• Journal of Environmental Science International
• /
• v.8 no.2
• /
• pp.255-261
• /
• 1999

To investigate the effects of strong acidic electrolytic water on the chloroplast, barley leaves were treated with strong acidic electrolytic water(pH 2.5). And to investigate the effects of weak acidic electrolytic water on the chloroplast development, etiolated barley leaves were treated with weak acidic electrolytic water(pH 6.5) during greening period. Chl contents, Fo, Fv, and Chl fluorescence quenching coefficient in barley leaves were measured during and after treatment of acidic electrolytic water. The following results were obtained. Chl a, b, and carotenoid were decreased with treatment of strong acidic electrolytic water. Chl contents were significantly decreased than that of the control after 5 min. These results provide evidence that the strong acidic electrolytic water dissimilate the Chl and so that the value of Fo was slightly increased. The strong acidic electrolytic water damaged PS II because Fo was increased and Fv, Fm, and Fv/Fm ratio were decreased. qP, qNP and qE were decreased. On the other hand qI was increased than that of the control. But Chl content and Chl fluorescence patterns were a little changed as the pH increase over 4.0 Chl a, b, and carotenoid were increased with treatment of weak acidic electrolytic water during greening period. Chl contents were significantly increased than that of control after 12 hours greening. These results provide evidence that the weak acidic electrolytic water accelerated the chlorophyll synthesis. And the weak acidic electrolytic water accelerated PS II development because Fv, Fm, qP and Fv/Fm ratio were increased than that of the control.

• Journal of the Korean institute of surface engineering
• /
• v.39 no.4
• /
• pp.190-197
• /
• 2006

The effects of blasting and acidic treatment on the corrosion characteristics of dental implant fabricated with Cp-Ti and Ti-6Al-4V alloy have been researched by using electrochemical methods. The fabricated implants were cleaned and sandblasted by $Al_2O_3$ powder and then acidic treatment was carried out in nitric acid solution. The surface morphology were observed using scanning electron microscope. The corrosion behaviors were investigated using potentiosat and EIS in 0.9% NaCl solution at $36.5{\pm}1^{\circ}C$. The potentio-dynamic test in 0.9% NaCl indicated that the corrosion potential of blasting and acidic treated implant was lower than that of non treated implant, but current density was higher than that of non treated implant. From the cyclic potentiodynamic test results of Ti implant, the passivation current density of blasting and acidic treated implant slightly higher than that of non treated implant. From A.C. impedance test results in 0.9% NaCl solution, polarization resistance($R_p$) value of blasting and acidic treated implant was lower than that of non treated implant. In case of blasting and acidic treated implant surface, the pits were observed in valley and crest of implant surface.

• Journal of environmental and Sanitary engineering
• /
• v.18 no.1
• /
• pp.41-50
• /
• 2003

Traditionally the supernatant after chemical treatment of metal acid wastewater is discharged in environment. The supernatant can be used as a coagulant as it contains effective metals. The aim of this study is to investigate the feasibility of treatment of dyeing wastewater using the supernatant after treatment by magnesium hydroxide and dolomite($Ca{\cdot}Mg(CO_3)_2$), of acidic metal wastewater. In dyeing wastewater treatment with the supernatant, optimum pH and dosage were determined. COD, turbidity and color were analyzed to evaluate the performance of treatment. In the case of magnesium hydroxide, the optimum dosage was 10%(v/v) for supernatant A and 3%(v/v) for supernatant B. Color, turbidity and COD removal was 99~100%, 85~97% and 43~53%, respectively. In the case of dolomite, the optimum dosage was 10%(v/v) for supernatant A and 3% for supernatant B. Color, turbidity and COD removal was 96~99%, 62~9l% and 52~53%, respectively.

• Journal of Korean Society of Water and Wastewater
• /
• v.12 no.3
• /
• pp.30-40
• /
• 1998

Increasing water consumption produced sludge problems of the water treatment plants. The objective of this study is to investigate aluminium coagulants recovery n acidic and alkaline conditions. Water treatment plant sludge produced in Pusan Metropolitan City were tested for the aluminium extraction process. Experiment samples were obtained in summer from water treatment plants of Deoksan and Myongjang. Aluminium coagulants used in these plants during the test period were polyaluminium chloride(PAC), polyaluminium sulfate organic(PSO), polyaluminium sulfate silicate(PASS). Aluminium contents of water treatment sludge were in the range of 7.2~10.9% of the total solids. The recovery percentages for aluminium and iron by acidic extraction method was evaluated to 88% and 42% respectively. Extracted mass variation for other materials such as iron, manganese, total organic carbon was observed during the extraction operation. Alkaline extraction produced more than two times amount of total organic carbon than that in the acidic extraction process.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.02a
• /
• pp.323-323
• /
• 2010

Saw damage of crystalline silicon wafer is unavoidable factor. Usually, alkali treatment for removing the damage has been carried out as the saw damage removal (SDR) process for priming the alkali texture. It usually takes lots of time and energy to remove the sawed damages for solar grade crystalline silicon wafers We implemented two different mixed acidic solution treatments to obtain the improved surface structure of silicon wafer without much sacrifice of the silicon wafer thickness. At the first step, the silicon wafer was dipped into the mixed acidic solution of $HF:HNO_3$=1:2 ration for polished surface and at the second step, it was dipped into the diluted mixed acidic solution of $HF:HNO_3:H_2O$=7:3:10 ratio for porous structure. This double treatment to the silicon wafer brought lower reflectance (25% to 6%) and longer carrier lifetime ($0.15\;{\mu}s$ to $0.39\;{\mu}s$) comparing to the bare poly-crystalline silicon wafer. With optimizing the concentration ratio and the dilution ratio, we can not only effectively substitute the time consuming process of SDR to some extent but also skip plasma enhanced chemical vapor deposition (PECVD) process. Moreover, to conduct alkali texture for pyramidal structure on silicon wafer surface, we can use only nitric acid rich solution of the mixed acidic solution treatment instead of implementing SDR.

• Analytical Science and Technology
• /
• v.19 no.4
• /
• pp.285-289
• /
• 2006

In this study, the effect of an acidic treatment on granular activated carbon (GAC) and activated carbon fibers (ACF) was investigated for a $Pb^{2+}$ and $Ni^{2+}$ ion adsorption. 1.0 M nitric acid solution was used as the acid solution for the surface treatment. Surface properties of the GAC and ACF were characterized by the pH, elemental analysis and pHpzc (pH of the point of zero charge). Their specific surface area and the pore structure were also evaluated by the nitrogen adsorption data at 77K. As a result, the acidic treatment led to an increase of the oxygen-containing functional groups. Furthermore, the adsorption capacity of the acid-treated GAC and ACF was improved in the order of acidic-ACF > untreated-ACF > acidic-GAC > untreated-GAC, though the decrease in specific surface area induced by a pore blocking of the functional groups was observed.

• Korean Journal of Human Ecology
• /
• v.16 no.5
• /
• pp.1051-1059
• /
• 2007

This study intends to find out possible variations in physical properties and color of hair depending on dye type(acidic and alkalic) and permanent treatment/hair dyeing procedure. To meet the goals, healthy hair samples were taken from 5 women's hair speciment in 20's without experiencing in any harmful substance via long-term medications. and beauty care using chemicals. To get possible findings depending upon hair dye type and treatment procedure, both acidic and alkalic hair dye were applied on some specimens after permanent treatment, while on other specimens before permanent treatment. In order to determine scale damage, this study used SEM(Hitachi S-2500C) both hair thickness and tensile strength were measured with optical microscope(Nikon, MM-60/L3T) and Instron (4482-standard). Wave configuration was measured transverse and longitudinal round diameter. The chromaticity of each specimen was measured using a spectrocolorimeter(Color Techno System, JP/JX-777) with visual $C/2^{\circ}$ (at $2^{\circ}$ with C light source) monitor fixed to determine Lab and CMYK values. As a result, it was found that hair specimens were more significantly damaged with alkalic hair dye treatment than with acidic hair dye treatment, while hair specimens were more effectively dyed with the former hair dye type than with the latter one. For possible results depending on treatment procedure, it was found that hair specimens were less damaged but more effectively dyed with permanent treatment followed by hair dyeing than vice versa. Therefore, it was concluded that permanent treatment followed by acidic hair dyeing would be more effective in reducing hair damages.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.37 no.3
• /
• pp.17-22
• /
• 2005

The cleaning efficiency of papermaking felt which is contaminated with fiber fines and various micro-materials was investigated and compared between the application of enzyme and commercial detergent. It was found that the cleaning efficiency by the treatment of acidic-based detergent was more efficient than that of alkaline-based one in the conventional commercial detergent. it was also observed that the treatment design of first acidic-based detergent treatment to second alkaline-based detergent procedure was better in the cleaning efficiency, compared to alkaline based-to-acidic based one. The cleaning property of felt with enzyme was resulted in good cleaning efficiency, without any addition of surfactant. Especially, the enzyme treatment under alkaline condition (pH 10) showed a better cleaning result than that under acidic condition(pH 5). The addition of nonionic surfactant to the enzyme increased the cleaning efficiency of felt and decreased the cationic demand of wastewater. These results showed more favour than the application of conventional commercial detergent.

• Resources Recycling
• /
• v.7 no.1
• /
• pp.41-49
• /
• 1998

This papcr covcrs ihe recovery process of aluminum coagulant by acidic exlraclion which can develop the dewaterability'of residual sludge solids and ihc reduclion ot sludge valumc and mass. Simultmeously, variables affecting acidic extaction of aluminum arc discussed It is represented that the characteristics of recovcrcd coagulant is assessed mth rcspcct to aluminum content. coagulalion effeaiveness, and trace contaminants. The treatment methods of residual sludge solid following acidic extraction arc also d~scussed. Fillally, we suggest some cases in which the results from laboratory can he applied to the fullscale operation and future domestic mosoect of it.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2011.10a
• /
• pp.335-343
• /
• 2011

We examined the effect of the acidic liquid from carbonized rice hull(ALCRH) treatments to molded fiber packages(MFP) on weight, Haugh unit, pH and microbial activity of egg to extend the shelf life in egg packaging. Higher concentration and surface spray treatment of the acidic liquid extended the shelf life of egg. ALCRH treatment to MFP improved the performance of the packaging for egg in terms of decreased weight loss and retarded microorganism growth of eggs during storage.