• Advances in concrete construction
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• v.14 no.5
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• pp.341-354
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• 2022

Treatment of solid waste building materials is a crucial method of disposal and an area of ongoing research. New standards for the treatment of solid waste building materials are necessary due to multisource features, huge quantities, and complicated compositions of solid waste. In this research, sustainable nanomaterial mixtures containing nano-paper waste (NPW) and nano-metakaolin (NMK) were used as a substitute for Portland cement. Portland cement was replaced with different ratios of NPW and NMK (0%, 4%, 8%, and 12% by weight of cement) while the cement-to-water ratio remained constant at 0.4 in all mortar mixtures. The fresh properties had a positive effect on them, and with the increase in the percentage of replacement, the fresh properties decreased. The results of compressive strength at 7 and 28 days and flexural strength at 28 days show that the nanomaterials improved the strength, but the results of NMK were better than those of NPW. The best replacement rate was 8%, followed by 4%, and finally 12% for both materials. The combination of NMK and NPW as a replacement (12% NMK + 12% NPW) showed less shrinkage than the others because of the high pozzolanic reactivity of the nanomaterials. The combination of NMK and NPW improved the microstructure by increasing the hydration volume and lowering the water in the cement matrix, as clearly observed in the C-S-H decomposition.

• Journal of Electrochemical Science and Technology
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• v.14 no.3
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• pp.272-282
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• 2023

Ni-rich layered oxides cathode has recently gained attention as an advanced cathode material due to their applicable energy density. However, as the Ni component in the layered site is increased, the high reactivity of Ni⁴⁺ results in parasitic reaction associated with decomposing electrolyte, which leads to a rapid decreasing the lifespan of the cell. The electrolyte additive triallyl borate (TAB) improves interfacial stability, leading to a stable cathode-electrolyte interphase (CEI) layer on the LNCM83 cathode. A multi-functionalized TAB additive can produce a uniformly distributed CEI layer via electrochemical oxidation, which implies an increase in long-term cycling performance. After 100 cycles at elevated temperature, the cell tested by 0.75 TAB retained 88.3% of its retention ratio, whereas the cell performed by TAB-free electrolyte retained 64.1% of its retention. Once the TAB additive formed CEI layers on the LNCM83 cathode, it inhibited the decomposition of carbonate-based solvents species in addition to the dissolution of transition metal components from the cathode. The addition of TAB to LNCM83 cathode material is believed to be a promising way to increase the electrochemical performance.

• Science of Emotion and Sensibility
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• v.2 no.2
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• pp.37-42
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• 1999

Long-term exposure to loud noise affects performance since it changes arousal level, distracts attention, and also is able to evoke subjective stress accompanied by negative emotional states. The purpose of the study was to analyze dynamics of subjective and physiological variables during a relatively long-lasting (30 min) exposure to white noise (85 dB[A]). Physiological signals were recorded on 15 college students during 30 min of intense auditory stimulation. Autonomic variables, namely skin conductance level , non-specific SCR number, inter-best intervals in ECG, heart rate variability index (HF/LF ratio of HRV), skin temperature, as well as respiration rate were analyzed on 5 min epoch basis. Psychological assessment (subjective rating of stress level) was also repeated every 5 min. Statistical analysis was employed to trace the time course of the dynamics of subjective and autonomic physiological variables and their relationships. Results showed that the intense noise evoked subjective stress as well as associated autonomic nervous system responses. However it was shown that physiological variables endured specific changes in the process of exposure to the loud white noise. Discussed were probable psychophysiological mechanisms mediating reactivity to long-term auditory stimulation of high intensity, namely short-term activation, followed by transient adaptation (with relatively stable autonomic balance) and then a subsequent wave of arousal due to tonic sympathetic dominance.

• Korean Journal of Veterinary Research
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• v.63 no.1
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• pp.2.1-2.7
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• 2023

Fenbendazole (FBZ) is a benzimidazole anthelmintic widely used to treat parasitic infections. The anticancer effect of FBZ has been recently highlighted leading to its consideration as a potential anticancer agent. Although previous studies have demonstrated the effect of FBZ on cancer cells, there is a paucity of studies on the effect of FBZ on lymphoma cells and normal immune cells. Herein, we investigated the effects of FBZ on a mouse lymphoma cell line, EL-4 cells, and spleen cells, using vincristine as a positive control. The cellular metabolic activity of EL-4 cells was decreased by FBZ, but that of the spleen cells was not decreased. Moreover, FBZ reduced the mitochondrial membrane potential and induced reactive oxygen species production in EL-4 cells, but not in spleen cells. FBZ induced G2/M phase arrest and increased the sub G0/G1 phase ratio, indicating apoptosis. Furthermore, compared to the control cells, the reactivity of spleen cells pretreated with FBZ to lipopolysaccharide was maintained. In summary, FBZ is cytotoxic to EL-4 cells, but not to spleen cells. This study provides experimental evidence that FBZ exerts an anticancer effect, and less cytotoxic effects and functional damage to normal spleen cells.

• Journal of the Korean Applied Science and Technology
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• v.34 no.2
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• pp.203-209
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• 2017

The propenyl ether-type monomers which are applicable for cationic photo-polymerization were synthesized by the condensation reaction of mono and di-functional alcohol with allyl bromide. To examine photo-curable reactivity, these monomers were combined with cationic photoinitiator to prepare coating composition. As a result, the initial rate of polymerization of POMB in mono propenyl ether type was 10.2, which was relatively lower than BPOB in di-propenyl ethers type. However, POMB containing 1.5mol% photoinitiator almost quantitatively reacted within 90 seconds. In addition, Sulfonium salt type photo-initiators containing long-alkyl group showed good solubility with monomers and apperaed to have comparatively higher rate of polymerization and conversion ratio when applying DPSA and DPST which have high acidity on all monomers.

• Journal of Energy Engineering
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• v.8 no.2
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• pp.309-316
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• 1999

A numerical study for the turbulent reacting flow in an orimulsion gasifier has been carried out to analyze the characteristics of chemical reaction by orimulsion droplets. In this study, our interest has been focused on the effect of oxidizer to orimulsion ratio, which is one of the key parameters of gasification operation, as well as on the distribution of chemical species. In addition, we have conducted numerical calculations to understand the effect of droplet size, spray angle and injection velocity of fuel so as to acquire the basic information on the operating range of orimulsion gasifier. The result of numerical calculations showed that the gas composition of CO and H$_2$concentrations was the highest when the oxidizer to orimulsion ratio was about 0.88 and the reactivity of orimulsion increased as the droplet size reduced with proper spray angle. Also, we have carried out the analysis on the orimulsion gasification in the 100 ton/day-scale gasifier based upon the prior study in order to obtain the basic data for the proper operating condition using orimulsion feed.

• CELLMED
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• v.5 no.1
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• pp.7.1-7.7
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• 2015

According to Ayurveda, an individual can be classified into any one of the seven constitutional types (Prakriti) depending on the dominance of one, two, or three Doshas. A 'Dosha' is representative of fundamental mechanisms that are responsible for homeostasis, and thus, to health. In the recent years, there have been several efforts to see whether certain physiological, haematological or biochemical parameters have any relationship with the constitutional types or not. The objective of the present study was to see if the results of autonomic function tests vary according to Prakriti of an individual. We conducted this study in clinically healthy volunteers of both the gender belonging to the age group of 17 to 35 years after obtaining their written consent. The Prakriti of these volunteers was assessed on the basis of a validated questionnaire and also by traditional method of interviewing. After confirming that the primary Dosha ascertained by both these methods matched, 106 volunteers were grouped into three on the basis of primary Dosha and were subjected to various autonomic function tests such as cold pressor test, standing-to-lying ratio, Valsalva ratio and pupillary responses such as pupil cycle time and pupil size measurement in light and dark. The results suggest that, the autonomic function tests in the healthy individuals may correlate linearly with the primary Dosha expressed in an individual. In particular, people with Kapha as the most dominant Dosha showed a tendency to have either a higher parasympathetic activity or a lower sympathetic activity with respect to their cardiovascular reactivity in comparison to the individuals with Pitta or Vata as the most dominant Dosha.

• Polymer(Korea)
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• v.25 no.3
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• pp.311-317
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• 2001

In this study, we synthesized bead-type GMA-DVB copolymer using glycidylmethacrylate (GMA) with high reactivity and hydrophilicity. Macrorecticular anion exchanger containing the trimethylammonium group were then prepared by amination with trimethylammonium chloride. We observed that the size of $NO_3^-$ is smaller than that of $SO_4^{2-}$ which disturb $NO_3^-$ removal in most of coexistent anions in ground water. Thus we investigated selective affinity for $NO_3^-$ and properties of individual ion exchangers with various DVB content. For each resins, we confirmed formation of copolymer by FT-IR spectrometer and investigated ion exchange capacity, swelling ratio, the amination yield and the effect with degree of crosslinking on adsorbability for nitrate. When amount of DVB is 4 wt%, amination yield, ion exchange capacity and swelling ratio was 384.3%, 3.25 meq/g and 77.1%, respectively. In these result, it can found that synthetic optimal condition is 4 wt% DVB content for monomer.

• Polymer(Korea)
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• v.38 no.4
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• pp.417-424
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• 2014

Reactivity and rheological behavior of highly concentrated polymer bonded explosives (PBX) simulant was studied. As a binder, thermosetting hydroxyl terminated polybutadiene (HTPB) was used. By using bimodal $CaCO_3$ (size ratio 10:1) and sugar particles (size ratio 25:1) as fillers, maximum 75 v% filling was possible during melt mixing. The relative viscosities of bimodal suspension were much lower than those of unimodal one and showed minimum values at 0.25 of fine particle fraction. In curing experiment, as curing temperature increased, the time of initiation and completeness of curing reaction became shortened, the torque kept low, and the change of internal temperature decreased.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.4
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• pp.257-262
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• 2013

The fluorine-containing waste water tends to show a higher removal efficiency through the coagulative precipitation process with calcium. However the tetrafluoroborate produced from the etching process is difficult to remaval due to it's low reactivity with calcium. The objective of this study is improving the efficiency of fluoride ion removal in tetrafluoroborate through decomposing. Research on tetrafluoroborate decomposition depending on reaction pH, temperature, and aluminum dosage were conducted, using a laboratory-scale reactor. The result shows that the reaction of tetrafluoroborate with aluminum is faster with lower pH, higher water temperature, and higher Al/T-F (Aluminum/Total Fluoride) mole ratio. It is found that there was no big change in concentration after over 120 minutes of reaction. This study is to be able to improve the efficiency of tetrafluoroborate and fluoride wastewater treatment by using aluminum.