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This study aims to develop an experimentally validated three-dimensional numerical model for predicting different flow patterns produced with a gas dynamic virtual nozzle (GDVN).

The physical model is posed in the mixture formulation and copes with the unsteady, incompressible, isothermal, Newtonian, low turbulent two-phase flow. The computational fluid dynamics numerical solution is based on the half-space finite volume discretisation. The geo-reconstruct volume-of-fluid scheme tracks the interphase boundary between the gas and the liquid. To ensure numerical stability in the transition regime and adequately account for turbulent behaviour, the k-ω shear stress transport turbulence model is used. The model is validated by comparison with the experimental measurements on a vertical, downward-positioned GDVN configuration. Three different combinations of air and water volumetric flow rates have been solved numerically in the range of Reynolds numbers for airflow 1,009–2,596 and water 61–133, respectively, at Weber numbers 1.2–6.2.

The half-space symmetry allows the numerical reconstruction of the dripping, jetting and indication of the whipping mode. The kinetic energy transfer from the gas to the liquid is analysed, and locations with locally increased gas kinetic energy are observed. The calculated jet shapes reasonably well match the experimentally obtained high-speed camera videos.

The model is used for the virtual studies of new GDVN nozzle designs and optimisation of their operation.

To the best of the authors’ knowledge, the developed model numerically reconstructs all three GDVN flow regimes for the first time.

The purpose of this paper is to artificially construct a functional surface with self-propulsion flow characteristics for the directional transportation of propellant in surface tension tanks.

In this study, a method to enhance the propulsion efficiency by using functional surfaces of self-propulsion performance was proposed. Superhydrophilic wedged-groove with the superhydrophobic background was fabricated and the self-propulsion capacity was verified.

It is found that the self-propulsion capacity is related to the divergence angle of the wedged-groove in the hydrophilic area, and the velocity of the droplets on the deflector plate is the largest with the divergence angle of 4°; the temperature gradient field formed by the condensing device at the nozzle can accelerate the droplet outflow from the tank.

Realization of this idea provides an accurate control strategy for the complex flow process of propellant in plate surface tension tanks, which could enhance the efficiency of the tension tank significantly.

The paper aims to throw light on the interactions taking place between the different chemical compositions at various temperatures. P-methylacetophenone is a polar dissolvable, which is positively related by dipole–dipole co-operations and is exceptionally compelling a direct result of the shortfall of any critical primary impacts because of the absence of hydrogen bonds; hence, it might work an enormous dipole moment (μ = 3.62 D). Alcohols additionally assume a significant part in industries and research facilities as reagents and pull in incredible consideration as helpful solvents in the green innovation. They are utilized as pressure-driven liquids in drugs, beauty care products, aromas, paints removers, flavors, dye stuffs and as a germ-free specialist.

Mixtures were prepared by mass in airtight ground stopper bottles. The mass measurements were performed on a digital electronic balance (Mettler Toledo AB135, Switzerland) with an uncertainty of ±0.0001 g. The uncertainty in mole fraction was thus estimated to be less than ±0.0001. The densities of pure liquids and their mixtures were determined using a density meter (DDH-2911, Rudolph Research Analytical). The instrument was calibrated frequently using deionized doubly distilled water and dry air. The estimated uncertainty associated with density measurements is ±0.0003 g.cm⁻³. Viscosities of the pure liquids and their mixtures were determined by using Ostwald’s viscometer. The viscometer was calibrated at each required temperature using doubly distilled water. The viscometer was cleaned, dried and is filled with the sample liquid in a bulb having capacity of 10 ml. The viscometer was then kept in a transparent walled water bath with a thermal stability of ±0.01K for about 20 min to obtain thermal equilibrium. An electronic digital stop watch with an uncertainty of ±0.01 s was used for the flow time measurements for each sample at least four readings were taken and then the average of these was taken.

Negative values of excess molar volume, excess isentropic compressibility and positive values of deviation in viscosity including excess Gibbs energy of activation of viscous flow at different temperatures (303.15, 308.15 and 313.15 K) may be attribution to the specific intermolecular interactions through the hetero-association interaction between the components of the mixtures, resulting in the formation of associated complexes through hydrogen bond interactions.

The excess molar volume (V^E) values were analyzed with the Prigogine–Flory–Patterson theory, which demonstrated that the free volume contribution is the one of the factors influencing negative values of excess molar quantities. The Jouyban–Acree model was used to correlate the experimental values of density, speed of sound and viscosity.

This study aims to investigate the existence of contagion between liquid and illiquid assets in the credit default swap (CDS) market around the recent financial crisis. The authors perform analyses based on vector autoregression model and the dynamic conditional correlation model. The estimation of vector autoregression models reveals that changes in liquid CDS (LCDS) spreads lead to changes in illiquid CDS spreads at least one week ahead during the financial crisis period, whereas the leading direction is reversed during the post-crisis period. Moreover, the results are robust after controlling for structural variables which are proven as determinants of CDS spreads and are empirically supported. This study interprets that information was incorporated first into the LCDSs because of the flight-to-liquidity during the recent crisis period but there is a default contagion effect by reflecting illiquidity-induced credit risk after the crisis. Finally, the dynamic conditional correlation analysis also confirms the main results.

The objective of this article is to propose a panel of management performance evaluation indicators at operator level. This panel would be the tool to be made available to an observatory that should be set up by regulation. The proposal comes at the right time given that Morocco is planning a major reform of the sector very soon. A framework law has already been promulgated for this purpose (Law 51-21 relating to the reform of public establishments).

The proposed panel is the result of (1) a review of the literature dealing with public management theories, in particular those relating to industrial and commercial public services and whose character is captive. The management of the latter requires a great deal of caution to preserve their economic balance and consequently their sustainability. (2) A review of experiences of countries is chosen because of contextual their similarities with Morocco like France having a similar legal background, Tunisia and Algeria chosen for geographical and economic similarities. The British experience is also discussed for what it represents as a liberal model in the management of public water and sanitation services, as opposed to the German model also studied and which stands as the only country where the management of public services has almost always been a communal prerogative. The analysis of these models has made it possible to identify management evaluation practices that could be adapted to the Moroccan context. (3) Research work by practitioners and reports from specialized international institutions (International Water Association [IWA]). (4) A critical analysis of a multitude of management and activity reports from 12 autonomous authorities and 4 private delegates covering 16 million inhabitants of the urban environment. A total of 15 indicators are developed. They aim to assess the effectiveness of management in terms of saving drinking water and preserving the natural environment from the pollution of water resources.

Approximately, 15 indicators for assessing water resource management in public water and sanitation services are proposed. These indicators relate to the efficiency of pipe networks, the performance of storage systems and losses in users' homes. Indicators specific to liquid sanitation systems, particularly with regard to the control of wastewater overflows into the public highway and their treatment before discharge into the natural environment, are also proposed.

The application of the results of this research could be confronted with its appropriation by the operators. Indeed, the investment involved in setting up the proposed evaluation system, as well as the conflict of interest that may arise in the process of formalizing and standardizing the system at the national level, may slow down the process of setting it up.

In practice, the implementation of a system for evaluating the performance of water resource management in public drinking water and liquid sanitation services would make it possible to optimize the volume of water to be mobilized. Substantial savings are expected both at the level of the resource itself and at the level of the investments that accompany the realization of the mobilization and distribution infrastructures. These savings will be very useful for the creation of other similar services and to serve more people.

The distribution of drinking water and liquid sanitation is a vital human need. These services are extremely captive. They are key factors in the socioeconomic development of the territory and the citizen. The impact is transversal and affects the lifestyle of the populations. On the one hand, it favors the sedentarization of the populations and on the other hand, preserves their health by fighting against the diseases of water origin. In addition, the comfort that it provides in the daily life of users is highly coveted when they are delivered in a modern way and arranged with modern technologies.

The regulation of public drinking water and liquid sanitation services in Morocco is the weakest link in the sector. The Ministry of the Interior is legally responsible for setting up a standard system for evaluating the management of these services to fill this gap (organic law 113-14 on municipalities). Unfortunately, this initiative is not yet underway. The opportunity to apply the results of this research is well timed. Morocco plans to launch a global reform of the sector starting in 2022–2023 (Law 50-21 on the reform of public institutions).

The paper targets on providing new experimental data for validation of the well-established mathematical models within the framework of the lattice Boltzmann method (LBM), which are applied to problems of casting processes in complex mould cavities.

An experimental campaign aiming at the free-surface flow within a system of narrow channels is designed and executed under well-controlled laboratory conditions. An in-house lattice Boltzmann solver is implemented. Its algorithm is described in detail and its performance is tested thoroughly using both the newly recorded experimental data and well-known analytical benchmark tests.

The benchmark tests prove the ability of the implemented algorithm to provide a reliable solution when the surface tension effects become dominant. The convergence of the implemented method is assessed. The two new experimentally studied problems are resolved well by simulations using a coarse computational grid.

A detailed set of original experimental data for validation of computational schemes for simulations of free-surface gravity-driven flow within a system of narrow channels is presented.

This paper aims to critically investigate the liquidity risk management of Islamic banks and develop an alternative regulatory framework appropriate for liquidity management of these banks.

The specific risk profile of an Islamic bank requires developing a new and more efficient regulatory framework, which relies on risk- sharing and symmetric information among parties. The paper makes a differentiation between small local banks and internationally active Islamic banks and proposes to apply liquidity requirements only for internationally active Islamic banks.

A new proposal for the liquidity coverage ratio (LCR) of Islamic banks is developed in this paper towards mitigating risks and concurrently protecting the interests of investment account holders. Minimum and maximum thresholds are proposed for each liquid asset in this new LCR framework. An alternative liquidity approach is discussed to complement the proposal and several policy options are suggested.

As participation banks are exposed to market liquidity and market risks, more high-quality liquid instruments within a risk-sharing regulatory framework may provide the inner adjustment process through which any mismatch regarding maturity, risk, value or linkage with the real economy is corrected systematically. It offers policy implications for regulators, supervisors and international organizations.

Economic studies have always underlined the cyclical trends of many industries and their different relations to the macro-economic cycles. Shipping is one of those industries and it has been often characterised by peaks that have influenced both the trade patterns and industry investment structure (e.g. fleet, shipyard activity, freight rates). One of the main issues related with the cycles is the effect on overcapacity and prices for newbuilding and how the understanding of these patterns can help in preventing short-hand strategies. The purpose of this paper is to evaluate different effects of business elements on shipbuilding activity, in relation to different economic-cycle phases.

This paper proposes a non-linear econometric model to identify the relations between shipbuilding and economic cycles over the past 30 years. The research focuses on identifying the cycle characteristics and understanding the asymmetrical effect of economic- and business-related variables on its development.

The study underlines the presence of an asymmetric effect of several business variables on the shipbuilding productions, depending on the cyclical phases (i.e. market expansion or economic slowdown). Moreover, lagged effects seem to be stronger than contemporaneous variables.

The paper is a first attempt of using non-linear modelling to shipbuilding cycles, giving indications that could be included in relevant investment policies.

Going beyond the usual approach of measuring port performance – focusing on the efficiency of port operations – this paper aims to look into shipping lines and other port users’ perceptions on port performance.

The paper develops a framework measuring the perceptions of port users (i.e. shipping companies, shippers, etc.) on port performance. A typology of elements that shape port users’ perceptions has been developed with an eye on capturing the peculiarities of different port markets. Based on this typology, a tool to assess users’ perspectives, and subsequently evaluate, any given port has been developed. The tool provides port authorities the flexibility they need for customized approaches. The developed evaluation mechanism has been tested on a group of European seaports, and the results are presented by this study.

The framework and its pilot application unveil the key parameters that port users take into consideration when evaluating the effectiveness component of port performance. Moreover, the importance and evaluation ratings of specific performance parameters allow for a GAP analysis of the collected data.

The paper advances scholarly and practical discussion on how of port users’ perceptions can be a valuable tool for port performance measurement.

The proposed tool can be a valuable add-on for port authorities to evaluate their performance from the port users’ point of view and take the necessary actions to improve it. Also, the tool can be used for the evaluation of a new process, infrastructure. The evaluation of port users’ perception of port performance can and must be part of a European ports observatory, as it is a set of indicators that clearly reflects the satisfaction of port users by engaging their view on port performance issues, instead of relying almost exclusively on port-generated data.

The paper develops a framework for measuring port user’s perception on port performance, which is flexible and can be applied in any port.