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1
Content available remote Retrofitting obrabiarek z wykorzystaniem narzędzi Open Source.
100%
Nitek W. , Wasiak Z. , Wojciechowski J.
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tom R. 81, nr 3
154-154
PL
Omówiono metodykę tworzenia aplikacji generujących program obróbki, która umożliwia szybkie i łatwe tworzenie prostych aplikacji, gdy dostępne rozwiązania nie nadają się do zastosowania. Przedstawiono metodykę prowadzenia retrofittingu z wykorzystaniem narzędzi Open Source.
EN
Discussed are basics for creation of the applications intended to generate machining programs, which would provide for fast and easy creation of plain applications in case, when the available issues show to be impracticable. Presented are process methods employing Open Source tools.
2
Content available Retrofitting issues of non-road vehicles on the example of a farm tractor
100%
Sokolnicka B. , Fuć P. , Lijewski P. , Szymlet N. , Siedlecki M.
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tom Vol. 63, nr 4
193--196
EN
It is not possible to meet the current type approval standards for the exhaust emission from internal combustion engines without the use of exhaust aftertreatment systems. An additional problem is in the increased emissions in real driving conditions compared to the values obtained in type approval tests. The current legislative trends are not limited to just lowering the emission limits for new vehicles, but also actions aimed at reducing the impact of vehicles that are already in operation. One of such actions is known as retrofitting, described as retrofitting older structures with modern exhaust aftertreatment systems, without the need for any changes in the engine design. Research has shown that the emission of toxic compounds from agricultural machinery engines can reach values up to 30 times higher than those of an average passenger vehicle. This problem has been noticed by the legislators and regulations concerning operated non-road machines are successively being introduced. Such restrictions are already present in the Berlin city center for example, where all vehicles operated within the given zone must meet the Stage 3b emission limits. Retrofitting is a multi-stage process. The article discusses the issue of performing this process, starting with NRMM (Non-Road Mobile Machinery) emission measurements, through simulation studies of a virtual model of a particulate filter in CFD software (Computational Fluid Dynamics), to verify its operation in an agricultural tractor, i.e. one of the most numerous vehicle types within the non-road vehicle group in Poland.
PL
Nie jest możliwe spełnienie aktualnych norm homologacji typu dla emisji spalin z silników spalinowych bez stosowania układów oczyszczania spalin. Dodatkowym problemem jest zwiększona emisja w rzeczywistych warunkach jazdy w porównaniu z wartościami uzyskanymi w badaniach homologacyjnych. Obecne tendencje legislacyjne nie ograniczają się tylko do obniżenia limitów emisji dla nowych pojazdów, ale także do działań mających na celu ograniczenie wpływu już eksploatowanych pojazdów. Jednym z takich działań jest modernizacja, opisywana jako modernizacja starszych konstrukcji za pomocą nowoczesnych systemów oczyszczania spalin, bez potrzeby wprowadzania jakichkolwiek zmian w projekcie silnika. Badania wykazały, że emisja szkodliwych związków z silników maszyn rolniczych może osiągnąć wartości do 30 razy wyższe niż w przypadku przeciętnego pojazdu pasażerskiego. Problem ten został zauważony przez ustawodawców i sukcesywnie wprowadzane są regulacje dotyczące eksploatowanych maszyn pozadrogowych. Takie ograniczenia są już obecne na przykład w centrum Berlina, gdzie wszystkie pojazdy eksploatowane w ramach danej strefy muszą spełniać limity emisji Stage 3b. Modernizacja jest procesem wieloetapowym. W artykule opisano problem prowadzenia tego procesu, wychodząc z pomiarów emisji NRMM (Non-Road Mobile Machinery), poprzez badania metodą symulacji wirtualnego modelu filtru cząstek w oprogramowaniu CFD (Computational Fluid Dynamics), w celu sprawdzenia jej działania w ciągniku rolniczym, czyli jeden z najliczniejszych rodzajów pojazdów w grupie pojazdów nieporuszających się po drogach w Polsce.
3
Content available Retrofitting the bow of a general cargo vessel andevaluating Energy Efficiency Operational Index
94%
Denev Y.
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tom nr 4
17--23
EN
This report examines the feasibility and impact of retrofitting the bulbous bow on a general cargo ship, in terms of the energy efficiency operational index (EEOI), in the areas of Western Europe and the Eastern Mediterranean. Three ship forms were developed and analysed: with a bulbous bow, without a bulbous bow, and with a modified bulbous bow. The goal in developing the ship forms and conducting the analysis was to achieve minimal differences in the ship’s characteristics with the same volumetric displacement, aided by PolyCAD software. A route was selected between two ports: Varna and Rotterdam. The labour intensity of the bulbous bow retrofitting process was evaluated and approximate values of labours costs and cost for the task were determined. The results obtained for resistance during ship motion, EEOI, and fuel consumption reductions, or increases, were compared against the retrofitting values. The return cost of retrofitting is evaluated and measured in terms of fuel saved.
4
Content available Flexure Behavior of Carbon Fiber Reinforced Polymers Retrofitted RC Beams
83%
Fahim M. , Saeed M. , Khan H. , Gir A. , Ullah S.
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2022
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tom Vol. 16, no 2
188--195
EN
Carbon fiber reinforced polymers (CFRP) have been widely used for retrofitting of reinforced concrete members over the past three decades. This study presents the experimental results of four reinforced concrete beams retrofitted with CFRP and tested under four point monotonic loading. CFRP strips (Sika Carbo-Dur S812) and wraps (Sika-Wrap 230C) were used in two different patterns to evaluate their effect on the flexural behavior of RC beams. Two beams were first tested until their ultimate capacity, retrofitted with the application of CFRP and re-tested again, and two beams were retrofitted before the application of any load. The CFRP strips provided in the middle one-third of the span with U-shaped anchorage at the ends enhanced the capacity of beams up to 15 percent. The stiffness of the beams were significantly increased as demonstrated by smaller displacement at the ultimate load. However, the CFRP wraps provided without the anchorage didn’t enhance the strength due to pre-mature debonding.
5
Content available Application of thermal insulating plaster for retrofitting of a building under conservation protection
59%
Owczarek M. , Sadowska B. , Kuczerowski M. J. , Baryłka A.
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tom Nr 2
17--25
EN
The article presents the results of measurements of selected thermal, moisture and mechanical properties of thermal insulating plaster, which is one of the alternatives to traditional methods of retrofitting the walls of buildings under conservation protection. An insulating plaster based on perlite was tested. Its thermal conductivity, vapor permeability and compression strength were determined. Images of the tested plaster under the microscope, at a magnification of 10-45x, were also taken. Through computer simulations, the possibility of improving the energy efficiency of an educational building by applying a layer of such plaster on external walls was determined. Changes in the heat loss structure were analyzed, and the obtained results were compared with the effectiveness of reducing heat loss through the walls using a traditional thermal insulation material. It turned out that the thermal conductivity coefficient of the tested plaster obtained by measurement was 0.0877 W/(m∙K), which confirmed the value declared by the manufacturer. Application of thermal insulating plaster with a thickness of 5 cm on the walls of the analyzed building, with other partitions of good thermal quality, reduced its energy demand by over 20%.
6
Content available Application of buckling restrained braces to upgrade vertical stiffness of existing RC frames
59%
Niyonyungu F. , Noroozinejad Farsangi E.
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2020
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tom Vol. 30, no. 3
68--93
EN
In this paper, based on the RC frame structure of an industrial building, the finite element model of the structure is developed, according to the Chinese code for seismic design of buildings [9]. Considering the lack of seismic performance, the buckling restrained brace (BRB) is adopted for seismic retrofitting, and various configurations of buckling restrained support are considered for reinforcement. The elastic response spectrum analysis (RSA) and direct integration nonlinear time history analyses (NL-TH) are carried out for the frame structure before and after reinforcement using ETABS finite element software. From the joints displacement, inter-story displacement, inter-story shear force, acceleration, energy dissipation, and other aspects of the seismic response of the strengthened structure and the non-strengthened structure, the comparison has been made. The effect of buckling restrained support and common support on the existing building structure is verified through analytical modeling. After reinforcement, there is a 40%, 39.3%, 40%, 36.4%, and 38.3% reduction in the first period of vibration after the building is strengthened by inverted BRB, V BRB, two-story BRB, single BRB, and ordinary steel braces, respectively. Strengthening of the structure by buckling restrained braces and ordinary steel braces both decrease the original building displacement by more than 50% from the first to the fourth floor. Under severe earthquakes, the use of BRB reduced the column shear by 46.6%; similarly, the incorporation of ordinary steel braces reduced the column shear by 4.72%. It is concluded that using buckling restrained braces will increase the vertical stiffness of the structure to a very high extent.
7
Content available remote Ocena efektywności modernizacji obrabiarek
48%
Nitek W. , Wasiak Z. , Wojciechowski J.
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tom R. 81, nr 2
112-115
PL
Omówiono możliwości modernizacji używanych obrabiarek: remanufacturing (modernizację kompleksową), rebuilding (remont) i szerzej retrofitting (modernizację napędów i sterowania).
EN
A discussion on machine tools upgrading methods with respect to the work range covering: remanufacturing (complex upgrade modification), rebuilding (overhaul) and, extensively presented retrofitting (covering upgrade to control and the drive trains).
8
Content available remote Kluczowe wyzwania stojące przed polskim budownictwem energooszczędnym w 2020 roku
36%
Węglarz A.
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2020
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tom nr 1
11--13
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