Increase In Impedance Research Articles

THE INFLUENCE OF COBALT ON DENSITY AND ELECTRICAL RESISTIVITY OF Al–Ni–Co–Ce ALLOYS IN CRYSTALLINE AND LIQUID STATES

In this work were studied density (by gamma-absorption method) and electrical resistivity (by contactless method in rotating magnetic field) of Al–Ni–Co–Ce glass-forming alloys with different ratios of transition metals. It was found the existence of a wide two-phase zone was established and jump-like changes in properties at solidus and liquidus temperatures. Increasing of cobalt content from 2 to 4 at % leads to 2% decrease of density and 3% increase of electrical resistivity in crystalline and liquid states. Temperature coefficients of change in properties were calculated. Density hysteresis was detected, which occurs when melts are overheated above 1350 K. This fact is related to the disintegration of large-scale microheterogeneities that exist in melts during heating. It is shown that these results can be used to optimize the process of obtaining rapidly hardened alloys.

Identifying the influence of technological factors on the structure and properties of contact wire from secondary copper

This paper reports the analysis of studies on the use of secondary copper for the production of articles based on it, namely the contact wire for electric transport. The effect of the drawing step on the macro- and microstructure and physical and mechanical properties of the copper wire was studied. The optimal draw pitch for continuous copper casting is 8.2 mm. At a temperature of the melt (casting) of 1200 °C and a draw step of 8.2 mm, the average crystallization rate is ~300 °C/s. This provides sufficient time for crystallization, and with such parameters, the heat transfer from the metal receiver does not have a noticeable effect on the structure. At the same time, it was established that Mg is a modifier for liquid Cu while all other elements do not have such an effect and form solid solutions with copper. It is shown that the increase in the concentration of silver from 0.082 at% to 0.092 at% led to an increase in specific electrical resistance by 0.582 %. As for other elements, namely, iron, the change in its amount from 0.002 at% to 0.005 at% increased the specific resistance of copper by 1.733 %. The change in nickel concentration from 0.024 at% to 0.036 at% and tin from 0.0010 at% to 0.0035 at% led to its growth by 2.927 % and 1.269 %, respectively

Ensuring standardized parameters for the transmission of digital signals by twisted pairs at the technological stage of manufacturing cables for industrial operating technologies

Introduction. In production control and control systems, buildings use many simple devices - sensors to detect light, heat, movement, smoke, humidity and pressure, mechanisms for activation and control of switches, closing devices, alarm, etc. - «operating technologies» (OT). Different communication protocols and field tire technologies, such as Modbus for conditioning systems, Bacnet for access control and Lonworks for lighting, have been traditionally used and used for their connection. Network fragmentation leads to the need to use gateways to transform protocols when creating a single automation system, which complicates the implementation of complex control systems for any object. At the same time, information networks are unified, but the Ethernet protocol used in them for operating technologies for various reasons (technological, cost) has not been widespread. Due to its high bandwidth compared to existing field tire networks, industrial Ethernet is significantly capable of increasing flexibility in the implementation of additional functions in OT. Modern industrial Ethernet networks are based on non - shielded and shielded twisted pair category 5E cables. The presence of additional metal screens in the structure of twisted pair causes the increase in electrical resistance of conductors due to the effect of closeness, the electrical capacity, and the ratio of attenuation in the range of transmission of broadband signals. Purpose. Substantiation of the range of settings of technological equipment to ensure standardized values of the extinction coefficient and immunity based on the analysis of the results of measurements in a wide frequency range of electrical parameters of shielded and unshielded cables for industrial operating technologies. Methodology. Experimental studies have been performed for statistically averaged electrical parameters of the transmission of pairs for 10 and 85 samples of 305 meters long and shielded cables of category 5e, respectively. It is determined that in the frequency range from 1 to 10 MHz, unshielded cables have less values of the attenuation coefficient. In the range of more than 30 MHz, the shielded cables have smaller values of the attenuation due to the influence of the alumopolymer tape screen. It is established that the coefficient of paired correlation between asymmetries of resistance and capacity of twisted pairs is 0,9735 - for unshielded and 0,9257 - for shielded cables. The impact has been proven to a greater extent asymmetry of resistance the pairs on the increasing noise immunity of cables. The influence noise interference on the deviation of the diameter and electrical capacity of the isolated conductor from the nominal values in the stochastic technological process is analyzed. The strategy of technological process settings to ensure the attenuation and the noise immunity in the high -frequency range is substantiated. Practical value. Multiplicative interference, caused by random changes in the stochastic technological process, can lead to a deviation of diameter 2 times from the nominal value at level of probability at 50 %. The equipment settings of the technological equipment must guarantee the coefficient of variation capacity of the insulated conductor at 0.3 % for high level of noise immunity.

Failure analysis from microcracks to a dominant crack in MEMS thin films using combined damage and fracture mechanics

Reliability issues in MEMS devices are generally rooted in the evolution of microdefects in materials. Although the failure occurs at the top level of the device (macroscopic function), the root cause of the functional failure can be traced back to the bottom level (material micro defects). Therefore, it is crucial to consider the influence of material damage in the stress–strain constitutive equations to calculate the magnitude of crack propagation force. In this paper, a combined method of damage and fracture is considered for calculating the stress of crack tip of MEMS thin films. To calculate the initiations and growths of microcracks, continuum damage mechanics (CDM) is used. Based on the CDM method, a relationship between material degradation and the increase of electrical resistance is established. Through the established computational methods, we can perform a calculation analysis on the failure of MEMS caused by cracks. A multiscale quantification result establishes pairwise connections between material degradation characterization (damage D), crack propagation (tip stress K), and macroscopic performance (resistance R). This article provides a valuable theoretical basis for investigating the failure mechanisms of MEMS.

EXTRAORDINARY MAGNETORESISTANCE OF LASERANNEALED NANO BORON DEPOSITEDON OXIDIZED POROUS SILICON

This study explores the impact of laser annealing on the electrical and magnetic properties of nano boron deposited on oxidized porous silicon (n-B/PSiO2) and its potential for spintronic applications. The Nd: YAG laser was used at varying energies to anneal the n-B thin films. Increasing the laser energy increased grain size and more ordered grain structures. It also increased surface roughness due to forming new grain boundaries and secondary phases. The electrical properties of the material were also affected by the laser annealing, with an increase in forward and reverse current and an increase in electrical resistivity with increased annealing temperature. The study also found that the magnetoresistance of the material increased with increasing laser temperature, attributed to tunnel injection through the thin silicon dioxide layer, and could be up to 7 times higher than non-annealed n-B/PSiO2in a magnetic field. The study highlights the importance of controlling materials’ grain size and structure for their physical and electrical properties. In addition, it provides insights into the electronic properties of n-B/PSiO2and the behavior of charge carriers in a magnetic field.

A ROCK inhibitor suppresses the transforming growth factor-beta-2-induced endothelial–mesenchymal transition in Schlemm’s canal endothelial cells

In the normal eye, most of the aqueous humor drains through the trabecular meshwork (TM) and Schlemm’s canal (SC). The concentration of transforming growth factor beta 2 (TGF-β2) is increased in the aqueous humor of primary open angle glaucoma patients. TGF-β2 increases outflow resistance by affecting the TM and SC, and endothelial–mesenchymal transition (EndMT) of SC cells is involved in these changes. Here, we investigated the effect of a ROCK inhibitor on TGF-β2-induced EndMT in SC cells. The ROCK inhibitor Y-27632 suppressed the TGF-β2-induced increase in the trans-endothelial electrical resistance (TER) and proliferation of SC cells. Y-27632 suppressed the expression of α-SMA, N-cadherin, and Snail, which are upregulated by TGF-β2. Moreover, TGF-β2 decreased mRNA levels of bone morphogenetic protein (BMP) 4 and increased those of the BMP antagonist gremlin (GREM1), but Y-27632 significantly suppressed these changes. Y-27632 also inhibited TGF-β2-induced phosphorylation of p-38 mitogen-activated protein kinase (MAPK). BMP4 and the p-38 MAPK inhibitor SB203580 suppressed the TGF-β2-induced TER elevation in SC cells. Moreover, SB203580 suppressed TGF-β2-induced upregulation of fibronectin, Snail, and GREM1. These results indicate that a ROCK inhibitor inhibited the TGF-β2-induced EndMT in SC cells, implying the involvement of p38 MAPK and BMP4 signaling.

Electrical properties and thermally induced aging processes in eco-friendly Cu0.1Ni0.1Co1.6Mn1.2O4 and Cu0.1Ni0.8Co0.2Mn1.9O4-based thick-film structures for multisensor systems

The electrical properties and kinetic dependences of thermally induced drift of electrical resistance in eco-friendly single- and multilayer temperature-sensitive thick-film structures based on Cu0.1Ni0.1Co1.6Mn1.2O4 (with p+-type electrical conductivity) and Cu0.1Ni0.8Co0.2Mn1.9O4 (with p-type of electrical conductivity) ceramics for multisensor nanosystems. It has been established that in the p- and p+-type thick films the processes of burning out the residues of the organic bond between grain spinels and simultaneous penetration of metallic silver into the space are activated. Such processes are described by a compressed exponential-power relaxation function. Thick-film p+-p structures are characterized by own aging processes, which manifest themselves in an increase in electrical resistance. Kinetics of their thermally-induced aging is adequately described by an extended exponential-power function.

Electrorecrystallization of Invar 36 alloy

The recrystallization of the Invar 36 alloy after current stressing, at 8000–18000 A/cm2, was investigated with X-ray diffraction, electron back scattered diffraction and magnetic hysteresis. The electrical resistivity of the alloy increased by 10 % after electrical current stressing, while the microhardness did not show significant change. The average grain size was slightly refined, yet the grain size uniformity was improved by current stressing. The crystal orientation map shows the transition trend from (001) to (101) after current stressing. The pole figure analysis indicated that the Cube texture and the annealed twin were degraded after current stressing. Current stressing resulted in the transition of the Cube texture to Copper texture. The magnetic hysteresis analysis showed the structure did not exhibit much change to influence the coercive force. The increase in electrical resistivity was ascribed to the variation in texture and the possible increment of dislocation density as indicated by the Kernel Average Misorientation and X-ray diffraction results.

Dendritic Solidification and Physical Properties of Co-4.54%Sn Alloy with Broad Mushy Zone

The high undercooling of binary Co-4.54%Sn alloy has a significant influence on its microstructural characteristics and physical properties. Here, we report that the dendritic growth and physical properties of broad-temperature-range Co-4.54%Sn alloy remarkably depends on the undercooling during the rapid solidification. The maximum undercooling attains 208 K at molten state, and the dendritic growth velocity is quite sluggish in highly undercooled liquid Co-4.54%Sn alloy because it has a broad solidification range of 375 K (0.21 TL); the maximum value is only 0.95 m/s at the undercooling of 175 K, which then decreases with undercooling. The microstructure refines visibly and the volume fraction of the interdendritic βCo3Sn2 phase obviously decreases with undercooling. The microhardness and electrical resistivity increase with undercooling owing to the enhancement of solute content of the primary αCo phase and refinement of the microstructure where the increased crystal boundary hinders the electronic transmission. Meanwhile, the saturation magnetization also reduces with undercooling due to the crystal particle and boundary increasing significantly, and the dendritic growth velocity and solute content increase in the primary αCo phase under rapid solidification.

The Effect of Operating Temperature on Galvanostatic Operation of Solid Oxide Electrolysis Cells

This study aims to investigate the effect of operating temperature on the galvanostatic operation of SOECs. Durability tests are conducted at four different temperatures but under the same current density. The analysis of the EIS data recorded during operation shows that the polarization and ohmic resistance increase considerably faster at lower temperatures. It also reveals that the main cause of degradation originates from the degradation of the Ni-YSZ electrode. Microstructure analysis reveals changes in the porosity and the %Ni atomic percentage in the active Ni-YSZ electrode layer, indicating that Ni migrates from the electrode/electrolyte interface towards the neighboring support layer. Over time, the resistance and overpotential attributed to Ni-migration exhibit linear increase. However, increase of temperature decreases their degradation rates. Overpotential thresholds for severe degradation of the Ni-YSZ electrode are identified at 750 oC and 800 oC but not at 850 oC and 900 oC due to the lower developed overpotentials.

Microstructure, mechanical properties, electrical resistivity, and corrosion behavior of (AlCr)x(HfMoNbZr)1-x films

Refractory high-entropy alloys (RHEAs) have emerged as a new class of materials due to their exceptional properties such as high strength, high-temperature stability, and potential for corrosion resistance. In this study, we investigate the effect of Al and Cr co-alloying on the crystal structure, mechanical properties, electrical resistivity, and corrosion resistance of HfMoNbZr film. (AlCr)x(HfMoNbZr)1-x films were grown using direct current magnetron sputtering, with Al50Cr50 and Hf25Mo25Nb25Zr25 target co-sputtering. Our findings reveal that all films possess a B2-type BCC fine-grained crystallite structure. Moreover, an increase in AlCr content results in an increase in hardness and electrical resistivity, which can be attributed to the stronger directionally angular bonds and higher local lattice distortion caused by Al atoms, as confirmed by density functional theory (DFT) calculations. Additionally, the (AlCr)x(HfMoNbZr)1-x films exhibit excellent corrosion resistance in 3.5 wt% NaCl solution, as indicated by a corrosion current below 10−8 A/cm2. Remarkably, at PAlCr = 90 W, the current density reaches a minimum value of 4.85 ± 0.43 × 10-9 A/cm2. These results demonstrate the tunable properties of RHEAs through element alloying, which offers promising opportunities for various applications.

Changes in geotechnical properties of soil contaminated by methyl tertiary butyl ether (MTBE)

As an extensively used gasoline additive, methyl tertiary butyl ether (MTBE) can leak into the subsurface, and this not only damages the ecological environment but also affects the geotechnical characteristics of the soil. In this study, the geotechnical properties of MTBE-contaminated soil, such as the basic physical properties of strength, compressibility, hydraulic conductivity, leachability, electrical resistivity and microstructural characteristics, are comprehensively investigated. The results show that the Atterberg limits consistently decrease with increasing MTBE content in the soil. As the MTBE content increases from 0 to 10%, the specific surface area of the soil decreases by 28%, the sand content increases by 22%, and the clay and silt contents decrease by 3 and 18%, respectively. The soil compression index, hydraulic conductivity, leached MTBE concentration and electrical resistivity increase, while the unconfined compressive strength (UCS) decreases, with increasing MTBE content. Microstructural analysis shows that increasing the MTBE content results in mineralogical alterations that decrease the illite and kaolinite content of the soil. The aggregation and flocculated structures can be detected by an increase in the number and size of inter-aggregate pores. In addition, the electrical resistivity of the contaminated soil is used to assess the geotechnical properties of the MTBE-contaminated soil based on well-established empirical relations.

Strain induced by temperature evolution of mesoporous ZnO nanopowders and its effect on structural, optical and electrical impedance properties

The structural and optical properties of ZnO nanopowder samples prepared by a novel green hydrothermal method have been studied. The prepared ZnO nanopowder samples were annealed (200, 250, 300, 400, 500 °C) and characterised through XRD (X-ray diffraction), FE-SEM (field emission scanning electron microscopy), BET (Brunauer–Emmett–Teller), FT-IR (Fourier transform infrared spectroscopy), UV–Vis (Ultraviolet–visible) spectroscopy, PL (Photoluminescence) spectroscopy and EIS (Electrochemical Impedance spectroscopy). The XRD Study revealed that the prepared samples were crystalline with ZnO hexagonal wurtzite structures. The crystallite sizes were determined using the Debye–Scherrer and Williamson–Hall methods and found to increase from 20.5037 to 25.9157 nm and 22.3261 to 31.4388 nm respectively with an increase in annealing temperature. The FE-SEM revealed that the prepared ZnO nanopowder samples were of spherical shape which corroborated the XRD results. The BET results showed that the prepared nanopowder samples were mesoporous with the average pore size varying between 15.125 and 25.583 nm and surface area varying between 15.337 and 23.959 m2/g. The presence of functional groups and chemical bonding were confirmed by the FTIR measurements. The energy band gaps were determined using the Kubelka-Munk function applied to UV–Vis spectra and found to be decreasing from 3.243 to 3.160 eV with an increase in annealing temperature. PL results revealed a clear dependence of the emission with annealing temperature which was caused by the decrease of free carrier concentration as the annealing temperature increased. EIS measurements indicated an increase in electrical resistance with an increase in annealing temperature with the sample annealed at 300 °C having the smallest resistance.

Cis-Nerolidol Inhibits MAP Kinase and NF-κB Signaling Pathways and Prevents Epithelial Tight Junction Dysfunction in Colon Inflammation: In Vivo and In Vitro Studies

Inflammation of the GI tract leads to compromised epithelial barrier integrity, which increases intestine permeability. A compromised intestinal barrier is a critical event that leads to microbe entry and promotes inflammatory responses. Inflammatory bowel diseases that comprise Crohn's disease (CD) and ulcerative colitis (UC) show an increase in intestinal permeability. Nerolidol (NED), a naturally occurring sesquiterpene alcohol, has potent anti-inflammatory properties in preclinical models of colon inflammation. In this study, we investigated the effect of NED on MAPKs, NF-κB signaling pathways, and intestine epithelial tight junction physiology using in vivo and in vitro models. The effect of NED on proinflammatory cytokine release and MAPK and NF-κB signaling pathways were evaluated using lipopolysaccharides (LPS)-stimulated RAW 264.7 macrophages. Subsequently, the role of NED on MAPKs, NF-κB signaling, and the intestine tight junction integrity were assessed using DSS-induced colitis and LPS-stimulated Caco-2 cell culture models. Our result indicates that NED pre-treatment significantly inhibited proinflammatory cytokine release, expression of proteins involved in MAP kinase, and NF-κB signaling pathways in LPS-stimulated RAW macrophages and DSS-induced colitis. Furthermore, NED treatment significantly decreased FITC-dextran permeability in DSS-induced colitis. NED treatment enhanced tight junction protein expression (claudin-1, 3, 7, and occludin). Time-dependent increases in transepithelial electrical resistance (TEER) measurements reflect the formation of healthy tight junctions in the Caco-2 monolayer. LPS-stimulated Caco-2 showed a significant decrease in TEER. However, NED pre-treatment significantly prevented the fall in TEER measurements, indicating its protective role. In conclusion, NED significantly decreased MAPK and NF-κB signaling pathways and decreased tight junction permeability by enhancing epithelial tight junction protein expression.

Einfluss der Mikrohärte der Ober- flächenschutzschicht auf den Verschleiß und die Lebensdauer von elektrischen Kontakten bei Reibverschleißbelastung

The lifetime of electrical contacts is influenced by various factors. Micromotions due to fluctuations in temperature and vibration in the field lead to fretting wear and fretting corrosion of electrical contacts. In case of the contacts with noble coatings, the fretting wear results in the wear through of the coating causing the exposure of the underlying non-noble metal to the surrounding atmosphere which in turn leads to fretting corrosion. These degradation mechanisms lead to an increase in electrical contact resistance and eventual failure of the system. In this study, the extent of contact degradation due to fretting war of galvanically silver-plated electrical contacts is investigated. To compare the extent of war occurring at different stages of the contacts’ lifetime, the fretting tests are conducted up to predefined fretting cycles. XRF measurements of the coating thickness before after the tests are performed and the wear depth after the given fretting cycles is determined via confocal microscopy. The results of two different types of silver plating are compared. Based on this, a prognosis regarding the wear behavior and expected lifetime of different coating systems can be made possible.

Link between cracking mechanisms of trilayer films on flexible substrates and electro-mechanical reliability under biaxial loading

The propagation of cracks from a top layer in trilayer systems (Cr/Cu/Mo) on a polyimide substrate is studied experimentally by in situ synchrotron x-ray diffraction under equi-biaxial loading. The results show that depending on the thickness of the ductile Cu middle layer (100 or 500 nm), the propagation can be a direct vertical path through all layers or a more complex path. These effects are analyzed by monitoring the individual stresses of each layer along with electrical resistance and resulting crack patterns. Cracks starting from the upper Cr layer propagate instantaneously through the whole system for a 100 nm Cu layer but are strongly deflected in a 500 nm Cu layer, thus delaying the global fracture of the system measured by the increase of electrical resistance. Mechanisms are proposed and allowed to anticipate the electro-mechanical performances of stretchable systems constructed of several layers.

Infiltration monitoring using carbon nanotube buckypaper for the characterization of out‐of‐plane unsaturated permeability

AbstractThis paper developed an out‐of‐plane permeability measuring method by utilizing conductive carbon nanotube (CNT) buckypaper and its piezoresistivity. A series of CNT sensors was arranged orderly in different interlaminar regions to achieve infiltration monitoring for both glass and carbon fabrics. The response of electrical resistance to flow front was investigated, and the out‐of‐plane unsaturated permeabilities at different fiber volume fractions were further calculated according to the monitoring results of those CNT sensors. The results show that the electrical resistance variation and time curves can be divided into three stages, including the initial baseline stage, rapid growth stage, and smooth growth stage. For most CNT sensors, ΔR/R0 becomes higher than 15% and 20% at the end of rapid growth stage and smooth growth stage, respectively. These CNT sensors show the sudden increase of electrical resistance successively along the infiltration direction. The squared infiltration distance and time show linear relationship, and the out‐of‐plane unsaturated permeability is further calculated based on Darcy's law. The out‐of‐plane unsaturated permeability of EW100 glass fabric is measured to be 4.76 × 10−13 m2 at a fiber volume faction of 63.0%. The unsaturated permeability increases with decreasing fiber volume fraction, and the carbon fabric with smaller fiber diameter shows smaller unsaturated permeability at the approximate fiber volume fraction.

Human Colonoid–Myofibroblast Coculture for Study of Apical Na+/H+ Exchangers of the Lower Cryptal Neck Region

Cation and anion transport in the colonocyte apical membrane is highly spatially organized along the cryptal axis. Because of lack of experimental accessibility, information about the functionality of ion transporters in the colonocyte apical membrane in the lower part of the crypt is scarce. The aim of this study was to establish an in vitro model of the colonic lower crypt compartment, which expresses the transit amplifying/progenitor (TA/PE) cells, with accessibility of the apical membrane for functional study of lower crypt-expressed Na+/H+ exchangers (NHEs). Colonic crypts and myofibroblasts were isolated from human transverse colonic biopsies, expanded as three-dimensional (3D) colonoids and myofibroblast monolayers, and characterized. Filter-grown colonic myofibroblast-colonic epithelial cell (CM-CE) cocultures (myofibroblasts on the bottom of the transwell and colonocytes on the filter) were established. The expression pattern for ion transport/junctional/stem cell markers of the CM-CE monolayers was compared with that of nondifferentiated (EM) and differentiated (DM) colonoid monolayers. Fluorometric pHi measurements were performed to characterize apical NHEs. CM-CE cocultures displayed a rapid increase in transepithelial electrical resistance (TEER), paralleled by downregulation of claudin-2. They maintained proliferative activity and an expression pattern resembling TA/PE cells. The CM-CE monolayers displayed high apical Na+/H+ exchange activity, mediated to >80% by NHE2. Human colonoid-myofibroblast cocultures allow the study of ion transporters that are expressed in the apical membrane of the nondifferentiated colonocytes of the cryptal neck region. The NHE2 isoform is the predominant apical Na+/H+ exchanger in this epithelial compartment.

Conductive properties of heavy-rare-earth A2Ir2O7 iridates synthesized by the CsCl-flux method

The A2Ir2O7 pyrochlores with A = rare-earth element have been the subject of intense scientific interest for their complex magnetic and conductive properties. The previous studies focused mainly on the light A members of the series. We report on the electrical resistivity and magnetoresistance of the heavy-rare-earth iridates (A = Dy - Lu), including newly synthesized Tm2Ir2O7 member. The measurements were performed on pelletized powder samples synthesized using the CsCl-flux. The transition from the semimetal/semiconductor to the insulating state is followed within the series. Related anomaly in electrical resistivity continuously broadens coming from A = Dy to Lu. Electrical resistivity increases by several orders (up to 6) of magnitude with decreasing temperature down to 2 K. The nature of the transition to the insulating state was discussed in the frame of various models, leaning towards the Slater mechanism without Brillouin zone-folding. Investigated iridates become insulating due to an opening of a gap at the Fermi level induced by the antiferromagnetic ordering. A negative magnetoresistance was observed for all members of the series. The highest resistivity drop to 8% of the zero-field value was revealed for Dy2Ir2O7. Ferromagnetic Ir domain walls between antiferromagnetic domains were discussed to influence the measured quantities for A2Ir2O7 iridates.

Hesperidin enhances intestinal barrier function in Caco-2 cell monolayers via AMPK-mediated tight junction-related proteins.

The intestinal epithelium is a single-cell layer on the mucosal surface that absorbs food-derived nutrients and functions as a barrier that protects mucosal integrity. Hesperidin (hesperetin-7-rhamnoglucoside) is a flavanone glycoside composed of the flavanone hesperetin and the disaccharide rutinose, which has various physiological benefits, including antioxidative, anti-inflammatory, and antiallergic effects. Here, we used human intestinal Caco-2 cell monolayers to examine the effect of hesperidin on intestinal barrier function. Hesperidin-treated Caco-2 cell monolayers displayed enhanced intestinal barrier integrity, as indicated by an increase in transepithelial electrical resistance (TEER) and a decreased apparent permeability (Papp ) for fluorescein. Hesperidin elevated the mRNA and protein levels of occludin, MarvelD3, JAM-1, claudin-1, and claudin-4, which are encoded by tight junction (TJ)-related genes. Moreover, hesperidin significantly increased the phosphorylation of AMP-activated protein kinase (AMPK), indicating improved intestinal barrier function. Thus, our results suggest that hesperidin enhances intestinal barrier function by increasing the expression of TJ-related occludin, MarvelD3, JAM-1, and claudin-1 via AMPK activation in human intestinal Caco-2 cells.