Impact of Two Drops on a Dry Surface

( Chun-kuei Chen ),( Sheng-qi Chen ),( Ta-hui Lin ) 한국액체미립화학회 2017 한국액체미립화학회 학술강연회 논문집 Vol.2017 No.-

A group of two streamwise drops could be successfully generated by using the free-falling drops technique incorporated with a drop severance device in this study. Therefore, the impact characteristics of a group of two streamwise drops impinging on a dry surface will be experimentally examined and analyzed in this study. The water was considered as the working fluid, and the velocity of the drop was fixed to 1.9 ± 0.1 m/s. The initial diameter of the drop was fixed to 930 ± 30 ㎛ and 1025 ± 5 ㎛, respectively. This study focused on four cases of two drops impinging on a dry surface which classified by space difference (ㅿt). Conditions respectively being Case 1: single drop impinging, Case 2: ㅿt = 0.5 ms, Case 3: ㅿt = 1 ms and Case 4: ㅿt = 2.5 ms. The results showed two drops impinging on a dry surface for Case 2~4, the maximum spread diameter of drop was 1.3 times compared with the single drop at the same initial drop diameter, but the variation process of two drops impinging on a dry surface was different to the single drop.

The Transition from Dripping to Jetting of a Water Jet Under Rigid Body Rotation

( Chun-chia Chang ),( Chun-kuei Chen ),( Ta-hui Lin ) 한국액체미립화학회 2017 한국액체미립화학회 학술강연회 논문집 Vol.2017 No.-

This research is dedicated to analyzing the characteristic of a liquid jet under various conditions, for example, different flow rate and rotating speed. In this study, we found out that the imposed rotation would shorten the breakup length of a liquid jet due to its extra disturbance. On the other hand, hysteresis behavior occurs when using relatively large nozzle diameter, which represents that the critical flow rate of the transition from dripping to jetting is different to that from jetting to dripping. Consequently, we further analyzed the critical rotating speed (Jetting→Dripping) and critical flow rate (Dripping→ Jetting) in this hysteresis zone. As for the last part of this study, the breakup patterns had been deducted, we can divided the breakup modes into three distinguished patterns basically by how the droplets are formed, which are steady formation, two-drop coalescence, multiple-drop coalescence, respectively. Last but not least, the mutual interaction between these three patterns and how the rotation affected the outcomes of a liquid jet are concluded in this research.

Drop Interaction in a Burning Drops Stream

( Wei Dong Hsieh ),( Chun Kuei Chen ),( Ta Hui Lin ),( Shuhn Shyurng Hou ) 한국액체미립화학회 2010 한국액체미립화학회 학술강연회 논문집 Vol.2010 No.-

In a spray combustion flow field, a burning drop may interact with other drops flowing in parallel streams or along the same flow stream. Many studies on drop interaction in parallel streams were reported. However, upstream/downstream interaction of drops along a burning drops stream has not been well studied literately. To understand such interesting phenomena, we established an experimental system to examine a burning dodecane drops stream with variable drop inter-spaces in a high-temperature oxygen-rich environment. Effects of the drop inter-space (s/di) and the oxygen concentration ΩO2) in the hot environment on the interaction of burning drops were investigated in the study. Drop inter-spaces were chosen to be 2.5, 5, 10, 30 and 100. Oxygen concentrations of 21%, 25% and 30% in the hot environment were considered. The flame propagation and interactions between the burning drops in the stream were performed. Results showed that the diffusion flame enclosing the drops stream is narrowed with the increase of ΩO2 whereas effect of ΩO2 is not obvious when s/di>30. The overall flame length was longer for lower s/di due to flame propagating across the drops. Evaporation rates remains constant when s/di>30 indicating a weak interaction of drops along the same stream.

Applying Multi-Criteria Method to the Decision of Assessment Tools for High-care Student Groups

Chen-Feng Wu,Chun-Ta Lin,Pei-Min Wang 보안공학연구지원센터 2013 International Journal of Hybrid Information Techno Vol.6 No.3

Quadrature Oscillators with Grounded Capacitors and Resistors Using FDCCIIs

Jiun-Wei Horng,Chun-Li Hou,Chun-Ming Chang,Hung-Pin Chou,Chun-Ta Lin,Yao-Hsin Wen 한국전자통신연구원 2006 ETRI Journal Vol.28 No.4

Two current-mode and/or voltage-mode quadrature oscillator circuits each using one fully-differential secondgeneration current conveyor (FDCCII), two grounded capacitors, and two (or three) grounded resistors are presented. In the proposed circuits, the current-mode quadrature signals have the advantage of high-output impedance. The oscillation conditions and oscillation frequencies are orthogonally (or independently) controllable. The current-mode and voltage-mode quadrature signals can be simultaneously obtained from the second proposed circuit. The use of only grounded capacitors and resistors makes the proposed circuits ideal for integrated circuit implementation. Simulation results are also included.

The influence of tetraphenylethylene moieties on the emissive properties of dipyrrolonaphthyridinediones

Sadowski, Bartłomiej,Su, Shih-Hao,Lin, Ta-Chun,Lohrey, Trevor D.,Deperasiń,ska, Irena,Chou, Pi-Tai,Gryko, Daniel T. The Royal Society of Chemistry 2018 Journal of materials chemistry. C, Materials for o Vol.6 No.45

<P>Despite being highly emissive in solution, aggregation of dipyrrolonaphthyridinedione (DPND) molecules typically results in the quenching of fluorescence. DPNDs can be efficiently converted into π-extended derivatives containing rotatable aryl rings <I>via</I> a direct arylation methodology. The presence of phenyl substituents at positions 3 and 9 of the DPND core is sufficient to cause moderate fluorescence in the solid state. When tetraphenylethylene moieties, typical aggregation induced emitters, are coupled through biaryl linkages in these same positions, a 50 nm shift in absorption and almost 120 nm shift in fluorescence compared to the parent DPND is observed. The radiative S1 → S0 transitions have large oscillator strengths regardless of whether phenyls or tetraphenylethylene groups are coupled to DPND and strong orange or red emission in solution is observed. Vibrations involving these substituents play an important role in the dissipation of the electronic excitation energy. X-ray crystallographic studies revealed that although the distance between DPND cores is strikingly larger in bis(TPE)2DPND compared to that in diphenylDPND, their photophysical properties in the solid state are very similar. Computational studies have also shown that, in contrast to our experimental results, neither of these DPNDs should be particularly emissive in the solid state, due to the low oscillator strengths calculated for model dimers derived from their X-ray crystal structures.</P>

Application of an image and environmental sensor network for automated greenhouse insect pest monitoring

Dan Jeric Arcega Rustia,Chien Erh Lin,Jui-Yung Chung,Yi-Ji Zhuang,Ju-Chun Hsu,Ta-Te Lin 한국응용곤충학회 2020 Journal of Asia-Pacific Entomology Vol.23 No.1

This work presents an automated insect pest counting and environmental condition monitoring system using integrated camera modules and an embedded system as the sensor node in a wireless sensor network. The sensor node can be used to simultaneously acquire images of sticky paper traps and measure temperature, humidity, and light intensity levels in a greenhouse. An image processing algorithm was applied to automatically detect and count insect pests on an insect sticky trap with 93% average temporal detection accuracy compared with manual counting. The integrated monitoring system was implemented with multiple sensor nodes in a greenhouse and experiments were performed to test the system’s performance. Experimental results show that the automatic counting of the monitoring system is comparable with manual counting, and the insect pest count information can be continuously and effectively recorded. Information on insect pest concentrations were further analyzed temporally and spatially with environmental factors. Analyses of experimental data reveal that the normalized hourly increase in the insect pest count appears to be associated with the change in light intensity, temperature, and relative humidity. With the proposed system, laborious manual counting can be circumvented and timely assessment of insect pest and environmental information can be achieved. The system also offers an efficient tool for long-term insect pest behavior observations, as well as for practical applications in integrated pest management (IPM).

Comparisons of Moisturizing Function Between Rayon Fabric with Collagen Peptides from Fish Scales and Regular Rayon Fabric Under Various Relative Humidity

Chi‑Shih Huang,Erh‑Jen Hou,Ying‑Chou Lee,Tzong‑Huei Lee,Yi‑Jun Pan,Ta Yu,Wei‑Hsin Lin,Chun‑Han Shih,Wei‑Che Chang 한국섬유공학회 2023 Fibers and polymers Vol.24 No.12

The study was inspired by the specialized facial masks made of rayon non-woven fabrics which contained collagen peptides for improving moisturizing function. This study explored the moisturizing function of a rayon fabric containing collagen peptides extracted from tilapia fish scales under various conditions of relative humidity. This research had implications for the development of clothing that can prevent dry skin. A two-stage nested design experiment was adopted. The first-stage factor such as the fabric has two levels and the second-stage factor such as the relative humidity with three levels nested under each level of the first-stage factor. Preliminary results indicated that introducing a new variable (i.e., fabric moisturizing value, which combines the moisture regains of adsorption and desorption) would be useful. The moisturizing value of the novel rayon fabric and regular rayon fabric increased with the increase in relative humidity, and moisturizing effect of the novel rayon fabric with collagen peptides was better than that of the regular rayon fabric. Therefore, the novel rayon fabric may be suitable for preventing dry skin in winter.