scholarly journals Investigating Source Conditions and Controlling Parameters of Explosive Eruptions: Some Experimental-Observational- Modelling Case Studies

10.5772/63422 ◽  
2016 ◽  
Author(s):  
Fabio Dioguardi ◽  
Tobias Dürig ◽  
Samantha L. Engwell ◽  
Magnus T. Gudmundsson ◽  
Susan C. Loughlin
Keyword(s):  
Case Studies ◽  
Explosive Eruptions

Role of rheology, ascent rate and outgassing on fragmentation: implications for basaltic lava fountains

2021 ◽  
Author(s):  
Giuseppe La Spina ◽  
Fabio Arzilli ◽  
Ed Llewellin ◽  
Mike Burton ◽  
Amanda Clarke ◽  
...  
Keyword(s):  
Case Studies ◽  
Parameter Space ◽  
Lava Flows ◽  
Explosive Eruptions ◽  
Explosive Activity ◽  
Lower Viscosity ◽  
Wide Range ◽  
Lava Fountains ◽  
Effusive Eruptions

<p>Basaltic volcanoes exhibit a wide range of eruptive styles, from relatively gentle effusive eruptions (producing lava flows and lava domes) to highly explosive activity (where pyroclastic materials are ejected from the vent as a jet or plume). The difference between explosive and effusive eruptions is dictated by the ability of magma to fragment during ascent. For lava fountains the distinction is unclear, as the liquid phase in the rising magma may remain continuous to the vent, fragment in the fountain, then re-weld on deposition to feed rheomorphic lava flows.</p><p>Here we use a magma ascent model to constrain the controls on basaltic eruption style, using Kilauea and Etna as case studies. Following our results, we suggest that lava fountaining is a distinct style, separate from effusive and explosive eruption styles, that is produced when magma ascends quickly and fragments above the vent, rather than within the conduit. Performing sensitivity analyses of Kilauea and Etna case studies we found that high lava fountains (> 50 m high) occur when the Reynolds number of the bubbly magma is greater than ~0.1, the bulk viscosity is less than 10<sup>6</sup> Pa s, and the gas is well-coupled to the melt. According to our results, explosive eruptions (Plinian and sub-Plinian) are expected over a wide region of parameter space for higher viscosity basalts, typical of Etna, but over a much narrower region of parameter space for lower viscosity basalts, typical of Kilauea. Numerical simulations indicate also that the magma that feeds high lava fountains ascends more quickly than the magma that feeds explosive eruptions, thanks to its lower viscosity. For the Kilauea case study, a decreasing ascent velocity is expected to produce a progressive evolution from high to weak fountaining, to ultimate effusion. For the Etna case study, instead, small changes in parameter values lead to transitions to and from explosive activity, indicating that eruption transitions may occur with little warning.</p>

Corporate Sustainability: Challenge to Managerial Orthodoxies

2003 ◽  
Vol 9 (1) ◽  
pp. 2-11 ◽  
Author(s):  
Dexter Dunphy
Keyword(s):  
Case Studies ◽  
Corporate Sustainability ◽  
Central Place ◽  
Marked Contrast ◽  
Sustainability Management

ABSTRACTThis paper addresses the issue of corporate sustainability. It examines why achieving sustainability is becoming an increasingly vital issue for society and organisations, defines sustainability and then outlines a set of phases through which organisations can move to achieve increasing levels of sustainability. Case studies are presented of organisations at various phases indicating the benefits, for the organisation and its stakeholders, which can be made at each phase. Finally the paper argues that there is a marked contrast between the two competing philosophies of neo-conservatism (economic rationalism) and the emerging philosophy of sustainability. Management schools have been strongly influenced by economic rationalism, which underpins the traditional orthodoxies presented in such schools. Sustainability represents an urgent challenge for management schools to rethink these traditional orthodoxies and give sustainability a central place in the curriculum.

Short-Form Application of the Screening Test of Spanish Grammar and the Northwestern Syntax Screening Test to Latino Children

1978 ◽  
Vol 9 (4) ◽  
pp. 220-235
Author(s):  
David L. Ratusnik ◽  
Carol Melnick Ratusnik ◽  
Karen Sattinger
Keyword(s):  
New York ◽  
Case Studies ◽  
Metropolitan Area ◽  
Screening Test ◽  
Normative Data ◽  
Short Form ◽  
Latino Children ◽  
Data Application ◽  
York Metropolitan Area ◽  
Multiple Regression Technique

Short-form versions of the Screening Test of Spanish Grammar (Toronto, 1973) and the Northwestern Syntax Screening Test (Lee, 1971) were devised for use with bilingual Latino children while preserving the original normative data. Application of a multiple regression technique to data collected on 60 lower social status Latino children (four years and six months to seven years and one month) from Spanish Harlem and Yonkers, New York, yielded a small but powerful set of predictor items from the Spanish and English tests. Clinicians may make rapid and accurate predictions of STSG or NSST total screening scores from administration of substantially shortened versions of the instruments. Case studies of Latino children from Chicago and Miami serve to cross-validate the procedure outside the New York metropolitan area.

Case Studies for Telepractice in AAC

2014 ◽  
Vol 23 (1) ◽  
pp. 42-54 ◽  
Author(s):  
Tanya Rose Curtis
Keyword(s):  
Service Delivery ◽  
Case Studies ◽  
Eye Gaze ◽  
Cognitive Impairments ◽  
Perceived Barriers ◽  
Computer Experience ◽  
Access Methods ◽  
Complex Communication Needs ◽  
Barriers To Service ◽  
Communication Needs

As the field of telepractice grows, perceived barriers to service delivery must be anticipated and addressed in order to provide appropriate service delivery to individuals who will benefit from this model. When applying telepractice to the field of AAC, additional barriers are encountered when clients with complex communication needs are unable to speak, often present with severe quadriplegia and are unable to position themselves or access the computer independently, and/or may have cognitive impairments and limited computer experience. Some access methods, such as eye gaze, can also present technological challenges in the telepractice environment. These barriers can be overcome, and telepractice is not only practical and effective, but often a preferred means of service delivery for persons with complex communication needs.

What Makes for Effective Online Treatment?

ASHA Leader ◽  
2013 ◽  
Vol 18 (1) ◽  
pp. 12-13
Author(s):  
Kristen Chmela
Keyword(s):  
Case Studies ◽  
Executive Director ◽  
Fluency Disorders ◽  
Online Treatment

In November, Kristen Chmela—executive director of the Chmela Fluency Center in Long Grove, Ill.—chatted with participants from ASHA’s online conference, Case Studies in Fluency Disorders. The Leader listened in.

Dysphagia in Hospice Care: The Roles of Social Work and Speech-Language Pathologists

2014 ◽  
Vol 23 (4) ◽  
pp. 173-186 ◽  
Author(s):  
Deborah Hinson ◽  
Aaron J. Goldsmith ◽  
Joseph Murray
Keyword(s):  
Social Work ◽  
End Of Life ◽  
Case Studies ◽  
End Of Life Care ◽  
Hospice Care ◽  
Patient Communication ◽  
Life Care ◽  
Speech Language Pathologists ◽  
Four Levels

This article addresses the unique roles of social work and speech-language pathologists (SLPs) in end-of-life and hospice care settings. The four levels of hospice care are explained. Suggested social work and SLP interventions for end-of-life nutrition and approaches to patient communication are offered. Case studies are used to illustrate the specialized roles that social work and SLP have in end-of-life care settings.

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