Search results for "Energy engineering"
showing 10 items of 1099 documents
Analysis of Lipophilic Extractives from Fast Pyrolysis Bio-Oils
2022
Fast pyrolysis bio-oils (FPBOs) originating from forest residues contain extractive-derived substances, which may form a separate, sticky layer with char particles on the surface of these bio-oils. In this study, first, the removal of extractive-derived substances from the bio-oil top phase was studied by common solvents with different polarities. In this case, the results indicated that when aimed at the maximum yield of single-phase fuel oil and thus the maximum amount of extractives removed, the use of n-heptane or n-hexane seems to be of benefit for this purpose. For safety reasons, the use of n-heptane was recommended. Second, an analysis practice (extraction time and the way of mixing…
Modeling biomass char gasification kinetics for improving prediction of carbon conversion in a fluidized bed gasifier
2014
Gasification of biomass in a fluidized bed (FB) was modeled based on kinetic data obtained from previously conducted thermo- gravimetic analysis. The thermogravimetric analysis experiments were designed to closely resemble conditions in a real FB gasifier by using high sample heating rates, in situ devolatilization and gas atmospheres of H 2 O / H 2 and CO 2 / CO mixtures. Several char kinetic models were evaluated based on their ability to predict char conversion based on the thermogravimetric data. A modified version of the random pore model was shown to provide good fitting of the char reactivity and suitability for use in a reactor model. An updated FB reactor model which incorporates t…
E-Fairs: a Cyber-Physical System for Aggregation and Economy of Scale in e-Commerce
2018
In recent years, the e-commerce arena has deeply changed because of the advent of new business models and the growing weight of huge global actors like Amazon. Some business models create competition between users, and the product price tends to rise (e.g., online auctions); other models, including group-buying, make users cooperate, and the price tends to go down. The present study extends the group-buying model and proposes a cyber-physical system called e-fair, in which both sellers and buyers are grouped to negotiate on a specific product or service. E-fairs minimize the global purchase price and the shipping resources respectively with the aggregation of demand and supply as well as or…
Parallel Behaviour – Primary Evidence of an Agreement
2013
Abstract The distinction between legitimate oligopoly and cartels is tackled by each competition authority. A parallel behaviour in an oligopolistic market might be seen as an anchor for competition's effectiveness, given that companies are required to respond to the decisions of other competitors, trying to keep a realistic and competitive position to ensure welfare. Cartels offer an opposite perspective of what competition really means. Apart from the observation of the econometrical model presented in the article, the final assessment should consider the particularities of the legal and economic environment, to conclude on the existence of a cartel based on reasonable grounds.
Using Factor Analysis in Relationship Marketing
2013
Abstract The purpose of the paper is to present a detailed application of the factor analysis technique within the domain of relationship marketing. A comprehensive literature review is undertaken regarding the concept of customer loyalty – an important variable of relationship marketing. Loyalty is defined by its two dimensions – behavioral and attitudinal; the second dimension is understood through the three components of the human psyche: affective, cognitive and conative. Conative Loyalty is measured through four items which are statistically and semantically reduced to two items without a heavy loss of information.
Analysis of Relationship between Net Wage and Consumer Price Index
2013
Abstract In the present paper is presented an econometric analysis of the relationship between net salary and consumer price index. After a brief historical overview will be review the calculating statistics for selected variables and coefficients and will be presented the obtained values. We will study the relationship between variables. It will be realized the cloud of points and will be applied Fisher test. The intensity of selected variables will be study too and some forms of relationship between the two chose variables will be done. Student test is applied. It will be performed the parameter estimation for regression functions and Akaike's criterion will be applied. The homoscedastici…
Modern Tendencies in Changing the Consumers’ Preferences
2014
Abstract In the middle of globalization era, when consumers have at their disposal more and more prosperous livelihood, when technology is more and more present, when everyone look for the newest and the most modern thing, food sector represents an exception. They try to establish links which go beyond the product itself and pay a special attention to the story behind the product. They want to know about the production site, the origin of ingredients, the persons involved in the production process. This is why the current consumers are looking for unique, sensorial experiences which, according to them, can be found only in original, simple, traditional products. The simplicity and authentic…
Subglottic stenosis imitating the carina – a case report of airway mimicry
2021
Summary We present a case of awake tracheal intubation with flexible bronchoscopy which resulted in incorrect tracheal tube placement. The presence of a stenotic subglottic lesion with an appearance similar to the carina led to the tube being positioned with only the tip within the trachea whilst the cuff was located between the vocal cords. A capnography trace was identified before induction of anaesthesia; however, visual confirmation of the carina was undertaken in a rushed manner due to the patient becoming agitated. Once the incorrect tracheal tube placement was identified, the decision was made to wake the patient. Thereafter, a more experienced operator successfully performed awake t…
Economic Globalization: From Microeconomic Foundation to National Determinants
2015
Abstract For many years, globalization was at the main source of economic growth for the world economy. During and after the 2009 crisis many questions about the positive effects of globalization have arisen. In this paper we argue there are two dimensions of economic globalization, micro and macro, and the perspectives of globalization is more related to the microeconomic determinants. Looking to the definitions and measures of globalization we conclude that for most of the countries the macro dimensions are important and many of them irreversible and not questionable in these days – barriers of trade, political integration, etc., but the microeconomic behavior of individuals and companies…
Energy and economic assessment of a small domestic wind turbine in Palermo
2016
The cost effectiveness of micro-wind technology is closely linked to the annual energy production plants, which strongly depends on the wind characteristics and on the morphological properties of the installation site. The power curve of a wind turbine, supplied by manufacturers, characterizes the theoretical energy performance that it should have at a particular site. The behavior of a wind turbine in the field is affected by the speed but also by wind direction variations. At each change of direction and speed, the turbine will try to adapt to new conditions and the phase transition negatively influences the energy production. In order to experimentally confirm what above mentioned, the a…