scholarly journals Two types of fog shapes above a cold evaporating liquid

2021 ◽  
Vol 5 ◽  
pp. 2
Author(s):  
A. Feasson ◽  
A. Taihi ◽  
B. Correge
Keyword(s):  
Liquid Nitrogen ◽  
Lower Limit ◽  
Controlled Environment ◽  
Air Humidity ◽  
Nitrogen Flux ◽  
Ice Clouds ◽  
Humidity Level ◽  
Cold Liquid

When liquid nitrogen is poured into a mug, a mist forms above. This article explores the influence of air humidity on the cloud and the formation of these boundaries in a controlled environment. We have identified that both homogeneous and heterogeneous nucleations occur during their formation. We highlight two types of ice clouds that differ only in the level of air humidity. Indeed, there is a critical humidity level at which one goes from a banded cloud to another without lower limit, extending to the cold liquid. We argue that this critical humidity level is related to the nitrogen flux.

Simulation of Humidification Within a Breather

2005 ◽  
Author(s):  
Y. C. Sun ◽  
A. M. Al-Jumaily ◽  
D. Makinson
Keyword(s):  
Power Input ◽  
Nasal Mask ◽  
Air Humidity ◽  
Delivery Tube ◽  
Empirical Relationships ◽  
Humidity Level ◽  
Ambient Relative Humidity ◽  
Heated Air ◽  
Delivery Unit ◽  
Series Of Experiments

A typical breather consists of an air delivery unit (ADU), a humidifying chamber, a connecting tube and a heated delivery tube. For an effective treatment of several respiratory syndromes such as sleep apnea, the chamber is recommended to generate the required moisture content and temperature of the air delivered by the breather. In this paper a mathematical model is developed for a complete breather with a focus on the humidification process. The model is simulated using Simulink™ in a Matlab™ environment. A series of experiments are conducted on various components of the breather for validation as well as to facilitate the necessary empirical relationships for the simulation process. The main outcomes of this work are: the ADU settings significantly alter the delivered air humidity level; the humidifier settings indirectly control the reservoir evaporation rate by controlling the chamber vapor pressure difference; the heated air delivering tube power input effectively controls the nasal mask airflow temperature; the ambient relative humidity level has a linear relationship with the nasal mask humidity level; and the ambient temperature variation can effectively influence the delivered air conditions.

scholarly journals Changes in humidity and temperature inside the pine cones (Pinus sylvestris L.) in two stages seed extraction

2013 ◽  
Vol 74 (3) ◽  
pp. 205-214 ◽  
Author(s):  
Monika Aniszewska
Keyword(s):  
Pinus Sylvestris ◽  
Lower Limit ◽  
Extraction Process ◽  
Continuous Control ◽  
Air Humidity ◽  
Two Stage ◽  
Second Stage ◽  
Seed Extraction ◽  
Pine Cones ◽  
Two Stages

Abstract Temperature measurements were taken: (1) under opening scales, (2) at the seed, and (3) in the stem, of pine cones. Changes in temperature were only examined during the second stage of a two-stage seed extraction process. During this phase a permanent dehydration temperature of 50°C was used, following comparison over a ranges of temperatures, between a lower limit of 35°C and a higher limited of 50°C. The temperature was slowest to increase in the cone’s stem, and fastest to increase under opening scales. The temperature at the seed remained constant at around 43°C for the first hour of dehydration, before increasing to 50°C. The two-stages method of cone extraction employed here, with a permanent dehydration temperature of 50°C in second stage, can be used in extraction cabinets equipped with seed extractors that allow the continuous control of air humidity. The time spent soaking during the inter-stage break should last 5 minutes. Viability of seeds obtained in two-stages process was 78% to 89%

Dewatering of Drying Beds–Combined Biological-Chemical Sludge Behaviour

1993 ◽  
Vol 28 (10) ◽  
pp. 65-72 ◽  
Author(s):  
S. Marklund
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Drying Rate ◽  
Controlled Environment ◽  
Air Humidity ◽  
Digested Sludge ◽  
Drying Time ◽  
Total Solids ◽  
Chemical Sludge

Aerobically digested sludge from a small wastewater treatment plant was dewatered on five sand drying pilot beds and four small drainage beds. The experiment was conducted in a controlled environment with constant air humidity and temperature. A total of between 147 and 263 kg of a combined biological-chemical sludge was used on each of the sand drying beds. Initial sludge total solids (TS) content was 4.6 - 5.5%. Sludge drainage was completed within 28 days, and the thinner sludge layers were drained within 16 days. The sludge evaporation phase, prior to equilibrium with air moisture, lasted a maximum of 84 days and resulted in a final TS content of 88 - 92%. The drying time to achieve 30% TS was 35-50 days, depending on initial sludge thickness. Sludge cracking behaviour or rate did not control the drying rate at less than 30% TS.

Effect of Moisture Transfer Through a Semipermeable Membrane on Condensation/Frosting Limit

2018 ◽  
Vol 140 (12) ◽  
Author(s):  
S. Niroomand ◽  
M. T. Fauchoux ◽  
C. J. Simonson
Keyword(s):  
Moisture Transfer ◽  
Air Flow ◽  
Semipermeable Membrane ◽  
Operating Conditions ◽  
Air Humidity ◽  
Liquid Desiccant ◽  
Humidity Ratio ◽  
Frost Formation ◽  
Effect Of Moisture ◽  
Cold Liquid

This paper investigates frost formation on a flat horizontal surface, with humid air flowing over the surface and a cold liquid desiccant flowing below the surface. Two different surfaces, a semipermeable membrane and an impermeable plate, are tested. The condensation/frosting limit, that is, the lowest air humidity ratio, Wair, at a constant liquid temperature, Tliq, or the highest Tliq at a constant Wair that leads to condensation/frosting, is determined for each surface. The main aim of this study is to find the effect of moisture transfer through the semipermeable membrane on the condensation/frosting limit. It is found that the semipermeable membrane has a lower condensation/frosting limit, due to the moisture transfer through the semipermeable membrane, which dehumidifies the air flow. For a given Wair, the surface temperature can be approximately 5 to 8 °C lower when using a semipermeable membrane, compared to an impermeable plate, before condensation/frosting occurs. Furthermore, it is shown that at some operating conditions, frost appears on the semipermeable membrane only at the air flow entrance of the test section, while the impermeable plate was fully covered with frost at the same operating conditions. Moreover, it is shown that increasing the moisture transfer rate through the semipermeable membrane decreases the frosting limit and delays frost formation.

Supernovae and interstellar gas dynamics

1967 ◽  
Vol 31 ◽  
pp. 117-119
Author(s):  
F. D. Kahn ◽  
L. Woltjer
Keyword(s):  
Lower Limit ◽  
High Velocity ◽  
Gas Dynamics ◽  
Interstellar Cloud ◽  
Interstellar Gas ◽  
Random Motions ◽  
Relativistic Particles

The efficiency of the transfer of energy from supernovae into interstellar cloud motions is investigated. A lower limit of about 0·002 is obtained, but values near 0·01 are more likely. Taking all uncertainties in the theory and observations into account, the energy per supernova, in the form of relativistic particles or high-velocity matter, needed to maintain the random motions in the interstellar gas is estimated as 1051·4±1ergs.

Electron Probe Microanalysis of Frozen Hydrated Kidneys, Isolated Cells, and Cultured Cells

1982 ◽  
Vol 40 ◽  
pp. 402-403 ◽  
Author(s):  
Claude Lechene
Keyword(s):  
Liquid Nitrogen ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Cultured Cells ◽  
Liquid Nitrogen Temperature ◽  
Elemental Content ◽  
Isolated Cells ◽  
Renal Tubular Cells ◽  
Diamond Saw ◽  
Saw Blade

Electron probe microanalysis of frozen hydrated kidneysThe goal of the method is to measure on the same preparation the chemical elemental content of the renal luminal tubular fluid and of the surrounding renal tubular cells. The following method has been developed. Rat kidneys are quenched in solid nitrogen. They are trimmed under liquid nitrogen and mounted in a copper holder using a conductive medium. Under liquid nitrogen, a flat surface is exposed by sawing with a diamond saw blade at constant speed and constant pressure using a custom-built cryosaw. Transfer into the electron probe column (Cameca, MBX) is made using a simple transfer device maintaining the sample under liquid nitrogen in an interlock chamber mounted on the electron probe column. After the liquid nitrogen is evaporated by creating a vacuum, the sample is pushed into the special stage of the instrument. The sample is maintained at close to liquid nitrogen temperature by circulation of liquid nitrogen in the special stage.

A Liquid Nitrogen Cooled Stage for STEM

1974 ◽  
Vol 32 ◽  
pp. 444-445
Author(s):  
Louis T. Germinario
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Liquid Nitrogen ◽  
Room Temperature ◽  
Objective Lens ◽  
Thermal Drift ◽  
Specimen Holder ◽  
Resolution Capability ◽  
Focal Position

A liquid nitrogen stage has been developed for the JEOL JEM-100B electron microscope equipped with a scanning attachment. The design is a modification of the standard JEM-100B SEM specimen holder with specimen cooling to any temperatures In the range ~ 55°K to room temperature. Since the specimen plane is maintained at the ‘high resolution’ focal position of the objective lens and ‘bumping’ and thermal drift la minimized by supercooling the liquid nitrogen, the high resolution capability of the microscope is maintained (Fig.4).

Field-Ion Microscopy of BCC Metals: A Study of Image Differences and Topographical Variations

1973 ◽  
Vol 31 ◽  
pp. 114-115
Author(s):  
O. T. Inal ◽  
L. E. Murr
Keyword(s):  
Liquid Nitrogen ◽  
Liquid Nitrogen Temperature ◽  
Surface Atom ◽  
Image Brightness ◽  
Field Ion Microscopy ◽  
Topographic Features ◽  
Bcc Metals ◽  
Electron Orbital ◽  
Ion Microscopy ◽  
Field Ion Microscope

When sharp metal filaments of W, Fe, Nb or Ta are observed in the field-ion microscope (FIM), their appearance is differentiated primarily by variations in regional brightness. This regional brightness, particularly prominent at liquid nitrogen temperature has been attributed in the main to chemical specificity which manifests itself in a paricular array of surface-atom electron-orbital configurations.Recently, anomalous image brightness and streaks in both fcc and bee materials observed in the FIM have been shown to be the result of surface asperities and related topographic features which arise by the unsystematic etching of the emission-tip end forms.

The Effects of Drying Techniques on Clay-Rich Soil Texture

1974 ◽  
Vol 32 ◽  
pp. 466-467
Author(s):  
T. G. Naymik
Keyword(s):  
Critical Point ◽  
Liquid Nitrogen ◽  
Liquid Nitrogen Temperature ◽  
Drying Methods ◽  
Air Drying ◽  
Freeze Dried ◽  
Critical Point Drying ◽  
Set Up ◽  
The Relationship ◽  
Quartz Grains

Three techniques were incorporated for drying clay-rich specimens: air-drying, freeze-drying and critical point drying. In air-drying, the specimens were set out for several days to dry or were placed in an oven (80°F) for several hours. The freeze-dried specimens were frozen by immersion in liquid nitrogen or in isopentane at near liquid nitrogen temperature and then were immediately placed in the freeze-dry vacuum chamber. The critical point specimens were molded in agar immediately after sampling. When the agar had set up the dehydration series, water-alcohol-amyl acetate-CO2 was carried out. The objectives were to compare the fabric plasmas (clays and precipitates), fabricskeletons (quartz grains) and the relationship between them for each drying technique. The three drying methods are not only applicable to the study of treated soils, but can be incorporated into all SEM clay soil studies.

Si(Li) detector for microanalysis cooled by thermoelectric device

1992 ◽  
Vol 50 (2) ◽  
pp. 1736-1737
Author(s):  
Shaul Barkan
Keyword(s):  
Solid State ◽  
Liquid Nitrogen ◽  
Thermoelectric Device ◽  
Peltier Cooler ◽  
Complicated Process ◽  
The Common

Cooling down solid state detecors, with other different way then liquid Nitrogen, is a goal of many vendors and customers since the invention of these detectors. THe disadvantage of the common way of liquid Nitrogen is first the inavailibility of the LN in many uses (like space military and any other applications that are not done inside a well organize Laboratory). The use of LN also considers as a Labor consumer in addition to the big dewar that has to be added to any detector for storing the LN, the boiling of the LN, may cause microphonics problesm and the refiling of the dewar in many Labs is a complicated process due to inconvenience location of the microscope.In this paper I will show a spectra result of 10mm2 SiLi detector for microanalysis use, cooled by peltier cooler. The peltier cooler has the advantage of non-microphonics and non-labor needed (like adding LN to the dewar).

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