Integrity Assessment of LCA Drop Tank under Internal Cyclic Pressure

A facility and expertise has been developed at NAL to conduct automated internal pressure cycling tests. The hardware and instrumentation includes capturing of pressure on the data logger along with strain gage data. Digital data can be recorded continuously during entire pressure cycle, thus enabling to provide comparative view of reduction in stiffness, if any,in terms of graphs. The Maximum Pressure up To Which the Central Shells Could Be Tested Was 188 .5psi. A Maximum Strain Of 5166 Micro Strains, At A Pressure Of 188 .5psi, Was Found Near The GFRP Bulkhead In The Circumferential Direction. The Integrity Of The Bulkhead Joint Appears Satisfactory. The Nose-Cone, Tested For Internal Pressure Cycling Between 3 And L Lpsi Did Not Show Any Leaks Anywhere On The Surface Or From The Filler Cap . However, After 1104 Pressure Cycles,The End Flange Failed With A Loud Pop.On Inspection, It Was Found That The Failure Is Due To Improper Adhesion Between The GFRP Base Material And The Aluminum Ring Holding The End-Flange. Subsequently, This Ring Was Joined To The GFRP Shell By Bolts And The Pressure Cycling Was Continued For A Further 5000 Cycles,As Required, Without Any Failure/Leaks Anywhere On The Nose Cone. The Nose Cone Was Then Subjected To A Steadily Increasing Pressure To Verify The Residual Strength.At About 60psi, Leaks Were Observed Around The Filler Cap And The Pressure Was Continued Up To 85psi . At This Pressure, The Filler Cap Seal Gave-Up And A Profuse Leak Sprouted Around The Cap This Was Verified Again By Replacing The Filler Cap With A New One That Also Failed Completely At About 85psi Pressure. Presently,It May Be Concluded That The Lca s Gfrp Drop Tank Internal Bulkheads Of Central Shell Can Withstand A Pressure Of 185psi And The Weak Link,In The DT Assembly, Is The Filler Cap Seal That Can Stand A Pressure Of Only 60psi

Soil stabilization

The subject of soil stabilization has been reviewed. The various stabilizing agents and the different methods of soil stabilization have been considered. Soil stability is dependent on the two important properties of soils-cohesion and internal-friction. A proper adjustment of these two properties and also water proofing are the main lines of approach to the problem of soil stabilizatio

On a large sample test for the traffic intensity in GI|G|s queue

A large sample test based on normal approximation for the traffic intensity parameter ρ in the cases of single and multiple-server queues has been proposed. The test procedure is developed without imposing steady-state assumptions and is applicable to queueing systems with general interarrival and service-time distributions

Digital Receiver-based Electronic Intelligence System Configuration for the Detection and Identification of Intrapulse Modulated Radar Signals

An optimum electronic intelligence system configuration incorporating the state of the art technologies and achieving the highest parameter accuracies while processing the complex intrapulse modulated radar signals is presented in this paper. The system is based on the quad digital receiver, a state of the art single board solution for the detection and analysis of modern radar signals. The system consists of base line interferometry  configuration for high accuracy direction finding measurement with sector selection based on amplitude direction finding technique. Advanced signal processing algorithms with time frequency analysis are implemented in real time in field programmable gate array to extract all the basic as well as advanced parameters of frequency and phase modulations such as chirp, barker, and poly-phase (Frank, P1-P4) codes in addition to the pulse and continuous wave signals. The intercepted intrapulse modulated signal parameters have been extracted with very high accuracy and sensitivity.Defence Science Journal, 2014, 64(2), pp. 152-158. DOI: http://dx.doi.org/10.14429/dsj.64.509

Role of polarizations and spin-spin correlations of W′sW's in e−e+→W−W+e^-e^+ \to W^-W^+ at s=250\sqrt{s} = 250 GeV to probe anomalous W−W+Z/γW^-W^+Z/\gamma couplings

We study anomalous $W^-W^+Z/\gamma$ couplings due to dimension-$6$ operators in the production process $e^-e^+ \to W^-W^+$ followed by semi-leptonic decay using polarizations and spin-spin correlations of $W$ bosons. The construction of some of the polarization and spin-spin correlation asymmetries required one to distinguish between two decay quarks coming from $W^+$ decay. We developed an artificial neural network (ANN) and a boosted decision tree (BDT) to distinguish down-type jets from up-type jets and used them to put constraint on anomalous couplings at International Linear Collider (ILC) running at $\sqrt{s} = 250$ GeV with integrated luminosities of $\mathcal{L} \in \{100 \ \text{fb}^{-1}, \ 250 \ \text{fb}^{-1}, \ 1000 \ \text{fb}^{-1}, \ 3000 \ \text{fb}^{-1}\}$. We find that the use of polarization and spin correlation observables, on top of the cross-sections, significantly improves the limits on anomalous coupling compared to the earlier studies.Comment: 17 pages, 26 figure