Role of barium enema examination for the diagnosis of submucosal invasion depth in T1 colorectal cancers

Background The indication for endoscopic resection for submucosally invasive colorectal cancer (T1-CRC) depends on the preoperative diagnosis of invasion depth. The aim of this investigation was to evaluate the association between barium enema examination (BE) profile views and depth of submucosal (SM) invasion in CRCs. Methods We reviewed the radiographic and endoscopic findings of 145 T1-CRCs diagnosed from 2008 to 2019. We measured the widths of horizontal and vertical rigidity under a BE profile view corresponding to CRC and compared the values with SM invasion depth. Horizontal rigidity was defined as the horizontal length and vertical rigidity as the vertical width of the barium defect corresponding to each target lesion. The most appropriate cut-off values for predicting SM invasion ≥1.8 mm were calculated by receiver operating characteristic curve analysis. Results Values of horizontal rigidity (r = 0.626, P < 0.05) and vertical rigidity (r = 0.482, P < 0.05) correlated significantly with SM invasion depth. The most appropriate cut-off values for the prediction of SM invasion depth ≥ 1.8 mm were 4.5 mm for horizontal rigidity, with an accuracy of 80.7%; and 0.7 mm for vertical rigidity, with an accuracy of 77.9%. The prevalence of lympho-vascular invasion was significantly different when those cut-off values were applied (43.2% vs. 17.5% for horizontal rigidity, P < 0.005). Conclusions In T1-CRC, values of horizontal and vertical rigidities under a BE profile view were correlated with SM invasion depth. While the accuracy of the rigidities for the prediction of SM invasion depth ≥ 1.8 mm was not high, horizontal rigidity may be predictive of lympho-vascular invasion, thus aiding in therapeutic decision-making.

Formation mechanism of super cluster over the tropics

A large-scale cloud phenomenon was analyzed to understand its internal structure, organization and movement. A westward moving uncommon super cluster was shown to have developed in the study region while each cloud cluster moved FJESE. The super cluster has horizontal length 2000 km, life time more than 2 days, very low TBB (<210 K) cloud area ~40× 104 km2 and moved westward with a speed of ~6 m/s. These features are some what different from the usual properties of super cluster as reported in several works. It was found that new clouds successively formed and interacted between themselves, and organized to form cloud clusters. The cloud clusters merged with the old large cluster to take part in the maintenance of super cluster. The propagation speed and the direction of the super cluster was followed by the formation of new cluster.

Long Horizontal Well Completion via a New Flotation Technique

The objective of the paper is to introduce a new technology which secures long horizontal casing deployment by a reliable casing flotation technology. It is common nowadays to drill a slim hole and extends to long horizontal extension to pay zones in condensate and shale oil and gas reservoir. To assure a successful casing deployment into the horizontal section, a flotation collar is often installed to float the casing in horizontal to mitigate the friction and Torque & Drag. However, slim casing may encounter difficulty in circulation and subsequent cementing even after the collar is broken. A new proprietary technique proposed in this paper solved above contingencies and secured 100% success in casing deployment, This technique secures smoothly circulation and cementing by flotating air in horizontal casing interval and purging air out of hole to overcome Spring Effect before circulation and cementing. Often, the flotation collar is made of proprietary material that can break or explodes under certain hydraulic pressure. After breaking, the whole collar becomes a portion of casing with exact the same ID of casing or a very small difference that does not have any negative effect to subsequent Plug & Perf, frac, tools running through and fluid movement. For long horizontal length of small open hole and casing sizes, casing deployment may be difficult if the Torque & Drag and friction through the low sides can not be mitigated. This paper proposes a new technique to fill air full of horizontal interval along inside the casing and ensure a sufficient of air purging to overcome Spring Effect before circulation and cementing. So far twelve (12) wells have been successfully completed including Asian longest horizontal gas well with 7,388.18m measured depth and 4,118.18m horizontal length. All jobs are 100% successful and there is no difficulty in mud circulation and cementing. Even for the longest 4,118.18m horizontal length casing deployment, the hook weight on surface when casing reached the total depth still remained 20 MT. Before this technique was applied, operators were unable to deploy 4 ½" casing through a 6" bit hole beyond 1500m horizontal length. Most often the hook weight at surface were zero when casing extended to almost 1500m in horizontal length. This new technique brings a great value to operators to complete longer horizontal well to yield more production with less investment.

Laboratory studies of the role of bandwidth in surface transport and energy dissipation of deep-water breaking waves

This paper presents laboratory measurements of surface transport due to non-breaking and breaking deep-water focusing surface wave packets and examines the dependence of the transport on the wave packet bandwidth, $\varDelta$ . This extends the work of Deike et al. (J. Fluid Mech., vol. 829, 2017, pp. 364–391) and Lenain et al. (J. Fluid Mech., vol. 876, 2019, p. R1), where similar numerical and laboratory experiments were conducted, but the bandwidth was held constant. In this paper, it is shown that the transport is strongly affected by the bandwidth. A model for the horizontal length scale of the breaking region is proposed that incorporates the bandwidth, central frequency, the linear prediction of the slope at focusing and the breaking threshold slope of the wave packet. This is then evaluated with data from archived and new laboratory experiments, and agreement is found. Furthermore, the horizontal length scale of the breaking region implies modifications to the model of the energy dissipation rate from Drazen et al. (J. Fluid Mech., vol. 611, 2008, pp. 307–332). This modification accounts for differing trends in the dissipation rate caused by the bandwidth in the available laboratory data.

Optimal Design and Numerical Analysis of Soil Slope Reinforcement by a New Developed Polymer Micro Anti-slide Pile

As a new material, polyurethane polymer has been widely used in engineering in recent years due to the excellent engineering mechanical properties. Based on the characteristics of this material, a multi pipe grouting micro anti-slide pile is proposed, which is formed by using polymer slurry as grouting material. Compared with traditional anti-slide pile, the polymer micro pile has the advantages of strong applicability, no water reaction, small disturbance, fast construction, economy and durability. As a flexible retaining structure, polymer micro-piles can strengthen the slope by cooperating with the forces. However, there is no report on the reinforcement of slope by polymer micro piles at present. In this paper, a three-dimensional multi row polymer micro piles model for slope reinforcement considering different embedded depth and pile location is established. Safety factor, thrust force of landslide behind pile, length of pile and mises stress are taken as four factors to evaluate reinforcement effect, the optimal reliability of polymer micro anti-slide pile for slope reinforcement is evaluated by giving different weight values to each factor through multi factor comprehensive evaluation method. The safety factor of slope (Fs), landslide thrust behind pile and mises stress of pile are analyzed under different embedded depth (le) and pile position (px). The results show that the best embedded depth is about1/8 − 1/12 of the horizontal length of the landslide behind the pile when multi row polymer micro piles are used to reinforce the slope; the optimum position of pile arrangement is 0.55–0.65 times the slope length from the top of the slope.

First Multistage Fracturing of a Horizontal Well Drilled in a Tight Carbonate Reservoir in UAE

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 203226, “First Multistage Fracturing of Horizontal Well Drilled in a Conventional Tight Carbonate Reservoir in an Onshore Field in the UAE: Challenges and Lessons Learned,” by Muhammad Aftab, SPE, Noor Talib, and Maad Subaihi, ADNOC, et al., prepared for the 2020 Abu Dhabi International Petroleum Exhibition and Conference, Abu Dhabi, held virtually 9–12 November. The paper has not been peer reviewed. The reservoir upon which this case study is focused is a tight, low-permeability carbonate reservoir with thin layers. The objective of the field case was to increase and sustain productivity of a pilot well consisting of an openhole completion. The complete paper summarizes the design processes, selection criteria, challenges, and lessons learned during design and execution phases. The study may provide a potential approach for selecting the proper hydraulic fracturing method and technique in similar cases. Introduction Reservoir X is divided into six layers. Layers X-3 through X-6 have reasonable porosity development; valid pressure points exist in X-3 and X-6. Pumpout was performed while collecting samples from X-3 and X-6, followed by short buildups. Production-logging-tool measurement was performed and found two major oil-producing layers across X-3 (60% of total production) and X-6 (40% of total production). The remaining intervals of the perforation were almost inactive. Petrophyscial and testing results of vertical Well A resulted in a decision to drill a horizontal oil producer (Well B) through Layer X-3. Well B was steered with a 2,220-ft horizontal length, out of which 1,930 ft was inside X-3 and 290 ft were above X-3 be-cause of a fault throw of 16 ft true vertical depth. The well was steered with a horizontal length of 2,080 ft in X-6. Well B was completed with a 3½-in. completion and horizontal section as an openhole. Matrix stimulation using coiled tubing was performed with 15% hydrochloric acid in Well B. The well ceased to flow after 2 weeks of declining production. Rapid pressure depletion was observed in Well B. Localized depletion around the wellbore was anticipated because of poor matrix/matrix connectivity. After comprehensive studies and risk assessments, the decision was made to recomplete Well B with a cemented fracturing string to perform hydraulic fracturing with the plug-and-perf technique. This technique will allow flexibility of stage count and stage spacing and a multi-cluster design to maximize the stimulated reservoir volume (SRV) along the upper, middle, and lower layers. In addition, the operator and service provider collaborated to enhance this design through a zero-overflush technique with diverting agents. The complete paper provides a detailed discussion of the core measurement and 1D mechanical Earth model used in the hydraulic fracturing design. Hydraulic Fracturing Design The main challenge in fracturing Well B was to ensure that the fracture generated is contained within the reservoir. Well B is completed in two layers (X-3 and X-6). The bottom part of the well is in X-6 and close to another underlying reservoir (Fig. 1).

Empirical α–β runout modelling of snow avalanches in the Catalan Pyrenees

A variation in the α−β model which is a regression model that allows a deterministic prediction of the extreme runout to be expected in a given path, was applied for calculating avalanche runout in the Catalan Pyrenees. Present knowledge of major avalanche activity in this region and current mapping tools were used. The model was derived using a dataset of 97 ‘extreme’ avalanches that occurred from the end of 19th century to the beginning of 21st century. A multiple linear regression model was obtained using three independent variables: inclination of the avalanche path, horizontal length and area of the starting zone, with a good fit of the function (R2 = 0.81). A larger starting zone increases the runout and a larger length of the path reduces the runout. The new updated equation predicts avalanche runout for a return period of ~100 years. To study which terrain variables explain the extreme values of the avalanche dataset, a comparative analysis of variables that influence a longer or shorter runout was performed. The most extreme avalanches were treated. The size of the avalanche path and the aspect of the starting zone showed certain association between avalanches with longer or shorter runouts.

Evaluating the Performance of Lightning Data Assimilation from BLNET Observations in a 4DVAR-Based Weather Nowcasting Model for a High-Impact Weather over Beijing

The Beijing Broadband Lightning Network (BLNET) was successfully set up in North China and had yielded a considerable detection capability of total lightning (intracloud and cloud to ground) over the regions with complex underlying (plains, mountains, and oceans). This study set up a basic framework for the operational application of assimilating total lightning activities from BLNET and assesses the potential benefits in cloud-scale, very short-term forecast (nowcasting) by modulating the vertical velocity using the 4DVar technique. Nowcast statistics aggregated over 11 cycles show that the nowcasting performances with the assimilation of BLNET lightning datasets outperform RAD and the assimilation of GLD360 (Global Lightning) datasets. The assimilation of BLNET data improves the model's dynamical states in the analysis by enhancing the convergence and updraft in and near the convective system. To better implement of assimilating real-time lightning data, this study also conducts sensitivity experiments to investigate the impact of the horizontal length scale of a distance-weighted interpolation, binning time intervals, and different vertical profile or distance weights prior to the DA. The results indicate that the best forecast performance for assimilating BLNET lightning datasets is obtained in a 4DVar cycle when the lightning accumulation interval is 3 min, the radius of horizontal interpolation is 5 × 5, and the statistically vertical velocity profile and the distance weights obtained from cumulus cloud.

Compact Wideband Coplanar Stripline-to-Microstrip Line Transition Using a Bended Structure on a Two-Layered Substrate

A design of a compact coplanar strip (CPS)-to-microstrip line (MSL) transition using a bended structure on a two-layered substrate is presented. The proposed transition consists of a CPS taper and a bended CPS-to-MSL transition on a two-layered substrate. The CPS taper is formed on the lower substrate with low permittivity (εr = 3.38), and the bended CPS-to-MSL transition is formed on the upper substrate with high permittivity (εr= 10.2). The proposed transition is designed with analytical formulas obtained by applying EM-based conformal mapping without parametric tuning trials. The conductor shape of the bended CPS-to-MSL transition is adjusted to form an optimal Klopfenstein impedance taper. The proposed CPS-to-MSL transition optimally connects between a high impedance CPS line (~160 Ω) and a 50 Ω MSL, which typically results in a long transition length for ultra-wideband performance. The implemented transition bended in a sinusoid shape on the two-layered substrate provides good performance from 2 GHz to 17 GHz with the maximum 2 dB insertion loss per transition, and the horizontal length of the bended transition is reduced to 42.9% of the straight transition length. This bended transition is developed for use in mm-wave balanced antenna/detector feeds but can be applied to a variety of wideband balanced circuit modules, where compact circuit size is critical.

A rigorous derivation and energetics of a wave equation with fractional damping

We consider a linear system that consists of a linear wave equation on a horizontal hypersurface and a parabolic equation in the half space below. The model describes longitudinal elastic waves in organic monolayers at the water–air interface, which is an experimental setup that is relevant for understanding wave propagation in biological membranes. We study the scaling regime where the relevant horizontal length scale is much larger than the vertical length scale and provide a rigorous limit leading to a fractionally damped wave equation for the membrane. We provide the associated existence results via linear semigroup theory and show convergence of the solutions in the scaling limit. Moreover, based on the energy–dissipation structure for the full model, we derive a natural energy and a natural dissipation function for the fractionally damped wave equation with a time derivative of order 3/2.