Tuesday, 21 March 2017
The structural importance of preserving historical buildings
History plays an important role in providing knowledge about a country’s culture, civilizations, beliefs, and religions. Historical buildings represent the past of that particular region and inform people about past structural constructions. The importance of the structural maintenance of historical buildings is to value history over progress. The major controversial issue surrounding historical buildings is whether to maintain them or demolish and replace them. While some people believe that it is important to maintain those buildings due to their historical value, others believe these buildings stand in the way of development.
It is very important to maintain historical buildings because they have cultural significance and economic value. However, it is not always possible to maintain historical buildings due to supporting construction costs and the availability of space around the existing structure. Historical buildings should be well-maintained, protected, and modernized for future generations. Structural engineering aspects and building codes govern the preservation and maintenance of these buildings. SE exam review courses cover the structural engineering standards and building codes for maintenance.
Renovations and Maintenance of Historical Buildings
There are various structural engineering standards that are used to assist with the long-term protection of historical buildings and features. The construction materials used in historical buildings are mainly from natural resources. The structural engineering procedures address the treatments of preservation, rehabilitation, and renovation based on the architectural value and heritage, construction technology, construction materials, design, and existing condition. If the historical building is to be kept in good condition for public access, periodic maintenance is essential. Historical buildings should be inspected often for maintenance issues; many historical buildings require serious repairs. Damaged structural elements should be renovated whenever possible. If renovation is necessary, the new material should match with the historical material in design, color, and other visual elements. The process of renovation and maintenance of the historical building should be inspected by professional structural engineers with their SE exam certification. For many repairs, knowledge of structural engineering techniques may be required. Most of those techniques are covered in structural engineer exam review courses.
Renovation and Maintenance Methods
Selection methods and techniques are based on the type of structure and its age. In the engineering practice, preservation and restoration are the desired methods. These methods reduce construction cost and time that is usually spent on construction and transportation of construction materials. Rehabilitation treatment highlights the retention and repair of historical structural elements. The public often views constructing a new building as more beneficial and economical instead of preserving an old building. However, preserving a historical building is a form of conservation.
Thursday, 16 March 2017
The main objective of this article is to explain the importance of stormwater management. Stormwater runoff is mainly from rains or through melting snow that does not penetrate into the natural ground. Stormwater collects from residential buildings, Parking lots, Asphalt pavements, and thru Natural vegetation. Stormwater runoff collects and carries decayed dead animals, organic waste, roadside trash, sediments due to soil erosion and other pollutants. Earlier days, Ponds are used effectively to manage stormwater. Stormwater management practices can be used efficiently to prevent erosion of loose soil and as well as flooding of wetlands. Considerable amount of groundwater quantity increases the probability of flooding frequency, stream channel slope instability. Uncontrolled stormwater runoff damages highway and utility infrastructure. The goal of best stormwater management is to protect groundwater and surface water systems from pollution for current and future generations. NPDES and EPA storm water management practices are most important topics for PE exam and they are thoroughly discussed in PE exam review course.
Parameters Influencing Stormwater Management practices
The need of stormwater management is to maintain water quality and quantity. Stormwater management systems should employ water treatment methods for collecting and purifying stormwater. Treated stormwater can be discharged into the natural streams or rivers. There are various methods to control stormwater runoff. Some of the methods are developing shrubs and swales, sodded ditches, and filter fabric systems. These methods are best and they are simple to construct and as well as for maintenance. Stormwater management also helps in preventing structural damages and flooding near construction sites. Stormwater runoff also considered as water resource that helps to increase groundwater table level and also natural stream levels.
Stormwater Management Practices and Common Problems
Water Resources and Civil Engineers facing problems in maintaining water quality with controlled turbidity levels during heavy stormwater runoff situations. The main task of stormwater management team is to manage retention ponds, treating the collected stormwater prior to discharge into main stream channel without affecting existing drainage facilities. Many agencies and local stormwater management bodies are insisted to design new systems that keeps groundwater environmentally safe and free from pollutants. Environmental protection of wetlands is one of the critical problem, where most of the water resources engineers are facing. Due to global climate changes and unanticipated high intensity of rainfall managing the flooding events is difficult task. It is on the shoulders of water resources engineer to estimate the runoff from all sources to design drainage facilities.Highway engineers should provide surface runoff calculations to estimate drainage structures intake capacity. Engineers with Professional Engineer Exam Certification will allowed to provide design calculations for the drainage structures.
Wednesday, 8 March 2017
Bearings are machine elements that allow components to move with respect to each other. There are two types of bearings: contact and non-contact. Contact-type bearings have mechanical contact with equipment, which includes sliding, rolling, or flexural bearings. Non-contact bearings include liquid, air, mixed phase, and magnetic bearings. The lack of mechanical contact eliminates static friction. PE Mechanical exam review courses cover industrial applications and material properties of bearings.
Every bearing type has its own application area. Every mechanical engineer should be aware of the applications and limitations of each bearing type as well as the fundamental operating principles of different bearings so that the correct bearing for the intended application can be selected. Our PE Mechanical review course recaps the fundamentals of bearings and their applications.
Bearings and Mechanical Applications:
· Ball Bearings
Ball bearings are a very common type of bearing, as they handle both radial and thrust loads. However, they can handle only a small amount of weight. These can be found in a wide range of applications such as roller blades and hard drives.
Unlike ball bearings, roller bearings are equipped to carry large loads. The load distribution is spread over a wide area as the primary roller is in the form of a cylinder to carry large loads. However, these bearings cannot handle thrust loads. If there are space constraints in the equipment, needle roller bearings need to be used.
· Ball Thrust Bearings
This type of bearing is designed for applications specified for low speed and low weight that can carry a thrust load. An example of a ball thrust bearing is a bar stool used to support a seat.
· Roller Thrust Bearings
These bearings are similar to ball thrust bearings as they are designed to exclusively handle thrust loads. However, unlike ball thrust bearings, they can handle larger loads. These bearings can be found in a wide range of applications including helical gears in car transmissions.
· Tapered Roller Bearings
Unlike ball bearings, tapered roller bearings can handle both large thrust and radial loads. These bearings are used in automobile transmissions, which contain huge thrust and axial loads.
· Sliding Contact Bearings
A wheel on a simple axle with sliding contact between the two is one of the most common types of bearings. Bushing is a sliding contact radial bearing element used to support a shaft and have integral flanges to support axial loads. Sliding contact bearings are commonly used for low and modest speed applications.
· Rotary Motion Bearings
This anti-friction bearing is often used for rolling elements, such as balls or rollers, which reduce friction. The rolling element is normally constrained between a ring (inner race) and another ring (outer race). A cage typically acts as a separator and keeps the rolling elements apart to prevent rubbing.
· Specialized Bearings
For some specific applications, specialized bearings are produced similarly to giant roller bearings for handling extremely large loads and magnetic bearings for high speeds.
Mechanical engineers preparing for the PE exam should be familiar with engineering applications of bearings.
Friday, 3 March 2017
Introduction to wind energy systems
Wind energy is the best source of electric power generation that is mainly from blowing wind across the earth's surface. Turbines develop kinetic energy and change it into electric power, which can provide electricity for household and business applications on small, medium, and large scales. Wind energy is the fastest growing technology of new electricity generation. The growth of wind energy has multi-dimensional benefits like its green power, sustainability and affordability. The earliest wind power technology principle is the sail boat, which influences later developments of sail-type windmills. During 500-900 A.D, Persia developed the first windmills to automate the jobs of grain-grinding and pumping water. The earliest design of wind energy is the vertical axis system. Wind energy is the fastest growing source of energy across the globe. Wind energy is efficient, cost effective, and does not cause pollution. Wind energy is currently one of the lowest cost options for renewable energy technologies. Industrial wind energy has become a valuable energy source. The energy generated from wind is free of pollution. Wind energy helps to ensure that electric demands are met. A small wind energy system is an economical source of electricity for domestic purposes. With large electric power projects, the need for structural engineers to design and execute the construction of electrical grid towers is great. Qualified professional structural engineers with their SE exam certification approve and sign as-built plans of structural engineering power grid tower systems.
Working principle of wind energy systems
The mechanical system of wind rotates the turbine blades to a considerable amount of speed by a shaft that connects to a generator to produce electricity. Renewable solar energy is energy generated from natural resources like sunbeams, wind, rain, and geothermal heat, which are naturally replaced. Wind electric systems are the most cost-effective renewable energy systems. Wind energy systems are connected to the electricity distribution system and are known as grid-connected systems. A grid-connected wind turbine system can reduce the consumption energy of electricity for lights, appliances, and electric heat. If the turbine generates more electrical power than the facility requires, the excess electricity is sold to the utility companies. Commercial production turbines are used to generate electric power, and they are three-bladed and pointed to the wind by computer-controlled motors. This kind of turbine has a high speed of up to six times the wind speed, high efficiency, and the speed of torque ripple is low, which contributes to good reliability. Reliability of the power structure system depends on the structural engineering calculations for various acting forces on members of towers. The calculation of tension and compression in the members is important for structural stability. Structural engineers are well aware of those calculations in their Structural Engineer exam preparation refresher course.
Environmental & social impacts of the wind power system
Wind energy provides an effective way of producing electric power for individuals or businesses. Wind turbines can be constructed in the form of vertical axis and horizontal axis. The most common type of wind turbine is horizontal. Wind turbines are used across the world. Wind energy is versatile and has both advantages as well as disadvantages that make it a bit difficult to implement on a large scale. Wind turbines have some effect on wildlife and the nearby environment. Wind energy does not pollute the air unlike power plants that depend on the combustion of fossil fuels. Wind turbines do not produce acid rain either. Wind power factories may be destructive sources of local environments. Wind turbines may cause environmental damage, and fragile ecosystems can be destroyed. Wind turbines are harmful to birds and other wild animals. Sound pollution may cause health hazards and nervous disorders in nearby neighborhoods. Out of all types of loads for assessing the stability of the structure, wind load is critical and has the tendency to uplift the structure. The types of loads and their load factors for design calculations are discussed in the SE exam review course.
Monday, 27 February 2017
Thermodynamics is a branch of science that explains energy and its transformation based on the physical state of the matter. The analysis of thermal activities is derived by means of energy conservation equations, which are based on the conservation of mass or the conservation of energy. Thermodynamic principles mainly depend either on the law of conservation of energy or the law of conservation of mass. Law of conservation of mass and energy equations and calculations are thoroughly reviewed in our FE exam review courses.
Thermodynamics Principles or Laws
· Thermodynamics First Principle: The most important law of physics is the conservation of energy. The first law of thermodynamics states that energy can move from one physical state to another during molecular interaction, but the total energy remains the same and cannot be destroyed.
· Thermodynamics Second Principle: The second law of thermodynamics states that the entropy of any independent or isolated system always increases, and the actual process of work moves in the direction of low energy quality.
· Thermodynamics Third Principle: The third law of thermodynamics states that as the temperature reaches absolute zero, the entropy of a system tends to reach constant value. Therefore, the entropy of a system is zero at absolute zero temperature.
· Thermodynamics Fourth Principle: The fourth law of thermodynamics states that if any two objects are in thermal equilibrium with the third object at the given time, then the heat transfer among the objects is “zero.” This principle is often referred to as the “zeroth principle.”
Working Principles of Thermodynamics
· System: a predefined medium to analyze thermodynamic activities; the complexity depends on the nature of the industry. The work is based on the quantity of matter and shape of the system. The boundary surface of the system is the layer between the system and its surroundings.
· Systems are classified as the following:
1)Open System: If material or matter can navigate through the boundary surface to its surroundings, then it is considered an open system.
2)Closed System: If material or matter cannot pass through the boundary surface to its surroundings, then it is said to be a closed system. Isolated systems are considered a type of closed system where there is no interaction with a material’s surroundings.
The physical state of a system is defined by its properties and its values. The properties of a system change due to the working process of energy inputs and outputs during the period of transformation energy. Thermodynamic cycles have a series of processes that start and stop at the fixed state. It is necessary to understand the above-mentioned systems and laws for the Fundamentals of Engineering exam.
Energy Inputs and Outputs
Thursday, 23 February 2017
Engineering economics is the process of forecasting the expenses or operating costs that must be incurred to manufacture a product or to provide a service. A cost analysis takes into consideration all the expenses that are involved in designing and manufacturing a product. A professional design engineer manages manufacturing costs, which requires physical data, whereas a cost estimate engineer compiles and applies the costing data to determine the final cost of the product. Engineers preparing for the FE exam should be familiar with engineering economic equations and calculations.
Purpose of Cost Analyses
Cost analyses play a significant role in the decision-making process that an engineer makes in selecting materials, methods, tools, and facilities. An understanding of the cost-estimation process is essential to ensure that decisions are based on reliable cost analyses.
Quantity takeoff and unit costs must be reasonably accurate to finalize the actual product cost. If a product is overpriced, it will negatively affect business. It is always better to analyze competitor pricing strategies for the cost assessment of the product. Our FE exam review courses provide accounting principles and cost analyses for selecting the best alternative.
Detailed cost estimates are prepared to:
· Determine the selling price of a product to ensure profit margin
· Examine the vendor’s quotations
· Check whether the product can be manufactured in house
· Determine the most economical process to manufacture a product
· Initiate means of cost reduction in existing production facilities
· Determine standards of production performance to control costs
Cost Estimating or Costing
Costing is the process of listing all expenses incurred in various functional departments during product development. Accounting systematically records all expenses to determine the final cost of a manufactured product. The work of costing begins at the pre-planning stage and ends only after the product has been sold out or has been handed over to the project owner.
Purpose of costing:
· To compare the actual cost with the estimated cost to understand whether the estimate had been realistic or not
· To find undesirable expenses that require corrective measures
· To change the selling price due to variations in material cost or labor cost
· To find the reasons for a loss or profit
· To formulate policies and plans for bidding on a new job
Differences between estimating and accounting:
· Estimating is the determination of the anticipated or probable cost of a product before production, whereas accounting is done only after production of the product has been completed
· Estimating is a highly technical job since the estimator should be well versed in factory methods, operation times etc. Costing consists of compiling data by an accountant
· Estimating provides predicted or standard costs; accounting gives actual costs
The above topics are covered in undergraduate engineering courses, but there is an opportunity to review the basics of estimating and accounting with School of PE’s Fundamentals of Engineering exam review courses.
Monday, 20 February 2017
Environmental pollution is the process of contaminating physical, chemical, and biological characteristics of natural air, land, and water resources. It is important for professional environmental engineers to understand the concept of environmental pollution.
Causes of Environmental Pollution
It is public responsibility to care for and to sustain a healthy environment. An imbalanced environment creates numerous problems. The most common environmental problems generally include air or water pollution, soil erosion due to storm water runoff, depletion of natural resources, land fillings, and deforestation.
Visualizing Environmental Problems
Environmental problems are visualized in terms of intensity and growth of pollution, industrialization, and unplanned urbanization. Migration of populations to urban areas has also led to air, water, and noise pollution. Our PE Environmental exam review course recaps various sections of environmental engineering principles and practices to prevent pollution or contamination.
Classification of Pollutants
Pollutants are classified into two types:
· Biodegradable: breaks down by the activity of bacteria and enters biogeochemical cycles. Some examples of such pollutants include domestic household waste, sewage, and agricultural waste.
· Non-biodegradable: does not break down into simple and harmless products by bacteria. Examples include industrial chemicals, pesticides, metals (mercury, lead, arsenic), plastics, and radioactive substances.
Environmental Pollution Control Measures
· Flammable strong wastes must be burned in incinerators because strong waste is being changed into vaporous waste. Without an incinerator, the air would become contaminated.
· Strong natural wastes, including fecal matter, must be changed over into fertilizer. The composting should be done in pits or in stacks of soil no less than 8-10 cm thick to prevent fly reproduction and rodent threats.
· Materials that are not combustible, including cinder and glass pieces, should be discarded via landfills in low-lying ranges.
· Extreme and undesirable destruction of vegetation must be halted. Wipes and fabric towels should be used in place of paper towels.
Topics related to environmental pollution control measures and methods are extensively covered on the PE Environmental exam. It is important for all engineers registered for the PE Exam to review environmental pollution concepts prior to the exam.