Empirical prediction of traffic noise transmission loss across plenum windows

A parametric study on the traffic noise transmission loss across plenum windows was carried out experimentally in this investigation in an attempt to establish a simple empirical model for predicting this transmission loss. A total of fourteen full scale plenum windows were included in this study. The results of a site mockup measurement were used for model validation. The present model was developed based on the existing plenum chamber theory in which the sound fields inside the plenum window cavities were assumed to make up of a diffracted wave and a reverberant field. Results suggest that both the diffracted and reverberant field inside the plenum window cavities are weaker than those assumed in existing plenum chamber theory. It is found that a model, which assumes frequency-independent diffraction directivity and percentage reverberant field attenuation, gives the best prediction of traffic noise transmission loss. This prediction model is also able to predict site test results with good accurac

EXPLORATIVE VERSUS EXPLOITATIVE ALLIANCES—EVIDENCE FROM THE GLASS INDUSTRY IN CHINA

This study empirically delineates the nature of explorative and exploitative alliances, examines how they affect product and process innovations, and investigates how such effects vary in different contexts. Using a sample of 220 Chinese firms in the glass industry, we find that explorative alliances have a stronger effect on both product and process innovations than exploitative alliances. Product and process innovations are positively related to both market and efficiency performance and environmental turbulence enhances the effect of product and process innovations. Our findings provide implications on how to choose between explorative and exploitative alliances relative to the alliance objectives and firm resources and environmental contexts

EXPLORATIVE VERSUS EXPLOITATIVE ALLIANCES—EVIDENCE FROM THE GLASS INDUSTRY IN CHINA

This study empirically delineates the nature of explorative and exploitative alliances, examines how they affect product and process innovations, and investigates how such effects vary in different contexts. Using a sample of 220 Chinese firms in the glass industry, we find that explorative alliances have a stronger effect on both product and process innovations than exploitative alliances. Product and process innovations are positively related to both market and efficiency performance and environmental turbulence enhances the effect of product and process innovations. Our findings provide implications on how to choose between explorative and exploitative alliances relative to the alliance objectives and firm resources and environmental contexts

Highly analysable, reusable, and realisable architectural designs with XCD

Connector-Centric Design (XcD) is a new approach to specifying software architectures. XcD views complex connectors as highly significant in architectural designs, as it is the complex connectors that non-functional quality properties in systems can emanate from. So, XcD promotes in designs a clean separation of connectors (interaction behaviours) from components (functional behaviours). Designers can then specify connectors in detail explicitly thus easing the analysis of system designs for quality properties. Furthermore, XcD separates control behaviour from connectors as control strategies. Architectural designs in XcD thus become highly modular with re-usable components, connectors, and control strategies (representing design solutions for quality properties). The end result is the eased architectural experimentation with different design solutions by re-using components/connectors and formal analysis of these solutions to find out the optimal ones

Impact of n-methyl-2-pyrrolidone in monoethanolamine solution to the co2 absorption in packed column: analysis via mathematical modeling

This work investigates the reason behind the change of CO2 absorption behaviour exhibited by monoethanolamine (MEA) solution via mathematical modeling analysis when physical absorbent, i.e. n-methyl-2-pyrrolidone (NMP), was added into the solution. The mathematical modeling included the heat model using time resolved numerical method. Based on the results, it was found that lower CO2 removal performance with the addition of NMP into MEA solution at pressure of 0.1 MPa was mainly due to the lower temperature rise along the column, which resulted in lower reaction rate. However, at 3 and 5 MPa pressure conditions, the high physical absorption capability contributed by the presence of NMP in MEA hybrid solution enhanced the CO2 absorption performance of MEA hybrid solution significantly. As such, temperature rise of solution was identified as the dominating factor affecting the performance of the hybrid solvent. The reaction rate of MEA was not affected by the addition of physical solvent. This finding shed crucial insight on the behaviour MEA-NMP hybrid solution which can be applied during scale-up of the process

Determinants of Innovative Activities: Evidence from Europe and Central Asia Region

Recent studies in the innovation literature reveal that Foreign Direct Investment (FDI) promotes the innovation activities in the recipent country through spillover effects. In this paper we extend the existing literature by incooprating the corruption index in the estimation procedure. Using a cross-country analysis from the Europe and Central Asia (ECA) region , covering 57 countries over the period of 1995-2010, we find no evidence of FDI spillover effect on innovative activity. However, corporate corruption and expenditure on education sector are positively related to the number of patents applications. Our study shed light on the national innovation activities and anti-corruption programs

Dependence of dielectric barrier discharge jet length on gas flow rate and applied voltage

The effect of gas flow rate of helium and argon on the length of dielectric barrier discharge (DBD) jet generated under atmospheric pressure using an AC source is investigated. It is found that as the flow rate increases, the jet length increases up to a maximum length. Upon further increase in flow rate, it will cause the jet length to decrease. Visual inspection shows the jet to be of laminar flow when its length was increasing, and gets turbulent when the jet length decreases with increased flow rate. There is an obvious increment in jet length of argon DBD system when the applied voltage is increased from 8.8 kV to 11.0 kV, but not in helium. Spectral analysis reveals the DBD jet to comprise of emission lines of its constituent flow gas. In addition to that, emission lines of component gases (N2 and O) in ambient air and water vapour were also present. Upstream jet was obtained only in helium DBD jet at low flow rate but high applied voltage

Conformation of a Polyelectrolyte Complexed to a Like-Charged Colloid

We report results from a molecular dynamics (MD) simulation on the conformations of a long flexible polyelectrolyte complexed to a charged sphere, \textit{both negatively charged}, in the presence of neutralizing counterions in the strong Coulomb coupling regime. The structure of this complex is very sensitive to the charge density of the polyelectrolyte. For a fully charged polyelectrolyte the polymer forms a dense two-dimensional "disk", whereas for a partially charged polyelectrolyte the monomers are spread over the colloidal surface. A mechanism involving the \textit{overcharging} of the polyelectrolyte by counterions is proposed to explain the observed conformations.Comment: 4 pages, 4 figures (6 EPS files

Measurement of Cosmic-ray Muon-induced Spallation Neutrons in the Aberdeen Tunnel Underground Laboratory

AbstractMuon-induced neutrons are one of the major backgrounds to various underground experiments, such as dark matter searches, low-energy neutrino oscillation experiments and neutrino-less double beta-decay experiments. Previous experiments on the underground production rate of muon-induced neutrons were mostly carried out either at shallow sites or at very deep sites. The Aberdeen Tunnel experiment aims to measure the neutron production rate at a moderate depth of 611 meters water equivalent. Our apparatus comprises of six layers of plastic-scintillator hodoscopes for tracking the incident cosmic-ray muons, and 760 L of gadolinium-doped liquid-scintillator for both neutron production and detection targets. In this paper, we describe the design and the performance of the apparatus. The preliminary result on the measurement of neutron production rate is also presented