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1.
Plants (Basel) ; 13(13)2024 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-38999638

RESUMO

The radioactive fission product 90Sr has a sufficient half-life (28.8 years) to be detected long after its appearance in the environment. After its uptake into the soil-edible plant system, it enters the food chain and represents a potential source of contamination that threatens human health. Due to these facts, tracking the distribution of the artificial radionuclide 90Sr in the soil-edible plant system is a subject of intense research. The tracking of the 90Sr radionuclide distribution in the soil profile, as well as in the crops on the long-term experimental fields was carried out using beta radiation spectrometry. The radiochemical analytical method was used to analyze the 90Sr content in cultivated soil and crops. The conducted study focused on the experimental substantiation of the developed model for predicting the behavior of 90Sr in the cultivated soil-crop system. The results of using the applied radioecological model for the transfer of 90Sr from the soil to the above-ground part of crops showed a relatively good agreement with the experimentally determined values of the soil-crop transfer factor, which indicates that the used model can be successfully applied for the prediction of the behavior of 90Sr in the soil-soil solution-crop system.

2.
J Pers Med ; 14(4)2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38673022

RESUMO

Our aim was to compare the stroke outcomes of a direct transfer (DT) to a thrombectomy-capable center vs. initial care at two local stroke centers: a nearby hospital (NH, 36 km) and a distant hospital (DH, 113 km). Patients who underwent a mechanical thrombectomy were analyzed (February 2017-October 2021), and the outcome was considered favorable if the modified Rankin scale (mRS) score was ≤ 2 at three months. A total of 300 patients were included, 55 of which were transferred from the NH and 58 from the DH. There was a difference in the median (IQR) transfer time of 39 min between the hospitals (149 min for the NH vs. 188 min for the DH, p = 0.003). After adjusting for confounding variables, a secondary transfer from the DH, compared to a DT, was associated with a lower functional independence: mRS score ≤ 2 (OR = 0.37, 95% CI = 0.14-0.97, p = 0.043), without significant differences in the mortality between the groups. These differences were not observed in patients from the NH. Conclusions: A secondary transfer from a distant hospital was associated with a poorer functional outcome at 3 months. This unfavorable outcome was not observed among patients transferred from a nearby hospital. These findings highlight the importance of categorizing the suitability of one transfer model over another based on the proximity of hospitals to the thrombectomy center, but also in accordance with organizational and geographic characteristics that vary within each health region.

3.
Natl Sci Rev ; 11(5): nwae090, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38628572

RESUMO

High heat transfer coefficient (HTC) and critical heat flux (CHF) are achieved in liquid film boiling by coupling vibrant vapor bubbles with a capillary liquid film, which has thus received increased interest for thermal management of high-power electronics. Although some experimental progress has been made, a high-fidelity heat transfer model for liquid film boiling is lacking. This work develops a thermal-hydrodynamic model by considering both evaporation atop the wick and nucleate boiling inside the wick to simultaneously predict the HTC and CHF. Nucleate boiling is modeled with microlayer evaporation theory, where a unified scaling factor is defined to characterize the change of microlayer area with heat flux. The scaling factor η is found to be independent of wicking structure and can be determined from a few measurements. This makes our model universal to predict the liquid film boiling heat transfer for various micro-structured surfaces including micropillar, micropowder, and micromesh. This work not only sheds light on understanding fundamental mechanisms of phase-change heat transfer, but also provides a tool for designing micro-structured surfaces in thermal management.

4.
J Chromatogr A ; 1718: 464704, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38330725

RESUMO

In this study, overloaded elution profiles under ultra-high-pressure liquid chromatographic (UHPLC) conditions and accounting for the severe pressure and temperature gradients generated, are compared with experimental data. The model system consisted of an C18 column packed with 1.7-µm particles (i.e., a UHPLC column) and the solute was 1,3,5-tri­tert-butylbenzene eluted with a mobile phase composed of 85/15 (v/v) acetonitrile/water. Two thermal modes were considered, and the solute was eluted at the very high inlet pressures necessary to achieve a highly efficient and rapid chromatographic process, as provided by using columns packed with small particles. However, the high inlet pressure and high linear velocity of the mobile phase caused the production of a significant amount of heat, and consequently, the formation of axial and radial temperature gradients. Due to these gradients, the retention and the mobile phase velocity were no longer constant. Thus, simple mathematical models consisting only of the mass balance equations are unsuitable to properly model the elution profiles. Here, the elution concentration profiles were predicted using a combined two-dimensional heat and mass transfer model, also including the calculation of the mobile phase velocity distribution. The isotherm adsorption model was the bi-Langmuir isotherm model with Henry constants that depended on the local temperature and pressure in the column. These adjustments allowed us to precisely account for changes in the shape and retention of the overloaded concentration profiles in the mobile phase. The proposed model provided accurate predictions of the overloaded concentration profiles, demonstrating good agreement with experimental profiles eluted under severe pressure and temperature gradients in the column even in the most extreme cases where the pressure drops reached 846 bar and the temperature gradients equaled 0.15 K mm-1 and 0.95 K mm-1 in the axial and the radial directions, respectively. In such cases 36 % decrease of the retention factor was observed along the column and 2 % increase in radial direction. These changes, combined with the velocity distribution, shifted the overloaded elution profile's shock towards the center of the column, advancing approximately 3 mm from its initial position close to the column wall. Ultimately, this resulted in the broadening of the elution band.


Assuntos
Temperatura Alta , Modelos Teóricos , Cromatografia Líquida de Alta Pressão/métodos , Temperatura , Água
5.
Foods ; 13(2)2024 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-38275699

RESUMO

The mass transfer and shrinkage characteristics of Chinese cabbage (CC) during osmotic dehydration (OD) were investigated. The leaves were grouped into four sections and analyzed based on their morphological characteristics (i.e., maturity, width, and thickness). The sections were immersed in 2.0 mol/m3 NaCl for 120 h at 25 ± 2 °C. The diffusion coefficient (D) of the leaf blade was not significantly different with respect to the sections that were formed, but it was significantly different in the midrib in the increasing order of P1, P4, P3, and P2, with values of 1.12, 1.61, 1.84, and 2.06 (× 10-6), respectively, after a 1 h soaking period due to the different characteristics in morphology and structure, such as porosity (0.31, 0.41, 0.42, and 0.38 for positions 1, 2, 3, and 4, respectively) and fiber contents. Numerical simulation (NS) for CC was conducted with and without the consideration of shrinkage during OD. The shrinkage effect on the NaCl uptake analyzed using NS indicated no significant difference between 0 to 48 h for both models. However, changes in the NaCl concentration were observed from 48 h onwards, with a lesser concentration in the model with shrinkage for all sections. The difference in NaCl concentration for the models with and without shrinkage was within the standard error range (±0.2 mol/m3) observed during experimental analysis. This implies that the shrinkage effect can be overlooked during the modeling of CC to reduce computational power.

6.
Sci Total Environ ; 912: 169270, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38086486

RESUMO

Clarifying the state of marine pollution is important for evaluating the health risk to predators in the marine food web such as fishes and mammals. Although previous studies have generally modeled marine pollution targeting a single organism, this study focused on the transfer of marine pollution in terms of ecological network. In this study, a biomass-based stochastic model was constructed for the transfer of 2,2',4,4',5,5'-hexachlorobiphenyl (PCB153) in a coupled pelagic-benthic system targeting populations of species. Incorporating the populations of species allows for discussions on predation pressure and anthropogenic activities such as fishing. The biomass parameters representing populations of species were set by using published data on the ecosystem in Tokyo Bay, Japan and were represented by probability density distributions to reflect population uncertainty. The PCB153 concentrations computed by the model were then compared with observations for validation. The results showed that the probability density distributions of PCB153 concentrations in marine species had a long tail to the right, which indicated the occurrence probabilities of individual organisms having considerably high contamination levels. A theoretical analysis was performed to quantify the response of species (e.g., fish, plankton, and benthos) to PCB153 accumulation accounting for population uncertainty, which indicated that a reduction in the population of predator species may contribute to the occurrence of high PCB153 concentrations in individual organisms in other species. The obtained probability density distributions were then used to compare the PCB153 human intake through ingesting seafood with the human's acceptable daily intake. The model can quantitatively demonstrate the probability distributions of PCB153 concentrations in marine species and PCB153 intake by humans through seafood, to which more attention should be paid.


Assuntos
Bifenilos Policlorados , Poluentes Químicos da Água , Animais , Humanos , Cadeia Alimentar , Bifenilos Policlorados/análise , Ecossistema , Biomassa , Peixes , Poluentes Químicos da Água/análise , Mamíferos
7.
Membranes (Basel) ; 13(12)2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-38132912

RESUMO

Membrane biofilm reactors are a growing trend in wastewater treatment whereby gas-transfer membranes provide efficient bubbleless aeration. Recently, there has been a growing interest in using these bioreactors for industrial biotechnology using microorganisms that can metabolise gaseous substrates. Since gas fermentation is limited by the low solubilities of gaseous substrates in liquid media, it is critical to characterise mass transfer rates of gaseous substrates to enable the design of membrane biofilm reactors. The objective of this study is to measure and analyse mass transfer rates and reaction engineering characteristics for a single tube membrane biofilm reactor using Cupriavidus necator H16. At elevated Reynolds numbers, the dominant resistance for gas diffusion shifts from the liquid boundary layer to the membrane. The biofilm growth rate was observed to decrease after 260 µm at 96 h. After 144 h, some sloughing of the biofilm occurred. Oxygen uptake rate and substrate utilisation rate for the biofilm developed showed that the biofilm changes from a single-substrate limited regime to a dual-substrate-limited regime after 72 h which alters the localisation of the microbial activity within the biofilm. This study shows that this platform technology has potential applications for industrial biotechnology.

8.
Sci Total Environ ; 902: 165945, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37541497

RESUMO

Indoor decoration generates a large number of volatile organic compounds (VOCs), which are simultaneously released from different paints. Nevertheless, the interaction mechanism of pollutant diffusion from multisource building materials (such as primer and finish) needs to be examined. In this paper, a multisource mass transfer model for VOC emissions from different combinations of paints is established, and the analytical solution is derived. The finite difference method is used to simulate the experimental results of VOC release in the environmental chambers, and its convergence and stability are verified. Using the optimization parameters of the single-source model and the law of conservation of mass, the key parameters of the multisource mass transfer model are obtained. The results show that the established model is in excellent agreement with both experimental data and literature data. In addition, the Little number Lt is used to analyse the change trend from the initial released concentration in the single-source and multisource models.

9.
Curr Treat Options Oncol ; 24(10): 1472-1488, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37566213

RESUMO

OPINION STATEMENT: Cardio-oncology is going under rapid development in various areas across an increasing number of provinces in China. However there are still a myriad of challenges that need to be overcome in order to ensure its gradual and consistent expansion. The Cardio-Oncology Knowledge Transfer Model (KTM) forms the basis to allow exponential development of effective cardio-oncology services. This would ensure the implementation of precision-based practice while dynamically evolving cardio-oncology to integrate both Western and Chinese medical practices to become an official clinical sub-speciality in its own right in China, for the ultimate benefit of the patient.


Assuntos
Doenças Cardiovasculares , Neoplasias , Humanos , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/etiologia , Neoplasias/epidemiologia , Neoplasias/terapia , Oncologia , China/epidemiologia
10.
Sci Total Environ ; 900: 165731, 2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-37495150

RESUMO

Soil vapor extraction (SVE) is a widely used technology for the remediation of volatile organic compounds (VOCs) contaminated soils. Residual concentrations of VOCs are crucial for assessing the SVE process and planning when to stop this process, however, the measurement of their residual concentrations in the soil is complicated. Herein, a pseudo-first-order sequential reaction model was established to predict the mass transfer of the BTEX (benzene, toluene, ethylbenzene, xylene) between the soil and off-gas during the SVE process. Based on this mass transfer model, the residual concentrations of BTEX in the soil during the trailing stage could be accurately estimated (R2 > 0.89) by their off-gas concentrations that were directly monitored in real time. Considering the removal efficiency and operating costs, a concept of the remediation target values (RTV) was proposed for the SVE technology, and its relevant model (R2 > 0.92, NRMSE = 6.4-16.8 %) was established based on the experimental data. The remediation endpoint can be further estimated based on the RTV with an overall accuracy of 84-100 %. These findings provide a simple and fast way to predict VOC concentrations in soil with easy-to-know factors and online monitoring of off-gas concentrations and will guide and optimize the SVE process toward more economical and efficient techniques for soil remediation.

11.
Toxics ; 11(7)2023 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-37505604

RESUMO

In this work, the overall adsorption kinetic process of hydroquinone on Phragmites australis biochar (PAC) was analyzed in depth. A 3D mass transfer model of pore volume and surface diffusion was established, and the diffusion mechanism was analyzed. The characterization results show PAC has a higher porosity value, which is conducive to the adsorption of hydroquinone. The adsorption process modeling results show that the combined effect of pore volume diffusion and surface diffusion promotes the total diffusion process of hydroquinone in the PAC particles, and the two mechanisms of pore volume and surface diffusion exist simultaneously. Under the different operating concentrations, the range of surface diffusion coefficient Ds is 2.5 × 10-10-1.74 × 10-9 cm2/s, and the contribution rate of surface diffusion SDCP% is close to 100%, which is much larger than pore volume diffusion, revealing that regardless of the contact time and position, surface diffusion occupies the main position in intraparticle diffusion.

12.
Artigo em Inglês | MEDLINE | ID: mdl-37482681

RESUMO

A bubbling reactor is an important type of gas scrubber to reduce SO2 emissions in maritime shipping. Both experiments and simulations were conducted to study the relationship between the periodic gas bubbling process and SO2 concentration at the outlet of the reactor, and the entrainment of liquid droplets on SO2 absorption. The accuracy of the model was verified by comparing the bubble size, the depth of bubbles injected into the water, and the SO2 concentration obtained in both experiments and simulations. The gas bubbling process is accompanied by bubble formation, rise, and collapse. The gas bubbling period is affected by the disturbance of the liquid level. The period of the SO2 concentration at the outlet of the gas bubbling reactor is smaller than that at the gas jar outlet which acts as the gas buffering region. The amounts of water carried out of the bubbling reactor by the gas bubbling process increase with the gas flow rates. The droplets and liquid film in the gas jar and the connecting tube play an important role in the absorption of SO2. This study encourages more research to reduce the fluctuation of SO2 concentration and consider droplet entrainment in the design of bubbling reactors.


Assuntos
Água
14.
Environ Toxicol Chem ; 42(10): 2171-2183, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37377347

RESUMO

Per- and polyfluoroalkyl substances (PFAS) are an emerging class of compounds that cause health and environmental problems worldwide. In aquatic environments, PFAS may bioaccumulate in sediment organisms, which can affect the health of organisms and ecosystems. As such, it is important to develop tools to understand their bioaccumulation potential. In the present study, the uptake of perfluorooctanoic acid (PFOA) and perfluorobutane sulfonic acid (PFBS) from sediments and water was assessed using a modified polar organic chemical integrative sampler (POCIS) as a passive sampler. While POCIS has previously been used to measure time-weighted concentrations of PFAS and other compounds in water, in our study, the design was adapted for analyzing contaminant uptake and porewater concentrations in sediments. The samplers were deployed into seven different tanks containing PFAS-spiked conditions and monitored over 28 days. One tank contained only water with PFOA and PFBS, three tanks contained soil with 4% organic matter, and three tanks contained soil combusted at 550 °C to minimize the influence of labile organic carbon. The uptake of PFAS from the water was consistent with previous research using a sampling rate model or simple linear uptake. For the samplers placed in the sediment, the uptake process was explained well using a mass transport based on the external resistance from the sediment layer. Uptake of PFOS in the samplers occurred faster than that of PFOA and was more rapid in the tanks containing the combusted soil. A small degree of competition was observed between the two compounds for the resin, although these effects are unlikely to be significant at environmentally relevant concentrations. The external mass transport model provides a mechanism to extend the POCIS design for measuring porewater concentrations and sampling releases from sediments. This approach may be useful for environmental regulators and stakeholders involved in PFAS remediation. Environ Toxicol Chem 2023;42:2171-2183. © 2023 SETAC.


Assuntos
Ácidos Alcanossulfônicos , Fluorocarbonos , Poluentes Químicos da Água , Monitoramento Ambiental , Ecossistema , Poluentes Químicos da Água/análise , Compostos Orgânicos/análise , Solo/química , Fluorocarbonos/análise , Água , Ácidos Alcanossulfônicos/análise
15.
J Pers Med ; 13(3)2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36983622

RESUMO

The aim of this 4-year observational study is to analyze the outcomes of stroke patients treated with direct mechanical thrombectomy (dMT) compared to bridging therapy (BT) (intravenous thrombolysis [IVT] + BT) based on 3-month outcomes, in real clinical practice in the "Stroke Belt" of Southern Europe. In total, 300 patients were included (41.3% dMT and 58.6% BT). The frequency of direct referral to the stroke center was similar in the dMT and BT group, whereas the time from onset to groin was longer in the BT group (median 210 [IQR 160-303] vs. 399 [IQR 225-675], p = 0.001). Successful recanalization (TICI 2b-3) and hemorrhagic transformation were similar in both groups. The BT group more frequently showed excellent outcomes at 3 months (32.4% vs. 15.4%, p = 0.004). Multivariate analysis showed that BT was independently associated with excellent outcomes (OR 2.7. 95% CI,1.2-5.9, p = 0.02) and lower mortality (OR 0.36. 95% CI 0.16-0.82, p = 015). Conclusions: Compared with dMT, BT was associated with excellent functional outcomes and lower 3-month mortality in this real-world clinical practice study conducted in a region belonging to the "Stroke Belt" of Southern Europe. Given the disparity of results on the benefit of BT in the current evidence, it is of vital importance to analyze the convenience of its use in each health area.

16.
J Hazard Mater ; 452: 131263, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-36989788

RESUMO

Capacitive deionization (CDI) is surprisingly efficient to remove the aqueous Cs ion due to its small hydrated size and low hydration energy. But current experimental techniques fail in investigating deeply into the influence of some key electrode characteristics due to the difficulty in experimentally fabricating the electrodes as desired. This work presents a dynamic transport model of salt ions in a flow-by CDI cell. By using this model, the electrode thickness, macro- and micro-porosity are investigated to evaluate Cs ion removal efficiency and energy efficiency particularly from the aspect of ion transfer by the approach of decomposing energy contribution. The results indicate that the thick electrode coupled with the high current could greatly improve the effluent quality, but reduce the salt adsorption capacity (SAC). The increasement of the current density from 3 A/m2 to 6 A/m2 greatly decreases the SAC from 4.0 mg/g to 0.8 mg/g. Lower current could prolong the charging period, leading to more ions stored in the micropore. Not all the electrical energy is consumed for separating ions from the feed as desired, but some are used for driving ions diffusing in the electrodes. Consequently charging efficiency will be reduced especially when the electrodes are characterized with high porosity. It is highlighted that future work is required to further consider the complex details of porous structure and pore connectivity.

17.
Geohealth ; 7(3): e2022GH000757, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36874169

RESUMO

In 2020, the Yangtze-Huai river valley (YHRV) experienced the highest record-breaking Meiyu season since 1961, which was mainly characterized by the longest duration of precipitation lasting from early-June to mid-July, with frequent heavy rainstorms that caused severe flooding and deaths in China. Many studies have investigated the causes of this Meiyu season and its evolution, but the accuracy of precipitation simulations has received little attention. It is important to provide more accurate precipitation forecasts to help prevent and reduce flood disasters, thereby facilitating the maintenance of a healthy and sustainable earth ecosystem. In this study, we determined the optimal scheme among seven land surface model (LSMs) schemes in the Weather Research and Forecasting model for simulating the precipitation in the Meiyu season during 2020 over the YHRV region. We also investigated the mechanisms in the different LSMs that might affect precipitation simulations in terms of water and energy cycling. The results showed that the simulated amounts of precipitation were higher under all LSMs than the observations. The main differences occurred in rainstorm areas (>12 mm/day), and the differences in low rainfall areas were not significant (<8 mm/day). Among all of the LSMs, the Simplified Simple Biosphere (SSiB) model obtained the best performance, with the lowest root mean square error and the highest correlation. The SSiB model even outperformed the Bayesian model averaging result. Finally, some factors responsible for the differences modeling results were investigated to understand the related physical mechanism.

18.
Sci Total Environ ; 871: 162157, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-36775174

RESUMO

The interaction of microplastics (MPs) and organic pollutants has recently become a focus of investigation. To understand how microplastic residues affect the migration of organic pollutants, it is necessary to examine the adsorption and desorption behavior of organic pollutants on MPs. In this study, integrated adsorption/desorption experiments and theoretical calculations were used to clarify the adsorption mechanism of 2-hydroxynaphthalene (2-OHN), naphthalene (NAP), phenanthrene (PHE), and pyrene (PYR) by polyvinyl chloride microplastics (PVC-MPs). Based on the phenomenological mathematical models, the rate-limiting step for analyte adsorption onto PVC-MPs was adsorption onto active sites (R2 = 0.865-0.995). Except for PHE, analyte adsorption isotherms were well described by the Freundlich model (R2 = 0.992-0.998), and adsorption thermodynamics showed that analyte adsorption on PVC-MPs was a spontaneous exothermic process (ΔH0 < 0; ΔG0 < 0). Based on the order of adsorption efficiency of 2-OHN < NAP < PHE < PYR, which is identical to the competitive adsorption experiment, polycyclic aromatic hydrocarbon (PAH) adsorption on PVC-MPs increased as the aromatic ring number increased and the hydroxyl content decreased. The release of 2-OHN (49 %-52 %) from PVC-MPs into the simulated gastrointestinal environment was greater than that of NAP (5.5 %-5.7 %). Theoretical calculations and adsorption tests indicated that hydrophobic interaction was the primary influence on the adsorption of PAHs and their hydroxylated derivatives by PVC-MPs. These findings improve our understanding of MPs' behavior and dangers as pollutant carriers in the aquatic environment and help us develop recommendations for the pollution control of MPs.


Assuntos
Poluentes Ambientais , Fenantrenos , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Humanos , Microplásticos/química , Plásticos/química , Cloreto de Polivinila , Água , Adsorção , Naftalenos , Hidrocarbonetos Policíclicos Aromáticos/análise , Fenantrenos/análise , Pirenos/análise , Poluentes Ambientais/química , Poluentes Químicos da Água/análise
19.
Biomimetics (Basel) ; 8(1)2023 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-36810377

RESUMO

To apply functional honeycomb panels (FHPs) in actual engineering projects, the heat transfer performance and intrinsic heat transfer mechanism of laminated honeycomb panels (LHPs, total thickness of 60 mm) with different structural parameters were investigated in this study by a heat flow meter. The results showed that (1) the equivalent thermal conductivity λequ of the LHP was almost independent of the cell size, when it consisted of a small single-layer thickness. Thus, LHP panels with a single-layer thickness of 15-20 mm are recommended. (2) A heat transfer model of LHPs was developed, and it was concluded that the heat transfer performance of LHPs depends greatly on the performance of their honeycomb core. Then, an equation was derived for the steady state temperature distribution of the honeycomb core. (3) The contribution of each heat transfer method to the total heat flux of the LHP was calculated using the theoretical equation. According to the theoretical results, the intrinsic heat transfer mechanism affecting the heat transfer performance of LHPs was revealed. The results of this study laid the foundation for the application of LHPs in building envelopes.

20.
Materials (Basel) ; 16(2)2023 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-36676222

RESUMO

This study proposed an extended multi-layer heat transfer model to simulate skin burns of firefighters during firefighting. The proposed model takes into account the effect of fabric movement frequencies, fabric movement amplitudes and human body movement speeds on the heat transfer between the skin and the heat source under low-level radiative exposure. The simulation performance was validated against the simulations in the published literature in terms of the heat transfer in the multi-layer fabric system, skin temperature and skin burns. The results indicated that the fabric periodic movement caused by human body movement decreased the time to skin burns and the skin temperature increased with increasing fabric movement amplitude. During firefighting, the time to 2nd degree burn was 33.3-35.2% shorter at medium human body movement speed than at low and high movement speeds. Furthermore, at low movement speeds, the time to 2nd degree burn was negatively associated with fabric movement amplitude, whereas it was delayed by 12.9-29.8% at the fabric movement amplitude of 2.5 mm at medium and high human body movement speeds. This research provides foundational knowledge for the development of a new generation of firefighters' protective clothing (FPC) and the assessment of skin burns in firefighters.

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