scholarly journals Water Sorption by Different Types of Filter Media Used for Particulate Matter Collection Under Varying Temperature and Humidity Conditions

2020 ◽  
Vol 17 (14) ◽  
pp. 5180 ◽  
Author(s):  
Kamila Widziewicz-Rzońca ◽  
Malwina Tytła
Keyword(s):  
Particulate Matter ◽  
Filter Material ◽  
Effect Of Temperature ◽  
Filter Media ◽  
Karl Fischer Titration ◽  
Different Types ◽  
Temperature And Humidity ◽  
Filter Type ◽  
Effects Of Temperature ◽  
Water Contents

The present study describes the effects of temperature and humidity on the level of water absorption by filter blanks most popularly used for gravimetric analyzes of particulate matter (PM) and the effects of those on the accuracy of its weight measurements. The main parts of the research quantified the effect of temperature and humidity conditions on water contents quartz fiber (Q), fiberglass (G), PTFE, and nylon (N) filters. Supplementary studies were conducted to estimate the effects of temperature, humidity and material on mass loss/gain and the shape of water retention. All chemical analyses of water contents were performed by the Karl Fischer titration method. The results indicate that quartz filters are the most susceptible to the variations in water contents under changing humidity levels and therefore, less suitable to high accuracy determinations of PM mass compared to nylon or glass filters; PTFE performed the best due to their hydrophobicity. For PM water contents determinations, the best choice of filter media is PTFE. Although many other factors determine the choice of filter type for PM analyses, the present study is an important contribution to knowledge of assessing the suitability of different types of filter material for specific measurements.

scholarly journals The Effect of Temperature and Humidity May Reduce the Growth Rate of the Coronavirus Disease 2019 Epidemic

2020 ◽  
Author(s):  
Lei Qin ◽  
Qiang Sun ◽  
Jiani Shao ◽  
Yang Chen ◽  
Xiaomei Zhang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Relative Humidity ◽  
Effect Of Temperature ◽  
Average Temperature ◽  
Temperature And Humidity ◽  
Scatter Plots ◽  
Low Humidity ◽  
Average Relative Humidity ◽  
Effects Of Temperature ◽  
The Relationship

Abstract Background: The effects of temperature and humidity on the epidemic growth of coronavirus disease 2019 (COVID-19)remains unclear.Methods: Daily scatter plots between the epidemic growth rate (GR) and average temperature (AT) or average relative humidity (ARH) were presented with curve fitting through the “loess” method. The heterogeneity across days and provinces were calculated to assess the necessity of using a longitudinal model. Fixed effect models with polynomial terms were developed to quantify the relationship between variations in the GR and AT or ARH.Results: An increased AT dramatically reduced the GR when the AT was lower than −5°C, the GR was moderately reduced when the AT ranged from −5°C to 15°C, and the GR increased when the AT exceeded 15°C. An increasedARH increased theGR when the ARH was lower than 72% and reduced theGR when the ARH exceeded 72%.Conclusions: High temperatures and low humidity may reduce the GR of the COVID-19 epidemic. The temperature and humidity curves were not linearly associated with the COVID-19 GR.

The Influence of Temperature and Humidity on Instar Length in Calandra Granaria Linn

1947 ◽  
Vol 24 (1-2) ◽  
pp. 79-94
Author(s):  
L. E. S. EASTHAM ◽  
F. SEGROVE
Keyword(s):  
Growth And Development ◽  
Effect Of Temperature ◽  
Threshold Temperature ◽  
Food Utilization ◽  
Optimum Temperature ◽  
Atmospheric Humidity ◽  
Larval Instars ◽  
Balance Sheets ◽  
Temperature And Humidity ◽  
Effects Of Temperature

1. The effects of temperature and humidity on the duration of each instar of the life cycle of Calandra granaria Linn. have been examined. The insects were reared at temperatures ranging from 15 to 30° C. and at atmospheric humidities ranging from 40 to 80% R.H. 2. A method is described for assessing the effect of temperature as an independent factor. 3. The temperatures employed fall within the ‘vital zone’. Extrapolation indicates the threshold temperature to be approximately 11° C. for the egg and larval instars though somewhat lower for the pupa. 30° C. is below the optimum temperature. 4. The durations of the egg and pupal stages are not affected by atmospheric humidity. 5. The duration of all larval instars is affected by moisture. It is suggested that this is largely due to atmospheric humidity and that food water is of little significance. 6. Shortage of moisture acts as an obstacle to development. Evidence is presented which indicates that drier atmospheres tend to desiccate the insect and that desiccation is responsible for retarded growth and development. 7. Since much earlier work on temperature and moisture has been done on fasting insects and, therefore, on insects deficient in one of the most important environmental factors, we suggest that our results, incomplete as they are, indicate the need for new approaches to be made. More complete data on feeding insects under controlled conditions of food, temperature and moisture are required, from which can be drawn up more complete balance sheets of development involving measurements of food utilization and respiratory rates.

Effects of Temperature and Humidity on the Rust-Red Flour Beetle, Tribolium-Castaneum (Herbst) (Coleoptera, Tenebrionidae), in Wheat-Grain

1987 ◽  
Vol 35 (1) ◽  
pp. 43 ◽  
Author(s):  
GG White
Keyword(s):  
Tribolium Castaneum ◽  
Larval Survival ◽  
Population Increase ◽  
Effect Of Temperature ◽  
Wheat Grain ◽  
Mathematical Functions ◽  
Temperature And Humidity ◽  
Survival And Development ◽  
Effects Of Temperature ◽  
Coleoptera Tenebrionidae

Rates of survival and development of the immature stages of Tribolium castaneum (Herbst) (Coleoptera : Tenebrionidae) were determined in wheat grain at constant temperatures from 20 to 37.5�C and constant relative humidities from 25 to 65%. The rates for eggs and pupae were similar to those previously published for T. castaneum in flour, but larval development was slower and mortality greater, except at low temperature and high humidity. The effect of temperature and humidity on rates of fertility and oviposition in young adults were also determined in wheat grain. The patterns of effects of temperature and humidity on oviposition were similar to those previously published for T. castaneum in flour, but the maximum observed oviposition rate was lower. Fertility was significantly reduced when densities of adults were greater than one pair per 250 g. Mathematical functions were fitted to data from the present and previous studies on age-specific survival and fecundity of adults; population growth rate statistics were calculated from life-table parameters defined by these functions. Under optimal conditions within the range of the present study (35�C, 65% RH), the innate capacity for increase rm was 0.84 per week. The limits for population increase, where rm is zero, were largely determined by.the limits for larval survival, which were approximately 35% RH, and 20-22�C at the lower limit and 40�C at the upper limit.

scholarly journals Strongly and Loosely Bound Water in Ambient Particulate Matter—Qualitative and Quantitative Determination by Karl Fischer Coulometric Method

2020 ◽  
Vol 12 (15) ◽  
pp. 6196
Author(s):  
Kamila Widziewicz-Rzońca ◽  
Malwina Tytła ◽  
Grzegorz Majewski ◽  
Patrycja Rogula-Kopiec ◽  
Krzysztof Loska ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Atmospheric Chemistry ◽  
Bound Water ◽  
Water Evaporation ◽  
Aerosol Formation ◽  
Water Release ◽  
Crystal Water ◽  
Karl Fischer ◽  
Different Types ◽  
Water Contents

Simple physical characterization of water evaporation can provide detailed information regarding its component distribution in particulate matter (PM) samples. The water presence in PM can greatly influence its polarity and subsequent reaction activity, for example, in secondary inorganic and organic matter formation. In this study, the presence of PM-bound water is detected using the Karl Fischer titration method in a temperature gradient with an aim to quantitatively assess different types of water occurrence. The analyses were initiated by testing two reference materials, namely urban particulate matter 1648a and urban dust 1649b (NIST). Four different types of water were found in both NIST materials, which helped to optimize the temperature ramp program and its adjustment for real PM samples. It was found that water contents in total suspended particles (TSP) are similar to those typically occurring in urban background stations—approximately 7.12–45.13% of the TSP mass, differentiated into the following water mass contributions: 48.5% of the total water found was loosely bound water; 23.3% was attributed to the absorption water; while the missing 20% could be probably attributed to crystal water removed only above 180 °C and artifacts connected with the drift correction problem. By comparing water release curves for single PM-compounds like pure SiO2; Al2O3; NH4NO3; (NH4)2SO4 and NH4Cl with water spectra obtained for real PM samples, it was found that water in particulate matter mainly comes from the dehydration of TSP-bound crystalline like Al2O3, SiO2 and to a lesser extent from salts like NH4NO3; (NH4)2SO4 and NH4Cl. A newly used thermal ramp method was able to assess water contents from Teflon–polypropylene baked filters characterized by low melting points and therefore filter degradation even under temperatures oscillating around 200 °C. The advantage of this new work is the separation of different types of TSP-bound water contributions, facilitating and promoting further research on the origin of PM-bound water and its role in atmospheric chemistry, secondary aerosol formation and visibility.

scholarly journals The Effects of Temperature and Humidity on the Cheese Skipper, Piophila Casei (L.)

1935 ◽  
Vol 12 (4) ◽  
pp. 384-388
Author(s):  
JOHN SMART
Keyword(s):  
High Temperatures ◽  
Effect Of Temperature ◽  
Secondary Effect ◽  
Short Series ◽  
Thermal Death ◽  
Temperature And Humidity ◽  
Series Of Experiments ◽  
Thermal Death Point ◽  
Effects Of Temperature ◽  
Lower Temperature

The paper gives the results of a short series of experiments carried out to determine the thermal death-point under conditions of controlled humidity of the larva and pupa of the Cheese Skipper, Piophila casei (L.). The larva is remarkable for the high temperatures it can withstand, namely 52° C., for 1 hour's exposure and 45° C. for an exposure of 24 hours. The death of the pupa at a much lower temperature is shown to be due to a secondary effect of temperature on its physiology.

Effect of Temperature and Humidity on Measuring Ionization Current Inside Contaminated Pipes

2013 ◽  
Author(s):  
Pingchuan Li ◽  
Xianguo Tuo ◽  
Mingzhe Liu ◽  
Jun Ren ◽  
Qibiao Wang ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Long Range ◽  
Regression Method ◽  
Experimental Results ◽  
Ion Current ◽  
Effect Of Temperature ◽  
Multiple Regression Method ◽  
Temperature And Humidity ◽  
Different Temperatures ◽  
Effects Of Temperature

This paper reported the experimental results of ion current under different temperatures and relative humidity using long range alpha detector (LRAD). An approximation relation between the measuring values, temperatures and relative humidity has been obtained using the linear multiple regression method. The experimental results have shown that the measuring values decrease with the increase of temperature and humidity. The influence of humidity on results outweighs that of temperatures. And both temperature and humidity are obviously negative correlated with measured values. Further experiments will be performed to confirm the coupling effects of temperature and humidity and reported later.

Effect of biotic and abiotic factors on the morphometric variability of Paratrichodorus rhodesiensis (Nematoda: Trichodoridae) from Senegal

Nematology ◽  
2003 ◽  
Vol 5 (3) ◽  
pp. 463-477
Author(s):  
Mandefro Wondirad ◽  
Wilfrida Decraemer ◽  
Pierre Baujard
Keyword(s):  
Body Length ◽  
Interaction Effect ◽  
Abiotic Factors ◽  
Tail Length ◽  
Effect Of Temperature ◽  
Morphometric Characters ◽  
Biotic And Abiotic Factors ◽  
Temperature And Humidity ◽  
Controlled Environments ◽  
Effects Of Temperature

AbstractEffects of temperature, humidity, temperature and humidity interaction and host on morphometric variability of Paratrichodorus rhodesiensis were studied. Nematode cultures were established in a glasshouse under controlled environments. Amongst the factors investigated, host was found to be the most influential on both sexes (P < 0.05) affecting all characters in females and eight out of 11 characters in males. Ratios b and c were found to be highly variable and hence their use is not suggested. On the contrary, ratio a was found to be a good indicator of nematode condition, particularly in association with hosts. Vulva position (V) was found to be the most stable character. Paratrichodorus rhodesiensis was affected by higher temperatures of 34 and 36°C. Change in humidity did not show a demonstrable trend on morphometric characters in both sexes. Interaction effect of temperature and humidity resulted in a significant effect on body length and body diameter in females and on ratio b and c, pharynx, onchiostyle and tail length in males.

Effect of temperature and humidity on the development of tea red spider mite, Oligonychus coffeae (Nietner)

1967 ◽  
Vol 57 (3) ◽  
pp. 433-436 ◽  
Author(s):  
G. M. Das ◽  
S. C. Das
Keyword(s):  
Spider Mite ◽  
Larval Mortality ◽  
Effect Of Temperature ◽  
Optimum Conditions ◽  
Red Spider Mite ◽  
Temperature And Humidity ◽  
Oligonychus Coffeae ◽  
The Mean ◽  
Effects Of Temperature ◽  
Very High

The effects of temperature and humidity on the development of Oligonychus coffeae (Nietner) were studied by exposing the various stages of the mite to air in equilibrium with saturated solutions of appropriate salts in containers within thermostatically controlled cabinets. Adults and early stages were maintained on fresh tea shoots.The pre-oviposition, oviposition and post-oviposition periods of adult females at 75–80% relative varied inversely with temperature, and averaged, respectively, 0.8, 5.9 and 1.4 days at 32° and 2.3, 30.6 and 2.0 days at 20°C. The mean number of eggs laid per female likewise varied inversely with temperature, from 12.0 at 32°C at 32° to 107.3 at 20°C.No eggs hatched when incubated at 34°C., irrespective of humidity, or at 17% R.H., irrespective of temperature. Optimum conditions for incubation (those affording over 90% hatch) were provied by a combination of temperatures and relative humidities within the ranges 20–30°C. and 49–94%. When eggs were exposed daily for five days to temperatures of 37 or 40° for six hours at 72–94% R.H. and then transferred to room conditions (24–32°C., 64–88% R.H.), the percentage of eggs hatching was reduced from 94.7 (room conditions) to about 75 or 5–12, respectively.The mean incubation period of eggs varied from 3.9 days at 32° to 10.8 at 20°C., and the mean duratio of the combined larval and nymphal stages from 4.9 days at 30° to 8.7 at 20°C. At 32°C., larval mortality was very high.

scholarly journals Determination of water content in infant formula

2019 ◽  
pp. 37-42
Keyword(s):  
Water Content ◽  
Infant Formula ◽  
Reference Method ◽  
Dry Mass ◽  
Karl Fischer Titration ◽  
Karl Fischer ◽  
Different Types ◽  
The Stability ◽  
Water Contents

Water is one of the most important constituents of food, very important to be accurately quantified. Furthermore, water content affects the stability and shelf life of food. The evaluation of most chemical parameters is based on dry mass and many methods use heating which result in losing all volatile compounds, including water. Also, it is much harder to extract all of water if we have a complex matrix. Regarding this, the aim of this study was to determine water content in different infant formula by various methods. For examination of water content in three different types of infant formula three different techniques were used (oven sample processor, drying oven and halogen drying) and compared to classical Karl Fischer titration with two different solvents. Each sample was measured in ten probes, and classical Karl Fischer titration was used as a reference. The results showed that the reference method was the best regarding speed of measurement, amount of sample needed and obtained water contents (3.01- 4.35%), followed by Karl Fischer in boiling methanol (2.80-4.30), oven sample processor (2.96-4.23%), halogen drying (2.74-4.03%) and drying oven (2.38-3.52). Methods using heating could not remove all water from the sample within a reasonable time.

Platelet Metabolism during the Interiorization of Two Different Types of Particulate Matter

1972 ◽  
Vol 27 (02) ◽  
pp. 263-271 ◽  
Author(s):  
I. A. Cooper ◽  
P Cochrane ◽  
B. G. Firkin ◽  
K. J. Pinkard
Keyword(s):  
Particulate Matter ◽  
Polymorphonuclear Leukocyte ◽  
Anaerobic Metabolism ◽  
Human Platelets ◽  
Metabolic Changes ◽  
Polystyrene Latex ◽  
Considerable Time ◽  
Difference Of Opinion ◽  
Different Types ◽  
Aerobic And Anaerobic

SummaryIt has been suggested that human platelets possess the ability to phagocytose particulate matter similar to the polymorphonuclear leukocyte. However some difference of opinion has arisen regarding this contention, particularly as differences have been demonstrated with regard to the observed metabolic changes occurring in platelets related to such a process.The experiments reported in this paper were designed to observe the aerobic and anaerobic metabolism in human platelets during and following interiorization of two different particles, viz. polystyrene latex and thorotrast. The results of these experiments show a marked difference between both types of particles with regard to observable metabolic changes despite the rapid interiorization of both types of material. Some alteration occurs in both aerobic and anaerobic metabolism a considerable time after interiorization of latex, whereas no alteration could be demonstrated after interiorization of thorotrast. It is suggested that the interiorization of particulate matter is by some process other than phagocytosis and that observed metabolic changes related to latex may be due to a release reaction.

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