Search results for " Humidity"

Observational Results On The Influence Of Surface Layer Stability And Inversion Entrainment On Surface Layer Marine Aerosol Number Density (1 Microme…

1983

Wind speed and relative humidity have been the physical variables used in empirical expressions for equilibrium marine aerosol distributions. Recent formulations, which include the role of hydrostatic stability because it influences turbulent transport and entrainment of clear air from aloft, are examined on the basis of 1 um radius aerosol number density values. The aerosol data were collected along with a quite complete meteorological data set in the Northeast Atlantic during the international Joint Air Sea Interaction Experiment (JASIN-78). The 1 um number density values are normalized for generation and relative humidity influences, and analyses are performed to gain reasonable assuranc…

Productive and vegetative responses of 'Gala' and 'Fuji' apple trees under controlled irrigation strategies

2008

We investigated the productive and vegetative responses of ‘Gala’ and 'Fuji' apple (Malus domestica Borkh.) trees to deficit irrigation and partial rootzone drying under the dry climate of central Sicily. Soil water tension (SWT), stomatal conductance, yield, fruit quality, fruit growth, and shoot extension of conventionally irrigated trees (CI), where drip emitters on both sides of each tree were left open, were compared to that of partial rootzone drying (PRD) trees, where only one side of the rootzone was irrigated for the entire season (receiving 50% of the CI irrigation water), and to that of deficit irrigated (DI) trees, where drip emitters on both sides of the rootzone were deliverin…

Humidity-enhanced sub-ppm sensitivity to ammonia of covalently functionalized single-wall carbon nanotube bundle layers

2017

International audience; A low-cost method for carbon nanotubes (CNTs) network production from solutions on flexible polyethylene naphthalate substrates has been adopted to prepare high quality and well characterized SWCNT bundle layers to be used as the active layer in chemiresistor gas sensors. Two types of SWCNTs have been tested: pristine SWCNTs, deposited from a surfactant solution, and covalently functionalized SWCNTs, deposited from a dimethyl-acetamide solution. The humidity effects on the sensitivity of the SWCNTs network to NH3 have been investigated. The results show that relative humidity favors the response to NH3, confirming recent theoretical predictions. The COOH-functionaliz…

Novel Porous Carbon Material for the Detection of Traces of Volatile Organic Compounds in Indoor Air

2021

International audience; A highly sensitive and selective silicon-based microanalytical prototype was used to identify a few ppb of volatile organic compounds (VOCs) in indoor air. Herein, a new nonactivated tannin-derived carbon synthesized by an environmentally friendly method, DM2C, a MIL-101(Cr) MOF, and a DaY zeolite were selected for the preconcentration of BTEX compounds (i.e., benzene, toluene, ethylbenzene, and xylenes). Integrating a small amount of these nanoporous solids inside a miniaturized preconcentration unit led to excellent preconcentration performance. By taking advantage of the high adsorption−desorption capacities of the DM2C adsorbent, concentrations as low as 23.5, 30…

Barrier properties of chitosan coated polyethylene

2012

The transfer properties of chitosan coated polyethylene (PE) films were studied. The barrier properties of non coated PE were not affected by relative humidity changes. The presence of the hydrophilic chitosan layer acted as a water reservoir on the polyethylene film surface which significantly promoted its sensitivity to the water vapour. The water vapour permeability increased 1.85 times at a higher RH. Coated PE films showed more than two-order decrease in the oxygen permeability (PO2) and three-order-decrease in the carbon dioxide permeability (PCO2). When the chitosan coated PE surface was exposed to the water vapour, the PO2 and the PCO2 were significantly increased. However, the perm…

Hygrothermal conditions in Cross Laminated Timber (CLT) dwellings

2020

The use of CLT has been increasing the last decade, and a subsequently focus on documentation of the accompanying indoor climate and exposed wooden surfaces on human well-being. This study presents the results of a measurement campaign conducted over one year of a CLT apartment building in Grimstad, Norway. The apartment building consists of three floors with 35 apartments and comply with the Norwegian passive house standard and energy grade A. Measurements of the relative humidity (RH), indoor air temperature and wood moisture content (MC) were performed in the exposed CLT spruce panels in three apartments in two different floors. The results from the three apartments show a relatively sma…

Establishing material hygrothermal characteristics via long-term monitoring and best-fit numerical models

2020

Numerical models of heat and moisture transfer for performance forecast of lightweight insulating assemblies require many inputs. These include exterior climate data (i.e. temperature, relative humidity, solar radiation), interior climate data or standard models, transfer coefficients, correct initial conditions, etc. Most importantly, one needs reliable material models. A material model includes porosity, density, heat capacity, but also non-constant properties, such as thermal conductivity, vapor/liquid water diffusivity, sorption curves. These are, in general, difficult to determine, and material database entries often are incomplete, or simply non-existent. However, if one performs long…

Survey of condition of light and humidity microclimate in some work and/or study areas

2012

Evaluation of interface pressure and temperature management in five wheelchair seat cushions and their effects on user satisfaction

2020

Abstract Background Factors such as the manufacturing materials, shape or even the mechanical and thermal response of sitting Pressure Redistribution Support Surfaces (PRSS) can be potential contributors to pressure ulcers. However, few studies have compared a number of characteristics of the most frequently used devices. Objective To compare three potential contributors to pressure ulcers in five commercial PRSS: pressure redistribution, temperature and perceived comfort. Method: Study with a cross-over randomized design in healthy volunteer participants. Data was collected in a temperature and relative humidity controlled environment. To assess thermal response, the temperature (Flir-E60)…

Dynamic in vitro dehydration patterns of unworn and worn silicone hydrogel contact lenses.

2008

Purpose: To evaluate the effect of wear on dynamic in vitro dehydration of silicone hydrogel (Si-Hi) contact lens (CL) using a previously described gravimetric procedure. Methods: Five different silicone hydrogel (Si-Hi) contact lenses (CL) were evaluated after being worn by patients under daily wear conditions for 15 days to 1 month. Lenses were conditioned and disinfected with a multipurpose solution after each day of wear. Lenses were left to dehydrate in an analytical balance under controlled conditions of temperature and relative humidity and the results compared with data from new lens samples of the same power and material. Several quantitative parameters were obtained and compared b…