EFFECTS OF CHANGES IN ATTRIBUTES OF RETICULAR CONTRACTION ON FECAL PARTICLE SIZES IN CATTLE

1990 ◽  
Vol 70 (1) ◽  
pp. 159-166 ◽  
Author(s):  
E. K. OKINE ◽  
G. W. MATHISON ◽  
R. T. HARDIN
Keyword(s):  
Particle Size ◽  
High Weight ◽  
Geometric Mean ◽  
Latin Square ◽  
Design Experiment ◽  
Particle Sizes ◽  
Low Weight ◽  
Large Particles ◽  
Mean Size ◽  
Period Duration

A 3 × 3 Latin square design experiment was conducted with three ruminally-cannulated Hereford steers (605 ± SD 98 kg) to determine the effects of changes in reticular contraction characteristics on the distribution of fecal particle size of cattle fed at maintenance. Addition of 0 (control; C) 9 (low weight; LW) or 18 (high weight; HW) kg weight to ventral sac of the rumen of steers linearly increased (P = 0.03) the geometric mean size of fecal particles. During the 1.5-h feeding period, duration and amplitude of reticular contractions linearly increased (P = 0.04) and decreased (P = 0.08), respectively, with the addition of weights. Frequency of reticular contractions increased linearly (P = 0.05) and quadratically (P = 0.07), reaching a maximum of 1.7 min−1 in LW steers, 1.6 min−1 and 1.4 min−1 in HW and C steers, respectively. Duration of reticular contractions, but not amplitude or frequency, was linearly related to the proportion of large particles and to the geometric mean size of fecal particles (r = 0.90, P = 0.002; and r = 0.61, P = 0.08, respectively). It was concluded that the increase in fecal geometric mean and the change in the distribution of fecal particle sizes with increasing weights in the rumen was associated with increases in the duration of reticular contractions rather than changes in frequency or amplitude. Key words: Steers, reticular contractions, fecal particle size, rumen, weight

scholarly journals THE EFFECT OF CAVITATION TREATMENT ON THE EXTINGUISHING OF PARTICLES OF OILS IN FUEL BOILERS

2019 ◽  
Vol 20 (9-10) ◽  
pp. 52-59
Author(s):  
M. A. Taymarov ◽  
R. V. Akhmetova ◽  
S. M. Margulis ◽  
L. I. Kasimova
Keyword(s):  
Particle Size ◽  
Combustion Zone ◽  
Consumption Rate ◽  
Fuel Oil ◽  
Particle Sizes ◽  
Oil Consumption ◽  
Boiler Efficiency ◽  
Large Particles ◽  
Oil Particles

The difficulties of burning the watered fuel oil used at the TPP as a reserve fuel for boilers are associated with its preparation by heating to reduce viscosity and the choice of a method of spraying with nozzles into the combustion zone. The quality of the preparation of fuel oil for combustion affecting the boiler efficiency is estimated by the length of the flame, the presence of burning large particles of fuel oil, the injection of coke and unburned particles onto screen and other heat-receiving surfaces. One of the ways to prepare fuel oil for combustion is cavitation treatment, which results in an emulsion consisting of fine micronsized particles. Heating of fuel oil particles after the nozzle in contact with the combustion zone is due to the flow of radiation from the burning torch. Therefore, in this article, the values of the flux density from the torch during the combustion of fuel oil are experimentally determined. The influence of particle size on the burning rate of the fuel oil M100 with the different density of the thermal radiation of the flame. It is found that the effect of cavitation treatment of fuel oil on the combustion rate is most significantly manifested in particle sizes less than 10 microns. For this purpose, the use of hydrodynamic cavitators are preferred at high fuel oil consumption rate.

scholarly journals Streaming instability of multiple particle species in protoplanetary disks

2018 ◽  
Vol 618 ◽  
pp. A75 ◽  
Author(s):  
Noemi Schaffer ◽  
Chao-Chin Yang ◽  
Anders Johansen
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
Protoplanetary Disks ◽  
Single Species ◽  
Stokes Number ◽  
Dust Particles ◽  
Particle Sizes ◽  
Particle Species ◽  
Streaming Instability ◽  
Large Particles

The radial drift and diffusion of dust particles in protoplanetary disks affect both the opacity and temperature of such disks, as well as the location and timing of planetesimal formation. In this paper, we present results of numerical simulations of particle-gas dynamics in protoplanetary disks that include dust grains with various size distributions. We have considered three scenarios in terms of particle size ranges, one where the Stokes number τs = 10−1−100, one where τs = 10−4−10−1, and finally one where τs = 10−3−100. Moreover, we considered both discrete and continuous distributions in particle size. In accordance with previous works we find in our multispecies simulations that different particle sizes interact via the gas and as a result their dynamics changes compared to the single-species case. The larger species trigger the streaming instability and create turbulence that drives the diffusion of the solid materials. We measured the radial equilibrium velocity of the system and find that the radial drift velocity of the large particles is reduced in the multispecies simulations and that the small particle species move on average outwards. We also varied the steepness of the size distribution, such that the exponent of the solid number density distribution, dN∕da ∝ a−q, is either q = 3 or q = 4. Overall, we find that the steepness of the size distribution and the discrete versus continuous approach have little impact on the results. The level of diffusion and drift rates are mainly dictated by the range of particle sizes. We measured the scale height of the particles and observe that small grains are stirred up well above the sedimented midplane layer where the large particles reside. Our measured diffusion and drift parameters can be used in coagulation models for planet formation as well as to understand relative mixing of the components of primitive meteorites (matrix, chondrules and CAIs) prior to inclusion in their parent bodies.

Die Gelchromatographie großer Partikel und ihre Grenzen / Limitation of Particles Size in Gel Chromatography

1970 ◽  
Vol 25 (11) ◽  
pp. 1235-1239 ◽  
Author(s):  
Wolfram Gerlich ◽  
Helmut Determann ◽  
Theodor Wieland
Keyword(s):  
Particle Size ◽  
Brownian Motion ◽  
Rat Liver ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Gel Chromatography ◽  
Particle Sizes ◽  
E Coli ◽  
Large Particles ◽  
Cellulose Gel

The behaviour of molecules and particles of 2 - 400 nm radius in gel chromatography was investigated using sephadex, agarose, and pearl shaped cellulose gel of different porosity. Correlations between elution volumes and particle sizes are given in Fig. 1. We found that particles from ca. 400 nm diameter upwards were more or less irreversibly adsorbed depending on the particle size. So only 15% of rat liver mitochondria and 5% of E. coli bacteria could be eluted from the loose cellulose Cu3. It is assumed that this adsorption is due to the absence of Brownian motion of large particles, which therefore are more or less subject to the gravity and to adsorption forces of the gel.

scholarly journals VIS-NIR/SWIR Spectral Properties of H2O Ice Depending on Particle Size and Surface Temperature

Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1328
Author(s):  
Katrin Stephan ◽  
Mauro Ciarniello ◽  
Olivier Poch ◽  
Bernard Schmitt ◽  
David Haack ◽  
...  
Keyword(s):  
Particle Size ◽  
Spectral Signature ◽  
Particle Sizes ◽  
Icy Satellites ◽  
Spectral Parameters ◽  
Spectral Changes ◽  
Large Particles ◽  
Band Depth ◽  
Increasing Temperature ◽  
Particle Shapes

Laboratory measurements were performed to study the spectral signature of H2O ice between 0.4 and 4.2 µm depending on varying temperatures between 70 and 220 K. Spectral parameters of samples with particle sizes up to ~1360 µm, particle size mixtures, and different particle shapes were analyzed. The band depth (BD) of the major H2O-ice absorptions at 1.04, 1.25, 1.5, and 2 µm offers an excellent indicator for varying particle sizes in pure H2O ice. The spectral changes due to temperature rather, but not exclusively, affect the H2O-ice absorptions located at 1.31, 1.57, and 1.65 µm and the Fresnel reflection peaks at 3.1 and 3.2 µm, which strongly weaken with increasing temperature. As the BDs of the H2O-ice absorptions at 1.31, 1.57, and 1.65 µm increase, the band centers (BCs) of the H2O-ice absorptions at 1.25 and 1.5 µm slightly shift to shorter wavelengths. However, the BCs of the strong H2O-ice absorptions can also be affected by saturation in the case of large particles. The collected spectra provide a useful spectral library for future investigations of icy satellites such as Ganymede and Callisto, the major targets of ESA’s JUICE mission.

scholarly journals Effect of carbohydrates in grass silage-based diets on in sacco ruminal degradability of barley (Hordeum vulgare L. cv. Lomerit) grain ground to different particle sizes

2009 ◽  
Vol 54 (No. 6) ◽  
pp. 260-269
Author(s):  
B. Niwińska
Keyword(s):  
Particle Size ◽  
Hordeum Vulgare ◽  
Latin Square ◽  
Barley Grain ◽  
Particle Sizes ◽  
Rumen Degradation ◽  
Grass Silage ◽  
Degradation Rates ◽  
Size Interaction ◽  
In Sacco

The effect of carbohydrates included in grass silage-based diets on <I>in sacco</I> degradability of dry matter (DM), crude protein (CP), neutral detergent fibre (NDF) and cellulose (CE) of barley (<I>Hordeum vulgare</I> L. cv. Lomerit) grain ground to different particle sizes was studied using 3 ruminally cannulated cows. The measurements were carried out as a 3 × 2 Latin square design with treatments being carbohydrates in the concentrate portion of diets (starch in diet I vs. pectin in diet II vs. sucrose in diet III) and particle size of ground barley grain (1.0 vs. 5.7 mm). The diet synchronization index between N and energy supply during the day was an average of 0.8. The rumen degradability of barley grain compounds was influenced by the type of carbohydrates included in grass silage-based diets. Higher rumen degradation rates (<I>P</I> < 0.05) of barley CP, NDF and CE after 8 h of incubation and of CP and CE after 16 h of incubation were found in the rumen of cows receiving the diet containing sucrose compared with degradation rates found in the rumen of cows receiving the diet containing pectin or starch. The effective degradability of DM, CP, NDF and CE of barley grain in the rumen of cows receiving diets I, II and III was similar (77, 74, 39 and 41%, respectively). Replacing barley starch or beet pulp pectin with molasses sucrose in the grass silage-based diet resulted in the higher rate of barley CP, NDF and CE degradation after 8 h of incubation and of CP and CE after 16 h of incubation. It seems that the energy availability from carbohydrates affected the ruminal microbial activity as a consequence of the degradation rate of substrates. Higher (<I>P</I> < 0.01) rumen degradability of CP, NDF and CE after 2, 4, 8, 16 and 24 h of incubation was estimated for 1.0 mm particle size in comparison with that found for grain ground to 5.7 mm particle size, and the degradability of CP after 48 h of incubation was not different (<I>P</I> > 0.05). The degradability of barley grain CP, NDF and CE during incubation time was not influenced by the diet composition by particle size interaction (<I>P</I> > 0.05). The increase in barley grain particle size from 1.0 to 5.7 mm slowed down the rumen digestion of barley DM, CP, NDF and CE, probably due to restricted access to microbial digestion.

scholarly journals Different Ground Corn Particle Size in Supplements for Young Bulls Grazing During Intensive System Production

2021 ◽  
Author(s):  
Lucien Bissi da Freiria ◽  
Joanis Tilemahos Zervoudakis ◽  
Nelcino Francisco de Paula ◽  
Mozart Alves Fonseca ◽  
Luciana Keiko Hatamoto-Zervoudakis ◽  
...  
Keyword(s):  
Particle Size ◽  
Growth Performance ◽  
Geometric Mean ◽  
Neutral Detergent Fiber ◽  
Particle Sizes ◽  
Starch Digestion ◽  
Whole Grain ◽  
Randomized Design ◽  
Ground Corn ◽  
Corn Particle Size

Abstract We hypothesized that a decrease in flint corn particle size in the supplements of young bulls during grazing promotes better use of starch in the total gastrointestinal tract, with less starch lost in the feces, thus increasing growth performance. This experiment aimed to evaluate the effects of supplements with different ground corn particle sizes on the growth performance, economic analysis, intake and apparent digestibility of nutrients for beef cattle in Urochloa brizantha cv. Marandu pastures during the rainy-dry transition season. Sixty-four Nelore bulls, with an average age of 16 months and 303.6 ± 18.0 kg of body weight (BW), were distributed in a completely randomized design. The treatments were WG = whole grain (geometric mean particle size, dgw, 6.262 µm); CG = coarse ground grain (dgw, 2.882 µm); MG = medium ground grain (dgw, 1.011 µm); and FG = fine ground grain (dgw, 0.621 µm). The supplements with ground grain or whole grain were similar (P > 0.05) in terms of intake and the digestibility of dry matter (DM), forage, organic matter (OM), crude protein (CP), neutral detergent fiber corrected for ash and protein (NDFap), and total digestible nutrients (TDN). However, the starch digestion in the total tract was higher (P < 0.05) with ground grain than with whole grain. The different geometric mean particle sizes of the grain in the supplements were not sufficient to alter (P > 0.05) the starch digestion in the total tract. The starch fecal concentration decreased with ground grain compared with that for whole grain (P < 0.05). However, no differences in growth performance were observed among the treatments (P > 0.05). Supplementation with CG promoted a slightly greater net revenue (+ 11.51%) and return per ha (+ 12.8%) compared with WG, while MG and FG yielded worse economic results. Therefore, CG showed higher economic performance and efficiency utilization of starch, suggesting it is a better strategy for providing supplements to young grazing bulls.

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.

Batch Precipitation of Lead Iodide

1994 ◽  
Vol 59 (6) ◽  
pp. 1301-1304
Author(s):  
Jaroslav Nývlt ◽  
Stanislav Žáček
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Crystal Size ◽  
Lead Nitrate ◽  
Lead Iodide ◽  
Constant Rate ◽  
Mean Size ◽  
The Mean

Lead iodide was precipitated by a procedure in which an aqueous solution of potassium iodide at a concentration of 0.03, 0.10 or 0.20 mol l-1 was stirred while an aqueous solution of lead nitrate at one-half concentration was added at a constant rate. The mean size of the PbI2 crystals was determined by evaluating the particle size distribution, which was measured sedimentometrically. The dependence of the mean crystal size on the duration of the experiment exhibited a minimum for any of the concentrations applied. The reason for this is discussed.

scholarly journals Effect of particle size on phytochemical composition and antioxidant properties of Sargassum cristaefolium ethanol extract

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
E. S. Prasedya ◽  
A. Frediansyah ◽  
N. W. R. Martyasari ◽  
B. K. Ilhami ◽  
A. S. Abidin ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Particle Size ◽  
Antioxidant Activities ◽  
Antioxidant Properties ◽  
Ethanol Extract ◽  
Total Phenolic ◽  
Particle Sizes ◽  
Epicatechin Gallate ◽  
Particle Size Reduction ◽  
Phytochemical Composition

AbstractSample particle size is an important parameter in the solid–liquid extraction system of natural products for obtaining their bioactive compounds. This study evaluates the effect of sample particle size on the phytochemical composition and antioxidant activity of brown macroalgae Sargassum cristaefolium. The crude ethanol extract was extracted from dried powders of S.cristeafolium with various particle sizes (> 4000 µm, > 250 µm, > 125 µm, > 45 µm, and < 45 µm). The ethanolic extracts of S.cristaefolium were analysed for Total Phenolic Content (TPC), Total Flavonoid Content (TFC), phenolic compound concentration and antioxidant activities. The extract yield and phytochemical composition were more abundant in smaller particle sizes. Furthermore, the TPC (14.19 ± 2.08 mg GAE/g extract to 43.27 ± 2.56 mg GAE/g extract) and TFC (9.6 ± 1.8 mg QE/g extract to 70.27 ± 3.59 mg QE/g extract) values also significantly increased as particle sizes decreased. In addition, phenolic compounds epicatechin (EC), epicatechin gallate (ECG), epigallocatechin (EGC), and Epigallocatechin gallate (EGCG) concentration were frequently increased in samples of smaller particle sizes based on two-way ANOVA and Tukey’s multiple comparison analysis. These results correlate with the significantly stronger antioxidant activity in samples with smaller particle sizes. The smallest particle size (< 45 µm) demonstrated the strongest antioxidant activity based on DPPH, ABTS, hydroxyl assay and FRAP. In addition, ramp function graph evaluates the desired particle size for maximum phytochemical composition and antioxidant activity is 44 µm. In conclusion, current results show the importance of particle size reduction of macroalgae samples to increase the effectivity of its biological activity.

In vivo apparent digestibility in ponies given rolled, micronised or extruded barley

1999 ◽  
Vol 1999 ◽  
pp. 133-133 ◽  
Author(s):  
B M L McLean ◽  
J J Hyslop ◽  
A C Longland ◽  
D Cuddeford ◽  
T Hollands
Keyword(s):  
Dry Matter ◽  
Latin Square ◽  
Design Experiment ◽  
Apparent Digestibility ◽  
Processing Methods ◽  
Physical Processing ◽  
Adaptation Phase

Processed cereals are used routinely in diets for equines but little information is available on how physical processing affects the digestibility of cereals in equines. This study examines the effects of three physical processing methods (rolling, micronisation and extrusion) on the in vivo apparent digestibility of barley fed to ponies.Three mature caecally-fistulated Welsh-cross pony geldings, (LW 284kg ± 3.8kg) were used in a 3 x 4 incomplete latin square changeover design experiment consisting of four 21 day periods. Each period comprised a sixteen day adaptation phase and a five day recording phase when apparent digestibility in vivo was determined. Ponies were offered 4kg dry matter (DM) per day of either 100% hay cubes (HC) or one of three diets consisting of a 50:50 barley:hay cubes mix. The barley in the mixed diets was either rolled barley (RB), micronised barley (MB) or extruded barley (EB). Diets were offered in 2 equal meals per day fed at 09:00 and 17:00 hours respectively.

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