Pneumatic Transport Research Articles

EDTA stabilizes the concentration of platelet-derived extracellular vesicles during blood collection and handling

Citrate is the recommended anticoagulant for studies on plasma extracellular vesicles (EVs). Because citrate incompletely blocks platelet activation and the release of platelet-derived EVs, we compared EDTA and citrate in that regard. Blood from healthy individuals (n = 7) was collected and incubated with thrombin receptor-activating peptide-6 (TRAP-6) to activate platelets, subjected to pneumatic tube transportation (n = 6), a freeze-thaw cycle (n = 10), and stored before plasma preparation (n = 6). Concentrations of EVs from platelets (CD61+), activated platelets (P-selectin+), erythrocytes (CD235a+), and leukocytes (CD45+) were measured by flow cytometry. Concentrations of EVs from platelets and activated platelets increased 1.4-fold and 1.9-fold in EDTA blood upon platelet activation, and 4.2-fold and 9.6-fold in citrate blood. Platelet EV concentrations were unaffected by pneumatic tube transport in EDTA blood but increased in citrate blood, and EV concentrations of erythrocytes and leukocytes were comparable. The stability of EVs during a freeze-thaw cycle was comparable for both anticoagulants. Finally, the concentration of platelet EVs was stable during storage of EDTA blood for six hours, whereas this concentration increased 1.5-fold for citrate blood. Thus, EDTA improves the robustness of studies on plasma EVs.

Impact of centrifugation time and pneumatic tube transport on plasma concentrations of direct oral anticoagulants

Rapid results are needed when plasma concentrations of direct oral anticoagulants (DOACs) are required in acute clinical settings. We evaluated the impact of centrifugation time and pneumatic tube transport on DOAC plasma concentrations with the overall aim of reducing turnaround time. Blood samples were spiked with rivaroxaban, apixaban or dabigatran in a low and a high concentration prior to centrifugation for 25minutes (3163g) or 5minutes (3000g) (n=20 for each DOAC). Both samples spiked with DOACs (n=20 for each DOAC) and patient samples (n=25 in total) were transported manually or by pneumatic tube system samples. For samples spiked with DOAC, statistically significant differences in DOAC plasma concentrations were found between centrifugation times for rivaroxaban in low (P<.05) and high (P<.05) concentrations. Relative bias was below 9% for all DOACs. Statistically significant differences were found between modes of transportation for rivaroxaban (P<.01) and dabigatran (P<.01) in high concentrations. Relative bias was 4%-23% for all DOACs. For patient samples, no statistically significant differences were found between modes of transportation, and relative bias was below 12% for all DOACs. Minor, clinically insignificant, differences regarding centrifugation times were found in DOAC plasma concentrations. Importantly, no significant differences were found according to transportation modes for samples collected from patients. Although statistically significant differences were found depending on mode of transportation of spiked samples, relative bias was clinically acceptable. Thus, reduced centrifugation time and pneumatic tube transport should be considered to reduce turnaround time for rapid measurement of DOAC plasma concentrations.

Design and Optimization of Centralized Pneumatic Fertilizer Transporting System for Deep Fertilization Device in Paddy Field

To improve the airflow distribution consistency of each branch in the pneumatic fertilizer transportation system, so as to reduce the influence of airflow instability on the uniformity and stability of fertilizer transportation, as well as the energy waste in the process of pneumatic fertilizer transportation, a centralized pneumatic fertilizer transportation system for deep fertilization device was designed. Through theoretical calculation, the needed air flow rate, airflow speed and fertilizer pipe diameter of the system were obtained, and the fan was selected. Based on the Fluent simulation and bench tests, the influence of three air distribution method of placing fan at the end of main duct, placing fan in the middle of main duct and centralized air distribution on the airflow velocity and consistency of each branch was analyzed. The results showed that the airflow consistency of each branch in the centralized air distribution method was the best. Taking the air velocity at the outlet of each branch and its variation coefficient as the evaluation index, single factor and orthogonal simulation tests was carried out to optimize the structural parameters of centralized air distribution device. The simulation results showed that the primary and secondary factors affecting the air distribution consistency were: A (sidewall inclination angle), B (branch diameter), C (branch distance), A×B (interaction between A and B), B×C (interaction between B and C), A×C (interaction between A and C), and all the factors and their interactions had significant effects. The best parameter combination was sidewall inclination angle 15°, branch diameter 32 ㎜, branch distance 43 ㎜. With the combination, the variation coefficient of airflow velocity was 0.27% in simulation test and 1.23% in bench test. This research optimized the structure and parameters of pneumatic fertilizer transporting system, and provided references for the design and optimization of pneumatic fertilization and seeding device.

Melt Electrospinning of PET and Composite PET-Aerogel Fibers: An Experimental and Modeling Study.

Increasingly advanced applications of polymer fibers are driving the demand for new, high-performance fiber types. One way to produce polymer fibers is by electrospinning from polymer solutions and melts. Polymer melt electrospinning produces fibers with small diameters through solvent-free processing and has applications within different fields, ranging from textile and construction, to the biotech and pharmaceutical industries. Modeling of the electrospinning process has been mainly limited to simulations of geometry-dependent electric field distributions. The associated large change in viscosity upon fiber formation and elongation is a key issue governing the electrospinning process, apart from other environmental factors. This paper investigates the melt electrospinning of aerogel-containing fibers and proposes a logistic viscosity model approach with parametric ramping in a finite element method (FEM) simulation. The formation of melt electrospun fibers is studied with regard to the spinning temperature and the distance to the collector. The formation of PET-Aerogel composite fibers by pneumatic transport is demonstrated, and the critical parameter is found to be the temperature of the gas phase. The experimental results form the basis for the electrospinning model, which is shown to reproduce the trend for the fiber diameter, both for polymer as well as polymer-aerogel composites.

The effects of transport by pneumatic tube system on urine analysis

The pneumatic tube transport system (PTS) is used frequently for the transport of samples in hospitals. Effects of PTS on urine components are unknown. In our study, we aim to examine the influence of PTS on the quality of routine urine microscopic parameters. Urine samples were divided into two groups: group 1 were transported to the laboratory manually and group 2 were transported to the laboratory via the PTS. Each of 187 urine samples was studied with iQ200 automated urine devices for erythrocytes, leukocytes, epithelial cells, crystal, cast and yeast cells. No statistically significant differences were detected between group 1 and group 2 for urine parameters. For erythrocytes, leukocytes, and epithelial cells, the gamma was 0.982, 0.959, and 1.0, respectively. For crystal, cast and yeast cells, the kappa values were 0.952, 0.866, and 1.0, respectively. PTS has no effect on erythrocytes, leukocytes, epithelial cells, crystal, cast, and yeast cells in urine analysis. We concluded that PTS can be used in the transport of urine samples.

A numerical study of the expansion of a gas-particles mixture with axial symmetry

The article deals with the study of new phenomena that accompany the free or wall-bounded expansion of a nonequilibrium in terms of velocities and temperatures mixture of gas and particles of various sizes with axial symmetry. The dynamics of the gas suspension is considered in the multifluid model of a calorically perfect inviscid gas and incompressible monodisperse spherical particles. The Eulerian approach is used to describe the motion of each phase of the mixture. For numerical simulation, a hybrid large-particle method of the second order of approximation in space and time with nonlinear correction of artificial viscosity, an additive combination of fluxes, and a semi-implicit scheme for calculating interfacial friction and heat transfer are implemented. The efficiency and accuracy of the method for a two-dimensional problem with axial symmetry are confirmed by comparing the solutions obtained in a one-dimensional formulation in a cylindrical coordinate system. In the case of small particles (with a diameter of d = 0.1 µm), the relaxation time of the phases is much less than the characteristic time of the problem and the gas and particles mixture behaves as a homogeneous medium similar to the gas flow. For sufficiently large particles (d = 20 µm), the effects of the difference in the inertia of the phases and nonequilibrium, associated with the mismatch of the velocities and temperatures of the gas and particles, are manifested. These effects cause the splitting of the initial interface of the media into a contact discontinuity in the gaseous phase and the surface between the suspension and the pure gas (a jump in porosity). At subsequent moments, the flow pattern changes to the opposite, which is explained by the deceleration of the gas, the appearance of a reverse flow to the center of expansion due to rarefaction in the vicinity of the axis of symmetry, and the formation of a secondary shock wave. Then there are fluctuations with a change in the relative position of the phase boundaries. In this case, fractures of the gas contact trajectories (the break of the first derivative) are observed, which are associated with the passage of the shock wave reflected from the wall and the plane of symmetry. Over time, due to baroclinic instability (the mismatch of density and pressure gradients), vortex structures begin to appear at the interface boundaries. In addition, in the case of expansion of the gas suspension in a closed volume, a complex shock-wave structure is formed, due to multiple reflections of shock waves from the walls and their interaction with the contact surfaces. The practical significance of the results obtained is to identify the fundamental physical effects that should be taken into account when setting and solving problems in chemical technologies, pneumatic transport, and other areas. In addition, the numerical solutions can be useful in testing the resolution of other difference schemes for reproducing the vortex instability of contact boundaries and shock wave structures in the flows of relaxing gas suspensions.

The effect of drone transport on the stability of biochemical, coagulation and hematological parameters in healthy individuals.

Transport of blood tubes is mainly by car or pneumatic transport. The transportation of blood tubes by drones is a novel approach for rapid transportation of blood tubes over long distances. However, limited data on the stability of biochemical, coagulation and hematological parameters is available after transport of blood tubes by drone. To investigate the effect of drone transport on the stability of blood parameters, four test flights were performed. Blood was drawn from 20 healthy individuals and 39 of the most frequently measured blood parameters were compared between 4 groups; immediate measurement (control), late measurement, transport by car and transport by drone. Total allowable error (TAE) of the EFLM Biological Variation Database was used to determine the clinical relevance of significant differences. The majority of blood parameters were not affected by drone transport. Eight of the measured parameters showed significant differences between all the groups; glucose, phosphate, potassium, chloride, hemoglobin, platelet count, activated partial thromboplastin time (APTT) and lactate dehydrogenase (LD). A clinically relevant increase for LD after transport and a decrease for glucose values in time and after transport compared with the control group was shown. Transportation of blood tubes from healthy individuals by drones has a limited clinically relevant effect. From the 39 investigated blood parameters only LD and glucose showed a clinically relevant effect.

Pneumatic transport of bulk materials in construction of composite floating docks

Investigations of pneumatic transport of bulk materials used in shipbuilding have carried out. Their abrasiveness, wear of straight and curved sections of pipelines were investigated. Theoretically, the dependences of the amount of wear on various factors were defined: abrasiveness and concentration of transported particles, flow rate, pipe diameter and wear resistance of its material, structural and operational features of the transport system, etc. Formulas for determining the maximum useful life of straight and curved sections of pipelines are obtained. Theoretical results confirmed experimentally.

Rock and roll: Incipient aeolian entrainment of coarse particles

Aeolian transport of coarse grains is an important topic, finding applications in nature (for infrastructure exposed to wind scour) as well as industry (e.g., considering pneumatic transport). Incipient particle entrainment due to turbulent winds refers to the wind conditions where aeolian transport initiates, and as such, it is at the core of such studies. The research presented herein focuses on identifying and quantifying the dynamical processes responsible for coarse particle entrainment. Specifically designed wind tunnel experiments are conducted for a range of wind conditions near the aeolian transport thresholds. A high-resolution laser distance sensor is employed to provide information for the displacement of an exposed particle ranging from small simple rocking motions to complete entrainments (rolling). Measurements of the exposed particle's angular displacements are acquired, which allow the probabilistic study of incipient motion. The variation of statistical parameters, such as the frequency of entrainments, duration of dislodgements, magnitude of displacements, and time between displacements, is studied for a range of increasing airflow rates. The main findings from these experiments suggest that rocking can be observed only up to a limit angular displacement (equal to 0.41π for the conditions tested herein), which defines the position beyond which the resistance force can be overcome by just the mean aerodynamic forcing. Following this experimental framework to establish aeolian thresholds for a wider range of environments may be useful for the identification of the wind conditions under which aeolian transport may start occurring.

INCREASE THE EFFICIENCY OF GRAIN COOLING AFTER DRYING AND HEAT TREATMENT

One of the main requirements for grain dryers is the need for high-quality cooling of grain material after drying. Today, the most widespread are grain coolers built into grain dryers. As the practice of operation has shown, the most widespread in agriculture mine grain dryers with their cooling zones are ineffective: the temperature of the grain after cooling often exceeds the ambient air temperature by 15-30 0C, which is unacceptable. Devices with boxes have such disadvantages as uneven distribution air in the volume of grain mass and the corresponding uneven temperature field of the cooling air, limited opportunities for intensifying heat transfer during grain cooling. More promising for agricultural grain dryers are external coolers, which are installed separately from the dryer and can operate in an independent mode, which has a number of advantages: the quality of cooling improves, the productivity of existing grain dryers increases due to the use of the cooling part as a dryer. The main disadvantages of using the existing external column coolers: the need for an additional vehicle - a bucket elevator for reloading grain from the dryer to the column; vertical arrangement, it is necessary to use transporting means for grain for feeding to a considerable height. But if a pneumatic transport loader with a pulsating air flow is used as a vehicle, then the efficiency of the coolers can be increased due to the removal of a part of the heat accumulated by the grain by the transporting air flow. The paper proposes an analytical rationale for increasing the efficiency of coolers with pneumatic transport in a pulsating air flow.

Numerical simulation of pneumatic conveying characteristics of micron particles in horizontal pipe

In this paper, a mathematical model for the pneumatic transport of micron silica particles in the dust removal pipeline is established, and the gas-solid two-phase flow in the pipeline is numerically simulated. This paper is mainly based on the FLUENT fluid simulation module in ANSYS WORKBENCH to simulate the motion behavior of particles in the pipeline, and obtained the penetration rate (particle deposition rate in pneumatic conveying) of silica particles in the horizontal straight pipe under different gas flow rates. In the numerical simulation, the influence of particle diameter, shape, lift and other factors on silica particles was considered. Under a large number of simulation conditions, the movement laws of micron silica particles in horizontal pipe pneumatic transport were obtained, and the influence of the above factors on the movement laws of the particles were determined.

Experimental study on electrostatic discharges from a metal protrusion inside a silo during continuous loading of polypropylene powder

In this study, the electrostatic discharges from a metal protrusion existing inside a conical-cylindrical silo during continuous loading of polypropylene powders (PP, 3 to 4 mm) were experimentally investigated. A pilot-scale silo connected to a pneumatic powder transport facility was used while all parts were electrically grounded. The metal protrusion used in this study had a diameter of 4 cm. The silo was continuously loaded with PP powders at a mass flow rate of 0.68 kg/s to a total mass of approximately 800 kg. An image intensifier unit was used to observe the electrostatic discharges generated from the metal protrusion, and a current probe attached to an oscilloscope was used to measure the discharge amount (Q [nC]). As for the results, a multiplicity of small electrostatic discharges (brush discharges) from the protrusion was observed. The electrostatic discharge from the protrusion during PP powder loading clearly developed at the 391 s mark, when approximately 270 kg of the powder had been loaded. In addition, a difference was observed in the electrostatic discharges before and after the protrusion was embedded in the accumulated powder. That is to say, after the metal protrusion was embedded in the accumulated powder, the electrostatic discharges were stronger than when the protrusion was not embedded. As well, the Q after the immersion of the metal protrusion in the accumulated powder was several times larger than that when the protrusion was out. Strong broad bulk surface discharges clearly appeared after the protrusion was fully immersed in the powder.

Innovation comprehensive solutions for off-gases cleaning in steel industry. Technical solutions for dusty gas flows cleaning

Metallurgical production associates with such processes as crushing, drying and pneumatic transportation of raw materials, roasting, melting etc., in the process of which hard particles and harmful gaseous components are emitted into atmosphere. At pneumatic transportation of raw materials and sand, their concentration in the atmosphere as a rule exceeds maximum permissible concentrations. Existing facilities of dusty flows cleaning in some cases don’t ensure sanitary norms ГН 2.1.6.3492‒17. Technical solutions proposed to clean gases in a centrifugal filter, a facility of complex gas cleaning – cyclo-filter and two-stage system of high-concentrated gas-dust flows cleaning. Description of the centrifugal filter, cyclo-filter, two-stage facility of gas cleaning design presented. The facility comprises centrifugal filter and ceramic pulse filter. Industrial tests of the centrifugal filter ЦФ2-6-1 under conditions of a system of pneumatic transportation of sand established, that efficiency of gas-dust flows cleaning of sand particles in a six-channel filter can reach 98.65%. Application of two-stage system of gas cleaning comprising centrifugal filter and ceramic pulse filter ФКИ enables to reach residual hard particles concentration at the exit of such a facility of 5 mg/m3, having initial dust level of 127878 mg/m3. Application of such a complex two-stage cleaning facility allows to reach values of 0.1 of maximum permissible concentrations near the source of emissions.

Vacuum Pneumatic Transport for Industrial and Utility Components

Waste generation in the life of people and enterprises is an inevitable process today. The level of utilization of municipal waste has increased on average to 23 % in Belarus. The paper provides an assessment of the existing systems for the collection and disposal of waste solid household items based on technological stages (preparation of waste for loading into a garbage collection vehicle; organization of temporary storage of waste in households, at enterprises; collection and removal of waste from the territories of households, organizations and enterprises; neutralization, processing and recycling of waste). The consequences of untimely collection of solid household and industrial waste are considered in the paper. The paper presents the factors that have a harmful effect on the human environment and the ecology of the territories of settlements and enterprises. An analysis of the effectiveness of the timely removal of such components in the systems of municipal services of cities and enterprises as an important component providing social, economic and environmental significance is given in the paper. At the present stage of the development of technology and available technologies, one of the most rational and economically justified ways of delivering waste to the areas for their sorting and processing is vacuum transportation using pipeline transport. Its application is justified for industrial zones and settlements with high and medium population density. Moreover, such a pipeline can be laid next to existing pipeline and other transport communications.

Laser excitation of BCl3 and consequential collision-induced reaction with carrier gases

A method is developed to demonstrate the laser excitation and consequential collision-induced reaction with carrier gases (G = He, N2, Ar, Xe) in isotope separation of BCl3. To investigate the mechanism of the transport process of excited molecules and the collision process with the carrier gases, the Lennard-Jones potential parameters of the molecule and the carrier gases, as well as the collision cross section σc and the repulsion distance parameter LR, are demonstrated. The transport equation (proposed by Eerkens in 2005) is used to study the transport mechanics of stimulated BCl3 molecules, including VT energy conversion and VV energy transfer caused by the collision of BCl3 molecules with the carrier gases during the supersonic pneumatic transportation, as de-excitation induced by transfer, dimer formation and dissociation, and so on.

Sustainable Pneumatic Transport Systems of Cereals

Technological pneumatic transport installations are designed to move materials from one place to another in various phases of the production process. For example: loadingunloading materials (cereals) using rail and marine transport, air tunnel container transport, supplying combustion installations with burning coal dust. The main parameter in pneumatic transport installations is the velocity of air. For the regime of motion with material particles in suspension, for a given flow material, the higher the velocity is the greater the pressure loss will be and thus the energy consumption for transportation will increase. In horizontal pipes at the beginning of motion flow we have a compact regime, and then due to decrease air velocity a continuous layer regime is forming. This is the apparent motion in wich the pressure losses increase with the decrease of velocity. By reducing the air velocity the thickness of the deposited material increases and the real air passage section decreases and therefore the real air velocity increases, which explains the increase in pressure loss. In vertical pipes if the air velocity decreases below the lower limit of volant transport, after a critical area of instability, a transportation fluidized bed is established, the pressure losses being much larger than the particles in suspension mode. If the velocity further decreases the particles can not be entrained in the air.

Elutriation characteristics of multi-component mixtures in a fluidized bed pyrolysis process

Multi-component mixtures were prepared to simulate a bed of walnut shells undergoing pyrolysis in acold fluidized bed. Four mixtures with different ratios of walnut shell, semi-chars, and clean char were used. Batch elutriation experiments using these mixtures were performed in a transparent fluidized bed to allow direct observation of the flow patterns and particle composition. The results indicated that the bubble wake rather than bubble nose was primarily responsible for particle entrainment at higher gas velocities, and that coarser particles would be “transformed” into elutriable particles. Dimensionless gas velocities ranged from 0.2 to 1.0 and an exponential decrease in particle concentration with respect to bed height was observed. The transport disengagement height (TDH) gradually increased with the gas velocity until the entire bed layer enters a pneumatic transport state. Notably, larger TDHs were required when the bed contained a larger fraction of light components. Two characteristic parameters were used to evaluate particle elutriation: the elutriation rate constant (K), and the residual volatile content of the elutriated particles (v′). These parameters were used to optimize operating gas velocity for the fluidized bed.

Efficient Adsorbent-Desiccant Based on Aluminium Oxide

The review describes the main methods of obtaining hydroxides and aluminium oxides (AO) of various structures from gibbsite. The promising techniques of obtaining AO adsorbents are discussed, namely the technique of thermal activation in the mode of pneumatic transport with gibbsite by heated air (TCA Gb) and the technique of thermal activation of gibbsite in centrifugal flash reactors (CTA Gb). The main methods of improving the adsorbent properties of AO, such as the optimisation of texture characteristics and phase composition, as well as the influence of the modification of aluminium oxide adsorbents, obtained using CTA and TCA technologies with cations of alkaline metals, are considered. It is shown that the modification allows a controlled variation of the characteristics of donor and acceptor active sites on the surface of adsorbents and, thus, a substantial increase in their adsorption activity, in particular, with respect to water vapour.

Effects of Pneumatic Tube Transport on Blood Gas and Supplemental Analytes.

Pneumatic tube transport of blood gas samples is a common method of delivery within a facility. The effects of pneumatic tube transport on blood gas analysis has been studied. However, other analytes that are often assessed in blood gas analysis (eg, electrolytes, metabolites, and oximetry) are not typically included in these studies. We sought to investigate the impact of pneumatic tube transport on some of these other analytes. The study was conducted at the blood gas laboratory at the University of Utah Hospital. A split sample comparison was performed. Both samples were walked to a pneumatic tube station, where one sample was sent via tube to the blood gas laboratory, while the other sample was walked back to blood gas laboratory. We examined 2 samples from each of the 27 different pneumatic tube stations in this hospital. Results were graphed with upper and lower control limits set to conform to acceptable College of American Pathologists proficiency testing evaluation criteria. Data were compared using the Student t test. Differences between walked and tubed specimens were neither clinically nor statistically significant. Pneumatic tube transport of blood gas specimens is acceptable for blood gas and supplementary analytes, as evidenced by multiple points of evaluation, including statistical analysis, clinical judgment, and concordance with regulatory guidelines.

BULK CONSTRUCTION MATERIALS. MOVING BULK MATERIALS BY PNEUMATIC AND HYDRAULIC TRANSPORT. LECTURE 6

The article consistently sets forth the material of the sixth lecture on the course “Theory of hoisting-and-transport, construction, road vehicles and equipment”, including the following questions. Characterization of bulk materials transported by continuous transport machines, their particle-and-size distribution. The law of the normal distribution of random variables (in this case, particle sizes) is considered. The relationship between the angles of external and internal friction in an array of bulk material is shown. The process of transporting bulk materials in an air stream, as well as a pneumatic transport installation of a technological complex for firing vermiculite, is considered. The forces influencing the particle in the air flow and its speed of rotation are determined. The article gives the solution to the problem of air movement in the installation suction pipe. In addition, the article considers the movement of bulk materials in a stream of water, the scheme of a hydro transport installation, and its calculation.