Performance evaluation of the explicit approximations of the implict colebroo...eSAT Journals
Abstract
The implicit Colebrook equation has been the standard for estimating pipe friction factor in a fully developed turbulent regime. Several artificial intelligence (AI)-based and non AI-based explicit models have been developed as viable replacement for the implicit Colebrook equation. However, it is not obvious which of the models and/or approaches is the best. In this paper, the performances of the available non AI-based explicit models were compared with those of the AI-based models. The results show that genetic algorithm has been successfully utilized in optimizing the explicit model parameters with the best improvements being from 0.12% to 0.0026% based on maximum relative error index. Although genetic programming and gene expression programming techniques offer the advantage of producing explicit analytical formulas for determination of output parameters, they are found to be grossly inaccurate with errors up to 7% for most accurate model developed. Artificial neural network, a prominent AI-based method has been used to significantly improve friction factor predictions with a high accuracy of 0.004% equivalent to that obtainable with the non-AI based models. The most accurate models are among those developed using the non AI -based techniques with errors up to 1.04 ×10-1 0 %. There is still possibility of improving on the gains made using the artificial intelligence techniques.
Performance evaluation of the explicit approximations of the implict colebroo...eSAT Journals
Abstract
The implicit Colebrook equation has been the standard for estimating pipe friction factor in a fully developed turbulent regime. Several artificial intelligence (AI)-based and non AI-based explicit models have been developed as viable replacement for the implicit Colebrook equation. However, it is not obvious which of the models and/or approaches is the best. In this paper, the performances of the available non AI-based explicit models were compared with those of the AI-based models. The results show that genetic algorithm has been successfully utilized in optimizing the explicit model parameters with the best improvements being from 0.12% to 0.0026% based on maximum relative error index. Although genetic programming and gene expression programming techniques offer the advantage of producing explicit analytical formulas for determination of output parameters, they are found to be grossly inaccurate with errors up to 7% for most accurate model developed. Artificial neural network, a prominent AI-based method has been used to significantly improve friction factor predictions with a high accuracy of 0.004% equivalent to that obtainable with the non-AI based models. The most accurate models are among those developed using the non AI -based techniques with errors up to 1.04 ×10-1 0 %. There is still possibility of improving on the gains made using the artificial intelligence techniques.
Esse diagnóstico foi realizado com apoio da Votorantim Cimentos, afim de conhecer a realidade social do município de Edealina/GO para, posteriormente, investir recursos em projetos nas áreas em que tiverem maior demanda.
A empresa já tem parceria com o Serviço de Convivência e Fortalecimento de Vínculos e Oficinas Integradas de Desenvolvimento Socioeducativo por meio do Instituto Votorantim.
Effects of anion on the corrosion behaviors of carbon steel under artificial ...eSAT Journals
Abstract
Rain is one of the main importance issues for atmospheric corrosion problem. Effects of rainfall on corrosion behaviors of carbon steels were investigated using artificial rainfall equipment. Three types of Atmospheric Corrosion Monitoring (ACM) sensors, which consist of Fe-Ag, Zn-Ag, and Al-Ag galvanic couples, were used to illustrate the correlation between the sensors output, Corrosion Rate (CR), and chemical concentration in the rain. The effects of ionic species on the corrosion behaviors were observed by using NaCl, KCl, Na2SO4, NaNO3, and KNO3 as rainfall solutions. The result revealed that the rainfall rate was insensitive to ACM sensors outputs and CRs. In contrast, the chemical species and their concentrations in the rainfall solution significantly affected the ACM outputs and CRs. The corrosivity of the cations (Na+ and K+) is negligible compared to the anions (Cl-, SO42-, NO3-).For a given number of molar concentration, the CRs resulted from the corrosivity of SO4-2anions were higher than that of Cl- and NO3- anions, respectively. According to the empirical data, the CRs is increased and then reach a steady state as the molar concentration is continuously increased. This research also indicates that the ACM sensors outputs of Fe-Ag and Zn-Ag couples are capable of estimating corrosivity of the atmosphere, while the ACM sensor of Al-Agcouple can be used to determine not only the time of wetness but also the typeofchemical species in the environment. The research methods discussed in this paper proves that the CRs are dependent on the atmospheric composition and can be forecasted through ACM sensors.
Diritto al lavoro e libera circolazione nell’area schengenRoberto Laera
Il principio di libera circolazione delle persone
La libera circolazione dei lavoratori
La libera circolazione di servizi
Il Caso della Svizzera
Importanza economica
Gli Accordi bilaterali e i relativi vantaggi economici
Dati economici Svizzera-Unione europea
La libera circolazione delle persone giova anche nella crisi economica
Attuazione delle misure di accompagnamento
Occupazione
Economia e prosperità
Riconoscimento dei diplomi
Sie sind Freiberufler oder Inhaber eines Dienstleistungsunternehmens. Doch leider wissen viele Ihrer potenziellen Kunden noch nicht, dass es Sie gibt? Dann sollten Sie Ihre Bekanntheit steigern, Ihren Ruf als Spezialist ausbauen um leichter an lukrative Aufträge zu gelangen.
Bernhard Kuntz, Autor mehrerer Fachbücher und Experte für Berater-PR illustriert in diesem Buch das Handwerkszeug für mehr Bekanntheit. Doch was wünscht der „Kunde“ Redakteur eigentlich? Wie nutzt man gezielt Online-Medien? Wie plant man ein PR-Aktion? Was ist das Geheimnis journalistischer Artikel? Antworten darauf liefert dieses Buch.
Esse diagnóstico foi realizado com apoio da Votorantim Cimentos, afim de conhecer a realidade social do município de Edealina/GO para, posteriormente, investir recursos em projetos nas áreas em que tiverem maior demanda.
A empresa já tem parceria com o Serviço de Convivência e Fortalecimento de Vínculos e Oficinas Integradas de Desenvolvimento Socioeducativo por meio do Instituto Votorantim.
Effects of anion on the corrosion behaviors of carbon steel under artificial ...eSAT Journals
Abstract
Rain is one of the main importance issues for atmospheric corrosion problem. Effects of rainfall on corrosion behaviors of carbon steels were investigated using artificial rainfall equipment. Three types of Atmospheric Corrosion Monitoring (ACM) sensors, which consist of Fe-Ag, Zn-Ag, and Al-Ag galvanic couples, were used to illustrate the correlation between the sensors output, Corrosion Rate (CR), and chemical concentration in the rain. The effects of ionic species on the corrosion behaviors were observed by using NaCl, KCl, Na2SO4, NaNO3, and KNO3 as rainfall solutions. The result revealed that the rainfall rate was insensitive to ACM sensors outputs and CRs. In contrast, the chemical species and their concentrations in the rainfall solution significantly affected the ACM outputs and CRs. The corrosivity of the cations (Na+ and K+) is negligible compared to the anions (Cl-, SO42-, NO3-).For a given number of molar concentration, the CRs resulted from the corrosivity of SO4-2anions were higher than that of Cl- and NO3- anions, respectively. According to the empirical data, the CRs is increased and then reach a steady state as the molar concentration is continuously increased. This research also indicates that the ACM sensors outputs of Fe-Ag and Zn-Ag couples are capable of estimating corrosivity of the atmosphere, while the ACM sensor of Al-Agcouple can be used to determine not only the time of wetness but also the typeofchemical species in the environment. The research methods discussed in this paper proves that the CRs are dependent on the atmospheric composition and can be forecasted through ACM sensors.
Diritto al lavoro e libera circolazione nell’area schengenRoberto Laera
Il principio di libera circolazione delle persone
La libera circolazione dei lavoratori
La libera circolazione di servizi
Il Caso della Svizzera
Importanza economica
Gli Accordi bilaterali e i relativi vantaggi economici
Dati economici Svizzera-Unione europea
La libera circolazione delle persone giova anche nella crisi economica
Attuazione delle misure di accompagnamento
Occupazione
Economia e prosperità
Riconoscimento dei diplomi
Sie sind Freiberufler oder Inhaber eines Dienstleistungsunternehmens. Doch leider wissen viele Ihrer potenziellen Kunden noch nicht, dass es Sie gibt? Dann sollten Sie Ihre Bekanntheit steigern, Ihren Ruf als Spezialist ausbauen um leichter an lukrative Aufträge zu gelangen.
Bernhard Kuntz, Autor mehrerer Fachbücher und Experte für Berater-PR illustriert in diesem Buch das Handwerkszeug für mehr Bekanntheit. Doch was wünscht der „Kunde“ Redakteur eigentlich? Wie nutzt man gezielt Online-Medien? Wie plant man ein PR-Aktion? Was ist das Geheimnis journalistischer Artikel? Antworten darauf liefert dieses Buch.
1. Ilitle Rückseite
beachten
Diese Aufenl hdl l s bew i l l i qunq qi l t für di e qanz e Sc hw ei z .
zEMrS-Nr./No
sYMrc/N.slMrc 015,620.377-2 Für oe n Stel l en- und Befüfs w ec hs el }l i r d k ei r l e Bew i l l tgung
ber ötigt. Spätes tens aw ei l ,l oc hen v or Abl auf der G ü1 g: ti
Kant.-Ref.-Nr. cant.N.rif.
/ Noräf. / keitsd;i r er i s t di e Ver l änger ung z u beantr dgen. Bei m l ,l egz üg
cant. 85069781210 r r , a:f:; d'0p'e bener r oe. etnen anoer en Kanr on 00er Ins
A,,slJnr i s t ei ne Abr el dunq am bi s her i qen i ,l ohnor t er for der
;C r es s änder unqen r - nd bei den z ar s tändi aenBehör denz u
Aufenth altsbewilligung EG/EFTA I ir h. s
r €lcen. l r es e i ufenfhal ts bew i l l i qünq er l i s c ht nr i t der Ab-
gültig für die ganze Schweiz r €ld,' ra i ns Aus l and oder nac h ei ner i Aus l andaufenthal t v on
bis 31.12.2013 B lehr :l ; :aahs fl onaten. s ofer n di es er ni c ht i m R ahm en
flilr r :' r j ens tea er fol qt.
aur ;." .r 3fqe. v or z uw ei Sen.
D i es er ' Aus w ei s i s t den Behör den
des
i' e. :" !€i r qeber i s t v er O fl i c htet. di e Ans tel l unq der
N a m e / N o m/Co g n o me l"l:;. :,;r des l nhabbr s di es es Aus w ei s es i nnör hal b
v0" a r 3.€f der z us töndi qen Stei r er behör de z u nel den. tr
Reichling 1,.;ie', :4, :i e :r tr i c htung- der ouel l ens teuer .
Vorname P.ö.om, Nome
Christoph
Geblnsda:,m Date de naLssa.ce, Da:ä c nasci:a 17.0E.1977
Slaal$ngersrg{eil / Netronal :6 'Naz.o.a, iä
BundesrepublikDeutschland
to..gl i Aa.ese / lndrlzc
Dornache:s!f.I 9 I
-il): -i B as a :
;._'e-:a:=*e:< 3-: c- se.c,- Sa::c :e s3;; 3-c
*-#' 1. :- - ::,te':s:a: g<e :
.'
'rior'< 'e ,i -, F'rhli nar RtlaSCiatO da
BF. ^ . .- .-cs- a-s e .- - M .re.r^n Basel-Stadt
N
01.u1.1009 Ba sei .. l . .{p:i l 0l I 'O
S c h w e i z e r isch e Eid g e n o sse n sch a ft
C o n f 6 d ö r a tio n su isse
C o n f e d e r a z io n e Svizze r a ZE[,,llS-Nr./No SIMIC
SYMIC/N. 015.620.377-2
C o n f e d e r a z iu n svizr a
N am e/N om /C ognom e
Reichling
Vo.name/PrönomiNome
Ausländerausweis Christoph
Livret pour 6trangers
Libretto per stranieri
Legitimaziun d'esters
rn
o
fo
o
't-:e -s:-
cl
N
Form.417.003
dfir