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        검색결과 8

        1.
        2022.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Copper nanoparticles (CuNPs) are considered of great importance due to their high catalytic and antimicrobial activities. This study focuses on the preparation and characterization of CuNPs, and on their antibacterial/antifungal activities. A copper salt (copper sulfate pentahydrate) as precursor, starch as stabilizing agent, and ascorbic acid as reducing agent were used to fabricate CuNPs. The resulting product was characterized via different techniques such as X-ray diffractrometry (XRD), Fourier Transform Infrared (FTIR) spectroscopy, and Scanning electron microscopy (SEM) to confirm its characteristic properties. Employing the Scherrer formula, the mean crystallite sizes of copper (Cu) and cuprous oxide (Cu2O) nanocrystals were found to be 29.21 and 25.33 nm, respectively, as measured from the main X-ray diffraction peaks. The functional groups present in the resulting CuNPs were confirmed by FTIR. In addition, the engineered CuNPs showed antibacterial and antifungal activity against tested pathogenic bacterial and fungal strains.
        4,000원
        2.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Foaling is a process of giving birth to foal which is prompt and forceful event in equine breeding. Dystocia is declared when 2nd stage of parturition exceeds from 20 min without fetal movements in mare. Dystocia is very challenging situation for both mare and veterinarian. Survivability of mare and foal, and subsequent fertility of mare depends on efficient management. Therefore, the current report described a rare case of wry neck (torticollis or unilateral bent neck) resulted in dystocia, that was efficiently resolved by partial fetotomy and repulsion technique in mare under field conditions. Intensive post operative care was performed to avoid infection and to achieve fertility subsequently.
        3,000원
        3.
        2015.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Bi0.5Na0.5TiO3 (BNT) based ceramics are considered potential lead-free alternatives for Pb(Zr,Ti)O3(PZT) based ceramics in various applications such as sensors, actuators and transducers. However, BNT-based ceramics have lower electromechanical performance as compared with PZT based ceramics. Therefore, in this work, lead-free bulk 0.99[(Bi0.5Na0.5)0.935Ba0.065](1-x)LaxTiO3-0.01SrZO3 (BNBTLax-SZ, with x = 0, 0.01, 0.02) ceramics were synthesized by a conventional solid state reaction The crystal structure, dielectric response, degree of diffuseness and electric-field-induced strain properties were investigated as a function of different La concentrations. All samples were crystallized into a single phase perovskite structure. The temperature dependent dielectric response of La-modified BNBT-SZ ceramics showed lower dielectric response and improved field-induced strain response. The field induced strain increased from 0.17% for pure BNBT-SZ to 0.38 % for 1 mol.% La-modified BNBT-SZ ceramics at an applied electric field of 6 kV/mm. These results show that Lamodified BNBT-SZ ceramic system is expected to be a new candidate material for lead-free electronic devices.
        4,000원
        4.
        2015.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The effects of Nb doping on the crystal structure, microstructure, and dielectric ferroelectric and piezoelectric properties of (Bi0.5Na0.5)0.935Ba0.065Ti(1-x)NbxO3-0.01SrZrO3 (BNBTNb-SZ, with x = 0, 0.01 and 0.02) ceramics have been investigated. X-ray diffraction patterns revealed that all ceramics have a pure perovskite structure with tetragonal symmetry. The grain size of the ceramics slightly decreased and a change in grain morphology from square to spherical shape was observed in the Nb-doped samples. The maximum dielectric constant temperature (Tm) increases with increasing amount of Nb; however, ferroelectric-relaxor transition temperature (TF-R) and maximum dielectric constant (εm) values decrease gradually. Nb addition disrupted the polarization hysteresis loops of the BNBT-SZ ceramics by leading a reduction in the remnant polarization coercive field and piezoelectric constant.
        4,000원
        5.
        2015.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        New lead-free piezoelectric ceramics 0.96[{Bi0.5 (Na0.84 K0.16)0.5}1-xLax(Ti1-y Nby)O3]-0.04SrTiO3 (BNKT-ST-LN, where x = y = 0.00 ≤ (x = y) ≤ 0.015) were synthesized using the conventional solid-state reaction method. Their crystal structure, microstructure, and electrical properties were investigated as a function of the La and Nb (LN) content. The X-ray diffraction patterns revealed the formation of a single-phase perovskite structure for all the LN-modified BNKT-ST ceramics in this study. The temperature dependence of the dielectric curves showed that the maximum dielectric constant temperature (Tm) shifted towards lower temperatures and the curves became more diffuse with an increasing LN content. At the optimum composition (LN 0.005), a maximum value of remnant polarization (33 C/cm2) with a relatively low coercive field (22 kV/cm) and high piezoelectric constant (215 pC/N) was observed. These results indicate that the LN co-modified BNKT-ST ceramic system is a promising candidate for lead-free piezoelectric materials.
        4,000원
        6.
        2018.06 KCI 등재 서비스 종료(열람 제한)
        The changes in extreme daily rainfall totals in Punjab Province, Pakistan, during the period (1981- 2014) are examined in this study. The analysis was focused on the extreme annual and monthly rainfall events, by processing the exceeding of the daily rainfall over various thresholds, which are indicators for the incidence of extreme rainfall events. To analyze the changes in extreme rainfall events and trends of the time series of the annual number of extreme rainfall days (%) the thresholds of 30mm and 50mm has been estimated. Evidence from the twelve stations considered shows that there is an increase in annual number of extreme rainfall days (%) in dataset. These changes of heavy and extreme rainfall events pronounce significant environmental consequences which cause considerable impact on society.
        7.
        2009.08 KCI 등재 서비스 종료(열람 제한)
        Hundreds of scientists are involved in the various climatic fields of research. Few of them have attempted to review some of research work already published. However, to our knowledge there has been no such work to overview the whole journal of research. Field experts have their own approach to understand the existing problems and school of thoughts for research aptitude. Thus, the review of numerous researches in the area of climatic issues is a little bit thorny. This study reveals a brief overview on the different aspects of climate. The journal of Pakistan Journal of Meteorology (a biannual online journal) from 2004 to 2009 (issues 1-10) has been overviewed in this paper. This work shows an intense effort of the contribution of climatic research in Pakistan Journal of Meteorology. In this respect, this journal covers a vide range of climatic issues from the climate forecast, the impact assessment, the climate change and vulnerability, the long range forecast, and especially the rainfall patterns.
        8.
        2009.02 KCI 등재 서비스 종료(열람 제한)
        The phenomenon climate change has become a common scientific term these days. Many international efforts devoted to understand the climate change and its impact on different sectors such as agriculture, tourism, forestry, livestock, heritage, air composition and sea level rise. Climate and weather conditions are a good example of factors which need to suitable adaptations. This article is a review of several climate studies of current climate change in different fields, and it summarizes the current knowledge about this area. Climate experts/scientists are working to better understand future climate changes and how these effects will vary by time to time and place to place.