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Enhanced air-coupled impact echo technique by phase analysis of signals from multiple sensors

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Earthquake Engineering and Engineering Vibration 2024年第2期23卷 297-310页

作者： Najjiya Almallah nenad Gucunski New Jersey Department of Transportation New Jersey 08625USA Department of Civil&Environmental Engineering Rutgers University-New BrunswickNJ 08854USA

This paper presents an air-coupled impact echo(IE)technique that relies on the phase spectrum of the collected data to find the frequencies corresponding to the reflections from *** proposed technique takes advantage of the fact that the IE compression wave is not a propagating wave,but it is the 1st order symmetrical(S1)mode Lamb wave at zero group velocity(S1-ZGV).Therefore,it searches the phase spectra of the data collected by multiple sensors to locate the frequency corresponding to the lowest phase *** a result,the technique reduces the effect of propagating waves,including the direct acoustic wave and ambient *** is named the Constant Phase IE(CPIE).The performance of the CPIE is experimentally compared with the regular amplitude spectrum-based IE technique and two other multisensor IE *** CPIE shows a performance advantage,especially in a noisy environment.

关键词： nondestructive testing(NDT) nondestructive evaluation(NDE) bridge inspection bridge evaluation impact echo bridge delamination concrete bridge deck air-coupled sensing MEMS

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Target acquisition performance in the presence of JPEG image compression

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Defence Technology（防务技术） 2024年第3期33卷 30-41页

作者： Boban Bondzulic nenad Stojanovic Vladimir Lukin Sergey A.Stankevich Dimitrije Bujakovic Sergii Kryvenko University of Defence in Belgrade Military AcademyVeljka Lukica Kurjaka 3311000 BelgradeSerbia National Aerospace University Department of Information-Communication TechnologiesChkalova 1761070 KharkivUkraine National Academy of Sciences of Ukraine Scientific Centre for Aerospace Research of the EarthOles Honchar 55-b01054 KyivUkraine

This paper presents an investigation on the effect of JPEG compression on the similarity between the target image and the background,where the similarity is further used to determine the degree of clutter in the *** new clutter metrics based on image quality assessment are introduced,among which the Haar wavelet-based perceptual similarity index,known as HaarPSI,provides the best target acquisition prediction *** is shown that the similarity between the target and the background at the boundary between visually lossless and visually lossy compression does not change significantly compared to the case when an uncompressed image is *** future work,through subjective tests,it is necessary to check whether this presence of compression at the threshold of just noticeable differences will affect the human target acquisition *** values are compared with the results of subjective tests of the well-known target Search_2 database,where the degree of agreement between objective and subjective scores,measured through linear correlation,reached a value of 90%.

关键词： JPEG compression Target acquisition performance Image quality assessment Just noticeable difference Probability of target detection Target mean searching time

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High-fidelity model to predict heat transfer enhancement for liquid film boiling on uniform micro-structured wicking surfaces

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National Science Review 2024年第06期 93-95页

作者： Vishwanath Ganesan Mohammad Jalal Inanlu nenad Miljkovic Department of Mechanical Science and Engineering University of Illinois Urbana-Champaign Department of Electrical and Computer Engineering University of Illinois Urbana-Champaign Materials Research Laboratory University of Illinois Urbana-Champaign International Institute for Carbon Neutral Energy Research (WPI-I2CNER) Kyushu University Institute for Sustainability Energy and Environment (iSEE)University of Illinois Urbana-Champaign

The field of thermal management in highpower electronic devices is a critical area of study, focusing on the efficient dissipation of heat to prevent device overheating and failure [1]. A key aspect of this field is understanding the dynamics of thin liquid film boiling, both on uniform and non-uniform micro-structured wicking surfaces, which can significantly enhance the heat transfer effectiveness[2].

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Functional Dependence of IM and HV Angle in Hallux Valgus Deformity before and after Operative

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Journal of Applied Mathematics and Physics 2024年第5期12卷 1626-1646页

作者： nenad Stojanović Mirko Sovilj Vesna Ivanišević Department of Mathematics Faculty of Philosophy University of Banja Luka Banja Luka Bosnia and Herzegovina Higher Medical School Prijedor Bosnia and Herzegovina Faculty of Medicine University of Banja Luka Banja Luka Bosnia and Hercegovina

Hallux valgus is a relatively common and multifaceted complex deformity of the front part of the foot. It is the result of multiple effects of innate (endogenous) and exogenous etiological factors with different degrees of influence. The degree of hallux valgus deformity is usually assessed by radiological values of hallux valgus (HV) and intermetatarsal (IM) angles. The aim of the paper is to justify the definition of hallux valgus deformity as a function of one angle, (HVA or IMA), and then to determine the functional connection and the most suitable function equalizing the values of the angles IMA and HVA. As hallux valgus is a double angulation deformity, the analytically determined connection between the HVA and IMA angles reduces the study of the deformity to the study of function with one argument, and makes the analysis of deformity changes before and after operative treatment simpler. For the determined connections between the angles, the values of linear proportionality coefficients and regression coefficients of corresponding linear functions of analytical equalization of the value of the IM angle and the degree of deformity for a given value of the HV angle were experimentally determined. The obtained results were checked on a sample of 396 operatively treated hallux valgus deformities. The presented analytical approach and the obtained functional links of IMA and HVA enable quantitative observation of the change in the degree of deformity based on the radiologically determined value of these angles, and the established nonlinear function will be useful for evaluating the expected value of the IM angle and the degree of deformity based only on the measured value of the HV angle. .

关键词： Functional Connection of Deformity Angles Analytical Equalization of IM Angle Values Hallux Valgus Intermetatarsal Angle Correction of Deformity

Pour un avenir plus sûr

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Associations of cerebrospinal fluid amyloidogenic nanoplaques with cytokines in Alzheimer’s disease

今日中国（法文版） 2024年第7期 38页

作者： nenad STEKIĆ

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Translational Neurodegeneration 2021年第2期10卷 230-239页

作者： Mari Aksnes Hans Christian DAass Ann Tiiman Trine Holt Edwin Lars Terenius nenad Bogdanovic Vladana vukojevic Anne-Brita Knapskog Department of Geriatric Medicine Institute of Clinical MedicineFaculty of MedicineUniversity of OsloOsloNorway Department of Medical Biochemistry Oslo University HospitalOsloNorway Department of Clinical Neurosciences(CNS) Center for Molecular Medicine CMM L8:01Karolinska InstitutetStockholmSweden Department of Geriatric Medicine The Memory ClinicOslo University HospitalOsloNorway Institute of Health and Society Faculty of MedicineUniversity of OsloOsloNorway Norwegian National Advisory Unit on Ageing and Health Vestfold Hospital TrustTonsbergNorway Department of Neurobiology Care Science and Society(NVS)Division of Clinical GeriatricsKarolinska InstitutetHuddingeSweden

Background:The aggregation of amyloidβ(Aβ)is central in the pathogenesis of Alzheimer’s disease(AD).Recently it has been shown that specifically,larger,Thioflavin T-binding Aβaggregates are associated with increased neuroinflammation and cytokine *** study was aimed to quantify fibrillary amyloid aggregates,so-called nanoplaques,and investigate their relationship with cytokines in the cerebrospinal fluid(CSF).Methods:CSF was collected from 111 patients assessed for cognitive complaints at the Oslo University Hospital Memory *** patients were grouped based on their amyloid *** CSF nanoplaque concentration was quantified with the Thioflavin T-fluorescence correlation spectroscopy(ThT-FCS)*** levels of nine cytokines(eotaxin-1,granulocyte stimulating factor,interleukin[IL]-6,IL-7,IL-8,monocyte chemoattractant protein-1,gammainduced protein 10,macrophage inflammatory protein[MIP]-1α,and MIP-1β)were quantified with a magnetic bead-based multiplex assay and read on a Luminex IS 200 ***:There were 49 amyloid-negative and 62 amyloid-positive patients in the cohort;none of the cytokines differed significantly between the amyloid *** increased nanoplaque levels were associated with levels of MIP-1βbelow the lower limit of quantification,and with decreased levels of MIP-1αand *** associations remained significant when adjusted for age,sex,cognitive function,apolipoproteinε4 status and CSF core biomarker ***:The cytokine levels were not associated with amyloid status in this *** nanoplaque levels were negatively associated with MIP-1β,MIP-1αand IL-8,which is in line with recent findings suggesting that the upregulation of some cytokine markers has a protective role and is negatively associated with AD progression.

关键词： Alzheimer's disease Amyloid Amyloid beta peptides Amyloidogenic proteins Biomarkers Cerebrospinal fluid Cytokines Inflammation Fluorescence correlation spectroscopy Thioflavin T

Numerical algorithm for rigid body position estimation using the quaternion approach

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Acta Mechanica Sinica 2018年第2期34卷 400-408页

作者： Miodrag Zigic nenad Grahovac Department of Mechanics Faculty of Technical SciencesUniversity of Novi Sad

This paper deals with rigid body attitude estimation on the basis of the data obtained from an inertial measurement unit mounted on the body. The aim of this work is to present the numerical algorithm, which can be easily applied to the wide class of problems concerning rigid body positioning, arising in aerospace and marine engineering, or in increasingly popular robotic systems and unmanned aerial vehicles. Following the considerations of kinematics of rigid bodies, the relations between accelerations of different points of the body are given. A rotation matrix is formed using the quaternion approach to avoid singularities. We present numerical procedures for determination of the absolute accelerations of the center of mass and of an arbitrary point of the body expressed in the inertial reference frame, as well as its attitude. An application of the algorithm to the example of a heavy symmetrical gyroscope is presented, where input data for the numerical procedure are obtained from the solution of differential equations of motion, instead of using sensor measurements.

关键词： Rigid body Kinematics Inertial measurement unit Euler parameters Quaternion

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Estimation of Stability Constants of Copper（Ⅱ） Complexes with a-Amino Acids Using Connectivity Index 3xV, Common Model for the Binary and Ternary Complexes

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Chinese Journal of Chemistry 2011年第9期29卷 1800-1804页

作者： Milicevic, Ante Raos, nenad Institute for Medical Research and Occupational Health Ksaverska c. 2 P. O. Box 291 HR-I O001 Zagreb Croatia

Models for estimation of the first （K1）, second （K2）, and overall stability constant （β2） of copper（II） chelates with naturally occurring amino acids, based on the valence connectivity index of the 3rd order （3Xr）, were improved by introduction of a square term and a new graph representation for mono-complexes （MLCor）. The models gave SE = 0.07, 0.05--0.07 and 0.05--0.08 for lg Ki, lg K2 and lg ,62 constants, respectively; models that encompass both bi- nary and ternary bis-complexes included indicator variable. We also validated our models on the test set which in- cluded two mono-, two binary and two ternary Cu（II） chelates with a-aminobutanoic acid and a-aminopentanoic acid, not included into the calibration. The absolute differences between experimental and predicted stability con- stants were in the range of 0.01--0.16.

关键词： copper(Ⅱ) chelate regression models topological indices computational chemistry molecular model-ing

Novel green technology for wastewater treatment: Geo-material/geopolymer applications for heavy metal removal from aquatic media

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International Journal of Sediment Research 2023年第1期38卷 33-48页

作者： nenad Grba Andre Baldermann Martin Dietzel Department of Chemistry Biochemistry and Environmental Protection Faculty of Sciences University of Novi Sad Institute of Applied Geosciences and NAWI Graz Geocenter Graz University of Technology

The aim of this paper is to show the concise chemico-physical adsorbent performance of water purification systems utilizing geo-(e.g., allophane, clinoptilolite, and smectite) and bio-polymer materials(e.g.,chitosan or cellulose nanocomposite materials) and to propose an optimal ground-water remediation technique. The performance of geo-materials is evaluated based on the individual sorption and immobilization capacities for various priority substances and pollutants(e.g., lead, zinc, cadmium, copper,arsenic, and others), their availability, and cost-efficient use. A systematic assessment of the sorption potential of geo-materials in comparison to other available sorbents used for the removal of harmful aqueous metal ions is made through a literature review. This paper introduces novel sustainable technologies based on natural and tailored silicate-polymerized substances(geo-materials and geopolymers),and highlights their applicability in the treatment of water and solid matter contaminated by heavy metal ions. The advantages of geo-materials and geopolymers over other commercially available sorbents used for heavy metal ion removal from solution are presented through a literature review. Benefits and current challenges of geo-materials and geopolymers applications in water processing technologies and in environmental remediation are discussed, with recognition of their performance, individual sorption and immobilization capacities, availability, and cost-efficient use. The applications described here comprise:(i) the removal of heavy metal ions from contaminated water using in-situ remediation strategies;(ii) heavy metal ion immobilization through co-precipitation with silicate binders in underground stabilization and waste solidification scenarios; and(iii) a proposal for a new geo-material/geopolymer-based solidification and stabilization technology for efficient, sustainable, and simultaneous treatment of soil/sediment and groundwater at environmental hotspots.

关键词： Geo-materials Heavy metal ions Environmental protection Water treatment Clay minerals Sustainability