Friday, January 24, 2020

Technology - Satellite Phones Save Lives :: Exploratory Essays Research Papers

Satellite Phones Save Lives Satellite phones are now becoming more important in many situations. Some such situations are on hunting trips in Alaska, backcountry hiking trips, overseas trips, etc. These phones have been popular for a while now, but have always been too big and heavy. Also, it is hard to gain a good signal to get out and make a call if in an emergency situation. The phones need to be reduced to the size of a small cell phone, and the signals need to be much stronger, allowing better service when it is most needed. The new, improved satellite phones could end up saving a person's life someday. Besides, improving the phone even more would be a great idea. In the year 1905, my grandfather went on a trip to Alaska to go hunting, and after many days of hard hunting, he was sitting at his spike camp eating some dinner. Out of nowhere, a big grizzly appeared from the creek bottom and started to charge my grandfather. The bear must have been hungry because he mauled my grandfather and then started eating the left over food. My grandfather was badly injured and all he could do was lay there and wait for the outfitter to show back up for a check up on him in two days. My grandfather fought hard to stay alive, when finally, the plane showed up for help. He was then escorted back to a big city in Alaska, where he was admitted into a large hospital. The doctor said that if he would have gone one more day, he wouldn't have lived. This was a very scary and frightening moment in my family's life. Just think what a great asset a satellite phone would have been on that day. If he would have had a satellite phone, he could have called and been rescued a couple of days earlier. This would have prevented much of the infection that occurred in his body. He was never the same after this horrible accident. The next time that my family scheduled an Alaskan hunting adventure was in 1999, and I was going along. The story about my grandfather was told to me many times, and it seemed to make me second guess myself a little; I wasn't sure that I wanted to go. Although I had fear, I decided to go anyway. My family and I connected on a long flight from Denver to Anchorage, Alaska.

Thursday, January 16, 2020

Manufacturing Plan For Wing Of PAV

Manufacturing processes are differed according to the fabrication techniques such as sheet metal forming and machining processes. For the wings of a new personal air vehicle (PAV); skins ands ribs are produced by sheet metal forming process and spars are produced by machining process. Finally all produced parts are assembled together to produce final wing structure. In addition, since the components that build up ailerons and flaps are very similar to wing structure, manufacturing techniques applied for skins, ribs and spars are also valid for them. Since there should be actuator and hinge fittings to connect ailerons and flaps to wing structure, they are considered in machined parts manufacturing process section. SKIN MANUFACTURING Manufacturing process of skins is shown in Figure -1; Figure-1 [1] Tools for sheet metal forming Operations; Stretching Dies, Drill fixtures, drill plates, holding tools First Cut Aluminums Raw Materials are cut by shearing machine or hand router to get available sizes for manufacturing with much enough excess portions. Heat Treatment Blanks are then solution heat treated to provide necessary mechanical properties to the parts. Heat treatment operations are done according to the design requirements which are defined by engineering drawings. Heat treatment processes are applied to make parts generally T4, T5 or T6 tempers. Stretch Forming – Skins On the stretch press, skins are stretch formed and their tooling holes are marked. After removing the skins from stretch presses, the marked tooling holes are drilled for succeeding assembly operations. An example of stretch forming process is shown in Figure – 2. Figure – 2 [2] Skin Routing Routing operation could be done with two techniques; The first one is using a routing shell tool which has two parts which have exactly same form of the skin. The skin is then located in between them which is fixed with the tooling holes previously opened after stretching and a hand router is traveled around the tool to shape the skin to its final contour. A photo of a router shell is shown in Figure – 3. The second technique is using a five axis gantry routing centre with flexible vacuum assisted table. The skin is positioned with the aids of vacuum assisted columns as shown in Figure -4 and tooling holes are used to set the machining coordinate axes. Figure – 3 [3] Figure – 4 [4] During routing operation, tack holes are also drilled. Also during routing operation, excess portions like access openings or some pockets are removed from the skin. Surface Treatment Surface treatment operations are also defined by the engineering drawings. Some of the surface treatment operations applied are rinsing for cleaning, chromic acid anodizing, primer and coating for corrosion prevention. Primer coating and painting are also called as Chemical Conversion Coating (CCC) which is beneficial for fatigue prevention. In our case, chromic acid anodizing is applied to 2024 skins for preventing corrosion and paving the way for painting. Before chromic acid anodizing, fine holes should be masked to keep dimensions accurate. A typical anodise process would consist of a solvent wash and/ or an alkaline clean to remove any oils or greases from the surface. followed by a de-oxidiser stage to remove the natural oxide film from the surface, followed by chromic acid. This gives you a clean oxide free surface which once anodised will give better adhesion of the anodised layer. There is a water rinse stage between each tank to prevent contamination of the bath solutions. From there you have two choices, spray directly onto te anodise ‘honeycomb' structure which will give good paint adhesion, or seal the anodised layer for enhanced corrosion protection but poorer paint adhesion. Painting Finally, primer, top coat and final paint are applied on the skin. RIB (SHEET METAL) MANUFACTURING Manufacturing process of ribs is shown in Figure – 5; Figure – 5 [1] Tools for sheet metal forming Operations; Hydro press forming dies, Drill fixtures, drill plates, holding tools The main difference of manufacturing of ribs from skins is hydro press forming process instead of stretch forming. Hydro press Forming After heat treatment, blanks become ready to be formed. In aerospace industry fluid cell forming (hydro press forming) is frequently used for forming operation. That is mostly because of the reality that aircraft parts are manufactured in small quantities and parts are mostly different in geometry. Therefore it is necessary to manufacture a different tool for every part and that is very costly. Although the machine is quite expensive, to decrease the tooling costs, hydro press forming is preferred since only male dies are necessary to form parts instead of male-female die combination. That is illustrated in the figure. Also another advantage of hydro press forming is that, on the table of the press machine, several tools, with the blanks on them, could be located randomly at once. In one cycle all the parts are formed simultaneously. Also in general press machines are equipped with two tables which make it possible to decrease set up time to half. Some photos related with hydro press forming are shown in Figure – 6. Figure – 6 [4] SPAR, HINGE, RIB AND FITTING MANUFACTURING Manufacturing process for machined parts, spars, hinges, ribs and fittings is shown in Figure-7; Figure – 7 [1] Tools specific to machining operations; Milling fixtures Machining If necessary those parts which will be machined on milling centers, are firstly cut from blocks of raw material to their required stock sizes. They are mostly skin milled. Skin mill is done to obtain a smooth flat plane to locate the stock on the milling machine table. After skin mill, some holes are drilled on the stock for the sake of transportation and fastening on the machine tables or fixtures. For complex milling operations in which there are more than one stages of operations, it is common to use a milling fixture, see Figure -8. Another reason for use of milling fixtures is that in aerospace industry manufacturing tolerances are so tight and geometries are mostly very complex that is why it is necessary to provide same machining conditions and set up for every single part. Milling fixtures are tools, on which stock material is located and clamped. Their main functionality is that they hold the machined part tightly throughout the machining process which prevents machining def ects and dimensional inaccuracies. , Figure – 8 [4] To obtain required dimensional tolerances, some holes require boring. Boring operation removes only a small quantity of material therefore before boring operation the hole must be drilled very close to the final dimension of the hole diameter. Dimensional accuracy of the machined parts are generally checked with the utilization of Coordinate Measuring Machines (CMM). These machines are very precise such as they are capable of measuring ten thousands of a millimeter in three dimensional spaces. Although they are quite expensive and they need an air conditioned, humidity controlled and vibration isolated chamber, they are the most accurate and flexible measurement equipments. Shot Peening Machined parts are exposured to shot peening operation. That process is done to remove and minimize the existing surface cracks on the machined parts. Machined parts are generally bear high amount of repetitive tensial and compressive loads and these repetitive loading is mostly the main cause of fatigue failure. Surface cracks are the mostly affected defects from repeated loading and they tend to grow under these conditions. That is why they must be removed or minimized to prevent them to grow and increase the fatigue durability of the part. Surface treatment As explained before both chromic acid anodizing, primer coating and painting are the surface treatment operations applied on the parts to make them resistant to corrosion. Another advantage of these chemical conversion coating processes is that they make the part more durable to the fatigue, since they penetrate to surface cracks, scratches and holes. For instance, pitting is a corrosion type which is more susceptible to such surface defects. Therefore surface treatment processes both provide a protective coating in corrosive environments and they generate a smoother aerodynamic surface, which is a requirement to decrease air drag, especially for the outer surfaces which are in contact with the air during flight. ASSEMBLY OPERATIONS Assembly Operations are shown in Figure – 9; Figure – 9 [1] Tools for assembly operations; Assembly and sub assembly jigs and fixtures Assembly Jig In aerospace fabrication processes, since the parts have very complex geometries and position tolerances are so tight, it necessary to use a fixture to locate parts in their required positions and apply assembly joining operation in these positions without letting them to move. For an air plane wing a single assembly jig could be used for this purpose, see Figure – 10. Figure – 10 [5] Spars are located on the jig. They must have a planar smooth contact surface and they must have previously opened tooling holes. Those holes are used to pin the spar on the jig and some clamps are used to fix the spar in its position. Ribs are located. They are installed on the jig with the utilization contacting surface of spar and some other location surfaces and they are pinned from their tooling holes. Clamps are used to fix ribs in their location. Some of the holes are transferred from ribs to spars or the contrary. Bottom skin is loaded on the jig by the aid of tooling holes on the lugs at each lateral short edge. To wrap the rib spar assembly the skin could be pressed by some belts or some header plates could be used to bring the skin to its required form and clamp it to hold it in its required position. Some of the tack holes on the skin are fastened with clecos, which is a temporary fastener. Pilot holes are drilled to their final sizes and countersinking is applied to locations where countersunk rivets and bolts will be used. After drilling and countersinking is applied parts are separated to remove chips. Before putting parts together again, sealant is applied. Sealant is a viscous chemical isolation material which is a polymer in general (polyurethane, polysulfide, etc). It is applied when it is still in fluid form and it solidifies as a result of chemical reaction which takes place as soon as the sealant is exposed to air. They are used to prevent fluid leakage into internal structural components. This leakage could result catastrophic failure since corrosion which erodes material would work against the mechanical strength and stiffness of the structure. For different purposes and for different locations specific types of sealants are applied. For instance polysulfide based sealant is applied to the surfaces where there is fuel content. For fuel tanks these polysulfide based sealants are used since they withstand the attack of sulfur compounds that are present in fuel. After sealant application, outer skin is brought to close the wing and it is fastened with blind rivets and bolts since it will only be possible to reach rivet from one side. When riveting and bolting completed the wing is removed from the assembly jig and it is sent to paint shop for the application of top coating and painting. After that manufacturing and assembly operations will be completed.

Wednesday, January 8, 2020

Essay on Types of Crimes - 619 Words

Types of Crimes A crime is an act against the public good, punishable by a fine, imprisonment, or both. There are two major classifications of crime. The first classification of crime is a felony. A felony is a major crime punishable by imprisonment or death. Murder, manslaughter, burglary, robbery, and arson are examples of felonies. The second major classification of a crime is a misdemeanor. A misdemeanor is a less serious crime with a less severe penalty. Misdemeanors that aren’t as serious are known as petty offenses. Driving an automobile without a license, lying about your age to purchase alcohol, and leaving the scene of an automobile accident are all examples of misdemeanors. Crimes are defined by two elements. The†¦show more content†¦Involuntary manslaughter occurs when you kill someone in a reckless act such as drunk driving. There are crimes against business interests such as larceny by false pretenses, forgery, bribery, and extortion. These crimes are known as white-collar crimes and usually involve fraud and are nonviolent. The act of taking someone’s money or property by intentionally deceiving that person is known as larceny by false pretenses. Forgery is the false making or changing of writing with the intent to defraud. The signing of another person’s name without authority to check or other document is known as forgery also. In order for a crime to take place there must be intent to defraud or deceive. Bribery is the illegal paying of public officials in order to influence their official authority or decisions. The penalty for bribery at the federal level is a fine of not more than $20,000 or three times the monetary equivalent of the bribe. Burglary is defined as the breaking and entering of a dwelling house at night with the intent to commit a felony. States have passed statutes covering other kinds of breaking and entering. If any part of the crime cannot be proven, you cannot be charged with burglary. Robbery is the wrongful taking and carrying away of the personal property of another accompanied by violence or threats. The main difference between larceny and robbery is that when you robShow MoreRelatedTypes Of Crime And Crime1902 Words   |  8 PagesAssignment 2: Chapter 2-Types of Crime, Chapter 3-Causes of Crime Data Collection for the UCR, NIBRS, and NCVS The Uniform Crime Reports collects reported crime data from the states’ law enforcement agencies on Part I offenses: murder and nonnegligent manslaughter, forcible rape, robbery, aggravated assault, burglary, larceny, motor vehicle theft, arson, and local law enforcement agencies are also required to provide additional details about a crime when it appears to be motivated by hate. Law enforcementRead MoreThe Six Types Of Crime953 Words   |  4 Pages1) The six types of crime are Violent - Violent crime is crimes that are against people such as murder, assault, rape, and robbery. Property- property crimes are crimes that are used for economic gains such as stealing someone’s belongings. Public order- this are crimes that go against the norms of what people think are right such as public drunkenness or prostitution. White-collar- these are crimes that are committed by an individual or a business with nonviolent actions for business advantageRead MoreFour Types of Crimes1348 Words   |  5 PagesCrime #1 – Murder – From Child Star to Alleged Killer 1. Physiognomy theory states that human behavioral characteristics have external physical manifestations (Understanding Crime: Essentials of Criminological Theory, pg 95, Unit 3). What does this mean exactly? Physical manifestation happens through detachment. Detached from your goal and not thinking about, the physical manifestation will be in process and eventually take place (http://www.lawsofmindsystem.com/physicalmanifestation.htm). CouldRead MoreThe Five Types Of Crime1398 Words   |  6 Pages Crime Classification Iliana Clark American InterContinental University Abstract This essay will explain the five different types of crime. These include: Crimes against persons, Crimes against property, and Crimes of public morality, White-collar crimes and Cyber crimes. Statistics show that we are likely to be a victim of one of these crimes. This essay will explain each crime and their differences, providing a definition by category of crime. They are many types of crimes butRead MoreTypes of White Collar Crime686 Words   |  3 PagesName Tutor Course Title Date Submitted Types of White Collar Crime: There are different types of criminal offenses since a criminal act can be regarded as a specific type of offense based on the nature of crime. The various types of criminal activities have developed to become more than a single problem to nearly all criminal justice systems across the globe. The main reason for the divergent classification of criminal activities is because they occur in different settings and are conductedRead More3 Types of Crime Measurement1016 Words   |  5 Pagesthree types of measurement. Uniform Crime Reports, victimization surveys and self report studies all have similar purposes of concluding the trends in different crimes and suggesting the attention of problematic issues. Although, theses types of crime measurement all have the same aim, results vary tremendously between them. Each type of measurement is conducted by a different group that hold their own techniques of gathering information. In the United States, the Uniform Crime ReportRead MoreInchoate Offences : A Type Of Crime908 Words   |  4 Pagesoffense is a type of crime completed by taking a punishable step towards the commission of another crime. The basic inchoate offenses are attempt, solicitation, and conspiracy. The crime allegedly intended is called the target offense. Except for conspiracy, inchoate offenses merge into the target crime. This means that if the defendant is prosecuted for the target crime, attempt and solicitation cannot be charged as well. However, both conspiracy to commit a crime and the crime itself may beRead MoreFour Different Types of Crime1515 Words   |  7 PagesCourse Conover: Dr Hennessey Hayes Tutor: Dr Jacqueline Homel Course Code: CCJ15 Course name: Introduction to Crime and Criminology Assessment number: 1 Due Date: 23.04.10 Extension confirmation number: 14177 Student name: Tamara Chatterton Student number: S2736240 This essay will examine four different types of crime. These include: Property, Violent, White-collar and Internet crimes. To examine these in detail this essay will define and explain each one. It will then describe how they are measuredRead MoreThe Association Between Drug Use And Crime Cycle1487 Words   |  6 PagesAssociation Between Drug Use and Crime Cycle Christina Herring Columbia College Abstract Since some of our states have made marijuana legal, the crime cycle in those states is becoming a topic of interest all across America. For what once was a crime, the act of making it legal cuts the amount of crime automatically. This study analyzes the effect of making drugs legal has on the crime cycle. It questions how legalizing marijuana has affected crime rates, either positively or negativelyRead MoreThe Relationship Between Violent Crime And The Following Five Themes : Race, Religion, Gender, Income, And Immigration1927 Words   |  8 Pagesfocus on violent crime in the U.S. Many studies in this review discuss how some sociological variables can influence crime for better or for worse. This literature review will discuss the relationship between violent crime and the following five themes: race, religion, gender, income, and immigration. Race Violent crime has consistently been a significant issue throughout U.S. history, especially between racial and ethnic groups. As a country, we’ve had to deal with violent crime dating back to slavery