A 12-MHz CW RFQ for the AEBL Project

D. L. Schrage,P. N. Ostroumov,A. Barcikowski,D. Fallin,A. A. Kolomiets 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.3

The Advanced Exotic Beam Laboratory (AEBL) at the Argonne National Laboratory (ANL) will provide a research facility for studies of nuclear phenomena by using beams of short-lived isotopes for research on the nature of nucleonic matter and the origin of the elements, for tests of the Standard Model, for applications in medicine and industry, and for other applied physics research. The proposed design of the AEBL driver linac evolved from the Rare Isotope Accelerator (RIA) project. The AEBL will be a CW linac capable of accelerating uranium ions up to 200 MeV/u and protons to 580 MeV with 400 kW beam power. The AEBL facility also includes a post-accelerator which is designed for acceleration of radioactive ions with charge-to-mass ratios in the range from 1/238 to 1/6. Very low charge-state ions can be most eciently bunched and accelerated by using normally-conducting radio-frequency quadrupole (RFQ) for the rst few MV of the post accelerator. A two-meter long, 12-MHz CW RFQ was designed, built, and tested in the late 1990s as the rst section of a three-section RFQ [18]. This RFQ achieved inter-electrode voltages of 110 kV CW (the peak surface eld was 15 MV/m) and accelerated beams with A/q as large as 132 (132Xe). The AEBL requires a similar RFQ for the post-acceleration of singly-charged unstable nuclides. Our plan is to replace the vanes of this RFQ with a design that incorporates a stronger focusing and that will achieve a higher peak surface eld (16 MV/m) at 82.2-kV inter-vane voltage. The objectives of this project are 1. to conrm the possibility of a low injection energy of 0.4 keV/u which signicantly reduces the voltage required for a high-voltage deck; 2. to test the highest possible peak surface eld on the RFQ electrodes designed for the lowest frequency of 12 MHz compared to existing RFQs worldwide; 3. to provide a technical base for the design of a post-accelerator for the future Advanced Exotic Beam Facility. At the present time, the design is complete, and the fabrication of the 12 MHz RFQ is scheduled to commence in October 2007 with testing planned in 2008. The physics and engineering design of the RFQ is discussed. The Advanced Exotic Beam Laboratory (AEBL) at the Argonne National Laboratory (ANL) will provide a research facility for studies of nuclear phenomena by using beams of short-lived isotopes for research on the nature of nucleonic matter and the origin of the elements, for tests of the Standard Model, for applications in medicine and industry, and for other applied physics research. The proposed design of the AEBL driver linac evolved from the Rare Isotope Accelerator (RIA) project. The AEBL will be a CW linac capable of accelerating uranium ions up to 200 MeV/u and protons to 580 MeV with 400 kW beam power. The AEBL facility also includes a post-accelerator which is designed for acceleration of radioactive ions with charge-to-mass ratios in the range from 1/238 to 1/6. Very low charge-state ions can be most eciently bunched and accelerated by using normally-conducting radio-frequency quadrupole (RFQ) for the rst few MV of the post accelerator. A two-meter long, 12-MHz CW RFQ was designed, built, and tested in the late 1990s as the rst section of a three-section RFQ [18]. This RFQ achieved inter-electrode voltages of 110 kV CW (the peak surface eld was 15 MV/m) and accelerated beams with A/q as large as 132 (132Xe). The AEBL requires a similar RFQ for the post-acceleration of singly-charged unstable nuclides. Our plan is to replace the vanes of this RFQ with a design that incorporates a stronger focusing and that will achieve a higher peak surface eld (16 MV/m) at 82.2-kV inter-vane voltage. The objectives of this project are 1. to conrm the possibility of a low injection energy of 0.4 keV/u which signicantly reduces the voltage required for a high-voltage deck; 2. to test the highest possible peak surface eld on the RFQ electrodes designed for the lowest frequency of 12 MHz compared to existing RFQs worldwide; 3. to provide a technical base for the design of a post-accelerator for the future Advanced Exotic Beam Facility. At the present time, the design is complete, and the fabrication of the 12 MHz RFQ is scheduled to commence in October 2007 with testing planned in 2008. The physics and engineering design of the RFQ is discussed.

Couette-Taylor crystallizer: Effective control of crystal size distribution and recovery of l-lysine in cooling crystallization

Nguyen, A.T.,Yu, T.,Kim, W.S. North-Holland Pub. Co 2017 Journal of crystal growth Vol.469 No.-

A Couette-Taylor crystallizer is developed to enhance the l-Lysine crystal size distribution and recovery in the case of continuous cooling crystallization. When using the proposed Couette-Taylor (CT) crystallizer, the size distribution and crystal product recovery were much narrower and higher, respectively, than those from a conventional stirred tank (ST) crystallizer. Here, the coefficient of the size distribution for the crystal product from the CT crystallizer was only 0.45, while it was 0.78 in the case of the conventional ST crystallizer at an agitation speed of 700rpm, mean residence time of 20min, and feed concentration of 900(g/L). Furthermore, when using the CT crystallizer, the crystal product recovery was remarkably enhanced up to 100%wt with a mean residence time of only 20min, while it required a mean residence time of at least 60min when using the conventional ST crystallizer. This result indicates that the CT crystallizer was much more effective than the conventional ST crystallizer in terms of controlling a narrower size distribution and achieving a 100%wt l-lysine crystal product recovery from continuous cooling crystallization. The advantage of the CT crystallizer over the conventional ST crystallizer was explained based on the higher energy dissipation of the Taylor vortex flow and larger surface area for heat transfer of the CT crystallizer. Here, the energy dissipation of the Taylor vortex flow in the CT crystallizer was 13.6 times higher than that of the random fluid motion in the conventional ST crystallizer, while the surface area per unit volume for heat transfer of the CT crystallizer was 8.0 times higher than that of the conventional ST crystallizer. As a result, the mixing condition and heat transfer of the CT crystallizer were much more effective than those of the conventional ST crystallizer for the cooling crystallization of l-lysine, thereby enhancing the l-lysine crystal size distribution and product recovery.

$n$-weak amenability and strong double limit property

A.R. Medghalchi,T. Yazdanpanah 대한수학회 2005 대한수학회보 Vol.42 No.2

Let {mathcal A} be a Banach algebra, we say that {mathcalA}has the strongly double limit property (SDLP) if for each boundednet (a_{alpha}) in {mathcal A} and each bounded net(a^*_{beta}) in {mathcal A}^*, lim_{alpha}lim_{beta}leftlangle a_{alpha} , a^*_{beta}rightrangle = lim_{beta} lim_{alpha} leftlangle a_{alpha}, a^*_{beta} rightrangle whenever both iterated limits exist. In this paperamong other results we show that if {mathcal A} has the SDLP and{mathcal A}^{**} is (n-2)-weakly amenable, then {mathcal A} isn-weakly amenable. In particular, it is shown that if {mathcalA}^{**} is weakly amenable and {mathcal A} has the SDLP, then ${\mathcal A}$ is weakly amenable

A microfluidic electrochemical aptasensor for enrichment and detection of bisphenol A.

Kashefi-Kheyrabadi, Leila,Kim, Junmoo,Gwak, Hogyeong,Hyun, Kyung-A.,Bae, Nam Ho,Lee, Seok Jae,Jung, Hyo-Il Elsevier 2018 Biosensors & bioelectronics Vol.117 No.-

<P><B>Abstract</B></P> <P>Bisphenol A (BPA) is an organic monomer used to make common consumer goods such as plastic containers, sports equipment, and cosmetics which are heavily produced worldwide. A growing interest has been drawn to general public as BPA is one of the major endocrine disrupting chemicals threating human health. To date, numerous BPA sensors have been attempted to be developed but important challenges still remained such as limited linearity range, easy to use, and long term response time. To address the present issues, a microfluidic channel should be integrated into an electrochemical aptasensor and it is called Geometrically Activated Surface Interaction (GASI) chip. The vigorous generation of the micro-vortex in the GASI fluidic chamber provides the high collision chances between BPA and anti-BPA aptamer (BPAPT) and consequently more BPA molecules can be captured on the aptasensor surface, which finally results in high sensitivity of the aptasensor. To construct the integrated aptasensor, a miniaturized gold electrode is fabricated using shadow mask and e-beam evaporation process. Afterward, BPAPT is immobilized on a nanostructured gold electrode via thiol chemistry, and other terminus of the aptamer is labeled with a ferrocene (Fc) redox probe. Then, the microfluidic channel is mounted over the miniaturized gold electrode to introduce and enrich BPA to the aptasensor. Upon the specific interaction between BPA and its aptamer, configuration of aptamer is changed so that Fc tag approaches to the electrode surface and direct oxidation signal of Fc and BPA are followed as analytical signals. The unique microfluidic integrated electrochemical aptasensor delivers a wide linear dynamic range over 5 × 10<SUP>–12</SUP> to 1 × 10<SUP>−9</SUP> M, with a limit of detection 2 × 10<SUP>–13</SUP> M. This aptasensor provides a precise platform for simple, selective and more importantly rapid detection of BPA. Such kind of sensing platforms can serve as a fertile ground for designing miniaturized portable sensors.</P> <P><B>Highlights</B></P> <P> <UL> <LI> GASI generates micro-vortex resulting in enhanced capture of BPA and subsequently enhanced sensitivity of the aptasensor. </LI> <LI> The aptasensor has low LOD, wide linear dynamic range and good response time compared to conventional aptasensors. </LI> </UL> </P>

지역사회간호사업의 내용 및 평가에 관한 연구 : 일부 저소득층 지역사회를 중심으로

방매륜,한영란 이화여자대학교 간호과학연구소 1990 Health & Nursing Vol.2 No.-

All people aspire to a life of health from birth to death. Health is both a right and a responsibility. Health as a human right is expressed in the WHO stated purpose of "Health for All by the Year 2000." In Korea an unequal distribution of health services is related to the ever increasing cost of medical care due to the professionalization of health services, the costly training and education of health care professionals and the soaring costs of medical equipment. It is now generally accepted that the health care wanted and needed by the people is first and foremost the activation and expansion of equally accessable primary health care. This study was carried out by the nursing staff of the Community Health Nursing Clinic of the Social Welfare Centre of Ewha Womans Uni versity. The research problems included the identification of principles from theories supportive of community health nursing services and of criteria from these theories useful for the evaluation of the services and as objectives to guide future services : the description of the i development of the services with a selected community group over a three year period : the evaluation of those services using the criteria developed from the theories and the recommendation of guide - lines for the planning and practice of these and similar community health nursing services. The purpose was to develop a community health nursing model for the expansion and activation of primary health care. The population was a group of women living with their families in a crowded poor area in one district in the Mapho area of Seoul. The women had organized as a mothers association to strength - en their autonomy and decision-making power. The study describes the process whereby the nurses and women worked together from 1987 to 1989 and how the women changed to become active and critical participants in decision making about their health and the nursing services. A theoretical framework was developed to support and guide the practice using Rogers Science of Unitary Human Beings, concepts of Primary Health Care from Health for All by the Year 2000, the health challenges, promotion mechanisms and implementation strategies of the Framework for Health Promotion of the Canadian Ministry of Health and Welfare and principles from the Ottawa Charter for Health Promotion. Four criteria for evaluation of the nursing services were developed from the concepts and principles of the theories. They were : 1. that a nursing theory worthy of providing a world view of the complexity of interrelationships between the human and environmental fields involved in community health nursing - the Science of Unitary Human Beings suplemented by concepts from Primary Health Care and Health Promotion-be used to direct services ; 2. that the people of a community participate in full partnership with service agencies in making decisions regarding the planning, provision and evaluation of their health care ; 3. that both the nurses and people be empowered , and 4. that the community health services be strengthened. Evaluation using the criteria demonstrated the effectiveness of the services in achieving the valued objectives of theory-directed care, empowerment and participation with this population, but relative ineffectiveness in achieving change in official public health policies which would strengthen services or promote a more healthy environment. The four criteria were proposed for use in building more concrete objectives for community health nursing services and the process as helpful for developing future services.

Lebesgue’s criterion for the Riemann integration with respect to a state on a separable unital C*- algebra

A. I. Shtern 장전수학회 2016 Advanced Studies in Contemporary Mathematics Vol.26 No.2

In the paper “Semicontinuous envelopes, Riemann integral, and uniform distribution in C*-algebras” (Funct. Anal. Appl. 29 (4), 268– 275 (1995)(1996)), the author had constructed the Riemann integral with respect to a state on a separable unital C*-algebra A. In particular, the semicontinuous hulls of elements of the enveloping von Neumann algebra A of A were introduced and studied and, for a given state ! on A, a class of selfadjoint elements of the algebra A that are Riemann integrable with respect to the state ω were introduced. It was also proved that this class is the self-adjoint part of a C*-algebra, and relations to the uniform distribution of states of the C*-algebra A with respect to the state ω were indicated. In the present note, we supplement these results by a version of Lebesgue’s criterion for the Riemann integrability of self-adjoint elements of A.

동부 콩열매에 있는 진균류와 균독소에 관한 연구

( A . A . Zohri,M . Khayria,A . El . Gawad ) 한국균학회 1992 韓國菌學會誌 Vol.20 No.3

A characterization of normal subgroups via -closed sets

A. Badawi 장전수학회 2012 Advanced Studies in Contemporary Mathematics Vol.22 No.2

Let (G, *) be a semigroup, D ⊆ G, and n ≥ 2 be an integer. We say that (D, *) is an n-closed subset of G if a_1 * ... * a_n ∈ D for every a_1, ..., a_n ∈ D. Hence every closed set is a 2-closed set. The concept of n-closed sets arise in so many natural examples. For example, let D be the set of all odd integers, then (D, +) is a 3-closed subset of (Z, +) that is not a 2-closed subset of (Z, +). If K = {1, 4, 7, 10, ...} , then (K, +) is a 4-closed subset of (Z, +) that is not an n-closed subset of (Z, +) for n = 2, 3. In this paper, we show that if (H, *) is a subgroup of a group (G, *) such that [H : G] = n < ∞,then H is a normal subgroup of G if and only if every left coset of H is an n + 1-closed subset of G.

2G HTS wire with enhanced engineering current density attained through the deposition of HTS layer with increased thickness

A. Molodyk,A. Markelov,A. Valikov,V. Chepikov,A. Petrzhik,B. Massalimov,P. Degtyarenko,R. Uzkih,A. Soldatenko,Kideok Sim,Soon Hwang 한국초전도.저온공학회 2019 한국초전도저온공학회논문지 Vol.21 No.4

2G HTS wire with high engineering current density is desired for applications where compact, high power density superconducting equipment is important. We have succeeded in enhancing engineering current density of commercial SuperOx 2G HTS wire based on GdBCO by increasing the HTS layer thickness without fast degradation of the HTS film microstructure. This was possible after improving the temperature uniformity along the HTS film deposition zone. In particular, the wire engineering current density was increased from 700-770 A/mm2 (for a 65 µm-thick wire without stabilisation) or 430-480 A/mm2 (for a 105 µm-thick stabilised wire) at the beginning of this study to almost 1200 A/mm2 (for a 67 µm-thick wire without stabilisation) or 770 A/mm2 (for a 107 µm-thick stabilised wire) at completion of this study.

A spick-and-span approach to the immobilization of horseradish peroxidase on Au nanospheres incorporated with a methionine/graphene biomatrix for the determination of endocrine disruptor bisphenol A

Vilian, A.T. Ezhil,Giribabu, Krishnan,Choe, Sang Rak,Muruganantham, Rethinasabapathy,Lee, Hoomin,Roh, Changhyun,Huh, Yun Suk,Han, Young-Kyu Elsevier Sequoia 2017 Sensors and actuators. B Chemical Vol.251 No.-

<P><B>Abstract</B></P> <P>In the present study, we employ a straightforward, benign strategy to prepare thiol-functionalized reduced graphene oxide (S-RGO) using methionine as the sulphur source and reducing agent. The immobilization of horseradish peroxidase (HRP) over the AuNPs/S-RGO was developed by incorporating AuNPs on the S-RGO surface. The fabricated HRP/AuNPs/S-RGO electrode exhibits a remarkable decrease in the overpotential and a significantly increased oxidation peak current of bisphenol A (BPA) compared with the bare glassy carbon electrode (GCE) and AuNPs/S-RGO electrode. The biosensor shows an excellent amperometric analytical performance with a low detection limit of 2.6×10<SUP>−12</SUP> M and a linear range from 2.0×10<SUP>−11</SUP> to 1.18×10<SUP>−9</SUP> M, with the response time <2s for BPA. From the results, the apparent Michaelis-Menten constant was calculated as 8.14nM. The HRP/AuNPs/S-RGO biosensor exhibited faster response, adequate storage stability, inexpensive, simple fabrication with disposability, satisfactory reproducibility and repeatability, and outstanding selectivity. Finally, the constructed biosensor was utilized successfully for detecting BPA in tomato juice and milk samples with acceptable results.</P> <P><B>Highlights</B></P> <P> <UL> <LI> HRP/AuNPs/S-RGO biocomposite has been prepared to determine bisphenol A. </LI> <LI> The AuNPs/S-RGO is a promising platform for HRP immobilization. </LI> <LI> The biosensor exhibits excellent stability, reproducibility and high selectivity. </LI> <LI> It exhibits LOD of 2.6×10<SUP>−12</SUP> in a wide linear range from 2.0×10<SUP>−11</SUP> to 1.18×10<SUP>−9</SUP> M. </LI> <LI> It detects bisphenol A in real samples such as tomato juice and milk. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>