Search results for " engineering"

Application of the PHREEQC Program to Assess the Chemical Stability of Tap Water in Kielce

2020

Badania przeprowadzono na próbkach wody w Kielcach pochodzące z dwóch ujęć: Białogon i Zagnańsk. Przedstawiono wyniki wybranych wskaźników dla tych wód, m.in. najważniejszych wpływających na ich stabilność chemiczną, tj. wapnia lub magnezu. Następnie, za pomocą programu PHREEQC, obliczono wskaźniki stabilności dla wód w Kielcach z dwóch ujęć, o których mowa. W kolejnym etapie sprawdzono poprawność metody badania wody za pomocą programu poprzez bilans jonowy wody i porównanie pH wyznaczonej wody z wartością wyznaczoną w wyniku obliczeń. Dla wyżej wymienionych czynności przygotowano tabele i obliczenia, na podstawie których wyciągnięto odpowiednie wnioski

Aliasing-Free and Additive Error in Mixed Spectra for Stable Processes. Application: Sound of a Bird just captivated in stress

2022

Consider a symmetric continuous time α stableprocess observed with an additive constant error. Theobjective of this paper is to give a non-parametric estimatorof this error by using discrete observations. As the time ofprocess is continuous and the observations are discrete, weencountered the aliasing phenomenon. Our process sampleis taken in a way to circumvent the difficulty related toaliasing and we smoothed the periodogram by using JacksonKernel. The rate of convergence of this estimator is studiedwhen the spectral density is zero at origin. Few long memoryprocesses are taken here as examples. We have applied ourestimator to the concrete case of modeling noise of a birdcaptured under st…

Coopetition, standardization and general purpose technologies : A framework and an application

2023

Funding Information: We thank Paul Wiegmann, Geerten van de Kaa, Filippo Grillo, Tuomo Uotila, Elina Berghäll, Joakim Wikström and a number of anonymous reviewers for helpful comments. Earlier versions of the paper have been presented at EURAS2022 conference at Adam Smith Business School of the University of Glasgow, 38th Summer Seminar of Finnish Economist at University of Jyväskylä and Lappeenranta-Lahti University of Technology LUT. Heikkilä gratefully acknowledges financial support from the Foundation for Economic Education (Liikesivistysrahasto, Reino Rossi Memorial Fund), PHP Säätiö and the Jyväskylä University School of Business and Economics. We argue that coopetition and standardiz…

A Proposal of Process Fragment Definition and Documentation

2012

This paper focuses on the field of Situational Method Engineering (SME) for the construction of agent-oriented design processes. Whatever SME approach a method designer wants to use, he has to manage two main elements: the (method or process) fragment and the repository where it is stored. Specific fragment definition and documentation are fundamental during these activities, for new process composition, and for the consequent system design activities. This paper aims at illustrating a proposal of fragment definition and documentation. This proposal is aimed to be an input for the IEEE FIPA Design Process Documentation and Fragmentation working group and, as regards our own research work, t…

Heterogeneous photocatalysis: guidelines on experimental setup, catalyst characterization, interpretation, and assessment of reactivity

2019

Soon after the publication of the first pioneering works on heterogeneous photocatalysis, the number of papers on this topic continuously increased. This intriguing field of research is very complex as it endows with an interdisciplinary overview that involves different aspects of chemistry, physics, material and environmental sciences. Even if photocatalytic applications in real processes are often difficult to be implemented and scaled-up, investigations at laboratory scale are easy to be performed, and in some cases they may give rise to misconceptions. For this reason, the present work aims to sum up most of the common experimental techniques and procedures generally used in heterogeneo…

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

2006

Modeling and Backstepping Control of the Electronic Throttle System

2013

Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2013/871674 Open access Electronic throttle is widely used in modern automotive engines. An electronic throttle system regulates the throttle plate angle by using a DC servo motor to adjust the inlet airflow rate of an internal combustion engine. Its application leads to improvements in vehicle drivability, fuel economy, and emissions. In this paper, by taking into account the dynamical behavior of the electronic throttle, the mechanism model is first built, and then the mechanism model is transformed into the state-space model. Based on the s…

Kinematic and Elastostatic Design Optimisation of the 3-DOF Gantry-Tau Parallel Kinematic Manipulator

2009

Published version of an article in the journal: Modeling Identification and Control. Also available from the publisher:http://dx.doi.org/10.4173/mic.2009.2.1 One of the main advantages of the Gantry-Tau machine is a large accessible workspace/footprint ratio compared to many other parallel machines. The Gantry-Tau improves this ration further by allowing a change of assembly mode without internal link collisions or collisions between the links and end-effector. The reconfigurable Gantry-Tau kinematic design obtained by multi-objective optimisation according to this paper gives the following features: 3-D workspace/footprint ration is more than 3.19, lowest Cartesian stiffness in the workspa…

Flexural Behavior of Steel Fibrous Reinforced Concrete Deep Beams

2012

Experimental research was carried out regarding the flexural behavior of deep beams cast with plain and fibrous concrete with hooked steel fibers, and subjected to monotonic vertical loads. Four deep fiber-reinforced concrete beams were cast. Two of them were made of plain concrete with main and web steel reinforcements (RC), and two were made of hooked steel fiber-reinforced concrete (SFRC) with main steel reinforcements. The experimental results show the brittle behavior of reinforced deep RC members characterized by crushing of concrete struts and fracture of web steel bars. SFRC deep beams exhibit higher strength and, above all, ductility with respect to RC members due to the bridging a…

MORPHOSTRUCTURAL ANALYSIS OF HUMAN DENTAL FOLLICULAR STEM CELLS ON HIGLY POROUS BONE HYDROXYAPATITE SCAFFOLD

2007

In this study we investigated the in vitro behaviour, morphostructure and extracellular matrix synthesis of human dental follicular stem cells (hDFSCs) isolated from human dental bud, which resulted to be positive for mesenchymal markers (CD29, CD90, CD146 and CD166) by FACS analysis. Cells were analysed by light and electronic microscopy to evaluate their biological response either at week 1, that is before differentiation, or at weeks 3-6, when they had been cultured in osteogenic medium onto a highly porous natural scaffold material (Bio-Oss). Microscopy analysis of primary culture cells showed they had a mesenchymal stem cell-like morphostructure, spindle shaped, similar to the culture …