The International Telecommunications Union (ITU) and the Organization for Economic Cooperation and Development (OECD) provide Internet penetration statistics, which are collected from official national sources worldwide, and they are widely used to inform policymakers and researchers about the expansion of digital technologies. Nevertheless, these statistics are derived with methodologies, whic...

In this paper, the needle penetrometer test was utilized to explore the reliability of the Needle Penetration Index (NPI) for estimating the Unconfined Compressive Strength (UCS) of sedimentary rocks including gypsum, marl, siltstone and sandstone collected from the Qom Formation. Following the UCS and NP test, regression analyses were carried out to control the predictive performances of NPI. ...

The utility scale of non-conventional generators (NCGs), such as wind and photovoltaic (PV) plants, are competitive alternatives to synchronous machines (SMs) for power generation. Higher penetration NCGs has been respondent causing several recent incidents leading up voltage collapse in systems due the distinct characteristics under different operating conditions. Consequently, so-called syste...

This paper addresses the dual questions: What is the appropriate storage size and its related properties for matching very large photovoltaic plants to the grid; and what are the available technologies for achieving this end. For this purpose a ‘‘Usefulness Index’’ is defined, which, for any grid flexibility, leads to a PV-storage combination that allows high grid-penetration without storage be...

BACKGROUND This study was designed as a "proof-of-concept" to establish whether coronary computed tomographic angiography (CTA) has the capability to identify morphological features of plaque disruption. METHODS AND RESULTS In patients with unstable angina undergoing CTA and invasive coronary angiography within 30 days, quantitative CTA analysis was performed on all plaques for percent stenos...

The voltage instability phenomena occur in both transmission systems and distribution systems. The weakening of voltage stability level will limit the growth of load served by distribution companies. Voltage instability in power distribution systems could lead to voltage collapse and thus power blackouts. The integration of distributed generation (DG) in the distribution system has increased to...

Total internal reflection fluorescence microscopy has become a powerful tool to study the dynamics of sub-cellular structures and single molecules near substrate surfaces. However, the penetration depth of the evanescent field, that is, the distance at which the excitation intensity has exponentially decayed to 1/e, is often left undetermined. This presents a limit on the spatial information ab...

This paper addresses the problem of frequency control in autonomous diesel-based power system with high penetration of renewables. Usually, small power systems with high penetration of renewable energies are supplied by one or two small diesel generators, resulting in a system with a relatively low moment of inertia, and which can be susceptible to significant frequency variations. However, fre...

The intent of this paper is to provide empirically tested and validated metrics to capture the gradual adoption of ecommerce among manufacturing SMEs. The results suggest that e-commerce adoption is purposely undertaken in a cumulative, and thus path-dependent, way. The findings also demonstrate that most SMEs follow e-commerce adoption trajectories. The proposed stage model for e-commerce adop...