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Artículos de revistas sobre el tema "Ultra-tight"

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Autor: Grafiati
Publicado: 14 de marzo de 2023

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1

Agyingi, Collins Amburo. "Ultra-Quasi-Metrically Tight Extensions of Ultra-Quasi-Metric Spaces". Chinese Journal of Mathematics 2015 (30 de septiembre de 2015): 1–7. http://dx.doi.org/10.1155/2015/646018.

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The concept of the tight extension of a metric space was introduced and studied by Dress. It is known that Dress theory is equivalent to the theory of the injective hull of a metric space independently discussed by Isbell some years earlier. Dress showed in particular that for a metric space X the tight extension TX is maximal among the tight extensions of X. In a previous work with P. Haihambo and H.-P. Künzi, we constructed the tight extension of a T0-quasi-metric space. In this paper, we continue these investigations by presenting a similar construction in the category of UQP-metric spaces and nonexpansive maps.
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2

Yao, Shanshan, Qi Wang, Yanfeng Bai y Huazhou Li. "A practical gas permeability equation for tight and ultra-tight rocks". Journal of Natural Gas Science and Engineering 95 (noviembre de 2021): 104215. http://dx.doi.org/10.1016/j.jngse.2021.104215.

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3

Darabi, Hamed, A. Ettehad, F. Javadpour y K. Sepehrnoori. "Gas flow in ultra-tight shale strata". Journal of Fluid Mechanics 710 (27 de septiembre de 2012): 641–58. http://dx.doi.org/10.1017/jfm.2012.424.

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AbstractWe study the gas flow processes in ultra-tight porous media in which the matrix pore network is composed of nanometre- to micrometre-size pores. We formulate a pressure-dependent permeability function, referred to as the apparent permeability function (APF), assuming that Knudsen diffusion and slip flow (the Klinkenberg effect) are the main contributors to the overall flow in porous media. The APF predicts that in nanometre-size pores, gas permeability values are as much as 10 times greater than results obtained by continuum hydrodynamics predictions, and with increasing pore size (i.e. of the order of the micrometre), gas permeability converges to continuum hydrodynamics values. In addition, the APF predicts that an increase in the fractal dimension of the pore surface leads to a decrease in Knudsen diffusion. Using the homogenization method, a rigorous analysis is performed to examine whether the APF is preserved throughout the process of upscaling from local scale to large scale. We use the well-known pulse-decay experiment to estimate the main parameter of the APF, which is Darcy permeability. Our newly derived late-transient analytical solution and the late-transient numerical solution consistently match the pressure decay data and yield approximately the same estimated value for Darcy permeability at the typical core-sample initial pressure range and pressure difference. Other parameters of the APF may be determined from independent laboratory experiments; however, a pulse-decay experiment can be used to estimate the unknown parameters of the APF if multiple tests are performed and/or the parameters are strictly constrained by upper and lower bounds.
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4

Mews, Alhubail y Barati. "A Review of Brittleness Index Correlations for Unconventional Tight and Ultra-Tight Reservoirs". Geosciences 9, n.º 7 (19 de julio de 2019): 319. http://dx.doi.org/10.3390/geosciences9070319.

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Rock brittleness is pivotal in the development of the unconventional reservoirs. However, the existence of various methods of calculating the brittleness index (BI) such as the mineral-based brittleness index (MBI), the log-based brittleness index (LBI), and the elastic-based brittleness index (EBI) lead to inconclusive estimations of the brittleness index. Hence, in this work, the existing correlations are applied on prolific unconventional plays in the U.S. such as the Marcellus, Bakken, Niobrara, and Chattanooga Formation to examine the various BI methods. A detailed comparison between the MBI, LBI, and EBI has also been conducted. The results show that a universal correlation cannot be derived in order to define brittleness since it is a function of lithology. Correlation parameters vary significantly from one shale play to another. Nevertheless, an overall trend shows that abundant quartz and carbonates content yield high brittleness values, while the high clay content and porosity lower the rock brittleness.
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5

Yang, Chun Cheng, Hong Jun Yin, Tang Qian Zhu y Lei Wang. "A Model for Predicting Productivity of Multi-Staged Fractured Horizontal Wells in Ultra-Low Permeability Tight Gas Reservoirs". Advanced Materials Research 934 (mayo de 2014): 143–49. http://dx.doi.org/10.4028/www.scientific.net/amr.934.143.

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Based on the equivalent radius model and superposition potential, a productivity model for ultra-low permeability tight gas reservoirs was developed, which considered the influence of the threshold pressure gradient and the variable mass flow in fractures, and pressure loss inside the wellbore. With examples for capacity sensitive factors are analyzed. The results show that the threshold pressure gradient must be accounted to evaluate the productivity in ultra-low permeability tight gas reservoirs; after considering wellbore pressure loss; close toe fractures inflow velocity segment has been reduced; the larger matrix permeability, the greater the optimum fracture conductivity; When the number of fracture is more, the greater the impact on the capacity of the fracture angle. The research results provide a scientific basis for the design of multi-fractured horizontal wells in the ultra-low permeability tight gas reservoirs.
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6

Mautner, Andreas, Koon-Yang Lee, Tekla Tammelin, Aji P. Mathew, Alisyn J. Nedoma, Kang Li y Alexander Bismarck. "Cellulose nanopapers as tight aqueous ultra-filtration membranes". Reactive and Functional Polymers 86 (enero de 2015): 209–14. http://dx.doi.org/10.1016/j.reactfunctpolym.2014.09.014.

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7

Sheng, Qiang, Livio Gibelli, Jun Li, Matthew K. Borg y Yonghao Zhang. "Dense gas flow simulations in ultra-tight confinement". Physics of Fluids 32, n.º 9 (1 de septiembre de 2020): 092003. http://dx.doi.org/10.1063/5.0019559.

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8

Zhao, Jiafan, Xin Zhao, Quanhu Li y Jingyu Zhang. "Research on ultra-tight integrated navigation method based on CKF filtering algorithm". Journal of Physics: Conference Series 2221, n.º 1 (1 de mayo de 2022): 012048. http://dx.doi.org/10.1088/1742-6596/2221/1/012048.

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Abstract This paper takes the SINS/BDS ultra-tight integrated navigation system as the background of research. Based on the existing integrated navigation nonlinear filtering algorithm, an ultra-tight integrated navigation method based on CKF filtering algorithm is proposed. Compared with the EKF and UKF algorithms, the CKF algorithm reduces the errors caused by intercepting higher order terms in the EKF, overcomes the problem of difficult to determine adjustable parameters in the UKF in practical applications, and greatly reduces the computational effort. Because of the above advantages nowadays the research focus of filtering algorithms is more on CKF algorithm related methods. The EKF, UKF and CKF are applied to the SINS/BDS ultra-tight integrated navigation system for simulation and comparison analysis in order to verify the performance of the algorithm. The simulation results show that the CKF algorithm is an effective and feasible algorithm for integrated navigation method because its stability, filtering accuracy and adaptability are synthetically better than those of the EKF and UKF algorithms.
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9

Li, Qunsheng y Yan Zhao. "An Innovative High-Precision Scheme for a GPS/MEMS-SINS Ultra-Tight Integrated System". Sensors 19, n.º 10 (17 de mayo de 2019): 2291. http://dx.doi.org/10.3390/s19102291.

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The Doppler-assisted error provided by a low-precision microelectromechanical system (MEMS) strapdown inertial navigation system (SINS) increases rapidly. Therefore, the bandwidth of the tracking loop for a global positioning system (GPS)/MEMS-SINS ultra-tight integration system is too narrow to track Doppler shift. GPS measurement error is correlated with the MEMS-SINS velocity error when the Doppler-assisted error exists, leading to tracking loop lock loss. The estimated precision of the integrated Kalman filter (IKF) also decreases. Even the integrated system becomes unstable. To solve this problem, an innovative GPS/MEMS-SINS ultra-tight integration scheme based on using high-precision carrier phase measurements as the IKF measurements is proposed in this study. By assisting the tracking loop with time-differenced carrier phase (TDCP) velocity, the carrier loop noise bandwidth and code correlator spacing are reduced. The tracking accuracies of the carrier and code are increased. The navigation accuracy of GPS/MEMS-SINS ultra-tight integration is further improved.
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10

Gao, G. y G. Lachapelle. "A Novel Architecture for Ultra-Tight HSGPS-INS Integration". Journal of Global Positioning Systems 7, n.º 1 (junio de 2008): 46–61. http://dx.doi.org/10.5081/jgps.7.1.46.

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11

Sun, Hai, Jun Yao, Dong-yan Fan, Chen-chen Wang y Zhi-xue Sun. "Gas transport mode criteria in ultra-tight porous media". International Journal of Heat and Mass Transfer 83 (abril de 2015): 192–99. http://dx.doi.org/10.1016/j.ijheatmasstransfer.2014.11.075.

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12

Ribeiro, A. N. y C. A. Macedo. "Anisotropic tight-binding model applied to zigzag ultra-small nanotubes". European Physical Journal B 74, n.º 4 (24 de marzo de 2010): 527–33. http://dx.doi.org/10.1140/epjb/e2010-00107-5.

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13

Wang, Kunye, Zheng Xu, Chengxiang Hao, Yunkai Deng, Yi Wang, Kaiming Xu y Haitao Xu. "Design of Tight Coupling Antenna to Realize Ultra-Wideband Function". Electronics 12, n.º 4 (16 de febrero de 2023): 988. http://dx.doi.org/10.3390/electronics12040988.

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In this paper, according to the tightly coupled antenna theory, the dual-polarized tightly coupled antenna of 15–40 GHz is designed. The antenna size is 3.75 mm × 3.75 mm × 2.38 mm, and the spacing between the elements is 3.75 mm. The media used from bottom to top are Rogers5880, PP adhesive, RogersTMM10, and feed line using coaxial line directly, with a coaxial line inner core radius of 0.2 mm. Based on the simulations, we find that the antenna can easily cover ±45° and maintain good active standing wave performance. The antenna can support ±60° maximum Angle scanning and maintain good active standing wave performance.
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14

Rodionova, I. I., M. A. Shabalin, A. A. Mironenko y G. I. Khabibullin. "Field development plan and well completion system optimization for ultra-tight and ultra-heterogeneous oil reservoirs". Neftyanoe khozyaystvo - Oil Industry 10 (2019): 72–76. http://dx.doi.org/10.24887/0028-2448-2019-10-72-76.

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15

Fang, Siyu, Xiansong Shi, Xingyuan Wang, Zhe Zhang, Congcong Yin, Zhipeng Zhang, Tong Ju, Sen Xiong y Yong Wang. "Large-pore covalent organic frameworks for ultra-fast tight ultrafiltration (TUF)". Journal of Membrane Science 637 (noviembre de 2021): 119635. http://dx.doi.org/10.1016/j.memsci.2021.119635.

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16

Jwo, Dah-Jing, Chia-Wei Hu y Chien-Hao Tseng. "Nonlinear Filtering with IMM Algorithm for Ultra-Tight GPS/INS Integration". International Journal of Advanced Robotic Systems 10, n.º 5 (enero de 2013): 222. http://dx.doi.org/10.5772/56320.

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17

Zhao, Handong y Zhipeng Li. "Ultra-tight GPS/IMU Integration based Long-Range Rocket Projectile Navigation". Defence Science Journal 66, n.º 1 (27 de enero de 2016): 64. http://dx.doi.org/10.14429/dsj.66.8326.

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<p>Accurate navigation is important for long-range rocket projectile’s precise striking. For getting a stable and high-performance navigation result, a ultra-tight global position system (GPS), inertial measuring unit integration (IMU)-based navigation approach is proposed. In this study, high-accuracy position information output from IMU in a short time to assist the carrier phase tracking in the GPS receiver, and then fused the output information of IMU and GPS based on federated filter. Meanwhile, introduced the cubature kalman filter as the local filter to replace the unscented kalman filter, and improved it with strong tracking principle, then, improved the federated filter with vector sharing theory. Lastly simulation was carried out based on the real ballistic data, from the estimation error statistic figure. The navigation accuracy of the proposed method is higher than traditional method.</p><p><strong>Defence Science Journal, Vol. 66, No. 1, January 2016, pp. 64-70, DOI: http://dx.doi.org/10.14429/dsj.66.8326</strong></p>
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18

Kawai, Takazumi, Yoshiyuki Miyamoto, Osamu Sugino y Yoshinori Koga. "Fusion of ultra thin carbon nanotubes: tight-binding molecular dynamics simulations". Physica B: Condensed Matter 323, n.º 1-4 (octubre de 2002): 190–92. http://dx.doi.org/10.1016/s0921-4526(02)00897-9.

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19

Zhou, Wei-dong, Jia-nan Cai, Long Sun y Chen Shen. "Time–space difference based GPS/SINS ultra-tight integrated navigation method". Measurement 58 (diciembre de 2014): 87–92. http://dx.doi.org/10.1016/j.measurement.2014.08.033.

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20

Kramer, Franca C., Ran Shang, Sebastiaan G. J. Heijman, Sigrid M. Scherrenberg, Jules B. van Lier y Luuk C. Rietveld. "Direct water reclamation from sewage using ceramic tight ultra- and nanofiltration". Separation and Purification Technology 147 (junio de 2015): 329–36. http://dx.doi.org/10.1016/j.seppur.2015.04.008.

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21

Zeng, Qinghua, Qian Meng, Jianye Liu, Shaojun Feng y Huanhao Wang. "Acquisition and loop control of ultra-tight INS/BeiDou integration system". Optik 127, n.º 19 (octubre de 2016): 8082–89. http://dx.doi.org/10.1016/j.ijleo.2016.06.009.

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22

Abaa, Kelvin, John Yilin Wang y Mku Thaddeus Ityokumbul. "Parametric study of fracture treatment parameters for ultra-tight gas reservoirs". Journal of Petroleum Exploration and Production Technology 3, n.º 3 (26 de junio de 2013): 159–68. http://dx.doi.org/10.1007/s13202-013-0058-x.

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23

Zhang, Chun Ming. "Evaluation and Classification of the Siegenian Formation Reservoir in Devonian, X Block, Algeria". Advanced Materials Research 356-360 (octubre de 2011): 2933–36. http://dx.doi.org/10.4028/www.scientific.net/amr.356-360.2933.

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Based on the identification of rock slice and cast thin sections, the observation of scanning electron microscopy, the technology of high pressure Hg injection and X-ray diffraction analysis of clay minerals, the Siegenian Formation reservoir in Devonian, X block, was evaluated and classified. The reservoir is a tight sandstone reservoir with relatively poor porosity and low permeability and it is divided into three types: mesopore-ultra low permeability reservoir (type I), low-middle porosity-ultra low permeability reservoir (type II) and low porosity-ultra low permeability reservoir (type III). The type II is the main reservoir in this area. The conclusions are useful for the petroleum exploration in future.
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24

Barati, Reza. "Application of nanoparticles as fluid loss control additives for hydraulic fracturing of tight and ultra-tight hydrocarbon-bearing formations". Journal of Natural Gas Science and Engineering 27 (noviembre de 2015): 1321–27. http://dx.doi.org/10.1016/j.jngse.2015.03.028.

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25

Karaim, Malek, Mohamed Tamazin y Aboelmagd Noureldin. "An Efficient Ultra-Tight GPS/RISS Integrated System for Challenging Navigation Environments". Applied Sciences 10, n.º 10 (23 de mayo de 2020): 3613. http://dx.doi.org/10.3390/app10103613.

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The Global Positioning System (GPS) provides an accurate navigation solution in the open sky. However, in some environments such as urban areas or in the presence of signal jamming, GPS signals cannot be easily tracked since they could be harshly attenuated or entirely blocked. This often requires the GPS receiver to go into a signal re-acquisition phase for the corresponding satellite. To avoid the intensive computations necessary for the signal re-lock in a GPS receiver, a robust signal-tracking mechanism that can hold and/or rapidly re-lock on the signals and keep track of their dynamics becomes a necessity. This paper augments a vector-based GPS signal tracking system with a Reduced Inertial Sensor System (RISS) to produce a new ultra-tight GPS/INS integrated system that enhances receivers’ tracking robustness and sensitivity in challenging navigation environments. The introduced system is simple, efficient, reliable, yet inexpensive. To challenge the proposed method with real jamming conditions, real experiment work was conducted inside the Anechoic Chamber room at the Royal Military College of Canada (RMC). The Spirent GSS6700 signal simulator was used to generate GPS signals, and an INS Simulator is used for simulating the inertial measurement unit (IMU) to generate the corresponding trajectory raw data. The NEAT jammer, by NovAtel, was used to generate real jamming signals. Results show a good performance of the proposed method under real signal jamming conditions.
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26

Babu, Ravindra y Jinling Wang. "Ultra-tight GPS/INS/PL integration: a system concept and performance analysis". GPS Solutions 13, n.º 1 (4 de julio de 2008): 75–82. http://dx.doi.org/10.1007/s10291-008-0097-9.

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27

Ho, Minh Tuan, Lianhua Zhu, Lei Wu, Peng Wang, Zhaoli Guo, Jingsheng Ma y Yonghao Zhang. "Pore-scale simulations of rarefied gas flows in ultra-tight porous media". Fuel 249 (agosto de 2019): 341–51. http://dx.doi.org/10.1016/j.fuel.2019.03.106.

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28

Ayoub, Fares, Sameeha AlShelleh y Iyad AL-Ammouri. "Circumferential stent fracture repaired using a covered stent in a 42-year-old man with coarctation of the aorta". Cardiology in the Young 26, n.º 2 (23 de junio de 2015): 375–77. http://dx.doi.org/10.1017/s1047951115001079.

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AbstractWe present a case of circumferential fracture of aortic coarctation stent with severe re-stentosis presenting 16 years after initial stent implantation with end-stage renal disease. The patient was treated with a covered stent using the stent-in-stent technique. The use of an ultra-high-pressure balloon was proved necessary to overcome the tight, non-compliant stenosis.
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29

Aziez, Sameir A., Nawar Al-Hemeary, Ahmed Hameed Reja, Tamás Zsedrovits y György Cserey. "Using KNN Algorithm Predictor for Data Synchronization of Ultra-Tight GNSS/INS Integration". Electronics 10, n.º 13 (23 de junio de 2021): 1513. http://dx.doi.org/10.3390/electronics10131513.

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The INS system’s update rate is faster than that of the GNSS receiver. Additionally, GNSS receiver data may suffer from blocking for a few seconds for different reasons, affecting architecture integrations between GNSS and INS. This paper proposes a novel GNSS data prediction method using the k nearest neighbor (KNN) predictor algorithm to treat data synchronization between the INS sensors and GNSS receiver and overcome those GNSS receiver’s blocking, which may occur for a few seconds. The experimental work was conducted on a flying drone over a minor Hungarian (Mátyásföld, 47.4992 N, 19.1977 E) model airfield. The GNSS data are predicted by four different scenarios: the first is no blocking of data, and the other three have blocking periods of 1, 4, and 8 s, respectively. Ultra-tight architecture integration is used to perform the GNSS/INS integration to deal with the INS sensors’ inaccuracy and their divergence throughout the operation. The results show that using the GNSS/INS integration system yields better positioning data (in three axes (X, Y, and Z)) than using a stand-alone INS system or GNSS without a predictor.
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30

Germanou, Lefki, Minh Tuan Ho, Yonghao Zhang y Lei Wu. "Intrinsic and apparent gas permeability of heterogeneous and anisotropic ultra-tight porous media". Journal of Natural Gas Science and Engineering 60 (diciembre de 2018): 271–83. http://dx.doi.org/10.1016/j.jngse.2018.10.003.

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31

Kramer, F. C., R. Shang, S. M. Scherrenberg, L. C. Rietveld y S. J. G. Heijman. "Quantifying defects in ceramic tight ultra- and nanofiltration membranes and investigating their robustness". Separation and Purification Technology 219 (julio de 2019): 159–68. http://dx.doi.org/10.1016/j.seppur.2019.03.019.

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32

Qin, Feng, Xingqun Zhan y Gang Du. "Performance Improvement of Receivers Based on Ultra-Tight Integration in GNSS-Challenged Environments". Sensors 13, n.º 12 (2 de diciembre de 2013): 16406–23. http://dx.doi.org/10.3390/s131216406.

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33

Jie, Yu, Wang Xinlong y Ji Jiaxing. "Design and analysis for an innovative scheme of SINS/GPS ultra‐tight integration". Aircraft Engineering and Aerospace Technology 82, n.º 1 (26 de enero de 2010): 4–14. http://dx.doi.org/10.1108/00022661011028065.

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34

Wang, Xiaoliang, Yanguang Wang, Zhe Su, Yansong Meng y Deren Gong. "Design and test of HiSGR: a novel GNSS/INS ultra tight coupled receiver". Journal of Communications and Information Networks 1, n.º 3 (octubre de 2016): 67–76. http://dx.doi.org/10.1007/bf03391571.

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35

Barsotti, Elizabeth, Evan Lowry, Mohammad Piri y Jin-Hong Chen. "Using Capillary Condensation and Evaporation Isotherms to Investigate Confined Fluid Phase Behavior in Shales". E3S Web of Conferences 146 (2020): 05003. http://dx.doi.org/10.1051/e3sconf/202014605003.

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The abundance of nanopores (pores with diameters between 2 and 100 nm) in shale and ultra-tight reservoirs precludes the use of common pressure-volume-temperature (PVT) analyses on reservoir fluids. The small sizes of the pores cause capillary condensation, which is a nanoconfinement-induced gas-to-liquid phase change, that can occur at pressures more than 50% below the corresponding bulk phase change of the fluid due to strong fluid-pore wall interactions. We quantify this phenomenon by measuring propane isotherms both in a synthetic nanoporous medium and a core from a shale gas reservoir. Comparison of our results in the two porous media indicates the occurrence of capillary condensation in shale rock. At the same time, we observe capillary condensation hysteresis for shale, in which the density of the fluid is significantly lighter during desorption than adsorption. This indicates structural changes to the rock matrix caused by the phase behavior of the confined fluid. We use scanning electron microscopy to corroborate our findings. These results have significant implications for determining the PVT properties, porosity, and permeability of shale and ultra-tight formations for use in reservoir modeling and production estimations.
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36

Schönemann, L., N. Sassi, R. Krüger, A. Bloem, B. Denkena y B. Kuhfuß. "Ultrapräzise Hochgeschwindigkeitsbearbeitung*/Ultra-precision high performance cutting – Part 2". wt Werkstattstechnik online 105, n.º 07-08 (2015): 469–74. http://dx.doi.org/10.37544/1436-4980-2015-07-08-27.

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Die ultrapräzise Fräsbearbeitung ist eine flexible Möglichkeit, um optische Freiformflächen herzustellen. Aufgrund der hohen Genauigkeitsanforderungen sind die anwendbaren Vorschub- und Schnittgeschwindigkeiten allerdings beschränkt. Deshalb werden hier zwei neue Ansätze zur Wirtschaftlichkeitssteigerung präsentiert: der Einsatz ultrapräziser Magnetführungen sowie die modellbasierte Vorhersage von Bahnabweichungen und deren Kompensation mithilfe der elektromagnetischen Führung (Teil 1: wt 6-2015, S. 366–370). &nbsp; Ultra-precision milling is a flexible process for generating optical freeform surfaces. However, due to the tight tolerances of such parts, only low feedrates and cutting velocities are applied. This publication presents two novel approaches to increase the productivity of ultra-precision machining: the use of electromagnetic guideways and the model-based prediction of path deviations and their compensation using the electromagnetic guideway.
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37

Lai, Jin, Dong Li, Yong Ai, Hongkun Liu, Deyang Cai, Kangjun Chen, Yuqiang Xie y Guiwen Wang. "Structural diagenesis in ultra-deep tight sandstones in the Kuqa Depression, Tarim Basin, China". Solid Earth 13, n.º 6 (21 de junio de 2022): 975–1002. http://dx.doi.org/10.5194/se-13-975-2022.

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Abstract. The Lower Cretaceous Bashijiqike Formation of the Kuqa Depression is made up of ultra-deeply buried sandstones in fold-and-thrust belts. Few researches have linked diagenetic processes with structure. To fill this gap, a comprehensive analysis integrating diagenesis with structure pattern, fracture and in situ stress is performed following a structural diagenetic approach. The results show that the pore spaces include residual intergranular pores, intergranular and intragranular dissolution pores, and micro-fractures. The sandstones experienced a high degree of mechanical compaction, but compaction is limited in well-sorted rocks or abundant in rigid quartz grains. The most volumetrically important diagenetic minerals are calcites. The framework grains experienced a varied degree of dissolution, and intergranular and intragranular dissolution pores are formed. Special attention is paid on the dissolution associated with the fracture planes. Large numbers of natural fractures are cemented by carbonate cements, which limit fluid flow. In addition, the presence of fracture enhances dissolution and the fracture planes are enlarged by dissolution. Cementation and dissolution can occur simultaneously in fracture surfaces, and the enlarged fracture surfaces can be cemented by late-stage cements. The in situ stress magnitudes are calculated using well logs. The horizontal stress difference (Δσ) determines the degree of mechanical compaction, and rocks associated with low Δσ experienced a low degree of compaction, and these contain preserved intergranular pores. Natural fractures are mainly related to the low Δσ layers. The presence of intergranular and intragranular dissolution pores is mainly associated with the fractured zones. The high-quality reservoirs with intergranular pores or fractures are related to low Δσ layers. The structural diagenesis researches above help the prediction of reservoir quality in ultra-deep sandstones and reduce the uncertainty in deep natural gas exploration in the Kuqa Depression.
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38

Badrouchi, Nidhal, Hui Pu, Steven Smith, Yang Yu y Foued Badrouchi. "Experimental investigation of CO2 injection side effects on reservoir properties in ultra tight formations". Journal of Petroleum Science and Engineering 215 (agosto de 2022): 110605. http://dx.doi.org/10.1016/j.petrol.2022.110605.

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39

Xin, Yi, Guiwen Wang, Bingchang Liu, Yong Ai, Deyang Cai, Shuwen Yang, Hongkun Liu, Yuqiang Xie y Kangjun Chen. "Pore structure evaluation in ultra-deep tight sandstones using NMR measurements and fractal analysis". Journal of Petroleum Science and Engineering 211 (abril de 2022): 110180. http://dx.doi.org/10.1016/j.petrol.2022.110180.

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40

Babu, S. Ravindra y Jinling Wang. "Comparative Study of Interpolation Techniques for Ultra-Tight Integration of GPS/INS/PL Sensors". Journal of Global Positioning Systems 4, n.º 1&2 (31 de diciembre de 2005): 192–200. http://dx.doi.org/10.5081/jgps.4.1.192.

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41

Jackson, J. C. "Tight cosmological constraints from the angular-size/redshift relation for ultra-compact radio sources". Journal of Cosmology and Astroparticle Physics 2004, n.º 11 (13 de noviembre de 2004): 007. http://dx.doi.org/10.1088/1475-7516/2004/11/007.

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42

Wang, Jie, Yixiao Huang, Fujian Zhou, Ziyu Song y Xingyuan Liang. "Study on reservoir damage during acidizing for high-temperature and ultra-deep tight sandstone". Journal of Petroleum Science and Engineering 191 (agosto de 2020): 107231. http://dx.doi.org/10.1016/j.petrol.2020.107231.

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43

Wang, Xin-long y Ya-feng Li. "An innovative scheme for SINS/GPS ultra-tight integration system with low-grade IMU". Aerospace Science and Technology 23, n.º 1 (diciembre de 2012): 452–60. http://dx.doi.org/10.1016/j.ast.2011.10.004.

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44

Wang, Meng, Zhaomeng Yang, Changjun Shui, Zhong Yu, Zhufeng Wang y Yulin Cheng. "Diagenesis and its influence on reservoir quality and oil-water relative permeability: A case study in the Yanchang Formation Chang 8 tight sandstone oil reservoir, Ordos Basin, China". Open Geosciences 11, n.º 1 (14 de marzo de 2019): 37–47. http://dx.doi.org/10.1515/geo-2019-0004.

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Abstract Different from conventional reservoirs, unconventional tight sand oil reservoirs are characterized by low or ultra-low porosity and permeability, small pore-throat size, complex pore structure and strong heterogeneity. For the continuous exploration and enhancement of oil recovery from tight oil, further analysis of the origins of the different reservoir qualities is required. The Upper Triassic Chang 8 sandstone of the Yanchang Formation from the Maling Oilfield is one of the major tight oil bearing reservoirs in the Ordos Basin. Practical exploration demonstrates that this formation is a typical tight sandstone reservoir. Samples taken from the oil layer were divided into 6 diagenetic facies based on porosity, permeability and the diagenesis characteristics identified through thin section and scanning electron microscopy. To compare pore structure and their seepage property, a high pressure mercury intrusion experiments (HPMI), nuclear magnetic resonance (NMR), andwater-oil relative permeability test were performed on the three main facies developed in reservoir. The reservoir quality and seepage property are largely controlled by diagenesis. Intense compaction leads to a dominant loss of porosity in all sandstones, while different degrees of intensity of carbonate cementation and dissolution promote the differentiation of reservoir quality. The complex pore structure formed after diagenesis determines the seepage characteristics, while cementation of chlorite and illite reduce the effective pore radius, limit fluid mobility, and lead to a serious reduction of reservoir permeability.
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45

Bizhani, Majid, Omid Haeri Ardakani, Steven B. Hawthorne, Jaime Cesar, Bethany Kurz y Jeanne B. Percival. "CO2-Enhanced Oil Recovery Mechanism in Canadian Bakken Shale". Minerals 12, n.º 6 (19 de junio de 2022): 779. http://dx.doi.org/10.3390/min12060779.

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The recovery factor in unconventional reservoirs is typically 5–10%, with extensive hydraulic fracturing and infill drilling to maintain the production rate. Concurrently, the rush towards decarbonization is opening up new possibilities for CO2 utilization, enhanced oil recovery (EOR) being one example. CO2-EOR in unconventional reservoirs presents an opportunity for both financial gain through improved recovery factors, as well as reducing the carbon footprint of the produced oil. In this work, we examine the CO2-EOR potential in 4 organic-rich shale samples from the Canadian Bakken Formation. A number of characterization tests alongside CO2 extraction experiments were performed to gain insight into the controlling factors of CO2-EOR in these ultra-tight formations. The results show CO2 can penetrate the tight rock matrix and recover a substantial amount of hydrocarbon. Concentration gradient driven diffusion is the dominant form of recovery.
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46

Puentes, Graciana. "Design and Construction of Magnetic Coils for Quantum Magnetism Experiments". Quantum Reports 2, n.º 3 (17 de julio de 2020): 378–87. http://dx.doi.org/10.3390/quantum2030026.

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We report on the design and construction of a spin-flip Zeeman slower, a quadrupole magnetic trap and a Feshbach field for a new machine for ultra-cold Li-7. The small mass of the Li-7 atom, and the tight lattice spacing, will enable to achieve a 100-fold increase in tunneling rates over comparable Rb-87 optical lattice emulator experiments. These improvements should enable to access new regimes in quantum magnetic phase transitions and spin dynamics.
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47

Xiu, Zengpeng, Linhai Qi y Li Liu. "Field test practice and understanding of effective utilization technology for dense and refractory reservoir in block A". E3S Web of Conferences 358 (2022): 02018. http://dx.doi.org/10.1051/e3sconf/202235802018.

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In view of the ultra-low permeability reservoirs in Block A of Hailar Oilfield, it is difficult to establish an effective driving system between oil and water wells due to the influence of many oil-bearing strata, poor reservoir physical properties and large vertical span of oil layers. With the deepening of development, it is more difficult to use reservoirs. In order to realize the effective utilization of low permeability reservoirs in Beier Oilfield, the successful experiences of tight oil and Hailar large-scale fracturing in peripheral oilfields are summarized, and the effective utilization technology of large-scale fracturing supplementary energy development is explored. The large-scale fracturing evaluation of ultra-low permeability reservoirs and the optimization of potential well areas are carried out, so as to fully tap the
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48

Havelka, Ondřej, Martin Cvek, Michal Urbánek, Dariusz Łukowiec, Darina Jašíková, Michal Kotek, Miroslav Černík, Vincenzo Amendola y Rafael Torres-Mendieta. "On the Use of Laser Fragmentation for the Synthesis of Ligand-Free Ultra-Small Iron Nanoparticles in Various Liquid Environments". Nanomaterials 11, n.º 6 (10 de junio de 2021): 1538. http://dx.doi.org/10.3390/nano11061538.

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Traditionally, the synthesis of nanomaterials in the ultra-small size regime (1–3 nm diameter) has been linked with the employment of excessive amounts of hazardous chemicals, inevitably leading to significant environmentally detrimental effects. In the current work, we demonstrate the potential of laser fragmentation in liquids (LFL) to produce highly pure and stable iron ultra-small nanoparticles. This is carried out by reducing the size of carbonyl iron microparticles dispersed in various polar solvents (water, ethanol, ethylene glycol, polyethylene glycol 400) and liquid nitrogen. The explored method enables the fabrication of ligand-free iron oxide ultra-small nanoparticles with diameter in the 1–3 nm range, a tight size distribution, and excellent hydrodynamic stability (zeta potential > 50 mV). The generated particles can be found in different forms, including separated ultra-small NPs, ultra-small NPs forming agglomerates, and ultra-small NPs together with zero-valent iron, iron carbide, or iron oxide NPs embedded in matrices, depending on the employed solvent and their dipolar moment. The LFL technique, aside from avoiding chemical waste generation, does not require any additional chemical agent, other than the precursor microparticles immersed in the corresponding solvent. In contrast to their widely exploited chemically synthesized counterparts, the lack of additives and chemical residuals may be of fundamental interest in sectors requiring colloidal stability and the largest possible number of chemically active sites, making the presented pathway a promising alternative for the clean design of new-generation nanomaterials.
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49

Deng, Jia, Jiujiang Li, Lan Zhang, Fuquan Song, Dong Wang y Hongjian Wang. "CH4 transport in micro–nano porous media associated with supercritical CO2 flooding". Physics of Fluids 34, n.º 7 (julio de 2022): 076112. http://dx.doi.org/10.1063/5.0100762.

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Injecting supercritical CO2 into tight gas reservoirs to displace CH4 is an extremely promising technology of unconventional gas exploitation. However, Darcy's law cannot describe the gas flow due to ultra-low permeability and micro–nano porosity of tight rock. The present work is an analytical approach to investigating the nonlinear seepage characteristics of CH4 displacement by supercritical CO2. Moreover, considering the steady and unsteady state conditions, mathematical models for planar linear flooding, planar radial flooding, and single well and one-well injection/one-well production types are presented, computed, and verified. Their equipotential and streamline charts are first determined by implementing the model. Additionally, by investigating variables such as formation pressure, producing pressure drop, permeability, temperature, well spacing, and mass flow, their contributions to gas production rate are determined. Finally, an approach for improving the gas recovery efficiency is obtained based on the obtained results.
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50

Kou, Yanhong y Han Zhang. "Sample-Wise Aiding in GPS/INS Ultra-Tight Integration for High-Dynamic, High-Precision Tracking". Sensors 16, n.º 4 (11 de abril de 2016): 519. http://dx.doi.org/10.3390/s16040519.

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