Shape memory effect reveals the recovery of original shape from deformed shape with residual strain through thermal cycling. This type of super-elastic behavior found in shape memory alloys are generally used as actuators in robotics, control and embedded systems. In the present study, first an experimental setup was developed to perform life tests of Nickel-Titanium Shape Memory Alloy (NiTi-SMA) springs. Laser displacement sensor and J-type thermocouple was used to measure the displacement and temperature respectively. Data was collected through the Data Acquisition (DAQ) device. Acquired data is then used for failure diagnosis and reliability assessment of NiTi-SMA springs. Accelerated life testing models are developed to estimate the parameters of the life distributions. It was observed that with the subsequent cycles, SMA spring starts losing its inherent property of being an elastic object, and thus a decrease in displacement of it was observed with each cycle. Gradual loss of actuation property of the material under accelerated conditions was investigated in detail using Scanning Electron Microscopy (SEM) and Thermo Gravimetric Analysis (TGA).
The limitations of the conventional MPPT technique are oscillations of the system at steady state leading to energy loss, slower response and the occurrence of drift. A simple zonal based MPPT controller is proposed in this paper which addresses the above limitations without additional requirement of sampling or sensors apart from the basic voltage and current sensors. The proposed system is simple, cost effective and easy to implement. Phase shift reference (Duty) for the DC-DC converter is varied dynamically by the proposed MPPT controller depending upon the operating point voltage to have a better dynamic response. The error in the perturbation direction, if any, is corrected by the controller while computing the change in duty reference ΔD). This ensures the drift free operation. The response speed of the proposed controller is improved compared to the conventional controller by having a variable step size. Solar PV fed full bridge series resonance DC-DC converter with resistive load is considered for evaluating the proposed control scheme. The performance of the proposed MPPT control technique is verified by simulations and hardware results.
Herbal supplements (HS) are one of the most commonly used complementary and alternative medicines in cancer. Reduced therapeutic efficacy of prescription anticancer agents through unwarranted herb-drug interactions is a major efficacy/safety concern. In view of the rising cancer prevalence in India along with a high degree of reliance and cultural acceptability in favor of traditional medicine drugs, prevalence data exclusively of HS usage during cancer treatment are of considerable epidemiological significance.This questionnaire-based prospective observational study aimed at estimating the prevalence of HS among cancer patients during treatment at our tertiary care medical center. Taken on a population of 220 patients within a period of 9 months, data were generated by a customized validated questionnaire and the same processed by IBM SPSS Statistics for Windows, version XXIV, Armonk, NY: IBM Corp. Differences between HS use and nonuse with respect to demographic, disease, and treatment characteristics were assessed by Chi-square test. For examining the latter variables as possible predictors of HS usage, they were entered into bivariate logistic regression with odds ratio and confidence intervals calculated for each.Out of 220 patients, 57 (26%) were HS users and 163 (74%) were nonusers. Majority of the users (42.1%) were on self-prepared folklore herbal medicine postdiagnosis of cancer (57.9%), the most common reason cited being symptom palliation (35.1%) on the advice of friends and family (64.9%). Fear of disapproval was the most common reason cited (68.4%) for not disclosing HS usage to the physician.Chemotherapy and unemployment are predictors of HS usage, and there is a significant association between occupation status and HS usage. This first study on HS prevalence among South Indian population proposes the need for a more robust evidence base for understanding all aspects of HS use in cancer.
Electrochemical synthesis of poly N-methyl aniline (PNMA) was achieved on Teflon coated cylindrical stainless steel electrodes with base diameter 2mm . N-methyl aniline in di N-propyl malonic acid was polymerized on the surface of stainless steel using cyclic voltametry technique. Adherent and red polymer films were obtained on the electrodes.. The corrosion inhibitive performance of PNMA+DPM , coated electrodes were investigated in 0.5 N H2SO4 solutions by potentiodynamic polarization technique and electrochemical impedance spectroscopy.
Super-luminescent diode (1535nm) based absorption spectroscopy is proposed for C 2 H 2 and CO 2 measurements. The experiment is performed with pure C 2 H 2 , CO 2 , mixture of C 2 H 2 and CO 2 and biogas and the results are presented here.
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