• Journal of the Korean Wood Science and Technology
• /
• v.22 no.3
• /
• pp.32-38
• /
• 1994

The methods in wood processing are so limited at present that a scope of its utilization is restricted. This often makes wood itself less valuable as a material comparing with other materials, that is, plastics, metals, and glass. Such differences are due to a lack of plasticity in wood, i.e. it cannot be melted, dissolved, or softened sufficiently for molding. However, once plastic properties are added to wood, it becomes more useful material. This further broadens the method in wood processing to a variety of fields. In this way, wooden material which is limited in use can be modified into a high quality product with additional value. Furthermore, utilization of wastes from wood, for example, would be made viable. In this study, thermoplasticization was carried out by benzylation of wood(sawdust). Various factors those affect the reaction were tested to produce benzylated wood with different degrees of substitution. Reaction temperature and time were the quite important factors. Optimum reaction temperature was 110$^{\circ}C$, and weight percent gains(WPG) of final products increased gradually with the increase of reaction time. The pretreatment (or preswelling) of wood with alkaline solution had a critical effect on benzylation. and the concentration of alkaline solution should be above 30% to obtain high weight percent gain. The thermal flow temperature of the benzylated wood decreased with the increase in weight percent gain, that of 80% weight percent gain is about 200$^{\circ}C$.

• Journal of the Korean Wood Science and Technology
• /
• v.37 no.4
• /
• pp.397-405
• /
• 2009

In this study, we investigated the potential of producing bioethanol from Liriodendron tulipifera by using oxalic acid pretreatment. Amounts of fermentable sugars, mostly xylose and glucose, in the liquid fraction (hydrolysate) was $40.22g/{\ell}$ after the biomass was pretreated with 0.037 g/g of oxalic acid for 20 minutes at $160^{\circ}C$. Production amounts of ethanol was $8.6g/{\ell}$ from the 72 hours of simultaneous saccharification and fermentation (SSF) on solid fraction of the pretreated sample. At the same condition, when the reaction time increased to 40 minutes, $32.66g/{\ell}$ of fermentable sugars in the hydrolysate and $9.5g/{\ell}$ of ethanol was produced from the process of pretreatment and SSF. As a result of analyzing the fermentation inhibitors, such as acetic acid, 5-HMF, furfural and total phenolic compounds, as the reaction time increased, the amount of the fermentation inhibitors in the hydrolysate increased. Production of the fermentation inhibitors was more affected by initial concentration of oxalic acid rather than reaction time. $3.39{\sim}5.78g/{\ell}$ of acetic acid was produced by pretreatment with 0.013 g/g of oxalic acid, and the amount of furfural produced by decomposition of xylose was 2~3 times higher than the amount of 5-HMF produced by decomposition of glucose. All the hydrolysates contained more than $5g/{\ell}$ of total phenols considered as the degradation product of lignin. Therefore, by analyzing the amount of fermentable sugars and fermentation inhibitors in the hydrolysate, and producing ethanol from SSF of solid fraction of the pretreated sample, the biomass pretreated with 0.037 g/g of oxalic acid for 20 minutes at $160^{\circ}C$ can be expected to produce the most ethanol.

• Microbiology and Biotechnology Letters
• /
• v.32 no.2
• /
• pp.184-189
• /
• 2004

Rice wine cake (RWC) is the solid waste obtained after rice wine fermentation. For the mass production of the spores of yeast Saccharomyces from RWC, the optimum pretreatment condition of RWC, the optimum composition of culture medium, and the optimum culture condition were examined. For sporulation, yeast cells were grown in the pre sporulation medium (PSM), transferred into sporulation medium (SM) containing 1 % potassium acetate, and incubated in a rotary shaking incubator at $25^{\circ}C$ for 4 days. The supernatant of the mixture of RWC and water was used as the presporulation medium (PSM). The optimum temperature and time for the pre-incubation of the mixture of RWC and water (1:2) to obtain maximum sporulation yield were $V^{\circ}C$ and 24 hr, respectively, and optimum culture time in PSM was 48 hr. Using these optimum conditions, the asci number obtained was 0.72$ 1.06${\times}$10^{8}$$m\ell$. The addition of wheat coat koji into SM increased the final number of asci to beTEX>$10^{8}$ $m\ell$. Spores were formed in the SM with the initial pH of 7-11, but no spores were formed in the SM with the initial pH of 5. To save the time and effort to pretreat the RWC, 2% and 0.5% RWC without any pretreatment were directly added into PSM containing 1 % brown sugar and SM, respectively, and the maximum asci number of $1.27${\times}$10^{8}$ /$m\ell$ was obtained.

• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.4
• /
• pp.524-531
• /
• 2012

The objective of this study was to investigate the organic solubilization (SCOD) and improvement of methane production for pig slurry by thermal hydrolysis. A sludge cake was pretreated by thermal hydrolysis at different reaction temperatures (200, 220, 250, $270^{\circ}C$). Ultimate methane potential (Bu) was determined at several substrate and inoculum (S/I) ratios (1:9, 3:7, 5:5, 7:3 in volume ratio) by biochemical methane potential (BMP) assay for 73 days. Pig slurry SCOD were obtained with 98.4~98.9% at the reaction temperature of $200{\sim}270^{\circ}C$. Theoretical methane potentials ($B_{th}$) of thermal hydrolysates at the reaction temperature of $200^{\circ}C$, $220^{\circ}C$, $250^{\circ}C$, $270^{\circ}C$ were 0.631, 0.634, 0.705, $0.748Nm^3\;kg^{-1}-VS_{added}$, respectively. $B_u$ of $200^{\circ}C$ thermal hydrolysate were decreased from $0.197Nm^3\;kg^{-1}-VS_{added}$ to $0.111Nm^3\;kg^{-1}-VS_{added}$ with the changes of S/I ratio from 1:9 to 7:3, and also $B_u$ of different thermal hydrolysates ($220^{\circ}C$, $250^{\circ}C$, $270^{\circ}C$) showed same tendency to $B_u$ of $200^{\circ}C$ thermal hydrolysate according to the changes of S/I ratio. Anaerobic biodegradability ($B_u/B_{th}$) of $200^{\circ}C$ thermal hydrolysate at different S/I ratios was decreased from 32.2% for S/I ratio of 1:9 to 17.6% for S/I ratio of 7:3. $B_u/B_{th}$ of $220^{\circ}C$, $250^{\circ}C$, and $270^{\circ}C$ thermal hydrolysat were decreased from 36.4% to 9.6%, from 31.3% to 0.8%, and from 26.6% to 0.8%, respectively, with the S/I ratio change, respectively. In this study, the rise of thermal reaction temperature caused the decrease of anaerobic digestibility and methane production while organic materials of pig slurry were more solubilized.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.40 no.2
• /
• pp.235-244
• /
• 2011

The physicochemical properties and quality changes in salted and dried brown croaker products using deep seawater salt were investigated for preparation with different pretreatment, salting and drying conditions. Optimum salt concentration, salting time and drying time for product were 20% of body weight, 12 hrs at room temperature ($25{\pm}2^{\circ}C$), and 24 hrs at $30{\pm}2^{\circ}C$, respectively. The volatile basic nitrogen (VBN), peroxide value (POV), viable cell count and acid value (AV) of viscera and blade removed products were 18.9~22.4 mg%, 21.0~32.5 meq/L, and 2.3~4.4 mg/mL, $2.0\sim3.5{\times}10^3$ CFU/g, respectively and only viscera removed products were 31.2~38.1 mg%, 40~55.2 meq/L, 7.0~11.5 mg/mL, $4.1\sim5.5{\times}10^3$ CFU/g, respectively. Changes in quality of salted and dried brown croaker products were investigated during storage at room temperature and $5{\pm}2^{\circ}C$. The POV, AV and viable cell counts of salted and dried brown croaker products increased in commercial salt used and only viscera removed products compared with deep seawater salt used and viscera and blade removed products during storage time. Results in this study showed that the deep seawater salt was very effective for quality control of salted and dried brown croaker products and pretreatment method was a very important factor for preparation products. The optimum conditions for preparation of salted and dried brown croaker product were 20% of body weight for salt concentration, 12 hrs at $25{\pm}2^{\circ}C$ for salting time, and 24 hrs at $30{\pm}2^{\circ}C$ for drying time. Optimum storage time for quality maintenance was 14 days at $5{\pm}2^{\circ}C$.

• Korean Chemical Engineering Research
• /
• v.54 no.4
• /
• pp.494-500
• /
• 2016

In order to remove acetyl group from yellow poplar, deacetylation was performed using sodium hydroxide (NaOH) prior to oxalic acid pretreatment. During the deacetylation ($60^{\circ}C$ for 80 min, 0.8% NaOH), most of the acetyl group were removed from hemicellulose. Simultaneous saccharification and fermentation (SSF) and semi-SSF were carried out based on solid loading (10, 12.5, 15%) of deacetylated biomass and pre-hydrolysis with enzymes (0, 6, 12, 24 h). The highest ethanol was obtained as 26.73 g/L after 120 h when 10% of biomass was used for SSF. It is corresponding to 88.41% of theoretical ethanol yield. At the 12.5% and 15% of biomass loading, the highest ethanol was obtained from 6 h pre-hydrolysis. It was 32.34 g/L and 27.15 g/L, respectively, and corresponding to ethanol yield of 85.58 and 59.87%. In order to remove fermentation inhibitors from hydrolysates, overliming was performed using calcium hydroxide ($Ca(OH)_2$). The highest ethanol was 5.28 g/L after 72 h of fermentation.

• Neonatal Medicine
• /
• v.15 no.1
• /
• pp.32-37
• /
• 2008

Purpose : Perinatal asphyxia is an important cause of neonatal mortality and subsequent lifelong neurodevelopmental handicaps. Although many treatment strategies have been tested, there is currently no clinically effective treatment to prevent or reduce the harmful effects of hypoxia and ischemia in humans. In the clinical setting, maternal hyperthermia induces adverse effects on the neonatal brain, but recent studies have shown that hyperthermic pretreatment (PT) plays some role in hypoxic-ischemic (HI) injuries of the developing brain. The present study investigated the effect of hyperthermic PT on HI brain injuries in newborn rats. Methods : HI was produced in 7-day-old neonatal rats by unilateral common carotid artery ligation, followed by hypoxia with 8% oxygen at $38^{\circ}C$ for 2 hours. Twenty-four hours before HI, one-half of the pups were exposed to a $40^{\circ}C$ environment for 2 hours. The severity of the brain injury was assessed 7 days after the HI. Results : Hyperthermic PT reduced the gross and histopathologic findings of brain injury from 64.7 to 31.2% (P<0.05). There were no differences in location and severity of injury between the pretreated and control brains. Conclusion : These findings indicate that hyperthermic PT provides neuroprotective benefits on HI in the developing brain. Also, these findings suggest maternal hyperthermia may have protective effect on perinatal HI brain injuries.

• Korean Journal of Veterinary Research
• /
• v.44 no.1
• /
• pp.15-21
• /
• 2004

This paper describes the development of $^{99m}Tc$ tricarbonyl cysteine as potential renal function diagnostic radiopharmaceutical and evaluation of its biological characteristics using experimental animals. l-Cysteine was labeled efficiently with $^{99m}Tc$ tricarbonyl precursor $([^{99m}Tc(CO)_3(H_2O)_3)]^{+})$ under 30 min heating at ${75^{\circ}C}$. Labeling yield and stability were analyzed by high performance liquid chromatography (HPLC). The biodistribution property of $^{99m}Tc$ tricarbonyl cysteine in mice and its dynamic imaging profiles in rabbits were carried out. To investigate the excretion mechanism of $^{99m}Tc$ tricarbonyl cysteine, tubular transport inhibition test with probenecid was adopted. $^{99m}Tc$ tricarbonyl cysteine was obtained with a high labeling yield under the moderate condition. The results of biodistribution experiments of $^{99m}Tc$ tricarbonyl cysteine in ICR mice at 3 and 90 min provided that $^{99m}Tc$ tricarbonyl cysteine was very highly accumulated in the kidney and bladder, thereby almost 99% of $^{99m}Tc$ tricarbonyl cysteine was excreted within 90 min post injection. The same results were confirmed by the whole body dynamic images for 30 minutes and static images in rabbits at given time intervals after injection. Renogram of $^{99m}Tc$ tricarbonyl cysteine in rabbits showed that its $T_{max}$ and $T_{1/2}$ of $^{99m}Tc$ tricarbonyl cysteine were $2.33{\pm}0.56$ and $4.30{\pm}0.79$ min, respectively. The $T_{max}$ of $^{99m}Tc$ tricarbonyl cysteine with probenecid pretreatment was $2.30{\pm}0.17$ min, whereas $T_{1/2}$ of that with probenecid pretreatment was $17.0{\pm}32.47$ min. $T_{1/2}$ of $^{99m}Tc$ tricarbonyl cysteine with probenecid pretreatment was significantly different, as compared to the result without probenecid (p<0.0001). The results showed that the excretion of $^{99m}Tc$ tricarbonyl cysteine was extremely affected by probenecid. Therefore, $^{99m}Tc$ tricarbonyl cysteine was rapidly excreted from the kidney principally by the tubular secretion.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2011.10a
• /
• pp.167-177
• /
• 2011

Renewable energy resources and technologies have the potential to provide long-lasting solutions of the global energy-requirements faced by the economic and environmental sectors of a nation. Therefore, waste money bills were used as renewable energy source for the production of bio-ethanol. In this study, different concentrated NaOH 0.5%. 1.0%, 2.0%, 3.0% and 0.0% (as a control) were used for 10, 20 and 30 mins at $121^{\circ}C$/15 psi in an autoclave. Saccharification and fermentation (aerobic and anaerobic) were carried out through commercial enzyme Celluclast 1.5 L, Novozymes 188 and Saccharomyces cerevisiae KCCM 11304 respectively. The results of pretreatment showed that the NaOH pre-treated substrate enhanced enzyme action and released more amount of glucose. The amount of glucose was found with the increasing concentration of NaOH and time $44996.95{\pm}6.30$, $46763.10{\pm}3.56$, $53421.32{\pm}4.72$, $63431.25{\pm}6.95$ and $56850.98{\pm}6.75\;ng/{\mu}l$ for 30 min respectively. As for bioethanol, the conversion rate of NaOH resulted $1010.08{\pm}4.71$, $1050.25{\pm}4.37$, $1109.49{\pm}4.39$, $1139.25{\pm}3.26$ and $1020.77{\pm}3.89$ ppm for aerobic; $16730.54{\pm}6.67$, $17076.45{\pm}6.25$, $17516.17{\pm}4.49$, $19782.68{\pm}6.19$ and $17973.39{\pm}7.50$ ppm for anaerobic and $18935.02{\pm}4.59$, $19895.45{\pm}5.39$, $21912.95{\pm}4.83$, $24895.21{\pm}6.72$ and $18961.21{\pm}4.90$ ppm for anaerobic condition with benzoic acid for respective condition. Thus, the results of the present work clearly revealed that with the increasing of alkali concentration might be more effective for bio-ethanol production from waste money bill, which is economic and environmental friendly.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.35 no.5
• /
• pp.62-71
• /
• 2003

This study was carried out to develop the bio-chemical pulping method to enhance the energy saving and decrease the capital cost through the soda pulping under atmospheric pressure ($100^{\circ}C$). Nonwood substrates, rice straw, were pretreated by white-rot fungi, Pleurotus cornucopiae. Several basic pieces of data that can be applied in soda pulping were acquired. The results of this study were as follows. Under the conditions without any nutrients or with glucose, N and glucose + N, the weight losses of rice straws inoculated by Pleurotus cornucopiae were 12.1∼32.6 %, 12.0∼26.3 %, 13.0∼25.4 % and 15.3∼24.7 % for 5, 10, 15, 20, 25 and 30 days incubation periods respectively. The more the fungal incubation was extended, the more the weight losses were gained. The yield of untreated rice straw was 54.8 % after pulping. When any nutrients was not added or glucose, N and glucose ＋ N were added for the pretreatment, the total yields were ranged to 57.3∼42.9 %, 51.0∼43.3 %, 51.7∼43.9 % and 52.1∼46.1 % for 5 different incubation periods respectively. The yields were gradually decreased based on the extending of the incubation periods. The physical properties of the rice straw soda pulp without fungal treatment, the density, breaking length, burst index, tear index and folding endurance were 0.24g/㎤, 2.32 Km, 0.91 kPaㆍ$m^2$/g, 46.7 mNㆍ$m^2$/g and 21 times, respectively. In the case of pretreatment without any nutrients or with glucose, N and glucose + N as nutrients, the density was 0.24g/㎤, the breaking length was 3.30∼6.46 Km, the burst index was 1.36∼3.01 kPaㆍ$m^2$/g, the tear index was 33.0∼57.0 mNㆍ$m^2$/g and the folding endurance was 14∼381 times at most incubating periods, when pulping was done. The physical properties were increased as the incubation duration was extended. Especially, when N and glucose ＋ N were added, the physical properties showed superior results during each incubation period.