403 research outputs found
Estimation of Capital Matrices for Multisectoral Models: An Application to Italy and Tuscany
This paper refers to the Tuscany case study which constitutes a systems analysis of integrated regional development in the Tuscany region. A core of this study is the development of applied models and methods undertaken by the Regional Development Group at IIASA, in collaboration with the Regional Institute for Economic Planning of Tuscany (IRPET). A bi-regional input-output model has a central part in the system of model development. In order to capture the dynamic process of capacity creation and removal, the capital formation has to be included into the input-output framework in a systematic way. This presupposes an estimation of capacity change and of capital coefficient matrices.
This paper presents a systematic approach to obtain these estimates, also in the case where only a limited set of data is available. In summary, the method combines a vintage type production theory and an estimation technique based on information theory
Distinguishing between yield advances and yield plateaus in historical crop production trends
Food security and land required for food production largely depend on rate of yield gain of major cereal crops. Previous projections of food security are often more optimistic than what historical yield trends would support. Many econometric projections of future food production assume compound rates of yield gain, which are not consistent with historical yield trends. Here we provide a framework to characterize past yield trends and show that linear trajectories adequately describe past yield trends, which means the relative rate of gain decreases over time. Furthermore, there is evidence of yield plateaus or abrupt decreases in rate of yield gain, including rice in eastern Asia and wheat in northwest Europe, which account for 31% of total global rice, wheat and maize production. Estimating future food production capacity would benefit from an analysis of past crop yield trends based on a robust statistical analysis framework that evaluates historical yield trajectories and plateaus
Distinguishing between yield advances and yield plateaus in historical crop production trends
Food security and land required for food production largely depend on rate of yield gain of major cereal crops. Previous projections of food security are often more optimistic than what historical yield trends would support. Many econometric projections of future food production assume compound rates of yield gain, which are not consistent with historical yield trends. Here we provide a framework to characterize past yield trends and show that linear trajectories adequately describe past yield trends, which means the relative rate of gain decreases over time. Furthermore, there is evidence of yield plateaus or abrupt decreases in rate of yield gain, including rice in eastern Asia and wheat in northwest Europe, which account for 31% of total global rice, wheat and maize production. Estimating future food production capacity would benefit from an analysis of past crop yield trends based on a robust statistical analysis framework that evaluates historical yield trajectories and plateaus
Sodium lactate solutions characterization using Electrochemical Impedance Spectroscopy
Lactate is an important metabolite in human body and, among possible medical applications, it can be used to monitor physical activity. Actually, its concentration represents a clear indication whether optimal training intensity is kept or if muscles are under anaerobic conditions. Routine procedures to measure lactate concentration during physical activity are represented by invasive measurements, which require blood sampling from the patient or the athlete. So, a great advantage would be derived by the possibility to monitor this analyte using non-invasive techniques. Considering the possibility to measure lactate in human sweat during sport activities, this paper presents the characterization of saline aqueous solutions containing sodium lactate by means of Electrochemical Impedance Spectroscopy (EIS). Measurements were performed using a two-electrode electrochemical cell and acquired spectra were analyzed also by means of equivalent electrical circuit (EEC) modeling. Results show an effect due to lactate concentration on solution impedance in the high-frequency region of spectrum, where a change in solution resistance is measured. At the same time, no changes in the measured capacitance were found. Future work will study the electrochemical behavior of lactate solutions also at higher frequencies to further investigate the possible use of EIS for lactate levels monitoring during sport activities
Environmental monitoring solution for cultural heritage
Environmental monitoring is crucial factor in the safeguard and conservation of the cultural heritage. Unsuitable environmental conditions can easily accelerate the degradation of several materials and, as consequence, damage the stored artifacts. Moreover, environmental conditions can easily change in an unpredictable way and, therefore, the employment of an environmental monitoring system is mandatory in almost all locations, including museums, storage rooms and outdoor exhibitions. This paper tries to explain the main constraints required for environmental monitoring in the cultural heritage field. Moreover, a novel distributed monitoring system, developed at Politecnico di Torino, is described and compared to several solutions that are commercially available. The proposed solution demonstrated excellent characteristics which satisfy the requirements of environmental monitoring in the cultural heritage at a very competitive cost
A low-cost automatic acquisition system for photogrammetry
Photogrammetry is a non-destructive technique commonly employed in the cultural heritage field for reconstructing a 3D virtual replica of an artifact by simply taking several photos of the artifact itself from different points of view. The 3D model can be used either for documenting the artifact or for preserving its geometrical information and appearance. Moreover, by using a digital 3D model is extremely easy sharing information with the public and researchers without physically moving the artifact, and this represents a unique opportunity which cannot be achieved with traditional methods. Unfortunately most systems already present on the market are complex and costly both due to their hardware and software. This paper presents a novel acquisition system which is extremely cheap and can be easily arranged in any conservation laboratory. The solution is based on a simple acquisition system designed with the aim of providing researchers with a user-friendly and low-cost platform for the reconstruction of an artifact 3D model. The proposed system can be virtually interfaced to every commercial camera and can be integrated with several 3D reconstruction software. As an example, the authors employed a free open-source software referred to as Meshroom
Corrosion prediction of metallic cultural heritage assets by EIS
Electrochemical Impedance Spectroscopy (EIS) was used to predict corrosion behaviour of metallic Cultural Heritage assets in two monitoring campaigns: 1) an iron bar chain exposed indoor from over 500 years in the Notre Dame Cathedral in Amiens (France); and 2) a large weathering steel sculpture exposed outdoor from tens of years in Ferrara (Italy). The EIS portable instrument employed was battery operated. In situ EIS measurements on the iron chain could be used to investigate the phenomena involved in the electrochemical interfaces among various corrosion products and assess and predict their corrosion behaviour in different areas of the Cathedral. Meanwhile, the sculpture of weathering steel, like most outdoor artefacts, showed rust layers of different chemical composition and colour depending on the orientation of metal plates. The EIS monitoring campaign was carried out on different areas of the artefact surface, allowing assessment of their protective effectiveness. Results of EIS measurements evidenced how employing a simple test that could be performed in situ without damaging the artefacts surface is possible to quickly gain knowledge of the conservation state of an artefact and highlight potential danger conditions
Input-Output Modeling: Proceedings of the Third IIASA Task Force Meeting
The papers in this volume fall into two groups: the first deals with the linkage of input-output models and describes several models that are now ready to be linked, while the second concentrates on the analysis of structural change as well as reporting recent developments in the INFORUM group of models. Some of the papers in the first group examine the linkage of seven national models using the INFORUM international trade model, the development of a linked system for modeling the small open economies of the Nordic countries, and the definition of an appropriate international scenario for a single national model. Others discuss problems of disaggregation, the relationship between regional and national models, and the role of input-output models as policy-making tools. The section closes with papers on national models for Poland and Finland and a report describing the price-income block of the advanced US INFORUM model. The second group opens with analyses of factor inputs and of energy-economy interactions. It continues with suggestions on how to develop consistent dynamic input-output models using poor data bases and describes how an input-output model can be used to derive aggregate characteristics of probable future structural change. Further papers are devoted to changes in technical coefficients, the development of effective national models using limited or inconsistent data bases, and estimation techniques. The volume closes with a "system for systems design" for use in input-output related work
Properties of potential eco-friendly gas replacements for particle detectors in high-energy physics
Gas detectors for elementary particles require F-based gases for optimal performance.
Recent regulations demand the use of environmentally unfriendly F-based gases to be limited or
banned. This work studies properties of potential eco-friendly gas replacements by computing the
physical and chemical parameters relevant for use as detector media, and suggests candidates to be
considered for experimental investigation
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