Electron stimulated desorption of atomic oxygen from silver

The electron stimulated desorption (ESD) of neutral oxygen atoms from polycrystalline silver and of oxygen ions from Ag(110) has been studied. Polycrystalline Ag charged with (16)O2 and (18)O2 and bombarded by low-energy electrons (approx 100 eV) under ultrahigh vacuum (UHV) conditions emitted O atom flux levels of 1 x 10 to the 12th power/sq cm/s at a Ag temperature of 300 C. The flux was detected with a quadrupole mass spectrometer operating in the appearance potential mode. The neutral cross section at about 100 C was determined to be 7 x 10 to the -19 sq cm. Ancillary experiments conducted in a UHV chamber equipped with a cylindrical mirror analyzer and rigged for ion energy distribution and ion angular distribution were used to study O ions desorbed from Ag(110). Two primary O(+) energies of 2.4 and 5.4 eV were detected from the Ag(110) after having been dosed with 2500 L of (16)O2. It also appears that in both experiments there was strong evidence for directionality of the emitted flux. The results of this study serve as a proof of concept for the development of a laboratory atomic oxygen beam generator that simulates the gas flux environment experienced by orbiting vehicles

Life safety assessment in multi-storey building fires

Life safety is one of the most important objectives of Performance Based Fire-Design and is commonly considered to be achieved if building occupants escape the effects of the fire unharmed. Numerical simulations are often used to predict fire dynamics and factors affecting the evacuation capabilities of occupants. The main scope of this research is to assess life safety in a multi-storey building fire. Statistics based fire risk assessment is used to choose the scenario to be simulated taking into consideration the damage severity and likelihood of occurrence. In the fire simulations, particular attention is given to the fuel modelling to consider the toxicity of combustion products and thus, its effects on the building occupants. Fire simulations results are then integrated with evacuation simulations. The fire risk assessment and fire/evacuation simulations are performed for a multi-storey hotel building located in Lecce, Italy

A BIM-Based Framework to Visually Evaluate Circularity and Life Cycle Cost of buildings

The Circular Economy paradigm seeks to shift products and systems from linear to “closed loop” life cycles applying specific business models and strategies to their designs and lifelines. The implementation of the circular economy in buildings depends on the efforts made by all the stakeholder involved in the life cycle of a building, where it can draw most of the benefits if the application of a circular business model is planned during the design phases. Building Information Modelling is an approach that helps designers in creating and managing semantically rich 3D-models describing the status of the building over its life cycle. In this paper, a BIM-based framework for evaluating the application of circular business models of buildings from the circularity and the life cycle cost points of views is proposed

From CO2 to Cell: Energetic Expense of Creating Biomass Using the Calvin-Benson-Bassham and Reductive Citric Acid Cycles Based on Genomic Data

Abstract The ubiquity of the Calvin-Benson-Bassham cycle (CBB) amongst autotrophic organisms suggests that it provides an advantage over a wide range of environmental conditions. However, in some habitats, such as hydrothermal vents, the reductive citric acid cycle (rCAC) is an equally predominant carbon fixation pathway. It has been suggested that the CBB cycle poses a disadvantage under certain circumstances due to being more energetically demanding compared to other carbon fixation pathways. The purpose of this study was to compare the relative metabolic cost of cell biosynthesis by an autotrophic cell using either the CBB cycle or the rCAC. For both pathways, the energy, in ATP, required to synthesize the macromolecules (DNA, RNA, protein, and cell envelope) for one gram of biomass was calculated, beginning with CO2. Two sulfur-oxidizing chemolithoautotrophic proteobacteria, Thiomicrospira crunogena XCL-2, and Sulfurimonas autotrophica were used to model the CBB cycle and rCAC, respectively while Escherichia coli was used to model both pathways because it has had its cell composition extremely well-characterized. Since these organisms have had their genomes sequenced, it was possible to reconstruct the biochemical pathways necessary for intermediate and macromolecule synthesis. Prior estimates, based solely on the ATP cost of pyruvate biosynthesis, suggested that the cellular energetic expense for biosynthesis from the CBB cycle was more than that from the rCAC. The results of this study support this conclusion; however the difference in expense between the two pathways may not be as extreme as suggested by pyruvate synthesis. Other factors, such as oxygen sensitivity, may act in concert with energetic expense in contributing to the selective advantages between different autotrophic carbon fixation pathways

Balancing exploration and exploitation in public management: Proposal for an organizational model

Over the last 30 years, a wave of reforms has reshaped the panorama of public administrations around the world, which have also stimulated debates on the subject reform in public sector relations. Much research has focused on discussing the validity of New Public Management (NPM) as a paradigm, including the recognition of regional versions of a number of universal problems in the Public Governance, NPM, and Public Value areas. This debate is focused on the need to give concrete answers to the new management needs of policy makers and to the growing demands of citizens. Increasingly public administration is based on meeting two needs: society requires creative, flexible, and innovation-oriented approaches, whilst economic pressures and budget cuts are forcing uses and models oriented toward efficiency, competitiveness, and cost savings. As regard the changing requirements of the public government, the new organizational system needs to incorporate the creativity, innovation capacity, and flexibility necessary to achieve sustainability and public value. The purpose of this research is to offer an organizational model, which balances exploration activities with those of exploitation, thus being able to meet the changing needs within the Administration, and the actions envisaged for its operations. This article also introduces the requirements for a decision support system to measure regional performance and service quality. It is hoped that we add to our knowledge and understanding of coordinated public policy and good governance that is effective even in these radically demanding Covid-19 times

Application of Technological System Based on Processes Modelling and Analysis: A Case Study in Italian Aquaculture Company

In recent years, cause of several scandals and incidents in agrifood context, consumer awareness about food product increased. That evolution of the consumer triggers new demand about transparency/accountability by the market. Food industry can face the emerging issues considering traceability principles. A traceability system could support the food companies to maneuver in the complex network of the supply chain and, simultaneously, to answer to the new consumer and market needs. In this work a theoretical approach based on business process modelling was proposed and tested in a real case study. Through an interview and using BPMN technique, the cherry cultivation process of a food companies was modelled. Each activities and actors involved in cultivation was identified in order to detect data stored in different source and format. These data could be strategical if elaborated and transmitted to different stakeholder of the supply chain

A Imigração Alemã na Literatura Brasileira: uma breve análise

O artigo propõe uma análise da passagem do imigrante alemão na literatura brasileira, com o intuito de observar a capacidade da literatura em registrar e representar aspectos históricos e aspectos socioculturais que condicionam comportamentos assumidos pela sociedade em determinadas épocas. Adiante, serão destacadas quatro obras, que serão brevemente analisadas, que retratam a imigração alemã, o que proporcionará uma conceituação mais prática da análise efetuada inicialmente e do percurso da imigração alemã na literatura brasileira: “Canaã” (Graça Aranha, 1905), “O Continente” (Erico Verissimo, 1949), “A Ferro e Fogo” (Josué Guimarães, 1972) e “Videiras de Cristal” (Luiz Antonio de Assis, 1990