Artykuły w czasopismach: „Alkane And Alkene”

1

Giuffrè, Angelo Maria. "n-Alkanes and n-Alkenes in Virgin Olive Oil from Calabria (South Italy): The Effects of Cultivar and Harvest Date". Foods 10, nr 2 (1.02.2021): 290. http://dx.doi.org/10.3390/foods10020290.

Pełny tekst źródła

Streszczenie:

n-Alkanes and n-alkenes are components of the unsaponifiable fraction of an olive oil. These were analysed by GC on-column analysis and are here proposed as an additional tool to certify the origin, authenticity, traceability and chemical quality of olive oil produced in the Reggio Calabria province (South Italy). Nine cultivars were studied: Cassanese, Coratina, Itrana, Leccino, Nociara, Ottobratica, Pendolino, Picholine and Sinopolese grown in the region of Calabria (South Italy). n-Alkanes in the range from 21 to 35 chain carbon atoms and alkenes in the range from 23:1 to 25:1 chain carbon atoms were found with the following elution order: heneicosane (C21), docosane (C22), tricosene (C23:1), tricosane (C23), tetracosene (C24:1), tetracosane (C24), pentacosene (C25:1), pentacosane (C25), hexacosane (C26), eptacosane (C27), octacosane (C28), nonacosane (C29), triacontane (C30), entriacontane (C31), dotriacontane (C32), tritriacontane (C33), tetratriacontane (C34), pentatriacontane (C35). The oil of all cultivars showed a decreasing trend in total n-alkane and n-alkene content, with the oil of Sinopolese showing the highest content, varying from 328.50 to 214.00 mg/kg. Odd-chain alkanes predominated over even-chain n-alkanes, and tricosane, tetracosane and pentacosane were the most represented alkanes. Cultivar and harvest date significantly influenced the n-alkane and n-alkene content. These findings can be useful to distinguish different olive cultivars and to decide the fruit harvest date for the oil of the Reggio Calabria province (South Italy). A daily quantity of 30 g of olive oil of the Sinoplese cv (the one with the highest n-alkane and n-alkene content) was found to be in accordance with the suggestions of the European Agency for the evaluation of medicinal products Committee for veterinary medicinal products and biogenic hydrocarbons intake for the human diet.

Style APA, Harvard, Vancouver, ISO itp.

2

Dove, H., i M. Oliván. "The possible use of the alkenes (unsaturated hydrocarbons) of plant cuticular wax as diet composition markers in sheep". BSAP Occasional Publication 34 (2006): 1–7. http://dx.doi.org/10.1017/s1463981500042187.

Pełny tekst źródła

Streszczenie:

SummaryThe objective of the current study was to investigate the possible use of alkenes (unsaturated hydrocarbons) of plant waxes as diet composition markers in sheep. Twenty-four sheep (30 kg live weight) were housed in individual pens (n=16, “pen” sheep) or in metabolism crates (n=8, “crate” sheep) for the total collection of faeces. Once daily, sheep were fed 720 g DM of a two-component diet consisting of a roughage source (chaffed perennial ryegrass) and a high-quality supplement (unpelleted sunflower meal, SFM) in different proportions, 7:1, 6:2, 5:3 and 4:4 (4 pen sheep and 2 crate sheep/treatment). SFM was labelled with a solution of beeswax to provide an alkane/ alkene profile different from the chaff. Diet composition was estimated from C27, C29, C31 and C33 alkene concentrations in diet and faeces (total faeces or rectal grab samples), using the least-squares package ‘EatWhat’. Estimates were conducted with or without correction of faecal alkane concentrations for incomplete faecal recovery, calculated from the alkene intakes and faecal outputs in the crate sheep.Although the faecal alkene recoveries of alkenes were low, they did not differ between chain lengths for alkenes C27 to C33. Therefore in cage sheep, alkene-based estimates of SFM proportions, with or without faecal recovery correction, did not differ significantly from the proportions fed and were as accurate as earlier alkane-based estimates. In pen sheep, SFM proportions estimated from rectal grab samples were slightly but significantly over-estimated, regardless of whether or not recovery corrections were used. The over-estimates were not related to recovery corrections but to the small differences in concentrations between rectal grab samples from pen sheep and the total faeces from cage sheep. The lack of effect of recovery corrections does not mean they should be excluded from such calculations, as there may be situations in which there is an effect of carbon-chain length on alkene recovery. Use of recovery corrections also permits an estimate of whole-diet digestibility.The present results indicate that alkenes could be useful additional markers to the alkanes for estimating the proportion of two dietary components in diets offered to sheep.

Style APA, Harvard, Vancouver, ISO itp.

3

Grossi, Vincent, Cristiana Cravo-Laureau, Alain Méou, Danielle Raphel, Frédéric Garzino i Agnès Hirschler-Réa. "Anaerobic 1-Alkene Metabolism by the Alkane- and Alkene-Degrading Sulfate Reducer Desulfatibacillum aliphaticivorans Strain CV2803T". Applied and Environmental Microbiology 73, nr 24 (26.10.2007): 7882–90. http://dx.doi.org/10.1128/aem.01097-07.

Pełny tekst źródła

Streszczenie:

ABSTRACT The alkane- and alkene-degrading, marine sulfate-reducing bacterium Desulfatibacillum aliphaticivorans strain CV2803T, known to oxidize n-alkanes anaerobically by fumarate addition at C-2, was investigated for its 1-alkene metabolism. The total cellular fatty acids of this strain were predominantly C-(even number) (C-even) when it was grown on C-even 1-alkenes and predominantly C-(odd number) (C-odd) when it was grown on C-odd 1-alkenes. Detailed analyses of those fatty acids by gas chromatography-mass spectrometry after 6- to 10-week incubations allowed the identification of saturated 2- and 4-ethyl-, 2- and 4-methyl-, and monounsaturated 4-methyl-branched fatty acids with chain lengths that correlated with those of the 1-alkene. The growth of D. aliphaticivorans on (per)deuterated 1-alkenes provided direct evidence of the anaerobic transformation of these alkenes into the corresponding 1-alcohols and into linear as well as 10- and 4-methyl-branched fatty acids. Experiments performed with [13C]bicarbonate indicated that the initial activation of 1-alkene by the addition of inorganic carbon does not occur. These results demonstrate that D. aliphaticivorans metabolizes 1-alkene by the oxidation of the double bond at C-1 and by the subterminal addition of organic carbon at both ends of the molecule [C-2 and C-(ω-1)]. The detection of ethyl-branched fatty acids from unlabeled 1-alkenes further suggests that carbon addition also occurs at C-3. Alkylsuccinates were not observed as potential initial intermediates in alkene metabolism. Based on our observations, the first pathways for anaerobic 1-alkene metabolism in an anaerobic bacterium are proposed. Those pathways indicate that diverse initial reactions of 1-alkene activation can occur simultaneously in the same strain of sulfate-reducing bacterium.

Style APA, Harvard, Vancouver, ISO itp.

4

Cely-Pinto, Melissa, Bowen Wang i Juan C. Scaiano. "Photocatalytic Semi-Hydrogenation of Alkynes: A Game of Kinetics, Selectivity and Critical Timing". Nanomaterials 13, nr 17 (22.08.2023): 2390. http://dx.doi.org/10.3390/nano13172390.

Pełny tekst źródła

Streszczenie:

The semi-hydrogenation reaction of alkynes is important in the fine chemicals and pharmaceutical industries, and it is thus important to find catalytic processes that will drive the reaction efficiently and at a low cost. The real challenge is to drive the alkyne-to-alkene reaction while avoiding over-hydrogenation to the saturated alkane moiety. The problem is more difficult when dealing with aromatic substitution at the alkyne center. Simple photocatalysts based on Palladium tend to proceed to the alkane, and stopping at the alkene with good selectivity requires very precise timing with basically no timing tolerance. We report here that the goal of high conversion with high selectivity could be achieved with TiO2-supported copper (Cu@TiO2), although with slower kinetics than for Pd@TiO2. A novel bimetallic catalyst, namely, CuPd@TiO2 (0.8% Cu and 0.05% Pd), with methanol as the hydrogen source could improve the kinetics by 50% with respect to Cu@TiO2, while achieving selectivities over 95% and with exceptional timing tolerance. Further, the low Palladium content minimizes its use, as Palladium is regarded as an element at risk of depletion.

Style APA, Harvard, Vancouver, ISO itp.

5

Carrara, Nicolás, Carolina Betti, Fernando Coloma-Pascual, María Cristina Almansa, Laura Gutierrez, Cristian Miranda, Mónica E. Quiroga i Cecilia R. Lederhos. "High-Active Metallic-Activated Carbon Catalysts for Selective Hydrogenation". International Journal of Chemical Engineering 2018 (5.07.2018): 1–11. http://dx.doi.org/10.1155/2018/4307308.

Pełny tekst źródła

Streszczenie:

A series of low-loaded metallic-activated carbon catalysts were evaluated during the selective hydrogenation of a medium-chain alkyne under mild conditions. The catalysts and support were characterized by ICP, hydrogen chemisorption, Raman spectroscopy, temperature-programmed desorption (TPD), temperature-programmed reduction (TPR), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR micro-ATR), transmission electronic microscopy (TEM), and X-ray photoelectronic spectroscopy (XPS). When studying the effect of the metallic phase, the catalysts were active and selective to the alkene synthesis. NiCl/C was the most active and selective catalytic system. Besides, when the precursor salt was evaluated, PdN/C was more active and selective than PdCl/C. Meanwhile, alkyne is present in the reaction media, and geometrical and electronic effects favor alkene desorption and so avoid their overhydrogenation to the alkane. Under mild conditions, nickel catalysts are considerably more active and selective than the Lindlar catalyst.

Style APA, Harvard, Vancouver, ISO itp.

6

Jiang, Jing, Ying Hu, Xin Cai, Liudi Wang, Yanwei Hu, Shaohua Chen, Shilei Zhang i Yinan Zhang. "Bis(phenylsulfonyl)methane mediated synthesis of olefins via a halogen elimination and double bond migration". Organic & Biomolecular Chemistry 16, nr 15 (2018): 2619–22. http://dx.doi.org/10.1039/c8ob00033f.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

7

Khaligh, Nader Ghaffari. "Recent Advances and Applications of tert-Butyl Nitrite (TBN) in Organic Synthesis". Mini-Reviews in Organic Chemistry 17, nr 1 (27.01.2020): 3–25. http://dx.doi.org/10.2174/1570193x15666181029141019.

Pełny tekst źródła

Streszczenie:

This mini-review will present the recent applications of Tert-Butyl Nitrite (TBN) in organic synthesis. Due to its unique structural feature and wide application, TBN holds a prominent and great potential in organic synthesis. The applications of TBN in three areas viz. aerobic oxidation, annulation, and diazotization were reviewed recently; now, the current mini-review will describe the studies carried out to date in areas such as nitration of alkane, alkene, alkyne, and aromatic compounds, nitrosylation and sequential nitrosylation reactions, using TBN as source of oxygen and nitrogen. The mechanisms of these transformations will be briefly described in this mini-review.

Style APA, Harvard, Vancouver, ISO itp.

8

Centi, G. "Selective heterogeneous oxidation of light alkanes. What differentiates alkane from alkene feedstocks?" Catalysis Letters 22, nr 1-2 (marzec 1993): 53–66. http://dx.doi.org/10.1007/bf00811769.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

9

Liu, Hongjun. "Transport diffusivity of propane and propylene inside SWNTs from equilibrium molecular dynamics simulations". Phys. Chem. Chem. Phys. 16, nr 45 (2014): 24697–703. http://dx.doi.org/10.1039/c4cp03881a.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

10

Yusoff, Durratul Fatini, Raja Noor Zaliha Raja Abd Rahman, Malihe Masomian, Mohd Shukuri Mohamad Ali i Thean Chor Leow. "Newly Isolated Alkane Hydroxylase and Lipase Producing Geobacillus and Anoxybacillus Species Involved in Crude Oil Degradation". Catalysts 10, nr 8 (1.08.2020): 851. http://dx.doi.org/10.3390/catal10080851.

Pełny tekst źródła

Streszczenie:

Isolation and studies of novel, crude oil biodegrading thermophilic strains may provide a wider knowledge in understanding their role in petroleum degradation. In this study, the screening of ten new thermophilic strains revealed that all strains were alkane hydroxylase producers and seven of them produced lipase concurrently. Three best strains were characterized and identified through 16S rRNA sequence analysis as Geobacillus sp. D4, Geobacillus sp. D7, and Anoxybacillus geothermalis D9 with GenBank accession numbers MK615934.1, MK615935.1, and MK615936.1, respectively. Gas chromatography (GC) analysis showed that all three strains were able to breakdown various compounds in crude oil such as alkanes, toxic poly-aromatic hydrocarbons (PAHs), organosulfur, carboxylic acids, alkene, resins, organosilicon, alcohol, organochlorine, and ester. For the first time, alkane hydroxylase and lipase activity as well as crude oil degradation by A. geothermalis species were reported. Geobacillus sp. D7 is the best alkane degrader followed by A. geothermalis D9 and Geobacillus sp. D4 with 17.3%, 13.1%, and 12.1% biodegradation efficiency (BE%), respectively. The potential of thermophiles isolated can be explored further for bioremediation of sites polluted by petroleum and oil spills.

Style APA, Harvard, Vancouver, ISO itp.

11

Du, Wenzhou, Yue Wang, Xuelin Liu i Lulu Sun. "Study on Low Temperature Oxidation Characteristics of Oil Shale Based on Temperature Programmed System". Energies 11, nr 10 (29.09.2018): 2594. http://dx.doi.org/10.3390/en11102594.

Pełny tekst źródła

Streszczenie:

Oil shale is a kind of high-combustion heat mineral, and its oxidation in mining and storage are worth studying. To investigate the low-temperature oxidation characteristics of oil shale, the temperature, CO, alkane and alkene gases were analyzed using a temperature-programmed device. The results showed that the temperature of oil shale underwent three oxidation stages, namely a slow low-temperature oxidation stage, a rapid temperature-increasing oxidation stage, and a steady temperature-increasing stage. The higher the air supply rate is, the higher the crossing point temperature is. Similar to coal, CO also underwent three stages, namely a slow low-temperature oxidation stage, a rapid oxidation stage, and a steady increase stage. However, unlike coal, alkane and alkene gases produced by oil shale underwent four stages. They all had a concentration reduction stage with the maximum drop of 24.20%. Statistical classification of inflection temperature of various gases as their concentrations change showed that the temperature of 140 °C is the key temperature for group reactions, and above the temperature of 140 °C, all alkane and alkene gases underwent the rapid concentration increase stage.

Style APA, Harvard, Vancouver, ISO itp.

12

Habets-Crützen, A. Q. H., i J. A. M. de Bont. "Inactivation of alkene oxidation by epoxides in alkene-and alkane-grown bacteria". Applied Microbiology and Biotechnology 22, nr 6 (październik 1985): 428–33. http://dx.doi.org/10.1007/bf00252785.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

13

Fraga, Braulio M., Carmen E. Díaz, Patricia Bolaños, María Bailén, María Fe Andrés i Azucena González-Coloma. "Alkane-, alkene-, alkyne-γ-lactones and ryanodane diterpenes from aeroponically grown Persea indica roots". Phytochemistry 176 (sierpień 2020): 112398. http://dx.doi.org/10.1016/j.phytochem.2020.112398.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

14

Hussain, Najrul, Ashwini Borah, Gitashree Darabdhara, Pranjal Gogoi, Vedi Kuyil Azhagan, Manjusha V. Shelke i Manash R. Das. "A green approach for the decoration of Pd nanoparticles on graphene nanosheets: An in situ process for the reduction of C–C double bonds and a reusable catalyst for the Suzuki cross-coupling reaction". New Journal of Chemistry 39, nr 8 (2015): 6631–41. http://dx.doi.org/10.1039/c5nj01221j.

Pełny tekst źródła

Streszczenie:

In situ synthesis of Pd nanoparticles on graphene nanosheets with simultaneous reduction of alkene to alkane using hydrogen gas were utilized as efficient catalysts for the Suzuki cross-coupling reaction.

Style APA, Harvard, Vancouver, ISO itp.

15

Fischer, Michael, i Robert G. Bell. "Cation-exchanged SAPO-34 for adsorption-based hydrocarbon separations: predictions from dispersion-corrected DFT calculations". Phys. Chem. Chem. Phys. 16, nr 39 (2014): 21062–72. http://dx.doi.org/10.1039/c4cp01049c.

Pełny tekst źródła

Streszczenie:

The interaction of C₂ and C₃ hydrocarbons with cation-exchanged SAPO-34 materials is studied using DFT-D calculations, permitting predictions regarding their suitability for alkene–alkane separations.

Style APA, Harvard, Vancouver, ISO itp.

16

Mirkhani, Valiollah, Shahram Tangestaninejad i Majid Moghadam. "Mild and Efficient Alkene Epoxidation and Alkane Hydroxylation by Manganese(III) Porphyrin Supported on IRA-400 Ion-exchange Resin". Journal of Chemical Research 23, nr 12 (grudzień 1999): 722–23. http://dx.doi.org/10.1177/174751989902301219.

Pełny tekst źródła

Streszczenie:

Sulfonated manganese(III) tetraphenylporphyrin supported on Amberlite IRA-400 ion-exchange resin (MnTPPS-Ad), can act as an efficient heterogeneous catalyst for alkene epoxidation and alkane hydroxylation by sodium periodate in the presence of imadazole.

Style APA, Harvard, Vancouver, ISO itp.

17

Lizhong, Yang, Wang Qingan, Fan Weicheng i Liu Ronghai. "Detonation reactivity of alkane and alkene–air mixtures". Combustion and Flame 120, nr 1-2 (styczeń 2000): 242–44. http://dx.doi.org/10.1016/s0010-2180(99)00072-3.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

18

Zatolokina, Ksenia Igorevna, Anatoly Alexeyevich Tomilenko i Taras Alexandrovich Bul’bak. "Fluid Components in Cordierite from the Rocks of Epidote-Amphibole Facies of the Muzkol Metamorphic Complex, Tajikistan: Pyrolysis-Free GC-MS Data". Minerals 13, nr 3 (24.02.2023): 323. http://dx.doi.org/10.3390/min13030323.

Pełny tekst źródła

Streszczenie:

The composition of volatile components of cordierite from the Muzkol metamorphic complex was studied using shock destruction with pyrolysis-free gas chromatography-mass spectrometry (GC-MS) with simultaneous IR and Raman spectroscopy. Applying the GC-MS procedure, the component relative concentrations (rel.%) and composition of different zones of cordierite crystals were determined. It was found that the substantially magnesian cordierite was formed with a predominantly aqueous-carbonic acid fluid (from 57.06 to 67.88 rel.% H2O, from 24.29 to 32.95 rel.% CO2). From the center towards the crystal periphery, the molar fraction of carbon dioxide (CO2/(H2O + CO2)) decreases from 0.36 to 0.26, whereas the alkane/alkene ratio increases from 0.80 to 0.88. At least 11 homologous series of organic compounds among the identified volatile components, in addition to water and carbon dioxide, were determined, including oxygen-free aliphatic and cyclic hydrocarbons (paraffins, olefins, cyclic alkanes and alkenes, arenes, polycyclic aromatic hydrocarbons (PAHs)), as well as oxygen-containing (alcohols, esters, aldehydes, ketones, carboxylic acids) and heterocyclic (furans, dioxanes) organic compounds.

Style APA, Harvard, Vancouver, ISO itp.

19

Wang, Wei, Yue Ma, Shuyuan Li, Changtao Yue i Jiancun Gao. "Effect of Retorting Temperature on the Pyrolysis Characteristic of Longkou Oil Shale". Geofluids 2021 (7.10.2021): 1–11. http://dx.doi.org/10.1155/2021/6442951.

Pełny tekst źródła

Streszczenie:

Oil shale samples from Longkou City, Shandong Province, China, were pyrolyzed in a fixed bed reactor at retorting temperature varied from 400 to 550°C under nitrogen atmosphere with heating rate of 15°C/min. The influence of retorting temperature on the yield and characteristics of shale oil and retorting gases were determined. It was observed that the oil yield increased to the maximum value, 15.68 wt%, as the retorting temperature increased from 440 to 550°C. And increasing retorting temperature improved also gas yields, but reduced the char yield. The contents of H2, CO2, and CH4 in the retorting gas increased with the rising of retorting temperature. The ratio of alkane/alkene hydrocarbon (C1-C5) decreased because of the secondary cracking reactions of gas phase in the high temperature. The carbon and nitrogen contents of shale oil increased with increasing retorting temperature, while those of hydrogen and oxygen decreased. The sulfur content was not significantly affected by the retorting temperature. In addition, the shale oil obtained from 550°C had the lowest aromatic content, 25.12 wt%, and the highest saturate content, 50.03 wt%, compared to the other retorting temperatures due to the cracking of aliphatic compounds. The alkanes with 8-34 carbons and alkenes with 8-27 carbons were detected in the shale oil. The concentration more than 20 mg/goil was C23-C30 in the range of 400-550°C. The total content of n-alkanes decreased to 369.25 mg g-1oil, and that of n-alkene reached the maximum value at 550°C, 181.62 mg/goil, with the rise of retorting temperature. It was demonstrated that the higher temperature was beneficial to promoting the reaction of aromatization, dehydrogenation, fraction, and other reactions in the pyrolysis process.

Style APA, Harvard, Vancouver, ISO itp.

20

Rassolov, Alexander V., Igor S. Mashkovsky, Galina N. Baeva, Galina O. Bragina, Nadezhda S. Smirnova, Pavel V. Markov, Andrey V. Bukhtiyarov, Johan Wärnå, Alexander Yu Stakheev i Dmitry Yu Murzin. "Liquid-Phase Hydrogenation of 1-Phenyl-1-propyne on the Pd1Ag3/Al2O3 Single-Atom Alloy Catalyst: Kinetic Modeling and the Reaction Mechanism". Nanomaterials 11, nr 12 (3.12.2021): 3286. http://dx.doi.org/10.3390/nano11123286.

Pełny tekst źródła

Streszczenie:

This research was focused on studying the performance of the Pd1Ag3/Al2O3 single-atom alloy (SAA) in the liquid-phase hydrogenation of di-substituted alkyne (1-phenyl-1-propyne), and development of a kinetic model adequately describing the reaction kinetic being also consistent with the reaction mechanism suggested for alkyne hydrogenation on SAA catalysts. Formation of the SAA structure on the surface of PdAg3 nanoparticles was confirmed by DRIFTS-CO, revealing the presence of single-atom Pd1 sites surrounded by Ag atoms (characteristic symmetrical band at 2046 cm−1) and almost complete absence of multiatomic Pdn surface sites (<0.2%). The catalyst demonstrated excellent selectivity in alkyne formation (95–97%), which is essentially independent of P(H2) and alkyne concentration. It is remarkable that selectivity remains almost constant upon variation of 1-phenyl-1-propyne (1-Ph-1-Pr) conversion from 5 to 95–98%, which indicates that a direct alkyne to alkane hydrogenation is negligible over Pd1Ag3 catalyst. The kinetics of 1-phenyl-1-propyne hydrogenation on Pd1Ag3/Al2O3 was adequately described by the Langmuir-Hinshelwood type of model developed on the basis of the reaction mechanism, which suggests competitive H2 and alkyne/alkene adsorption on single atom Pd1 centers surrounded by inactive Ag atoms. The model is capable to describe kinetic characteristics of 1-phenyl-1-propyne hydrogenation on SAA Pd1Ag3/Al2O3 catalyst with the excellent explanation degree (98.9%).

Style APA, Harvard, Vancouver, ISO itp.

21

Billaud, Francis, François Baronnet i Michel Niclause. "Influence cinétique et chimique d'alcènes sur la pyrolyse d'alcanes: mise au point et nouveaux résultats". Canadian Journal of Chemistry 63, nr 11 (1.11.1985): 2869–84. http://dx.doi.org/10.1139/v85-478.

Pełny tekst źródła

Streszczenie:

On the basis of previously reported, as well as new, experimental results, a review is presented of the kinetic and chemical influences of alkenes on the pyrolysis of alkanes. The results confirm that the addition of free H• atoms to the double bonds of alkenes is not sufficient to explain their inhibiting influence on the pyrolysis of alkanes. On the contrary, our results show that the processes of addition can account for the chemical effects of added alkenes on the pyrolysis of alkanes, namely, the modifications brought to the nature and the ratio of the products formed during the reaction. The results presented here confirm that the addition of alkyl free radicals to the double bond of alkenes does not lead to important chemical effects. The previously reported experimental results (pyrolysis of ethane in the presence of ethylene or propene, the pyrolysis of 2,2-dimethylbutane in the presence of propene, isobutene, or two isopentenes), completed by our new results (pyrolysis of ethane in the presence of isobutene, pyrolysis of isobutane in the presence of ethylene, of propene, of trans-2-butene, or of 2-methyl-2-butene), can lead to very simple general rules, on the basis of which it is possible to explain the results and to predict the modifications (relating to the nature of the products and to their ratios) that will result from the addition of an alkene during the pyrolysis of an alkane at a temperature of 500 °C (773 K). Aside from their fundamental aspects, these observations and their mechanistic consequences could be useful for the preparation of models for these thermal reactions, especially for the simplification of complex models. These observations also explain certain facts observed in industry and can help in solving some of the problems associated with the thermal cracking of heavy oils.

Style APA, Harvard, Vancouver, ISO itp.

22

Suda, Hiroyuki, i Kenji Haraya. "Alkene/alkane permselectivities of a carbon molecular sieve membrane". Chemical Communications, nr 1 (1997): 93–94. http://dx.doi.org/10.1039/a606385c.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

23

Morikawa, Masaaki, Mitsuhide Kanemoto i Tadayuki Imanaka. "Biological oxidation of alkane to alkene under anaerobic conditions". Journal of Fermentation and Bioengineering 82, nr 3 (1996): 309–11. http://dx.doi.org/10.1016/0922-338x(96)88825-8.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

24

Atashi, Hossein, Mehdi Shiva, Farshad Farshchi Tabrizi i Ali Akbar Mirzaei. "Study of Syngas Conversion to Light Olefins by Response Surface Methodology". Journal of Chemistry 2013 (2013): 1–12. http://dx.doi.org/10.1155/2013/945735.

Pełny tekst źródła

Streszczenie:

The effect of adding MgO to a precipitated iron-cobalt-manganese based Fischer-Tropsch synthesis (FTS) catalyst was investigated via response surface methodology. The catalytic performance of the catalysts was examined in a fixed bed microreactor at a total pressure of 1–7 bar, temperature of 280–380°C, MgO content of 5–25% and using a syngas having a H2to CO ratio equal to 2.The dependence of the activity and product distribution on MgO content, temperature, and pressure was successfully correlated via full quadratic second-order polynomial equations. The statistical analysis and response surface demonstrations indicated that MgO significantly influences the CO conversion and chain growth probability as well as ethane, propane, propylene, butylene selectivity, and alkene/alkane ratio. A strong interaction between variables was also evidenced in some cases. The decreasing effect of pressure on alkene to alkane ratio is investigated through olefin readsorption effects and CO hydrogenation kinetics. Finally, a multiobjective optimization procedure was employed to calculate the best amount of MgO content in different reactor conditions.

Style APA, Harvard, Vancouver, ISO itp.

25

Vincent, Jean-Marc, Alain Rabion, Vittal K. Yachandra i Richard H. Fish. "Fluorous biphasic catalysis. 2. Synthesis of fluoroponytailed amine ligands along with fluoroponytailed carboxylate synthons, [M(C8F17(CH2)2CO2)2] (M = Mn2+ or Co2+): Demonstration of a perfluoroheptane soluble precatalyst for alkane and alkene functionalization in the presence of tert-butyl hydroperoxide and oxygen gas". Canadian Journal of Chemistry 79, nr 5-6 (1.05.2001): 888–95. http://dx.doi.org/10.1139/v01-012.

Pełny tekst źródła

Streszczenie:

Fluorous biphasic catalysis (FBC) is a relatively new concept for homogeneous catalysis where the fluorocarbon soluble catalyst resides in a separate phase from the substrate and products. Therefore, separation of the catalyst and the products occurs by a facile decantation process. In this contribution, we present the synthesis of new Rf-fluoroponytailed synthons, 2-iodo-1-perfluorooctyl-3-propanol (1), 3-perfluorooctyl-1-propanol (2), and 3-perfluorooctyl-1-iodopropane (3), a variety of new Rf-fluoroponytailed ligands (48), with starting amines, 1,4,7-triazacyclononane, bis-picolylamine, and bis-picolylaminoethylenediamine, as well as new RfMn2+ and RfCo2+ fluoroponytailed carboxylate synthons, [Mn(O2C(CH2)2C8F17)2] (9), and [Co(O2C(CH2)2C8F17)2] (10), where Rf is C8F17. The only totally perfluoralkane soluble ligand we found was 1,4,7-tris-N-(4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,11-heptadecafluoroundecyl)-1,4,7-triazacyclononane (RfTACN, 4), and it was utilized, along with synthons 9 and 10, to generate in situ RfMn2+RfTACN and RfCo2+RfTACN complexes as precatalysts for functionalization of alkanes and alkenes. We will demonstrate that indeed this novel FBC approach for the separation of the precatalyst from the substrates and (or) products is viable for oxidation of alkanes and alkenes in the presence of the necessary oxidants, tert-butyl hydroperoxide (TBHP), and O2 gas. We will also show that these oxidation reactions occur via an autoxidation mechanism under our FBC conditions, while using electron spin resonance (ESR) techniques to ascertain the redox chemistry occurring with the starting mononuclear RfMn2+RfTACN complex.Key words: fluorous solvents, biphasic catalysis, alkane/alkene oxidation.

Style APA, Harvard, Vancouver, ISO itp.

26

Strachecka, Aneta, Grzegorz Borsuk, Jerzy Paleolog, Krzysztof Olszewski, Milena Bajda i Jacek Chobotow. "Body-Surface Compounds in Buckfast and Caucasian Honey Bee Workers (Apis Mellifera)". Journal of Apicultural Science 58, nr 1 (1.06.2014): 5–15. http://dx.doi.org/10.2478/jas-2014-0001.

Pełny tekst źródła

Streszczenie:

Abstract Body-surface chemical compounds were studied in 1-day-old nest workers and foragers both in Buckfast and Caucasian bees. The workers of these two age-castes were sampled twice in each of two consecutive years. Body-surface lipids were determined by means of gas chromatography, with a GCQ mass spectrometer. Protein concentrations and activities on the body surface were examined in bee cuticle rinsings obtained from worker bees according to the methods of Lowry, of Anson, and of Lee and Lin. Protease and protease inhibitor activities were determined. Polyacrylamide gel electrophoresis was performed. Caucasian bees, particularly foragers, had more lipids, but Buckfast bees (two age-castes) had more proteins on their body surfaces. A total of 17 alkane types (C17 - C33), 13 alkene types (C21 - C33), 21 esters (C12 - C32), and a phenol (C14) were detected in both races. Alkene C33 was detected only in Caucasian bees. More alkanes, esters, and phenols were found in Caucasian 1-day-old nest workers and foragers than in these age-castes of Buckfast bees. The protein concentration and protease inhibitor activities were lower in Caucasian bees that had higher protease activities. These values corresponded with specific numbers and widths of the electrophoretic bands.

Style APA, Harvard, Vancouver, ISO itp.

27

Eberhard, Friederike Susette, Leslie Bowtell, Brian Lenske i Md Mainul Islam. "Investigation of Gas Release from Recycled Plastic Shopping Bags during Melting at Low Temperatures". Advances in Materials Science and Engineering 2023 (10.05.2023): 1–9. http://dx.doi.org/10.1155/2023/2378231.

Pełny tekst źródła

Streszczenie:

Recycling plastic is an excellent way to reduce the environmental impact of its production and use. In a circular economy, recycling of recycled plastic is necessary. Most plastic bags are made of thermoplastic, like high-density polyethylene (HDPE) with a melting point of 130°C, and low-density polyethylene (LDPE). In contrast, recycled plastic bags are made up of many different unknown substances. In this study, the melting of used plastic bags containing 80% unknown recycled material was investigated. FTIR analysis showed that the bags consisted mainly of HDPE. The bags were melted at 160°C, 200°C, and 250°C for 30 min. GC-FID and HP-SPME GCMS analyses showed that the bags released flammable gases (methane, ethylene, and alkane/alkene hydrocarbons) but little acetylene. Aromatic and aliphatic hydrocarbons eluded from the bags at 10% of the gas volume at 250°C. Long-chain alkanes, mostly hexadecane, were the dominant compound, amounting to 28% at 160°C and increasing to 43% at 250°C. On the other hand, alkenes decreased with a rising temperature (23% at 160°C to 3% at 250°C), as they were transformed into alkanes. Methylated compounds, for example, methylated alkanes at 10%, were present at all temperatures. Methane and methylated compounds are released from plastic and contamination of the bags with organic matter. The bags released small amounts of toxic phthalates. The results show that melting recycled plastic bags for remoulding is promising if safety precautions that ensure sufficient ventilation are utilised.

Style APA, Harvard, Vancouver, ISO itp.

28

Karunananda, Malkanthi K., i Neal P. Mankad. "Heterobimetallic H2 Addition and Alkene/Alkane Elimination Reactions Related to the Mechanism of E-Selective Alkyne Semihydrogenation". Organometallics 36, nr 1 (15.06.2016): 220–27. http://dx.doi.org/10.1021/acs.organomet.6b00356.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

29

Koch, Lorena, i Aileen Girschik. "Power‐to‐X: Alkane, Alkene und Wasserstoff aus biologischen Quellen". Chemie in unserer Zeit 55, nr 1 (luty 2021): 67–69. http://dx.doi.org/10.1002/ciuz.202110002.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

30

Lee, Sarah E., Joseph S. Vyle, David M. Williams i Jane A. Grasby. "Novel syntheses of (Z)-alkene and alkane base-modified nucleosides". Tetrahedron Letters 41, nr 2 (styczeń 2000): 267–70. http://dx.doi.org/10.1016/s0040-4039(99)02029-8.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

31

Andreev, S. L., V. M. Berezutskii, O. G. Larionov i O. A. Cherednichenko. "Liquid-phase adsorption of alkene-alkane mixtures on NaY zeolite". Chemistry and Technology of Fuels and Oils 21, nr 2 (luty 1985): 94–97. http://dx.doi.org/10.1007/bf00719686.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

32

Neumann, Ronny, i Chalil Abu-Gnim. "A ruthenium heteropolyanion as catalyst for alkane and alkene oxidation". Journal of the Chemical Society, Chemical Communications, nr 18 (1989): 1324. http://dx.doi.org/10.1039/c39890001324.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

33

van den Bergh, Johan, Canan Gücüyener, Evgeny A. Pidko, Emiel J. M. Hensen, Jorge Gascon i Freek Kapteijn. "Understanding the Anomalous Alkane Selectivity of ZIF-7 in the Separation of Light Alkane/Alkene Mixtures". Chemistry - A European Journal 17, nr 32 (13.07.2011): 8832–40. http://dx.doi.org/10.1002/chem.201100958.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

34

Hasibuan, Radja Zulfan, Bambang Admadi Harsojuwono i Anak Agung Made Dewi Anggreni. "Pengaruh Konsentrasi Polikaprolakton dan Kompatibiliser Asam Maleat Anhidrida Terhadap Karakteristik Komposit Bioplastik Maizena-Glukomanan". JURNAL REKAYASA DAN MANAJEMEN AGROINDUSTRI 10, nr 4 (8.12.2022): 398. http://dx.doi.org/10.24843/jrma.2022.v10.i04.p02.

Pełny tekst źródła

Streszczenie:

The weaknesses of cornstarch and glucomannan bioplastic composites is they are hydrophilic, as a result, these bioplastic composites have swelling values, WVTR, tensile strength, elongation at break, and young modulus that not SNI. This study was to determine the effect of the concentration of polycaprolactone and maleic anhydride and their interaction on the characteristics of the cornstarch-glucomannan bioplastic composite, and to determine the concentration of polycaprolactone and maleic anhydride compatibilizer which can produce the best cornstrach-glucomannan bioplastic composite. This study used a randomized block design with two factors. The concentration of polycaprolactone which consists of 3 levels (10% ; 12.5% ; 15%). Factor II is the concentration of maleic anhydride which consists of 3 levels (2.5%; 5%; 7.5%). The variables observed were tensile strength, elongation at break, young modulus, swelling, WVTR, biodegradation and FTIR. The data obtained were analyzed for diversity (ANOVA) and continued with Duncan's test. The results showed that the concentration of polycaprolactone and maleic anhydride and their intereaction had a significant effect on tensile strength, young modulus, WVTR, and swelling except for the elongation at break and biodegradation. Concentration of 15% polycaprolactone and 5% maleic anhydride produced the best composite bioplastic with a tensile strength of 16.16 MPa, elongation at break of 2.610%, modulus young of 627 MPa, swelling of 30.26%, WVTR 0.64g/m2.hour and degradation time for 7.33 days. Cornstarch and glucomannan bioplastic composites with concentrations of polycaprolactone and maleic anhydride contain functional groups of expression -(CH2)n, alkane, hydroxyl alcohol, carboxyl, alkene, alkyne, alkanes, and carbonyl .

Style APA, Harvard, Vancouver, ISO itp.

35

Shelepova, Ekaterina V., i Aleksey A. Vedyagin. "Theoretical Prediction of the Efficiency of Hydrogen Production via Alkane Dehydrogenation in Catalytic Membrane Reactor". Hydrogen 2, nr 3 (11.09.2021): 362–76. http://dx.doi.org/10.3390/hydrogen2030019.

Pełny tekst źródła

Streszczenie:

The hydrogen economy is expected to dominate in the nearest future. Therefore, the most hydrogen-containing compounds are considered as potential pure hydrogen sources in order to achieve climate neutrality. On the other hand, alkanes are widely used to produce industrially important monomers via various routes, including dehydrogenation processes. Hydrogen is being produced as a by-product of these processes, so the application of efficient separation of hydrogen from the reaction mixture can give double benefits. Implementation of the dehydrogenation processes in the catalytic membrane reactor is that case. Since the use of dense metal membranes, which possess the highest perm-selectivity towards hydrogen, is complicated in practice, the present research is aimed at the optimization of the porous membrane characteristics. By means of a mathematical modeling approach, the effects of pore diameter on the hydrogen productivity and purity for the cases of ethane and propane dehydrogenation processes were analyzed. The pore size value of 0.45 nm was found to be crucial as far as the diffusion of both the alkane and alkene molecules through the membrane takes place.

Style APA, Harvard, Vancouver, ISO itp.

36

Gao, Xiang, Wen-Hui Yan, Bo-Yang Hu, Yu-Xin Huang i Shi-Mei Zheng. "Porous Metal–Organic Frameworks for Light Hydrocarbon Separation". Molecules 28, nr 17 (30.08.2023): 6337. http://dx.doi.org/10.3390/molecules28176337.

Pełny tekst źródła

Streszczenie:

The separation of light hydrocarbon compounds is an important process in the chemical industry. Currently, its separation methods mainly include distillation, membrane separation, and physical adsorption. However, these traditional methods or materials have some drawbacks and disadvantages, such as expensive equipment costs and high energy consumption, poor selectivity, low separation ratios, and separation efficiencies. Therefore, it is important to develop novel separation materials for light hydrocarbon separation. As a new type of organic–inorganic hybrid crystalline material, metal–organic frameworks (MOFs) are promising materials for light hydrocarbon separation due to their designability of structure and easy modulation of function. This review provides an overview of recent advances in the design, synthesis, and application of MOFs for light hydrocarbon separation in recent years, with a focus on the separation of alkane, alkene, and alkyne. We discuss strategies for improving the adsorption selectivity and capacity of MOFs, including pore size limitation, physical adsorption, and chemisorption. In addition, we discuss the advantages/disadvantages, challenges, and prospects of MOFs in the separation of light hydrocarbon.

Style APA, Harvard, Vancouver, ISO itp.

37

Jiang, Renxia, i Hongguan Yu. "The Extraction Effect of Supercritical CO2 on Coal Organic Matter Based on CO2 Sequestration in Unmineable Coal Seam". Minerals 12, nr 10 (30.09.2022): 1254. http://dx.doi.org/10.3390/min12101254.

Pełny tekst źródła

Streszczenie:

On the basis of the effect of extraction components of supercritical CO2 (Sc-CO2) from coal on groundwater in the fields of greenhouse gas CO2 sequestration into deep and unmineable coal seams, Sc-CO2 extracts from coals were analyzed using GC/MS to investigate the compositions and their contents of the extracts under different experimental conditions. The results show that Sc-CO2 extracts from coals contain hydrocarbons and organic compounds containing heteroatoms. The main compound in the extract is hydrocarbons which include a large concentration of acyclic alkanes and alkenes and a small concentration of cycloalkanes and aromatic hydrocarbons. Even-numbered n-alkane dominates in the extract, and hexacosene is the main alkene in the extracts from lignite and bituminous coal. The aromatic hydrocarbons are more difficult to extract and their concentration decreases with the increase of coal rank. The main oxygen-containing compounds are esters and carboxylic acids which are more easily extracted from lignite. The concentrations of nitrogen-containing compounds are very small and are more difficult to extract from coal with the rank increase. A small concentration of sulfur-containing compounds is extracted from coal. The results demonstrate that Sc-CO2 has the potential to mobilize organic compounds from coal seams, which affect the transport of CO2 in coal seams and cause groundwater pollution.

Style APA, Harvard, Vancouver, ISO itp.

38

Labinger, Jay A., David C. Leitch, John E. Bercaw, Mark A. Deimund i Mark E. Davis. "Upgrading Light Hydrocarbons: A Tandem Catalytic System for Alkane/Alkene Coupling". Topics in Catalysis 58, nr 7-9 (2.04.2015): 494–501. http://dx.doi.org/10.1007/s11244-015-0380-2.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

39

IMANAKA, TADAYUKI. "Bacteria That Are Able to Produce n-Alkane/alkene from CO2." Microbes and environments 13, nr 3 (1998): 171–75. http://dx.doi.org/10.1264/jsme2.13.171.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

40

Pawelke, Gottfried, i Hans B�rger. "Trifluoromethyl-substituted Aminoboranes and Amine Boranes Revealing Alkene and Alkane Chemistry". Applied Organometallic Chemistry 10, nr 3-4 (kwiecień 1996): 147–74. http://dx.doi.org/10.1002/(sici)1099-0739(199604)10:3/4<147::aid-aoc462>3.0.co;2-f.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

41

Qari, Rashida, i Saima Haider. "Agar Extraction, Physical Properties, FTIR Analysis and Biochemical Composition of Three Edible Species of Red Seaweeds Gracilaria corticata (J. Agardh), Gracilaria dentata (J. Agardh) and Gracilariopsis longissima (S. G. Gmelin)........" Biological Sciences - PJSIR 64, nr 3 (11.10.2021): 263–73. http://dx.doi.org/10.52763/pjsir.biol.sci.64.3.2021.263.273.

Pełny tekst źródła

Streszczenie:

Three species of red algae Gracilaria corticata (J. Agardh), Gracilaria dentata (J. Agardh) and Gracilariopsis longissima (S.G. Gmelin), Steentoft, L. M; Irvine and Farnham (formerly Gracilaria verrucosa (Hudson) were collected from four different sites (Buleji, Hawks Bay, Manora and Paradise Point) of Karachi coast. The G. corticata was the dominant species and the highest yield of agar was compared to other studied species. The physical properties such as gel temperature, melting temperature, density, viscosity and gel strength showed large variations. Interestingly, the gel temperature, melting temperature, density, and gel strength had the highest value in G. corticata samples collected, while gel viscosity recorded the highest value in G. dentata samples. Intensive spectroscopic FTIR analysis was determined in all three species of G. corticata, G. dentata and G. longissima. The bands at 414.7/cm to 3917.2/cm represents stretching and bending vibrations of alcohol O-H, amine N-H, alkane C-H, alkyne C=C, nitriles C=N, carboxyl C=O, nitro aromatic N=O, alkane C-C, nitro methane C-N, aliphatic amines C-N, sulfoxides S=O, alkene C-H alkyl halide C-Cl, C-I groups. The ash content of all studied species (G. corticata, G. dentata and G. longissima) was in the range of 20-30%, while the carbohydrate content was in the range of 22-24%. The results of this study suggested the utilization of our natural resources present in Karachi coast. This could be achieved by determining the quantity and quality of agar in the edible species of Gracilaria/Gracilariopsis.

Style APA, Harvard, Vancouver, ISO itp.

42

Bower, John F., Timothy P. Aldhous, Raymond W. M. Chung i Andrew G. Dalling. "Enantioselective Intermolecular Murai-Type Alkene Hydroarylation Reactions". Synthesis 53, nr 17 (25.05.2021): 2961–75. http://dx.doi.org/10.1055/s-0040-1720406.

Pełny tekst źródła

Streszczenie:

AbstractStrategies that enable the efficient assembly of complex building blocks from feedstock chemicals are of paramount importance to synthetic chemistry. Building upon the pioneering work of Murai and co-workers in 1993, C–H-activation-based enantioselective hydroarylations of alkenes offer a particularly promising framework for the step- and atom-economical installation of benzylic stereocenters. This short review presents recent intermolecular enantioselective Murai-type alkene hydroarylation methodologies and the mechanisms by which they proceed.1 Introduction2 Enantioselective Hydroarylation Reactions of Strained Bicyclic Alkenes3 Enantioselective Hydroarylation Reactions of Electron-Rich Acyclic Alkenes4 Enantioselective Hydroarylation Reactions of Electron-Poor Acyclic Alkenes5 Enantioselective Hydroarylation Reactions of Minimally Polarized Acyclic Alkenes6 Conclusion and Outlook

Style APA, Harvard, Vancouver, ISO itp.

43

Scheiner, Steve. "Versatility of the Cyano Group in Intermolecular Interactions". Molecules 25, nr 19 (30.09.2020): 4495. http://dx.doi.org/10.3390/molecules25194495.

Pełny tekst źródła

Streszczenie:

Several cyano groups are added to an alkane, alkene, and alkyne group so as to construct a Lewis acid molecule with a positive region of electrostatic potential in the area adjoining these substituents. Although each individual cyano group produces only a weak π-hole, when two or more such groups are properly situated, they can pool their π-holes into one much more intense positive region that is located midway between them. A NH3 base is attracted to this site, where it forms a strong noncovalent bond to the Lewis acid, amounting to as much as 13.6 kcal/mol. The precise nature of the bonding varies a bit from one complex to the next but typically contains a tetrel bond to the C atoms of the cyano groups or the C atoms of the linkage connecting the C≡N substituents. The placement of the cyano groups on a cyclic system like cyclopropane or cyclobutane has a mild weakening effect upon the binding. Although F is comparable to C≡N in terms of electron-withdrawing power, the replacement of cyano by F substituents substantially weakens the binding with NH3.

Style APA, Harvard, Vancouver, ISO itp.

44

Yang, Xi, Xuwei Deng, Guangxin Li, Yu Liu i Qiang Gao. "Human Activities Aggravate VOC Pollution in the Huangshui River of the Tibetan Plateau". Sustainability 14, nr 19 (22.09.2022): 11983. http://dx.doi.org/10.3390/su141911983.

Pełny tekst źródła

Streszczenie:

Many xenobiotic compounds can threaten human health and natural ecosystems. The ability to predict the level of human activities and identify major impact factors is crucial for the design of pollutant risk-reduction plans. In this study, a total of 25 volatile organic compounds (VOCs) including eight alkenes, six alkanes, and eleven aromatics were identified at 11 monitoring locations along the Huangshui River of the Tibetan Plateau. GC-MS analysis was applied to detect the concentrations of the VOCs. The results showed that the alkene, alkane, and aromatic concentrations in the sediment were significantly higher than in the water in all seasons (p < 0.001). The VOC concentrations in summer were significantly higher than in spring and winter (p < 0.01). In addition, several VOCs were found to surpass the national standard, i.e., bromoform reached 312.43 μg/L in water during the summer (the national standard is 100 μg/L), carbon tetrachloride was 209.58 μg/L (the national standard is 2 μg/L), and vinyl chloride was 10.99 μg/L (the national standard is 5 μg/L), which were all related to human activities. Principal component analysis (PCA) was used to comprehensively evaluate the water quality and the VOCs. The total organic carbon (TOC) was found to be responsible for the presence of the VOCs in the river, accounting for 77.93%, 81.97%, and 82.13% of the total variance in the datasets in spring, summer, and winter, respectively.

Style APA, Harvard, Vancouver, ISO itp.

45

Neonufa, Godlief F., Lidya Elizabeth, Endar Puspawiningtiyas, Meiti Pratiwi, Astri Nur Istyami, Ronny Purwadi i Tatang H. Soerawidjaja. "Comparison of Liquid Product Characteristics of PFAD Metal Soap Decarboxylation by Batch and Continuous Process". Journal of Engineering and Technological Sciences 53, nr 3 (12.07.2021): 210311. http://dx.doi.org/10.5614/j.eng.technol.sci.2021.53.3.11.

Pełny tekst źródła

Streszczenie:

Well-run continuous processes will benefit the industrial world in the future. This paper investigated the effect of batch and continuous processes on metal basic soap decarboxylation in terms of the liquid product characteristics. The metal soap used in the process was made from palm fatty acid distillate (PFAD) reacted with mixed metal oxides of Zn, Mg, and Ca. While the batch decarboxylation was carried out in a batch reactor at 400 °C for 5 hours, the continuous decarboxylation was conducted at 400 °C with a feed flow rate of 3.75 gr/minutes. Theoretically, the yield of batch decarboxylation is 76.6 wt% while the yield of continuous decarboxylation is 73.37 wt%. The liquid product was fractionated to separate short-chain hydrocarbon of C7-C10 (gasoline fractions) from medium- to long-chain hydrocarbons, or greater than C11 (green diesel fraction). The result showed that the alkane content from the batch process was higher than from the continuous process, whereas the continuous process produced more ketone products compared to the batch process. Furthermore, the GC-FID analysis showed a similar amount of total hydrocarbon (alkane, iso-alkane, and alkene) in both the batch and the continuous process.

Style APA, Harvard, Vancouver, ISO itp.

46

La, Y. S., M. Camredon, P. J. Ziemann, R. Valorso, A. Matsunaga, V. Lannuque, J. Lee-Taylor, A. Hodzic, S. Madronich i B. Aumont. "Impact of chamber wall loss of gaseous organic compounds on secondary organic aerosol formation: explicit modeling of SOA formation from alkane and alkene oxidation". Atmospheric Chemistry and Physics Discussions 15, nr 17 (3.09.2015): 23893–930. http://dx.doi.org/10.5194/acpd-15-23893-2015.

Pełny tekst źródła

Streszczenie:

Abstract. Recent studies have shown that low volatility gas-phase species can be lost onto the smog chamber wall surfaces. Although this loss of organic vapors to walls could be substantial during experiments, its effect on secondary organic aerosol (SOA) formation has not been well characterized and quantified yet. Here the potential impact of chamber walls on the loss of gaseous organic species and SOA formation has been explored using the Generator for Explicit Chemistry and Kinetics of the Organics in the Atmosphere (GECKO-A) modeling tool which explicitly represents SOA formation and gas/wall partitioning. The model was compared with 41 smog chamber experiments of SOA formation under OH oxidation of alkane and alkene series (linear, cyclic and C12-branched alkanes and terminal, internal and 2-methyl alkenes with 7 to 17 carbon atoms) under high NOx conditions. Simulated trends match observed trends within and between homologous series. The loss of organic vapors to the chamber walls is found to affect SOA yields as well as the composition of the gas and the particle phases. Simulated distributions of the species in various phases suggest that nitrates, hydroxynitrates and carbonylesters could substantially be lost onto walls. The extent of this process depends on the rate of gas/wall mass transfer, the vapor pressure of the species and the duration of the experiments. This work suggests that SOA yields inferred from chamber experiments could be underestimated up to 0.35 yield unit due to the loss of organic vapors to chamber walls.

Style APA, Harvard, Vancouver, ISO itp.

47

La, Y. S., M. Camredon, P. J. Ziemann, R. Valorso, A. Matsunaga, V. Lannuque, J. Lee-Taylor, A. Hodzic, S. Madronich i B. Aumont. "Impact of chamber wall loss of gaseous organic compounds on secondary organic aerosol formation: explicit modeling of SOA formation from alkane and alkene oxidation". Atmospheric Chemistry and Physics 16, nr 3 (8.02.2016): 1417–31. http://dx.doi.org/10.5194/acp-16-1417-2016.

Pełny tekst źródła

Streszczenie:

Abstract. Recent studies have shown that low volatility gas-phase species can be lost onto the smog chamber wall surfaces. Although this loss of organic vapors to walls could be substantial during experiments, its effect on secondary organic aerosol (SOA) formation has not been well characterized and quantified yet. Here the potential impact of chamber walls on the loss of gaseous organic species and SOA formation has been explored using the Generator for Explicit Chemistry and Kinetics of the Organics in the Atmosphere (GECKO-A) modeling tool, which explicitly represents SOA formation and gas–wall partitioning. The model was compared with 41 smog chamber experiments of SOA formation under OH oxidation of alkane and alkene series (linear, cyclic and C12-branched alkanes and terminal, internal and 2-methyl alkenes with 7 to 17 carbon atoms) under high NOx conditions. Simulated trends match observed trends within and between homologous series. The loss of organic vapors to the chamber walls is found to affect SOA yields as well as the composition of the gas and the particle phases. Simulated distributions of the species in various phases suggest that nitrates, hydroxynitrates and carbonylesters could substantially be lost onto walls. The extent of this process depends on the rate of gas–wall mass transfer, the vapor pressure of the species and the duration of the experiments. This work suggests that SOA yields inferred from chamber experiments could be underestimated up a factor of 2 due to the loss of organic vapors to chamber walls.

Style APA, Harvard, Vancouver, ISO itp.

48

Whajah, Bernard, Natalia da Silva Moura, Justin Blanchard, Scott Wicker, Karleigh Gandar, James A. Dorman i Kerry M. Dooley. "Catalytic Depolymerization of Waste Polyolefins by Induction Heating: Selective Alkane/Alkene Production". Industrial & Engineering Chemistry Research 60, nr 42 (14.10.2021): 15141–50. http://dx.doi.org/10.1021/acs.iecr.1c02674.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

49

Morikawa, Masaaki, Tsuyoshi Iwasa, Shozo Yanagida i Tadayuki Imanaka. "Production of alkane and alkene from CO2 by a petroleum-degrading bacterium". Journal of Fermentation and Bioengineering 85, nr 2 (styczeń 1998): 243–45. http://dx.doi.org/10.1016/s0922-338x(97)86776-1.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

50

Dvoyashkina, Nina, Dieter Freude, Alexander G. Stepanov, Winfried Böhlmann, Rajamani Krishna, Jörg Kärger i Jürgen Haase. "Alkane/alkene mixture diffusion in silicalite-1 studied by MAS PFG NMR". Microporous and Mesoporous Materials 257 (luty 2018): 128–34. http://dx.doi.org/10.1016/j.micromeso.2017.08.015.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Artykuły w czasopismach na temat „Alkane And Alkene”

Utwórz poprawne odniesienie w stylach APA, MLA, Chicago, Harvard i wielu innych