scholarly journals Experimental model of ammonia elimination by ozone in the air

2013 ◽  
Vol 59 (No. 2) ◽  
pp. 39-45
Author(s):  
P. Hutla ◽  
B. Petráčková ◽  
J. Kára

Experimental device was created to model stable atmosphere. The device consists of the glass vessel filled with air. Volume of the vessel is 30 litres. The ammonia concentration is similar to stable air. Amount of ozone in 2.4 mg was added and subsequently weight loss of ammonia was measured. Measurements were performed at different temperatures (20°C, 45°C) and different air humidity. The observed ratio of reacting ozone and ammonia is 5.2:1. It was also found, that this ratio is practically independent of temperature and relative humidity that occur in a stable environment. The results are the basis for the design of ozone air purification technology.  

2014 ◽  
Vol 14 (1) ◽  
pp. 153-166 ◽  
Author(s):  
Piotr Herbut ◽  
Sabina Angrecka

AbstractThe paper presents the results of research on indoor ammonia (NH3) concentrations in the air in a free-stall barn. The differences in measurement results mainly depended on the season and weather conditions. The study also showed a significant correlation (P<0.01) between the NH3 concentration and temperature, relative humidity and air movement velocity inside the barn. The lowest NH3 concentration was recorded in the summer (0.0 ppm) in the presence of high air temperatures, low humidity and increased exchange of ventilated air. In winter during severe frosts, highest ammonia concentration (8.0 ppm) was noted, caused by limited ventilation. The highest daily ammonia concentration was usually recorded during the night. This was due to increased relative air humidity and low air velocities. It was concluded that the average level of ammonia of 2.73 ppm during the entire year was significantly below values defined as harmful for animals and people.


2020 ◽  
Vol 222 ◽  
pp. 02046
Author(s):  
Irina Tkachenko ◽  
Sergey Tkachenko ◽  
Viktor Dedkov

This article presents the results of a study into the influence of the diet, air temperature and relative air humidity, and soil temperature on the average weight of Helix pomatia in captivity. It was shown that vegetables included in the mixed leaf-vegetable diet mitigated the effect of a high air temperature and a low relative humidity. It was established that the air temperature and relative humidity had opposite effects on weight gain in Helix pomatia. The increase in temperature predetermined the weight loss. Despite the high temperature, a humidity of over 75% caused all the molluscs gain weight regardless of their diet.


2020 ◽  
pp. 152808372097062
Author(s):  
Muhammad Yameen Solangi ◽  
Umair Aftab ◽  
Muhammad Ishaque ◽  
Aqeel Bhutto ◽  
Ayman Nafady ◽  
...  

Solid polymer electrolytes (SPEs) are the best choice to replace liquid electrolytes in supercapacitors, fuel cells, solar cells and batteries. The main challenge in this filed is the ionic conductivity and thermal stability of SPEs which is still not up to mark, therefore more investigations are needed to address these issues. In this study, PVA/salt based SPEs was fabricated using both solution cast and electro-spinning methods to probe the effect of different salts such as (NaCl, KCl and KI) and their concentrations on the ionic conductivity. Scanning electron microscopy (SEM) x and Fourier Transform Infra-Red (FTIR) have been employed to study the morphology as well as the different functional groups of SPEs, respectively. It was noted that small addition of NaCl, KCl and KI salts in SPEs dramatically increased the ionic conductivity to 5.95×10−6, 5.31×10−6 and 4.83×10−6 S/cm, respectively. Importantly, the SPEs obtained with NaCl via electro-spinning have higher ionic conductivity (5.95×10−6 S/cm) than their casted SPEs (1.87×10−6 S/cm). Thermal stability was also studied at two different temperatures i.e. 80 °C and 100 °C. The weight loss percentage of electrospun SPEs have zero percent weight loss than the solution based SPEs. The combined results clearly indicated that the nature of salt, concentration and fabrication process play a vital role in the ionic conductivity. Also, the NaCl salt with low molecular weight at low concentrations shows an enhanced ionic conductivity.


2021 ◽  
Vol 18 (1) ◽  
pp. 51-57
Author(s):  
F.A. Faruwa ◽  
K. Duru

The study investigated the use of thermal modification to improve the hygroscopic properties of False Iroko [Antiaris toxicaria (Lesch)]. Samples of Antiaris toxicara Lesch wood were subjected to thermal modification in a furnace at temperatures of 160, 180 and 200°C for 30 and 60 minutes. Results showed that wood properties were improved with exposure to different temperatures. Subsequent to the thermal process, a colour change from pale yellow to darkish brown was observed progressively with increase in temperature, accompanied by a weight loss in the range of 12.08% to 23.67%. The outcome of these treatments resulted in a decrease in volumetric swelling and increase in dimensional stability of modified wood; this can be attributed to observed decrease in moisture intake. The thermal modification of Antiaris toxicara Lesch wood affected the dimensional stability properties. Thus, due to significant changes via modification carried out on the selected species which is classified as lesser utilized wood species, lesser utilized wood,Antiaristoxicara Lesch wood is recommended for use due to its efficient dimensional stability after modification . keywords:, Thermally modified wood ;False Iroko


2017 ◽  
Vol 18 (4) ◽  
pp. 549-559
Author(s):  
Elisângela Borsoi Pereira ◽  
Magali Soares dos Santos Pozza ◽  
Paula Martins Olivo ◽  
Osmar Dalla Santa ◽  
Suzana da Cruz Pires ◽  
...  

SUMMARY Cheese is the oldest form of preserving milk nutrients having nutritional, economic and cultural importance. The objective of this study was to identify the best time of the year for production, and period, in months, for maturation of traditional colonial cheese, through analysis of water activity, weight loss and counts of lactic acid, mesophilic microorganisms—proteolytic and lipolytic. Records of temperature and relative humidity (RH) were maintained. A completely randomized experimental design was used in a double factorial scheme, considering production periods and maturation times. For all production periods evaluated, there was a significant reduction in the periods for water activity values. The counts of lactic acid bacteria ranged from 104 to 109 CFU/g. There was also stability in the number of colonies for lipolytic mesophilic microorganisms, until the third month of maturation. Low counts of proteolytic mesophiles were observed for the samples produced in May and June (5.70 and 5.53 log), respectively. The production period for the months of May and June corresponding to RH of 80% and average temperatures of 15°C were the most effective for production. Due to the presence of Listeria, it is recommended to respect the minimum time of 60 days of maturation for commercialization.


2014 ◽  
Vol 60 (2) ◽  
pp. 105-110 ◽  
Author(s):  
Brena Melo ◽  
Melania Amorim ◽  
Leila Katz ◽  
Isabela Coutinho ◽  
José Natal Figueiroa

Objective: The present study aimed at assessing the association between environmental temperature and the relative humidity of the air with frequency of hypertensive disorders of pregnancy. Methods: A prospective and retrospective, descriptive, ecological study was held at a teaching maternity in Recife, Brazil. Data from all 26.125 pregnant women admitted between 2000 and 2006 were analysed and 5.051 had the diagnosis of hypertensive disorder of pregnancy. The incidence percentages were calculated monthly per deliveries. Data on mean monthly temperature and relative humidity of the air were collected and monthly comparisons were conducted. February was chosen as the reference month due to its lowest incidence of the disease. The relative chance of hypertensive disorders of pregnancy for each other month was estimated by odds ratio and Pearson's correlation coefficient was used to calculate the relation between the incidence of hypertensive disorders of pregnancy and the mean monthly temperature and relative air humidity. Results: February presented the lowest mean monthly incidence (9.95%) and August the highest (21.54%). Pearson correlation coefficient revealed a higher incidence of hypertensive disorders of pregnancy in the cooler months (r= -0.26; p=0.046) and no significant effect of relative air humidity (r=0.20; p=0.128). Conclusion: The incidence of hypertensive disorders of pregnancy may be affected by variations in temperature, increasing during cooler periods.


2014 ◽  
Vol 1041 ◽  
pp. 307-310
Author(s):  
Mária Budiaková

The paper is oriented on the hygrothermal microclimate of residential interiors in reconstructed building. The questionnaire survey has showed significant increase in number of allergies, respiratory diseases and occurrence of fungi after reconstruction. In order to find causes, experimental measurements of hygrothermal microclimate were carried out. The long term high values of relative humidity were found out and the link with number of efficient natural ventilation was searched for. Ventilation once a day was usual, what was proved as insufficient. Dwellers were informed about right way and number of ventilation. Furthermore, measurements proved decrease of air humidity, but not sufficiently. It was proved that nobody was able to achieve recommended number of ventilation and almost all of them considered it annoying and unreal to sustain. The biggest problem was proved night 7 hour interval. Therefore allergic and respiratory problems were significant in the morning. In conclusions of paper is suggestion for solution of researched problem.


1972 ◽  
Vol 35 (2) ◽  
pp. 98-101 ◽  
Author(s):  
P. P. Graham ◽  
T. N. Blumer

Hams were frozen, stored, and thawed before dry-curing to study the profiles of quality as related to environmental conditions. Quality appraisals and sampling were done after thawing, after curing, and after 30 days aging in an atmosphere where temperature and relative humidity were controlled at about 34.5 C and 62.5%, respectively. The pH, water, NaCl, and fat contents were determined. Surface pH of hams increased from the thawed fresh state to the unstored cured state, but decreased generally after the aging period (stored cured ham). The pH was higher on the surface than that of corresponding internal areas. The pH of the internal tissue was lower for thawed product than cured or aged product. The average percent water decreased during curing and aging periods. Water loss after curing and after aging in the prefrozen hams was greater than that reported for unfrozen hams. The quantity of water, NaCl, and fat varied among the several muscle areas and reasons for variation are discussed. All hams were of acceptable quality at each appraisal period. Decreasing moisture levels of hams were reflected by decreases in conformation scores throughout the processing periods. Increased firmness was accompanied by weight loss, moisture loss, and increased NaCl percentage.


2014 ◽  
Vol 900 ◽  
pp. 39-42
Author(s):  
Quan Tong Jiang ◽  
Xing Gang Li ◽  
Yong Jun Li ◽  
Ming Long Ma ◽  
Guo Liang Shi ◽  
...  

The corrosion behaviors of peak-aged Mg-7Gd-5Y-1Nd-0.5Zr alloys in CO2atmosphere under different relative humidity were investigated by OM, SEM. The weight loss rates, corrosion morphology and residual mechanical properties were also analyzed. The corrosion rates of specimens in CO2atmosphere at 70% relative humidity were highest than others. Relevancy of the influence factors included relative humidity and concentration of CO2were researched. The results show that relative humidity and concentration of CO2in the environment both played an important role in corrosion behaviors.


Sign in / Sign up

Export Citation Format

Share Document