scholarly journals Effects of Humidity Pretreatment Devices on the Loss of HCl Gas Emitted from Industrial Stacks

Atmosphere ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 33
Author(s):  
Han-Nui Gil ◽  
Trieu-Vuong Dinh ◽  
Jee-Hyun Lee ◽  
Byeong-Gyu Park ◽  
In-Young Choi ◽  
...  
Keyword(s):  
High Temperature ◽  
Air Pollutants ◽  
Room Temperature ◽  
High Humidity ◽  
Single Tube ◽  
Hcl Gas ◽  
Low Humidity ◽  
Removal Efficiencies ◽  
Stationary Sources ◽  
Loss Rates

A high humidity at a high temperature presents a common challenge in monitoring the air pollutants emitted from stationary sources. Thus, humidity removal is a pivotal issue. In this study, the effect of humidity pretreatment devices (HPDs) on hydrogen chloride (HCl) gas emitted from an incinerator stack was investigated. A conventional cooler (HPD_CL), and poly-tube (HPD_NP) and single-tube (HPD_NS) Nafion™ dryers were used as HPDs in this study. HCl concentrations varied at five and 10 parts per million in volume (ppmv). Low (i.e., ~4%) and high (i.e., ~17%) humidities were generated at 180 °C. The removal efficiencies of humidity and the loss rates of HCl by the devices were determined. The removal efficiencies of humidity by HPD_CL and the two dryers were found to be similar, at approximately 85% at a low humidity and 95% at a high humidity. In terms of HCl loss rates, HPD_CL revealed the highest loss rates in all conditions (i.e., >95%), followed by HPD_NP and HPD_NS. At normal room temperature (i.e., 25 °C), the HCl loss rates of HPD_NP were >40% at a low humidity and >70% at a high humidity, while those of HPD_NS were >10% at a low humidity and >60% at a high humidity. The performance of the two dryers improved when they were heated to 80 °C. However, this temperature caused damage to the dryers, which reduced their lifetime.

scholarly journals Sensitivity of shotcrete Brazilian discs coated with thin spray-on liners to environmental conditions

2021 ◽  
Vol 121 (7) ◽  
Author(s):  
M.J. Kanda ◽  
T.R. Stacey
Keyword(s):  
High Temperature ◽  
Environmental Conditions ◽  
Laboratory Testing ◽  
Laboratory Tests ◽  
Room Temperature ◽  
Mining Industry ◽  
High Humidity ◽  
Rock Support ◽  
Strength Enhancement ◽  
Indirect Tensile

SYNOPSIS Thin spray-on liners (TSLs) have been used as sealants and rock support in tunnels for over 25 years. Laboratory tests have indicated satisfactory properties that can provide adequate strength, adhesion, toughness, and elasticity as part of rock support systems in mining excavations. These characteristics are, however, not always demonstrated in practice, when mine environmental conditions do not correspond with laboratory environmental conditions. The shortcomings of TSLs experienced in the mining industry have raised concerns, resulting in scepticism from some operators regarding their utilization. The research described in this paper aims to investigate TSL performance in environmental conditions similar to those experienced in mines. Brazilian indirect tensile (BIT) specimens were prepared from precast shotcrete and coated with TSLs. The specimens were then exposed to different environmental conditions for up to 112 days before BIT testing under various conditions: laboratory room temperature and humidity; saturated room temperature; and combined saturated and high temperature (50°C). Additional uncoated shotcrete and TSL BIT specimens were prepared for comparison purposes. The results of the BIT tests showed that environmental conditions have a significant influence on the tensile strength enhancement of shotcrete by TSLs. Water-based TSLs are most likely to be suitable for high humidity environments, although their performance decreases at higher temperatures. Numerical modelling of TSL-coated BIT samples confirms the potential limitations of designing TSL support based only on laboratory testing carried out under room conditions. Keywords: thin spray-on liner, Brazilian indirect tensile (BIT) test, TSL performance, environmental conditions, humidity, high temperature.

Laboratory Studies of Questing Behavior in Colonized Nymphal Amblyomma maculatum Ticks (Acari: Ixodidae)

2020 ◽  
Vol 57 (5) ◽  
pp. 1480-1487
Author(s):  
José Santos Portugal ◽  
Robert Wills ◽  
Jerome Goddard
Keyword(s):  
High Temperature ◽  
Vapor Pressure Deficit ◽  
High Humidity ◽  
Height Distribution ◽  
Stem Height ◽  
Amblyomma Maculatum ◽  
Host Seeking ◽  
Seeking Behavior ◽  
Low Humidity ◽  
Preferred Hosts

Abstract Environmental factors affect host-seeking behavior in ticks. In this study, 80 nymphal Amblyomma maculatum Koch were released in an observation arena containing four different heights of broomsedge stems (Andropogon virginicus L.) anchored in sand. Observations were made over three days as to proportion of ticks questing, questing height, and stem height distribution This scenario was replicated three times with different cohorts of ticks (n = 80 per replicate) for each of three treatment combinations of temperature and humidity: High temperature/high humidity (HTHH), high temperature/low humidity (HTLH), and low temperature/high humidity (LTHH). A fourth treatment utilizing the same size cohort and number of replicates included Wind (HTHHW+/−) by alternating days of wind and no-wind conditions over four days. Mean questing height for ticks under HTHH, HTLH, and LTHH conditions ranged from 4.45 to 6.03 cm with ticks questing significantly higher in HTHH. A significantly lower proportion ticks quested in HTLH (8.64%) than HTHH (14.06%) and LTHH (15.33%). In HTHH and LTHH, a significantly higher proportion of ticks were observed questing on 5-cm stems. Wind significantly reduced average questing height, and when absent, ticks on 20- and 30-cm stems quested significantly higher. These data indicate that A. macuatum nymphs randomly select stems to quest upon and climb upward until environmental conditions are prohibitive/ideal. Conditions with reduced vapor pressure deficit (VPD) led to higher questing frequency and height. Relatively low questing heights observed correspond with size of preferred hosts and may explain infrequency of collection by dragcloth in the field.

Wood-Based Panels’ Properties when Subject to Temperature and Humidity Variation

2013 ◽  
Vol 787 ◽  
pp. 106-110
Author(s):  
Hai Xia Yu ◽  
Man Ping Xu ◽  
Chong Rong Fang ◽  
Fei Yan Guo
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Moisture Content ◽  
Internal Bond ◽  
Modulus Of Rupture ◽  
High Humidity ◽  
Thickness Swelling ◽  
Temperature And Humidity ◽  
Low Humidity ◽  
European Standards

In order to reveal impact of environment humidity and temperature on properties of indoor decorated materials, the paper tested physical and mechanical prosperities of 5 kinds of wood-based panels according to European standards after equilibrium treatments in 3 types of atmosphere. The results showed that the tested materials were very hydrophilic and their strength were closely related to moisture content. Internal bond, modulus of rupture, 24h-thickness swelling and surface soundness of wood-based panels decreased at high temperature and high humidity atmosphere and increased in low temperature and low humidity surroundings, and the decrement are greater than the increment. In contrast, density almost kept the same value during these treatments.

Stigma receptivity in cytoplasmic male sterile wheat

1966 ◽  
Vol 6 (21) ◽  
pp. 175 ◽  
Author(s):  
BC Imrie
Keyword(s):  
High Temperature ◽  
Seed Set ◽  
Moderate Temperature ◽  
High Humidity ◽  
Male Sterile ◽  
Stigma Receptivity ◽  
Cytoplasmic Male Sterile ◽  
Low Humidity ◽  
Effects Of Temperature ◽  
High Level

The effects of temperature and relative humidity on stigma receptivity in a cytoplasmic male sterile wheat line were estimated by measuring per cent seed set on plants raised in controlled environments in the phytotron at Canberra. Three levels of temperature (26�C day : 21�C night, 18�C : 13�C, 10�C : 5�C) and two levels of humidity (75-90 per cent, 40-60 per cent) were combined with four times of pollination (1, 3, 5, and 7 days after flowering) in a factorial design. Stigma receptivity was maintained at a high level under moderate temperature and low humidity conditions. Mean seed set on plants pollinated seven days after flowering was 41.2 per cent at the moderate temperature compared with 0.5 per cent at the high temperature, and 43.2 per cent at the low humidity compared with 7.1 per cent at the high humidity. The effects of temperature and humidity were additive. With a moderate temperature-low humidity combination seed set was as high as 77.4 per cent on plants pollinated seven days after flowering. With the combination of high temperature and high humidity seed set decreased to 0.4 per cent on plants pollinated five days after flowering.

ABOUT HEAT CAPACITY OF TITANIUM CARBIDE TiCx

2019 ◽  
pp. 56-66
Author(s):  
I. Khidirov ◽  
V. V. Getmanskiy ◽  
A. S. Parpiev ◽  
Sh. A. Makhmudov
Keyword(s):  
Heat Capacity ◽  
High Temperature ◽  
Titanium Carbide ◽  
Temperature Dependence ◽  
Carbon Concentration ◽  
Room Temperature ◽  
Thermodynamic Characteristics ◽  
Liquid Nitrogen Temperature ◽  
Analysis Data ◽  
Thermal Excitation

This work relates to the field of thermophysical parameters of refractory interstitial alloys. The isochoric heat capacity of cubic titanium carbide TiCx has been calculated within the Debye approximation in the carbon concentration  range x = 0.70–0.97 at room temperature (300 K) and at liquid nitrogen temperature (80 K) through the Debye temperature established on the basis of neutron diffraction analysis data. It has been found out that at room temperature with decrease of carbon concentration the heat capacity significantly increases from 29.40 J/mol·K to 34.20 J/mol·K, and at T = 80 K – from 3.08 J/mol·K to 8.20 J/mol·K. The work analyzes the literature data and gives the results of the evaluation of the high-temperature dependence of the heat capacity СV of the cubic titanium carbide TiC0.97 based on the data of neutron structural analysis. It has been proposed to amend in the Neumann–Kopp formula to describe the high-temperature dependence of the titanium carbide heat capacity. After the amendment, the Neumann–Kopp formula describes the results of well-known experiments on the high-temperature dependence of the heat capacity of the titanium carbide TiCx. The proposed formula takes into account the degree of thermal excitation (a quantized number) that increases in steps with increasing temperature.The results allow us to predict the thermodynamic characteristics of titanium carbide in the temperature range of 300–3000 K and can be useful for materials scientists.

Nanocomposite Polyurethane Foams Via POSS Blends

2002 ◽  
Vol 733 ◽  
Author(s):  
Brock McCabe ◽  
Steven Nutt ◽  
Brent Viers ◽  
Tim Haddad
Keyword(s):  
High Temperature ◽  
Sample Preparation ◽  
Room Temperature ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Polyurethane Foams ◽  
Development Projects ◽  
Polymer Systems ◽  
Polyurethane Resin ◽  
Military Development

AbstractPolyhedral Oligomeric Silsequioxane molecules have been incorporated into a commercial polyurethane formulation to produce nanocomposite polyurethane foam. This tiny POSS silica molecule has been used successfully to enhance the performance of polymer systems using co-polymerization and blend strategies. In our investigation, we chose a high-temperature MDI Polyurethane resin foam currently used in military development projects. For the nanofiller, or “blend”, Cp7T7(OH)3 POSS was chosen. Structural characterization was accomplished by TEM and SEM to determine POSS dispersion and cell morphology, respectively. Thermal behavior was investigated by TGA. Two methods of TEM sample preparation were employed, Focused Ion Beam and Ultramicrotomy (room temperature).

FANSTEEL 85 METAL

Alloy Digest ◽  
1981 ◽  
Vol 30 (6) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Creep Strength ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Base Alloy ◽  
Heat Treating ◽  
Good Combination ◽  
Bend Strength ◽  
Temperature Performance

Abstract FANSTEEL 85 METAL is a columbium-base alloy characterized by good fabricability at room temperature, good weldability and a good combination of creep strength and oxidation resistance at elevated temperatures. Its applications include missile and rocket components and many other high-temperature parts. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, tensile properties, and bend strength as well as creep. It also includes information on low and high temperature performance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Cb-7. Producer or source: Fansteel Metallurgical Corporation. Originally published December 1963, revised June 1981.

MAGNESIUM AZ31B

Alloy Digest ◽  
1962 ◽  
Vol 11 (9) ◽  
Keyword(s):  
High Temperature ◽  
Magnesium Alloy ◽  
Physical Properties ◽  
Room Temperature ◽  
Heat Treating ◽  
General Purpose ◽  
Bearing Strength ◽  
Temperature Performance ◽  
Wrought Magnesium Alloy ◽  
Metal Products

Abstract Magnesium AZ31B is a general purpose wrought magnesium alloy for room temperature service. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive, shear, and bearing strength as well as creep. It also includes information on low and high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Mg-53. Producer or source: The Dow Metal Products Company.

Mechanical Alloying Behavior in the Nb-Si, Ta-Si, and Nb-Ta-Si Systems

1988 ◽  
Vol 133 ◽  
Author(s):  
K. S. Kumar ◽  
S. K. Mannan
Keyword(s):  
High Temperature ◽  
Mechanical Alloying ◽  
Mechanical Milling ◽  
Room Temperature ◽  
Crystalline Compound ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase ◽  
Α Phase

ABSTRACTThe mechanical alloying behavior of elemental powders in the Nb-Si, Ta-Si, and Nb-Ta-Si systems was examined via X-ray diffraction. The line compounds NbSi2 and TaSi2 form as crystalline compounds rather than amorphous products, but Nb5Si3 and Ta5Si3, although chemically analogous, respond very differently to mechanical milling. The Ta5Si3 composition goes directly from elemental powders to an amorphous product, whereas Nb5Si3 forms as a crystalline compound. The Nb5Si3 compound consists of both the tetragonal room-temperature α phase (c/a = 1.8) and the tetragonal high-temperature β phase (c/a = 0.5). Substituting increasing amounts of Ta for Nb in Nb5Si3 initially stabilizes the α-Nb5Si3 structure preferentially, and subsequently inhibits the formation of a crystalline compound.

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