scholarly journals Near-infraed scattering method for fabric thermal comfort

2014 ◽  
Vol 18 (5) ◽  
pp. 1469-1472
Author(s):  
Shou-Wei Gao ◽  
Min-Zhen Du ◽  
Wang Ye ◽  
Yao-Xing Jiang ◽  
Yu-Qing Liu
Keyword(s):  
Thermal Comfort ◽  
Transfer Process ◽  
Near Infrared ◽  
Surface Conductivity ◽  
Scattering Method ◽  
Conductivity Method ◽  
Wetting Behavior ◽  
Moisture Management ◽  
Liquid Transfer ◽  
The Difference

Wetting behavior of a clothing assembly plays an important role in thermophysiological body comfort. The instruments and methods utilised for testing purposes should adequately quantify wetting parameters of fabric thermal comfort. The surface conductivity method has been used to for moisture management testing in fabrics, but that method cannot give the detailed information for fiber-liquid interaction. With the new near-infrared scattering method, the wetting mechanism is introduced and interpreted through liquid transfer process from an infinite liquid reservoir. Wetting results from two kinds of fabrics show the difference in fabric thermal comfort.

Thermal comfort performances of cellulosic socks evaluated by a foot manikin system and moisture management tester

2019 ◽  
Vol 31 (2) ◽  
pp. 272-283 ◽  
Author(s):  
Sibel Kaplan ◽  
Ceren Karaman
Keyword(s):  
Water Vapor ◽  
Thermal Resistance ◽  
Thermal Comfort ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
Thermal Manikin ◽  
Content Type ◽  
Cellulosic Fibers ◽  
Moisture Management ◽  
Liquid Transfer

Purpose The purpose of this paper is to investigate thermal comfort performances of socks produced from cotton and regenerated cellulosic fiber yarns by thermal resistance (by a newly designed foot thermal manikin), moisture management tester (MMT) parameters and permeability (air and water vapor) tests. Design/methodology/approach Single jersey fabrics and socks were knitted from 30 Ne yarns produced from cotton, different regenerated cellulosic fibers (viscose, modal, bamboo, micromodal, Tencel®, Tencel LF®) and their blends. Thermal resistances of the socks were compared by a newly developed thermal foot manikin in a more realistic way than measurements in fabric form. Besides air and water vapor permeability, moisture management parameters of the fabrics were tested to differentiate performances of cellulosic fibers. Findings Results show that air permeability, liquid absorption and transfer parameters measured by MMT are generally identical and better for regenerated cellulosic fabrics than cotton. Micromodal and Tencel® have better performances for liquid transfer and overall moisture management capacities are superior for bamboo and Tencel LF®. Thermal resistances of the socks are minimum for Tencel LF® having a cross-linked structure and maximum for viscose socks. Originality/value It is thought that thermal resistance measured in socks form is more realistic than fabric measurements and results of this study that can be valid for all knitted garments. Moreover, comprehensive material plan of the study is valuable for getting reliable results for regenerated cellulosic fibers that have small differences in cases of thermal resistance and liquid transfer.

scholarly journals Towards Sustainable Development: Building’s Retrofitting with PCMs to Enhance the Indoor Thermal Comfort in Tropical Climate, Malaysia

2021 ◽  
Vol 13 (7) ◽  
pp. 3614
Author(s):  
Zeyad Amin Al-Absi ◽  
Mohd Isa Mohd Hafizal ◽  
Mazran Ismail ◽  
Azhar Ghazali
Keyword(s):  
Climate Change ◽  
Sustainable Development ◽  
Thermal Comfort ◽  
Phase Change Materials ◽  
Thermal Environment ◽  
High Energy ◽  
Transition Temperatures ◽  
Indoor Thermal Environment ◽  
Adaptive Thermal Comfort ◽  
The Difference

Building sector is associated with high energy consumption and greenhouse gas emissions, which contribute to climate change. Sustainable development emphasizes any actions to reduce climate change and its effect. In Malaysia, half of the energy utilized in buildings goes towards building cooling. Thermal comfort studies and adaptive thermal comfort models reflect the high comfort temperatures for Malaysians in naturally conditioned buildings, which make it possible to tackle the difference between buildings’ indoor temperature and the required comfort temperature by using proper passive measures. This study investigates the effectiveness of building’s retrofitting with phase change materials (PCMs) as a passive cooling technology to improve the indoor thermal environment for more comfortable conditions. PCM sheets were numerically investigated below the internal finishing of the walls. The investigation involved an optimization study for the PCMs transition temperatures and quantities. The results showed significant improvement in the indoor thermal environment, especially when using lower transition temperatures and higher quantities of PCMs. Therefore, the monthly thermal discomfort time has decreased completely, while the thermal comfort time has increased to as high as 98%. The PCM was effective year-round and the optimum performance for the investigated conditions was achieved when using 18mm layer of PCM27-26.

scholarly journals Characteristics of Knitted Structures Produced by Engineered Polyester Yarns and Their Blends in Terms of Thermal Comfort

2015 ◽  
Vol 10 (1) ◽  
pp. 155892501501000 ◽  
Author(s):  
Nida Oğlakcioğlu ◽  
Ahmet Çay ◽  
Arzu Marmarali ◽  
Emel Mert
Keyword(s):  
Water Vapor ◽  
Thermal Comfort ◽  
Moisture Transfer ◽  
Water Vapor Permeability ◽  
Air Permeability ◽  
Vapor Permeability ◽  
Moisture Management ◽  
Thermal Comfort Properties ◽  
Knitted Structure ◽  
Drying Properties

Engineered yarns are used to provide better clothing comfort for summer garments because of their high levels of moisture and water vapor management. The aim of this study was to investigate the characteristics of knitted structures that were produced using different types of polyester yarns in order to achieve better thermal comfort properties for summer clothing. However they are relatively expensive. Therefore, in this study engineered polyester yarns were combined with cotton and lyocell yarns by plying. This way, the pronounced characteristics of these yarns were added to the knitted structure as well. Channeled polyester, hollow polyester, channeled/hollow blended polyester, cotton, and lyocell yarns were plied with each other and themselves. Then, single jersey structures were knitted using these ply yarn combinations and air permeability, thermal resistance, thermal absorptivity, water vapor permeability, moisture management, and drying properties were tested. The results indicate that channeled PES fabrics are advantageous for hot climates and high physical activities with regards to high permeability and moisture transfer and also to fast drying properties. Besides, air permeability and thermal properties improved through the combination of lyocell yarn with engineered polyester yarns. However, the use of lyocell or cotton with engineered yarns resulted in a to a decrease in moisture management properties and an increase in drying times

scholarly journals Influence of Hyperthermia on Efficacy and Uptake of Carbon Nanohorn-Cisplatin Conjugates

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Matthew R. DeWitt ◽  
Allison M. Pekkanen ◽  
John Robertson ◽  
Christopher G. Rylander ◽  
Marissa Nichole Rylander
Keyword(s):  
Cellular Uptake ◽  
Near Infrared ◽  
Drug Efficacy ◽  
Infrared Light ◽  
Exterior Surface ◽  
Mild Hyperthermia ◽  
Carbon Nanohorns ◽  
Thermal Enhancement ◽  
The Difference

Single-walled carbon nanohorns (SWNHs) have significant potential for use in photothermal therapies due to their capability to absorb near infrared light and deposit heat. Additionally, their extensive relative surface area and volume makes them ideal drug delivery vehicles. Novel multimodal treatments are envisioned in which laser excitation can be utilized in combination with chemotherapeutic-SWNH conjugates to thermally enhance the therapeutic efficacy of the transported drug. Although mild hyperthermia (41–43 °C) has been shown to increase cellular uptake of drugs such as cisplatin (CDDP) leading to thermal enhancement, studies on the effects of hyperthermia on cisplatin loaded nanoparticles are currently limited. After using a carbodiimide chemical reaction to attach CDDP to the exterior surface of SWNHs and nitric acid to incorporate CDDP in the interior volume, we determined the effects of mild hyperthermia on the efficacy of the CDDP-SWNH conjugates. Rat bladder transitional carcinoma cells were exposed to free CDDP or one of two CDDP-SWNH conjugates in vitro at 37 °C and 42 °C with the half maximal inhibitory concentration (IC50) for each treatment. The in vitro results demonstrate that unlike free CDDP, CDDP-SWNH conjugates do not exhibit thermal enhancement at 42 °C. An increase in viability of 16% and 7% was measured when cells were exposed at 42 deg compared to 37 deg for the surface attached and volume loaded CDDP-SWNH conjugates, respectively. Flow cytometry and confocal microscopy showed a decreased uptake of CDDP-SWNH conjugates at 42 °C compared to 37 °C, revealing the importance of nanoparticle uptake on the CDDP-SWNH conjugate's efficacy, particularly when hyperthermia is used as an adjuvant, and demonstrates the effect of particle size on uptake during mild hyperthermia. The uptake and drug release studies elucidated the difference in viability seen in the drug efficacy studies at different temperatures. We speculate that the disparity in thermal enhancement efficacy observed for free drug compared to the drug SWNH conjugates is due to their intrinsic size differences and, therefore, their mode of cellular uptake: diffusion or endocytosis. These experiments indicate the importance of tuning properties of nanoparticle-drug conjugates to maximize cellular uptake to ensure thermal enhancement in nanoparticle mediated photothermal-chemotherapy treatments.

scholarly journals Efektifitas Pembayangan yang dihasilkan Pohon dan Bangunan di Koridor Jalan Perkotaan Untuk Mencapai Kenyamanan Termal

2018 ◽  
Vol 4 (1) ◽  
pp. 65-70
Author(s):  
Jockie Zudhy Fibrianto ◽  
Mochamad Hilmy
Keyword(s):  
Thermal Comfort ◽  
Temperature Difference ◽  
Weather Conditions ◽  
The Sun ◽  
The Road ◽  
Analysis Phase ◽  
Measurement Results ◽  
The Difference ◽  
Road Corridors ◽  
East West

The road corridor in Pontianak City has different shading output depending on the sun orientation. The difference has caused a temperature difference that affects the pedestrian thermal comfort along the corridor. Identification and measurement of shading temperatures that occur due to buildings and trees were carried out for three days in each afternoon with relatively similar weather conditions. The road corridor that becomes the research location was at A. Yani St.-Gajah Mada St.-Tanjung Pura St., which has a North-South orientation and Teuku Umar St.-Diponegoro St.-Sisingamangaraja St., who has an East-West direction. The analysis phase is done by comparing the effectiveness of imagery produced by buildings and trees. After that, the identification and measurement results are compared with Indonesian thermal comfort standards SNI T-14-1993-03 to obtain suitable thermal comfort in the road corridors in Pontianak City.

scholarly journals Summertime canopy albedo is sensitive to forest thinning

2013 ◽  
Vol 10 (9) ◽  
pp. 15373-15414 ◽  
Author(s):  
J. Otto ◽  
D. Berveiller ◽  
F.-M. Bréon ◽  
N. Delpierre ◽  
G. Geppert ◽  
...  
Keyword(s):  
Forest Management ◽  
Tree Species ◽  
Structural Changes ◽  
Near Infrared ◽  
Canopy Structure ◽  
Model Parameters ◽  
Transfer Model ◽  
Forest Thinning ◽  
Crown Volume ◽  
The Difference

Abstract. Despite an emerging body of literature linking canopy albedo to forest management, understanding of the process is still fragmented. We combined a stand-level forest gap model with a canopy radiation transfer model and satellite-derived model parameters to quantify the effects of forest thinning, that is removing trees at a certain time during the forest rotation, on summertime canopy albedo. The effects of different forest species (pine, beech, oak) and four thinning strategies (light to intense thinning regimes) were examined. During stand establishment, summertime canopy albedo is driven by tree species. In the later stages of stand development, the effect of tree species on summertime canopy albedo decreases in favour of an increasing influence of forest thinning on summertime canopy albedo. These trends continue until the end of the rotation where thinning explains up to 50% of the variance in near-infrared canopy albedo and up to 70% of the variance in visible canopy albedo. More intense thinning lowers the summertime shortwave albedo in the canopy by as much as 0.02 compared to unthinned forest. The structural changes associated with forest thinning can be described by the change in LAI in combination with crown volume. However, forests with identical canopy structure can have different summertime albedo values due to their location: the further north a forest is situated, the more the solar zenith angle increases and thus the higher is the summertime canopy albedo, independent of the wavelength. Despite the increase of absolute summertime canopy albedo values with latitude, the difference in canopy albedo between managed and unmanaged forest decreases with increasing latitude. Forest management thus strongly altered summertime forest albedo.

scholarly journals City-Scale Distance Sensing via Bispectral Light Extinction in Bad Weather

2020 ◽  
Vol 12 (9) ◽  
pp. 1401
Author(s):  
Dong Zhao ◽  
Yuta Asano ◽  
Lin Gu ◽  
Imari Sato ◽  
Huixin Zhou
Keyword(s):  
Extinction Coefficient ◽  
Near Infrared ◽  
Imaging System ◽  
Weather Conditions ◽  
Light Extinction ◽  
Selection Strategy ◽  
Infrared Wavelengths ◽  
The Difference ◽  
Bad Weather ◽  
Almost All

In this paper, we propose a novel city-scale distance sensing algorithm based on atmosphere optics. The suspended particles, especially in bad weather, would attenuate the light at almost all wavelengths. Observing this fact and starting from the light scattering mechanism, we derive a bispectral distance sensing algorithm by leveraging the difference of extinction coefficient between two specifically selected near infrared wavelengths. The extinction coefficient of the atmosphere is related to both wavelength and meteorological conditions, also known as visibility, such as the fog and haze day. To account for different bad weather conditions, we explicitly introduce visibility into our algorithm by incorporating it into the calculation of extinction coefficient, making our algorithm simple yet effective. To capture the data, we build a bispectral imaging system that is able to take a pair of images with a monochrome camera and two narrow band-pass filters. We also present a wavelength selection strategy that allows us to accurately sense distance regardless of material reflectance and texture. Specifically, this strategy determines two distinct near infrared wavelengths by maximising the extinction coefficient difference while minimizing the influence of building’s reflectance variance. The experiments empirically validate our model and its practical performance on the distance sensing for the city-scale buildings.

Thermal Performance Comparison between Single and Double Storey Terrace Houses in Melaka, Malaysia

2016 ◽  
Vol 835 ◽  
pp. 416-422
Author(s):  
Fahanim Abdul Rashid ◽  
Asrul Mahjuddin Ressang Aminuddin ◽  
Norafida Ab. Ghaffar
Keyword(s):  
Relative Humidity ◽  
Thermal Comfort ◽  
Case Studies ◽  
Thermal Performance ◽  
High Energy ◽  
Performance Comparison ◽  
Building Envelope ◽  
The Difference ◽  
Economic Developments ◽  
Housing Typology

Over the past decade many studies were conducted to investigate the thermal performance of terraced houses in Malaysia. It was found that this housing typology failed to address the need for thermal comfort and alternatives to the narrow frontage with deep plan have been proposed with simulated good thermal performance. Although this is good progress for new generation of terraced houses, millions of units of terraced houses are still in use and new units with the outdated existing plans continued to get built due to consistently very high demand due to progressive urbanisation and rapid economic developments. Therefore, it is imperative that the thermal comfort issue for existing terraced houses is dealt with and through this paper a comparison between single and double storey terraced houses is made through analysis of indoor environmental monitoring (ambient temperature, relative humidity and air velocity) of two (2) selected case studies in Merlimau, Melaka. Contrary to popular belief, it is found that there is no statistical difference between both sets of indoor temperature and relative humidity between the case studies. This finding is indicative of the consistent and stable temporal temperature highs and lows in a 24 hour cycle despite the difference in indoor volume and distance between the ground floor and the roof cavity. Much of the reason is due to the materiality of the terraced houses construction and unsealed and uninsulated building envelope. Therefore, further research into improving the thermal performance of existing terraced houses of any typology have to be conducted to allow thermal comfort and to reduce reliance on high energy consuming air-conditioning.

Identification of the Minimum Number of Measurements Required for Thermal Comfort Assessment in Large Workplaces

2019 ◽  
Vol 63 (7) ◽  
pp. 729-742
Author(s):  
Paolo Lenzuni ◽  
Pierangelo Tura ◽  
Pierfrancesco Cervino
Keyword(s):  
Thermal Comfort ◽  
Thermal Environment ◽  
Significant Loss ◽  
Spatial Inhomogeneity ◽  
Main Window ◽  
Room Size ◽  
Synthetic Index ◽  
Minimum Number ◽  
The Difference ◽  
A Minor

Abstract Optimization of resources is the key to improve our ability to perform multiple tasks with limited time and money. In the context of thermal comfort assessment, optimization becomes important in large rooms where tens of individuals perform similar tasks. This work focuses on the identification of the minimum number of measurement points that allows an accurate description of the thermal environment. Accuracy of description is assumed if no significant loss of information is associated to the transition from the ‘primary’ thermal map based on all available measurement points to a ‘secondary’ thermal map based on a reduced set of measurement points. The concept of ‘no significant loss’ is quantified by requiring that the difference in PMV (Predicted Mean Vote) between the two maps is kept <0.1 in the vast majority (95%) of points. PMV is a standardized synthetic index that is used worldwide for quantifying thermal comfort (ISO 7730, 2005) taking into account both environmental (thermo-hygrometric) and personal (activity, clothing) quantities. We show that the uncertainty induced by the degraded resolution of the thermal map has a limited impact on the overall uncertainty on PMV. Application of the method to a few test environments shows that the room size perpendicular to the main window and the windows orientation play the largest role in determining spatial inhomogeneity in thermal maps. A minor concurring factor is the room area.

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