A weapon, arm or armament is any device that can be used with intent to inflict damage or harm. Weapons are used to increase the efficacy and efficiency of activities such as hunting, law enforcement, self-defense, warfare. In broader context, weapons may be construed to include anything used to gain a tactical, material or mental advantage over an adversary or enemy target. While ordinary objects such as sticks, cars, or pencils can be used as weapons, many are expressly designed for the purpose – ranging from simple implements such as clubs and axes, to complicated modern intercontinental ballistic missiles, biological weapons and cyberweapons. Something, re-purposed, converted, or enhanced to become a weapon of war is termed weaponized, such as a weaponized virus or weaponized laser; the use of objects as weapons has been observed among chimpanzees, leading to speculation that early hominids used weapons as early as five million years ago. However, this can not be confirmed using physical evidence because wooden clubs and unshaped stones would have left an ambiguous record.
The earliest unambiguous weapons to be found are the Schöningen spears, eight wooden throwing spears dating back more than 300,000 years. At the site of Nataruk in Turkana, numerous human skeletons dating to 10,000 years ago may present evidence of traumatic injuries to the head, ribs and hands, including obsidian projectiles embedded in the bones that might have been caused from arrows and clubs during conflict between two hunter-gatherer groups, but the evidence interpretation of warfare at Nataruk has been challenged. The earliest ancient weapons were evolutionary improvements of late neolithic implements, but significant improvements in materials and crafting techniques led to a series of revolutions in military technology; the development of metal tools began with copper during the Copper Age and was followed by the Bronze Age, leading to the creation of the Bronze Age sword and similar weapons. During the Bronze Age, the first defensive structures and fortifications appeared as well, indicating an increased need for security.
Weapons designed to breach fortifications followed soon after, such as the battering ram, in use by 2500 BC. The development of iron-working around 1300 BC in Greece had an important impact on the development of ancient weapons, it was not the introduction of early Iron Age swords, however, as they were not superior to their bronze predecessors, but rather the domestication of the horse and widespread use of spoked wheels by c. 2000 BC. This led to the creation of the light, horse-drawn chariot, whose improved mobility proved important during this era. Spoke-wheeled chariot usage peaked around 1300 BC and declined, ceasing to be militarily relevant by the 4th century BC. Cavalry developed; the horse increased the speed of attacks. In addition to land based weaponry, such as the trireme, were in use by the 7th century BC. European warfare during the Post-classical history was dominated by elite groups of knights supported by massed infantry, they were involved in mobile combat and sieges which involved various siege tactics.
Knights on horseback developed tactics for charging with lances providing an impact on the enemy formations and drawing more practical weapons once they entered into the melee. By contrast, infantry, in the age before structured formations, relied on cheap, sturdy weapons such as spears and billhooks in close combat and bows from a distance; as armies became more professional, their equipment was standardized and infantry transitioned to pikes. Pikes are seven to eight feet in length, used in conjunction with smaller side-arms. In Eastern and Middle Eastern warfare, similar tactics were developed independent of European influences; the introduction of gunpowder from the Asia at the end of this period revolutionized warfare. Formations of musketeers, protected by pikemen came to dominate open battles, the cannon replaced the trebuchet as the dominant siege weapon; the European Renaissance marked the beginning of the implementation of firearms in western warfare. Guns and rockets were introduced to the battlefield.
Firearms are qualitatively different from earlier weapons because they release energy from combustible propellants such as gunpowder, rather than from a counter-weight or spring. This energy is released rapidly and can be replicated without much effort by the user; therefore early firearms such as the arquebus were much more powerful than human-powered weapons. Firearms became important and effective during the 16th century to 19th century, with progressive improvements in ignition mechanisms followed by revolutionary changes in ammunition handling and propellant. During the U. S. Civil War new applications of firearms including the machine gun and ironclad warship emerged that would still be recognizable and useful military weapons today in limited conflicts. In the 19th century warship propulsion changed from sail power to fossil fuel-powered steam engines. Since the mid-18th century North American French-Indian war through the beginning of the 20th century, human-powered weapons were reduced from the primary weaponry of the battlefield yielding to gunpowder-based weaponry.
Sometimes referred to as the "Age of Rifles", this period was characterized by the development of firearms for infantry and cannons for support, as well as the beginnings of mechanized weapons such as the machine gun. Of particular note, Howitzers were able to destroy masonry fortresses and other fortifications, this single invention caused a Revolution in
Mauser, begun as Königliche Waffen Schmieden, is a German arms manufacturer. Their line of bolt-action rifles and semi-automatic pistols have been produced since the 1870s for the German armed forces. In the late 19th and early 20th centuries, Mauser designs were exported and licensed to a large number of countries which adopted them as military and civilian sporting firearms; the Mauser Model 98 in particular was adopted and copied, is the foundation of many of today's sporting bolt action rifles. Founded as Königliche Waffen Schmieden on 31 July 1811 by Frederick I. Located at Ludwigsburg and in Christophsthal, the factory was transferred to Oberndorf in the former Augustine Cloister. Andreas Mauser was the master gunsmith there. Of his seven sons who worked with him there Peter Paul Mauser showed an outstanding ability to develop methods of operation that were faster and more efficient, his older brother Wilhelm assumed many of his father's duties. Peter Paul Mauser referred to as Paul Mauser, was born on 27 June 1838, in Oberndorf am Neckar, Württemberg.
His brother Wilhelm was four years older. A brother, Franz Mauser, worked at E. Remington & Sons. Peter Paul was conscripted in 1859 as an artilleryman at the Ludwigsburg arsenal, where he worked as a gunsmith. By December 1859 he had so impressed his superiors that he was placed on inactive military service and assigned to the royal factory at Oberndorf. Paul engaged his older brother Wilhelm in working on a new gun system in their spare time after work. Paul was the engineer and designer but Wilhelm took on the task of manager for their interests with the Oberndorf factory. Paul's first invention was its ammunition, his ability to produce both the gun and the ammunition for it was followed during his entire career and made him unique in this ability. Following the success of the Dreyse needle gun Paul turned his energies to improving on that design and producing a new one. Paul and Wilhelm had separated due to differences during this time. After Paul developed a new turning bolt design Wilhelm was impressed enough to rejoin the business and succeeded in obtaining the financing to purchase machinery and continue development.
While the original needle gun used a pin that pierced the base of the cartridge to ignite the primer in the middle, Mauser soon developed a needle that ignited the charge at the base, a superior design. Locally the Dreyse Needle gun had just been adopted so the brother turned to the Austrian Ambassador to try to sell their gun, he forwarded their new gun to Vienna for testing. It was here. In 1867 Norris hired the Mauser brother to go to Luttich to work on a new design, he stipulated that patents were to be taken out in his name and that a royalty would be paid to the Mauser brothers for rifles sold. Norris was convinced; the Norris-Mauser patent was taken out in the United States. Remington was never made an effort to sell the new rifle. Based on the Dreyse needle gun, he developed a rifle with a turn-bolt mechanism that cocked the gun as it was manipulated by the user; the rifle used a firing needle. The rifle was shown to the Austrian War Ministry by Samuel Norris of E. Sons. Norris believed the design could be adapted to convert Chassepot needle guns to fire metallic cartridges.
Shortly thereafter, a partnership was formed in Oberndorf between the Mauser brothers. The partners went to Liège in 1867, but when the French government showed no interest in a Chassepot conversion, the partnership was dissolved. Paul Mauser returned to Oberndorf in December 1869, Wilhelm arrived in April 1870. Before leaving Luttich, the Mausers insisted that he submit the rifle to Royal Prussian School of Riflemanship; the results were impressive and Wilhelm was invited to the arsenal at Spandau. Peter Paul and Wilhelm Mauser continued development of their new rifle in Paul's father-in-law's home; the Mauser rifle was accepted by the Prussian government on 2 December 1871, was accepted for service until 14 February 1872, after a requested design change to the safety lock. The Mauser brothers received an order for 3,000 rifle sights, but actual production of the rifle was given to government arsenals and large firms; the sights were produced at the Xaver Jauch house starting 1 May 1872. After an order for 100,000 rifle sights was received from the Bavarian Rifle Factory at Amberg, the Mauser brothers began negotiations to purchase the Württemberg Royal Armoury.
A delay in the purchase forced them to buy real estate overlooking the Neckar River Valley, where the upper works was built that same year. A house in Oberndorf was rented to fulfill the Bavarian order; the Königlich Württembergische Gewehrfabrik was acquired on May 23, 1874, after an agreement between the Württemberg government and the Mausers to produce 100,000 Model 71 rifles. The partnership of Mauser Brothers and Company was formed between the Württemberg Vereinsbank of Stuttgart and Paul and Wilhelm Mauser on February 5, 1874. By 23 May 1874, the Mauser partnership had three factories in Oberndorf. Wilhelm Mauser suffered from health problems throughout his life, which were aggravated by his frequent business travels. A combination of these led to his death on 13 January 1882; the partnership became a stock company with the name of Waffenfabrik Mauser on 1 April 1884. The shares held by the Württemberg Vereinsbank and Paul Mauser were sold to Ludwig Löwe & Company on 28 December 1887, Paul Mauser stayed as the technical lea
A submachine gun is a magazine-fed, automatic carbine designed to fire pistol cartridges. The term "submachine gun" was coined by John T. Thompson, the inventor of the Thompson submachine gun; the submachine gun was developed during World War I. At its zenith during World War II, millions of SMGs were made. After the war, new SMG designs appeared frequently. However, by the 1980s, SMG usage decreased. Today, submachine guns have been replaced by assault rifles, which have a greater effective range and are capable of penetrating the helmets and body armor used by modern infantry. However, submachine guns are still used by military special forces and police SWAT teams for close quarters battle because they are "a pistol-caliber weapon that's easy to control, less to over-penetrate the target". During World War I, the Austrians introduced the world's first machine pistol the Steyr Repetierpistole M1912/P16; the Germans experimented with machine pistols by converting pistols such as the Mauser C96 and Luger P-08 from semiautomatic to automatic operation and adding detachable stocks.
Carbine-type automatic weapons firing pistol rounds were developed during the latter stages of World War I by Italy and the United States. Their improved firepower and portability offered an advantage in trench warfare. In 1915, the Italians introduced the Villar-Perosa aircraft machine gun, it fired pistol-caliber 9mm Glisenti ammunition, but was not a true submachine gun, as it was designed as a mounted weapon. This odd design was modified into the OVP 1918 carbine-type submachine gun, which evolved into the 9×19mm Parabellum Beretta Model 1918 after the end of World War I. Both the OVP 1918 and the Beretta 1918 had a traditional wooden stock, a 25-round top-fed box magazine, had a cyclic rate of fire of 900 rounds per minute; the Germans used heavier versions of the P08 pistol equipped with a detachable stock, larger-capacity snail-drum magazine and a longer barrel. By 1918, Bergmann Waffenfabrik had developed the 9 mm Parabellum MP 18, the first practical submachine gun; this weapon used the same 32-round snail-drum magazine as the Luger P-08.
The MP 18 was used in significant numbers by German stormtroopers employing infiltration tactics, achieving some notable successes in the final year of the war. However, these were not enough to prevent Germany's collapse in November 1918. After World War I, the MP 18 would evolve into the MP28/II SMG, which incorporated a simple 32-round box magazine, a semi & full auto selector, other minor improvements. The.45 ACP Thompson submachine gun had been in development at the same time as the Bergmann and the Beretta. However, the war ended. Although it had missed its chance to be the first purpose-designed submachine gun to enter service, it became the basis for weapons and had the longest active service life of the three. In the interwar period the "Tommy Gun" or "Chicago Typewriter" became notorious in the U. S. as a gangster's weapon. However, the FBI and other U. S. police forces themselves showed no reluctance to prominently display these weapons. The submachine gun was accepted by many military organizations as World War II loomed, with many countries developing their own designs.
The Italians were among the first to develop submachine guns during World War I. However, they were slow to produce them during World War II; the 9 mm Parabellum Beretta Model 1938 was not available in large numbers until 1943. The 38 was made in a successive series of improved and simplified models all sharing the same basic layout; the Beretta has the front for semi-auto and rear for full-auto. Most models use standard wooden stocks, although some models were fitted with an MP 40-style under-folding stock and are mistaken for the German SMG; the 38 series was robust and proved popular with both Axis forces and Allied troops. It is considered the most successful and effective Italian small arm of World War II; the 38 series is the longest serving of the world's SMGs, as models can still be seen in the hands of Italian military and police forces. In 1939, the Germans introduced the 9 mm Parabellum MP38 during the invasion of Poland. However, the MP38 production was still just starting and only a few thousand were in service at the time.
It proved to be far more practical and effective in close quarters combat than the standard-issue German Kar 98K bolt-action rifle. From it, the nearly identical MP40 was made in large numbers; the MP40 was lighter than the MP38. It used more stamped parts, making it faster and cheaper to produce; the MP38 and MP40 were the first SMGs to use a practical folding stock. They would set the fashion for all future SMG designs. During the Winter War, the badly outnumbered Finnish used the Suomi KP/-31 in large numbers against the Russians with devastating effect. Finnish ski troops became known for appearing out of the woods on one side of a road, raking Soviet columns with SMG fire and disappearing back into the woods on the other side. During the Continuation War, the Finnish Sissi patrols would equip every soldier with KP/-31s; the Suomi fired 9 mm Parabellum ammo from a 71-round drum magazine. "This SMG showed to the world the importance of the submachine gun to the modern warfare", prompting the development and mass production of submachine guns by mo
A sewing machine is a machine used to sew fabric and other materials together with thread. Sewing machines were invented during the first Industrial Revolution to decrease the amount of manual sewing work performed in clothing companies. Since the invention of the first working sewing machine considered to have been the work of Englishman Thomas Saint in 1790, the sewing machine has improved the efficiency and productivity of the clothing industry. Home sewing machines are designed for one person to sew individual items while using a single stitch type. In a modern sewing machine the fabric glides in and out of the machine without the inconvenience of needles and thimbles and other such tools used in hand sewing, automating the process of stitching and saving time. Industrial sewing machines, by contrast to domestic machines, are larger and more varied in their size, cost and task. Charles Fredrick Weisenthal, a German-born engineer working in England was awarded the first British patent for a mechanical device to aid the art of sewing, in 1755.
His invention consisted of a double pointed needle with an eye at one end. In 1790, the English inventor Thomas Saint invented the first sewing machine design, but he did not advertise or market his invention, his machine was meant to be used on canvas material. It is that Saint had a working model but there is no evidence of one, his sewing machine used the chain stitch method, in which the machine uses a single thread to make simple stitches in the fabric. A stitching awl would pierce the material and a forked point rod would carry the thread through the hole where it would be hooked underneath and moved to the next stitching place, where the cycle would be repeated, locking the stitch. Saint's machine was designed to aid the manufacture of various leather goods, including saddles and bridles, but it was capable of working with canvas, was used for sewing ship sails. Although his machine was advanced for the era, the concept would need steady improvement over the coming decades before it could become a practical proposition.
In 1874, a sewing machine manufacturer, William Newton Wilson, found Saint's drawings in the London Patent Office, made adjustments to the looper, built a working machine owned by the London Science Museum. In 1804, a sewing machine was built by the Englishmen Thomas Stone and James Henderson, a machine for embroidering was constructed by John Duncan in Scotland. An Austrian tailor, Josef Madersperger, began developing his first sewing machine in 1807 and presented his first working machine in 1814. Having received financial support from his government, the Austrian tailor worked on the development of his machine until 1839, when he built a machine imitating the weaving process using the chain stitch; the first practical and used sewing machine was invented by Barthélemy Thimonnier, a French tailor, in 1829. His machine sewed straight seams using chain stitch like Saint's model, in 1830, he signed a contract with Auguste Ferrand, a mining engineer, who made the requisite drawings and submitted a patent application.
The patent for his machine was issued on 17 July 1830, in the same year, he opened the first machine-based clothing manufacturing company in the world to create army uniforms for the French Army. However, the factory was burned down by workers fearful of losing their livelihood following the issuing of the patent. A model of the machine is exhibited at the London Science Museum; the machine is made of wood and uses a barbed needle which passes downward through the cloth to grab the thread and pull it up to form a loop to be locked by the next loop. The first American lockstitch sewing machine was invented by Walter Hunt in 1832, his machine used an eye-pointed needle carrying the upper thread and a falling shuttle carrying the lower thread. The curved needle moved through the fabric horizontally; the shuttle passed through the loop. The feed let the machine down, requiring the machine to be stopped and reset up. Hunt lost interest in his machine and sold individual machines without bothering to patent his invention, only patenting it at a late date of 1854.
In 1842, John Greenough patented the first sewing machine in the United States. The British partners Newton and Archibold introduced the eye-pointed needle and the use of two pressing surfaces to keep the pieces of fabric in position, in 1841; the first machine to combine all the disparate elements of the previous half-century of innovation into the modern sewing machine was the device built by English inventor John Fisher in 1844, thus a little earlier than the similar machines built by Isaac Merritt Singer in 1851, the lesser known Elias Howe, in 1845. However, due to the botched filing of Fisher's patent at the Patent Office, he did not receive due recognition for the modern sewing machine in the legal disputations of priority with Singer, it was Singer who won the benefits of the patent. Elias Howe, born in Spencer, created his sewing machine in 1845, using a similar method to Fisher's except that the fabric was held vertically. An important improvement on his machine was to have the needle running away from the point, starting from the eye.
After a lengthy stay in England trying to attract interest in his machine, he returned to America to find various people infringing his patent, among them Isaac Merritt Singer. He won a case f
Personal defense weapon
Personal defense weapons are a class of compact selective fire, magazine-fed, submachine gun like firearms – a hybrid between a submachine gun and compact assault rifle. Most PDWs fire a small-caliber, high-velocity bottleneck cartridge, resembling a small or shortened intermediate rifle cartridge; this gives the PDW better range and armor-penetrating capability than submachine guns, which fire pistol-caliber cartridges. The name describes the type's original role: as a compact but powerful defensive weapon that can be carried by troops behind the front line such as military engineers, artillery crews or signallers; these soldiers may be at risk of encountering the enemy, but enough that a long-barrel service rifle would be an unnecessary burden during their normal duties. Because of their ease of use, light weight and controllability, they have been used by special forces and by heavily-armed police. In the 19th and early 20th centuries, shortened versions of the infantry rifle were issued as'carbines' for cavalry troops and gun crews.
This designation was dropped as infantry rifle designs were shortened, such as in the Short Magazine Lee–Enfield rifle. Thereafter, pistols were issued as a self-defense weapons. However, they were not effective in most combat situations; as a result, during the First World War, the Mauser C96 and artillery versions of the Luger pistol were issued with attachable shoulder stock holsters, which allowed for greater control and accuracy. During World War I, the United States secretly developed the Pedersen device attachment for the M1903 Springfield rifle that allowed it to fire a.30 caliber pistol type cartridge in semi-automatic mode. This attachment was developed to allow an infantryman to convert "his rifle to a form of submachine gun or automatic rifle" in 15 seconds. Production of the device and modified M1903 rifles started during 1918. However, the war ended; the contract was cancelled on March 1, 1919, after production of 65,000 devices, 1.6 million magazines, 65 million cartridges and 101,775 modified Springfield rifles.
The Pedersen device was declared surplus in 1931. To prevent them from falling into the hands of the lawless, nearly all of the stored devices were destroyed by the Army except for a few examples kept by Ordnance Department. In 1938, the U. S. Army Ordnance Department received a request for a light rifle to be issued to mortarmen, drivers, clerks and similar grades. During field exercises, these troops found that the M1 Garand rifle was too heavy and too cumbersome for general issue. And, while handguns are undeniably convenient, they had limited range and power; this request was refused by authorities. In 1940, after Germany's use of glider-borne and paratroop forces to infiltrate and attack strategic points behind the front lines, the request for a light rifle was resubmitted and subsequently approved. U. S. Army Ordnance issued a requirement for a "light rifle" with greater range and accuracy than the M1911 pistol, while weighing half as much as the M1 Garand; as result, the U. S. developed the semi-automatic M1 Carbine and shortly thereafter the select-fire M2 Carbine.
Employed until the end of Vietnam War, these carbines are considered the forerunners of modern personal defense weapons. Developed during the late 1980s, the "Personal Defense Weapon" concept was created in response to a NATO request as a replacement for 9×19mm Parabellum submachine guns; the PDW is a compact automatic weapon that can defeat enemy body armor and which can be used conveniently by non-combatant and support troops, as well as a close quarters battle weapon for special forces and counter-terrorist groups. Introduced in 1991, the FN P90 features a bullpup design with a futuristic appearance, it has a 50-round magazine housed horizontally above the barrel, an integrated reflex sight and ambidextrous controls. A simple blow-back automatic weapon, it was designed to fire the FN 5.7×28mm cartridge which can penetrate soft body armor. The P90 was designed to have a length no greater than a man's shoulder width, to allow it to be carried and maneuvered in tight spaces, such as the inside of an armored vehicle.
Introduced in 2001, the Heckler & Koch MP7 is a direct rival to the FN P90. Featuring a more conventional looking design, the MP7 uses a short stroke piston gas system as used on H&K's G36 and HK416 assault rifles, in place of a blow-back system traditionally seen on submachine guns; the MP7 is able to use 20-, 30- and 40-round magazines and fires 4.6×30mm ammunition which can penetrate soft body armor. Due to the heavy use of polymers in its construction, the MP7 is much lighter than older SMG designs, weighing only 1.2 kg with an empty 20 round magazine. The PDW concept has not been successful because PDWs are not cheaper to manufacture than full size military rifles. PDWs use a proprietary cartridge, such as the 5.7×28mm cartridge for the FN P90 or 4.6×30mm for the Heckler & Koch MP7, neither of which were compatible with any existing pistols or rifles. A different take on the PDW concept is the Russian made PP-2000, which can fire common 9×19mm Parabellum ammunition or a special high-pressure armor-piercing version to give it similar capabilities as other PDWs.
Though personal defense weapons have not been popular for their intended application, they have been acquired by many special forces and law enforcement groups as direct replacements for submachine guns. The FN P90 and Five-seven pistol are used by military and police f
A polymer is a large molecule, or macromolecule, composed of many repeated subunits. Due to their broad range of properties, both synthetic and natural polymers play essential and ubiquitous roles in everyday life. Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers, their large molecular mass relative to small molecule compounds produces unique physical properties, including toughness, a tendency to form glasses and semicrystalline structures rather than crystals. The terms polymer and resin are synonymous with plastic; the term "polymer" derives from the Greek word πολύς and μέρος, refers to a molecule whose structure is composed of multiple repeating units, from which originates a characteristic of high relative molecular mass and attendant properties. The units composing polymers derive or conceptually, from molecules of low relative molecular mass.
The term was coined in 1833 by Jöns Jacob Berzelius, though with a definition distinct from the modern IUPAC definition. The modern concept of polymers as covalently bonded macromolecular structures was proposed in 1920 by Hermann Staudinger, who spent the next decade finding experimental evidence for this hypothesis. Polymers are studied in the fields of biophysics and macromolecular science, polymer science. Products arising from the linkage of repeating units by covalent chemical bonds have been the primary focus of polymer science. Polyisoprene of latex rubber is an example of a natural/biological polymer, the polystyrene of styrofoam is an example of a synthetic polymer. In biological contexts all biological macromolecules—i.e. Proteins, nucleic acids, polysaccharides—are purely polymeric, or are composed in large part of polymeric components—e.g. Isoprenylated/lipid-modified glycoproteins, where small lipidic molecules and oligosaccharide modifications occur on the polyamide backbone of the protein.
The simplest theoretical models for polymers are ideal chains. Polymers are of two types: occurring and synthetic or man made. Natural polymeric materials such as hemp, amber, wool and natural rubber have been used for centuries. A variety of other natural polymers exist, such as cellulose, the main constituent of wood and paper; the list of synthetic polymers in order of worldwide demand, includes polyethylene, polystyrene, polyvinyl chloride, synthetic rubber, phenol formaldehyde resin, nylon, polyacrylonitrile, PVB, many more. More than 330 million tons of these polymers are made every year. Most the continuously linked backbone of a polymer used for the preparation of plastics consists of carbon atoms. A simple example is polyethylene. Many other structures do exist. Oxygen is commonly present in polymer backbones, such as those of polyethylene glycol, DNA. Polymerization is the process of combining many small molecules known as monomers into a covalently bonded chain or network. During the polymerization process, some chemical groups may be lost from each monomer.
This happens in the polymerization of PET polyester. The monomers are terephthalic acid and ethylene glycol but the repeating unit is —OC—C6H4—COO—CH2—CH2—O—, which corresponds to the combination of the two monomers with the loss of two water molecules; the distinct piece of each monomer, incorporated into the polymer is known as a repeat unit or monomer residue. Laboratory synthetic methods are divided into two categories, step-growth polymerization and chain-growth polymerization; the essential difference between the two is that in chain growth polymerization, monomers are added to the chain one at a time only, such as in polyethylene, whereas in step-growth polymerization chains of monomers may combine with one another directly, such as in polyester. Newer methods, such as plasma polymerization do not fit neatly into either category. Synthetic polymerization reactions may be carried out without a catalyst. Laboratory synthesis of biopolymers of proteins, is an area of intensive research. There are three main classes of biopolymers: polysaccharides and polynucleotides.
In living cells, they may be synthesized by enzyme-mediated processes, such as the formation of DNA catalyzed by DNA polymerase. The synthesis of proteins involves multiple enzyme-mediated processes to transcribe genetic information from the DNA to RNA and subsequently translate that information to synthesize the specified protein from amino acids; the protein may be modified further following translation in order to provide appropriate structure and functioning. There are other biopolymers such as rubber, suberin and lignin. Occurring polymers such as cotton and rubber were familiar materials for years before synthetic polymers such as polyethene and perspex appeared on the market. Many commercially important polymers are synthesized by chemical modification of occurring polymers. Prominent examples inclu
The Bundeswehr is the unified armed forces of Germany and their civil administration and procurement authorities. The States of Germany are not allowed to maintain armed forces of their own, since the German Constitution states that matters of defense fall into the sole responsibility of the federal government; the Bundeswehr is divided into a military part and a civil part with the armed forces administration. The military part of the federal defense force consists of the German Army, the German Navy, the German Air Force, the Joint Support Service, the Joint Medical Service, the Cyber and Information Space Command; as of 28 February 2019, the Bundeswehr has a strength of 182,055 active soldiers, placing it among the 30 largest military forces in the world and making it the second largest in the European Union behind France in terms of personnel. In addition the Bundeswehr has 28,250 reserve personnel. With German military expenditures at €43.2 billion, the Bundeswehr is among the top ten best-funded forces in the world if in terms of share of German GDP, military expenditures remain average at 1.23% and below the NATO target of 2%.
Germany aims to expand the Bundeswehr to around 203,000 soldiers by 2025 to better cope with increasing responsibilities. The name Bundeswehr was first proposed by the former Wehrmacht general and Liberal politician Hasso von Manteuffel; the Iron Cross is its official emblem. It is a symbol; the Schwarzes Kreuz is derived from the black cross insignia of the medieval Teutonic knights. When the Bundeswehr was established in 1955, its founding principles were based on developing a new military force for the defence of West Germany. In this respect the Bundeswehr did not consider itself to be a successor to either the Reichswehr of the Weimar Republic or Hitler's Wehrmacht. Neither does it adhere to the traditions of any former German military organization, its official ethos is based on three major themes: the aims of the military reformers at the beginning of the 19th century such as Scharnhorst and Clausewitz the conduct displayed by members of the military resistance against Adolf Hitler the attempt of Claus von Stauffenberg and Henning von Tresckow to assassinate him.
Its own tradition since 1955. One of the most visible traditions of the modern Bundeswehr is the Großer Zapfenstreich; the FRG reinstated this formal military ceremony in 1952, three years before the foundation of the Bundeswehr. Today it is performed by a military band with 4 fanfare trumpeters and timpani, a corps of drums, up to two escort companies of the Bundeswehr's Wachbataillon and Torchbearers; the Zapfenstreich is only performed during solemn public commemorations. It can honour distinguished persons present such as the German federal president or provide the conclusion to large military exercises. Another important tradition in the modern German armed forces is the Gelöbnis. There are two kinds of oath: for conscripts/recruits it is a pledge but it's a solemn vow for full-time personnel; the pledge is made annually on 20 July, the date on which a group of Wehrmacht officers attempted to assassinate Adolf Hitler in 1944. Recruits from the Bundeswehr's Wachbataillon make their vow at the Bendlerblock in Berlin.
This was the headquarters of the resistance but where the officers were summarily executed following its failure. National commemorations are held nearby within the grounds of the Reichstag. Similar events take place across the German Republic. Since 2011, the wording of the ceremonial vow for full-time recruits and volunteer personnel is: "Ich gelobe, der Bundesrepublik Deutschland treu zu dienen und das Recht und die Freiheit des deutschen Volkes tapfer zu verteidigen." "I pledge to serve the Federal Republic of Germany loyally and to defend the right and the freedom of the German people bravely."Serving Bundeswehr personnel replace "Ich gelobe..." with "Ich schwöre...". After World War II the responsibility for the security of Germany as a whole rested with the four Allied Powers: the United States, the United Kingdom and the Soviet Union. Germany had been without armed forces since the Wehrmacht was dissolved following World War II; when the Federal Republic of Germany was founded in 1949, it was without a military.
Germany remained demilitarized and any plans for a German military were forbidden by Allied regulations. Only some naval mine-sweeping units continued to exist, but they remained unarmed and under Allied control and did not serve as a national defence force; the Federal Border Protection Force, a mobile armed police force of 10,000 men, was only formed in 1951. A proposal to integrate West German troops with soldiers of France, the Netherlands and Italy in a European Defence Community was proposed but never implemented. There was a discussion among the United States, the United Kingdom and France over the issue of a revived German military. In particular, France was reluctant to allow Germany to rearm in light of recent history (Germany had invaded France twice in living memory, in World War I and World War II, defeated France in the Franco-German War of 1870/71.