Small-scale variability of orographic precipitation in the Alps: Case studies and semi-idealized numerical simulations

2007 ◽  
Vol 133 (628) ◽  
pp. 1701-1716 ◽  
Author(s):  
G. Zängl
Keyword(s):  
Numerical Simulations ◽  
Case Studies ◽  
Small Scale ◽  
Orographic Precipitation ◽  
The Alps

scholarly journals Multilingualism in Vanuatu: Four case studies

2021 ◽  
pp. 136700692110231
Author(s):  
Mary Walworth ◽  
Amy Dewar ◽  
Thomas Ennever ◽  
Lana Takau ◽  
Iveth Rodriguez
Keyword(s):  
Case Studies ◽  
Primary Data ◽  
Small Scale ◽  
Language History ◽  
Speech Communities ◽  
The Pacific ◽  
Historical Processes ◽  
The Social ◽  
Original Contribution ◽  
B Mobility

Each of the 65 inhabited islands of Vanuatu hosts its own unique linguistic environment in which varying degrees of multilingualism are found. This paper defines various types of small-scale multilingual settings in Vanuatu and explores what sociohistorical factors have led to them. This paper is based on first-hand observations and primary data collected by the authors in four locations in the Pacific Island nation of Vanuatu since 2016: two neighboring villages of Emae Island (Makatu and Tongamea), North Malekula, and on Maewo Island. The assessments of multilingualism in these examples from Vanuatu were qualitative, based on observations of sociolinguistic practices in each of these areas, as well as data from language history and language use surveys carried out in each place. Through defining and comparing the types of multilingualism present in the four case studies, we identify patterns in the social and historical processes that lead to various kinds of multilingualism: (a) interaction of linguistic and sociocultural identities and (b) mobility of both individuals and entire speech communities. The examples described in this paper are used to highlight the diversity of multilingualism found in Vanuatu and to explore how their differing linguistic environments and histories have contributed to their varying degrees of multilingualism. This paper makes an original contribution to knowledge about the small-scale multilingual situations in Vanuatu, offering descriptions of previously undocumented and endangered multilingual environments. Through an examination of the sociocultural motivations for multilingualism, alongside historical migrations of speaker groups and marked sociolinguistic identities, this paper contributes to research on why and how small-scale multilingualism can develop. Furthermore, this paper provides the foundation for future, more rigorous investigations into the small-scale multilingual situations of this highly understudied region.

2D and 2.5D Numerical Simulations for Vortex-Induced Vibration (VIV) of a 1.5:1 Rectangular Cylinder

2021 ◽  
Author(s):  
Bowen Yan ◽  
Yangjin Yuan ◽  
Dalong Li ◽  
Ke Li ◽  
Qingshan Yang ◽  
...  
Keyword(s):  
Wind Speed ◽  
Numerical Simulations ◽  
Phase Difference ◽  
Vortex Shedding ◽  
Lift Force ◽  
Small Scale ◽  
Aerodynamic Damping ◽  
Displacement Response ◽  
Wind Speeds ◽  
Rectangular Cylinder

The semi-periodic vortex-shedding phenomenon caused by flow separation at the windward corners of a rectangular cylinder would result in significant vortex-induced vibrations (VIVs). Based on the aeroelastic experiment of a rectangular cylinder with side ratio of 1.5:1, 2-dimensional (2D) and 2.5-dimensional (2.5D) numerical simulations of the VIV of a rectangular cylinder were comprehensively validated. The mechanism of VIV of the rectangular cylinder was in detail discussed in terms of vortex-induced forces, aeroelastic response, work analysis, aerodynamic damping ratio and flow visualization. The outcomes showed that the numerical results of aeroelastic displacement in the cross-wind direction and the vortex-shedding procedure around the rectangular cylinder were in general consistence with the experimental results by 2.5D numerical simulation. In both simulations, the phase difference between the lift and displacement response increased with the reduced wind speed and the vortex-induced resonance (VIR) disappeared at the phase difference of approximately 180∘. The work done by lift force shows a close relationship with vibration amplitudes at different reduced wind speeds. In 2.5D simulations, the lift force of the rectangular cylinder under different wind speeds would be affected by the presence of small-scale vortices in the turbulence flow field. Similarly, the phase difference between lift force and displacement response was not a constant with the same upstream wind speed. Aerodynamic damping identified from the VIV was mainly dependent on the reduced wind speed and negative damping ratios were revealed at the lock-in regime, which also greatly influenced the probability density function (PDF) of wind-induced displacement.

Metal Flow and Die Filling in Coining of Micro Structures with and without Flash

2005 ◽  
Vol 6-8 ◽  
pp. 631-638 ◽  
Author(s):  
M. Thome ◽  
Gerhard Hirt ◽  
B. Rattay
Keyword(s):  
Numerical Simulations ◽  
Sheet Metal ◽  
Metal Forming ◽  
Production Systems ◽  
Metal Flow ◽  
Small Scale ◽  
Die Filling ◽  
Metal Plates ◽  
Micro Structures ◽  
Channel Structures

The continuing miniaturization of production systems and products poses a challenge for metal forming technologies to produce precise small scale products with microscopic geometric details. Thin metal plates with channel structures are considered to be typical examples for microfluidic applications [1,2]. In this study the coining process of sheet metal to produce channel and rib structures is examined in terms of geometrical die parameters and tool design. For this reason extensive experimental series and numerical simulations have been realized and evaluated.

scholarly journals Synoptic Control over Orographic Precipitation Distributions during the Olympics Mountains Experiment (OLYMPEX)

2018 ◽  
Vol 146 (4) ◽  
pp. 1023-1044 ◽  
Author(s):  
David J. Purnell ◽  
Daniel J. Kirshbaum
Keyword(s):  
Numerical Simulations ◽  
Physical Interpretation ◽  
Large Scale ◽  
Local Development ◽  
Moisture Flux ◽  
Heavy Precipitation ◽  
Static Stability ◽  
Orographic Precipitation ◽  
Areal Extent ◽  
Precipitation Enhancement

The synoptic controls on orographic precipitation during the Olympics Mountains Experiment (OLYMPEX) are investigated using observations and numerical simulations. Observational precipitation retrievals for six warm-frontal (WF), six warm-sector (WS), and six postfrontal (PF) periods indicate that heavy precipitation occurred in both WF and WS periods, but the latter saw larger orographic enhancements. Such enhancements extended well upstream of the terrain in WF periods but were focused over the windward slopes in both PF and WS periods. Quasi-idealized simulations, constrained by OLYMPEX data, reproduce the key synoptic sensitivities of the OLYMPEX precipitation distributions and thus facilitate physical interpretation. These sensitivities are largely explained by three upstream parameters: the large-scale precipitation rate [Formula: see text], the impinging horizontal moisture flux I, and the low-level static stability. Both WF and WS events exhibit large [Formula: see text] and I, and thus, heavy orographic precipitation, which is greatly enhanced in amplitude and areal extent by the seeder–feeder process. However, the stronger stability of the WF periods, particularly within the frontal inversion (even when it lies above crest level), causes their precipitation enhancement to weaken and shift upstream. In contrast, the small [Formula: see text] and I, larger static stability, and absence of stratiform feeder clouds in the nominally unsaturated and convective PF events yield much lighter time- and area-averaged precipitation. Modest enhancements still occur over the windward slopes due to the local development and invigoration of shallow convective showers.

scholarly journals Investigating deaf children’s plural and diverse use of sign and spoken languages in a super diverse context

2016 ◽  
Vol 7 (2) ◽  
pp. 117-147 ◽  
Author(s):  
Ruth Swanwick ◽  
Sue Wright ◽  
Jackie Salter
Keyword(s):  
Case Studies ◽  
Deaf Education ◽  
Individual Case ◽  
Deaf Children ◽  
Small Scale ◽  
Unique Type ◽  
The North ◽  
Context Data ◽  
Language Exposure ◽  
Diverse Context

AbstractThis paper examines the meaning of plurality and diversity with respect to deaf children’s sign and spoken language exposure and repertoire within a super diverse context. Data is drawn from a small-scale project that took place in the North of England in a Local Authority (LA) site for deaf education. The project documented the language landscape of this site and gathered five individual case studies of deaf children to examine their plural and diverse language practices at home and at school. Analysis of the language landscape and case studies from this context is undertaken in order to define and exemplify deaf children’s language plurality and diversity in terms of context and individual experience. Concepts of repertoire are explored with particular reference to the unique type of translanguaging that the plural use of sign and spoken languages affords. Implications of these preliminary insights are discussed in terms of the development of methodologies that are sensitive to the particular translanguaging practices of deaf children, and approaches to pedagogy that are appropriately nuanced and responsive to deaf children’s language plurality and diversity.

scholarly journals Characteristics of Large-Scale Orographic Precipitation in a Linear Perspective

2011 ◽  
Vol 12 (1) ◽  
pp. 27-44 ◽  
Author(s):  
Michael Kunz
Keyword(s):  
Time Scales ◽  
Characteristic Time ◽  
Large Scale ◽  
Linear Perspective ◽  
Horizontal Wind ◽  
Small Scale ◽  
Orographic Precipitation ◽  
Observation Data ◽  
Horizontal Wind Speed ◽  
Precipitation Patterns

Abstract Simulations of orographic precipitation over the low mountain ranges of southwestern Germany and eastern France with two different physics-based linear precipitation models are presented. Both models are based on 3D airflow dynamics from linear theory and consider advection of condensed water and leeside drying. Sensitivity studies for idealized conditions and a real case study show that the amount and spatial distribution of orographic precipitation is strongly controlled by characteristic time scales for cloud and hydrometeor advection and background precipitation due to large-scale lifting. These parameters are estimated by adjusting the model results on a 2.5-km grid to observed precipitation patterns for a sample of 40 representative orography-dominated stratiform events (24 h) during a calibration period (1971–80). In general, the best results in terms of lowest rmse and bias are obtained for characteristic time scales of 1600 s and background precipitation of 0.4 mm h−1. Model simulations of a sample of 84 events during an application period (1981–2000) with fixed parameters demonstrate that both models are able to reproduce quantitatively precipitation patterns obtained from observations and reanalyses from a numerical model [Consortium for Small-scale Modeling (COSMO)]. Combining model results with observation data shows that heavy precipitations over mountains are restricted to situations with strong atmospheric forcings in terms of synoptic-scale lifting, horizontal wind speed, and moisture content.

Numerical Simulations and Case Studies Using Visual C++.Net

2005 ◽  
Author(s):  
Shaharuddin Salleh ◽  
Albert Y. Zomaya ◽  
Stephan Olariu ◽  
Bahrom Sanugi
Keyword(s):  
Numerical Simulations ◽  
Case Studies

scholarly journals Practice-Focused Research in Initial Teacher Education

2019 ◽  
Author(s):  
Jane Abbiss ◽  
Eline Vanassche
Keyword(s):  
Qualitative Research ◽  
Teacher Education ◽  
Student Teachers ◽  
Case Studies ◽  
Teacher Educators ◽  
Teacher Educator ◽  
Initial Teacher Education ◽  
Small Scale ◽  
Educational Systems ◽  
Theoretical Contribution

A review of the field of practice-focused research in Initial Teacher Education (ITE) reveals four broad genres of qualitative research: case studies of teacher education programs and developments; research into student teacher experience and learning; inquiry into teacher educators’ own learning, identity, and beliefs; and conceptual or theory-building research. This is an eclectic field that is defined by variation in methodologies rather than by a few clearly identifiable research approaches. What practice-focused research in ITE has in common, though, is a desire on the behalf of teacher educator researchers to understand the complexity of teacher education and contribute to shifts in practice, for the benefit of student teachers and, ultimately, for learners in schools and early childhood education. In this endeavor, teacher educator researchers are presented with a challenge to achieve a balance between goals of local relevance and making a theoretical contribution to the broader field. This is a persistent tension. Notwithstanding the capacity for practice-focused research to achieve a stronger balance and greater relevance beyond the local, key contributions of practice-focused research in ITE include: highlighting the importance of context, questioning what might be understood by “improvement” in teacher education and schooling, and pushing back against research power structures that undervalue practice-focused research. Drawing on a painting metaphor, each genre represents a collection of sketches of practice-focused research in ITE that together provide the viewer with an overview of the field. However, these genres are not mutually exclusive categories as any particular research study (or sketch) might be placed within one or more groupings; for example, inquiry into teacher educators’ own learning often also includes attention to student teachers’ experiences and case studies of teacher education initiatives inevitably draw on theory to frame the research and make sense of findings. Also, overviewing the field and identifying relevant research is not as simple as it might first appear, given challenges in identifying research undertaken by teacher educators, differences in the positioning of teacher educators within different educational systems, and privileging of American (US) views of teacher education in published research, which was counteracted in a small way in this review by explicitly including voices located outside this dominant setting. Examples of different types of qualitative research projects illustrate issues in teacher education that matter to teacher educator researchers globally and locally and how they have sought to use a variety of methodologies to understand them. The examples also show how teacher educators themselves define what is important in teacher education research, often through small-scale studies of context-specific teacher education problems and practices, and how there is value in “smaller story” research that supports understanding of both universals and particularities along with the grand narratives of teacher education.

Sign in / Sign up

Export Citation Format

Share Document