• 제목/요약/키워드: Pure sciences

검색결과 796건 처리시간 0.023초

Comparative Toxicity Studies of Ultra-Pure Ag, Au, Co, and Cu Nanoparticles Generated by Laser Ablation in Biocompatible Aqueous Solution

  • Kim, Yea-Seul;Kim, Kuk-Ki;Shin, Seon-Mi;Park, Seung-Min;Hah, Sang-Soo
    • Bulletin of the Korean Chemical Society
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    • 제33권10호
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    • pp.3265-3268
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    • 2012
  • Nanoparticles (NPs) are increasingly used in consumer products, which have aroused many concerns and debates regarding their fate in biological systems from a point of their safety/toxicity. Although a number of studies on the biological effects of NPs have been published, these are often complicated by the possible toxicity of conventional NPs, caused by contamination with chemical precursors or additives during their synthesis and/or purification procedures. To explicitly understand the toxicity basis of NPs, it is necessary to directly address a main problem related to their intrinsic/inherent toxicity and/or incompatibility with biological objects. The present study is designed to take advantage of a novel laser-assisted method called laser ablation to generate Ag, Au, Co, and Cu NPs in biocompatible aqueous solution, and to evaluate the toxicity of the resulting ultra-pure NPs. Our results show that the ultra-pure NPs with nascent surfaces possess moderate cytotoxicity to human cells in a cell-dependent manner.

ON THE CONHARMONIC CURVATURE TENSOR OF A LOCALLY CONFORMAL ALMOST COSYMPLECTIC MANIFOLD

  • Abood, Habeeb M.;Al-Hussaini, Farah H.
    • 대한수학회논문집
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    • 제35권1호
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    • pp.269-278
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    • 2020
  • This paper aims to study the geometrical properties of the conharmonic curvature tensor of a locally conformal almost cosymplectic manifold. The necessary and sufficient conditions for the conharmonic curvature tensor to be flat, the locally conformal almost cosymplectic manifold to be normal and an η-Einstein manifold were determined.

가시광영역에서 TiO$_{2}$ 광촉매의 광활성에 관한 연구

  • 남수경;박상원;현병욱;윤태관;김승민;홍대일;김정배
    • 한국환경과학회:학술대회논문집
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    • 한국환경과학회 2005년도 봄 학술발표회지 제14권(제1호)
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    • pp.281-283
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    • 2005
  • TiO$_{2}$ 광촉매 구조 변환에 따른 실험을 행하기 위해 sol-gel 법으로 17%, 59%, 91% rutile과 pure anatase를 제조하였다. Rutile의 비율이 증가할수록 비표면적은 감소하였고, 입자크기는 증가하였다. Pure anatase 보다 rutile이 포함된 TiO$_{2}$ 광촉매가 가시광영역에서 흡수률이 더 뛰어났으며 분해효율도 좋은 것으로 나타났다.

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STRONG SHELLABILITY OF SIMPLICIAL COMPLEXES

  • Guo, Jin;Shen, Yi-Huang;Wu, Tongsuo
    • 대한수학회지
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    • 제56권6호
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    • pp.1613-1639
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    • 2019
  • Imposing a strong condition on the linear order of shellable complexes, we introduce strong shellability. Basic properties, including the existence of dimension-decreasing strong shelling orders, are developed with respect to nonpure strongly shellable complexes. Meanwhile, pure strongly shellable complexes can be characterized by the corresponding codimension one graphs. In addition, we show that the facet ideals of pure strongly shellable complexes have linear quotients.

Vaisman-Gray Manifold of Pointwise Holomorphic Sectional Conharmonic Tensor

  • Abood, Habeeb Mtashar;Abdulameer, Yasir Ahmed
    • Kyungpook Mathematical Journal
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    • 제58권4호
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    • pp.789-799
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    • 2018
  • The purpose of the present paper is to discuss the geometrical properties of the Vaisman-Gray manifold (VG-manifold) of a pointwise holomorphic sectional conharmonic tensor (PHT-tensor). Furthermore, the necessary and sufficient conditions required for the VG-manifold to admit such a PHT-tensor have been determined. In particular, under certain conditions, we have established that the aforementioned manifold was an Einstein manifold.

IDENTICAL THEOREM OF APPROXIMATION UNBOUNDED FUNCTIONS BY LINEAR OPERATORS

  • ALAA ADNAN AUAD;FAISAL AL-SHARQI
    • Journal of applied mathematics & informatics
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    • 제41권4호
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    • pp.801-810
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    • 2023
  • The aim of this paper, investigated of weighted space which contained the unbounded functions which is to be approximated by linear operators in terms some Well-known approximation tools such as the modulus of smoothness and K-functional. The characteristics of the identical theorem between modulus of smoothness and K-functional are consider. In addition to the establish the direct, converse and identical theorem by using some linear operators in terms modulus Ditzian-Totik.

Determination of Adulteration of Chicken Meat into Minced Beef Mixtures using Front Face Fluorescence Spectroscopy Coupled with Chemometric

  • Saleem, Asima;Sahar, Amna;Pasha, Imran;Shahid, Muhammad
    • 한국축산식품학회지
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    • 제42권4호
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    • pp.672-688
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    • 2022
  • The objective of this study was to explore the potential of front face fluorescence spectroscopy (FFFS) as rapid, non-destructive and inclusive technique along with multi-variate analysis for predicting meat adulteration. For this purpose (FFFS) was used to discriminate pure minced beef meat and adulterated minced beef meat containing (1%, 2%, 3%, 4%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100%) of chicken meat as an adulterant in uncooked beef meat samples. Fixed excitation (290 nm, 322 nm, and 340 nm) and fixed emission (410 nm) wavelengths were used for performing analysis. Fluorescence spectra were acquired from pure and adulterated meat samples to differentiate pure and binary mixtures of meat samples. Principle component analysis, partial least square regression and hierarchical cluster analysis were used as chemometric tools to find out the information from spectral data. These chemometric tools predict adulteration in minced beef meat up to 10% chicken meat but are not good in distinguishing adulteration level from 1% to 5%. The results of this research provide baseline for future work for generating spectral libraries using larger datasets for on-line detection of meat authenticity by using fluorescence spectroscopy.