Reynolds Stress Modeling of Flow in Compound Channels with Vegetated Floodplains

Experimental and Computational Hydraulic

Big Data and Democracy

One of the biggest questions in the digital age pertains to the relevance of democracy in the era of big data. Unquestioningly, the digital revolution is growing at a rapid pace and many are being caught unaware by its impact in various avenues. The amount of data available has been doubling year on year, and the conditions of usage have been evolving at a pace faster than the policies are being provided to ensure proper usage. Many have started looking for ways of turning big data into big money, an aspect that is coming at the expense of the democratic values countries have upheld for generations. Instead, it is becoming a huge problem as the history of humankind is becoming more documented now and messages are easier to send compared to a century ago. Understanding the impact of big data on democracy can help accentuate the best way of improving democratic institutions and their ability to overcome the pressure coming from evolving technology

The Youngest Victims: Children and Youth Affected by War

In 1989, the United Nation Convention on the Rights of the Child declared, “[state parties] shall take all feasible measures to ensure protection and care of children who are affected by an armed conflict.” In addition to attempting to secure the welfare of children in armed conflict, the Convention went on to ban the recruitment and deployment of children during armed conflict. Despite the vast majority of sovereign nations signing and ratifying this agreement, this treaty, unfortunately, has not prevented children and youth from witnessing, becoming victims of, or participating in political, ethnic, religious, and cultural violence across the past three decades. This chapter offers an “ecological perspective” on the psychosocial consequences of exposure to the trauma of war-related violence and social disruption

Social justice and leadership development

The revised professional standards for the teaching profession in Scotland are underpinned by a set of values which includes a detailed articulation of social justice for education covering rights, diversity and sustainability. There is a future orientation in these standards that privileges the contribution of teachers and leaders to realizing a wider social aspiration for social justice. This expectation on leaders to contribute to this wider aspiration for social justice raises questions about the practice of leaders and their development. This article considers the implications of the articulation of social justice in the professional standards for career-long leadership development. The article explores some of the issues related to social justice and the role of leadership in school. The article then focuses on the context of Scottish education, looking firstly at the professional standards and secondly at the issues related to social justice leadership. From this discussion the implications for career-long leadership development are considered. The article concludes with a framework for social justice leadership development identifying key aspects of values, knowledge and understanding, inclusive practice, policy, issues of equity and equality that can be developed progressively across a leadership development continuum

Zinc and Cadmium in the Aetiology and Pathogenesis of Osteoarthritis and Rheumatoid Arthritis

Osteoarthritis (OA) and rheumatoid arthritis (RA) are inflammatory articular conditions with different aetiology, but both result in joint damage. The nutritionally essential metal zinc (Zn2+) and the non-essential metal cadmium (Cd2+) have roles in these arthritic diseases as effectors of the immune system, inflammation, and metabolism. Despite both metal ions being redox-inert in biology, they affect the redox balance. It has been known for decades that zinc decreases in the blood of RA patients. It is largely unknown, however, whether this change is only a manifestation of an acute phase response in inflammation or relates to altered availability of zinc in tissues and consequently requires changes of zinc in the diet. As a cofactor in over 3000 human proteins and as a signaling ion, zinc affects many pathways relevant for arthritic disease. How it affects the diseases is not just a question of zinc status, but also an issue of mutations in the many proteins that maintain cellular zinc homoeostasis, such as zinc transporters of the ZIP (Zrt-/Irt-like protein) and ZnT families and metallothioneins, and the multiple pathways that change the expression of these proteins. Cadmium interferes with zinc’s functions and there is increased uptake under zinc deficiency. Remarkably, cadmium exposure through inhalation is now recognized in the activation of macrophages to a pro-inflammatory state and suggested as a trigger of a specific form of nodular RA. Here, we discuss how these metal ions participate in the genetic, metabolic, and environmental factors that lead to joint destruction. We conclude that both metal ions should be monitored routinely in arthritic disease and that there is untapped potential for prognosis and treatment

Wave damping over artificial Posidonia oceanica meadow: a large-scale experimental study

An experimental study, conducted in the large wave flume of CIEM in Barcelona, is presented to evaluate the effects of Posidonia oceanica meadows on the wave height damping and on the wave induced velocities. The experiments were performed for irregular waves from intermediate to shallow waters with the dispersion parameter h/? ranging from 0.09 to 0.29. Various configurations of the artificial P. oceanica meadow were tested for two stem density patterns (360 and 180 stems/m2) and for plant's height ranging from 1/3 to 1/2 of the water depth.The results for wave height attenuation are in good agreement with the analytical expressions found in literature, based on the assumption that the energy loss over the vegetated field is due to the drag forces. Based on this hypothesis, an empirical relationship for the drag coefficient related to the Reynolds number, Re, is proposed. The Reynolds number, calculated using the artificial P. oceanica leaf width as the length scale and the maximum orbital velocity over the meadow edge as the characteristic velocity scale, ranges from 1000 to 3500 and the drag coefficient Cd ranges from 0.75 to 2.0.The calculated wave heights, using the analytical expression from literature and the proposed relationship for the estimation of Cd, are in satisfactory agreement with those measured. Wave orbital velocities are shown to be significantly attenuated inside the meadow and just above the flume bed as indicated by the calculation of an attenuation parameter. Near the meadow edge, energy transfer is found in spectral wave velocities from the longer to the shorter wave period components. From the analysis it is shown that the submerged vegetation attenuates mostly longer waves

Numerical solution of a 2 - D axisymmetric flow using the method of pseudocompressibility and determination of the form of the outlet flow through a Pelton nozzle

187 σ.Σκοπός της παρούσας εργασίας είναι η ανάπτυξη μιας αριθμητικής μεθοδολογίας για τον υπολογισμό μόνιμης διδιάστατης ροής χρησιμοποιώντας την μέθοδο της ψευδοσυμπιεστότητας και του προσδιορισμού της μορφής της δέσμης εξόδου απο ακροφύσιο τύπου Pelton. Αναλυτικότερα, η μεθοδολογία αυτή πρέπει να μπορεί να είναι σε θέση να επιλύει τις εξισώσεις Navier - Stokes με την χρήση γενικευμένων καμπυλόγραμμων πλεγμάτων , σε μόνιμα δισδιάστατα τυρβώδη πεδία ροής καθώς και να προσδιορίζει την δέσμη εξόδου για διάφορα ανοίγματα του ακροφυσίου.The purpose of the following paper is to develop a numerical method for the calculation of a steady state 2 - D flow using the method of pseudocompressibility and to evaluate the form of the outlet flow for a Pelton nozzle. Specifically, this method should be able to solve the Navier Stokes system of equations using generalized algebraic grids, in steady state 2 -D turblulent flow such as to determin the outlet flow for several different types of nozzles.Θεοχάρης Γ. Κουτρογιάννη