Method for static divergence analysis of sting-mounted wind tunnel models

Occurrence of static divergence will result in a catastrophic failure of wind tunnel models supported13; on sting or other types of support . The report presents an analysis method that can be used to design and/or13; verify the design of a model-balance-sting system for preventing occurrence of static divergence of the system. Detailed explanations are given to provide a clear understanding of the static divergence phenomenon. A brief discussion indicating the conditions for which divergence can become a concern and various design factors that the designer can consider to meet the stipulated criteria, is also included . In order to ensure adequate margin of safety against divergence in pitch plane the system must13; satisfy the following criteria : i) divergence parameter D shall not exceed a value of 0 .2, and, ii) elastic13; deflection of the balance-sting combination should be limited to 3 xB0;. Excellent agreement shown between calculated and test deflection data on a typical model indicates the high accuracy of the method of obtaining model deflection and angle of attack

Design Features And Stress Analysis Of A 0.686-Scale Standard Dynamics Model

A 0 .686-Scale Standard Dynamics Model Incorporating Some Tpecial Features Was Designed And Built At NAL .A Brief . Description Of The Various Design And Construction Features, Load Estimations And A Detailed Stress Analysis Of The Model Are Presented In The Report To Provide An Idea Of The Current Practice Adopted At NAL For The Design And Construction Of Wind Tunnel Models For Dynamic Stability Testing . The Model Was Successfully Employed For Check-Out And Validation Of A Forced-Oscillation Rig At Mach Numbers Up to 1.3 And Angles Of Attack Up to 20 Deg In The NAL 1.2m Blowdown Tunne

Estimation of stability derivatives and dynamic stability characteristics of basic and AEW HS-748 aircraft

Longitudinal and lateral stability derivatives of the basic and the AEW configurations of the HS-748 aircraft have been estimated. DATCOM and ESDU Data Sheet methods were employed to estimate the complete set of derivatives of the basic aircraft. Derivatives of the AEW aircraft were obtained by a judicious use of some of the measured static wind-tunnel force and moment data in the estimation scheme. Stick-fixed and stick-free dynamic stability characteristics of the basic and the AEW aircraft were computed using the estimated stability derivatives for a range of values of the aircraft weight and C.G. location. The dynamic stability characteristics are expressed in terms of the period, damping and time-to-half amplitude of the different modes of longitudinal and lateral motions. Both the basic and the AEW aircraft are found to be stable in all modes except the spiral mode, which exhibits a mild divergence. Damping of the lateral oscillatory mode with rudder-free, although positive, is rather low for both the basic and the AEW configurations. In general, installation of rotodome reduces the effectiveness of horizontal and vertical stabilizers and also the control effectiveness of the elevator and rudder, but it does not cause any major qualitative changes In the dynamic stability characteristics of the aircraft

Measurement Of Pitch-Damping Derivatives On Prithvi Model In The Nal 1.2m Tunnel

Pitch Damping Derivatives Were Measured On A 1/12 .5 Scale Prithvi Model Using The Forced Oscillation Technique In The NAL 1 .2m Tunnel. The Tests Were Made In The Mach Number Range Of 1 .5 To 3 .0 And At Angles Of Attack 0, 3 And 6 Deg . The Tests Were Conducted For Two Axes Of Oscillation Located At 3 .8 And 4 .05 Times The Body Diameter From The Nose. While A Majority Of The Tests Were Conducted On The 'Plus' Configuration, A Few Tests Were Also Conducted On The Into Configuration To Study The Effect Of Roll Orientation Of The Model . Both Configurations Exhibited Positive Damping Over The Range Of Test Parameters. Effects Of Angle Of Attack And Model Roll Orientation Were Found To Be Small

A Description Of Sub-Systems And Calibration Formulations Of The NAL Automatic Balance Calibration System (ABCS)

A Description Of Automatic Balance Calibration System (ABCS) Recently Installed And Commissioned At NAL Is Presented . The Description Includes Details Of The,Major Subsystems, Viz, Loading System, Measuring System And Data Acquisition And Processing System. Details Of The Various Calibration Formulations (Or The Mathematical Models) Adopted In The ABCS To Generate Different Types Of Calibration Matrices Are Presented. Methods Used For Determining The Calibration Co-Efficients And The Balance Loads Using The Outputs Are Briefly Described. A General Description Based On A Brief Review Of The Calibration Methods Of Balances Is Included For A Better Understanding Of The Methods Adopted In ABCS And Facilitate Effective Utilization Of The System. Balance Calibration Procedure Is Briefly Described And Details Of Various Data And Setup Files I That Are Required To Be Created Are Noted.Calibration Results Of A Typical 6-Component Balance, Consisting Of The Set Of 6 X 84 Calibration Co-Efficients, Plots Of Load Measurement Errors And Overall Measurement Accuracy Are Included

The impacts of the transgenes on the modified crops, non-target soil and terrestrial organisms

Agriculture forms a basis for survival and advancement of civilization of mankind and economic growth. The production and quality of food depends on nature of cultivars that have hitherto been obtained by mutation and hybridization of selected plants. Since the productivity of many crops has reached a plateau the gene transfer technology is used to break the yield barriers to meet the demand of the growing population of mankind. The gene transfer although yielded intended effects including reduction of emission of greenhouse gases, caused several changes in the modified crop plants, interacted with soil food webs, affected the biota associated with agro system, inflicted damage to mammals and birds, and contaminated both the related and unrelated plant species through horizontal gene transfer.The gene transfer also caused the phenomena of resistance and ecological succession of biota in different habitats Keywords: Gene transfer, transgene, agriculture, modified crop

Hydrogen-bonded multilayer thin films and capsules based on poly(2-n-propyl-2-oxazoline) and tannic acid : investigation on intermolecular forces, stability, and permeability

In recent years, hydrogen-bonded multilayer thin films and capsules based on neutral and nontoxic building blocks have been receiving interest for the design of stimuli-responsive drug delivery systems and for the preparation of thin-film coatings. Capsule systems made of tannic acid (TA), a natural polyphenol, as a hydrogen bonding donor and poly(2-n-propyl-2-oxazoline) (PnPropOx), a polymer with lower critical solution temperature around 25 degrees C, as a hydrogen bonding acceptor are advantageous over other conventional hydrogen-bonded systems because of their high stability in physiological pH range, biocomparibility, good renal clearance, stealth behavior, and stimuli responsiveness for temperature and pH. In this work, investigations on the interactive forces in TA/PnPropOx capsule formation, film thickness, stability, and permeability are reported. The multilayer thin films were assembled on quartz substrates, and the layer-by-layer film growth was investigated by UV-vis spectroscopy, atomic force microscopy, and profilometry. Hollow capsules were fabricated by sequential coating of TA and PnPropOx onto CaCO3 colloidal particles, followed by template dissolution with a 0.2 M ethylenediaminetetraacetic acid solution. The obtained capsules and multilayer thin films were found to be stable over a wide pH range of 2-9. It is found that both hydrogen bonding and hydrophobic interactions are responsible for the enhanced stability of the capsules at higher pH range. Swelling followed by dissolution of the capsules was observed at a pH value lower than 2, while the capsules undergo shrinking at a pH value higher than 8 and finally transform into a particle-like morphology before dissolution. The TA/PnPropOx capsules reported here could be used as a temperature-responsive drug delivery system in controlled drug delivery applications

Systems Biology: To Meet Challenges for Biology in the Twenty-first Century

Genomics, structural biology, and bioinformatics deal with identification, cataloguing and characterization of the components that make up a cell. The focus on individual genes and proteins, which has proven so powerful for the molecular genetics in the past century, is in itself inadequate to describe the dynamic processes involving interactions among tens, hundreds and even thousands of components. Cell function, including growth, differentiation, division, and apoptosis, are temporal processes and we will only be able to  understand them if we treat them as dynamic systems. There is a general agreement that systems approach is necessary to understand the causal and functional relationships that generate the dynamics of biological networks and pathways

Computational prediction and analysis of impact of the cross‐talks between JNK and P38 kinase cascades

Signal transduction is a complex protein signaling process with a rich network of multifunctional interactions that occur in a non‐linear fashion. Mitogen‐activated protein kinase (MAPK) signal transduction pathways regulate diverse cellular processes ranging from proliferation and differentiation to apoptosis. In mammals, out of five, there are three well characterized subfamilies of MAPKs ‐ ERKs (Extracellular signal‐regulated kinases), JNKs (c‐Jun N‐terminal kinases), and P38 kinases, and their activators, are implicated in human diseases and are targets for drug development. Kinase cascades in MAPK pathways mediate the sensing and processing of stimuli. To understand how cells makes decisions, the dynamic interactions of components of signaling cascades are important rather than just creating static maps. Based on enzyme kinetic reactions, we have developed a mathematical model to analyze the impact of the cross‐talks between JNK and P38 kinase cascades. Cross‐talks between JNK and P38 kinase cascades influence the activities of P38 kinases. Responses of the signals should be studied for network of kinase cascades by considering cross‐talks