Online analysis of macrostickies in a sorted office waste recycling plant making tissue

TAPPI Journal ◽  
2014 ◽  
Vol 13 (4) ◽  
pp. 47-55
Author(s):  
MICHELLE RICARD ◽  
GILLES M. DORRIS ◽  
NATALIE PAGÉ ◽  
DENISE FILION
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Distribution Patterns ◽  
Waste Recycling ◽  
The Other ◽  
Particle Sizes ◽  
Flotation Cell ◽  
Wide Range ◽  
Removal Efficiencies ◽  
Office Waste

An online macrocontaminant analyzer, the FPAutoSpeck, was used for 8000 measurements of deinked pulp to determine the number and area of heavy stickies, light macrocontaminants, and dirt. The analyzer detected a wide range of macrocontaminant levels, during which the three types of macrocontaminants varied independently of each other. “Stickies storm” levels were detected and visualized by the analyzer, with heavy stickies levels exceeding 17000/kg in the final pulp. Different particle size distribution patterns were noted for the light macrocontaminants when compared to those obtained for heavy stickies and dirt. Mill surveys of the fine screens and flotation cell showed different removal efficiencies for heavy stickies and light macrocontaminants. Fine screening was slightly more efficient in the removal of heavy stickies than of light macrocontaminants. Fine screens were more efficient at removing heavy stickies with particle sizes larger than 400 μm in diameter. On the other hand, flotation could remove heavy stickies with particle sizes of 200-300 μm. Furthermore, flotation was able to remove most of the light macrocontaminants independent of their particle size.

scholarly journals A mechanistic particle flux model applied to the oceanic phosphorus cycle

2014 ◽  
Vol 11 (19) ◽  
pp. 5381-5398 ◽  
Author(s):  
T. DeVries ◽  
J.-H. Liang ◽  
C. Deutsch
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Particle Flux ◽  
Particle Sizes ◽  
Biogeochemical Models ◽  
Wide Range ◽  
Flux Model ◽  
Surface Particle

Abstract. The sinking and decomposition of particulate organic matter are critical processes in the ocean's biological pump, but are poorly understood and crudely represented in biogeochemical models. Here we present a mechanistic particle remineralization and sinking model (PRiSM) that solves the evolution of the particle size distribution with depth. The model can represent a wide range of particle flux profiles, depending on the surface particle size distribution, the relationships between particle size, mass and sinking velocity, and the rate of particle mass loss during decomposition. The particle flux model is embedded in a data-constrained ocean circulation and biogeochemical model with a simple P cycle. Surface particle size distributions are derived from satellite remote sensing, and the remaining uncertain parameters governing particle dynamics are tuned to achieve an optimal fit to the global distribution of phosphate. The resolution of spatially variable particle sizes has a significant effect on modeled organic matter production rates, increasing production in oligotrophic regions and decreasing production in eutrophic regions compared to a model that assumes spatially uniform particle sizes and sinking speeds. The mechanistic particle model can reproduce global nutrient distributions better than, and sediment trap fluxes as well as, other commonly used empirical formulas. However, these two independent data constraints cannot be simultaneously matched in a closed P budget commonly assumed in ocean models. Through a systematic addition of model processes, we show that the apparent discrepancy between particle flux and nutrient data can be resolved through P burial, but only if that burial is associated with a slowly decaying component of organic matter such as might be achieved through protection by ballast minerals. Moreover, the model solution that best matches both data sets requires a larger rate of P burial (and compensating inputs) than have been previously estimated. Our results imply a marine P inventory with a residence time of a few thousand years, similar to that of the dynamic N cycle.

scholarly journals Spruce Woodmeal for Newsprint Applications: A Handsheet Study

2020 ◽  
pp. 1-14
Author(s):  
Klaus Dölle ◽  
Sandro Zier
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Wood Flour ◽  
Fiber Content ◽  
The Other ◽  
Particle Sizes ◽  
Tensile Index ◽  
First Pass

This study shows that spruce woodmeal can be an alternative cellulosic-based wood additive               for newsprint applications. This study used unbleached wood flour produced from Spruce  sawdust, ground and sieved to a particle size of 20-40 µm, 40-70 µm, 70-120 µm and 200-500        µm. Woodmeal was added at levels of 2%, 4%, 6%, 8% and 10% based on oven dry fiber content. The basis weight of the newsprint handsheet manufactured was 80 g/m². The study revealed the following outcomes: Woodmeal with a particle size distribution of 20-40 µm had the highest density followed by woodmeal with 70–150 µm, 40-70 µm, and 200-500µm. Increasing the woodmeal amount resulted in higher porosity. Woodmeal with a particle size distribution of 20-40 µm gave the lowest porosity and a particle size of 40-70 µm gave the highest porosity. The Tensile index and burst index show decreasing values for the addition of all woodmeals and particle sizes. Woodmeal with strength additive and a particle size of 20 – 40 µm outperforms the other woodmeal types at additions of 2%, 4%, 6% and 8%. For woodmeal with a particle size of 70–150 µm at an addition of 2% and 4% an increased and similar burst index resulted for the handsheets. First pass retention and ash retention increased for all wood flours with a maximum at 92% and 81% respectively for the wood flour with a particle size of 40-70 µm.

SILICA-RICH FILLER FOR THE REINFORCEMENT IN NATURAL RUBBER

2012 ◽  
Vol 85 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Kanoktip Boonkerd ◽  
Saowaroj Chuayjuljit ◽  
Dalip Abdulraman ◽  
Weerakul Jaranrangsup
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Tensile Strength ◽  
Particle Size Distribution ◽  
Natural Rubber ◽  
The Other ◽  
Particle Sizes ◽  
Reinforcing Efficacy ◽  
Cure Time ◽  
Jet Milling

Abstract The aim of the study was to determine the reinforcing efficacy of a silica-rich filler, pottery stone (PS), in natural rubber (NR). The effects of amount and particle size of PS on curing and mechanical properties of the NR compounds were determined. The PS was first divided into four groups. Two of these were raw PS without grinding, which were sieved to particle sizes of less than 106 μm (PS(<106)) and less than 38 μm (PS(<38)). The other two were ground PS, one by current jet milling to obtain PS(JM), and the other by wet ball milling to obtain PS(BM). The particle size distribution of the four different PS prior to ultrasonication was in the ranked order (largest to smallest size), based upon their d(0.5) and d(0.9), of PS(BM), PS(<106), PS(<38), and PS(JM). However, after ultrasonication for 10 min, PS(BM) had the smallest d(0.5) at less than a micron, while the remaining three PS groups showed nearly the same d(0.5) being within the range of 3–5 μm. The presence of PS shortened the cure time, with PS(BM) inducing the greatest decrease in the cure time, while this was somewhat dose independent for at least PS(JM) and PS(<106). For all four PS groups, when present at 20 phr or more, the delta torque of the PS filled NR was higher than that of the unfilled one. However, the addition of PS had no significant effect on the number of crosslinks. With respect to the mechanical properties of the NR filled with PS, it was generally observed that NR filled with PS(BM) at 20–50 phr gave a higher tear and tensile strength, abrasion resistance, and hardness than both the unfilled NR and also the NR filled with the other three PS groups. The optimum PS(BM) loading was at 30 phr.

scholarly journals A mechanistic particle flux model applied to the oceanic phosphorus cycle

2014 ◽  
Vol 11 (3) ◽  
pp. 3653-3699 ◽  
Author(s):  
T. DeVries ◽  
J.-H. Liang ◽  
C. Deutsch
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Particle Flux ◽  
Particle Model ◽  
Particle Sizes ◽  
Phosphorus Cycle ◽  
Biogeochemical Models ◽  
Wide Range

Abstract. The sinking and decomposition of particulate organic matter are critical processes in the ocean's biological pump, but are poorly understood and crudely represented in biogeochemical models. Here we present a mechanistic model for particle fluxes in the ocean that solves the evolution of the particle size distribution with depth. The model can represent a wide range of particle flux profiles, depending on the surface particle size distribution, the relationships between particle size, mass and velocity, and the rate of particle mass loss during decomposition. Spatially variable flux profiles are embedded in a data-constrained ocean circulation model, where the most uncertain parameters governing particle dynamics are tuned to achieve an optimal fit to the global distribution of phosphate. The resolution of spatially variable particle sizes has a significant effect on modeled organic matter production rates, increasing production in oligotrophic regions and decreasing production in eutrophic regions compared to a model that assumes spatially uniform particle sizes and sinking fluxes. The mechanistic particle model can reproduce global nutrient distributions better than, and sediment trap fluxes as well as, other commonly used empirical formulas. However, these independent data constraints cannot be simultaneously matched in a closed P budget commonly assumed in ocean models. Through a systematic addition of model processes, we show that the apparent discrepancy between particle flux and nutrient data can be resolved through P burial, but only if that burial is associated with a slowly decaying component of organic matter as might be achieved through protection by ballast minerals. Moreover, the model solution that best matches both datasets requires a larger rate of P burial (and compensating inputs) than have been previously estimated. Our results imply a marine PO4 inventory with a residence time of a few thousand years, similar to that of the relatively dynamic N cycle.

Effects of Multiple Impacts and Size Distribution of Particles on Erosion Predictions Using CFD

2007 ◽  
Author(s):  
Yongli Zhang ◽  
Brenton S. McLaury ◽  
Siamack A. Shirzai
Keyword(s):  
Experimental Data ◽  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Target Material ◽  
Average Particle ◽  
Multiple Impacts ◽  
Cfd Simulations ◽  
Erosion Damage ◽  
Wide Range

Erosion equations are usually obtained from experiments by impacting solid particles entrained in a gas or liquid on a target material. The erosion equations are utilized in CFD (Computational Fluid Dynamics) models to predict erosion damage caused by solid particle impingements. Many erosion equations are provided in terms of an erosion ratio. By definition, the erosion ratio is the mass loss of target material divided by the mass of impacting particles. The mass of impacting particles is the summation of (particle mass × number of impacts) of each particle. In erosion experiments conducted to determine erosion equations, some particles may impact the target wall many times and some other particles may not impact the target at all. Therefore, the experimental data may not reflect the actual erosion ratio because the mass of the sand that is used to run the experiments is assumed to be the mass of the impacting particles. CFD and particle trajectory simulations are applied in the present work to study effects of multiple impacts on developing erosion ratio equations. The erosion equation as well as the CFD-based erosion modeling procedure is validated against a variety of experimental data. The results show that the effect of multiple impacts is negligible in air cases. In water cases, however, this effect needs to be accounted for especially for small particles. This makes it impractical to develop erosion ratio equations from experimental data obtained for tests with sand in water or dense gases. Many factors affecting erosion damage are accounted for in various erosion equations. In addition to some well-studied parameters such as particle impacting speed and impacting angle, particle size also plays a significant role in the erosion process. An average particle size is usually used in analyzing experimental data or estimating erosion damage cases of practical interest. In petroleum production applications, however, the size of sand particles that are entrained in produced fluids can vary over a fairly broad range. CFD simulations are also performed to study the effect of particle size distribution. In CFD simulations, particle sizes are normally distributed with the mean equaling the average size of interest and the standard deviation varying over a wide range. Based on CFD simulations, an equation is developed and can be applied to account for the effect of the particle size distribution on erosion prediction for gases and liquids.

scholarly journals Theoretical and Experimental Evaluation of Particle size Effect of Iron , Cobalt ,and Nickel Powders Suspended in Al Dura oil on XRF Intensities

2007 ◽  
Vol 4 (3) ◽  
pp. 475-481
Author(s):  
Baghdad Science Journal
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Laser System ◽  
Particle Size Effect ◽  
Particle Sizes ◽  
Iron Cobalt ◽  
X Ray ◽  
Nickel Powders ◽  
Good Agreement ◽  
Cobalt And Nickel

Iron , Cobalt , and Nickel powders with different particle sizes were subjected to sieving and He-Ne laser system to determine the particle size . 1wt% from each powders was blended carefully with 99wt% from Iraqi oil . Microscopic examination were carried for all samples to reveal the particle size distribution . A Siemens type SRS sequential wavelength dispersive(WDS) X-ray spectrometer was used to analyze all samples , and the XRF intensity were determined experimentally and theoretically for all suspended samples , Good agreement between theoretical and experimental results were found .

scholarly journals MINERAL ABUNDANCE AND PARTICLE SIZE DISTRIBUTION DERIVED FROM IN-SITU SPECTRA MEASUREMENTS OF YUTU ROVER OF CHANG’E-3

2017 ◽  
Vol XLII-3/W1 ◽  
pp. 85-89
Author(s):  
H. Lin ◽  
X. Zhang ◽  
Y. Yang ◽  
X. Wu ◽  
D. Guo
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Landing Site ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Particle Sizes ◽  
The Mean ◽  
The Difference ◽  
Yutu Rover

From geologic perspective, understanding the types, abundance, and size distributions of minerals allows us to address what geologic processes have been active on the lunar and planetary surface. The imaging spectrometer which was carried by the Yutu Rover of Chinese Chang’E-3 mission collected the reflectance at four different sites at the height of ~ 1 m, providing a new insight to understand the lunar surface. The mineral composition and Particle Size Distribution (PSD) of these four sites were derived in this study using a Radiative Transfer Model (RTM) and Sparse Unmixing (SU) algorithm. The endmembers used were clinopyroxene, orthopyroxene, olivine, plagioclase and agglutinate collected from the lunar sample spectral dataset in RELAB. The results show that the agglutinate, clinopyroxene and olivine are the dominant minerals around the landing site. In location Node E, the abundance of agglutinate can reach up to 70 %, and the abundances of clinopyroxene and olivine are around 10 %. The mean particle sizes and the deviations of these endmembers were retrieved. PSDs of all these endmembers are close to normal distribution, and differences exist in the mean particle sizes, indicating the difference of space weathering rate of these endmembers.

scholarly journals Particle size effect on XRF measurements of Copper and Zinc particles suspended in hydrocarbon materials

2007 ◽  
Vol 4 (4) ◽  
pp. 653-657
Author(s):  
Baghdad Science Journal
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Effect ◽  
Microscopic Examination ◽  
Laser System ◽  
Particle Size Effect ◽  
Particle Sizes ◽  
Intensity Measurements ◽  
Copper And Zinc ◽  
Zinc Powders

Copper and Zinc powders with different particle sizes were subjected to sieving of range (20-100?m) and He-Ne laser system to determine the particle size . 1wt% from each powders was blended carefully with 99wt% from Iraqi oil . Microscopic examination were carried for all samples to reveal the particle size distribution . XRF intensity measurements were conducted for all suspended samples , and the relation between XRF intensity and the particle size was found .

DEVELOPMENT OF CALCULATION TOOL FOR RESPIRATORY TRACT DEPOSITION DEPENDING ON AEROSOLS PARTICLE DISTRIBUTION

2019 ◽  
Vol 184 (3-4) ◽  
pp. 388-390
Author(s):  
Kazuki Iwaoka ◽  
Masahiro Hosoda ◽  
Shinji Tokonami ◽  
Eliza B Enriquez ◽  
Lorna Jean H Palad ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Respiratory Tract ◽  
Particle Distribution ◽  
Health Impact ◽  
Atmospheric Environment ◽  
Radiological Protection ◽  
Particle Sizes ◽  
Radioactive Nuclides ◽  
Polydisperse Particles

Abstract Inhalation exposures occur by inhaled radioactive nuclides depositing in the various locations in the respiratory tract (International Commission on Radiological Protection Publication 66). Respiratory tract deposition depends on particle size. The sensitivity to ionising radiation is different among respiratory regions. Under actual atmospheric environments, the radionuclides attach to aerosols of various size in the atmosphere, so the particle size of radionuclides changes differently. Therefore, it is important for the estimation of health impact to calculate the respiratory tract deposition under atmospheric environment wherein the various sizes of radioactive nuclides (i.e. polydisperse particles) exists. In this study, a tool which can calculate the respiratory tract deposition on the basis of polydisperse particle size distribution was developed to estimate dose depending on variable aerosol particle sizes.

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