Search results for "Humidity"
showing 10 items of 291 documents
Boosting Long-Term Stability of Pure Formamidinium Perovskite Solar Cells by Ambient Air Additive Assisted Fabrication
2021
Due to the high industrial interest for perovskite-based photovoltaic devices, there is an urgent need to fabricate them under ambient atmosphere, not limited to low relative humidity (RH) conditions. The formamidinium lead iodide (FAPI) perovskite α-black phase is not stable at room temperature and is challenging to stabilize in an ambient environment. In this work, we show that pure FAPI perovskite solar cells (PSCs) have a dramatic increase of device long-term stability when prepared under ambient air compared to FAPI PSCs made under nitrogen, both fabricated with N-methylpyrrolidone (NMP). The T80 parameter, the time in which the efficiency drops to 80% of the initial value, increases f…
Frame fungi on insulated windows.
1985
Insulated windows (fixed triple glass window elements), became common in Finland during and after the energy crisis. Moisture tends to condense along the edges causing mold growth on the frames. Nine houses with insulated glass windows and eight with other types of window were studied. Fungus samples were taken from the window edges and from the inside air and cultivated on malt extract agar. In five of the houses with insulated windows there was visible mold growth on the window edges. The predominant fungus was Aureobasidium pullulans. With other types of windows there was only one case of visible mold. The concentrations of fungi were about the same in the air of houses with both types o…
In-situ measurements of hemp-lime insulation materials for energy efficiency improvement
2018
Abstract Reduction of the CO2 emissions in the atmosphere is one of the goals set forth by the European Union, hence various directives have been adopted, such as the European directive 2012/27/EU on energy efficiency, i.e. ensuring from 2019 the construction of the near-zero energy buildings (nZEB). The construction segment plays a very important part in solving the current global problem of the greenhouse gas emissions and related processes of global warming, because in certain countries (i.e. in Latvia) it represents more than a half of the total energy consumption. Hence the necessity to elaborate means on how to boost the energy efficiency of the buildings meanwhile not rising pressure…
An Original Approach to Active Climate Control Based on Equilibrium Moisture Content (EMC) as Set Point in a Middle-Age Building in Palermo, Italy
2019
In the frame of a more sustainable approach to climate control, a long term strategy has been developed and is under advanced phase of implementation by technical staff of the University of Palermo in an important building, Palazzo Steri, owned by the University. The monumental room under climate control, the Sala dei Baroni (also known as Sala Magna), has a precious wooden ceiling where the previously loadbearing elements are covered with wooden painted panels. Many of them, painted in the fourteenth c, underwent important restorations in the past due to climate related damage (cracks, warpings, paint layer delamination) and biological infestations. The room is currently undergoing an impo…
How to Use the DHT22 Sensor for Measuring Temperature and Humidity with the Arduino Board
2016
Abstract The objective of this paper is to achieve a functional system in terms of hardware and software, to measure temperature and humidity. Also, this system will allow to monitoring the time. In this, we use an Arduino board with interfacing a sensor placed in local environment to measure temperature and humidity. The paper aims to achieve the following goals: - achieving a functional system in terms of hardware and software that allows measuring and monitoring temperature, humidity and the time; - using a development board for the communication with the sensor and clock; - implementation a program that allows requirements.
The effectiveness of various types of ventilation on air quality in multi-family buildings
2017
Przepisy prawne oraz normy obligują do kontroli systemów wentylacji budynków jedynie pod względem prędkości strumienia powietrza, co niestety nie zawsze gwarantuje zalecaną ze względów zdrowotnych jakość powietrza. W pracy podjęto badania skuteczności różnych typów wentylacji wielorodzinnych budynków mieszkalnych, ze szczególnym uwzględnieniem wentylacji naturalnej, stanowiącej najczęściej spotykane rozwiązanie w budynkach mieszkalnych w Polsce. Badano wpływ skuteczności wentylacji na podstawowe parametry charakteryzujące jakość powietrza, tj. stężenie ditlenku węgla, wilgotność względną oraz temperaturą. Badano również możliwość regulacji pracy systemu wentylacji budynków wielorodzinnych w…
Water Adsorption Properties of Free and Dehydrated β-Cyclodextrin Studied by near Infrared Spectroscopy and Gravimetry
2016
β-cyclodextrin, like other carbohydrates has a tendency to adsorb water molecules and the properties are attributed to the hydroxyl groups in the molecules. β-cyclodextrin, the cyclic oligomer of glucose has a hydrophobic interior and hydrophilic exterior. The cyclic structure favours the formation of hydrogen bonds between the OH groups on the adjacent glucose units and affects the formation of hydrogen bonds with water molecules. The hydoxyl groups engaged in hydrogen bondings can be eliminated at high temperatures and the adsorption properties of the dehydrated β-cyclodextrin will depend on the new functional groups formed. The aim of the report is to discuss the issue of the water adsor…
The Swelling Behavior of Polyelectrolyte Multilayers in Air of Different Relative Humidity and in Water
2002
The swelling properties of physisorbed polyelectrolyte multilayer self-assemblies with alternating polyion charge in humid air and in aqueous environment were investigated via X-ray and neutron reflectometry as well as optically, using surface plasmon spectroscopy. The sorption behavior was similar to that found for neutral polymers and was related to an internal screening of the charges of the adjacent layers owing to the high entanglement of the polyelectrolyte chains and the resulting low mobility of the polymer segments. The screening was found to be incomplete only in the top layer, resulting in a net charged surface.
Influence of the physical state of water on the barrier properties of hydrophilic and hydrophobic films.
2000
Water transfer through different films, as a function of the physical state of water in contact with the film, the relative humidity difference, and the water vapor pressure difference, was investigated. The films were two synthetic packagings (hydrophobic polyethylene and hydrophilic cellophane) and an edible film. The physical state of water affects water sensitive films, such as cellophane, inducing a higher liquid water transfer due to interactions with the polymer. For hydrophobic polymers, such as polyethylene, neither the physical state of water nor the relative humidity has an influence on the water permeability. In complex system, such as an edible film composed of hydrophilic part…
Polymer-doped UHF RFID tag for wireless-sensing of humidity
2012
Passive UHF RFID tags, beside item labelling, are also able to exploit capability of sensing the physical state of the tagged object as well as of the surrounding environment. Here a family of polymer-doped tags are proposed and fully characterized for the detection of ambient humidity. A sensitive chemical species based on PEDOT:PSS is used to dope a properly shaped slot carved into a folded-like patch tag. The communication and sensing capabilities of the radio-sensor are investigated by means of simulation and measurements showing how to control and balance above opposite requirements by dosing the quantity of sensitive material. The device could have interesting application in the asses…