Control strategies for seamless transfer between the grid-connected and islanded modes of a microgrid system

Design of control strategies for Distributed generation systems is very important to achieve smoother transition between the grid connected and islanding modes of operation. The transition between these two modes of operation should be seamless, without any severe transients during the changeover. In this paper, two different control strategies namely inverter output current control and indirect grid current control for the seamless transfer between the modes of operation has been explored for the suitability. The design and analysis of the cascaded control loops based on Proportional Integral (PI) controller has been dealt in detail for both inverter output current control and indirect grid current control strategy. Control parameters are designed using the control system toolbox in MATLAB. A 10kW grid connected microgrid system has been designed and simulated in MATLAB/Simulink and the results are presented under grid connected operation, islanding operation and the transition between the modes considering fault condition in the grid side. The simulation studies are carried out using both the control strategies and the results are presented to validate the design methodology

A Scheme for Detecting the Sinkhole for Secured WSN

Because of the limited computation capability as well as transmissions being broadcasted in a wireless sensor network (WSN) they are supposed to be more susceptible for attacks related to the security. As present wireless sensor networks have low-power constraints as well as increased complexity, thus for nodes’ performance analysis related to the embedded software and network simulation efficient approaches are required. Additionally, as these networks are used to deal with the sensitive information and operated in the adverse unattended environments, thus, security feature must be added in most of these wireless sensor networks. In this paper a novel scheme for detecting various sinkhole nodes for wireless sensor network (WSN). The results of this proposed scheme show the 1.75% fake positive rate and 96% of detection rate. In comparison to the previous schemes, these aspects are considerably better. In addition to these aspects, our scheme also achieves the communication as well as computational efficiencies. As a result of which, this proposed scheme proved to have better results in many applications.

DETERMINATION OF 2-CYANO-4'-BROMOMETHYL BIPHENYL GENOTOXIC IMPURITY IN IRBESARTAN DRUG SUBSTANCES USING HPLC TECHNIQUE

Objective: The objective of present study was to develop and validate a specific and sensitive HPLC method for the quantitative determination of genotoxic impurity 2-cyano-4'-bromomethyl biphenyl present in irbesartan drug substance.Methods: The development activity was conducted by HPLC with UV as a detector. The impurity was separated on Kromasil C18 250 x 4.6 mm, 5 µm analytical column with a mobile phase consisting of buffer pH 3.2 and acetonitrile in the ratio of 60:40 v/v at a flow rate 1.5 ml/min. The effluent was monitored by UV detection at 258 nm with column temperature maintained at 40 °C and the injection volume 30 μl. Acetonitrile was selected as diluent.Results: Validation activity was planned and completed based on the ICH guideline. The LOD and LOQ value were found to be 0.167 µg/g and 0.506 µg/g and accuracy results were well in the range 98.34 to 103.46 %. The linearity curve showed the correlation coefficient of 0.9999 and method very sensitive.Conclusion: From validation data, it was confirmed that the developed method is specific, sensitive, linear, precise and accurate for the determination of 2-cyano-4'-bromomethyl biphenyl genotoxic impurity in irbesartan drug substances

A prospective study on functional outcome of Bimalleolar Ankle Fractures

AIM: To analyse the results of Surgical management of bimalleolar ankle fractures. MATERIALS AND METHODS: This prospective study done in Government Royapettah Hospital, Chennai. In our study, 30 cases of bimalleolar ankle fractures were analysed. Classification used was Lauge-Hansen and A.O. classification. Road traffic accident was major mode of injury. Average injury surgery interval was 6 days. Malleolar screw for medial malleolus and plate and screws for fibula was common mode of fixation. RESULTS: Results were analysed using Olerud and Molendar subjective and objective scoring. The subjective scoring was excellent and good in 80% of cases and objective scoring was good in 22 cases. CONCLUSION: Accurate anatomical reduction and fixation results in good functional outcome

A Study on Padarthamarai (படர் தாமரை)

SUMMARY: The disease Padarthamarai was taken for the clinical study. The clinical study on Padarthamarai with reference to its aetiology, pathogenesis, clinical features, investigation, diagnosis and treatment was conducted at the Post Graduate Department of Sirappu Maruthuvam, Government Siddha Medical College, Palayamkottai. Twenty cases with the signs and symptoms of Padarthamarai were selected and a thorough observation was made. They were found out from the outpatient department and admitted in the inpatient ward. No adverse reactions like nausea, vomiting, diarrhoea were reported during the study period. The drugs employed in the clinical study were put to use only after careful purification process laid down for them individually. Both male and female were equally affected. The trial drug had mainly kaippu suvai and this mainly accounts for the therapeutic effect in skin diseases. The results were found to be encouraging. Among the inpatients treated 60% shows good result. 30% shows moderate result and 10% shows mild results. Along with the In- Patient ward patients nearly 36 patients were treated as out patients, and out of these 16 cases show remarkable result. 10 cases shows moderate result and 10 were poor result. For chronic skin diseases, Siddha system of medicine confers excellent therapeutic agents than the other systems. Also clinical evaluations and specific laboratory tests confirm this statement. The drugs of choice for both internal as well as external are economically less costly. Regarding the preparation point of view the drug was easy to be prepared. In biochemical analysis, Oosithagarai vidhai chooranam contains starch, ferrous iron and unsaturated compound. In pharmacological analysis of Oosithagarai vidhai chooranam shows significant anti- inflammatory and significant anti- histaminic effects and Padarthamarai kalimbu shows significant anti- inflammatory effect. No side effect was so for reported for the drug and with short duration with certain restriction this disease can be cured. In research point of view the author has a challenging work by these preparations for this skin disorder. CONCLUSION: 1. The treatment was given for Padarthamarai on the basis of Siddha system principles. Deranged three doshas were corrected by the author’s medicine given to the Padarthamarai case. 2. Oosithagarai vidhai chooranam as an internal medicine and Padarthamarai kalimbu as an external application respectively. 3. The internal medicine was selected from Gunapadam-Mooligai vaguppu –K.Murugesan mudaliyar and the external medicine from the Naatu marunthukal(Sulaba murai)- T.S.Janaga Kumari. 4. Signs and symptoms were relieved in 90% and reduced in 10% of cases. 5. Clinically the drugs were free from adverse effect. 6. Preparation of both, Internal and External Medicine were simple. 7. Hence it is concluded that the trial drugs were effective against Padarthamarai

A Comparative study between effectiveness of external electrical muscle stimulation versus TENS in the Management of Diabetic Peripheral Neuropathy.

INTRODUCTION : Diabetes is severe disease affecting over hundred millions of people endure from diabetes with in the world. In USA about 16 million people are affected from diabetes. It affects all age group from children to elderly individual by type II Diabetes have greater damage of nerve ,kidney, eye and coronary heart diseases. Diabetes believed to be the national IV leading for death. In the nervous system could also be disturbed or damaged causing severe pain, loss of felling this situation is referred to neuropathy Diabetic neuropathy is a complication caused by diabetes symptoms includes numbness and some time pain in the hand, feet or in legs Peripheral neuropathy is a problem with the nerve that carry information to and from the brain and spinal cord this produce pain loss of sensation and in ability to control muscle. Peripheral means away from the center of the body distance from spinal cord, ‘neuro” means nerve, ‘pathy’ means abnormal about 60 to 70% of diabetic patient have mild to severe form of nervous system damage which leads to diabetic poly neuropathy. AIM OF THE STUDY : To compare the effectiveness of External Electrical Muscle Stimulator and Transcutaneous electrical nerve stimulation in Management of Diabetic Peripheral Neuropathy. OBJECTIVES OF THE STUDY : 1. To determine the effectiveness of External Electrical Muscle Stimulator in Diabetic Peripheral Neuropathy. 2. To determine the effectiveness of transcutaneous electrical nerve stimulation in Diabetic Peripheral Neuropathy. 3. To compare the effects of External Electrical Muscle Stimulator and Transcutaneous electrical nerve stimulation in Management of Diabetic Peripheral Neuropathy in sensory reeducation. 4. To compare the effects of External Electrical Muscle Stimulator and Transcutaneous electrical nerve stimulation in Management of Diabetic Peripheral Neuropathy using lower extremity functional scale. 5. To find out the effective treatment regarding pain, functional status, and sensation in Diabetic Peripheral Neuropathy. MATERIALS AND METHDOLOGY : MATERIALS - Couch, Pillows, External Electrical Muscle Stimulator, Transcutaneous Electrical Muscle Stimulator(TENS), Electrode gel, Strap, Cotton, Lower extremity functional scale and Neuropathy Total Symptom Score-6 chart. METHODOLOGY : A total number of 30 patients having Diabetic peripheral neuropathy who met the inclusion criteria were recruited by convenient sampling method. After the informed consent obtained, they were partitioned into two groups as Group A and Group B, with 15 patients in each. Study Design - Quasi Experimental Study Design. Study Setting - The study was conducted at out patient department in J.K.K. Munirajahh Medical Research Foundation College of Physiotherapy, Komarapalayam under the supervision of the higher concerns. Sampling Method - Convenient sampling method. Sample Size - Thirty patients with diabetic peripheral neuropathy, who comes under the inclusion criteria, were taken for the study. Study Duration - The study was conducted for a course of 6 months, and treatment duration for each patient was 20 min per sitting, 4 sittings per week for one month. Inclusion Criteria - Age group –50 years and above, Sex – both sexes, Diabetic peripheral neuropathy, HbA1(C) <8, Neuropathy Disability Score (NDS) <6. Exclusion Criteria - Pregnancy, Malignancy. vessel involvement, Patient with cardiac pacemaker, Infective skin lesion, Varicose vein, Presence of ulcer, Insulin dependent diabetes mellitus, HbA1(C)>8, Amputation. Parameters - Neuropathy Total Symptom Score-6 (NTSS-6), Lower Extremity Functional Scale. CONCLUSION : This study shows that there was reduction in cold, warm ,cold pain threshold ,heat pain threshold, vibration perception threshold and touch perception threshold diabetic peripheral neuropathy after treatment with external electrical muscle stimulation. Thus the study concluded that external electrical muscle stimulation is effective treatment for diabetic peripheral neuropathy and Neuropathy Total Symptom Score-6 (NTSS-6) and Lower Extremity Functional Scale could be used as the assessment tools for cold, warm ,cold pain threshold ,heat pain threshold, vibration perception threshold and touch perception threshold

Evaluation of changes in hyoid bone position and pharyngeal airway dimensions following mandibular setback surgery: A Cephalometric study

AIM OF THE STUDY: The Aim of this study is to evaluate the changes in hyoid bone and pharyngeal airway dimensions in patients with prognathic mandible who had undergone mandibular setback surgery OBJECTIVES: 1. To evaluate the hyoid bone posit ion and pharyngeal airway dimensions in skeletal class III patients who had undergone mandibular setback surgery at pretreatment (T1), postsurgical (T2) and post treatment (T3) stages. 2. To evaluate the hyoid bone posit ion and pharyngeal airway dimension in normal skeletal class I patients. 3. To compare the changes in hyoid bone position and pharyngeal airway in the above two groups. MATERIALS AND METHODS: The samples for this study were chosen from the record archives of the Department of Orthodontics and Dentofacial Orthopaedics, Tamilnadu Government Dental College and Hospital, Chennai. Standardized lateral cephalograms of 20 patients diagnosed with Class III malocclusion due to prognathic mandible who underwent combined orthodontic and orthognathic surgical procedures between years 2009 and 2012 were analyzed. All these patients underwent presurgical orthodontics followed by mandibular setback surgery through Bilateral Sagittal Split ramus Osteotomy (BSSO) to correct mandibular prognathism and post surgical orthodontics for final settling of occlusion. Standardized lateral cephalograms of 20 patients diagnosed with class I malocclusion were taken as control group and analyzed. A good visibility of hyoid bone was ensured in all these lateral cephalograms. The age range was between 18 and 25 years. Inclusion and exclusion criteria were analyzed from clinical records of these patients. SUMMARY AND CONCLUSION: Pharyngeal airway dimension plays an important role in dentofacial development. Although mandibular setback surgeries like Bilateral Sagittal Split ramus Osteotomy (BSSO) could improve the occlusion, function and esthetics by changing the position of prognathic mandible in patients, it is likely to cause narrowing of pharyngeal airway space and changes in hyoid bone posit ion5. Narrowing of pharyngeal airway through setback surgery may contribute to treatment relapse apart from inducing the development of Obstructive Sleep Apnoea Syndrome (OSAS) 80. Hence it is essential to estimate and understand the changes in airway dimension s and hyoid bone positions following the mandibular set back surgeries. This study was therefore performed to evaluate the changes if any in hyoid bone position and pharyngeal airway dimensions following mandibular setback surgery in patients with prognathic mandible, at immediate post -operative stage and at the end of the whole orthodontic treatment. Following conclusions were derived from this study: 1. Skeletal Class III patients with prognathic mandible exhibited significantly larger pharyngeal airway space than the skeletal Class I individuals at pretreatment stage. 2. Significant narrowing of pharyngeal airway space occurred in Skeletal Class III patients with prognathic mandible immediately after surgery. 3. The post treatment pharyngeal airway parameters of the Skeletal Class III patients with prognathic mandible corresponded to the pretreatment parameters of skeletal Class I individuals. 4. Al though some surgical relapse following BSSO occurred in the said Skeletal Class III patients at post treatment stage, the pharyngeal airway parameters which were narrowed immediately after surgery, did not subsequently increase and was still maintained in the same narrowed dimension as found at postsurgical time. 5. The hyoid bone moved inferiorly and posteriorly immediately after surgery probably due to the attached soft tissue structures. 6. However the hyoid bone returned to its presurgical posit ion at the time of treatment completion

Discovery of Frequent Itemsets: Frequent Item Tree-Based Approach

Mining frequent patterns in large transactional databases is a highly researched area in the field of data mining. Existing frequent pattern discovering algorithms suffer from many problems regarding the high memory dependency when mining large amount of data, computational and I/O cost. Additionally, the recursive mining process to mine these structures is also too voracious in memory resources. In this paper, we describe a more efficient algorithm for mining complete frequent itemsets from transactional databases. The suggested algorithm is partially based on FP-tree hypothesis and extracts the frequent itemsets directly from the tree. Its memory requirement, which is independent from the number of processed transactions, is another benefit of the new method. We present performance comparisons for our algorithm against the Apriori algorithm and FP-growth