Influence of Gas Flooding Pressure on Groundwater Flow during Oil Shale In Situ Exploitation

In order to weaken the influence of external groundwater on in situ pyrolysis exploitation, the flow characteristics of groundwater were studied according to the oil shale reservoir characteristics of Qingshankou Formation in Songliao Basin, China. In addition, the parameters of marginal gas flooding for water-stopping were optimized. Taking a one-to-one pattern and a five-spot pattern as examples, the characteristics of groundwater flow under the in situ process were studied. Under the one-to-one pattern, the external groundwater flows into the production well from the low-pressure side, and the water yield was basically stable at 1000 kg/d. In the five-spot pattern, the groundwater can flow into the production wells directly from the windward side, and the water yield of the production well on the leeward side mainly comes from the desaturated zone; the water yield of each production well remains at a high level. By setting water-stopping wells around the production well and keeping the gas flooding pressure slightly higher than the production well, the water yield of the production well can be reduced and stabilized within 100 kg/d under gas flooding pressures of 3 and 5 MPa. However, the gas yield of the production well slightly decreased when the gas flooding pressure reduced from 5 to 3 MPa. Therefore, the gas flooding pressure of water-stopping wells shall be determined in combination with the water yield and gas yield, so as to achieve the best process effect. It is expected that the results will provide technical support for large-scale oil shale in situ pyrolysis exploitation.

The Role of Intra-Clutch Variation of Magpie Clutches in Foreign Egg Rejection Depends on the Egg Trait Considered

The existence of a coevolutionary process between avian brood parasites and their hosts predicts a lower intra-clutch variation in egg appearance of host eggs among rejecters as this would favor egg discrimination of parasite eggs by hosts once parasitic egg mimicry had evolved. So far empirical tests of this prediction have ignored the fact that different aspects of host egg phenotypes may differ in the relative role of environmental vs. genetic determination, and hence that the role of intra-clutch variation in egg rejection within a population cannot be invariant. Here, we estimated whether the intra-clutch variation in several aspects of host eggshell features is consistently associated to rejection of parasitic foreign eggs across years in a magpie host population parasitized by great spotted cuckoos. We innovatively estimated spottiness by means of the fractal dimension of eggs, which considers the homogeneity of spot pattern complexity in eggshells. Our results show that low intra-clutch variation in the blue-green coloration at the middle area of the eggs associated with a high chance of rejection, but only in one of the 3 years we conducted the study. In addition, females that rejected foreign eggs presented more homogenous spot patterns in their clutches as estimated by their fractal dimension than females that accepted experimental eggs, independently of the year of study. Finally, intra-clutch variation in egg volume of host eggs was not associated to rejection. Analyses at the individual level revealed that the relative role of genetic vs. environmental factors that determine egg phenotype would be feature-specific in magpies, females having a characteristic spottiness, but not color or volume, pattern. Our work stresses the importance of considering a holistic approach including several aspects of variation in host egg phenotype (size, color, and homogeneity of spot pattern), as some aspects might be more susceptible to selection through egg rejection than others, presumably because they are less influenced by variation in the environmental conditions. Moreover, our study highlights the importance of replication in studies on the adaptive value of host traits in egg rejection.

Diversity of white spot patterns in the eagle ray Aetobatus laticeps (Myliobatiformes: Aetobatidae) in the north Pacific coast of Costa Rica

Introduction: The Pacific white-spotted eagle ray Aetobatus laticeps, has recently separated from the Atlantic A. narinari based on both morphological and genetic evidence. This species is characterized by a dark body with numerous white spots all over its dorsal side. Considering the type, shape, number, and distribution of these natural markings as potential identifiers at the individual level, we studied the variation in the spot patterns. Objective: Describe and compare the white spot pattern (type and distribution) of individuals and evaluate their potential use as identifiers at the individual level. Methods: We analyzed 54 videos (105 subsequent extracted photos) and 19 photographic records that were taken at different sites along the Pacific coast of northern Costa Rica. Results: Seventeen distinctive types of white spots were identified across the entire dorsal side of the rays. Significant differences between each major body section (pectoral fins, back, head, and pelvic fins) were found in the type and frequency of white spots. The type ‘single spot’ was commonly distributed across the entire dorsal side, and the spot pattern on the pelvic fins was informative to identify 72 individuals. Conclusions: The analysis of the type, shape, and distribution of white spots in A. laticeps determined several combinations of white spot patterns that be used for further taxonomic description and provide potential identification of the individual for future population studies along with its distribution.

3D-Printed Miniature Fiber-Coupled Multi-pass Cell with Dense Spot Pattern for ppb-level Methane Detection Using a Near-IR Diode Laser

<p>Tunable diode laser absorption spectroscopy (TDLAS) based on multi-pass cell (MPC)<sup> [1-4]</sup> is a powerful analytical tool for field applications in air quality monitoring, industrial process control and medical diagnostics. However, the conventional MPC as a core component in TDLAS devices has a large size, low utilization efficiency of the mirror surfaces and tight optical alignment tolerances<sup> [5]</sup>. Design of miniaturized long-path MPC for the development of handheld portable high sensitivity sensing devices is one of the mainstream trends nowadays. In this work, we designed and fabricated a mini-MPC with an effective optical absorption path length of 4.2 m and dimensions of 4×4×6 cm<sup>3</sup>, which to our best knowledge is the current smallest MPC in terms of the same optical path length. The mini-MPC generates a seven-nonintersecting-circle dense spot pattern on two 25.4 mm spherical mirror surfaces providing a high fill factor of 21 cm<sup>-2</sup>. A fiber-coupled collimator and an InGaAs photodetector are integrated into the mini-MPC via a high-resolution 3D-printed frame, hence removing the requirement of active optical alignment. Using a 1.65 μm distributed-feedback laser, the performance of this mini-MPC for methane detection was evaluated in terms of linearity, flow response time, stability, minimum detectable limit and measurement precision. Continuous measurements of methane near a sewer and in the atmosphere were performed to demonstrate the stability and robustness of the highly integrated mini-MPC based gas sensor. This work paves the way towards a sensitive, low-cost, miniature trace gas sensor inherently suitable for large-scale deployment of distributed sensor networks and for handheld mobile devices.</p><p><strong>Acknowledgments</strong></p><p>The project is sponsored by National Key R&D Program of China (2017YFA0304203), National Natural Science Foundation of China (NSFC) (61622503, 61575113, 61805132, 11434007), Outstanding Innovative Teams of Higher Learning Institutions of Shanxi, Foundation for Selected Young Scientists Studying Abroad, Sanjin Scholar (2017QNSJXZ-04) and Shanxi “1331KSC”. Frank K. Tittel acknowledges support by the Robert Welch Foundation (Grant #C0586)<strong>.</strong></p><p><strong>References</strong></p><p>[1] L. Dong; F. K. Tittel; C. Li; N. P. Sanchez; H. Wu; C. Zheng, Y. Yu, A. Sampaolo, R. J. Griffin, Opt. Express <strong>24</strong> (2016) A528.</p><p>[2] K. Liu, L. Wang, T. Tan, G. S. Wang, W. J. Zhang, W. D. Chen, X. M. Gao, Sensor. Actuat. B-Chem. <strong>220</strong> (2015) 1000.</p><p>[3] R. Cui, L. Dong, H. Wu, S. Li, L. Zhang, W. Ma, W. Yin, L. Xiao, S. Jia, F. K. Tittel, Opt. Express <strong>26</strong> (2018) 24318.</p><p>[4] C. T. Zheng, W. L. Ye, J. Q. Huang, T. S. Cao, M. Lv, J. M. Dang, Y. D Wang, Sensor. Actuat. B-Chem. <strong>190</strong> (2014) 249.</p><p>[5] P. Weibring, D. Richter, A. Fried, J. G. Walega, C. Dyroff, Appl. Phys. B <strong>85</strong> (2006) 207.</p>

Wavelength of a Turing-type mechanism regulates the morphogenesis of meshwork patterns

The meshwork pattern is a significant pattern in the development of biological tissues and organs. It is necessary to explore the mathematical mechanism of meshwork pattern formation. In this paper, we found that the meshwork pattern is formed by four kinds of stalk behaviours: stalk extension, tip bifurcation, side branching and tip fusion. The Turing-type pattern underlying the meshwork pattern is a Turing spot pattern, which indicates that the Turing instability of the spot pattern promotes activator peak formation and then guides the formation of meshwork patterns. Then, we found that the Turing wavelength decreased in turn from tip bifurcation to side branching to tip fusion via statistical evaluation. Through the functional relationship between the Turing wavelength and model parameters ($$\upvarepsilon ,{ \rho }_{A}$$ ε , ρ A and $${\rho }_{H}$$ ρ H ), we found that parameters $$\upvarepsilon $$ ε and $${\rho }_{H}$$ ρ H had monotonic effects on the Turing wavelength and that parameter $${\rho }_{A}$$ ρ A had nonmonotonic effects. Furthermore, we performed simulations of local meshwork pattern formation under variable model parameter values. The simulation results verified the corresponding relationship between the Turing wavelength and stalk behaviours and the functional relationship between the Turing wavelength and model parameters. The simulation results showed that the Turing wavelength regulated the meshwork pattern and that the small Turing wavelength facilitated dense meshwork pattern formation. Our work provides novel insight into and understanding of the formation of meshwork patterns. We believe that studies associated with network morphogenesis can benefit from our work.

Quantitative imagery analysis of spot patterns for the three-haplogroup classification of Triatoma dimidiata (Latreille, 1811) (Hemiptera: Reduviidae), an important vector of Chagas disease

Background Spots and coloring patterns evaluated quantitatively can be used to discriminate and identify possible cryptic species. Species included in the Triatoma dimidiata (Reduviidae: Triatominae) complex are major disease vectors of Chagas disease. Phylogenetic studies have defined three haplogroups for Mexico and part of Central America. We report here our evaluation of the possibility of correctly discriminating these three T. dimidiata haplogroups using the pattern of the dorsal spots. Methods Digital images of the dorsal region of individuals from the three haplogroups were used. Image processing was used to extract primary and secondary variables characterizing the dorsal spot pattern. Statistical analysis of the variables included descriptive statistics, non-parametric Kruskal–Wallis tests, discriminant function analysis (DFA) and a neural classification network. Results A distinctive spot pattern was found for each haplogroup. The most differentiated pattern was presented by haplogroup 2, which was characterized by its notably larger central spots. Haplogroups 1 and 3 were more similar to each other, but there were consistent differences in the shape and orientation of the spots. Significant differences were found among haplogroups in almost all of the variables analyzed, with the largest differences seen for relative spot area, mean relative area of central spots, central spots Feret diameter and lateral spots Feret diameter and aspect ratio. Both the DFA and the neural network had correct discrimination values of > 90%. Conclusions Based on the results of this analysis, we conclude that the spot pattern can be reliably used to discriminate among the three haplogroups of T. dimidiata in Mexico, and possibly among triatomine species.

GC/MS and HPTLC-based Methods of Comparison among Standard and Different Commercial Samples of Ferula gummosa Boiss

Ferula gummosa (Apiaceae) Boiss. as a valuable herbal medicine possesses various medical and industrial applications. The oleo-gum resin of F. gummosa, called Galbanum, holds several biological activities for its numerous terpenoid compounds. This study has been conducted on quality control of the F. gummosa oleo-gum resin prepared from standard plants, and commercial samples belong to different parts of Iran. For this purpose, essential oil and dichloromethane extracts and standard fruit essential oil were obtained and evaluated by Gas Chromatography/Mass Spectrometry (GC/MS). Moreover, all dichloromethane oleo-gum resin samples (Standards and commercials) were qualitatively analyzed by High-Performance Thin-Layer Chromatography (HPTLC). Based on the GC/MS analysis, β-Pinene, δ-3-Carene and, α-Pinene in standard and β-Pinene, α-Pinene and, δ-3-Carene in essential oil, commercial samples were recognized as major compounds, respectively. The GC/MS analysis indicates that all commercial oleo-gum resin samples may obtain from the rhizome except one of them. The HPTLC analysis also revealed that the same spot pattern in all samples might be related to the major resin constituents. However, the source of oleo-gum resin could not be clarifying. Based on the results, both GC/FID and HPTLC analysis are useful methods for quality control of oleo-gum resin. The plant part used for oleo-resin extraction can be recognized via the percentage of essential compounds in it.