Solder is a fusible metal alloy used to create a permanent bond between metal workpieces. The word solder comes from the Middle English word soudur, via Old French solduree and soulder, from the Latin solidare, meaning "to make solid". In fact, solder must first be melted in order to adhere to and connect the pieces together after cooling, which requires that an alloy suitable for use as solder have a lower melting point than the pieces being joined; the solder should be resistant to oxidative and corrosive effects that would degrade the joint over time. Solder used in making electrical connections needs to have favorable electrical characteristics. Soft solder has a melting point range of 90 to 450 °C, is used in electronics and sheet metal work. Alloys that melt between 180 and 190 °C are the most used. Soldering performed using alloys with a melting point above 450 °C is called "hard soldering", "silver soldering", or brazing. In specific proportions, some alloys are eutectic — that is, the alloy's melting point is the lowest possible for a mixture of those components.
Eutectic alloys have markedly different solidus and liquidus temperatures, having a distinct liquid and solid transition. Non-eutectic mixtures exist as a paste of solid particles in a melt of the lower-melting phase as they approach high enough temperatures. In electrical work, if the joint is disturbed while in this "pasty" state before it full solidified, a poor electrical connection may result; the pasty state of a non-eutectic solder can be exploited in plumbing, as it allows molding of the solder during cooling, e.g. for ensuring watertight joint of pipes, resulting in a so-called "wiped joint". For electrical and electronics work, solder wire is available in a range of thicknesses for hand-soldering, with cores containing flux, it is available as a room temperature paste, as a preformed foil shaped to match the workpiece which may be more suited for mechanized mass-production, or in small "tabs" that can be wrapped around the joint and melted with a flame when where an iron isn't usable or available as for instance in field repairs.
Alloys of lead and tin were used in the past and are still available. Lead-free solders have been increasing in use due to regulatory requirements plus the health and environmental benefits of avoiding lead-based electronic components, they are exclusively used today in consumer electronics. Plumbers use bars of solder, much thicker than the wire used for electrical applications and apply flux separately. Jewelers use solder in thin sheets, which they cut into snippets; the European Union Waste Electrical and Electronic Equipment Directive and Restriction of Hazardous Substances Directive were adopted in early 2003 and came into effect on July 1, 2006, restricting the inclusion of lead in most consumer electronics sold in the EU, having a broad effect on consumer electronics sold worldwide. In the US, manufacturers may receive tax benefits by reducing the use of lead-based solder. Lead-free solders in commercial use may contain tin, silver, indium, zinc and traces of other metals. Most lead-free replacements for conventional 60/40 and 63/37 Sn-Pb solder have melting points from 50 to 200 °C higher, though there are solders with much lower melting points.
Lead-free solder requires around 2% flux by mass for adequate wetting ability. When lead-free solder is used in wave soldering, a modified solder pot may be desirable to reduce maintenance cost due to increased tin-scavenging of high-tin solder. Lead-free solder may be less desirable for critical applications, such as aerospace and medical projects, because its properties are less known. Tin-silver-copper solders are used by two-thirds of Japanese manufacturers for reflow and wave soldering, by about 75% of companies for hand soldering; the widespread use of this popular lead-free solder alloy family is based on the reduced melting point of the Sn-Ag-Cu ternary eutectic behavior, below the 22/78 Sn-Ag eutectic of 221 °C and the 59/41 Sn-Cu eutectic of 227 °C. The ternary eutectic behavior of Sn-Ag-Cu and its application for electronics assembly was discovered by a team of researchers from Ames Laboratory, Iowa State University, from Sandia National Laboratories-Albuquerque. Much recent research has focused on the addition of a fourth element to Sn-Ag-Cu solder, in order to provide compatibility for the reduced cooling rate of solder sphere reflow for assembly of ball grid arrays.
Examples of these four-element compositions are 18/64/14/4 tin-silver-copper-zinc and 18/64/16/2 tin-silver-copper-manganese. Tin-based solders dissolve gold, forming brittle intermetallic joins. Indium-rich solders are more suitable for soldering thicker gold layer as the dissolution rate of gold in indium is much slower. Tin-rich solders readily dissolve silver. If the soldering time i
Gillian Bennett is a British historian and civil servant the Chief Historian of the Foreign and Commonwealth Office between 1995 and 2005. After graduating from Somerville College, University of Oxford in 1969, Bennett began her career in the Foreign Office in 1972 as a research assistant in what was called the Historical Branch, she held a number of roles within the wider FCO, in 1995 was appointed to the newly-created position of Chief Historian. In this role, she edited the documentary history of British foreign policy since 1945, Documents on British Policy Overseas, give historical advice to ministers and officials. In 1998, FCO historians were commissioned by Foreign Secretary Robin Cook to investigate the authenticity of the Zinoviev Letter, Bennett authored the report of their findings, concluding that the letter was a forgery though not to have been directly the work of MI6 officers. In researching the origins of the letter, Bennett had full access to British government sources, drew upon Russian archival records.
Bennett retired from the civil service in 2005, was succeeded as chief historian by Patrick Salmon. Since 2005, Bennett has published three monographs, Churchill's Man of Mystery: Desmond Morton and the World of Intelligence, Six Moments of Crisis: Inside British Foreign Policy, The Zinoviev Letter: The Conspiracy that Never Dies. Bennett, Gill. Churchill's Man of Mystery: Desmond Morton and the World of Intelligence. Government Official History Series. Doi:10.4324/9780203966785. ISBN 9780415394307. Bennett, Gill. Six Moments of Crisis: Inside British Foreign Policy. Oxford University Press. ISBN 9780199583751. Bennett, Gill; the Zinoviev Letter: The Conspiracy that Never Dies. Oxford University Press. ISBN 9780198767305. Gill Bennett on Twitter
The William I. Fine Theoretical Physics Institute is a research institute in the University of Minnesota College of Science and Engineering. FTPI was the work of physics Professor Emeritus, Stephen Gasiorowicz and University alumnus and Twin-Cities real-estate developer William I. Fine; the Institute came into existence in January 1987. FTPI faculty consists of seven permanent members: Andrey V. Chubukov, Alex Kamenev, Keith Olive, Maxim Pospelov, Mikhail Shifman, Boris Shklovskii, Mikhail Voloshin as well as postdoctoral and graduate students; the William I. Fine Theoretical Physics Institute has on Oversight Committee consisting of ten members; the Oversight Committee is the board of directors that make decisions concerning the staffing and budgeting of the Institute. The Misel Family Lecture Series The Irving and Edythe Misel Family Lecture Series, hosted by FTPI, invites physicists from around the world to the University of Minnesota to discuss physics with the general public, it is funded by a generous gift from the Irving Misel family.
The list of the Misel Lecturers to date is: 2006: Frank Wilczek, 2007: Leo Kadanoff, 2008: Jim Peebles, 2009: Helen Quinn, 2010: N. David Mermin, 2011: Roger Blandford, 2012: John Ellis, 2013: Eric Cornell, 2014: Andrei Linde, 2015: Joseph Polchinski, 2016: John Preskill, 2017: Wendy Freedman, 2018: Nergis Mavalvala, 2019: Charles Marcus. Visitor Program FTPI has a worldwide reach; the Institute has hosted over 800 individual researchers, from institutions in more than 18 different countries, for working visits of one day to six months. Workshops FTPI hosts up to three workshops per year for physicists from around the world; this includes the 2013 CAQCD meeting, special because it was the tenth meeting in the series. The proceedings of the previous conferences – they are held biannually – reveal the developments of QCD and related theories from the early 1990s; as well as a workshop in October 2000 celebrating 30 years of supersymmetry. Current and former faculty members of FTPI have been honored with a number of awards.
Keith Olive is a current Distinguished McKnight University Professor of Physics and was awarded the 2018 Hans Bethe Prize. Former faculty, Leonid Glazman was a McKnight Presidential Endowed Chair. Boris Shklovskii is the recipient of the 1986 Landau Award and the 2019 Oliver E. Buckley Condensed Matter Prize. Former faculty,Arkady Vainshtein and Mikhail Shifman were awarded the 2016 Dirac Medal and Prize.. Andrey V. Chubukov was awarded the 2018 John Bardeen Prize. Three faculty members have been awarded the Sakurai Prize: former faculty, Arkady Vainshtein, Mikhail Shifman, Mikhail Voloshin. Former faculty, Arkady Vainshtein and Mikhail Shifman received the Pomeranchuk Prize. Mikhail Shifman was honored with the Lilienfeld Prize, elected as Laureate of Les Chaires Internacionales de Recherche Blaise Pascal. Former member Anatoly Larkin was awarded the Fritz London Memorial Prize in Low Temperature Physics, the Hewlett Packard Europhysics Prize, the Lars Onsager Prize in Theoretical Statistical Physics as well as the Bardeen Prize for Superconductivity.
The William I. Fine Theoretical Physics Institute is financed from a combination of private and University funds. In the world of fundamental-science research institutes, FTPI is, for its part, something of an oddity. While most such organizations are large, National Science Foundation-funded enterprises, Minnesota's FTPI was created in large part out of the generosity of a single private donor, it is dedicated to the research efforts of its members; the United States Department of Energy ER40823 grant is mutually submitted between the Department of Physics at the University of Minnesota and FTPI. This grant is entitled "Experimental and Theoretical High Energy Physics" and helps to support faculty and postdoctoral salaries. William I. Fine Theoretical Physics Institute Homepage
Trofeo delle Regioni is an Italian football tournament for amateur teams which represent the Italian regions. It has been played since 1959 and, from 1998, the winner has taken part in the UEFA Regions' Cup. In 2010 it merged with Coppa Nazionale Primavera, an event for Allievi and Giovanissimi representative teams of Italian regions; the trophy now had 6 events, Juniores for U18 players, Allievi for U16 players and Giovanissimi for U15 players, as well as female representative teams and 5-a-side football. 1959 Lazio 1960 Lazio 1961 Emilia Romagna 1962 Campania 1963 Puglia 1964 Lazio 1965 Campania 1966 Friuli Venezia Giulia 1967 Piemonte Val d’Aosta 1968 Toscana 1969 1970 Toscana 1971 Lazio 1972 Sicilia 1973 Lombardia 1974 1975 Abruzzo 1976 Veneto 1977 Veneto 1978 Calabria 1979 Lombardia 1980 Lombardia 1981 Marche 1982 Veneto 1983 Friuli Venezia Giulia 1984 Friuli Venezia Giulia 1985 Veneto 1986 Toscana 1987 Toscana 1988 Toscana 1989 Abruzzo 1990 Toscana 1991 Toscana 1992 Campania 1993 Toscana 1994 Sicilia 1995 Veneto 1996 Lazio 1997 Umbria 1998 Veneto 1999 Abruzzo 2000 Piemonte Valle d'Aosta 2001 Piemonte Valle d'Aosta 2002 Veneto 2003 Tuscany 2004 Lombardy 2005 Tuscany 2006/07 Piedmont Aosta Valley 2008 Piedmont Aosta Valley 2009 Abruzzo 2010 Abruzzo 2011 Veneto 2012 Umbria Coppa Nazionale Primavera2006 Campania 2007 Veneto 2008 2009 SardiniaAllievi del Trofeo delle Regioni2010 2011 2012 Coppa Nazionale Giovanissimi Giovanissimi del Trofeo delle Regioni FA Inter-League Cup Spanish stage of the UEFA Regions' Cup UEFA Regions' Cup SPECIALE TORNEO DELLE REGIONI LND - Torneo delle regioni - Home
Dally is the name of a gene that encodes a HS-modified-protein found in the fruit fly. The protein has to be processed after being codified, in its mature form it is composed by 626 amino acids, forming a proteoglycan rich in heparin sulfate, anchored to the cell surface via covalent linkage to glycophosphatidylinositol, so we can define it as a glypican. For its normal biosynthesis it requires sugarless, a gene that encodes an enzyme which plays a critical role in the process of modification of dally. Dally works as a co-receptor of some secreted signaling molecules as fibroblast growth factor, vascular endothelial growth factor, hepatocyte growth factor and members of the Wnt signaling pathway, TGF-b and Hedgehog families, it is necessary for the cell division patterning during the post-embryonic development of the nervous system. It is a regulatory component of the Wg receptor and is part of a multiprotein complex together with Frizzled transmembrane proteins. Therefore, it regulates two cell growth factors in Drosophila melanogaster and Decapentaplegic.
It must be said that in vertebrates the equivalent to Dpp are Bone Morphogenetic Proteins, the mammalian equal to Wg might be integrin-beta 4. The first one controls cell proliferation and differentiation during embryos development in epidermis, whereas the latter plays a role in the imaginal discs’ growth. Dpp and Wg are mutually antagonistic in patterning genitalia. Concretely, dally selectively regulates Dpp in genitalia; this selectivity is supposed to be controlled by the type of Glycosaminoglycan GAG bonded to the dally protein, considering that there is a huge structural variety in GAGs. Tissue malformations occur in various situations; as said in the introduction, the sgl enzyme is essential for a normal biosynthesis of dally. That is why the absence or malfunction of this enzyme doesn’t allow the correct Wg and Dpp signalling; the expression of mutated dally proteins alters Wnt signalling pathways, which leads to anomalies in Drosophila melanogaster’s eye, genital and neural morphogenesis.
Dally's gene was located in the chromosome 3, concretely in the region 3L 8820605-8884292. The mutation of Dally is a consequence of the place where it is located, it is possible to differentiate between the mutants Dally-P1 and Dally-P2, depending on where the insertion of P-element is. It is known; this mutated Dally disrupts the cell cycle progression, delaying the process during the G2-mitosis transition. As a matter of fact, mutations affecting Dally disrupt patterning of many tissues, for instance of the nervous system. Dally mutants display cell cycle progression defects in specific sets of dividing cells; those mutations are pleiotropic and can affect viability and produce morphological defects in several adult tissues, such as the eye, antenna and genitalia. Once the mutation has been codified and the protein is functional, there is no chance to turn back and we will speak about a mutated individual. However, if the mutant dally is codified but it is not performing its function yet, a chaperone can identify it and try to correct the mutation, or directly send it to a proteasome using ubiquitins and degrade it.
Notwithstanding, there is another possible solution when malformations have occurred as a result of Wg activity loss. Ectopic dally can potentiate Wg signaling but this effect is dependent on some Wg activity remaining at the cell surface. Moreover, ectopic expression of dally+ from hs-dally+ transgene, stimulates Wg signaling. Thus, naked larval cuticle loss is recuperated and once the larva has become an adult, its tissues execute their normal function. Despite this fact, an intense expression of dally+ results in the death of most of the Drosophila melanogaster’s embryos. Mammalian homologue of Wg that might be integrin-beta 4 Wnt signaling pathway - Homo sapiens Silvert, Donald J.. "Pupal and larval cuticle proteins of Drosophila melanogaster". Biochemistry. 23: 5767–74. Doi:10.1021/bi00319a015. PMID 6441593
PS Glen Rosa was a 306 GRT passenger paddle steamer that J&G Thomson launched in 1893 for the Glasgow and South Western Railway. She served with the Royal Navy in the First World War as HMS Glencross, she was absorbed into the London and Scottish Railway fleet in 1923, transferred to the Caledonian Steam Packet Company in 1938 and scrapped in 1939. J&G Thomson of Clydebank built Glen Rosa for the G&SWR for £17,500. Thomson's launched her at Clydebank on 31 May 1893 and she completed her sea trials on 27 June, she had a 150-foot promenade deck. At the same time Thomson built an exact sister ship, PS Slieve Donard, for the Belfast and County Down Railway. Another sister ship, PS Minerva, had been launched for the G&SWR a few weeks previously. Minerva had detail differences from Slieve Donard. Glen Rosa was named after Glen Rosa on the Isle of Arran, she worked various G&SWR ferry routes in the Firth of Clyde including off-season crossings to Arran. In the First World War the Admiralty requisitioned Glen Rosa, renamed her HMS Glencross and had her converted into a minesweeper.
With the Royal Navy she was based in Belfast Lough and at Swansea. After the First World War she returned to G&SWR service serving Fairlie, North Ayrshire, she worked on the route between Wemyss Bay on the North Ayrshire coast, Millport on Great Cumbrae and Kilchattan on the Isle of Bute. In the 1923 grouping of Britain's railways the G&SWR became part of the new London and Scottish Railway, Glen Rosa became part of the LMS fleet. In 1926 she was re-boilered, as a result. In 1938 the LMS transferred Glen Rosa to the Caledonian Steam Packet Company. In 1939 she was laid up at Greenock, in August of that year she was scrapped at Dalmuir