AN OVERVIEW OF ROAD SAFETY IN LEBANON

Road traffic injuries are a growing public health and development problem. According to the World Health Organization (WHO), 1.2 million people are killed in road traffic crashes around the world each year. Most of those killed are in the prime of their lives. The road traffic deaths represent a picture of the total waste of human and societal resources from road injuries. Between 20 and 50 million people are injured or disabled by road crashes around the world (WHO, 2012). In Lebanon, a Middle Eastern country, over 1000 people are killed every year, with nearly onethird involving vulnerable road users like pedestrians and motorcyclists. More than twice as many are permanently disabled by their injuries. These statistics need to be multiplied and seen in the context of deep family tragedy, of unimaginable grief and anguish, and of tremendous health and economic and disability costs

Integrating STEM Education and OHS: A Comprehensive Approach for Effective Learning!

This paper explores the complex relationship between STEM (science, technology, engineering, and mathematics) education and occupational health and safety (OHS) practices, proposing an in-depth analysis of their integration for improved educational outcomes. It gives educators, policymakers, and researchers who want to create a holistic and effective learning environment an in-depth look at the different benefits of STEM education and OHS principles, a look at different ways to combine them, and detailed case studies

Transition to turbulence in particle laden flows

Suspended particles can alter the properties of fluids and in particular also affect the transition from laminar to turbulent flow. In the present experimental study, we investigate the impact of neutrally buoyant, spherical inertial particles on transition to turbulence in a pipe flow. At low particle concentrations, like in single phase Newtonian fluids, turbulence only sets in when triggered by sufficiently large perturbations and, as characteristic for this transition localized turbulent regions (puffs) co-exist with laminar flow. In agreement with earlier studies this transition point initially moves to lower Reynolds number (Re) as the particle concentration increases. At higher concentrations however the nature of the transition qualitatively changes: Laminar flow gives way to a globally fluctuating state following a continuous, non-hysteretic transition. A further increase in Re results in a secondary instability where localized puff-like structures arise on top of the uniformly fluctuating background flow. At even higher concentration only the uniformly fluctuating flow is found and signatures of Newtonian type turbulence are no longer observed

Exceeding the asymptotic limit of polymer drag reduction

The drag of turbulent flows can be drastically decreased by addition of small amounts of high molecular weight polymers. While drag reduction initially increases with polymer concentration, it eventually saturates to what is known as the maximum drag reduction (MDR) asymptote; this asymptote is generally attributed to the dynamics being reduced to a marginal yet persistent state of subdued turbulent motion. Contrary to this accepted view we will show in the following that for an appropriate choice of parameters polymers can reduce the drag beyond the suggested asymptotic limit, eliminating turbulence and giving way to laminar flow. However at higher polymer concentrations the laminar state becomes unstable, resulting in a fluctuating flow with the characteristic drag of the MDR asymptote. The asymptotic state is hence dynamically disconnected from ordinary turbulence.Comment: 6 pages, 6 figure

Recent advances in MPD thruster research at Princeton

A summary of last years anode, plasma, and cathode findings is presented. A summary of this years activities and findings is also presented. A brief discussion of previous and current understanding is given and covers the following topics: existence of microinstabilities; the scaling of Va with the Hall parameter; the scaling of anomalous resistivity with the Hall parameter; the relation between anomalous resistivity and the anode drop; the presence of turbulence in the anode region; numerical simulation with anomalous transport; the use of magnets to decrease dissipation; performance testing with the new anode; the mechanisms behind the ionization sink; and lithiated cathode research

Dynamics of viscoelastic pipe flow in the maximum drag reduction limit

Polymer additives can substantially reduce the drag of turbulent flows and the upper limit, the so called "maximum drag reduction" (MDR) asymptote is universal, i.e. independent of the type of polymer and solvent used. Until recently, the consensus was that, in this limit, flows are in a marginal state where only a minimal level of turbulence activity persists. Observations in direct numerical simulations using minimal sized channels appeared to support this view and reported long "hibernation" periods where turbulence is marginalized. In simulations of pipe flow we find that, indeed, with increasing Weissenberg number (Wi), turbulence expresses long periods of hibernation if the domain size is small. However, with increasing pipe length, the temporal hibernation continuously alters to spatio-temporal intermittency and here the flow consists of turbulent puffs surrounded by laminar flow. Moreover, upon an increase in Wi, the flow fully relaminarises, in agreement with recent experiments. At even larger Wi, a different instability is encountered causing a drag increase towards MDR. Our findings hence link earlier minimal flow unit simulations with recent experiments and confirm that the addition of polymers initially suppresses Newtonian turbulence and leads to a reverse transition. The MDR state on the other hand results from a separate instability and the underlying dynamics corresponds to the recently proposed state of elasto-inertial-turbulence (EIT).Comment: 18 pages, 5 figure

Biomarkers: the next therapeutic hurdle in metastatic renal cell carcinoma

Despite recent advances, metastatic renal cell carcinoma remains largely an incurable disease. Vascular endothelial growth factor and mammalian target of rapamycin inhibitors have provided improvements in clinical outcomes. High-dose interleukin 2 remains an option for highly selected patients and is associated with durable remissions in a small minority of patients. The toxicity profiles of specific agents and patient characteristics and comorbidities and costs have an important role in the current choice of therapy. Major challenges encountered in developing molecular biomarkers to guide therapy are tumour heterogeneity and standardisation of tissue collection and analysis. Although biomarkers are in their infancy of development, they should be a priority in early preclinical and clinical development in order to guide rational tailored development of emerging agents

The Design Process as a Life Skill

AbstractProblem-solving and decision-making are highly desirable assets when facing the unpredictable and complex environments of today and tomorrow. Education promotes innovative approaches and leadership skills capable of coping with change and embracing human qualities, and guiding students to embrace holistic thinking. Universities of Lebanon can play a major role in reforming students from the out-dated schooling system that focuses on teaching critical thinking only to solve problems of yesterday and does not prepare them for surviving in an ambiguous future. This paper presents a new design process as a teaching tool that allows instructors and students to alternate between creative and critical thinking that is not bound to context, encouraging them to accept change proactively

Navigating Uncharted Waters: The Disruption and Resilience of Elective Surgery Amidst the COVID-19 Pandemic in Lebanon

The COVID-19 pandemic ushered in previously unseen difficulties across the entirety of the world's healthcare system, dramatically reshaping several facets of clinical medicine in the process. Among the industries that were hit particularly hard was elective surgery, which is a fundamental component of medical systems all across the world. In the present study, we investigate the complex relationship between the widespread COVID-19 epidemic and the effects that it has had on elective surgery in the particular setting of Lebanon. This paper seeks to provide insights that can inform future healthcare preparedness and contribute to the ongoing efforts to build a resilient healthcare system that is capable of effectively navigating crises while ensuring the delivery of essential medical services by examining the challenges, adaptations, and implications. The goal of this paper is to provide these insights by examining the challenges, adaptations, and implications

Isolation performance metrics for personal sound zone reproduction systems

Two isolation performance metrics, Inter-Zone Isolation (IZI) and Inter-Program Isolation (IPI), are introduced for evaluating Personal Sound Zone (PSZ) systems. Compared to the commonly-used Acoustic Contrast metric, IZI and IPI are generalized for multichannel audio, and quantify the isolation of sound zones and of audio programs, respectively. The two metrics are shown to be generally non-interchangeable and suitable for different scenarios, such as generating dark zones (IZI) or minimizing audio-on-audio interference (IPI). Furthermore, two examples with free-field simulations are presented and demonstrate the applications of IZI and IPI in evaluating PSZ performance in different rendering modes and PSZ robustness