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Found 6374 publications

Improving HPLC Analysis of Vitamin A and E: Use of Statistical Experimental Design

Lorinc Garai

Publication Name: Procedia Computer Science

Publication Date: 2017-01-01

Volume: 108

Issue: Unknown

Page Range: 1500-1511

Description:

Analyses of vitamin supplements A and E in food samples are performed mostly with high performance liquid chromatography (HPLC). In majority of cases, sample preparation preceding HPLC implies saponification, a step critical to heat sensitivity of analytes. The method of saponification is clearly defined by ISO standards, however, two important factors, temperature and time of saponification are only given in value ranges instead of exact settings. Resolving this deficiency with the promise of eliminating time and cost consuming experimental probes, statistical experimental design (SED) is introduced to find optimum settings of temperature and time for the best recovery of vitamin supplements in food samples. Finding the optimum settings in SED was supported with Statsoft Statistica 13 For illustrating SED, margarine samples supplemented with vitamin A and E were applied.

Open Access: Yes

DOI: 10.1016/j.procs.2017.05.177

Assessing the Performance of Machine Learning Algorithms in Predicting Buckling Moments of Corrugated Web Beams

Andreas Müller Nurullah Bektaş G. Hajdú

Publication Name: Advances in Transdisciplinary Engineering

Publication Date: 2024-01-01

Volume: 59

Issue: Unknown

Page Range: 121-127

Description:

I-beams with corrugated webs have higher torsional stiffness than that of flat web beams. Furthermore, the geometrical dimensions of the beam and the web corrugation heavily influence the precision of the currently used traditional pen-andpaper methods for determining the elastic lateral-torsional buckling moment. This study aims to suggest several machine learning models with the intention of predicting the elastic lateral-torsional buckling moment of corrugated web beams. Multiple machine learning models, including Random Forests, Gradient Boosting, Categorical Boosting, and Deep Neural Networks, were deployed to develop and train models to predict the elastic critical lateral-torsional buckling moments of Ibeams with corrugated web. The database used for training the different models was compiled through linear bifurcation analyses conducted on shell finite element models. The study evaluates the precision of the various machine learning models by examining their performance against statistical parameters derived from both predicted and test data. The findings from the parametric evaluation highlight the surprisingly high performance and accuracy of the machine learning models.

Open Access: Yes

DOI: 10.3233/ATDE240535

Exosomal small RNA profiling in first-trimester maternal blood explores early molecular pathways of preterm preeclampsia

Nándor Gábor Than Tamás I. Orbán Sándor Nagy Ábel Fóthi Gergő Orosz Luca Gál

Publication Name: Frontiers in Immunology

Publication Date: 2024-01-01

Volume: 15

Issue: Unknown

Page Range: Unknown

Description:

Introduction: Preeclampsia (PE) is a severe obstetrical syndrome characterized by new-onset hypertension and proteinuria and it is often associated with fetal intrauterine growth restriction (IUGR). PE leads to long-term health complications, so early diagnosis would be crucial for timely prevention. There are multiple etiologies and subtypes of PE, and this heterogeneity has hindered accurate identification in the presymptomatic phase. Recent investigations have pointed to the potential role of small regulatory RNAs in PE, and these species, which travel in extracellular vesicles (EVs) in the circulation, have raised the possibility of non-invasive diagnostics. The aim of this study was to investigate the behavior of exosomal regulatory small RNAs in the most severe subtype of PE with IUGR. Methods: We isolated exosomal EVs from first-trimester peripheral blood plasma samples of women who later developed preterm PE with IUGR (n=6) and gestational age-matched healthy controls (n=14). The small RNA content of EVs and their differential expression were determined by next-generation sequencing and further validated by quantitative real-time PCR. We also applied the rigorous exceRpt bioinformatics pipeline for small RNA identification, followed by target verification and Gene Ontology analysis. Results: Overall, >2700 small RNAs were identified in all samples and, of interest, the majority belonged to the RNA interference (RNAi) pathways. Among the RNAi species, 16 differentially expressed microRNAs were up-regulated in PE, whereas up-regulated and down-regulated members were equally found among the six identified Piwi-associated RNAs. Gene ontology analysis of the predicted small RNA targets showed enrichment of genes in pathways related to immune processes involved in decidualization, placentation and embryonic development, indicating that dysregulation of the induced small RNAs is connected to the impairment of immune pathways in preeclampsia development. Finally, the subsequent validation experiments revealed that the hsa_piR_016658 piRNA is a promising biomarker candidate for preterm PE associated with IUGR. Discussion: Our rigorously designed study in a homogeneous group of patients unraveled small RNAs in circulating maternal exosomes that act on physiological pathways dysregulated in preterm PE with IUGR. Therefore, our small RNA hits are not only suitable biomarker candidates, but the revealed biological pathways may further inform us about the complex pathology of this severe PE subtype.

Open Access: Yes

DOI: 10.3389/fimmu.2024.1321191

Thermodynamic tests with nano-ceramic thermal insulation coatings

David Bozsaky

Publication Name: Pollack Periodica

Publication Date: 2017-01-01

Volume: 12

Issue: 1

Page Range: 135-145

Description:

From nanotechnology-based thermal insulation materials nano-ceramic thermal insulation coatings are generally considered to be the most critical because of contradictory technical data that could be founded in special literature. Complete agreement had not been already found about the mechanism how does their insulating effect take. In the Laboratory of Building Materials and Building Physics at Széchenyi István University (Gyo′r, Hungary) several thermodynamic tests were made in order to find out thermodynamic process inside this material. Several building structures with different order of layers were tested with heat flow meter. Results showed that convective heat transfer coefficient cannot be taken account in usual way using this material as thermal insulation.

Open Access: Yes

DOI: 10.1556/606.2017.12.1.11

Plastic-limit probabilistic structural topology optimization of steel beams

Majid Movahedi Rad Muayad Habashneh

Publication Name: Applied Mathematical Modelling

Publication Date: 2024-04-01

Volume: 128

Issue: Unknown

Page Range: 347-369

Description:

This work presents a novel geometrically nonlinear analysis with imperfections reliability-based topology optimization (RBTO) approach, considering the volume fraction and geometric imperfections as random variables due to their crucial connections to the manufacturability of web openings in steel I-beams. The objective is achieved by controlling the plastic behavior through limit analysis, which imposes a limit on the plastic ultimate load multipliers. The suggested method is developed by imposing constraints related to the available material volume. The bi-directional evolutionary structural optimization (BESO) method is utilized to fulfill the objectives of this paper. The adequacy of the proposed technique is demonstrated by comparing the results of the algorithm with benchmark steel beams that have conventional web openings. Based on the numerical examples, it appears that the selected technique has the potential to increase the load capacity of steel beams while utilizing the same quantity of material within the design domain. Moreover, the improved beams also exhibit better performance in terms of stress levels. The results of this research suggest that the proposed technique enhances the load capacity of steel beams while maintaining the same quantity of material and improving their performance in terms of stress levels.

Open Access: Yes

DOI: 10.1016/j.apm.2024.01.029

Rattling detection of electric components

Zoltán Gazdagh J. A. Erdelyi A. Bartus B. Fukker

Publication Name: Proceedings of ISMA 2024 International Conference on Noise and Vibration Engineering and Usd 2024 International Conference on Uncertainty in Structural Dynamics

Publication Date: 2024-01-01

Volume: Unknown

Issue: Unknown

Page Range: 2799-2813

Description:

The study emphasizes the importance of detecting and addressing the issue of nonlinear phenomena in electronic components, due to their potential implications for structural integrity, damage or malfunction to sensitive electronic elements, and a reduction in overall vehicle reliability. This investigation based on time-domain experimental data facilitates rattling detection that aims to distinguish rattling from other type of nonlinearities. The sample is screwed on a fixture, which is mounted on an electrodynamic shaker that serves as the excitation source. The excitation signal is a closed loop sinusoidal sweep, measured in both directions and at different amplitudes. The paper will focus on several methods for identifying nonlinear phenomena, such as the Poincare map or Hilbert transformation. Phase plots are produced, that serve as a valuable tool for studying anomalies, which can be correlated to the extremes of Lyapunov exponents. The above methods are evaluated on their ability to separate rattling form other phenomena to identify genuine instances of rattling.

Open Access: Yes

DOI: DOI not available

FinTech credit using CBDC: Transformation of lending market

Jewel Kumar Roy Md Foysal Hasan

Publication Name: Exploring Central Bank Digital Currencies Concepts Frameworks Models and Challenges

Publication Date: 2024-03-07

Volume: Unknown

Issue: Unknown

Page Range: 158-168

Description:

The advancement of financial technology and the development of central bank digital currency (CBDC) are revolutionizing the lending market. FinTech credit and CBDC have disrupted traditional lending practices, providing new channels of financing for borrowers and increasing access to credit. This chapter explores the transformation in the lending market due to the advent of FinTech credit and CBDC. It analyses the impact of these developments on the lending market, borrowers, and financial institutions. The chapter also evaluates the challenges and opportunities presented by these innovations and the implications for regulators. Financial technology (FinTech) credit has rapidly emerged as a disruptive force in the lending market, and the use of central bank digital currency (CBDC) has the potential to further transform the lending market. This chapter aims to examine the potential impact of FinTech credit using CBDC on the lending market, analyse the benefits and challenges of this model, and provide recommendations for policymakers and market participants to foster its adoption.

Open Access: Yes

DOI: 10.4018/979-8-3693-1882-9.ch010

Theoretical models of cross-border integration

Tamás Hardi Andrea Uszkai

Publication Name: Socialni Studia Social Studies

Publication Date: 2017-01-01

Volume: 14

Issue: 1

Page Range: 9-30

Description:

This article attempts to summarize the most important definitions and theoretical models related to cross-border spatial integration based on scientific literature. It would not be possible without defining several border phenomena, because different types of borders have distinct features and form space differently. The role of borders has constantly changed over time, depending on the historical, political, geographical and other characteristics of the given region. There were times when a given border was easily permeable and at other times it was difficult to cross. Therefore, the depth of integration is also changeable. This article tries to collect the most important theoretical models which explain these cross-border spatial processes and emphasizes the importance of the characteristics of urban networks in cross-border integration. We think there are many conceptual models in international border studies which explain several border processes from different points of view, but they are not properly collected in order to explain the cross-border integration process. In addition, some theoretical models are inadequately positioned in the research of cross-border integration that is why we intend to analyze their relevance to this topic as well. Hopefully, our work will help to understand the main factors and elements influencing crossborder integration through the explanatory theoretical models collected here.

Open Access: Yes

DOI: 10.5817/soc2017-1-9

Experimental determination of plastic zones

E. Czoboly I. Havas B. Csizmazia

Publication Name: Materials Science

Publication Date: 1996-01-01

Volume: 32

Issue: 1

Page Range: 87-98

Description:

We present four experimental series for the determination of the size and shape of plastic zones due to monotonic and cyclic loadings. Specimens contain notches of various geometries but not cracks. This provides the possibility to study the effect of notch radius and the repetitions of loading without the disturbing influence of crack closure and the previous loading history. Different steels and aluminum alloys are involved. It is shown that the size of the zone increases significantly as a function of load cycles. © 1997 Plenum Publishing Corporation.

Open Access: Yes

DOI: 10.1007/BF02538929