bluuebunny/crossref_metadata_2025 huggingface dataset:
Low-Density Fan-Out Heterogeneous Integration of MEMS Tunable Capacitor and RF SOI Switch
Authors: Hadizadeh Rameen , Laitinen Anssi , Kuusniemi Niko , Blaschke Volker , Molinero David , O'Toole Eoin , Pinheiro Márcio
Published: December 2019

Using Low-Density Fan-Out (LDFO) packaging technology, a radio frequency (RF) microelectromechanical systems (MEMS) tunable capacitor array composed of electrostatically actuated beams on 180nm high-voltage CMOS silicon was heterogeneously integrated with a single-pole four-terminal (SP4T) RF switch on 180nm CMOS silicon-on-insulator (SOI). The primary objective of this study was to determine the manufacturability of this System-in-Package (SiP) design, which is proven at time zero through survival of the MEMS device based on acceptable MEMS performance metrics.

In addition, the RF SOI switch provides high-voltage electrostatic discharge (ESD) protection for the MEMS device. Capacitive MEMS structures are particularly sensitive to unpredictable electrostatic charging scenarios, such as handling after package assembly and printed circuit board (PCB) surface mount processing. Consequently, resistance to dielectric breakdown by means of robust ESD protection is a very desirable quality. Integrating the RF switch in close proximity with the MEMS device not only enables the ability to withstand charging scenarios in excess of 1kV (human body model), it mitigates the impact of parasitics on RF performance by minimizing interconnect lengths and complexity.
Solder Joint Interconnections in Automotive Electronics: Design-for-Reliability and Accelerated Testing
Authors: Suhir E. , Yi S. , Nicolics J.
Published: December 2019

Three practically important reliability-related questions for solder joint interconnections (SJIs) in automotive electronics, and particularly in its actuator and sensor electron devices, are addressed in this analysis:Could inelastic strains in the solder material be avoided by a rational physical design of the IC package, and, if not, could the sizes of the peripheral inelastic strain areas be predicted and minimized? It is clear that the low cycle fatigue lifetime is inversely proportional to the sizes of the inelastic zones and that the material's fatigue lifetime could be improved dramatically, if the induced strains remain within the elastic range. The Palmgren-Miner rule of linear accumulation of damages can be used, instead of Coffin-Manson relationships, in such a situation.Realizing that, because of the inevitable uncertainties, the difference between highly reliable and an insufficiently robust electronic products is “merely” in the levels of their never-zero probabilities of failure, could these probabilities be assessed, and could this be done at the design stage? A possibility of doing that is particularly critical for SJIs, the most vulnerable structural elements in the today's IC package designs. Reliability of an electronic material or a product cannot be assured, if it is not quantified, and, because of the inevitable and critical uncertainties, this should be done on the probabilistic basis.Should SJI accelerated testing based on costly, time- and labor-consuming and, because of temperature dependency of material properties, possibly even misleading temperature cycling, be replaced by a more physically meaningful, less expensive and more trustworthy accelerated test vehicle, and could low-temperature/random-vibrations bias be employed in this capacity? The rationale behind such a question has to do with the facts that the highest thermal stresses take place at the lowest temperature conditions, and that fatigue cracks, whether elastic or inelastic, propagate most rapidly, when the material experiences random vibrations. This technique has been already reduced to practice in an industrial lab two years ago.

The objective of the analysis is to shed light, by using analytical (“mathematical”) modeling, rather than widely spread computer simulation, on the mechanical behavior and the underlying physics of failure in the SJI. Future work should focus primarily on experimentations to confirm theoretical findings and recommendations.
Study to Lower Cu Pillar Flip-Chip Failure Rate
Authors: Rosario Bong , Holyoak Joseph , Haji-Rahim Mohsen , Lambird Gene , Wang Yong , Lyons Kendra , Johnson Todd , Makowenskyj Paul , Myers Brian , Pan Shannon
Published: December 2019

Cu pillar flip-chip die technology has proved reliable and is widely used in chip-to-package mobile module products. There was a time when customers considered 500ppm (Parts per million) an acceptable defect rate. Now, tier 1 customers expect a defect rate of less than 50ppm. This high customer expectation drove this in-depth research and problem solve. Our main work includes: 1) Mapping and analyzing initial defects. 2) Developing an effective way to detect a low defect rate. 3) 3D mechanical modeling that focuses on multiple failure interfaces and modes. 4) Simulating stress factors and their impacts. 5) Verifying hypothesis with assembly design of experiment (DOE) and ultimately improved yield.
Passive Die Alignment in Glass Embedded Fan-Out Packaging
Authors: Ostholt Roman , Santos Rafael , Ambrosius Norbert , Dunker Daniel , Delrue Jean-Pol
Published: December 2019

The objective of this paper is to demonstrate the feasibility of glass mounting substrates made by Laser Induced Deept Etching (LIDE) technology, which include newly developed passive die alignment structures. The aim of these structures is to compensate for potential die misalignments and die shift issues which become severe when moving to panel level fan-out packaging.

The passive alignment structures are located at two adjacent edges of the rectangular cavity and are created in the same process step as the open cavities. The filigree spring-like alignment structures benefit from being processed in a crack- and stress-free manner. Although the spring elements have a minimal dimension of less than 100 μm, these structures show an outstanding break strength while deformed when active dies are placed in the mounting cavity. Depending on the design, the spring elements can have a stroke of several tenths of micrometer which enable the compensation of rather large die displacements.

Here, we present examples for LIDE-processed mounting glass substrates with the described features. The performance of the proposed design and method was evaluated with a die accuracy study. Test dies with alignment marks were placed in the cavities and measured relatively to alignments marks on the mounting glass substrate. The Fan-Out packaging concept based on the research shown here combines several advantages: due to the relatively high Young's modulus of the glass, the reconstituted wafer shows less warpage than in the state-of-art; while the passive alignment structures reduce the die shift to a minimum (depending on dicing accuracies and through package vias for package-on-package or antenna-in-package application), and can be readily integrated.
Mechanical Modeling and Continuous Process Improvement
Authors: Harker Shane D. , Hernandez Mercedes T. , Lambird Gene
Published: December 2019

Short design cycles for integrated circuits and packages drive the need for efficient problem solving and rapid results. Improved mechanical modeling software and increased computing power have taken these computation-heavy tools and made them versatile enough to support main-stream, real-time production needs. The utility of these tools has been significantly improved by simplified work flows to create detailed geometries and complex assemblies, improved mesh generation algorithms, and solve time reduction. Mechanical modeling software has a wide range of application which traditionally has been focused on design of large structures. Despite their general applicability, these tools have not been optimized for microelectronics in terms of absolute dimensions, fine structure count, and range of scale from the smallest to the largest component. Finding solutions to these problems pays off in fewer design cycles and significant process yield improvements. This paper will show multiple examples of process-induced stress, driven by material properties and manufacturing. They have been created using a variety of FEM tools, including ANSYS and Abaqus.
Quasi-Half Loop Bond Wire Antennas for Emerging Wireless Communication and Radar Sensor Systems
Authors: Ndip Ivan , Le Thi Huyen , Schneider-Ramelow Martin , Lang Klaus-Dieter
Published: December 2019

Emerging wireless communication and radar sensing systems require large channel bandwidths to meet the requirements of some key applications. Antennas used for the development of these systems must be designed to enable these large bandwidths. In this work, we present the characteristics of a quasi-half loop bond wire antenna (QHL-BWA) which enable large bandwidths and high gains at mmWave frequencies. The antenna was modelled and simulated using Ansys HFSS. Test samples were designed and measured. Very good correlation was obtained between measurement and simulation results.
Flip Chip Underfill RF Characterization
Authors: Paul Robert B. , Engin A. Ege , Aguirre Jerry
Published: December 2019

To develop reliable high-speed packages, characterization of the underfill material used in the flip-chip process has become of greater importance. The underfill, typically an epoxy resin-based material, offers thermal and structural benefits for the integrated circuit (IC) on package. With so many inputs and outputs (IOs) in close proximity to one another, the integrated circuits on package can have unexpected signal and power integrity issues.

Furthermore, chip packages can support signals only up to the frequency where noise coupling (e.g., crosstalk, switching noise, etc.) leads to the malfunctioning of the system. Vertical interconnects, such as vias and solder bumps, are major sources of noise coupling. Inserting ground references between every signal net is not practical. For the solder bumps, the noise coupling depends on the permittivity of the underfill material. Therefore, characterizing the permittivity of the underfill material helps in predicting signal and power integrity issues.

Such liquid or semi-viscous materials are commonly characterized from a simple fringe capacitance model of an open-ended coaxial probe immersed in the material. The open-ended coaxial method, however, is not as accurate as resonator-based methods. There is a need for a methodology to accurately extract the permittivity of liquid or semi-viscous materials at high frequencies. The proposed method uses solid walled cavity resonators, where the resonator is filled with the underfill material and cured.

Dielectric characterization is a complex process, where the physical characteristics of the cavities must be known or accurately measured. This includes the conductivity of the conductors, roughness of the conductors, the dimensions of the cavity, and the port pin locations. This paper discusses some of the challenges that are encountered when characterizing dielectrics with cavity resonators. This characterization methodology can also be used to characterize other materials of interest.
Cu Core Column Application for Fine Pitch 3D Mounting
Authors: SUDO Hiroki , SOMA Daisuke , OKADA Hiroshi
Published: December 2019

Cu core columns, a cylindrical-shaped copper core material with Ni and solder plating, are attracting attentions as next generation joint material instead of normal solder balls, Cu core balls, and even Cu plating pillars. Cu core columns have the ability to control and maintain a consistent stand-off height, and can achieve remarkable electric and thermal conductivity because of excellent physical properties of Cu. However, it is unclear whether it can be mounted stably like normal solder balls because of its cylindrical shape. Therefore, in this paper, we set our goal to establish Cu Core Column application for next generation bumping material by examining the melting behavior, wettability of Cu core column bumps, and reliability for drop impact and thermal stress.
Semiconductor manufacturing strategy: Where in the world to locate a fab or cleanroom?
Authors: Rothrock Stephen M.
Published: December 2019

The global market for advanced technology manufacturing assets is becoming ever tighter, compelling semiconductor companies, including OSATs (outsourced semiconductor assembly and test), IDMs (integrated device manufacturers), and foundries, to carefully explore all available options when planning manufacturing operations relating to fabs, tools, and cleanrooms. Despite the semiconductor industry's optimistic growth forecasts, global uncertainty generated by the continuing trade wars between the U.S. and China is causing anxiety among advanced technology companies and forcing them to constantly rethink their manufacturing strategies – buy vs. build, best fab location, risk mitigation, local incentives, etc. In 2018, semiconductor companies showed increased renewed interest in U.S.-based manufacturing in the midst of a continued lack of 200mm and 300mm capacity. As we have seen with the recent sale of Texas Instrument's 150mm / 200mm facility in Greenock, UK to Diodes Incorporated and Vanguard International Semiconductor Corporation's acquisition of GLOBALFOUNDRIES' 200mm Fab E3 in Tampines, Singapore, 200mm fabs are still in very high demand and manufacturers are becoming increasingly proactive as they look to expand capacity.

In 2019, infrastructure-rich cleanroom manufacturing assets are going to continue to play an essential part in shaping these strategies to ensure global competitive advantage as more wafers are needed and more facilities are being built worldwide, particularly in China. Despite a slowdown in semiconductor mergers and acquisitions activity, the global semiconductor market will continue to consolidate as the manufacturing needs of advanced technology companies evolve with market changes. This has put a strain on manufacturing space and resulted in a number of new capital projects and expansions that may become difficult to fulfill in the current market. A shortage of existing manufacturing space means cleanrooms and operational fabs will sell at a premium. Many companies are also looking at greenfield sites with local government incentives playing an active role. Running in tandem, there is still a shortage of used and new production tools with lead times in excess of one year to purchase new fabs from OEMs (original equipment manufacturers) or equip new fabs.

Drawing on some 20 years of infrastructure-rich manufacturing asset dispositions and acquisitions as well as a series of real-world fab transaction case studies, ATREG Founder, President and CEO Stephen M. Rothrock will provide insights into how to best approach manufacturing strategy decisions in the context of today's global semiconductor landscape.
Control of Solder Bump Growing Morphology in Lead Free Plating
Authors: Weng Berdy , Liu Wei-Wei (Xenia) , Lai Lu-Ming , Chen Kuang-Hsiung
Published: December 2019

Plating Solder bump is one of the key enabling technologies for flip chip assembly methodology. Flip chip assembly has advanced to support higher levels of interconnect and small feature sizes. Electroplating is a very promising technology for finer bump features when compared with solder printing and ball mounting. Hence, the plated-solder bump morphology is quite important for process quality control and design realization. This paper aims to study the plated solder behavior from as-plated mushroom structure to after reflowed bump stage photoresist sizing. In addition, this activity will consider the full bumping process integration relative to the electroplated solder bump design rules.
On-Chip Diffusion Bonding creates Stable Interconnections Usable at Temperatures over 300°C
Authors: Richter Jessica , Steenmann Anna , Schellscheidt Benjamin , Licht Thomas
Published: December 2019

In this paper, we present a conceptual design of an on-chip solder stack to connect silicon devices faster and more reliable. Almost all electronic devices rely on solder layers to provide electrical, mechanical, and thermal connections between components. We improve the solder connection with industry-standard solder parameters of 300°C and some minutes of soldering time.

An ideal solder connection is composed of intermetallic phases (IMPs) at the interfaces between device and solder, and substrate and solder. Typically, a thin region of Sn-based solder remains between the two IMP layers at the interfaces. IMPs of copper (Cu) and tin (Sn) are Cu6Sn5 and Cu3Sn. The formation of IMPs is decisive for a good mechanical connection because of their high melting point and mechanical stability. To achieve these requirements, we implement the solder stack as a transient liquid phase bonding (TLPB) system. To realize durable interconnections, we use the diffusion of a high-melting first component in a second component, which is liquid at solder process temperature. Ongoing diffusion leads to the formation of IMPs with a melting point above process temperature, resulting in a solidification of the connection at constant temperature. By this isothermal solidification, the solder connection becomes more durable against mechanical and thermal load and is usable at temperatures exceeding 300°C.
A High Performance Full SiC Power Module Based On a Novel Stacked DBCs Hybrid Packaging Structure
Authors: Wang Zhiwei , Zhang Chi , Huang Zhizhao , Chen Cai , Luo Fang
Published: December 2019

This paper proposed a novel stacked DBCs hybrid package structure and designed a low inductive 1200V/120A SiC half-bridge power module based on the package structure. Using the multi-layer structure of DBC+DBC, the main loop parasitic inductance of the power module has been reduced to 1.8nH by optimizing the three-dimensional commutation loop and using the mutual inductance cancellation concept. The module was designed and fabricated, the low inductance characteristics of the module was verified by dual pulse testing and power testing. Dynamic test results show that the module can switch safely with a low overvoltage under zero ohm external drive resistance, and the switching loss is reduced by 57% compared to commercial modules.
Risk minimization by median-of-means tournaments
Authors: Lugosi Gábor , Mendelson Shahar
Published: December 2019

We consider the classical statistical learning/regression problem, when the value of a real random variable

Y

is to be predicted based on the observation of another random variable

X

. Given a class of functions

\mathcal F

and a sample of independent copies of

(X,Y)

, one needs to choose a function

\widehat{f}

from

\mathcal F

such that

\widehat{f}(X)

approximates

Y

as well as possible, in the mean-squared sense. We introduce a new procedure, the so-called median-of-means tournament, that achieves the optimal tradeoff between accuracy and confidence under minimal assumptions, and in particular outperforms classical methods based on empirical risk minimization.
Combinatorial Optimization
Authors: De Loera Jesús , Iwata Satoru , Skutella Martin
Published: December 2019

Combinatorial Optimization is an active research area that developed from the rich interaction among many mathematical areas, including combinatorics, graph theory, geometry, optimization, probability, theoretical computer science, and many others. It combines algorithmic and complexity analysis with a mature mathematical foundation and it yields both basic research and applications in manifold areas such as, for example, communications, economics, traffic, network design, VLSI, scheduling, production, computational biology, to name just a few. Through strong inner ties to other mathematical fields it has been contributing to and benefiting from areas such as, for example, discrete and convex geometry, convex and nonlinear optimization, algebraic and topological methods, geometry of numbers, matroids and combinatorics, and mathematical programming. Moreover, with respect to applications and algorithmic complexity, Combinatorial Optimization is an essential link between mathematics, computer science and modern applications in data science, economics, and industry.
Convex Geometry and its Applications
Authors: Barthe Franck , Henk Martin , Ludwig Monika
Published: December 2019

The geometry of convex domains in Euclidean space plays a central role in several branches of mathematics: functional and harmonic analysis, the theory of PDE, linear programming and, increasingly, in the study of algorithms in computer science. The purpose of this meeting was to bring together researchers from the analytic, geometric and probabilistic groups who have contributed to these developments.
El debate sobre la validez externa en economía experimental
Authors: Moro Rodrigo , Auday Marcelo
Published: December 2019

We focus on the debate on the external validity of lab results in the area of experimental economics. More specifically, we focus on Colin Camerer’s and John List’s views, who postulate opposite positions on the issue. The problem is that they partially analyze the same empirical evidence and draw from it opposite conclusions. The goal of this work is to analyze such empirical evidence to try to explain the difference in interpretation of results. We argue that the dispute in interpretations can be expressed in terms of difference of criteria used to determine external validity. From our analysis we propose the formulation of different types of external validity.
Lateral facet growth of ice and snow – Part 1: Observations and applications to secondary habits
Authors: Nelson Jon , Swanson Brian D.
Published: December 2019

Abstract. Often overlooked in studies of ice growth is how the crystal facets increase in area, that is, grow laterally. This paper reports on observations and applications of such lateral facet growth for vapor-grown ice in air. Using a new crystal-growth chamber, we observed air pockets forming at crystal corners when a sublimated crystal is regrown. This observation indicates that the lateral spreading of a face can, under some conditions, extend as a thin overhang over the adjoining region. We argue that this extension is driven by a flux of surface-mobile molecules across the face to the lateral-growth front. Following the pioneering work on this topic by Akira Yamashita, we call this flux “adjoining surface transport” (AST) and the extension overgrowth “protruding growth”. Further experiments revealed other types of pockets that are difficult to explain without invoking AST and protruding growth. We develop a simple model for lateral facet growth on a tabular crystal in air, finding that AST is required to explain observations of facet spreading. Applying the AST concept to observed ice and snow crystals, we argue that AST promotes facet spreading, causes protruding growth, and alters layer nucleation rates. In particular, depending on the conditions, combinations of lateral- and normal-growth processes can help explain presently inexplicable secondary features and habits such as air pockets, small circular centers in dendrites, hollow structure, multiple-capped columns, scrolls, sheath clusters, and trigonals. For dendrites and sheaths, AST may increase their maximum dimensions and round their tips. Although these applications presently lack quantitative detail, the overall body of evidence here demonstrates that any complete model of ice growth from the vapor should include such lateral-growth processes.
The role of HONO in O3 formation and insight into its formation mechanism during the KORUS-AQ Campaign
Authors: Gil Junsu , Kim Jeonghwan , Lee Meehye , Lee Gangwoong , Lee Dongsoo , Jung Jinsang , An Joonyeong , Hong Jinkyu , Cho Seogju , Lee Jeonghoon , Long Russell
Published: December 2019

Abstract. Photolysis of nitrous acid (HONO) has long been recognized as an early morning source of OH radicals in urban air, but the detailed mechanism of its formation is still unclear. During the Korea-US Air Quality (KORUS-AQ) campaign, HONO was measured using Quantum Cascade Tunable Diode Laser Absorption Spectroscopy (QC-TDLAS) at Olympic Park in Seoul from 17 May to 10 June, 2016. HONO concentrations ranged from 0.07 ppbv to 3.46 ppbv with an average of 0.93 ppbv. HONO remained high at night from 1 am to 5 am, during which the mean concentration was higher in high-O3 episodes (1.82 ppbv) than non-episode (1.20 ppbv). In the morning, OH budget due to HONO photolysis were higher by 50 % (0.95 pptv) during high-O3 episodes compared to non-episode. Diurnal variations of HOx and O3 simulated by the F0AM model demonstrated a difference of ~ 20 ppbv in daily maximum O3 between the two periods. The HONO concentration increased with relative humidity (RH) until 80 %, of which the highest HONO was associated with the top 10 % NOx, confirming that NOx is a crucial precursor of HONO and its formation is facilitated by humidity. The conversion ratio of NOx to HONO was estimated to be 0.86 × 10−2 h−1 at night and also increased with RH. As surrogate for the catalyst surface, the mass concentrations of black carbon (eBC) and the surface areas of particles smaller than 120 nm showed a tendency for RH similar to conversion ratio. Using an Artificial Neuron Network (ANN) model, HONO concentrations were successfully simulated with measured variables (r = 0.8 for the best suite), among which NOx, surface area, and RH were found to be main factors affecting ambient HONO concentrations with weigh values of 26.2 %, 11.9 %, and 10.6 %, respectively. This study demonstrates the coupling of HONO with HOx-VOCs-O3 cycle in Seoul Metropolitan Areas (SMA) and provides practical evidence for heterogeneous formation of HONO by employing the ANN model to atmospheric chemistry.
New Particle Formation and Sub-10 nm Size Distribution Measurements during the A-LIFE field experiment in Paphos, Cyprus
Authors: Brilke Sophia , Fölker Nikolaus , Müller Thomas , Kandler Konrad , Gong Xianda , Peischl Jeff , Weinzierl Bernadett , Winkler Paul M.
Published: December 2019

Abstract. Atmospheric particle size distributions were measured in Paphos, Cyprus, during the A-LIFE (Absorbing aerosol layers in a changing climate: aging, lifetime and dynamics) field experiment from April 3–30, 2017. The newly developed DMA-train is deployed for the first time in an atmospheric environment for the direct measurement of the nucleation mode size range between 1.8–10 nm diameter. The DMA-train setup consists of seven size channels, of which five are set to fixed particle mobility diameters and two additional diameters are obtained by alternating voltage settings in one DMA every 10 s. In combination with a conventional Mobility Particle Size Spectrometer (MPSS) and an Aerodynamic Particle Sizer (APS) the complete atmospheric aerosol size distribution from 1.8 nm–10 µm is covered. The focus of the A-LIFE study is to characterize new particle formation (NPF) in the Eastern Mediterranean region at a measurement site with strong local pollution sources. The nearby Paphos airport was found to be a large emission source for nucleation mode particles and we analysed the size distribution of the airport emission plumes at approximately 500 m from the main runway. The analysis yielded 9 NPF events in 27 measurement days from the combined analysis of the DMA-train, MPSS and trace gas monitors. Growth rate calculations were performed and a size-dependency of the initial growth rate (
Atmospheric observations of the water vapour continuum in the near-infrared
windows between 2500–6600 cm−1
Authors: Elsey Jonathan , Coleman Marc D. , Gardiner Tom D. , Menang Kaah P. , Shine Keith P.
Published: December 2019

Abstract. Water vapour continuum absorption is potentially important for both closure of the Earth’s energy budget and remote sensing applications. Currently, there are significant uncertainties in its characteristics in the near-infrared atmospheric windows at 2.1 and 1.6 μm. There have been several attempts to measure the continuum in the laboratory; not only are there significant differences amongst these measurements but there are also difficulties in extrapolating the laboratory data taken at room temperature or higher to atmospheric temperatures. Validation is therefore required using field observations of the real atmosphere. There are currently few published observations in atmospheric conditions with enough water vapour to detect a continuum signal within these windows, or where the self-continuum component is significant. We present observations of the near-infrared water vapour continuum from Camborne, UK at sea level using a sun-pointing, radiometrically-calibrated Fourier transform spectrometer in the window regions between 2000–10000 cm−1. Analysis of this data is challenging, particularly because of the need to remove aerosol extinction, and the large uncertainties associated with such field measurements. Nevertheless, we present data that is consistent with recent laboratory datasets in the 4 and 2.1 μm windows (when extrapolated to atmospheric temperatures). These results indicate that the most recent revision (3.2) of the MT_CKD foreign continuum, versions of which are widely used in atmospheric radiation models, requires strengthening by a factor of ~ 5 in the centre of the 2.1 µm window. In the higher-wavenumber window at 1.6 µm, our estimated self and foreign continua are significantly stronger than MT_CKD. The possible contribution of the self and foreign continua to our derived total continuum optical depth is estimated by using laboratory or MT_CKD values of one, to estimate the other. The obtained self-continuum shows some consistency with temperature-extrapolated laboratory data in the centres of the 4 and 2.1 µm windows. The 1.6 μm region is more sensitive to atmospheric aerosol and continuum retrievals and therefore more uncertain than the more robust results at 2.1 and 4 μm. We highlight the difficulties in observing the atmospheric continuum and make the case for additional measurements from both the laboratory and field, with discussion of the requirements for any new field campaign.
Technical note: Uncertainty in multi-source partitioning using large tracer data sets
Authors: Correa Alicia , Ochoa-Tocachi Diego , Birkel Christian
Published: December 2019

Abstract. The availability of large tracer data sets opened up the opportunity to
investigate multiple source contributions to a mixture. However, the source
contributions may be uncertain and, apart from Bayesian approaches, to date
there are only solid methods to estimate such uncertainties for two and
three sources. We introduce an alternative uncertainty estimation method for
four sources based on multiple tracers as input data. Taylor series
approximation is used to solve the set of linear mass balance equations. We
illustrate the method to compute individual uncertainties in the calculation
of source contributions to a mixture, with an example from hydrology, using
a 14-tracer set from water sources and streamflow from a tropical,
high-elevation catchment. Moreover, this method has the potential to be
generalized to any number of tracers across a range of disciplines.
Past ice sheet-seabed interactions in the northeastern Weddell Sea Embayment, Antarctica
Authors: Arndt Jan Erik , Larter Robert D. , Hillenbrand Claus-Dieter , Sørli Simon H. , Forwick Matthias , Smith James A. , Wacker Lukas
Published: December 2019

Abstract. The Antarctic Ice Sheet extent in the Weddell Sea Embayment (WSE) during the Last Glacial Maximum (LGM; ca. 19–25 calibrated kiloyears before present, cal. ka BP) and its subsequent retreat from the shelf are poorly constrained, with two conflicting scenarios being discussed. Today, the modern Brunt Ice Shelf, the last remaining ice shelf in the northeastern WSE, is only pinned at a single location and recent crevasse development may lead to its rapid disintegration in the near future. We investigated the seafloor morphology on the northeastern WSE shelf and discuss its implications, in combination with marine geological records, for reconstructions of the past behaviour of this sector of the East Antarctic Ice Sheet (EAIS), including ice-seafloor interactions. Our data show that an ice stream flowed through Stancomb-Wills Trough and acted as the main conduit for EAIS drainage during the LGM. Post-LGM ice-stream retreat occurred stepwise, with at least three documented grounding line still stands, and the trough had become free of grounded ice by ~10.5 cal. ka BP. In contrast, slow-flowing ice once covered the shelf in Brunt Basin and extended westwards toward McDonald Bank. During a later time period, only floating ice was present within Brunt Basin, but large ‘ice slabs’ enclosed within the ice shelf occasionally ran aground at the eastern side of McDonald Bank, forming ten unusual ramp-shaped seabed features. These ramps are the result of temporary ice-shelf grounding events buttressing the ice further upstream. To the west of this area, Halley Trough very likely was free of grounded ice during the LGM, representing a potential refuge for benthic shelf fauna at this time.
Modelling regional glacier length changes over the last millennium using the Open Global Glacier Model
Authors: Parkes David , Goosse Hugues
Published: December 2019

Abstract. A large majority of the direct observational record for glacier changes falls within the post-industrial period, associated with global glacier retreat. Given this availability of data, and significant focus in contemporary glacier modelling falling on post-industrial retreat, glacier models are typically calibrated using – and validated with – only observations from points where glaciers were considerably out of equilibrium. In order to develop a broader picture of the skill of one glacier model in active development – the Open Global Glacier Model (OGGM) – we model glaciers for extended historical timescales of 850–2004 CE using a selection of 6 climate model outputs, including recent post-industrial history. We select glaciers for which long term glacier length observations are available, in order to compare these observations with the model results, and we find glaciers for this purpose in almost all glacierised regions globally. In many regions, the modelled glacier changes are consistent with observations, with recent retreat often as rapid as – or sometimes more rapid than – modelled retreats. We also model this set of glaciers using modified climate timeseries from each of the 6 climate models to keep temperature or precipitation constant, testing the impact of each individually. Temperature typically explains considerably more variance in glacier lengths than precipitation, but results suggest that the interaction between the two is also significant within OGGM and neither can be seen as a simple proxy for glacier length changes. Overall, with the vast majority of glaciers successfully modelled, and recent observational trends in many regions reproduced by the model running over a considerably larger timescale than it is calibrated for, prospects are good for more widespread use of OGGM for timescales extending to the pre-industrial, where glaciers are typically larger and experience less rapid (and less globally consistent) geometry changes.
Supporting First-Year Students During the Transition to Higher Education: The Importance of Quality and Source of Received Support for Student Well-Being
Authors: Maymon Rebecca , Hall Nathan C , Harley Jason M
Published: December 2019

The present exploratory study evaluated perceptions of actual support received in relation to stress and well-being among first-year students attending Canadian and U.S. higher education institutions (N = 126). Given that traditional assessments of received support account only for how often support was received, the present research examined unique effects of support quality in addition to frequency with respect to four distinct sources of support (family, friends, faculty/staff, institution). Following from empirical confirmation of received support frequency (RSF) and received support quality (RSQ) as distinguishable constructs, RSQ was found to significantly mediate effects of RSF across varied well-being outcomes (e.g., stress, burnout, quitting intentions) in relation to family, faculty/staff, and institution support. Overall, study findings highlight the importance of evaluating the quality of support received by first-year students during the transition to higher education and show faculty/staff support to be an important contributor to student well-being.
Corporate Governance and Accounting Earnings Management: The Case of Tunisia
Authors: Lajmi Azhaar , Khiari Wided , Kanzari Khaled
Published: December 2019

This paper aims to test the impact of some corporate governance characteristics on the management of the accounting earnings measured by discretionary accruals. As for the prior research we treat the level of management of accounting earnings as a "proxy" for the quality of the accounting and financial information published by companies. Empirical analysis is based on the modified Jones model (1995) to estimate discretionary accruals and a panel data model applied to a sample of 21 companies listed on the Tunis Stock Exchange (BVMT) over a period of 3 years from 2008 to 2010. The main findings of the current study reveal that, in the Tunisian context, the affiliation of auditors to a "Big" international network and the independence of the board of directors significantly constrain the practice of managing the accounting earnings and, consequently, they improve the quality of the published result. However, the number of independent members in the audit committee has a negative but not significant impact on the practice of earnings management, whereas the duration of the audit mandate does not affect this practice.Finally, the control variables taken into account in our study have a significant effect on the quality of the accounting result.Thus, the results of this study helped to improve our understanding of earnings management in Tunisian companies, with reference to some characteristics of corporate governance.
Cameron Crowe’s Aloha (2015): Hollywood and American Militourism in the Pacific
Authors: Voeltz Richard A.
Published: December 2019

When Aloha was released in 2015 critics attacked the film for having a muddled plot involving the Hawaiian independence movement, traditional Hawaiian culture and religion, ethnicity, and the greed of the American military industrial complex. Partially using the evidence from the 2014 email hack of Sony Studios, I will examine Hollywood’s and Sony’s cinematic representations of Hawai’i that have been so fashioned by U.S. imperialism in the Pacific and tourism leading to the phenomenon of militourism. All of this produces in Aloha a conflicted, utopian, faux-ecological, white tourist/military version of Hawai’i that ignores the realities of the massive presence of the American military industrial complex throughout the Pacific area.
Algorithmic Regulation in Media and Cultural Policy: A Framework to Evaluate Barriers to Accountability
Authors: Hunt Robert , McKelvey Fenwick
Published: December 2019

The word “algorithm” is best understood as a generic term for automated decision-making. Algorithms can be coded by humans or they can become self-taught through machine learning. Cultural goods and news increasingly pass through information intermediaries known as platforms that rely on algorithms to filter, rank, sort, classify, and promote information. Algorithmic content recommendation acts as an important and increasingly contentious gatekeeper. Numerous controversies around the nature of content being recommended—from disturbing children's videos to conspiracies and political misinformation—have undermined confidence in the neutrality of these systems. Amid a generational challenge for media policy, algorithmic accountability has emerged as one area of regulatory innovation. Algorithmic accountability seeks to explain automated decision-making, ultimately locating responsibility and improving the overall system. This article focuses on the technical, systemic issues related to algorithmic accountability, highlighting that deployment matters as much as development when explaining algorithmic outcomes. After outlining the challenges faced by those seeking to enact algorithmic accountability, we conclude by comparing some emerging approaches to addressing cultural discoverability by different international policymakers.
Mucus Retention Cyst of the Soft Palate in a Dog
Authors: Wainberg Shannon , Powers Barbara , Liptak Julius
Published: December 2019

A 10 yr old 6.6 kg (14.5 lb) castrated male Chihuahua was referred to the Alta Vista Animal Hospital for evaluation of a mass of the soft palate. The cystic structure was bluntly dissected from the soft palate submucosal tissue, and the dog recovered from surgery and anesthesia without complication. Histopathology revealed salivary tissue with a large multiloculated cyst lined by a single layer of cystic and dilated cuboidal epithelium. Follow up 7 mo after surgery revealed complete resolution of clinical signs with no evidence of local recurrence. To the authors' knowledge, this is the first confirmed report of a mucus retention cyst in a dog.
Carbono de biomasa microbiana influenciada por los residuos de cinco especies de abonos verdes sobre un suelo bajo uso pecuario
Authors: Colque Arispe Karina , Ruiz-Alderete David
Published: December 2019

Se evaluó la influencia de residuos de abonos verdes (AV) sobre el Carbono (C) de la Biomasa microbiana del suelo (BMS) correspondiente a un área de uso pecuario (ganadero). El estudio fue desarrollado en el Proyecto Ganadería y Suelos del Centro de Investigación Agrícola Tropical (CIAT) Santa Cruz, Bolivia; el diseño experimental fue el de bloques completamente al azar, que contaba con 6 tratamientos y 4 repeticiones. La evaluación de la BMS fue a los 30 días de la incorporación de los residuos de las cinco especies de leguminosas empleadas como AV siendo Mucuna negra (Stizolobium aterrinum), Lab lab (Lablab purpureus), Mucuna ceniza (Stizolobium niveum),  Crotalaria (Crotalaria juncea),  Frejol de puerco (Canavalia ensiformis) y como testigo (vegetación espontánea) con el método de irradiación e incubación. Se encontró que las especies de AV tienen mayor concentración de C-BMS respecto al testigo, y entre los AV las especies de hábito rastrero son las que concentran mayor C en su BM.
n. 42 - POLÍTICAS CURRICULARES PARA ALFABETIZAÇÃO: QUESTÕES E DILEMAS A PARTIR DA BNCC
Authors: Amarante Lucilene , Moreira Jani Alves da Silva
Published: December 2019

O texto tem como objetivo analisar a reforma atual nas políticas curriculares para o ciclo de alfabetização na educação infantil e no ensino fundamental. Para essa compreensão, o texto tangencia uma problematização a partir das proposições explicitadas na BNCC referentes às duas etapas da educação básica. Apresenta algumas propostas de encaminhamentos para implementação do documento nos municípios com o propósito de inferir algumas questões relacionadas à prática pedagógica e gestora no campo da alfabetização. Demonstra a análise dos limites e as possibilidades de um efetivo processo de efetivação do currículo visando o desenvolvimento da prática alfabetizadora a partir do trabalho de formação continuada  desenvolvido com os professores, em específico, os alfabetizadores.
Filtros de acesso às Cortes Constitucionais: a Questão Prioritária de Constitucionalidade e os filtros de acesso ao Conselho Constitucional francês
Authors: Diniz Araújo Luiz Henrique
Published: December 2019

O presente artigo inaugura uma série que se propõe a analisar os filtros de acesso a Cortes Constitucionais em diversos sistemas democráticos. Este trabalho analisa especificamente a questão prioritária de constitucionalidade (QPC) e os filtros de acesso ao Conselho Constitucional Francês. Assim, trata do sistema normativo e da práxis relacionados a esse instrumento introduzido naquele sistema em 2008, marcado até então, pelo caráter a priori, ou seja, um texto infraconstitucional apenas poderia ser objeto de controle pelo Conselho Constitucional até a sua aprovação pelo parlamento. Com a questão prioritária, introduz-se o controle a posterioi, i.e., de diplomas já vigentes, mediante a iniciativa de uma das partes em um processo. Para que o Conselho Constitucional seja efetivamente provocado a se pronunciar, é necessário ultrapassar filtros de acesso em dois níveis: o primeiro, realizado pelo juiz da causa; o segundo, por uma das cortes supremas (Conselho de Estado ou Corte de Cassação).
Editorial - A Revista de Investigações Constitucionais é indexada na Redalyc
Authors: Hachem Daniel Wunder , Luzardo Faria
Published: December 2019

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Expediente
Authors: Masthead Journal
Published: December 2019

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Using In Situ Monazite and Xenotime U-Pb Geochronology to Resolve the Fate of the “Missing” Banded Iron Formation-Hosted High-Grade Hematite Ores of the North China Craton
Authors: Li Li-Xing , Zi Jian-Wei , Meng Jie , Li Hou-Min , Rasmussen Birger , Sheppard Stephen , Wilde Simon A. , Li Yan-He
Published: December 2019

High-grade hematite mineralization is widely developed in banded iron formations (BIFs) worldwide. However, in the North China craton where Neoarchean-Paleoproterozoic BIFs are abundant, economic high-grade hematite ores are scarce. High-grade hematite ores hosted in the Paleoproterozoic Yuanjiacun BIFs represent the largest occurrence of this type of ore in the North China craton. The orebodies are fault controlled and show sharp contacts with lower greenschist facies metamorphic BIFs. In situ U-Pb geochronology of monazite and xenotime intergrown with microplaty hematite and martite in high-grade ore established two episodes of metamorphic-hydrothermal monazite/xenotime growth after deposition of the BIFs. The earlier episode at ca. 1.94 Ga is interpreted as the timing of lower greenschist-facies metamorphism, and the later episode at 1.41 to 1.34 Ga represents the timing of high-grade hematite mineralization. Petrography and microthermometry of primary fluid inclusion assemblages indicate that the high-grade hematite ore formed from hot (313°–370°C), CO2-rich, and highly saline (~20 wt % NaCl equiv) hydrothermal fluids. These fluids channeled along faults, which concentrated iron through interaction with the BIFs—a process similar to typical hematite mineralization elsewhere. The deposition of hematite was probably related to tectonic extension in the North China craton related to the breakup of the Columbia/Nuna supercontinent. Our results challenge a previously proposed model ascribing the scarcity of high-grade hematite ores in the North China craton to the lack of prolonged weathering conditions. Rather, we argue that the high-grade ore formed in lower metamorphic-grade BIFs at shallower depths than magnetite mineralization and was largely eroded during later exhumation and uplift of the craton.