Geotechnical Investigation Methods and their Importance in Civil Engineering

In spite of differences in using various geotechnical testing methods and equipment by geotechnical engineers around the globe, there are set of acceptable standards and the required number of tests and testing procedures that are recommended prior to the construction at the project site. Project site investigation and inspection is one the major project management tasks. Soil boring methods, material testing, and ASTM standards and procedures are important in PE exam preparation.

In civil engineering professional practice, compromising with short cut methods of investigation procedures can maximize the risk of structural durability and life. Therefore, it is always recommended to perform appropriate and accurate soil investigations to reduce the risks and failures. Department standards and quality assurance investigation procedures required to be followed for minimizing the risks and improving the overall engineering performance of the structure. It is an engineer's responsibility to implement the ASTM specified standards and testing codes along with skills and techniques for adopting the best engineering practices to meet the emerging needs of construction activities in the engineering environment. The geotechnical engineers and their engineering skills ensure better foundations, good transportation facilities and safe infrastructure for public facilities.

Geotechnical engineering is an important and critical topic for the Professional Engineering exam in civil engineering. This engineering section requires application techniques and testing skills, recommended equipment and qualified personnel. The above mentioned key areas are necessary to fulfill the requirements of geotechnical engineering attributes for the economical design and construction, for maximum life of the structure, environment friendly infrastructure that could serve for generations. 

The employment of an enormous amount of resources for adopting the geo-technical challenges are the major essentials in the construction engineering industry. Many big projects require all sub disciplines of civil engineering for better outcome. However, the implementation of selective geotechnical investigative methods in designing major projects in seismic zones, high-rise structures in sandy soils, atomic power stations and for projects requiring 100% disaster-free facilities. 

The geo technical engineering area has huge scope to provide the safe, and quality projects for public and also for infrastructure advancement. Business developments, public and economic growth in all countries across the globe compounded with a shortage of quality procedures and standards Therefore, the need of implementing quality assurance and quality control procedures by professional civil engineers with a PE exam certification than ever before.

Digital Signal Processing in Electrical Engineering

Table of Contents

1. An Introduction to Signal Processing

2. Digital Signal Processing Applications

3. Digital Signal Processing Applications - Engineering Devices

4. The Components of Digital Signal Processing

5. Digital Signal Processor Performance

An Introduction to Signal Processing

Signal processing is an emerging technology that incorporates the fundamental theory, algorithms, processing, and transferring information in different patterns, which is broadly designated as signals. Transmission of information, or signals, is done through a channel. The digital signal processor consists of anti-aliasing filter and analog to digital and digital to analog converters. Analog, frequency, and digital modulations are various aspects of transmission. The concept of signal processing is a part of the FE exam syllabus, and it is reviewed in most FE exam prep courses. The main goal of signal processing applications is to be efficient and perform reliable transmission, display of information, and storage. 

Digital Signal Processing Applications

Audio compression, digital image processing, compression of videos, speech processing and recognition, digital communications, radio detection and ranging systems, seismology, and sound navigation and ranging systems are examples of digital signal processing applications. The implementation of digital signal processing is based on the requirements of the application. 

Digital Signal Processing Applications - Engineering Devices 

Radar is an object-detection system; it uses radio waves to control the range, angle, or velocity of objects. Radar is used to transmit radio signals at distant objects and analyze the reflection. Radar is used for air-traffic control to avoid mid-air collision and to predict weather conditions. Radar is also used in meteorology to aid in forecasting the weather. 

Sonar is an application of digital signal processing (DSP); sonar uses sound propagation to navigate and communicate with or detect an object under the surface of the water. Generally, two types of technologies are used in sonar: passive sonar and active sonar technologies. Passive sonar is used to listen to the sound of the vessels; active sonar is used to release pulses of sounds and to listen to echoes. Sonar may also be used for acoustic measurements.

The Components of Digital Signal Processing 

Computation: performs 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 uses the program memory to compress or manipulate data.

Input/Output Ports: used for data processing and analysis.

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. General-purpose microprocessors can execute digital signal processing algorithms successfully. DSPs use a special memory architecture that can fetch multiple data and instructions at a time. DSP processors execute one instruction per clock cycle in complex or multi-operation type of instructions. These processors include a single multiplier or MAC unit and ALU unit. DSP processors show good performance even at the modest power and memory usage. Digital signal processing is one of the courses taught in undergraduate electrical engineering, and it is reviewed in fundamentals of engineering exam prep courses for those taking the FE exam.

Significance of Solar Energy in Power Generation for Mechanical Engineering Operations

Table of Contents

1. Introduction

2. Arrangement of Solar Power Panels

3. Utilization of Solar Power Panels for Mechanical Engineering Applications

1. 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. 

2. 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.

3. 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. 

Historical Background of Roadway Construction for Transportation Engineers

Table of Contents

1. Introduction

2. The Romans' Roadway Construction Technology

3. Roadway Construction Technology Improvement Methods

1. 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. 

2. 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.

3. Roadway Construction Technology Improvement Methods 

Tresaguet construction technique 

Pierre Tresaguet, 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.