Order of Saint Stanislaus (House of Romanov)
The Order of Saint Stanislaus spelled Stanislas, is a Russian dynastic order of knighthood founded as Order of the Knights of Saint Stanislaus and Martyr in 1765 by King Stanisław II Augustus of the Polish-Lithuanian Commonwealth. In 1831 after the downfall of the November Uprising, the order was incorporated into the Chapter of Russian Orders as part of the honours system of the Russian Empire by Emperor Nicholas I of Russia. In 1839, the Russian Order of Saint Stanislaus received new statutes, including granting status of nobility on its recipients in all three classes; as a result of the Russian Revolution 1917, activities were suspended by the Soviet Union, although it has since been awarded by the head of the Imperial House of Romanov as a dynastic order. When in 1918 Poland regained its independence as the Second Polish Republic, a Polish order was introduced as a successor to the Polish Order of Saint Stanislaus, the Order of Polonia Restituta. However, the Order of Saint Stanislas continued to be awarded after the revolution by Grand Duke Kirill Vladimirovich, Grand Duke Vladimir Kirillovich, Grand Duchess Maria Vladimirovna.
It has been approved for wear with military uniform by the Russian Federation. Stanislaus II Augustus Poniatowski, King of Poland established the Order of the Knights of Saint Stanislaus and Martyr on May 7, 1765 to honour the service to the King. After the partition of Poland it was renewed in the Duchy of Warsaw in 1807. Since 1815 in the Polish Kingdom, the order in a single class, was retained and divided into four classes; when in 1918 Poland regained its independence as the Second Polish Republic, a Polish order was introduced as an alleged successor to the Polish Order of Saint Stanislaus, the Order of Polonia Restituta. In 1831 after the downfall of the November Uprising, the order was added to the honours system of the Russian Empire in 1832, where it remained until 1917, included in the Chapter of Russian Orders. In 1832 the image of Saint Stanislaus was removed, replacing it with the cypher "SS"; the single-headed eagle on the Polish order's cross was replaced with the double-headed eagle of the Russian Empire.
All administration and management of the imperial and royal order were transferred from Warsaw to St. Petersburg. In 1839 Nicholas I issued a new statute for the order, according to which it was divided into three degrees, was awarded to "any subject of the Russian Empire and the Kingdom of Poland" for military and civilian distinction, or for private services such as charity and philanthropy; the Second Class insignia of the Order was divided into two types: a cross decorated with the imperial crown, the cross without the crown. In 1844, it was decreed that when the order was granted to non-Christians, the cypher of St. Stanislaus was replaced by a black double-headed Imperial Russian eagle; the Order of Sant Stanislaus 3rd degree became the junior most award in the order of precedence of Russian orders and was the most common reward. It was awarded to all military and government employees as well as civilians who served the empire with a blameless record, who has status in the Russian table of ranks.
At the time of the establishment of the Order, the award of every class provided the right of hereditary noble status, but there was discontent among the nobility that too many new nobles were being created from the ranks of merchants and civil employees, so in 1845 the highest command suspended the awarding of the 2nd and 3rd class. Awarding resumed on 28 June 1855, but from this date the right of hereditary nobility was awarded only with the 1st class of the Order of Saint Stanislaus. In 1855 the symbol of crossed swords was added to Military awards of the order. In 1874 the Chapter of Orders canceled the awarding of the symbol of the imperial crown, but any such orders awarded retained the right to wear them with the crown. After the February Revolution, the order was not canceled; the Provisional Government of Russia arguably usurped the Order of Saint Stanislaus, changing its appearance: the imperial eagles were changed to crown less republican eagles. However, after 1917, the order was not awarded in Soviet Russia in any form.
Both Grand Duke Kirill Vladimirovich, Grand Duke of Russia and his successor Grand Duke Vladimir Kirillovich of Russia awarded the Order of Saint Andrew, which automatically awards the recipient membership First class in all the lower Orders, including the Order of Saint Stanislaus. Furthermore, Grand Duke Vladimir Kirillovich of Russia awarded the order independently at least once, in 1973; as a result, the Order of Saint Stanislaus is considered to have been awarded continually by the legitimist pretender to the Russian throne since 1917. Present fount of honour is Maria Vladimirovna, Grand Duchess of Russia, preeminent pretender to the Russian throne. Active in exile after the revolution, in recent years it has enjoyed degrees of recognition by some prominent Russian institutions, as well as full recognition by the International Commission on Orders of Chivalry and others; the heads of the Russian Imperial House in exile have continued to award Imperial and Royal Order of Saint Stanislaus.
H. I. H. Grand Duchess Maria Vladimirovna, pretender to the Russian throne, head of the Russian Imperial House, continues to award the Russian Imperial Order of Saint Stanislaus as a dynastic order of knighthood; these actions are disputed by some other members of the Romanov Family. Knights of the Order of Saint Stanislaus are granted nobility in every class if they do not posses
Radio is the technology of signalling or communicating using radio waves. Radio waves are electromagnetic waves of frequency between 300 gigahertz, they are generated by an electronic device called a transmitter connected to an antenna which radiates the waves, received by a radio receiver connected to another antenna. Radio is widely used in modern technology, in radio communication, radio navigation, remote control, remote sensing and other applications. In radio communication, used in radio and television broadcasting, cell phones, two-way radios, wireless networking and satellite communication among numerous other uses, radio waves are used to carry information across space from a transmitter to a receiver, by modulating the radio signal in the transmitter. In radar, used to locate and track objects like aircraft, ships and missiles, a beam of radio waves emitted by a radar transmitter reflects off the target object, the reflected waves reveal the object's location. In radio navigation systems such as GPS and VOR, a mobile receiver receives radio signals from navigational radio beacons whose position is known, by measuring the arrival time of the radio waves the receiver can calculate its position on Earth.
In wireless remote control devices like drones, garage door openers, keyless entry systems, radio signals transmitted from a controller device control the actions of a remote device. Applications of radio waves which do not involve transmitting the waves significant distances, such as RF heating used in industrial processes and microwave ovens, medical uses such as diathermy and MRI machines, are not called radio; the noun radio is used to mean a broadcast radio receiver. Radio waves were first identified and studied by German physicist Heinrich Hertz in 1886; the first practical radio transmitters and receivers were developed around 1895-6 by Italian Guglielmo Marconi, radio began to be used commercially around 1900. To prevent interference between users, the emission of radio waves is regulated by law, coordinated by an international body called the International Telecommunications Union, which allocates frequency bands in the radio spectrum for different uses. Radio waves are radiated by electric charges undergoing acceleration.
They are generated artificially by time varying electric currents, consisting of electrons flowing back and forth in a metal conductor called an antenna. In transmission, a transmitter generates an alternating current of radio frequency, applied to an antenna; the antenna radiates the power in the current as radio waves. When the waves strike the antenna of a radio receiver, they push the electrons in the metal back and forth, inducing a tiny alternating current; the radio receiver connected to the receiving antenna detects this oscillating current and amplifies it. As they travel further from the transmitting antenna, radio waves spread out so their signal strength decreases, so radio transmissions can only be received within a limited range of the transmitter, the distance depending on the transmitter power, antenna radiation pattern, receiver sensitivity, noise level, presence of obstructions between transmitter and receiver. An omnidirectional antenna transmits or receives radio waves in all directions, while a directional antenna or high gain antenna transmits radio waves in a beam in a particular direction, or receives waves from only one direction.
Radio waves travel through a vacuum at the speed of light, in air at close to the speed of light, so the wavelength of a radio wave, the distance in meters between adjacent crests of the wave, is inversely proportional to its frequency. In radio communication systems, information is carried across space using radio waves. At the sending end, the information to be sent is converted by some type of transducer to a time-varying electrical signal called the modulation signal; the modulation signal may be an audio signal representing sound from a microphone, a video signal representing moving images from a video camera, or a digital signal consisting of a sequence of bits representing binary data from a computer. The modulation signal is applied to a radio transmitter. In the transmitter, an electronic oscillator generates an alternating current oscillating at a radio frequency, called the carrier wave because it serves to "carry" the information through the air; the information signal is used to modulate the carrier, varying some aspect of the carrier wave, impressing the information on the carrier.
Different radio systems use different modulation methods: AM - in an AM transmitter, the amplitude of the radio carrier wave is varied by the modulation signal. FM - in an FM transmitter, the frequency of the radio carrier wave is varied by the modulation signal. FSK - used in wireless digital devices to transmit digital signals, the frequency of the carrier wave is shifted periodically between two frequencies that represent the two binary digits, 0 and 1, to transmit a sequence of bits. OFDM - a family of complicated digital modulation methods widely used in high bandwidth systems such as WiFi networks, digital television broadcasting, digital audio broadcasting to transmit digital data using a minimum of radio spectrum bandwidth. OFDM has higher spectral efficiency and more resistance to fading than AM or FM. Multiple radio carrier waves spaced in frequency are transmitted within the radio channel, with each carrier modulated with bits from the incoming bitstream
A relay is an electrically operated switch. Many relays use an electromagnet to mechanically operate a switch, but other operating principles are used, such as solid-state relays. Relays are used where it is necessary to control a circuit by a separate low-power signal, or where several circuits must be controlled by one signal; the first relays were used in long distance telegraph circuits as amplifiers: they repeated the signal coming in from one circuit and re-transmitted it on another circuit. Relays were used extensively in telephone exchanges and early computers to perform logical operations. A type of relay that can handle the high power required to directly control an electric motor or other loads is called a contactor. Solid-state relays control power circuits with no moving parts, instead using a semiconductor device to perform switching. Relays with calibrated operating characteristics and sometimes multiple operating coils are used to protect electrical circuits from overload or faults.
Magnetic latching relays require one pulse of coil power to move their contacts in one direction, another, redirected pulse to move them back. Repeated pulses from the same input have no effect. Magnetic latching relays are useful in applications where interrupted power should not affect the circuits that the relay is controlling. Magnetic latching relays can have either dual coils. On a single coil device, the relay will operate in one direction when power is applied with one polarity, will reset when the polarity is reversed. On a dual coil device, when polarized voltage is applied to the reset coil the contacts will transition. AC controlled magnetic latch relays have single coils that employ steering diodes to differentiate between operate and reset commands, it was used in long distance telegraph circuits, repeating the signal coming in from one circuit and re-transmitting it to another. In 1809 Samuel Thomas von Sömmerring designed an electrolytic relay as part of his electrochemical telegraph.
American scientist Joseph Henry is claimed to have invented a relay in 1835 in order to improve his version of the electrical telegraph, developed earlier in 1831. It is claimed that English inventor Edward Davy "certainly invented the electric relay" in his electric telegraph c.1835. A simple device, now called a relay, was included in the original 1840 telegraph patent of Samuel Morse; the mechanism described acted as a digital amplifier, repeating the telegraph signal, thus allowing signals to be propagated as far as desired. The word relay appears in the context of electromagnetic operations from 1860. A simple electromagnetic relay consists of a coil of wire wrapped around a soft iron core, an iron yoke which provides a low reluctance path for magnetic flux, a movable iron armature, one or more sets of contacts; the armature is mechanically linked to one or more sets of moving contacts. The armature is held in place by a spring so that when the relay is de-energized there is an air gap in the magnetic circuit.
In this condition, one of the two sets of contacts in the relay pictured is closed, the other set is open. Other relays may have fewer sets of contacts depending on their function; the relay in the picture has a wire connecting the armature to the yoke. This ensures continuity of the circuit between the moving contacts on the armature, the circuit track on the printed circuit board via the yoke, soldered to the PCB; when an electric current is passed through the coil it generates a magnetic field that activates the armature, the consequent movement of the movable contact either makes or breaks a connection with a fixed contact. If the set of contacts was closed when the relay was de-energized the movement opens the contacts and breaks the connection, vice versa if the contacts were open; when the current to the coil is switched off, the armature is returned by a force half as strong as the magnetic force, to its relaxed position. This force is provided by a spring, but gravity is used in industrial motor starters.
Most relays are manufactured to operate quickly. In a low-voltage application this reduces noise; when the coil is energized with direct current, a diode is placed across the coil to dissipate the energy from the collapsing magnetic field at deactivation, which would otherwise generate a voltage spike dangerous to semiconductor circuit components. Such diodes were not used before the application of transistors as relay drivers, but soon became ubiquitous as early germanium transistors were destroyed by this surge; some automotive relays include a diode inside the relay case. If the relay is driving a large, or a reactive load, there may be a similar problem of surge currents around the relay output contacts. In this case a snubber circuit across the contacts may absorb the surge. Suitably rated capacitors and the associated resistor are sold as a single packaged component for this commonplace use. If the coil is designed to be energized with alternating current, some method is used to split the flux into two out-of-phase components which add together, increasing the minimum pull on the armature during the AC cycle.
This is done with a small copper "shading ring" crimped around a portion of the core that creates the delayed, out-of-phase component, which holds the contacts during the zero crossings of the control voltage. Contact materials for relays vary by application. Mate
Saint Petersburg State University
Saint Petersburg State University is a Russian federal state-owned higher education institution based in Saint Petersburg. It is one of the largest universities in Russia. Founded in 1724 by a decree of Peter the Great, the University from the beginning has had a strong focus on fundamental research in science and humanities, equipped its graduates with what it takes to contribute to Russia’s success, it is made up of 24 specialized faculties and institutes,the Academic Gymnasium, the Medical College, the College of Physical culture and Sports and Technology. The university has the other in Peterhof. During the Soviet period, it was known as Leningrad State University, it was named after Andrei Zhdanov in 1948. Saint Petersburg State University is the second best multi-faculty university in Russia after Moscow State University. In international rankings, the university was ranked 240th in 2013/2014, by the QS World University Rankings, it was placed 351–400th by the Times Higher Education World University Rankings and 301–400th by the Academic Ranking of World Universities outperforming the rest of universities in Russia excluding Moscow State University.
The university has a reputation for having educated the majority of Russia's political elite. The university is Russia's oldest university, founded in 1724 by Peter the Great, which predates the foundation of Moscow State University in 1755. Saint Petersburg state university is included in all ratings and lists of the best universities in the world and is one of the leaders in all indicators in Russia; the university was the first from Russian universities to join The Coimbra Group, it now represents Russia. It is disputed by the university administration whether Saint Petersburg State University or Moscow State University is the oldest higher education institution in Russia. While the latter was established in 1755, the former, in continuous operation since 1819, claims to be the successor of the university established along with the Academic Gymnasium and the Saint Petersburg Academy of Sciences on January 24, 1724, by a decree of Peter the Great. In the period between 1804 and 1819, Saint Petersburg University did not exist.
The Petersburg Pedagogical Institute, renamed the Main Pedagogical Institute in 1814, was established in 1804 and occupied a part of the Twelve Collegia building. On February 8, 1819, Alexander I of Russia reorganized the Main Pedagogical Institute into Saint Petersburg University, which at that time consisted of three faculties: Faculty of Philosophy and Law, Faculty of History and Philology and Faculty of Physics and Mathematics; the Main Pedagogical Institute was restored in 1828 as an educational institution independent of Saint Petersburg University, trained teachers until it was closed in 1859. In 1821, the university was renamed Saint Petersburg Imperial University. In 1823, most of the university moved from the Twelve Collegia to the southern part of the city beyond the Fontanka. In 1824, a modified version of the charter of Moscow University was adopted as the first charter of the Saint Petersburg Imperial University. In 1829, there were 19 full 169 full-time and part-time students at the university.
In 1830, Tsar Nicholas returned the entire building of the Twelve Collegia back to the university, courses resumed there. In 1835, a new Charter of the Imperial Universities of Russia was approved, it provided for the establishment of the Faculty of Law, the Faculty of History and Philology, the Faculties of Physics and Mathematics, which were merged into the Faculty of Philosophy as the 1st and 2nd Departments, respectively. In 1849, after the Spring of Nations, the Senate of the Russian Empire decreed that the Rector should be appointed by the Minister of National Enlightenment rather than elected by the Assembly of the university. However, Pyotr Pletnyov was reappointed Rector and became the longest-serving rector of Saint Petersburg University. In 1855, Oriental studies were separated from the Faculty of History and Philology, the fourth faculty, Faculty of Oriental Languages, was formally inaugurated on August 27, 1855. In 1859–1861, female part-time students could attend lectures in the university.
In 1861, there were 1,270 full-time and 167 part-time students in the university, of them 498 were in the Faculty of Law, the largest subdivision. But this subdivision had the cameral studies department, where students learnt safety, occupational health and environmental engineering management and science, including chemistry, agronomy along with law and philosophy. Many Russian, Georgian etc. managers and scientists studied at the Faculty of law therefore. During 1861–1862, there was student unrest in the university, it was temporarily closed twice during the year; the students were denied freedom of assembly and placed under police surveillance, public lectures were forbidden. Many students were expelled. After the unrest, in 1865, only 524 students remained. A decree of the Emperor Alexander II of Russia adopted on February 18, 1863, restored the right of the university assembly to elect the rector, it formed the new faculty of the theory and history of art as part of the faculty of
The coherer was a primitive form of radio signal detector used in the first radio receivers during the wireless telegraphy era at the beginning of the 20th century. Its use in radio was based on the 1890 findings of French physicist Edouard Branly and adapted by other physicists and inventors over the next ten years; the device consists of a tube or capsule containing two electrodes spaced a small distance apart with loose metal filings in the space between. When a radio frequency signal is applied to the device, the metal particles would cling together or "cohere", reducing the initial high resistance of the device, thereby allowing a much greater direct current to flow through it. In a receiver, the current would activate a bell, or a Morse paper tape recorder to make a record of the received signal; the metal filings in the coherer remained conductive after the signal ended so that the coherer had to be "decohered" by tapping it with a clapper actuated by an electromagnet, each time a signal was received, thereby restoring the coherer to its original state.
Coherers remained in widespread use until about 1907, when they were replaced by more sensitive electrolytic and crystal detectors. The behavior of particles or metal filings in the presence of electricity or electric sparks was noticed in many experiments well before Edouard Branly's 1890 paper and before there was proof of the theory of electromagnetism. In 1835 Swedish scientist Peter Samuel Munk noticed a change of resistance in a mixture of metal filings in the presence of spark discharge from a Leyden jar. In 1850 Pierre Guitard found that when dusty air was electrified, the particles would tend to collect in the form of strings; the idea that particles could react to electricity was used in English engineer Samuel Alfred Varley's 1866 lightning bridge, a lightning arrester attached to telegraph lines consisting of a piece of wood with two metal spikes extending into a chamber. The space was filled with powdered carbon that would not allow the low voltage telegraph signals to pass through but it would conduct and ground a high voltage lightning strike.
In 1879 the Welsh scientist David Edward Hughes found that loose contacts between a carbon rod and two carbon blocks as well as the metallic granules in a microphone he was developing responded to sparks generated in a nearby apparatus. Temistocle Calzecchi-Onesti in Italy began studying the anomalous change in the resistance of thin metallic films and metal particles at Fermo/Monterubbiano, he found that copper filings between two brass plates would cling together, becoming conductive, when he applied a voltage to them. He found that other types of metal filings would have the same reaction to electric sparks occurring at a distance, a phenomenon that he thought could be used for detecting lightning strikes. Calzecchi-Onesti's papers were published in il Nuovo Cimento in 1884, 1885 and 1886. In 1890, French physicist Edouard Branly published On the Changes in Resistance of Bodies under Different Electrical Conditions in a French Journal where he described his thorough investigation of the effect of minute electrical charges on metal and many types of metal filings.
In one type of circuit, filings were placed in a tube of glass or ebonite, held between two metal plates. When an electric discharge was produced in the neighbourhood of the circuit, a large deviation was seen on the attached galvanometer needle, he noted the filings in the tube would react to the electric discharge when the tube was placed in another room 20 yards away. Branly went on to devise many types of these devices based on "imperfect" metal contacts. Branly's filings tube came to light in 1892 in Great Britain when it was described by Dr. Dawson Turner at a meeting of the British Association in Edinburgh; the Scottish electrical engineer and astronomer George Forbes suggested that Branly's filings tube might be reacting in the presence of Hertzian waves, a type of air-borne electromagnetic radiation proven to exist by German physicist Heinrich Hertz. In 1893 physicist W. B. Croft exhibited Branly's experiments at a meeting of the Physical Society in London, it was unclear to Croft and others whether the filings in the Branly tube were reacting to sparks or the light from the sparks.
George Minchin noticed the Branly tube might be reacting to Hertzian waves the same way his solar cell did and wrote the paper "The Action of Electromagnetic Radiation on Films containing Metallic Powders". These papers were read by English physicist Oliver Lodge who saw this as a way to build a much improved Hertzian wave detector. On 1 June 1894, a few months after the death of Heinrich Hertz, Oliver Lodge delivered a memorial lecture on Hertz where he demonstrated the properties of "Hertzian waves", including transmitting them over a short distance, using an improved version of Branly's filings tube, which Lodge had named the "coherer", as a detector. In May 1895, after reading about Lodge's demonstrations, the Russian physicist Alexander Popov built a "Hertzian wave" based lightning detector using a coherer; that same year, Italian inventor Guglielmo Marconi demonstrated a wireless telegraphy system using Hertzian waves, based on a coherer. The coherer was replaced in receivers by the simpler and more sensitive electrolytic and crystal detectors around 1907, became obsolete.
One minor use of the coherer in modern times was by Japanese tin-plate toy manufacturer Matsudaya Toy Co. who beginning 1957 used a spark-gap transmitter and coherer-based receiver in a range of radio-controlled toys, called Radicon toys. Several different types using the same RC system were commercially sold, including a Radicon Boat, Radicon Oldsmobile Car and a Radicon Bus. Unlike modern AM
A monopole antenna is a class of radio antenna consisting of a straight rod-shaped conductor mounted perpendicularly over some type of conductive surface, called a ground plane. The driving signal from the transmitter is applied, or for receiving antennas the output signal to the receiver is taken, between the lower end of the monopole and the ground plane. One side of the antenna feedline is attached to the lower end of the monopole, the other side is attached to the ground plane, the Earth; this contrasts with a dipole antenna which consists of two identical rod conductors, with the signal from the transmitter applied between the two halves of the antenna. The monopole is a resonant antenna. Therefore, the length of the antenna is determined by the wavelength of the radio waves it is used with; the most common form is the quarter-wave monopole, in which the antenna is one quarter of the wavelength of the radio waves. The monopole antenna was invented in 1895 by radio pioneer Guglielmo Marconi.
Common types of monopole antenna are the whip, rubber ducky, random wire, inverted-L and T-antenna, inverted-F, mast radiator, ground plane antennas. The load impedance of the quarter-wave monopole is half that of the dipole antenna or 37.5+j21.25 ohms. The monopole antenna was invented in 1895 and patented 1896 by radio pioneer Guglielmo Marconi during his historic first experiments in radio communication, he began by using dipole antennas invented by Heinrich Hertz consisting of two identical horizontal wires ending in metal plates. He found by experiment that if instead of the dipole, one side of the transmitter and receiver was connected to a wire suspended overhead, the other side was connected to the Earth, he could transmit for longer distances. For this reason the monopole is called a Marconi antenna, although Alexander Popov independently invented it at about the same time. Like a dipole antenna, a monopole has an omnidirectional radiation pattern: it radiates with equal power in all azimuthal directions perpendicular to the antenna.
However, the radiated power varies with elevation angle, with the radiation dropping off to zero at the zenith of the antenna axis. It radiates vertically polarized radio waves. A monopole can be visualized as being formed by replacing the bottom half of a vertical dipole antenna with a conducting plane at right-angles to the remaining half. If the ground plane is large enough, the radio waves from the remaining upper half of the dipole reflected from the ground plane will seem to come from an image antenna forming the missing half of the dipole, which adds to the direct radiation to form a dipole radiation pattern. So the pattern of a monopole with a conducting, infinite ground plane is identical to the top half of a dipole pattern, with its maximum radiation in the horizontal direction, perpendicular to the antenna; because it radiates only into the space above the ground plane, or half the space of a dipole antenna, a monopole antenna will have a gain of twice the gain of a similar dipole antenna, a radiation resistance half that of a dipole.
Since a half-wave dipole has a gain of 2.19 dBi and a radiation resistance of 73 ohms, a quarter-wave monopole, the most common type, will have a gain of 2.19 + 3 = 5.19 dBi and a radiation resistance of about 36.8 ohms if it is mounted above a good ground plane. The general effect of electrically small ground planes, as well as imperfectly conducting earth grounds, is to tilt the direction of maximum radiation up to higher elevation angles; the ground plane used with a monopole may be the actual earth. This design is used for the mast radiator antennas employed in radio broadcasting at low frequencies, as well as other low frequency antennas such as the T-antenna and umbrella antenna. At VHF and UHF frequencies the size of the ground plane needed is smaller, so artificial ground planes are used to allow the antenna to be mounted above the ground. A common type of monopole antenna at these frequencies consists of a quarter-wave whip antenna with a ground plane consisting of several wires or rods radiating horizontally or diagonally from its base.
At gigahertz frequencies the metal surface of a car roof or airplane body makes a good ground plane, so car cell phone antennas consist of short whips mounted on the roof, aircraft communication antennas consist of a short conductor in an aerodynamic fairing projecting from the fuselage. The most common antenna used in mobile phones is the inverted-F antenna, a variant of the inverted-L monopole. Bending over the antenna saves space and keeps the it within the bounds of the mobile's case but the antenna has a low impedance. To improve the match the antenna is not fed from the end, rather some intermediate point, the end is grounded instead; the quarter-wave whip and rubber ducky antennas used with handheld radios such as walkie-talkies and cell phones are monopole antennas. These don't use a ground plane, the ground side of the transmitter is just connected to the ground connection on its circuit board; the hand and body of the person holding them may function as a rudimentary ground plane. Sometimes, monopole antennas are printed on a dielectric substrate to make it less fragile and they may be fabricated using the printed circuit board technologies.
Such antennas are
A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists are interested in the root or ultimate causes of phenomena, frame their understanding in mathematical terms. Physicists work across a wide range of research fields, spanning all length scales: from sub-atomic and particle physics, through biological physics, to cosmological length scales encompassing the universe as a whole; the field includes two types of physicists: experimental physicists who specialize in the observation of physical phenomena and the analysis of experiments, theoretical physicists who specialize in mathematical modeling of physical systems to rationalize and predict natural phenomena. Physicists can apply their knowledge towards solving practical problems or to developing new technologies; the study and practice of physics is based on an intellectual ladder of discoveries and insights from ancient times to the present.
Many mathematical and physical ideas used today found their earliest expression in ancient Greek culture, for example in the work of Euclid, Thales of Miletus and Aristarchus. Roots emerged in ancient Asian culture and in the Islamic medieval period, for example the work of Alhazen in the 11th century; the modern scientific worldview and the bulk of physics education can be said to flow from the scientific revolution in Europe, starting with the work of Galileo Galilei and Johannes Kepler in the early 1600s. Newton's laws of motion and Newton's law of universal gravitation were formulated in the 17th century; the experimental discoveries of Faraday and the theory of Maxwell's equations of electromagnetism were developmental high points during the 19th century. Many physicists contributed to the development of quantum mechanics in the early-to-mid 20th century. New knowledge in the early 21st century includes a large increase in understanding physical cosmology; the broad and general study of nature, natural philosophy, was divided into several fields in the 19th century, when the concept of "science" received its modern shape.
Specific categories emerged, such as "biology" and "biologist", "physics" and "physicist", "chemistry" and "chemist", among other technical fields and titles. The term physicist was coined by William Whewell in his 1840 book The Philosophy of the Inductive Sciences. A standard undergraduate physics curriculum consists of classical mechanics and magnetism, non-relativistic quantum mechanics, statistical mechanics and thermodynamics, laboratory experience. Physics students need training in mathematics, in computer science. Any physics-oriented career position requires at least an undergraduate degree in physics or applied physics, while career options widen with a Master's degree like MSc, MPhil, MPhys or MSci. For research-oriented careers, students work toward a doctoral degree specializing in a particular field. Fields of specialization include experimental and theoretical astrophysics, atomic physics, biological physics, chemical physics, condensed matter physics, geophysics, gravitational physics, material science, medical physics, molecular physics, nuclear physics, radiophysics, electromagnetic field and microwave physics, particle physics, plasma physics.
The highest honor awarded to physicists is the Nobel Prize in Physics, awarded since 1901 by the Royal Swedish Academy of Sciences. National physics professional societies have many awards for professional recognition. In the case of the American Physical Society, as of 2017, there are 33 separate prizes and 38 separate awards in the field; the three major employers of career physicists are academic institutions and private industries, with the largest employer being the last. Physicists in academia or government labs tend to have titles such as Assistants, Professors, Sr./Jr. Scientist, or postdocs; as per the American Institute of Physics, some 20% of new physics Ph. D.s holds jobs in engineering development programs, while 14% turn to computer software and about 11% are in business/education. A majority of physicists employed apply their skills and training to interdisciplinary sectors. Job titles for graduate physicists include Agricultural Scientist, Air Traffic Controller, Computer Programmer, Electrical Engineer, Environmental Analyst, Medical Physicist, Oceanographer, Physics Teacher/Professor/Researcher, Research Scientist, Reactor Physicist, Engineering Physicist, Satellite Missions Analyst, Science Writer, Software Engineer, Systems Engineer, Microelectronics Engineer, Radar Developer, Technical Consultant, etc.
A majority of Physics terminal bachelor's degree holders are employed in the private sector. Other fields are academia and military service, nonprofit entities and teaching. Typical duties of physicists with master's and doctoral degrees working in their domain involve research and analysis, data preparation, instrumentation and development of industrial or medical equipment and software development, etc. Chartered Physicist is a chartered status and a professional qualification awarded by the Institute of Physics, it is denoted by the postnominals "CPhys". Achieving chartered status in any profession denotes to the wider community a high level of specialised subject knowledge and professional competence. According to the Institute of Physics, holders of the award of the Chartered Physicist demonst