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The stout short leaves are c. 5 10 cm long and occur in groups of threes on dwarf shoots. The male cones are visible during May June when pollination takes place. The cones are large hard and woody having reflexed triangular umbos. Each cone is 15 20 cm × 10 13 cm.. The seed is c. 2.5 cm long with a very short rudimentary wing.

The dehydrogenation of γ-terpinene was studied under catalyst- and solvent-free reaction conditions using air as an oxidant. The dehydrogenation affords p-cymene in good yields in a continuous flow reaction setup.The initial optimization of the reaction parameters showed that the dehydrogenation is highly dependent on the vapour/liquid phase equilibrium and the …

The scale-up of the Knoevenagel-condensation between vanillin and barbituric acid carried out in planetary ball mills is investigated from an engineering perspective. Generally, the reaction proceeded in the solid state without intermediate melting and afforded selectively only one product. The reaction has been used as a model to analyze the influence and relationship of …

Superior dehydrogenation kinetics was achieved at 250 °C, indicated by the very short time (2 min) required to release −1.9 wt% H 2, as presented in Fig. 8d. Further increasing the dehydrogenation time (4 min and 7 min) led to the release of −4 and −5.5 wt% H 2, respectively, as shown in Fig. 8d. Increasing the desorption time to 10 min ...

[8] Szuppa, T.; Stolle, A.; Ondruschka, B.; Hopfe, W. Solvent-free dehydrogenation of γ-terpinene in a ball mill: investigation of reaction parameters. Green Chem. 2010, 12: 1288-1294. Search in Google Scholar [9] Thorwirth, R.; Stolle, A. Solvent-free synthesis of enamines from alkyl esters of propiolic or but-2-yne dicarboxylic acid in a ...

The present article reports on the solvent-free dehydrogenation of γ-terpinene (1) in a planetary ball mill affording p-cymene (2) as the predominant reaction product.

Reaction parameters for oxidative dehydrogenation of γ-terpinene 9 to p-cymene 10 were studied in great detail by Stolle et al. (Scheme 6.4) [5].It was found that potassium permanganate is the most efficient oxidant in mechanochemical reaction.

Reaction parameters for oxidative dehydrogenation of γ-terpinene 9 to p-cymene 10 were studied in great detail by Stolle et al. (Scheme 6.4) [5]. It was found that potassium permanganate is the most efficient oxidant in mechanochemical reaction.

The reaction temperature can vary from 120° up to 200°C, with a temperature range of 150°-180°C being preferred. At lower temperatures longer reaction times are required. In view of the nature of the catalyst used, the temperature of 120°-200°C gives rise to the use of pressures higher than atmospheric.

The present article reports on the solvent-free dehydrogenation of γ-terpinene (1) in a planetary ball mill affording p-cymene (2) as the predominant reaction product.

The catalytic influence of Ni, Zr 2 Ni 5, and LaNi 5 on the dehydrogenation properties of milled MgH 2 was investigated. MgH 2 milled in the presence of Ni (5 wt%) and Zr 2 Ni 5 (5 wt%) catalysts for 2 h showed apparent activation energies, E A, of 81 and 79 kJ/mol, respectively, corresponding to ~50% decrease in E A and a moderate decrease (~100 °C) in …

a milling material: agate, 20 min, 800rpm ≙ 13.3 Hz. b 20 min at 20 °C with maximal power input. c 60 in at 80 °C. d 30 min at 80 °C, maximal power input = 300 W.. The effective transfer of energy from the power socket into a product of interest has been proven for a number of examples. When different ball mills are compared with respect to their gross power …

The present article reports on the solvent-free dehydrogenation of γ-terpinene (1) in a planetary ball mill affording p-cymene (2) as the predominant reaction product.

We report that the hydrogen de/resorption of the 2LiBH4+MgH2 system was modified by introducing Ni nanoparticles. Dehydrogenation analysis revealed that the first-step dehydrogenation, i.e., the decomposition of MgH2, can be significantly promoted by adding a small amount of Ni because of the catalytic effect. However, the improvement of the second …

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The present article reports on the solvent-free dehydrogenation of γ-terpinene (1) in a planetary ball mill affording p-cymene (2) as the predominant reaction product.The influence of various reaction parameters and technical variables on the transformation of 1 has been assessed. has been assessed.

planetary ball milling in hydrogen is explained in detail in previous works [4,8]. The quantities of hydrogen absorbed by hydrogenation at 593 K in 12 bar hydrogen or released by dehydrogenation at 593 K in 1.0 bar hydrogen, as hydrogenation or dehydrogenation progressed, were measured using a

The composite carriers prepared by the three methods are mixed with copper nitrate and ground using a ball mill. A series of Cu/ZrO 2 -reduced graphene oxide (RGO) composites were prepared by calcination under nitrogen at 450 °C for 3 h and hydrogen reduction at 250 °C for 4 h.

Solvent-free dehydrogenation of γ-terpinene in a ball mill ...Contrary to particle refinement processes the size of the milling balls d ... a planetary ball mill Pulverisette 7 Fritsch Idar-Oberstein Germany for ... of experiments with one milling ball is …

Fruits produce a range of volatile compounds that make up their characteristic aromas and contribute to their flavor. Fruit volatile compounds are mainly comprised of esters, alcohols, aldehydes, ketones, lactones, terpenoids and apocarotenoids. Many factors affect volatile composition, including the genetic makeup, degree of maturity, environmental …

The present article reports on the solvent-free dehydrogenation of γ-terpinene (1) in a planetary ball mill affording p-cymene (2) as the predominant reaction product.

Fig. 10 presents the variation of Ti valence states in prepared Ti 3 C 2 and LiAlH 4 +20 wt% Ti 3 C 2 before and after dehydrogenation. For Ti 3 C 2 before ball milling with LiAlH 4, the high-resolution XPS spectrum of Ti 2p can be deconvoluted into four peak components, which are assigned to Ti–C and Ti 2+ species, as seen in Fig. 10(a).

Oxidative cracking prevails in the n-butane dehydrogenation with CO 2, and most of the products will be propylene and ethylene [154].So it is difficult to understand the role of CO 2 in the dehydrogenation process. Whatever the small promoting effects of CO 2 were observed on the other catalysts [143].Unlike the conversion of C-1–C-3 alkanes in the presence of CO 2, the …

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Dehydrogenation kinetics achieved at 250 °C and 275 °C for MgH 2 powders milled with Ni-balls milling media for different RBM time (12.5, 25 h, 50 and 100 h) are shown in (g) and (h), respectively.

the milling auxiliary surface is beneficial for solvent-free transformation in ball mills.[1,2] However, reactions in presence of different amounts of water (0-0.4 g) added to the reaction mixture resulted in indifferent yields of p-cymene (2) from the dehydrogenation of γ-terpinene (1) initiated by ball-milling (Figure S1). Additionally, the ...

Szuppa T, Stolle A, Ondruschka B, Hopfe W (2010) Solvent-free dehydrogenation of γ-terpinene in a ball mill: investigation of reaction parameters. Green Chem 12:1288–1294 CrossRef Google Scholar 63.

006 Solvent-free dehydrogenation of -terpinene in a ball mill: Investigation of reaction parameters 007 Biomimetic green chemistry 009 Biomimicry 010 Molecular biomimetics: Nanotechnology through biology 012 Green engineering …

Organic reactions of sulfur dioxide. Reactions with nucleophilic double bonds leading to the isomerization, aromatization, selective hydrogen-deuterium exchange, and …

A new mechanochemical method was developed to convert polymer wastes, polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC), to fuel gases (H2, CH4, and CO) under ball-milling with KMnO4 at room temperature. By using various solid-state characterizations (XPS, SEM, EDS, FTIR, and NMR), and density functional theory …

ball mill made in taiwan - rancho-rewal.pl. Ball millWikipedia the free encyclopedia- ball mill 1000 made in taiwan A ball mill consists of a hollow cylindrical shell rotating about its axis The axis of the shell may be either horizontal or at a small angle to the horizontal it is partially filled with balls The grinding media is the balls which may be made of steelHorizontal Boring and

Moreover, our system possessed rather low-pressure plateau (~1.5 bar/200 °C) closed to that value reported for Mg 3 PrNi 0.1 (1.6 bar/297 °C) 38 Mg 80 Ce 18 Ni 2 (3 bar/311 °C) 39, but it shows ...

Significantly Improved Dehydrogenation of Ball-milled MgH2 Doped with CoFe2O4 Nanoparticles. By Alex A Volinsky. Download pdf.

Ball Mills afforded some precautions since azides are in general shock-sensitive materials. ... dehydrogenation of γ-terpinene to -cymene [p 10] and the oxidative cleavage of β-pinene affording nopinone [11]. Especially the last example proved to be a real alternative for

The ball-milling process was performed at 25°C in a vertical planetary ball mill (DECO-PBM-V-0.4L) ... W. Solvent-free dehydrogenation of [gamma]-terpinene in a ball mill: Investigation of reaction parameters. Green Chem. 2010, 12, 1288–1294. [Google Scholar]

Mechanochemistry enabled the selective synthesis of the recherché orange polymorph of Wilkinson's catalyst [RhCl(PPh 3) 3].The mechanochemically prepared Rh-complex catalysed the solvent-free dehydrogenation of Me 2 NH·BH 3 in a ball mill. The in situ-generated hydrogen (H 2) could be utilised for Rh-catalysed hydrogenation reactions by ball …

mechanical dehydrogenation rate at ambient temperature is much higher than their thermal dehydrogenation rate within the 100-250°C range. Mechanical dehydrogenation of the (3LiBH 4-TiF 3) system was rather slow without and with additives such as ultrafine filamentary Ni and graphene. Only minimal mechanical dehydrogenation was observed

It may be derived biogenetically from a C 20 quassinoid via a 1,2-dioxo derivative by oxidative bond cleavage between C-l and C-2, decarboxylation, contraction of ring B, and formation of the oc,fJ-unsaturated y-lactone [25]. 52 Ailanthus altissima (Mill.)

The present article reports on the solvent-free dehydrogenation of γ-terpinene (1) in a planetary ball mill affording p-cymene (2) as the predominant reaction product.

Formation of the latter may be explained by the process of dehydrogenation of the initial α-terpinene under the conditions of the reaction. Diene condensation of α-terpinene with dienophiles (2 ...