Search results for "science and technology"

Compost Amendment Impact on Soil Physical Quality Estimated from Hysteretic Water Retention Curve

2022

Capacity-based indicators of soil physical quality (SPQ) and pore distribution parameters were proposed to assess the effects of compost amendment but their determination was limited to desorption water retention experiments. This study also considered the pore size distribution obtained from adsorption experiments to establish the effectiveness of compost amendment in modifying the physical and hydrological attributes of a sandy loam soil. Repacked soil samples with different compost to soil ratios, r, were subjected to a wetting–drying cycle, and the water retention data were fit to the van Genuchten model to obtain the pore volume distribution functions. The soil bulk density was m…

Modelling flow and heat transfer in spacer-filled membrane distillation channels using open source CFD code

2013

Abstract A good understanding of the details of hydrodynamic and heat transport conditions and their impact on temperature polarisation and pressure drops is essential for optimum design of membrane distillation (MD) modules. To this end, the present work reports on initial progress in the development of a tool for 3D simulation of spacer-filled MD channels based on the open source CFD code library OpenFOAM. The paper discusses a number of modelling and implementation aspects including model geometry and computational domain, choice of boundary conditions, and discretisation schemes. The results pertaining to the effect of three different spacer types on the fluid dynamics and heat transfer…

Joint second-order parameter estimation for spatio-temporal log-Gaussian Cox processes

2018

We propose a new fitting method to estimate the set of second-order parameters for the class of homogeneous spatio-temporal log-Gaussian Cox point processes. With simulations, we show that the proposed minimum contrast procedure, based on the spatio-temporal pair correlation function, provides reliable estimates and we compare the results with the current available methods. Moreover, the proposed method can be used in the case of both separable and non-separable parametric specifications of the correlation function of the underlying Gaussian Random Field. We describe earthquake sequences comparing several Cox model specifications.

The role of fouling mechanisms in a submerged membrane bioreactor during the start-up

2006

In situ measurements of background aerosol and subvisible cirrus in the tropical tropopause region

2002

[1] In situ aerosol measurements were performed in the Indian Ocean Intertropical Convergence Zone (ITCZ) region during the Airborne Polar Experiment-Third European Stratospheric Experiment on Ozone (APE-THESEO) field campaign based in Mahe, Seychelles between 24 February and 6 March 1999. These are measurements of particle size distributions with a laser optical particle counter of the Forward Scattering Spectrometer Probe (FSSP)-300 type operated on the Russian M-55 high-altitude research aircraft Geophysica in the tropical upper troposphere and lower stratosphere up to altitudes of 21 km. On 24 and 27 February 1999, ultrathin layers of cirrus clouds were penetrated by Geophysica directly…

An explicit unconditionally stable numerical solution of the advection problem in irrotational flow fields

2004

[1] A new methodology for the Eulerian numerical solution of the advection problem is proposed. The methodology is based on the conservation of both the zero- and the first-order spatial moments inside each element of the computational domain and leads to the solution of several small systems of ordinary differential equations. Since the systems are solved sequentially (one element after the other), the method can be classified as explicit. The proposed methodology has the following properties: (1) it guarantees local and global mass conservation, (2) it is unconditionally stable, and (3) it applies second-order approximation of the concentration and its fluxes inside each element. Limitati…

Agricultural potential of anaerobically digested industrial orange waste with and without aerobic posttreatment

2012

The potential of anaerobically digested orange waste with (AAD) and without (AD) aerobic post-treatment for use in agriculture was evaluated through chemical analyses, short-term phytotoxicity and long-term plant assays. Chemical analyses showed that AD contained ammonia and organic acids, and aerobic post-treatment did not significantly remove these phytotoxins. The N:P2O5:K2O ratio in AD was 1:0.26:0.96 and aerobic post-treatment did not change the composition in AAD except for K2O (1:0.26:1.24). Heavy metal contents in AD and AAD were more or less the same and were below the upper limit recommended for non-sewage sludge application on agricultural soils. Short-term phytotoxicity tests sh…

Equal access to the top? Measuring selection into finnish academia

2019

In this article, we draw a parallel between equality of opportunity in educational transitions and equality of opportunity in academic careers. In both cases, many methodological problems can be ameliorated by the use of longitudinal rather than cross-sectional data. We illustrate this point by using Finnish full-population register data to follow the educational and academic careers of the 1964–1966 birth cohorts from birth to the present day. We show how the Finnish professoriate is highly selected both in terms of parental background and in terms of gender. Individuals of different backgrounds differ greatly in the likelihood of completing different educational and academic transitions, …

Making the case for policy : persuasiveness in higher education, science and technology policy discourse

2015

Policy texts present problems, propose solutions to those problems and persuade multiple audiences of the legitimacy of the proposed problems and solutions. The rhetorical analysis of two decades of higher education and science and technology discourse in Finland, Germany, UK, Portugal and USA highlights the discursive elements that contribute to persuasiveness of policy, construe it as rational and logical, and create a sense of urgency in bringing it about. I argue that the analytical and hortatory registers of policy discourse foreground competitive and hierarchical relations of countries and their higher education systems. By construing certain state of affairs and courses of action as …

Group‐based instant messaging in Finnish residential elder care work : taming the technology or vice versa?

2022

As new communication technologies become embedded in care work, there is a need to understand how they affect its temporal order. This article analyses group-based mobile instant messaging (IM) in residential elder care work in Finland. The article asks (i) how care workers use group-based messaging for work; and (ii) how they negotiate the rules for its use. Theoretically, the article draws on science and technology studies focusing on ‘taming’ and ‘unleashing’ (Pols, 2017), and temporality (Wajcman, 2008). Analysis is based on a qualitative interview study of care workers and nurses (n = 25) conducted in 2018. The results showed how the time-shifting functionality of IM allows employees t…