Suction Process Research Articles

Novel approach to outpatient endometrial biopsy to detect endometrial cancer.

e16522 Background: Currently there is no consensus on the best device and technique for obtaining endometrial biopsies to rule out cancer. Outpatient methods available include aspiration devices (Pipelle) and disruption devices (Tao brush). This study evaluated a new device which combines Global endometrial Disruption using a brush with a built in suction Process (GDP-Tao). Methods: After IRB approval, endometrial specimens were collected using the GDP-Tao from fresh uteri after completion of hysterectomies. Endometrial pathology results from the new device were compared to the final hysterectomy diagnosis by blinded review. Results: Patients (n = 33) were 29-86 years old (median 56), 67% obese, 52% menopausal. Uterine sounds were 2.5-11cm (median 6.6 cm), weight 45-3500g (median 238g), 15% of cervical os were stenotic but all allowed the device to pass without other instrumentation with overall diagnostic rate of 91% (30/33) 15/15 pathologically confirmed malignant specimens were correctly identified by the new device including 2 GDP-Tao specimens with atypical hyperplasia (AH) and hysterectomy pathology with AH and focal adenocarcinoma. Classifying any atypia from the GDP-Tao as “positive” then the detection rate for malignancy was 100% (PPV). 11/11 samples were benign in GDP-Tao and final pathology. There were 3 non-diagnostic (ND) samples from GDP-Tao with final pathology of benign endometrium. One specimen was ND due to absence of tissue from prior endometrial ablation. There was one device result of “proliferative endometrium” with final pathology of focal complex atypical hyperplasia and one device result of “rare atypical cells” with final diagnosis of endometrial polyp. Sensitivity and specificity were 94% and 92%, and negative predictive value was 82% for the identification of both atypical hyperplasia and malignancy. When stratified by uterine size, benign or malignant, the results were similar. Conclusions: Our validation study showed encouraging data thatthis new endometrial sampling device, which combines tissue disruption and aspiration into a single process, provides a reliable mean of obtaining adequate sample to accurately detect endometrial cancer with a high negative and positive predictive value.

COMPONENTS OF SUCCESS ON THE PATH TO PROLONGATION OF THE BREAST-FEEDING

Breast milk is a perfect nutrition for infants during their first year of life. Despite the enormous significance of breast feeding for the formation of children health, its prevalence is still very low. Careful doctors’ attention to every woman, consulting on the issues of breast feeding will help to overcome its inadequate prevalence and prolong its duration to the maximum. Advantages of the breast feeding, including situations when a child requires supplementary bottle feeding, are described in this article. Selection of appropriate nipples and bottles, for one thing, will help to reduce children’s anxiety, associated with colic, and, in the second place, will contribute to maintaining of the breast feeding, if the process of suction from bottles is analogous to the process of feeding from mother’s breast.

Hydrodynamic Simulation for Intake Valve of Reciprocating Compressor

The aim of the present paper is to simulate the work process of intake valve in reciprocating compressor.To understand the flow, temperature characters and valve plate movement, the Computational Fluid Dynamics (CFD) is used to simulate the process of expansion and suction. In each time step, the fluid motion equation is iteratively solved to obtain the pressure distribution on the valve plate, and the valve plate moving can been determined by solving the valve plate motion equation at the end of time step. The simulation result shows the pressure and temperature field is uniform in cylinder during compressor expansion, but very different in suction process. The valve plate opens from 53.2° to 219.5°, which is well consistent with the theoretical calculation results (56°, 220°). This study identifies that CFD is a valid tool for exactly investigating the flow and valve plate movement.

Thermal performance analysis of reciprocating compressor with stepless capacity control system

On the basic principle of stepless capacity control system for large reciprocating compressor, the thermal cycle was analyzed. The equations for the process of suction, reverse flow, compression, discharge and expansion of clearance gas were established. According to these equations, p–V diagrams at various situations were simulated. An experimental platform was setup and the compressor with designed stepless capacity control system run well. The experimental results show that the capacity of compressor can be regulated steplessly, and the motor power is reduced proportionally with respect to the reduction of capacity. During the suction process, both the flow resistance of valve and the pressure fluctuation in cylinder can be reduced by opening the suction valves with the actuators. The simulated and experimental results showed good coincidence. The clearance volume and valve clearance Mach number had a negative influence on the thermal performance of compressor with stepless capacity control system.

Use of a purse-string suture method and blunt-ended dissector in arthroscopic surgery for axillary osmidrosis

In recent years, the use of a suction-assisted arthroscopic shaver has become a popular method for the treatment of axillary osmidrosis. The dissection method is essential for creating adequate space for the curettage and suction process of the shaver. However, the traditional dissection process using scissors extends the wound and affects the final cosmetic result. Therefore, we developed a method to minimize the surgical wound to decrease the side-effects related to wound size and achieve a better cosmetic outcome. A 3-mm diameter blunt-ended dissector was used for dissection, and a temporary purse-string suture was used to minimize wound tension during curettage. The clinical efficacy, complication rate, and satisfaction rate of this new method were evaluated in 15 patients recruited over a 6-month period. Using this refinement, postsurgical wound size could be limited to 4 mm with a low complication rate (3.3%). Good clinical efficacy was achieved in 93.3% of patients, with excellent agreement between the clinicians and patients. We introduced a simple method to decrease wound tension during suction-assisted arthroscopic shaver surgery for axillary osmidrosis. This modification is simple and convenient for dermatologists to perform, and the final cosmetic result is satisfactory.

연료전지용 캐소드 공기블로어의 비정상 내부유동장 연구

This paper describes unsteady internal flow characteristics of a cathode air blower, used for the 1 kW fuel cell system. The cathode air blower considered in the present study is a diaphragm type blower. To analyze the flow field inside the diaphragm cavity, compressible unsteady numerical simulation is performed. Moving mesh system is applied to the numerical analysis for describing the volume change of the diaphragm cavity in time. Throughout a numerical simulation by modeling the inlet and outlet valves in a diaphragm cavity, unsteady nature of an internal flow is successfully analyzed. Variations of mass flow rate, force and pressure on the lower moving plate of a diaphragm cavity are evaluated in time. The computed mass flow rate at the same pressure and rotating frequency of a motor has a maximum of 5 percent error with the experimental data. It is found that flow pattern at the suction process is more complex compared to that at the discharge process. Unsteady nature of internal flow in the cathode air blower is analyzed in detail.

THE APPLICATION OF MODERN TECHNOLOGICAL MODES FOR THE MAINTENANCE OF BREAST FEEDING

The maintenance of breast feeding when it is complicated due to mother and/or child health state is an important and difficult challenge. The application of bottles and nipples which contribute to imitation of the child’s suction process of mother’s breast is urgent to the lactation maintenance. The aim of the study was to perform comparative evaluation of different series bottles with nipples usage for artificial feeding of infants of the first months of life. The received results showed that the majority of children were more willingly to be fed with «Natural » series nipples, continuing to be breast-fed.

Removal of blue-green algae using the hybrid method of hydrodynamic cavitation and ozonation

A suspension of Microcystis aeruginosa (30μgL−1chlorophyll a) was circulated in a hydrodynamic cavitation device and ozone was introduced at the suction side of the pump. The removal of algae over 10min using hydrodynamic cavitation alone and ozone alone is less than 15% and 35%, respectively. The destruction of algae rises significantly from 24% in the absence of the orifice to 91% with the optimized orifice on 5min of processing using hydrodynamic cavitation along with ozone (HC/O3) and the utilization of ozone increases from 32% to 61%. Interestingly, the suction process is more effective than the extrusion method (positive pressure) and the optimal bulk temperature for algal elimination was found to be 20°C. Increasing the input concentration of ozone is favorable for the removal of algae but leads to a greater loss of ozone and a decrease in the utilization of ozone. Under the optimal conditions, the algal cells and chlorophyll a are completely destroyed in 10min by use of the hybrid method.

Considerations on a suction drill for lunar surface drilling and sampling: II. experimental tests in vacuum conditions

Drilling devices with the ability to create narrow, but deep, boreholes in a planetary surface are important tools for the exploration of the structure and properties of planetary surface layers. Therefore, they are usually proposed for planetary landers for the Moon, Mars, Venus or small planetary bodies. A method based on the use of a cold gas flow for ejecting debris particles from the borehole has recently been suggested and investigated theoretically (Komle et al. in Acta Geotech 3:201–214, 2008a). The current paper reports on laboratory experiments designed to validate this method under vacuum or low pressure conditions. Two different sample materials were used: (1) glass beads in the sub-millimeter size range, and (2) the certified lunar analog material JSC-1A, a finely crushed basaltic rock. For both materials, the suction process for removing the particles from a simulated borehole worked well and with a moderate gas consumption.

Dynamic Mesh Method for Two-Dimensional Synthetic Jet

A numerical simulation method using dynamic mesh for two-dimensional synthetic jet flow was developed, in which dynamic mesh conservation equations and spring-based smoothing method were used. A computing model of an isolated jet to validate this method, the max velocity of oscillation is 0.47 m/s, Renault number is 180 and the Strouhal number is 0.056. The simulation results of different phases show that a shear layer is formed at the orifice edge and the shear layer rolls up to form a vortex ring, then fluid nearby the orifice enters into the cavity, and the vortex pair moves away from the orifice under its own momentum when the membrane moves to the bottom position. The suction process is affected by the outside vortex ring, and the second vortex pair impacts acutely the vortex ring outside. Comparing with other similar examples, the results show that the flow structure and action mechanism of synthetic jet flow are reasonable, and therefore this method could be used to simulate two-dimensional synthetic jet flow.

Modeling Analysis and Simulation of Hydraulic Axial Piston Pump

Based on characteristics of AMESim software and structural characteristics of aviation piston pump, the model of a rational aviation piston pump was constructed after simplified. In this issue, the equations of motion of the piston and the process of oil suction and oil discharge for a single piston are theoretically analyzed. The effects of the four kinds of leakage to the loss of flow rate and to the pulsing of the pump are emphatically analyzed. Through build the model of axial piston pump, which provides certain theoretical basis for design different kinds of model of the piston pump.

Research on CAE System Software of the High-Pressure Reciprocating Pump

To improve the design analysis efficiency of the high-pressure reciprocating pump, the study adopted a kind of visual programming software and programmed the CAE system software of the high-pressure reciprocating pump. The sortware developed three modules in correspondence with three aspects, namely, the analysis of power end’s motion theory, the analysis of the hydraulic end’s suction and discharge process, and the finite element analysis of the structure and the analysis of fatigue life. It is proved that the system software has a friendly interface, easy to operate and highly precise, providing a powerful professional tool for analyzing suction and discharge performance of the high-pressure reciprocating pump.

Research and development of a semi-hermetic reciprocating compressor for transcritical CO2 refrigeration cycle

A semi-hermetic reciprocating compressor was designed and developed for the transcritical carbon dioxide (CO2) refrigeration cycle. In addition, a mathematical model was established to simulate the thermodynamic process in this transcritical CO2 compressor. The internal leakage, heat transfer, and flows through the suction/discharge valves together with the valve motion were taken into account in the model. In order to evaluate the overall performance of the developed compressor, a test rig was built to measure the volumetric efficiency, isentropic efficiency, and coefficient of performance (COP), and also recorded the pressure—volume diagram. The calculated indicated power deviated by 4.16 per cent from the measured one, and the maximum deviations of the isentropic and volumetric efficiencies were −2.86 per cent and 4.87 per cent, respectively. Both the calculated and measured data showed that the compressor had a cooling COP of 2.0—3.2. As the pressure ratio increased from 2.3 to 3.5, the volumetric and isentropic efficiencies ranged from 0.70 to 0.86 and from 0.62 to 0.66, respectively. The recorded p— V diagram indicated that the power losses associated with the suction and discharge processes accounted for 4.6 per cent and 6.8 per cent of the total indicated power, respectively. The validated model can be used to investigate the thermodynamic process of the reciprocating CO2 compressor with the aim of enhancing the compressor efficiency.

Numerical study on particle removal performance of pickup head for a street vacuum sweeper

The purpose of this paper is to investigate the particle removal performance of pickup head for a street vacuum sweeper numerically. An integrated 3D numerical model was constructed based on particle suction process in computational fluid dynamics (CFD) software. The airflow through the pickup head was treated as a continuum, while particles were modeled as dispersed phase. The Reynolds stress model (RSM) and discrete particle model (DPM) were chosen in order to predict the air and particles flow accurately. The numerical simulation results show that the sweeper-traveling speed and the pressure drop across the pickup head have great effects on the particle removal performance. The removal efficiency of particles increases with the lower sweeper-traveling speed or the higher pressure drop, and small size particles have higher grade efficiency than that of large size particles under the same operating conditions. Moreover, the removal mass flow rate of particles increases with the higher sweeper-traveling speed. Therefore, a trade-off should be considered among high removal efficiency, low energy consumption, and high removal mass flow rate. Through the numerical simulation, the effectiveness of street vacuum sweeper for removing particles from road surface is evaluated, and an optimal operating condition is obtained. Besides, more information is generated to better understand the particle suction process of the pickup head.

Numerical Analysis on Cave-Formation Process behind Seawall by Particle Method

A suction of backfill sand behind a seawall causes damages of seawall, such as local subsidence of seawall or cave-in of backfill sand. Some field observations show that caves were formed due to suction through a corroded hole found in a sheet pile under the seawall. Therefore, in this study, a numerical simulation on such a cave-formation process is carried out by a particle method. The simulation consists of two stages: The one is a simulation of a suction process of sand under the seawall, and the other is an erosion process of backfill sand. The cave reproduced by the simulation showed good agreement with the observed one.

Internal waves and short‐scale distribution patterns of chlorophyll in the Strait of Gibraltar and Alborán Sea

A selection of ASAR images have been analyzed, together with instantaneous images of surface chlorophyll recorded with MERIS and MODIS, in order to study the relationship between the physical and biological processes associated with internal waves in the Strait of Gibraltar and Alborán Sea. The images show peak levels of chlorophyll at the coastal edges to the north and south of the Camarinal Sill (CS) during the generation of internal waves, and peak levels of chlorophyll associated with the wave fronts as they travel into the Alborán Sea. The images have been compared with in‐situ data. The results seem to indicate that, during the generation of the internal waves, a suction process takes place by which coastal waters rich in chlorophyll are drawn towards the center of the channel and then accompany the internal waves as they move towards the Alborán Sea.

1A1-G07 吸引作業に対応する脳変形シミュレータ

1A1-G07 吸引作業に対応する脳変形シミュレータ

A computational modeling for micropipette-manipulated cell detachment from a substrate mediated by receptor–ligand binding

We perform computer simulations of using a micropipette to attach and then detach a red blood cell on a flat substrate mediated by receptor–ligand binding. The cell is initially swollen with osmotic pressure, coated with a specific kind of bio-molecular receptor, sucked into the micropipette and then allowed to approach a substrate coated with the corresponding ligand. Binding interactions between the membrane-bound receptors and the substrate-anchored ligands cause the cell to spread onto the substrate surface. While the specific interaction between a pair of receptor and ligand is described by a chemical reaction equation, a traction-separation law is adopted to describe the non-specific interactions between the receptors and the substrate. A surface diffusion model is introduced to describe the mobility of the receptors within the cell membrane. After the equilibrium state of adhesion is achieved, a pulling force is applied on the micropipette to detach the cell from the substrate. The governing equations of cell–substrate interactions and receptor diffusion are implemented in a finite element scheme to simulate the entire process of cell suction, cell spreading, receptor diffusion, and cell detachment, and to investigate the effects of membrane stiffness, cohesive parameters, micropipette size, and suction pressure on the unbinding kinetics of the cell. The simulation results are shown to agree qualitatively with existing experimental data.

Investigation of suction process of a large R134a scroll compressor

The suction process of a scroll compressor was investigated. The investigation started from the numerical simulation of the entire scroll compressor working process. The simulation included the upper main bearing housing, thrust plate, scrolls, dummy and discharge ports, check valve, plenum, and discharge line. The basic geometric features and physical mechanisms that the scroll compressor performance is associated with were simulated first. The working fluid was Refrigerant 134a. The suction process was studied as a part of the integrated working environment. The fundamental mechanism of the suction process was defined. The interaction of the compressor design features was quantified. The overall parameters were calculated from the field quantities. The relationship between design details, flow physics, and performance characteristics was established. The methodology developed and the data obtained can be applied to the design and optimization of scroll compressors.

Development of a double acting free piston expander for power recovery in transcritical CO 2 cycle

To replace the throttling valve with an expander is considered as an efficient method to improve the performance of the transcritical CO 2 refrigeration cycle. This paper presents the design and experimental validation of a double acting free piston expander, in which a slider-based inlet/outlet control scheme is used to realize a full expansion process for the expander. The power extracted from the expansion process is utilized by an auxiliary compressor, which is arranged in parallel with the main compressor. A design model is developed to determine the geometric parameters of the expander together with the auxiliary compressor. An expander prototype is manufactured and validated experimentally in the air test system, mainly by means of analyzing the dynamic pressures in the expander chamber. The experimental results show that the expander can work stably in a wide range of pressure differences/ratios at the frequency approximately linear with the pressure difference through the expander. The p– t diagrams in the expander indicate that the slider-based inlet/outlet control scheme enables the expander to have the proper suction, expansion and discharge processes. However, the prototype at high frequency doesn’t present isobaric suction process, which results in insufficient gas suction and therefore decrease in the expander efficiency. With the p– t diagrams at various frequencies compared, the optimal working frequency is found to range from 10 to 17 Hz in the air system. The isentropic efficiency of 62% is obtained from the p– V diagram analysis. Further validation of the expander in the CO 2 system will be conducted in the near future.