We construct potentially new manifolds homeomorphic but not diffeomorphic to CP 2 #8CP 2 and CP 2 #9CP 2 via rational blowdown surgery along certain 4-valent plumbing graphs. This way all the graph classes from [4] have a representative which admits a rational blowdown leading to an exotic manifold. We emphasize the simplicity of the constructions which boils down to finding a good configuration of complex lines and quadrics in CP 2 , and deciding which intersections to blow up.
Increasing profits by reducing costs during product development and its production and quality increasingare challenges that companies face every day in their operations. The aspiration of modern production is to achievean effect similar to those in mass production (or at least in large series production) even on extremely small series ofproducts, even on personalized products. Techno-economic analysis in modern companies is an integral part of thecompany's modern information system. This paper presents a techno-economic analysis of innovative technologiesfor the production of a wagons triangle brake, a product that is an integral part of the brake system of freight andpassenger wagons of the older generation: casting and additive technologies. Given that there are currently availabledifferent production technologies that can be applied, one of the criteria for choosing a production technology is itsprofitability. The choice of solution, whether the product will be made by casting (or welding) or additivetechnology, is mostly influenced by the size of the series. In the case of the cast part, the so-called constant costs(model, molds for cores), but variable costs are therefore lower, i.e., costs proportional to the number ofmanufactured pieces. Additive technologies that can be used to make such parts can use numerous methods, three ofwhich stand out due to their application in practice. These are stereolithography (STL), extruded material (EBM)and direct metal laser sintering (DMLS). Machine cost is the main factor for stereolithography and melt extrusion,while material cost is the main factor for laser sintering. The price of additively manufactured parts is calculatedaccording to the cost model that follows activities, where each cost is linked to a specific activity. The analysisindicates that additive technologies are not such a cheap process, especially in serial production, but they areexcellent in individual production or during rapid prototyping, and the price of the product obtained by additivetechnology is the same for each piece. Also, cast parts have high initial costs (casting molds, etc.), but castings arerelatively cheap, which leads to a drop in the total price as the series increases. Both technologies have limitations interms of the materials that can be used in casting or additive manufacturing processes. Based on the technoeconomicanalysis, it can be concluded, also, that certain activities require the engagement of other companies thatshould be entrusted with certain business activities or tasks - in this way, the company's resources are saved andemployed on other more expedient activities that will bring greater benefits, and the system work is not disturbed ordisturbed. The advantage of casting technology over additive technologies is already profitable for series over 42pieces, and compared to forging, the casting of this part of the product is 2.5 times cheaper.
U radu je obrađeno projektno rešenje armirano-betonske temeljne ploče zgrade spratnosti Po+P+6 sa posebnim osvrtom na analizu interakcije temeljne ploče i tla. Analiza svih relevantnih opterećenja koja deluju na konstrukciju i dimenzionisanje karakterističnih armiranobetonskih elemenata je razmatrano prema Evrokodovima. Za proračun konstrukcije korišćen je softverski paket Tower 8.
– The information age is characterized by the ability of individuals or businesses to freely exchange information and to have unhindered access to the market. Available online services allow fleet owners to offer available capacity and/or support goods for transport and the transport route that suits them. Also, such arranged services enable the owners of goods and/or providers of logistic services to submit a request for the transport of goods and/or to look for a transport vehicle and a transport route that suits them. This paper presents the forms and manner of functioning of services for the supply and the demand of transport services as well as their impact on the market of transport of goods in the Republic of Serbia. Keywords – Transport exchanges, Transport market, Supply and Demand.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.