Narin Tammarugwattana

Application of parallel ladder technique for purging oil residual inside the copper pipe

In iron pipe industry, one of the most important problems in manufacturing processes is the great amount of oil residual in copper pipe. This problem can be affected the use of copper pipe further such as difficulty in pipe soldering, pipe rust and leakage. This study aims to demonstrate the use of parallel ladder technique, the simple process with low additional costs, to purge out liquid residual in the pipe after ironing. This technique can improve the efficiency of the manufacturing process as well as increase the quality of the product. Nitrogen was applied in this process with the step-increasing pressure of 0, 5, 10, and 15 Bar. This supplied pressure levels are a function of time which depend on the length of pipe. Nitrogen with specified pressure levels were controlled by 3 sets of control valves which were parallelly arranged. For efficiency test, two sizes of copper pipe which are commonly used for producing coil of air conditioner were used as a case study, Pipe A (diameter of 7.29 mm, thickness of 0.25 mm, length of 10 km) and Pipe B (diameter of 8 mm, thickness of 0.25 mm, length of 10 km). From experiments, the parallel ladder technique can eventually reduce the liquid residual inside the pipe. For Pipe A, the residual was reduced from 1.468 mg to 0.045 mg or 3.65 %. For Pipe B, the residual was reduced from 1.916 mg to 0.054 mg or 7.29%. The average oil residual purged out from Pipe A and Pipe B were 1.42 mg or 96.35%, and 1.86 mg or 92.71%, respectively. It can also be indicated that water and oil residual in the pipe were significantly less than the standard limitation (0.1 mg/m or 30%).

An experimental study of natural lighting for energy conservation using top-up control method

This paper presents the experiment-based analysis of interior illuminance from natural lighting through clear glazed window of a reference room located in Bangkok, Thailand, during February to May 2007 as a case study. The point illuminances measured by photoconductive sensors were collected every 5 minutes and the average interior illuminance from natural lighting were then calculated instantaneously. In this study, natural lighting also aims to reduce the requirement of electric lighting during daytime (7 am-5 pm) of the reference room. If natural lighting alone cannot supply the light at the required value, the electric lighting is assumed to be switched on under top-up control method to maintain the standard illuminance level. The average interior illuminance, which comprises of natural light and electric light, is controlled to be stable at the IES standard level of 500 lux. Nine sets of high performance lamp, 56 lm/W of efficacy, are assumed to supply the light to meet the standard condition. The requirements of supplementary lighting and possible savings during the test months are finally estimated.

Study on Optical and Electrical Properties of Bismuth-Doped Nickel-Phthalocyanine Thin Films

The objective of this work is to investigate the optical and electrical properties of bismuth-doped nickel-phthalocyanine thin films (Bi-doped NiPc). The doped films were prepared by thermal co-evaporation as a function of Bi concentration. The amount of Bi in NiPc was controlled via different deposition rates between metal dopant and organic host. The optical properties of the hybrid films were characterized by spectroscopic techniques. Furthermore, the electrical properties e.g. charge carrier concentration and carrier mobility of Al/Bi-doped-NiPc/ITO devices were characterized by current-voltage and capacitance-voltage measurements. The results of optical properties suggest that the crystalline packing of NiPc molecules in all preparation conditions is a combination of α-phase (majority) and β-phase (minority). However, the evolution of β-phase NiPc is observed with the increase of metal doping concentration. Raman spectroscopic results reveal that there is no chemical bond taken place between Bi and NiPc. In addition, with increasing dopant concentration, electrical properties present the enhancement of conducting current of hybrid devices as result from the increment of both charge carrier concentration and charge carrier mobility.

Study of Optical and Electrical Properties of Tin-Doped Magnesium Phthalocyanine Thin Films Grown by Thermal Co-Evaporation

The aim of this work is to investigate specific properties of tin-doped magnesium phthalocyanine (Sn-doped MgPc) thin films grown by thermal co-evaporation. Morphological, optical and chemical properties of the doped-films were characterized by atomic force microscopy (AFM), UV-Visible spectroscopy and X-ray photoelectron spectroscopy (XPS). Furthermore, electrical properties of ITO/Sn-doped-MgPc/Al devices such as carrier mobility and carrier concentration were extracted from current-voltage and capacitance-voltage measurements. Morphology of the doped films shows strong dependence on the existence of Sn in the doped films as clearly observed by changing of features of the film surface e.g. surface grain size and roughness. Optical absorption spectra of all conditions provide regular three dominant beta-phase peaks at 352, 640 and 691 nm corresponding to absorption from B-band and Q-band, respectively. The electrical properties obtained from ITO/Sn-doped MgPc/Al device suggest that the enhancement of the current flow in the doped device is a result from the increase of both carrier mobility and carrier concentration. Moreover, photoelectron analysis reveals two formations of Sn dopant in MgPc those are tin metal and derivative of tin oxide.

Study on Optical and Electronic Properties of Sn-Doped ZnPc

Sn doped ZnPc films were deposited on intrinsic Si and glass substrates by organic source thermal co-evaporation technique with different deposition rates. Optical properties and electronic structure were characterized by UV-Vis spectroscopy and X-ray photoelectron spectroscopy (XPS) respectively. The UV-Vis results showed that phase transition of ZnPc from α-phase to β-phase occurred when Sn:ZnPc deposition rate is 0.3:0.7 or higher. XPS results indicated that the outer s electron of Sn atom is transferred to the ZnPc. Broadening of the C 1s spectra is observed with the increasing of Sn deposition rate. This broadening corresponds to the change of molecular environment surrounding carbon atoms in the Sn-doped ZnPc films.