Essays on Currents

Three phase induction motors

Introduction The three-phase induction machine is the most widely used among the rotating machines. An induction machine offers an almost constant speed within its normal operating range when operated off a constant-voltage, constant-frequency, and with the electric power source. The cost of purchasing these machines is very low, and they require little maintenance. However, speed control is difficult and very expensive. Therefore, the rotor current of the three phase induction motors is not induced by electrical connections, but rather the rotation of magnetic field.

Squirrel Cage Rotor construction

The rotor type of the motor is made up of a laminated core which is ...

Introduction

Zika virus also termed as ZIKV is a known to have gained worldwide attention, especially in the USA, South East Asia, and Australia. The Zika belongs to the Flaviviridae family which comes under the genus Flavivirus (Wikan & Smith. 2016). The Zika virus is spread though day time mosquitoes belonging to the Aedes family. Some of the most common mosquitoes to contain and spread Zika include A. aegypti and A. albopictus. The name of Zika originated in 1947 where it was first isolated from the Zika forest in Uganda. Based on evidence, the Zika virus was associated with varying viral ...

Rip currents are major coastal hazards

Eighty percent of lifeguard rescues are caused by rip currents Rip current frequently occur in surfs Beaches are the most preferred recreational sites for many Americans Limited knowledge concerning rip currents is the major cause of drowning Long-shore variation in wave height is the major cause of rip currents Superposition of various waves trains can also cause rip currents Geological engineering structures along shores and beaches also cause rip currents The magnitude of rip currents increase with rising wave heights Common terms used to describe dangerous currents include, rip current, undertow and riptide Rip currents may measure 10 meters ...

Hebrews

In Hebrews 2:1-4, this passage of the Bible speaks of our spiritual well-being and the importance of not straying away from the Holy word. It teaches many lessons within this small passage. “The Biblical verse is giving Christians a command, or a duty” (Piper). We will review four various reasons for the exhortation the Bible speaks of. “The first reason focuses on the significant factor of danger when we drift from our salvation and neglect it” (Stroud). It can become possible to depart from the teachings of God so much to the point where it might be impossible for ...

Lab Experiment #4: Fundamentals of Electric Circuits

Goals The main objective of this laboratory practice is to gain understanding on the basic laws that describe electric circuits and their application.

Background and Theory

Ohm’s Law. According to Alexander and Sadiku (2013), “Ohm’s Law states that the voltage v across a resistor is directly proportional to the current i flowing through the resistor” (p. 31). The constant of proportionality is the element’s resistance, R, which depends on several factors that will not be analyzed in this report. The equation for Ohm’s Law is then: v=iR (where v: voltage, i: current and R: resistance). The units for ...

Electromagnetic induction can be defined as the production of electromotive voltage or force across an electrical conductor when it dynamically interacts with a magnetic field. There are numerous uses of electromagnetic induction, for example, in electromagnetic elements such as transformers and inductors, electric motors, generators, and transcranial magnetic stimulators.

Applications of Electromagnetic Induction

Electromagnetic induction is an extremely useful phenomenon with various applications. It’s applied in the creation of eddy currents, which are swirling currents set up in conductors in response to changing magnetic fields. Electrons in the field swirl in a perpendicular plane to the magnetic field causing loss or transformation ...

In the history of philosophy, the problem of determinism and free will has always sparked a debate between philosophers who take opposing views on the issue. Determinism is a philosophical belief and thinking that assumes that all things which include human behavior are causally determined. On the other hand, free will is a philosophical idea that views things such as human will and behavior as free from causal determination. This topic in itself creates other issues that relate to morality and religion. On one hand, to believe in free simply does not in itself mean that human conduct is ...

The climate of Canada is governed by a number of elements of climate which lead to a regional variety of weather patterns in the country. These weather patterns are pertinent in determining the type of climate which each particular region experiences. Climate has many impacts on a country’s ecosystem, sociology and economy, and is therefore a key component in the overall health of any economy. Disruptions to climate can have enduring outcomes for Canada and its people. This paper attempts to discuss the current climactic patterns which occur in Canada, and outlines some ways in which climate change ...

Introduction

Taking measurements may require the conversion of the measured quantity to electrical quantity. Transducers are devices or elements that perform this function by transforming physical quantities such as quantities like sound, light, or temperature into electrical signals like current, voltage, or capacity. Transducers consist of inputs, sensing elements, transduction elements, signal processing, and electrical outputs. The inputs known as the measurands are the quantities, states, or properties that are to be translated into electrical outputs. The sensing elements accurately measure these input energies and sends the information to the transduction elements to be transformed into the desired form. The ...

Wave and Wind Power Generation

Wind Physics Basics Wind is atmospheric air which is in motion Energy Source The earth surface absorbs solar radiation differently. Some parts absorb more radiation than other. This creates pressure zones. As a result of pressure, air moves from high-pressure zones to low-pressure zones. This causes atmospheric air motion known as wind. Wind is a renewable source of energy. It is constantly available free of charge (Bhattacharyya, 2011).

Spatial scales

Atmospheric air motion can be categorized depending in terms of spatial scale. Four spatial scales identified include planetary scale, synoptic scale, mesoscale, and microscale. There are various types of spatial scales ...

Background Information

Flooding occurs in many countries around the world and the need to have proper response plan is inevitable. The case in no different this year as floods continue to hit various countries around the world leaving deaths and property damage on its way. A recent report by the United Nations, The Human Cost of Weather-related Disasters 1995-2015 documents the danger posed by floods around the world and the lack of preparedness among several institutions involved. From 1995 to date, flooding has accounted for over 47% of weather related disasters which is significant when compared to other disasters. In recent ...

Impact of Benjamin Franklin's Charts of the Golf Stream on the Shipping Industry

The Gulf Stream is a gigantic current that flows from the Mexican Gulf, past the Florida Peninsula, U.S. East Coast and up to Cape Hatteras. The current then flows across the Atlantic towards Iceland, British Isles, and to Norway. Viewed from the Straits of Florida, the stream has a width of approximately forty miles. Its speed can go as high as five miles per hour (4.3 nautical knots). As the current flows into North Atlantic, the width widens and can increase to up to hundreds of miles at some points (Richardson 51). The amount of water carried by the ...

Global warming is the rise in average global temperatures. The rise in global temperatures is occasioned by the emission of greenhouses gases such as carbon dioxide, carbon monoxide, methane, and nitrogen oxides. The gases are released from industrial process that combust fossil fuels such as diesel, coal, and petrol. Such processes include generation of electrical energy in thermal power stations, burning of coal in industrial boilers, and combustion of fossil fuels in internal combustion engines. When these greenhouse gases are emitted, they rise to upper levels of the atmosphere and form a layer that blankets the earth. This layer ...

Impact of Benjamin Franklin's Charts of the Golf Stream on the Shipping Industry

The Gulf Stream is a gigantic river that flows inside ocean from the Mexican Gulf, passing through Florida Peninsula, the East Coast and to Cape Hatteras. The current flows into the Iceland, British Isles, and to Norway. Viewed from the Straits of Florida, the stream has a width of approximately forty miles. Its speed can go as high as five miles per hour. As the Current flows into North Atlantic, the width widens and can increase to up to hundreds of miles at some points (Richardson 51). The amount of water carried by the Gulf Stream is more than ...

Introduction to Meteorology

Introduction to Meteorology

General Overview of Weather-related Accidents For every accident investigation attributed to a weather-related factor, NTSB was able to attach a subject modifier to the individual weather condition. This is because a single accident may be linked to several weather phenomena hence resulting in a citation of several subject modifiers for a single accident. For the purpose of this paper, several subject modifiers were amalgamated into one weather phenomenon for example under the category of wind; the paper includes reports whereby the NTSB was more specific on dust whirlwind, sudden wind shift, high wind, and crosswind as ...

Introduction:

This is the ninth experiment in which we will be doing a few experiments that involve inductors and capacitors in order to gain a deeper insight into these elements. We will carry out a few experiments that concern open-close switch circuits and the first order circuit. We shall determine the R(internal) value for the inductors as well as the capacitors in the first order circuit.

Theory:

A capacitor is an element with two terminals that models a device that contains two plates capable of conduction, with the plates being separated by a material that is a non-conductor.

The relationship between voltage and current for a capacitor is-

Vc(t) ...

Abstract

This paper analyzes the importance of generator synchronization to the power grid, the required conditions to perform this procedure and the consequences of imprecise synchronization. For a generator to be synchronized to a grid, the voltage magnitude, frequency, phase sequence and phase angle must match. Manual synchronization depends on an operator to modify generator voltage and frequency, confirm phase sequences of generator and grid, and monitor phase angle difference to timely initiate breaker closure. Automatic synchronizers perform all these function through a computerized system that consists of complex algorithms and control systems, and are categorized in phase lock type ...

The increased pace of job globalization, in developing and developed countries, has focused attention on outsourcing as an object of both praise and criticism. The loss of job opportunities (locally), lower quality products and/or services and, not least, further imbalances in income pay are all outcomes critics of outsourcing cite. On upside, job outsourcing, particularly at a global level, is apt to enhance productivity, lower costs and, for one, enhances core efficiencies for outsourcing companies, according to supporters of outsourcing. If anything, cost assumes center stage in a decades-long debate now on outsourcing. There are, however, more in outsourcing ...

Summary: In the article titled, “Abnormal Cortex Plasticity in Juvenile Myoclonic Epilepsy”, the authors investigate the role of defective motor plasticity in the pathogenesis of Juvenile Myoclonic Epilepsy (Strigaro et al.). Prior to this study, JME was linked to motor cortex hyper-excitability and to the abnormal function of thalamic networks. This study, identifies a new mechanism that can cause JME, a common form of generalized epilepsy seen in children. The motor cortex plasticity was studied using an interesting technique called the Paired Associated Stimulation (PAS). The details of this technique are discussed in the methodology section. The role of ...

Introduction:

The debate surrounding global warming is important due to the growing concern of potential consequences for not only humans, but all that inhabit the Earth. A changing climate produces uncertainty regarding the future, which places a great deal of stress on human institutions as well as the natural ecosystem. However, others argue that the effects on the environment are primarily natural processes and were not impacted by human behavior. In assessing the current state of research regarding this debate a better understanding of the contribution that various activities have on the climate can be attained. This can help to ...

Introduction

Cyclones have been affecting populations throughout the world for a very a long time. From Southeast Asia, the Americas, the Western Pacific, and now so often the Island of Madagascar, cyclones have been having a significant influence on people, societies, and nations for centuries. For instance, over the last century alone, tropical storms have affected more than 629 million people and caused an estimated 1.33 million deaths in this timeframe (Doocy, Dick, Daniela, and Kirsch). Whereas the effects of cyclones on humans are widespread and devastating, studies show that this trend is poised to continue due to factors such ...

Introduction

Aphasia is a disorder that attacks the sensory system. The person is unable to use the oral, written, auditory comprehension adequately. The interpretation of objects, sounds and feeling is impaired. It is highly associated with diseases such as stroke which leads to paralysis of the brain and nervous system in general. It can also be caused by tumors or cancers that affect the brain as well as any vascular problems affecting the circulation supplying the brain tissues. The problem does not affect the intelligence of the person, but rather their synthesis and interpretation of the same information.

Are all types of speech difficulties aphasia?

All speech ...

This video highlights the development of theory of interaction of electricity with magnetism. A number of scientists were involved in understanding, interpreting and validating electromagnetism with simple experiments involving current and magnetic elements. During September 1820, Ampere investigated magnetic effects of repulsion/attraction between like/unlike poles. He developed theory of electro-dynamics related to magnetism as interaction of current elements. Laplace was skeptical of his ideas while some other scientists like Fernel started thinking on converse patterns. Some other scientists like Jean Fernel focused on theory of production of electricity by magnetism and production of currents in conducting metals. Jean Fernel ...

Simply put, a three phase electric power transmission is a means of transmitting electric power using three wires. Transmission of an ac (alternating current) relies on this bit of technology. Also a type of polyphone system, it is the most widespread means used by electric power distribution grids all over the world to distribute power.

This method of power transmission was introduced by Nikola Tesla in between 1887 and 1888. The workings of this system are quite easy to grasp. There are three circuit conductors which carry three alternating currents that are of the same frequency and which also reach their immediate ...

I was born and bred in our Midwest farm whereby I had dreamt for a long time of visiting the ocean until one day, at the summer of 1980, my mother told me that we were to pay my aunt Carolyn who by then resided in Havelock a visit. I was so much ecstatic since I could finally get to feel the sand and the ocean water, something I had dreamt of for long. The journey to Havelock was smooth and we managed to get to our destination safe and sound.

Upon reaching the ocean, and after the usual family debating ...