Initial Port Research Articles

An empirical study of the performance of the sixth generation ports model with smart ports with reference to major container ports in mainland China

Since the UNCTAD proposed the initial port model, called the first generation port model (1GP) in 1994, its adaptation and transformation have evolved, reflecting not only the evolution of port operations and technological advancements, but also the resilience of ports to natural disasters and supply disruptions. Recently, the trio of COVID-19, digitalization, and decarbonization (CDD) has emerged as core challenges whilst providing numerous opportunities for building adaption and resilience for the port industry. In light of this, the sixth generation ports (6GP) model has emerged. This paper addresses crucial research gaps by empirically testing the 6GP model, emphasizing the impact of emerging factors of the CDD, including 1) the lack of empirical testing for the 6GP model and the emphasis on the CDD; 2) the exploration of factors contributing to the significant development of Chinese container ports; 3) the investigation into how the CDD lead to the reversal of the port devolution continuum path. In doing so, an empirical study has been conducted, focusing on six major container ports in mainland China, all of which are among the world’s top 10 container ports in terms of container throughput. It evaluates the importance of the criteria of the 6GP model with the performance of the six ports. The findings of this research are discussed for managerial and policy implications, enriching the existing literature on port devolution, and providing the port industry with a holistic view of port development and strategy in the post-pandemic period.

Laparoscopy in Pregnancy: A Comparative Review of National Guidelines.

Gynecological and general surgical conditions requiring surgical management during pregnancy constitute a medical challenge, which often entailsthe collaboration of numerous medical specialties. In recent years, laparoscopy in pregnancy has been accepted as a safe alternative to open surgery. This has led gynecological societies to conduct studies and issue guidelines related to laparoscopy in pregnancy, with a view to assisting and guiding clinicians and surgeons. The aim of this study was to review and compare the recommendations from various published national guidelines on laparoscopy in pregnant women. To that end, a descriptive review of guidelines fromthe British Society for Gynaecological Endoscopy (BSGE), the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES), the Society of Obstetricians and Gynaecologists of Canada (SOCG), and the Collège National des Gynécologues et Obstétriciens Français (CNGOF) was conducted. Regarding diagnosis, the SAGES andSOCG societies recommend ultrasound as the preferred and safe imaging technique during pregnancy. In terms of the optimal timing for laparoscopic intervention,BSGE andSAGES do not restrict the laparoscopic approach based on safety, depending on the gestation week, whereasSOCG and CNGOF proposeearly second trimester and first and second quarter of pregnancy respectively. There is an overall consensus regarding patient positioning, initial port placement, insufflation pressure during the operation, venous thromboembolic (VTE) prophylaxis, fetal heart monitoring, and tocolysis among the reviewed guidelines. Moreover, only the BSGE mentions the need for corticosteroids, magnesium sulfate, and anti-D prophylactic administration.

Injuries incurred from minimally invasive access for abdominal surgery.

Injuries during initial port placement in minimally invasive abdominal surgery are rare but can cause major morbidity. We aimed to characterize the incidence, consequence, and risk factors for injury occurring on initial port placement. This is a retrospective review of a General Surgery quality collaborative database with supplementary input from the Morbidity and Mortality conference database at our institution between 6/25/2018 and 6/30/2022. Patient characteristics, operative details, and postoperative course were assessed. Cases with an injury on entry were compared to cases without an injury to identify risk factors for injury. 8844 minimally invasive cases were present between the two databases. Thirty-four injuries (0.38%) occurred during initial port placement. Seventy-one percent of injuries were bowel injuries (full or partial thickness) and the majority (79%) of injuries were recognized during the index operation. Median surgeon experience for the cases with an injury was 9years (IQR 4.25-14.5) compared to 12years of experience for all surgeons contributing to the database (p = 0.004). Previous laparotomy was also significantly correlated with the rate of injury on entry (p = 0.012). There was no significant difference in the rate of injury based on method of entry (cut-down: 19 (55.9%), optical entry without Veress: 10 (29.4%), Veress followed by optical entry: 5 (14.7%), p = 0.11). BMI > 30kg/m2 (injury: 16/34 vs no injury: 2538/8844, p = 0.847) was not associated with an injury. Fifty-six percent (19/34) of patients with an injury on initial port placement required laparotomy at some point in their hospital course. Injuries are rare during initial port placement for minimally invasive abdominal surgery. In our database, history of a previous laparotomy was a significant risk factor for an injury and appears to be more consequential than commonly implicated factors such as technique, patient body habitus, or surgeon experience.

Efficient ship weather routing using probabilistic roadmaps

This paper introduces the probabilistic roadmap (PRM) concept in maritime transportation for solving the ship weather routing (SWR) problem. SWR is a path finding problem that seeks for the optimum route (path) for a ship moving from an initial port to a final desired port considering the weather conditions (winds, waves, sea currents). PRM is an old effective algorithm for robot motion planning based on a systematic use of a graph-based map which represents the robot's workspace. Using this map PRM explores feasible paths around the obstacles until finding a collision-free path between the starting and goal configurations of the robot. Considering the digital map of the ship's navigation area as well as forecasting data (updated every 3 h) concerning the weather conditions, a modified PRM algorithm is presented for tackling SWR. The proposed algorithm starts by taking random samples across the ship's navigation area which follow a particular distribution. Then, it uses a local planner to construct a large undirected graph (a roadmap) with nodes all the generated sample points connected with feasible (collision-free) edges (paths). Each path is related with a weight estimated by considering the weather conditions in the corresponding sea's region. Finally, given the departure and desired arrival ports, a modified Dijkstra's algorithm is applied to the resulting graph to search for the optimal path in terms of both fuel consumption and travel time that connects the two ports in the roadmap. The proposed algorithm operates in real-time determining the best solution within less than 1 min. Simulation simulations over the Aegean archipelagos as well as the Mediterranean Sea demonstrate the efficiency of the developed algorithm.

Prediction of preoperative intrathoracic adhesions for ipsilateral reoperations: sliding lung sign

IntroductionVideo-assisted thoracic surgery (VATS) for ipsilateral reoperations is controversial, because after the first surgical intervention, pleural adhesions occur frequently in the thoracic cavity and/or chest wall. This study assessed the usefulness of preoperative ultrasonography to reduce the incidence of lung injury at the time of the initial port insertion during secondary ipsilateral VATS.Materials and methodsThis was a retrospective, single-center study. Nine patients who underwent thoracic surgery at Vanvitelli Hospitalfrom September 2019 to February 2022, were scheduled for a second VATS surgeryon ipsilateral lung, because of inconclusive intraoperative histologic examination. All nine patients underwent preoperative ultrasonography to assess the possible presence of pleural adhesions. We evaluated the lung sliding, since the presence of pleural adhesions does not permit to appreciate it.Statistical analysisHard severe adhesions were observed in all nine patients without sliding lung sign (specificity 100%). In this series, the sensitivity, PPV, and NPV of the sliding lung sign were 93%, 100% and 94% respectively.ResultsThe presence of the lung respiratory changes can be evaluated as the “sliding lung sign” by chest ultrasonography; we believe that the sliding lung sign might also predict intrathoracic adhesion.ConclusionsPreoperative detection of pleural adhesions using transthoracic ultrasonography was useful for ipsilateral secondary pulmonary resection patients undergoing VATS. Using preoperative ultrasonography can improve the safety and feasibility of placing the initial port in VATS.

Design and research of a broadband mode-division multiplexer based on three-core photonic crystal fiber

A broadband mode-division multiplexer based on asymmetric three-core photonic crystal fiber is proposed in this paper. The device is mainly composed of a central core, which can provide the transmission of fundamental mode and higher-order mode, and two side cores providing fundamental mode transmission. According to the theory of optical coupling, the LP<sub>01</sub> mode light is input to the three fiber cores at the initial port separately, and in the transmission process the LP<sub>01</sub> mode on the left side core will be coupled and converted into the LP<sub>21</sub> mode light in the central core gradually. Similarly, the LP<sub>01</sub> mode of the right side core is transformed into the LP<sub>31</sub> mode of the center core. By optimizing the structural design and selecting the length of optical fiber, the best conversion from side core into central core can be completed at the output end simultaneously, thereby realizing the multiplexing of LP<sub>01</sub>, LP<sub>21</sub> and LP<sub>31</sub> modes in the central core. In the opposite direction, if the output end of the device is used as the initial port, the demultiplexing of three modes of light from the central core to the three cores can be realized. In thiswork, the finite element method and beam propagation method are used to optimize the simulation, and the optical coupling theory and supermode theory are combined to conduct analysis and calculation. The results show that at wavelength band from 1.49 μm to 1.63 μm, the maximum insertion loss of the device is 0.72 dB, and the lowest insertion loss is 0.543 dB at 1.55 μm, which is far lower than the general evaluation standard of 1 dB insertion loss. The low insertion loss also makes it possible to design cascaded multi-core photonic-crystal-fiber mode-division multiplexer. Compared with the existing mode-division multiplexing scheme, the device is more integrated and less affected by the external environment. When it is used with multi-core space division multiplexing fiber, it can better improve the mode-conversion efficiency and mode purity, reduce the coupling complexity and expand the communication capacity.

Do Clinical Experience and Surgical Technique Affect Outcomes in Initial Laparoscopic Trocar Placement? A Prospective Randomized Clinical Trial

Aim: The aim of this study was to compare the intraoperative and postoperative complications of laparoscopic cholecystectomy by closed (supraumbilical Veress needle) versus open infraumbilical technique for initial, first port laparoscopic access. Patients and Methods: Our study included 560 adult patients, who were randomized into four groups (i.e., expert Veress, expert open, junior Veress, or junior open). Time for placement of the first trocar and time to complete the port-site closure were compared in all study groups. The mean operative time for cholecystectomy was compared after successful placement of the initial trocar until removal of the gallbladder. Intraoperative, early, and late postoperative complications were compared. Results: Duration of the initial port placement was significantly shorter among senior compared to junior surgeons. The Veress technique had a significantly shorter duration of port entry, but a longer duration of port-site closure compared to the open technique. Apart from the extraperitoneal insufflation incidents that were significantly more reported by junior surgeons, no significant differences in incidents were reported by senior and junior surgeons between open and closed techniques. Junior surgeons showed a better satisfaction with the open than the closed technique. Conclusions: Both the closed and open techniques for laparoscopic cholecystectomy are equally safe and effective for initial port-site entry whether performed by senior or junior surgeons. Junior surgeons are more satisfied with the open technique than the Veress needle technique, due to a perceived concern of injuring intra-abdominal structures. Therefore, junior surgeons would benefit from additional training during their residency to use both the techniques confidently.

Experimental investigation of the axial oxidizer injectors geometry on a 1-kN paraffin-fueled hybrid rocket motor

The showerhead is the most common type of injector used in hybrid rocket motors due to its design and manufacture simplicity. The main drawback of the showerheads (SH) is the relatively low performance in terms of combustion efficiency because of the poor atomization of the liquid oxidizer. This study investigates the problem to enrich the technical literature by presenting detailed experimental data on showerhead injectors by a series of static firing tests using a 1-kN lab-scale hybrid rocket, applying four kinds of showerhead injectors, named SH1 (benchmark), SH2, SH3, and SH4. They differ from each other by the number, distribution, and dimension of the orifice elements. Main performance parameters such as fuel regression rate, specific impulse, and combustion efficiency are experimentally obtained.Two different series of tests were carried out. At first, the influence of SH injector geometries was studied. The injectors SH2, SH3, and SH4 were used under the same initial conditions, and the results were compared with SH1. In the second set of tests, the SH4 injector was chosen, and the effects of the fuel grain initial port diameter were investigated. Using the data obtained in the second battery of tests was possible to determine the influence of the fuel port diameter on the motor efficiency and establish the regression rate law of nitrous oxidizer/paraffin-based fuel for this specific configuration.

Robotic-assisted left lower-lobe pulmonary lobectomy: Eleven steps.

Robotic-assisted left lower-lobe pulmonary lobectomy: Eleven steps.

Vertical integration and capacity investment in a two-port system

We model the vertical investment of a container shipping line in the port capacity in a two-port system. Our analytical and numerical analyss suggests that the relative scale of the capacity investment depend on the initial port capacity and the relationship between the ports. When a port has a sufficiently large initial capacity and the ports do not have highly complementary operations, a vertical investment leads to higher investments. Moreover, the investment of a shipping line in a port always increases its own profit and reduces the competitor’s profit. However, when compared with port self-investment, vertical investment always reduces the local social welfare.

Optically guided peritoneal access in pediatric laparoscopy: is it a good alternative for open access? A prospective comparative study

Background A minimally invasive approach has become the method of choice for treating many surgical cases. The superiority of open peritoneal access is owing to the low probability of visceral injury. Optically guided trocars were designed to decrease the injury risk to intra-abdominal contents by permitting the surgeon to see abdominal wall layers while traversing it and abdominal contents once access is complete. Materials and methods A prospective comparative study was done between optical trocar access using Fengh optical port, trocar model FLTC5 (Fengh medical Co. Ltd, Jiangsu, China), and open access using Hasson technique in pediatric patients. The study included 187 patients from the age of 1 year to the age of 16 years. Patients with previous open abdominal surgery, abdominal masses in the periumbilical region, and/or traumatic abdominal injury were excluded from the study. Access time and initial port insertion complications were reported to clarify safety and time for optical access. Results Optical access was done in 92 patients and open access in 95 patients. No visceral or major vascular complications were reported in both types of access. Access time in group IA (optical) was 58.06±16.1 s. in comparison with 175.7±54.7 s. in group IB (open) (P=0.0001*), and it was 49.7±9.4 s. in group IIA (optical) in comparison with 169.3±38.3 s. in group IIB (open) (P=0.0001*). Conclusions In selected cases, optical access is feasible, safe, and time-saving and avoids many problems in initial port insertion in pediatric laparoscopy.

Thornado-transport: Anderson- and GPU-accelerated nonlinear solvers for neutrino-matter coupling1 1This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published

Algorithms for neutrino-matter coupling in core-collapse supernovae (CCSNe) are investigated in the context of a spectral two-moment model, which is discretized in space with the discontinuous Galerkin method, integrated in time with implicit-explicit (IMEX) methods, and implemented in the toolkit for high-order neutrino-radiation hydrodynamics (thornado). The model considers electron neutrinos and antineutrinos and tabulated opacities from Bruenn (1985), which includes neutrino-electron scattering and pair processes. The nonlinear system arising from implicit time discretization of the equations governing neutrino-matter coupling is iterated to convergence using Anderson-accelerated fixed-point methods, which avoid formation of Jacobians and inversion of dense linear systems. Numerical experiments show that, for a given tolerance, a nested iteration scheme which aims to reduce opacity evaluations can lower the computational cost. Our initial port to GPUs, using both OpenMP and OpenACC, shows an overall speedup of up to ∼ 100× when compared to results using a single CPU core. These results indicate that the algorithms implemented in thornado are well-suited to GPU acceleration.

The Effect of Immediate Versus Delayed Port Access on 30-Day Infection Rate.

This study compared the 30-day infection risk of chest ports accessed on the same day as placement and chest ports with delayed initial access. The aim was to evaluate a larger data set that provided evidence for the development of port access guidelines. A retrospective chart review of 3322 chest port placement procedures performed between October 15, 2003, and June 10, 2015, was conducted at the interventional radiology department of a single institution. Procedure notes and health records were reviewed to determine time of initial port access, evidence of infection within a 30-day window of port placement, and causal organism(s) of infection. The results demonstrated that 64 ports (1.93%) met infection criteria within 30 days of placement, including 30 of the 945 ports immediately accessed and 34 of the 2377 ports not immediately accessed (3.17% vs 1.43%; P < .005). Dual lumen devices had a statistically significant higher rate of infection compared with single lumen devices (P = .006). This study concluded that there is a statistically significant higher rate of infection if a port is accessed immediately versus when access is deferred to later than 24 hours after placement.

Initial Investigations into the Benefits and Challenges of Eliminating Port Overlap in Wankel Rotary Engines

&lt;div class="section abstract"&gt;&lt;div class="htmlview paragraph"&gt;The Wankel rotary engine historically found limited success in automotive applications due in part to poor combustion efficiency and challenges around emissions. This is despite its significant advantages in terms of power density, compactness, vibrationless operation, and reduced parts count in relation to the 4-stroke reciprocating engine, which is now-dominant in the automotive market. A large part of the reason for the poor fuel economy and high hydrocarbon emissions of the Wankel engine is that there is a very significant amount of overlap when the ports are opened and/or closed by the rotor apices (so-called peripheral ports). This paper investigates the benefits of zero overlap from a production engine with this characteristic and the effect of configuring a peripherally-ported Wankel engine in such a manner. As discussed in the paper, arranging this condition for peripherally-ported engines unfortunately reduces the trapped compression and/or expansion ratios significantly, such that when naturally-aspirated operation is simulated, a large reduction in performance ensues.&lt;/div&gt;&lt;div class="htmlview paragraph"&gt;In order to demonstrate the potential of zero port overlap in Wankel engines with respect to emissions, a 2007 model year Mazda RX-8 was rebuilt, run-in, degreened, and tested on a chassis dynamometer. As standard, the engine in this vehicle is configured with no port overlap through the adoption of side intake and exhaust ports. This testing was performed in order to see subjectively how successful such an approach could be in controlling emissions. The vehicle easily met Euro 5 limits for all criteria emissions and was even better in terms of hydrocarbon emissions versus Euro 6 on the WLTP cycle, giving the lie to the belief that a Wankel engine can no longer meet current automotive emissions targets.&lt;/div&gt;&lt;div class="htmlview paragraph"&gt;The analytical work reported here studies the result of eliminating overlap on the performance of a peripherally-ported single-rotor Wankel engine using a 1-D model. This was implemented and correlated to the in-production Advanced Innovative Engineering (UK) Ltd 225CS engine used in the UK government-funded ADAPT project. The initial port study focused on advancing and retarding the exhaust and intake port respectively to achieve zero port overlap and then sweeping their zero-overlap positions together around the trochoid housing. The best location for the ports was then identified; this was essentially an “Otto” timing set, with broadly equal compression and expansion ratios. Notwithstanding this, potential performance was found to be severely curtailed, as was to be expected given the marked reduction in trapped compression and/or expansion ratios necessary due to peripheral porting.&lt;/div&gt;&lt;div class="htmlview paragraph"&gt;Countermeasures to this reduction are discussed. Those that will be studied later in the project will be reported in a later publication.&lt;/div&gt;&lt;/div&gt;

Use of Artificial Intelligence as a Problem Solution for Maritime Transport

The purpose of this article is to propose a solution for the transport problem in sea freight using machine learning algorithms. An important aspect of sea transport is the organization of freight. In particular, the maritime freight network is a large complex system whose complexity of route maps and the variety of ship traffic render it difficult to model. When investigating the characteristics of the sea freight system, it is generally advisable to use rough models in which only significant approximations are introduced and a number of details are not taken into account. At the same time, an exact model is used in a detailed study of isolated areas of the network wherein it is the area which is explored in detail and not the connections between the said areas. By so doing, one should be careful not to overlook the deviations of the model from the real network in the first case and the connections between areas in the second.Building a model that accurately takes into account and describes all the details results in excessive complications in the design process, so, in practice, a number of assumptions are always used in the simulation which are basically approximations of the real characteristics related to ship movement, depending on the specific task. Four models are used in order to build an optimal cargo transportation system: Transnational cargo model; model of cargo transportation with a dedicated initial port of cargo departure; model of cargo transportation with dedicated initial ports of departure and final port of cargo distribution; model of cargo transportation on a circular chain of ports. The route conditions are given by the traveling wave equation and on the basis of these calculations the optimal route of cargo ship movement is put forth whereby conditions affecting freight traffic include: Number of ports, fuel quantity, port of cargo destination, as well as distances between ports and intermediate ports of call. The scientific contribution lies in the fact that the human role is reduced only to that of the system observer, which, in turn, simplifies the freight calculations, as well as helps reduce the cost of fuel and human resources.

Surgical considerations of combined laparoscopic cholecystectomy and cesarean delivery

A 32-year-old female, with history of two previous cesarean sections. She was scheduled for an elective cesarean section. The night before surgery, she hada spike of fever and abdominal pain in the epigastrium and felt nauseated. She was brought to the emergency room, and her ultrasound examination revealed edema n the peri- gallbladder area and cholecystitis. A general surgical consult was made, and the opinion was that she needs to be operated urgently. Laparoscopic cholecystectomy was done with initial port placement at Palmer's point with a 5-cm Covidien optical port. Procedure completed with no complication. The obstetric team then made a Pfannenstiel incision to deliver the baby. The delivery was completed in 10 min after the closure of the laparoscopic ports. The patient was in hospital for the next 3 days, and her puerperium was unremarkable. There were no further complications during her stay. The baby was discharged from NICU on the1stpostoperativeday.

Preoperative Detection of Pleural Adhesions Using Ultrasonography for Ipsilateral Secondary Thoracic Surgery Patients

Video-assisted thoracic surgery (VATS) for ipsilateral reoperations is challenging because of the potential for pleural adhesions. Insertion of the initial port can lead to lung injury because of the blinded intrathoracic area. We assessed the usefulness of ultrasonography before VATS to reduce the incidence of lung injury at the time of the initial port insertion during secondary ipsilateral VATS. Thirty-three patients who underwent repeat VATS for ipsilateral pulmonary lesions were included. All patients underwent preoperative ultrasonography to assess the possible presence of pleural adhesions using the lung sliding sign. Seven adhesions were found at the VATS ports. Two of these adhesions were not evaluated as pleural adhesions using ultrasonography; however, they were loose. All initial ports were inserted without lung injury. There were no major complications. Preoperative detection of pleural adhesions using ultrasonography can determine the best initial port for secondary ipsilateral VATS.

Initial port integration concept for EC and NB systems in EU DEMO tokamak

The integration of the heating and current drive (HCD) systems in the EU DEMO tokamak must address a number of issues, namely space constraints in the tokamak building, remote handling requirements, breeding blanket penetration, neutron and photon radiation shielding, compliance of penetrations of the primary vacuum with safety and vacuum criteria, and a large number of loading conditions, in particular heat, electromagnetic (EM), and pressure loads in normal and off-normal conditions. A number of pre-conceptual design options for the vacuum vessel (VV) port and the port-plug are under assessment and need to be verified against all requirements and related criteria. The identification of the functional (or physics) requirements of the HCD systems remains an on-going process during the pre-conceptual design phase, hence some initial assumptions had to be made as a basis for development of the design of the VV ports and the HCD port plugs.The paper will provide an overview of present margins in the functional/physics requirements and the rationale behind the assumptions made in order to facilitate development of the pre-conceptual design options. Furthermore it will introduce the initial design concepts of the electron cyclotron (EC) Launchers and the neutral beam (NB) injectors integrated in equatorial ports. The NB duct design in DEMO and related issues such as transmission and re-ionization losses will be also addressed.

Numerical optimization and comparative study of n-butanol concentration stratification combustion and n-butanol/diesel reactivity stratification combustion for advanced compression ignition (CI) engine

Previous studies show that satisfactory engine performance can be achieved by using both the reactivity stratification combustion (RSC) and the concentration stratification combustion (CSC) fueled with n-butanol. However, the different ignition and combustion characteristics between RSC and CSC have not been well explored yet. In this study, the n-butanol/diesel RSC and n-butanol CSC strategies were compared by integrating the KIVA-3V code and the non-dominated sort genetic algorithm II (NSGA-II). For both RCS and CSC, n-butanol was premixed in the initial port. However, diesel and n-butanol were injected into the cylinder for RSC and CSC, respectively. Five important operating parameters were selected as the variables for optimization, including premixed fraction (PF), start of injection (SOI), the initial in-cylinder pressure at the initial valve close (IVC) timing, the initial in-cylinder temperature at the IVC timing (Tivc), and exhaust gas recirculation (EGR) rate. The optimization results show that, for the realization of the clean and high-efficiency combustion, a wide range of SOI and the high PF are introduced in RSC, whereas a wide range of PF and the early SOI are employed in CSC. Due to the lower reactivity of n-butanol than diesel, CSC requires the higher Tivc than RSC. As a fixed EGR rate, the optimal operating range of the initial temperature is restricted in a narrow range, especially for CSC. The optimal operating range of SOI and PF of RSC is larger than that of CSC.In RSC, the homogeneous charge compression ignition (HCCI)-like combustion shows the lowest fuel consumption and NOx emissions, and the highest ringing intensity (RI). The reactivity control compression ignition (RCCI) combustion demonstrates the overall balanced engine performance. The benefit of the diesel induced ignition combustion on RI is evident, but the high NOx emissions are still a challenge. For CSC, the optimal case with the low concentration stratification of n-butanol achieves the good EISFC, the low NOx emissions, and the high RI. Generally, the RSC strategy is superior to the CSC strategy in terms of the control of combustion phasing, fuel efficiency, and emissions.

The Use of Mechanical Bowel Preparation in Pelvic Reconstructive Surgery: A Randomized Controlled Trial.

To compare mechanical bowel preparation (MBP) using oral magnesium citrate with sodium phosphate enema to sodium phosphate (NaP) enema alone during minimally invasive pelvic reconstructive surgery. We conducted a single-blind, randomized controlled trial of MBP versus NaP in women undergoing minimally invasive pelvic reconstructive surgery. The primary outcome was intraoperative quality of the surgical field. Secondary outcomes included surgeon assessment of bowel handling and patient-reported tolerability symptoms. One hundred fifty-three participants were enrolled; 148 completed the study (71 MBP and 77 NaP). Patient demographics, clinical and intraoperative characteristics were similar. Completion of assigned bowel preparation was similar between MBP (97.2%) and NaP (97.4%). The MBP group found the preparation more difficult (P<0.01) and reported more overall discomfort and negative preoperative side effects (all P≤0.01). Quality of surgical field at initial port placement was excellent/good in 80.0% of the MBP group compared with 62.3% in the NaP group (P=0.02). This difference was not maintained by the conclusion of surgery (P=0.18). Similar results were seen in the intent-to-treat population. Surgeons accurately guessed preparation 65.7% of the time for MBP versus 41.6% for NaP (P=0.36). At 2 weeks postoperatively, both reported a median time for return of bowel function of 3.0 (2.0-4.0) days. Mechanical bowel preparation with oral magnesium citrate before minimally invasive pelvic reconstructive surgery offered initial improvement in the quality of surgical field, but this benefit was not sustained. It was associated with an increase in patient discomfort preoperatively, but did not seem to impact postoperative return of bowel function. I.