INFLUENCE OF VERTICAL GARDENS ON THE AIR QUALITY OF A CITY HISTORIC CENTER

Quito is an Andean city with 2.7 million inhabitants that regularly exceeds the WHO air quality guidelines for O3, SO2, PM2.5, and PM10. Within the historic center in an area of 920.000 m2, only 4% is green space. However, 14.000 m2 of vertical walls exist that could potentially host vertical gardens. The present study evaluates the ability of four vertical gardens to improve air quality and quantifies the area of viable spaces to host vertical gardens in the Historic Center. The air quality was monitored with continuous measuring systems near each vertical garden and in areas outside the area of influence. The capacity for retention of gaseous emissions from an internal combustion engine in an active garden was also evaluated. The results were a mixture of advantages and uncovering possible myths: a) the presence of vertical gardens causes a significant decrease in O3 (up to 99%), NO2 (up to 80%), SO2 (up to 83%), PM2.5 (up to 79%) and PM10 (up to 85%); b) however, a poor choice of plant species in vertical gardens may increase the formation of O3; and c) in the case of exposing an active vertical garden to emissions injected directly into the garden by a combustion engine, the particle size distribution influences its removal, being more efficient with a size greater than 4 μm but not effective for smaller diameters.

Measurement of the Beruforge 152DL thin-film lubricant using a developed thin-film thickness standard

Systematic deviations due to remaining lubricant on the workpiece have a significant influence on the measurement of sheet-bulk metal formed parts. The expected layer thickness for the workpieces after the forming process is less than 35 µm. For the determination of the refractive index of the lubricant and thus the effects of the lubricant on optical measurement techniques, a lubricant thin-film thickness standard was developed which represents a continuous measuring range from 6 to 100 µm. To determine the refractive index, the thin-film thickness standard was measured with a coaxial interferometric measurement system in various thickness ranges. Due to the knowledge of the optical and the geometrical path length, the refractive index can then be determined approximately. In addition, an XY stage was used to scan the entire thin-film area of the standard. The measurement setup in a temperature box allows for determining the effects of temperature changes on the optical properties of the lubricant.

Development and reproducibility of an instrument to assess behavioral and environmental aspects related to cyclist safety

In urgency and emergency services, the bicycle is the second means of transportation more widely used by the victims at the time of the accident. However, aspects associated with major and minor accidents are poorly understood. The aim was to develop an instrument and test its reproducibility, in order to evaluate behavioral and environmental aspects related to cyclist safety. The instrument was based on footage taken through a camera attached to the cyclist helmet and from a review of literature. Take part in the study academics that used the bicycle to travel at least once a week. Participants were instructed to indicate any safety-critical events on their way and situations of minor gravity based on the perception of real imminence of an accident. In order to identify aspects related to cyclist safety, the routes were divided in periods of 30 seconds. In order to test inter-rater reproducibility, two researchers received theoretical-practical training and performed the instrument in a sample of 100 periods. In order to evaluate the intra-rater reproducibility, one of the evaluators performed a second application after 07 days. The reproducibility of the categorical variables of the instrument were tested through general agreement and Kappa index. For the variables with continuous measuring range, the Intraclass Correlation Coefficient (ICC) was used. The percentage agreement varied between 88-100% and the Kappa values varied between 0.76-1.00. The ICC values ranged from 0.96-0.99. The developed instrument presents adequate reproducibility for use in research to evaluate the cyclist safety in urban contexts.

Behavior of capacitive humidity sensors in monitoring the drying of concrete walls

This research examines the behavior of capacitive humidity sensors in monitoring the drying of concrete walls in continuous measurements in laboratory conditions. Tests are carried out using continuous measuring of moisture with different capacitive sensors in concrete structures varied with three different types of thermal insulation materials. Sensors are sealed in plastic tubes that were preinstalled into the casting molds. Three borehole measurements are carried out as reference during the research. Results show differences in performance between the examined humidity sensors from two different manufacturers. The main difference is related to stability as sensors from the other manufacturer prove to be more prone to error. The study affirms that measuring humidity in concrete is challenging even when using high-quality humidity sensors.

Impact of calculation method, sampling frequency and hysteresis on suspended solids and total phosphorus load estimations in cold climate

Load calculations of nutrients and suspended solids (SS) transported by rivers are usually based on discrete water samples. Water quality changes in cold climate regions often occur very rapidly and therefore discrete samples are unrepresentative of the range of water quality occurring. This leads to errors of varying magnitude in load calculation. High-resolution turbidity data were used to determine the SS and total phosphorus (TP), and paired with discharge to determine loads from two small catchments in southern Finland. The effect of sampling frequency was investigated by artificially sub-sampling the high frequency concentrations. Regardless of the sampling frequency, the TP load was more likely underestimated while using discrete samples. To achieve ±20% accuracy compared with the reference load, daily sampling should be performed. Hysteresis was detected to have an impact on TP load. Hysteresis analysis also revealed the main source of the TP to be in the fields of the catchment. Continuous measuring proved to be a valuable method for defining loads and short-term fluctuations in water quality in small clayey watercourses in a boreal cold climate, where the climate change will increase the frequency of winter floods.