Accurately predicting maintainability has been a challenge due to the complex nature of buildings, yet it is an important research area with a rising necessity. This paper explores the use of ...multicriteria decision making approach for merging maintainability and sustainability elements into building grading systems to attain long-term sustainability in the building industry. The paper conducts a systematic literature review on multicriteria decision analysis approach and builds on the existing knowledge of maintainability to achieve this. A conceptual framework is developed to bridge the gap between building operations and maintenance with green facilities management by forecasting green maintainability at the design stage.
Elevator system is a highly specialized machinery that requires technicians that have a wider array of knowledge in maintaining the system to be safe and reliable. While attaining reliable data of ...elevator malfunction become challenges, this study has filled the gap by gathering the management-maintenance issues and operational defects of elevator system. Forty-three types of operation defects were found and the consequence defects and their possible causes of occurrences were discussed. To respond to the prime challenges of maintaining elevator system provided by the industry players' perspective, a theoretical framework is established as a recommendation to improve knowledge base of defects in elevator system which comprises good practices, and solutions to rectify each defects found. Hence, this research paper has theoretically improved the knowledge base of maintainability of elevator system and provide meaningful guidelines in practical senses to the industry professionals.
On-site surface applications of superhydrophobic paint and coating products were investigated for their self-cleaning effectiveness in this study. This paper presents findings from the ensuing visual ...assessments using a novel method based on digital image processing. Findings confirm the self-cleaning ability of the superhydrophobic surface applications, which has sustained effects over a period of one year. This paper discusses how these findings contribute to the domain of facilities management (FM) to increases the ease of façade maintenance and the maintainability of the superhydrophobic façade coating systems.
•Self-cleaning effects of superhydrophobic products were observed over time.•Novel technique using digital image processing used to assess surface dirt staining.•Superhydrophobic surface applications improve ease of façade maintenance.•Knowledge bridge to disseminate maintainability information to practitioners.
Inclusive non-diffractive photoproduction of rho(770)^0, K^*(892)^0 and phi(1020) mesons is investigated with the H1 detector in ep collisions at HERA. The corresponding average \gamma p ...centre-of-mass energy is 210 GeV. The mesons are measured in the transverse momentum range 0.5
A measurement of the inclusive ep scattering cross section is presented in the region of low momentum transfers, 0.2 GeV^2 < Q^2 < 12 GeV^2, and low Bjorken x, 5x10^-6 < x < 0.02. The result is based ...on two data sets collected in dedicated runs by the H1 Collaboration at HERA at beam energies of 27.6 GeV and 920 GeV for positrons and protons, respectively. A combination with data previously published by H1 leads to a cross section measurement of a few percent accuracy. A kinematic reconstruction method exploiting radiative ep events extends the measurement to lower Q^2 and larger x. The data are compared with theoretical models which apply to the transition region from photoproduction to deep inelastic scattering.
A detailed analysis is presented of the diffractive deep-inelastic scattering process ep→eXY, where Y is a proton or a low mass proton excitation carrying a fraction 1-xIP>0.95 of the incident proton ...longitudinal momentum and the squared four-momentum transfer at the proton vertex satisfies |t|<1 GeV2. Using data taken by the H1 experiment, the cross section is measured for photon virtualities in the range 3.5≤Q2≤1600 GeV2, triple differentially in xIP, Q2 and β=x/xIP, where x is the Bjorken scaling variable. At low xIP, the data are consistent with a factorisable xIP dependence, which can be described by the exchange of an effective pomeron trajectory with intercept αIP(0)=1.118±0.008(exp.)+0.029-0.010(model). Diffractive parton distribution functions and their uncertainties are determined from a next-to-leading order DGLAP QCD analysis of the Q2 and β dependences of the cross section. The resulting gluon distribution carries an integrated fraction of around 70% of the exchanged momentum in the Q2 range studied. Total and differential cross sections are also measured for the diffractive charged current process e+p→ν̄eXY and are found to be well described by predictions based on the diffractive parton distributions. The ratio of the diffractive to the inclusive neutral current ep cross sections is studied. Over most of the kinematic range, this ratio shows no significant dependence on Q2 at fixed xIP and x or on x at fixed Q2 and β.
Elastic J/ψ production at HERA Aktas, A.; Andreev, V.; Anthonis, T. ...
The European physical journal. C, Particles and fields,
06/2006, Letnik:
46, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Cross sections for elastic production of J/ψ mesons in photoproduction and electroproduction are measured in electron proton collisions at HERA using an integrated luminosity of 55 pb-1. Results are ...presented for photon virtualities Q2 up to 80 GeV2. The dependence on the photon-proton centre of mass energy Wγp is analysed in the range 40≤Wγp≤305 GeV in photoproduction and 40≤Wγp≤160 GeV in electroproduction. The Wγp dependences of the cross sections do not change significantly with Q2 and can be described by models based on perturbative QCD. Within such models, the data show a high sensitivity to the gluon density of the proton in the domain of low Bjorken x and low Q2. Differential cross sections dσ/dt, where t is the squared four-momentum transfer at the proton vertex, are measured in the range |t|<1.2 GeV2 as functions of Wγp and Q2. Effective Pomeron trajectories are determined for photoproduction and electroproduction. The J/ψ production and decay angular distributions are consistent with s-channel helicity conservation. The ratio of the cross sections for longitudinally and transversely polarised photons is measured as a function of Q2 and is found to be described by perturbative QCD based models.
Inclusive charm and beauty cross sections are measured in
e
−
p
and
e
+
p
neutral current collisions at HERA in the kinematic region of photon virtuality 5≤
Q
2
≤2000 GeV
2
and Bjorken scaling ...variable 0.0002≤
x
≤0.05. The data were collected with the H1 detector in the years 2006 and 2007 corresponding to an integrated luminosity of 189 pb
−1
. The numbers of charm and beauty events are determined using variables reconstructed by the H1 vertex detector including the impact parameter of tracks to the primary vertex and the position of the secondary vertex. The measurements are combined with previous data and compared to QCD predictions.
Diffractive electroproduction of ρ and ϕ mesons is measured at HERA with the H1 detector in the elastic and proton dissociative channels. The data correspond to an integrated luminosity of 51 pb
−1
. ...About 10500 ρ and 2000 φ events are analysed in the kinematic range of squared photon virtuality 2.5 ≤
Q
2
≤ 60 GeV
2
, photon-proton centre of mass energy 35 ≤
W
≤ 180 GeV and squared four-momentum transfer to the proton |
t
| ≤ 3 GeV
2
. The total, longitudinal and transverse cross sections are measured as a function of
Q
2
,
W
and |
t
|. The measurements show a transition to a dominantly “hard” behaviour, typical of high gluon densities and small
dipoles, for
Q
2
larger than 10 to 20 GeV
2
. They support flavour independence of the diffractive exchange, expressed in terms of the scaling variable (
Q
2
+
M
2
V
)/4, and proton vertex factorisation. The spin density matrix elements are measured as a function of kinematic variables. The ratio of the longitudinal to transverse cross sections, the ratio of the helicity amplitudes and their relative phases are extracted. Several of these measurements have not been performed before and bring new information on the dynamics of diffraction in a QCD framework. The measurements are discussed in the context of models using generalised parton distributions or universal dipole cross sections.
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