• Nuclear Engineering and Technology
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• v.54 no.3
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• pp.984-990
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• 2022

Corrosion release behavior of Alloy 690 in high-temperature water was investigated under the conditions of injected Zn concentrations of 0 ppb, 10 ppb and 50 ppb. A protective oxide film composed of Zn(Fe_xCr_1-x)₂O₄ and Cr₂O₃ was formed with Zn injection, resulting in a better corrosion resistance. In comparison with the Zn-free condition, the corrosion release rate under the Zn-injection conditions was smaller. The corrosion release inhibiting factors were 1.7 and 1.9 under the conditions of 10 ppb and 50 ppb Zn-injection respectively. A foreseen application of the corrosion and corrosion release rates has been proposed and discussed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.4
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• pp.79-85
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• 2009

This paper describes the degradation properties of ZnO surge arresters impressed by lightning impulse currents. To investigate the deterioration behaviors of ZnO surge arresters due to lightning surges, the 8/20[${\mu}s$], 2.5[kA] standard lightning impulse currents were injected to the ZnO surge arrester under test. The power frequency AC and DC leakage currents flowing through the ZnO surge arresters with and without the injection of lightning impulse currents were measured. As a result, the leakage currents are increased and the asymmetry of the AC leakage current is pronounced as the number of injection of the impulse current increases. The ZnO grain of the surge arrester without the injection of lightning surges are uniform but the ZnO grain of the ZnO surge arrester with the injection of lightning impulse currents are deformed. Also, it was found that the decrease of the $Bi_2O_3$ due to the lightning impulse current leads to the lack of grain boundary layer and the current concentrated by the lack of grain boundary layer play an important role to degrade nonlinear property of ZnO surge arrester blocks.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.860-863
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• 2007

ZnO nano film for transparent thin film transistors is prepared by injection type source delivery system of atomic layer deposition. By using this delivery system the source delivery pulse time can dramatically be reduced to 0.005s in ALD system. ZnO nanofilms obtained at $150^{\circ}C$ are characterized.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.5
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• pp.471-477
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• 1997

A study detennined whether certain biochemical and physiological variables were altered during marginal Zn deficiency. Ten weaned crossbred Hereford Angus heifer calves, weighing $163{\pm}2kg$, were utilized. Five calves were fed a Zn - deficient (- Zn) brome-alfalfa hay diet containing 17 mg Zn/kg diet DM, and five calves were fed a Zn-adequate (+Zn) diet with 23 mg Zn/kg diet DM from $ZnSO_4$ added to the - Zn diet (total diet, 40 mg Zn/kg diet DM), for 32 d. At 21 d the - Zn calves had a reduction (p < .05) in feed efficiency. By 25 d, plasma Zn and alkaline phosphatase concentrations were reduced (p < .05) in the - Zn calves. Blood urea nitrogen, glucose, insulin, IGF-I, Cu plasma concentration and Zn and Cu concentrations of red blood cell (RBC) and liver were not altered (p > .05) by the - Zn diet through 25 d. In response to a single i. m. injection of dexamethasone (20 mg) on d 25, calves fed the two dietary Zn amounts showed no changes (p > .05) in plasma or RBC Zn and Cu concentrations, serum IGF-I, insulin, and glucose when measured at 6, 12, 24, 48, 72, and 96 h after injection. In response to an intradermal injection of phytohemagglutinin on d 30, cell mediated immune (CMI) response was reduced (p < .05) in the - Zn calves. These observations indicate that during a marginal Zn deficiency in calves, there was a decrease in feed efficiency, plasma Zn, serum alkaline phosphatase, and CMI response.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.5
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• pp.257-262
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• 2006

To evaluate the change in protective levels of zinc oxide (ZnO) varistors after the surge absorption, this paper investigated the effects of the number of injection and amplitude of lightning surges on the life of ZnO varistors for low voltages. Leakage currents flowing through ZnO varistors subjected to the $8/20{\mu}s$ impulse currents under 60 Hz AC voltages were measured. The surge simulator system ECAT that can generate $8/20{\mu}s$ impulse currents with a peak short-circuit of 5 $[kA_p]$ was used. The ZnO varistor leakage current increases with exposure to impulse current, and the number of injection of $8/20{\mu}s$ impulse currents to breakdown was inversely proportional to the amplitude of the test current. Behaviors of ZnO varistor leakage currents were strongly dependent on the number of injection and amplitude of $8/20{\mu}s$ impulse currents. ZnO varistors degrade gradually when subjected to impulse current, and the resistive leakage current flowing through ZnO varistors subjected to the $8/20{\mu}s$ impulse currents under 60 Hz AC voltages was significantly increased after a certain number of injection that is dependent on the amplitude of the test impulse current. As a result, the life of ZnO varistors mainly depends on the amplitude and occurrence frequency of lightning surges.

• Journal of the Semiconductor & Display Technology
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• v.9 no.1
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• pp.35-40
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• 2010

We have investigated the effects of hydrogen injection via in-situ gas addition ($O_2$, $H_2$, or $O_2$ + $H_2$ gas) and plasma post-treatment (Ar or Ar + H plasma) on material properties of ZnO that is considered to be as a channel layer in transparent thin film transistors. The variations in the electrical resistivity, optical transmittance and bandgap energy, and crystal quality of ZnO thin films were characterized in terms of the methods and conditions used in hydrogen injection. The resistivity was significantly decreased by injection of hydrogen; approximately $10^6\;{\Omega}cm$ for as-grown, $1.2\;{\times}\;10^2\;{\Omega}cm$ for in-situ with $O_2/H_2\;=\;2/3$ addition, and $0.1\;{\Omega}cm$ after Ar + H plasma treatment of 90 min. The average transmittance of ZnO films measured at a wavelength of 400-700 nm was gradually increased by increasing the post-treatment time in Ar + H plasma. The optical bandgap energy of ZnO films was almost monotonically increased by decreasing the $O_2/H_2$ ratio in in-situ gas addition or by increasing the post-treatment time in Ar + H plasma, while the post-treatment using Ar plasma hardly affected the bandgap energy. The role of hydrogen in ZnO was discussed by considering the creation and annihilation of oxygen vacancies as well as the formation of shallow donors by hydrogen.

• YAKHAK HOEJI
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• v.43 no.1
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• pp.48-54
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• 1999

Effects of zinc chloride (Zn) on the immune responses of lipopolysaccharide (LPS) were studied by using ICR mice. Mice were divided into 4 groups (10 mice/group), and Zn was given to the mice with i.p. injection at 0.3 mg/kg 5 times a week for 14 days, and 1 hr after Zn administration, LPS was given with i.p. injection at 5 mg/kg twice a week. Mice were immunized and challenged with sheep red blood cells (SRBC). Immunobiological responses were evaluated by humoral, cellular and nonspecific immunity. LPS treatment significantly increased the relative weights of spleen and thymus, hemagglutination titer (HA) and proliferation of splenocytes compared with those in controls, but significantly decreased the body weight gain. Zn treatment significantly increased proliferation of splenocytes and circulating leukocytes compared with those in controls. Combination of Zn and LPS significantly decreased the body weight gain and proliferation of splenocytes compared with those in controls. Combination of Zn and LPS significantly decreased HA and proliferation of splenocytes than in LPS alone. These findings indicate that zinc lowered the humoral immune responses of LPS.

• YAKHAK HOEJI
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• v.43 no.1
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• pp.98-103
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• 1999

Effects of Astragali Radix extract (AG) on the cell mediated-and nonlpecific immunotoxic responses of zinc chloride (Zn) were studied usign ICR mice. Mice were divided into 4 groups (10 mice/group), and Zn was given to the mice 1 hr after i.p. injection with 0.5g/kg of AG by i.p. injection daily for 10 days at a dose of 25 mg/kg. Immune responses on the responses on the relative weight of thymus, delayed-type hypersensitivity to SRBC (DTH), phagocytic activity and circulating leukocytes were evaluated. Zn treatment decreased body weight gain, the relative weight of thymus, DTH and circulating leukocytes compared with those in controls. AG treatment increased DTH, phagocytic activity and circulating leukocytes compared with those in controls. Combination of AG and Zn increased DTH and circulating leukocytes compared with those in controls, but decreased body weight gain and the relative weight of thymus. These findings indicated that AG decreased immunotoxicity of Zn on the DTH and circulating leukocytes.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.2
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• pp.139-144
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• 1998

Eighteen lambs were used to determine the effects of zinc (Zn) level and source on Zn status and immune function during both normal conditions and conditions of physiologic stress. Treatments consisted of a basal diet (27.6 mg of Zn/kg), and the basal diet supplemented with 25 mg of Zn/kg, added as either zinc oxide or zinc methionine. The basal diet was a corn-cottonseed hull-isolated soy protein- based diet (14% CP). Lambs were weighed and blood samples taken at 28-d intervals for determination of serum Zn and alkaline phosphatase activity. Weights and serum Zn were similar (p > 0.10) among treatments at all sampling days. To evaluate immune responses and Zn status during conditions of physiologic stress lambs were administered 100 I.U. of adrenocorticotrophin (ACTH) on d 112 and feed was withheld for 48 h. Cortisol levels were elevated (p < .01) 5 h post ACTH injection, but had returned to initial levels after 48 h. Lymphocyte blastogenesis ([$^3H$]-thymidine incorporation) on d 112 (prior to ACTH injection) and 114 was unaffected (p > .10) by dietary treatment. However, blastogenesis in response to pokeweed mitogen was greater (p < .0001), whereas the response to phytohemagglutinin was reduced (p < .01) following ACTH administration and fasting. Antibody response to administration of porcine red blood cells was unaffected (p > .05) by dietary treatment. These results indicate that, given the Zn concentration of the basal diet, there was no enhancement of immune function by supplemental Zn, either before or after lambs were subjected to stress.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.763-764
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• 2006

Ceramic Injection Moulding (CIM) technology has been successfully used for the fabrication of Mn-Zn Ferrite part. The binder was composed by polypropylene and paraffin wax. The optimal powder loading (58% vol.) was determined by means of rheological measurements. Threedifferent parts, toroids, bending and tensile probes were injected. Thermal and solvent-thermal debinding was designed based on DSC and TGA studies of the binder. The time of the debinding cycle was reduced using n-heptane to dissolve previously the paraffin wax. Final properties have been determined and compared with uniaxial pressure parts values. The densities obtained were slightly higher than those of uniaxial pressure parts and the magnetic properties presented similar values.