STUDY OF MODULUS OF ELASTICITY PROPERTIES IN TERMS TENSION AND COMPRESSION MODE BY REINFORCEMENT OF CALCIUM CARBONATE IN DIFFERENT RATIO IN HIGH DENSITY POLYETHYLENE

Modulus of Elasticity - is a measure of stiffness of an elastic material. It is used to describe the elastic properties of objects like wires, rods or columns when they are stretched or compressed. Rate of change of strain as a function of stress. The slope of the straight line portion of a stress strain diagram. Tangent modulus of elasticity is the slope of the stress-strain diagram at any point. In present experiment Particular size of calcium carbonate is reinforced in high density polyethylene (HDPE) in different weight ratio .The objective of present experiment to study the tensile properties and Impact properties of reinforced blended material as compare to neat material

Tachycardia mediated cardiomyopathy: pathophysiology, mechanisms, clinical features and management.

Tachycardia mediated cardiomyopathy (TMC) is a reversible form of dilated cardiomyopathy that can occur with most supraventricular and ventricular arrhythmias. Despite the plethora of literature describing this entity in animal models, as well as humans, it remains poorly understood. Over the last decade, new etiologies of TMC, such as frequent premature ventricular complexes in normal hearts, have been identified. Recent advances in catheter-based ablation therapies, particularly for atrial fibrillation and ventricular arrhythmias, have added a new dimension to the treatment of this condition. This review describes the pathophysiology, proposed mechanisms, clinical features and management in various arrhythmic conditions

Lilliputian Hallucinations and Marijuana Dependence in a Bipolar Patient

Lilluputian hallucinations are rarely seen in manic patients. Here we present a case of isolated lilluputian hallucinations against a backdrop of psychosis and marijuana use. The phenomenon is interesting and worth following up with. The patient recovered and a brief literature search is included

Incidence of, predictors for, and mortality associated with malignant ventricular arrhythmias in non-ST elevation myocardial infarction patients.

BACKGROUND: The incidence of non-ST elevation myocardial infarction (NSTEMI) is increasing. Although life-threatening ventricular arrhythmias have been well-documented in patients with ST elevation MI (STEMI), their incidence and importance in NSTEMI have not been examined in similar detail. We examined the incidence, predictors, and mortality rates of ventricular arrhythmias in a cohort of NSTEMI patients undergoing an early invasive strategy. METHODS: Consecutive patients admitted with NSTEMI who underwent cardiac catheterization within 48 h of admission were identified by chart review. Presence and type of ventricular arrhythmias and 30-day mortality were recorded. Malignant arrhythmias were defined as sustained ventricular tachycardia (VT, \u3e100 beats/min lasting \u3e30 s) or fibrillation (VF). Clinical risk factors, laboratory values, findings on electrocardiogram, echocardiogram, cardiac catheterization, and revascularization procedure data were recorded. RESULTS: VT/VF occurred in 21 (7.6%) of 277 NSTEMI patients. Sixty percent of these events occurred within the first 48 h after hospital admission, with a median occurrence at 72 h. Twelve patients (4.3%) required defibrillation. Troponin levels were higher and left ventricular ejection fraction was lower in the VT/VF group. Multivariable analysis also identified the presence of left bundle branch block and need for urgent coronary artery bypass grafting as significant predictors of malignant ventricular arrhythmias. Thirty-day mortality was significantly higher in NSTEMI patients with malignant ventricular arrhythmias than without (38 vs. 3%, P\u3c0.001). CONCLUSION: Despite an early invasive strategy, malignant ventricular arrhythmias are frequent in NSTEMI patients and are associated with increased 30-day mortality

Distribution of left ventricular ejection fraction in angina patients with severe coronary artery disease not amenable to revascularization.

BACKGROUND: As the number of angina patients with severe coronary artery disease not amenable to revascularization increases, new therapies will be developed. How patients with depressed compared to normal left ventricular ejection fraction (LVEF) will respond to new therapies may differ. HYPOTHESIS: We conducted a retrospective chart review to determine the distribution of LVEF in angina patients with severe coronary artery disease (three-vessel disease with \u3e50% stenosis major epicardial vessels or \u3e50% stenosis left main) not amenable to revascularization. METHODS: Patients underwent cardiac catheterization between 2004 and 2009. LVEF, measured by echocardiography, nuclear-gated imaging or radioventriculography within 6 months of catheterization, was recorded. Demographics, symptoms, risk factors, past myocardial infarction, catheterization results, medications, and the Duke Coronary Artery Jeopardy Score were recorded. RESULTS: Eight thousand six hundred and ninety-nine patient charts were reviewed; 124 met criteria. There was a continuous, and not bimodal, distribution of LVEF. Fifty-eight patients (47%) in the normal LVEF group were compared to 66 patients (53%) in the abnormal LVEF group ( CONCLUSION: There is a wide distribution of LVEF among angina patients not amenable to revascularization. A novel finding of this study showed that mortality was high regardless of LVEF. As new therapies for angina are developed, attention will need to be paid to how such therapies affect these two patient groups

Optimised design of nested oblong tube energy absorbers under lateral impact loading

Dynamic lateral crushing of mild steel (DIN 2393) nested tube systems was conducted using a ZWICK ROELL impact tester. The tests were performed with impact velocities ranging between 3 and 5 m/s, achieved using a fixed mass impinging onto the specimens under the influence of gravity. The various nested tube systems consisted of one standard and one optimised design. Their crushing behaviour and energy absorption capabilities were obtained and analysed. In addition to the experimental work, numerical simulations using the explicit code LS-DYNA were conducted; boundary conditions matching those observed in experiments were applied to the models. Results from the numerical method were compared against those obtained from experiments. An over-prediction in force-deflection responses was obtained from the numerical code. An attempt was made to explain this inconsistency on the basis of the formation of plastic hinges and the validity of strain rate parameters used in the Cowper Symonds relation. It was found that the optimised energy absorbers exhibited a more desirable force-deflection response than their standard counterparts due to a simple design modification which was incorporated in the optimised design

Response spectra for differential motion of columns, paper II: Out-of-plane response

It is shown that the common response spectrum method for synchronous ground motion can be extended to make it applicable for earthquake response analyses of extended structures experiencing differential out-of-plane ground motion. A relative displacementspectrum for design of first-story columns SDC (T, TT, z, zT, t, d) is defined. In addition to the natural period of the out-of-plane response, T, and the corresponding fraction of critical damping, z, this spectrum also depends on the fundamental period of torsional vibrations, TT, and the corresponding fraction of critical damping, zT, on the ‘‘travel time,’’ t (of the waves in the soil over a distance of about one-half the length of the structure), and on a dimensionless factor d, describing the relative response of the first floor. The new spectrum, SDC, can be estimated by using the empirical scaling equations for relative displacement spectra, SD, and for peak ground velocity, vmax. For recorded strong-motion acceleration, and for symmetric buildings, the new spectrum can be computed from Duhamel’s integrals of two uncoupled equations for dynamics equilibrium describing translation and rotation of a two-degree-offreedom system. This representation is accurate when the energy of the strong-motion is carried by waves in the ground the wavelengths of which are one order of magnitude or more longer than the characteristic length of the structure