Prikupljanje statističkih podataka međunarodnog turističkog prometa na otvorenom prostoru: metodologija i primjena - slučaj Regije Veneto

It is now generally acknowledged the need of collecting information on the expenditure behaviour of inbound tourists, which is crucial for estimating the macro-economic impact of tourism in an area (open or closed) in terms of GDP, employment and balance of payments. The survey on inbound tourist expenditure in the Veneto region here described represents the first step towards the development of a Regional Tourism Information System, useful not only for researchers but also for all public and private operators involved in tourism management, marketing and planning. The paper describes objectives, methodology and organisation of this survey, by providing the analytical framework for the systematic collection of data on characteristics and consumption behaviour of inbound tourists.Danas je opće poznata potreba za prikupljanjem informacija o potrošnji stranih turista, što je ključno za ocjenjivanje makroekonomskog utjecaja turizma na GDP, zaposlenost i bilancu plaćanja u jednom području (otvorenom ili zatvorenom). Prikaz istraživanja o potrošnji stranih turista u Regiji Veneto, koje je u radu prezentirano, predstavlja prvi korak prema razvoju informacijskog sustava same regije, koji ne samo daje koristan istraživačima i znanstvenicima nego i svim javnim i privatnim poduzetnicima turističkog menadžmenta, marketinga i planiranja. U radu su opisani ciljevi, metodologija i organizacija tog istraživanja, koje je dalo odgovarajući analitički okvir za sustavno prikupljanje podataka o karakteristikama i potrošnji stranih turista

Optimizing the Heat Treatment Process of Cast Aluminium Alloys

The influence of heat treatment process on the microstructure and mechanical properties, and the distortion of a low-pressure die-cast AlSi7Mg0.3 alloy is reported. This work is aimed at optimizing the whole heat treatment process, including solution heat treatment, quenching and artificial ageing, of A356 alloy wheels, produced by low pressure die casting. In particular, the optimization process is focused on reducing time and temperature of solution and ageing heat treatments, and on selecting the right quenching medium, reducing the distortion of A356 alloy 17-in and 18-in wheels and obtaining the required mechanical properties. The time and temperature of solution treatment are normally chosen to dissolve coarse \u3b2-Mg2Si phase coming from the solidification process, especially where the solidification rate is slow as in the thickest zones of wheel, e.g. the hub and the spoke regions. Generally, the time required is about 45 minutes at the temperature of 540\ub0C, which is the typical solution temperature used for A356-type alloy. More time is however required at this temperature to change the morphology of eutectic silicon particles. This is aimed to improve the mechanical properties, especially ductility and fatigue properties, of wheels after further artificial ageing. The solutionising temperature is here selected to reduce the time of the heat treatment and to avoid any type of incipient melting of the material within an industrial tunnel furnace. The quenching is the most critical step in the sequence of heat-treating operations. The objective of quenching is to preserve the solid solution formed at the solution heat-treating temperature, by rapidly cooling to some lower temperature, usually near the room temperature. The most rapid quench rate, giving the best mechanical properties, can also cause unacceptable amounts of distortion or cracking in components. This is particularly true for aluminium wheels where the different thickness throughout the casting can produce distortion higher than 2-3 mm, critics for subsequent machining operations. The optimization process is here focused on the quenching rate, which is varied by changing the temperature of the quenchant, in order to reduce the wheels\u2019 distortion and to guarantee the appropriated supersaturation level of atoms for subsequent ageing treatment. Therefore, the temperature of forced water, used as quenchant, has been varied in the range of 50 to 95\ub0C, and the distortion level and the hardness of the wheels systematically measured. A temperature of 95\ub0C is observed to be the optimum solution, but useless from an industrial point of view. The extreme vapour produced by the boiling water can compromise the automatism for handling of wheels and delay too much the cooling of the wheels after solutioning. Therefore, the best compromise between distortion and mechanical properties and productivity has been revealed to be at a temperature of 75\ub0C. The time and temperature of ageing are considered in the present work in order to reach an underageing temper of the material, which is typical for the manufacture of wheels to improve impact and fatigue properties. The influence of the different painting processes, generally carried out at a temperature of 180\uf7190\ub0C for several minutes after ageing and subsequent machining operations, have to be considered to determine the final mechanical properties. These temperatures are typical temperature for ageing treatment of cast aluminium alloys, such as the A356-type alloys. Therefore, the present study takes into account the painting temperatures and times to optimize the ageing treatment of the wheels, reaching the desired mechanical properties. This study develop an optimization approach of the whole heat treatment process of cast aluminium alloy wheels. The work evidences the typical problems and targets of wheels\u2019 producers, suggesting an integrated approach to improve the productivity and the quality of castings. Metallographic and image analysis techniques have been used to quantitatively examine the microstructural changes occurring during heat treatment; while hardness and tensile testing measurements have been carried out to monitor the evolution of the mechanical properties after each step of T6 heat treatment

Frozen mitochondria as rapid water quality bioassay

A rapid and relatively low cost bioassay, usable in routine screening water test has been developed modifying the beef heart mitochondria test. In our experiments, mitochondria (FM22) were frozen at 22 °C, instead of 80 °C (FM80), and their applicability and sensitivity was verified. The oxygen consumption was measured by a Clark elec- trode that was interfaced to a PC to collect test analysis data. Blank tests were carried out to verify the oxygen con- sumption linear fitting. Toxicity tests were performed using pure organic and inorganic compounds, such to verify the FM22 sensitivity. A piecewise regression, through an Excelâ Macro, identified the break-point in the oxygen con- sumption and calculated the toxicity. The IC50s of the tested compounds were calculated and ranged from 0.123 to 0.173 mg/l for heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) and from 0.572 to 10.545 mg/l for organics (benzene, DMSO, DDE, endrin, dichloromethane, chlorobenzene, 1,2-dichlorobenzene and 1,3-dichlorobenzene). Water effluent samples were then tested. The FM22 gave different toxic reactions to them. Water samples were characterised for heavy metals. The FM22 bioassay had a higher sensitivity than the FM80 and a high reproducibility in the toxicity test with pure compounds. The FM22 test was a good predictor of toxicity for water samples; the bioassay is easy, low cost and rapid, then usable for routine tests

Sourcing Hydrogen for the Production of Sustainable Aviation Fuels

Sustainable aviation fuels (SAFs) are the near-term technological solution to decarbonize the aviation industry sector. There are several pathways to obtain biojet fuels, which can be classified into four main categories, namely oil-to-jet, alcohol-to-jet, gas-to-jet, and sugar-to-jet. All of them share the need for hydrogen to obtain a drop-in fuel that can be blended with petroleum-based jet fuel. The hydrogen input requirements affect the life cycle greenhouse gas emissions, increase the biojet fuel cost and hinder the construction of distributed processing plants. This study addresses the problem of hydrogen sourcing in the production of SAFs through a systematic literature review. Techno-economic studies of biojet fuel production using different feedstocks and conversion pathways are analyzed focusing on the methods of hydrogen provision. The technological options used to generate the required hydrogen within the conversion process itself as well as externally, along with the main strategies to reduce the hydrogen demand are identified. The production yields and the hydrogen consumption of several SAF production pathways are compared. The jet fuel yields reach values as high as 0.66 for hydroprocessing of vegetable oils with external hydrogen provision, while they drop to 0.10 for production from lignocellulosic biomass with internal hydrogen sourcing. The results of the analysis highlight the real potential of four among the most promising routes for the production of biojet fuels when the burden related to hydrogen demand is properly taken into account

Trifluoroacetic Acid Hydroxylamine System as Organocatalyst Reagent in a One-Pot Salt Free Process for the Synthesis of Caprolactam and Amides of Industrial Interest

Abstract In this work we studied the reactivity of the Trifuoroacetic acid hydroxylamine system in the one step salt free synthesis of amides from ketones. A particular regards was paid to the caprolactam synthesis because of its industrial relevance. Synthesis, reactivity and characterization of the hydroxylamine trifuoroacetate is given. Fast oximation reaction of several ketones was gained at room temperature (1 h of reaction quantitative conversion for several ketones). In the same reactor, by raising the temperature at 383 K, the Beckmann rearrangement of the so obtained oximes is easily accomplished in the presence of three equivalent of TFA. The possibility of obtaining the trifuoroacetate of the hydroxylamine with a modifed nitric acid hydrogenation reactions was verifed, too. Reuse of solvent and trifuoroacetic acid is easily achieved by distillation

The pyrolysis and gasification pathways of automotive shredder residue targeting the production of fuels and chemicals

Automotive shredder residue (ASR), also referred to as car fluff, is the 15-25% of end-of-life vehicle’s mass remaining after de-pollution, dismantling, shredding of the hulk and removal of metals from the shredded fraction. ASR typically consists of metals, plastics, rubber, textile, wood and glass, and is commonly landfilled. The use of ASR as a fuel in incineration processes is controversial since toxic pollutants can be generated as by-products if operational conditions and gas cleaning systems are not carefully controlled. Thermochemical treatment of ASR consists of advanced technology processes that convert ASR components liable to decomposition under the application of heat into liquids and/or gases and a solid residue containing metals. Within the thermochemical treatment options for ASR, pyrolysis and gasification are generally considered as the emerging technologies. The pyrolysis process uses medium temperatures (400-600°C) and an oxygen-free environment to decompose ASR chemically, thus producing minimum emissions and allowing metals to be recovered. Gasification is operated at higher temperatures (>700-800°C) and typically uses air as a gasification agent, which raises some issues in terms of emissions. Lab and pilot-scale plants fed with ASR have been built using both technologies, also considering a combination of them. The aim of this paper is the identification of the best conversion pathway for the production of transportation fuels, aviation fuels or chemicals (hydrogen, methanol, etc.) from ASR. The intermediate products from gasification and pyrolysis are used as feedstock in secondary processes for the production of the final products. The heterogeneous and complex composition of ASR raises several challenges upon its thermochemical treatment, so that the second step of the conversion process is typically not even addressed. Instead, this further step is fundamental to obtain some valuable products that can directly replace fossil derived fuels or chemicals. The updated picture presented in this work should help identify the main advantages and drawbacks of the pyrolysis and gasification processes when considered part of an overall ASR to fuels or chemicals plant

Isabelle De Crousaz, Ur Shlonsky, The Distribution of a Subject Clitic Pronoun in a Franco-Provençal Dialect and the Licensing of Pro

Dans leur article The Distribution of a Subject Clitic Pronoun in a Franco-Provençal Dialect and the Licensing of Pro, Isabelle De Crousaz et Ur Shlonsky abordent, sous une perspective générativiste, le phénomène du sujet nul (pro) dans une variété de français parlé aux alentours de Gruyère, village situé dans le canton de Fribourg en Suisse. Le domaine de leur recherche est restreint à un pronom sujet clitique dont la prononciation est [i] et qui est employé à la première et à la deuxième pe..

First-Year Experience (FYE) & Student Success and Engagement Among First-Generation Students

This research focuses on how we can use first-year experience (FYE) seminars to support first-generation students in college. There is a heavy focus on how integrating student support services into a classroom setting can help promote social engagement, academic success, and retention among first-generation students by giving them all of the tools they need under one curriculum

Michael Herslund, Irène Baron (ed.), Le génie de la langue française. Perspectives typologiques et contrastives

Autour du vaste thème: Le génie de la langue française, les auteurs ont regroupé six contributions qui, à partir d’une analyse lexicale contrastive des langues, arrivent à toucher aussi les domaines de la syntaxe et du discours dans une optique générale de typologie linguistique. Sur la base d’une analyse contrastive, Peter Koch, (Aspects cognitifs d’une typologie lexicale synchronique. Les hiérarchies conceptuelles en français et dans d’autres langues, pp. 11-34) étudie les hiérarchies conce..

Aa. Vv., Le français parmi les langues romanes

C’est à Mario Barra Jover qu’a été confiée la composition du numéro 141 de cette revue, consacré au thème suivant: Le français parmi les langues romanes. Les contributions regroupées dans ce volume traitent de la spécificité du français dans différents domaines de l’analyse linguistique. Certaines d’entre elles analysent la spécificité du français par rapport à d’autres langues romanes. Patrick Sauzet analyse dans les détails deux phénomènes bien connus de la phonologie du français, notamment..