scholarly journals The influence of detachment strength on the evolving deformational energy budget of physical accretionary prisms

Solid Earth ◽  
2018 ◽  
Vol 9 (6) ◽  
pp. 1421-1436 ◽  
Author(s):  
Jessica McBeck ◽  
Michele Cooke ◽  
Pauline Souloumiac ◽  
Bertrand Maillot ◽  
Baptiste Mary

Abstract. Tracking the evolution of the deformational energy budget within accretionary systems provides insight into the driving mechanisms that control fault development. To quantify the impact of these mechanisms on overall system efficiency, we estimate energy budget components as the first thrust fault pair develops in dry-sand accretion experiments. We track energy budget components in experiments that include and exclude a basal layer of glass beads in order to investigate the influence of detachment strength on work partitioning. We use the measurements of normal force exerted on the backwall to estimate external work, and measurements of strain observed on the sides of the sand packs to estimate the internal work, frictional work and work against gravity done within increments of each experiment. Thrust fault development reduces the incremental external work and incremental internal work, and increases the incremental frictional work and incremental gravitational work. The faults that develop within higher-friction detachment experiments produce greater frictional work than the faults in experiments with glass bead detachments because the slip distribution along the detachments remains the same, while the effective friction coefficient of the detachment differs between the experiments. The imbalance of the cumulative work budget suggests that additional deformational processes that are not fully captured in our measurements of the energy budget, such as acoustic energy, consume work within the deforming wedge.

2018 ◽  
Author(s):  
Jessica McBeck ◽  
Michele Cooke ◽  
Pauline Souloumiac ◽  
Bertrand Maillot ◽  
Baptiste Mary

Abstract. Tracking the evolution of the deformational energy budget within accretionary systems provides insight into the driving mechanisms that control fault development. To quantify the impact of these mechanisms on overall system efficiency, we estimate energy budget components as the first thrust fault pair develops in dry sand accretion experiments. We track energy budget components in experiments that include and exclude a basal layer of glass beads in order to investigate the influence of detachment strength on work partitioning. We use the measurements of normal force exerted on the backwall to estimate external work, and measurements of strain observed on the sides of the sandpacks to estimate the internal work, frictional work and work against gravity done within increments of each experiment. Thrust fault development reduces the incremental external work and incremental internal work, and increases the incremental frictional work and incremental gravitational work. The faults that develop within higher friction detachment experiments produce greater frictional work than the faults in experiments with glass bead detachments because the slip distribution along the detachments remain the same while the effective friction coefficient of the detachment differs between the experiments. The imbalance of the cumulative work budget suggests that additional deformational processes that are not fully captured in our measurements of the energy budget, such as acoustic energy, consume work within the deforming wedge.


2019 ◽  
Vol 10 (12) ◽  
pp. 1183-1199
Author(s):  
Mohammed Alrouili ◽  

This study attempted to identify the impact of internal work environment on the retention of healthcare providers at Turaif General Hospital in the Kingdom of Saudi Arabia. In particular, the study aimed to identify the dimensions of work circumstances, compensation, and relationship with colleagues, professional growth, and the level of healthcare providers’ retention. In order to achieve the study goals, the researcher used the descriptive analytical approach. The researcher used the questionnaire as the study tool. The study population comprised all the healthcare providers at Turaif General Hospital. Questionnaires were distributed to the entire study sample that consisted of 220 individuals. The number of questionnaires valid for study was 183 questionnaires. The research findings were as follows: the participants’ estimate of the work circumstances dimension was high (3.64), the participants’ estimate of the compensation dimension was moderate (3.32), the participants’ estimate of the relationship with colleagues dimension was high (3.62), the participants’ estimate of the professional growth dimension was weak (2.39), and the participants’ estimate of healthcare providers’ retention level was intermediate (2.75). Accordingly, the researcher’s major recommendations are: the need to create the right atmosphere for personnel in hospitals, the interest of the hospital to provide the appropriate conditions for the staff in terms of the physical and moral aspects for building the work adjustment in the staff, and conducting training courses and educational lectures for personnel in hospitals on how to cope with the work pressures.


2020 ◽  
Author(s):  
Jonathan Day ◽  
Gabriele Arduini ◽  
Irina Sandu ◽  
Linus Magnusson ◽  
Anton Beljaars ◽  
...  

2021 ◽  
Author(s):  
Cathryn Birch ◽  
Lawrence Jackson ◽  
Declan Finney ◽  
John Marsham ◽  
Rachel Stratton ◽  
...  

<p>Mean temperatures and their extremes have increased over Africa since the latter half of the 20th century and this trend is projected to continue, with very frequent, intense and often deadly heatwaves likely to occur very regularly over much of Africa by 2100. It is crucial that we understand the scale of the future increases in extremes and the driving mechanisms. We diagnose daily maximum wet bulb temperature heatwaves, which allows for both the impact of temperature and humidity, both critical for human health and survivability. During wet bulb heatwaves, humidity and cloud cover increase, which limits the surface shortwave radiation flux but increases longwave warming. It is found from observations and ERA5 reanalysis that approximately 30% of wet bulb heatwaves over Africa are associated with daily rainfall accumulations of more than 1 mm/day on the first day of the heatwave. The first ever pan-African convection-permitting climate model simulations of present-day and RCP8.5 future climate are utilised to illustrate the projected future change in heatwaves, their drivers and their sensitivity to the representation of convection. Compared to ERA5, the convection-permitting model better represents the frequency and magnitude of present-day wet bulb heatwaves than a version of the model with more traditional parameterised convection. The future change in heatwave frequency, duration and magnitude is also larger in the convective-scale simulation, suggesting CMIP-style models may underestimate the future change in wet bulb heat extremes over Africa. The main reason for the larger future change appears to be the ability of the model to produce larger anomalies relative to its climatology in precipitation, cloud and the surface energy balance.</p>


2020 ◽  
Author(s):  
Christiaan T. van Dalum ◽  
Willem Jan van de Berg ◽  
Michiel R. van den Broeke

Abstract. This study evaluates the impact of a new snow and ice albedo and radiative transfer scheme on the surface mass and energy budget for the Greenland ice sheet in the latest version of the regional climate model RACMO2, version 2.3p3. We also evaluate the modeled (sub)surface temperature and snow melt, as subsurface heating by radiation penetration now occurs. The results are compared to the previous model version and are evaluated against stake measurements and automatic weather station data of the K-transect and PROMICE projects. In addition, subsurface snow temperature profiles are compared at the K-transect, Summit and southeast Greenland. The surface mass balance is in good agreement with observations, and only changes considerably with respect to the previous RACMO2 version around the ice margins and in the percolation zone. Snow melt and refreezing, on the other hand, are changed more substantially in various regions due to the changed albedo representation, subsurface energy absorption and melt water percolation. Internal heating leads to considerably higher snow temperatures in summer, in agreement with observations, and introduces a shallow layer of subsurface melt.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Katharine McGowan ◽  
Latasha Calf Robe ◽  
Laura Allan ◽  
Elinor Flora Bray-Collins ◽  
Mathieu Couture ◽  
...  

Purpose The purpose of this paper is to explore multiple Canadian educators' experiences with the Map the System (MTS) competition, designed to foster and grow systems thinking capacity among students exploring complex questions. The challenge has been an opportunity for social innovation programs (from the nascent to the established) across Canadian post-secondaries to engage both with their own communities and with social innovators internationally, connecting social innovation spaces as part of their third mission. Across the organizations, students valued the interdisciplinary and systems thinking qualities, and organizations benefited from the external competition, there remain questions about organizational engagement in social innovation as a deeply transformative process internally. Design/methodology/approach All Canadian post-secondary institutions who participated in the 2020 MTS competition (17) were invited to a digital roundtable to discuss their experiences. Ten were able to participate, representing a range of post-secondaries (including large research institutions, undergraduate-only universities and colleges). To facilitate discussion, participants met to discuss format and topics; for the roundtable itself, participant educators used a google form to capture their experiences. These were summarized, anonymized and redistributed for validation and clarification. To reflect this collaborative approach, all participant educators are listed as authors on this paper, alphabetically after the organizing authors. Findings For students participating in MTS, they have built both their interdisciplinary and systems thinking skills, as well as their commitment to achieving meaningful change in their community. But MTS arrived in fertile environments and acted as an accelerant, driving attention, validation and connection. Yet while this might align with post-secondary education’s third mission, educators expressed concerns about sustainability, internal commitment to change and navigating tensions between a challenge approach and collaborative work, and internal work and national competition limitations. This complicates the simple insertion of MTS in a post-secondary’s social innovation-related third mission. Research limitations/implications This study was limited to Canadian post-secondaries participating in MTS, and therefore are not representative of either post-secondaries in Canada, or all the MTS participants although Canada is well represented in the challenge itself. Additionally, while the authors believe their approach to treat all participants as authors, and ensured multiple feedback opportunities in private and collectively, this is a deliberate and potentially controversial move away from a traditional study. Social implications More than half of Canadian universities (a subgroup of post-secondaries) had at least one social innovation initiative, but questions have been raised about whether these initiatives are being evaluated internally, or are triggering the kinds of transformative internal work that might be an outcome. Understanding the impact of MTS one example of a social innovation-related initiative can help advance the broader conversation about the place (s) for social innovation in the post-secondary landscape – and where there is still significant work to be done. Originality/value As Canada has only participated in MTS for four years, this is the first inter-institution consideration of its related opportunities and obstacles as a vehicle for transformational social innovation. As well, educators talking openly and frankly to educators reinforces the collaborative quality of social innovation across the post-secondary landscape.


Author(s):  
Janusz Wielki

Currently there are many studies which deal with the impact of the Internet and Internet technology-based tools on organizations. Most of them are focused on such issues as the opportunities which have emerged with the development of the digital economy, possible new business models, establishing new kind of relations with customers, and security aspects. The impact of Internet technology-based tools on the internal work environment of organizations is an issue which is relatively rarely analyzed. Although more and more publications concerning this field are being released, they are only focused to a small degree on the challenges connected with the utilization, and, particularly, the misuse, of Internet technology-based tools in the workplace. Thus, this article is an attempt to deal with this issue in a more holistic way.


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