Wyniki wyszukiwania - BazTech

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Evaluation of titanium alloy thread quality during cutting

Zawada-Tomkiewicz Anna, Żurawski Łukasz, Tomkiewicz Dariusz

Metrology and Measurement Systems

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2020

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Vol. 27, nr 4

563-574

EN

This article concerns a new method of assessing the thread cutting process and the quality of the formed thread using the method of optical observation of the workpiece during machining. A series of digital images of the thread profile was taken in transmitted light for each tool infeed. Such images, obtained with high resolution for three angular positions, were binarized, with the space between ridges taken in successive infeeds identified as “void”, and its projection was then parameterized. Two of these parameters, area of void and aspect ratio, were used as indicators of the technological quality of the thread. The suitability of the selected parameters for technological description of the thread was verified using the example of titanium alloy thread turning under ambient and cryogenic conditions.

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A new approach in separation process evaluation. Efficiency ratio and upgrading curves

Irannajad M., Nuri O. S., Allahkarami E.

Physicochemical Problems of Mineral Processing

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2018

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Vol. 54, iss. 3

847--857

EN

In mineral processing separation efficiency (SE), operation efficiency (OE), selectivity index (SI) and other indices have been used to evaluate the separation process. Up to now, no study has been conducted on the relationship between the SE, OE and SI indices. In this research, two upgrading curves are proposed based on the above indices for process and selectivity evaluation. The first upgrading curve is based on recovery R, SE, and OE as a function of concentrate grade. This curve has three background lines, including no upgrading line, ideal upgrading line and the ideal mixing line. The proposed upgrading curve is applicable not only for process evaluation by specification of OE and SE, but also for selectivity evaluation with the lowest difference between SE and OE. The curve showed that the recovery value is always greater than the SE and OE values. The parameters of OE, SE and R were used for plotting the upgrading curve as a function of concentrate grade taking into consideration all of them at a time. A new selectivity indicator, namely Efficiency Ratio (ER) as the selectivity parameter, is proposed as the ratio of OE to SE. The ER values fluctuate between 1 and . It can be presented as a function of concentrate and tailing grades (ER = [c(1-t)]/[1(c-t)]). The results showed that ER is insensitive to the feed grade and has the inverse relationship with SI. To measure the separation selectivity, another upgrading curve is proposed based on ER and SI parameters. This curve is divided into seven separation classes for evaluation the class of a separation process from ideal class to no separation one. The results of this research can be useful for separation process evaluation.

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Ocena procesów logistycznych w przedsięwzięciach budowlanych

Górecki J.

Czasopismo Inżynierii Lądowej, Środowiska i Architektury / Journal of Civil Engineering, Environment and Architecture

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2016

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z. 63, nr 1/I

181--188

PL

Procesy logistyczne w toku realizacji przedsięwzięć budowlanych, stanowią istotny element systemu produkcji budowlanej. Zatem winny być postrzegane jako determinanta sukcesu tych przedsięwzięć. Trzeba jednak zauważyć znaczącą rolę przedsiębiorstw budowlanych, jako wykonawców robót budowlanych. O szczególnym splocie celów przedsięwzięć i ich wykonawców – przedsiębiorstw budowlanych – decyduje specyfika produkcji budowlanej. Celem artykułu jest przedstawienie charakteru produkcji budowlanej, realizowanej na placach budowy, w której procesy logistyczne mają szczególną rolę. W celu zdiagnozowania sposobu prowadzenia procesów logistycznych przeprowadzono badania ankietowe 55 przedsiębiorstw budowlanych. Badania wykazały znaczące uczestnictwo przedsiębiorstw budowlanych w prowadzeniu procesów logistycznych, a co za tym idzie ponoszenie w dużej mierze kosztów logistycznych i podejmowanie ryzyka logistycznego. Metoda „just in time” jest wprowadzana w celu minimalizacji czasu realizacji przedsięwzięć budowlanych. Z kolei jako największe zagrożenie wynikające ze stosowania tej metody przedsiębiorcy wskazywali trudności w synchronizacji harmonogramów budowlanych i harmonogramów dostaw zasobów produkcyjnych.

EN

Logistics processes are an essential component of the construction projects. Therefore, they should be treated as a determinant success of these projects. It should be noticed an important role of construction companies, as building contractors. About particular connection between project targets and targets of the project contractors - construction enterprises - decides a specificity of the building production. An aim of the article is to present a character of the construction industry, implemented on construction sites, in which logistics processes play a special role. In order to study a way of conducting logistics processes it was conducted 55 surveys of construction companies. The research has revealed a significant participation of the construction companies in conducting logistics processes, and thus covering the costs of logistics and taking the risk of logistics. A "just in time" (JIT) method is used in order to minimize duration of construction projects. On the other hand, as the greatest threat coming from a use of this method, companies indicated the difficulties in synchronization of construction schedules and delivery schedules of production resources.