256 research outputs found
Vibrational Stability of NLC Linac accelerating structure
The vibration of components of the NLC linac, such as accelerating structures
and girders, is being studied both experimentally and analytically. Various
effects are being considered including structural resonances and vibration
caused by cooling water in the accelerating structure. This paper reports the
status of ongoing work.Comment: 3 pages 8 figures Presented at EPAC 2002 Paris Franc
Vibrational Stability of NLC Linac and Final Focus Components
Vertical vibration of linac components (accelerating structures, girders and
quadrupoles) in the NLC has been studied experimentally and analytically.
Effects such as structural resonances and vibration caused by cooling water
both in accelerating structures and quadrupoles have been considered.
Experimental data has been compared with analytical predictions and simulations
using ANSYS. A design, incorporating the proper decoupling of structure
vibrations from the linac quadrupoles, is being pursued.Comment: 3 pages, 8 figures presented at the LINAC 2002 conference, Gyeongju
Kore
(2E)-2-[(2H-1,3-Benzodioxol-5-yl)methylidene]-2,3-dihydro-1H-inden-1-one
In the title compound, C17H12O3, each of the five-membered rings in the inden-1-one and 1,3-benzodioxole residues is almost planar (r.m.s. deviations = 0.041 and 0.033 Å, respectively). A small twist about the single bond linking the two residues is evident [the C—C—C—C torsion angle = 8.7 (4)°]. Supramolecular zigzag layers propagating in the ac plane are formed in the crystal via C—H⋯O interactions. The layers are linked via π–π interactions between the five- and six-membered rings of 1,3-benzodioxole residues [centroid–centroid distance = 3.4977 (14) Å]
Effect of Cooling Water on Stability of NLC Linac Components
Vertical vibration of linac components (accelerating structures, girders and
quadrupoles) in the NLC has been studied experimentally and analytically.
Effects such as structural resonances and vibration caused by cooling water
both in accelerating structures and quadrupoles have been considered.
Experimental data has been compared with analytical predictions and simulations
using ANSYS. A design, incorporating the proper decoupling of structure
vibrations from the linac quadrupoles, is being pursued.Comment: 6 Pages 13 Figures Presented at The Nanobeam 2002 Workshop (Lausanne
Switzerland
Internet Addiction and its Predictors in Guilan Medical Sciences Students, 2012
Background: Internet is one of the technologies of the modern era that is being extensively used around the world. It is believed that excessive Internet use can be pathological and addictive. Though, academic use of the Internet is primarily intended for learning and research, students are one of the groups at risk of Internet addiction.
Objectives: Due to the expanding use of Internet among the university students, this study was conducted to examine the Internet addiction and its predictors among Guilan University of Medical Sciences students.
Materials and Methods: A cross-sectional study was conducted on 583 students during the first semester of 2012. A two-stage stratified random sampling was conducted and a two-part instrument was used for data collection. The first part of the instrument was consisted of questions about demographic characteristics and the second part was the Young's Internet addiction inventory. Chi-square, Kruskal-Wallis testes, Spearman correlation coefficient and ranked logistic regression were used for data analysis.
Results: About 5.7% of the students were moderately dependent to the Internet, while 44.1% were at risk for Internet addiction. Significant relationships were observed between the Internet addiction with age (P < 0.001), gender (P < 0.001), marital status (P < 0.001), major (P = 0.016), Grade point average (P = 0.017), semester of studying (P = 0.009) and student residence place (P = 0.014). However, no significant relationship was observed between the internet addiction score and level of discipline, parental job status and education level or the students’ accommodation.
Conclusion: About half of the participants in this study were at risk of Internet addiction. This finding can be a warning sign for the authorities in universities to pay more attention to this issue. A wide range of education along with empowering programs may be needed to inform the university students about the advantages and disadvantages of internet and the correct manner of using it
Interoperability Benefits and Challenges in Smart City Services: Blockchain as a Solution
The widespread usage of smart devices with various city-centric services speeds up and improves civic life, in contrast to growing privacy and security concerns. Security issues are exacerbated when e-government service providers trade their services within a centralised framework. Due to security concerns, city-centric centralised services are being converted to blockchain-based systems, which is a very time-consuming and challenging process. The interoperability of these blockchain-based systems is also more challenging due to protocol variances, an excessive amount of local transactions that raise scalability and rapidly occupy memory. In this paper, we have proposed a framework for interoperability across various blockchain-based smart city services. It also summarises how independent service providers might continue self-service choices (i.e., local transactions) without overloading the blockchain network and other organisations. A simulated interoperability network is used to show the network’s effectiveness. The experimental outcomes show the scalability and memory optimization of the blockchain network
(2E)-2-(Furan-2-ylmethylidene)-2,3-dihydro-1H-inden-1-one
In the title compound, C14H10O2, the five-membered ring of the inden-1-one residue is almost planar (r.m.s. deviation = 0.035 Å). A twist about the single bond linking the two residues is evident [C—C—C—C torsion angle = −13.2 (5)°]. The three-dimensional architecture is stabilized by C—H⋯O (involving the trifurcated carbonyl O atom), C—H⋯π and π–π interactions [between the five- and six-membered rings of inden-1-one residues; ring centroid–centroid distance = 3.7983 (17) Å]. The sample studied was a non-merohedral twin; the minor component refined to approximately 36%
(2E)-2-[(2E)-3-Phenylprop-2-en-1-ylidene]-2,3-dihydro-1H-inden-1-one
The title indan-1-one derivative, C18H14O, is planar with an r.m.s. deviation for all 19 non-H atoms of 0.098 Å. The conformation about each of the C=C bonds [1.343 (3) and 1.349 (3) Å] is E. Supramolecular layers in the bc plane, mediated by C—H⋯O and π–π [ring centroid–centroid distance = 3.5282 (15) Å] interactions, feature in the crystal packing
(2E)-2-(4-Bromobenzylidene)-2,3-dihydro-1H-inden-1-one
The title indan-1-one derivative, C16H11BrO, is planar, the r.m.s. deviation for all 18 non-H atoms being 0.071 Å. The configuration about the C=C bond [1.337 (5) Å] is E. In the crystal, supramolecular layers in the ab plane are formed by C—H⋯O interactions, involving the bifurcated carbonyl O atom, as well as C—H⋯π interactions. The studied crystal was an inversion twin
(2E)-2-(4-Methoxybenzylidene)-2,3-dihydro-1H-inden-1-one
In the title compound, C17H14O2, the indan-1-one system is almost planar (r.m.s. deviation = 0.007 Å) and the benzene ring is twisted out of its plane by 8.15 (6)°. The conformation about the C=C double bond [1.348 (2) Å] is E. Helical supramolecular chains along [010] feature in the crystal packing; these are sustained by C—H⋯O hydrogen bonds and π–π interactions between translationally related indan-1-one systems [centroid–centroid distance = 3.7970 (10) Å]
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