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1.
Article in English | MEDLINE | ID: mdl-39387143

ABSTRACT

Thermal resistance at interfaces/contacts stands as a persistent and increasingly critical issue, which hinders ultimate scaling and the performance of electronic devices. Compared to the extensive research on contact electrical resistance, contact thermal resistance and its mitigation strategies have received relatively less attention. Here, we report on an effective, in situ, and energy-efficient approach for enhancing thermal transport through the contact between semiconducting nanoribbons. By applying microampere-level electrical currents to the contact between Bi2Se3 nanoribbons, we demonstrate that the contact thermal resistance between two nanoribbon segments is reduced dramatically by a factor of 4, rendering the total thermal resistance of two ribbon segments with a contact approximately the same as that of the corresponding single continuous nanoribbon of the same length. Analysis suggests that the ultralow contact thermal resistance is due to enhanced phonon transmission as a result of enhanced adhesion energy at the contact, with marginal contributions from direct electron-phonon coupling, even for ohmic contacts. Our work introduces a broadly applicable electrical treatment approach to various contacts between conducting and semiconducting materials, which has important implications for the design and operation of nanoelectronic devices and energy converters.

2.
Article in English | MEDLINE | ID: mdl-39360618

ABSTRACT

The application of traditional isocyanate-based polyimide (PI) foams is highly hindered due to limited flame retardancy, poor mechanical properties, and relatively single functionality. Herein, we propose an effective method to fabricate dual cross-linked polyimide/bismaleimide (PI-BMI) foams with outstanding heat resistance and enhanced mechanical properties by incorporating bis(3-ethyl-5-methyl-4-maleimidophenyl)methane (ME-BMI) as the interpenetrating network. The results show that the prepared PI-BMI composite foams exhibit enhanced mechanical properties with lightweight characteristics (23-80 kg·m-3). When the ME-BMI loading reached 120 wt %, the tensile and compressive strength of PI-BMI composite foam can reach 1.9 and 7.8 MPa, which are 9.6 and 63.3 times higher than that of pure PI foam, respectively. In comparison with PIF-0, the 10% heat loss temperature (Td,10%) of PIF-90 improved by 156 °C. Moreover, the PI-BMI foam piezoelectric sensor containing fluorine groups presents a short response time (14.22 ms), high sensitivity (0.266 V/N), and outstanding stability (10 000 cycles). Besides, the sensor can accurately monitor human activity in different states. This work provides a promising strategy for designing multifunctional PI foams, making them suitable for applications in aerospace and microelectronics.

3.
Int J Biol Macromol ; 280(Pt 3): 135926, 2024 Sep 23.
Article in English | MEDLINE | ID: mdl-39322170

ABSTRACT

Rising climate change and extreme weather conditions underpin thermoregulation limitations of conventional textiles. This study investigates enhancing the thermal properties of cotton fabric by incorporating synthesized 1-tetradecanol (TD) phase change material (PCM) microcapsules. Characterization of the TD microcapsules was performed using dynamic light scattering (DLS), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The microcapsules (average size of 0.49 µm) displayed a melting enthalpy (∆Hm) of 105 J·g-1 and a crystallization enthalpy (∆Hc) of 51 J·g-1. The microcapsules were mixed with the acrylic binder in three different ratios (75:25, 50:50, and 25:75). Hydrothermal, knife-over-roll, and pad-dry-cure methods were employed for coating microcapsules to cotton fabric. Microcapsule coating on cotton fabric using hydrothermal coating with a 75:25 microcapsule binder ratio achieved the highest add-on (55 %) and good durability after 25 home washes. The thermal insulation R-value of the coated fabric was enhanced (0.0029 m2 K·W-1) at 40 °C. The real-time test showed a temperature difference of 2.8 °C and thermal imaging displayed lower emissivity for TD-coated fabric. The TD microcapsule coating offers a promising method for developing climate-responsive textiles, enhancing thermal comfort, and reducing energy consumption in heating and cooling systems.

4.
ACS Appl Mater Interfaces ; 16(32): 42917-42930, 2024 Aug 14.
Article in English | MEDLINE | ID: mdl-39102288

ABSTRACT

Material thermal conductivity is a key factor in various applications, from thermal management to energy harvesting. With microstructure engineering being a widely used method for customizing material properties, including thermal properties, understanding and controlling the role of extended phonon-scattering defects, like grain boundaries, is crucial for efficient material design. However, systematic studies are still lacking primarily due to limited tools. In this study, we demonstrate an approach for measuring grain boundary thermal resistance by probing the propagation of thermal waves across grain boundaries with a temperature-sensitive scanning probe. The method, implemented with a spatial resolution of about 100 nm on finely grained Nb-substituted SrTiO3 ceramics, achieves a detectability of about 2 × 10-8 K m2 W-1, suitable for chalcogenide-based thermoelectrics. The measurements indicated that the thermal resistance of the majority of grain boundaries in the STiO3 ceramics is below this value. While there are challenges in improving sensitivity, considering spatial resolution and the amount of material involved in the detection, the sensitivity of the scanning probe method is comparable to that of optical thermoreflectance techniques, and the method opens up an avenue to characterize thermal resistance at the level of single grain boundaries and domain walls in a spectrum of microstructured materials.

5.
Food Res Int ; 192: 114765, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39147557

ABSTRACT

In this study, Listeria monocytogenes from minced pork was evaluated for changes in resistance to thermal treatment and gastric fluid following environmental stresses during food processing. Bacteria were exposed to cold stress, followed by successive exposures to different stressors (lactic acid (LA), NaCl, or Nisin), followed by thermal treatments, and finally, their gastrointestinal tolerance was determined. Adaptation to NaCl stress reduced the tolerance of L. monocytogenes to subsequent LA and Nisin stress. Adaptation to LA stress increased bacterial survival in NaCl and Nisin-stressed environments. Bacteria adapted to Nisin stress showed no change in tolerance to subsequent stress conditions. In addition, treatment with NaCl and LA enhanced the thermal tolerance of L. monocytogenes, but treatment with Nisin decreased the thermal tolerance of the bacteria. Almost all of the sequential stresses reduced the effect of a single stress on bacterial thermal tolerance. The addition of LA and Nisin as a second step of stress reduced the tolerance of L. monocytogenes to gastric fluid, whereas the addition of NaCl enhanced its tolerance. The results of this study are expected to inform processing conditions and sequences for meat preservation and processing and reduce uncertainty in risk assessment of foodborne pathogens due to stress adaptation.


Subject(s)
Food Handling , Food Microbiology , Listeria monocytogenes , Meat Products , Nisin , Listeria monocytogenes/drug effects , Listeria monocytogenes/physiology , Nisin/pharmacology , Meat Products/microbiology , Animals , Food Handling/methods , Hot Temperature , Sodium Chloride , Swine , Stress, Physiological , Food Preservation/methods , Adaptation, Physiological
6.
Microb Pathog ; 194: 106792, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39004153

ABSTRACT

Foodborne pathogens have become a major concern for public health. Bacillus cereus, a representative foodborne pathogen, is particularly challenging due to its ability to cause food poisoning and its resilient spores that are difficult to completely eradicate. Therefore, it is crucial to develop measures to prevent and control B. cereus. Bacteriophages, which are high specific towards their host strains and cannot infect eukaryotes, have proven to be effective in combating foodborne pathogens and are safe for human use. In this study, we isolated and characterized a novel bacteriophage named vBce-DP7 that specifically targets B. cereus strains belonging to three different sequence types (STs). Phage vBce-DP7 is a lytic one and has a short latent time of only 15 min. Moreover, it exhibites a good temperature tolerance, retaining high activity across a broad range of 4-55 ℃. Additionally, its activity remains unaffected within a wide pH range spanning from 2 to 10. Interestingly, with only 4 % genetic similarity with known bacteriophages, vBce-DP7 shows a possible classification on a family level though it shares many similar functional proteins with Salasmaviridae bacteriophages. Taken together, vBce-DP7 demonstrates its significant potential for further exploration in terms of phage diversity and its application in controlling B. cereus.


Subject(s)
Bacillus Phages , Bacillus cereus , Genome, Viral , Host Specificity , Phylogeny , Temperature , Bacillus cereus/virology , Bacillus Phages/isolation & purification , Bacillus Phages/classification , Bacillus Phages/genetics , Bacillus Phages/physiology , Hydrogen-Ion Concentration , DNA, Viral/genetics
7.
ACS Appl Mater Interfaces ; 16(31): 41633-41641, 2024 Aug 07.
Article in English | MEDLINE | ID: mdl-39047150

ABSTRACT

Confined geometries are used to increase measurement sensitivity to thermal boundary resistance at buried SiO2 interfaces with frequency-domain thermoreflectance (FDTR). We show that radial confinement of the transducer film and additional underlying material layers prevents heat from spreading and increases the thermal penetration depth of the thermal wave. Parametric analyses are performed with finite element methods and used to examine the extent to which the thermal penetration depth increases as a function of a material's effective thermal resistance and the degree of material confinement relative to the pump beam diameter. To our surprise, results suggest that the measurement technique is not always the most sensitive to the largest thermal resistor in a multilayer material. We also find that increasing the degree to which a material is confined improves measurement sensitivity to the thermal resistance across material interfaces that are buried 10s of µm to mm below the surface. These results are used to design experimental measurements of etched, 200 nm thick SiO2 films deposited on Al2O3 substrates, and offer an opportunity for thermal scientists and engineers to characterize the thermal resistance across a broader range of material interfaces within electronic device architectures that have historically been difficult to access via experiment.

8.
Heliyon ; 10(12): e32307, 2024 Jun 30.
Article in English | MEDLINE | ID: mdl-38975123

ABSTRACT

The objective of this paper is to present new heat transfer enhancement approaches in plate-fin heat sinks (PFHS) using copper foam and twisted tapes. The motivation behind these concepts is to reduce pressure drop while enhancing heat transfer compared to PFHSs fully inserted with copper foam. The impact of twisted tape type, twist ratio, and Reynolds number (Re) on the heat and flow behaviors inside the PFHS equipped with copper foam (PFHSCF) is investigated. Copper foam has a porosity of 0.932 and a pore density of 40 pores per inch. Stationary and rotating twisted tapes with twist ratios between 2.7 and 4 are tested at Re between 3000 and 6000. The experimental results indicated that the pressure drop of the airflow inside a PFHS equipped with copper foam and a stationary twisted tape (PFHSCF_STT) as well as a PFHS equipped with copper foam and rotating twisted tapes (PFHSCF_RTT) decreased by an average of 34.8 % and 37.9 %, respectively, compared to a PFHSCF. When the twist ratio is decreased from 4 to 2.7, the thermal resistances of PFHSCF_STT and PFHSCF_RTT are reduced by 14.2 and 14.8 %, respectively. Based on assessment, the thermal-hydraulic performance of a PFHSCF_RTT with twist ratios of 2.7 and 3.3 is higher than that of a PFHSCF. To facilitate practical applications, correlations are proposed to predict the Nusselt number and friction factor. Additionally, considering the outcomes of the current study, conducting numerical investigations on the thermal performance of PFHS under different pore densities of copper foam and wider twist ratios of twisted tapes is recommended to determine optimal working conditions for future research.

9.
ACS Appl Mater Interfaces ; 16(30): 40069-40076, 2024 Jul 31.
Article in English | MEDLINE | ID: mdl-39037051

ABSTRACT

Passive radiative cooling technology without electric consumption is an emerging sustainability technology that plays a key role in advancing sustainable development. However, most radiative cooling materials are vulnerable to outdoor contamination and thermal/UV exposure, which leads to decreased performance. Herein, we report a hierarchically structured polyimide/zinc oxide (PINF/ZnO) composite membrane that integrates sunlight reflectance of 91.4% in the main thermal effect of the solar spectrum (0.78-1.1 µm), the mid-infrared emissivity of 90.0% (8-13 µm), UV shielding performance, thermal resistance, and ideal hydrophobicity. The comprehensive performance enables the composite membrane to yield a temperature drop of ∼9.3 °C, compared to the air temperature, under the peak solar irradiance of ∼800 W m-2. In addition, the temperature drop of as-obtained composite membranes after heating at 200 °C for 6 h in a nitrogen/air atmosphere can be well maintained at ∼9.0 °C, demonstrating their ideal radiative cooling effect in a high-temperature environment. Additionally, the PINF/ZnO composite membrane shows excellent chemical durability after exposure to the outdoor environment. This work provides a new strategy to integrate chemical durability and thermal resistance with radiative cooling, presenting great potential for passive radiative cooling materials toward practical applications in harsh environments.

10.
Food Microbiol ; 122: 104544, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38839230

ABSTRACT

The objective of this study was to identify a suitable surrogate for E. coli O157:H7 strain 19685/91 and O113:H21 strain TS18/08, by assessing their thermal resistance at temperatures of 60 °C, 65 °C, and 72 °C in strawberry nectar. The influence of the matrix and the research methodology on the decimal reduction time (D-value) was investigated. Thermal kinetics and safety assessment demonstrated that E. coli ATCC 8739 is a suitable surrogate. The study demonstrated that the presence of fruit particles in the nectar increased thermal resistance of the tested strains. Variations in D-values were observed depending on the research method employed, with D-values in glass capillaries were up to 6.6 times lower compared to larger sample volumes. Encapsulation of E. coli ATCC 8739 exhibited high efficiency of 90.25 ± 0.26% and maintained stable viable counts after 26 days of storage in strawberry nectar at 4 °C. There were no significant differences in thermal resistance between surrogates directly inoculated into strawberry nectar and those encapsulated in alginate beads. Additionally, the encapsulated strains did not migrate outside the beads. Therefore, encapsulated E. coli ATCC 8739 in alginate beads can be effectively utilized in industrial settings to validate thermal treatments as a reliable and safe method.


Subject(s)
Enterohemorrhagic Escherichia coli , Fragaria , Fruit , Hot Temperature , Fruit/microbiology , Fragaria/microbiology , Enterohemorrhagic Escherichia coli/growth & development , Food Microbiology , Colony Count, Microbial , Microbial Viability , Plant Nectar/chemistry , Escherichia coli O157/growth & development , Food Contamination/analysis , Food Contamination/prevention & control , Kinetics
11.
Sensors (Basel) ; 24(12)2024 Jun 19.
Article in English | MEDLINE | ID: mdl-38931764

ABSTRACT

The quality of aerial remote sensing imaging is heavily impacted by the thermal distortions in optical cameras caused by temperature fluctuations. This paper introduces a lumped parameter thermal network (LPTN) model for the optical system of aerial cameras, aiming to serve as a guideline for their thermal design. By optimizing the thermal resistances associated with convection and radiation while considering the camera's unique internal architecture, this model endeavors to improve the accuracy of temperature predictions. Additionally, the proposed LPTN framework enables the establishment of a heat leakage network, which offers a detailed examination of heat leakage paths and rates. This analysis offers valuable insights into the thermal performance of the camera, thereby guiding the refinement of heating zones and the development of effective active control strategies. Operating at a total power consumption of 26 W, the thermal system adheres to the low-power limit. Experimental data from thermal tests indicate that the temperatures within the optical system are maintained consistently between 19 °C and 22 °C throughout the flight, with temperature gradients remaining below 3 °C, satisfying the temperature requirements. The proposed LPTN model exhibits swiftness and efficacy in determining thermal characteristics, significantly facilitating the thermal design process and ensuring optimal power allocation for aerial cameras.

12.
Polymers (Basel) ; 16(11)2024 May 22.
Article in English | MEDLINE | ID: mdl-38891408

ABSTRACT

Ablative composites serve as sacrificial materials, protecting underlying materials from high-temperature environments by endothermic reactions. These materials undergo various phenomena, including thermal degradation, pyrolysis, gas generation, char formation, erosion, gas flow, and different modes of heat transfer (such as conduction, convection, and radiation), all stemming from these endothermic reactions. These phenomena synergize to form a protective layer over the underlying materials. Carbon, with its superb mechanical properties and various available forms, is highlighted, alongside phenolics known for good adhesion and fabric ability and elastomers valued for flexibility and resilience. This study focuses on recent advancements in carbon-and-phenolic and carbon-and-elastomeric composites, considering factors such as erosion speed; high-temperature resistance; tensile, bending, and compressive strength; fiber-matrix interaction; and char formation. Various authors' calculations regarding the percentage reduction in linear ablation rate (LAR) and mass ablation rate (MAR) are discussed. These analyses inform potential advancements in the field of carbon/phenolic and carbon/elastomeric ablative composites.

13.
Sci Rep ; 14(1): 14277, 2024 Jun 20.
Article in English | MEDLINE | ID: mdl-38902317

ABSTRACT

With the development of green buildings, people pay more attention to the quality of the indoor sound environment. The air sound insulation performance of floors and exterior walls plays a key role in today's green buildings. The thermal performance of the enclosure structure's floor and exterior wall heat transfer resistance is an important factor in reducing building carbon emissions in green buildings. The aim of this paper is to study the efficiency of the acoustic and thermal insulation of a foaming system with porous carbon balls and the combination of different structural ways of construction boards and external walls. The acoustic and thermal parameters of different sound insulation and thermal insulation systems designed with porous carbon sphere foam and inserted into the floors and exterior walls are compared to highlight the optimal structure. The theoretical and experimental tests showed that to improve the sound insulation performance of the floor, a sound insulation system needs to be placed on the surface of the floor in contact with the impact object and inlaid in the vertical gap in contact with the floor and the wall. Furthermore, it has been determined that the surface of the foam particle acoustic ball with micropores has good sound absorption performance. Finally, the high-quality building thermal insulation material with low thermal conductivity in any combination with the floor slabs and the external wall structure improves the thermal insulation performance.

14.
Ecology ; 105(7): e4359, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38877760

ABSTRACT

An understanding of thermal limits and variation across geographic regions is central to predicting how any population may respond to global change. Latitudinal clines, in particular, have been used to demonstrate that populations can be locally adapted to their own thermal environment and, as a result, not all populations will be equally impacted by an increase in temperature. But how robust are these signals of thermal adaptation to the other ecological challenges that animals commonly face in the wild? Seasonal changes in population density, food availability, or photoperiod are common ecological challenges that could disrupt patterns of thermal tolerance along a cline if each population differentially used these signals to anticipate future temperatures and adjust their thermal tolerances accordingly. In this study, we aimed to test the robustness of a cline in thermal tolerance to simulated signals of seasonal heterogeneity. Experimental animals were derived from clones of the Australian water flea, Daphnia carinata, sampled from nine distinct populations along a latitudinal transect in Eastern Australia. We then factorially combined summer (18 h light, 6 h dark) and winter (6 h light, 18 h dark) photoperiods with high (5 million algal cells individual-1 day-1) and low (1 million algal cells individual-1 day-1) food availabilities, before performing static heat shock assays to measure thermal tolerance. We found that the thermal tolerances of the clonal populations were sensitive to both measures of seasonal change. In general, higher food availability led to an increase in thermal tolerances, with the magnitude of the increase varying by clone. In contrast, a switch in photoperiod led to rank-order changes in thermal tolerances, with heat resistance increasing for some clones, and decreasing for others. Heat resistance, however, still declined with increasing latitude, irrespective of the manipulation of seasonal signals, with clones from northern populations always showing greater thermal resistance, most likely driven by adaptation to winter thermal conditions. While photoperiod and food availability can clearly shape thermal tolerances for specific populations, they are unlikely to overwhelm overarching signals of thermal adaptation, and thus, observed clines in heat resistance will likely have remained robust to these forms of seasonal heterogeneity.


Subject(s)
Daphnia , Seasons , Animals , Daphnia/physiology , Climate Change , Hot Temperature , Thermotolerance , Demography , Models, Biological
15.
Food Res Int ; 190: 114652, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38945589

ABSTRACT

The objective of this study was to evaluate the effect of fat on thermal resistance of L. monocytogenes, E. coli O157:H7, and Salmonella spp. A 4-strain cocktail of each microorganism was inoculated to beef tallow and heated isothermally at temperatures between 55 and 80℃. All survival curves did not follow the 1st-order inactivation kinetics but conformed to a two-stage linear pattern. The first stage was markedly less heat-resistant than the second, as manifested by significantly lower D values. The z values of E. coli O157 H7 and Salmonella spp. were 11.8 °C and 12.3 °C in the first stage (z1) but increased to 23.7 °C and 20.8 °C in the second stage (z2), respectively. For L. monocytogenes, while the z values were similar for both stages (z1 = 19.6 °C and z2 = 18.5 °C), the second stage D values are 3.6-5.9 times of those in the first stage. One-step analysis was used to fit the nonlinear curves to the Weibull model, yielding < 1 exponents for the model (0.495, 0.362, and 0.282, respectively, for L. monocytogenes, E. coli O157:H7, and Salmonella spp.), suggesting gradually increased thermal resistance during heating. The experimental results showed that these microorganisms could resist heating for longer time and at higher temperatures in tallow than they do in regular meats containing lower levels of fat. The kinetic models can be used to develop thermal processes to properly inactivate pathogens contaminated in the fat portions of meat products or other high fat products.


Subject(s)
Escherichia coli O157 , Food Microbiology , Hot Temperature , Listeria monocytogenes , Salmonella , Listeria monocytogenes/growth & development , Escherichia coli O157/growth & development , Salmonella/growth & development , Animals , Kinetics , Cattle , Colony Count, Microbial , Fats , Models, Theoretical , Microbial Viability
16.
Int J Biol Macromol ; 270(Pt 1): 132223, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38777688

ABSTRACT

The combination of crystallization, transparency, and strength is still a challenge for broadening the application of polylactic acid (PLA) films, while it is also difficult to balance. In this work, the long aliphatic chains of octadecylamine (ODA) were grafted onto the surface of cellulose nanocrystal (CNC) by tannic acid oxidation self-polymerization and Michael addition/Schiff base reaction between polytannic acid and ODA. Furthermore, the ODA grafted CNC (g-CNC) was used as green reinforcement for the PLA matrix and a series of PLA/g-CNC nanocomposite films were prepared by the casting method. The DSC, WAXD, POM, UV-vis and stretching test were employed to examine the effect of g-CNC on the properties of the as-prepared PLA/g-CNC nanocomposite films. It shows that the g-CNC is effective to improve the melt crystallization rate of PLA from 11 min to 7.3 min. Most importantly, the crystal size of the PLA spherulites was significantly reduced due to the well dispersion in the amorphous PLA matrix, which would effectively improve the transmittance of the PLA films and synchronously realize the combination of crystallization (62 %) and transparency (80.6 %). Moreover, the improved crystallization could also enhance the heat deformation performance of the PLA films since the heat resistance is closely associated with the crystallinity. Besides, the grafted ODA long chains improve the compatibility between CNC and PLA, leading to the reinforcement of PLA matrix, where the tensile strength reaches 65.05 MPa from 44.31 MPa. Compared with the pristine CNC, the addition of g-CNC makes more comprehensive improvement in the properties of the PLA films.


Subject(s)
Cellulose , Crystallization , Polyesters , Polyesters/chemistry , Cellulose/chemistry , Nanocomposites/chemistry , Tensile Strength , Nanoparticles/chemistry , Amines/chemistry , Tannins/chemistry
17.
Article in English | MEDLINE | ID: mdl-38669057

ABSTRACT

Flexible thermoelectric generators (f-TEGs) offer an opportunity to realize wearable, self-powered electronic devices. A typical f-TEG consists of flexible electrodes and rigid thermoelectric (TE) legs in a flexible package. In the realm of f-TEGs utilizing flexible electrodes and TE cuboids, our unwavering objective lies in the attainment of enhanced flexibility and elevated energy conversion efficiency. In this paper, we employ a quasi-three-dimensional thermal model to design an f-TEG with a rhombus gap structure (E/A-RhTEG) with its optimized performance validated by simulation and experiment. Additionally, the lateral and vertical thermal resistances are introduced to further explain the optimizing principle in the f-TEG's output performance. Compared with the conventional TEG with a rectangular air gap structure (E/A-ReTEG), E/A-RhTEG demonstrates improved energy conversion efficiency to some extent. Simulation results indicate that the output power and energy conversion efficiency of a 25-np-pair E/A-RhTEG at a 30 K temperature gradient reach 8.45 mW and 2.55%, which represent a performance improvement of 3.09 and 6.28%, respectively, compared to E/A-ReTEG. To further elucidate the optimization principle in the performance of f-TEGs, additional considerations are given to the lateral and vertical resistances. In this study, E/A-RhTEG comprising 25 np pairs is fabricated utilizing TE cuboids. Experimental findings indicate that E/A-RhTEG exhibits a voltage output of 127.07 mV when subjected to a temperature difference of 30 K, which demonstrates a performance enhancement of 4.06% compared to E/A-ReTEG. Furthermore, this study also demonstrates its implementation when wrapped around a curved surface and successfully achieves a self-powered device system after device performance optimization.

18.
Materials (Basel) ; 17(8)2024 Apr 12.
Article in English | MEDLINE | ID: mdl-38673136

ABSTRACT

Natural fiber/degradable epoxy composites have received much attention for their advantages of low carbon emissions, low environmental pollution, and utilization of renewable resources. However, the poor interfacial bonding strength and inferior moisture resistance of natural fiber/degradable epoxy composites restrict their application areas. In order to improve the moisture and heat resistance of natural fiber/degradable epoxy resin-based composites, this study modified the surfaces of ramie fibers with hydroxylated carbon nanotubes, silane coupling agents, and sodium hydroxide, respectively. Three types of modified ramie fiber/degradable epoxy composites, namely F-CN-DEP, F-Si-DEP, and F-OH-DEP, were prepared using a winding forming process. The water absorption rate and short-beam shear strength of the materials were tested under different environments, and the fiber morphology and thermal-mechanical properties of the materials were investigated by scanning electron microscopy (SEM) and dynamic mechanical analysis (DMA). The results show that F-CN-DEP exhibited the lowest moisture absorption rate; the highest shear strength, of 43.8 MPa; and a glass transition temperature (Tg) of 121.7 °C. The results demonstrate that carbon nanotubes on the fiber surface can improve the interfacial stability of ramie fiber/degradable epoxy composites in humid and hot environments. These results give guidelines for the development of natural fiber/degradable epoxy composites.

19.
Adv Mater ; 36(28): e2401359, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38663867

ABSTRACT

With the continuous upsurge in demand for wearable energy, nanogenerators are increasingly required to operate under extreme environmental conditions. Even though they are at the cutting edge of technology, nanogenerators have difficulty producing high-quality electrical output at very extreme temperatures. Here, a triboelectric basalt textile (TBT) with an ultrawide operational temperature range (from -196 to 520 °C) is created employing basalt material as the main body. The output power density of the TBT, in contrast to most conventional nanogenerators, would counterintuitively rise by 2.3 times to 740.6 mW m-2 after heating to 100 °C because the high temperature will enhance the material's interface polarization and electronic kinetic energy. The TBT retains ≈55% of its initial electrical output even after heating in the flame of an alcohol lamp (520 °C). Surprisingly, the TBTs output voltage may retain over 85% of its initial value even after submerging in liquid nitrogen. The TBTs exceptional resistance to heat and cold indicates its possible use in high and low latitudes, high altitudes, deserts, and even space settings.

20.
mBio ; 15(4): e0014624, 2024 Apr 10.
Article in English | MEDLINE | ID: mdl-38477572

ABSTRACT

The emergence and evolutionary path of Candida auris poses an intriguing scientific enigma. Its isolation from a pet dog's oral cavity in Kansas, reported by White et al. (T. C. White, B. D. Esquivel, E. M. Rouse Salcido, A. M. Schweiker, et al., mBio 15:e03080-23, 2024, https://doi.org/10.1128/mbio.03080-23), carries significant implications. This discovery intensifies concerns about its hypothetical capacity for zoonotic transmission, particularly considering the dog's extensive human contact and the absence of secondary animal/human cases in both animals and humans. The findings challenge established notions of C. auris transmissibility and underscore the need for further investigation into the transmission dynamics, especially zooanthroponotic pathways. It raises concerns about its adaptability in different hosts and environments, highlighting potential role of environmental and animal reservoirs in its dissemination. Critical points include the evolving thermal tolerance and the genetic divergence in the isolate. This case exemplifies the necessity for an integrated One Health approach, combining human, animal, and environmental health perspectives, to unravel the complexities of C. auris's emergence and behavior.


Subject(s)
Candida , Candidiasis , Dogs , Humans , Animals , Candida/genetics , Candida/isolation & purification , Candidiasis/veterinary , Candidiasis/microbiology , Candida auris , Kansas , Climate Change , Fungi , Zoonoses , Mouth
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