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Use of drilling performance to improve rock-breakage efficiencies:A part of mine-to-mill optimization studies in a hard-rock mine

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International Journal of Mining Science and Technology 2020年第2期30卷 179-188页

作者： Junhyeok park Kwangmin Kim Department of Mining and Geological Engineering University of ArizonaTucsonAZ 85721USA

In a hard-rock mine,blasting is an important rock-breakage process that impacts energy consumption both in downstream comminution processes and mine *** the blast fragmentation to improve rock-breakage efficiencies during crushing and grinding is key to mine-to-mill(MTM)*** study explores the use of monitoring while drilling(MWD)data to achieve this *** penetration rates(PRs)were extracted from blastholes to estimate intact rock properties and predict the breakage efficiencies that directly affect comminution energy *** intact rock properties,tensile strength(TS)and Bond work index(BWI),were correlated with the PR data to predict these efficiencies in crushing and grinding,*** of the complexity of the raw MWD data and effects of various disturbances,the MWD data was preprocessed and normalized to achieve a representative PR value at each *** preprocessing entailed defining valid PR ranges from the MWD data that could eliminate the noise related to discontinuity features in the rock mass structure as well as errors in operator *** PR data was also normalized using the adjusted penetration rate(APR)to minimize the effects of mechanical factors such as drill feed force,torque,and rotational *** correlate the representative APR value with intact rock properties,TS and BWI,various laboratory experiments were conducted:drilling tests using a high-precision coring machine,Brazilian disc tests,and Bond grindability *** on the results of these experiments,models were developed to predict rock-breakage efficiencies during crushing and grinding based on *** result of this study can be used to obtain blast energy designs that consider comminution energy consumption and efficiency in the downstream rock-breakage processes.

关键词： Monitoring while drilling(MWD) Mine-to-mill(MTM)optimization Rock-breakage efficiency Drilling penetration rates

B(C6F5)3-Catalyzed sp3 C-Si Bond Forming Consecutive Reactions

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Chinese Journal of Chemistry 2019年第10期37卷 1057-1071页

作者： Sehoon park Department of Chemistry Guangdong Technion Israel Institute of TechnologyShantouGuangdong 515063China

Transition metal-catalyzed hydrosilylation is one of the most widely utilized reduction methods as an alternative to hydrogenation in academia and *** feature distinct from hydrogenation would be able to install sp3 C—Si bond(s)onto substrates skeleton vio hydrosilylation of ***,B(C6F5)3 with hydrosilanes has been demonstrated to be an efficient,metal-free catalyst system for the consecutive transformation of heteroatom-containing substrates accompanied by the formation of sp3 C—Si bond(s),which has not been realized thus far under the transition meta卜catalyzed hydrosilylative *** this review,I outline the B(C6F5)3-mediated consecutive hydrosilylations of heteroarenes containing quinolines,pyridines,and furans,and of conjugated nitriles/imines to provide a new family of compounds having sp?C—Si bond(s)with high chemo-,regio-and/or *** silylative cascade conversion of unactivated A/-aryl piperidines to sila-/V-heterocycles catalyzed by B(C6F5)3 involving consecutive dehydrogenation,hydrosilylation,and intramolecular C(sp2)—H silylation,is presented in another *** selectivity and mechanism of the boron catalysis focused on the sp3 C—Si bond formation are highlighted.

关键词： catalyzed hydrogenation boron

The Betti Numbers of Real Toric Varieties Associated to Weyl Chambers of Type B

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Chinese Annals of Mathematics,Series B 2017年第6期38卷 1213-1222页

作者： Suyoung CHOI Boram park Hanchul park Department of Mathematics Ajou University School of Mathematics Korea Institute for Advanced Study

The authors compute the(rational) Betti number of real toric varieties associated to Weyl chambers of type B, and furthermore show that their integral cohomology is p-torsion free for all odd primes p.

关键词： Real toric variety Real toric manifold Betti number Torsion-free cohomology Root system Weyl chambers Type B Generalized Euler number Springernumber Shellability

Approaches for enhancing the photocatalytic activities of barium titanate:A review

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Journal of Energy Chemistry 2022年第10期31卷 160-188,I0004页

作者： Gopal Panthi Mira park Carbon Composite Energy Nanomaterials Research Center Woosuk UniversityWanjuChonbuk 55338Republic of Korea Woosuk Institute of Smart Convergence Life Care(WSCLC)Woosuk UniversityWanjuChonbuk 55338Republic of Korea

Barium titanate(Ba TiO_(3)),a dielectric/ferroelectric semiconductor with perovskite structures is the most widely used photocatalyst in the field of environmental applications due to its low-cost,chemical stability,and *** types and forms of Ba TiO_(3)have shown their great potential toward the significant photocatalytic reactions owing to the several beneficial properties,including appropriate band positions,high oxygen vacancies,multiple crystal structures,the feasibility of size and morphology tailoring,spontaneous polarization,rapid migration of photogenerated charge carriers,and band ***,the large band gap and recombination of photogenerated charge carriers limit the overall photocatalytic efficiency of Ba TiO_(3).These difficulties can be further overcome by modifying the electronic band structure of Ba TiO_(3)to broaden its absorption to the visible region of the ***,this review encompasses various strategies,including modification of sizes and morphologies of particles by varying the reaction time and synthesis temperature,doping with non-metals/metals,loading with noble metals,and forming heterojunctions for enhancing the photocatalytic activities of Ba TiO_(3)-based photocatalysts possessing the effective capability of charge carrier separation,trapping and their transfer to the surface of ***,this review highlights the photocatalytic applications of Ba TiO_(3)-based photocatalysts along with the proposed mechanism in dyes/drugs degradation,H_(2)production,and bacteria killing.

关键词： Electrospinning BaTiO_(3)-photocatalyst Ferroelectricity Heterojunction Environmental remediation

QUADRATIC ρ-FUNCTIONAL INEQUALITIES IN BANACH SPACES

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Acta Mathematica Scientia 2015年第6期35卷 1501-1510页

作者： Choonkil park Research Institute for Natural Sciences Hanyang University

In this paper, we solve the quadratic p-functional inequalities ……where p is a fixed complex number with ｜P｜〈 1, and^where p is a fixed complex number with ｜P｜〈 2^-*** the direct method, we prove the Hyers-ulam stability of the quadratic p-functional inequalities （0.1） and （0.2） in complex Banach spaces and prove the Hyers-ulam stability of quadratic p-functional equations associated with the quadratic p-functional inequalities （0.1） and （0.2） in complex Banach spaces.

关键词： Hyers-ulam stability quadratic p-functional equation quadratic p-functionalinequality complex Banach space

Attractors for a von Karman equation with memory

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Science China Mathematics 2015年第12期58卷 2505-2516页

作者： park SunHye Center for Education Accreditation Pusan National University

In this paper a von Karman equation with memory,utt + α?2u- γ?utt- integral from n=-∞ to t μ(t- s)?2u(s)ds = [u, F(u)] + h is considered. This equation was considered by several authors. Existing results are mainly devoted to global existence and energy decay. However, the existence of attractors has not yet been considered. Thus, we prove the existence and uniqueness of solutions by using Galerkin method, and then show the existence of a finitedimensional global attractor.

关键词： von Karman equation global attractor viscoelasticity memory

Isomorphisms Between Quasi-Banach Algebras

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Chinese Annals of Mathematics,Series B 2007年第3期28卷 353-362页

作者： Choonkil park Department of Mathematics Hanyang UniversitySeoul 133-791Korea.

In this paper, the author proves the Hyers-ulam-Rassias stability of homomorphisms in quasi-Banach algebras. This is used to investigate isomorphisms between quasi-Banach algebras.

关键词： Cauchy functional equation Jensen functional equation Quasi-Banachalgebra Hyers-ulam-Rassias stability Homomorphism p-Banach algebra

Wedge Operations and Doubling Operations of Real Toric Manifolds

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Chinese Annals of Mathematics,Series B 2017年第6期38卷 1321-1334页

作者： Hanchul park School of Mathematics Korea Institute for Advanced Study85 Hoegiro Dongdmemun-guSeoul 130-722Republic of Korea

This paper deals with two things. First, the cohomology of canonical extensions of real topological toric manifolds is computed when coefficient ring G is a commutative ring in which 2 is unit in G. Second, the author focuses on a specific canonical extensions called doublings and presents their various properties. They include existence of infinitely many real topological toric manifolds admitting complex structures, and a way to construct infinitely many real toric manifolds which have an odd torsion in their cohomology ***, some questions about real topological toric manifolds related to Halperin's toral rank conjecture are presented.

关键词： Real toric manifold Small cover Real topological toric manifold Coho-mology ring Doubling Simplicial wedge Rational homology sphere

Technological requirements of profile machining

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第9期7卷 1461-1466页

作者： park Sangchul Department of Industrial Information & Systems Engineering Ajou University Suwon 443-749 Korea

The term ‘profile machining’ is used to refer to the milling of vertical surfaces described by profile curves. Profile machining requires higher precision (1/1000 mm) than regular 3D machining (1/100 mm) with the erosion of sharp vertices should being especially avoided. Although, profile machining is very essential for making trimming and flange dies, it seldom brought into focus. This paper addresses the technological requirements of profile machining including machining width and depth control, minimizing toolware, and protecting sharp vertices. Issues of controller alarms are also addressed.

关键词： Profile machining Technological requirements Protecting sharp vertices