Multi-Valued Majority Logic Circuits Using Spin Waves

With increasing data sets for processing, there is a requirement to build faster and smaller arithmetic circuits. One of the ways to improve the performance of higher order arithmetic units is to reduce the carry propagation levels. Multi-valued logic enables this by reducing the number of digits required to represent a range of numbers. Area reduction is also obtained through fewer operations and signals required to realise a function. Though theoretically multi-valued logic has these advantages, implementation of the multi-valued logic using CMOS has not been efficient. The main reason is because multi-valued logic is emulated in CMOS using binary switches. Two main approaches are followed in CMOS in implementing multi-valued logic using CMOS. Voltage mode logic, where the logic states are encoded using the node voltages suffer from low noise margins and limitation of radix due to the power supply. Current mode logic, where the branch currents are used to represent the logic levels suffer from high power consumption due to static current flow and requirement of restoration devices. The mindset of the post-CMOS approaches explored so far for multi-valued logic circuit design has been to replace the CMOS switches with their novel nano switches. Hence they too suffer from the same issues as CMOS implementation. Our value proposition is through the use of a truly multi-state device based on electron spin. Spin waves, which are a collection of electron spins of an atom enables multi-valued logic by allowing encoding information in the amplitude and phase of the wave.Another advantage of the spin wave fabric is that the computation is through wave propagation and interference which does not involve any movement of charge. This enables building low energy,smaller and faster multi-valued circuits. In this thesis, implementation of the basic building blocks of multi-valued logic using these novel spin wave based devices is shown. Building of arithmetic circuits like adders using these building blocks have also been demonstrated. To quantify the benefits of spin wave based multi-valued circuits, they are benchmarked with CMOS. For 32-bits, our projected comparisons show a 5X increased performance, 125X area improvement and 1717X power reduction for hexa-decimal spin wave based adders compared to binary CMOS. Similarly there is a 4X increase in performance of hexa-decimal SPWF multiplier compared to CMOS for 16 bits. Finally, we have implemented the I/O circuits for smooth interface between binary CMOS and multi-valued SPWF logic

An Exploratory Case Study Of Leadership Practices That Enable International Schools To Become Highly Effective and Learning Progressive Environments

Highly effective learning progressive (HELP) environments can prepare students to be future-ready with the needed knowledge and skills to thrive in an ever-changing world. This case study captured the characteristics and measured the effectiveness of an international school working to become a HELP environment using the high-reliability schools (HRS) framework and the leadership practices that enabled them. This mixed-method study used an explanatory sequential design, beginning with a survey of 122 teachers based on the HRS model (Marzano et al., 2014), where teachers were asked to respond to a series of statements designed to measure the case-study school’s effectiveness and the associated leadership practices. A regression analysis of the survey results showed divisional differences to be statistically significant. This survey was followed by the second phase, with three focus groups and 15 individual interviews as the qualitative part of the study. A cross-case analysis between divisions revealed the leadership practices that helped to enable the divisions to implement the HELP characteristics. The findings showed that effective leadership was indispensable to effecting change. The findings presented two extreme cases: (a) one in the elementary division, where the leadership effectively implemented the HELP characteristics, and (b) in the high school division, where the leadership did not effectively implement the characteristics. Results revealed establishing a trusting environment that allows for openness and risk-taking, feeling the pulse of the environment and providing constant support, developing a learning culture where learning is happening among the teams and from outside the teams, and building cohesion were some of the key leadership practices that effected significant change. The study also identified the key leadership practices that enabled each of the five levels identified by the HRS model. The results revealed that Level 1: safe, supportive, and collaborative culture was foundational for schools to effect the change. This study had all the limitations of single case studies, so the findings are not generalizable in a traditional social science sense. However, the schools that are attempting to be effective in creating a reliable HELP environment can use this study as a marker to align their leadership practices

Magnesium: A wonder material?

This presentation is aimed to give a glimpse of the role of Mg in human life and healt

Graphene - Its role in energy storage devices

This presentation provides an overview of graphene, methods of preparation of graphene, important applications and its role in energy storage devices, namely, fuel cells, supercapacitors, lithium batteries and hydrogen storage

Surface pretretament by phosphate conversion coatings - A review

Phosphating is the most widely used metal pretreatment process for the surface treatment and finishing of ferrous and non-ferrous metals. Due to its economy, speed of operation and ability to afford excellent corrosion resistance, wear resistance, adhesion and lubricative properties, it plays a significant role in the automobile, process and appliance industries. Though the process was initially developed as a simple method of preventing corrosion, the changing end uses of phosphated articles have forced the modification of the existing processes and development of innovative methods to substitute the conventional ones. To keep pace with the rapid changing need of the finishing systems, numerous modifications have been put forth in their development - both in the processing sequence as well as in the phosphating formulations. This review addresses the various aspects of phosphating in detail. In spite of the numerous modifications put forth on the deposition technologies to achieve different types of coatings and desirable properties such as improved corrosion resistance, wear resistance, etc., phosphate conversion coating still plays a vital part in the automobile, process and appliance industries

The role of surfactants in phosphate conversion coatings

Surface active agents occupy a predominant role in the metal finishing industry. Being capable of reducing the surface tension and improving the wettability of the surface, the importance of such additives is very well realized and phosphating baths have been developed with surfactants as one of the additives. However, surfactant additives could influence the nucleation and growth of phosphate crystals and alter the kinetics of the phosphating process. Addition of surfactants in phosphating baths is beneficial in obtaining the desired orientation of the phosphate crystal and the crystallites of the base metal, leading to an improved adherence and excellent corrosion resistance of the resultant phosphate coating. The influence of surfactant additives on the nucleation, growth, refinement of crystals and the continuous dissolution and re-precipitation of the phosphate coating, calls for a through understanding of role of surfactant additives often incorporated in phosphating baths so that the desirable qualities can be successfully built-in in the resultant phosphate coating

Corrosion Science and Engineering

This presentation provides an overview of corrosion and corrosion prevention method

Tin plated contacts - Problems due to fretting corrosion and whisker growth

This presentation provides an overview of the most common type of failures in tin plated contacts - fretting corrosion and whisker growth. The fretting corrosion behaviour of tin plated copper contacts as a function of different conditions were addressed. The mechamism of fretting corrosion is proposed

Role of C Reactive Protein and Interleukin-6 in the Diagnosis of Neonatal Sepsis

Neonatal sepsis is a major cause of and mortalities in developing countries. Early diagnosis and treatment of the newborn infant with suspected sepsis are essential to prevent severe and life threatening complications. Early detection of bacterial sepsis is difficult for various reasons: firstly, early warning signs and symptoms are often nonspecific. Then there is the difficulty of distinguishing the clinical picture of neonatal sepsis from non-infectious causes. Further, microbiological culture results are not usually available until at least 48-72 hours after the specimen reaches the laboratory, and high false-negative rates of culture results may occur The findings of the present study confirm that the serum level of IL-6 is a more reliable marker than the serum levels of CRP. Serum level of IL-6 is also useful in evaluation of response of neonatal sepsis to antibiotic therapy

Case Analysis study of Post Myocardial Infarction Cardiac Failure

INTRODUCTION: Post infarction cardiac failure is one among the common complication of acute myocardial infarction. It is clinically observed when the contractile dysfunction of the heart, resulting from Acute myocardial infarction exceeds more than 25 to 40% of left ventricular diameter, barring the limitation observed as compensation mechanism by means of increased adrenergic activity and increased Left ventricular End-diastolic volume; when these compensatory mechanisms are overwhelmed, the increased LVEDV will result in increased myocardial wall tension and augment the myocardial oxygen demand, predisposing further augmentation of increased left ventricular end diastolic pressure and pulmonary venous congestion. For individuals free of Heart failure at age to 40 years, the remaining life time risk for developing heart failure is 21% for men and 20.3% for women. If mechanical complications are associated in Acute myocardial infarction such as Papillary muscle dysfunction, Mitral regurgitation, Ventricular septal rupture, further increase in left ventricular volume will result in further increase in wall tension and oxygen demand and pulmonary venous congestion and consequent left heart failure. Percentage to changes in norepinephrine and BNP over 12 months are independently associated with corresponding changes in morbidity and mortality. The symptoms of post - myocardial infarction cardaic failure are varied. It is recognized in the usual way by the advent of dysponea, fine basal rales, orthopnea, gallop rhythm, distended neck veins, hepatic engorgement, positive abdomino - jugular reflux and in more advanced cases peripheral edema. In severe cases they may present as expectoration of frothy sputum and central cyanosis. Rarely it is diagnosed with the help of X-ray chest with slight enlargement of cardiac stilhoutte and alveolar infiltrate of pulmonary edema, in the absence of clinical features. In general, male gender, the presence of coronary artery disease as the etiology of heart failure, the presence of an audible S3 or elevated JVP, low pulse and systolic arterial pressures, a high NYHA classes and reduced exercise capacity, have been shown to be associated with increased mortality. AIM OF THE STUDY: It is a prospective study of 100 cases of post - myocardial infarction - cardiac failure analyzing various factors like 1. Incidence: a. Age, b. Sex. 2. Influences: a. No. of infarction, b. Associated systemic illness, c. Dietary Habits, d. Occupational Stress, e. Body mass index, f. Substance abuse like smoking, alochol and drugs on clinical presentations, with reference to history, symptomatology, electrocardiogram and 2-Dimentional Echocardiogram and X-ray chest in selective cases. MATERIALS AND METHODS: This study was conducted at Madras Medical College, Chennai - 3, during the period of May 2004 to January 2006. Hundred cases of post myocardial infarction cardiac failure were included in this study. The patients were selected from those who were admitted in the medical wards and those who attend cardiology clinics. All the patients were evaluated in detail by clinical, ECG, X-ray, Echo - methods. In the analysis of clinical findings elaborate history regarding the modes of presentation and symptoms were sought for and recorded. Symptoms of cardiac failure such as NYHA, Grade dyspnoea, orthopnoea, PND, NYHA classifiaction of angina, palpitation, fatiguability, giddiness, syncopy, coughs, hemoptysis, dysphagia and hoarseness of voice are recorded. In history taking, number of previous infarction, time window between onset of chest pain and admission in hospital, angina and dyspnoea free interval between attacks were recorded, systemic diseases, treatment regularity, relevant family history, substance abuse, basic investigations and their findings were also documented. All volunteers of this study were subjected to ECG, echo study and X-ray (in selective cases). In echo studies, the territory of wall motion abnormalities, systolic, diastolic dysfunction, presence and absence of pericardial effusion, clot, aneurysm and calcification were noted. Left atrial and right ventricular dilatation were looked into for the presence of residual post MI failure especially when they are planned for discharge. A copy of the echo cardiogram was issued to the patient for the future reference and follow up. In relevant patients blood investigation were done to study the biochemical parameters. CONCLUSIONS: 1. Post MI cardiac failure is commoner in urban dwelling (54%) than rural (30%) than semi urban (16%). 2. Post infarction cardiac failure is common in male (90%). After 40 years of age raising incidence are observed in female. 3. Smoking (More than 20 cigarette's per day) and consumption of alcohol has linear relationship with incidence of post MI failure. 4. Sedentary Life Styles (58%), mixed diet pattern (78%), consumption of sheep or goat flesh rather chicken, egg, fish have positive and profound influence over the occurrence of post MI failure. 5. Most common clinical presentation is Tachycardia 100%, in a patient with chest pain or history of infarction. This is followed by cardiamegaly in 60% of case and LVS3 in 44% of patients and pansystolic murmur in 44%. 6. Most common symptomatology are NYHA IV 28%, orthopnoea 60% and Paroxysmal Nocturnal Dysponea 52%, NYHA III 32%, Rest angina 44%, effort angina 32%, nocturnal 30% and postural cough 26%. 7. Systemic high blood pressure with infarction (48%) was the single most aetiological factor for Post MI cardiac failure. Multitude of other factors, NIDDM 24%, history of one or two more infarction, chronic obstructive airway disease (16%) are other factors for post MI cardiac failure. 8. Anteroseptal wall and extensive anterior wall infarctions are the leading causes of post MI cardiac failure (24%) each. Perinfarction blocks (18%), ventricular premature contractions (10%) are the ECG manifestations concluded. 9. In 2D echo analysis hypokinesia (72%), Systolic Dysfunction (72%), small pericardial effusion (32%), Papillary muscle - Dysfunction / Mitral Regurgitation (PMD / MR) (22%), valves calcification (20%), left atrial enlargement (42%) are the observations made