Bibliografie tematiche / Ethylene

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Letteratura scientifica selezionata sul tema "Ethylene"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 16 novembre 2024

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Articoli di riviste sul tema "Ethylene"

Guo, Weijun, Junqing Yin, Zhen Xu, Wentao Li, Zhantao Peng, C. J. Weststrate, Xin Yu et al. "Visualization of on-surface ethylene polymerization through ethylene insertion". Science 375, n. 6585 (11 marzo 2022): 1188–91. http://dx.doi.org/10.1126/science.abi4407.

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Polyethylene production through catalytic ethylene polymerization is one of the most common processes in the chemical industry. The popular Cossee-Arlman mechanism hypothesizes that the ethylene be directly inserted into the metal–carbon bond during chain growth, which has been awaiting microscopic and spatiotemporal experimental confirmation. Here, we report an in situ visualization of ethylene polymerization by scanning tunneling microscopy on a carburized iron single-crystal surface. We observed that ethylene polymerization proceeds on a specific triangular iron site at the boundary between two carbide domains. Without an activator, an intermediate, attributed to surface-anchored ethylidene (CHCH 3 ), serves as the chain initiator (self-initiation), which subsequently grows by ethylene insertion. Our finding provides direct experimental evidence of the ethylene polymerization pathway at the molecular level.

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Liu, Chunyan. "Biodegradable Poly(ethylene succinate-co-ethylene oxalate-co-diethylene glycol succinate): Effects of a Small Amount of Ethylene Oxalate Content on the Properties of Poly(ethylene succinate)". Polymer Korea 45, n. 2 (31 marzo 2021): 294–302. http://dx.doi.org/10.7317/pk.2021.45.2.294.

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Gu, Mengmeng, James A. Robbins e Curt R. Rom. "The Role of Ethylene in Water-deficit Stress Responses in Betula papyrifera Marsh". HortScience 42, n. 6 (ottobre 2007): 1392–95. http://dx.doi.org/10.21273/hortsci.42.6.1392.

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One-year-old paper birch (Betula papyrifera Marsh.) seedlings were exposed to water deficit, ethylene, or inhibitors of ethylene action under greenhouse conditions to investigate ethylene's role in water-deficit stress-induced leaf abscission. Exposing well-watered and water-stressed paper birch to 20 ppm ethylene resulted in more than 50% leaf abscission after 96 h regardless of plant water status. However, application of a physiological level (1 ppm) of ethylene did not cause leaf abscission in either well-watered or water-stressed paper birch. Inhibitors of ethylene action (1ppm 1-methylcyclopropene or 0.1 mm silver thiosulfate) did not affect predawn water potential, gas exchange, or chlorophyll fluorescence. A significant increase in ethylene production was not detected in water-stressed paper birch before the onset of significant leaf abscission. Based on these observations, ethylene would appear to play a minor role in water-deficit stress-induced leaf abscission in paper birch.

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Khan, Sheen, Ameena Fatima Alvi e Nafees A. Khan. "Role of Ethylene in the Regulation of Plant Developmental Processes". Stresses 4, n. 1 (8 gennaio 2024): 28–53. http://dx.doi.org/10.3390/stresses4010003.

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Ethylene, a gaseous phytohormone, is emerging as a central player in the intricate web of plant developmental processes from germination to senescence under optimal and stressed conditions. The presence of ethylene has been noted in different plant parts, including the stems, leaves, flowers, roots, seeds, and fruits. This review aims to provide a comprehensive overview of the regulatory impact of ethylene on pivotal plant developmental processes, such as cell division and elongation, senescence, abscission, fruit and flower development, root hair formation, chloroplast maturation, and photosynthesis. The review also encompasses ethylene biosynthesis and signaling: a snapshot of the regulatory mechanisms governing ethylene production. Understanding of the impact of ethylene’s regulatory functions on plant developmental processes has significant implications for agriculture, biotechnology, and our fundamental comprehension of plant biology. This review underscores the potential of ethylene to revolutionize plant development and crop management.

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Cheong, Minserk, e Ajeet Singh. "A Density Functional Study on Ethylene Trimerization and Tetramerization Using Real Sasol Cr-PNP Catalysts". Molecules 28, n. 7 (30 marzo 2023): 3101. http://dx.doi.org/10.3390/molecules28073101.

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To gain molecular-level insight into the intricate features of the catalytic behavior of chromium–diphosphine complexes regarding ethylene tri- and tetramerizations, we performed density functional theory (DFT) calculations. The selective formation of 1-hexene and 1-octene by the tri- and tetramerizations of ethylene are generally accepted to follow the metallacycle mechanism. To explore the mechanism of ethylene tri- and tetramerizations, we used a real Sasol chromium complex with a nitrogen-bridged diphosphine ligand with ortho- and para-methoxyaryl substituents. We explore the trimerization mechanism for ethylene first and, later on for comparison, we extend the potential energy surfaces (PES) for the tetramerization of ethylene with both catalysts. The calculated results reveal that the formation of 1-hexene and 1-octene with the ortho-methoxyaryl and para-methoxyaryl Cr-PNP catalysts have nearly similar potential energy surfaces (PES). From the calculated results important insights are gained into the tri- and tetramerizations. The tetramerization of ethylene with the para-methoxyaryl Cr-PNP catalyst lowers the barrier height by ~2.6 kcal/mol compared to that of ethylene with the ortho-methoxyaryl Cr-PNP catalyst. The selectivity toward trimerization or tetramerization comes from whether the energy barrier for ethylene insertion to metallacycloheptane is higher than β-hydride transfer to make 1-hexene. The metallacycle mechanism with Cr (I)–Cr (III) intermediates is found to be the most favored, with the oxidative coupling of the two coordinated ethylenes to form chromacyclopentane being the rate-determining step.

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Cao, Yihan, Wei-Chun Shih, Nattamai Bhuvanesh e Oleg V. Ozerov. "Reversible addition of ethylene to a pincer-based boryl-iridium unit with the formation of a bridging ethylidene". Chemical Science 11, n. 40 (2020): 10998–1002. http://dx.doi.org/10.1039/d0sc04748a.

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Truong Quoc, Hung, Nhat Phan Long e Tuy Dao Quoc. "Synthesis of mesoporous Co/Al-SBA-15 catalyst and application to ethylene hydropolymerization". Vietnam Journal of Catalysis and Adsorption 9, n. 2 (31 luglio 2020): 107–13. http://dx.doi.org/10.51316/jca.2020.037.

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Liquid fuel, a mixture of ethylene’s liquid oligomer, from ethylene was successfully carried out by oligomerization of ethylene in the presence of Co/Al-SBA-15. The mesoporous Co/Al-SBA-15 catalyst was prepared through impregnation of varies amount of Co (5, 7.5, 10, and 15 wt.%) into Al-SBA-15. The conversion of ethylene was performed at atmospheric pressure and 190°C in the presence of CO and H2, and 08 hour/day. Through all of Co impregnated proportion on Al-SBA-15 (5, 7.5, 10 and 15 wt.%), the GC-MS result showed the liquid hydrocarbon were obtained as naptha (15.37÷30.53%), gasoline (10.65÷21.17%), kerosene (1.49÷20.50%) and diesel (3.21÷3.69%) fraction. The highest conversion of ethylene into liquid fuel was found in the presence of 7.5%Co/Al-SBA-15, with the yield of 20%. Byproducts was also obtained during the conversion, e.g. 3,4,5-methylnonane, 2,3 dimethylnonane, 3-methylheptane, and 4-ethylheptane, which was approximately 30% of total product volume.

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Ali, Amjad, Muhammad Nadeem, Jinwei Lu, Jamile Mohammadi Moradian, Tahir Rasheed, Tariq Aziz, Chanez Maouche et al. "Rapid kinetic evaluation of homogeneous single-site metallocene catalysts and cyclic diene: how do the catalytic activity, molecular weight, and diene incorporation rate of olefins affect each other?" RSC Advances 11, n. 50 (2021): 31817–26. http://dx.doi.org/10.1039/d1ra06243c.

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Foster, Gillian. "Low-Carbon Futures for Bioethylene in the United States". Energies 12, n. 10 (22 maggio 2019): 1958. http://dx.doi.org/10.3390/en12101958.

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The manufacture of the chemical ethylene, a key ingredient in plastics, currently depends on fossil-fuel-derived carbon and generates significant greenhouse gas emissions. Substituting ethylene’s fossil fuel feedstock with alternatives is important for addressing the challenge of global climate change. This paper compares four scenarios for meeting future ethylene supply under differing societal approaches to climate change based on the Shared Socioeconomic Pathways. The four scenarios use four perspectives: (1) a sustainability-focused pathway that demands a swift transition to a bioeconomy within 30 years; (2) a regional energy-focused pathway that supports broad biomass use; (3) a fossil-fuel development pathway limited to corn grain; and (4) a fossil-fuel development pathway limited to corn grain and corn stover. Each scenario is developed using the latest scientifically informed future feedstock analyses from the 2016 Billion-Ton report interpreted with perspectives on the future of biomass from recent literature. The intent of this research is to examine how social, economic, and ecological changes determining ethylene supply fit within biophysical boundaries. This new approach to the ethylene feedstocks conundrum finds that phasing out fossil fuels as the main source of U.S. ethylene is possible if current cellulosic ethanol production expands.

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Ali, Amjad, Muhammad Khurram Tufail, Muhammad Imran Jamil, Waleed Yaseen, Nafees Iqbal, Munir Hussain, Asad Ali, Tariq Aziz, Zhiqiang Fan e Li Guo. "Comparative Analysis of Ethylene/Diene Copolymerization and Ethylene/Propylene/Diene Terpolymerization Using Ansa-Zirconocene Catalyst with Alkylaluminum/Borate Activator: The Effect of Conjugated and Nonconjugated Dienes on Catalytic Behavior and Polymer Microstructure". Molecules 26, n. 7 (2 aprile 2021): 2037. http://dx.doi.org/10.3390/molecules26072037.

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The copolymerization of ethylene‒diene conjugates (butadiene (BD), isoprene (IP) and nonconjugates (5-ethylidene-2-norbornene (ENB), vinyl norbornene VNB, 4-vinylcyclohexene (VCH) and 1, 4-hexadiene (HD)), and terpolymerization of ethylene-propylene-diene conjugates (BD, IP) and nonconjugates (ENB, VNB, VCH and HD) using two traditional catalysts of C2-symmetric metallocene—silylene-bridged rac-Me2Si(2-Me-4-Ph-Ind)2ZrCl2 (complex A) and ethylene-bridged rac-Et(Ind)2ZrCl2 (complex B)—with a [Ph3C][B(C6F5)4] borate/TIBA co-catalyst, were intensively studied. Compared to that in the copolymerization of ethylene diene, the catalytic activity was more significant in E/P/diene terpolymerization. We obtained a maximum yield of both metallocene catalysts with conjugated diene between 3.00 × 106 g/molMt·h and 5.00 × 106 g/molMt·h. ENB had the highest deactivation impact on complex A, and HD had the most substantial deactivation effect on complex B. A 1H NMR study suggests that dienes were incorporated into the co/ter polymers’ backbone through regioselectivity. ENB and VNB, inserted by the edo double bond, left the ethylidene double bond intact, so VCH had an exo double bond. Complex A’s methyl and phenyl groups rendered it structurally stable and exhibited a dihedral angle greater than that of complex B, resulting in 1, 2 isoprene insertion higher than 1, 4 isoprene that is usually incapable of polymerization coordination. High efficiency in terms of co- and ter- monomer incorporation with higher molecular weight was found for complex 1. The rate of incorporation of ethylene and propylene in the terpolymer backbone structure may also be altered by the conjugated and nonconjugated dienes. 13C-NMR, 1H-NMR, and GPC techniques were used to characterize the polymers obtained.

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Tesi sul tema "Ethylene"

Robinson, Leslie A. (Leslie Anne) 1982. "Structural opportunities of ETFE (ethylene tetra fluoro ethylene)". Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/31127.

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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2005.
Includes bibliographical references (leaves 53-54).
An exploration of ETFE (ethylene tetra fluoro ethylene) foil cushions was performed in its use for building cladding. ETFE foil cushions consist of alternating layers of ETFE film and air cavities. An inflation system pressurizes the foil cushions prestressing the film layers to carry applied load. The ETFE cushion system is an extremely lightweight plastic offering considerable advantages over traditional cladding materials. ETFE foil cushions are self-cleaning, highly transparent to light, resistant to weathering and can be manufactured in almost any shape and size. Incorporating ETFE into a building's cladding results in a more efficient and low maintenance structure. ETFE foil cushions are successfully being implemented in cladding for botanical gardens, zoo buildings, and swimming pools. ETFE is currently finding its place as an effective alternative to glass in more traditional buildings as roofing for courtyards, atria, and shopping malls.
by Leslie A. Robinson.
M.Eng.

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Glikman, Jean-François. "Oxydation photo-thermique des copolymeres ethylene-acetate de vinyle, ethylene-acrylate d'ethyle, ethylene-acide acrylique". Clermont-Ferrand 2, 1987. http://www.theses.fr/1987CLF21050.

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Irradiation sous vide et dans l'air. La vitesse d'apparition des produits de photooxydation depend du type de copolymere. Cinetique et mecanisme. Mise en evidence de la labilite croissante de l'atome d'hydrogene tertiaire situe en position alpha des groupes substituants quand on passe de l'acetate a l'ethylate et a l'acide. Influence de charges et de stabilisants

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Mbarawa, M., W. Lee, YW Nam e SH Chung. "Ethylene propane and ethylene ester synergistic effects on soot formation". R&D Journal of the South African Institution of Mechanical Engineering, 2007. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1000860.

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In this study, the synergistic elfects of ethylene-propane and ethylene-dimethyl ester (DME) mirtures on soot formation were investigated experimentully using u coflow dilfusion flame burnen The soot volume fraction, soot particle diameter and number density were measured and compured to the homogenous mixture. Addition of DME and propane to the ethylene fuel increased soot volume fraction in the ethylene flames. The ethylene- propnne has more pronounced synergistic ffict in compsrison to the ethylene-DME flame* This is due to the fact that during the decomposition of propane some methyl radicals are generated, The reuctions related to these methyl radicals promote the formation of propargyl rodiculs and conseqaently the formation of benzene through propargyl self-reaction and finally to the soot formation. Althoagh DME decomposition produces methyl, the C-O bond in the DME removes some carbon from the reaction puth that produces soot, Hence the soot formation in ethylene-DME mixture is much slower than that in ethylene-propane mixtuFe,

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Shaikh, Yacoob. "Towards Selective Ethylene Tetramerization". Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/23161.

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There is an increasing trend towards advancing the understanding and development of ethylene oligomerization catalysts, both in academia and industry. The metal of choice in this chemistry is invariably chromium, which has shown great versatility in selective trimerization/tetramerization, non-selective oligomerization and polymerization of ethylene. While much success has been achieved in ethylene trimerization, the same con not be said about tetramerization catalysis. Aminophosphine based ligands have demonstrated their ability towards selective 1-octene production, however, the popular PNP catalyst is able to achieve only 70% selectivity. In order to explore the possibility of developing and enhancing the selectivity of chromium based ethylene tetramerization catalyst, this thesis work was undertaken. The ligand systems we chose for our work were bidentate aminophosphine based (PN(CH2)nNP), which has yielded interesting selective oligomerization. Subtle modifications were found to result in drastic changes in selectivity, from tetramerization (PN(CH2)3NP) to trimerization (PN(CH2)2NP). We managed to successfully develop the first truly selective (over 90%) 1-octene catalyst with polymer-free behavior. Further modifications on the ligand framework, where one atom of Si was used to link the two NP units, resulted in non-selective oligomerization, in which case we determined that the oxidation-state of chromium is a key player. We explored other modifications on our selective ligands in which one of the arms on the bidentate ligand was replaced with a base-donor amine, phosphine or pyridine, and resulted in interesting selectivity changes. The final modification that we tested was a novel N(CH2)2P ligand and found it to be a highly active, non-selective oligomerization catalyst.

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Auden, Noel Geraint. "Ethylene-vinyl acetate copolymers". Thesis, Lancaster University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239046.

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Porter, Andrew J. R. "The regulation of ethylene biosynthesis by the ethylene-forming enzyme in plant tissues". Thesis, University of Reading, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.259342.

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Burgess, Steven K. "Fundamentals of transport in poly(ethylene terephthalate) and poly(ethylene furanoate) barrier materials". Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/54887.

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The increasing use of polymeric materials in food packaging applications is due to many factors; however, most are related to cost. While poly(ethylene terephthalate) (PET) is currently the industry standard for soft-drink bottles, more stringent requirements on the barrier properties to oxygen are needed for PET to expand further into more demanding markets (i.e., juice, etc). The current work examines the fundamental oxygen and carbon dioxide permeation and sorption properties of amorphous, caffeine antiplasticized PET and amorphous poly(ethylene furanoate) (PEF), which is a new biologically sourced polyester that exhibits significantly enhanced performance compared to petroleum-sourced PET. The fundamental transport data reported herein at 35°C illustrate that amorphous PEF exhibits significant reductions in permeability for oxygen (11X), carbon dioxide (19X), and water (2X) compared to amorphous PET. Such impressive barrier enhancements are unexpected since PEF exhibits a higher free volume compared to PET. Further investigation into the fundamental chain motional processes which contribute to penetrant diffusion, as probed via dynamic mechanical and solid-state NMR methods, reveals that the polymer ring-flipping motions in PEF are largely suppressed compared to those for PET. Such behavior allows for rationalization of the reduced transport properties compared to PET. Additional characterization techniques (i.e., thermal, mechanical, density, etc.) are used to develop a more complete understanding of PEF and caffeine antiplasticized PET, with the ultimate goal of relating these properties to penetrant transport.

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Ndiripo, Anthony. "Comparative study on the molecular structure of ethylene/1-octene, ethylene/1-heptene and ethylene/1-pentene copolymers using advanced analytical methods". Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/96889.

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Thesis (MSc)--Stellenbosch University, 2015.
ENGLISH ABSTRACT: Linear low density polyethylene (LLDPE), one of the fastest growing types of polyethylene, is made from the copolymerisation of ethylene and higher 1-olefin comonomers. 1-octene is the comonomer of choice as it gives mechanically better LLDPEs as compared to other 1-olefins. Recently, a shortage of 1-octene has been observed in the global market. Considering the fact that ethylene/1-heptene (EH) copolymers may have properties that are very similar to those of ethylene/1-octene (EO), replacing 1-octene with 1-heptene as the comonomer in the manufacture of commercial linear low density polyethylene (LLDPE) is a viable option. In order to do so, evaluation of microstructural and mechanical properties of both types of resins and their comparison were carried out first. Several LLDPE resins were synthesised using Ziegler-Natta (ZN) and metallocene type catalysts. The LLDPE resins were made using varying amounts of the comonomer to obtain copolymers of different compositions. Ten of the ZN-LLDPE resins became the core focus of the present study. Carbon-13 nuclear magnetic resonance spectroscopy (13C NMR) showed the differences in the compositions of both the EH and EOresins. Crystallisation analysis fractionation (CRYSTAF), differential scanning calorimetry (DSC) and high temperature high performance liquid chromatography (HT-HPLC) revealed the presence of at least two fractions within the EH and EO copolymers which varied in quantity and chemical composition as the comonomer content was increased. The fractions were identified as being the copolymer (of ethylene and the comonomer) and polyethylene. Comparisons of the EH and EO CRYSTAF and HPLC data showed similarities in the microstructures of the resins. Preparative-temperature rising elution fractionation (prep-TREF) was used to obtain several fractions from each resin for quantification and analyses. DSC, HT-HPLC, CRYSTAF, and 13CNMR revealed close similarities in the fractions of EH and EO copolymers with comparable comonomer contents. It also was revealed that TREF fractionations are influenced by the bulk resin comonomer content. EH and EO copolymers demonstrated high similarities in tensile strength and Young’s modulus at comonomer contents of < 3 mol %. Minor differences in the mentioned properties at comonomer content of > 3 mol % were attributed to the slightly better ability of 1-octene at reducing crystallinity as compared to 1-heptene as well as small differences in the comonomer contents of the test samples. The results of the study suggest that 1-heptene can be used in the place of 1-octene in the commercial manufacture of LLDPE.
AFRIKAANSE OPSOMMING: Lineêre lae digtheid poliëtileen (LLDPE), een van die vinnigste groeiende poliëtileen tipes, word produseer deur die ko-polimerisasie van etileen en ‘n hoër 1-olefien ko-monomeer. 1-okteen is die ko-monomeer wat die meeste gebruik word aangesien dit LLDPE met die beste meganiese eienskappe produseer. Daar is egter ‘n tekort aan 1-okteen in die globale mark. Aangesien etileen/1-hepteen (EH) kopolimere moontlik soortgelyke eienskappe het as etileen/1-okteen (EO), kan 1-okteen moontlik vervang word deur 1-hepteen as ‘n komonomeer in die produksie van LLDPE. Om dit te doen is die meganiese en mikrostrukturele eienskappe van beide polimere geëvalueer. Verskeie LLDPE polimere is gesintetiseer met behulp van Ziegler-Natta (ZN) en metalloseen kataliste. Die komonomeer inhoud is gevarieer om LLDPE polimere te produseer met verskillende komposisie. Tien van die gesintetiseerde ZN-LLDPE polimere is gekies en is die kernfokus van die huidige studie. 13-Koolstof kern magnetiese resonans spektroskopie (13C KMR) het die variasie in ko-monomeer inhoud bevestig van beide die EH en EO polimere. Kristallisasie analise fraksioneering (CRYSTAF), differensiële skandeer kalorimetrie (DSC) en 'n hoë temperatuur hoë verrigting vloeistof chromatografie (HT-HPLC) het die teenwoordigheid van ten minste twee fraksies binne die EH en EO ko-polimeer bevestig wat ‘n variasie in hoeveelheid en chemise samestelling getoon het met ‘n toename van die ko-monomeer inhoud in die ko-polimeer. CRYSTAF en HT-HPLC data het getoon dat hierdie fraksies in EH en EO ooreenkomstige mikrostrukturele gedrag getoon het. Preparatiewe temperatuur styging elueering fraksioneering (prep-TREF) is gebruik om die polimere te fraksioneer om sodoende kwantitief die poliëtileen fraksies te verky en te analiseer. Verdere analise van die fraksies deur DSC, HT-HPLC, CRYSTAF en 13C KMR het getoon dat die fraksies, bekom van die EH en EO kopolimere met vergelykbare ko-monomeer inhoud, baie dieselfde eienskappe toon. Die analises het ook getoon dat die TREF fraksionering beinvloed word deur die ko-monomeer inhoud van die oorspronklike ko-polimeer.

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Resnick, Josephine Stockton. "Reversion-to-ethylene-sensitivity1 a novel regulator of ethylene receptor function in Arabidopsis thaliana /". College Park, Md. : University of Maryland, 2006. http://hdl.handle.net/1903/4142.

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Thesis (Ph. D.) -- University of Maryland, College Park, 2006.
Thesis research directed by: Cell Biology & Molecular Genetics. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

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Nehring, Ramlah Bliss. "Characterization of ETHYLENE INSENSITIVE SIX and the ENHANCER OF ETHYLENE INSENSITIVE in Arabidopsis thaliana". Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2007. http://wwwlib.umi.com/cr/ucsd/fullcit?p3262184.

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Thesis (Ph. D.)--University of California, San Diego, 2007.
Title from first page of PDF file (viewed April 9, 2008). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 102-117).

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Libri sul tema "Ethylene"

Arshad, Muhammad, e William T. Frankenberger. Ethylene. Boston, MA: Springer US, 2002. http://dx.doi.org/10.1007/978-1-4615-0675-1.

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Binder, Brad M., e G. Eric Schaller, a cura di. Ethylene Signaling. New York, NY: Springer New York, 2017. http://dx.doi.org/10.1007/978-1-4939-6854-1.

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T, Jacobsen Richard, Reuck K. M. de e Thermodynamic Tables Project, a cura di. Ethylene (ethene). Oxford [England]: Blackwell Scientific Publications, 1988.

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United States. Dept. of Labor, a cura di. Ethylene oxide. [Washington, D.C.?]: U.S. Dept. of Labor, 1995.

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United States. Occupational Safety and Health Administration, a cura di. Ethylene oxide. [Washington, D.C.?: U.S. Dept. of Labor, Occupational Safety and Health Administration, 1988.

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Programme, United Nations Environment, International Labour Organisation e World Health Organization, a cura di. Ethylene oxide. Geneva: World Health Organization, 1985.

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E, Meek M., Lewis Mark Andrew 1962-, United Nations Environment Programme, International Labour Organisation, Inter-Organization Programme for the Sound Management of Chemicals. e World Health Organization, a cura di. Ethylene oxide. Geneva: World Health Organization, 2003.

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Wen, Chi-Kuang, a cura di. Ethylene in Plants. Dordrecht: Springer Netherlands, 2015. http://dx.doi.org/10.1007/978-94-017-9484-8.

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Harris, J. Milton, e Samuel Zalipsky, a cura di. Poly(ethylene glycol). Washington, DC: American Chemical Society, 1997. http://dx.doi.org/10.1021/bk-1997-0680.

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Dobson, S. Ethylene glycol: Environmental aspects. Geneva: World Health Organization, 2000.

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Capitoli di libri sul tema "Ethylene"

Arshad, Muhammad, e William T. Frankenberger. "The Plant Hormone, Ethylene". In Ethylene, 1–9. Boston, MA: Springer US, 2002. http://dx.doi.org/10.1007/978-1-4615-0675-1_1.

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Arshad, Muhammad, e William T. Frankenberger. "Ethylene in Plant Physiology". In Ethylene, 11–50. Boston, MA: Springer US, 2002. http://dx.doi.org/10.1007/978-1-4615-0675-1_2.

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Arshad, Muhammad, e William T. Frankenberger. "Biochemistry of Microbial Production of Ethylene". In Ethylene, 51–96. Boston, MA: Springer US, 2002. http://dx.doi.org/10.1007/978-1-4615-0675-1_3.

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Arshad, Muhammad, e William T. Frankenberger. "Factors Affecting Microbial Production of Ethylene". In Ethylene, 97–138. Boston, MA: Springer US, 2002. http://dx.doi.org/10.1007/978-1-4615-0675-1_4.

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Arshad, Muhammad, e William T. Frankenberger. "Ethylene in Soil". In Ethylene, 139–93. Boston, MA: Springer US, 2002. http://dx.doi.org/10.1007/978-1-4615-0675-1_5.

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Arshad, Muhammad, e William T. Frankenberger. "Ethylene in Symbiosis". In Ethylene, 195–240. Boston, MA: Springer US, 2002. http://dx.doi.org/10.1007/978-1-4615-0675-1_6.

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Arshad, Muhammad, e William T. Frankenberger. "Ethylene in Pathogenesis". In Ethylene, 241–88. Boston, MA: Springer US, 2002. http://dx.doi.org/10.1007/978-1-4615-0675-1_7.

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Arshad, Muhammad, e William T. Frankenberger. "Ethylene in Agriculture: Synthetic and Natural Sources and Applications". In Ethylene, 289–335. Boston, MA: Springer US, 2002. http://dx.doi.org/10.1007/978-1-4615-0675-1_8.

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Moore, Thomas C. "Ethylene". In Biochemistry and Physiology of Plant Hormones, 228–54. New York, NY: Springer US, 1989. http://dx.doi.org/10.1007/978-1-4612-3654-2_6.

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Bhatla, Satish C. "Ethylene". In Plant Physiology, Development and Metabolism, 643–61. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-13-2023-1_19.

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Atti di convegni sul tema "Ethylene"

Alcalde-Castro, Juan Jose, Laura Álvarez-Gil e Alejandro Restrepo-Martínez. "Experimental Evaluation of Photothermal Conversion Magnetite Nanofluids under the Influence of Dynamic Magnetic Field". In Propagation Through and Characterization of Atmospheric and Oceanic Phenomena, FD1.8. Washington, D.C.: Optica Publishing Group, 2024. http://dx.doi.org/10.1364/pcaop.2024.fd1.8.

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The study investigates improved energy conversion efficiency in solar thermal systems using an oscillating magnetic field in nanofluid applications. Three concentrations of magnetite/ethylene glycol nanoparticles and ethylene glycol alone are evaluated.

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Alcalde-Castro, Juan Jose, Laura Álvarez-Gil e Alejandro Restrepo-Martínez. "Experimental Evaluation of Photothermal Conversion Magnetite Nanofluids under the Influence of Dynamic Magnetic Field". In Imaging Systems and Applications, FD1.8. Washington, D.C.: Optica Publishing Group, 2024. http://dx.doi.org/10.1364/isa.2024.fd1.8.

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Alcalde-Castro, Juan Jose, Laura Álvarez-Gil e Alejandro Restrepo-Martínez. "Experimental Evaluation of Photothermal Conversion Magnetite Nanofluids under the Influence of Dynamic Magnetic Field". In Computational Optical Sensing and Imaging, FD1.8. Washington, D.C.: Optica Publishing Group, 2024. http://dx.doi.org/10.1364/cosi.2024.fd1.8.

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Alcalde-Castro, Juan Jose, Laura Álvarez-Gil e Alejandro Restrepo-Martínez. "Experimental Evaluation of Photothermal Conversion Magnetite Nanofluids under the Influence of Dynamic Magnetic Field". In Adaptive Optics: Methods, Analysis and Applications, FD1.8. Washington, D.C.: Optica Publishing Group, 2024. http://dx.doi.org/10.1364/aopt.2024.fd1.8.

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Alcalde-Castro, Juan Jose, Laura Álvarez-Gil e Alejandro Restrepo-Martínez. "Experimental Evaluation of Photothermal Conversion Magnetite Nanofluids under the Influence of Dynamic Magnetic Field". In 3D Image Acquisition and Display: Technology, Perception and Applications, FD1.8. Washington, D.C.: Optica Publishing Group, 2024. http://dx.doi.org/10.1364/3d.2024.fd1.8.

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Rodriguez-Gil, Edwin A., e Rakesh Agrawal. "Internally Heated Crackers for Decarbonization and Optimization of Ethylene Production". In Foundations of Computer-Aided Process Design, 883–91. Hamilton, Canada: PSE Press, 2024. http://dx.doi.org/10.69997/sct.168053.

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Ethylene is a crucial precursor for a diverse spectrum of products and services. As global production exceeds 150 million tons annually and is projected to surpass 255 million tons by 2035, the imperative for sustainable and efficient ethylene production becomes increasingly clear. Despite Externally Heated Crackers (EHCs) dominating ethylene production for over a century, they face intrinsic limitations that necessitate transformative solutions, including intense radial thermal gradients, high metal demand, and substantial CO2 emissions. This study employs a robust combination of Computational Fluid Dynamics (CFD) coupled with detailed chemical kinetics to rigorously assess selected configurations of Internally Heated Crackers (IHCs) against the leading EHC designs. Our findings reveal that IHCs exhibit the potential to enhance ethylene output by a factor of 1.66 when compared to EHCs of the same length, diameter, and surface temperature. These results herald a promising era for developing more efficient cracking reactor designs, poised to redefine the landscape of sustainable chemical manufacturing towards achieving Net-Zero emissions. Embracing innovative technologies like IHCs presents an opportunity for the chemical industry to make significant strides in reducing its environmental footprint while meeting the growing global demand for ethylene and its derivatives.

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Balme, Lionel, e Joëlle Coutaz. "Ethylene". In the 21st International Conference. New York, New York, USA: ACM Press, 2009. http://dx.doi.org/10.1145/1629826.1629839.

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Cutler, Andrew D. "WIDECARS Measurement of Ethylene in Ethylene-Air Combustion". In Laser Applications to Chemical, Security and Environmental Analysis. Washington, D.C.: OSA, 2016. http://dx.doi.org/10.1364/lacsea.2016.lw5g.1.

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Mahadeva, Suresha K., Jyoti Nayak e Jaehwan Kim. "Poly (ethylene oxide) - poly (ethylene glycol) blended cellulose electroactive paper actuator". In The 15th International Symposium on: Smart Structures and Materials & Nondestructive Evaluation and Health Monitoring, a cura di Marcelo J. Dapino e Zoubeida Ounaies. SPIE, 2008. http://dx.doi.org/10.1117/12.776536.

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Zamboulis, Alexandra, Eleftheria Xanthopoulou, Evangelia Mpalla, Lazaros Papadopoulos, Zoi Terzopoulou, Dimitrios N. Bikiaris e George Z. Papageorgiou. "Synthesis and Characterization of Novel Poly(ethylene furanoate-co-ethylene vanillate) Copolymers". In The First International Conference on “Green” Polymer Materials 2020. Basel, Switzerland: MDPI, 2020. http://dx.doi.org/10.3390/cgpm2020-07207.

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Rapporti di organizzazioni sul tema "Ethylene"

Woodson, William, Shimon Mayak e Haim Rabinowitch. Physiological and Molecular Characterization of the Response to Ethylene during Senescence of Carnation Genotypic Variants. United States Department of Agriculture, luglio 1995. http://dx.doi.org/10.32747/1995.7613011.bard.

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The senescence of carnation (Dianthus caryophyllus L.) flowers is associated with increased production of the phytohormone ethylene, which in turn serves to initiate and regulate the processes involved in programmed petal death. We investigated the regulation of ethylene production and petal senescence in carnation. Several carnation genotypes were identified that exhibited extended vase-life in comparison to flowers from typical commercial cultivars. The capacity of these genotypes to produce ethylene during postharvest vase-life and to respond to exogenous ethylene was investigated. Several genotypes, represented by 'Sandrosa' and 87-37G produced little ethylene durig their postharvest vase-life and as a result failed to exhibit the symptoms (in-rolling and wilting) typical of flowers producing elevated levels of ethylene. These genotypes were further separated by their capacity to respond to exogenous ethylene by both increased ethylene synthesis and premature petal senescence. In one case a genotype (799) was identified that was not capable of responding to exogenous ethylene by either increased ethylene production or premature petal senescence. The regulation of ethylene production during petal senescence was investigated both at the enzyme and gene levels. A full length cDNA was identified for the petal senescence-related ACC synthase gene. Utilizing this, and other ethylene biosynthetic pathway cDNA probes, an increase in both ACC synthase and ACC oxidase mRNAs were detected following ethylene treatment. An increase in ACC oxidase mRNA and enzyme activity was detected within 2-3 h following ethylene treatment, indicating the expression of this gene is an early response to ethylene. An investigation into the expression of novel proteins during petal senescence revealed a number of polypeptides increased in abundance and possibly play a role in the regulation or biochemical processes of senescence. One polypeptide of 70 kDa was identified as being encoded by the previously characterized gene SR12 and possibly represents a b-galactosidase involved in the remobilization of carbohydrates during senescence.

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O'Neill, Sharman, Abraham Halevy e Amihud Borochov. Molecular Genetic Analysis of Pollination-Induced Senescence in Phalaenopsis Orchids. United States Department of Agriculture, 1991. http://dx.doi.org/10.32747/1991.7612837.bard.

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The project investigated the molecular genetic and biochemical basis of pollination-induced senescence of Phalaenopsis flowers. This experimental system offered unique advantages in that senescence is strictly regulated by pollination, providing the basis to experimentally initiate and synchronize senescence in populations of flowers. The postpollination syndrome in the Phalaenopsis orchid system was dissected by investigating the temporal and spatial regulation of ACC synthase gene expression. In the stigma, pollen-borne auxin induces the expression of the auxin-regulated ACC synthase (PS-ACS2) gene, resulting in ACC synthesis within 1 h following pollination. Newly formed ACC is oxidized by basal constitutive ACC oxidase to ethylene, which then induces the expression of the ethylene-regulated ACC synthase(PS-ACS1) and oxidase (ACO1) genes for further autocatalytic production of ethylene. It is speculated that during the 6-h period following pollination, emasculation leads to the production or release of a sensitivity factor that sensitizes the cells of the stigma to ethylene. ACC and ethylene molecules are translocated from the stigma to the labellum and perianth where ethylene induces the expression of PS-ACS1 and ACO1 resulting in an increased production of ACC and ethylene. Organ-localized ethylene is responsible for inrolling and senescence of the labellum and perianth. The regulation of ethylene sensitivity and signal transduction events in pollinated flowers was also investigated. The increase in ethylene sensitivity appeared in both the flower column and the perianth, and was detected as early as 4 h after pollination. The increase in ethylene sensitivity following pollination was not dependent on endogenous ethylene production. Application of linoleic and linoleic acids to Phalaenopsis and Dendrobium flowers enhanced their senescence and promoted ethylene production. Several major lipoxygenase pathway products including JA-ME, traumatic acid, trans-2-hexenal and cis-3-hexenol, also enhanced flower senescence. However, lipoxygenase appears to not be directly involved in the endogenous regulation of pollination-induced Phalaenopsis and Dendrobium flower senescence. The data suggest that short-chain saturated fatty acids may be the ethylene "sensitivity factors" produced following pollination, and that their mode of action involves a decrease in the order of specific regions i the membrane lipid bilayer, consequently altering ethylene action. Examination of potential signal transduction intermediates indicate a direct involvement of GTP-binding proteins, calcium ions and protein phosphorylation in the cellular signal transduction response to ethylene following pollination. Modulations of cytosolic calcium levels allowed us to modify the flowers responsiveness to ethylene.

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none,. Final Report: Evaluation of Alternative Technologies for Ethylene, Caustic-Chlorine, Ethylene Oxide, Ammonia, and Terephthalic Acid. Office of Scientific and Technical Information (OSTI), dicembre 2007. http://dx.doi.org/10.2172/1218630.

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Eshel, Amram, Jonathan P. Lynch e Kathleen M. Brown. Physiological Regulation of Root System Architecture: The Role of Ethylene and Phosphorus. United States Department of Agriculture, dicembre 2001. http://dx.doi.org/10.32747/2001.7585195.bard.

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Specific Objectives and Related Results: 1) Determine the effect of phosphorus availability on ethylene production by roots. Test the hypothesis that phosphorus availability regulates ethylene production Clear differences were found between the two plants that were studied. In beans ethylene production is affected by P nutrition, tissue type, and stage of development. There are genotypic differences in the rate of ethylene production by various root types and in the differential in ethylene production when P treatments are compared. The acceleration in ethylene production with P deficiency increases with time. These findings support the hypothesis that ethylene production may be enhanced by phosphorus deficiency, and that the degree of enhancement varies with genotype. In tomatoes the low-P level did not enhance significantly ethylene production by the roots. Wildtype cultivars and ethylene insensitive mutants behaved similarly in that respect. 2) Characterize the effects of phosphorus availability and ethylene on the architecture of whole root systems. Test the hypothesis that both ethylene and low phosphorus availability modify root architecture. In common bean, the basal roots give rise to a major fraction of the whole root system. Unlike other laterals these roots respond to gravitropic stimulation. Their growth angle determines the proportion of the root length in the shallow layers of the soil. A correlation between ethylene production and basal root angle was found in shallow rooted but not deep-rooted genotypes, indicating that acceleration of ethylene synthesis may account for the change in basal root angle in genotypes demonstrating a plastic response to P availability. Short-time gravitropic response of the tap roots of young bean seedlings was not affected by P level in the nutrient solution. Low phosphorus specifically increases root hair length and root hair density in Arabidopsis. We tested 7 different mutants in ethylene perception and response and in each case, the response to low P was lower than that of the wild-type. The extent of reduction in P response varied among the mutants, but every mutant retained some responsiveness to changes in P concentration. The increase in root hair density was due to the increase in the number of trichoblast cell files under low P and was not mediated by ethylene. Low P did not increase the number of root hairs forming from atrichoblasts. This is in contrast to ethylene treatment, which increased the number of root hairs partly by causing root hairs to form on atrichoblasts. 3) Assess the adaptive value of root architectural plasticity in response to phosphorus availability. A simulation study indicated that genetic variation for root architecture in common bean may be related to adaptation to diverse competitive environments. The fractal dimension of tomato root system was directly correlated with P level.

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Perl-Treves, Rafael, Rebecca Grumet, Nurit Katzir e Jack E. Staub. Ethylene Mediated Regulation of Sex Expression in Cucumis. United States Department of Agriculture, gennaio 2005. http://dx.doi.org/10.32747/2005.7586536.bard.

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Monoecious species such as melon and cucumber develop separate male and female (or bisexual) flowers on the same plant individual. They display complex genetic and hormonal regulation of sex patterns along the plant. Ethylene is known to play an important role in promoting femaleness and inhibiting male development, but many questions regarding critical sites of ethylene production versus perception, the relationship between ethylene and the sex determining loci, and the possible differences between melon and cucumber in this respect are still open. The general goal of the project was to elucidate the role of ethylene in determining flower sex in Cucumis species, melon and cucumber. The specific Objectives were: 1. Clone and characterize expression patterns of cucumber genes involved in ethylene biosynthesis and perception. 2. Genetic mapping of cloned genes and markers with respect to sex loci in melon and cucumber. 3. Produce and analyze transgenic melons altered in ethylene production or perception. In the course of the project, some modifications/adjustments were made: under Objective 2 (genetic mapping) a set of new mapping populations had to be developed, to allow better detection of polymorphism. Under Objective 3, cucumber transformation systems became available to us and we included this second model species in our plan. The main findings of our study support the pivotal role of ethylene in cucumber and melon sex determination and later stages of reproductive development. Modifying ethylene production resulted in profound alteration of sex patterns in melon: femaleness increased, and also flower maturation and fruit set were enhanced, resulting in earlier, more concentrated fruit yield in the field. Such effect was previously unknown and could have agronomic value. Our results also demonstrate the great importance of ethylene sensitivity in sex expression. Ethylene perception genes are expressed in sex-related patterns, e.g., gynoecious lines express higher levels of receptor-transcripts, and copper treatments that activate the receptor can increase femaleness. Transgenic cucumbers with increased expression of an ethylene receptor showed enhanced femaleness. Melons that expressed a defective receptor produced fewer hermaphrodite flowers and were insensitive to exogenous ethylene. When the expression of defective receptor was restricted to specific floral whorls, we saw that pistils were not inhibited by the blocked perception at the fourth whorl. Such unexpected findings suggest an indirect effect of ethylene on the affected whorl; it also points at interesting differences between melon and cucumber regarding the mode of action of ethylene. Such effects will require further study. Finally, our project also generated and tested a set of novel genetic tools for finer identification of sex determining genes in the two species and for efficient breeding for these characters. Populations that will allow easier linkage analysis of candidate genes with each sex locus were developed. Moreover, effects of modifier genes on the major femaleness trait were resolved. QTL analysis of femaleness and related developmental traits was conducted, and a comprehensive set of Near Isogenic Lines that differ in specific QTLs were prepared and made available for the private and public research. Marker assisted selection (MAS) of femaleness and fruit yield components was directly compared with phenotypic selection in field trials, and the relative efficiency of MAS was demonstrated. Such level of genetic resolution and such advanced tools were not used before to study these traits, that act as primary yield components to determine economic yields of cucurbits. In addition, this project resulted in the establishment of workable transformation procedures in our laboratories and these can be further utilized to study the function of sex-related genes in detail.

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Sisler, Edward C., Raphael Goren e Akiva Apelbaum. Controlling Ethylene Responses in Horticultural Crops at the Receptor Level. United States Department of Agriculture, ottobre 2001. http://dx.doi.org/10.32747/2001.7580668.bard.

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Ethylene is a plant hormone that controls many plant responses, such as growth, senescence, ripening, abscission and seed germination. Recently, 1-methy- cyclopropene (1-MCP), was shown to bind to ethylene receptor for a certain period of time and prevent ethylene action. The objectives of this research were to synthesize analogues of 1-MCP and test their potency to block the ethylene receptor and inhibit ethylene action. During the course of this project, procedures for synthesis and shipment of the cyclopropene compounds were developed as well assay procedures for each compound were worked out. Thirteen new compounds were synthesized. All of them are structural analogues of 1-MCP, with substitution in the 1-position and a side chain containing 2 to 10 carbons. After preliminary studies, nine promising compounds were selected for in-depth study. The potency of the compounds to inhibit ethylene action was tested on a wide scope of systems like: climacteric fruits (banana, avocado and tomato), the triple response (etiolated peas), and leaf abscission (citrus). As the putative inhibitors are suspected to compete for the site of binding and a competitive type of inhibition could be considered, a high concentration of ethylene (300 m1.L-1) was used to induce ripening and other physiological processes. The tests were conducted under extreme conditions which hasten ripening like treatment and storage at 22 to 25oC. There were fluctuations in the responses as related to the concentrations of the inhibitors. Some required much higher concentration to exert the same effect, while some, when applied at the same concentration, blocked the receptor for a longer period of time than the others. Some fruits and other plant organs responded differently to the same inhibitor, indicating differences in characteristics and availability of the ethylene receptors in the various tissues. The potency of the putative inhibitors was found to be greatly affected by their molecular structural and size. In addition, it was found that treatment with the inhibitor should be given before the onset of ethylene action In the case of fruit, treatment should be carried out before the pre-climacteric stage. Simultaneous treatment with ethylene and the inhibitors reduced the inhibitors' effect. The relationship between ethylene and the inhibitors is of a non-competitive nature. All the fruits treated with the putative inhibitors resumed normal ripening after recovery from the inhibition. This fact is of great importance when considering the inhibitors for practical use. The advantage of using inhibitors of ethylene action over inhibitors of ethylene production lies in the ability of the inhibitors of ethylene action to protect the tissue against both endogenous and exogenous ethylene, thus providing better overall protection. Our findings indicate that 1-MCP and its structural analogues are potent inhibitors of ethylene action capable of providing good protection against endogenous and exogenous ethylene. The fact that the compounds are in a gas phase and are non-phytotoxic, odorless and effective at minute concentrations, renders them promising candidates for commercial use. However, the development of water-soluble inhibitors will expand the potential use of the inhibitors in agriculture.

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Marinov, N. M., e P. C. Malte. Ethylene oxidation in a well-stirred reactor. Office of Scientific and Technical Information (OSTI), ottobre 1994. http://dx.doi.org/10.2172/110240.

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Atac, M., e G. Bauer. Aging tests of ethylene contaminated argon/ethane. Office of Scientific and Technical Information (OSTI), settembre 1994. http://dx.doi.org/10.2172/10193147.

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Yang, H., e G. C. Farrington. Poly(Ethylene Oxide) Electrolytes Containing Mixed Salts. Fort Belvoir, VA: Defense Technical Information Center, giugno 1992. http://dx.doi.org/10.21236/ada254816.

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Boring, Matt. PR-186-214508-R01 In-Service Welding onto Ethylene Pipelines. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), febbraio 2023. http://dx.doi.org/10.55274/r0012253.

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Welding onto an operating pipeline, or in-service welding, for modification and repair has been used safely by pipeline operating companies for many years. The two primary concerns when welding onto carbon steel pipelines are the safety of the repair crew and the integrity of the pipeline after the in-service welds have been completed. However in-service welding has been limited for some products that could react at the pipeline operating pressure if they reach a sufficient temperature that can occur during in-service welding. Even with this additional risk mitigation approach, some companies have historically been extremely cautious or have not allowed welding onto pipelines that contained some products. One such product is ethylene. Welding onto ethylene pipelines has been performed in the past but has more recently been considered a product for which in-service welding should not be undertaken due to the potential of an ethylene decomposition reaction that is exothermic and could result in a pipeline failure. The weld trials performed during this project were to test the hypothesis that an ethylene decomposition reaction that could result in a pipeline failure would not be produced as a result of in-service welding onto an ethylene pipeline. This was based on the background literature search and industry survey that showed in-service welding onto ethylene pipelines has been performed safely but generally there has been no detailed reporting of how those in-service welds were deposited. If an ethylene decomposition reaction does not result in a pipeline failure, then this work will be used to develop a relationship between welding heat inputs, pipeline wall thickness, and pipeline operating pressure under which in-service welds could safely be deposited onto an ethylene pipeline.

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