Experimental investigation of unbalance and misalignment in rotor bearing system using order analysis

Unbalance and misalignment are the main causes of vibration in rotating machinery. Vibration analysis is the important tool for fault diagnosis in rotating machinery. In this paper, order analysis technique of vibration analysis for unbalance and misalignment fault diagnosis is proposed. In order analysis, both phase and amplitude are obtained. From phase and amplitude, the fault type and location are usually identified. Experimental results show order analysis is an effective technique for fault diagnosis

Response surface methodology and artificial neural network-based models for predicting performance of wire electrical discharge machining of inconel 718 alloy

This paper deals with the development and comparison of prediction models established using response surface methodology (RSM) and artificial neural network (ANN) for a wire electrical discharge machining (WEDM) process. The WEDM experiments were designed using central composite design (CCD) for machining of Inconel 718 superalloy. During experimentation, the pulse-on-time (TON), pulse-off-time (TOFF), servo-voltage (SV), peak current (IP), and wire tension (WT) were chosen as control factors, whereas, the kerf width (Kf), surface roughness (Ra), and materials removal rate (MRR) were selected as performance attributes. The analysis of variance tests was performed to identify the control factors that significantly affect the performance attributes. The double hidden layer ANN model was developed using a back-propagation ANN algorithm, trained by the experimental results. The prediction accuracy of the established ANN model was found to be superior to the RSM model. Finally, the Non-Dominated Sorting Genetic Algorithm-II (NSGA- II) was implemented to determine the optimum WEDM conditions from multiple objectives

Antimicrobial prescribing pattern in a tertiary care teaching hospital: a pilot study

Background: The emergence of antimicrobial resistance is a worldwide challenge threatening to negate the gains made by discovery of antimicrobial agents (AMAs).  Antimicrobial Stewardship Program (ASP) is an important strategy for ensuring appropriate use of AMAs and controlling emergence of antibiotic resistance. Implementation of ASP must start with assessment of the current state of antimicrobial use. This study was therefore conducted to assess the prevalent prescribing patterns in a tertiary care hospital and identify gaps which warrant corrective intervention.Methods: This prospective pilot study presents analysis of the first 30 Patients from the medicine ward prescribed at least one antimicrobial agent during the two months of study period. Relevant data was collected in AMA record form. Appropriateness of AMAs was analyzed regarding selection as well as administration protocol as per the hospital antibiotic policy.Results: Out of the 60 AMAs prescribed to these patients, most commonly prescribed were cephalosporins (63.3%), anti-amoebics (26.6%) and macrolides (23.3%). Common diseases involved were urinary tract infection, acute gastroenteritis, sepsis and lower respiratory tract infections.  Use of AMAs was found to be appropriate for the indication in 42 %, dose in 97%, duration 60 %, route 93% and frequency 90 %.Conclusions: This gap between the appropriate and the actual practice use of AMAs indicates an urgent need of rigorous implementation of ASP in order to avoid emergence of resistance and to conserve the sensitivity to the available AMAs

Prox-imal Femoral Nail in Reverse Trochanteric Femoral Fractures: An Analysis of 53 Cases at One Year Follow-Up

Abstract Treatment of reverse oblique trochanteric femoral fractures poses a lot of challenges. There have been proponents of intramedullary devices as well as extramedullary devices. We present the results of proximal femoral nailing surgery performed for reverse obliquity intertrochanteric fractures using two proximal lag screws and a nail of 250 mm. There is prospective study of fifty three patients with AO/OTA 31 A-A3 fractures being treated by proximal femoral nailing in our institute after seeking approval from the Hospital ethics board. The quality of the reduction, the operative time, complications and the functional status of the patients were the parameters on which the results were evaluated. The mean Harris hip score was 76.66 (range 70 -93) and the mean Barthel activity score was 16.21 (range 12 -20). The average surgical time was 50 minutes and the mean consolidation time was 11.5 weeks. Intramedullary nailing with proximal femoral nails seems to be a good option in the treatment of reverse obliquity intertrochanteric fractures as against the various existing options available for the management

Search for the eta-mesic 4He with WASA-at-COSY detector

An exclusive measurement of the excitation function for the dd->3Heppi- reaction was performed at the Cooler Synchrotron COSY-Juelich with the WASA-at-COSY detection system. The data were taken during a slow acceleration of the beam from 2.185 GeV/c to 2.400 GeV/c crossing the kinematic threshold for the eta meson production in the dd->4He-eta reaction at 2.336 GeV/c. The corresponding excess energy with respect to the 4He-eta system varied from -51.4MeV to 22MeV. The integrated luminosity in the experiment was determined using the dd->3Hen reaction. The shape of the excitation function for the dd->3Heppi- was examined. No signal of the 4He-eta bound state was observed. An upper limit for the cross-section for the bound state formation and decay in the process dd->(4He-eta)bound->3Heppi- was determined on the 90% confidence level and it varies from 20nb to 27nb for the bound state width ranging from 5MeV to 35MeV, respectively.Comment: 8 pages, 9 figure

Charge Symmetry Breaking in dd->4He{\pi}0 with WASA-at-COSY

Charge symmetry breaking (CSB) observables are a suitable experimental tool to examine effects induced by quark masses on the nuclear level. Previous high precision data from TRIUMF and IUCF are currently used to develop a consistent description of CSB within the framework of chiral perturbation theory. In this work the experimental studies on the reaction dd->4He{\pi}0 have been extended towards higher excess energies in order to provide information on the contribution of p-waves in the final state. For this, an exclusive measurement has been carried out at a beam momentum of p=1.2 GeV/c using the WASA-at-COSY facility. The total cross section amounts to sigma(tot) = (118 +- 18(stat) +- 13(sys) +- 8(ext)) pb and first data on the differential cross section are consistent with s-wave pion production.Comment: 14 pages, 5 figure

ABC Effect and Resonance Structure in the Double-Pionic Fusion to 3^3He

Exclusive and kinematically complete measurements of the double pionic fusion to $^3$He have been performed in the energy region of the so-called ABC effect, which denotes a pronounced low-mass enhancement in the $\pi\pi$-invariant mass spectrum. The experiments were carried out with the WASA detector setup at COSY. Similar to the observations in the basic $pn \to d \pi^0\pi^0$ reaction and in the $dd \to ^4$He$\pi^0\pi^0$ reaction, the data reveal a correlation between the ABC effect and a resonance-like energy dependence in the total cross section. Differential cross sections are well described by the hypothesis of $d^*$ resonance formation during the reaction process in addition to the conventional $t$-channel $\Delta\Delta$ mechanism. The deduced $d^*$ resonance width can be understood from collision broadening due to Fermi motion of the nucleons in initial and final nuclei

Measurement of the pn→ppπ0π−pn \to pp\pi^0\pi^- Reaction in Search for the Recently Observed Resonance Structure in dπ0π0d\pi^0\pi^0 and dπ+π−d\pi^+\pi^- systems

Exclusive measurements of the quasi-free $pn \to pp\pi^0\pi^-$ reaction have been performed by means of $pd$ collisions at $T_p$ = 1.2 GeV using the WASA detector setup at COSY. Total and differential cross sections have been obtained covering the energy region $\sqrt s$ = (2.35 - 2.46) GeV, which includes the region of the ABC effect and its associated resonance structure. No ABC effect, {\it i.e.} low-mass enhancement is found in the $\pi^0\pi^-$-invariant mass spectrum -- in agreement with the constraint from Bose statistics that the isovector pion pair can not be in relative s-wave. At the upper end of the covered energy region $t$-channel processes for Roper, $\Delta(1600)$ and $\Delta\Delta$ excitations provide a reasonable description of the data, but at low energies the measured cross sections are much larger than predicted by such processes. Adding a resonance amplitude for the resonance at $m$=~2.37 GeV with $\Gamma$ =~70 MeV and $I(J^P)=~0(3^+)$ observed recently in $pn \to d\pi^0\pi^0$ and $pn \to d\pi^+\pi^-$ reactions leads to an agreement with the data also at low energies