Calibration approach to electron probe microanalysis: A study with PWA-1480, a nickel base superalloy

The utility of an indirect calibration approach in electron probe microanalysis is explored. The methodology developed is based on establishing a functional relationship between the uncorrected k-ratios and the corresponding concentrations obtained using one of the ZAF correction schemes, for all the desired elements in the concentration range of interest. In cases where a very large number of analyses are desired, such a technique significantly reduces the total time required for the microprobe analysis without any significant loss of precision in the data. A typical application of the method in the concentration mapping of the transverse cross-section of a dendrite in directionally solidified PWA-1480, a nickel-based superalloy, is described

Allelopathic Effect of Jatropha curcas on Selected Intercropping Plants (Green Chilli and Sesame)

The aqueous leaf extracts of Jatropha curcas showed inhibitory effects on seed germination, shoot length and root length in Capsicum annum L.(green chilli).The inhibitory effect of the crop plant is directly proportional to the increasing concentration (5%, 10%, 15%, 20%) of aqueous leaf extracts of Jatropha curcas. The Jatropha curcas leaf extract showed stimulatory effects on seed germination and shoot length in Sesamum indicum L. (sesame). The stimulatory effect is directly proportional to the increasing concentration (5%, 10%, 15%, 20%), but the root growth was inhibited in all treatment when compared with the control. The result of bioassay studies revealed that the inhibitory and stimulatory effect may be due to the presence of water soluble allelochemicals like phenols and tannins etc

Secondary arm coarsening and microsegregation in superalloy PWA-1480 single crystals: Effect of low gravity

Single crystal specimens of nickel base superalloy PWA-1480 were directionally solidified on ground and during low gravity (20 sec) and high gravity (90 sec) parabolic maneuver of KC-135 aircraft. Thermal profiles were measured during solidification by two in-situ thermocouples positioned along the sample length. The samples were quenched during either high or low gravity cycles so as to freeze the structures of the mushy zone developing under different gravity levels. Microsegregation was measured by examining the solutal profiles on several transverse cross-sections across primary dendrites along their length in the quenched mushy zone. Effect of gravity level on secondary arm coarsening kinetics and microsegregation have been investigated. The results indicate that there is no appreciable difference in the microsegregation and coarsening kinetics behavior in the specimens grown under high or low gravity. This suggests that short duration changes in gravity/levels (0.02 to 1.7 g) do not influence convection in the interdendritic region. Examination of the role of natural convection, in the melt near the primary dendrite tips, on secondary arm spacings requires low gravity periods longer than presently available on KC-135. Secondary arm coarsening kinetics show a reasonable fit with the predictions from a simple analytical model proposed by Kirkwood for a binary alloy

A COMPARATIVE STUDY ON THE EFFECT OF TWO INDIGENOUS AYURVEDIC FORMULATIONS ON LACTATION

A clinical trial was conducted to compare the lactogenic properties of two indigenous formulations, the trial drug mentioned in Arogyakalpadrumam and control drug- some selected drugs from Chikithsamanjari, the efficacy of which was already proved. The study was carried out in the outpatient section of the Department of Prasuthi and Sthreeroga, Govt. Ayurveda college Hospital for women and children, Poojappura, Thiruvananthapuram during 2013-2014. Lactating mothers, complaining of reduced breast milk even after 2 weeks from delivery were screened and grouped into two groups each containing of 15 patients. Data were collected by interviewing mothers using a pre-structured questionnaire with a scoring system. Study drug and control drug are given to each group, in a dose of 6gm powder with 24ml milk twice daily 1hr before food for three months. Evaluations of all the parameters were done at an interval of 30 days in each group. Differences in the score values were noted. Assessment of growth and development of children using Anthropometric parameters and CDC chart were recorded. The data were analyzed using the most appropriate statistical tests. Significant changes were obtained in the clinical parameters in the study group used for assessment such as number of feeds per day, interval between feeling of fullness of breasts, duration of feeds, sleep habits of the baby. There was no statistical significance in increasing number of feeds during night time in both groups. Both drugs have lactogenic properties. All children in both groups attained their natural growth and development. There was a small statistical significance in increasing birth weight in study group when compared with the control group. In the study group poor and moderate response was 0% while in control group they were 13.3%. Good response in the study group was 86.7% while it in the control group was 60.1%. There was a very good response in both groups which was 13.3%

Nonlinear Control Concepts for a UA

A reconfigurable flight control method is developed to be implemented on an Unmanned Aircraft (UA), a thirty percent scale model of the Cessna 150. This paper presents the details of the UA platform, system identification, reconfigurable controller design, development, and implementation on the UA to analyze the performance metrics. A Crossbow Inertial Measurement Unit provides the roll, pitch, and yaw accelerations and rates along with the roll and pitch. The 100-400 mini-air data boom from SpaceAge Control provides the airspeed, altitude, angle of attack, and the side slip angles. System identification is accomplished by commanding preprogrammed inputs to the control surfaces and correlating the corresponding variations at the outputs. A Single Network Adaptive Critic, which is a neural network-based optimal controller, is developed as part of a nonlinear flight control system. An online learning neural network is augmented to form an outer loop to reconfigure and supplement the optimal controller to guarantee a practical stability for the airplane. This paper also presents some simulations from the hardware-in-the-loop testing and concludes with an analysis of the flight performance metrics for the controller under investigation

Development and Implementation of New Nonlinear Control Concepts for a UA

A reconfigurable flight control method is developed to be implemented on an Unmanned Aircraft (UA), a thirty percent scale model of the Cessna 150. This paper presents the details of the UAV platform, system identification, reconfigurable controller design, development, and implementation on the UA to analyze the performance metrics. A Crossbow Inertial Measurement Unit provides the roll, pitch and yaw accelerations and rates along with the roll and pitch. The 100400 mini-air data boom from spaceage control provides the airspeed, altitude, angle of attack and the side slip angles. System identification is accomplished by commanding preprogrammed inputs to the control surfaces and correlating the corresponding variations at the outputs. A Single Network Adaptive Critic, which is a neural network based optimal controller, is developed as part of a nonlinear flight control system. An online learning neural network is augmented to form an outer loop to reconfigure and supplement the optimal controller to guarantee a practical stability for the airplane. This paper also presents some simulations from the hardware-in-the-loop testing and concludes with an analysis of the flight performance metrics for the controller under investigation

Discrete Wavelet Transform based Cryptosystem

In this article, the authors proposed, implemented and analysed a symmetric key cryptographic algorithm that can be considered as a lossless encryption and decryption technique, advantageous especially in situations where, even a slight marginal distortion is not tolerable. In the proposed system, Haar wavelet is used initially, to transform the original target image into its frequency domain, followed by  encrypting the resulting sub-bands, so as to obtain a secure and reliable encrypted image. The resulting coefficients after Haar decomposition is scattered using a reversible weighing factor, suitably reversed and swapped to get the secure encrypted image. The encrypted image is  then correspondingly decrypted, by the reverse process to get back the original decrypted image. Statistical testing and security methods were used to evaluate and analyse the proposed cryptosystem and the results showed that the proposed system is cryptographically resistant to attacks and is also highly secure when compared to other cryptographic systems in the frequency domain