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The understanding of the mechanisms that govern spontaneous water imbibition in gas-water systems plays a significant role in operating the hydraulic fracturing and the development of unconventional gas reservoirs. The main purpose of this paper is addressing how the spontaneous imbibition in coal reservoir affects reservoir permeability, and what is the microscopic mechanism of water transport during this process. To solve this problem, air-water co-current imbibition experiments, contact-angle tests and permeability tests were carried out on eight coal plugs originated from three Chinese coalbed methane hot spots. Moreover, NMR spectrometer is introduced as a method for monitoring the volume of water imbibed in pores with different sizes. The results reveal that the water imbibition rate of bituminous coal follows microfracture > micropores > meso/macropores, whereas for anthracite, the imbibition rate is in the order of microfracure > meso/macroproes > micropores. Permeability damage ratio due to the spontaneous imbibition follows a positive exponential relationship with increasing contact angle. Considering the multi-scale pore system and complex pore tortuosity, we established a model to estimate the spontaneous imbibition rate, which agrees well with experimental results at the early stage of imbibition process when the capillary force is dominant. Finally, four successive stages of moisture migration during spontaneous imbibition and spontaneous evaporation were divided based on the movement of the NMR T 2 peak. The implications from this work is important for better understanding the mechanism controlling fluid loss and gas production in unconventional reservoir, which is significant for optimizing the recovery program and minimizing reservoir damage. Image 1 • What factors affect the spontaneous imbibition in coal? • How does the spontaneous imbibition in coal affect gas permeability? • How does moisture migrate in coal during spontaneous imbibition? • Proposed a new model to estimate the spontaneous imbibition rate in coal. • Traced dynamics of spontaneous imbibition and water evaporation in different pores. [ABSTRACT FROM AUTHOR]

The paper discusses the technique of environmental condition monitoring based on the phenomenon of nuclear magnetic resonance (NMR). Express control is an integral part of agriculture. It is especially necessary when working on the farm or in the fields. In this case, situations often arise when it is impossible to deliver samples for research in a stationary laboratory (e.g., results are needed immediately or samples can change their properties during transportation). Now, there are many methods for monitoring the states of media in the express mode. Therefore, a brief review of these methods as well as their limitations was carried out. To overcome these limitations, a new technological solution was proposed for the creation of an NMR spectrometer. The proposed compact NMR spectrometer allows measuring the longitudinal and transverse relaxation times of the medium. To enhance its functionality, a new magnetic system and a signal registration circuit have been developed. These improvements allow detection of the NMR signal at different frequencies, thus registering the signal spectrum. With the help of the proposed device, studies of various media have been carried out; the results of these studies are presented. [ABSTRACT FROM AUTHOR]

This study investigated the effects of highland barley's germination time (24, 48, and 72 h) on the thermomechanical, pasting, fermentation, dynamic rheological, molecular mobility, and protein structural properties of oat-wheat composite flour dough. Germination significantly reduced flour water absorption, freezable water, melting enthalpy, and increased protein weakening compared with native barley (NB) samples. In addition, germination decreased bound and immobilized water and increased the free water compared to the NB-composite flour dough samples, according to the results of a low-field nuclear magnetic resonance spectrometer (LF-NMR). Germination also increased the protein's extractability and surface hydrophobicity while negatively impacting the starch-protein network; however, it decreased bread-specific volume. Germination for 24 h, on the other hand, had minor effects on dough and bread samples compared to 48 and 72 h. As a result, germination for 24 h under controlled conditions could be used to improve the rheological qualities of highland barley and avoid the adverse rheological effects of the prolonged germination period. [ABSTRACT FROM AUTHOR]

A FPGA based radio frequency source and pulse programmer for NQR is described. With the use of direct digital synthesis (DDS), the RF source has the ability to yield RF signal with short switching time and high resolution in frequency and phase. To facilitate the generation of RF pulses, pulse programmer implemented in FPGA, is also used as auxiliary controller of DDS. The pulse programmer controls the DDS to generate RF pulses according to predefined parameters. [ABSTRACT FROM AUTHOR]

This study aimed to investigate potential biosurfactant production of Stenotrophomonas acidaminiphila TW3 isolated from sediments contaminated with palm oil soapstocks using low cost substrates. The combination of central composite rotatable design (CCRD) and response surface methodology (RSM) was used to optimize biosurfactant production. The highest biosurfactant production (2.31 g/L) was obtained under the optimal conditions of 49.96 g/L used palm oil as a carbon source, 3.00 g/L NaNO 3 as a nitrogen source and medium pH 6.0. RSM increased the yield of biosurfactant up to 2.1 folds however, the productivity is still low further improvement is needed. The biosurfactant obtained from the S. acidaminiphila TW3 was able to lower the surface tension of medium from 72 to 32 mN/m. The biosurfactant was purified by liquid column chromatography and identified as glycolipid using thin layer chromatography, Fourier transform infrared spectroscopy, Mass spectrometer and Nuclear Magnetic Resonance. The biosurfactant could reduce surface tension of pure water to 32 mN/m with a critical micelle concentration of 0.2 g/L. It is an effective biosurfactant over a wide range of temperatures, pH and salt concentrations. Moreover, the biosurfactant showed ability to enhance PAHs solubility and removed used lubricating oil contaminated in sand. • The production of biosurfactant by strain TW3 was optimized by RSM methodology. • The biosurfactant produced by strain TW3 was identified as glycolipid. • Biosurfactant activity was stable under extreme conditions. • This glycolipid increased PAHs solubility and removed ULO. [ABSTRACT FROM AUTHOR]

The article discusses the introduction of a Nuclear Magnetic Resonance (NMR) Spectrometer by Munich-based chemical company Wacker at its Research and Development (R&D) facility in Kolkata, India and highlights the uses of the product.