1,245 research outputs found
Hydrates for Gas Transport Technology: Pressure–Temperature Dependence and Ice Microstructures
No full textSelf-preservation is a kinetic anomaly that allows for storing a substantial amount of gas locked in gas hydrate far outside its thermodynamic stability field for a period of days, weeks, or even months under very mild pressuretemperature (pT) conditions, by merely maintaining temperatures below the melting point of ice. Utilizing this phenomenon for low-cost storage and transportation of natural gas is not yet sufficiently developed to be competitive with already existing, well-established methods (e.g., liquefied natural gas (LNG), gas to liquid (GTL), compressed natural gas (CNG), or pipeline (PL)). Aside from the refinement of numerous engineering and safety aspects, a deeper understanding of the self-preservation phenomenon is needed in order to promote these technologies. We address some of these outstanding issues in a series of isothermalisobaric pressurevolumetemperature (pVT) experiments exploring the kinetics of the dissociation of pure sI methane hydrate to ice and CH4 gas in a wide pT field applicable to gas-hydrate-based technologies. By means of ex situ cryo-SEM, we correlate the kinetic data with the morphology of initially formed ice coatings recovered at various stages of the transformation. The pT dependence of the self-preservation strength is seen as a complex interplay between (1) ice microstructures (shape, arrangement, and size of ice crystals) and (2) annealing rate of the ice coating that acts as a diffusion barrier for escaping gas. Moreover, we recognize a progressive sintering of ice coatings of individual particles when close to the melting point of ice. The optimal conditions for the transport and storage at ambient pressure, where this issue is minimized and the preservation strength is still very high, have been found at similar to 250 K. Further fine-tuning of the storage capacity may involve elevating the storage pressure and active temperature control.German Federal Ministry of Economics and Technology (BMWi) [03SX250J
Spectrophotometric pH measurements from continuous surface water supply and discrete samples
No full textThe BONUS INTEGRAL field expeditions on RV Aranda took place from February 28th 2019 to March 11th 2019 (RV Aranda Cruise 04/19). The scientific program of was tailored to serve the purposes of BONUS INTEGRAL. This dataset provides surface data for the creation of maps of surface concentrations of pH via continuous surface water measurements and discrete samples.
Spectrophotometric determination of pH by using CONTROS HydroFIA pH system. The HydroFIA pH system (4H Jena Engineering, 24148 Kiel, Germany) is a continous sample flow instrument for determination of the pH value. In the dependence of the sample pH value the injekted indicator m-cresol purple (supplier of the instrument) change the coulor and from the resulting absorption ranges (ratio) the pH can be calculated. The measuring principle and calculation is based on Dickson et al. [2007] and Müller and Rehder [2018].
For the pH measurement of discrete samples 250 ml ground-glass bottles were used. These bottles are measured directly after sampling. A 5-fold measurement is performed from the same bottle. The last 3 measurements are used for averaging. According to the manufacturer an accuracy of 0.005 is guaranteed and a precision of 0.002 is possible. For control measurements, in-house buffer solutions are used, which are measured at regular intervals
The piano music by Čestmír Gregor
No full textIn my thesis, I introduce a complete list of piano works by Cestmír Gregor, a contemporary Czech composer of modern classical music. 1 have tried to define his compositional techniques and sources of inspiration by analysing the individual pieces of music. I have found that the major features of the author's highly unique style are polyphonic thinking, the development of motives from small nuclei, expressive themes, plastic tunes, inventive work with rhythm, and the absence of a tonal centre which he compensates for by distinctive melodies . The author finds his inspiration in folklore, especially Moravian (Leoš Janácek), the works of Czech interwar avantgarde (Pavel Borkovec) and in jazz (Jaroslav Ježek). His music reflects the emotional states of a man living in the twenty-first century whose life style is predominantly determined by an urban environment. Gregor does not use any of the Musica Nova theories, instead he founded his own music language. The basis for his compositions is communicative music, which follows the patterns of human perceptive psychology. Gregor's concertant compositions are typical for a new instrument stylization and nontraditional attitudes towards instrument virtuosity (playing with a palm, elbow; an unconventional fingering). His piano sonatas and concerts enable the..
Physical oceanography and methane of surface water measured during cruise ALKOR 66/2
No full textmean values were calculated at full latitude/longitude; a mean of 6 atmospheric measurements and 16 surface water measurements are include
Methane in air measured during cruise POS211
No full textmean values were calculated at full latitude/longitude; a mean of 6 atmospheric measurements and 16 surface water measurements are include
Methane in air measured during cruise ALKOR 66/2
No full textMethane in air measured during cruise ALKOR 66/
Methane in air measured during cruise SO97/3
No full textmean values were calculated at full latitude/longitude; a mean of 6 atmospheric measurements and 16 surface water measurements are include
Methane in surface water measured during cruise SO97/3
No full textmean values were calculated at full latitude/longitude; a mean of 6 atmospheric measurements and 16 surface water measurements are include
Methane in surface water measured during cruise BG9506
No full textmean values were calculated at full latitude/longitude; a mean of 6 atmospheric measurements and 16 surface water measurements are include
Methane in air measured during cruise BG9506
No full textmean values were calculated at full latitude/longitude; a mean of 6 atmospheric measurements and 16 surface water measurements are include
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