scholarly journals Design of a low-cost steerable textile antenna array operating in varying relative humidity conditions

2011 ◽  
Vol 54 (1) ◽  
pp. 40-44 ◽  
Author(s):  
Maria Lucia Scarpello ◽  
Dries Vande Ginste ◽  
Hendrik Rogier
Keyword(s):  
Relative Humidity ◽  
Antenna Array ◽  
Low Cost ◽  
Textile Antenna

scholarly journals High-Gain Textile Antenna Array System for Off-Body Communication

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Maria Lucia Scarpello ◽  
Luigi Vallozzi ◽  
Hendrik Rogier ◽  
Dries Vande Ginste
Keyword(s):  
Antenna Array ◽  
Mutual Coupling ◽  
Low Cost ◽  
Beam Steering ◽  
High Gain ◽  
Antenna System ◽  
Fully Integrated ◽  
Textile Antenna ◽  
Coupling Characteristics ◽  
The Stability

A novel high-gain textile antenna array system, fully integrated into a rescue-worker’s vest and operating in the Industrial, Scientific, and Medical wireless band (2.4–2.4835 GHz), is presented. The system comprises an array consisting of four tip-truncated equilateral triangular microstrip patch antennas (ETMPAs), a power divider, line stretchers, and coaxial cables. The array is vertically positioned on the human torso to produce a narrow beam in elevation, as such reducing fading and allowing to steer the maximum gain in a small angular sector centered around the broadside direction. To allow simple low-cost beam steering, we specifically minimize mutual coupling by using a relative large distance between the patches and by selecting the ETMPA element as the most suited topology from three potential patch geometries. Moreover, we investigate the stability of return loss and mutual coupling characteristics under different relative humidity conditions, when bending the array, when placing the system on-body, and when covering it by different textile layers. Reflection coefficient and gain patterns are simulated and measured for the antenna system in free space and placed on the human body.

scholarly journals Developing Relative Humidity and Temperature Corrections for Low-Cost Sensors Using Machine Learning

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3338
Author(s):  
Ivan Vajs ◽  
Dejan Drajic ◽  
Nenad Gligoric ◽  
Ilija Radovanovic ◽  
Ivan Popovic
Keyword(s):  
Machine Learning ◽  
Air Quality ◽  
Relative Humidity ◽  
Low Cost ◽  
Quality Monitoring ◽  
Air Quality Monitoring ◽  
Lower Accuracy ◽  
Wide Range ◽  
The Impact ◽  
Monitoring Stations

Existing government air quality monitoring networks consist of static measurement stations, which are highly reliable and accurately measure a wide range of air pollutants, but they are very large, expensive and require significant amounts of maintenance. As a promising solution, low-cost sensors are being introduced as complementary, air quality monitoring stations. These sensors are, however, not reliable due to the lower accuracy, short life cycle and corresponding calibration issues. Recent studies have shown that low-cost sensors are affected by relative humidity and temperature. In this paper, we explore methods to additionally improve the calibration algorithms with the aim to increase the measurement accuracy considering the impact of temperature and humidity on the readings, by using machine learning. A detailed comparative analysis of linear regression, artificial neural network and random forest algorithms are presented, analyzing their performance on the measurements of CO, NO2 and PM10 particles, with promising results and an achieved R2 of 0.93–0.97, 0.82–0.94 and 0.73–0.89 dependent on the observed period of the year, respectively, for each pollutant. A comprehensive analysis and recommendations on how low-cost sensors could be used as complementary monitoring stations to the reference ones, to increase spatial and temporal measurement resolution, is provided.

EFFECTS OF ENVIRONMENT ON GROWING HYDROPONICS MAIZE FODDER USING LOW-COST GREENHOUSE CULTIVATING UNIT FOR LIVESTOCK PRODUCTION.

2021 ◽  
pp. 71-72
Author(s):  
Adamu, B. ◽  
Abdullahi, S. ◽  
Saidu, S. G ◽  
Yustus Sunday Francis
Keyword(s):  
Relative Humidity ◽  
Environmental Factors ◽  
Production System ◽  
Low Cost ◽  
Factors Affecting ◽  
Production Water ◽  
Fodder Production ◽  
Food Requirement ◽  
Greenhouse Cultivation ◽  
Near Future

The term 'Hydroponics' was derived from Greek words 'hydro' means water and 'ponics' means labor. Hydroponic is a modern agricultural technique that uses nutrient solution rather than soil solution for fodder production. As population increases the food demand also increased, the existing system of agriculture will not be able to meet the food requirement in the near future due to environmental challenges in the industry. The major environmental factors affecting the hydroponics production system are; Temperature, relative humidity, and light. The objectives of this studies are to examine the hydroponics greenhouse technologies, impact of environmental factors on hydroponics greenhouse cultivation and challenges of growing on hydroponics greenhouse system. This study revealed that hydroponics greenhouse cultivation is a better option for improved fodder production, water utilization, palatability and digestibility.

scholarly journals A LOW-COST WIDEBAND QUASI-YAGI SIW-BASED TEXTILE ANTENNA

2017 ◽  
Vol 67 ◽  
pp. 53-59 ◽  
Author(s):  
Mir Emad Lajevardi ◽  
Manouchehr Kamyab
Keyword(s):  
Low Cost ◽  
Textile Antenna

A low cost relative humidity sensor fabricated by coating optical fused fiber coupler with sol-gel material

2008 ◽  
Author(s):  
Fufei Pang ◽  
Ping Xu ◽  
Min Wang ◽  
Xianglong Zeng ◽  
Zhenyi Chen ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Humidity Sensor ◽  
Low Cost ◽  
Sol Gel ◽  
Fiber Coupler ◽  
Relative Humidity Sensor

A K band self‐packaged SISL Rotman lens antenna array using low‐cost FR4

2021 ◽  
Author(s):  
Guoshuai Zhang ◽  
Kaixue Ma ◽  
Ningning Yan ◽  
Yu Luo ◽  
Haipeng Fu
Keyword(s):  
Antenna Array ◽  
Low Cost ◽  
Lens Antenna ◽  
K Band

Secondary organica aerosol formation from the reactions of 2,5-dimethylfuran with OH radicals and ozone

2021 ◽  
Author(s):  
Ana Rodriguez Cervantes ◽  
Mercedes Tajuelo Diaz-Pavón ◽  
Diana Rodriguez Rodriguez ◽  
Alba Escalona Verbo ◽  
Gabriela Viteri Tovar ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Lignocellulosic Biomass ◽  
Low Cost ◽  
Fine Particulate Matter ◽  
Simulation Models ◽  
Pollutant Emissions ◽  
Oh Radicals ◽  
Aerosol Formation ◽  
Furan Derivatives ◽  
Seed Particles

<p>Biomass is a significant renewable energy source and is expected to grow in importance in the transition away from fossil energy sources at a relatively low cost. Lignocellulosic biomass, which is the most abundant biomass, has critical importance as sustainable production of chemicals and fuels. Catalytic production methods of converting lignocellulosic biomass into furan derivatives have been improved significantly. One of these furan derivatives, 2,5-dimethylfuran (2,5-DMF), has attracted interest as a potential biofuel due to its physicochemical properties, in some aspects better than gasoline and ethanol, such as the low pollutant emissions in its combustion. However, before 2,5-DMF can be accepted as an alternative transport fuel, some outstanding problems, as its atmospheric fate, must be resolved.</p><p>2,5-DMF can be degraded by the main tropospheric oxidants, resulting in furan derivatives such as furanones which are efficient precursors of SOA. To this end, the present study had the aim of analyzing the OH radical photooxidation and ozonolysis of 2,5-DMF, characterizing the conditions that lead to the formation and growth of new particles. Factors such as relative humidity (RH), NOx and SO<sub>2</sub> level and pre-existing inorganic seed particles, which could influence in SOA formation, has been assessed. The study was carried out in two different chambers at (296±1) K and atmospheric pressure. Results for OH-photooxidation indicate that SOA yields decrease (from 6.2 to 0.4%) with the rise of 2,5-DMF concentration (from10 to 1000 ppb). In the absence of NOx and under high relative humidity (RH) conditions (60%), higher aerosol yields are favored. SOA formation is dependent on the initial seed surface for two kinds of inorganic seed particles ((NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub> and CaCl<sub>2</sub>), being the effect slightly greater for CaCl<sub>2</sub>. The ozonolysis only generates particles in the presence of SO<sub>2</sub> and the increase of relative humidity from 0 to 15% lowers the particle number and particle mass concentrations. The water-to-SO<sub>2</sub> rate constant ratio of the Criegee intermediate was derived from the SOA yield in experiments with different relative humidity values.</p><p>The obtained results provide detailed daytime chemistry about SOA formation from 2,5-DMF oxidation and improves our understanding of the chemical evolution of biomass burning plumes. Moreover, these results could be integrated into air quality simulation models, especially in developing countries which are suffering severe fine particulate matter pollution.</p>

Sign in / Sign up

Export Citation Format

Share Document