Potato harvesters operating in hilly and mountainous areas are often subjected to harsh working conditions such as high temperature, sun exposure, and high torque excavation. Due to the fluid sealing characteristics, closed loop hydraulic systems are prone to high temperatures during long-term continuous operation, resulting in a decrease in fluid viscosity, poor lubrication, severe wear, and power attenuation. This study investigates the hydraulic system of potato harvesters in hilly terrain, systematically analyzing its energy transfer process and identifying key heat-generating components. Based on an optimization strategy that extends the flow path of high-temperature fluid within the tank, four distinct tank designs were proposed. Computational fluid dynamics (CFD) and thermodynamic simulations were conducted to evaluate their heat dissipation performance, followed by full-machine validation testing. Results indicate that the walking and lifting systems are the primary heat sources. The dual pump contributes the highest proportion of heat (52.07%), followed by the walking motor (20.54%). The heat exchanger dissipates 72.91% of the heat, while the hydraulic oil tank accounts for 14.93%. Among the four tank designs, Tank 0 exhibited the fastest temperature rise, reaching a thermal equilibrium of 83.27 °C, whereas Tank 1 had the lowest equilibrium temperature (78.62 °C). Heat dissipation efficiencies for the tanks were 7.8%, 12.9%, 10.1%, and 11.6%, respectively. The residual gas volume fraction decreases significantly as the bubble diameter increases, due to the higher buoyancy and faster rise velocity of larger bubbles, which leads to shorter residence times and more effective precipitation. Tank 1 achieved the lowest equilibrium temperature, indicating the best thermal efficiency. Tank 3 showed the best overall degassing performance, particularly for medium-to-large bubbles. Tank 1 was selected as the optimal final design because it could offer an excellent balance, with very good cooling and competitive degassing (especially for small bubbles). Field tests confirmed a 14.8% reduction in thermal equilibrium temperature for Tank 1 (75.6 °C) compared to Tank 0 (88.7 °C). Simulation and experimental data showed strong agreement, with maximum errors of 9.2% for return fluid temperature, 12.7% for cooling return fluid temperature, 9.7% for pressure, and 8.5% for flow rate. Average errors remained below 8.4% for pressure and 7.6% for flow rate. These results validate the accuracy of the simulation model and the effectiveness of the tank optimization method.

Gas–water two-phase flow in porous media is vital in groundwater management and hydrocarbon development, yet most experiments use small cores (5–10 cm) or etched micro-models. These studies often overlook the quantitative characterization of residual gas, long-distance gas–water flow behavior, and effects of gas–water flow on pore structure. This study presents a series of 3 m-long artificial unconsolidated sandstone models with permeabilities of 5, 10, 30, 50, and 100 mD, fabricated via rock–electric testing techniques to simulate edge-water invasion in gas reservoirs. The results indicate that (1) by adjusting clay content, cementing agents, grain size, and sand mix, artificial cores achieve permeability, porosity, cementation strength, sensitivity, and pore structure similar to natural cores; this approach addresses the sampling challenge from unconsolidated sandstone. (2) During long-distance gas–water flow, pressure drops rapidly in the gas–water transition zone. As permeability increases, the zone shifts downstream and becomes narrower. (3) The flow of gas–water causes a large number of particles to gather near the gas–water interface and block the throat, and effective stress on unconsolidated sandstone intensifies this blockage effect. (4) Residual gas exists in the forms of dead-end trapped gas, bypass trapped gas, and snap-off trapped gas. The residual gas volume is mainly controlled by gas saturation and pressure, but the largest amount of residual gas accumulates near the gas–water interface. This study addresses the research gap in understanding long-distance gas–water flow and presents a novel experimental method for unconsolidated porous media.

Severe gas hazards are increasing in deep mining areas, and there exists an enormous traditional challenge for protected seam mining. In this work, we conducted a multifaceted investigation into the spatiotemporal effectiveness exerted by pressure unloading from a distant safeguarded stratum in concert with the application of gas extraction methodologies. The stress and displacement evolution in the protected coal seam (PCS) are analyzed by applying Flac3D, and then positives are verified by the measurement of coal seam deformation and investigation of the unloading boundary. The results show that diminution coefficient of 0.62, and record an expansive deformation rate of 5.83%. The opportune temporal window for effective gas drainage is discerned, with its time window spans from 58 to 67 days as the expanse between 350 and 400 m progresses at the working face. Continuous and effective gas extraction occurs when transverse cracks in the PCS reach an optimal state of pressure relief. The final cumulative gas extraction was 320,300 m3 with an extraction efficiency of 34.3%. A residual gas volume of 3.68 m3/t and a residual gas pressure of 0.5 MPa reflect the efficient gas extraction.

A comprehensive estimation of shale generation/storage capacity (original generative organic carbon (GOCo)) and hydraulic fracturing characteristics (brittleness index (BI)) was conducted in the Upper Devonian shale sequence of the Liard Basin.GOCo was calculated from fraction of type II kerogen inferred from biogenic silica concentrations.BI was estimated from mechanical properties calculated from well-log data.Without well-log data, BI was converted from the relative contribution of biogenic and detrital silica concentrations.Based on GOCo and BI, the shale sequences were divided into four resource facies (RFs): RF1 (GOCo <1 wt%, BI 20-40), RF2 (GOCo 1-3 wt%, BI 20-60), RF3 (GOCo 2-5 wt%, BI 60-95), and RF4 (GOCo 5-14 wt%, BI 60-95).Shale with RF3 and RF4 characteristics were determined to have high hydraulic fracturing efficiency, high organic porosity, and capability to generate large amounts of gas.Considering the vertical variation of RFs, the Patry and Lower Exshaw formations are estimated as favorable shale gas reservoirs with abundant gas content and high hydraulic fracturing efficiency.If 30% of the total gas generation potential estimated from GOCo remains in the shale gas reservoir, the sum of residual gas volume of both formations in the study wells exceeds 280 bcf/section.

Experimental study of a leakage location method based on plug flow mass transfer characteristics

Postoperative pain is a common issue following laparoscopic cholecystectomy. This meta-analysis aimed to determine if active gas aspiration is more effective than passive gas aspiration in reducing postoperative pain and analgesic requirements. The study conducted a systematic search of various databases, including Embase, Medline, and Cochrane Central Register of Controlled Trials (CENTRAL) via Ovid. It also searched trial registries and reference lists of included studies, with no date restrictions but limited to English language, up to December 21, 2022. The study included all randomized clinical trials that had documented elective laparoscopic cholecystectomy procedure and reported at least one relevant outcome. Articles that included subdiaphragmatic drain, intraperitoneal normal saline infusion, or pulmonary recruitment maneuver were excluded from the analysis. Two reviewers independently and in duplicate assessed the eligibility of studies and extracted data. The study reported findings according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. The risk of bias of the included trials was assessed using the Revised Cochrane Risk of Bias Assessment Tool. The study used a random-effects model to pool data. This meta-analysis included 5 randomized clinical trials with 367 participants and found that active gas aspiration resulted in significantly lower residual gas volume and total analgesia requirements compared to passive gas aspiration. Active gas aspiration also led to significantly lower shoulder pain scores at 24h postoperatively. However, no significant differences were observed in hospital stay duration or abdominal pain scores. The study found that active gas aspiration can be effective in reducing postoperative shoulder pain and analgesic requirements after laparoscopic cholecystectomy, which has important implications for patient care and healthcare costs. Importantly, this intervention does not impose any additional time or financial burden. However, further research is needed to evaluate its impact on other laparoscopic procedures.

Free residual gas after laparoscopy may cause shoulder pain, decreasing patient satisfaction with the procedure. We analyzed the correlation between postoperative residual carbon dioxide gas and shoulder pain, explored the peri- and postoperative factors associated with residual carbon dioxide and determined the effects of the use of a drainage tube. A cohort of 326 patients who underwent laparoscopic adnexal surgery between March 2005 and June 2018 at a teaching hospital in Korea was retrospectively analyzed through a medical records review. The enrolled patients were divided into 1-, 2-, and 3-port groups. The right volume, left volume, and total volume of residual gas were calculated using a formula based on measurements obtained from chest X-rays. Continuous variables were compared using Student t tests. Categorical variables were compared with the chi-square test or Kruskal–Wallis test. The total volumes of postoperative residual carbon dioxide gas were significantly different between the 1- and 2-port groups and between the 1- and 3-port groups (157.3 ± 179.2 vs 25.1 ± 92.3 mL and 157.3 ± 179.2 vs 12.9 ± 36.4 mL, respectively). The volume of residual gas and the time to the first passage of gas were positively correlated. The total volume of residual gas was more strongly correlated with the operative wound pain score than with the shoulder pain score. Additionally, the pre- and postoperative white blood cell counts, postoperative hospitalization duration, residual carbon dioxide volume, and shoulder pain score were significantly different between patients with and without a drainage tube. Although the volume of residual gas was not correlated with the shoulder pain score, the author found that both were lower in patients with a drainage tube than in those without, indicating that a drainage tube could be safely used to decrease residual gas volume and the shoulder pain score without increasing the risk of postoperative infection.

After laparoscopic surgical procedures, residual gas in the abdominal cavity can cause post-operative pain, which is commonly located in the shoulder region. Previous studies suggested that post-laparoscopy pain can be prevented by active suctioning of intraabdominal gas at the end of surgery. This randomized controlled trial (registered at DRKS 00,023,286) compared active suctioning versus manual compression in their ability to reduce pain after laparoscopic cholecystectomy. Patients scheduled for laparoscopic cholecystectomy were eligible for trial participation. The primary outcome measure was post-operative pain intensity after 12h. All the patients were examined by MRI scanning to quantify the intraabdominal gas volume after the intervention. As planned, 60 patients were recruited. The two groups (n = 30 each) were very similar at the end of surgery. Active suctioning reduced the amount of residual pneumoperitoneum more than simple compression (median volume 1.5 versus 3.0ml, p = 0.002). The primary outcome measure, abdominal pain after 12h, was slightly lower in the intervention group (- 0.5 points, 95% confidence interval + 0.5 to - 1.7), but without reaching statistical significance (p = 0.37). After 12h, shoulder pain was present in 10 patients in each group (p = 1.0). Independent of group assignment, however, residual gas volume was significantly associated with higher pain intensity. Active suctioning appears to have only a minor preventive effect on post-laparoscopy pain, probably because evacuation of the pneumoperitoneum remains incomplete in some patients. Other more effective maneuvers for gas removal should be preferred.

Shoulder pain after natural orifice transluminal endoscopic surgery decreased with abdominal compression and pulmonary recruitment maneuver: A retrospective study

Purpose To observe the efficacy and safety of pars plana vitrectomy (PPV) combined with filtered air tamponade in the treatment of rhegmatogenous retinal detachment (RRD) with inferior retinal breaks. Methods This retrospective study included 20 patients (20 eyes) with inferior retinal breaks in RRD; all underwent PPV combined with filtered air tamponade. Preoperative examinations included BCVA, IOP, anterior segment, fundus and locations, numbers, and sizes of retinal breaks and ocular B-mode ultrasonography. Postoperative examinations included BCVA, IOP, residual gas volume, retinal reattachment, and complications. Results After follow-up for 1 year, the primary retinal reattachment rate was 95% and the final reattachment rate was 100%. Pre- and postoperative BCVA averaged 1.51 ± 0.63 and 0.97 ± 0.58 logMAR, respectively; the difference was statistically significant (P < 0.001). Average pre- and postoperative IOP were not statistically different. The average volume of residual gas on the first day after the surgery was 77.5%; the gas was absorbed in all patients within 2 weeks; no significant postoperative complications were observed. Conclusion PPV combined with filtered air tamponade is a safe and effective treatment for RRD with inferior retinal breaks. Notably, the retinal reattachment rate is high, gas absorption is rapid, and incidence of complications is low.

BackgroundTo investigate whether human papillomavirus (HPV) infection is associated with primary lung cancer among the Fujian population.MethodsHPV infection was detected in 140 pairs of lung cancer tissues and matched paracancerous tissues by examining the 21 clinically relevant HPV types using a combination of viral highly conserved L1 region PCR amplification and specific probe reverse hybridization. Paired χ2 test was used to analyze differences in detection rates of HPV between lung cancer and paracancerous tissues. Differences in detection rates of HPV in lung cancer tissues were analyzed using χ2 test or the exact probability method. The rank sum test was used to analyze differences in the distributions of routine indices of blood and pulmonary function in lung cancer tissues between the HPV negative and positive groups.ResultsHPV infection was detected in 13 of the 140 tumor specimens and in 16 of the paired normal lung tissues. There was no significant correlation between HPV infection and lung cancer (P > 0.05). The diagnosed HPV infection rates did not differ significantly among lung cancer tissues with different stratification (P > 0.05). However, the platelet count, platelet pressure, residual gas volume, functional residual volume, and residual gas volume/lung total distribution may differ between HPV‐negative and HPV‐positive lung cancer tissues (0.000625 < P < 0.05).ConclusionsWe concluded that HPV infection may not be associated with the risk of primary lung cancer in the Fujian population. However, HPV infection may affect platelet and residual lung function in primary lung cancer patients.

Objective:To investigate the overweight and obesity effects on pulmonary function in OSA patients.Method:Randomly selected 90 cases OSA patients who were treated January 2017 to December 2017. On the basis of BMI were divided into three groups, the normal OSA group(A,30 cases), overweight OSA group(B,30 cases) and obesity OSA group(C,30 cases). Comparative analysis between groups of age, AHI, lowest arterial saturation oxygen(LSaO₂), the longest apnea time(LAD) and pulmonary function indicators include: a second volume(FEV1),forced vital capacity(FVC), FEV1/FVC,the chase volume(MVV), per minute resting ventilation(MV), peak expiratory flow velocity(PEF),tidal volume(VT), the residual gas volume(RV), functional residual capacity(FRC) and expiratory reserve volume volume(ERV), total lung volume(TLC) vital capacity(VC), deep inspiratory capacity(IC), RV/TLC. Result:Compared group C with B and A, B and A, AHI increased significantly(P<0.01); compared group C with B and A, LSaO₂ significantly reduced(P<0.01); compared group C with A, LAD is prolonged(P<0.05).Compared group C with A, MVV, MV, TLC and IC increased significantly(P<0.05), FRC, ERV significantly reduced(P<0.05); compared C with B, MVV, MV and TLC increased significantly(P<0.05). Compared group B with A,MVV,MV,MEF75,ERV and IC increased significantly(P<0.05); AHI and VT,RV,TLC and FRC has significant positive correlation(P<0.05), and VT, MVV and FEV1/FVC has significant negative correlation(P<0.05);LAD with BMI,VC,FVC,FEV1,MEF50,PEF and MVV is a significant positive correlation(P<0.05).FEV1/FVC, IC is the independence of overweight and obesity OSA severe impact factor. Conclusion:With the increasing of BMI, not only increase the severity of OSA, and further damage to the pulmonary function; the OSA severity of overweight and obesity are closely associated with multiple pulmonary function index; FEV1% FVC, IC for overweight and obesity independent factor influencing the severity of OSA. Pulmonary function can be used as overweight and obesity auxiliary to assess the severity of OSA patients.

Although combined cycle gas turbine (CCGT) has been utilized and studied intensively, little attention was paid on optimizing its shutdown process. Under limited residual natural gas, the optimization of shutdown process of CCGT becomes a problem needed to be solved, and no research has been conducted on solving this particular problem. In this study, the overall performance and characteristics of the shutdown process of CCGT were analyzed and modeled. This model was proposed to allocate gas consumption during shutdown process for creating maximum power generation and maximum economic benefit. Based on the shutdown process model, optimal shutdown scheme was proposed and proved, and optimizing algorithms were developed to facilitate the decision making procedure. The calculations of different load-up rates and load-off rates of CCGT showed that the total power generation is more relevant with the load-off rates rather than the load-up rates. When the residual natural gas volume assumed to be 105 m3, the shutdown optimization could generate an extra power of 28.41 MW⋅h and an extra profit of 4.79 million Yuan annually. This program was applied on three CCGTs in a power plant in Zhejiang Province, China, as a case study. The testing results proved that the obtained optimization scheme is technically stable and effective in the real working condition. Thus, the model and the optimization algorithms were also valid and feasible for potential applications.

The Intensity of Postlaparoscopic Shoulder Pain Is Positively Correlated with the Amount of Residual Pneumoperitoneum

BackgroundCarbon dioxide (CO2) insufflation is increasingly used for endoscopic submucosal dissection (ESD) owing to the faster absorption of CO2 as compared to that of air. Studies comparing CO2 insufflation and air insufflation have reported conflicting results.ObjectivesThis meta-analysis is aimed to assess the efficacy and safety of use of CO2 insufflation for ESD.MethodsClinical trials of CO2 insufflation versus air insufflation for ESD were searched in PubMed, Embase, the Cochrane Library and Chinese Biomedical Literature Database. We performed a meta-analysis of all randomized controlled trials (RCTs).ResultsEleven studies which compared the use of CO2 insufflation and air insufflation, with a combined study population of 1026 patients, were included in the meta-analysis (n = 506 for CO2 insufflation; n = 522 for air insufflation). Abdominal pain and VAS scores at 6h and 24h post-procedure in the CO2 insufflation group were significantly lower than those in the air insufflation group, but not at 1h and 3h after ESD. The percentage of patients who experienced pain 1h and 24h post-procedure was obviously decreased. Use of CO2 insufflation was associated with lower VAS scores for abdominal distention at 1h after ESD, but not at 24h after ESD. However, no significant differences were observed with respect to postoperative transcutaneous partial pressure carbon dioxide (PtcCO2), arterial blood carbon dioxide partial pressure (PaCO2), oxygen saturation (SpO2%), abdominal circumference, hospital stay, white blood cell (WBC) counts, C-Reactive protein (CRP) level, dosage of sedatives used, incidence of dysphagia and other complications.ConclusionUse of CO2 insufflation for ESD was safe and effective with regard to abdominal discomfort, procedure time, and the residual gas volume. However, there appeared no significant differences with respect to other parameters namely, PtcCO2, PaCO2, SpO2%, abdominal circumference, hospital stay, sedation dosage, complications, WBC, CRP, and dysphagia.

Modeling and optimization of shutdown process of combined cycle gas turbine under limited residual natural gas

The aim of the current study was to directly investigate whether active gas suction reduces intraperitoneal residual carbon dioxide and to analyze the effect of active gas suction on postoperative pain after laparoscopic cholecystectomy. This prospective, randomized clinical study included patients between 19 and 65 years of age with gallbladder disease who were eligible for elective laparoscopic cholecystectomy. Patients were allocated into either the natural evacuation group (NE group) or the active suction group (AS group). In the AS group, active suction was applied by inserting the laparoscopic suction irrigation device through a 5-mm trocar for 60 seconds at the end of surgery. A chest X-ray was taken at postoperative Day 1, and the residual intraabdominal gas volume was measured. Perioperative data including pain score and analgesic requirement were collected. Thirty-nine patients were allocated to the NE group, and 36 were allocated to the AS group. There was no statistically significant difference between the two groups in terms of demographic data and operative findings. However, a significant difference was observed in the residual intraperitoneal gas volume, with 15.9±6.8 mL in the NE group and 6.7±4.0 mL in the AS group (P<.001). Significant differences were also observed in the pain scores measured 6 hours after surgery, on postoperative Day 1, and on postoperative Day 2. Active gas suction is a very simple procedure that is safe and feasible. Performing this procedure significantly decreases the residual intraperitoneal gas volume and postoperative pain after laparoscopic surgery.

In semiconductor manufacturing, potential wetting issues with aqueous chemistries are becoming a concern as feature dimensions are continuously scaled down and novel materials with different wetting properties are introduced in new technology nodes. The wetting behavior of silicon nanopillars with different dimensions and surface modifications has been studied using static contact angle, decoration by etching, and attenuated total reflection infra-red spectroscopy (ATR-FTIR). The contact angle measurements showed a consistent deviation from the classic wetting models for patterned substrates with an hydrophilic surface termination. Under these conditions the decoration and ATR-FTIR studies gave evidence for partial wetting, with residual gas lasting for more than 30 min. It is proposed that this was resulting from the formation of long-lasting surface nanobubbles localized in-between or at the bottom of nanopillars. On the other hand the residual gas volume estimated by ATR-FTIR seemed too small to explain the contact angle deviations. It is proposed that the apparent extension of the superhydrophobic regime to lower contact angles resulted from modifications of the wettability of the surface of nanopillars caused by the manufacturing process. Both the formation of nanobubbles and the extension of the superhydrophobic regime may present challenges for aqueous cleaning in semiconductor manufacturing.

Abstract Background: Postoperative abdominal and shoulder pains after laparoscopic cholecystectomy (LC) are the most frequent complaints and are related to delayed recovery. There is a strong correlation between the residual gas volume and the severity of pain following various laparoscopic procedures. We aimed to investigate the effects of aspiration of residual gas on postoperative outcomes and pain following LC. Patients were randomly assigned to either the active gas reduction group (Group 1, n=105) or the control group (Group 2, n=95). After completion of the operative procedures, residual gas was aspirated with a flexible cannula in Group 1. In Group 2, gas release from the abdomen was performed using the port site by opening the gas tap only. The demographic data, operation time, insufflated CO2 volume during the operation, hospitalization period, and time to return to daily activities were recorded. Postoperative shoulder and abdominal pain assessment was performed using a numerical pain intensity scale (NPIS) at 1 hour, 24 hours, 3 days, and 7 days postoperatively. There was no statistically significant difference between the groups in terms of demographic data, operative findings, and clinical outcomes. NPIS scores for shoulder pain at 1 hour and 24 hours were significantly lower in Group 1 (P=.001 and P=.021, respectively). However, there were no significant differences in the NPIS scores for shoulder and abdominal pain following 24 hours. No differences were found in the hospitalization duration and time to return to daily activities data (P>.05). Active aspiration of the residual gas just before the removal of the trochars is a simple procedure and leads to a more comfortable hospital stay for patients.

Structural aspects of gas and dolomite outburst in Rudna copper mine, Poland