• Journal of the Microelectronics and Packaging Society
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• v.21 no.3
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• pp.51-56
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• 2014

The reliability of solder joint is significantly affected by the property of surface finish. This paper reports on a study of high speed shear energy and failure mode for Sn-4.0wt%Ag-0.5wt%Cu (SAC405) solder joints with the time of Pd activation. The nodule size of electroless Ni-P deposit increased with increasing the time of Pd activation. The roughness (Ra) of electroless Ni-P deposit decreased with increasing the time of Pd activation. Then, with $HNO_3$ vapor, the quasi-brittle and brittle mode of SAC405 solder joint decreased with increasing the time of Pd activation. This results indicate that the increase in the Pd activation time for Electroless Ni/ Electroless Pd/ Immersion Au (ENEPIG) surface finish play a critical role for improving the robustness of SAC405 solder joint.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.6_3
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• pp.1333-1339
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• 2023

To produce activated carbon fibers, the process is carried out through either physical activation method or chemical activation method. In this study, we present the results regarding the characteristics of activated carbon fibers manufactured under various conditions through the quantitative control of steam. The yield after activation indicates a decreasing trend with the increase in steam quantity and activation time. Additionally, specific surface area characteristics exhibit variations based on activation time and steam flow rate. The SEM analysis results reveal that higher steam flow rates lead to the presence of both mesopores and macropores on the surface of activated carbon fibers (ACF).

• Proceedings of the KOSOMBE Conference
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• v.1992 no.11
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• pp.146-149
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• 1992

The cardiac depolarization model using three dimensional ventricular model is simulated. To study this theme, we constructed a cardiac ventricular model and simulated the cardiac activation process using the action potential duration and the activation time. The cardiac potential model is generated by the logical combination of the elliptic equations. The action potential duration could be obtained from the fact that it is linearly distributed between model cells. The cardiac activation process was simulated by the law of "all-or-none". Based on the activation time and the action potential duration the cardiac potential at the arbitrary time after the activation of the model cell was computed. To test the validity of model, the comparison the results of model simulation with the physiological data was performed.

• Tribology and Lubricants
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• v.14 no.3
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• pp.7-16
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• 1998

The electrorheological (ER) behavior of suspensions in silicone oil of phosphoric ester cellulose powder (average particle size: 17.77 $\mu$m) was investigated at room temperature with electric fields up to 2.5 KV/mm. For development of anhydrous ER suspensions using at wide temperature range, we aimed to know the effect of activation of phosphoric ester cellulose particles on the ER activities. As a first step, the anhydrous ER suspensions mixing with the phosphoric ester cellulose particles which were treated with 2M phosporic acid and 4M urea were measured. After activating the anhydrous ER suspensions at 12$0^{\circ}C$, not only the analysis of dispersing cellulose particles which were reacted by phosphoric ester but also the electrorheological characteristics of ER suspensions such as dielectric constant, current density, electrical conductivity and rheological properties were studied. From the experimental results, the activation of phosphoric ester cellulose particles had an influence on the ER properties of anhydrous ER suspensions. As the activation time went by, the size and number of dispersing particles, the electrical properties and the initial apparent viscosity $(η_0)$ of ER suspensions were increased till the activation time passed 5 hours. Also, it was possible, the electrorheological effect $($\tau$/$\tau$_0)$ of ER fluids was grown by the activation of phosphoric ester cellulose particles.

• Journal of Energy Engineering
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• v.13 no.2
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• pp.166-172
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• 2004

The activated carbon was produced from Sancheong bamboo by steam and carbon dioxide gas activation methods. The carbonization of raw material was conducted at 90$0^{\circ}C$ and gas activation reactions were conducted with respect to various conditions. -activation temperature 750-90$0^{\circ}C$, the flow rate of steam 0.5-2g-$H_2O$/g-char$.$hr, the flow rate of carbon dioxide 5-30$m\ell$-$CO_2$/g-char-min and activation time 1-5 hr. The prepared activated carbons were measured yield, the adsorption capacity of iodine and methylene blue, BET specific surface area and pore size distribution. The adsorption capacity of iodine (680.5-1526.1 mg/g) and methylene blue (18.3-221.5 mg/g) increased with creasing activation temperature and activation time. The adsorption capacity of iodine and methylene blue increased with the activation gas quantity in the range of 0.5-1.5g-$H_2O$/g-charㆍhr, 5-18.9$m\ell$-Co$_2$/g-charㆍmin. But those decreased over those range due to the pore shrinkage. The steam activation method was superior in efficiency to carbon dioxide activation method.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.87-90
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• 2006

The experimental study has been done for two kinds of pelletized RDFs to Investigate the carbonization effect to the chlorine concentrations, the heating value and the yield of Produced char in variable conditions of the carbonizing temperature and reaction time. One(RDF-1) is made of 100% wasted plastics and the other(RDF-2) is made of 60% wasted paper with 40% wasted plastics. The screw type carbonizer heated Indirectly by oil burner was used for the experiment and RDF feeding rate was 3kg/hr. The carbonizing temperature was 300, 350 400 and $45^{\circ}C$ and the reaction tine was 5, 10 and 15 minutes respectively. As the increase of carbonizing reaction time and temperature, the chlorine reduction rate was increased and oppositely the yield of char was decreased At the temperature of $400^{\circ}C$ and reaction time of 10 minutes the chlorine reduction rate was 60% and the char yield rate was 80% for the RDF-1 and those of RDF-2 were 80% and 75%, respectively. Additional activation experiment to the char produced from RDF-2 was done in the activation reactor by hot steam supply. As the increase of activation time the iodine number was increased. At the activation time of 20 minutes the iodine number was 552mg/g and the yield of activated carbon was 16%.

• Journal of Biomedical Engineering Research
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• v.36 no.5
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• pp.198-203
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• 2015

The purpose of the study is to examine the effects of pacemaker location on cardiac pumping efficacy theoretically. We used a three-dimensional finite element cardiac electromechanical model of canine ventricles with models of the circulatory system. Electrical activation time for normal sinus rhythm and artificial pacing in apex, left ventricular free wall, and right ventricular free wall were obtained from electrophysiological model. We applied the electrical activation time maps to the mechanical contraction model and obtained cardiac mechanical responses such as myocardial contractile ATP consumption, stroke work, stroke volume, ejection fraction, and etc. Among three artificial pacing methods, left ventricle pacing showed best performance in ventricular pumping efficacy.

• Fire Science and Engineering
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• v.34 no.3
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• pp.35-42
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• 2020

The accurate prediction of fire detector activation time is required to ensure the reliability of fire modeling during the safety assessment of performance-based fire safety design. The main objective of this study is to determine the activation temperature and the response time index (RTI) of a fixed heat detector, which are the main input factors of a fixed-temperature heat detector applied to the fire dynamics simulator (FDS), a typical fire model. Therefore, a fire detector evaluator, which is a fire detector experimental apparatus, was applied, and 10 types of domestic fixed-temperature heat detectors were selected through a product recognition survey. It was found that there were significant differences in the activation temperature and RTI among the detectors. Additionally, the detector activation time of the FDS with the measured DB can be predicted more accurately. Finally, the DB of the activation temperature and RTI of the fixed-temperature heat detectors with reliability was provided.

• Journal of the Semiconductor & Display Technology
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• v.3 no.1
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• pp.35-39
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• 2004

Statistical design of experiments was successfully employed to investigate the effect of alternating magnetic field on activation of polycrystalline Si (p-Si) doped as n-type using $\textrm{PH}_3$, by full factorial design of three factors with two levels. In this design, the input variables are graphite size, alternating current, and activation time. The output parameter, sheet resistance, is analyzed in terms of the primary effects and multi-factor interactions. Notably, the three-factor interaction is calculated to be a dominant interaction. The interaction between graphite size and activation time and the main effect of current are important effects compared to the other variables and relevant interactions. Alternating magnetic flux activation is proved a significantly beneficial processing technique.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.5
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• pp.506-517
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• 2000

In distributed real-time system, a task activated by the completion of its preceding task can be modeled as a periodic task with activation jitter. An activation jitter of a task is defined asthe difference between the worst case and the best case response time of its preceding task. Becausethe existing approaches assume that the best case response time is much smaller than the actual one,the activation jitter and the worst case response time of lower priority tasks are overestimated. Thispaper proposes a new analysis technique to calculate the best case response time more precisely andto reduce the activation jitter bounds. The proposed technique obtains the best case response time byconsidering the relative phase between tasks. The precise analysis of the activation jitters can reducethe worst case response time of other tasks and increase the schedulability. The simulation resultsshow that the proposed analysis technique improves the accuracy of the best case and the worst caseresponse time up to 40% and 6%, respectively.