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Quantitative Identification of Delamination Damage in Composite Structure Based on Distributed Optical Fiber Sensors and Model Updating

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Structural Durability & Health Monitoring 2024年第6期18卷 785-803页

作者： Hao Xu Jing Wang Rubin Zhu alfred.Strauss Maosen Cao Zhanjun Wu School of Materials Science and Engineering Dalian University of TechnologyDalian116000China School of Mechanics and Aerospace Engineering Dalian University of TechnologyDalian116000China Department of Civil Engineering and Natural Hazards University of Natural Resources and Life SciencesVienna1180Austria Department of Engineering Mechanics Hohai UniversityNanjingChina

Delamination is a prevalent type of damage in composite laminate *** accumulation degrades structural performance and threatens the safety and integrity of *** study presents a method for the quantitative identification of delamination identification in composite materials,leveraging distributed optical fiber sensors and a model updating ***,a numerical analysis is performed to establish a parameterized finite element model of the composite ***,this model subsequently generates a database of strain responses corresponding to damage of varying sizes and *** radial basis function neural network surrogate model is then constructed based on the numerical simulation results and strain responses captured from the distributed fiber optic ***,a multi-island genetic algorithm is employed for global optimization to identify the size and location of the *** efficacy of the proposed method is validated through numerical examples and experiment studies,examining the correlations between damage location,damage size,and strain *** findings confirm that the model updating technique,in conjunction with distributed fiber optic sensors,can precisely identify delamination in composite structures.

关键词： Composite structures fiber optic sensor damage identification model updating surrogate model

Prevalence of visual impairment and estimation of refractive errors among school children in Kakamega,Kenya

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International Journal of Ophthalmology(English edition) 2024年第5期17卷 932-939页

作者： Isabel Signes-Soler alfred.Ragot Sheilah Nangena Andrew Wekesa Raúl Montalbán Llamusí Department of Optics and Optometry and Vision Sciences Universidat de ValènciaBurjassotValencia 46010Spain NGO Vision Without Borders(Visio Sense Fronteres VSF)Calpe 03710AlicanteSpain Masinde Muliro University of Science and Technology P.O Box 190-50100KakamegaKenya Clinica Baviera Alicante C/Ausóy Monzó 16Alicante 03006Spain

AIM:To investigate the prevalence of visual impairment(VI)and provide an estimation of uncorrected refractive errors in school-aged children,conducted by optometry students as a community ***:The study was *** 3343 participants were included in the *** initial examination involved assessing the uncorrected distance visual acuity(UDVA)and visual acuity(VA)while using a+2.00 D *** inclusion criteria for a subsequent comprehensive cycloplegic eye examination,performed by an optometrist,were as follows:a UDVA<0.6 decimal(0.20 logMAR)and/or a VA with+2.00 D≥0.8 decimal(0.96 logMAR).RESULTS:The sample had a mean age of 10.92±2.13y(range 4 to 17y),and 51.3%of the children were female(n=1715).The majority of the children(89.7%)fell within the age range of 8 to *** the ethnic groups,the highest representation was from the Luhya group(60.6%)followed by Luo(20.4%).Mean logMAR UDVA choosing the best eye for each student was 0.29±0.17(range 1.70 to 0.22).Out of the total,246 participants(7.4%)had a full eye *** estimated prevalence of myopia(defined as spherical equivalent≤-0.5 D)was found to be 1.45%of the total *** around 0.18%of the total sample had hyperopia value exceeding+1.75 *** astigmatism(cil<-0.75 D)was found in 0.21%(7/3343)of the *** VI prevalence was 1.26%of the total *** our cases of VI,76.2%could be attributed to uncorrected refractive *** was detected in 0.66%(22/3343)of the screened *** was no statistically significant correlation observed between age or gender and refractive ***:The primary cause of VI is determined to be uncorrected refractive errors,with myopia being the most prevalent refractive error *** findings underscore the significance of early identification and correction of refractive errors in school-aged children as a means to alleviate the impact of VI.

关键词： visual impairment refractive errors myopia amblyopia sustainable development goals

Three- and Four-Dimensional Generalized Pythagorean Numbers

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Advances in Pure Mathematics 2024年第1期14卷 1-15页

作者： alfred.Wünsche Institute of Physics Humboldt University Berlin Germany

The Pythagorean triples (a, b | c) of planar geometry which satisfy the equation a2+b2=c2 with integers (a, b, c) are generalized to 3D-Pythagorean quadruples (a, b, c | d) of spatial geometry which satisfy the equation a2+b2+c2=d2 with integers (a, b, c, d). Rules for a parametrization of the numbers (a, b, c, d) are derived and a list of all possible nonequivalent cases without common divisors up to d2 is established. The 3D-Pythagorean quadruples are then generalized to 4D-Pythagorean quintuples (a, b, c, d | e) which satisfy the equation a2+b2+c2+d2=e2 and a parametrization is derived. Relations to the 4-square identity are discussed which leads also to the N-dimensional case. The initial 3D- and 4D-Pythagorean numbers are explicitly calculated up to d2, respectively, e2.

关键词： Number Theory Pythagorean Triples Tesseract 4-Square Identity Diophantine Equation

Confucius and American Democracy

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China Today 2024年第6期73卷 48-50页

作者： alfred.HORNUNG The Obama Institute for Transnational American Studies Johannes Gutenberg UniversityMainzGermany

UPON the establishment of European universities in the Middle Ages,the educational system in Western countries became characterized by an essentially Eurocentric *** was reflected in the study of Latin and Greek in high school,and in basing public life and political systems on philosophies of classical *** work of the influential Chinese philosopher Confucius(551-479 B.C.),a near-contemporary of the major Greek philosophers Socrates(469-399 B.C.),Plato(428-348 B.C.)and Aristotle(384-322 B.C.),whose ethical and political ideas entered into the constitutions of European states,remained unknown.

关键词： Latin Middle Confucius

Convergence Phenomenon with Fourier Series of tg(x2)and Alike

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Advances in Pure Mathematics 2024年第7期14卷 556-595页

作者： alfred.Wünsche Institut fr Physik Humboldt-Universitt Berlin Berlin Germany

The Fourier series of the 2π-periodic functions tg(x2)and 1sin(x)and some of their relatives (first of their integrals) are investigated and illustrated with respect to their convergence. These functions are Generalized functions and the convergence is weak convergence in the sense of the convergence of continuous linear functionals defining them. The figures show that the approximations of the Fourier series possess oscillations around the function which they represent in a broad band embedding them. This is some analogue to the Gibbs phenomenon. A modification of Fourier series by expansion in powers cosn(x)for the symmetric part of functions and sin(x)cosn−1(x)for the antisymmetric part (analogous to Taylor series) is discussed and illustrated by examples. The Fourier series and their convergence behavior are illustrated also for some 2π-periodic delta-function-like sequences connected with the Poisson theorem showing non-vanishing oscillations around the singularities similar to the Gibbs phenomenon in the neighborhood of discontinuities of functions. .

关键词： Gibbs Phenomenon Generalized Functions Weak Convergence Chebyshev Polynomials of First and Second Kind Even and Odd Generating Functions for Chebyshev Polynomials Polylogarithms Completeness Relations

Exactly Solvable Two-Parameter Models of Relativistic δ′s -Sphere Interactions in Quantum Mechanics

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Journal of Applied Mathematics and Physics 2024年第4期12卷 1263-1285页

作者： Jules Manirambona Juma Shabani alfred.Vyabandi Doctoral School University of Burundi Bujumbura Burundi Faculty of Sciences Doctoral School University of Burundi Bujumbura Burundi Institute of Applied Pedagogy University of Burundi Bujumbura Burundi

We make a systematic study of two-parameter models of δ ′ s -sphere interaction and δ ′ s -sphere plus a Coulomb interaction. Where δ ′ s interaction denotes the δ ′ -sphere interaction of the second kind. We provide the mathematical definitions of Hamiltonians and obtain new results for both models, in particular the resolvents equations, spectral properties and some scattering quantities.

关键词： Boundary Conditions Problem -Sphere Interactions Self-Adjoint Operator Resolvent Equation Spectral Properties Scattering Theory

Antimony, Arsenic and Thallium Bioaccumulation in Asiatic Clam (Corbicula fluminea) Transplanted along the Manadas Creek, Laredo, Texas

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Journal of Environmental Protection 2024年第4期15卷 379-400页

作者： Natasha Garcia Vaughan Thomas alfred.Addo-Mensah Department of Biology & Chemistry Texas A&M International University Laredo USA

Manadas Creek is an urban tributary of the Rio Grande that flows past a decommissioned antimony smelter and processing plant. This antimony plant is associated with heavy metal contamination in the creek and still poses a threat to the surrounding aquatic environment. Corbicula fluminea was used to determine bioaccumulation from the water column and sediments in Manadas Creek. The metals arsenic (As), antimony (Sb) and thallium (Tl) were analyzed in the water, sediments, gills, mantle, foot, digestive (DI) tract, gonads and shell of clams being monitored at eight sites between March and August 2013. Sediment, water, and dissected Corbicula fluminea samples from different sites in the Creek were acid-digested and analyzed by Inductively Coupled Plasma Optical Emission Spectroscopy. High levels of antimony (25.88 ug/L;75.96 mg/kg) and arsenic (8.26 ug/L;6.41 mg/kg) in the water and sediments were observed at the site downstream from the smelter. There were no detectable concentrations of arsenic, antimony, or thallium in the shell of C. fluminea. Arsenic and antimony were detected in the tissues of C. fluminea but thallium was not detected. Based on the results, the organotropism for arsenic is DI tract > gills > gonads > foot > mantle > shell and the organotropism for antimony is gills > DI tract > gonads > mantle > foot > shell. This study shows that the Asiatic clam (Corbicula fluminea) is a useful bio-monitor to provide data on the status of metal pollution in Manadas Creek, Laredo, Texas.

关键词： Biomarker Manadas Creek Rio Grande Heavy Metals Corbicula fluminea Biota Sediment Accumulation

Structural characterization and anti-inflammatory activities of novel polysaccharides obtained from Pleurotus eryngii

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Food Science and Human Wellness 2024年第5期13卷 3031-3042页

作者： Han Wang Sai Ma alfred.Mugambi Mariga Qiuhui Hu Qian Xu Anxiang Su Ning Ma Gaoxing Ma College of Food Science and Engineering Nanjing University of Finance and Economics/Collaborative Innovation Center for Modern Grain Circulation and SafetyNanjing 210023China School of Agriculture and Food Science Meru University of Science and TechnologyMeru 972-60200Kenya

Natural polysaccharides named PEP-0.1-1,PEP-0-1 and PEP-0-2 from edible mushroom species Pleurotus eryngii were obtained in the present *** showed that molecular weights of these polysaccharides were 3235,2041 and 23933 Da,***,structural characterization revealed that PEP-0.1-1 had a→4-α-D-Glcp-1→backbone and contained→4)-α-D-Glcp and→4)-β-D-Glcp reducing end ***-0-1 backbone contained→4-α-D-Glcp-1→and→6-α-3-O-Me-D-Galp-1→,and the side chains containedα-D-Glcp,β-D-Manp-1→andα-D-Glcp-3→.However,PEP-0-2 backbone consisted of→4-α-DGlcp-1→and→6-α-3-O-Me-D-Galp-(1→6)-α-D-Galp-1→while the side chains containedα-D-Glcp andβ-D-Manp-1→.Biological activity analysis was then carried out and found that all these polysaccharides could significantly suppress the relative mRNA expression of toll-like receptor 4,nitric oxide(NO),tumor necrosis factor-α,interleukin(IL)-1βand IL-6 in lipopolysaccharide(LPS)-induced inflammation of RAW264.7 cells,as well as the over secretion of the above cell ***,Western blotting analysis revealed that all these purified fractions displayed significant inhibition effects on the expression of c-Jun N-terminal kinases protein induced by LPS in mitogen activated protein kinase pathway,along with the relieving on the inhibition effect of LPS on IκB-αprotein *** summary,the information generated by the present study could provide a theoretical basis for the exploration of novel healthy food materials from edible mushroom with antiinflammation activities.

关键词： Pleurotus eryngii Polysaccharides Structural characterization Anti-inflammatory activity

The Value of Rural Access Roads: The Case Study of Chepyuk and Mitira Wards in Bungoma and Kirinyaga Counties

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Open Journal of Applied Sciences 2024年第8期14卷 2249-2266页

作者： alfred.Eshitera Lawrence Esho Casty Gataaka Njoroge Yvone Balan Department of Spatial Planning and Design Technical University of Kenya Nairobi Kenya DigiReg Nairobi Kenya

In this paper we assess the impact of road network on rural regions development using a case study of Chepyuk and Mitira wards. The two case study areas were selected owing to their comparable agro ecological conditions but different political orientation. The wards have identical agro economic activities due to their similarity in climatic and ecological conditions. Household incomes earned from agricultural enterprises and bid rent per unit area of land are used as indicators of development. The condition of road network is used as an indicator of accessing the rural regions in various seasons of the year. The study provides evidence of the economic advantages associated with better market access, primarily due to the good road infrastructure in Mitira compared to Chepyuk. The good road condition is advantageous to Mitira ward residents allowing them to access other markets hence improving the farm gate value of their products. On the other hand, the prices for Chepyuk products are cheap due to constrained market access necessitated by the poor road condition. For instance, the average price of a liter of milk in Chepyuk ward is Kshs.36.65 compared to Mitira where it goes at Kh.55.08. It therefore implies in Chepyuk milk has to be sold at lower price since access to alternative markets is constrained by poor road condition. The disparity in the road network quality has been occasioned by investment policy by both colonial and consecutive post-independence governments which have given preference to the region where Mitira region is located. This is against the constitutional requirement which proposes an equalization fund for infrastructure development to regions lagging behind in terms of development.

关键词： Rural Areas Regional Development Road Network Kenya