Epoxy refers to any of the basic components or cured end products of epoxy resins, as well as a colloquial name for the epoxide functional group. Epoxy resins known as polyepoxides, are a class of reactive prepolymers and polymers which contain epoxide groups. Epoxy resins may be reacted either with themselves through catalytic homopolymerisation, or with a wide range of co-reactants including polyfunctional amines, phenols and thiols; these co-reactants are referred to as hardeners or curatives, the cross-linking reaction is referred to as curing. Reaction of polyepoxides with themselves or with polyfunctional hardeners forms a thermosetting polymer with favorable mechanical properties and high thermal and chemical resistance. Epoxy has a wide range of applications, including metal coatings, use in electronics/electrical components/LEDs, high tension electrical insulators, paint brush manufacturing, fiber-reinforced plastic materials, adhesives for structural and other purposes. Most of the commercially used epoxy monomers are produced by the reaction of a compound with acidic hydroxy groups and epichlorohydrin: First a hydroxy group reacts in a coupling reaction with epichlorohydrin, followed by dehydrohalogenation.
Epoxy resins produced from such epoxy monomers are called glycidyl-based epoxy resins. The hydroxy group may be derived from aliphatic diols, phenolic compounds or dicarboxylic acids. Phenols can be compounds such as bisphenol novolak. Polyols can be compounds such as 1,4-butanediol. Di- and polyols lead to diglycid polyethers. Dicarboxylic acids such as hexahydrophthalic acid are used for diglycide ester resins. Instead of a hydroxy group the nitrogen atom of an amine or amide can be reacted with epichlorohydrin; the other production route for epoxy resins is the conversion of aliphatic or cycloaliphatic alkenes with peracids: As can be seen, in contrast to glycidyl-based epoxy resins, this production of such epoxy monomers does not require an acidic hydrogen atom but an aliphatic double bond. The epoxide group is sometimes referred to as a oxirane group; the most common epoxy resins are based on reacting epichlorohydrin with bisphenol A, resulting in a different chemical substance known as bisphenol A diglycidyl ether.
Bisphenol A-based resins are the most commercialised resins but other bisphenols are analogously reacted with epichlorohydrin, for example Bisphenol F. In this two-stage reaction, epichlorohydrin is first added to bisphenol A a bisepoxide is formed in a condensation reaction with a stoichiometric amount of sodium hydroxide; the chlorine atom is released as the hydrogen atom as of water. Higher molecular weight diglycidyl ethers are formed by the reaction of the bisphenol A diglycidyl ether formed with further bisphenol A, this is called prepolymerization: A product comprising a few repeat units is a viscous, clear liquid. A product comprising more repeating units is at room temperature a colourless solid, correspondingly referred to as solid epoxy resin. Instead of bisphenol A, other bisphenols or brominated bisphenols can be used for the said epoxidation and prepolymerisation. Bisphenol F may undergo epoxy resin formation in a similar fashion to bisphenol A; these resins have lower viscosity and a higher mean epoxy content per gram than bisphenol A resins, which gives them increased chemical resistance.
Important epoxy resins are produced from combining epichlorohydrin and bisphenol A to give bisphenol A diglycidyl ethers. Increasing the ratio of bisphenol A to epichlorohydrin during manufacture produces higher molecular weight linear polyethers with glycidyl end groups, which are semi-solid to hard crystalline materials at room temperature depending on the molecular weight achieved; this route of synthesis is known as the "taffy" process. More modern manufacturing methods of higher molecular weight epoxy resins is to start with liquid epoxy resin and add a calculated amount of bisphenol A and a catalyst is added and the reaction heated to circa 160 °C; this process is known as "advancement". As the molecular weight of the resin increases, the epoxide content reduces and the material behaves more and more like a thermoplastic. High molecular weight polycondensates form a class known as phenoxy resins and contain no epoxide groups; these resins do however contain hydroxyl groups throughout the backbone, which may undergo other cross-linking reactions, e.g. with aminoplasts and isocyanates.
Epoxy resins are polymeric or semi-polymeric materials or an oligomer, as such exist as pure substances, since variable chain length results from the polymerisation reaction used to produce them. High purity grades can be produced for certain applications, e.g. using a distillation purification process. One downside of high purity liquid grades is their tendency to form crystalline solids due to their regular structure, which require melting to enable processing. An important criterion for epoxy resins is the epoxide group content; this is expressed as the "epoxide equivalent weight", the ratio between the molecular weight of the monomer and the number of epoxide groups. This parameter is used to calculate the mass of co-reactant to use. Epoxies are cured with stoichiom
Zutphen is a city and municipality located in the province of Gelderland, Netherlands. It lies some 30 km northeast of Arnhem, on the eastern bank of the river IJssel at the point where it is joined by the Berkel. First mentioned in the 11th century, the place-name appears to mean "south fen". In 2005, the municipality of Zutphen was merged with the municipality of Warnsveld, retaining its name. In 2019, the municipality had a population of 47,609. In about 300 AD, a Germanic settlement was the first permanent town on a complex of low river dunes. Whereas many such settlements were abandoned in the early Middle Ages, Zutphen on its strategic confluence of IJssel and Berkel stayed. After the incorporation of the IJssel lands in Charlemagne's Francia, Zutphen became a local centre of governance under a count; the Normans raided and ravaged it in 882. Afterwards a circular fortress was built to protect the budding town against Viking attacks. In the eleventh century, Zutphen was a royal residence for a number of years.
The counts of Zutphen acquired a lot of power, until the line of counts became extinct in the twelfth century. After the death of her father and her brother, the heiress of Zutphen married the count of Guelders; the settlement received town rights between 1191 and 1196, making it one of the oldest towns in the country. This allowed it to have a judicial court. Only Utrecht, Deventer preceded it in receiving town rights. Zutphen, in turn, became the mother town of several other towns in Guelders, such as Arnhem, Doesburg, Harderwijk and Emmerich, it became part of the Hanseatic League, a group of towns with great wealth. During the 12th century, coins were minted in Zutphen by the Counts of Guelders and Zutphen: Henry I and Otto I. Although the city had minting rights for a few centuries this was only used during four periods: 1478–1480, 1582–1583, 1604–1605 and 1687–1692; the largest and oldest church of the city is the St. Walburgis church, which dates from the eleventh century; the present Gothic building contains monuments of the former counts of Zutphen, a fourteenth-century candelabrum, an elaborate copper font, a monument to the Van Heeckeren family.
The chapter-house's library contains a pre-Reformation collection, including some valuable manuscripts and incunabula. It is considered one of only five remaining medieval libraries in Europe; this chained library's books are still chained to their ancient wooden desk – a custom from centuries ago, when the "public library" used chains to prevent theft. Having been fortified the town withstood several sieges, specially during the Eighty Years' War, the most celebrated fight under its walls being the Battle of Zutphen in September 1586 when Sir Philip Sidney was mortally wounded. Taken by the Spanish in 1587 by the treachery of the English commander Rowland York, Zutphen was recovered by Maurice, prince of Orange, in 1591, except for two short periods, one in 1672 and the other during the French Revolutionary Wars, it has since remained a part of the Netherlands, its fortifications were dismantled in 1874. In World War II the town was bombed several times by the allied forces because the bridge over the IJssel was vital to support the German troops at Arnhem after the Operation Market Garden.
After two weeks of battle the town was liberated on 14 April 1945. After the war a renovation program started. Nowadays Zutphen has one of the best preserved medieval town centres of northwestern Europe, including the remains of the medieval town wall and a few hundred buildings dating from the 13th, 14th and 15th centuries; the old center survived the Second World War in its entirety, though some parts of the city were lost the area around the railway station, in the northern part of the city center, known as the Nieuwstad. The city center includes many monumental buildings dating back to the 14th and 15th centuries, some date back to the 13th century, such as a retirement home area. There are remains of the old town walls in several places. Today, Zutphen is a modern small city; the urban area, which includes the village of Warnsveld, has about 51,000 inhabitants. Food shops are open from 8:30 am and other stores are open from 9:30 am to 6 pm on weekdays, on Friday evening until 9 pm and on Saturday until 5 pm.
Some stores open earlier, the larger supermarkets stay open until 10 pm. Because Zutphen contains a large number of historical buildings with a tower, Zutphen is called the tower city; because there are no modern high-rise buildings in the city centre the historical tower spires are visible and form the skyline of Zutphen. The title of tower city is used in advertising to draw tourists to Zutphen; the Walburgis church was built as a Roman collegiate church around 1050, after that it was redecorated and remodeled on several occasions. There are six bells in the tower. Since 1561 a library called, it was founded as a public library for the rich citizens of Zutphen. These days the library contains an important collection of 15th- to 17th-century books; the Broederen church is a large early 14th-century monastery church of the Dominican order. Since 1983 the church has been used as the city's public library, it was been extensively restored. On
Graphene applications as optical lenses. The unique honeycomb 2-D structure of graphene contributes to its unique optical properties; the honeycomb structure allows electrons to exist as massless quasiparticles known as Dirac fermions. Graphene's optical conductivity properties are thus unobstructed by any material parameters represented by equation 1, where e is the electron charge, h is Planck's constant and "e^2"/"h" represents the universal conductance. Equation 1 σ uni = e 2 2 h This simple behavior is the result of an undoped graphene material at zero temperature. In contrast to traditional semiconductors or metals. However, the band gap is tunable via doping and electrical gating, resulting in changes in graphene's optical properties; as a result of its tunable conductivity, graphene is employed in various optical applications. Electrical gating and doping allows for adjustment of graphene's optical absorptivity; the application of electric fields transverse to staggered graphene bilayers generates a shift in Fermi energy and an artificial, non-zero band gap.
Equation 2 δD=Dt - Db where Dt = top electrical displacement field Db = bottom electrical displacement field Varying δD above or below zero allows electrons to pass through the bilayer without altering the gating-induced band gap. As shown in Figure 2, varying the average displacement field, ▁D, alters the bilayer's absorption spectra; the optical tunability resulting from gating and electrostatic doping lends to the application of graphene as ultra-broadband photodetectors in lenses. Chang-Hua et al. implemented graphene in an infrared photodetector by sandwiching an insulating barrier of Ta2O5 between two graphene sheets. The graphene layers became electrically isolated and exhibited an average Fermi difference of 0.12eV when a current was passed through the bottom layer. When the photodetector is exposed to light, excited hot electrons transitioned from the top graphene layer to the bottom, a process promoted by the structural asymmetry of the insulating Ta2O5 barrier. A consequence of the hot electron transition, the top layer accumulates positive charges and induces a photogating effect on the lower graphene layer, measured as a change in current correlating with photon detection.
Utilizing graphene both as a channel for charge transport and light absorption, the graphene ultra-broadband photodetectors ably detects the visible to mid-infrared spectrum. Nanometers thin and functional at room temperature, graphene ultra-broadband photodetectors show promise in lens application. Figure 4 the graphene Fresnel Zone Plate reflects the light off to a single point. Fresnel zone plates are devices; these devices concentrate light reflected off a lens onto a singular point8. Composed of a series of discs centered about an origin, Fresnel zone plates are manufactured using laser pulses, which embed voids into reflective lens. Despite its weak reflectance, graphene has utility as a lens for Fresnel zone plates, it has been shown that graphene lenses concentrate light of ʎ = 850 nm onto a single point 120 um away from the Fresnel zone plate8. Further investigation illustrates that the reflected intensity increases linearly with the number of graphene layers within the lens. Optoelectronic components such as light-emitting diode displays, solar cells, touch screens require transparent materials with low sheet resistance, Rs.
For a thin film, the sheet resistance is given by equation 3: Equation 3 R s = t σ with t = film thickness σ = d. c. C o n d u c t i v i t y A material with tunable thickness, t, conductivity, σ, possesses useful optoelectronic applications if Rs is reasonably small. Graphene is such a material. Figure 7 shows graphene's potential relative to other known transparent conductors; the need for alternative transparent conductors is well documented. Current semiconductor based transparent conductors such as doped indium oxides, zinc oxides, or tin oxides suffer from practical downfalls including rigorous processing requirements, prohibitive cost, sensitivity toward acidic or basic media, a brittle consistency. However, graphene does not suffer from these downfalls
G. I. S. M. is a Japanese hardcore punk band formed in Tokyo in 1981. Though the guitar style resembled heavy metal in many aspects, GISM was one of the first Japanese hardcore bands, while at the same time drawing influence from the early industrial/avant-garde music scene—something uncommon in punk bands at that time; the acronym GISM has many different variations. GISM has attained a cult status in the international punk scene, duly for their unique blend of heavy metal and hardcore punk. Roadrunner Records ranked Sakevi Yokoyama No. 49 out of 50 of The Greatest Metal Frontmen of All Time. GISM had their first performance in 1981 at the University of Tokyo. In 1984, GISM released their first album titled'Detestation' on Dogma Records.. The album has been applauded for having unique vocals and a guitar style, uncommon in hardcore punk.'M. A. N.', was released in 1987 on Beast Arts Records. The album was quite a departure from the'Detestation' album, putting more emphasis on a slower, metal style of music compared to the hardcore punk sound of the previous release.
GISM released their last album on compact disc titled'SoniCRIME TheRapy' in 2001. The band featured Kiichi Takahashi on Ironfist Tatsushima on drums. Guitarist Randy Uchida died from cancer on February 10, 2001, shortly after the release of the album.. GISM played two shows in Tokyo in honor of Randy Uchida, broke up. In 2002, GISM made the cover of an underground Japanese magazine. GISM performed in the Netherlands on April 2016 at Lee Dorian's Roadburn event, it was their first performance after a 13-year hiatus, along with being their first show outside of Japan. Sakevi Yokoyama continues to make collage art with his own clothing brand "stlTH", which makes T-shirt designs.. In 1987, he made a cameo appearance in the Japanese film "Robinson's Garden". In the movie, he attacks a Rastafarian man for teaching children spirituality; this film is the only documentation of his "acting" career. In 2004, Sakevi released a solo album titled'The War' under the name S. K. V.. In 2006, he designed the artwork for World Burns To Death's album titled Totalitarian Sodomy.
Randy Uchida & Hiroshima played with Ronny Wakamats & Michel Hammer in a side project called R. U. G. which released one vinyl EP titled “Deathly Fighter” in 1984. Uchida died in 2001 of cancer. Kiichi Takahashi was the vocalist for the occult heavy metal band Sabbrabells.. Cloudy played bass for female-fronted speed metal band Front Guerrilla, which released an EP titled Fight Back in 1986. Ironfist Tatushima continues to play in the bands Die You Bastard! and Crow, which he had been playing with prior to GISM. During the mid 80's, Sakevi published a Japanese punkzine titled P. O. W; the acronym of P. O. W. Initially stood for Punk On Wave, but changed to Performance Of War for the third, final issue; the magazine promoted local punk bands from the Tokyo scene at the time. Sakevi personally interviewed the Tokyo Medical Examiners Office, wrote the P. L. O. and wrote prisoners of war from Anti Japanese Armed Fronts by asking them all their opinions on death, included vivid instructions on different ways to kill people and showed vivid drawings on how ABC weapons are made with images of their horrific consequences.
John Duncan, the guest-editor for the magazine, stated in the introduction of the third issue that Sakevi attacked a salaryman for staring with a makeshift flamethrower on a Tokyo commuter train, subsequently landing him in prison. "Detestation" Dogma Records "M. A. N." Beast Arts "DETESTation" Beast Arts "SoniCRIME TheRapy" Beast Arts "Outsider" LP Tracks: "Incest", "Gash, Snatch", "AAHB" "Great Punk Hits" LP Tracks: "Death Exclamations", "Fire" "Hardcore Unlawful Assembly" LP Tracks: "Still Alive", "Nervous Corps" "International P. E. A. C. E. Benefit Compilation" 2xLP Track: "Endless Blockads for the Pussyfooter" "The Punx" Cassette Tape Tracks: "Shoot to Kill", "GISM" "Determination" Beast Arts "Performance" Beast Arts "BOOTLEG 1986" Beast Arts "Gay Individual Social Mean - Subj & Egos, chopped" Beast Arts "+R, Regicide Reverberation" Beast Arts GISM Fan site I GISM at Kill From The Heart GISM at Metal Archives A review of GISM - Detestation
A Question of Taste is a 2000 French film directed by Bernard Rapp. Rapp and Gilles Taurand wrote the screenplay, based on the book "Affaires de goût" by Philippe Balland; the film received 5 César Award nominations, including the nomination for Best Film. César Awards Nominated: Best Actor – Leading Role Nominated: Best Actress – Supporting Role Nominated: Best Film Nominated: Best Writing Nominated: Most Promising Actor Karlovy Vary Film Festival Won: Special Mention Nominated: Crystal Globe A Question of Taste on IMDb
John Loike is an American research biologist and bioethicist in Columbia University. Loike has a Ph. D from the Albert Einstein College of Medicine of Yeshiva University, his research focuses on the role of inflammation in neurodegenerative diseases. He has published many articles in leading scientific journals including Science, Journal of Experimental Medicine, Journal of Cell Biology, New England Journal of Medicine, Lancet, PNAS, PlosOne, Journal of Biological Chemistry and The Scientist. In addition he has co-authored several books, he is the Director for Special Programs for the Center for Bioethics in Columbia University and is a faculty member of the Department of Physiology and Cellular Biophysics at Columbia University College of Physicians and Surgeons. He teaches one graduate course, he is the creator and faculty editor of the "Columbia University'Journal of Bioethics. Dr. Loike has published many ground-breaking articles on bioethics and deals with bioethics from a Jewish perspective, for which he teams with Rabbi Dr. Moshe David Tendler.
His articles have dealt with such issues as stem cells, neuroethics and the interface of science and religion. Many of these issues are hotly debated around the world, in Israel, where religious leaders have a big influence in public policy. Dr. Loike has weighed in on these issues in Israeli forums, leading to policy changes there. Serving on a Rabbinical Council of America panel on stem cell research, Dr. Loike highlighted scientific innovations that could allow for additional research, while alleviating the ethical questions posed by the scientific use of embryonic stem cells. In 1982, Loike and his longtime study partner, David Hurwitz, published a first-of-its-kind guide to Passover medications. Up until that point, no one had produced a scientific study of leaven ingredients in medications and as a result, many religious Jews had to decide on their own whether their medication could be consumed during Passover according to Jewish Law. Loike and Hurwitz painstakingly contacted various drug manufacturers to ascertain the status of their various medications.
This led to a yearly publication of passover medications. Lignans: Chemical and Clinical Properties by David C. Ayres and John D. Loike. Cambridge University Press, 2008. ISBN 978-0521065436'"Frontiers in Bioethics" by John D. Loike and Ruth L. Fischbach, 2012. Loike, J. D; the Evolving Bioethical Landscape of Human-Animal Chimeras, in "Human Dignity in Bioethics: From Worldviews to the Public Square.". 2013. Loike, J. L.. J Bioterr Biodef. 2013: S01–S12. Loike, J. D.. "Surface Acoustic Waves Enhance Neutrophil Killing of Bacteria". PLOS One. 8: e68334. Doi:10.1371/journal.pone.0068334. PMC 3735547. Loike, J. D. Rush, B. S. Schweber, A. Fischbach, R. L. Lessons Learned from Undergraduate Students in Designing a Science-based Course in Bioethics, Cell Biology Education—A Journal of Life Science Education, December, 2013. Loike, J. D. and Miller, J. Personalized Medicine, Encyclopedia of Bioethics, In Press 2013. Loike, J. D. Tendler, M. D. Halachic Perspectives of Gestational Surrogacy, Hakirah, In Press, 2013. Loike, J.
D. Tendler. "Becoming a Surrogate for an Infertile Jewish Couple". Journal of Halacha and Contemporary Society. 66: 5–21. Margolit, Y. Levy, O. Loike, J. D. Advanced Reproductive Technologies: Reevaluating Modern Parentage, Harvard Journal of Law and Gender, in press 2013. Loike, J. D. Hirano, M. Margalit, H. Three-Way Parenthood: dealing with the logistics of embryos created by three-parent IVF technologies that avoid the transmission of mitochondrial disease. Oct 1, The Scientist, 2013. Loike, J. D; the Power to Predict: Using DNA Technologies to Assess the Genetics and Health of a Fetus. B’Or Ha’Torah. Jan, 2012. Miller, J. Loike. "BioCEP: A Model Educational Program for Cross-cultural Bioethics". Cambridge Quarterly of Healthcare Ethics. 21: 409–415. Doi:10.1017/s0963180112000187. PMID 22624549. Phani, S.. D.. "Neurodegeneration and Inflammation in Parkinson's Disease". Parkinsonism Related Disorders. 18: S207–9. Doi:10.1016/s1353-802070064-5. Arslanoglu, J.. D.. "An improved method of protein localization in artworks through SERS nanotag-complexed antibodies".
Analytical and Bioanalytical Chemistry. 399: 2997–3010. Doi:10.1007/s00216-010-4378-0. PMID 21079929. Kothari1, K.. D.. "Surface Acoustic Waves cause Net Reduction in Human Melanoma Growth in vitro. C". Columbia Undergraduate Science Journal. 5: 35–41. Loike, J. D. Tendler. "Halachic Bioethics Guidelines Journal of Halacha in Contemporary Society". Journal of Halacha in Contemporary Society. 16: 92–118. Budhu, S.. D.. C.. "CD8+ T-cell concentration determines the efficiency of killing of cognate antigen-expressing syngeneic mammalian cells in vitro and in vivo". Journal of Experimental Medicine. 207: 223–235. Doi:10.1084/jem.20091279. PMC 2812553. PMID 20065066. Zhang, W.. R.. A.. S.. F..