An Efficient and Accurate Car-Parrinello-like Approach to Born-Oppenheimer Molecular Dynamics

We present a new method which combines Car-Parrinello and Born-Oppenheimer molecular dynamics in order to accelerate density functional theory based ab-initio simulations. Depending on the system a gain in efficiency of one to two orders of magnitude has been observed, which allows ab-initio molecular dynamics of much larger time and length scales than previously thought feasible. It will be demonstrated that the dynamics is correctly reproduced and that high accuracy can be maintained throughout for systems ranging from insulators to semiconductors and even to metals in condensed phases. This development considerably extends the scope of ab-initio simulations.Comment: 4 pages, 3 figures; Accepted by Phys. Rev. Lett. for publicatio

Impact of wastewater effluent on the diatom assemblages structure of a brackish small stream: Oued Hassar (Morocco)

AbstractThe impact of the wastewater input of Médiouna agglomeration (southeastern area of Casablanca) on the diatom flora and water quality of Oued Hassar stream (Morocco) was studied from July 1997 to August 1998. This wastewater effluent, which was highly loaded with ammonia, orthophosphates and organic matters, had disturbed the diatom assemblages structure and water quality of this stream.The study of the epilithic algal assemblages revealed the presence of 130 taxa of diatoms, 21 of which, according to the available literature, were recorded for the first time in the Moroccan inland waters. Almost all the latter taxa are mesohalobic or oligohalobic-indifferent. Nitzschia inconspicua Grun. was the most abundant species (47.7%) and grows particularly at the source of the stream. Navicula subminuscula Manguin, Nitzschia capitellata Hust. and Nitzschia desertorum Hust. have their dominance in the highly polluted zones, especially downstream the wastewater input

Study of the Effect of Poor Quality Irrigation Water on Soil Chemical Properties

Agronom

Method to link data in 3D environment

The aim of this work is to discuss a novel method to access information through an interactive 3D model that has has a connection to places in the real world. This information can be textual (historical, artistic and architectural), photographic (textures, views, plans) and spatial (3D data). The geographical aspects introduce some complexities, but they allow a common and uniform access to the data. The proposed method links information to extended zones of the 3D space and can be used with 3D models that are not subdivided in logical zones, like meshes generated by 3D scanners. The use of an intuitive ranking function lets one find the relevant information by just “looking around”. The possibility to acquire, process and analyse geographic information without the need for installing proprietary GIS software or having deep GIS knowledge has been taken into account in this work, so as to make information more accessible to a larger audience. The method is applied on two case studies: the Napoleone Square in Lucca (Italy) and the crypt of the Cathedral of St. Servatius in Quedlinburg (Sachsen-Anhalt, Germany). In the case in Quedlinburg we wanted to integrate the data produced in the last seven years, during an important investigation and conservation program, that has used extensively GIS format as documentation tool

Chefs’ Perspectives of Failures in Foodservice Kitchens, part 2: A phenomenological Exploration of the Consequences and Handling of Food Production Failure

This paper explores the consequences of food production failure (FPF) and its handling in foodservice operations from the perspective of chefs. A phenomenological epistemology and qualitative methodology were followed. Fifteen semi-structured interviews with chefs working in independent restaurants and hotels were carried out using purposive sampling, and employing an emic posture. Interviews were transcribed verbatim, read repetitively, and coded. Thematic analysis yielded themes on the consequences of FPF, on operation and staff, handling failures with kitchen staff, front of the house (FOH), and management. The findings revealed that the major ramification of FPF is financial through food loss. Representing both internal and external failure costs, FPF costs were classified into four tangible types: bin cost, rework cost, lost sales cost, and recovery cost. However, the serious intangible cost of staff demoralization was also identified. Handling failure is a complex task involving different parties and the management of various emotions (anger, frustration, etc.). Furthermore, the phenomena of failure ownership, secrecy, and historic marginalization of chefs, coupled with doubts over management competency, can all obstruct learning from mistakes, the much-cherished by product of FPF, thereby negating the notion of the “learning organization.” Moreover, error management training (EMT) seems to be a potential approach to combat FPF

Chefs’ Perspectives of Failures in Foodservice Kitchens, Part 1: A phenomenological exploration of the concepts, types, and causes of food production failure

Customers visit restaurants for varying reasons ranging from utilitarian – to satisfy hunger – to hedonistic – displaying cultural capital (Bourdieu, 1984) more recently theorized as culinary capital (Naccarato & Lebesco, 2012). Restaurants are even more significant in the new ‘experience economy’ (Pine & Gilmore, 1998) where lunch or dinner are conceptualized as ‘meal experiences.’ There is widespread acceptance of the pivotal role (about 33% of tourist spend) that food now plays in the tourism product of any country (Quigley et al., 2019)

Qualifying Human Resources for Building a Knowledge Economy in Arab Countries through Continuing Education

The study aimed at finding a strategy for qualifying human resources in Arab countries in order to fulfill the requirements for building the knowledge economy in those countries. The study also discussed the concept of the knowledge economy, its requirements, its availability in the Arab countries, and the role of continuing education as a tool for the development of human resources which represents one of the requirements of building a knowledge economy. In light all this, the study proposed a future strategy for building a knowledge economy in Arab countries by activating the role of continuing education. The study used descriptive, critical, and analytical approaches to achieve the study objectives