• Analytical Science and Technology
• /
• v.16 no.2
• /
• pp.159-165
• /
• 2003

To develop an ionic equilibria model applicable to the sulfuric acid leaching solutions of zinc oxide ore, the method of the Pitzer equation and that of the Vasil'ev equation were compared. As the ionic strength of the solution increased to 9 m, the results of ionic equilibria by the Pitzer equation were more accurate than those by Vasil'ev. To simulate the sulfuric acid leaching solutions of zinc oxide ore, the mixed solutions with the various composition of $ZnSO_4-Fe_2(SO_4)_3-Na_2SO_4-H_2SO_4-NaOH-H_2O$ were prepared. The pH values calculated in this study agreed well with those measured at $25^{\circ}C$.

• Journal of the Korean Mathematical Society
• /
• v.58 no.1
• /
• pp.29-44
• /
• 2021

The set D of column vectors of a generator matrix of a linear code is called a defining set of the linear code. In this paper we consider the problem of constructing few-weight (mainly two- or three-weight) linear codes from defining sets. It can be easily seen that we obtain an one-weight code when we take a defining set to be the nonzero codewords of a linear code. Therefore we have to choose a defining set from a non-linear code to obtain two- or three-weight codes, and we face the problem that the constructed code contains many weights. To overcome this difficulty, we employ the linear codes of the following form: Let D be a subset of ��2n, and W (resp. V ) be a subspace of ��2 (resp. ��2n). We define the linear code ��D(W; V ) with defining set D and restricted to W, V by $${\mathcal{C}}_D(W;V )=\{(s+u{\cdot}x)_{x{\in}D^{\ast}}|s{\in}W,u{\in}V\}$$. We obtain two- or three-weight codes by taking D to be a Vasil'ev code of length n = 2m - 1(m ≥ 3) and a suitable choices of W. We do the same job for D being the complement of a Vasil'ev code. The constructed few-weight codes share some nice properties. Some of them are optimal in the sense that they attain either the Griesmer bound or the Grey-Rankin bound. Most of them are minimal codes which, in turn, have an application in secret sharing schemes. Finally we obtain an infinite family of minimal codes for which the sufficient condition of Ashikhmin and Barg does not hold.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2003.07a
• /
• pp.1065-1070
• /
• 2003

Controlling synthesis conditions of ZnS:Cu,Al and ZnS:Cu electroluminescent phosphors we optimized particle size, color properties and efficiency. Surface properties were studied by new method and showed correlation with luminescence as shown by the analysis of EL spectra with Fok-Alentsev method. Luminance and maintenance improvement was achieved by the electron-beam annealing due to additional decomposition of $ZnS-Cu_{2}S$ solid solution and formation of centers of blue luminescence.

• Nuclear Engineering and Technology
• /
• v.54 no.7
• /
• pp.2579-2585
• /
• 2022

Ceramics of quaternary garnets (Gd,Y)₃Al₂Ga₃O₁₂ doped with Ce, Tb have been fabricated and evaluated as prospective materials for indirect energy converters of α-and β-voltaic. Samples were characterized at excitation with an X-ray source and an intense 150 keV electron beam and showed good temperature stability of their emission and tolerance to irradiation. The role of X-rays accompanied the α-particle emitting in the increase of the conversion efficiency is clarified. The garnet-type structure of the matrix in the developed materials allows the production of quality crystalline mass with a light yield exceeding that of the commonly used YAG: Ce scintillator by a factor of two times.

• Archives of Plastic Surgery
• /
• v.49 no.3
• /
• pp.296-303
• /
• 2022

Background In recent years thread lift has become widespread; however, existing methods need to improve their long-term outcome, which requires considering topographic anatomy of face and neck, especially the ligamentous apparatus. This study aims to assess the effectiveness and safety of an innovative method of one-time three-step thread facelift, which provides an additional support to the ligamentous structures of the upper, middle, and lower thirds of the face and neck. Methods The study included 357 patients aged 32 to 67 years with various morphotypes of aging. The original method of thread lift was applied, and its effectiveness was followed up for to 2 years. The Wrinkle Severity Rating Score (WSRS) and Global Aesthetic Improvement Scale (GAIS) scores were used for assessment by investigators, independent observers, and patients. Statistical significance was determined using paired t-test and chi-square test. Results The mean WSRS score was 3.88 ± 0.88 before the thread lift, 1.93 ± 0.81 one month after the procedure, and 2.36 ± 0.85 after 2 years of follow-up. The mean GAIS was 4.80 ± 0.04 one month after thread lift, and 4.01 ± 0.04 after 2 years, while in the patients' assessment Global Satisfaction Scale was 4.86 ± 0.02 and 4.10 ± 0.02, respectively. There were no clinically significant complications throughout the observation period. Conclusion The new method of one-time three-step thread fixation of the soft tissues of the face and neck demonstrated a high degree of satisfaction by both experts and patients after 2 years of follow-up. It showed high efficacy and safety, including in the group of patients with pronounced age-related changes of the skin of face and neck.