Stability Analysis and Robust Controller Design of Indirect Vector Controlled Induction Motor

The thesis considers stability analysis and controller design through different performance measures for indirect vector controlled induction motor (IVCIM).These problems are known to be complex due to nonlinearity, large order and multi-loop scenario. Some new approaches and results on IVCIM are proposed in this work. IVCIM dynamics is well known for having different bifurcation behavior, viz., saddle-node, Hopf, Bogdanov–Takens and Zero–Hopf bifurcations due to rotor resistance variation. These bifurcations affect the control performance and may lead to stalling or permanent damage of motor. A numerical analysis of these bifurcations for proportional integral (PI) controlled IVCIM is made in this thesis using full-order induction motor model (stator dynamics is included). This analysis aids to determine the allowable bifurcation parameter variation range as well as suitable choice of speed-loop gains to avoid these. Some new observations on the bifurcation behavior are made. Simulation and experimental results are presented validating the bifurcation behaviors. For improving dynamic performance in the presence of load torque and rotor resistance variation, a new method for designing PI gains is proposed for IVCIM. The inner-loop current PI controllers are tuned simultaneously along with the speed controller. This method is implemented using a static output feedback scheme in which iterative linear matrix inequality (ILMI) based∞control technique is employed. Such a design makes stator currents and speed response to be robust against rotor resistance and load variations. A comparison between proposed design and a conventional one is shown using simulation and experimental results that validate the superiority of the proposed approach. Owing to multi-loop and nonlinear system behavior, IVCIM dynamics is known to have coupling in between the two inner-loop stator current components (flux and torque). Such coupling affects the dynamic torque output of the motor. Decoupling of the stator currents are important for smoother torque response of IVCIM. Conventionally, additional feedforward decoupler is used to take care of the coupling that requires exact knowledge of the motor parameters and additional circuitry or signal processing. A method is proposed to design the regulating PI gains while minimizing coupling without any requirement of additional decoupler. The variation of the coupling terms for change in load torque is considered as the performance measure. The same ILMI based∞control design approach is used to obtain the controller gains. A comparison between the conventional feedforward decoupling and proposed decoupling scheme is presented through simulation and experimental results that establish the effectiveness of the proposed method riding over its simplicity. Finally, since the PI controller can yield limited performance, a dynamic controller is designed for the IVCIM drive system. In the design process, iron-loss dynamics are incorporated into induction motor model to fetch benefit through better performance. A sequential design method is used for the controller design in which, first, the inner-loop controllers are designed. The designed inner-loop controllers is then used for designing the outer speed-loop controller. The proposed design employs ILMI based∞control design for dynamic output feedback controller that makes stator currents and speed response to be robust against disturbances. A comparison among proposed dynamic controller design, PI controller and compensator design is shown using simulation and experimental results demonstrate enhanced performance of the proposed controller and suitability for industrial purpose

Normal Body Mass Index and Heart Rate Variability

The autonomic nervous system (ANS) works in synergy with the Endocrine system that affects the body-mass and height and in turn the body mass index (BMI). The ANS activities are often assessed with one index that is heart rate variability (HRV). Reduced HRV has been reported in underweight (low BMI) and overweight (high BMI) individuals, but there is scarce information available on the relationship between normal BMI and HRV. Further, as per WHO expert consultation report, the Asian population has higher percentage of body fat than their European counterparts, therefore Asian people may have greater risk factors for type 2 diabetes and cardiovascular disease even below the existing upper edge of normal BMI. Thus it was recommended by WHO to consider the intermediate cutoff points within the normal BMI range as 18.5 Kg/m2, 20 Kg/m2, 23 Kg/m2, and 25 Kg/m2 for the Asian population. Therefore, the present study was aimed to investigate ANS activity among intermediate cutoff points of normal BMI using HRV. Seventy young individuals participated in the non-invasive and benign study. Subjects were divided into three groups based on their BMI as per the recommendation of the WHO report; NB1 (18.5<BMI≤20), NB2 (20<BMI<23) and NB3 (23<BMI<25). For all the subjects, 10 min of electrocardiogram was recorded and short term HRV analysis was carried out. Student t test was carried out to find the significance of study parameters in BMI groups. The BMI was correlated with HRV measures using Spearman’s correlation method. Statistically significant negative correlation was found between BMI and various HRV parameters. The sympathovagal balance was comparable in NB1 and NB2 group whereas it shifted towards sympathetic dominance in NB3 group. Higher sympathetic activity for BMI greater than 23 in Indian youth may lead to predictability of risks associated with overweight and obesit

Silver triflate catalyzed synthesis of 3-aminoalkylated indoles and evaluation of their antibacterial activities

An efficient, one-pot synthesis was developed for 3-aminoalkylated indoles by three-component coupling reaction of aldehydes, N-methylanilines, and indoles using AgOTf as a catalyst. A series of twenty 3-aminoalkylated indoles was evaluated for their antibacterial activities against both Gram negative and Gram positive bacteria. Compounds 4b and 4r showed good antibacterial activity against both Gram positive and Gram negative strains. However, inversing the property of substituent (from 4r to 4q) resulted in the significant fall in the magnitude of antibacterial activity against Escherichia coli

Study of clinical profile of infantile tremor syndrome and its correlation with serum Vitamin B12 level

Objective: The objective of this study was to assess the clinical profile of infantile tremor syndrome (ITS) and to correlate serum Vitamin B12 level with ITS. Materials and Methods: This prospective study was done in the Department of Pediatrics of a Medical College of Kota. A total of 40 children, presenting with clinical features of ITS, were included in the study. A detailed history was taken. Investigations including complete blood count with blood indices (mean corpuscular volume, mean corpuscular hemoglobin [MCH], and MCH concentration), peripheral smear, and serum Vitamin B12 level were done in accordance with the WHO guidelines. Vitamin B12 deficiency was defined as serum Vitamin B12 concentration <150 pmol/L or 203 pg/mL. Results: All patients with ITS had pallor (100%) and skin hyperpigmentation (100%). Psychomotor changes in the form of apathy and/or developmental regression/stasis were found in 40 (100%) cases. Regression of developmental milestones was found in 26 (65%) and 10 (25%) patients had stasis of milestones. Tremor was present in 14 (35%) cases. Hepatomegaly was present in the majority 25 (62.5%) of these children, whereas splenomegaly was present in only 8 (20%) patients. Hypopigmented hair was found in only 12 (30%) cases. Twenty-five (62.5%) children were exclusively breastfed (p<0.05). Of the 40 cases, 26 (65%) presented in prodromal phase and 14 (35%) presented in the tremor phase. Among 26 patients of prodromal phase, 22 (84.62%) had Vitamin B12 deficiency while among 14 cases of tremor phase, 9 (64.28%) had Vitamin B12 deficiency. The majority of ITS children had macrocytic anemia (65%) followed by dimorphic anemia (25%). A significant number of ITS patients (21, 80.77%), having macrocytic anemia, had Vitamin B12 deficient. Conclusion: We conclude that children of ITS presented with anemia, skin hyperpigmentation, psychomotor changes, apathetic look, and developmental abnormality. The majority of children were on faulty feeding in the form of prolonged exclusive breastfeeding. Vitamin B12 deficiency was present in a significant number of patients with IT

Prevalence of hypertension and its association with anthropometric parameters in adult population of Raipur city, Chhattisgarh, India

Background: Obesity is now an important emerging public health problem in India. It is one of the major risk factor for hypertension. Overweight persons have two to six fold increase in the risk of developing hypertension. This study was carried out with objective to find out prevalence of Hypertension and assess its association with four obesity-related indices- body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR).Methods: A cross-sectional community-based study was done among 640 study subjects of age group 25-59 years during July 2015 to June 2016. Multi stage random sampling method was used. Data collection was done using WHO STEPS instrument V 3.1. Privacy and confidentiality of data was maintained. Data was entered in the Microsoft excel, collected data was checked for its completeness and correctness before data analysis with the help of PSPP software.Results: Prevalence of hypertension among study subjects was found to be 22.19% (142 out of 640).With respect to body mass index, waist circumference, waist hip ratio and waist height ratio, 4.38%, 64.35%, 85.33%, 76.2% were found to be obese respectively. Hypertension was strongly associated with BMI (p<0.001), waist circumference (p<0.001), waist hip ratio (p<0.05), waist height ratio (p<0.05). Out of the four anthropometric variables waist hip ratio (WHR) was most strongly associated with hypertension (β=420.236, p=0.007).Conclusions: The study shows a rising burden of hypertension among study population. As WHR is the best indicator for measuring obesity, so measurement of WHR should be made compulsory in healthy life style clinics along with other parameters

RF Based Remote Control for Electrical Appliances

This work presented here is to control electrical appliances through RF based remote system. From anywhere without any line of sight, RF based wireless remote control system can change the state of the electrical appliances either in off state or in on state. The controlling circuit is built around RF transmitter and RF Receiver modules which are operating at certain frequency along with a encoder and a decoder with few passive components. The four different channels at the encoder IC are used as input switches and the four channels at the decoder output are connected to the electrical devices through a relay. Here the transmission technique is amplitude shift keying (ASK) and the circuit is powered with 9 Volt. The main objective of this work is to control electrical appliances without line of sight requirement using the RF technology. It has many applications like we can control any independent electrical appliance such as T.V, room light, fan just from a remote. Operating them manually is a tedious job and become hectic sometimes. If one can control devices like fan, TV, lights and music system with a remote from a distance place just by pressing the button, life will become simpler. This will make our life more comfortable and easier

Role of Physiotherapy in Hospitalised Patients of COVID-19 disease

Introduction: Respiratory physiotherapy is one of the therapeutic methods in various respiratory viral infections. Breathing exercises with other interventions, could enhance the total lung capacity and symptom alleviation in patients with virus-related acute respiratory distress syndrome (ARDS). Aim: To study the clinical evaluation of the role of physiotherapy in hospitalised patients of covid-19 diseases. Method: This was an Observational (prospective, cross-sectional) study. 187 patients were recruited and diagnosed as COVID-19 as per RTPCR at NSCB Medical College, Jabalpur (MP). Patients were randomised into the physiotherapy group and controlled group. Patients in the physiotherapy group were undergone positional changes, prone ventilation, Breathing exercise, Resistive training, Passive joint motion, Muscle stretching, Bedside standing training, endurance exercise by a specialized physiotherapist. Mean cough severity index, MMRC grade, respiration rate and peripheral blood saturation were recorded before and after intervention and compared with the controlled group. Result: There was significant improvement found in MMRC grade and respiration rate after physical therapy in the physiotherapy group (p-value &lt; 0.05). Exertional dyspnoea and cough severity index significant deceased in physiotherapy group. The positive change was found in peripheral blood saturation. There was decreased in hospitalization stay in the physiotherapy group as compared to the controlled group. Conclusion: Our study revealed the positive effect of physiotherapy on covid-19 disease in terms of symptoms and hospitalization duration among the physiotherapy group. Physiotherapy exerts a beneficial role in the management of the covid-19 disease

Tillage-based nutrient management practices for sustaining productivity and soil health in the soybean-wheat cropping system in Vertisols of the Indian semi-arid tropics

To achieve higher crop production in a soybean-wheat cropping system, comprehensive knowledge of soil fertility status and its variability is crucial. However, a significant gap exists between the potential and actual productivity of this system in the Vertisols of Indian semi-arid tropics. Therefore, 2 years of field research were conducted to investigate how different crop management practices affect soil fertility in this cropping system. The trial was conducted using a randomized complete block design (RCBD) with five crop management practices: CAO (conservation tillage + organic nutrient and weed management), CAC (conservation tillage + chemical nutrient and weed management), CTC (conventional tillage + chemical nutrient and weed management), OCT (conventional tillage + organic nutrient and weed management), and PoPs (package of practices). Results showed that CAO significantly (p &lt; 0.05) increased soil organic C (6.8 g kg−1), available N (129.5 mg kg−1), P (11.0 mg kg−1), K (232.6 mg kg−1), Fe (9.17 mg kg−1), and Mn (10.48 mg kg−1) at topsoil (0–15 cm) and deeper layers (15–60 cm). In contrast, CAC had significantly (p &lt; 0.05) higher soil availability of Ca (5,072 mg kg−1) and Mg (901 mg kg−1) and Cu (0.84 mg kg−1). On the other side, PoPs resulted in the highest S (10.05 mg kg−1) and Zn (0.85 mg kg−1) availability in the topsoil. Our results evidently suggested S and Zn availability as key indicators of soil health sustenance in the present agroecosystem. Notably, CAC had significantly (p &lt; 0.05) higher system productivity (4.62 t ha−1) than the other treatments, showing a 14.0, 6.3, and 18.2% increase over CAO, CTC, and OCT, respectively. Based on the results, it is recommended that CAC is a better option for achieving higher system productivity, while CAO is the best option for ensuring long-term sustainability of soil fertility. The findings of this study could be useful for farmers and agricultural researchers in designing efficient crop management practices to improve the productivity and sustainability of soybean-wheat cropping system in arid to semiarid ecology

Assessing the feasibility of integrating ecosystem-based with engineered water resource governance and management for water security in semi-arid landscapes: A case study in the Banas catchment, Rajasthan, India

Much of the developing world and areas of the developed world suffer water vulnerability. Engineering solutions enable technically efficient extraction and diversion of water towards areas of demand but, without rebalancing resource regeneration, can generate multiple adverse ecological and human consequences. The Banas River, Rajasthan (India), has been extensively developed for water diversion, particularly from the Bisalpur Dam from which water is appropriated by powerful urban constituencies dispossessing local people. Coincidentally, abandonment of traditional management, including groundwater recharge practices, is leading to increasingly receding and contaminated groundwater. This creates linked vulnerabilities for rural communities, irrigation schemes, urban users, dependent ecosystems and the multiple ecosystem services that they provide, compounded by climate change and population growth. This paper addresses vulnerabilities created by fragmented policy measures between rural development, urban and irrigation water supply and downstream consequences for people and wildlife. Perpetuating narrowly technocentric approaches to resource exploitation is likely only to compound emerging problems. Alternatively, restoration or innovation of groundwater recharge practices, particularly in the upper catchment, can represent a proven, ecosystem-based approach to resource regeneration with linked beneficial socio-ecological benefits. Hybridising an ecosystem-based approach with engineered methods can simultaneously increase the security of rural livelihoods, piped urban and irrigation supplies, and the vitality of river ecosystems and their services to beneficiaries. A renewed policy focus on local-scale water recharge practices balancing water extraction technologies is consistent with emerging Rajasthani policies, particularly Jal Swavlamban Abhiyan (‘water self-reliance mission’). Policy reform emphasising recharge can contribute to water security and yield socio-economic outcomes through a systemic understanding of how the water system functions, and by connecting goals and budgets across multiple, currently fragmented policy areas. The underpinning principles of this necessary paradigm shift are proven and have wider geographic relevance, though context-specific research is required to underpin robust policy and practical implementation