468 research outputs found
Persistent integrality: product architecture and inter-firm coordination in the auto industry
Not Doomed to Death: A Map of Small Firms' Business Models in the Italian Textile Apparel Industry
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A Scientific Approach to Entrepreneurial Decision Making: Large Scale Replication and Extension
This paper runs a large-scale replication of Camuffo et al. (2020), involving 759 firms in four randomized control trials. The larger sample generates novel and more precise insights about the teachability and implications of a scientific approach in entrepreneurship. We observe a positive impact on idea termination and results that are consistent with a non-linear effect on radical pivots, with treated firms running few over no or repeated pivots. We provide a theoretical interpretation of the empirical results: the scientific approach enhances entrepreneurs' efficiency in searching for viable ideas and raises their methodic doubt because, like scientists, they realize that there may be alternative scenarios from the ones that they theorize
Evidences for a quasi 60-year North Atlantic Oscillation since 1700 and its meaning for global climate change
The North Atlantic Oscillation (NAO) obtained using instrumental and
documentary proxy predictors from Eurasia is found to be characterized by a
quasi 60-year dominant oscillation since 1650. This pattern emerges clearly
once the NAO record is time integrated to stress its comparison with the
temperature record. The integrated NAO (INAO) is found to well correlate with
the length of the day (since 1650) and the global surface sea temperature
record HadSST2 and HadSST3 (since 1850). These findings suggest that INAO can
be used as a good proxy for global climate change, and that a 60-year cycle
exists in the global climate since at least 1700. Finally, the INAO ~60-year
oscillation well correlates with the ~60- year oscillations found in the
historical European aurora record since 1700, which suggests that this 60-year
dominant climatic cycle has a solar-astronomical origin
Western Mediterranean precipitation over the last 300Â years from instrumental observations
Microclimate monitoring of Ariadne's house (Pompeii, Italy) for preventive conservation of fresco paintings
Background: Ariadne's house, located at the city center of ancient Pompeii, is of great archaeological value due to the fresco paintings decorating several rooms. In order to assess the risks for long-term conservation affecting the valuable mural paintings, 26 temperature data-loggers and 26 relative humidity data-loggers were located in four rooms of the house for the monitoring of ambient conditions. Results: Data recorded during 372 days were analyzed by means of graphical descriptive methods and analysis of variance (ANOVA). Results revealed an effect of the roof type and number of walls of the room. Excessive temperatures were observed during the summer in rooms covered with transparent roofs, and corrective actions were taken. Moreover, higher humidity values were recorded by sensors on the floor level. Conclusions: The present work provides guidelines about the type, number, calibration and position of thermohygrometric sensors recommended for the microclimate monitoring of mural paintings in outdoor or semi-confined environments. © 2012 Merello et al.; licensee Chemistry Central Ltd.This work was partially supported by the Spanish Government (Ministerio de Ciencia e Innovacion) under projects HAR2010-21944-C02-01 and HAR2010-21944-C02-02.Merello Giménez, P.; GarcÃa Diego, FJ.; Zarzo Castelló, M. (2012). Microclimate monitoring of Ariadne's house (Pompeii, Italy) for preventive conservation of fresco paintings. Chemistry Central Journal. 6:145-161. https://doi.org/10.1186/1752-153X-6-145S1451616Ribera A, Olcina M, Ballester C: Pompeya Bajo Pompeya, las Excavaciones en la Casa de Ariadna. Valencia: Fundación MARQ; 2007.World Monuments Fund: World Monuments Watch: 100 Most Endangered Sites. New York: World Monuments Fund; 1996.Anter KF: Colours in Pompeiian cityscape: Adding pieces to the puzzle. Color Res Appl 2006,31(4):331–340.Harris J: Protecting Pompeii and the Italian heritage in 2012. http://www.i-italy.org/bloggers/18935/protecting-pompeii-and-italian-heritage-2012Augusti S: La Tecnica Dell’antica Pittura Parietale Pompeiana. Napoli: Gaetano Macchiaroli Editore; 1950.Miriello D, Barca D, Bloise A, Ciarallo A, Crisci GM, De Rose T, Gattuso C, Gazineo F, La Russa MF: Characterisation of archaeological mortars from Pompeii (Campania, Italy) and identification of construction phases by compositional data analysis. J Arch Sci 2010, 37:2207–2223.Castriota M, Cosco V, Barone T, De Santo G, Carafa P, Cazzanelli E: Micro-Raman characterizations of Pompei’s mortars. J Raman Spectrosc 2008,39(2):295–301.Maguregui M, Knuutinen U, Castro K, Madariaga JM: Raman spectroscopy as a tool to diagnose the impact and conservation state of Pompeian second and fourth style wall paintings exposed to diverse environments (House of Marcus Lucretius). J Raman Spectrosc 2010,41(11):1400–1409.Genestar C, Pons C, Más A: Analytical characterisation of ancient mortars from the archaeological Roman city of Pollentia (Balearic Islands, Spain). Anal Chim Acta 2006, 557:373–379.Duran A, Perez-Maqueda LA, Poyato J, Perez-Rodriguez JL: A thermal study approach to roman age wall painting mortars. J Therm Anal Calorim 2010,99(3):803–809.Pérez MC, GarcÃa Diego F-J, Merello P, D’Antoni P, Fernández Navajas A, Ribera Lacomba A, Ferrazza L, Pérez Miralles J, Baró JL, Merce P, D’Antoni H, Curiel Esparza J: Ariadne’s house (Pompeii, Italy) wall paintings: a multidisciplinary study of its present state focused on a future restoration and preventive conservation. Mater Constr in pressBernardi A: Microclimate in the British Museum. London. Museum Manag Curat 1990, 9:169–182.Bernardi A, Camuffo D: Microclimate in the Chiericati Palace Municipal Museum. Vicenza. Museum Manag Curat 1995, 14:5–18.Camuffo D, Bernardi A, Sturaro G, Valentino A: The microclimate inside the Pollaiolo and Botticelli rooms in the Uffizi Gallery. Florence. J Cult Herit 2002, 3:155–161.La Gennusa M, Rizzo G, Scaccianoce G, Nicoletti F: Control of indoor environments in heritage buildings: Experimental measurements in an old Italian museum and proposal of a methodology. J Cult Herit 2005,6(2):147–155.Camuffo D, Sturaro G, Valentino A: Thermodynamic exchanges between the external boundary layer and the indoor microclimate at the Basilica of Santa Maria Maggiore, Rome, Italy: the problem of conservation of ancient works of art. Bound Lay Meteorol 1999, 92:243–262.Tabunschikov Y, Brodatch M: Indoor air climate requirements for Russian churches and cathedrals. Indoor Air 2004,14(Suppl 7):168–174.Loupa G, Charpantidou E, Kioutsioukis I, Rapsomanikis S: Indoor microclimate, ozone and nitrogen oxides in two medieval churches in Cyprus. Atmos Environ 2006, 40:7457–7466.Vuerich E, Malaspina F, Barazutti M, Georgiadis T, Nardino M: Indoor measurements of microclimate variables and ozone in the church of San Vincenzo (Monastery of Bassano Romano – Italy): a pilot study. Microchem J 2008, 88:218–223.GarcÃa-Diego F-J, Zarzo M: Microclimate monitoring by multivariate statistical control: the renaissance frescoes of the cathedral of valencia (Spain). J Cult Herit 2010,11(3):339–344.Zarzo M, Fernández-Navajas A, GarcÃa-Diego F-J: Long-term monitoring of fresco paintings in the Cathedral of Valencia (Spain) through humidity and temperature sensors in various locations for preventive conservation. Sensors 2011,11(9):8685–8710.Maekawa S, Lambert F, Meyer J: Environmental monitoring at Tiwanaku. Mater Res Soc Symp Proc 1995, 352:885–892.Lillie M, Smith R, Reed J, Inglis R: Southwest Scottish Crannogs: using in situ studies to assess preservation in wetland archaeological contexts. J Archaeol Sci 2008,35(7):1886–1900.Verdecchia F, Zoccatelli C, Norelli E, Miandro R: Integrated monitoring network for surface deformation in Capo Colonna archaeological area, Crotone. Italy. IAHS-AISH P 2010, 339:345–351.Nava S, Becherini F, Bernardi A, Bonazza A, Chiari M, GarcÃa-Orellana I, Lucarelli F, Ludwig N, Migliori A, Sabbioni C, Udisti R, Valli G, Vecchi R: An integrated approach to assess air pollution threats to cultural heritage in a semi-confined environment: the case study of Michelozzo’s Courtyard in Florence (Italy). Sci Total Environ 2010,408(6):1403–1413.Hygrochron Temperature/Humidity Logger iButton with 8KB Data-Log Memory. Maxim Integrated Products. http://datasheets.maxim-ic.com/en/ds/DS1923.pdfTemperature Logger iButton with 8KB Data-Log Memory. Maxim Integrated Products. http://datasheets.maxim-ic.com/en/ds/DS1922L-DS1922T.pdfVisco G, Plattner SH, Fortini P, Di Giovanni S, Sammartino MP: Microclimate monitoring in the Carcer Tullianum: temporal and spatial correlation and gradients evidenced by multivariate analysis; first campaign. Chem Cent J 2012,6(Suppl 2):S11.UNI 10829: Works of Art of Historical Importance. Ambient Conditions for the Conservation. Measurement and Analysis. Milano: UNI Ente Nazionale Italiano di Unificazione; 1999.DM 10/2001: Atto di Indirizzo sui Criteri Tecnico-scientifici e Sugli Standard di Funzionamento e Sviluppo dei Musei. Ministero per i Beni e le Attività Culturali. Gazzeta Ufficiale della Repubblica Italiana (Official Bulletin of Italian Republica), Rome (Italy); 2001. DL 112/1998 art. 150 comma 6Camuffo D: Microclimate for Cultural Heritage. Amsterdam: Elsevier Science; 1998.ASTM E 104–02: Standard Practice for Maintaining Constant Relative Humidity by Means of Aqueous Solutions. West Conshohocken, PA: ASTM Intl; 2012.Statgraphics Software. http://www.statgraphics.ne
Influence of environment on the corrosion of glass–metal connections
'Glass sensors' of the eighteenth century Backer glass and the sixteenth century enamel from Limoges have been chosen for a series of experiments. Combinations of these materials with different base materials such as copper and bronze has been investigated. To create surface changes on the 'glass sensor', a corrosion process was induced in a controlled environment. A variety of corrosive agents such as hydrochloric acid, sulfuric acid, water and formaldehyde were used. The sample immersed in the corrosive solution was exposed alternately to light and high temperature for a total of 38 weeks. During this period, macroscopic and microscopic observations were made and series of tests such as SEM/EDS and Raman spectroscopy were performed on the surface of the samples. ICP-MS methods were used to determine the change in the chemical composition of the solutions where the samples had corroded. The primary aim of this study was to identify the impact of a number of external corrosive variables such as temperature, humidity and local environment to identify the most damaging environments for glass–metal objects. The obtained results showed the chemical and physical phenomena acting on the surface of the glass, metal or in the place of their joints. Information obtained on this study was used to explain the influence of the environment on the surface of glass–metal materials. Results can be used in the design of conservation work as well as for sustainable conservation
Preservation of York Minster historic limestone by hydrophobic surface coatings
Magnesian limestone is a key construction component of many historic buildings that is under constant attack from environmental pollutants notably by oxides of sulfur via acid rain, particulate matter sulfate and gaseous SO 2 emissions. Hydrophobic surface coatings offer a potential route to protect existing stonework in cultural heritage sites, however, many available coatings act by blocking the stone microstructure, preventing it from 'breathing' and promoting mould growth and salt efflorescence. Here we report on a conformal surface modification method using self-assembled monolayers of naturally sourced free fatty acids combined with sub-monolayer fluorinated alkyl silanes to generate hydrophobic (HP) and super hydrophobic (SHP) coatings on calcite. We demonstrate the efficacy of these HP and SHP surface coatings for increasing limestone resistance to sulfation, and thus retarding gypsum formation under SO/H O and model acid rain environments. SHP treatment of 19th century stone from York Minster suppresses sulfuric acid permeation
Carbonyl compounds indoors in a changing climate
<p>Abstract</p> <p>Background</p> <p>Formic acid, acetic acid and formaldehyde are important compounds in the indoor environment because of the potential for these acids to degrade calcareous materials (shells, eggs, tiles and geological specimens), paper and corrode or tarnish metals, especially copper and lead. Carbonyl sulfide tarnishes both silver and copper encouraging the formation of surface sulfides.</p> <p>Results</p> <p>Carbonyls are evolved more quickly at higher temperatures likely in the Cartoon Gallery at Knole, an important historic house near Sevenoaks in Kent, England where the study is focused. There is a potential for higher concentrations to accumulate. However, it may well be that in warmer climates they will be depleted more rapidly if ventilation increases.</p> <p>Conclusions</p> <p>Carbonyls are likely to have a greater impact in the future.</p
Evaluation of corrective measures implemented for the preventive conservation of fresco paintings in Ariadne s house (Pompeii, Italy)
BACKGROUND:
A microclimate monitoring study was conducted in 2008 aimed at assessing the conservation risks affecting the valuable wall paintings decorating Ariadne s House (Pompeii, Italy). It was found that thermohygrometric conditions were very unfavorable for the conservation of frescoes. As a result, it was decided to implement corrective measures, and the transparent polycarbonate sheets covering three rooms (one of them delimited by four walls and the others composed of three walls) were replaced by opaque roofs. In order to examine the effectiveness of this measure, the same monitoring system comprised by 26 thermohygrometric probes was installed again in summer 2010. Data recorded in 2008 and 2010 were compared.
RESULTS:
Microclimate conditions were also monitored in a control room with the same roof in both years. The average temperature in this room was lower in 2010, and it was decided to consider a time frame of 18 summer days with the same mean temperature in both years. In the rooms with three walls, the statistical analysis revealed that the diurnal maximum temperature decreased about 3.5 ºC due to the roof change, and the minimum temperature increased 0.5 ºC. As a result, the daily thermohygrometric variations resulted less pronounced in 2010, with a reduction of approximately 4 ºC, which is favorable for the preservation of mural paintings. In the room with four walls, the daily fluctuations also decreased about 4 ºC. Based on the results, other alternative actions are discussed aimed at improving the conservation conditions of wall paintings.
CONCLUSIONS:
The roof change has reduced the most unfavorable thermohygrometric conditions affecting the mural paintings, but additional actions should be adopted for a long term preservation of Pompeian frescoes.This work was partially supported by the Spanish Government (Ministerio de Ciencia e Innovacion) under projects HAR2010-21944-C02-01 and HAR2010-21944-C02-02.Merello Giménez, P.; GarcÃa Diego, FJ.; Zarzo Castelló, M. (2013). Evaluation of corrective measures implemented for the preventive conservation of fresco paintings in Ariadne s house (Pompeii, Italy). Chemistry Central Journal. 7(1):87-87. doi:10.1186/1752-153X-7-87S878771DELOSRIOS, A., CAMARA, B., GARCIADELCURA, M., RICO, V., GALVAN, V., & ASCASO, C. (2009). Deteriorating effects of lichen and microbial colonization of carbonate building rocks in the Romanesque churches of Segovia (Spain). Science of The Total Environment, 407(3), 1123-1134. doi:10.1016/j.scitotenv.2008.09.042Nava, S., Becherini, F., Bernardi, A., Bonazza, A., Chiari, M., GarcÃa-Orellana, I., … Vecchi, R. (2010). An integrated approach to assess air pollution threats to cultural heritage in a semi-confined environment: The case study of Michelozzo’s Courtyard in Florence (Italy). Science of The Total Environment, 408(6), 1403-1413. doi:10.1016/j.scitotenv.2009.07.03
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