Design of a Stitched Textile-Based Thermal Actuator Garment to Attenuate Peripheral Microclimate Experience

2018 ◽  
Author(s):  
Nika Gagliardi ◽  
Esther Foo ◽  
Ellen Dupler ◽  
Simon Ozbek ◽  
Lucy Dunne
Keyword(s):  
Thermal Comfort ◽  
Thermal Sensitivity ◽  
The Body ◽  
Vascular Response ◽  
Chemical Heat ◽  
Cold Temperatures ◽  
Thermoneutral Zone ◽  
Commercial Market ◽  
Body Core ◽  
Emotional Effects

Temperature is an important influencer of homeostatic comfort for humans, and its influence extends beyond life-preservation functions into cognitive and emotional effects. To augment metabolic processes in cold climates, many on-body heating solutions are currently available in the commercial market, ranging from chemical heat packs to electrically heated accessories and clothing. These products typically prioritize heating the body core in extreme conditions. By contrast, the experience of thermal comfort in the band around homeostatic comfort temperatures is much more strongly driven by experience of temperature in the body’s periphery: the hands, feet, and face [1]. Thermal sensitivity is highest in the distal extremities and has been established as the best correlate of overall perception of thermal comfort [2], [3]. In the medical context, this is especially significant in treating vasospastic disorders such as Raynaud’s Syndrome, where a spastic vascular response in peripheral vessels results in an over-reaction to cold temperatures proximal to the thermoneutral zone [4].

Thermal regulation and comfort during a mild-cold exposure in young Japanese women complaining of unusual coldness

2002 ◽  
Vol 92 (3) ◽  
pp. 1029-1035 ◽  
Author(s):  
Kei Nagashima ◽  
Tamae Yoda ◽  
Tomoko Yagishita ◽  
Aki Taniguchi ◽  
Takayoshi Hosono ◽  
...  
Keyword(s):  
Cold Exposure ◽  
Baseline Level ◽  
Thermal Sensitivity ◽  
Japanese Women ◽  
The Body ◽  
Body Core ◽  
Young Japanese Women ◽  
C And N ◽  
Baseline Levels ◽  
Skin Temperatures

We examined body core and skin temperatures and thermal comfort in young Japanese women suffering from unusual coldness (C, n = 6). They were selected by interview asking whether they often felt severe coldness even in an air-conditioned environment (20–26°C) and compared with women not suffering from coldness (N, n = 6). Experiments were conducted twice for each subject: 120-min exposure at 23.5°C or 29.5°C after a 40-min baseline at 29.5°C. Mean skin temperature decreased ( P < 0.05) from 33.6 ± 0.1°C (mean ± SE) to 31.1 ± 0.1°C and from 33.5 ± 0.1°C to 31.1 ± 0.1°C in C and N during the 23.5°C exposure. Fingertip temperature in C decreased more than in N ( P < 0.05; from 35.2 ± 0.1°C to 23.6 ± 0.2°C and from 35.5 ± 0.1°C to 25.6 ± 0.6°C). Those temperatures during the 29.5°C exposure remained at the baseline levels. Rectal temperature during the 23.5°C exposure was maintained at the baseline level in both groups (from 36.9 ± 0.2°C to 36.8 ± 0.1°C and 37.1 ± 0.1°C to 37.0 ± 0.1°C in C and N). The rating scores of cold discomfort for both the body and extremities were greater ( P < 0.05) in C than in N. Thus the augmented thermal sensitivity of the body to cold and activated vasoconstriction of the extremities during cold exposure could be the mechanism for the severe coldness felt in C.

scholarly journals Development of a Deep Neural Network Model for Estimating Joint Location of Occupant Indoor Activities for Providing Thermal Comfort

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 696
Author(s):  
Eun Ji Choi ◽  
Jin Woo Moon ◽  
Ji-hoon Han ◽  
Yongseok Yoo
Keyword(s):  
Neural Network ◽  
Thermal Comfort ◽  
Deep Neural Network ◽  
Mean Squared Error ◽  
Thermal Environment ◽  
The Body ◽  
Estimation Accuracy ◽  
Accurate Estimation ◽  
Body Parts ◽  
Joint Location

The type of occupant activities is a significantly important factor to determine indoor thermal comfort; thus, an accurate method to estimate occupant activity needs to be developed. The purpose of this study was to develop a deep neural network (DNN) model for estimating the joint location of diverse human activities, which will be used to provide a comfortable thermal environment. The DNN model was trained with images to estimate 14 joints of a person performing 10 common indoor activities. The DNN contained numerous shortcut connections for efficient training and had two stages of sequential and parallel layers for accurate joint localization. Estimation accuracy was quantified using the mean squared error (MSE) for the estimated joints and the percentage of correct parts (PCP) for the body parts. The results show that the joint MSEs for the head and neck were lowest, and the PCP was highest for the torso. The PCP for individual activities ranged from 0.71 to 0.92, while typing and standing in a relaxed manner were the activities with the highest PCP. Estimation accuracy was higher for relatively still activities and lower for activities involving wide-ranging arm or leg motion. This study thus highlights the potential for the accurate estimation of occupant indoor activities by proposing a novel DNN model. This approach holds significant promise for finding the actual type of occupant activities and for use in target indoor applications related to thermal comfort in buildings.

scholarly journals Occupant behaviour and thermal comfort in buildings: Monitoring the end user

2019 ◽  
Vol 111 ◽  
pp. 04056
Author(s):  
Loes Visser ◽  
Boris Kingma ◽  
Eric Willems ◽  
Wendy Broers ◽  
Marcel Loomans ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Energy Performance ◽  
The Body ◽  
Activity Level ◽  
Biophysical Model ◽  
Zone Model ◽  
Occupant Behaviour ◽  
Ambient Conditions ◽  
Skin Temperatures ◽  
Thermoregulatory Behaviour

Studies indicate that the energy performance gap between real and calculated energy use can be explained for 80% by occupant behaviour. This human factor may be composed of routine and thermoregulatory behaviour. When occupants do not feel comfortable due to high or low operative temperatures and resulting high or low skin temperatures, they are likely to exhibit thermoregulatory behaviour. The aim of this study is to monitor and understand this thermoregulatory behaviour of the occupant. This is a detailed study of two females living in a rowhouse in the city of Heerlen (Netherlands). During a monitoring period of three weeks over a time span of three months the following parameters were monitored: activity level, clothing, micro climate, skin temperatures and thermal comfort and sensation. Their micro climate was measured at five positions on the body to assess exposed near body conditions and skin temperature. Every two hours they filled in a questionnaire regarding their thermal comfort and sensation level (7-point scale), clothing, activities and thermoregulatory behaviour. The most comfortable (optimal) temperature was calculated for each person by adopting a biophysical model, a thermoneutral zone model. This study shows unique indivual comfort patterns in relation to ambient conditions. An example is given how this information can be used to calculate the buildings energy comsumption.

scholarly journals DNA methyltransferase 3a mediates developmental thermal plasticity

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Isabella Loughland ◽  
Alexander Little ◽  
Frank Seebacher
Keyword(s):  
Environmental Change ◽  
Dna Methyltransferase ◽  
Developmental Plasticity ◽  
Citrate Synthase ◽  
Thermal Sensitivity ◽  
Short Term ◽  
Cold Temperatures ◽  
Knock Out ◽  
Thermal Plasticity ◽  
Dna Methyltransferase 3A

Abstract Background Thermal plasticity is pivotal for evolution in changing climates and in mediating resilience to its potentially negative effects. The efficacy to respond to environmental change depends on underlying mechanisms. DNA methylation induced by DNA methyltransferase 3 enzymes in the germline or during early embryonic development may be correlated with responses to environmental change. This developmental plasticity can interact with reversible acclimation within adult organisms, which would increase the speed of response and could alleviate potential mismatches between parental or early embryonic environments and those experienced at later life stages. Our aim was to determine whether there is a causative relationship between DNMT3 enzyme and developmental thermal plasticity and whether either or both interact with short-term acclimation to alter fitness and thermal responses in zebrafish (Danio rerio). Results We developed a novel DNMT3a knock-out model to show that sequential knock-out of DNA methyltransferase 3a isoforms (DNMT3aa−/− and DNMT3aa−/−ab−/−) additively decreased survival and increased deformities when cold developmental temperatures in zebrafish offspring mismatched warm temperatures experienced by parents. Interestingly, short-term cold acclimation of parents before breeding rescued DNMT3a knock-out offspring by restoring survival at cold temperatures. DNMT3a knock-out genotype interacted with developmental temperatures to modify thermal performance curves in offspring, where at least one DNMT3a isoform was necessary to buffer locomotion from increasing temperatures. The thermal sensitivity of citrate synthase activity, an indicator of mitochondrial density, was less severely affected by DNMT3a knock-out, but there was nonetheless a significant interaction between genotype and developmental temperatures. Conclusions Our results show that DNMT3a regulates developmental thermal plasticity and that the phenotypic effects of different DNMT3a isoforms are additive. However, DNMT3a interacts with other mechanisms, such as histone (de)acetylation, induced during short-term acclimation to buffer phenotypes from environmental change. Interactions between these mechanisms make phenotypic compensation for climate change more efficient and make it less likely that thermal plasticity incurs a cost resulting from environmental mismatches.

scholarly journals ADAPTIVE HOUSE DESIGN AND PEOPLE’S HABITS IN ACHIEVING THERMAL COMFORT IN GAYO HIGHLAND ACEH, INDONESIA

2021 ◽  
Vol 8 (1) ◽  
pp. 23
Author(s):  
Erna Meutia ◽  
Laina Hilma Sari
Keyword(s):  
Thermal Comfort ◽  
Thermal Environment ◽  
The Body ◽  
Mental Condition ◽  
Human Adaptation ◽  
Cold Environment ◽  
Adaptive Thermal Comfort ◽  
Aceh Province ◽  
Lower Temperature ◽  
House Design

The Gayo Highland is one of the districts in Aceh Province, Sumatra. Due to the topography, this area has a lower  temperature compared than the flat and coastal areas in Aceh. The thermal comfort that is felt is based on a person's mental condition and how he expresses his satisfaction with his thermal environment. In other words, it shows how humans adapt to their thermal environment. Thermal comfort based on human adaptation is known as adaptive thermal comfort. The form of dwelling for the Gayo Highland community has shifted and changed from traditional dwelling to Transitional and Modern forms that influence the Gayo Highland community's adaptation to achieve thermal comfort. Therefore, this paper aims to investigate the house design in Gayo highland in providing warmth to the occupants naturally in the cold environment. Another aim of this study is to investigate the people's habits in warming up the body to deal with the low air temperature in the area.  This study shows how the local people adapt themselves through the house element and daily habit to gain the internal thermal comfort.

scholarly journals Field Study Of A Radiant Heating System For Sleep Thermal Comfort And Potential Energy Saving

2021 ◽  
Author(s):  
Christopher L. K. Wang
Keyword(s):  
Potential Energy ◽  
Thermal Comfort ◽  
Energy Saving ◽  
Energy Savings ◽  
Thermal Environment ◽  
Residential Buildings ◽  
Thermal Conditions ◽  
Heating System ◽  
The Body ◽  
Radiant Temperature

As sleep is unconscious, the traditional definition of thermal comfort with conscious judgment does not apply. In this thesis sleep thermal comfort is defined as the thermal condition which enables sleep to most efficiently rejuvenate the body and mind. A comfort model was developed to stimulate the respective thermal environment required to achieve the desired body thermal conditions and a new infrared sphere method was developed to measure mean radiant temperature. Existing heating conditions according to building code conditions during sleeping hours was calculated to likely overheat a sleeping person and allowed energy saving potential by reducing nighttime heating set points. Experimenting with existing radiantly and forced air heated residential buildings, it was confirmed that thermal environment was too hot for comfortable sleep and that the infrared sphere method shows promise. With the site data, potential energy savings were calculated and around 10% of energy consumption reduction may be achieved during peak heating.

scholarly journals Proton block of proton-activated TRPV1 current

2015 ◽  
Vol 146 (2) ◽  
pp. 147-159 ◽  
Author(s):  
Bo Hyun Lee ◽  
Jie Zheng
Keyword(s):  
Tissue Injury ◽  
Ion Selectivity ◽  
Extracellular Ph ◽  
The Body ◽  
Ion Permeation ◽  
Nociceptive Neurons ◽  
Trpv1 Channels ◽  
Highly Sensitive ◽  
Body Core ◽  
Polymodal Nociceptor

The TRPV1 cation channel is a polymodal nociceptor that is activated by heat and ligands such as capsaicin and is highly sensitive to changes in extracellular pH. In the body core, where temperature is usually stable and capsaicin is normally absent, H+ released in response to ischemia, tissue injury, or inflammation is the best-known endogenous TRPV1 agonist, activating the channel to mediate pain and vasodilation. Paradoxically, removal of H+ elicits a transient increase in TRPV1 current that is much larger than the initial H+-activated current. We found that this prominent OFF response is caused by rapid recovery from H+ inhibition of the excitatory current carried by H+-activated TRPV1 channels. H+ inhibited current by interfering with ion permeation. The degree of inhibition is voltage and permeant ion dependent, and it can be affected but not eliminated by mutations to acidic residues within or near the ion selectivity filter. The opposing H+-mediated gating and permeation effects produce complex current responses under different cellular conditions that are expected to greatly affect the response of nociceptive neurons and other TRPV1-expressing cells.

Temperature Difference Between the Body Core and the Arterial Blood Supplied to the Brain During Hyperthermia or Hypothermia

2001 ◽  
Author(s):  
Liang Zhu ◽  
Maithreyi Bommadevara
Keyword(s):  
Blood Vessel ◽  
Temperature Difference ◽  
Carotid Arteries ◽  
Brain Temperature ◽  
Indirect Evidence ◽  
Blood Perfusion ◽  
The Body ◽  
Arterial Blood ◽  
Body Core ◽  
The Brain

Abstract In this study a theoretical model was developed to evaluate the temperature difference between the body core and the arterial blood supplied to the brain. Several factors including the local blood perfusion rate, blood vessel bifurcation in the neck, and blood vessel pairs on both sides of the neck were considered in the model. The theoretical approach was used to estimate the potential for cooling of blood in the carotid artery on its way to the brain by heat exchange with its countercurrent jugular vein and by the radial heat conduction loss to the cool neck surface. It shows that blood temperature along the common and internal carotid arteries typically decreases up to 0.86°C during hyperthermia. Selectively cooling the neck surface during hypothermia increases the heat loss from the carotid arteries and results in approximately 1.2°C in the carotid arterial temperature. This research could provide indirect evidence of the existence of selective brain cooling (SBC) in humans during hyperthermia. The simulated results can also be used to evaluate the feasibility of lowering brain temperature effectively by selectively cooling the head and neck surface during hypothermia treatment for brain injury or multiple sclerosis.

The metabolic rate and thermal conductance of the eastern barred bandicoot (Perameles gunnii) at different ambient temperatures

2003 ◽  
Vol 51 (6) ◽  
pp. 603 ◽  
Author(s):  
M. P. Ikonomopoulou ◽  
R. W. Rose
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Thermal Conductance ◽  
The Body ◽  
High Metabolic Rate ◽  
Ambient Temperatures ◽  
Reduced Body ◽  
Thermoneutral Zone ◽  
Reproductive Females

We investigated the metabolic rate, thermoneutral zone and thermal conductance of the eastern barred bandicoot in Tasmania. Five adult eastern barred bandicoots (two males, three non-reproductive females) were tested at temperatures of 3, 10, 15, 20, 25, 30, 35 and 40°C. The thermoneutral zone was calculated from oxygen consumption and body temperature, measured during the daytime: their normal resting phase. It was found that the thermoneutral zone lies between 25°C and 30°C, with a minimum metabolic rate of 0.51 mL g–1 h–1 and body temperature of 35.8°C. At cooler ambient temperatures (3–20°C) the body temperature decreased to approximately 34.0°C while the metabolic rate increased from 0.7 to 1.3 mL g–1�h–1. At high temperatures (35°C and 40°C) both body temperature (36.9–38.7°C) and metabolic rate (1.0–1.5 mL g–1 h–1) rose. Thermal conductance was low below an ambient temperature of 30°C but increased significantly at higher temperatures. The low thermal conductance (due, in part, to good insulation, a reduced body temperature at lower ambient temperatures, combined with a relatively high metabolic rate) suggests that this species is well adapted to cooler environments but it could not thermoregulate easily at temperatures above 30°C.

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