scholarly journals Determination of Dehumidification Capacity of Water Wall with Controlled Water Temperature: Experimental Verification under Laboratory Conditions

2021 ◽  
Vol 13 (10) ◽  
pp. 5684
Author(s):  
Katarina Cakyova ◽  
Frantisek Vranay ◽  
Marian Vertal ◽  
Zuzana Vranayova
Keyword(s):  
Relative Humidity ◽  
Water Temperature ◽  
Experimental Verification ◽  
Water Film ◽  
Effective Area ◽  
Measuring System ◽  
Condensation Rate ◽  
Water Wall ◽  
Laboratory Conditions ◽  
Air Temperatures

Water elements with flowing water on the surface are common in buildings as a form of indoor decoration, and they are most often perceived as passive humidifiers. However, by controlling water temperature, they can be also used for air dehumidification. The dehumidification capacity of indoor water elements was investigated experimentally under laboratory conditions. For the experimental verification of dehumidification capacity, a water wall prototype with an effective area of falling water film of 1 m2 and a measuring system were designed and developed. A total of 15 measurements were carried out with air temperatures ranging from 22.1 °C to 32.5 °C and relative humidity from 58.9% to 85.6%. The observed dehumidification capacity varied in the range of 21.99–315.36 g/h for the tested measurements. The results show that the condensation rate is a dynamic process, and the dehumidification capacity of a water wall strongly depends on indoor air parameters (air humidity and temperature). To determine the dehumidification capacity of a water wall for any boundary conditions, the equations were determined based on measured data, and two methods were used: the linear dependence between humidity ratio and condensation rate, and nonlinear surface fitting based on the dependence between the condensation rate, air temperature, and relative humidity.

scholarly journals Using water wall like air humidifier

2020 ◽  
Vol 15 (1) ◽  
pp. 13-18
Author(s):  
Katarína Čákyová ◽  
František Vranay ◽  
Zuzana Vranayová
Keyword(s):  
Relative Humidity ◽  
Water Film ◽  
Plate Heat Exchanger ◽  
Measuring System ◽  
Climate Chamber ◽  
Film Evaporation ◽  
Water Wall ◽  
Air Temperatures ◽  
Different Temperatures ◽  
Definition Of

Abstract This paper presents experimental results of the study of falling water film evaporation from water wall. The contribution is divided into several parts. The introduction is devoted to the theoretical part of the use, then the prototype of the water wall is presented and its most important parts are described. In order to verify the humidification performance of the water wall, experimental verification under laboratory conditions (climate chamber) was chosen. One task for the definition of water wall evaporation potential is to determine and develop the measuring system, which is clearly defined in article. The present document describes the methodology and boundary conditions during experiments. Plate heat exchanger ensured a water temperature in the system approximately 23 °C hot during all measurements. A total of 4 measurements were performed at different air temperatures and relative humidity. The results showed that at different temperatures and relative humidity of air, the water wall has a different humidification performance.

INFLUENCE OF TEMPERATURE AND HUMIDITY ON THE EMERGENCE BEHAVIOUR OF ANAX JUNIUS (ODONATA: AESHNIDAE)

1973 ◽  
Vol 105 (7) ◽  
pp. 975-984 ◽  
Author(s):  
Robert Trottier
Keyword(s):  
Relative Humidity ◽  
Water Temperature ◽  
Air Temperature ◽  
Water Surface ◽  
Average Speed ◽  
Anax Junius ◽  
Air Temperatures ◽  
Stage 4 ◽  
Temperature And Humidity ◽  
Three Stages

AbstractEmergence from the water of Anax junius Drury normally occurred after sunset. The onset was affected independently by water temperature and air temperature; low water temperature and high air temperature delayed the onset of emergence. In the field, the net vrtical distance travelled above the water, before ecdysis, was positively correlated with air temperature. In the laboratory, the vertical distance travelled above the water was greatest when air and water temperatures were approximately the same. The average speed of climbing to the first resting position above the water surface was faster at high than low water temperature, but the average speed of climbing from there to the final position, where ecdysis occurred, was reduced due to the effects of air temperature and humidity. Air temperatures below 12.6 °C were found to retard ecdysis and larvae returned to the water and emerged early the following day making the final process of emergence and ecdysis diurnal instead of nocturnal. The duration of ecdysis was shorter at high than low air temperatures and only the first three stages, as arbitrarily defined, were longer at low than high relative humidity; stage 4, shortened with low relative humidity. This study shows that A. Junius, emerging from the water is affected at first by the temperature experienced when submerged, but it becomes gradually and cumulatively affected by air temperature and humidity while climbing to the ecdysial position and moulting.

scholarly journals Quantifying the Independent Influences of Land Cover and Humidity on Microscale Urban Air Temperature Variation in Hot Summer: Methods of Path Analysis and Genetic SVR

Atmosphere ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1377
Author(s):  
Weifang Shi ◽  
Nan Wang ◽  
Aixuan Xin ◽  
Linglan Liu ◽  
Jiaqi Hou ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Land Cover ◽  
Path Analysis ◽  
Temperature Variation ◽  
Direct Effect ◽  
Air Temperature ◽  
Urban Areas ◽  
Support Vector ◽  
Urban Air ◽  
Air Temperatures

Mitigating high air temperatures and heat waves is vital for decreasing air pollution and protecting public health. To improve understanding of microscale urban air temperature variation, this paper performed measurements of air temperature and relative humidity in a field of Wuhan City in the afternoon of hot summer days, and used path analysis and genetic support vector regression (SVR) to quantify the independent influences of land cover and humidity on air temperature variation. The path analysis shows that most effect of the land cover is mediated through relative humidity difference, more than four times as much as the direct effect, and that the direct effect of relative humidity difference is nearly six times that of land cover, even larger than the total effect of the land cover. The SVR simulation illustrates that land cover and relative humidity independently contribute 16.3% and 83.7%, on average, to the rise of the air temperature over the land without vegetation in the study site. An alternative strategy of increasing the humidity artificially is proposed to reduce high air temperatures in urban areas. The study would provide scientific support for the regulation of the microclimate and the mitigation of the high air temperature in urban areas.

Temperature and hunger mediate sablefish (Anoplopoma fimbria) feeding motivation: implications for stock assessment

2004 ◽  
Vol 61 (2) ◽  
pp. 238-246 ◽  
Author(s):  
Allan W Stoner ◽  
Erick A Sturm
Keyword(s):  
Water Temperature ◽  
Food Deprivation ◽  
Stock Assessment ◽  
Effective Area ◽  
Activity Level ◽  
Anoplopoma Fimbria ◽  
Feeding Motivation ◽  
Population Sizes ◽  
Increasing Temperature ◽  
Olfactory Cue

Laboratory experiments were conducted to test the hypothesis that temperature (2–8 °C) and recent feeding history (1–6 days of food deprivation) influence feeding motivation and attacks on baits by adult sablefish (Anoplo poma fimbria). Activity level after introduction of a bait-related olfactory cue increased with increasing water temperature and food deprivation. Fish at the lowest temperature (2 °C) attacked and consumed fewer squid baits (33–71%) than those at higher temperatures (100% at 8 °C). Baits were frequently inspected or handled multiple times before consumption in low temperatures, and time to attack (seconds to >40 min), time to consume, and time to handle baits (2–20 s) all decreased significantly with increasing temperature, with some temperature × feeding history interactions. The total ration consumed increased (<1–8% of body weight) with increasing water temperature. The observed variability in activity and feeding motivation in sablefish may have a large impact on the effective area of baited gear but is rarely considered in stock assessment models. In particular, population sizes based upon baited gear surveys may be underestimated in conditions where temperature is low, natural prey density is high, or where other environmental variables reduce feeding motivation.

Skinfolds and resting heat loss in cold air and water: temperature equivalence

1975 ◽  
Vol 39 (1) ◽  
pp. 93-102 ◽  
Author(s):  
R. M. Smith ◽  
J. M. Hanna
Keyword(s):  
Heat Transfer ◽  
Water Temperature ◽  
Heat Loss ◽  
Air Temperature ◽  
Indirect Calorimetry ◽  
Cold Water ◽  
Heat Conductance ◽  
Air Temperatures ◽  
Body Core ◽  
Male Subjects

Fourteen male subjects with unweighted mean skinfolds (MSF) of 10.23 mm underwent several 3-h exposures to cold water and air of similar velocities in order to compare by indirect calorimetry the rate of heat loss in water and air. Measurements of heat loss (excluding the head) at each air temperature (Ta = 25, 20, 10 degrees C) and water temperature (Tw = 29–33 degrees C) were used in a linear approximation of overall heat transfer from body core (Tre) to air or water. We found the lower critical air and water temperatures to fall as a negative linear function of MSF. The slope of these lines was not significantly different in air and water with a mean of minus 0.237 degrees C/mm MSF. Overall heat conductance was 3.34 times greater in water. However, this value was not fixed but varied as an inverse curvilinear function of MSF. Thus, equivalent water-air temperatures also varied as a function of MSF. Between limits of 100–250% of resting heat loss the followingrelationships between MSF and equivalent water-air temperatures were found (see article).

scholarly journals Predicting harvest of non-native signal crayfish in lakes — a role for changing climate?

2016 ◽  
Vol 73 (5) ◽  
pp. 785-792 ◽  
Author(s):  
Patrik Bohman ◽  
Lennart Edsman ◽  
Alfred Sandström ◽  
Per Nyström ◽  
Marika Stenberg ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Water Temperature ◽  
Temperature Data ◽  
Adult Survival ◽  
Winter Mortality ◽  
Freshwater Crayfish ◽  
Catch Per Unit Effort ◽  
Signal Crayfish ◽  
Cool Water ◽  
Air Temperatures

The signal crayfish (Pacifastacus leniusculus) was introduced to Sweden in 1960, and it has a high commercial and recreational value, but it may also have negative effects on native ecosystems. To better predict how climate warming will affect population dynamics of this cool-water crayfish, we explored the role of temperature and density dependence as explanatory factors of the subsequent years’ catch rates of commercially sized signal crayfish in four Swedish lakes. We found air temperatures to be good proxies for water temperatures in all lakes, except during winter. We could only obtain water temperature data for Lake Vättern, and winter temperature data were therefore only included in the analysis of catch-per-unit-effort patterns in this lake. Our results indicate that increasing mean air temperatures will potentially affect the population dynamics of cool-water freshwater crayfish species such as the signal crayfish. Based on data from four lakes, it seems that the population dynamics of signal crayfish are lake-specific and could be affected by either recruitment during the juvenile stage, the survival and growth of adults, or both. Increased fluctuations in water temperature during winter may potentially influence adult survival. To better predict the effects of global warming on the dynamics of cool-water crayfish populations, we suggest that future studies should investigate recruitment in crayfish along temperature gradients and the influence of variations in water temperature on winter mortality.

scholarly journals Densidade de fêmeas de Trichospilus diatraeae (Hymenoptera: Eulophidae) por pupa de Diatraea saccharalis (Lepidoptera: Crambidae)

2013 ◽  
Vol 13 ◽  
Author(s):  
Elizangela Leite Vargas ◽  
Fabricio Fagundes Pereira ◽  
Vanessa Rodrigues Ferreira Calado ◽  
Daniele Fabiana Glaeser ◽  
Bruna Aparecida Cáceres Rodrigues ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Sex Ratio ◽  
Light Regime ◽  
Climatic Chamber ◽  
Offspring Number ◽  
Diatraea Saccharalis ◽  
Laboratory Conditions ◽  
Glass Tubes

Density of parasitoid females affects their capacity to develop within the host. The number of Trichospilus diatraeae (Hymenoptera: Eulophidae) females per pupa of Diatraea saccharalis (Lepidoptera: Crambidae) was adjusted to study the effect of parasitoid production in the laboratory. Host pupae were parasitised by females of T. diatraeae at densities of 1:1, 7:1, 14:1, 21:1, 28:1 and 35:1 (parasitoid:host). The females of the parasitoid remained in contact with pupae for 24 h in glass tubes (8.5 × 2.5 cm), packed in a climatic chamber regulated at 25 ± 2ºC, 70 ± 10% relative humidity and light regime of 14 h. The percentage of parasitism and emergence of T. diatraeae on pupae of D. saccharalis was 100% in all parasitoid densities. The length of thr cycle (egg-adult) of Trichospilus diatraeae was 19.25 ± 0.22 days at a density of 1:1 and 17.00 ± 0.00 days at 35:1. The offspring number of T. diatraeae was 106.00 ± 12.38 and 514.67 ± 54.55 individuals per pupa at densities of 1:1 and 35:1, respectively. The sex ratio decreased with increasing density, ranging between 0.97 ± 0.01 and 0.89 ± 0.01 at densities of 1:1 and 35:1, respectively. The percentages of parasitism and emergence of T. diatraeae on pupae of D. saccharalis were not affected by the densities of female parasitoids. The densities of 14 to 21 females of T. diatraeae per pupa of D. saccharalis are suitable for rearing this parasitoid under laboratory conditions.

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