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Modeling and Control of Time-pressure Dispensing for Semiconductor Manufacturing
Cong-Ping Chen,Han-Xiong Li,Han Ding,
Cong-Ping
,Chen,Han-Xiong,Li,Han,Ding

国际自动化与计算杂志 , 2007,
Abstract: To improve the consistency of the adhesive amount dispensed by the time-pressure dispenser for semiconductor manu- facturing,a non-Newtonian fluid flow rate model is developed to represent and estimate the adhesive amount dispensed in each cycle. Taking account of gas compressibility,an intelligent model-based control strategy is proposed to compensate the deviation of adhesive amount dispensed from the desired one.Both simulations and experiments show that the dispensing consistency is greatly improved by using the model-based control strategy developed in this paper.
On the distribution and swim pressure of run-and-tumble particles in confinement  [PDF]
Barath Ezhilan,Roberto Alonso-Matilla,David Saintillan
Physics , 2015, DOI: 10.1017/jfm.2015.520
Abstract: The spatial and orientational distribution in a dilute active suspension of non-Brownian run-and-tumble spherical swimmers confined between two planar hard walls is calculated theoretically. Using a kinetic model based on coupled bulk/surface probability density functions, we demonstrate the existence of a concentration wall boundary layer with thickness scaling with the run length, the absence of polarization throughout the channel, and the presence of sharp discontinuities in the bulk orientation distribution in the neighborhood of orientations parallel to the wall in the near-wall region. Our model is also applied to calculate the swim pressure in the system, which approaches the previously proposed ideal-gas behavior in wide channels but is found to decrease in narrow channels as a result of confinement. Monte-Carlo simulations are also performed for validation and show excellent quantitative agreement with our theoretical predictions.
A Harsh Environment Wireless Pressure Sensing Solution Utilizing High Temperature Electronics  [PDF]
Jie Yang
Sensors , 2013, DOI: 10.3390/s130302719
Abstract: Pressure measurement under harsh environments, especially at high temperatures, is of great interest to many industries. The applicability of current pressure sensing technologies in extreme environments is limited by the embedded electronics which cannot survive beyond 300 °C ambient temperature as of today. In this paper, a pressure signal processing and wireless transmission module based on the cutting-edge Silicon Carbide (SiC) devices is designed and developed, for a commercial piezoresistive MEMS pressure sensor from Kulite Semiconductor Products, Inc. Equipped with this advanced high-temperature SiC electronics, not only the sensor head, but the entire pressure sensor suite is capable of operating at 450 °C. The addition of wireless functionality also makes the pressure sensor more flexible in harsh environments by eliminating the costly and fragile cable connections. The proposed approach was verified through prototype fabrication and high temperature bench testing from room temperature up to 450 °C. This novel high-temperature pressure sensing technology can be applied in real-time health monitoring of many systems involving harsh environments, such as military and commercial turbine engines.
Influence of container structures and content solutions on dispensing time of ophthalmic solutions
Keiji Yoshikawa, Hiroshi Yamada
Clinical Ophthalmology , 2010, DOI: http://dx.doi.org/10.2147/OPTH.S10804
Abstract: fluence of container structures and content solutions on dispensing time of ophthalmic solutions Original Research (3009) Total Article Views Authors: Keiji Yoshikawa, Hiroshi Yamada Published Date May 2010 Volume 2010:4 Pages 481 - 486 DOI: http://dx.doi.org/10.2147/OPTH.S10804 Keiji Yoshikawa1, Hiroshi Yamada2 1Yoshikawa Eye Clinic, Tokyo, Japan; 2Santen Pharmaceutical Co., Ltd., Osaka, Japan Purpose: To investigate the influence of container structures and content solutions on the time of dispensing from eye dropper bottles. Methods: Eye dropper bottle models, solution models (filtrate water/surfactant solution) and a dispensing time measuring apparatus were prepared to measure the dispensing time. Results: With filtrate water and pressure thrust load of 0.3 MPa, the dispensing time significantly increased from 1.1 ± 0.5 seconds to 4.6 ± 1.1 seconds depending on the decrease of inner aperture diameters from 0.4 mm to 0.2 mm (P < 0.0001). When using the bottle models with inner aperture diameters of 0.4 mm or larger, the dispensing time became constant. The dispensing time using surfactant solution showed the same tendency as above. When pressure thrust load was large (0.07 MPa), the solution flew out continuously with inner aperture diameters of 0.4 mm or larger and the dispensing time could not be measured. The inner aperture diameter most strongly explained the variation of the dispensing time in both the content solutions in the multiple linear regression analysis (filtrate water: 46%, R2 = 0.462, surfactant solution: 56%, R2 = 0.563). Conclusions: Among content solutions and container structures, the dispensing time was mostly influenced by the diameter of the inner aperture of bottles.
Influence of container structures and content solutions on dispensing time of ophthalmic solutions  [cached]
Keiji Yoshikawa,Hiroshi Yamada
Clinical Ophthalmology , 2010,
Abstract: Keiji Yoshikawa1, Hiroshi Yamada21Yoshikawa Eye Clinic, Tokyo, Japan; 2Santen Pharmaceutical Co., Ltd., Osaka, JapanPurpose: To investigate the influence of container structures and content solutions on the time of dispensing from eye dropper bottles.Methods: Eye dropper bottle models, solution models (filtrate water/surfactant solution) and a dispensing time measuring apparatus were prepared to measure the dispensing time.Results: With filtrate water and pressure thrust load of 0.3 MPa, the dispensing time significantly increased from 1.1 ± 0.5 seconds to 4.6 ± 1.1 seconds depending on the decrease of inner aperture diameters from 0.4 mm to 0.2 mm (P < 0.0001). When using the bottle models with inner aperture diameters of 0.4 mm or larger, the dispensing time became constant. The dispensing time using surfactant solution showed the same tendency as above. When pressure thrust load was large (0.07 MPa), the solution flew out continuously with inner aperture diameters of 0.4 mm or larger and the dispensing time could not be measured. The inner aperture diameter most strongly explained the variation of the dispensing time in both the content solutions in the multiple linear regression analysis (filtrate water: 46%, R2 = 0.462, surfactant solution: 56%, R2 = 0.563).Conclusions: Among content solutions and container structures, the dispensing time was mostly influenced by the diameter of the inner aperture of bottles.Keywords: dispensing time, model eye dropper bottle, model ophthalmic solution, nozzle internal space volume, nozzle inner aperture diameter
Design and Fabrication of a MEMS Flow Sensor and Its Application in Precise Liquid Dispensing  [PDF]
Yaxin Liu,Liguo Chen,Lining Sun
Sensors , 2009, DOI: 10.3390/s90604138
Abstract: A high speed MEMS flow sensor to enhance the reliability and accuracy of a liquid dispensing system is proposed. Benefitting from the sensor information feedback, the system can self-adjust the open time of the solenoid valve to accurately dispense desired volumes of reagent without any pre-calibration. First, an integrated high-speed liquid flow sensor based on the measurement of the pressure difference across a flow channel is presented. Dimensions of the micro-flow channel and two pressure sensors have been appropriately designed to meet the static and dynamic requirements of the liquid dispensing system. Experiments results show that the full scale (FS) flow measurement ranges up to 80 μL/s, with a nonlinearity better than 0.51% FS. Secondly, a novel closed-loop control strategy is proposed to calculate the valve open time in each dispensing cycle, which makes the system immune to liquid viscosity, pressure fluctuation, and other sources of error. Finally, dispensing results show that the system can achieve better dispensing performance, and the coefficient of variance (CV) for liquid dispensing is below 3% at 1 μL and below 4% at 100 nL.
Encapsulation by Janus spheroids  [PDF]
Wei Li,Ya Liu,Genevieve Brett,James D. Gunton
Physics , 2011,
Abstract: The micro/nano encapsulation technology has acquired considerable attention in the fields of drug delivery, biomaterial engineering, and materials science. Based on recent advances in chemical particle synthesis, we propose a primitive model of an encapsulation system produced by the self-assembly of Janus oblate spheroids, particles with oblate spheroidal bodies and two hemi-surfaces coded with dissimilar chemical properties. Using Monte Carlo simulation, we investigate the encapsulation system with spherical particles as encapsulated guests, for different densities. We study the anisotropic effect due to the encapsulating agent's geometric shape and chemical composition on the encapsulation morphology and efficiency. Given the relatively high encapsulation efficiency we find from the simulations, we believe that this method of encapsulation has potential practical value.
Transparent Electronics  [PDF]
Lokesh D Shah,S. M. Gulhane
International Journal of Advanced Electrical and Electronics Engineering , 2013,
Abstract: Transparent electronics is an emerging science and technology field concentrates on producing ‘invisible’ electronics circuit and optoelectronics devices. The application contains consumer electronics such as automobile windshield, transparent solar panel, transparent display and real time wearable display. In the conventional Si/III-V based electronics, the structure is based on semiconductor junction & transistor. However, the basic building material for transparent electronic devices which is to be transparent and in visible range is a true challenge! .Therefore to understand and implement such technology there are two scientific goals, to have a material which are optically transparent and electrically conductive and to implement an invisible circuitry. Development of such invisible transparent electronic devices needs expertise together from pure and applied science, material science, chemistry, physics &electronic science.
A MEMS Flow Sensor for Self-adjusted Precise Non-Contact Liquid Dispensing  [cached]
Liu Yaxin,Zhong Ming,Yao Yufeng
Research Journal of Applied Sciences, Engineering and Technology , 2013,
Abstract: A MEMS flow sensor was proposed to enhance the reliability and accuracy of liquid dispensing system. Benefiting from the feedback of sensor information, the system can self-adjust the open time of the solenoid vale to accurately dispensing desired reagent volume without pre-calibration. This study focuses on the design, fabrication and application of this flow sensor. Firstly, the design, fabrication and characteristics of the MEMS flow sensor based on the measurement of the pressure difference across a flow channel are presented. Secondly, the liquid dispensing system in which the flow sensor is integrated will be introduced. A novel closed-loop control strategy is proposed to calculate valve open-time for each dispensing cycle. Finally, experiments results are presented with different dispensing volumes, Coefficient of Variance (CV) has been shown to be below 3%. It indicates that integration of the MEMS flow sensor and using of a compound intelligent control strategy make the system immune to liquid viscosity, pressure fluctuation and some other disturbances.
Medication dispensing errors at a public pediatric hospital
Costa, Lindemberg Assun??o;Valli, Cleidenete;Alvarenga, Angra Pimentel;
Revista Latino-Americana de Enfermagem , 2008, DOI: 10.1590/S0104-11692008000500003
Abstract: objective: assess the safety of medication dispensing processes through the dispensing error rate. method: cross-sectional study carried out at a pharmaceutical service of a pediatric hospital in espírito santo, brazil. data collection was performed between august and september 2006, totaling 2620 prescribed medication doses. any deviation from the medical prescription in dispensing medication was considered a dispensing error. the categories of medication errors were: content, labeling, and documentation errors. the dispensing error rate was computed by dividing the number of errors by the total of dispensed doses. results: from the 300 identified errors, 262 (87.3 %) were content errors. the rate of errors in the labeling and documentation categories was 33 (11%) and 5 (1.7%), respectively. conclusion: the total dispensing error rate was higher than rates reported in international studies. the most frequent category was "content error".
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