9,119 research outputs found
[Letter from V. C. Perini, Jr. to T. N. Carswell - October 6, 1948]
No full textA letter addressed to Mr. T. N. Carswell, Abilene, Texas from V. C. Perini, Jr., President, West-Central Texas Oil & Gas Ass'n dated October 6, 1948. An invitation to the Chuck Wagon Luncheon to be held on the day of the J. C. Hunter Memorial Building dedication
Multi-material bronze-steel plain bearings produced by laser-directed energy deposition
No full textPurpose: This study aims to manufacture bimetallic bearings by achieving a sound deposition of bronze. Indeed, systems with rotating components use parts that reduce friction by allowing them to rotate freely. This is typically achieved with either rolling bearings or plain bearings. The last ones are usually made of self-lubricating materials, which may not excel in mechanical properties. An interesting alternative lies in bimetallic brass bearings, like bronze-steel combinations. However, they are limited in terms of available shapes and sizes due to challenges associated with the conventional manufacturing process. Design/methodology/approach: This study addresses the problems of mechanical weakness and production limitations of conventional brass bearings by introducing the use of Hybrid Manufacturing techniques: Laser Directed Energy Deposition technology in combination with five-axis milling. Specifically, Cu89Sn11 was deposited on a C45 substrate by varying the number of layers, and based on the results obtained, two kinds of bimetallic bearings were produced. Findings: The results of the one, two and five-layers samples indicate a sound deposition of Cu89Sn11, without defects such as detachments, cracks or porosities. The microhardness profile shows a decreasing trend from the substrate to the deposition zones. Bending and adhesion tests confirmed the excellent material bonding. Five-layers of Bronze were deposited on a C45 substrate to fabricate hemispherical and flat-face bearings. Originality/value: This study validates the feasibility of expanding the new class of 3D-printed high-performance materials, highlighting the advantages of additive manufacturing technologies, such as the design and material mixing freedom, by manufacturing two kinds of bimetallic bearings
Developing a synthetic index of land vulnerability to drought and desertification
No full textThis paper develops an index of the vulnerability of land to drought and desertification (LVI) for Italy. The index takes into account changes in climate, land use, vegetation cover, soil properties, and population during the period 1990-2000. The LVI was built up through a multivariate approach aimed at assessing the importance of the various indicators included in the synthetic index. Increasing land vulnerability was observed during this time, especially in dry areas of the southern regions. This is interpreted as a consequence of land management practices, agricultural intensification, population pressure, and bio-physical degradation. The LVI can be used in an integrated, decision-support system to evaluate the impact of mitigation policies in rural environments. © Journal compilation © 2009 Institute of Australian Geographers
Comparative experimental approach to investigate the thermal behaviour of vertical greened façades of buildings
No full textGreening the building envelope is not a new concept, however it has not been fully approved as an energy saving method for the built environment. Vertical green can provide a cooling potential on the building surface, as plants are functioning as a solar filter and prevent the adsorption of heat radiation of building materials extensively. In this study a comparative thermal analysis of vertical green attached to a façade element is presented. An experimental set up (stationary conditions) has been developed to measure the temperature gradient through a reference cavity wall, in order to quantify the contribution of vegetation to the thermal behaviour of the building envelope. The results show temperature differences between the bare wall and between the different vertical greening systems analysed, up to 1.7 °C for the direct greening system and 8.4 °C for the living wall system based on planter boxes after 8 h of heating for summer conditions, due to the different “material” layers involved. However, the insulation material of the bare wall moderates the prevailing temperature difference between the outside and inside climate chamber, resulting in no temperature difference for the interior climate chamber for summer conditions.Materials and Environmen
Sostenibilità dell’agricoltura, fattori di pressione e sensibilità alla desertificazione in Italia – un indicatore multidimensionale a livello comunale
No full textLos Partidos Polìticos
No full textEsame dei principi costituzionali messicani e della giurisprudenza del TEPJF in materia di partiti politic
L’AMICO DI GELLIO (E DI ALTRI AMICI): su "Le Muse in gioco" di Giorgio Bernardi Perini
No full textThis paper carefully examines the rich book that Giorgio Bernardi Perini
aims to present as «his farewell work». The author has collected his verse
translations of Latin works that frequently feature as art re-writings of
ancient originals. As well as such «sovrascritture», or «overwritings» as Bernardi
Perini himself defines them, the collection shows occasional poems and
short memoirs linked to some of the most relevant friend relations the writer
has had throughout a culturally committed life. The review high-lights some
of the most refined and poetical features that make the work not just a
farewell but the first of new contributions that will make our relationship
with the past more valuable and richer in humanity
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