Research on Low Density Cementing Technology of Coalbed Methane Well

The pressure of the coalbed methane (CBM) reservoir is relatively low, there is serious loss circulation, andlow mechanical strength of the coal, which seriously influence the cementing quality. In this paper, according to the characteristics of coal in southern Qinshui basin, an ultra-low density cement slurry system and a foamed cement slurry system are designed and developed to reduce the density of cement slurry by adding lightening admixture and foaming agent through the experimental method. An appropriate bridging type preflush system is also researched and developed. Considering the drilling conditions, the operation technologies are put forward.The ultra-low density cement slurry system has good rheological performance, small API filter loss (≤ 45 mL/ (30 min·6.9 MPa)), excellent sedimentation stability, suitable thickening time and higher early strength. Foamed cement slurry systemhas good rheological performance, excellent sedimentation stability andsuitable thickening time, and can satisfy the compressive strength requirements for the cementing of CBM wells. The fluid loss of the bridging type preflush system is small under the medium or high pressure, withgood rheological performance,andexcellent plugging ability. The ultra-low density cement slurry system and foamed cement slurry system were applied in 14 and 11 CBM wells respectively, and good results have been achieved

Short-term effects of intravenous batroxobin in treatment of sudden sensorineural hearing loss: a propensity score-matched study

BackgroundSudden sensorineural hearing loss (SSNHL) can cause great panic in patients. Whether it is advantageous to add intravenous batroxobin in the treatment of SSNHL remains to be determined. This study aimed to compare the short-term efficacy of therapy combined with intravenous batroxobin and that without intravenous batroxobin in SSNHL patients.MethodsThis retrospective study harvested the data of SSNHL patients hospitalized in our department from January 2008 to April 2021. The hearing levels on the admitted day (before treatment) and the discharge day were considered pre-treatment hearing and post-treatment hearing, respectively. The hearing gain was the difference value of pre-treatment hearing and post-treatment hearing. We used Siegel's criteria and the Chinese Medical Association of Otolaryngology (CMAO) criteria to evaluate hearing recovery. The complete recovery rate, overall effective rate, and hearing gain at each frequency were considered outcomes. Propensity score matching (PSM) was conducted to balance the baseline characteristics between the batroxobin group and the non-batroxobin group. Sensitivity analysis was carried out in flat-type and total-deafness SSNHL patients.ResultsDuring the study period, 657 patients with SSNHL were admitted to our department. Among them, a total of 274 patients met the enrolled criteria of our study. After PSM, 162 patients (81 in each group) were included in the analysis. Once the hospitalized treatment was completed, the patients would be discharged the next day. Logistic regression analysis of the propensity score-matched cohort indicated that both the complete recovery rates [Siegel's criteria, OR: 0.734, 95% CI: 0.368–1.466, p = 0.381; CMAO criteria, OR: 0.879, 95% CI: 0.435–1.777, p = 0.720] and the overall effective rates [Siegel's criteria and CMAO criteria, OR: 0.741, 95% CI: 0.399–1.378, p = 0.344] were not significantly different between the two treatment groups. Sensitivity analysis has shown similar results. For flat-type and total-deafness SSNHL patients, no significant difference was found in post-treatment hearing gain at each frequency between the two groups after PSM.ConclusionThere was no significant difference in short-term hearing outcomes between treatment with batroxobin and treatment without batroxobin in SSNHL patients by Siegel's and CMAO criteria after PSM. Future studies for better therapy regimens of SSNHL are still needed

1.28 and 5.12 Gbps multi-channel twinax cable receiver ASICs for the ATLAS Inner Tracker Pixel Detector Upgrade

We present two prototypes of a gigabit transceiver ASIC, GBCR1 and GBCR2, both designed in a 65-nm CMOS technology for the ATLAS Inner Tracker Pixel Detector readout upgrade. The first prototype, GBCR1, has four upstream receiver channels and one downstream transmitter channel with pre-emphasis. Each upstream channel receives the data at 5.12 Gbps through a 5 meter AWG34 Twinax cable from an ASIC driver located on the pixel module and restores the signal from the high frequency loss due to the low mass cable. The signal is retimed by a recovered clock before it is sent to the optical transmitter VTRx+. The downstream driver is designed to transmit the 2.56 Gbps signal from lpGBT to the electronics on the pixel module over the same cable. The peak-peak jitter (throughout the paper jitter is always peak-peak unless specified) of the restored signal is 35.4 ps at the output of GBCR1, and 138 ps for the downstream channel at the cable ends. GBCR1 consumes 318 mW and is tested. The second prototype, GBCR2, has seven upstream channels and two downstream channels. Each upstream channel works at 1.28 Gbps to recover the data directly from the RD53B ASIC through a 1 meter custom FLEX cable followed by a 6 meter AWG34 Twinax cable. The equalized signal of each upstream channel is retimed by an input 1.28 GHz phase programmable clock. Compared with the signal at the FLEX input, the additional jitter of the equalized signal is about 80 ps when the retiming logic is o . When the retiming logic is on, the jitter is 50 ps at GBCR2 output, assuming the 1.28 GHz retiming clock is from lpGBT. The downstream is designed to transmit the 160 Mbps signal from lpGBT through the same cable connection to RD53B and the jitter is about 157 ps at the cable ends. GBCR2 consumes about 150 mW when the retiming logic is on. This design was submitted in November 2019.Comment: 7 pages, 15 figure

Compact Circular-Shaped MIMO Antenna Covers UWB Bandwidth With Four Frequently-Used Band-Notched Characteristics for Multi-Scenario Applications

In this work, a tapered fed circular-shaped monopole antenna for ultrawideband (UWB) applications integrated with four frequently-used band-notched properties is designed. By the design of notch structures inside the radiation patch, on the feedline, and on either side of the feedline, four notch bands covering from3.3–3.8 GHz, 5.25–5.75 GHz, 7.25–7.75 GHz, and 8.01–8.5 GHz are obtained possibly, which suppress the interference with WiMax, WLAN, satellite downlink and ITU applications, respectively. Based on these, the proposed antenna is operable from 1.4 GHz to 25 GHz with maximum coupling value of −20 dB covering almost operational band, and it has compact dimensions of $43\times 36\times 1.59$ mm3. Evolution and accomplishment of final results, involving the reduction of mutual coupling suppression, are illustrated gradually. The property of the monopole antenna considering reflection coefficient, isolation among different ports, realized gain, radiation pattern, efficiency, and envelope correlation coefficient (ECC) are studied. Moreover, experimental results are verified with the simulations. In addition, using the antenna inserted in chest badge, the chance of infection will greatly reduce. Ultimate, the proposed MIMO monopole antenna has a potential application in the medical, high precision machining, and biopharming relevant domains

Durable and Washable Antibacterial Copper Nanoparticles Bridged by Surface Grafting Polymer Brushes on Cotton and Polymeric Materials

To increase the durability of antibacterial coating on cotton and polymeric substrates, surface initiated grafting polymer brushes are introduced onto the substrates surface to bridge copper nanoparticles coatings and substrate. The morphologies of the composites consisting of the copper nanoparticles and polymer brushes were characterized with scanning electron microscopy (SEM). It was found that copper nanoparticles were uniformly and firmly distributed on the surfaces of the substrates by the polymer brushes; meanwhile, the reinforced concrete-like structures were formed in the composite materials. The substrates coated by the copper nanoparticles showed the efficient antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) even after washing by 30 cycles. The copper nanoparticles were tethered on the substrates by the strong chemical bonds, which led to the excellent washable fitness and durability. The change of the phase structure of the copper was analyzed to investigate the release mechanism of copper ions

Rapeseed Stand Count Estimation at Leaf Development Stages With UAV Imagery and Convolutional Neural Networks

Rapeseed is an important oil crop in China. Timely estimation of rapeseed stand count at early growth stages provides useful information for precision fertilization, irrigation, and yield prediction. Based on the nature of rapeseed, the number of tillering leaves is strongly related to its growth stages. However, no field study has been reported on estimating rapeseed stand count by the number of leaves recognized with convolutional neural networks (CNNs) in unmanned aerial vehicle (UAV) imagery. The objectives of this study were to provide a case for rapeseed stand counting with reference to the existing knowledge of the number of leaves per plant and to determine the optimal timing for counting after rapeseed emergence at leaf development stages with one to seven leaves. A CNN model was developed to recognize leaves in UAV-based imagery, and rapeseed stand count was estimated with the number of recognized leaves. The performance of leaf detection was compared using sample sizes of 16, 24, 32, 40, and 48 pixels. Leaf overcounting occurred when a leaf was much bigger than others as this bigger leaf was recognized as several smaller leaves. Results showed CNN-based leaf count achieved the best performance at the four- to six-leaf stage with F-scores greater than 90% after calibration with overcounting rate. On average, 806 out of 812 plants were correctly estimated on 53 days after planting (DAP) at the four- to sixleaf stage, which was considered as the optimal observation timing. For the 32-pixel patch size, root mean square error (RMSE) was 9 plants with relative RMSE (rRMSE) of 2.22% on 53 DAP, while the mean RMSE was 12 with mean rRMSE of 2.89% for all patch sizes. A sample size of 32 pixels was suggested to be optimal accounting for balancing performance and efficiency. The results of this study confirmed that it was feasible to estimate rapeseed stand count in field automatically, rapidly, and accurately. This study provided a special perspective in phenotyping and cultivation management for estimating seedling count for crops that have recognizable leaves at their early growth stage, such as soybean and potato

A Combined Fuzzy Optimization Model for the Location of an Intelligent Energy-Efficient Manufacturing Industrial Park

With the background of implementing carbon peaking and carbon neutralization, identifying methods to realize energy-saving and carbon reduction effectively has become an important issue in the intelligent energy-conservation manufacturing industry. During the process of achieving this goal, determining an optimal location for a low-carbon and intelligent manufacturing industrial park is a foremost decision-making problem for manufacturing corporations’ energy-efficient development. The article established a multi-criteria decision framework to assist manufacturing companies when selecting suitable industrial park sites. To begin with, an evaluation criteria framework is confirmed by literature search. Then, a fuzzy optimization model, which combines the fuzzy Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) and the fuzzy VlseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR) is presented, where fuzzy TOPSIS is used to determine the decision-maker criteria weights. Then, criteria weights are calculated by the optimization model with construction of a Lagrange function. Moreover, the fuzzy VIKOR method is applied to sort alternatives and choose the best alternative location. In addition, five alternative sites for a manufacturing company are evaluated and ranked according to the values of the ranking index as a numerical case to demonstrate the proposed framework’s application. Finally, a comprehensive analysis of diverse methods and sensitivity analyses for the volatility in criteria weights and decision-maker weights is illustrated to confirm that the framework is practicable for the problem of intelligent and sustainable manufacturing industrial park-site selection

A Combined Fuzzy Optimization Model for the Location of an Intelligent Energy-Efficient Manufacturing Industrial Park

With the background of implementing carbon peaking and carbon neutralization, identifying methods to realize energy-saving and carbon reduction effectively has become an important issue in the intelligent energy-conservation manufacturing industry. During the process of achieving this goal, determining an optimal location for a low-carbon and intelligent manufacturing industrial park is a foremost decision-making problem for manufacturing corporations’ energy-efficient development. The article established a multi-criteria decision framework to assist manufacturing companies when selecting suitable industrial park sites. To begin with, an evaluation criteria framework is confirmed by literature search. Then, a fuzzy optimization model, which combines the fuzzy Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) and the fuzzy VlseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR) is presented, where fuzzy TOPSIS is used to determine the decision-maker criteria weights. Then, criteria weights are calculated by the optimization model with construction of a Lagrange function. Moreover, the fuzzy VIKOR method is applied to sort alternatives and choose the best alternative location. In addition, five alternative sites for a manufacturing company are evaluated and ranked according to the values of the ranking index as a numerical case to demonstrate the proposed framework’s application. Finally, a comprehensive analysis of diverse methods and sensitivity analyses for the volatility in criteria weights and decision-maker weights is illustrated to confirm that the framework is practicable for the problem of intelligent and sustainable manufacturing industrial park-site selection