Effect of Defects on the Line shape of Electron Paramagnetic Resonance Signals from the Single-Molecule Magnet Mn12: A Theoretical Study

We herein estimate the effect of lattice defects on the line shape of electron paramagnetic resonance (EPR) signals from a single crystal of the S=10 single-molecule magnet Mn$_{12}$ with the external magnetic field along the crystal c axis. A second-order perturbation treatment of an effective single-spin Hamiltonian indicates that a small, random, static misorientation of the magnetic symmetry axes in a crystalline lattice can lead to asymmetric EPR peaks. Full spectra are simulated by calculating probability-distribution functions for the resonant fields, employing distributions in the tilt angle of the easy axis from the c axis, in the uniaxial anisotropy parameter, and in the $g$-factor. We discuss conditions under which the asymmetry in the EPR spectra becomes prominent. The direction and magnitude of the asymmetry provide information on the specific energy levels involved with the EPR transition, the EPR frequency, and the distribution in the tilt angle.Comment: published versio

Performance Based Plastic Design of Concentrically Braced Frame attuned with Indian Standard code and its Seismic Performance Evaluation

In the Performance Based Plastic design method, the failure is predetermined; making it famous throughout the world. But due to lack of proper guidelines and simple stepwise methodology, it is not quite popular in India. In this paper, stepwise design procedure of Performance Based Plastic Design of Concentrically Braced frame attuned with the Indian Standard code has been presented. The comparative seismic performance evaluation of a six storey concentrically braced frame designed using the displacement based Performance Based Plastic Design (PBPD) method and currently used force based Limit State Design (LSD) method has also been carried out by nonlinear static pushover analysis and time history analysis under three different ground motions. Results show that Performance Based Plastic Design method is superior to the current design in terms of displacement and acceleration response. Also total collapse of the frame is prevented in the PBPD frame

The Emerging Distributed Information Systems Infrastructure: Some Implications for ISResearch and Teaching

The rapidly evolving Worldwide Information Infrastructure (WII) (Neumann, 1994), of which the Internet is arguably the most visible component, marks the emergence of the information superhighway. The WII is very broad in scope and may be seen as a worldwide super-set of the National Information Infrastructure (NII). The NII consists of: (1) thousands of interconnected, interoperable telecommunication networks; (2) computer systems, televisions, fax machines, and other information appliances ; (3) software, information services, and information databases (e.g., digital libraries ); and (4) trained people who can build, maintain, and operate these systems. In the future, the NII will enable all Americans to get the information they need, when they need it, where they need it, for an affordable price (https://WWW.NTIA.DOC.GOV/). In this paper, we use the term Distributed Information Systems Infrastructure (DISI) for a restricted subsystem of the WII consisting of all networked computers and the distributed information systemsthey represent. This paper proposes a framework to organize and view the major components of the DISI and suggests a classification scheme for information tasks. The paper identifies and examines some key issues relating to the content and process of ISresearch and ISteaching. Why can\u27t existing ISframeworks be used directly to study the DISI? Classical ISframeworks have been invaluable in guiding ISwork in the last two decades, but they were developed with traditional ISin mind and fall short in capturing the unique aspects of the emerging DISI. It is clear that the DISI significantly differs from conventional ISin characteristics as well as in the types of opportunities it offers and the consequent risks

Simulating spatial variability of cereal yields from historical yield maps and satellite imagery

[Abstract]: The management of spatial variability of crop yields relies on the availability of affordable and accurate spatial data. Yield maps are a direct measure of the crop yields, however, costs and difficulties in collection and processing to generate yield maps results in poor availability of such data in Australia. In this study, we used historical mid-season normalised difference vegetation index (NDVI), generated from Landsat imagery over 4 years. Using linear regression model, the NDVI was compared to the actual yield map from a 257 ha paddock. The difference between actual and predicted yield showed that 77% and 93% of the paddock area had an error of <20% and <30%, respectively. The linear model obtained in the paddock was used to simulate crop yield for an adjoining paddock of 162 ha. On an average of 4 years, the difference between actual and simulated yield showed that 87% of the paddock had an error of <20%. However, this error varied from season to season. Paddock area with <20% error increased exponentially with decreasing in-crop rainfall between anthesis and crop maturity. Furthermore, the error in simulating crop yield also varied with the soil constraints. Paddock zones with high concentrations of subsoil chloride and surface soil exchangeable sodium percentage generally had higher percent of error in simulating crop yields. Satellite imagery consistently over-predicted cereal yields in areas with subsoil constraints, possibly due to chloride-induced water stress during grain filling. The simulated yield mapping methodology offers an opportunity to identify within-field spatial variability using satellite imagery as a surrogate measure of biomass. However, the ability to successfully simulate crop yields at farm scale or regional scale requires wider evaluation across different soil types and climatic conditions

Study of the local field distribution on a single-molecule magnet-by a single paramagnetic crystal; a DPPH crystal on the surface of an Mn12-acetate crystal

The local magnetic field distribution on the subsurface of a single-molecule magnet crystal, SMM, above blocking temperature (T >> Tb) detected for a very short time interval (~ 10-10 s), has been investigated. Electron Paramagnetic Resonance (EPR) spectroscopy using a local paramagnetic probe was employed as a simple alternative detection method. An SMM crystal of [Mn12O12(CH3COO)16(H2O)4].2CH3COOH.4H2O (Mn12-acetate) and a crystal of 2,2- diphenyl-1-picrylhydrazyl (DPPH) as the paramagnetic probe were chosen for this study. The EPR spectra of DPPH deposited on Mn12-acetate show additional broadening and shifting in the magnetic field in comparison to the spectra of the DPPH in the absence of the SMM crystal. The additional broadening of the DPPH linewidth was considered in terms of the two dominant electron spin interactions (dipolar and exchange) and the local magnetic field distribution on the crystal surface. The temperature dependence of the linewidth of the Gaussian distribution of local fields at the SMM surface was extrapolated for the low temperature interval (70-5 K)

Rethinking the Role of Information Systemsin a Changing Age: An Exploration

The purpose of this paper is to explore the impact of Information Systems (IS) on the fundamental questions of life. This paper presents a few of the many issues that lie at the intersection of IS, philosophy, and spirituality. Such issues include the need to incorporate meaning and values in the foundation of IS; the evolution of IS from transaction processing systems to virtual community networks; the distinction between data, information, knowledge, and wisdom; and the evolving role of IS in a changing context. A Web site will be created to enable further discussion of these significant issue

Video Object Detection with an Aligned Spatial-Temporal Memory

We introduce Spatial-Temporal Memory Networks for video object detection. At its core, a novel Spatial-Temporal Memory module (STMM) serves as the recurrent computation unit to model long-term temporal appearance and motion dynamics. The STMM's design enables full integration of pretrained backbone CNN weights, which we find to be critical for accurate detection. Furthermore, in order to tackle object motion in videos, we propose a novel MatchTrans module to align the spatial-temporal memory from frame to frame. Our method produces state-of-the-art results on the benchmark ImageNet VID dataset, and our ablative studies clearly demonstrate the contribution of our different design choices. We release our code and models at http://fanyix.cs.ucdavis.edu/project/stmn/project.html

Enucleation of the solitary epithelial cyst of pancreatic head in an adult: A case report and review of the literature

Solitary true pancreatic cyst is a rare entity, and only a few cases are reported in the literature. We report a case of a 35&#8209;year&#8209;old woman who had a cyst in the head of the pancreas and gall stones and presented with complaints of pain in the epigastric region. The patient underwent open cholecystectomy with aspiration of the pancreatic cyst at some other private hospital. After 4 months, she presented to us with no relief in pain. Repeat contrast&#8209;enhanced computed tomography of the abdomen showed recurrence of the cyst. The patient underwent enucleation of the cyst at our hospital. During a 2&#8209;year follow&#8209;up after the enucleation, she remained asymptomatic

The imprints of primordial non-gaussianities on large-scale structure: scale dependent bias and abundance of virialized objects

We study the effect of primordial nongaussianity on large-scale structure, focusing upon the most massive virialized objects. Using analytic arguments and N-body simulations, we calculate the mass function and clustering of dark matter halos across a range of redshifts and levels of nongaussianity. We propose a simple fitting function for the mass function valid across the entire range of our simulations. We find pronounced effects of nongaussianity on the clustering of dark matter halos, leading to strongly scale-dependent bias. This suggests that the large-scale clustering of rare objects may provide a sensitive probe of primordial nongaussianity. We very roughly estimate that upcoming surveys can constrain nongaussianity at the level |fNL| <~ 10, competitive with forecasted constraints from the microwave background.Comment: 16 pages, color figures, revtex4. v2: added references and an equation. submitted to PRD. v3: simplified derivation, additional reference