, confidence and connection featured strongly, whilst the C of connection appeared to be important to young people’s experience of the program. Young people and adults prioritized different outcomes, with adults focusing more on future impacts and young people identifying more immediate benefits. The findings of this study add to an understanding of the 5 Cs model beyond the American context and highlight areas for future research.
A Residential Camp’s Impact on Youths’ Leadership Skills and Natural Resource Knowledge
Authors: Frey Shandra Nicole , Parent Vernon
Published: December 2019

Learning transcends the classroom. To better understand the natural world around them, it is critical that youth have opportunities to make connections and apply their learning in real-world settings. Improving youths’ perceived skills and knowledge contributes to increased academic motivation and continued leadership development. Multi-day residential natural resource camps have shown the ability to teach ecological concepts and develop land management skills, critical thinking skills, and decision-making skills. We tested the ability of a remotely located residential camp to improve leadership skills and natural resource knowledge, using a pre- and post-camp self-assessment, combined with a pre- and post-camp knowledge test. The teaching strategies of the camp—independent investigations, discussion groups, interactions with field scientists, recreational activities, and group problem solving—resulted in participants feeling they had increased their leadership skills and knowledge of natural resource topics. The campers’ perceived increase in knowledge was supported by an increase in score on a knowledge-based test. A residential natural resource camp is an effective activity to engage youth to develop leadership skills and academic motivation, while connecting them to their natural environment.
How Do Students Adapt in Response to Academic Failure?
Authors: Ajjawi Rola , Boud David , Zacharias Nadine , Dracup Mary , Bennett Sue
Published: December 2019

Ensuring student success has long been on the research agenda in higher education. In this study, we seek to understand if the changes students make in light of academic failure are consistent with this literature. Little is known about students who fail but subsequently persist in their studies. Through an online survey with students who had failed and persisted, we identified drivers for persistence and how students adapted in response to academic failure. Thematic analysis showed that the majority of students did not seek institutional support following academic failure but they did seek support from peers, family and friends. These adaptations occurred at multiple levels: dispositional, situational and institutional. Drivers reported were internal (desire to complete) and external (desire to meet expectations). Although the majority of our students showed positive adaptations following academic failure, a significant portion reported no changes to their academic strategies. The paper poses the question of how students who fail can be better supported to continue successfully.
Make it Measurable: Assessing Psychological Distress, Wellbeing and Resilience at Scale in Higher Education
Authors: Van Agteren Joep , Woodyatt Lydia , Iasiello Matthew , Rayner Julie , Kyrios Michael
Published: December 2019

There is an ever-increasing focus on the importance of addressing the mental health of students across the higher education sector. Measuring psychological distress or symptoms of common mental disorders as a proxy for mental health does however provide a limited picture of someone’s mental health status. There is a need to comprehensively measure mental health via outcomes of psychological distress combined with “positive” and “adaptive” states of mental health such as mental wellbeing and resilience. This paper describes a study of 905 students in which an online mental health and wellbeing platform was used to measure the mental health of students, all the while providing real-time individual reports to each individual student. The data provides evidence of high levels of psychological distress (i.e. anxiety) and low levels of mental wellbeing and resilience in students, relative to population norms, with merely 18.6% of students demonstrating optimal scores on all outcomes. Contrary to predictions we found no evidence of poorer wellbeing amongst international students when compared to domestic students. The results indicate that complimenting measurement of distress with measurement of positive and adaptive states can more comprehensively capture the precarious mental status of our tertiary students. Providing this measurement in a scalable and targeted way provides universities and its students the opportunity to provide and use mental health interventions based on the needs of particular cohorts of students, moving beyond resource-intense but intermittent or untargeted approaches to intervention.