scholarly journals RSM-Based Optimization of the Parameters Affecting TiO2-Mediated UV Photocatalysis of Vehicular Emissions in Enclosed Parking Garages

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Sandeep Singh ◽  
Parteek Thind ◽  
Manpreet Kaur Verma ◽  
Dapinder Deep Singh ◽  
Arjun Sareen ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Process Parameters ◽  
Laboratory Experiments ◽  
Limiting Factor ◽  
Vehicular Emissions ◽  
Optimal Conditions ◽  
Box Behnken Design ◽  
Toxic Emissions ◽  
Uv Irradiance ◽  
Parking Garages

In the preceding times, the number of enclosed parking garages has increased significantly in developing nations. The toxic emissions from vehicular exhausts are expected to drastically compromise the environmental conditions of the parking garages. Subsequently, exposure of humans to these accumulated pollutants is also expected to degrade their health. Therefore, in the present investigation, efforts were made to estimate the applicability of TiO2-mediated UV photocatalysis in degrading the concentration of vehicular emissions, viz., NOx and SO2, in the enclosed parking garages (EPGs). In this regard, an artificial EPGs’ environment was created and experiments were designed using the Box-Behnken design in combination with response surface methodology. The process parameters chosen for maximizing the degradation of the pollutants were a concentration of TiO2 emulsion (20 to 120 ml/m2), UV irradiance (1 to 5 mW/cm2), and relative humidity (10 to 50%). Optimization of the laboratory experiments revealed that at optimal conditions of the process parameters, i.e., a concentration of TiO2 emulsion = 77.50   ml / m 2 , intensity of UV irradiance = 3   mW / c m 2 , and relative humidity = 43.2 % , maximum degradation of the NOx and SO2, i.e., 61.24% and 55.05%, respectively, was achieved. Further, it was revealed that relative humidity may prove to be the limiting factor while using the TiO2-mediated UV photocatalysis in humid areas. Findings of this study may prove beneficial in urban planning as it may assist scientific auditory and local authorities in identifying the applicability of TiO2-based photocatalysis in mitigating the impacts of vehicular emissions.

Episodic basin-scale soil moisture anomalies associated with high relative humidity events in the McMurdo Dry Valleys, Antarctica

2021 ◽  
pp. 1-15
Author(s):  
Joseph Levy
Keyword(s):  
Soil Moisture ◽  
Relative Humidity ◽  
Mcmurdo Dry Valleys ◽  
Limiting Factor ◽  
High Humidity ◽  
Dry Valleys ◽  
Surface Soils ◽  
Basin Scale ◽  
Soil Reflectance

Abstract Outside of hydrologically wetted active layer soils and humidity-sensitive soil brines, low soil moisture is a limiting factor controlling biogeochemical processes in the McMurdo Dry Valleys. But anecdotal field observations suggest that episodic wetting and darkening of surface soils in the absence of snowmelt occurs during high humidity conditions. Here, I analyse long-term meteorological station data to determine whether soil-darkening episodes are present in the instrumental record and whether they are, in fact, correlated with relative humidity. A strong linear correlation is found between relative humidity and soil reflectance at the Lake Bonney long-term autonomous weather station. Soil reflectance is found to decrease annually by a median of 27.7% in response to high humidity conditions. This magnitude of darkening is consistent with soil moisture rising from typical background values of < 0.5 wt.% to 2–3 wt.%, suggesting that regional atmospheric processes may result in widespread soil moisture generation in otherwise dry surface soils. Temperature and relative humidity conditions under which darkening is observed occur for hundreds of hours per year, but are dominated by episodes occurring between midnight and 07h00 local time, suggesting that wetting events may be common, but are not widely observed during typical diel science operations.

Water Relationships of Aphis Fabae Scop. During Tethered Flight

1961 ◽  
Vol 38 (1) ◽  
pp. 175-180
Author(s):  
A. J. COCKBAIN
Keyword(s):  
Body Weight ◽  
Relative Humidity ◽  
Water Loss ◽  
Total Body Weight ◽  
Aphis Fabae ◽  
Limiting Factor ◽  
Saturation Deficit ◽  
Tethered Flight ◽  
C 23 ◽  
Total Body

1. Water content varies from 64 to 73% of the total body weight and 72-76% of the fatless body weight of 24 hr. old unflown alatae of Aphis fabae. 2. Water loss during flight may be attributed to evaporation and excretion. A mean of 0.07 mg. water is lost per aphid during a 6 hr. tethered fligh a 25-26° C. and 57-82% R.H., corresponding to c. 9% body weight; at least 66% of the loss (c. 1% body weight/hr.) is by evaporation. 3. Excretion during fligh is not affected by relative humidity differences over the range 41-75% at 25%26° C., but the relative amounts of water lost during prolonged flight are inversely related to relative humidity, because of the effect of humidity on evaporation. 4. Proportion of water in he body does no change significantly during tethered fligh. Mean percentage water to total body weight increases from c. 68-69% during 6 hr.; mean percentage water to fatless body weight decreases from c. 74 to 73%. 5. Water loss is evidently not a limiting factor to fligh in atmospheres of saturation deficit less than c. 23 mm. Hg.

Application of Response Surface Methodology to Predict Ovality of AA6082 Flow Formed Tubes

2013 ◽  
Vol 3 (1) ◽  
pp. 52-65 ◽  
Author(s):  
M. Srinivasulu ◽  
M. Komaraiah ◽  
C.S. Krishna Prasada Rao
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Process Parameters ◽  
Response Surface Model ◽  
Surface Model ◽  
Flow Forming ◽  
Box Behnken Design ◽  
Standard Response ◽  
Tubular Components ◽  
Roller Radius

Flow-forming is eco-friendly, chipless manufacturing process employed in the manufacture of thin walled seamless tubes. Ovality, the out of roundness is one of basic form of errors encountered in the tubular components. In the present research, a response surface model has been developed to predict ovality of AA6082 alloy pre-forms using Design of Experiments. The experiments are performed on a flow forming machine with a single roller. The process parameters selected for the present investigation are axial feed of the roller, the speed of the mandrel, and roller radius. Box-Behnken Design, a standard response surface methodology has been used to conduct the experimental runs. The developed response surface model successfully predicts the ovality of AA6082 flow formed tube within the range of selected process parameters. It has been found that, roller feed is the most important process parameter influencing the ovality of AA6082 flow formed tube.

scholarly journals Oospore Production of Phytophthora infestans in Potato and Tomato Leaves

1997 ◽  
Vol 87 (2) ◽  
pp. 191-196 ◽  
Author(s):  
Y. Cohen ◽  
S. Farkash ◽  
Z. Reshit ◽  
A. Baider
Keyword(s):  
Relative Humidity ◽  
Environmental Factors ◽  
Phytophthora Infestans ◽  
Optimal Conditions ◽  
In Planta ◽  
Fungal Host ◽  
Factors Affecting ◽  
Detached Leaves ◽  
Oospore Formation ◽  
Initial Lesions

Fungal, host, and environmental factors affecting sexual reproduction of Phytophthora infestans in planta were studied. Intact and detached leaves were coinoculated with sporangia of various combinations of A1 and A2 mating-type isolates; leaves were incubated under various conditions, and oospore production was estimated microscopically within whole, clarified leaflets. Some A1 + A2 isolate combinations were more reproductive than others, whereas some potato genotypes better supported oospore formation than others. Tomato usually supported more oospore formation than potato. To induce oospore formation, A1 and A2 sporangia were usually mixed at a 1:1 ratio. Ratios of 1:19 to 19:1, however, also allowed abundant production of oospores. Optimal temperatures for sexual sporulation ranged from 8 to 15°C, but oospores also were produced at 23°C. Oogonia developed 5 to 6 days after sporangial coinoculation, and oospores developed after 8 to 10 days. Light had little effect on oospore formation in both tomato and potato leaves provided that initial lesions were established under photoperiodic conditions. Although A1 and A2 sporangia usually were mixed before inoculation on leaves to obtain oospores, we found that discrete A1 and A2 lesions produced on opposite sides of the midvein of tomato leaves also induced oospore formation in the midvein and adjacent tissues. Oospores also formed when the two halves of the leaves were cut and separated at 3 days after sporangial coinoculation, which corresponded with the appearance of late blight lesions. The continuous supply of moisture to infected leaves was essential to oospore production. No oospores or oogonia formed in severely diseased plants kept at 50 to 80% relative humidity. Such plants did allow some oospore formation when kept continuously wet for 2 weeks in plastic boxes or tents. Detached leaves floated on water supported the highest sexual sporulation. Under optimal conditions of wetness and temperature, as many as 100 oospores per mm2 of tissue were observed.

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