272 research outputs found
An Audience Centred Approach to Business Process Reengineering
This paper describes a method for process modelling which is designed to provide guidance to the business process modeller. The method has evolved from our experience of attempting to apply software process modelling approaches to business processes. A major influence on the method has been our observations that a pragmatic approach to notation selection is required in order to maintain a
meaningful dialogue with end-users. Business process modelling methods typically fall into two camps. General methods attempt to describe the managerial activities which surround the modelling itself (Coulson-Thomas, 94; GISIP, 95). Specific methods, on the other hand, tend to
concentrate on the details of a particular notational approach. However, as with programming languages or design methods, no single notational approach is best suited to all problems. Ideally, the process modeller should be able to incorporate the appropriate notational approach into some coherent generic modelling method.This paper addresses the needs of the modeller at the detailed level without prescribing a specific notation. This is achieved by describing categories of modelling activities which the modeller should undertake within process modelling, and
suggesting how notations may be used within these categories. Our method is generally applicable, and is illustrated here by models of processes within the
Construction industry
Scalar one-loop integrals for QCD
We construct a basis set of infra-red and/or collinearly divergent scalar
one-loop integrals and give analytic formulas, for tadpole, bubble, triangle
and box integrals, regulating the divergences (ultra-violet, infra-red or
collinear) by regularization in dimensions. For scalar triangle
integrals we give results for our basis set containing 6 divergent integrals.
For scalar box integrals we give results for our basis set containing 16
divergent integrals. We provide analytic results for the 5 divergent box
integrals in the basis set which are missing in the literature. Building on the
work of van Oldenborgh, a general, publicly available code has been
constructed, which calculates both finite and divergent one-loop integrals. The
code returns the coefficients of and
as complex numbers for an arbitrary tadpole, bubble, triangle or box integral.Comment: 27 pages, 5 figures, associated fortran code available at
http://qcdloop.fnal.gov/. New version corrects typographical error in Eq. 5.
A study of soil formation rates using 10Be in the wet-dry tropics of northern Australia
A catchment level study to obtain soil formation rates using beryllium-10 (10Be) tracers has been undertaken in the Daly River Basin in the wet-dry tropics of northern Australia. Three soil cores have been collected to bedrock, with depths ranging from
Probing CP Violation with the Deuteron Electric Dipole Moment
We present an analysis of the electric dipole moment (EDM) of the deuteron as
induced by CP-violating operators of dimension 4, 5 and 6 including theta QCD,
the EDMs and color EDMs of quarks, four-quark interactions and the Weinberg
operator. We demonstrate that the precision goal of the EDM Collaboration's
proposal to search for the deuteron EDM, (1-3)\times 10^{-27} e cm, will
provide an improvement in sensitivity to these sources of one-two orders of
magnitude relative to the existing bounds. We consider in detail the level to
which CP-odd phases can be probed within the MSSM.Comment: 5 pages, 4 figures; precision estimates clarified, to appear in Phys.
Rev.
Hierarchical Assembly of a Micro- and Macroporous Hydrogen-Bonded Organic Framework with Tailored Single-Crystal Size
Porous organic molecular materials represent an emergent field of research in Chemistry and Materials Science due to their unique combination of properties. To enhance their performance and expand the number of applications, the incorporation of hierarchical porosity is required, as exclusive microporosity entails several limitations. However, the integration of macropores in porous organic molecular materials is still an outstanding challenge. Herein, we report the first example of a hydrogen-bonded organic framework (MM-TPY) with hierarchical skeletal morphology, containing stable micro- and macroporosity. The crystal size, from micro to centimetre scale, can be controlled in a single step without using additives or templates. The mechanism of assembly during the crystal formation is compatible with a skeletal crystal growth. As proof of concept, we employed the hierarchical porosity as a platform for the dual, sequential and selective co-recognition of molecular species and microparticles.J.F.-S. thanks âRamĂłn y Cajalâ program (RYC2019-02794-I), MINECO (Spain) (Projects PID2019â104778GBâI00 and Excellence Unit âMaria de Maeztuâ CEX2019â000919âM) and Generalitat Valenciana (SEJI/2020/034). E.V.R.F. thanks Ministerio de Ciencia e innovaciĂłn (PID2020-116998RB-I00) and Ministerio de EducaciĂłn y FormaciĂłn Profesional (PRX21/00407)
Towards ecologically sustainable crop production : a South African perspective
Food production comes at an ecological cost, and the lack of sustainability of South Africaâs crop
production systems is becoming increasingly worrisome. While small scale emerging and homestead
subsistence farming are significant in the agricultural sector, food production is dominated by large scale
commercial agriculture. In this paper we analyse the ecological impact of South African commercial crop
production and what can be done about it. Impact categories considered are divided into what we
consider âbetter-researchedâ problems: fresh water depletion, salinisation, soil degradation, eutrophication
and land use change; and into what we consider âemergingâ problems for agriculture: greenhouse gas
emissions, soil profile acidification, ecotoxicity and non-renewable resource consumption. While there is
a paucity of quantitative information, it is clear that after decades of cultivation many of our
agroecosystems are degraded or degrading. Sustainable crop production and food security are âwickedâ
problems â containing dynamic social, economic and biophysical complexities. Increased stakeholder
engagement to better understand these problems, the tradeoffs linked to finding solutions and to involve
those with the resources to turn knowledge into action is required. Collecting key data, turning it into
information within local contexts (involving the ecology, agronomy, sociology, psychology, economics
and other disciplines simultaneously) and communicating it effectively to allow learning and adaptive
management at various spatial and temporal scales is essential. An example is the display of river flows
on a website in real-time to help farmers manage and adapt irrigation practices better, and to connect
them with other stakeholders to improve understanding of the responsibilities of managing water at
local and catchment scales.The Water Research
Commissionhttp://www.elsevier.com/locate/agee2018-01-31hb2017Plant Production and Soil Scienc
Constraints on the Variations of the Fundamental Couplings
We reconsider several current bounds on the variation of the fine-structure
constant in models where all gauge and Yukawa couplings vary in an
interdependent manner, as would be expected in unified theories. In particular,
we re-examine the bounds established by the Oklo reactor from the resonant
neutron capture cross-section of 149Sm. By imposing variations in \Lambda_{QCD}
and the quark masses, as dictated by unified theories, the corresponding bound
on the variation of the fine-structure constant can be improved by about 2
orders of magnitude in such theories. In addition, we consider possible bounds
on variations due to their effect on long lived \alpha- and \beta-decay
isotopes, particularly 147Sm and 187Re. We obtain a strong constraint on \Delta
\alpha / \alpha, comparable to that of Oklo but extending to a higher redshift
corresponding to the age of the solar system, from the radioactive life-time of
187Re derived from meteoritic studies. We also analyze the astrophysical
consequences of perturbing the decay Q values on bound state \beta-decays
operating in the s-process.Comment: 25 pages, latex, 5 eps figure
Interpretation of electrical conductivity measurements from ceramic suction cups, wetting front detectors and ECH2O-TE sensors
Electrical conductivity (EC) measurements are often used
to identify and address soil salinity issues in irrigated cropping
systems. In this study, measurements of soil solution
EC (EC-sol) collected in ceramic suction cups (SCs), wetting
front EC (EC-wf) collected in Fullstop wetting front
detectors (WFDs) and soil bulk EC (EC-bulk) measurements
made using ECH2O-TE sensors and converted to
EC-sol, were compared. As a result of different methods of
measurement and different components of soil waterflow
being sampled, variations in EC measurement between
SCs and WFDs were observed. EC-sol was usually higher
than EC-wf, as expected for this system, due to incomplete
mixing between the draining and resident soil water during
infiltration. For periods of high solute leaching, however,
the opposite can occur, indicating that WFDs are sampling
when solutes are first mobilised at the beginning of the
leaching event. The ECH2O-TE sensors were less effective
in measuring the short-term EC dynamics but were
able to detect general changes in soil salinity. This could
reflect difficulties estimating soil EC-sol from measured
EC-bulk, especially at low soil water contents. Each of
these instruments show good potential for application to
guide salinity management practices, but a more detailed
study on a range of soils subjected to different watering
regimes is needed to further improve interpretation of EC
measurements and their application.The Water Research
Commission (Project 1574), the National Research Foundation,
the Cooperative Research Centre for Irrigation Futures
and CSIRO.http://www.plantandsoil.co.zanf201
Modelling nitrogen leaching : are we getting the right answer for the right reason?
The complexities and challenges in quantifying N leaching have led to development of a range of measurement and modelling techniques, but none are widely applied. Observations that N moves more slowly than water through the soil profile has resulted in different approaches being used to simulate impeded N movement in crop models: (i) by accounting for nitrate NOâ3 adsorption to the soil, (ii) by considering incomplete mixing between resident and draining soil water fractions or (iii) a combination of both.We compare and discuss strengths and weaknesses of these approaches. Our inability to directly measure model parameters (especially with regards to simulating N dynamics), and the risk of compensating errors during model testing and calibration, often results in low confidence in simulated N leaching. We caution that our current ability to simulate N leaching is in most cases not yet well enough developed for reliable and accurate predictions. We recommend a more strategic approach involving better linking measurement and modelling to improve understanding of the critical soil processes that control N leaching as one way of further improving our understanding and quantification of N leaching.http://www.elsevier.com/locate/agwathb201
Species richness and functional structure of fish assemblages in three freshwater habitats:effects of environmental factors and management
In this study, the inverted trophic hypothesis was tested in the freshwater fish communities of a reservoir. The distribution of fish species in three freshwater habitats in the Jurumirim Reservoir, Brazil, was examined using both species richness and the relative proportions of different trophic groups. These groups were used as a proxy for functional structure in an attempt to test the ability of these measures to assess fish diversity. Assemblage structures were first described using nonâmetric multidimensional scaling (NMDS). The influence of environmental conditions for multiple fish assemblage response variables (richness, total abundance and abundance per trophic group) was tested using generalised linear mixed models (GLMM). The metric typically employed to describe diversity; that is, species richness, was not related to environmental conditions. However, absolute species abundance was relatively well explained with up to 54% of the variation in the observed data accounted for. Differences in the dominance of trophic groups were most apparent in response to the presence of introduced fish species: the iliophagous and piscivorous trophic groups were positively associated, while detritivores and herbivores were negatively associated, with the alien species. This suggests that monitoring functional diversity might be more valuable than species diversity for assessing effects of disturbances and managements policies on the fish community
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