Product Distribution of Chemical Product Using Catalytic Depolymerization of Lignin

Lignin depolymerization is a very promising process which can generate value-added products from lignin raw materials. The main objective of lignin depolymerization is to convert the complex molecules of lignin into small molecules. Nevertheless, lignin is natural polymer which the molecules of lignin are extremely complicated due to their natural variability, and it will be a big challenge to depolymerize lignin, particularly high water yield. The various technology and methods are developed to depolymerize lignin into biofuels or bio chemical products including acid/base/metallic catalyzed lignin depolymerization, pyrolysis of lignin, hydroprocessing, and gasification. The distribution and yield of chemical products depend on the reaction operation condition, type of lignin and kind of catalyst. The reactor type, product distributions and specific chemicals (benzene, toluene, xylene, terephthalic acid) production of lignin depolymerization are intensive discussed in this review. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Red list and checklist of the planthoppers and leafhoppers

Erstmalig wird für das Land Berlin eine Rote Liste der Zikaden vorgelegt, außerdem eine aktualisierte Gesamtartenliste. Von insgesamt 337 Arten gelten demnach 39 Arten als verschollen, 25 als vom Aussterben bedroht (Kategorie 1), 5 als stark gefährdet (Kategorie 2) und 15 als gefährdet (Kategorie 3). 20 Arten gelten als gefährdet mit unbekannten Ausmaß (Kategorie G), 14 Arten als extrem selten (Kategorie R), 12 Arten wurden auf die Vorwarnliste gesetzt (Kategorie V) und für 14 Arten wurde der Befund „Daten defizitär“ gestellt (Kategorie D). Für drei Arten wurde eine besondere Verantwortlichkeit Berlins festgestellt, die Schmuckseggenzirpe (Cicadula ornata), die Braune Kragenzirpe (Anoplotettix fuscovenosus) und die Dünenzirpe (Pinumius areatus). Die beiden erstgenannten kommen deutschlandweit nur in Berlin vor, die letztere weist hier Schwerpunktvorkommen auf.We present, for the first time, a Red List of the planthoppers and leafhoppers of the federal state of Berlin, as well as an updated checklist. Altogether 337 species have been recorded so far, 39 of them are considered as regionally extinct (category 0), 25 as critically endangered (category 1), 5 as endangered (category 2), 15 as vulnerable (category 3), 20 as indeterminate (category G), 14 rare (category R), 12 near-threatened (category V). The data base is deficient (category D) for 14 further species. Berlin is assigned a particular responsibility for conservation of Cicadula ornata, Anoplotettix fuscovenosus and Pinumius areatus. The first two species are in Germany so far only known from Berlin. For the latter species most recent German records are from Berlin

Bulletin of the Jefferson Nurses\u27 Alumnae

Greetings to Alumnae Members Everywhere The Class Rooms - 1907-1935 Curtis Clinic Treasurer\u27s Report Commencement Week Jefferson Alumnae, 1893-1934 Lost Alumna

The Crisis of Ornament: Evaluation and Intercultural Divergences in the Visual Arts of the 19th and Early 20th Centuries

From the beginning of the 19th century up to the present, ornament has faced different crises because it is not an autonomous art but traditionally attached to a surface, be it architecture or applied arts. The fate of ornament has varied, according to leading theorists and critics in these fields. In 1812, Percier and Fontaine exhorted architects and artisans to use ornament with consciousness and care. Gottfried Semper could even conceive of applied arts without ornament, and his utmost concern was to show the original function of objects that they had lost over time. He wanted to clarify the purpose of an object, not only from a functional point of view, but also iconographically. Christopher Dresser, with a background as a biologist and ‘ornamentist’, was the first industrial designer to create objects without ornament, following the influence of Japanese art. The death knell apparently tolled for ornament in 1908 with Adolf Loos’ talk on Ornament and Crime. The subsequent opposition of Art Deco and Modernism was a clash of cultures, perceptible even nowadays among architects and art historians. At a certain point, as recent studies have pointed out, there was a merging of these two art movements. At present, ornament has made a comeback and been reintegrated into architecture in a new way and spirit

Šezdesetgodišnjica Ziegler-Nattinih katalizatora i stereospecifičnih polimerizacija

This review article highlights the history of the discoveries of organometallic catalysts and stereospecific polymerization of α-olefins, dienes and a number of vinyl monomers by Karl Ziegler and Giulio Natta sixty years ago, their developments and recent progress. As one of the most important achievements in the field of catalysis, macromolecular science and polymer materials, their inventors were awarded the Nobel Prize in Chemistry in 1963 “for their discoveries in the field of chemistry and technology of high polymers”. These discoveries have stimulated an intensive, both basic and applied research all over the world, up to the present times, leading to great development of the polymer industry. The important biographical data and scientific advancements of K. Ziegler and G. Natta are presented as well. Karl Ziegler, a German scientist, Director of Max Planck Institute for Coal Research in Mülheim, besides many scientific achievements, in 1953 discovered a new process for the polymerization of ethylene into linear polyethylene under mild conditions by using titanium chloride and alkyl aluminium catalytic system that was superior to all existing polymerization. Giulio Natta, an Italian scientist, Director of the Department of Industrial Chemistry at Polytechnic, University of Milan, besides many achievements in petrochemical processes, in 1954 obtained for the first time isotactic polypropylene and Montecatini Co. started its production already in 1958. He conducted pioneering studies on the chain microstructure of synthetic organic polymers and postulated the mechanisms of stereospecific polymerizations. Since the discovery of the Zeigler-Natta catalyst, stereospecific polymerization and processes, significant developments have occurred. The breakthrough in polymerization processes such as fluid bed, liquid phase loop reactor and reactor granule technology led to significant development and growth of polyolefin production. In the 1980s, a new family of transition metal complexes known as metallocene catalysts were discovered, based on biscyclopentadienyl and transition metal as Zr, Hf and Ti and appropriate cocatalysts. There major advantage is solubility, high catalytic activity, and the easy tailoring of the polymer microstructure. In 1986, the first synthesis of syndiotactic polystyrene was performed using monocyclopentadienyl/titanium chloride catalyst. The development of catalysts based on diimine complexes of nickel and palladium, and of phenoxy-imino complexes of zirconium and nickel, resulted in polyolefins of different structure and morphology, and many new copolymers of ethylene particularly with polar monomers, producing a variety of new functional polymers, reactive oligomers, and block copolymers. The described discoveries of organometallic catalysts and their applications are one of the most valid models and sources of inspiration for the progress in chemistry and chemical engineering.Prikazana je povijest otkrića, razvitak i mogućnosti organometalnih katalizatora i stereospecifičnih polimerizacija α-olefina, diena i brojnih vinilnih monomera, Karla Zieglera i Giulia Natte, šezdesetih godina 20. stoljeća. Smatraju se najznačajnijim otkrićima u području katalize, makromolekulnih znanosti i polimernih materijala, pa su njihovim autorima 1963. dodijeljene Nobelove nagrade za kemiju. Uz biografske opise i putova njihovih znanstvenih postignuća, opisan je značaj i velik utjecaj tih otkrića na razvitak temeljnih i primijenjenih istraživanja i novih polimerizacijskih postupaka i procesa. Organometalni katalizatori kompleksi su halogenida prijelaznih metala, najčešće titanija, vanadija, kroma, kobalta, nikla i drugih, te metalnih alkila kao što je trietilaluminij, a u većini slučaja nastaju polimeri stereoregularnih struktura. Danas su još uvijek u uporabi poznati kao Ziegler- Nattini (Z-N) katalizatori i Z-N stereospecifične polimerizacije. Karl Ziegler, njemački znanstvenik, direktor Instituta Max Planck za istraživanje ugljena u Mülheimu, uz veliki broj otkrića, godine 1953. razvio je novi postupak polimerizacije etilena u linearni polietilen pri blagim reakcijskim uvjetima uz katalitičke kompleksne spojeve Ti/Al. Giulio Natta, talijanski znanstvenik, direktor Instituta za industrijsku kemiju Sveučilišta u Milanu, istraživao je pretežito katalitičke petrokemijske procese, a 1954. prvi je dobio izotaktni polipropilen polimerizacijom propilena preinačenim Ti/Al-kalizatorom. Postavio je mehanizme stereospecifičnih polimerizacija i utvrdio molekulske strukture organskih polimera. Organometalni katalizatori stalno se usavršavaju pa tijekom 1980-ih dolazi do otkrića i nove skupine tzv. metalocenskih katalizatora na temelju kompleksa supstituiranih diciklopentadiena i prijelaznih metala, posebice Zr, Hf, Sc, Th, Ti. Prednost im je dobra topljivost (homogeni sustavi), velika katalitička aktivnost i stereospecifičnost. Njihovom primjenom 1986. dobiven je i proizvodi se i sindiotaktni polistiren. Otkriveni su također i katalizatori na temelju kompleksa Ni, Pd, Zr i Fe s diiminskim i fenoksiiminskim spojevima kojima se dobivaju poliolefini željene strukture i morfološke građe kao i mnogi funkcijski polimeri, blok-kopolimeri i reaktivni oligomeri. Opisana otkrića i istraživanja organometalnih katalizatora i njihove široke uporabe svrstavaju ih u najbolje primjere razvitka i napretka u kemiji i kemijskom inženjerstvu

COLLABORATIVE RESEARCH: Microparticle/tephra analysis of the WAIS Divide ice core

This award supports a project to perform continuous microparticle concentration and size distribution measurements (using coulter counter and state-of-the-art laser detector methods), analysis of biologically relevant trace elements associated with microparticles (Fe, Zn, Co, Cd, Cu), and tephra measurements on the WAIS Divide ice core. This initial three-year project includes analysis of ice core spanning the instrumental (~1850-present) to mid- Holocene (~5000 years BP) period, with sample resolution ranging from subannual to decadal. The intellectual merit of the project is that it will help in establishing the relationships among climate, atmospheric aerosols from terrestrial and volcanic sources, ocean biogeochemistry, and greenhouse gases on several timescales which remain a fundamental problem in paleoclimatology. The atmospheric mineral dust plays an important but uncertain role in direct radiative forcing, and the microparticle datasets produced in this project will allow us to examine changes in South Pacific aerosol loading, atmospheric dynamics, and dust source area climate. The phasing of changes in aerosol properties within Antarctica, throughout the Southern Hemisphere, and globally is unclear, largely due to the limited number of annually dated records extending into the glacial period and the lack of atephra framework to correlate records. The broader impacts of the proposed research are an interdisciplinary approach to climate science problems, and will contribute to several WAIS Divide science themes as well as the broader paleoclimate and oceanographic communities. Because the research topics have a large and direct societal relevance, the project will form a centerpiece of various outreach efforts at UMaine and NMT including institution websites, public speaking, local K-12 school interaction, media interviews and news releases, and popular literature. At least one PhD student and one MS student will be directly supported by this project, including fieldwork, core processing, laboratory analysis, and data interpretation/publication. We expect that one graduate student per year will apply for a core handler/assistant driller position through the WAIS Divide Science Coordination Office, and that undergraduate student involvement will result in several Capstone experience projects (a UMaine graduation requirement). Data and ideas generated from the project will be integrated into undergraduate and graduate course curricula at both institutions

Water vapour sorption and humidity - a survey on measuring methods and standards

Under environmental conditions water exists in all three classical states of matter: solid, liquid and gas. The water molecule is non-linear and therefore polar. In comparison with other liq-uids water has anomalous features; about 63 exceptional properties are recorded. This article starts with reviewing properties of water, typical occurrences and definitions such as relative and absolute humidity and moisture content. Water is present everywhere in nature and engineering; it may be helpful or harmful. The survey concerns both: atmospheric hygrometry and usual measuring methods of the mois-ture content of solids and liquids as well as water sorption. The determination of the atmos-pheric humidity is among the more difficult problems in metrology. In contrast, humidity de-termination of materials is simple; however the definition of the dry state is difficult. Because water is bound at and in solids and liquids in many different ways it turns out that the humidi-ty content of materials is difficult to define and to measure accurately. We provide a survey on the measuring methods, describe the most important ones and discuss advantages and ac-curacy. In the search for extraterrestrial water special remote measuring methods have been developed analysing the spectrum of electromagnetic radiation either of natural sources or produced by a probe and reflected. Spacious deposits have been detected photographically. In situ investigations are made using conventional methods. With regard to the problems of measurements, standardisation of measuring methods and procedures is required. There exist many institutions, which are engaged in investigating the use of water and standardising measuring methods. In tabular form, we give a survey on existing standards