scholarly journals The Humidity Reactions of the Wood-louse, Porcellio scaber (Latreille)

1937 ◽  
Vol 14 (2) ◽  
pp. 178-186
Author(s):  
D. L. GUNN
Keyword(s):  
Moist Air ◽  
Head Region ◽  
Porcellio Scaber ◽  
Dry Air ◽  
Humidity Gradient ◽  
Humidity Range ◽  
Different Parts

1. Porcellio scaber exhibits hygrokinesis, being very active in dry air and almost motionless in nearly saturated air. With rising humidity a steadily increasing proportion of a batch of specimens is found to be inactive at any one moment. 2. P. scaber also shows hygrophobotactic behaviour. 3. The effect of both reactions is to collect the animals into moist air. 4. In a humidity gradient of given steepness the intensity of the humidity preference varies at different parts of the humidity range. There is no reaction at all if the gradient does not include a region below 65 per cent R.H. There is definite reaction to a difference of 6 per cent R.H. in approximately half-saturated air. 5. The humidity receptors, if they are confined to one area, apparently do not lie on the abdomen or on the head region.

Cutaneous Respiration in Woodlice

1955 ◽  
Vol 32 (2) ◽  
pp. 256-269
Author(s):  
E. B. EDNEY ◽  
J. O. SPENCER
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Oxygen Tension ◽  
Oxygen Deficit ◽  
Oxygen Absorption ◽  
Moist Air ◽  
Survival Times ◽  
Porcellio Scaber ◽  
Dry Air ◽  
Carbon Dioxide Output

1. Oxygen uptake and carbon dioxide output were measured in the woodlice Ligia oceanica, Oniscus asellus, Porcellio scaber and Armadillidium vulgare, in moist and in dry air, using normal animals and animals whose pleopods had been blocked by emulsion paint. 2. In moist air, the rate of oxygen uptake which occurred through the general integument in animals whose pleopods had been blocked was about 50% of normal in Ligia and Oniscus, but less than this in Porcellio and Armadillidium. 3. After exposure to moving dry air, oxygen uptake in dry air was below normal in intact animals and nearly ceased in animals with blocked pleopods. Both showed a somewhat higher uptake if the oxygen tension was raised. 4. Carbon dioxide output in moist air was not immediately inhibited by blocking the pleopods, suggesting free diffusion through the integument. Output fell during the first hour, but the R.Q. remained above 1 in all species. 5. Survival times of blocked animals in moist air corresponded qualitatively with rates of oxygen absorption in the four species. In dry air survival was further curtailed, but prolonged again by an increased oxygen tension. Blocked animals of all species survived for a shorter time in moist nitrogen than in moist air. 6. Injection of reduced indigo showed that oxygen was absorbed by intact animals through the thin ventral integument and bases of the legs in Ligia, and to a lesser extent, through the ventral abdominal integument in Oniscus and Porcellio. 7. The ecological implications of these results are discussed, particularly with reference to the relation between survival and humidity. The dehydration death point is probably affected by the level of oxygen deficit and vice versa. A water-permeable integument is of value for respiration as well as for temperature control, but restricts the habitat range of terrestrial animals.

On the Behaviour of Wireworms of the Genus Agriotes Esch. (Coleoptera, Elateridae)

1943 ◽  
Vol 20 (1) ◽  
pp. 43-53
Author(s):  
A. D. LEES
Keyword(s):  
Water Loss ◽  
The Other ◽  
Sudden Increase ◽  
Great Activity ◽  
Moist Air ◽  
Steep Gradient ◽  
Dry Air ◽  
Constant Rate ◽  
Rate Of Evaporation ◽  
Humidity Range

1. The general humidity behaviour, the humidity receptors and the orientation mechanisms have been studied in the larvae of Agriotes. 2. Wireworms avoid dry air, the intensity of avoidance being greatest when the alternatives are close to saturation . Within this humidity range a difference of 7.5 % R.H. in the alternative chamber (at 17 ° C.) is sufficient to ensure the successful avoidance of the lower humidity by nearly every individual, while statistically significant reactions are obtained with differences as small as 0.5 % R.H. At lower ranges of humidity the same differences yield progressively less intense reactions; at low humidities the response is entirely eliminated. 3. The intensity of the reaction is in better accord with the humidity differences when these are expressed as saturation deficiencies rather than as relative humidities. This suggests that the reaction is initiated by the evaporation of water (‘evapori-meter’ receptor) and not by the operation of receptors which function hygrometrically (‘hygrometer’ receptors). 4. The humidity ‘receptors’ lie on the head. Amputation experiments indicate that the relevant sites of evaporation are distributed between the antennae, maxillary and labial palps; the structure of these appendages is compatible with such a function;- on the other hand, sensilla which might conceivably have a hygroscopic function are absent. 5. Orientation is achieved by the operation of two mechanisms. First, larvae are more active in dry than in moist air (low hygro-kinesis); secondly, larvae show a directed response to low humidities (klinotaxis); this is displayed as a powerful backward recoil if the wireworm crosses a steep gradient from moist into dry air. No tropo-tactic component is involved. The failure of the reaction at low humidities is explained by the great activity of the larvae which interferes with the operation of the klino-tactic mechanism. It is suggested that the kinesis is maintained by a relatively constant rate of water loss from the head appendages, while the klino-taxis is initiated by any sudden increase in the rate of evaporation. 6. The behaviour can readily be correlated with the humidity conditions prevailing in the soil; the necessity for such a sensitive response is possibly dictated by the permeability of the cuticle which renders wireworms peculiarly liable to water loss in unsaturated atmospheres.

scholarly journals Post-Plasma Catalysis for Trichloroethylene Abatement with Ce-Doped Birnessite Downstream DC Corona Discharge Reactor

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 946
Author(s):  
Grêce Abdallah ◽  
Jean-Marc Giraudon ◽  
Rim Bitar ◽  
Nathalie De Geyter ◽  
Rino Morent ◽  
...  
Keyword(s):  
Corona Discharge ◽  
Active Oxygen Species ◽  
Surface Acidity ◽  
Good Stability ◽  
Ozone Decomposition ◽  
Moist Air ◽  
Plasma Catalysis ◽  
Dry Air ◽  
Water Tolerance ◽  
By Products

Trichloroethylene (TCE) removal was investigated in a post-plasma catalysis (PPC) configuration in nearly dry air (RH = 0.7%) and moist air (RH = 15%), using, for non-thermal plasma (NTP), a 10-pin-to-plate negative DC corona discharge and, for PPC, Ce0.01Mn as a catalyst, calcined at 400 °C (Ce0.01Mn-400) or treated with nitric acid (Ce0.01Mn-AT). One of the key points was to take advantage of the ozone emitted from NTP as a potential source of active oxygen species for further oxidation, at a very low temperature (100 °C), of untreated TCE and of potential gaseous hazardous by-products from the NTP. The plasma-assisted Ce0.01Mn-AT catalyst presented the best CO2 yield in dry air, with minimization of the formation of gaseous chlorinated by-products. This result was attributed to the high level of oxygen vacancies with a higher amount of Mn3+, improved specific surface area and strong surface acidity. These features also allow the promotion of ozone decomposition efficiency. Both catalysts exhibited good stability towards chlorine. Ce0.01Mn-AT tested in moist air (RH = 15%) showed good stability as a function of time, indicating good water tolerance also.

Transport properties of real moist air, dry air, steam, and water

2021 ◽  
pp. 1-9
Author(s):  
Sebastian Herrmann ◽  
Hans-Joachim Kretzschmar ◽  
Vikrant C. Aute ◽  
Donald P. Gatley ◽  
Eckhard Vogel
Keyword(s):  
Transport Properties ◽  
Moist Air ◽  
Dry Air

scholarly journals A Study of Moist Air Condensation Characteristics in a Transonic Flow System

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4052
Author(s):  
Jie Wang ◽  
Hongfang Gu
Keyword(s):  
Mach Number ◽  
Relative Humidity ◽  
Transonic Flow ◽  
Flow System ◽  
Plane Surface ◽  
Droplet Growth ◽  
Moist Air ◽  
Dry Air ◽  
Hydraulic Equipment ◽  
Non Equilibrium

When water vapor in moist air reaches supersaturation in a transonic flow system, non-equilibrium condensation forms a large number of droplets which may adversely affect the operation of some thermal-hydraulic equipment. For a better understanding of this non-equilibrium condensing phenomenon, a numerical model is applied to analyze moist air condensation in a transonic flow system by using the theory of nucleation and droplet growth. The Benson model is adopted to correct the liquid-plane surface tension equation for realistic results. The results show that the distributions of pressure, temperature and Mach number in moist air are significantly different from those in dry air. The dry air model exaggerates the Mach number by 19% and reduces both the pressure and the temperature by 34% at the nozzle exit as compared with the moist air model. At a Laval nozzle, for example, the nucleation rate, droplet number and condensation rate increase significantly with increasing relative humidity. The results also reveal the fact that the number of condensate droplets increases rapidly when moist air reaches 60% relative humidity. These findings provide a fundamental approach to account for the effect of condensate droplet formation on moist gas in a transonic flow system.

Mucosal injury and eicosanoid kinetics during hyperventilation-induced bronchoconstriction

1999 ◽  
Vol 87 (5) ◽  
pp. 1724-1733 ◽  
Author(s):  
Arthur N. Freed ◽  
Yongqiang Wang ◽  
Sharron McCulloch ◽  
Teresa Myers ◽  
Ryoichi Suzuki
Keyword(s):  
Epithelial Cells ◽  
Mucosal Injury ◽  
Mucosal Damage ◽  
Mediator Release ◽  
Moist Air ◽  
Dry Air ◽  
Peripheral Airways ◽  
Airway Constriction ◽  
Peripheral Airway ◽  
Balf Cell

Bronchoalveolar lavage (BAL) of canine peripheral airways was performed at various times after hyperventilation, and BAL fluid (BALF) cell and mediator data were used to evaluate two hypotheses: 1) hyperventilation-induced mucosal injury stimulates mediator production, and 2) mucosal damage is correlated with the magnitude of hyperventilation-induced bronchoconstriction. We found that epithelial cells increased in BALF immediately after a 2- and a 5-min dry air challenge (DAC). Prostaglandins D2 and F2α and thromboxane B2 were unchanged immediately after a 2-min DAC but were significantly increased after a 5-min DAC. Leukotriene C4, D4, and E4 did not increase until 5 min after DAC. Hyperventilation with warm moist air did not alter BALF cells or mediators and caused less airway obstruction that occurred earlier than DAC. BALF epithelial cells were correlated with mediator release, and mediator release and epithelial cells were correlated with hyperventilation-induced bronchoconstriction. These observations are consistent with the hypothesis that hyperventilation-induced mucosal damage initiates peripheral airway constriction via the release of biochemical mediators.

scholarly journals The lightness of water vapor helps to stabilize tropical climate

2020 ◽  
Vol 6 (19) ◽  
pp. eaba1951 ◽  
Author(s):  
Seth D. Seidel ◽  
Da Yang
Keyword(s):  
Water Vapor ◽  
Longwave Radiation ◽  
Tropical Climate ◽  
Climate Feedback ◽  
Tropical Atmosphere ◽  
Radiative Effect ◽  
Buoyancy Effect ◽  
Moist Air ◽  
Dry Air ◽  
Earth’S Climate

Moist air is lighter than dry air at the same temperature, pressure, and volume because the molecular weight of water is less than that of dry air. We call this the vapor buoyancy effect. Although this effect is well documented, its impact on Earth’s climate has been overlooked. Here, we show that the lightness of water vapor helps to stabilize tropical climate by increasing the outgoing longwave radiation (OLR). In the tropical atmosphere, buoyancy is horizontally uniform. Then, the vapor buoyancy in the moist regions must be balanced by warmer temperatures in the dry regions of the tropical atmosphere. These higher temperatures increase tropical OLR. This radiative effect increases with warming, leading to a negative climate feedback. At a near present-day surface temperature, vapor buoyancy is responsible for a radiative effect of 1 W/m2 and a negative climate feedback of about 0.15 W/m2 per kelvin.

scholarly journals <i>A Tale of Two Dust Storms</i>: analysis of a complex dust event in the Middle East

2019 ◽  
Vol 12 (9) ◽  
pp. 5101-5118 ◽  
Author(s):  
Steven D. Miller ◽  
Louie D. Grasso ◽  
Qijing Bian ◽  
Sonia M. Kreidenweis ◽  
Jack F. Dostalek ◽  
...  
Keyword(s):  
Water Vapor ◽  
Mineral Dust ◽  
Weather Prediction ◽  
Detection Threshold ◽  
Dust Storms ◽  
Moist Air ◽  
Air Mass ◽  
Dry Air ◽  
Environmental Controls ◽  
Dust Detection

Abstract. Lofted mineral dust over data-sparse regions presents considerable challenges to satellite-based remote sensing methods and numerical weather prediction alike. The southwest Asia domain is replete with such examples, with its diverse array of dust sources, dust mineralogy, and meteorologically driven lofting mechanisms on multiple spatial and temporal scales. A microcosm of these challenges occurred over 3–4 August 2016 when two dust plumes, one lofted within an inland dry air mass and another embedded within a moist air mass, met over the southern Arabian Peninsula. Whereas conventional infrared-based techniques readily detected the dry air mass dust plume, they experienced marked difficulties in detecting the moist air mass dust plume, becoming apparent when visible reflectance revealed the plume crossing over an adjacent dark water background. In combining information from numerical modeling, multi-satellite and multi-sensor observations of lofted dust and moisture profiles, and idealized radiative transfer simulations, we develop a better understanding of the environmental controls of this event, characterizing the sensitivity of infrared-based dust detection to column water vapor, dust vertical extent, and dust optical properties. Differences in assumptions of dust complex refractive index translate to variations in the sign and magnitude of the split-window brightness temperature difference commonly used for detecting mineral dust. A multi-sensor technique for mitigating the radiative masking effects of water vapor via modulation of the split-window dust-detection threshold, predicated on idealized simulations tied to these driving factors, is proposed and demonstrated. The new technique, indexed to an independent description of the surface-to-500 hPa atmospheric column moisture, reveals parts of the missing dust plume embedded in the moist air mass, with the best performance realized over land surfaces.

Applied Anatomy of the Maxillofacial and Mandibular Regions of Indian Mithun (Bos frontalis) and its Clinical Significance in Regional Anesthesia

2020 ◽  
Author(s):  
O.P. Choudhary ◽  
Priyanka . ◽  
P.C. Kalita ◽  
Keneisenuo . ◽  
B. Konwar ◽  
...  
Keyword(s):  
Clinical Significance ◽  
Regional Anesthesia ◽  
Head Region ◽  
Nerve Blocks ◽  
Surgical Interventions ◽  
Applied Anatomy ◽  
Significant Statistical Difference ◽  
Intraoral Approach ◽  
Males And Females ◽  
Different Parts

Background: The topographic and morphometric anatomy of various foramina provides an easy approach in performing nerve blocks by their proper tracking for regional anesthesia in surgical interventions. There is no previously reported information on the applied anatomy and clinical significance of the maxillofacial and mandibular regions of the Indian mithun. The present study was designed to provide important clinical landmarks related to tracking of the infraorbital, mental and mandibular nerves with its clinical significance in regional anesthesia in mithun. Methods: The study was conducted on the maxillofacial and mandibular regions of twelve (n=12) adult Indian mithun of either sex (n=6, male and n=6, female). The head region samples of naturally died mithun were collected from different parts of the Mizoram and Nagaland state of India and processed as per the standard maceration technique. Altogether, a total of twelve measurements were taken in the maxillofacial and mandibular regions of mithun by using a digital vernier caliper and the results were expressed as mean±standard deviation. The obtained parameters from the present study can be useful for an extraoral and intraoral approach for nerve block of the infraorbital, mental and mandibular nerve in the maxillofacial and mandibular regions of mithun. Result: The present study revealed that all the obtained parameters related to regional anesthesia showed a significant statistical difference (P less than 0.01** and P less than 0.05*) between the males and females of mithun. It can be concluded from the present study that the various applied parameters of the present study will aid the clinicians in the implication of regional anesthesia in the head region of mithun.

Effects of Temperature and Humidity on the Metabolism of the Fasting Bed-Bug (Cimex lectularius), Hemiptera

Parasitology ◽  
1932 ◽  
Vol 24 (3) ◽  
pp. 419-428 ◽  
Author(s):  
Kenneth Mellanby
Keyword(s):  
Dry Matter ◽  
Moist Air ◽  
Bed Bugs ◽  
Bed Bug ◽  
Dry Air ◽  
Loss Of Weight ◽  
Cent Relative Humidity ◽  
Effects Of Temperature ◽  
Rate Of Evaporation ◽  
Food Reserves

A method is described by which individual bed-bugs, weighing only 5 mg., can be accurately weighed, and their rate of loss of weight measured during starvation.Fasting bed-bugs were kept for various periods at five temperatures, ranging from 8° C. to 37° C., and at four humidities—0, 30, 60 and 90 per cent. relative humidity—at each temperature. Analysis after the experiments showed that the same amounts of food reserves were used up at each humidity for one temperature, and, as more water was evaporated from those kept in dry air than from those in moist, the proportion of dry matter rose most rapidly in dry air. Protein was the main food reserve used.Although the rate of loss of water was greatest in dry air, the rate of loss was relatively greater in moist air when the saturation deficiencies are compared. It appears that the insects conserve their water in dry air, but their surface area being so great in comparison with their volume, they cannot prevent all evaporation. This evaporation is at a rate nearly proportional to the saturation deficiency of the air.In moist air water appears to be evaporated freely. It is suggested that the spiracles are kept closed more in dry air and less in moist, which accounts for the fact that the rate of evaporation is proportionately greatest in moist air.A comparison is made between the results obtained with Cimex and Rhodnius.

Sign in / Sign up

Export Citation Format

Share Document