A first principles simulation of rigid water

We present the results of Car-Parrinello (CP) simulations of water at ambient conditions and under pressure, using a rigid molecule approximation. Throughout our calculations, water molecules were maintained at a fixed intramolecular geometry corresponding to the average structure obtained in fully unconstrained simulations. This allows us to use larger time steps than those adopted in ordinary CP simulations of water, and thus to access longer time scales. In the absence of chemical reactions or dissociation effects, these calculations open the way to ab initio simulations of aqueous solutions that require timescales substantially longer than presently feasible (e.g. simulations of hydrophobic solvation). Our results show that structural properties and diffusion coefficients obtained with a rigid model are in better agreement with experiment than those determined with fully flexible simulations. Possible reasons responsible for this improved agreement are discussed

The Arab world's contribution to solid waste literature: a bibliometric analysis

BACKGROUND: Environmental and health-related effects of solid waste material are considered worldwide problems. The aim of this study was to assess the volume and impact of Arab scientific output published in journals indexed in the Science Citation Index (SCI) on solid waste. METHODS: We included all the documents within the SCI whose topic was solid waste from all previous years up to 31 December 2012. In this bibliometric analysis we sought to evaluate research that originated from Arab countries in the field of solid waste, as well as its relative growth rate, collaborative measures, productivity at the institutional level, and the most prolific journals. RESULTS: A total of 382 (2.35 % of the overall global research output in the field of solid waste) documents were retrieved from the Arab countries. The annual number of documents published in the past three decades (1982–2012) indicated that research productivity demonstrated a noticeable rise during the last decade. The highest number of articles associated with solid waste was that of Egypt (22.8 %), followed by Tunisia (19.6), and Jordan (13.4 %). the total number of citations over the analysed years at the date of data collection was 4,097, with an average of 10.7 citations per document. The h-index of the citing articles was 31. Environmental science was the most researched topic, represented by 175 (45.8 %) articles. Waste Management was the top active journal. The study recognized 139 (36.4 %) documents from collaborations with 25 non-Arab countries. Arab authors mainly collaborated with countries in Europe (22.5 %), especially France, followed by countries in the Americas (9.4 %), especially the USA. The most productive institution was the American University of Beirut, Lebanon, with 6.3 % of total publications. CONCLUSIONS: Despite the expected increase in solid waste production from Arab world, research activity about solid waste is still low. Governments must invest more in solid waste research to avoid future unexpected problems. Finally, since solid waste is a multidisciplinary science, research teams in engineering, health, toxicology, environment, geology and others must be formulated to produce research in solid waste from different scientific aspects

Assessing the transition of municipal solid waste management using combined material flow analysis and life cycle assessment

Faced with the challenges to deal with increasingly growing and ever diversified municipal solid waste (MSW), a series of waste directives have been published by European Commission to divert MSW from landfills to more sustainable management options. The presented study assessed the transition of MSW man-agement in Nottingham, UK, since the enforcement of the EU Landfill Directive using a tool of combined materials flow analysis (MFA) and life cycle assess-ment (LCA). The results show that the MSW management system in Nottingham changed from a relatively simple landfill & energy from waste (EfW) mode to a complex, multi-technology mode. Improvements in waste reduction, material re-cycling, energy recovery, and landfill prevention have been made. As a positive result, the global warming potential (GWP) of the MSW management system re-duced from 1,076.0 kg CO2–eq./t of MSW in 2001/02 to 211.3 kg CO2–eq./t of MSW in 2016/17. Based on the results of MFA and LCA, recommendations on separating food waste and textile at source and updating treatment technologies are made for future improvement

Understanding our experience of music: What kind of psychology do we need?

   Background in the psychology of music. The historical development of the psychology of music largely followed that of psychology in general. In the 20th century it adopted the research methods and interests of cognitive psychology and more recently has turned to new interdisciplinary connections with psychobiology and the neurosciences. There remains, however, a certain inadequacy regarding work in the psychology of music and cultural psychology and as well of interpretative research aimed at interpreting the role of music in those processes, processes Bruner called "the nature and cultural shaping of meaning-making, and the central place it plays in human action". Background in historical musicology and cultural anthropology. Historical musicology and cultural anthropology maintain that experiencing and understanding music represents a process fundamentally dependent upon cultural context. This begs the question as to how cultural context influences social and individual representations of music in the sense that a particular "style of aesthetic experience" typifies a historical period. Although this is a genuine psychological question, it cannot be answered by a psychology which is restricted to "ahistorical" explanations of information processing. Thus from a cultural anthropological perspective there is strong interest in any kind of "cultural psychology" which is able to conceptualise the dynamic interactions between culturally determined "social representations" of music and the individual mind. Goals. We argue for a "cultural turn" in the psychology of music. Following developments within psychology, research over recent decades in the psychology of music has concentrated on neuro-cognition while cultural aspects have been underestimated as they continue to be in psychology in general. Conclusions. An important task for an interdisciplinary framework that wishes to include the cultural sciences and psychology should be to review recent cultural psychological theories to assess their implications for a psychological theory of music. As examples we use Ernst E. Boesch's Symbolic Action Theory which explicitly refers to the role of aesthetic experience in cultural contexts and Alfred Lang's "semiotic ecology" which provides an appropriate model for conceptualising the complex relations between the development of cultural patterns and the development of related individual representations

First Principals and Classical Molecular Dynamics Simulations of Solvated Benzene

We have performed extensive ab initio and classical MD simulations of benzene in water in order to examine the unique solvation structures that are formed. Qualitative differences between classical and ab initio MD simulations are found and the importance of various technical simulation parameters is examined. Our comparison indicates that non-polarizable classical models are not capable of describing the solute-water interface correctly if local interactions become energetically comparable to water hydrogen bonds. In addition, a comparison is made between a rigid water model and fully flexible water within ab initio MD simulations which shows that both models agree qualitatively for this challenging system