Keresés
Keresési eredmények
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Developing a Financial Sustainability Model of the Performance Indicators Applied by Jordan Water Company (Miyahuna)
75-87Megtekintések száma:260Jordan is now facing real challenges to satisfy the current population water needs due to limited resources. Moreover, unfortunately, as a result of the increased demand for water in developing countries, water resources become scarce, thus, the sustainable management of water resources is very important everywhere and especially in these areas. The Ministry of Water and Irrigation in Jordan is aiming to improve both its quality of service and financial sustainability, therefore, it started to apply the performance measurement system developed by the International Water Association (IWA) to monitor its performance towards achieving these goals. In this article, a model connecting a financial sustainability indicator (operating cost coverage ratio) with other performance indicators applied by the ministry is developed. To assess the performance indicators and to build the model secondary data are collected from the targeted company, the data are analyzed using SPSS and Excel computer programs. Non-revenue water (NRW), speed of repair of bursts, and training per employee are found to be the indicators that have a major impact on Miyahuna’s financial sustainability, the NRW is found to have a negative relationship with the financial sustainability, whereas the other two indicators have a positive relationship. As a conclusion, reducing the NRW and increasing both the speed of repair and training per employee are recommended, by applying some methods that continuously diagnose problems in the water systems and defining clear and strict policies to control the water theft. Furthermore, using Active Leakage Control (ALC) methods, providing the needed equipment, tools and resources, and adopting new methods for training.
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The Role Of Leader In Work Addiction
1-13.Megtekintések száma:0Over-attachment to work is an increasingly common phenomenon in the lives of people in organisations, and can also be a condition of work addiction. Whoever becomes involved in an organisation, be it a subordinate or even a manager, work addiction has a number of negative consequences at both individual and organisational level. Without being exhaustive, work addiction can have an impact on organisational performance, organisational effectiveness, workplace conflict, career prospects, health maintenance. In this paper, we aim to highlight the most relevant publications from the last five years to report on the impact in an organisation when work addiction arises among subordinates or managers, and how different leadership styles are associated with work addiction among organisational members. The publications were retrieved from Google Scholar and Scopus, and the results of 19 articles are presented in this paper after a review of 263 papers retrieved. The results show that transformational, servant and ethical leadership styles have ambiguous effects on work addiction, unlike laissez-faire or abusive leadership styles, the former enhancing and the latter reducing the incidence of work addiction in an organisation. Work addiction of managers also has a dual effect: on the one hand, it can enhance creativity, but it can also increase turnover among subordinates. Social support from the manager can be an antidote to subordinates' work addiction, but this effect may be modified by the quantity and quality of interaction between manager and subordinate, the sense of meaningfulness of the work, or even the organisational culture. Overall, the manager, as a key actor, can have an impact on work addiction in the organisation, but there is not always a consistent position in the research on the cases and the way in which this is done, which calls for further research in the future.
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Economic Effect of the Coronavirus on the Companies Involved in Car and Automotive Parts Trading, and Manufacture of Tires of Hungary, Including Szabolcs-Szatmár-Bereg County, in Respect of 2020
1-12Megtekintések száma:237In Hungary the wake of the first wave of the Covid-19 epidemic (March 2020), caused a decline in demand for goods and services in most sectors. There were sectors (accommodation services, art, recreation, etc.), which were economically severely burdened by the imposition of restrictive measures, and there were some (financial services, communication), which experienced the change positively. In our research, our goal was to assess the changes caused by the Covid-19 epidemic in the property, financial and profitability situation of the companies involved in car and automotive parts trading, and tire manufacturing, in Hungary, and within the country, in Szabolcs-Szatmár-Bereg county. We established three hypotheses: (1) As a result of the spread of coronavirus epidemic, in Hungary and in Szabolcs-Szatmár-Bereg county as well, the profitability of companies of NAICS codes 441 (car and automotive parts trading) and 4231 (wholesale of road vehicles and parts), decreased. (2) The outbreak of the epidemic had a negative impact on the liquidity of companies established in Hungary, including Szabolcs- Szatmár-Bereg county. (3) As a result of the Covid-19 epidemic, the resource structure of Szabolcs-Szatmár-Bereg county companies, analysed in the framework of research work, transformed. To prove or disprove these, secondary research was used. Finally, we put forward conclusions and proposals for the management of the companies active in this industry.
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Design of Experiments Application for Machining Process Analyse
257-265Megtekintések száma:141In this contribution are results from machining of the aluminium alloy by spiral router. The experiment was designed as full 3 - factors and 2-levels process and for evaluation of input factors to output parameters – Fx and Fy components were used Paret´s diagram and Lorentz´s line. The input parameters were: revolution speed (4000/min. and 6000/min.), working engagement of a cutting edge (depth of cut) ae (1 mm and 3 mm), back engagement of a cutting edge (with of cut) ap (5 mm and 15 mm) and down (climb) milling.
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Speed Variation along an Imposed Linear Trajectory, for Robotic Arms Motion
495-502Megtekintések száma:93The paper describes a method of speed (velocity) computation, named mixt profile, during a motion upon an imposed linear trajectory. The method assures an accurate positioning at the end of motion (movement), in a well determinate time lapse. The described method is linked with position vector computation, about a robotic arm.
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Investigation on Double Oxide Film Initiated Pore Formation in Aluminum Casting Alloys
141-153Megtekintések száma:363The most common, and in fact, the most deleterious defects of aluminum casting alloys are the so-called double oxide films or bifilms, which have a central role in porosity formation, as they can easily unfurl and inflate into pores during the solidification of the alloys. Sr addition is generally used in the foundry industry for the modification of the eutectic Si phase of hypoeutectic Al-Si alloys. However, Sr microalloying usually leads to an increased pore formation tendency. As bifilms are preferred sites for pore formation, it should be expected that Sr additions have a significant effect on the number and/or the structure of double oxide films present in the melt. In this work, the relationship between Sr-concentration and the susceptibility to pore formation has been investigated through the evaluation of melt quality of melts which had different levels of Sr. The bifilm content of the melts was investigated by the analysis of K-mold specimens and X-ray computed tomography (CT) of reduced pressure test (RPT) samples. It was found that liquid alloys with a higher Sr concentration had a significantly greater tendency to pore formation, which can be explained by the presence of a larger number of bifilm defects in the liquid alloy.
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Ultrasonic Powder Atomization for Additive Manufacturing
69-75Megtekintések száma:199The following article presents a special case of metal powder production, ultrasonic metal atomization. In this case, ultrasound technology is based on the capillary wave phenomenon. We verify the suitability of the produced powders for 3D metal printing with various tests. In the case of prints with a metal powder bed fusion (PBF), the properties of the raw material of the powder are extremely important. The main results of the tests carried out in the article (SEM images, EDS composition analysis, sieve analysis) were described.
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Efficiency of the Machining Process of Circular Shapes by Electrical Discharge Technology
53-61Megtekintések száma:115Due to its high machining precision, EDM technology is nowadays very important in the production of high-precision parts for various industries. The high precision of the machined surface in combination with the ability to machine circular surfaces brings, in addition to several advantages, some negatives. The most significant negative of this machining technology is the relatively low productivity as well as the overall production efficiency. The latter is affected by many accompanying phenomena. The main accompanying phenomenon that contributes to the decline in the overall economic efficiency of EDM is the microgeometry errors that occur due to the non-homogeneity of the EDM process. Another accompanying negative phenomenon is the geometric accuracy errors of the machined surface, as a consequence of systematic destruction of the wire tool electrode, faulty interpolation in its guidance, and, last but not least, its vibration. These aspects consequently lead to the requirement for multiple applications of additional finishing cuts, which significantly reduces the overall economic efficiency of the machining process. Therefore, the experimental research aimed to search for options that can effectively help to achieve higher productivity but especially the overall economic efficiency of the machining process.
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Investigating the Impact of Nature in Designing Cultural Environments for Children
244-256Megtekintések száma:216There is a tendency to communicate with nature in human beings as a set of emotional experiences. This study investigates the impact of organic architecture in creating cultural spaces for children. The concepts of nature, naturalist architecture and children educational psychology, from the perspective of scholars and researchers in this area are investigated. The children’s perception of nature and their feelings were assessed and one hundred forty respondents among the instructors of cultural centres in different regions of Tehran have answered the questionnaires. To investigate the hypotheses, Univariate T - test and F - test were applied. The results showed that the stimulation of the natural environment has a positive and meaningful effect on curiosity, participation, and fantasy in children, while they show their impressions of nature indirectly. Therefore, designing applicable spaces according to children’s physics, using appropriate colours and furniture as well as more environmentally-related spaces, can have positive effects on social participation, intuitive and verbal skills of the children.
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Adaptability of Powdered Activated Carbon Production from Ground Catering Waste Pyrolysis Coke
162-171Megtekintések száma:147Three mixture of catering waste was pyrolyzed at 650, 725 and 900 °C and the solid residue (coke) was examined for powdered activated carbon production. For this, the carbon content, iodine number, particle size distribution and scanning electron microscopic images were analysed. Based on the carbon content, these cokes are suitable for activated carbon production, which were 60-85 wt.% (depending on the base material and pyrolysis temperature). The studied cokes showed slightly porous structure with smooth surfaces. Because of this, the iodine number was mostly small (13-30). Based on the grinding experiments, 10 minutes of grinding was found to be optimal. After this grinding time, the reached iodine number of powdered activated carbon was 350-610.
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A modern járművekben alkalmazott hajtásrendszerek áttekintése
728-732Megtekintések száma:198Jelen közleményben áttekintjük a modern elektromos és hibrid rendszerű járműhajtásokat. Továbbá áttekintjük az azokban alkalmazott villanymotorok, akkumulátorok és üzemanyagcellák típusait, valamint a felépítésükkel és jellemző tulajdonságaikkal foglalkozó szakirodalmat. Továbbá, mivel a hibrid járművek fontos része a belsőégésű motor, áttekintjük azok hatékonyságának növelésére, valamint emissziójuk csökkentésére alkalmazott eljárásokat.
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Digitalizáció hatása a hazai kereskedelmi stratégiákra
318-333Megtekintések száma:1455Tanulmányunk célja, hogy feltérképezzük a digitális tér illeszkedését napjaink és a jövő kereskedelmébe és meghatározzuk a digitalizáció hatását a hazai kereskedelmi stratégiákra. A fogyasztók információszerzési és vásárlási szokásai drámaian megváltoztak. A ma fogyasztója számára elsősorban a kényelem, a hatékonyság (a termékhez való gyors, kényelmes hozzáférés a megfelelő ár-érték arányban) és az élmény jelentik azokat a kulcstényezőket, melyek alapján döntését meghozza. A kereskedők igazodva ezekhez újszerű kereskedelmi stratégiákat alakítottak ki, melyeknek szerves része a digitalizáció vívmányainak felhasználása. Ennek egyik vetülete az e-kereskedelem egyre erőteljesebb globális fejlődése. A hazai online kereskedelem is évről évre jelentősen bővül. 2018. évi adatok alapján a belföldi és külföldi online értékesítés volumene meghaladta az 1000 milliárd forintot. A hazai online fogyasztók egyre gyakrabban és egyre nagyobb értékben vásárolnak az interneten. Az online bevásárlás virtuális valóság platformokon való megvalósulása pedig élményszerűbbé teheti ezt a vásárlási módot. A webshopoknak újabb fogyasztói igényeknek kell megfelelni és a megrendelt árut mielőbb, lehetőleg 24 órán belül kiszállítani. A csomagok kézbesítésének számos változata kezd egyre népszerűbbé válni (pl. csomagautomaták, pick pack pontok). A hagyományos csatornákat sem szabad azonban eltemetni. Óriási előnyük, hogy a vásárló több érzékszerven keresztül válogathat a termékek között és az impulzusvásárlásnak is nagyobb teret enged. Ezt a kor követelményeinek megfelelő digitális technológiával kombinálva teljes körű vásárlási élmény nyújtható. Felismerve ezt az igényt az online és hagyományos csatornák manapság sok esetben már keverednek (pl. multichannel, omnichannel, crosschannel) és rengeteg lehetőséget nyújtanak a fogyasztóknak a vásárlási folyamat során. A vásárlók kényelmét szolgálja a hagyományos üzletek eladóterének optimalizálása és a vásárlói útvonalak digitális technológiákkal (pl. digitális polccímke) való támogatása is. Az újabb innovációk a vásárlási folyamat automatizációját vonják maguk után és szenzorok (pl. Amazon Go) vagy robotok (pl. Pepper) segítségével teszik kényelmesebbé és személyre szabottabbá a vásárlási folyamatot. A digitális személyi asszisztensek az eladószemélyzet digitális változataként fognak feltűnni a jövőbeli vásárlásaink során.
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Introduction to Design and Analysis of Torsional Vibration Dampers in Vehicle Industry
310-324Megtekintések száma:343The crankshaft of today’s internal combustion engines with high performance output are exposed to harmful torsional oscillations originated from the unbalanced gas and inertial forces. To avoid the fatigue damage of engine components, caused by the undesired vibrations, torsional vibration dampers can be applied. Viscodampers are one type of the torsional vibration dampers, which operational fluid is silicone oil. For cost-effective R&D activities and production, finite element and finite volume numerical discretization methods based calculation techniques must be involved into the engineering work supported by the modern computer technology. The aim of this paper is to provide an insight into the multidisciplinary design and development process of visco-dampers in vehicle industry applications. Four different examples as structural, fatigue, CFD analyses and structural optimization have been introduced in the present work. It turned out from the static structural and fatigue analyses, that the investigated damper has safety factor over the limit for both static structural and fatigue analyses, so it is suitable for the given load conditions. In the structural optimization process 34.36% mass reduction has been achieved. According to the coupled fluid dynamic and heat transfer simulations a rather stagnating air zone evolved between the engine and the damper during the operation, which can cause efficiency reduction of cooling fins mounted onto the housing. In light of the numerical results, the suitable damper position has been determined for the highest heat transfer.
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HAZ Characterization of Automotive DP Steels by Physical Simulation
478-487Megtekintések száma:191DP steels were extensively used in the vehicles industry due to its extraordinary combined properties of strength, ductility, formability and weldability which contributed great significance in reducing strength to weight ratio and CO2 emission. High strength steel i.e. DP steels (3 different grades) were experimentally investigated and thermophysically simulated using Gleeble 3500 simulator to determine softening and hardening in heat affected zone. Samples were heated to different peak temperatures (1350 °C, 950 °C, 775 °C and 650 °C), two cooling time (t8.5/5 = 5 s and 30 s) and Rykalin 2D model were selected. The hardness and microstructure of the specimens were tested and analysed. For longer cooling time (t8.5/5= 30 s), we observed that softening occurs in all grade of investigated DP steels to all sub-regions. But for shorter cooling time i.e. t8.5/5= 5 s the softening is higher in intercritical HAZ compared to other sub-regions for all the types of DP steel with short cooling time (t8.5/5 = 5 s). However, the hardening zone in the CGHAZ occurs when Tmax is 1350 ºC for DP600, DP800 & DP1000 steels but it is more prominent in DP800 as compared to others two steel grade.
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Polylactic Acid as a Potential Alternatives of Traditional Plastic Packagings in Food Industry
123-129Megtekintések száma:372Huge quantity of synthetic polymers is used as packaging materials in different fields of food industries. A significant part of these polymers applied as a primary, direct food contact construction. The scoped application area is the sweet industry. In this field Polystyrol (PS), Polypropylene (PP) and Polyethylene terephthalate (PET) have used but during the last fifteen years the usage of PET has been grown. In one hand the price of this material is efficient, form other hand the PET is the one of the most safe (for food industrial applications) petrol chemical plastic that can be used as primary or secondary food contact packaging material. To maximize the customer safety and minimize the environmental impact of traditional PET, a new bio-sourced and bio-degradable alternative polymer aimed to be used in this special food industrial segment. One of the potential alternatives is the Polylactic acid (PLA) that would be a possible substitute as it is compostable and produced from renewable sources and has good physical and mechanical properties [1].
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Szabadidősport szolgáltatások értékelési lehetőségei – Felsőoktatási környezetbe adaptálva
150-164Megtekintések száma:236A tanulmányban a sportszolgáltatások minőségi aspektusaival kapcsolatos kutatásokat és a minőség értelmezésével kapcsolatos minőségi modelleket elemezzük. A primer kutatás eredményei, öt hazai kutatóegyetem hallgatóinak véleményét dolgozza fel az egyetemi szabadidősport szolgáltatásokkal kapcsolatban. A sportszolgáltatások a szolgáltató ipar része, működésük és fenntarthatóságuk a piaci szabályozások mentén alakul. Tekintettel arra, hogy az egyetemi szabadidősport szolgáltatások a versenypiaci környezetben kapnak helyet, sok esetben az egyetemeknek külső sportszolgáltatókkal kell versenyezniük a fiatal generációk bizalmának elnyeréséért. Minőségi vizsgálatukhoz a sportcentrumok esetében alkalmazott QSport-14 mérési skálát használtuk. Utóbbi skála három szempont szerint osztja fel a sportszolgáltatásokat, nevezetesen az (1) oktatók, az (2) infrastrukturális létesítmények és eszközök és végül a kínált (3) sportprogramok szerint. A külső sportszolgáltatók és az egyetemi sportszolgáltatások természetéből fakadó különbségek és sajátosságok miatt a mérési skálát egyetemi környezetre adaptáltuk.
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Személygépjárművek dinamikai modellezési eljárásainak áttekintése
723-727Megtekintések száma:234A járműdinamikai modellek a modell egyszerűsítése alapján két csoportra oszthatók. Vannak egyszerűsített modellek, amelyek során elhanyagolásokkal élünk: ezek jellemzően a hossz-, oldal- és függőleges irányok közül nem tartalmazzák az összes irányt. Az egyszerűsített modellekre több ok miatt is szükség lehet: vannak szabályozási, becslési, valamint analízis módszerek, amelyek csak egyszerűsített modellek alapján alkalmazhatók, valamint a számítási idő miatt is szükség lehet egyszerűsítésre. Az egyszerűsített modellek mellett léteznek valós modellek, amelyek célja egy virtuális plant biztosítása a valós járműről, virtual prototyping alapú fejlesztésekhez. Ebben a cikkben egy rövid bevezetés után néhány egyszerűsített járműmodell kerül bemutatásra.
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A társadalmi vállalkozások Balanced Scorecard rendszerének kialakítása a szociális szövetkezetek példáján – külső szervezetek igényeinek való megfelelés
300-317Megtekintések száma:239A szociális szövetkezetek gazdálkodási problémáinak feltárása érdekében kérdőíves kutatást végeztünk. A kutatásunk megállapította, hogy a rendelkezésre álló munkaerő minősége és a megfelelő célpiacok megtalálása jelenti a szociális szövetkezetek fő gondját. A kérdőíves felmérés alapján elkészítettük a szociális szövetkezetek Balanced Scorecard rendszerének (továbbiakban BSC) egy lehetséges modelljét. Modellünk a Bull által kidolgozott modell egy adaptációja (Bull, 2006). Jelen cikkünkben a BSC külső szervezetek igényeinek való megfelelés modulját dolgoztuk ki. Meghatároztuk a követelmények körét, a követelmények teljesítését nyomon kísérő mutatószámokat, továbbá javaslatot teszünk a mutatószámok mérésének gyakoriságára is.
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Formation of Oxide Layers with Femtosecond Laser on Steel Surfaces for Color Marking
174-178Megtekintések száma:215With the appearance of ultrashort pulse lasers, the researchers have begun working on various laser marking technology. Atmospheric heating and ablation of a surface induce laser coloration of metal surfaces. However, their application is still problematic today in the industry. With the appearance of femtosecond pulse lasers, a new concept became available for color marking. This concept is based on the formation of laser-induced periodic surface structures (LIPSS) on metal surfaces. The purpose of this article is to summarize the literature of laser color marking with ultrashort pulse lasers.
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Improvement of High Strength Automotive Steels Wettability Properties Using CO2 Laser Surface Treatment
422-427Megtekintések száma:168As a result of stricter environmental and safety standards, vehicle manufacturers have to reduce the weight of the vehicles, because 10% weight loss cause 8-10% reduction of fuel consumption. To reduce car’s weight and increase safety, vehicle manufacturers use high-strength steels. Further weight reduction can be achieved by using corresponding bonding technology (soldering, sticking) and optimizing these technologies can increase the strength of the joints. According to literature research, the improvement of interface properties has a large effect on bonding technologies. In order to improve interface properties, we can use multiple surface treatments. In our research we investigate the effects of CO2 laser surface treatment on high strength steels, because CO2 lasers are often used in the vehicle industry. In order to detect the effect of surface treatment, we investigate the wettability of the treated and untreated steels. In our research we measure the surface tension of treated and untreated steels. Our main goal is to improve wettability properties thus the bonding technology. In our research we used DP 600 high strength steel sheet with the thickness of 1 mm. We cut the steel sheet to 25mm wide and 55mm long workpieces. Before the surface treatment, the workpieces had to be cleaned and degreased using methanol. We searched for parameters that do not cause any visible changes on the surfaces. Among the parameters of the treatment we were able to change the output power of the laser. We used contact angle measurement to examine the wettability.
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The Pressure Characteristics of the Released Gases from Sand Cores
73-79Megtekintések száma:157The core packages used for the production of castings are generally made from cores of different quality (no- bake phenol, HB-phenol, and HB-furan) and resin quantity, to meet the various requirements for the casting. In our research, the effect of the amount of resin on the pressure of the gases evolved from the cores was investigated. Experiments have shown that increasing the amount of resin has a different effect on different binder systems.
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Examination of Infrared Tomato Drying
303-309Megtekintések száma:101Tomato is a highly perishable food, thus preservation is required to meet the continuous market demand compared to the unbalanced yearly production peak. The aim of this paper is to show a detailed insight into infraradiation based drying process. Furthermore, to widen the possible usage range of a well-known approximation method for describing the temporal moisture variation in function of process parameters. The mass decrease of tomato slices was examined, in function of specific radiation power, heat source and sample distance, in forced and natural airflow. Based on the results dimensionless moisture ratio change over time was fitted as an exponential function, which may be used in industrial drying process optimization.
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Modeling the Thermal Behavior of Permanent Magnet Synchronous Motors
466-477Megtekintések száma:155The aim of this study is to present a thermal analysis of a permanent magnet synchronous machine based on finite element method. The developed model can be used to predict temperature distribution inside the studied motor during the rated operation. Electromagnetic computation is carried out with the aid of two 2D finite-element (FE) simulations on the cross-section of the PM motor. To analyse the process of heat transfer in an electrical machine, empirical correlations are used to describe the convective heat transfer from the different surfaces of the PM motor. The heat transfer coefficient is determined using dimensionless numbers and Nusselt number. After the loss calculation, the temperatures of the machine are calculated by using 3D finite element method. The results obtained by the model are compared with experimental results from testing the prototype electric motor.
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Analysis of Vibration During Turning Process of Different Materials
200-205Megtekintések száma:132In this article, we would like to introduce the problems caused by vibrations in case of polymer turning processes. Nowadays there is a lot of research in this topic, to avoid the unnecessary phenomena of vibrations. The two most common methods are the Spindle Speed Variation (SSV), and the Vibration Assisted Machining (VAM). In case of SSV, the CNC machine can increase and decrease the speed of spindle continuously during turning which can significantly reduce the effects of chatter. This method is beneficial for longer workpieces when there is not any support except the chuck. Vibration-assisted machining can be used to minimise the problems caused by vibrations. VAM combines precision machining with small-amplitude tool vibration to improve the fabrication process. It has been applied to some processes ranging from turning, drilling to grinding. Based on the enumerated above we made some trial measurements about the basic vibrations of the turning tool shank. The tests were done on an NCT EUROturn-12B CNC machine which can found in the workshop of our institute. The tested material was Polyamide 6 because this is the most commonly used polymer in the industry. In the future, we would like to test some other basic and composite polymer materials too. The equipment was served by a specialist from SPM Budapest Kft. With these tests, our goal was to make sure that the equipment and the measuring setup are suitable for our future research.
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What Fields Can Technology Management be Applied to?
637-645Megtekintések száma:183There are two types of technology management definitions. The narrow ones only refer to business organizations, the broad ones refer to any kind of organizations, including non-profit and governmental organizations. By using the narrow definitions, the interest of the non-profit and governmental organizations cannot be attracted, they could think that they do not need to deal with technology management, but in reality they obviously use it. To avoid the undue failing to utilize technology management knowledge outside the business world the broad definitions are recommended.
