Search results for " generation."
showing 10 items of 1108 documents
Governance of Projects: Generating value by linking projects with their permanent organisation
2019
Abstract There exists little research into how value is effectively generated by temporary projects from the wider perspective of a permanent organisation. This paper investigates empirically how ‘Governance of Projects’ – the way in which a single, permanent organisation identifies, creates, and subsequently harvests value through multiple projects – occurs in four private-sector case companies. Data were collected from in-depth interviews with a wide range of employees and from internal operational documents. These data were codified and analysed as evidence of the types and intensity of links between organisational elements. The results illuminate the complex interplay of links that are …
Dual Inequalities for Stabilized Column Generation Revisited
2014
Column generation (CG) models have several advantages over compact formulations: they provide better linear program bounds, may eliminate symmetry, and can hide nonlinearities in their subproblems. However, users also encounter drawbacks in the form of slow convergence, also known as the tailing-off effect, and the oscillation of the dual variables. Among different alternatives for stabilizing the CG process, Ben Amor et al. [Ben Amor H, Desrosiers J, Valério de Carvalho JM (2006) Dual-optimal inequalities for stabilized column generation. Oper. Res. 54(3):454–463] suggest the use of dual-optimal inequalities (DOIs) in the context of cutting stock and bin packing problems. We generalize th…
Partial least squares-near infrared determination of pesticides in commercial formulations
2007
Abstract A solvent free, fast and environmentally friendly near infrared-based methodology (NIR) was developed for pesticide determination in commercially available formulations. This methodology was based on the direct measurement of the diffuse reflectance spectra of solid samples and a multivariate calibration model (partial least squares, PLS) to determine the active principle concentration in commercial formulations. The PLS calibration set was built on using the spiked samples by mixing different amounts of pesticide standards and powdered samples. Buprofezin, Diuron and Daminozide were used as test analytes. Concentration of Buprofezin in the samples was calculated employing a 4-fact…
Energy and environmental assessment of residual bio-wastes management strategies
2021
Abstract This paper assesses the potential energy and environmental impacts of an anaerobic digester coupled with a combined heat and power plant powered with bio-wastes from the agri-food sector. The analysis is carried out through the Life Cycle Assessment methodology following a “cradle-to-grave” approach and is based mostly on primary data. The anaerobic digester - combined heat and power plant is analysed considering a twofold perspective: one more energy – oriented where the main function of the system is to generate renewable electricity and a waste – oriented one in which the main function is treating bio-wastes. In addition, the environmental indirect effects related to potential c…
Sustainable Energy Supply Based on Sunflower Seed Husk for Oil mills
2019
The use of biomass, including sunflower husk, for in-situ energy generation has undergone a development in Ukraine last decades. Within this work, four combined heat and power technologies based on oil utilization, husk combustion, gasification, and methanization have been investigated. Their electricity and heat potential has been determined. Criteria for techno-economical assessment of CHP technologies have been suggested. Husk biogas and gasification technologies are not mature. CHP plants based on husk combustion are competitive. Steam turbine generators with a nominal electric capacity higher 1.5 MW may be profitable too.
Universal charts for optical difference frequency generation in the terahertz domain
2010
We present a universal and rigorous approach to study difference frequency generation in the terahertz domain, keeping the number of degrees of freedom to a minimum, through the definition of a suitable figure of merit. The proposed method relies on suitably normalized charts, that enable to predict the optical-to-terahertz conversion efficiency of any system based on wave propagation in quadratic nonlinear materials. The predictions of our approach are found to be in good agreement with the best experimental results reported to date, enabling also to estimate the d22 nonlinear coefficient of high quality GaSe.
<title>Second harmonic generation in selenium thin films</title>
2008
Results of second harmonic (SH) generation in amorphous and crystalline selenium films induced by titanium-sapphire femtosecond laser (wavelength λ - 800-1000 nm) are presented. It is found that the highest intensity of SH is provided by fundamental wave at wavelength 1000 nm and it reaches maximum in approximately 100 sec. The intensity of transmitted SH depends on film thickness while that of reflected does not.
<title>Second harmonic generation in selenium-metal structures</title>
2008
The article examines the processes of second harmonic generation (SHG) when selenium-metal (Cu) film structures are illuminated by femtosecond radiation (180 fs, 80 MHz) at wavelength 800 - 1000 nm. Selenium-copper structures were obtained by successive thermal evaporation of selenium and copper onto the glass substrate in vacuum. Microanalysis of the film composition was performed to determine amount of copper in thin films. The as-evaporated selenium-copper structures were crystallised by annealing in inert atmosphere at temperature 85°C. Just evaporated as well as annealed thin films were explored. The experiment was performed by confocal microscope [1] where the femtosecond radiation fr…
Modeling a non-stationary bots’ arrival process at an e-commerce Web site
2017
Abstract The paper concerns the issue of modeling and generating a representative Web workload for Web server performance evaluation through simulation experiments. Web traffic analysis has been done from two decades, usually based on Web server log data. However, while the character of the overall Web traffic has been extensively studied and modeled, relatively few studies have been devoted to the analysis of Web traffic generated by Internet robots (Web bots). Moreover, the overwhelming majority of studies concern the traffic on non e-commerce websites. In this paper we address the problem of modeling a realistic arrival process of bots’ requests on an e-commerce Web server. Based on real…
A Micro Wind Generation System for Local DoS Applications
2010
In this paper a wind electrical power generation system for Distributed on Site (DoS) applications is proposed. This system was developed and conceived in order to guarantee simple installation, use and service, obtaining a product that can be easily industrialized and put into the market with limited costs. The field of application of such an electrical generation system is addressed towards domestic or at the most toward condominium applications concerning moreover the opportunity of working in addition to combined photovoltaic and solar-thermal systems to enhance the renewable energy generation at house level (DoS). The proposed system has its hot spot in the blades shape, in the wind fl…