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  • 1
    Online Resource
    Online Resource
    Design of Experiment in the Milling Process of Aluminum Alloys in the Aerospace Industry
    MDPI AG ; 2020
    In:  Applied Sciences Vol. 10, No. 19 ( 2020-10-04), p. 6951-
    Details
    In: Applied Sciences, MDPI AG, Vol. 10, No. 19 ( 2020-10-04), p. 6951-
    Abstract: For many years, surface has quality received a serious attention due to its influence on various mechanical properties. The main contribution made in this scientific paper is the performance of actual experiments, as well as the experimental processing obtained in order to develop a model for predicting the surface roughness based on the optimization of cutting parameters. The novelty of this paper is brought by the method of obtaining the regression equation of the surface roughness, resulted from a standard end-milling process (standard milling tools, standard milling parameters, recommended by the tool manufacturer, 3 axis CNC machine and standard vice), on aluminum alloy 7136 in temper T76511, through two statistical methods of data analysis. This material is used for the production of extruded parts and is poorly understood for the proposed line of research. This study’s aim is to determine the surface roughness equation obtained by the milling of aluminum alloy 7136 in two ways: using Taguchi′s experimental design once and the other, using the central composite design. The Taguchi method and the central composite design are used to develop an efficient mathematical model to predict the optimal level of certain processing parameters. Using ANOVA analysis, a comparative study of calculated and experimental surface roughness values is carried out. The initial characteristics (surface roughness) and the controlled factors (cutting speed, depth of cut and feed) are analyzed with the Minitab program. Finally, an analysis of the advantages and disadvantages of the two methods used is presented. This study has a great industrial application, since the main task of every manufacturer is to achieve a better quality of the final product with minimal processing time.
    Type of Medium: Online Resource
    ISSN: 2076-3417
    URL: Article
    DOI: 10.3390/app10196951
    Language: English
    Publisher: MDPI AG
    Publication Date: 2020
    detail.hit.zdb_id: 2704225-X
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  • 2
    Online Resource
    Online Resource
    Reliability Modelling through the Three-Parametric Weibull Model Based on Microsoft Excel Facilities
    MDPI AG ; 2022
    In:  Processes Vol. 10, No. 8 ( 2022-08-12), p. 1585-
    Details
    In: Processes, MDPI AG, Vol. 10, No. 8 ( 2022-08-12), p. 1585-
    Abstract: The paper aims to capitalize on the new features that are offered by the Microsoft Excel calculation program for reliability modeling, using the Median Ranks estimator that is calculated directly with the BETA.INV function, not estimated by various algebraic estimators, as is generally the case. Starting from this first step, a method of modeling reliability is elaborated through the three-parametric Weibull model that is based exclusively on this software, which is accessible to anyone and can be used even in the case of online learning, which is widespread in recent years due to the pandemic situation. The probability plotting method is applied, using the Median Ranks estimator that is calculated directly with the BETA.INV function for a probability equal to 0.5. A flowchart is made for the proposed method, which could be easily translated into a calculation program. By representing in logarithmic coordinates, we determined the Weibull models for different values that were initially adopted for the location parameter: using as a criterion the coefficient of determination that was obtained using the trendline function for the linear model, it was possible to identify, by successive tests, the optimal value of the location parameter—for which the three-parametric model has a good likelihood. By the proposed method, this value can be found following this iterative process. So, based on the current facilities of the Microsoft Excel program, a precise and easy-to-apply method has been achieved, through which an appropriate three-parametric Weibull model can be identified.
    Type of Medium: Online Resource
    ISSN: 2227-9717
    URL: Article
    DOI: 10.3390/pr10081585
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2720994-5
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  • 3
    Online Resource
    Online Resource
    Experimental Research on the Cutting of Metal Materials by Electrical Discharge Machining with Contact Breaking with Metal Band as Transfer Object
    MDPI AG ; 2020
    In:  Materials Vol. 13, No. 22 ( 2020-11-20), p. 5257-
    Details
    In: Materials, MDPI AG, Vol. 13, No. 22 ( 2020-11-20), p. 5257-
    Abstract: The scientific paper presents practical research carried out by a mixed team of Romanian researchers from universities and the business environment. The research consists in applying the process of cutting metallic materials through electrical discharge machining with contact breaking using a metal band as a transfer object. The research was implemented with the help of a specially designed installation in the laboratory and subsequently all the necessary steps were taken to obtain the patent for it. Various metallic materials were cut using this process, but first of all, high alloy steels. In the global research conducted by the authors, active experimental programs and classic experimental programs were used. The composite central factorial experiment was the method that led to the most effective results in terms of interpretations and conclusions. The research as a whole includes unique elements from an engineering point of view and here we can highlight the use of a metal band as a transfer object for this type of process as well as the designed, realized, and subsequently patented installation.
    Type of Medium: Online Resource
    ISSN: 1996-1944
    URL: Article
    DOI: 10.3390/ma13225257
    Language: English
    Publisher: MDPI AG
    Publication Date: 2020
    detail.hit.zdb_id: 2487261-1
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  • 4
    Online Resource
    Online Resource
    Innovation – A Challenge for the 21st Century Managers
    Elsevier BV ; 2015
    In:  Procedia Economics and Finance Vol. 27 ( 2015), p. 126-135
    Details
    In: Procedia Economics and Finance, Elsevier BV, Vol. 27 ( 2015), p. 126-135
    Type of Medium: Online Resource
    ISSN: 2212-5671
    URL: Article
    DOI: 10.1016/S2212-5671(15)00981-8
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2015
    detail.hit.zdb_id: 2691979-5
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  • 5
    Online Resource
    Online Resource
    Comparative educational study between online and offline interactions in the knowledge-based economy
    Walter de Gruyter GmbH ; 2017
    In:  Balkan Region Conference on Engineering and Business Education Vol. 2, No. 1 ( 2017-12-20), p. 320-327
    Details
    In: Balkan Region Conference on Engineering and Business Education, Walter de Gruyter GmbH, Vol. 2, No. 1 ( 2017-12-20), p. 320-327
    Abstract: The aim of this paper is to analyse from the educational point of view which are the interactions between online and offline, starting from a set of values that contribute to the stability and functionality of the knowledge-based economy. There are four factors that allow the integration and sharing of values through online and offline interactions: organizational culture, digital technology, implementation of creative methodologies and digital transformation. In this respect, the interactions specific to systems based on open governance were analyzed. Interactions between online and offline are also very important in the educational process. For this reason, we introduced a new concept, called TOTO ("Teaching Online, Transfer Offline" ↔ "Transfer Offline, Teaching Online"). This slogan is meant to promote the acquisition and transfer of knowledge in the future. Particular importance was given to studying the effects of the interactions between Personal Online Learning Networks and Offline Learning Teams. Since social media is a common tool for most socio-economic activities, it has been considered necessary to carry out a case study on the interactions specific to this environment.
    Type of Medium: Online Resource
    ISSN: 2391-8160
    URL: Article
    DOI: 10.1515/cplbu-2017-0042
    Language: English
    Publisher: Walter de Gruyter GmbH
    Publication Date: 2017
    detail.hit.zdb_id: 2935624-6
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  • 6
    Online Resource
    Online Resource
    The Influence of Sample Size on Long-Term Performance of a 6σ Process
    MDPI AG ; 2023
    In:  Processes Vol. 11, No. 3 ( 2023-03-06), p. 779-
    Details
    In: Processes, MDPI AG, Vol. 11, No. 3 ( 2023-03-06), p. 779-
    Abstract: There are many criticisms for the association between the Six Sigma concept and the two statistical metrics associated to 6σ processes: 1.5σ shift for maximum deviation and 3.4 PPM non-conformities for the long-term performance. As a result, the paper aims to carry out an analysis of this problem, and the first result obtained is that a stable process can reach a maximum drift, but its value depends on the volume of the sample. It is also highlighted that, using only the criterion “values outside the control limits” for monitoring stability through the Xbar chart, a minimum value can be calculated for the long-term performance of a process depending on the sample size. The main conclusion resulting from the calculations is that, in the case of a 6σ process, the long-term performance is much better than the established value of 3400 PPB: For small volume samples of two pieces it is below 700 PPB, for three pieces it is below 200 PPB, and for samples with a volume greater than or equal to four pieces the performance already reaches values below 100 PPB! So, the long-term performance of 6σ processes is certainly even better than the known value of 3.4 PPM.
    Type of Medium: Online Resource
    ISSN: 2227-9717
    URL: Article
    DOI: 10.3390/pr11030779
    Language: English
    Publisher: MDPI AG
    Publication Date: 2023
    detail.hit.zdb_id: 2720994-5
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  • 7
    Online Resource
    Online Resource
    Intellectual Capital Policy in Universities. Case study: "Lucian Blaga" University of Sibiu, Romania
    National University of Political Studies and Public Administration (SNSPA) ; 2013
    In:  Management Dynamics in the Knowledge Economy Vol. 6, No. 4 ( 2013), p. 627-643
    Details
    In: Management Dynamics in the Knowledge Economy, National University of Political Studies and Public Administration (SNSPA), Vol. 6, No. 4 ( 2013), p. 627-643
    Type of Medium: Online Resource
    ISSN: 2392-8042
    URL: Issue
    URL: Journal
    URL: Article
    DOI: 10.25019/MDKE/6.4.
    DOI: 10.25019/MDKE
    DOI: 10.25019/MDKE/6.4.08
    Language: Unknown
    Publisher: National University of Political Studies and Public Administration (SNSPA)
    Publication Date: 2013
    detail.hit.zdb_id: 2819566-8
    SSG: 3,2
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  • 8
    Online Resource
    Online Resource
    Actualities and pragmatic perspectives of total quality management in the automotive knowledge-based organization
    Academia Oamenilor de Stiinta din Romania ; 2023
    In:  Annals of the Academy of Romanian Scientists Series on Engineering Sciences Vol. 15, No. 1 ( 2023), p. 5-20
    Details
    In: Annals of the Academy of Romanian Scientists Series on Engineering Sciences, Academia Oamenilor de Stiinta din Romania, Vol. 15, No. 1 ( 2023), p. 5-20
    Abstract: In the context of sustainable development and continuous improvement, it can be stated that the implementation of an integrated quality management in a modern organization can only be achieved under the conditions of implementing a series of concepts, among which we can mention knowledge management, total quality management, Kaizen management and related standards, quality management strategies and policies but also quality management techniques, methods, and tools. The scientific paper presents an own point of view regarding the pathway for a sustainable implementation of the previously presented concepts in an organization in the automotive field. The aspects identified in a real organization in the automotive industry are presented as well as the way considered to be possible to implement so that the organization can be considered a knowledge-based organization. In this context, the role of management in the organization is extremely important and value analysis becomes a priority. The main objective of the scientific paper is to propose a certain way of managerial thinking so that those interested can apply the quality management strategies and policies proposed for the sustainable implementation of total quality management within an organization based on knowledge in the automotive field.
    Type of Medium: Online Resource
    ISSN: 2066-6950 , 2066-8570
    URL: Issue
    URL: Journal
    URL: Article
    DOI: 10.56082/annalsarscieng.2023.1
    DOI: 10.56082/annalsarscieng
    DOI: 10.56082/annalsarscieng.2023.1.5
    Language: Unknown
    Publisher: Academia Oamenilor de Stiinta din Romania
    Publication Date: 2023
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  • 9
    Online Resource
    Online Resource
    Irregular Shape Effect of Brass and Copper Filler on the Properties of Metal Epoxy Composite (MEC) for Rapid Tooling Application
    MDPI AG ; 2022
    In:  Journal of Manufacturing and Materials Processing Vol. 6, No. 6 ( 2022-11-02), p. 134-
    Details
    In: Journal of Manufacturing and Materials Processing, MDPI AG, Vol. 6, No. 6 ( 2022-11-02), p. 134-
    Abstract: Due to their low shrinkage and easy moldability, metal epoxy composites (MEC) are recognized as an alternative material that can be applied as hybrid mold inserts manufactured with rapid tooling (RT) technologies. Although many studies have been conducted on MEC or reinforced composite, research on the material properties, especially on thermal conductivity and compressive strength, that contribute to the overall mold insert performance and molded part quality are still lacking. The purpose of this research is to investigate the effect of the cooling efficiency using MEC materials. Thus, this research aims to appraise a new formulation of MEC materials as mold inserts by further improving the mold insert performance. The effects of the thermal, physical, and mechanical properties of MEC mold inserts were examined using particles of brass (EB), copper (EC), and a combination of brass + copper (EBC) in irregular shapes. These particles were weighed at percentages ranging from 10% to 60% when mixed with epoxy resin to produce specimens according to related ASTM standards. A microstructure analysis was made using a scanning electron microscope (SEM) to investigate brass and copper particle distribution. When filler composition was increased from 10% to 60%, the values of density (g/cm3), hardness (Hv), and thermal conductivity (W/mK) showed a linear upward trend, with the highest value occurring at the highest filler composition percentage. The addition of filler composition increased the compressive strength, with the highest average compressive strength value occurring between 20% and 30% filler composition. Compressive strength indicated a nonlinear uptrend and decreased with increasing composition by more than 30%. The maximum value of compressive strength for EB, EC, and EBC was within the range of 90–104 MPa, with EB having the highest value (104 MPa). The ANSYS simulation software was used to conduct a transient thermal analysis in order to evaluate the cooling performance of the mold inserts. EC outperformed the EB and EBC in terms of cooling efficiency based on the results of thermal transient analysis at high compressive strength and high thermal conductivity conditions.
    Type of Medium: Online Resource
    ISSN: 2504-4494
    URL: Article
    DOI: 10.3390/jmmp6060134
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2911715-X
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  • 10
    Online Resource
    Online Resource
    The Role of Intermediaries in Supporting Collaboration for Sustainability: A Model of Commissioning Intervention in the Multi-Stakeholder Collaboration for Sustainable Territorial Development
    MDPI AG ; 2020
    In:  Sustainability Vol. 12, No. 17 ( 2020-08-20), p. 6769-
    Details
    In: Sustainability, MDPI AG, Vol. 12, No. 17 ( 2020-08-20), p. 6769-
    Abstract: The intervention of intermediaries in supporting collaboration for sustainability is considered an effective way to address the challenges faced by all parties involved in this type of commitment. Our paper includes several less frequently approached perspectives in this field of research and refers to the intervention of commissioning in supporting collaborative relationships with multiple stakeholders for sustainable territorial development. This paper proposes a model of structural and systemic development of commissioning at the national level, by specific geographical regions and development domains, and analyzes how commissioning structures intermediate the connection between multiple stakeholders, public authorities, and other relevant actors from different sectors of society, which mobilize resources to solve sustainability issues. The results show that the intervention of commissioning adds value to sustainability collaboration by providing stakeholders with an accessible and updated database specialized in development domains, where demands and offers for development resources can be managed safely, and the identification of the appropriate offer is carried out operatively through fast and secure computer systems able to create efficient and prompt connections. We believe that the model presented in the paper can be extended internationally to support global collaboration for sustainability, and we suggest further research in this direction.
    Type of Medium: Online Resource
    ISSN: 2071-1050
    URL: Article
    DOI: 10.3390/su12176769
    Language: English
    Publisher: MDPI AG
    Publication Date: 2020
    detail.hit.zdb_id: 2518383-7
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