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135-599: The Test Track provides its services to a wide variety of American defense and governmental agencies such as the Air Force, Army , Navy , and the Missile Defense Agency , as well as America's allies. The HHSTT's mission is to provide a cost-effective, realistic, dynamic test environment for the entire acquisition community, including the DoD, other government agencies, contractors, and foreign governments. As

270-410: A metonym for the federal government. The United States government is based on the principles of federalism and republicanism , in which power is shared between the federal government and state governments . The interpretation and execution of these principles, including what powers the federal government should have and how those powers can be exercised, have been debated ever since the adoption of

405-402: A square wave pattern instead of the normal sine wave , making rapid zero crossings possible and minimizing the effects of the problem. Resistance welding involves the generation of heat by passing current through the resistance caused by the contact between two or more metal surfaces. Small pools of molten metal are formed at the weld area as high current (1,000–100,000 A ) is passed through

540-502: A Russian, Konstantin Khrenov eventually implemented the first underwater electric arc welding. Gas tungsten arc welding , after decades of development, was finally perfected in 1941, and gas metal arc welding followed in 1948, allowing for fast welding of non- ferrous materials but requiring expensive shielding gases. Shielded metal arc welding was developed during the 1950s, using a flux-coated consumable electrode, and it quickly became

675-707: A complex set of relationships between state and federal courts. Federal courts can sometimes hear cases arising under state law pursuant to diversity jurisdiction , state courts can decide certain matters involving federal law, and a handful of federal claims are primarily reserved by federal statute to the state courts. Both court systems have exclusive jurisdiction in some areas and concurrent jurisdiction in others. The U.S. Constitution safeguards judicial independence by providing that federal judges shall hold office "during good behavior"; in practice, this usually means they serve until they die, retire, or resign. A judge who commits an offense while in office may be impeached in

810-613: A few cases. The judicial power extends to cases arising under the Constitution, an Act of Congress ; a U.S. treaty ; cases affecting ambassadors , ministers and consuls of foreign countries in the U.S.; cases and controversies to which the federal government is a party; controversies between states (or their citizens) and foreign nations (or their citizens or subjects); and bankruptcy cases (collectively "federal-question jurisdiction"). The Eleventh Amendment removed from federal jurisdiction cases in which citizens of one state were

945-548: A ground-based test facility, the HHSTT provides a cost-effective, controlled test environment for high-speed weapons, systems, and components. Full-scale flight tests tend to be more expensive than sled testing and present fewer opportunities to recover the test article for post-test evaluation. The HHSTT was originally 3,350 ft (1,020 m) long when initial construction was completed in August 1949. The first test performed at

1080-414: A highly concentrated, limited amount of heat, resulting in a small HAZ. Arc welding falls between these two extremes, with the individual processes varying somewhat in heat input. To calculate the heat input for arc welding procedures, the following formula can be used: where Q = heat input ( kJ /mm), V = voltage ( V ), I = current (A), and S = welding speed (mm/min). The efficiency is dependent on

1215-409: A highly focused laser beam, while electron beam welding is done in a vacuum and uses an electron beam. Both have a very high energy density, making deep weld penetration possible and minimizing the size of the weld area. Both processes are extremely fast, and are easily automated, making them highly productive. The primary disadvantages are their very high equipment costs (though these are decreasing) and

1350-513: A modest amount of training and can achieve mastery with experience. Weld times are rather slow, since the consumable electrodes must be frequently replaced and because slag, the residue from the flux, must be chipped away after welding. Furthermore, the process is generally limited to welding ferrous materials, though special electrodes have made possible the welding of cast iron , stainless steel, aluminum, and other metals. Gas metal arc welding (GMAW), also known as metal inert gas or MIG welding,

1485-478: A single elected term." Under the Presentment Clause of Article I, a bill that passes both chambers of Congress shall be presented to the president, who may sign the bill into law or veto the bill by returning it to the chamber where it originated. If the president neither signs nor vetoes a bill "within ten Days (Sundays excepted) after it shall have been presented to him" it becomes a law without

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1620-619: A special election can take place. The House and Senate each have particular exclusive powers. For example, the Senate must approve (give " advice and consent " to) many important presidential appointments, including cabinet officers, federal judges (including nominees to the Supreme Court), department secretaries (heads of federal executive branch departments), U.S. military and naval officers, and ambassadors to foreign countries. All legislative bills for raising revenue must originate in

1755-447: A suitable torch was developed. At first, oxyfuel welding was one of the more popular welding methods due to its portability and relatively low cost. As the 20th century progressed, however, it fell out of favor for industrial applications. It was largely replaced with arc welding, as advances in metal coverings (known as flux ) were made. Flux covering the electrode primarily shields the base material from impurities, but also stabilizes

1890-434: A susceptibility to thermal cracking. Developments in this area include laser-hybrid welding , which uses principles from both laser beam welding and arc welding for even better weld properties, laser cladding , and x-ray welding . Like forge welding (the earliest welding process discovered), some modern welding methods do not involve the melting of the materials being joined. One of the most popular, ultrasonic welding ,

2025-515: A trade embargo, declare war upon a foreign government that the President had recognized, or decline to appropriate funds for an embassy in that country." The president may also negotiate and sign treaties, but ratifying treaties requires the consent of two-thirds of the Senate. Article II's Appointments Clause provides that the president "shall nominate, and by and with the Advice and Consent of

2160-524: A tungsten electrode but uses plasma gas to make the arc. The arc is more concentrated than the GTAW arc, making transverse control more critical and thus generally restricting the technique to a mechanized process. Because of its stable current, the method can be used on a wider range of material thicknesses than can the GTAW process and it is much faster. It can be applied to all of the same materials as GTAW except magnesium, and automated welding of stainless steel

2295-407: A wide variety of component sensors to collect specialized data such as acceleration forces, strain, temperature, etc. The data are collected with a variety of onboard data acquisition systems or telemetered for post-test analysis. Additionally, world-class technical imagery, including high-speed digital images, is available for customers to examine the status of their payloads. Track personnel use

2430-466: Is a fabrication process that joins materials, usually metals or thermoplastics , primarily by using high temperature to melt the parts together and allow them to cool, causing fusion . Common alternative methods include solvent welding (of thermoplastics) using chemicals to melt materials being bonded without heat, and solid-state welding processes which bond without melting, such as pressure, cold welding , and diffusion bonding . Metal welding

2565-419: Is a hazardous undertaking and precautions are required to avoid burns , electric shock , vision damage, inhalation of poisonous gases and fumes, and exposure to intense ultraviolet radiation . Until the end of the 19th century, the only welding process was forge welding , which blacksmiths had used for millennia to join iron and steel by heating and hammering. Arc welding and oxy-fuel welding were among

2700-427: Is a highly productive, single-pass welding process for thicker materials between 1 inch (25 mm) and 12 inches (300 mm) in a vertical or close to vertical position. To supply the electrical power necessary for arc welding processes, a variety of different power supplies can be used. The most common welding power supplies are constant current power supplies and constant voltage power supplies. In arc welding,

2835-472: Is a ring surrounding the weld in which the temperature of the welding process, combined with the stresses of uneven heating and cooling, alters the heat-treatment properties of the alloy. The effects of welding on the material surrounding the weld can be detrimental—depending on the materials used and the heat input of the welding process used, the HAZ can be of varying size and strength. The thermal diffusivity of

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2970-430: Is a semi-automatic or automatic process that uses a continuous wire feed as an electrode and an inert or semi-inert gas mixture to protect the weld from contamination. Since the electrode is continuous, welding speeds are greater for GMAW than for SMAW. A related process, flux-cored arc welding (FCAW), uses similar equipment but uses wire consisting of a steel electrode surrounding a powder fill material. This cored wire

3105-433: Is allowed to cool, and then another weld is performed on top of it. This allows for the welding of thick sections arranged in a single-V preparation joint, for example. After welding, a number of distinct regions can be identified in the weld area. The weld itself is called the fusion zone—more specifically, it is where the filler metal was laid during the welding process. The properties of the fusion zone depend primarily on

3240-442: Is characterized by a stable arc and high-quality welds, but it requires significant operator skill and can only be accomplished at relatively low speeds. GTAW can be used on nearly all weldable metals, though it is most often applied to stainless steel and light metals. It is often used when quality welds are extremely important, such as in bicycle , aircraft and naval applications. A related process, plasma arc welding, also uses

3375-407: Is commonly used for making electrical connections out of aluminum or copper, and it is also a very common polymer welding process. Another common process, explosion welding , involves the joining of materials by pushing them together under extremely high pressure. The energy from the impact plasticizes the materials, forming a weld, even though only a limited amount of heat is generated. The process

3510-627: Is commonly used for welding dissimilar materials, including bonding aluminum to carbon steel in ship hulls and stainless steel or titanium to carbon steel in petrochemical pressure vessels. Other solid-state welding processes include friction welding (including friction stir welding and friction stir spot welding ), magnetic pulse welding , co-extrusion welding, cold welding , diffusion bonding , exothermic welding , high frequency welding , hot pressure welding, induction welding , and roll bonding . Welds can be geometrically prepared in many different ways. The five basic types of weld joints are

3645-413: Is distinct from lower temperature bonding techniques such as brazing and soldering , which do not melt the base metal (parent metal) and instead require flowing a filler metal to solidify their bonds. In addition to melting the base metal in welding, a filler material is typically added to the joint to form a pool of molten material (the weld pool ) that cools to form a joint that can be stronger than

3780-645: Is established in Article Two of the United States Constitution , which vests executive power in the president of the United States . The president is both the head of state (performing ceremonial functions) and the head of government (the chief executive). The Constitution directs the president to " take care that the laws be faithfully executed " and requires the president to swear or affirm to "preserve, protect and defend

3915-402: Is intended to prevent waste and fraud, protect civil liberties and individual rights, ensure executive compliance with the law, gather information for making laws and educating the public, and evaluate executive performance. It applies to cabinet departments, executive agencies, regulatory commissions, and the presidency. Congress's oversight function takes many forms: The executive branch

4050-484: Is made of filler material (typical steel) and is covered with a flux that protects the weld area from oxidation and contamination by producing carbon dioxide (CO 2 ) gas during the welding process. The electrode core itself acts as filler material, making a separate filler unnecessary. The process is versatile and can be performed with relatively inexpensive equipment, making it well suited to shop jobs and field work. An operator can become reasonably proficient with

4185-433: Is more expensive than the standard solid wire and can generate fumes and/or slag, but it permits even higher welding speed and greater metal penetration. Gas tungsten arc welding (GTAW), or tungsten inert gas (TIG) welding, is a manual welding process that uses a non-consumable tungsten electrode, an inert or semi-inert gas mixture, and a separate filler material. Especially useful for welding thin materials, this method

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4320-420: Is obtained by a metallic or chemical bond that is formed between the constituent atoms. Chemical bonds can be grouped into two types consisting of ionic and covalent . To form an ionic bond, either a valence or bonding electron separates from one atom and becomes attached to another atom to form oppositely charged ions . The bonding in the static position is when the ions occupy an equilibrium position where

4455-604: Is one delegate each from Washington, D.C. , Guam , the Virgin Islands , American Samoa , the Commonwealth of the Northern Mariana Islands , and a resident commissioner from Puerto Rico . Unlike the U.S. Senate , all members of the U.S. House must be elected and cannot be appointed. In the case of a vacancy, the seat must be filled through a special election, as required under Article 1 of

4590-430: Is one important application of the process. A variation of the process is plasma cutting , an efficient steel cutting process. Submerged arc welding (SAW) is a high-productivity welding method in which the arc is struck beneath a covering layer of flux. This increases arc quality since contaminants in the atmosphere are blocked by the flux. The slag that forms on the weld generally comes off by itself, and combined with

4725-720: Is related to the Old Swedish word valla , meaning 'to boil', which could refer to joining metals, as in valla järn (literally "to boil iron"). Sweden was a large exporter of iron during the Middle Ages , so the word may have entered English from the Swedish iron trade, or may have been imported with the thousands of Viking settlements that arrived in England before and during the Viking Age , as more than half of

4860-400: Is sometimes protected by some type of inert or semi- inert gas , known as a shielding gas, and filler material is sometimes used as well. One of the most common types of arc welding is shielded metal arc welding (SMAW); it is also known as manual metal arc welding (MMAW) or stick welding. Electric current is used to strike an arc between the base material and consumable electrode rod, which

4995-438: Is still widely used for welding pipes and tubes, as well as repair work. The equipment is relatively inexpensive and simple, generally employing the combustion of acetylene in oxygen to produce a welding flame temperature of about 3100 °C (5600 °F). The flame, since it is less concentrated than an electric arc, causes slower weld cooling, which can lead to greater residual stresses and weld distortion, though it eases

5130-588: Is the commander-in-chief of the armed forces . Under the Reception Clause , the president is empowered to "receive Ambassadors and other public Ministers"; the president has broad authority to conduct foreign relations, is generally considered to have the sole power of diplomatic recognition , and is the United States' chief diplomat, although the Congress also has an important role in legislating on foreign affairs, and can, for example, "institute

5265-483: Is used both for material development (usually involving systematic testing of material samples) and for qualifying flight hardware. A separate system is currently under construction to support magnetic levitation , or maglev, sled development. The reason for this system is to produce flight-like vibration environments that can not be achieved on the main steel rail track. This system performed its first test in 2012 and continues to be operational. Other facilities at

5400-470: Is used to connect thin sheets or wires made of metal or thermoplastic by vibrating them at high frequency and under high pressure. The equipment and methods involved are similar to that of resistance welding, but instead of electric current, vibration provides energy input. When welding metals, the vibrations are introduced horizontally, and the materials are not melted; with plastics, which should have similar melting temperatures, vertically. Ultrasonic welding

5535-474: The Constitution , and this is the name that appears on money, in treaties, and in legal cases to which the nation is a party. The terms "Government of the United States of America" or "United States Government" are often used in official documents to represent the federal government as distinct from the states collectively. In casual conversation or writing, the term "Federal Government" is often used, and

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5670-532: The U.S. Tax Court , are specialized courts handling only certain kinds of cases, known as subject matter jurisdiction . The Bankruptcy Courts are supervised by the district courts, and, as such, are not considered part of the Article III judiciary. As such, their judges do not have lifetime tenure, nor are they Constitutionally exempt from diminution of their remuneration. The Tax Court is an Article I Court, not an Article III Court. The district courts are

5805-505: The United States District Courts , which are the general trial courts for federal law, and for certain controversies between litigants who are not deemed citizens of the same state, known as diversity jurisdiction . There are three levels of federal courts with general jurisdiction, which are courts that handle both criminal and civil suits between individuals. Other courts, such as the bankruptcy courts and

5940-914: The United States Postal Service (USPS), NASA , the Central Intelligence Agency (CIA), the Environmental Protection Agency (EPA), and the United States Agency for International Development (USAID). In addition, there are government-owned corporations , including the Federal Deposit Insurance Corporation and the National Railroad Passenger Corporation . The Judiciary, under Article III of

6075-713: The White House staff, the National Security Council , the Office of Management and Budget , the Council of Economic Advisers , the Council on Environmental Quality , the Office of the U.S. Trade Representative , the Office of National Drug Control Policy , and the Office of Science and Technology Policy . Outside of the EOP and the executive departments are a number of independent agencies . These include

6210-508: The federal district (national capital) of Washington, D.C. , where the majority of the federal government is based. The U.S. federal government is composed of three distinct branches: legislative , executive , and judicial , whose powers are vested by the U.S. Constitution in the Congress , the president , and the federal courts , respectively. The powers and duties of these branches are further defined by acts of Congress, including

6345-593: The militia , exercise exclusive legislation in the District of Columbia , regulate interstate commerce , and to make laws necessary to properly execute powers. Over the two centuries since the United States was formed, many disputes have arisen over the limits on the powers of the federal government. These disputes have often been the subject of lawsuits that have ultimately been decided by the United States Supreme Court . Congressional oversight

6480-461: The 1590 version this was changed to " ...thei shullen welle togidere her swerdes in-to scharris... " (they shall weld together their swords into plowshares), suggesting this particular use of the word probably became popular in English sometime between these periods. The Old English word for welding iron was samod ('to bring together') or samodwellung ('to bring together hot'). The word

6615-421: The 1930s and then during World War II. In 1930, the first all-welded merchant vessel, M/S Carolinian , was launched. During the middle of the century, many new welding methods were invented. In 1930, Kyle Taylor was responsible for the release of stud welding , which soon became popular in shipbuilding and construction. Submerged arc welding was invented the same year and continues to be popular today. In 1932

6750-484: The 50 states is determined by state populations, and it is updated after each decennial U.S. Census. Each member serves a two-year term. In order to be elected as a representative, an individual must be at least 25 years of age, must have been a U.S. citizen for at least seven years, and must live in the state that they represent. In addition to the 435 voting members, there are six non-voting members, consisting of five delegates and one resident commissioner . There

6885-886: The Cabinet who are appointed by the president. These are the White House Chief of Staff, Administrator of the Environmental Protection Agency, Director of the Office of Management & Budget, United States Trade Representative, U.S. Ambassador to the United Nations, Chairman of the Council of Economic Advisers, and Administrator of the Small Business Administration. The heads of the 15 departments are chosen by

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7020-470: The Civil War) or when states' rights proponents have succeeded in limiting federal power through legislative action, executive prerogative or by a constitutional interpretation by the courts. One of the theoretical pillars of the U.S. Constitution is the idea of " checks and balances " among the powers and responsibilities of the three branches of American government: the executive, the legislative, and

7155-510: The Congress. The United States Congress , under Article I of the Constitution, is the legislative branch of the federal government. It is bicameral , comprising the House of Representatives and the Senate . The U.S. House of Representatives is made up of 435 voting members, each of whom represents a congressional district in a state from where they were elected. Apportionment of seats among

7290-659: The Constitution of the United States." Legal scholars William P. Marshall and Saikrishna B. Prakash write of the Clause: "the President may neither breach federal law nor order their subordinates to do so, for defiance cannot be considered faithful execution. The Constitution also incorporates the English bars on dispensing or suspending the law, with some supposing that the Clause itself prohibits both." Many presidential actions are undertaken via executive orders , presidential proclamations , and presidential memoranda . The president

7425-705: The Constitution, explains and applies the laws. This branch does this by hearing and eventually making decisions on various legal cases. Article III section I of the Constitution establishes the Supreme Court of the United States and authorizes the United States Congress to establish inferior courts as their need shall arise. Section I also establishes a lifetime tenure for all federal judges and states that their compensation may not be diminished during their time in office. Article II section II establishes that all federal judges are to be appointed by

7560-497: The Constitution. Some make a case for expansive federal powers while others argue for a more limited role for the central government in relation to individuals, the states, or other recognized entities. Since the American Civil War , the powers of the federal government have generally expanded greatly, although there have been periods since that time of legislative branch dominance (e.g., the decades immediately following

7695-615: The Constitution; all other powers are reserved to the states and the people. The Constitution also includes the Necessary and Proper Clause , which grants Congress the power to "make all laws which shall be necessary and proper for carrying into execution the foregoing powers". Members of the House and Senate are elected by first-past-the-post voting in every state except Louisiana and Georgia , which have runoffs , and Maine and Alaska , which use ranked-choice voting . Congress has

7830-436: The HHSTT include fabrication shops, project management and engineering buildings, munitions storage buildings, and heavy equipment staging areas. Electronic data, which include test timing, vehicle position, velocity , and acceleration , are routinely collected at the HHSTT. These data are captured by various means, including Doppler radar , optical beam interrupter blades, breakwire installations and magnetic sensors, and

7965-476: The HHSTT infrastructure, there is a 6,000-foot (1,800 m) rainfield that is used to study the erosive effects caused by the impact of raindrops on material samples or components of weapon systems carried on rocket sleds. The rainfield system has been characterized for droplet size distribution and can simulate various combinations of rain environments from light rain to heavy rain, and produce flight conditions ranging from subsonic to hypersonic . This capability

8100-582: The HHSTT was the launching of the Northrop N-25 Snark in 1950, but soon included human tolerance testing under the command of Colonel John P. Stapp . Col. Stapp was the last human test subject to ride the rocket-powered sleds at the HHSTT in December 1954. The track was lengthened to 5,000 ft (1,500 m) in 1956, followed by another extension to 35,000 ft (11,000 m) in 1957. The next major track extension occurred in 1974 when

8235-517: The HHSTT, including aircraft crew-escape systems , rain and particle erosion tests, impact testing , weapons dispense testing, electronic warfare , guidance system testing, and a wide array of aerodynamic tests. Because of the HHSTT's location on a military reservation in a sparsely populated area, tests may be performed in a secure environment. These large areas of open space may also be used to test items that are explosive , ballistic , or otherwise hazardous . The most prominent feature of

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8370-530: The HHSTT. The first sled tests were performed in 1950; the facility has been in continuous operation since. The HHSTT is unusual within the DoD Test and Evaluation community because it has organic management, engineering, fabrication, and test-operation capabilities in one location. This ability to provide a "one-stop-shop" reduces test costs and schedule issues associated with geographically separated project functions. A wide variety of tests have been performed at

8505-582: The House and 19 in the Senate, plus 4 joint permanent committees with members from both houses overseeing the Library of Congress , printing, taxation, and the economy. In addition, each house may name special, or select, committees to study specific problems. Today, much of the congressional workload is borne by the subcommittees, of which there are around 150. The Constitution grants numerous powers to Congress. Enumerated in Article I, Section 8, these include

8640-425: The House of Representatives. The approval of both chambers is required to pass all legislation, which then may only become law by being signed by the president (or, if the president vetoes the bill, both houses of Congress then re-pass the bill, but by a two-thirds majority of each chamber, in which case the bill becomes law without the president's signature). The powers of Congress are limited to those enumerated in

8775-469: The House plus its two senators). The District of Columbia has a number of electoral votes "equal to the whole number of Senators and Representatives in Congress to which the District would be entitled if it were a State, but in no event more than the least populous State". A President may also be seated by succession . As originally drafted, there was no limit to the time a President could serve, however

8910-568: The Senate, shall appoint Ambassadors, other public Ministers and Consuls, Judges of the supreme Court, and all other Officers of the United States " while providing that "Congress may by Law vest the Appointment of such inferior Officers, as they think proper, in the President alone, in the Courts of Law, or in the Heads of Departments." These appointments delegate "by legal authority a portion of

9045-564: The Soviet scientist N. F. Kazakov proposed the diffusion bonding method. Other recent developments in welding include the 1958 breakthrough of electron beam welding, making deep and narrow welding possible through the concentrated heat source. Following the invention of the laser in 1960, laser beam welding debuted several decades later, and has proved to be especially useful in high-speed, automated welding. Magnetic pulse welding (MPW) has been industrially used since 1967. Friction stir welding

9180-493: The Twenty-second Amendment, ratified in 1951, originally limits any president to serving two four-year terms (8 years); the amendment specifically "caps the service of a president at 10 years" by providing that "if a person succeeds to the office of president without election and serves less than two years, he may run for two full terms; otherwise, a person succeeding to office of president can serve no more than

9315-404: The U.S. Constitution. In contrast, the Senate is made up of two senators from each state, regardless of population. There are currently 100 senators (2 from each of the 50 states), who each serve six-year terms. Approximately one-third of the Senate stands for election every two years. If a vacancy occurs, the state governor appoints a replacement to complete the term or to hold the office until

9450-469: The arc and can add alloying components to the weld metal. World War I caused a major surge in the use of welding, with the various military powers attempting to determine which of the several new welding processes would be best. The British primarily used arc welding, even constructing a ship, the "Fullagar" with an entirely welded hull. Arc welding was first applied to aircraft during the war as well, as some German airplane fuselages were constructed using

9585-437: The atmosphere. Porosity and brittleness were the primary problems, and the solutions that developed included the use of hydrogen , argon , and helium as welding atmospheres. During the following decade, further advances allowed for the welding of reactive metals like aluminum and magnesium . This in conjunction with developments in automatic welding, alternating current, and fluxes fed a major expansion of arc welding during

9720-433: The base material plays a large role—if the diffusivity is high, the material cooling rate is high and the HAZ is relatively small. Conversely, a low diffusivity leads to slower cooling and a larger HAZ. The amount of heat injected by the welding process plays an important role as well, as processes like oxyacetylene welding have an unconcentrated heat input and increase the size of the HAZ. Processes like laser beam welding give

9855-486: The base material. Welding also requires a form of shield to protect the filler metals or melted metals from being contaminated or oxidized . Many different energy sources can be used for welding, including a gas flame (chemical), an electric arc (electrical), a laser , an electron beam , friction , and ultrasound . While often an industrial process, welding may be performed in many different environments, including in open air, under water , and in outer space . Welding

9990-402: The butt joint, lap joint, corner joint, edge joint, and T-joint (a variant of this last is the cruciform joint ). Other variations exist as well—for example, double-V preparation joints are characterized by the two pieces of material each tapering to a single center point at one-half their height. Single-U and double-U preparation joints are also fairly common—instead of having straight edges like

10125-402: The case from state court to federal court. The United States Courts of Appeals are appellate courts that hear appeals of cases decided by the district courts, and some direct appeals from administrative agencies, and some interlocutory appeals. The U.S. Supreme Court hears appeals from the decisions of the courts of appeals or state supreme courts, and in addition has original jurisdiction over

10260-404: The chambers to consider urgent matters. The vice president is the second-highest official in rank of the federal government. The vice president's duties and powers are established in the legislative branch of the federal government under Article 1, Section 3, Clauses 4 and 5 as the president of the Senate ; this means that they are the designated presiding officer of the Senate. In that capacity,

10395-440: The creation of executive departments and courts subordinate to the U.S. Supreme Court . In the federal division of power, the federal government shares sovereignty with each of the 50 states in their respective territories. U.S. law recognizes Indigenous tribes as possessing sovereign powers , while being subject to federal jurisdiction. The full name of the republic is the "United States of America". No other name appears in

10530-518: The distance between the wire and the base material is quickly rectified by a large change in current. For example, if the wire and the base material get too close, the current will rapidly increase, which in turn causes the heat to increase and the tip of the wire to melt, returning it to its original separation distance. The type of current used plays an important role in arc welding. Consumable electrode processes such as shielded metal arc welding and gas metal arc welding generally use direct current, but

10665-443: The durability of many designs increases significantly. Most solids used are engineering materials consisting of crystalline solids in which the atoms or ions are arranged in a repetitive geometric pattern which is known as a lattice structure . The only exception is material that is made from glass which is a combination of a supercooled liquid and polymers which are aggregates of large organic molecules. Crystalline solids cohesion

10800-600: The electrode can be charged either positively or negatively. In welding, the positively charged anode will have a greater heat concentration, and as a result, changing the polarity of the electrode affects weld properties. If the electrode is positively charged, the base metal will be hotter, increasing weld penetration and welding speed. Alternatively, a negatively charged electrode results in more shallow welds. Non-consumable electrode processes, such as gas tungsten arc welding, can use either type of direct current, as well as alternating current. However, with direct current, because

10935-442: The electrode only creates the arc and does not provide filler material, a positively charged electrode causes shallow welds, while a negatively charged electrode makes deeper welds. Alternating current rapidly moves between these two, resulting in medium-penetration welds. One disadvantage of AC, the fact that the arc must be re-ignited after every zero crossings, has been addressed with the invention of special power units that produce

11070-404: The electrode perfectly steady, and as a result, the arc length and thus voltage tend to fluctuate. Constant voltage power supplies hold the voltage constant and vary the current, and as a result, are most often used for automated welding processes such as gas metal arc welding, flux-cored arc welding, and submerged arc welding. In these processes, arc length is kept constant, since any fluctuation in

11205-418: The executive branch when becoming president upon the death, resignation, or removal of the president, which has happened nine times in U.S. history. Lastly, in the case of a Twenty-fifth Amendment succession event, the vice president would become acting president, assuming all of the powers and duties of president, except being designated as president. Accordingly, by circumstances, the Constitution designates

11340-523: The facility is the rail system (similar in appearance to railroad tracks) used to launch rocket -powered test vehicles known as " sleds ". The rail system is located just east of the White Sands National Park , and consists of a concrete foundation known as the girder that supports the two primary rails and a single tertiary rail. The westernmost rail is known as "A rail", followed by the adjacent "B rail" and "C rail". The alignment of

11475-438: The filler metal used, and its compatibility with the base materials. It is surrounded by the heat-affected zone , the area that had its microstructure and properties altered by the weld. These properties depend on the base material's behavior when subjected to heat. The metal in this area is often weaker than both the base material and the fusion zone, and is also where residual stresses are found. Many distinct factors influence

11610-613: The first processes to develop late in the century, and electric resistance welding followed soon after. Welding technology advanced quickly during the early 20th century, as world wars drove the demand for reliable and inexpensive joining methods. Following the wars, several modern welding techniques were developed, including manual methods like shielded metal arc welding , now one of the most popular welding methods, as well as semi-automatic and automatic processes such as gas metal arc welding , submerged arc welding , flux-cored arc welding and electroslag welding . Developments continued with

11745-582: The invention of laser beam welding , electron beam welding , magnetic pulse welding , and friction stir welding in the latter half of the century. Today, as the science continues to advance, robot welding is commonplace in industrial settings, and researchers continue to develop new welding methods and gain greater understanding of weld quality. The term weld is derived from the Middle English verb well ( wæll ; plural/present tense: wælle ) or welling ( wællen ), meaning 'to heat' (to

11880-536: The invention of metal electrodes in the late 1800s by a Russian, Nikolai Slavyanov (1888), and an American, C. L. Coffin (1890). Around 1900, A. P. Strohmenger released a coated metal electrode in Britain , which gave a more stable arc. In 1905, Russian scientist Vladimir Mitkevich proposed using a three-phase electric arc for welding. Alternating current welding was invented by C. J. Holslag in 1919, but did not become popular for another decade. Resistance welding

12015-483: The judiciary. For example, while the legislative branch ( Congress ) has the power to create law, the executive branch under the president can veto any legislation—an act which, in turn, can be overridden by Congress. The president nominates judges to the nation's highest judiciary authority, the Supreme Court (as well as to lower federal courts), but those nominees must be approved by Congress. The Supreme Court, in turn, can invalidate unconstitutional laws passed by

12150-486: The law and creating precedent for future law and decisions. The United States Constitution does not specifically mention the power of judicial review , which is the power to declare a law unconstitutional. There have been instances in the past where such declarations have been ignored by the other two branches. Below the U.S. Supreme Court are the United States Courts of Appeals , and below them in turn are

12285-412: The length of the arc is directly related to the voltage, and the amount of heat input is related to the current. Constant current power supplies are most often used for manual welding processes such as gas tungsten arc welding and shielded metal arc welding, because they maintain a relatively constant current even as the voltage varies. This is important because in manual welding, it can be difficult to hold

12420-532: The material may not have the ability to withstand the stress and could cause cracking, one method the control these stress would be to control the heating and cooling rate, such as pre-heating and post- heating The durability and life of dynamically loaded, welded steel structures is determined in many cases by the welds, in particular the weld transitions. Through selective treatment of the transitions by grinding (abrasive cutting) , shot peening , High-frequency impact treatment , Ultrasonic impact treatment , etc.

12555-715: The maximum temperature possible); 'to bring to a boil'. The modern word was probably derived from the past-tense participle welled ( wællende ), with the addition of d for this purpose being common in the Germanic languages of the Angles and Saxons . It was first recorded in English in 1590. A fourteenth century translation of the Christian Bible into English by John Wycliffe translates Isaiah 2:4 as " ...thei shul bete togidere their swerdes into shares... " (they shall beat together their swords into plowshares). In

12690-426: The metal. In general, resistance welding methods are efficient and cause little pollution, but their applications are somewhat limited and the equipment cost can be high. Spot welding is a popular resistance welding method used to join overlapping metal sheets of up to 3 mm thick. Two electrodes are simultaneously used to clamp the metal sheets together and to pass current through the sheets. The advantages of

12825-697: The method include efficient energy use , limited workpiece deformation, high production rates, easy automation, and no required filler materials. Weld strength is significantly lower than with other welding methods, making the process suitable for only certain applications. It is used extensively in the automotive industry—ordinary cars can have several thousand spot welds made by industrial robots . A specialized process called shot welding , can be used to spot weld stainless steel. Like spot welding, seam welding relies on two electrodes to apply pressure and current to join metal sheets. However, instead of pointed electrodes, wheel-shaped electrodes roll along and often feed

12960-650: The most common English words in everyday use are Scandinavian in origin. The history of joining metals goes back several millennia. The earliest examples of this come from the Bronze and Iron Ages in Europe and the Middle East . The ancient Greek historian Herodotus states in The Histories of the 5th century BC that Glaucus of Chios "was the man who single-handedly invented iron welding". Forge welding

13095-415: The most popular metal arc welding process. In 1957, the flux-cored arc welding process debuted, in which the self-shielded wire electrode could be used with automatic equipment, resulting in greatly increased welding speeds, and that same year, plasma arc welding was invented by Robert Gage. Electroslag welding was introduced in 1958, and it was followed by its cousin, electrogas welding , in 1961. In 1953,

13230-702: The office of vice president. Article II, Section 2 of the Constitution sets forth the creation of a presidential Cabinet. The role of the Cabinet is to advise the president and carry out the programs and laws of the federal government. The Cabinet is composed of the vice president and the leaders of 15 executive departments. Those executive departments are the Departments of State, Treasury, Defense, Justice, Interior, Agriculture, Commerce, Labor, Health and Human Services, Housing and Urban Development, Transportation, Energy, Education, Veterans Affairs, and Homeland Security. Additionally, there are seven other members of

13365-488: The plaintiffs and the government of another state was the defendant. It did not disturb federal jurisdiction in cases in which a state government is a plaintiff and a citizen of another state the defendant. The power of the federal courts extends both to civil actions for damages and other redress, and to criminal cases arising under federal law. The interplay of the Supremacy Clause and Article III has resulted in

13500-497: The power to adjourn Congress whenever the House and Senate cannot agree when to adjourn; no president has ever used this power. The president also has the constitutional power to, "on extraordinary Occasions, convene both Houses, or either of them"; this power has been used "to consider nominations, war, and emergency legislation." This Section invests the President with the discretion to convene Congress on "extraordinary occasions"; this special session power that has been used to call

13635-478: The power to re-organize or even abolish federal courts lower than the Supreme Court. The U.S. Supreme Court decides cases and controversies , which include matters pertaining to the federal government, disputes between states, and interpretation of the United States Constitution, and, in general, can declare legislation or executive action made at any level of the government as unconstitutional , nullifying

13770-437: The power to remove the president, federal judges, and other federal officers from office. The House of Representatives and Senate have separate roles in this process. The House must first vote to impeach the official. Then, a trial is held in the Senate to decide whether the official should be removed from office. As of 2023 , three presidents have been impeached: Andrew Johnson , Bill Clinton , and Donald Trump (twice). None of

13905-420: The powers to levy and collect taxes ; to coin money and regulate its value; provide for punishment for counterfeiting; establish post offices and roads, issue patents, create federal courts inferior to the Supreme Court , combat piracies and felonies , declare war , raise and support armies , provide and maintain a navy , make rules for the regulation of land and naval forces, provide for, arm and discipline

14040-502: The president and approved with the "advice and consent" of the U.S. Senate. Once confirmed, these "Cabinet secretaries" serve at the pleasure of the president. In addition to the executive departments, a number of staff organizations are grouped into the Executive Office of the President (EOP), which was created in 1939 by President Franklin D. Roosevelt. The EOP is overseen by the White House Chief of Staff. The EOP includes

14175-485: The president and confirmed by the United States Senate. The Judiciary Act of 1789 subdivided the nation jurisdictionally into judicial districts and created federal courts for each district. The three tiered structure of this act established the basic structure of the national judiciary: the Supreme Court, 13 courts of appeals, 94 district courts, and two courts of special jurisdiction. Congress retains

14310-474: The president has major agenda-setting powers to influence lawmaking and policymaking, and typically has a major role as the leader of their political party . The president and vice president are normally elected as running mates by the Electoral College ; each state has a number of electoral votes equal to the size of its Congressional delegation ( i.e. , its number of Representatives in

14445-525: The president's signature, "unless the Congress by their Adjournment prevent its Return in which Case it shall not be a Law" (called a pocket veto ). A presidential veto may be overridden by a two-thirds vote in both houses of Congress; this occurs relatively infrequently. The president may be impeached by a majority in the House and removed from office by a two-thirds majority in the Senate for " treason , bribery , or other high crimes and misdemeanors ". The president may not dissolve Congress , but has

14580-436: The process, and the industry continued to grow during the following centuries. In 1800, Sir Humphry Davy discovered the short-pulse electrical arc and presented his results in 1801. In 1802, Russian scientist Vasily Petrov created the continuous electric arc, and subsequently published "News of Galvanic-Voltaic Experiments" in 1803, in which he described experiments carried out in 1802. Of great importance in this work

14715-553: The process. Also noteworthy is the first welded road bridge in the world, the Maurzyce Bridge in Poland (1928). During the 1920s, significant advances were made in welding technology, including the introduction of automatic welding in 1920, in which electrode wire was fed continuously. Shielding gas became a subject receiving much attention, as scientists attempted to protect welds from the effects of oxygen and nitrogen in

14850-442: The quality of welding procedure specification , how to judge the skill of the person performing the weld, and how to ensure the quality of a welding job. Methods such as visual inspection , radiography , ultrasonic testing , phased-array ultrasonics , dye penetrant inspection , magnetic particle inspection , or industrial computed tomography can help with detection and analysis of certain defects. The heat-affected zone (HAZ)

14985-650: The quality of a weld, either destructive or nondestructive testing methods are commonly used to verify that welds are free of defects, have acceptable levels of residual stresses and distortion, and have acceptable heat-affected zone (HAZ) properties. Types of welding defects include cracks, distortion, gas inclusions (porosity), non-metallic inclusions, lack of fusion, incomplete penetration, lamellar tearing, and undercutting. The metalworking industry has instituted codes and specifications to guide welders , weld inspectors , engineers , managers, and property owners in proper welding technique, design of welds, how to judge

15120-481: The rails from the Edwards Air Force Base test track were shipped to Holloman and added to the existing tracks to give a new total length of 50,771 ft (15,475 m). During this upgrade, a third rail, approximately 15,000 ft (4,600 m), was added for high-speed, narrow-gauge sleds. In 2000, pulldown extensions of 149 ft (45 m) were added to the north end of each rail, bringing

15255-403: The rails is nearly north–south. All three rails are fabricated from heavy-duty crane rail (171 pounds per yard or 85 kilograms per meter) and are maintained to an alignment of no more than 0.025 inches (0.64 mm) deviation from a nominal reference line between rail tiedowns. A and B rails constitute the primary rails and are 50,917 feet (15,520 m) long. C rail, located at the north end of

15390-428: The resulting force between them is zero. When the ions are exerted in tension force, the inter-ionic spacing increases creating an electrostatic attractive force, while a repulsing force under compressive force between the atomic nuclei is dominant. Covalent bonding takes place when one of the constituent atoms loses one or more electrons, with the other atom gaining the electrons, resulting in an electron cloud that

15525-476: The same imagery to determine the status of the sled vehicle during tests. All data can be post-processed and merged using a common time reference to verify the accuracy of the data, and to produce a unified data product. Optical imagery is captured with high-speed digital cameras. Local meteorological data (e.g., temperature and barometric pressure) are also collected for each test for the calculation of Mach number or knots equivalent air speed as desired by

15660-433: The same way as the president or other officials of the federal government. U.S. judges are appointed by the president, subject to confirmation by the Senate. Another Constitutional provision prohibits Congress from reducing the pay of any present Article III judge. However, Congress is able to set a lower salary for all future judges who take office after such a pay reduction is passed by Congress. Welding Welding

15795-667: The single-V and double-V preparation joints, they are curved, forming the shape of a U. Lap joints are also commonly more than two pieces thick—depending on the process used and the thickness of the material, many pieces can be welded together in a lap joint geometry. Many welding processes require the use of a particular joint design; for example, resistance spot welding, laser beam welding, and electron beam welding are most frequently performed on lap joints. Other welding methods, like shielded metal arc welding, are extremely versatile and can weld virtually any type of joint. Some processes can also be used to make multipass welds, in which one weld

15930-594: The sovereign powers of the federal government." The Constitution grants the president the "Power to grant Reprieves and Pardons for Offences against the United States , except in Cases of Impeachment"; this clemency power includes the power to issue absolute or conditional pardons, and to issue commute sentences , to remit fines, and to issue general amnesties . The presidential clemency power extends only to federal crimes, and not to state crimes. The president has informal powers beyond their formal powers. For example,

16065-604: The strength of welds and the material around them, including the welding method, the amount and concentration of energy input, the weldability of the base material, filler material, and flux material, the design of the joint, and the interactions between all these factors. For example, the factor of welding position influences weld quality, that welding codes & specifications may require testing—both welding procedures and welders—using specified welding positions: 1G (flat), 2G (horizontal), 3G (vertical), 4G (overhead), 5G (horizontal fixed pipe), or 6G (inclined fixed pipe). To test

16200-525: The term "U.S. Government" is sometimes used. The terms "Federal" and "National" in government agency or program names generally indicate affiliation with the federal government; for instance, the Federal Bureau of Investigation , National Oceanic and Atmospheric Administration , and National Park Service . Because the seat of government is in Washington, D.C. , "Washington" is sometimes used as

16335-538: The test customer. Federal government of the United States [REDACTED] [REDACTED] The federal government of the United States ( U.S. federal government or U.S. government ) is the common government of the United States , a federal republic located primarily in North America , comprising 50 states , five major self-governing territories , several island possessions , and

16470-434: The three were removed from office following trial in the Senate. Article I, Section 2, paragraph 2 of the U.S. Constitution gives each chamber the power to "determine the rules of its proceedings". From this provision were created congressional committees , which do the work of drafting legislation and conducting congressional investigations into national matters. The 118th Congress (2023–2025) has 20 standing committees in

16605-445: The track facility, is 20,379 feet (6,212 m) long. A and B rails are spaced 84 inches (210 cm), center to center, while C rail is spaced 26.3 inches (67 cm) to the east of B rail. Despite the simple appearance of the setup, the tracks constitute the straightest system of track ever laid. Rails A, B, and C are continuously welded and pre- stressed to be under tension at temperatures below 120 °F (49 °C). Within

16740-529: The trial courts wherein cases that are considered under the Judicial Code (Title 28, United States Code) consistent with the jurisdictional precepts of federal question jurisdiction , diversity jurisdiction, and pendent jurisdiction can be filed and decided. The district courts can also hear cases under removal jurisdiction , wherein a case brought in a state court meets the requirements for diversity jurisdiction, and one party litigant chooses to "remove"

16875-541: The two primary rails to 50,917 feet (15,520 m). The last major upgrade to the primary rail system occurred in 2002, when the narrow-gauge track was lengthened to 20,379 ft (6,212 m). The HHSTT currently holds the world land speed record for rocket sleds set in April 2003, at Mach 8.6, or 9,465 feet per second (2,885 meters per second), or 6,453.409 miles per hour (10,385.755 kilometres per hour). As of April 2014, over 12,400 sled tests have been performed at

17010-468: The use of a continuous wire feed, the weld deposition rate is high. Working conditions are much improved over other arc welding processes, since the flux hides the arc and almost no smoke is produced. The process is commonly used in industry, especially for large products and in the manufacture of welded pressure vessels. Other arc welding processes include atomic hydrogen welding , electroslag welding (ESW), electrogas welding , and stud arc welding . ESW

17145-518: The vice president as routinely in the legislative branch, or succeeding to the executive branch as president, or possibly being in both as acting president pursuant to the Twenty-fifth Amendment . Because of circumstances, the overlapping nature of the duties and powers attributed to the office, the title of the office and other matters, such has generated a spirited scholarly dispute regarding attaching an exclusive branch designation to

17280-522: The vice president has the authority ( ex officio , for they are not an elected member of the Senate) to cast a tie-breaking vote . Pursuant to the Twelfth Amendment , the vice president presides over the joint session of Congress when it convenes to count the vote of the Electoral College . As first in the U.S. presidential line of succession , the vice president's duties and powers move to

17415-415: The welding of high alloy steels. A similar process, generally called oxyfuel cutting, is used to cut metals. These processes use a welding power supply to create and maintain an electric arc between an electrode and the base material to melt metals at the welding point. They can use either direct current (DC) or alternating current (AC), and consumable or non-consumable electrodes . The welding region

17550-420: The welding process used, with shielded metal arc welding having a value of 0.75, gas metal arc welding and submerged arc welding, 0.9, and gas tungsten arc welding, 0.8. Methods of alleviating the stresses and brittleness created in the HAZ include stress relieving and tempering . One major defect concerning the HAZ would be cracking at the toes , due to the rapid expansion (heating) and contraction (cooling)

17685-585: The workpiece, making it possible to make long continuous welds. In the past, this process was used in the manufacture of beverage cans, but now its uses are more limited. Other resistance welding methods include butt welding , flash welding , projection welding , and upset welding . Energy beam welding methods, namely laser beam welding and electron beam welding , are relatively new processes that have become quite popular in high production applications. The two processes are quite similar, differing most notably in their source of power. Laser beam welding employs

17820-415: Was also developed during the final decades of the 19th century, with the first patents going to Elihu Thomson in 1885, who produced further advances over the next 15 years. Thermite welding was invented in 1893, and around that time another process, oxyfuel welding , became well established. Acetylene was discovered in 1836 by Edmund Davy , but its use was not practical in welding until about 1900, when

17955-519: Was invented in 1991 by Wayne Thomas at The Welding Institute (TWI, UK) and found high-quality applications all over the world. All of these four new processes continue to be quite expensive due to the high cost of the necessary equipment, and this has limited their applications. The most common gas welding process is oxyfuel welding, also known as oxyacetylene welding. It is one of the oldest and most versatile welding processes, but in recent years it has become less popular in industrial applications. It

18090-457: Was the description of a stable arc discharge and the indication of its possible use for many applications, one being melting metals. In 1808, Davy, who was unaware of Petrov's work, rediscovered the continuous electric arc. In 1881–82 inventors Nikolai Benardos (Russian) and Stanisław Olszewski (Polish) created the first electric arc welding method known as carbon arc welding using carbon electrodes. The advances in arc welding continued with

18225-532: Was used in the construction of the Iron pillar of Delhi , erected in Delhi , India about 310 AD and weighing 5.4  metric tons . The Middle Ages brought advances in forge welding , in which blacksmiths pounded heated metal repeatedly until bonding occurred. In 1540, Vannoccio Biringuccio published De la pirotechnia , which includes descriptions of the forging operation. Renaissance craftsmen were skilled in

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