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Author(s):  
Christopher J Byrd ◽  
Betty R Mc Conn ◽  
Brianna N Gaskill ◽  
Allan P Schinckel ◽  
Angela R Green-Miller ◽  
...  

Abstract Characterizing the sow physiological response to an increased heat load is essential for effective heat stress mitigation. The study objective was to characterize the effects of a 400-min heating episode on sow heart rate variability (HRV) at different reproductive stages. Heart rate variability is a commonly used non-invasive proxy measure of autonomic function. Twenty-seven sows were enrolled in the study according to their gestation stage at time of selection: 1) non-pregnant (NP; n = 7), 2) mid-gestation (MID; 57.3 ± 11.8 d gestation; n = 11), and 3) late-gestation (LATE; 98.8 ± 4.9 d gestation; n = 8). The HRV data utilized in the study were collected from each pig as the dry bulb temperature in the room increased incrementally from 19.84 ± 2.15 °C to 35.54 ± 0.43 °C (range: 17.1 – 37.5 °C) over a 400-min period. After data collection, one 5-min set of continuous heart rate data were identified per pig for each of nine temperature intervals (19 to 20.99, 21 to 22.99, 23 to 24.99, 25 to 26.99, 27 to 28.99, 29 to 30.99, 31 to 32.99, 33 to 34.99, 35 to 36.99 °C). Mean inter-beat interval length (RR), standard deviation of r-r intervals (SDNN), root mean square of successive differences (RMSSD), high frequency spectral power (HF), sample entropy (SampEn), short-term detrended fluctuation analysis (DFAα1), and three measures (%REC, DET, LMEAN) derived from recurrence quantification analysis were calculated for each data set. All data were analyzed using the PROC GLIMMIX procedure in SAS 9.4. Overall, LATE sows exhibited lower RR than NP sows (P < 0.01). The standard deviation of r-r intervals and RMSSD differed between each group (P < 0.01), with LATE sows exhibiting the lowest SDNN and RMSSD and NP sows exhibiting the greatest SDNN and RMSSD. Late-gestation sows exhibited lower HF than both MID and NP sows (P < 0.0001), greater DFA values than NP sows (P = 0.05), and greater DET compared to MID sows (P = 0.001). Late-gestation also sows exhibited greater %REC and LMEAN compared to MID (P < 0.01) and NP sows (all P < 0.01). In conclusion, LATE sows exhibited indicators of greater autonomic stress throughout the heating period compared to MID and NP sows. However, temperature by treatment interactions were not detected as dry bulb increased. Future studies are needed to fully elucidate the effect of gestational stage and increasing dry bulb temperature on sow HRV.


2021 ◽  
Author(s):  
Adnan Bin Asif ◽  
Jon Hansen ◽  
AbdulMuqtadir Khan ◽  
Mohamed Sheshtawy

Abstract Hydrocarbon development from tight gas sandstone reservoirs is revolutionizing the current oil and gas market. The most effective development strategy for ultralow- to low-permeability reservoirs involves multistage fracturing. A cemented casing or liner completed with the plug-and-perf method allows nearly full control of fracture initiation depth. In uncemented completions equipped with fracturing sleeves and packers, clearly identifying the fracture initiation points is difficult due to lack of visibility behind the completion and long openhole intervals between packers. Also, the number of fractures initiated in each treatment is uncertain. A lateral was completed with access to 3,190 ft of openhole section across five fracturing stages in a high-temperature and high-pressure tight-gas interval. All stages were successfully stimulated, fracture cleanup flowback was conducted, and entry ports were milled out. A high-definition spectral noise log (SNL) was then conducted along with numerical temperature modeling. Additional logging was done with a set of conventional multiphase sensors. A multi-array production log suite was also performed. Finally, the bottom four stages were isolated with a high-temperature isolation plug based on the integrated diagnosis. The SNL helped to analyze the isolation packer integrity behind the liner. The initiation of multiple fractures was observed, with as many as nine fractures seen in a single-stage interval. A correlation was found between the openhole interval length and the number of fractures. A correlation of fracture gradient (FG) and initiation depths was made for the lateral in a strike-slip fault regime. The fractures were initiated at depths with low calculated FG, confirming the conventional understanding and increasing confidence in rock property calculations from openhole log data. SNL and temperature modeling aided quantitative assessment of flowing fractures and stagewise production behind the liner. Multi-array production logging results quantified the flow and flow profile inside the horizontal liner. The production flow assessments from both techniques were in good agreement. The integration of several datasets was conducted in a single run, which provided a comprehensive understanding of well completion and production. High water producing intervals were isolated. Downstream separator setup after the isolation showed a water cut reduction by 95%. The integration of the post-fracturing logs with the openhole logs and fracturing data is unique. The high-resolution SNL provided valuable insight on fracture initiation points and the integrity of completion packers. Fracturing efficiency, compared to the proppant placed, provides treatment optimization for similar completions in the future.


2021 ◽  
Author(s):  
Charlotte Rahlves ◽  
Frank Beyrich ◽  
Siegfried Raasch

Abstract. Lidar scan techniques for wind profiling rely on the assumption of a horizontally homogeneous wind field and stationarity for the duration of the scan. As this condition is mostly violated in reality, detailed knowledge of the resulting measurement error is required. The objective of this study is to quantify and compare the expected error associated with Doppler-lidar wind profiling for different scan strategies and meteorological conditions by performing virtual measurements implemented in a large-eddy simulation (LES) model. Various factors influencing the lidar retrieval error are analyzed through comparison of the wind measured by the virtual lidar with the ‘true’ value generated by the LES. These factors include averaging interval length, zenith angle configuration, scan technique and instrument orientation. For the first time, ensemble simulations are used to determine the statistically expected uncertainty of the lidar error. The analysis reveals a root-mean-square deviation (RMSD) of less than 1 m s−1 for 10 min averages of wind speed measurements in a moderately convective boundary layer, while RMSD exceeds 2 m s−1 in strongly convective conditions. Unlike instrument orientation and scanning scheme, the zenith angle configuration proved to have significant effect on the retrieval error. Horizontal wind speed error is reduced when a larger zenith angle configuration is used, but is increased for measurements of vertical wind. Results suggest that the scan strategy has a relevant effect on the lidar retrieval error and that instrument configuration should be chosen depending on the quantity of interest and the flow conditions in which the measurement is performed.


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Qing Liu ◽  
Ping Li ◽  
Zuqiao Yang ◽  
Zhibing Liu

Robustness refers to the ability of a system to maintain its original state under a continuous disturbance conditions. The deviation argument (DA) and stochastic disturbances (SDs) are enough to disrupt a system and keep it off course. Therefore, it is of great significance to explore the interval length of the deviation function and the intensity of noise to make a system remain exponentially stable. In this paper, the robust stability of Hopfield neural network (VPHNN) models based on differential algebraic systems (DAS) is studied for the first time. By using integral inequalities, expectation inequalities, and the basic control theory method, the upper bound of the interval of the deviation function and the noise intensity are found, and the system is guaranteed to remain exponentially stable under these disturbances. It is shown that as long as the deviation and disturbance of a system are within a certain range, there will be no unstable consequences. Finally, several simulation examples are used to verify the effectiveness of the approach and are described below.


2021 ◽  
Author(s):  
Zhaobo He ◽  
Xingxing Hu ◽  
Yuntian Teng ◽  
Xiuxia Zhang ◽  
Xiaoyu Shen

Abstract Geomagnetism, similar to other areas of geophysics, is an observation-based science. Data agreement between comparative geomagnetic vector observations is one of the most important evaluation criteria for high-quality geomagnetic data. The main influencing factors affecting the agreement between comparative observational data are the attitude angle, scale factor, long-term time drift, and temperature. In this paper, we propose a method based on a genetic algorithm and linear regression to correct for these effects and use the distribution pattern of points in Bland–Altman plots with a 95% confidence interval length to qualitatively and quantitatively evaluate the agreement between the comparative observational data. In Bland–Altman plots with better agreement, that is, with the corrected data, more than 95% of the points are distributed within the 95% confidence interval and there is no obvious pattern in the distribution of the points. Meanwhile, the length of 95% confidence interval decreased significantly after the correction. The method presented here has positive effects on the vector instrumentation detection, enhancing the robustness of comparative observatory observations and reducing errors in judgments of the size and arrival time of large magnetic disturbances or rapid magnetic variations.


2021 ◽  
Vol 10 (20) ◽  
pp. 4646
Author(s):  
Victorien L. M. N. Soomers ◽  
Emma Lidington ◽  
Bhawna Sirohi ◽  
Michael A. Gonzalez ◽  
Anne-Sophie Darlington ◽  
...  

Purpose: Teenagers and young adults (TYAs; aged 13–24) experience prolonged intervals to cancer diagnosis. Insight into diagnostic intervals in young adults (YAs; aged 25–39) and subgroups at risk for long intervals is lacking. We investigated the diagnostic pathway of YA cancer patients, examined patient and tumor characteristics associated with its length, and compared the patient interval length of our sample with a TYA cohort. Methods: In this cross-sectional survey YAs diagnosed with cancer in the UK in the past five years completed a questionnaire describing their patient (time from first symptom to first doctor consultation) and healthcare interval (from first consultation until consultation with a cancer specialist), sociodemographic, and clinical characteristics. Associations between characteristics and interval length were examined and compared with previously published data in TYAs. Results: Among 341 YAs the patient interval lasted ≥2 weeks, ≥1 month, and ≥3 months in 60%, 42%, and 21%, respectively, compared to 48%, 27%, and 12% in the TYA group. The healthcare interval lasted ≥2 weeks, ≥1 month, and ≥3 months in 62%, 40%, and 17% of YA patients, respectively. YAs with melanoma or cervical cancer were most likely to experience long intervals, whereas YAs with breast cancer and leukemia were most likely to experience short intervals. Conclusions: Most YAs were not seen by a cancer specialist within 2 weeks of GP consultation. Interval lengths in YAs were associated with cancer diagnosis. Patient intervals were longer among YAs than among TYAs. Our study highlights long diagnostic pathways among YAs and calls for more awareness among healthcare professionals about malignancies in this age group.


2021 ◽  
Vol 73 (10) ◽  
pp. 73-74
Author(s):  
Chris Carpenter

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 202419, “Performance Review of Chemical Sand Consolidation and Agglomeration for Maximum Potential as Downhole Sand Control: An Operator’s Experience,” by Nur Atiqah Hassan, SPE, Wei Jian Yeap, SPE, and Ratan Singh, Petronas, et al., prepared for the 2020 SPE Asia Pacific Oil and Gas Conference and Exhibition, originally scheduled to be held in Perth, Australia, 20–22 October. The paper has not been peer reviewed. Chemical sand consolidation (SCON) and sand agglomeration have been identified as effective chemical treatments to control sand production downhole. Both treatments involve injection of chemicals into the near-wellbore area of the reservoir with the aim of improving the strength of the formation and thus reducing the tendency for sand production. The complete paper presents lessons learned and best practices from several chemical SCON and sand-agglomeration treatments performed in mature fields in Malaysia. SCON and Sand Agglomeration History and Performance Petronas has deployed approximately 20 SCON and three sand-agglomeration treatments over nine different offshore fields since 2009. Of 20 planned SCON jobs, four were suspended for a variety of reasons such as budget constraints or operational complexity. Of the 16 SCON jobs executed, a success rate of approximately 75% was achieved. The number of sand agglomeration jobs executed is significantly lower; only three were completed, with one failure case. In terms of effective production, SCON has better overall performance than sand agglomeration. The average effective production period for SCON is approximately 2.9 years, while the average effective production period for sand agglomeration is approximately 2.5 years. Criteria for Candidate Selection Completion Type. - In considering the historical success rate of SCON and sand-agglomeration jobs according to completion type, most viable candidates were completed with perforated cased hole, contributing to approximately 87% of all chemical SCON and sand-agglomeration jobs. Despite the challenges caused by chemical placement in openhole completions, all of these jobs have been successful because of stringent planning. Overall, the success rate for chemical SCON and agglomeration under cased-hole completion is approximately 73%. Perforation Interval Length. - For effective chemical placement, the perforation interval length is limited to 20 ft according to internal guidelines, especially for cases using bullheading as the placement method. For perforation interval lengths greater than 120 ft, the failure rate can be as high as 10%. According to historical trends, no failure was encountered for chemical SCON and sand-agglomeration jobs with perforation intervals of less than 40 ft. The historical analysis indicates, therefore, that the benchmark criteria of perforation interval length could be extended to 40 ft from the current 20 ft. Placement Method. - Most chemical treatment jobs executed were completed using bullheading, contributing to approximately 80% of all chemical SCON and sand-agglomeration jobs. No failure cases were recorded for treatments that used coiled tubing because of the controlled chemical placement. Perforation intervals of almost 100 ft using bullheading placement methods have succeeded. One contributing factor for successful treatment in long intervals using bullheading is the use of diversion techniques. Nitrogen is commonly used as part of a diversion method along with chemical application.


2021 ◽  
Vol 19 (4) ◽  
pp. 147470492110461
Author(s):  
Annika Gunst ◽  
Elin Sjöström ◽  
My Sundén ◽  
Jan Antfolk

To test the hypothesis that infant night waking is an adaptation to increase interbirth intervals (IBIs) (i.e., the time between a mother’s consecutive births) by exhausting the mother, we made an initial attempt at investigating whether maternal sleep disturbance is associated with longer IBIs. We also explored whether postpartum depression symptoms mediated the association between maternal sleep disturbance and IBI length. We used retrospective self-reports from 729 mothers living in Finland. We conducted structural regressions separately for the mother’s two first children at two different age intervals (0–1 and 1–3 years). Infant night waking was associated with maternal sleep disturbance (β  =  .78–.84) and maternal sleep disturbance was associated with postpartum depression symptoms (β  =  .69–.81). Postpartum depression symptoms were also associated with longer IBIs for the first child (β  =  .23–.28). This result supports the notion that postpartum depression in and of itself could be viewed as adaptive for the offspring’s fitness, and not just as an unintentional byproduct of the mother’s sleep disturbance. Contrary to our prediction, maternal sleep disturbance was, however, associated with shorter IBIs for the first child (β  =  −.22 to −.30) when including postpartum depression symptoms in the model. We discuss the potential role of social support as an explanation for this unexpected result.


2021 ◽  
pp. 129-134
Author(s):  
Rainer Schandry ◽  
Siegfried Hoefling

2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Wael S. Abu El Azm ◽  
Ehab M. Almetwally ◽  
Abdulaziz S. Alghamdi ◽  
Hassan M. Aljohani ◽  
Abdisalam Hassan Muse ◽  
...  

For the first time and by using an entire sample, we discussed the estimation of the unknown parameters θ 1 , θ 2 , and β and the system of stress-strength reliability R = P Y < X for exponentiated inverted Weibull (EIW) distributions with an equivalent scale parameter supported eight methods. We will use maximum likelihood method, maximum product of spacing estimation (MPSE), minimum spacing absolute-log distance estimation (MSALDE), least square estimation (LSE), weighted least square estimation (WLSE), method of Cramér-von Mises estimation (CME), and Anderson-Darling estimation (ADE) when X and Y are two independent a scaled exponentiated inverted Weibull (EIW) distribution. Percentile bootstrap and bias-corrected percentile bootstrap confidence intervals are introduced. To pick the better method of estimation, we used the Monte Carlo simulation study for comparing the efficiency of the various estimators suggested using mean square error and interval length criterion. From cases of samples, we discovered that the results of the maximum product of spacing method are more competitive than those of the other methods. A two real‐life data sets are represented demonstrating how the applicability of the methodologies proposed in real phenomena.


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