This study presents the experimental analysis of an innovative floatover installation method with the rapid transfer technique, in which the topside loads can be transferred fast and safely. In the ...rapid transfer process, 30% loads were firstly transferred onto the jackets within only 1 min using the jacking system. Then both the ballast system and the jacking system were employed to gradually transfer the loads onto the jackets. After 70% topside loads were transferred, the jacking system quickly offloads the remaining 30% loads within 1 min. The continuous load transfer operation was simulated in model tests. The complex motions of the barge and the topside as well as the loads on the Deck Support Unite (DSU) and the Leg Mating Unite (LMU) were analyzed. The maximum and minimum motions of the barge and the topside were statistically analyzed as well as DSU and LMU loads. Results indicate the barge pitch motions largely synchronize with the topside pitch before the second jack-down operation. The barge moved forward a little distance after twice jack-down operations. Results indicate DSU loads varied significantly during the jack-down operations and the jacking system should be designed to provide lateral restraints equivalent to 20% of the topside weight.
In response to the problem that traditional anti-interference performance evaluation indices are concentrated at the level of missile guidance systems, which cannot meet the anti-interference ...performance evaluation of guidance systems, based on the analysis of the internal error transmission principle of guidance systems during the anti-interference process and the measurement error of guidance systems, this paper proposes a guidance system anti-interference performance evaluation index based on line of sight angular velocity accuracy, so as to evaluate its anti-interference performance timely in the development process of guidance systems.Due to the difficulty for measurement of the line-of-sight angular velocity accuracy in field experiments, in order to improve the testing efficiency, a simplified calculation method for line-of-sight angular velocity accuracy is proposed based on the principle of proportional guidance. Furthermore, for non proportional guidance scenarios, an equivalent testing method for l
A new anionic polymer poly(acrylamide-co-N-vinylpyrrolidone-co-sodium p-styrene sulfonate) (abbreviated as PANS) is synthesized by using acrylamide(AM), N-vinylpyrrolidone(NVP) and sodium p-styrene ...sulfonate(SSS) as monomers and used as filter loss agents. The optimal synthesis process conditions are explored by orthogonal experiments: molar ratio is AM:NVP:SSS = 3.5; 2; 1, the monomer concentration is 35 wt%, the initiator concentration is 0.40 wt%, the reaction temperature is 45 °C, and the reaction time is 4 h. Fourier infrared spectroscopy(FTIR)and nuclear magnetic resonance hydrogen spectroscopy(
1
HNMR) hydrogen spectroscopy are used to characterize it. Through thermogravimetric analysis(TG) testing, its temperature resistance is tested, and it is found that it has good thermal stability before 350 °C. The performance test is carried out using American Petroleum Institute(API) evaluation criteria, and it is found that the filter loss before aging is 7.5 mL under 2 wt% addition, and only 8 mL after aging. At the same time, after the addition of PANS, the salt resistance of drilling fluid after high temperature aging is improved, and the filtration loss after aging is only 8.25 mL under the addition of 12 wt% NaCl, while the filtration loss after aging is 8.2 mL under the addition of CaCl
2
at 3 wt%. Through Zeta potential and particle size analysis, after adding PANS, the particle size of clay particles can be greatly reduced after aging, and the zeta potential value of drilling fluid is optimized under calcium salt contamination.
Abstract
By controlling the heat treatment temperature, the influence of aging process on the microstructure and mechanical properties of depleted uranium No.2 alloy was studied, and the dynamic ...properties of No.2 alloy were analyzed by Hobkinson device, and the stress-strain relationship was tested. The results show that, after solution treatment at 850 °C × 2h and aging treatment at 350 °C × 4h, the microstructure of No.2 alloy is mainly U(γ) phase and U (α /), and the dynamic yield strength of the alloy reaches the peak, which can reach 1580MPa, which is more than 40% higher than the quasi-static yield strength and has a strong strain rate hardening effect.
Significance Diapause is an alternative developmental pathway exploited by insects and other invertebrates to survive inimical seasons. Like many insects that enter an adult diapause, the mosquito ...Culex pipiens responds to the short day lengths of autumn by feeding extensively on sugar, stockpiling huge fat reserves, halting reproduction, suppressing metabolism, boosting defense responses, and migrating to protected sites where it can safely bridge the winter months. In the experiments presented here, we propose that many of the diverse features of the diapause phenotype are the consequence of activating forkhead transcription factor (FOXO), a transcription factor downstream of insulin and juvenile hormone signaling. Our experimental results reveal how these upstream hormonal signaling pathways act through FOXO to generate the complex phenotype known as diapause.
Insulin and juvenile hormone signaling direct entry of the mosquito Culex pipiens into its overwintering adult diapause, and these two critical signaling pathways appear to do so by converging on the regulation of forkhead transcription factor (FOXO). Diapause is a complex phenotype, and FOXO emerges as a prime candidate for activating many of the diverse physiological pathways that generate the diapause phenotype. Here, we used ChIP sequencing to identify direct targets of FOXO. The nearest gene in a 10-kb region surrounding a predicted binding site was extracted for each binding site, resulting in a dataset containing genes potentially regulated by FOXO. By selecting candidate genes based on their functional relevance to diapause, we identified five gene categories of potential interest, including stress tolerance, metabolic pathways, lifespan extension, cell cycle and growth regulation, and circadian rhythms. Twelve targets were prioritized for further analysis, 10 of which were validated by ChIP-quantitative PCR and quantitative real-time PCR. These 10 genes activated by FOXO are highly up-regulated during diapause and are thus strong candidates for implementation of the diapause syndrome.
► Image-based detection technology for two growth stages of maize was explored. ► Crops in the images can be extracted properly by our proposed method AP-HI. ► Emergence stage is judged by modeling ...the distribution pattern of seedlings. ► To evaluate three-leaf stage, we proposed a probabilistic model using skeleton endpoint. ► The automatic results are in good agreement with those acquired manually.
Growth stage information of field crops is not only an important basic data for analyzing the relationship between the crop growth process and the agrometeorological conditions, but it is also useful for various aspects of precision agriculture. Up to now, it is primarily obtained manually, which is time-consuming, labor-intensive, subjective and discontinuous. Therefore, a noninvasive method to note observations that also proves to be more efficient, continuous, and automatic is needed. At present, an alternative method based on computer vision has been widely used for monitoring crop growth status due to advantages linked to its low-cost, its intuitiveness and non-contact manner of data gathering it provides. However, little research has been done to improve close observation of different growth stages of field crops using digital cameras. To overcome the drawbacks caused by the current manual observation, a study was conducted to explore the application of computer vision technology for the automatic detection technology of two critical growth stages of maize (emergence and three-leaf stage). In order to identify the growth stages, the first task is to extract the plants from images properly. According to complex factors on farm fields, we proposed a novel crops segmentation method (AP-HI) which is robust and not sensitive to the challenging variation of outdoor luminosity and complex environmental elements. It has laid the foundation for subsequent studies. By virtue of the AP-HI, two automatic detection methods based on imaging were investigated for the two critical growth stages of maize. The former method uses the spatial distribution feature to judge accurately whether the field crop has reached the emergence stage or not. The latter uses the skeleton endpoint to characterize the leaf of seedling and transforms a matter of judgment into that of probability estimation, which leads to the final conclusion. In order to verify the feasibility and validity of our proposed methods, the comparing experiments have been carried out. Five well-established algorithms were utilized to make comparison with AP-HI and its results showed that our method outperformed the other algorithms in yielding the highest performance of 96.68% with the lowest standard deviation of 2.37%. As for the two automatic detection methods, the crops of two experimental fields located in Zhengzhou, Henan and Taian, Shandong provinces in China were observed both with a human observer and by using automated routines to process images obtained from a camera. In determining the time at which a growth stage occurred, the proposed methods produced the similar results to the manual observation method. Overall, the automated methods can meet the demand for practical observation needed for agronomic modeling and in triggering action alerts to farmers.
Synergetic elongation of mesocotyl and coleoptile are crucial in governing maize seedlings emergence, especially for the maize sown in deep soil. Studying the genomic regions controlling maize ...deep-sowing tolerance would aid the development of new varieties that are resistant to harsh conditions, such as drought and low temperature during seed germination. Using 346 F
maize population families from W64A × K12 cross at three sowing depths, we identified 33 quantitative trait loci (QTLs) for the emergence rate, mesocotyl, coleoptile, and seedling lengths via composite interval mapping (CIM). These loci explained 2.89% to 14.17% of phenotypic variation in a single environment, while 12 of 13 major QTLs were identified at two or more sowing environments. Among those, four major QTLs in Bin 1.09, Bin 4.08, Bin 6.01, and Bin 7.02 supported pleiotropy for multiple deep-sowing tolerant traits. Meta-analysis identified 17 meta-QTLs (MQTLs) based on 130 original QTLs from present and previous studies. RNA-Sequencing of mesocotyl and coleoptile in both parents (W64A and K12) at 3 cm and 20 cm sowing environments identified 50 candidate genes expressed differentially in all major QTLs and MQTLs regions: six involved in the circadian clock, 27 associated with phytohormones biosynthesis and signal transduction, seven controlled lignin biosynthesis, five regulated cell wall organization formation and stabilization, three were responsible for sucrose and starch metabolism, and two in the antioxidant enzyme system. These genes with highly interconnected networks may form a complex molecular mechanism of maize deep-sowing tolerance. Findings of this study will facilitate the construction of molecular modules for deep-sowing tolerance in maize. The major QTLs and MQTLs identified could be used in marker-assisted breeding to develop elite maize varieties.
To compare the outcomes of open reduction and hook plate fixation (ORHPF) and modified TightRope loop plate fixation (MTRLPF) in the treatment of Rockwood type III acromioclavicular joint ...dislocation.
This was a retrospective study. Data on 71 patients with Rockwood type III acromioclavicular joint dislocation who underwent either ORHPF (n = 39) or MTRLPF (n = 32) between January 2016 and October 2019 were extracted and analyzed. Baseline data at injury were compared to evaluate the balance. The disabilities of the arm, shoulder, and hand (DASH) score, Constant-Murley score and visual analog scores (VAS) score at 1 month, 3 months, 6 months and 12 months after operation were compared; further, at 12 months coracoclavicular distance and related complications were evaluated and compared.
Both groups did not differ for any baseline data. At 1 and 3 months after operation, MTRLPF group exhibited a significantly better performance than the ORHPF group in VAS (1 month: 2.4 ± 1.8 vs 3.0 ± 1.7; 3 months: 1.2 ± 1.4 vs 1.8 ± 1.6), Constant-Murley (1 month: 75.2 ± 11.2 vs 63.8 ± 13.7; 3 months: 81.4 ± 9.8 vs 75.8 ± 10.6), DASH (1 month: 33.6 ± 6.8 vs 40.6 ± 6.1; 3 months: 21.2 ± 7.4 vs 25.6 ± 6.6). At 6 months, only Constant-Murley remained marginally significant (p = 0.048). At 12 months, no statistical difference was observed for any outcome variable (all P > 0.05 for VAS, Constant-Murley and DASH), coracoclavicular distance (12.7 ± 1.6 mm vs 12.2 ± 1.6 mm; P = 0.374), or overall complication rate (P = 0.763).
For Rockwood type III acromioclavicular joint dislocation, both methods can achieve satisfactory 1-year results, but modified minimally invasive TightRope treatment is more advantageous in early functional recovery at 1 and 3-month follow-ups.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The RIPK2 kinase transduces signaling downstream of the intracellular peptidoglycan sensors NOD1 and NOD2 to promote a productive inflammatory response. However, excessive NOD2 signaling has been ...associated with numerous diseases, including inflammatory bowel disease (IBD), sarcoidosis and inflammatory arthritis, making pharmacologic inhibition of RIPK2 an appealing strategy. In this work, we report the generation, identification, and evaluation of novel RIPK2 specific inhibitors. These compounds potently inhibit the RIPK2 tyrosine kinase activity in in vitro biochemical assays and cellular assays, as well as effectively reduce RIPK2-mediated effects in an in vivo peritonitis model. In conjunction with the development of these inhibitors, we have also defined a panel of genes whose expression is regulated by RIPK2 kinase activity. Such RIPK2 activation markers may serve as a useful tool for predicting settings likely to benefit from RIPK2 inhibition. Using these markers and the FDA-approved RIPK2 inhibitor Gefitinib, we show that pharmacologic RIPK2 inhibition drastically improves disease in a spontaneous model of Crohn Disease-like ileitis. Furthermore, using novel RIPK2-specific inhibitors, we show that cellular recruitment is inhibited in an in vivo peritonitis model. Altogether, the data presented in this work provides a strong rationale for further development and optimization of RIPK2-targeted pharmaceuticals and diagnostics.
The dynamic response and impact loads during the mating operation in the elastically-connected twin-barge floatover installation are experimentally analyzed. Three representative intermediate load ...transfer stages of the floatover installation were modeled in the physical model test, including 0%, 50% and 100% stages. Motion behaviors of two identical barges connected with the topsides by the rotatable hemisphere-type mating units in head, quarter, and beam waves were investigated. The short-term extreme values of the nonlinear impact loads on mating units were evaluated. The results show that the twin-barge motions are largely synchronized in head waves and differ greatly in quarter and beam waves. The topsides exhibit relatively small motions, which are beneficial for the mating operation. The results indicate that the mating units are subject to larger impact loads at the 100% stage than the 0% stage. In the quarter and beam waves, the hawsers attached to the leeward barge bear large forces at the 100% stage, indicating that much attention should be paid on the 100% stage in the twin-barge floatover system. Sensitivity analysis of loads to the wave direction indicates that the quarter and beam waves lead to much larger motions and impact loads. The impact loads are greatly sensitive to the wave height and increase significantly with increasing the wave height.
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