Wednesday, 7 December 2016

Significance of Solar Energy in Power Generation for Mechanical Engineering Operations

Introduction

The sun emits very high, intensive energy in the form of solar radiation. The energy emitted by the sun in three minutes is equal to the world’s energy consumption during a year. Most of the energy we receive from the sun is in the form of light by short-wave radiation, which is visible light to the human eye. When this radiation strikes a solid or liquid, it is transformed into heat energy. Within the past several years, solar panels have become increasingly popular as energy-saving devices that use this ideology. Solar panels are flat plate collectors that are used to collect solar energy. Solar energy has many uses including water pumping, solar heaters, solar driers, and solar power generation. 

PE Mechanical Review Course

Arrangement of Solar Power Panels 

In a flat-plate collector, radiation energy from the sun falls on the flat surface coated with a solar film. This surface has a high absorbing capacity and is placed toward the general direction of the sun for maximum efficiency. The materials used for the plates are copper, steel, or aluminum, and the thickness of the plate is approximately 1 to 2 mm. When evaluating the mechanics of a copper plate, thermal energy is transformed from the absorber plate to a fluid, which is then distributed in the copper tubes through the flat-plate collector. Panels are designed to have thermal insulation, with the preferred material being fiber glass behind the absorber plate to prevent heat loss from the rear surface. Engineering materials and their properties are important for the PE exam. Many PE review courses stress this topic.

Utilization of Solar Power Panels for Mechanical Engineering Applications

The solar panel collector reflecting surface is considered parabolic. The solar energy falling on the collector surface is focused on the absorber tube. When a large quantity of energy falls on the collector surface, it results in the temperature of the absorber liquid being higher than the flat plate collector. The flat-plate collectors may be used to heat water up to 80 degrees Celsius; the concentrators are designed to heat water from a medium temperature to high temperatures. The heated water in the flat plate solar collector is used for boiling butane under high pressure in the butane boiler; the boiling point of butane is about 50 degrees Celsius. The butane vapor, which is part of solar power plant arrangement, is used to run the steam turbine. This results in electricity. 

PE mechanical engineering review courses cover the principles of turbines and boilers. Qualified mechanical or electrical power plant engineers with professional engineering licenses can install and setup solar power plants for mechanical engineering applications.

Advantages of Solar Energy
  • The sun is an infinite source of energy, so solar energy is inexhaustible and renewable and available all over the world. 
  • It is environmentally clean and pollution free. 
  • It is the best alternative for the rapid depletion of fossil fuels. 
Disadvantages of Solar Energy 
  • The intensity of solar energy on sunny days is approximately 1.1 KW/square meter area. Therefore, a very large collecting area is required. 
  • Collecting solar energy creates a need for a large amount of land. 
  • Solar energy is not available at night or on cloudy or rainy days. 

Friday, 2 December 2016

Historical Background of Roadway Construction for Transportation Engineers

Introduction

Throughout history, humans have constantly been inventing new ways of travel. The oldest mode of travel was by foot but eventually evolved to using animals to help carry both people and materials. When motorized vehicles came along, people realized the dire need for a hard surface to accommodate wheels, which would make traveling smoother. 

These surfaces were constructed in a large scale during the period of the Roman empire with the earliest construction techniques birthing “Roman roads.” The Romans, who are considered to be the pioneers of road construction, developed roads in many directions, mainly for military operations. 

FE Exam Review Courses

The Romans’ Roadway Construction Technology

During the Roman civilization, many roads were built by stone blocks of considerable thickness. Generally, the total thickness of the road was as thick as 0.75 to 1.2 meters. 

Overall, the required layer thickness of each course of the material depends on the average traffic load. Structural number and layer thickness calculation problems are reviewed in FE exam review courses

When examining Roman roads, the cross section typically has a trench of width equal to that of the carriage way. When constructing a road, the trench was excavated up to a depth until a hard stratum was reached. One or two layers of large foundation stones were laid with lime mortar at the bottom, creating a thickness of 10-20 cm for the bottom layer. Vertical curbstones were placed along the edges of the pavement. Then, a second layer of large, broken stones, which were mixed with lime motor, was laid over the bottom course up to a thickness of 25 cm to 40 cm or more depending on the requirement. The wearing course of roadway consisted of dressed large stone blocks set in lime motor at the top; the thickness of wearing course varied from 10 cm to 15 cm. This technique of construction was much stronger than that was required for animal-drawn carts during those days. Pavement design and construction is an interesting topic for professional civil engineers who are engaged in highway engineering infrastructure development projects. Fundamentals of Engineering exam certification will authenticate the design and construction process of roadways.

Roadway Construction Technology Improvement Methods 

  • Tr├ęsaguet construction technique 
Pierre Tr├ęsaguet, a French Engineer in the 1700s, developed a new method of construction, which greatly enhanced the roadway system. The system he created allowed the road to sustain less wear than the prior system of constructing roads. His method involved a layering system with both small and large stones. When constructing the road, the subgrade was prepared, and a layer of large foundation stones were laid on edge by hand. The corners of these heavy foundation stones were hammered, while the interstices were filled with smaller stones. Broken stones were placed to a thickness of about 8 cm and were compacted. The top wearing course was made of smaller stones and compacted to a thickness of approximately 5 cm at the edge and gradually increased toward the center. The shoulders were also provided with a cross slope to drain the surface water to the side drain.

  • Macadam construction 
John Macadam developed an entirely new method of construction compared to previous methods. His method included adding multiple steps during pavement construction, such as preparing a subgrade with a cross slope of 1 inch up to the desired width, then compacting it to the required density. Broken stones of high strength passing through a 5-cm size sieve were placed and compacted to a uniform thickness of 10 cm throughout the width of the pavement. The second layer of 3.5 cm stones were placed and compacted to a thickness of 10 cm. The top layer consisted of stones less than 2 cm and were placed and compacted to a thickness of 5 cm. These techniques provided a wide scope of ideas for recent highway engineering projects. Most of the transportation engineering related topics are reviewed in FE and PE exam prep courses for civil engineers.

Wednesday, 30 November 2016

Digital Signal Processing in Electrical Engineers

An Introduction to Signal Processing

Signal processing is an emerging technology that incorporates the fundamental theory, algorithms, processing and transferring information in different patterns broadly designated as signals.

The Components of Digital Signal Processing

Computation: Mathematical operations, and processes by accessing the program from the program memory, and the information stored in the data memory.
Data Memory: Stores the information to be processed and works with program memory.
Program Memory: Stores the programs; the processor compresses or manipulates data.
Input/output ports: Used for data processing and analysis.

Digital Signal Processing Applications

Audio compression. digital image processing. compression of videos, speech processing and recognition, digital communications, radio detection and ranging system, seismology and sound navigation and ranging system.

Digital Signal Processing Applications - Engineering Devices

Radar is an object -detection system. Sonar is an application of DSP.

Digital Signal Processor Performance

The most important challenge in executing DSP algorithms is transferring the data from the memory.The goal of digital signal processing is to measure, filter and compress analog signals.

Electrical Engineer FE Exam









Thursday, 24 November 2016

Significance of Pavement Performance and Its Measurement for Highway Maintenance Program

The Importance of Pavement Performance

Pavement performance is an important issue in the operation and planning of highway engineering. There are several factors that affect pavement performance, such as traffic, soil, environmental, economic and stress distribution factors. The primary function of pavement is to provide a smooth riding surface and suitable surface friction. Commuters and the residential public would like to see the pavement surface smoothness last for the maximum of its life. The magnitude of road safety has been discussed worldwide due to a day by day increase in incident rate due to road accidents. Similarly, the related environmental effects while developing and maintaining the long-term pavement performance is an important concern. Department standards and specifications thoroughly insist on adhering to quality assurance procedures. Productivity and quality control act as key control measures of the project. To become a licensed professional engineer through the PE exam (Civil), geometrics and transportation engineering topics are important for your success.

PE Exam Civil

Selection of Pavement Construction Materials for Better Performance and Safety

Highway safety is an important feature of highway construction and engineering. The selection of highway construction materials is based on the type of roadway, identified and predictable traffic volume and the climatic conditions of the region. Nowadays transportation engineers have a more scientific approach; they use eco-friendly methods to construct roads, bridges and highway facilities. The highways are designed to stand up to the different stresses of heavy traffic, and they should support traffic during the different weather conditions. There are different policies of specifications and standards that are followed nationwide and are also discussed in the PE exam review course. 

Methods that are Used to Control Pavement Cracking for Better Riding Surface

Pavement joints are dynamic to control pavement cracking and pavement movement. If the pavement joints are not used in highway construction, most of the rigid pavements would be damaged with cracks within one or two years after placement. Joint spacing is highly dependent on the environment, materials and subgrade. Jointed plain concrete pavement is the most popularly used pavement construction method. The jointed plain concrete pavement has a reliable design, and it can be used in all locations. Jointed plain concrete pavement has many joints to control the location of cracking. Transverse joint spacing is selected based on temperature and moisture stresses; therefore, they do not produce intermediate cracking between joints. Types of construction joints and properties of filling materials are important for the Principles and Practice of Engineering (PE) exam. Long-term development of pavement performance and automated faulting measurements are used to identify transverse joint locations on rigid pavement surfaces. The faulting measures at those locations are measured by using the profile data collected by high speed long-term pavement performance inertial profilers. Faulting measure software is used to process and analyze the profile data. Performance models relating to the pavement distress conditions, like cracking and roughness, are also analyzed through long-term pavement performance faulting measure software.

Sunday, 20 November 2016

Master Organic Chemistry

While organic chemistry may seem scary, in reality, there is no class more rewarding than organic chemistry when it is understood correctly.

Ask Questions 
Reason out every single step of the mechanism and every formula you derive.

Try the Notecard Trick 
Prepare notecards with different reactions and chemical naming rules, and carry them around while quizzing yourself.

Make Optimal Use of Resources 
Leverage resources to learn the nomenclature rules, draw the complex molecular structures and gain an in-depth understanding of the various mechanisms involved. 

Opt for Spaced Repetition 
“Spaced repetition” is a smart learning technique which involves breaking down the information into smaller chunks and reviewing them regularly for an extended period of time. 

Remember, organic chemistry is not just meant for chemical engineers who will be appearing for FE chemical exams. It involves the study of molecular mechanisms and chemical reactions that lay the foundation for other branches of science too.

FE Chemical Engineering

Monday, 14 November 2016

Personal Protective Equipment for Safety Operations at Construction Sites

Need for Personal Protective Equipment 

Safety is a major issue for people who work in the construction industry. Each and every year, fatal incidents happen in the construction industry due to the absence of personal protective equipment (PPE). Protection equipment protects employees against health or safety risks during construction operations. The purpose of protective equipment is to reduce employee exposure to risks when administrative control is not effective in the field to reduce these risks. Personal protective equipment includes items such as head protection, goggles for eye protection, protective footwear, and respiratory protective equipment in cases of asbestos or chemical operations. Everyone in the workplace is responsible for keeping the working environment safe. Employers and project safety managers need to know the safety regulations that are relevant to their industry and ensure that their organizations are up to Occupational Safety and Health Administration (OSHA) standards. Construction personnel have to do their part to understand and follow the procedures. OSHA enforces safety standards and codes at all project sites to prevent incidents. Incident rate calculations and restricted days work calculations according to the OSHA manual are important for FE exam preparation. 

FE Exam Review Course

Engineering Risk Factors in An Organization 

Risks exist in every workplace in many different forms like falling objects from top floors of construction, sharp edges at guardrails, flying sparks during welding operations, chemical exposures during various treatment processes, and exposure to noise for long periods of time at a project site. Controlling a risk in an organization is the best method to protect employees. Depending on the category of risks, the implementation of incident controls can eliminate risks to the greatest extent possible. Project engineers must carry out a risk assessment before suggesting any personal protective equipment to safeguard an individual’s health and safety. The assessment process specifies the equipment that is essential to overcome risks and identifies the suitability and compatibility of the equipment.

The Use of Personal Protective Equipment 

Personal protective equipment is generally considered a critical topic in FE exam review courses as well as on the Fundamentals of Engineering exam. Personal protective equipment helps to minimize exposure to a variety of threats and injuries. Some of the examples of PPE includes gloves, protective hearing devices, foot and eye protection devices, respirators and full body protection aprons. This personal protective equipment helps to decrease the number of workplace incidents. Many organizations use an employee safety manual and field meetings to educate employees on safety procedures. Employers are also responsible for enforcing safety procedures. Project engineers are responsible for employee actions and ensuring that organizational policies provide a safe working environment. PPE decreases the number of incidents and helps companies save money on their insurance policies. Companies with several safety incidents are generally considered high risk organizations by insurance companies. The need for personal protective equipment must be assessed by a qualified person who is capable of identifying quality equipment for a better protection of safety.

Friday, 4 November 2016

Impact of Air Pollution on Health and the Environment

Air pollution is an atmospheric condition that causes undesirable effects on people and on the environment. Gaseous pollutants include oxides of sulfur, carbon monoxide, volatile organic compounds, and particulate pollutants include smoke and dust. The presence of aerosols, pollen grains and radioactive pollutants, which includes radon-222 and iodine-131, may cause air pollution. If pollutants are emitted directly from a point source, they are called primary pollutants. If pollutants are formed by an interaction of primary pollutants or with some natural constituents of the atmosphere like ozone or photochemical smog, they are called secondary pollutants. 

FE Exam Review Course

Sources of Air Pollution

Volcanic eruptions, forest fires, and photochemical oxidations of terpenes are natural sources of air pollutants. Electrical power plants, factories, traffic emissions, fuel burning, and agriculture activities are forms of synthetic air pollutants. Vehicles used for transportation are another major source of air pollution; automobiles release gases such as carbon dioxide and other hydrocarbons. Heavy duty vehicles spew more nitrogen oxides (NOx) and suspended particulate matter (SPM). Radon gas is a form of indoor air pollution that is  responsible for health problems including lung cancer. Radon gas is emitted from building material like bricks, concrete, and tiles that are manufactured from soil containing radium. The incomplete combustion of fuels, such as coal, wood, and kerosene, can produce a toxic gas known as carbon monoxide. Coal upon burning produces sulfur dioxide, and fossil fuels upon burning produces black soot. Both sulfur dioxide and black soot are considered to be polluting agents.

Health Disorders Due to Air Pollution

Air pollution affects human health, plants, aquatic life, materials and the environment. The human respiratory system has a number of mechanisms for protection from air pollution, but years of exposure to air pollutants adversely affects the body’s resistance against these pollutants. Air pollution can cause cancer, asthma, chronic bronchitis, emphysema, loss of lung elasticity and shortness of breath. Sulfur dioxide causes bronchitis, carbon monoxide causes suffocation, and long exposure to carbon monoxide causes dizziness, unconsciousness and even death. Pollutants like benzene formaldehyde and polychlorinated biphenyls (PSBS) causes mutations and reproductive problems. The presence of many other hazardous materials like asbestos, mercury, arsenic and radioactive substances causes lung diseases and affects other vital organs like the kidney, liver, spleen and brain. Human health disorders due to air pollution or through any other sources of working environments are frequently inspected by Occupational Safety and Health Administration (OSHA) officials to prevent serious incidents. The presence of minimum levels of each contaminant is important to take appropriate preventive measures for air pollution. Engineers preparing for the FE exam can refresh their memory on contaminant levels as per OSHA standards through a fundamentals of engineering exam review course.

Environmental Engineering Concerns Due to Air Pollution

Air pollution impacts plants by destroying chlorophyll and effecting photosynthesis, necrosis, and chlorosis. Peroxylacetyl nitrate (PAN) causes silvering of lower surface of leaves and suppressed growth. High acidity in fresh water lakes may harm aquatic life. Presences of sulfur dioxide and moisture results in the formation of acid that causes damage to metal parts of buildings, vehicles, bridges and railway tracks. It is the responsibility of environmental engineers to protect the environment by controlling air pollution. Engineering concepts of air pollution monitoring and controlling are topics that are discussed in undergraduate environmental engineering courses as well as in FE exam review courses.