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Found 6289 publications

A friction and wear study of laboratory aged engine oil in the presence of diesel fuel and oxymethylene ether

Ibolya Zsoldos András Lajos Nagy Jan Knaup

Publication Name: Tribology Materials Surfaces and Interfaces

Publication Date: 2019-01-02

Volume: 13

Issue: 1

Page Range: 20-30

Description:

Non-fossil fuels for the commercial and passenger vehicle sector are gaining more importance due to their positive effects on exhaust gas emissions. Ongoing research investigating a broad variety of biofuels, synthetic fuels and regenerative fuels shows that a reduction of CO 2 emissions can be possible without major modifications to the existing vehicle infrastructure. An internal combustion engine is a complex system of physical and chemical mechanisms, all of which contribute to the performance output, exhaust gas composition, durability and longevity of the engine. Modifying the fuel will not only result in differing chemical reactions and thermodynamic efficiency but will also affect friction and wear through the dilution and degradation of the lubricant. This study aims to investigate the variation of friction and wear in a model system due to the introduction of oxymethylene ether and regular diesel fuel to the lubricant. High-frequency reciprocating rig experiments will be carried out on 100Cr6 steel specimen with laboratory aged fully formulated commercially available SAE 0W-20 grade engine oil containing defined amounts of OME 3−5 and regular diesel fuel. The surface of the steel specimen will be analysed using optical microscopy and scanning electron microscopy.

Open Access: Yes

DOI: 10.1080/17515831.2018.1558026

The Development of Mood Repair Response Repertories: I. Age-Related Changes Among 7- to 14-Year-Old Depressed and Control Children and Adolescents

Krisztina Kapornai László Mayer Nestor L. Lopez-Duran Maria Kovacs ldiko Baji Ágnes Vetró Enikö Kiss Maria Kovacs Charles George

Publication Name: Journal of Clinical Child and Adolescent Psychology

Publication Date: 2019-01-02

Volume: 48

Issue: 1

Page Range: 143-152

Description:

The purpose of this study was to test developmentally informed hypotheses about regulatory responses to sadness that attenuate versus exacerbate it (adaptive versus maladaptive mood repair responses, respectively) across late childhood, early adolescence, and mid-adolescence. In a multi-site study in Hungary, clinic-based, 7- to 14-year-olds with Diagnostic and Statistical Manual of Mental Disorders’ (4th ed., text rev.) depressive disorders (N = 697; 55% male) and age/sex matched (at 1:2) nondepressed, school-based controls (N = 1,394) reported on their usual responses to sadness/dysphoria; parental reports were obtained separately. Adaptive and maladaptive response repertoire scores were compared across ages within and across subject groups, and by informant, controlling for confounds. Contrary to Hypothesis 1, older (vs. younger) youths in both groups reported fewer adaptive regulatory responses. Maladaptive response repertoires were unrelated to age among controls but significantly increased with age among depressed youths, particularly the girls. Partially supporting Hypothesis 2, subject groups differed in age-related trajectories of mood repair repertories, but not as expected (e.g., younger depressed children reported larger adaptive response repertoires than did controls). Parental reports revealed no developmental changes in offspring’s mood repair repertories. Parent-offspring reports were most discordant for younger (vs. older) offspring, tended to converge around age 11, and were consistently and significantly larger in the depressed sample. Self-reported adaptive mood repair repertories appear to have been laid down by late childhood and then undergo “trimming” across ages 7–14 years. The extensive maladaptive mood repair response repertoires of depressed youths, which increased with age, distinguish them primarily from controls. Therefore, reducing maladaptive regulatory responses to sadness should be a priority when treating depressed youths.

Open Access: Yes

DOI: 10.1080/15374416.2017.1399399

Validation of the overall stability design methods (OSDM) for tapered members

No authors available

Publication Name: Stability and Ductility of Steel Structures - Proceedings of the International Colloquia on Stability and Ductility of Steel Structures, 2019

Publication Date: 2019-01-01

Volume:

Issue:

Page Range: 1111-1119

Description:

Two new stability design methods are demonstrated and validated: the Overall Strength Reduction Method (OSRM) and the Overall Imperfection Method (OIM). Both methods are based on the linear buckling analysis (LBA) of global structural models and use the standard reduction curves. The OSRM is formulated in the classic way using generalized slenderness and reduction factors while the OIM uses equivalent amplitude for the buckling mode based geometrical imperfection. These new design methods cover all types of buckling modes, which can be calculated by LBA of structural models composed of tapered members with arbitrary support conditions and subjected to any complex loading. This paper clarifies the mechanical interpretation and proper calculation of all the components of the two methods in case of tapered members with arbitrary support conditions. The validation is performed on GMNIA results for several different buckling situations of tapered members proving the accuracy of the OSDM.

Open Access: No

DOI: DOI not available

Warping transfer superelement model for bolted end-plate connections subject to 3D loads

No authors available

Publication Name: Stability and Ductility of Steel Structures - Proceedings of the International Colloquia on Stability and Ductility of Steel Structures, 2019

Publication Date: 2019-01-01

Volume:

Issue:

Page Range: 1210-1217

Description:

A simple beam element based modelling technique has been developed which makes possible to analyze frames made of I sections with column-rafter bolted end-plate connections, subject to 3D loads, compatible with the thin walled beam theory with 7DOF beam elements. The model previously developed by the same team for welded connections has been ex-tended with the addition of linear spring elements to model the bolts located at the upper and lower beam flange level. The spring stiffnesses are calculated based on the extension of the Eurocode component method and verified by simulations performed with FEA software Abaqus.

Open Access: No

DOI: DOI not available

The Method of Fundamental Solutions Combined with a Multi-level Technique

Csaba Gáspár

Publication Name: Lecture Notes in Computer Science Including Subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics

Publication Date: 2019-01-01

Volume: 11386 LNCS

Issue: Unknown

Page Range: 241-249

Description:

A traditional idea of the Method of Fundamental Solutions is to use some external source points where the fundamental solution should be shifted to. However, the proper definition of the locations of the sources can hardly be performed in an automated way. To circumvent this difficulty, in this paper, the source points defined along the boundary, and the collocation points are shifted to the interior of the domain together with a proper modification of the boundary conditions. Thus, the problem of singularity is avoided. The modified boundary conditions are defined on the basis of the tools of the classical finite difference methods. Several schemes are presented. The schemes can be embedded in a multi-level context in a natural way. The proposed method avoids the computational difficulties due to ill-conditioned matrices and also reduces the computational complexity of the Method of Fundamental Solutions.

Open Access: Yes

DOI: 10.1007/978-3-030-11539-5_26

Warping transfer superelement model for bolted end-plate connections subject to 3D loads

B. Vaszilievits-Sömjén Majid Movahedi Rad J. Szalai

Publication Name: Stability and Ductility of Steel Structures Proceedings of the International Colloquia on Stability and Ductility of Steel Structures 2019

Publication Date: 2019-01-01

Volume: Unknown

Issue: Unknown

Page Range: 1210-1217

Description:

A simple beam element based modelling technique has been developed which makes possible to analyze frames made of I sections with column-rafter bolted end-plate connections, subject to 3D loads, compatible with the thin walled beam theory with 7DOF beam elements. The model previously developed by the same team for welded connections has been ex-tended with the addition of linear spring elements to model the bolts located at the upper and lower beam flange level. The spring stiffnesses are calculated based on the extension of the Eurocode component method and verified by simulations performed with FEA software Abaqus.

Open Access: Yes

DOI: DOI not available

Development of a reduced fat and lactose-free dairy spread containing viable lactic acid bacteria – part 1: Technology of manufacture

Gábor Kátay László Varga

Publication Name: Elelmiszervizsgalati Kozlemenyek

Publication Date: 2019-01-01

Volume: 65

Issue: 2

Page Range: 2470-2485

Description:

The popularity of buttercream, considered to be a reduced energy, cheaper version of butter with a better function of use, has been constant in Hungary for three and a half decades. Our objective was to develop a new type of functional buttercream manufacturing technology. In order to achieve this, the pressure value resulting in parameters ensuring the adequate texture and good adsorption of the finished product during the one-stage homogenization of 30% fat cream was determined, as well as to what extent the viscosity of cream and its ease of handling are affected by ho-mogenization. It has been found that the criteria for the homogenization effect can be achieved by single homogenization of a 30% fat cream containing a milk protein con-centrate serving as the raw material for the new type of butter product on a single-stage homogenization machine at 65 °C and 15 MPa (150 bar). Due to the increased viscosity of the cream treated this way, the use of a tubular or scraped-surface heat exchanger is recommended. Our reduced fat, lactose-free buttercream with live cul-ture can be manufactured safely with the technology developed, and with the enzyme and starter cultures used, the lactose content of the product will be less than 0.1%.

Open Access: Yes

DOI: DOI not available

Validation of the Overall Stability Design Methods (OSDM) for tapered members

G. Hajdú Ferenc Papp J. Szalai

Publication Name: Sdss 2019 International Colloquium on Stability and Ductility of Steel Structures

Publication Date: 2019-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

Two new stability design methods are demonstrated and validated: the Overall Strength Reduction Method (OSRM) and the Overall Imperfection Method (OIM). Both methods are based on the linear buckling analysis (LBA) of global structural models and use the standard reduction curves. The OSRM is formulated in the classic way using generalized slenderness and reduction factors while the OIM uses equivalent amplitude for the buckling mode based geometrical imperfection. These new design methods cover all types of buckling modes, which can be calculated by LBA of structural models composed of tapered members with arbitrary support conditions and subjected to any complex loading. This paper clarifies the mechanical interpretation and proper calculation of all the components of the two methods in case of tapered members with arbitrary support conditions. The validation is performed on GMNIA results for several different buckling situations of tapered members proving the accuracy of the OSDM.

Open Access: Yes

DOI: DOI not available

The mechanical and the geometrical state of railway vehicle carriages

No authors available

Publication Name: Proceedings - 25th Danubia-Adria Symposium on Advances in Experimental Mechanics, DAS 2008

Publication Date: 2019-01-01

Volume:

Issue:

Page Range: 181-182

Description:

Open Access: No

DOI: DOI not available