Journal of heat transfer最新文献

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Bioheat Transfer Basis of Human Thermoregulation: Principles and Applications. 人体体温调节的生物传热基础:原理与应用。

Journal of heat transfer Pub Date : 2022-03-01 Epub Date: 2022-01-18 DOI: 10.1115/1.4053195

Laura H Namisnak, Shahab Haghayegh, Sepideh Khoshnevis, Kenneth R Diller

{"title":"Bioheat Transfer Basis of Human Thermoregulation: Principles and Applications.","authors":"Laura H Namisnak, Shahab Haghayegh, Sepideh Khoshnevis, Kenneth R Diller","doi":"10.1115/1.4053195","DOIUrl":"https://doi.org/10.1115/1.4053195","url":null,"abstract":"Thermoregulation is a process that is essential to the maintenance of life for all warm-blooded mammalian and avian species. It sustains a constant core body temperature in the face of a wide array of environmental thermal conditions and intensity of physical activities that generate internal heat. A primary component of thermoregulatory function is the movement of heat between the body core and the surface via the circulation of blood. The peripheral vasculature acts as a forced convection heat exchanger between blood and local peripheral tissues throughout the body enabling heat to be convected to the skin surface where is may be transferred to and from the environment via conduction, convection, radiation, and/or evaporation of water as local conditions dictate. Humans have evolved a particular vascular structure in glabrous (hairless) skin that is especially well suited for heat exchange. These vessels are called arteriovenous anastomoses (AVAs) and can vasodilate to large diameters and accommodate high flow rates. We report herein a new technology based on a physiological principle that enables simple and safe access to the thermoregulatory control system to allow manipulation of thermoregulatory function. The technology operates by applying a small amount of heating local to control tissue on the body surface overlying the cerebral spine that upregulates AVA perfusion. Under this action, heat exchangers can be applied to glabrous skin, preferably on the palms and soles, to alter the temperature of elevated blood flow prior to its return to the core. Therapeutic and prophylactic applications are discussed.","PeriodicalId":520672,"journal":{"name":"Journal of heat transfer","volume":" ","pages":"031203"},"PeriodicalIF":0.0,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8823203/pdf/ht-21-1572_031203.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40589777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Spatiotemporal Evolution of Temperature During Transient Heating of Nanoparticle Arrays. 纳米粒子阵列瞬态加热过程中温度的时空演化。

IF 1.9

Journal of heat transfer Pub Date : 2022-03-01 Epub Date: 2022-01-18 DOI: 10.1115/1.4053196

Chen Xie, Zhenpeng Qin

{"title":"Spatiotemporal Evolution of Temperature During Transient Heating of Nanoparticle Arrays.","authors":"Chen Xie, Zhenpeng Qin","doi":"10.1115/1.4053196","DOIUrl":"10.1115/1.4053196","url":null,"abstract":"Nanoparticles (NPs) are promising agents to absorb external energy and generate heat. Clusters of NPs or NP array heating have found an essential role in several biomedical applications, diagnostic techniques, and chemical catalysis. Various studies have shed light on the heat transfer of nanostructures and greatly advanced our understanding of NP array heating. However, there is a lack of analytical tools and dimensionless parameters to describe the transient heating of NP arrays. Here we demonstrate a comprehensive analysis of the transient NP array heating. Firstly, we develop a set of analytical solutions for the NP array heating and provide a useful mathematical description of the spatial-temporal evolution of temperature for 2D, 3D, and spherical NP array heating. Based on this, we introduce the concept of thermal resolution that quantifies the relationship between minimal heating time, NP array size, energy intensity, and target temperature. Lastly, we define a set of dimensionless parameters that characterize the transition from confined heating to delocalized heating. This study advances the understanding of nanomaterials heating and guides the rational design of innovative approaches for NP array heating.","PeriodicalId":520672,"journal":{"name":"Journal of heat transfer","volume":" ","pages":"031204"},"PeriodicalIF":1.9,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8823199/pdf/ht-21-1578_031204.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40592246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Diffusive Transport in the Vitreous Humor: Experimental and Analytical Studies. 玻璃体内弥漫性转运:实验与分析研究。

Journal of heat transfer Pub Date : 2019-05-01 Epub Date: 2019-04-01 DOI: 10.1115/1.4042297

Anita Penkova, Rex Moats, Mark S Humayun, Scott Fraser, Satwindar Singh Sadhal

{"title":"Diffusive Transport in the Vitreous Humor: Experimental and Analytical Studies.","authors":"Anita Penkova, Rex Moats, Mark S Humayun, Scott Fraser, Satwindar Singh Sadhal","doi":"10.1115/1.4042297","DOIUrl":"https://doi.org/10.1115/1.4042297","url":null,"abstract":"In relation to intravitreal drug delivery, predictive mathematical models for drug transport are being developed, and to effectively implement these for retinal delivery, the information on biophysical properties of various ocular tissues is fundamentally important. It is therefore necessary to accurately measure the diffusion coefficient of drugs and drug surrogates in the vitreous humor. In this review, we present the studies conducted by various researchers on such measurements over the last several decades. These include imaging techniques (fluorescence and magnetic resonance imaging (MRI)) that make use of introducing a contrast agent or a labeled drug into the vitreous and tracking its diffusive movement at various time points. A predictive model for the same initial conditions when matched with the experimental measurements provides the diffusion coefficient, leading to results for various molecules ranging in size from approximately 0.1 to 160 kDa. For real drugs, the effectiveness of this system depends on the successful labeling of the drugs with suitable contrast agents such as fluorescein and gadolinium or manganese so that fluorescence or MR imagining could be conducted. Besides this technique, some work has been carried out using the diffusion apparatus for measuring permeation of a drug across an excised vitreous body from a donor chamber to the receptor by sampling assays from the chambers at various time intervals. This has the advantage of not requiring labeling but is otherwise more disruptive to the vitreous. Some success with nanoparticles has been achieved using dynamic light scattering (DLS), and presently, radioactive labeling is being explored.","PeriodicalId":520672,"journal":{"name":"Journal of heat transfer","volume":" ","pages":"050801"},"PeriodicalIF":0.0,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1115/1.4042297","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40503483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4