Highly sensitive, room temperature operated gold nanowire-based humidity sensor: adoptable for breath sensing

A novel, highly sensitive gold nanowire (AuNW) resistive sensor is reported here for humidity sensing in the relative humidity range of 11% to 92% RH as well as for breath sensing.

Experimental Investigation of a Novel Extracting Water System from Air by Soil Cold Source

The distribution of fresh water resources is extremely uneven at home and abroad, and the air contains a large amount of water vapor that can be used, so air water has been a widespread concern. Air condensation method is simple and efficient and has strong water intake capacity, but it often needs to consume huge energy. Therefore, this work proposes a new simple and innovative method of drawing water from the air, based on extracting water from air process achieved by using the soil as the cold source. The new type of ground cold air water intake system is designed by the new innovative method, which uses the soil with constant temperature as the cold source to reduce energy consumption. By comparing the central composite design experiment with the field experiment and analyzing the condensate water and outlet temperature under different wind speed and humidity conditions, the quadratic equation expression of condensate water and outlet temperature is obtained, and the optimal import wind speed range under a certain humidity range is obtained according to the mathematical model. The experimental results show that the heat transfer effect between air and soil is ideal, the water intake can reach 2.2 kg in 20-hour continuous collection experiment, the air temperature is close to the soil temperature after cooling, and the effect of water intake is good, which confirms the feasibility of soil as a cold source of air condensation.

Intensity variation of gamma radiation on ground level interface in São Jose dos Campos, SP, Brazil

In the period June 22 to September 24, 2012 São José dos Campos region experienced dry climate with low relative humidity. The net rain intensity measured in this period was 60 mm/h and the relative humidity range between 30% to 40% on most days. The intensity of gamma radiation from 0.03 to 10.0 MeV, in the measurement period presents a daily fluctuation well clearly, and some small increases when there is rainfall. These measures were realized at ITA's campus with a scintillator of NaI(Tl), photomultiplier and associated electronics laptop to a Dell 630 PC. A data acquisition interface purchased from (Aware Eletronics, USA) provides a file with measurements versus time, in the range from minute to minute recorded in txt. It was observed that the variation of gamma radiation in the interface soil/air at the region is originating from the local radon gas dynamics and of the presence of wind shear near the ground level. No período de 22 de junho a 24 de setembro de 2012, a região de São José dos Campos experimentou um clima seco com baixa umidade relativa. A intensidade líquida de chuva medida neste período foi de 60 mm/h e a umidade relativa varia entre 30% a 40% na maioria dos dias. A intensidade de radiação gama de 0,03 a 10,0 MeV, no período de medição apresenta uma flutuação diária bem clara, e alguns pequenos aumentos quando há chuva. Estas medidas foram realizadas no campus da ITA com um cintilador de NaI(Tl), fotomultiplicador e laptop eletrônico associado a um PC Dell 630. Uma interface de aquisição de dados adquirida da (Aware Eletronics, EUA) fornece um arquivo com medidas versus tempo, na faixa de minutos a minutos gravados em txt. Foi observado que a variação da radiação gama na interface solo/ar na região é originada pela dinâmica local do gás radônio e da presença de cisalhamento do vento próximo ao nível do solo.

The Effect of Au Nanoparticle Addition on Humidity Sensing with Ultra-Small TiO2 Nanoparticles

In this paper, we investigate humidity sensing through impedance measurements with TiO2 nanoparticles (about 6 nm in diameter). The transient behavior and the impedance spectra are measured and interpreted from the theoretical point of view. Large responses are shown especially in the relative humidity range from 30% to 80%, which are essentially explained by condensation in the nanopores. The effect of the addition of Au nanoparticles is investigated and as expected, the Au/TiO2 interfaces allow for dramatically reducing the sensing film response time and above all, its recovery time; moreover, it seems to favor condensation when the relative humidity overcomes 70%.

Effect of Relative Humidity on Mycelial Growth of Cercospora canescens

The relative humidity studies revealed that maximum mycelial of fungus was observed at 90 per cent relative humidity (89.00 mm), which was followed by 100 per cent (86.30 mm). The least mycelia growth was observed at 50 per cent (45.30 mm). A significant decrease in mycelium growth was observed at 80, 70 and 60 per cent (80.40 mm, 70.20 mm and 57.00 mm) humidity level, respectively. Each fungus has its relative humidity range for the growth.

Flexible and Transparent Polymer-Based Optical Humidity Sensor

Thin spin-coated polymer films of amphiphilic copolymer obtained by partial acetalization of poly (vinyl alcohol) are used as humidity-sensitive media. They are deposited on polymer substrate (PET) in order to obtain a flexible humidity sensor. Pre-metallization of substrate is implemented for increasing the optical contrast of the sensor, thus improving the sensitivity. The morphology of the sensors is studied by surface profiling, while the transparency of the sensor is controlled by transmittance measurements. The sensing behavior is evaluated through monitoring of transmittance values at different levels of relative humidity gradually changing in the range 5–95% and the influence of up to 1000 bending deformations is estimated by determining the hysteresis and sensitivity of the flexible sensor after each set of deformations. The successful development of a flexible sensor for optical monitoring of humidity in a wide humidity range is demonstrated and discussed.