Search

Surface acoustic waves have considerable potential to rapidly generate micron to submicron sized aerosols due to the capillary wave at the liquid–air interfacial boundary. The atomization process, however, is often found to be unstable and discontinuous due to the inconsistency of the droplet position and the lack of accuracy of resonance frequency, resulting in less efficient atomization performance. We developed a rapid and sustainable surface acoustic wave (SAW) atomizer to generate aerosols in a robust, straightforward, and stable mechanism for a continuous, consistent, and reliable deposition of a functional material (i.e., poly(3,4-ethylenedioxythiophene) polystyrene sulfonate [PEDOT:PSS]). Two identical progressive focused surface acoustic wave devices were arranged in angles and in opposite directions with 1 mm wide opening to regulate appropriate amount of liquid sample to be atomized. Several parametrical studies (i.e., on the design of the SAW device, liquid flow rate, applied voltage, and depo...

A new green dopant of TCBzC-substituted carbazole units was investigated in a solution processed white organic light-emitting diode (WOLED) device. 4-(10-(3′,5′-diphenyl-biphenyl-4-yl)anthracen-9-yl)-N,N-diphenyl-aniline (TATa) and 4-(dicyanomethylene4)-2-t-butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) were used for the blue host and red dopant. Structure of the device was fabricated as ITO / PEDOT: PSS (40 nm) / PVK (14 nm) / EML: TATa + TCBzC: 3.0wt% + DCJTB: 0.08wt% (50 nm) / TPBi (20 nm) / LiF (1 nm) / Al. As a result, a TCBzC device of 1.44 cd/A was obtained. Commission Internationale de l′Eclairage (CIE) value of the TCBzC device was (0.26, 0.41).

A new blue emitting material including coumarin moiety, 7-phenylamino-bis(4-methyl-coumarin) (P-DMC), was synthesized by Ullman reaction.[1] Optical and electronic properties were examined by UV-Vis. absorption spectrum, PL spectrum, and cyclic voltammetry. The UV-Vis. spectra of P-DMC in solution and film states showed maximum absorption wavelengths of 396 nm and 403 nm, respectively. The PL spectra of P-DMC showed maximum emission wavelengths of 449 nm and 488 nm in solution and film states. A non-doped OLED was fabricated using the synthesized material as an emitting material. The P-DMC compound exhibited efficient luminescence property. The EL spectrum of P-DMC had a maximum value of 482 nm.

New host material of 2-tert-butyl-9,10-bis(3′′,5′′-diphenylbiphenyl-4′-yl)anthracene [T-TAT] substituted t-butyl group was investigated in solution process WOLED device compared with 9,10-bis (3′′,5′′-diphenylbiphenyl-4’-yl) anthracene [TAT]. A two-color WOLED of a co-host system using solution process method was demonstrated. The device configuration was ITO / PEDOT:PSS (40 nm) / emitting layer (50 nm) / TPBi (20 nm) / LiF (1 nm) / Al. The emitting layer consisted of TAT or T-TAT, NPB, DPAVBi (blue dopant), and rubrene (yellow dopant). NPB was used to help hole carrier transport as well as blue host role. The device using the T-TAT compound as a co-host showed a luminance efficiency of 2.73 cd/A, which is 77% higher than TAT device of 1.54 cd/A at 20 mA/cm2.

Three new emitting compounds of 5P-VCB, 5P-VAn and 5P-VPy for OLED based on hexaphenylbenzene moiety were synthesized. Physical properties by the change of the substitution groups of the synthesized materials were systematically examined. Photoluminescence spectrum of the synthesized materials showed maximum emitting wavelengths of about 420∼487 nm in solution state and 452∼488 nm in film state, indicating blue emission color. OLED devices were fabricated by the synthesized compounds using vacuum deposition process as an emitting layer. Current efficiencies and CIE values of 5P-VCB, 5P-VAn and 5P-VPy were 1.76, 0.38 and 7.91 cd/A and (0.15, 0.07), (0.20, 0.31) and (0.20, 0.36), respectively.

This study proposes a method for examining storage function of intercepting sewers, following sewerage rehabilitation works to convert combined-type to separate-type systems. The selected case study sewage treatment area recently completed a large-scale rehabilitation work; the area incorporates six sub-areas (SAs) and one wastewater treatment plant (WWTP), the latter having treatment capacity of 11,000 m3/d. Sewage flow generated in dry weather was domestic sewage flow only. Wet weather wastewaters consist of the dry weather sewage flow, in addition to rainfall-derived infiltration/inflow. In order to calculate wet weather wastewater flows of the six SAs, an advanced regression model was used. This was calibrated and verified using long-term monitoring flow data of 816 and 204 h, respectively; the model was then used to predict wastewater flows for 168 h. Hydraulic simulations of intercepting sewers were conducted using a conventional pipe hydrodynamic model (i.e. Saint-Venant equations). By assu...

9,10-bis(3′′,5′′-diphenylbiphenyl-4′-yl)anthracene (TAT) and 4-(1′-(3′,5′-diphenylbiphenyl-4-yl)anthracen-9-yl)-N,N-diphenylaniline (TATa) which have electroluminescence (EL) maximum values of 441nm and 469 nm were used blue emitting materials in organic light emitting diodes (OLED). OLED devices were fabricated and characterized by co-deposited emitters of TAT and TATa with different ratios. C.I.E. values of the devices using TAT and TATa were changed from (0.148, 0.081) to (0.139, 0.194).

Two color white EML is proposed by using blending and spin-coating method through a co-host/dopant system. Device performances were systematically compared based on the optical property of with/without interlayer PVK. When 1-[1,1’;3’,1’’]Terphenyl-5’-yl-6-(10-[1,1′;3′,1′′] terphenyl-5′-yl-anthracen-9-yl)-pyrene (TP-AP-TP) is a blue emitter with high luminance and external quantum efficiency, NPB is used as a co-host material which has HTL property and wide band gap like a blue emitter. DPAVBi and Rubrene were each used as blue dopant and yellow dopant. Luminance efficiency of the device used interlayer was 4.31cd/A, a value 30% higher than without interlayer (3.31 cd/A) at 10 mA/cm2.