• Journal of Home Health Care Nursing
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• v.22 no.1
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• pp.88-97
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• 2015

Purpose: This study was conducted to identify the effects of a suction care self video-based debriefing-assisted learning in the fundamentals of nursing practice for nursing students on clinical performance, self-efficacy and problem-solving process. Methods: A nonequivalent control group non-synchronized design study was used and included 97 junior nursing students at P University as participants, 48 of whom were assigned to the experimental group, and 49 of whom were assigned to the control group. The outcome measurements were clinical performance for suction care, self-efficacy, and the problem-solving process. Results: The scores of clinical performance were 23.75 in the experimental group who used the materials and 21.55 in the control group, and the difference was statistically significant (p<.000). Self-efficacy was 4.30 in the experimental group and 4.18 in the control group, which was a statistically significant difference (p=.000), and the pre-to-post differences of self-efficacy was statistically significant as well (p<.001). However, there were no significant differences in the pre-to-post differences of the problem-solving process (p<.802). Conclusions: Self video-based debriefing-assisted learning may be more effective in enhancing clinical performance and self-efficacy than that of conventional practice. Whether self-efficacy will contribute to enhanced learning motivation for nursing students needs further examination.

• International Journal of Fluid Machinery and Systems
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• v.4 no.1
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• pp.191-198
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• 2011

Based on the consideration that the cavitation would affect the operation stability of miniature pumps, the 3-D turbulent cavitating flow in a test pump was simulated by using a mixed cavitation model and k-${\omega}$ SST turbulence model. In order to investigate the influence of inlet geometry parameters on the cavitation performance of the miniature pump, two more impellers are designed for comparison. Based on the results, the following conclusions are drawn: 1) Cavitation performance of the double suction shaft-less miniature pump having different impeller is equivalent to the centrifugal pump having ordinary size, though the flow passage at impeller inlet is small; 2) The miniature pump having radial impeller can produce much higher pump head, but lower cavitation performance than that having the impeller based on the conventional design method; 3) It is believed that by applying the double suction design, the miniature pump achieved relatively uniform flow pattern upstream the impeller inlet, which is favorable for improving cavitation performance.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.208-211
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• 2006

Flow resistance induced by each element in suction nozzle of a vacuum cleaner with a rotary fan is investigated numerically and its relation with flow-induced noise is examined. Flow resistance and vorticity in suction nozzle are calculated and it is found that they are closely related with flow-induced noise. From numerical results, it is suggested that reduction of flow resistance effectively increases all-suction performance and decreases sound pressure level of noise generated in the suction nozzle.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.935-938
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• 2007

In suction nozzle of a vacuum cleaner, where flow-induced noise is generated mainly by flow resistance, several ideas to reduce noise are investigated. To increase fan performance, blade number is optimized and a centrifugal fan is replaced by a cross-flow fan, In addition, gear ratio of fan to drum brush is changed. It is found that fan performance is increased by adopting these methods. Next, the blade height of the fan is decreased to reduce sound pressure level, which causes inevitably decrease in fan performance. Eventually, flow-induced noise is reduced by 6.3 dBA in its overall level with the fan performance maintained.

• The KSFM Journal of Fluid Machinery
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• v.17 no.4
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• pp.47-52
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• 2014

An inducer is forward-attached to an impeller to improve the suction performance. This paper described the experimental and numerical investigations on the concept of NPSH similarity about the inducer scale. As Reynolds number decreased for the same scale inducer, the hydraulic performance is slightly reduced because of the viscosity. The suction performance similarity is in good agreement. For different scale inducers, the NPSH similarity did not follow the conventional rule which is proportional to the square of the inducer diameter. A cavity of two times scale inducer grows faster under cavitation inception, and the head is more drop as the fluid passes blades. Because of the simplified cavitation model and vapor pressure, the NPSH similarity dose not have an accuracy. This study suggested an empirical formula for the NPSH similarity.

• Journal of Biosystems Engineering
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• v.33 no.3
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• pp.179-185
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• 2008

The seeding rates of the vacuum suction nozzle seeders are affected by the jumping height of the seeds on the vibrating seed hopper. This study was performed to investigate the optimum vibration condition of the seed hopper on the vacuum suction nozzle seeder for improving seeding performance. Experiments were carried out to determine the vibration conditions of the seed hopper by air pressure and eccentric weight, and to optimize the seed-pickup performance of each nozzle by suction pressure. As the result with the experiments, the fluctuations of the jumping height of the seeds were showed at amplitude 0.4 mm and frequency 42 Hz, and jumping heights of the seeds were increased as the air pressure increase and the eccentric weight decrease, regardless number of seeds of the hopper. The best seeding rate of the seed hopper was 98% at the 300-seed cell, when the condition of the seed hopper was the suction air pressure of 94.6 kPa-abs., amplitude and frequency of the seed hopper vibration were at 0.57 mm and 43.6 Hz, respectively. The optimum vibrating conditions of the seed hopper were decided into frequency 43.6-43.8 Hz and the amplitudes 0.61-0.62 mm.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.5
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• pp.263-268
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• 2015

In this study, the performance of an ejector in the refrigeration cycle was experimentally studied using R600a. The performance of the ejector is analyzed according to the inlet pressure and nozzle position. The increase in the primary nozzle pressure decreased the pressure difference across the ejector. In the low entrainment region, the increased suction flow pressure led to an increase in the pressure difference. In the high entrainment region, the pressure difference was inversely proportional to the suction pressure. The effects of nozzle position ($L_n$) were also analyzed and for $L_n<0$, the decreased suction chamber volume led to a large pressure drop with the small increase in the suction mass flow rate. For $L_n>0$, the increased $L_n$ disturbed the primary nozzle flow and thus an increase in the primary nozzle flow increased the pressure lifting effect. In contrast, the increased suction mass flow rate decreased the pressure difference. When the nozzle outlet was located at the mixing part entrance ($L_n=0$), the ejector showed the highest pressure lifting effect.

• International Journal of Air-Conditioning and Refrigeration
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• v.6
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• pp.148-157
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• 1998

This study presents test results of a residential window air-conditioner using R22 and two potential alternative refrigerants, R407C and R410B. A series of performance tests has been carried out for the basic and liquid-suction heat exchange cycles in a psychometric calorimeter test facility. For R407C, the same rotary compressor was used as in the R22 system. However, compressor for the R410B system was modified to provide the similar cooling capacity. The evaporator circuit was changed to get a counter-cross flow heat exchanger to take advantage of zeotropic mixture's temperature glide, and liquid-suction heat exchange cycle was also considered to improve the system performance. Test results were compared with those for the basic R22 system. The modified system with a liquid-suction heat exchanger increased cooling capacity and energy efficiency by up to 5%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.290-297
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• 2016

The performance of track cleaning trains to remove accumulated fine particulate matter in subway tunnels depends on the design of the suction system equipped under the train. To increase the efficiency of the suction system under the cleaning vehicle, this paper proposes a novel dust suction module equipped with both air blowing nozzles and a dust suction structure. Computational Fluid Dynamics (CFD) analysis with turbulent flow was conducted to optimize the dust suction system with a particle intake and blowing function. The optimal angle of the air blowing nozzle to maximize the dust removal rate was found to be 6 degrees. The performance of the track cleaning vehicle can be increased by at least 10 percent under an operation speed of 5km/h.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1197-1206
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• 2013

The purpose of this study was to develop a suction care education program and to evaluate the effects on clinical performance, self-efficacy, and problem-solving process regarding suction practice. The participants were 96 in second-year nursing students at P university in Pusan, Korea. The data was collected from Oct. 6th toward Oct. 19th, 2011, and analyzed by ${\chi}^2$, t-test, ANCOVA test using SPSS 18.0. The scores of clinical performance were 23.72 in the experimental group who learned this program and 22.16 in the control group, and were statistically significant(p<.001). Self-efficacy were 7.58 in the experimental group and 7.08 in the control group, which was statistically significant(p=.03), and the pre-to-post difference of self-efficacy was statistically significant as well(p<.001). However, there were no significant differences in the problem-solving process(p=.06) and the pre-to-post difference related to this(p=.011). This study showed that clinical performance and self-efficacy were improved by suction care education program.