scholarly journals Improved solution reliability through generalised finite integral methods

2013 ◽  
Vol 16 (3) ◽  
pp. 600-616
Author(s):  
A. G. Barnett
Keyword(s):  
Numerical Solutions ◽  
Computational Method ◽  
Control Element ◽  
Integral Methods ◽  
Wide Range ◽  
Cell Energy ◽  
Finite Integral ◽  
Solution Robustness ◽  
Energy Balances

Model solution reliability is shown to be important for applications, where the computational method should accommodate a wide range of flow conditions through each model run without failure through instability or excessive run times. Such difficulties are linked to the use of poor assumptions in the derivation of models, in particular those neglecting energy solutions and the proper treatment of gradient discontinuities and shocks. Finite integral methods are introduced as a formal extension of longstanding traditional hydraulic analysis, leading through Control Element Lifetime Locus (CELL) Integral analysis to a new set of fundamental balance equations, the Full Hydraulic equations. These are then formulated for hydraulic streamtube analysis and discretised for separate numerical solutions for momentum and energy balances. Case studies for steady flow are referenced, where CELL energy balances improve solution robustness through a variable weighting scheme, accelerating convergence in comparison with widely used fixed weighting Upstream Differencing and Central Differencing schemes. A standard dambreak case study is then used to show the same robust system also copes with severe unsteady flow discontinuities, even while Courant Numbers are varied by orders of magnitude.

Site specific agricultural soil management with the use of new technologies

2013 ◽  
Vol 16 (1) ◽  
pp. 59-67
Keyword(s):  
New Technologies ◽  
Digital Interface ◽  
Appropriate Treatment ◽  
Wide Range ◽  
Soil Variation ◽  
Soil Information ◽  
Remote Sensing Techniques ◽  
Agricultural Areas

<p>The Soil Science Institute of Thessaloniki produces new digitized Soil Maps that provide a useful electronic database for the spatial representation of the soil variation within a region, based on in situ soil sampling, laboratory analyses, GIS techniques and plant nutrition mathematical models, coupled with the local land cadastre. The novelty of these studies is that local agronomists have immediate access to a wide range of soil information by clicking on a field parcel shown in this digital interface and, therefore, can suggest an appropriate treatment (e.g. liming, manure incorporation, desalination, application of proper type and quantity of fertilizer) depending on the field conditions and cultivated crops. A specific case study is presented in the current work with regards to the construction of the digitized Soil Map of the regional unit of Kastoria. The potential of this map can easily be realized by the fact that the mapping of the physicochemical properties of the soils in this region provided delineation zones for differential fertilization management. An experiment was also conducted using remote sensing techniques for the enhancement of the fertilization advisory software database, which is a component of the digitized map, and the optimization of nitrogen management in agricultural areas.</p>

Oxford Studies in Ancient Philosophy, Volume 55

2018 ◽  
Keyword(s):  
Middle Ages ◽  
Ancient Philosophy ◽  
Recent Book ◽  
Loss Of Control ◽  
Ancient Greek ◽  
Original Essays ◽  
Constant Change ◽  
Wide Range ◽  
Metaphysical Principle

Oxford Studies in Ancient Philosophy provides, twice each year, a collection of the best current work in the field of ancient philosophy. Each volume features original essays that contribute to an understanding of a wide range of themes and problems in all periods of ancient Greek and Roman philosophy, from the beginnings to the threshold of the Middle Ages. From its first volume in 1983, OSAP has been a highly influential venue for work in the field, and has often featured essays of substantial length as well as critical essays on books of distinctive importance. Volume LV contains: a methodological examination on how the evidence for Presocratic thought is shaped through its reception by later thinkers, using discussions of a world soul as a case study; an article on Plato’s conception of flux and the way in which sensible particulars maintain a kind of continuity while undergoing constant change; a discussion of J. L. Austin’s unpublished lecture notes on Aristotle’s Nicomachean Ethics and his treatment of loss of control (akrasia); an article on the Stoics’ theory of time and in particular Chrysippus’ conception of the present and of events; and two articles on Plotinus, one that identifies a distinct argument to show that there is a single, ultimate metaphysical principle; and a review essay discussing E. K. Emilsson’s recent book, Plotinus.

scholarly journals Assessing the Relation between Mud Components and Rheology for Loss Circulation Prevention Using Polymeric Gels: A Machine Learning Approach

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1377
Author(s):  
Musaab I. Magzoub ◽  
Raj Kiran ◽  
Saeed Salehi ◽  
Ibnelwaleed A. Hussein ◽  
Mustafa S. Nasser
Keyword(s):  
Machine Learning ◽  
Rheological Properties ◽  
Nearest Neighbor ◽  
Drilling Fluid ◽  
Gradient Boosting ◽  
K Nearest Neighbor ◽  
Wide Range ◽  
Machine Learning Approach ◽  
Drilling Operations

The traditional way to mitigate loss circulation in drilling operations is to use preventative and curative materials. However, it is difficult to quantify the amount of materials from every possible combination to produce customized rheological properties. In this study, machine learning (ML) is used to develop a framework to identify material composition for loss circulation applications based on the desired rheological characteristics. The relation between the rheological properties and the mud components for polyacrylamide/polyethyleneimine (PAM/PEI)-based mud is assessed experimentally. Four different ML algorithms were implemented to model the rheological data for various mud components at different concentrations and testing conditions. These four algorithms include (a) k-Nearest Neighbor, (b) Random Forest, (c) Gradient Boosting, and (d) AdaBoosting. The Gradient Boosting model showed the highest accuracy (91 and 74% for plastic and apparent viscosity, respectively), which can be further used for hydraulic calculations. Overall, the experimental study presented in this paper, together with the proposed ML-based framework, adds valuable information to the design of PAM/PEI-based mud. The ML models allowed a wide range of rheology assessments for various drilling fluid formulations with a mean accuracy of up to 91%. The case study has shown that with the appropriate combination of materials, reasonable rheological properties could be achieved to prevent loss circulation by managing the equivalent circulating density (ECD).

scholarly journals Using citizen science data to monitor the Sustainable Development Goals: a bottom-up analysis

2021 ◽  
Author(s):  
Laura Ballerini ◽  
Sylvia I. Bergh
Keyword(s):  
Sustainable Development ◽  
Citizen Science ◽  
Sustainable Development Goals ◽  
Comparative Case Study ◽  
Science Data ◽  
The Sustainable Development ◽  
Case Study Analysis ◽  
Wide Range ◽  
Development Goals

AbstractOfficial data are not sufficient for monitoring the United Nations Sustainable Development Goals (SDGs): they do not reach remote locations or marginalized populations and can be manipulated by governments. Citizen science data (CSD), defined as data that citizens voluntarily gather by employing a wide range of technologies and methodologies, could help to tackle these problems and ultimately improve SDG monitoring. However, the link between CSD and the SDGs is still understudied. This article aims to develop an empirical understanding of the CSD-SDG link by focusing on the perspective of projects which employ CSD. Specifically, the article presents primary and secondary qualitative data collected on 30 of these projects and an explorative comparative case study analysis. It finds that projects which use CSD recognize that the SDGs can provide a valuable framework and legitimacy, as well as attract funding, visibility, and partnerships. But, at the same time, the article reveals that these projects also encounter several barriers with respect to the SDGs: a widespread lack of knowledge of the goals, combined with frustration and political resistance towards the UN, may deter these projects from contributing their data to the SDG monitoring apparatus.

scholarly journals Evaluating the efficacy of technical measures: a case study of selection device legislation in the UK Crangon crangon (brown shrimp) fishery

2008 ◽  
Vol 65 (2) ◽  
pp. 267-275 ◽  
Author(s):  
Tom L. Catchpole ◽  
Andrew S. Revill ◽  
James Innes ◽  
Sean Pascoe
Keyword(s):  
Brown Shrimp ◽  
Crangon Crangon ◽  
Shrimp Fishery ◽  
The North ◽  
Ex Post ◽  
Wide Range ◽  
The Uk ◽  
The Impact ◽  
Technical Measures

Abstract Catchpole, T. L., Revill, A. S., Innes, J., and Pascoe, S. 2008. Evaluating the efficacy of technical measures: a case study of selection device legislation in the UK Crangon crangon (brown shrimp) fishery. – ICES Journal of Marine Science, 65: 267–275. Bycatch reduction devices are being introduced into a wide range of fisheries, with shrimp and prawn fisheries particularly targeted owing to the heavy discarding common in these fisheries. Although studies are often undertaken to estimate the impact of a technical measure on the fishery before implementation, rarely have the impacts been assessed ex post. Here, the efficacy of the UK legislation pertaining to the use of sievenets in the North Sea Crangon crangon fishery is assessed. Three impacts were evaluated: on fisher behaviour (social), on the level of bycatch (biological), and on vessel profitability (economic). An apparent high level of compliance by skippers was identified despite a low level of enforcement. The estimated reduction in fleet productivity following the introduction of the legislation was 14%, equalling the mean loss of Crangon landings when using sievenets calculated from catch comparison trawls. Sievenets did reduce the unnecessary capture of unwanted marine organisms, but were least effective at reducing 0-group plaice, which make up the largest component of the bycatch. Clearly the legislation has had an effect in the desired direction, but it does not address sufficiently the bycatch issue in the Crangon fishery.

Socio-Semantic Processes in Social Actors Representation: A Case Study of “Ya-Sin”

2017 ◽  
Vol 15 (2) ◽  
pp. 145-169
Author(s):  
Roghayeh Farsi
Keyword(s):  
Case Study Approach ◽  
Academic Field ◽  
Social Actors ◽  
Study Approach ◽  
Wide Range ◽  
New Perspective ◽  
Linear Nature ◽  
Do So ◽  
Semantic Processes

AbstractThe academic field of Qurʾānic Studies employs a wide range of approaches, each one of which helps to open up a new perspective on the Qurʾānic text. The Holy Book was revealed to guide people; it is thus of relevance to all aspects of people’s lives. This article focuses on the way social actors are represented in one Meccansūra, entitled “Ya-Sin”, and employs a case-study approach to do so. The analysis carried out includes the socio-semantic processes that thesūrauses in order to represent social actors either by behavior (action) or meaning (reflection), and it also analyzes the actors as they are represented in processes such as activation and passivation. The methodology adopted is eclectic and analytic. It is a hybrid of Swales’ move analysis, El-Awa’s identification of shift-markers, and Halliday’s and Van Leeuwen’s theories of social actor representation. This study shows how such an analysis can contribute to understanding the apparently fragmented and non-linear nature of “Ya-Sin”.

Managing integration in infrastructure alliance projects

2017 ◽  
Vol 10 (1) ◽  
pp. 5-31 ◽  
Author(s):  
Anna-Maija Hietajärvi ◽  
Kirsi Aaltonen ◽  
Harri Haapasalo
Keyword(s):  
Construction Projects ◽  
Research Approach ◽  
Content Type ◽  
Complex Projects ◽  
Wide Range ◽  
Project Organizations ◽  
Integration Mechanisms ◽  
Organizational Integration ◽  
Time Critical

Purpose The effective management of inter-organizational integration is central to complex projects. Such projects pose significant challenges for integration, as organizations struggle with constantly changing inter-organizational interdependencies and must develop and adapt integration mechanisms to meet new demands. The purpose of this paper is to understand what kinds of integration mechanisms are used and how they are developed and adjusted during the infrastructure alliance projects. Design/methodology/approach This study provides empirical evidence of integration dynamics in project alliancing by analyzing two infrastructure alliance projects – a complex tunnel construction project and a railway renovation project. The research approach is an inductive case study. Findings This paper identifies integration mechanisms adopted in two case projects and three central triggers that led to changes in the integration mechanisms: project lifecycle phase, unexpected events and project team’s learning during the project. Practical implications Integration capability should be a precondition for alliance project organizations and requires the adoption of a wide range of integration mechanisms, as well as an ability to adjust those mechanisms in response to everyday dynamics and emergent situations. Originality/value Although unplanned contingencies and the responses to them represent important influences in organizations, there is limited amount of research on the dynamics of integration. The findings will be of value in supporting the management of inter-organizational integration in complex, uncertain and time-critical construction projects.

Quantitative Content Analysis of the United Nations Seabed Debate: Methodology and a Continental Shelf Case Study

1970 ◽  
Vol 24 (3) ◽  
pp. 479-502 ◽  
Author(s):  
R. L. Friedheim ◽  
J. B. Kadane
Keyword(s):  
United Nations ◽  
Continental Shelf ◽  
Ad Hoc ◽  
Mineral Resources ◽  
Outer Edge ◽  
General Assembly ◽  
Wide Range ◽  
The Subject ◽  
The United Nations

International arrangements for the uses of the ocean have been the subject of long debate within the United Nations since a speech made by Ambassador Arvid Pardo of Malta before the General Assembly in 1967. Issues in question include the method of delimiting the outer edge of the legal continental shelf; the spectrum of ocean arms control possibilities; proposals to create a declaration of principles governing the exploration for, and the exploitation of, seabed mineral resources with the promise that exploitation take place only if it “benefits mankind as a whole,” especially the developing states; and consideration of schemes to create international machinery to regulate, license, or own the resources of the seabed and subsoil. The discussions and debates began in the First (Political and Security) Committee of the 22nd General Assembly and proceeded through an ad hoc committee to the 23rd and 24th assembly plenary sessions. The creation of a permanent committee on the seabed as a part of the General Assembly's machinery attests to the importance members of the United Nations attribute to ocean problems. Having established the committee, they will be faced soon with the necessity of reaching decisions. The 24th General Assembly, for example, passed a resolution requesting the Secretary-General to ascertain members' attitudes on the convening of a new international conference to deal with a wide range of law of the sea problems.

Intense dB/dt variations driven by near-Earth Bursty Bulk Flows (BBFs): A case study

2021 ◽  
Author(s):  
Dong Wei ◽  
Malcolm Dunlop ◽  
Junying Yang ◽  
Xiangcheng Dong ◽  
Yiqun Yu ◽  
...  
Keyword(s):  
Large Scale ◽  
Current System ◽  
Geomagnetically Induced Currents ◽  
Inner Magnetosphere ◽  
Wide Range ◽  
Ground System ◽  
Induced Currents ◽  
Ground Magnetic ◽  
Bursty Bulk Flows

&lt;p&gt;During geomagnetically disturbed times the surface geomagnetic field often changes abruptly, producing&amp;#160;geomagnetically induced currents (GICs) in a number of ground based systems. There are, however,&amp;#160;few studies reporting GIC effects which are driven directly by bursty bulk flows (BBFs) in the inner&amp;#160;magnetosphere. In this study, we investigate the characteristics and responses of the magnetosphere-ionosphere-ground system during the 7 January 2015 storm by using a multi-point approach which combines space-borne measurements and ground magnetic observations. During the event, multiple BBFs are&amp;#160;detected in the inner magnetosphere while the magnetic footprints of both magnetospheric and ionospheric&amp;#160;satellites map to the same conjugate region surrounded by a group of magnetometer ground stations. It is&amp;#160;suggested that the observed, localized substorm currents are caused by the observed magnetospheric BBFs,&amp;#160;giving rise to intense geomagnetic perturbations. Our results provide direct evidence that the wide-range&amp;#160;of intense dB/dt&lt;strong&gt;&amp;#160;&lt;/strong&gt;(and dH/dt) variations are associated with a large-scale, substorm current system, driven&amp;#160;by multiple BBFs.&lt;/p&gt;

Evaporite Palynology: a case study on the Permian (Lopgingian) Zechstein Sea

2021 ◽  
pp. jgs2020-174
Author(s):  
Martha E. Gibson ◽  
David J. Bodman
Keyword(s):  
Thermal Conductivity ◽  
Heat Flux ◽  
Rapid Growth ◽  
Western Europe ◽  
Thermal Maturity ◽  
Near Surface ◽  
Wide Range ◽  
Terrestrial Environments ◽  
Insight Into

Evaporites characterize the Lopingian of Europe but present obstacles for biostratigraphic analysis. Here we present a case study for processing the Lopingian Zechstein Group evaporites of central-western Europe for the recovery of palynomorph assemblages. We demonstrate that full recovery is easily achieved with two main modes of palynomorph preservation observed; palynomorphs are either exceptionally well-preserved and orange-brown in colour, or poorly-preserved, brown-black, opaque and fragmented. The latter are reminiscent of palynomorphs of high thermal maturity. However, we propose that the intact nature of preservation is a result of the rapid growth of near-surface halite crystals, with their darkening a consequence of locally-enhanced heat flux due to the relatively high thermal conductivity of salt. This case study has enabled novel insight into an otherwise undescribed environment, and demonstrates the utility and possibility of extracting palynomorphs from a variety of rock salt types. This method should be applicable to a wide range of ancient evaporite and could also be applied to other Permian evaporite systems, which are used as analogues for extra-terrestrial environments.

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