scholarly journals Evaluation of Residual Efficacy of Pyrethrin + Methoprene Aerosol on Two Dermestids: Impact of Particle Size, Species, and Temperature

Insects ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 142 ◽  
Author(s):  
Srinivas K. Lanka ◽  
Frank H. Arthur ◽  
James F. Campbell ◽  
Kun Yan Zhu
Keyword(s):  
Particle Size ◽  
Residual Activity ◽  
Adult Emergence ◽  
Residual Effects ◽  
Effect Of Temperature ◽  
Particle Sizes ◽  
Dependent Variables ◽  
Developmental Index ◽  
Residual Efficacy ◽  
The Impact

Residual effects of pyrethrin + methoprene aerosol dispensed at 4 and 16-µm particle sizes and an untreated control, was assessed against late-stage larvae of Trogoderma inclusum (LeConte), the larger cabinet beetle, and T. variabile (Ballion), the warehouse beetle. Treated arenas were stored at 25, 30, 35, and 40 °C and bioassays were conducted at 1, 3, or 6 weeks post-treatment. Larval development was monitored through adult emergence to compare the efficacy of treatments by using both the percentage of normal adult emergence and a developmental index as dependent variables. There was no overall effect of temperature on residual activity as measured using either adult emergence or developmental index values. Both the 4 and 16-µm particle sizes resulted in reduced adult emergence and low developmental index values compared to untreated controls. The insecticide was more effective on T. variabile than on T. inclusum. The impact of particle size varied between species, both particle sizes reduced adult emergence and developmental index in T. variabile, but only the 16-µm particle size resulted in reduction of adult emergence of T. inclusum. Furthermore, there was a reduction in activity of methoprene with residual exposure time. The variations in susceptibility of species to methoprene, differences in efficacy of particle sizes, and decrease in residual persistence at smaller particle sizes highlight the need for attaining optimal particle size to improve overall efficacy of aerosol mixtures containing methoprene.

scholarly journals Experimental Study on Limestone Cohesive Particle Model and Crushing Simulation

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Huaiying Fang ◽  
Dawei Xing ◽  
Jianhong Yang ◽  
Fulin Liu ◽  
Junlong Chen ◽  
...  
Keyword(s):  
Particle Size ◽  
Simulation Model ◽  
Impact Velocity ◽  
Distribution Curve ◽  
Particle Model ◽  
Particle Sizes ◽  
Particle Crushing ◽  
Discrete Element Method Simulation ◽  
Impact Crushing ◽  
The Impact

This study investigates the effect of impact velocity and particle size on crushing characteristics. We use a discrete-element method simulation and construct cohesive limestone particles with internal microinterfaces and cracks for impact crushing experimentation. The simulation model follows the same process as the impact crushing experiment. Results show that, after crushing at impact velocities of 30 and 40 m/s, the simulated particle-size distribution curve matches experimental results as closely as 95%. For different particle sizes, results are more than 90% in agreement. These results indicate the feasibility of the cohesive-particle crushing simulation model. When the particle size is 15 mm, an approximate linear relationship exists on impact velocity and crushing ratio. For a constant impact velocity, the particle size of 18 mm results in the maximum crushing ratio.

scholarly journals Valorisation of brewers’ spent grain in different particle size in yogurt production

2021 ◽  
Vol 332 ◽  
pp. 01008
Author(s):  
Joncer Naibaho ◽  
Emir Jonuzi ◽  
Nika Butula ◽  
Adam Figiel ◽  
Baoru Yang ◽  
...  
Keyword(s):  
Particle Size ◽  
Lactic Acid ◽  
Positive Impact ◽  
Particle Sizes ◽  
Food Ingredient ◽  
Rheological Analysis ◽  
Spent Grain ◽  
The Impact ◽  
Water Holding ◽  
Lower Particle Size

The potential of brewers’ spent grain (BSG) as a functional food ingredient has been investigated for having high nutritional value. A high amount of dietary fiber of BSG shows a high ability to bind water; thus, it tends to solidify food mixture. This characteristic has a beneficial effect in the utilization of BSG as a filler and texturizer in yogurt. The study aims to evaluate the impact of the BSG addition in yogurt production and its quality. BSG was prepared in three different particle sizes, and an amount of 10% was added for yogurt fermentation. The impact of BSG addition was evaluated after 24 h of storage. The result shows that different particle sizes of BSG had no significant impact on pH and syneresis, while it significantly affected the amount of lactic acid and countable S. thermophilus. However, BSG increased the fermentation rate of yogurt, and had a positive impact on water holding capacity. A lower particle size had a higher amount of lactic acid and a lower S. thermophilus. The lower particle size lowered the lightness of the yogurt. Rheological analysis showed that a higher particle size of BSG increased the shear stress and viscosity of yogurt.

Effect of bed particle size and temperature variation on the minimum fluidisation velocity: A comparison with minimum fluidisation velocity correlations for bubbling fluidised bed designs

2019 ◽  
Vol 233 (5) ◽  
pp. 1001-1012 ◽  
Author(s):  
Musademba Downmore ◽  
Simbi David Jambgwa ◽  
Kuipa Pardon Kusaziwa
Keyword(s):  
Particle Size ◽  
Temperature Variation ◽  
Good Choice ◽  
Column Height ◽  
Effect Of Temperature ◽  
Internal Diameter ◽  
Particle Sizes ◽  
Fluidised Bed ◽  
Bed Temperature ◽  
Experimental Values

This work presents hydrodynamic studies on the effect of temperature and bed particle variation on minimum fluidisation velocity. A lab-scale bubbling fluidised bed made of stainless steel, with column height of 1 m and internal diameter of 0.15 m was used. Five Geldart-B-type alumina bed materials of mean particle sizes 75, 177, 250, 320 and 500 µm were used and the bed temperature was varied between 50 ℃ and 600 ℃. The hydrodynamic results showed that minimum fluidisation velocity varied directly with mean particle size and inversely with temperature. The pressure drop was found to increase with bed temperature for all the sizes of bed particles. The minimum fluidisation velocity is a key parameter in the design of fluidised bed systems and as such its prediction lies with good choice of correlation. The experimental values were compared with predicted minimum fluidisation velocity from six correlations, with the overall objective of verifying the most suitable correlation. Of the correlations used, the Hartman et al. correlation showed very good fitting with experimental data for beds of 75 and 177 µm particles, and the Mohanta et al. correlation showed good fitting with 250–500 µm bed particles. The models exhibited very good coefficient of multiple determination ( R2), very low fitting errors and low geometric standard deviations across the range of particle sizes and temperature variation. However, the lack of understanding of the parameters such as voidage, particle sphericity, density and viscosity would need more attention, particularly in view of the sensitivity of the minimum fluidisation velocity predictions to these parameters. Further studies are therefore recommended for the verification of the correlations in this regard.

scholarly journals Application of Taguchi method to investigate the effect of temperature, heating time, concentration and particle size on improved gel spinning process of UHMWPE

2018 ◽  
Vol 69 (05) ◽  
pp. 347-351
Author(s):  
RAJPUT ABDUL WAQAR ◽  
ZAHID BILAL ◽  
JAMSHAID HAFSA ◽  
ALI USMAN ◽  
ABBAS AMIR ◽  
...  
Keyword(s):  
Particle Size ◽  
Processing Parameters ◽  
Major Effect ◽  
Heating Time ◽  
Fractional Factorial ◽  
Effect Of Temperature ◽  
Gel Spinning ◽  
Spinning Process ◽  
The Impact ◽  
Temperature Heating

In this research UHMWPE filaments were extruded utilising newly developed terpene based gel spinning process. Taguchi’s fractional factorial experimental design was implemented to study the impact of different factors on the tenacity of the fibres. Extruded filaments were characterized by taking filament tenacity as response. The extrusion was carried out utilising terpene base gel spinning process developed by the author reported previously, which uses environmentally friendly terpene (orange oil) instead of petrochemicals used in the conventional extrusion of UHMWPE. Four selected processing parameters were used and their effect on the tenacity of resultant filaments was assessed using standard statistical methods. It was found that the concentration and heating time exerts significant effect on the tenacity of filaments. In addition, interaction between concentration and particle size, temperature and concentration, heating time and concentration indicated major effect on the response.

scholarly journals The Impact of Equilibrium Gas Pressure and Coal Particle Size on Gas Dynamic Diffusion in Coal

Processes ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 571
Author(s):  
Li ◽  
Nie ◽  
Tian ◽  
Zhao ◽  
Zhang
Keyword(s):  
Particle Size ◽  
Diffusion Coefficient ◽  
Diffusion Coefficients ◽  
Effective Diffusion ◽  
Gas Pressure ◽  
Particle Sizes ◽  
Gas Desorption ◽  
The Impact ◽  
And Diffusion ◽  
Dynamic Diffusion

The diffusion coefficient of gases in coal varies with time. This study aims to develop an unsteady dynamic diffusion (UDD) model based on the decay of diffusion coefficient with time and the change of integral. This study conducted a series of gas desorption and diffusion experiments with three different combinations of particle sizes and gas pressures and compared the diffusion coefficients of the three models. The UDD model exhibited good fitting results, and both the UDD and bidisperse models fitted the experimental data better than the unipore model. In addition, the dynamic diffusion coefficient (DDe) decreased rapidly in the initial stage but gradually decreased to a stable level in the later stage. All the effective diffusion coefficients of the three models negatively correlated with the particle size. In the unipore model, the diffusion coefficient of coal samples with three particle sizes increased with gas pressure. In the bidisperse and UDD models, the diffusion coefficients (Dae, Die, and DDe) of 0.25–0.5 mm and 0.5–1.0 mm coal samples increased with gas pressure. However, DDe and Dae of 1.0–1.25 mm coal samples increased first and then decreased. Furthermore, Die decreased first and then increased, with no sign of significant pressure dependence. Finally, the correlation and significance between the constant and diffusion coefficient in the UDD model was investigated.

scholarly journals Research to Develop a Promising Technology for the Joint Disposal of Man-made Wastes

2020 ◽  
Author(s):  
Igor Nikolaevich Tanutrov ◽  
Marina Nikolaevna Sviridova ◽  
Sergey Anatolievich Lyamkin ◽  
Yriy Anatolievich Chesnokov ◽  
Lubov Andreevna Ovchinnikova ◽  
...  
Keyword(s):  
Particle Size ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Granulometric Composition ◽  
Average Diameter ◽  
Water Soluble ◽  
Particle Sizes ◽  
Main Components ◽  
The Impact

The main components of RM are: Fe (35.7 %) in the form of hematite and complex hydroalumination, Ca (11.0 %) in the form of calcite and hydro-aluminosilicates, Al (6.8 %) and Si (4.7 %) in the composition of hydroalumination, Na (2.8 %) in the form of hydroalumination, carbonate and hydroxide, Ti (2.5 %) in the form of rutile. The main components of the OMS are: Fe (71 %) in the form of magnetite, wustite and hematite with a very small amount of fayalite. The contents of Si (in the form of quartz), Al and P (non-forming phases) are within 1–3 %. Granulometric composition of RM is characterized by high dispersion. With an average diameter of 1.6 μm, all particle sizes are in the range of 0.5–12 μm. Granulometric composition of OMS is characterized by complexity. With an average diameter of 8.6 μm, maxima of 0.9 μm and 15 μm and a minimum of about 1.2 μm are observed in the particle size distribution. The specific surface area of the materials is equal to RM 23.7 m2/g, and OMS – 1.9 m2/g. The change of waste properties after exposure to aqueous solutions of alkalis and acids neutralizing the effect of organic (OMS) and alkaline (RM) surface compounds was studied. Neutralization of aqueous suspension with HCl solution leads to removal of alkaline film from the surface. As a result of the impact of reagents, there is a decrease in the content of water-soluble components in the processing products. At the same time, the average particle sizes of RM and OMS increase to 2 and 14 μm, respectively, and the specific surface area to 25.7 and 2.3 m2/g. The distribution of particle size of RM is almost constant, and the OMS is approximately 5 and 10 % of the smoothed maximum and minimum in the area of at least 0.5 and 15 μm. Keywords: red mud, oiled mill scale, chemical, phase, granulometric, composition, specific surface

Stream habitat hydraulics: interannual variability in three reaches of Catamaran Brook, New Brunswick

1998 ◽  
Vol 55 (2) ◽  
pp. 485-494 ◽  
Author(s):  
Donna J Giberson ◽  
Daniel Caissie
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
New Brunswick ◽  
Size Distribution ◽  
Stream Habitat ◽  
Particle Sizes ◽  
Substrate Stability ◽  
The Impact ◽  
Substrate Particle ◽  
Different Levels

The hydraulic habitat of 12 sites in a small salmon stream in central New Brunswick was investigated between 1992 and 1995 to determine patterns of habitat (substrate) stability between and within reaches. Stability was evaluated by measuring particle size distribution in replicated erosional and depositional sites in each reach and calculating the proportion of the bed predicted to be in motion at given flood flows. Erosional (riffle) sites in all reaches showed significant differences (ANOVA, p < 0.05) in substrate particle sizes from year to year, movement of embedded sediment samplers, and high predicted bedload mevement, even in small spates. In contrast, depositional sites (flats, some runs) appeared stable, showing no significant year-to-year differences in particle sizes, no movement of embedded samplers, and no increase in predicted bedload movement until high flow. The impact of the flood on the streambed depends heavily on the particle size distribution present during the flood, resulting in different levels of substrate disturbance during equal-magnitude floods in different years. Certain sites (e.g., flats) may be able to serve as hydraulic refugia to stream fauna during some floods. It is clear that year-to-year variations in substrate stability must be considered when evaluating habitat stability for stream fauna.

scholarly journals Mechanistic Study of Pb2+ Removal from Aqueous Solutions Using Eggshells

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2517
Author(s):  
Mohamed A. Hamouda ◽  
Haliemeh Sweidan ◽  
Munjed A. Maraqa ◽  
Hilal El-Hassan
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Mechanistic Study ◽  
Particle Sizes ◽  
Acid Digestion ◽  
Initial Concentration ◽  
Removal Capacity ◽  
Removal Experiments ◽  
The Impact ◽  
Predictive Relationship

This study investigates the impact of eggshell particle size and solid-to-water (s/w) ratio on lead (Pb2+) removal from aqueous solution. Collected raw eggshells were washed, crushed, and sieved into two particle sizes (<150 and 150–500 µm). Batch Pb2+ removal experiments were conducted at different s/w ratios with initial Pb2+ concentrations of up to 70 mg/L. The contribution of precipitation to Pb2+ removal was simulated by quantifying removal using eggshell water, whereas sorbed Pb2+ was quantified by acid digestion. Results indicated that eggshell particle sizes did not affect Pb2+ removal. High removal (up to 99%) of Pb2+ was achieved for low initial Pb2+ concentrations (<30 mg/L) across all s/w ratios studied. However, higher removal capacity was observed at lower s/w ratios. In addition, results confirmed that precipitation played a major role in the removal of Pb2+ by eggshells. Yet, this role decreased as the s/w ratio and initial concentration of Pb2+ increased. A predictive relationship that relates the normalized removal capacity of eggshells to the s/w ratio was developed to potentially facilitate the design of the reactor.

scholarly journals The Effect of Temperature and Particle Size on the Pyrolysis Products of Waste Tires and the Formation Mechanism of Limonene

2021 ◽  
Vol 72 (3) ◽  
pp. 45-57
Author(s):  
Lei Gong ◽  
Jin Wang ◽  
Hong Wei Yu ◽  
Ying Zhou ◽  
Tong Zou ◽  
...  
Keyword(s):  
Particle Size ◽  
Pyrolysis Temperature ◽  
Rapid Development ◽  
Pyrolysis Product ◽  
Raw Material ◽  
Effect Of Temperature ◽  
Gas Chromatography Mass Spectrometry ◽  
Particle Sizes ◽  
Pyrolysis Products ◽  
Waste Tires

The rapid development of the automotive industry has led to the accumulation of a large number of waste tires that contain a lot of reusable energy. Macromolecular organics in waste tires can be crack small molecule organics via pyrolysis. In this experiment, thermogravimetry (TG) and pyrolizer-gas chromatography/mass spectrometry (PY-GC/MS) were used to study the pyrolysis behavior of waste tires with different particle sizes, and the effect of temperature and particle size on the pyrolysis products of waste tires under low-temperature pyrolysis conditions, respectively. The volatile substances in waste tires decomposed intensively at 300-500�C and were completely pyrolyzed at 500�C. The content of limonene in the pyrolysis product was significant, and the yield of limonene could reach 27.73% when the waste tire particles were 0.180-0.250 mm and the pyrolysis temperature was 380�C. The mechanism of limonene formation from waste tires was discussed. This study indicated that raw material particle sizes and pyrolysis temperature could change the components and content of pyrolysis products.

Surface energy of cellulosic materials: The effect of particle morphology, particle size, and hydroxyl number

TAPPI Journal ◽  
2015 ◽  
Vol 14 (9) ◽  
pp. 565-576 ◽  
Author(s):  
YUCHENG PENG ◽  
DOUGLAS J. GARDNER
Keyword(s):  
Particle Size ◽  
Surface Energy ◽  
Particle Morphology ◽  
Nanofibrillated Cellulose ◽  
Particle Sizes ◽  
Hydroxyl Number ◽  
Small Individual ◽  
Dispersion Component ◽  
Commercial Applications ◽  
Lower Temperature

Understanding the surface properties of cellulose materials is important for proper commercial applications. The effect of particle size, particle morphology, and hydroxyl number on the surface energy of three microcrystalline cellulose (MCC) preparations and one nanofibrillated cellulose (NFC) preparation were investigated using inverse gas chromatography at column temperatures ranging from 30ºC to 60ºC. The mean particle sizes for the three MCC samples and the NFC sample were 120.1, 62.3, 13.9, and 9.3 μm. The corresponding dispersion components of surface energy at 30°C were 55.7 ± 0.1, 59.7 ± 1.3, 71.7 ± 1.0, and 57.4 ± 0.3 mJ/m2. MCC samples are agglomerates of small individual cellulose particles. The different particle sizes and morphologies of the three MCC samples resulted in various hydroxyl numbers, which in turn affected their dispersion component of surface energy. Cellulose samples exhibiting a higher hydroxyl number have a higher dispersion component of surface energy. The dispersion component of surface energy of all the cellulose samples decreased linearly with increasing temperature. MCC samples with larger agglomerates had a lower temperature coefficient of dispersion component of surface energy.

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