The Characteristics of Stack Separator Prepared from Composites of Stainless Steel and Tin<SUB>x</SUB> for Fuel Cell

Farkhod Turaev,Sung Bum Park,Taeho Bahn,Jung-Ho Ahn,Tae Hwan Hong,Sungjin Kim 한국표면공학회 2008 한국표면공학회 학술발표회 초록집 Vol.2008 No.-

Impact of the Introduction of New ISA on Uzbekistan’s Auditing Environment

Abdurakhim Turaev,문태형 한국무역연구원 2020 무역연구 Vol.16 No.4

Purpose The International Audit and Assurance Standards Board (IAASB) has released the Revised International Audit Reporting Standard to mitigate the expected differences in financial statement sacries and improve the value of the audit report. Design/Methodology/Approach In this study, a survey of 128 certified public accountants was conducted in order to predict the impact of New International Standards Auditing (ISA) on the audit environment in Uzbekistan and to prepare for them. Findings The results of the study are as follows: First, the key audit matters in the audit report said that the quality of the audit and the quality of the financial report ingested would be improved. Second, whether or not it is positive to distinguish between management and auditor responsibilities for going concern, and it is believed that these results did not provide an accurate answer because there was no accurate information on this. Third, it is not known whether the audit time will increase if the auditor’s other information verification procedures are strengthened, but it is said that it is highly likely that this will lead to an increase in audit fee. Fourth, although the disclosure of the name of the executive director was said to improve the quality of the audit, it was necessary to exclude the obligation to disclose the name of the executive director through the enactment of domestic laws. Research Implications There is a contribution to this study in that the New ISA sifts through the impact of audit quality, financial reporting quality, information value, etc. on the audit environment and provides prior knowledge of the problems that may arise after implementation.

Characteristics of a Stack Separator Prepared from Composites of Stainless Steel and TiNx for Fuel Cells

Farkhod R. Turaev,Sung Bum Park,Taeho Bahn,Sung Jin Kim,Jung-Ho Ahn,홍태환 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.54 No.3

A stack separator made from carbon or carbon composites has many advantages, such as electrochemical stability, low density, low contact resistance and good corrosion resistance. However, it has some weak points, including higher thickness and low manufacturing reliability. Therefore, many attempts have been made to fabricate a stack separator from materials that have low-cost, high manufacturing reliability and corrosion resistance. It is very important to take into account that it is very difficult to achieve good corrosion resistance of a stack separator at high temperatures. Therefore, many researchers have tried to use expensive materials that are high temperature and corrosion resistant superalloys. In this paper, the fabrication of a stack separator made of low-price metal and TiNx is investigated. Stainless steel, which is a low-price, corrosion resistant metal and TiNx are used as a reinforcement support to reveal high heat resistance and corrosion resistance and to decrease the hydrogen permeability. We fabricated the plates for use as stack separators reinforced by TiNx by mixing stainless-steel powders with 2 % of nano-sized TiNx. Spark plasma sintering (SPS) was chosen for sintering the composites. The physical properties of the specimens were analyzed by performing hardness tests, biaxial strength tests and shear strength tests. The electrochemical properties, such as the corrosion resistance and the hydrogen permeability, were also investigated. The microstructures of the specimens were investigated by using eld-emission scanning electron microscopy and the proles of the chemical compositions were analyzed by using energy dispersive X-Ray analysis. A stack separator made from carbon or carbon composites has many advantages, such as electrochemical stability, low density, low contact resistance and good corrosion resistance. However, it has some weak points, including higher thickness and low manufacturing reliability. Therefore, many attempts have been made to fabricate a stack separator from materials that have low-cost, high manufacturing reliability and corrosion resistance. It is very important to take into account that it is very difficult to achieve good corrosion resistance of a stack separator at high temperatures. Therefore, many researchers have tried to use expensive materials that are high temperature and corrosion resistant superalloys. In this paper, the fabrication of a stack separator made of low-price metal and TiNx is investigated. Stainless steel, which is a low-price, corrosion resistant metal and TiNx are used as a reinforcement support to reveal high heat resistance and corrosion resistance and to decrease the hydrogen permeability. We fabricated the plates for use as stack separators reinforced by TiNx by mixing stainless-steel powders with 2 % of nano-sized TiNx. Spark plasma sintering (SPS) was chosen for sintering the composites. The physical properties of the specimens were analyzed by performing hardness tests, biaxial strength tests and shear strength tests. The electrochemical properties, such as the corrosion resistance and the hydrogen permeability, were also investigated. The microstructures of the specimens were investigated by using eld-emission scanning electron microscopy and the proles of the chemical compositions were analyzed by using energy dispersive X-Ray analysis.

DECOMPOSITION FORMULAS FOR THE GENERALIZID HYPERGEOMETRIC ₄F₃ FUNCTION

Hasanov, Anvar,Turaev, Mamasali,Choi, June-Sang The Honam Mathematical Society 2010 호남수학학술지 Vol.32 No.1

By using the generalized operator method given by Burchnall and Chaundy in 1940, the authors present one-dimensional inverse pairs of symbolic operators. Many operator identities involving these pairs of symbolic operators are rst constructed. By means of these operator identities, 11 decomposition formulas for the generalized hypergeometric $_4F_3$ function are then given. Furthermore, the integral representations associated with generalized hypergeometric functions are also presented.

INTEGRAL REPRESENTATIONS FOR SRIVASTAVA'S HYPERGEOMETRIC FUNCTION HB

최준상,Anvar Hasanov,Mamasali Turaev 한국수학교육학회 2012 純粹 및 應用數學 Vol.19 No.2

While investigating the Lauricella's list of 14 complete second-order hypergeometric series in three variables, Srivastava noticed the existence of three additional complete triple hypergeometric series of the second order, which were denoted by HA, HB and HC. Each of these three triple hypergeometric functions HA, HB and HC has been investigated extensively in many di®erent ways including,for example, in the problem of ¯nding their integral representations of one kind or the other. Here, in this paper, we aim at presenting further integral representations for the Srivatava's triple hypergeometric function HB.

DECOMPOSITION FORMULAS FOR THE GENERALIZID HYPERGEOMETRIC 4F3 FUNCTION

HASANOV ANVARDJAN,최준상,TURAEV MAMASALI 호남수학회 2010 호남수학학술지 Vol.32 No.1

By using the generalized operator method given by Burchnall and Chaundy in 1940, the authors present one-dimensional inverse pairs of symbolic operators. Many operator identities in-volving these pairs of symbolic operators are rst constructed. By means of these operator identities, 11 decomposition formulas for the generalized hypergeometric 4F3 function are then given. Fur-thermore, the integral representations associated with generalized hypergeometric functions are also presented.

INTEGRAL REPRESENTATIONS FOR SRIVASTAVA'S HYPERGEOMETRIC FUNCTION H_C

Choi, Junesang,Hasanov, Anvar,Turaev, Mamasali The Honam Mathematical Society 2012 호남수학학술지 Vol.34 No.4

While investigating the Lauricella's list of 14 complete second-order hypergeometric series in three variables, Srivastava noticed the existence of three additional complete triple hypergeo-metric series of the second order, which were denoted by $H_A$, $H_B$ and $H_C$. Each of these three triple hypergeometric functions $H_A$, $H_B$ and $H_C$ has been investigated extensively in many different ways including, for example, in the problem of finding their integral representations of one kind or the other. Here, in this paper, we aim at presenting further integral representations for the Srivatava's triple hypergeometric function $H_C$.

DECOMPOSITION FORMULAS AND INTEGRAL REPRESENTATIONS FOR THE KAMP¶E DE F¶ERIET FUNCTION F0:3;3

June sang Choi,Mamasali Turaev 충청수학회 2010 충청수학회지 Vol.23 No.4

By developing and using certain operators like those initiated by Burchnall-Chaundy, the authors aim at investigating several decomposition formulas associated with the Kamp¶e de F¶eriet function F0:3;3 2:0;0 [x; y]. For this purpose, many operator identities in- volving inverse pairs of symbolic operators are constructed. By employing their decomposition formulas, they also present a new group of integral representations of Eulerian type for the Kamp¶e de F¶eriet function F0:3;3 2:0;0 [x; y], some of which include several hyperge- ometric functions such as 2F1, 3F2, an Appell function F3, and the Kamp¶e de F¶eriet functions F0:3;3 2:0;0 and F0:2;31:0;1 .

Decomposition Formulas for the Generalizid Hypergeometric 4F3 Function

( Anvar Hasanov ),( Mamasali Turaev ),( June Sang Choi ) 호남수학회 2010 호남수학학술지 Vol.32 No.1

CERTAIN INTEGRAL REPRESENTATIONS OF EULER TYPE FOR THE EXTON FUNCTION X2

최준상,HASANOV ANVARDJAN,TURAEV MAMASALI 한국수학교육학회 2010 純粹 및 應用數學 Vol.17 No.4

Exton [Hypergeometric functions of three variables, J. Indian Acad. Math. 4 (1982), 113{119] introduced 20 distinct triple hypergeometric functions whose names are Xi (i = 1, . . . , 20) to investigate their twenty Laplace integral representations whose kernels include the con°uent hypergeometric functions ₀F₁,₁F₁, a Humbert functionΨ2, a Humbert function Φ2. The object of this paper is to present 16 (presumably new) integral representations of Euler type for the Exton hypergeometric function X₂ among his twenty Xi (i = 1, . . . , 20), whose kernels include the Exton function X₂ itself, the Appell function F₄and the Lauricella function FC.