Search results for "energy [jet]"
showing 10 items of 1760 documents
On the distribution of lightning current among interconnected grounding systems in medium voltage grids
2018
This paper presents the results of a first investigation on the effects of lightning stroke on medium voltage installations' grounding systems, interconnected with the metal shields of the Medium Voltage (MV) distribution grid cables or with bare buried copper ropes. The study enables us to evaluate the distribution of the lightning current among interconnected ground electrodes in order to estimate if the interconnection, usually created to reduce ground potential rise during a single-line-to-ground fault, can give place to dangerous situations far from the installation hit by the lightning stroke. Four different case studies of direct lightning stroke are presented and discussed: (1) two …
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…
Industrial symbiosis for increasing the efficiency in the use of materials and energy
2015
In industrial ecosystems efficiency and optimization of resources and energy, waste minimization and enhancement of the products represent an important strategy in a perspective of circular economy. From this comes the concept of industrial metabolism, intended as the whole process that includes resource fluxes through the industrial systems, their transformation and finally their disposal in minimum percentage, as waste. Currently Industrial Ecology (EI) includes all those multidisciplinary contributions for the eco-optimization of the relationship between industry and the environment as a further step forward in the concept of sustainable development. The industrial symbiosis, which repre…
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…
Estimating Heart Rate, Energy Expenditure, and Physical Performance With a Wrist Photoplethysmographic Device During Running
2017
BackgroundWearable sensors enable long-term monitoring of health and wellbeing indicators. An objective evaluation of sensors’ accuracy is important, especially for their use in health care. ObjectiveThe aim of this study was to use a wrist-worn optical heart rate (OHR) device to estimate heart rate (HR), energy expenditure (EE), and maximal oxygen intake capacity (VO2Max) during running and to evaluate the accuracy of the estimated parameters (HR, EE, and VO2Max) against golden reference methods. MethodsA total of 24 healthy volunteers, of whom 11 were female, with a mean age of 36.2 years (SD 8.2 years) participated in a submaximal self-paced outdoor running test and maximal voluntary exe…