• Title/Summary/Keyword: NCA

Search Result 82, Processing Time 0.022 seconds

Usage potential of recycled aggregates in mortar and concrete

  • Yaragal, Subhash C.;Muhammad, Roshan A.K.
    • Advances in concrete construction
    • /
    • v.5 no.3
    • /
    • pp.201-219
    • /
    • 2017
  • With the rapid growth in construction sector, it becomes all the more important to assess the amount of Construction and Demolition (C&D) waste being generated and analyze the practices needed to handle and use this waste before final disposal. This serves waste management and disposal issues, paving way to waste utilization in construction industry from the sustainability point of view. C&D waste constitutes a major bulk of total solid waste produced in the world. In this work, an attempt is made to study the performance of concrete using water soaked Recycled Coarse Aggregates (RCA) in replacement levels of 0%, 25%, 50%, 75% and 100% to Natural Coarse Aggregates (NCA). Experiments were designed and conducted to study the performance of RCA based concrete. Further suitable performance enhancement techniques to RCA based concrete were attempted, to achieve compressive strength at least equal to or more than that for no RCA based concrete (control concrete). Performance enhancement study is reported here for 50% and 100% RCA based concretes. All four techniques attempted have given favorable results encouraging use of RCA based concretes with full replacement levels, to adopt RCA based concrete in structural applications, without any kind of concern to the stake holder. Further attempts have also been made to use Recycled Fine Aggregates (RFA) with appropriate modifications to serve as fine aggregates in mortar and concrete. Using RFA blended with river sand fractions as well as RFA with Iron Ore Tailings (IOT) fractions, have given good results to serve as fine aggregates to the extent of 100% replacement levels in mortars and concretes.

A Novel Aromatic Fluorine-18 Labeling Method Using Iodonium Salts Precursor (이오도늄 솔트 전구체를 이용한 새로운 방향족 화합물 플루오린-18 표지 기술)

  • Moon, Byung-Seok;Lee, Byung-Chul;Kim, Sang-Eun
    • Nuclear Medicine and Molecular Imaging
    • /
    • v.43 no.1
    • /
    • pp.1-9
    • /
    • 2009
  • As many new drug substances contained various aromatic rings and fluorine attached to an electron rich aromatic ring or on the meta-position, a strategy towards improvement in aromatic fluorination of these compounds is highly desirable. The introduction of fluorine-18 onto aromatic rings showed in the limited condition containing electron withdrawing group (EWG) on the para- or ortho-position to get reasonable radiochemical yield so far. No-carrier added (NCA) [$^{18}F$]fluoroarene syntheses by iodonium salts recently reported that has the potential to greatly increase the yield in systems or positions that normally not reactive enough to give sufficient yields in simple model reaction. This review describes the methodological approach towards effective aromatic fluorination by diaryliodonium salts and future prospects in an application of novel PET radiotracer.

Study of Metal(Au) Bump for Transverse Ultrasonic Bonding (금속(Au)범프의 횡초음파 접합 조건 연구)

  • Ji, Myeong-Gu;Song, Chun-Sam;Kim, Joo-Hyun;Kim, Jong-Hyeong
    • Journal of Welding and Joining
    • /
    • v.29 no.1
    • /
    • pp.52-58
    • /
    • 2011
  • In this paper, the direct bonding process between FPCB and HPCB was studied. By using an ultrasonic horn which is mounted on the ultrasonic bonding machine, it is alternatively possible to bond the gold pads attached on the FPCB and HPCB at room temperature without an adhesive like ACA or NCA. The process condition for obtaining more bonding strength than 0.6 Kgf, which is commercially required, was carried out as 40 kHz of frequency, 0.6 MPa of bonding pressure and 2 second of bonding time. The peel off test was performed for evaluating bonding strength which results in more than 0.8 Kgf.

Experimental Study on the Effects of Upstream Wakes on Cascade Flow (상류 후류의 익렬 유동에 미치는 영향에 대한 실험적 연구)

  • Kim, Hyeong-Ju;Jo, Gang-Rae;Ju, Won-Gu
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.25 no.3
    • /
    • pp.330-338
    • /
    • 2001
  • This paper is concerned with the effect of cylinder wakes upstream on blade characteristics of compressor cascade(NCA 65 series). At first, it is found that the velocity defect ratio of cylinder wake varies according to the acceleration and deceleration in a flow field but, is conserved nearly constant at flow downstream the cascade, irrespective of the flow path in the cascade. When a cylinder wake flows along near the suction surface of the blade, or impinges on the leading edge, the turbulent velocities are supplied on or inside the outer edge of boundary layer near the leading edge of suction surface, and the transition to a transitional or turbulent boundary layers is induced, so that the laminar separation is prevented, but the profile loss increases. The transition of boundary layer to a transitional or turbulent one is strongly related with the strength of added turbulent velocities near the leading edge on the suction surface, which is influenced by the flow path of a cylinder wake.

188Re Labeled liver therapeutic drugs for hepatic carcinoma (HCC)

  • Seelam, Sudhakara Reddy;Banka, Vinay Kumar;Lee, Yun-Sang;Jeong, Jae Min
    • Journal of Radiopharmaceuticals and Molecular Probes
    • /
    • v.5 no.1
    • /
    • pp.26-35
    • /
    • 2019
  • $^{188}Re$ is one of the most readily available generator derived and useful radionuclides for therapy emitting ${\beta}^-$ particles (2.12 MeV, 71.1% and 1.965 MeV, 25.6%) and imageable gammas (155 keV, 15.1%). The $^{188}W/^{188}Re$ generator is an ideal source for the long term (4-6 months) continuous availability of no carrier added (NCA) $^{188}Re$ suitable for the preparation of radiopharmaceuticals for radionuclide therapy. Rhenium-188 has been used for the preparation of therapeutic radiopharmaceuticals for the management of diseases such as bone metastasis, rheumatoid arthritis and primary cancers. Several early phase clinical studies using radiopharmaceuticals based on $^{188}Re$ -labeled phosphonates, antibodies, peptides, lipiodol and particulates have been reported. In this review, we addressed the current development status of $^{188}Re$ radiopharmaceuticals for liver cancer therapy and their applications.

The ensemble approach in comparison with the diverse feature selection techniques for estimating NPPs parameters using the different learning algorithms of the feed-forward neural network

  • Moshkbar-Bakhshayesh, Khalil
    • Nuclear Engineering and Technology
    • /
    • v.53 no.12
    • /
    • pp.3944-3951
    • /
    • 2021
  • Several reasons such as no free lunch theorem indicate that there is not a universal Feature selection (FS) technique that outperforms other ones. Moreover, some approaches such as using synthetic dataset, in presence of large number of FS techniques, are very tedious and time consuming task. In this study to tackle the issue of dependency of estimation accuracy on the selected FS technique, a methodology based on the heterogeneous ensemble is proposed. The performance of the major learning algorithms of neural network (i.e. the FFNN-BR, the FFNN-LM) in combination with the diverse FS techniques (i.e. the NCA, the F-test, the Kendall's tau, the Pearson, the Spearman, and the Relief) and different combination techniques of the heterogeneous ensemble (i.e. the Min, the Median, the Arithmetic mean, and the Geometric mean) are considered. The target parameters/transients of Bushehr nuclear power plant (BNPP) are examined as the case study. The results show that the Min combination technique gives the more accurate estimation. Therefore, if the number of FS techniques is m and the number of learning algorithms is n, by the heterogeneous ensemble, the search space for acceptable estimation of the target parameters may be reduced from n × m to n × 1. The proposed methodology gives a simple and practical approach for more reliable and more accurate estimation of the target parameters compared to the methods such as the use of synthetic dataset or trial and error methods.

Effect of micro-silica on mechanical and durability properties of high volume fly ash recycled aggregate concretes (HVFA-RAC)

  • Shaikh, Faiz;Kerai, Sachin;Kerai, Shailesh
    • Advances in concrete construction
    • /
    • v.3 no.4
    • /
    • pp.317-331
    • /
    • 2015
  • This paper presents the effect of different micro-silica (MS) contents of 5, 10 and 15 wt.% as partial replacement of cement on mechanical and durability properties of high volume fly ash - recycled aggregate concretes (HVFA-RAC) containing 50% class F fly ash (FA) and 35% recycled coarse aggregate (RCA) as partial replacement of cement and natural coarse aggregate (NCA), respectively. The measured mechanical and durability properties are compressive strength, indirect tensile strength, elastic modulus, drying shrinkage, water sorptivity and chloride permeability. The effects of different curing ages of 7, 28, 56 and 91 days on above properties are also considered in this study. The results show that the addition of MS up to 10% improved the early age (7 days) strength properties of HVFA-RAC, however, at later ages (e.g. 28-91 days) the above mechanical properties are improved for all MS contents. The 5% MS exhibited the best performance among all MS contents for all mechanical properties of HVFA-RAC. In the case of measured durability properties, mix results are obtained, where 10% and 5% MS exhibited the lowest sorptivity and drying shrinkage, respectively at all ages. However, in the case of chloride ion permeability a decreasing trend is observed with increase in MS contents and curing ages. Strong correlations of indirect tensile strength and modulus of elasticity with square root of compressive strength are also observed in HVFA-RAC. Nevertheless, it is established in this study that MS contributes to the sustainability of HVFA-RAC significantly by improving the mechanical and durability properties of concrete containing 50%less cement and 35% less natural coarse aggregates.

Contact Resistance of the Flip-Chip Joints Processed with Cu Mushroom Bumps (Cu 머쉬룸 범프를 적용한 플립칩 접속부의 접속저항)

  • Park, Sun-Hee;Oh, Tae-Sung
    • Journal of the Microelectronics and Packaging Society
    • /
    • v.15 no.3
    • /
    • pp.9-17
    • /
    • 2008
  • Cu mushroom bumps were formed by electrodeposition and flip-chip bonded to Sn substrate pads. Contact resistances of the Cu-mushroom-bump joints were measured and compared with those of the Sn-planar-bump joints. The Cu-mushroom-bump joints, processed at bonding stresses ranging from 19.1 to 95.2 MPa, exhibited contact resistances near $15m\Omega$/bump. Superior contact-resistance characteristics to those of the Sn-planar-bump joints were obtained with the Cu-mushroom-bump joints. Contact resistance of the Cu-mushroom-bump joints was not dependent upon the thickness of the as-elecroplated Sn-capcoating layer ranging from $1{\mu}m$ to $4{\mu}m$. When the Sn-cap-coating layer was reflowed, however, the contact resistance was greatly affected by the thickness and the reflow time of the Sn-cap-coating layer.

  • PDF

Architecture of Cerebral Neuroendocrine System in the Lawa of Cabbage Butterfly Pieris rapue (배추흰나비 5령유충의 뇌신경내분비계의 구조)

  • 이봉희;윤혜련심재원
    • The Korean Journal of Zoology
    • /
    • v.36 no.2
    • /
    • pp.285-292
    • /
    • 1993
  • This investigation has been carried out to clarify structural architecture of cerebral neuroendocrine systems in the fifth instar lanra of cabbage butterfly Pieris rapae. In order to examine the cerebral neurosecretorv cell systems the brain and retrocerebral neuroendocrine complex were histochemically stained with the paraldehvde fuchsin. The brain of the fifth instar laMa contains three kinds of neurosecretorv cells: medial, lateral and tritocerebral neurosecretorv cells. The axon bundles of medial and lateral neurosecretory cells form medial neurosecretory pathway(MNSP) and lateral neurosecretorv pathwav(LNSP) within the brain respectively. Especially, prior to exiting the brain, the axon bundles of medial neurosecretorH cells located in both left and right cefebral hemispheres decussate in cerebral medial region and project to contralateral retrocerebral neuroendocrine complexes. Outside the brain the axon bundles of medial and lateral neurosecretory cells form the nenri corporis cardiaca(NCC) I and II respectively. The NCC I and ll run together to the retrocerebral neuroendocrine complex, forming the large nenre bundles in both left md right sides. The anon bundles of tritocerebral neurosecretory cells which pass through the brain along the tritocerebral neurosecretory pathway (TNSP) form the Ncc III outids the train. some of the Ncc I and it terminate in the corpus cardiacum, while the others pass through the corpus cardiacum without termination. The nerve bundle which passes the corpus cardiacum forms the nenrus corforis allatum(NCA) I which runs between the corpus cardiacum and the corpus allatum. Theyt are finally innervated to the corpus allatum. The Ncc III Projects to the corpus cardiRcum. However, most of NCC III priss through the corpus cardiacum without branching and then run down for another organ.

  • PDF

Poly(Ethylene Glycol)-branched Polyethylenimine-poly(L-phenylalanine) Block Copolymer Synthesized by Multi-initiation Method for Formation of More Stable Polyelectrolyte Complex with Biotherapeutic Drugs

  • Park, Woo-Ram;Na, Kun
    • Journal of Pharmaceutical Investigation
    • /
    • v.41 no.2
    • /
    • pp.95-102
    • /
    • 2011
  • An amphiphilic cationic branched methoxy poly (ethylene glycol)-branched polyethylenimine - poly(L-phenylalanine) (mPEG-bPEI-pPhe) block copolymer was successfully synthesized by ring-opening polymerization (ROP) of N-carboxyanhydride of L-phenylalanine (Phe-NCA) with mPEG-bPEI for the preparation of more stable polyelectrolyte complex (PEC) included a hydrophobic interaction. mPEG-bPEI was firstly prepared by the coupling of mPEG and bPEI using hexamethylene diisocyanate (HMDI). The structural properties of mPEG-bPEI-pPhe copolymers were confirmed by $^1H$ NMR. The copolymers exhibited a self-assemble behavior in water above critical aggregate concentration (CAC) in the range of 0.01-0.14 g/L. The CAC of copolymers obviously depended on the hydrophobic block content in the copolymers (the value decreased with the increase of the pPhe block content). The cationic copolymers have the ability to form multi-interaction complex (MIC) with bovine serum albumin (BSA) and plasmid DNA through multi-interaction (electrostatic and hydrophobic interaction). The physicochemical characterization of the complex was carried out by the measurement of zeta potential and particle size. Their zeta-potentials were positive (approximately +10 mV) and their sizes decreased with increasing pPhe contents in the copolymers (PPF/BSA wt% ratio = 2). The complex showed good stability at high ionic strength. Therefore, mPEG-bPEI-pPhe block copolymer was considered as a potential material to enhance the stability of complex including biotherapuetic drugs.