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Injection molding is a widely utilized manufacturing process across various industries. The cooling time in injection molding is an important factor that affects the productivity and energy consumption of the process. The production efficiency is directly proportional to the cooling efficiency, yet optimizing this cooling process presents significant challenges. The fixed cooling parameters are not suitable for all types of material, thus increasing the molding deviation. To address these challenges, this research work proposed a Regularized with Mish Linear Unit-based Deep Learning Neural Network-based material prediction with optimization of derived variables using the Banana Function-centric Green Anaconda Optimization approach. Initially, the features are extracted from the raw materials, and then the material type is predicted by using Regularized with Mish Linear Unit-based Deep Learning Neural Network. Conversely, various machine properties are clustered utilizing the binomial distribution with damping factor-based farthest first clustering methodology. Subsequently, parameters are derived from both the predicted material and the clustered machine property. The pressure of the machine is controlled by a quasi-conservative with an optimized proportional integral derivative controller. Then, the optimal parameters are selected from the Banana Function-centric Green Anaconda Optimization algorithm. In the optimal parameter selection, the multi-objective is considered by minimization of temperature, cooling time, pressure drop, and power consumption. In experimental analysis, the performance of the proposed approach is analyzed with the existing approaches. The proposed approach attains 98.9% accuracy, which is higher than existing approaches. [ABSTRACT FROM AUTHOR]

Hydro-viscous clutch has become an inevitable choice for special vehicle transmissions. As a nonlinear dynamic system with large lagging link, its timing performance is affected by input rotational speed, lubricating oil temperature and pressure and other factors. However, from the control perspective, the speed regulation law, formation mechanism control characteristics, global model of hydro-viscous speed control system (HSCS) are unclear. To solve these problems, this paper presents a comprehensive analysis of the Hydro-viscous Speed Control System (HSCS), focusing on its steady-state and dynamic speed control characteristics. A data-driven model is established to describe the relationship between input rotational speed, output speed, control oil pressure, and lubricating oil temperature. The findings provide a foundation for optimizing HSCS structure and parameters, enhancing the performance and reliability of such systems in special vehicle transmissions and establishing a temperature-speed control system for special vehicle transmissions. [ABSTRACT FROM AUTHOR]

Sociologists have long identified job pressure as a central work-related stressor with far-reaching consequences for workers' well-being, their families, and organizations. However, surprisingly little empirical work examines how schedule control influences job pressure in a longitudinal framework—or the status-based contingencies in the resource functions of schedule control. Drawing on five waves of population-level panel data from the Canadian Work, Stress, and Health Study (2011–2019), I use fixed-effects analyses to examine the relationship between schedule control and job pressure, examining whether schedule control operates differently across occupations (professionals versus non-professionals) and levels of authority in the workplace. My findings help advance the sociological study of work-stress research by resolving competing predictions about the relationship between schedule control and job pressure across status. While others have argued the possibility for schedule control to intensify work-related pressures, I find that schedule control helps reduce job pressure. However, my results reveal that schedule control does not benefit all workers equally: it has unequal upsides for higher status workers. These discoveries sharpen existing knowledge about the resource functions of schedule control and are discussed in light of synthesizing key ideas from the sociology of work, and the stress process and job demands-resources models. [ABSTRACT FROM AUTHOR]

Although pressure regulation valves (PRVs) are commonly used for reducing leakage in water distribution networks (WDNs), in recent years, many studies have highlighted the opportunity of using pumps as turbines (PATs) so as to couple pressure reduction (and thus leakage reduction) with hydropower generation. Unlike in water transmission systems however, flow discharge in a WDN varies continuously, consequently requiring real-time control (RTC) of pressure. Nevertheless, RTC of a PAT in a WDN remains an open issue, due to the lack of information and knowledge about PAT operation in a real environment. Whereas previous experimental studies have described PAT installation with a frequency converter in which the power produced gets dissipated through electrical resistance, in the hydraulic regulation layout, impeller speed depends on the electrical grid. Consequently, this paper proposes a comprehensive algorithm to both control the pressure at the control node of a WDN and produce power through a PAT directly connected to the electrical grid. The operation of the prototype was considered under hydraulic regulation, demonstrated by several studies to represent the most effective trade-off between costs and benefits. Further testing by means of laboratory experiments designed to simulate the operation of a grid-connected PAT installed in a WDN effectively validated the robustness of the proposed method. The results proved the ability of the prototype and algorithm to couple hydropower generation with pressure control even when the flow varied suddenly. [ABSTRACT FROM AUTHOR]

This work presents nonlinear and linear controls ensuring the global stability of a pressure-reducing valve. The global property using both nonlinear and linear controls is very important to guarantee stability even though the pressure-reducing valve operates far from its nominal working point. To this goal, this work develops the mathematical description of a pressure-reducing valve. It is a second-order model, nonlinear, and nonaffine in control implemented with two secondary (solenoid) valves. Due to the nonlinear nature of the system, the Lyapunov theory allows developing the control, which ensures the global stability of the system using one input. In addition, the second control input is modified to enlarge the operating range of the pressure-reducing valve. To implement the control in (nowadays) industrial controllers, a linear proportional-integral (PI) control, ensuring all the stabilizing properties of the nonlinear control, is included as a subset of the nonlinear law. Experimental results demonstrate the good performance of the proposed PI. Practical Applications: The importance of controlling pressures in water distribution systems is widely recognized. This study delves into the analysis of a pressure-reducing valve, beginning with its mathematical model and culminating in its control mechanism. Two secondary (solenoid) valves serve to operate the pressure-reducing valve, acting as the system's control inputs. The research showcases that the achieved control operates effectively across a broader range of operating conditions, a notable distinction from other pressure-reducing valve controls. Furthermore, it demonstrates the feasibility of utilizing only one control input while keeping the other fixed. Additionally, a strategy is proposed to maximize the operational range of the pressure-reducing valve within the constraints of the inputs. Finally, considering implementation in the field using validated hardware, and acknowledging the complexity of the obtained control, this study substitutes the original control with a well-established (PI) control, ensuring the desired properties. Experimental results validate the effectiveness of the proposed control strategy. [ABSTRACT FROM AUTHOR]

In a multi‐cavity mold, parts from each cavity have consistent properties if the runner system ensures balanced melt‐front advancement. An unbalanced mold, however, narrows the processing window, complicating quality control and making it harder to maintain standards. Molds with an inherently balanced filling, such as the H‐type runner system, are preferred. However, as the number of cavities increases, improvements are needed to address the issues caused by shear heating. Additionally, the material waste in the H‐type runner system is significantly greater than in the fishbone runner system. Based on the rheological concept, a two‐stage analytical approach is established to optimize the fishbone runner system. The diameter of each runner in the fishbone runner system is optimized by controlling pressure drop and remaining time to achieve balanced filling. The impact of these factors is thoroughly examined, as well as why they must be controlled during optimization. The proposed work links the physical situation to its mathematical model, proving highly beneficial for new runner system designs, especially without commercial software assistance. Highlights: A new approach to solving unbalanced filling in multi‐cavity molds.Pressure drop and remaining time are key factors for optimization.Two‐stage analytical approach ensures optimization accuracy.The optimal runner system reduces injection pressure for molding.An alternative method for designing fishbone runners without CAE assistance. [ABSTRACT FROM AUTHOR]

The self-excited thermoacoustic instability (SETAI) frequently occurs in combustion equipment, leading to intense mechanical vibration, big noise and flame instability. SETAI poses a substantial challenge to the advancement of combustion technology, chiefly due to its complex mechanism. Our previous research has demonstrated that altering the premixed chamber length upstream of furnace can impact the interaction between heat release and sound pressure oscillations, which potentially enables SETAI control. However, supply duct is generally not straight, and changing the premixed section is impractical and unsafe. This paper aims to investigate the influence of introducing elbows and adjusting the supply duct length preceding the premixing stage on SETAI behavior. The goal is to offer guidance for the safe and convenient control of SETAI. Finds reveal that incorporating an elbow in the premixed chamber or changing its position does not affect sound wave propagation along the duct's center axis within a low frequency regime when maintaining a constant total equivalent length. In systems with both separate and premixed sections, the oscillation pattern is determined by the total time required for acoustic propagation throughout the entire supply system. Consequently, modifications to either of these lengths can impact SETAI. [ABSTRACT FROM AUTHOR]

The plastic deformation of the complex thin-walled components is not uniform. Applying a non-uniform load can decrease the thickness reduction and improve the thickness uniformity. In recent years, the application of non-uniform pressure to deform the sheet (such as magnetorheological pressure forming and viscous pressure forming) has attracted researchers' attention. However, the characteristics of the non-uniform pressure have not been researched. Control of the non-uniform pressure in the forming process lacks theoretical support. In this study, the mechanism of the non-uniform pressure in the viscous pressure bulge test is investigated. The pressure-carrying medium, called viscous medium, is semi-solid and flowable. The inhomogeneous flow behavior of the medium produces non-uniform pressure when the maximum is at the bulged pole. The inhomogeneous deformation behavior of the medium produces non-uniform pressure when the minimum is at the bulged pole. The effects of flow and deformation are opposite. The non-uniform pressure function is derived, and the evolution of the pressure is presented. During forming, the viscosity of the medium increases with the pressure, so the effect of the flow behavior increases, and the pressure weight at the pole increases. Viscous pressure bulge tests are carried out to verify the theory. The gradient and evolution of the pressure can be controlled by the loading velocity and the property of the medium. The results provide theoretical guidance for the control of the pressure in viscous pressure forming, and the methodology is expected to analyze the non-uniform pressure in other flexible die forming processes. [ABSTRACT FROM AUTHOR]

Study of the interaction between fault activation and mining stress evolution in the longwall working face is helpful to provide a targeted area for fault type heavy mine pressure disaster control. Combining theoretical analysis, physical and numerical simulation, the mechanical mechanism of fault activation is analyzed, the interaction law between mining stress and fault activation is studied, and the influence of fault dip angle on the evolution of fault activation and mining stress is discussed. The minimum critical dip angles α of normal and reverse fault activation are π/4 + φ/2 and π/4-φ/2, respectively. During the mining process, the activation position of the fault surface, the peak values of stress and displacement gradually increase and transfer from the high position of the fault to the low position, and the peak value of the advance abutment pressure reaches the maximum at the fault. The advancing distance of the working face required for fault activation gradually decreases with the decrease of the fault dip angle, and the peak elevation area of the working face gradually increases with the decrease of the fault dip angle. Combined with the on-site microseismic monitoring results, it can be seen that when the working face is about 20 m away from the fault, the stress and energy increase sharply, which is the main control area of the impact disaster. [ABSTRACT FROM AUTHOR]

ABSTRACT This work presents a novel wide tuning range ring voltage controlled oscillator (RVCO) designed to generate six‐phase signals. The proposed circuit is realized by coupling two identical three‐stage single‐ended inverter‐based RVCOs. The coupling network injects the common mode signals from one RVCO to the other one and vice versa in a cross‐connected manner. Three‐stage RVCOs used for coupling have been configured by modifying the conventional current‐starved RVCO. The proposed six‐phase RVCO is optimized using an improved version of non‐dominated Sorting Genetic Algorithm III (NSGAIII). In this algorithm, the sigma scaling method is used to control selection pressure and enhance the algorithm's performance. The proposed RVCO oscillates at 3.46 GHz. It can operate from 970 MHz to 4 GHz with a supply voltage of 1.5 V, demonstrating a wide frequency tuning range of 120%. Additionally, another six‐phase oscillator is proposed, achieved by capacitively coupling two identical three‐stage RVCOs. Both proposed oscillators are designed in TSMC 0.18 μm CMOS technology. [ABSTRACT FROM AUTHOR]

In the field of cement, if the formation cannot be given sufficient pressure to maintain stability during construction, pressure control failure may occur, leading to the leakage of liquids and gasses from the formation to the wellbore. In addition, irregular wellbore diameter and casing eccentricity are important factors that are easily overlooked and affect the prediction of ECD (Equivalent Circulation Density) calculation. This results in major accidents and ecological disasters, further impacting the global environment. This study focuses on a well in the eastern oilfields of China, and based on a rheological experiment of high temperature and high pressure, an irregular eccentric wellbore model is established according to the measured wellbore diameter and eccentricity data to calculate the ECD of the whole cementing process. Then, a data set is constructed and analyzed using the random forest method to quantitatively evaluate influencing factors such as displacement, rheology, density, and eccentricity on the bottomhole and wellbore ECD. Results find that the density of cement slurry and drilling fluid has the most significant impact on the maximum ECD, with the impact reaching 0.3142 and 0.2902, respectively, and the main factors that affect the minimum ECD are the density and rheological changes in the drilling fluid, reaching 0.7014 and 0.2846. These research findings will contribute to the precise control of wellbore pressure during cementing operations, further ensuring the safety of cementing operations, and laying a technical foundation for the automation and intelligentization of subsequent cementing operations. [ABSTRACT FROM AUTHOR]

During the fuel injection stage of the FCC unit, the connection between the reaction and the compressor is very important, which is the key to ensure the control of the reaction pressure and work without flaring at the inlet of the compressor. Due to the many interference factors during the start-up fuel injection process, the operation is unstable, it is necessary to discharge flaring at the compressor inlet several times to control the reaction pressure, so that a large number of gas-rich components are discharged to the flaring system for combustion. Through practical exploration, combined with the performance parameters of the compressor, several ways of start-up without flaring are compared, and finally the shortest way of using dry gas and injection of feedstock is chosen to start the unit. By formulating detailed start-up plans and operating principles, optimizing the process, accurate control of start-up pressurized dry gas, reaction injection amount, compressor speed, compressor anti-surge amount and other parameters can be carried out in the actual start-up process. The goal of without flaring during the start-up process is achieved, effectively reducing environmental pollution, avoiding material loss during the start-up process, and realizing green environmentally friendly start-up. [ABSTRACT FROM AUTHOR]

Purpose: To determine the feasibility of a prototype needle that enhances vitreous reflux (VR) to control intraocular pressure (IOP) in intravitreal injection (IVI). Methods: We created an eye model to compare IVI using a standard 30-G needle with four different versions of a 30-G prototype needle with one to four surface grooves that enhanced VR. We injected 50, 70, and 100 µl saline through porcine sclera or 460-µm-thick rubber and measured the peak and 3-second pressure before we extracted the needle and measured the 10-second pressure. Results: 50-µl injection through sclera with the standard needle resulted in mean (SD) pressure of 58.6 (3.8) mmHg at peak, 52.8 (4.7) mmHg at 3 s, and 39.6 (18.0) mmHg at 10 s. The prototype needle lowered the pressure; four grooves resulted in mean (SD) pressure of 29.4 (5.6) mmHg at peak, 22.0 (3.7) mmHg at 3 s, and 7.2 (6.6) mmHg at 10 s. 70-µl and 100-µl injections through sclera with the standard needle resulted in mean (SD) pressure of 68.8 (3.6) and 86.0 (6.0) mmHg at peak. Similar to 50-µl injection, the prototype needle lowered the pressure for 70-µl and 100-µl injections. At 10 s, we observed varying leakage at the injection site for sclera but not for rubber. Conclusions: The study provides proof of concept for a needle design for which surface grooves enhance VR and counteract the effect of IVI on IOP. The safety and efficacy of the prototype needle must be studied further in a clinical trial. [ABSTRACT FROM AUTHOR]

Background: We previously showed in animals that transpulmonary driving pressure (PL) can be estimated during Neurally Adjusted Ventilatory Assist (NAVA) and Neural Pressure Support (NPS) using a single lower assist maneuver (LAM). The aim of this study was to test the LAM-based estimate of PL (PL_LAM) in patients with acute respiratory failure. Methods: This was a prospective, physiological, and interventional study in intubated patients with acute respiratory failure. During both NAVA and simulated NPS (high and low levels of assist), a LAM was performed every 3 min by manually reducing the assist to zero for one single breath (by default, ventilator still provides 2 cmH2O). Following NAVA and NPSSIM periods, patients were sedated and passively ventilated in volume control and pressure control ventilation, to obtain PL during controlled mechanical ventilation (PL_CMV). PL using an esophageal balloon (PL_Pes) was also compared to PL_LAM and PL_CMV. We measured diaphragm electrical activity (Edi), ventilator pressure (PVent), esophageal pressure (Pes) and tidal volume. PL_LAM and PL_Pes were compared to themselves, and to PL_CMV for matching flows and volumes. Results: Ten patients were included in the study. For the group, PL_LAM was closely similar to PL_CMV, with a high correlation (R2 = 0.88). Bland–Altman analysis revealed a low Bias of 0.28 cmH2O, and 1.96SD of 5.26 cmH2O. PL_LAM vs PL_Pes were also tightly related (R2 = 0.77). Conclusion: This physiological study in patients confirms our previous pre-clinical data that PL_LAM is as good an estimate as PL_Pes to determine PL, in spontaneously breathing patients on assisted mechanical ventilation. Trial registration The study was registered at clinicaltrials.gov (ID NCT05378802) on November 6, 2021 [ABSTRACT FROM AUTHOR]

Hypertension is a major risk of morbidity and mortality in patients when it is uncontrolled. In spite of improved therapies currently available for blood pressure control, their complications are far away from being accomplished. Therefore, chronic renal failure is frequently observed in hypertensive patients. Thus, insights on mechanisms that may contribute to arterial pressure control should be studied to prevent life-threatening cardiovascular disorders. Purinergic receptors have been recognized in the physiopathology of hypertension; this review summarizes their participation in the renal abnormalities of the kidney in hypertension. Several studies have suggested the activation of renal purinergic receptors under an elevated interstitial ATP milieu as a fundamental pathway that leads to generation and maintained hypertension. Elevated ATP concentration alters fundamental mechanisms involved in the long-term control of blood pressure such as pressure natriuresis, autoregulation of glomerular filtration rate and renal blood flow, as well as increased tubule-glomerular feedback responses, overall, these alterations decrease sodium excretion; in addition, the expression of ATP receptors is modified. Under a genetical background, ATP induces the production of vasoactive compounds, decreases renal function and induces tubulointerstitial injury before glomerular damage. Simultaneously, a deleterious interaction between angiotensin II and purinergic receptors lead to the progression of renal damage. [ABSTRACT FROM AUTHOR]

Through data collection and field investigations of a gold mine-s goaf, a 3D digital model of the mines goaf and roadways was established using 3Dmine software. This model accurately provided information on the actual boundaries and shapes of the goaf at different levels. Based on the comprehensive analysis of goaf conditions and the mine-s production reality, a management plan was proposed. The management strategy includes the following:for goaf groups/collapse pits (above the fourth level) that have interconnected, surface waste rock filling is used; for isolated goafs on the fourth level, forced roof caving through medium-long hole blasting is employed to fill the goaf with waste rock from the surface. In addition, closed-off isolation methods are applied for joint management. For other goafs where mining has ceased and access is no longer possible, the goafs are managed by sealing off the level stone doors. For goafs under mining, filling with in-pit coarse rocks and sealed isolation methods are implemented. Through the integrated application of these various measures, the risk of large-scale ground pressure activities and surface subsidence has been thoroughly eliminated, creating favorable conditions for continued underground production operations. [ABSTRACT FROM AUTHOR]

Injected fuel mass per stroke (IFMPS) was measured by varying the driving current pattern of a solenoid-type diesel common rail injector. Repeated measurements of IFMPS were statistically analyzed to determine deviation from the average. The control of the injector's driving current waveform was achieved through pulse width modulation (PWM) on the microcontroller's CCP (capture compare and PWM) pin. The solenoid injector driving current pattern took the form of a peak & hold shape. A total of 36 types of driving current patterns were generated by manipulating peak and hold conditions in different combinations, and each driving current waveform was applied to drive injector. To evaluate the solenoid's thermal dissipation characteristics, the injector solenoid's driving energy was calculated by integrating the injector's driving current waveform over time. The IFMPS per energy consumed by the solenoid was then calculated based on the injector driving current waveform, defining it as the thermal parameter for injector solenoid (TPIS). The TPIS value can be used as a reference to identify the optimal injector drive current pattern concerning the solenoid's thermal dissipation. The fuel rail pressure was controlled at three levels: 40, 80 and 120 MPa. [ABSTRACT FROM AUTHOR]

We describe the transcription and quality control processes for rescuing around 570,000 sub‐daily and daily weather observations which were recorded in the UK Met Office Daily Weather Reports during the 1861–1875 period. These data are from the start of coordinated weather observations and were collected with the aim of making the first‐ever weather forecasts. The observations were rescued thanks to 3500 volunteers and include sub‐daily sea‐level pressure, dry and wet bulb temperatures, daily maximum and minimum temperatures, and daily rainfall amounts from 70 different locations across Western Europe, and one in Canada. We highlight how these observations will be used to fill gaps in existing pressure and temperature datasets and use two case studies to show how the pressure observations will likely better constrain the atmospheric circulation during two severe storms. We also compare a sub‐sample of the newly rescued observations with data that were previously digitized for a small number of locations for the same dates, finding good agreement in general, although some discrepancies remain. [ABSTRACT FROM AUTHOR]

Nine copolymers of acrylic acid and sodium methallyl sulfonate were tested as scale inhibitors in thermal desalination. The nine antiscalants covered molar masses between 2000 and 9500 g.mol–1 and concentrations of sulfonated monomer ranging between 10 and 30 mole percent. A pressure measurement and control (P-MAC) unit and a high-temperature pressurized vessel were used to measure the effectiveness of the scale inhibitors in seawater, concentrated seawater, and model solutions at 125 °C. The effectiveness of the novel copolymers was comparable to commercial antiscalant at times up to 15 min and improved at longer times. Molar mass was a more important determinant of effectiveness than degree of sulfonation, with the greatest mitigation of calcium sulfate precipitation observed for antiscalants of molar mass 2000 to 2500 g.mol–1 regardless of sulfonate content. Antiscalants of molar mass 4500 to 5000 g.mol–1 showed a higher threshold effect than antiscalants of molar mass 7000 to 9500 g.mol–1, with a 30% sulfonated polymer of molar mass 4500 g.mol–1 performing appreciably better than other polymers of a similar molar mass. [ABSTRACT FROM AUTHOR]

This paper aims to develop a theoretical model for a viscoelastic hard-magnetic elastomer membrane (HMEM) actuated by pressure and uniform magnetic field. The HMEM is initially a flat, circular film with a fixed boundary. The HMEM undergoes nonlinear large deformations in the transverse direction. The viscoelastic behaviors are characterized by using a rheological model composed of a spring in parallel with a Maxwell unit. The governing equations for magneto-visco-hyperelastic membrane under the axisymmetric large deformation are constructed. The Zeeman energy, which is related to the magnetization of the HMEM and the magnetic flux density, is employed. The governing equations are solved by the shooting method and the improved Euler method. Several numerical examples are implemented by varying the magnitude of the pre-stretch, pressure, and applied magnetic field. Under different magnetic fields, field variables such as latitudinal stress exhibit distinct curves in the radial direction. It is observed that these varying curves intersect at a point. The position of the intersection point is independent of the applied magnetic field and only controlled by pressure and pre-stretch. On the left side of the intersection point, the field variables increase as magnetic field strength increases. However, on the other side, this trend is reversed. During viscoelastic evolution, one can find that the magnetic field can be used to modulate the instability behaviors of the HMEM. These findings may provide valuable insights into the design of the hard-magnetic elastomer membrane structures and actuators. [ABSTRACT FROM AUTHOR]

To evaluate effectiveness of using MLT tubes for transoral laser MLS in terms of surgical visualization, complete excision of vocal cord lesions, maintenance of adequate oxygenation and ventilation and the occurrence of any airway related complications. In a retrospective case series study, review of electronic medical records was conducted for 64 patients who underwent transoral laser MLS over an 18-month period. The collected data included vital parameters, mode of ventilation, ET tube details, surgical field of vision, perioperative adverse events and postoperative ventilation requirements. Among the 64 patients, 82.8% of the time, 5 size MLT tubes were used, fixed at mean lengths of 21.6cm in females and 23.07cm in males respectively. A good surgical field of exposure was achieved in 92.2% of patients, with an average FiO2 of 0.29 during laser use and pressure control ventilation mode being the majority choice. 98.4% were extubated on table. The incidence of cuff rupture and bronchospasm was 4.7% and 1.6% respectively with no instances attributable to laser related events. Even though Laser resistant tubes are considered gold standard, MLT tubes can be used by taking adequate precautions to reduce Laser related complications when there is limited availability of laser tubes. Level of evidence Case series. [ABSTRACT FROM AUTHOR]

The extraction of thick coal seams at high intensity inevitably leads to more severe strata pressure, especially when influenced by adjacent goaf areas. The combination of multiple strata pressures results in significant deformation of the surrounding rock along the goaf roadway. In order to the problem of large deformation of the surrounding rock of the gob-side roadway, this study proposes a novel method for protecting gob-side roadway using energy-gathering blasting (EGB) to cut roof and relieve pressure, which combines parallel pull-rods fracture theory with the Weibull strength of rock microelements to establish a new energy-gathering blasting model. The optimal spacing of blast holes is determined and the correlation between damage degree and energy-absorbing coefficient as well as explosive center distance is analyzed. Numerical simulation methods are employed for validation, and the results demonstrate that the EGB technique effectively blocks the transmission of stress in non-energy-absorbing directions, further enhancing energy accumulation in the energy-gathering direction. This leads to slower attenuation of effective stress and particle vibration velocity in the energy-gathering direction, promoting the directional expansion of energy-gathering fractures and revealing the mechanical mechanism of energy-gathering fracture directional expansion. Based on this technology, a method for relieving overburden pressure in the surrounding rock is proposed. Through EGB technique cutting the long cantilever structure of thick and hard rock layers is snapped, force them to collapse and expand, thereby supporting the overlying structure and reducing stress concentration in the roadway's surrounding rock. This method reveals the mechanism of pressure unloading in the mining area after roof cutting. Furthermore, based on theoretical analysis, the parameters for roof-cutting pressure unloading are designed, and engineering practice confirms the successful reduction of stress on both sides of the roadway ahead of the working face, optimizing the stress environment of the roadway and achieving the goal of protecting the tests have validated the effectiveness of the method, significantly reducing stress and deformation in the surrounding rock of the roadway. The research findings provide a scientific basis for controlling roadway deformation under similar conditions. Highlights: A new EGB method is proposed based on characteristics of rock. A novel damage model for EGB has been constructed by combining the rock micro element strength with the tension rod fracture theory. The application of EGB method in coal mining can effectively reduce mine pressure and protect roadway. [ABSTRACT FROM AUTHOR]

Aiming at the problem of safe mining of coal seam under the condition of hard roof, taking Xiagou coal mine as the background, the expression of coal seam supporting force in isolated island working face mining is derived through the analysis of the "umbrella arch" overlying rock structure mechanism in isolated island working face mining. Combined with the mine geological conditions, it is concluded that the supporting force near the inclined gob of ZF2822 isolated island working face is more than 1.26 times that near the strike gob. Based on the numerical simulation analysis, it is known that the stress and elastic energy of the working face near the inclined gob are obviously greater than that towards the gob, and the peak stress on the side of the transport gateway after the first square and the second square is 1.41 times and 1.55 times that of the return air gateway, respectively. Strata discrimination determines that the key stratum is medium-grained sandstone 22.32 m above the coal seam. The reasonable blasting pressure relief angle is determined according to the field situation. Pressure relief control makes the "high energy-high frequency" feature of mining face change into "low energy-low frequency". After pressure relief, the daily average microseismic energy of working face mining is reduced to below 104 J, which is 27.77% and 39.74% lower than that in March and April before pressure relief. The changes of width and height of transport gateway after pressure relief are 22.73% and 24.75% of those before pressure relief, respectively. The research results provide a scientific basis for the safe mining of isolated island working face under the condition of hard roof. Highlights: The "umbrella arch" overlying strata structure of isolated island working face mining is put forward, and the expression of supporting force of working face mining is deduced. The corresponding relationship between the side close to the gob and the side close to the gob in the isolated island working face is mastered theoretically. The variation law of peak value difference of elastic energy of solid coal side in transportation gateway and return gateway of irregular island mining face is mastered. The asymmetric pressure relief control strategy of roadway surrounding rock in isolated island working face mining is formed. [ABSTRACT FROM AUTHOR]

We have designed and realized a temperature and pressure controlled cell for Neutron Reflectometry (NR) and Small Angle Neutron Scattering (SANS) that is compatible with simultaneous optical transmission and resistivity measurements. The cell can accommodate samples up to 102 mm (4 inch) in diameter, can be pressurized from vacuum up to 10 bar gas pressure and the sample temperature can be controlled up to 350°C. The four single crystal quartz windows ensure both a good neutron and optical transmission and hence can be used in combination with in-situ optical transmission measurements. We present the cell and illustrate its performance with a series of neutron reflectometry experiments performed on Ta based thin films under a hydrogen containing atmosphere. [ABSTRACT FROM AUTHOR]

Copyright of Current Retina Journal / Güncel Retina Dergisi is the property of Anadolu Kitabevi Basim Yayim Medikal Turizm Kirtasiye Tic. Ltd. Sti. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Current Retina Journal / Güncel Retina Dergisi is the property of Anadolu Kitabevi Basim Yayim Medikal Turizm Kirtasiye Tic. Ltd. Sti. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Objective] As automated drilling technologies become more prevalent, the demand for data communication while drilling has significantly risen, leading to increased requirements for downhole data communication systems. Currently, pressure wave data communication, which utilizes mud as the transmission medium, is the leading technology in these systems. The core component of these systems is the mud pressure wave generator (MPWG), which produces pressure wave signals with specific phases by adjusting the flow area of the mud through the operation of a rotary valve. Therefore, phase modulation of pressure wave signals and the control method of the rotary valve are critical technologies for the MPWG. Unlike conventional phase modulation methods, the phase of the pressure wave signal cannot change abruptly. Additionally, the drilling mud scours the rotary valve, introducing torque disturbances that make it challenging for the valve to accurately reach the desired position, ultimately reducing the quality of the pressure wave signal. [Methods] To tackle the issues of phase modulation of pressure wave signals and rotary valve position control, this paper proposes a lower sideband constant envelope smooth phase modulation method for pressure signals. Under the condition of maintaining a constant pressure wave amplitude, we introduce a parameter called the adjustable symbol transition time ratio (ASTTR) to achieve smooth phase modulation, along with a lower-sideband modulation method designed to reduce power consumption. Following this, a rotary valve position control system for the MPWG is designed. The speed and position controllers are designed using the active disturbance rejection control algorithm to ensure accurate tracking of the rotary valve position setpoint, even in the presence of external disturbance torques. Finally, a testing device is developed that integrates torque loading, parameter tuning, and data management functions to validate the proposed methods. This device allows for teaching experiments and testing of the MPWG to be conducted without the need for hydraulic circulation. [Results] Two experiments were conducted using the testing device. In Experiment 1, the valve control performance was evaluated under constant and fluctuating torque disturbances. The transmitted symbols of the MPWG are {0, 1, 0, 0, 1, 1}, the symbol period is 0.333 s, and the carrier frequency is 18π rad/s. When the ASTTR is set to 1, the position control errors under constant and fluctuating torque disturbances are 0.039 rad and 0.040 rad, respectively. When the ASTTR is set to 0.5, the position control errors are 0.059 rad and 0.058 rad under constant and fluctuating torque disturbances, respectively. The test results indicated that smooth phase modulation was successfully achieved. Moreover, a larger ASTTR, which facilitates smoother changes in the position setpoint, corresponds to smaller position tracking errors. Additionally, the tracking errors for the same position setpoint under different torque disturbances are similar, indicating that the control system performs effectively in the presence of torque disturbances. In Experiment 2, the power consumption of conventional double-sideband modulation is compared to that of the proposed lower-sideband modulation. The average power consumption for double-sideband modulation was 35.2 W, whereas the average power consumption for the proposed method is 32.6 W, demonstrating a 7.4% reduction in power consumption. [Conclusions] The experimental results demonstrate that the proposed method effectively achieves smooth phase modulation of pressure wave signals and disturbance rejection control of the rotary valve. Furthermore, the proposed method and experimental device exhibit multidisciplinary integration characteristics, enhancing students' ability to address real-world complex engineering problems. [ABSTRACT FROM AUTHOR]

Copyright of Journal of National University of Defense Technology / Guofang Keji Daxue Xuebao is the property of NUDT Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the fuel system of an aircraft engine, aero-fuel centrifugal pumps are widely utilized as boost pumps. In this research, we propose the integration of an inlet injector with an aero-fuel centrifugal pump to optimize its flow characteristics and enhance performance. The key geometric parameters of the impeller, volute, and injector are meticulously designed. The effectiveness of our approach is validated through a combination of experimental and numerical analysis, which involves comparing simulation results with experimental data. The findings demonstrate that the presence of the injector significantly impacts the flow characteristics and hydraulic performance of the pump. Specifically, it effectively reduces flow losses in the specific channels of the impeller and volute. Furthermore, the injector enhances the regulation of the inlet flow fields by adjusting the inlet pressure and controlling the suction flow direction. Consequently, the pump's efficiency is enhanced when equipped with the injector compared to its performance without it. Therefore, incorporating an injector in an aero-fuel centrifugal pump has a positive effect on regulating flow characteristics and improving hydraulic efficiency. [ABSTRACT FROM AUTHOR]

In ex vivo heart perfusion (EVHP), the control of aortic pressure (AoP) is critical for maintaining the heart's physiologic aerobic metabolism. However, the complexity of and variability in cardiac parameters present a challenge in achieving the rapid and accurate regulation of AoP. In this paper, we propose a method of AoP control based on deep reinforcement learning for EVHP in Langendorff mode, which can adapt to the variations in cardiac parameters. Firstly, a mathematical model is developed by coupling the coronary artery and the pulsatile blood pump models. Subsequently, an aortic pressure control method based on the Deep Deterministic Policy Gradient (DDPG) algorithm is proposed. This method enables the regulation of the blood pump and the realization of closed-loop control. The control performance of the proposed DDPG method, the traditional proportional–integral–derivative (PID) method, and the fuzzy PID method are compared by simulating single and mixed changes in mean aortic pressure target values and coronary resistance. The proposed method exhibits superior performance compared to the PID and fuzzy PID methods under mixed factors, with 68.6% and 66.4% lower settling times and 70.3% and 54.1% lower overshoot values, respectively. This study demonstrates that the proposed DDPG-based method can respond more rapidly and accurately to different cardiac conditions than the conventional PID controllers. [ABSTRACT FROM AUTHOR]

This paper presents an experimental investigation of the displacement characteristics of a hydrostatic spindle used in a medium-sized circular grinding machine. The study focuses on the influence of lubricant pressure and oil viscosity on spindle displacement under varying load conditions. Experiments were conducted using a specially designed testing bench, which allowed precise control of pump pressure and oil viscosity. The results demonstrate a significant impact of both parameters on spindle displacement. An increase in oil viscosity leads to a decrease in displacement, with the optimal viscosity identified as 2 mPa.s. Similarly, higher pump pressure results in reduced displacement, with 5 MPa being the optimal pressure for the system studied. These findings highlight the importance of carefully selecting lubricant properties and operating conditions to achieve optimal machining accuracy and stability. This research provides valuable insights into the understanding and optimization of hydrostatic bearing systems in precision machining applications. [ABSTRACT FROM AUTHOR]

The Caledonian pinewoods of northern Scotland represent the remnants of once extensive forests found at the western edge of the natural range of Scots pine (Pinus sylvestris L.). The surviving pinewoods are of international significance and are of high conservation and cultural value. However, for many decades, there has been concern about their long-term future because of a lack of regenerating seedlings and young trees. This problem is thought to be driven by high deer populations resulting in intensive browsing and severe damage to young trees, as well as a lack of favourable micro-sites for seedling germination. An experiment was established on the Mar Lodge estate in 2007–08 adjacent to native pinewood stands to test the effects of protection and site cultivation upon seedling numbers and growth. The experiment was located within a regeneration zone where intensive deer control had reduced numbers to <5 animals km−2. Ten years after initiation, occurrence and numbers of both Scots pine and birch seedlings were substantially increased in cultivated treatments compared with uncultivated controls. There were no effects of protection upon seedling numbers. Protection improved height growth of Scots pine, but not of birch. Cultivation had no effect upon the growth of pine seedlings but did influence the height of birch seedlings due to the rapid growth of some pre-existing seedlings in the uncultivated control. Vegetation cover had increased from ~60%to at least 80% cover 6 years after cultivation. The results suggest that site cultivation may be desirable to boost seedling germination within a Caledonian pinewood, but sustained measures to control browsing pressure are a prerequisite for satisfactory establishment of these seedlings. [ABSTRACT FROM AUTHOR]

Although there has been an increase in bench test evaluation of mechanical ventilators in recent years, a publication gap remains in assessing Pressure Control Continuous Mandatory Ventilation Modes with a set point targeting scheme PC-CMVs. This study evaluates the operational variability in PC-CMVs of eleven transport and emergency ventilators used in ICU units in Brazil during the COVID-19 pandemic. The assessment involved a comprehensive set of test scenarios derived from existing literature and the NBR ISO 80601-2-12:2014 standard. Nine parameters were computed for five consecutive breaths, offering a comprehensive characterization of pressure and flow waveforms. Most ventilators had Inspiratory pressure and PEEP values that fell outside of the tolerance ranges. Notably, three mechanical ventilators failed to reach the target pressures within the specified inspiratory times during test scenarios with a higher time constant (τ). We observed significant differences among emergency and transport ventilators in all assessed parameters, indicating a performance difference in PC-CMVs modes. The current results might help clinicians determine which ventilator models are suitable for specific clinical situations, particularly when unfavorable circumstances compel doctors to use ventilators that may not provide adequate support for patients in intensive care units. [ABSTRACT FROM AUTHOR]

Cryogenic hydrogen circulation system is a critical infrastructure of the China Spallation Neutron Source phase II project. Safety considerations related to hydrogen are paramount for the stable operation of the system. This study focuses on the cryogenic hydrogen circulation system within the context of the China Spallation Neutron Source phase II project and conducts a detailed investigation of hydrogen safety issues throughout the process. The operational modes and fault occurrence mitigation strategies of the cryogenic hydrogen circulation system are analyzed and discussed. Additionally, employing centralized layout, zoning management, and multiple barrier layers as guiding concepts for hydrogen safety design, the study addresses physical and interlocking control designs concerning hydrogen distribution, hydrogen venting, vacuum, hydrogen circulation pressure control, and hydrogen leakage. Drawing upon the successful experiences of the first-phase project, the hydrogen safety design of the cryogenic hydrogen circulation system in the China Spallation Neutron Source phase II project provides valuable insights for the development and optimization of hydrogen safety designs across various industrial domains. • Cryogenic hydrogen circulation system of CSNS-Ⅱ is introduced. • Principles and concepts of hydrogen safety in CSNS-Ⅱ are elucidated. • Operational modes and fault analysis of hydrogen circulation system are presented. • Physical and interlock control designs of hydrogen-related system are illustrated. [ABSTRACT FROM AUTHOR]

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In recent years, the volcanic–plutonic relationship has been a contentious topic among researchers. Based on this issue, they have delved deeper into the constraints of magma reservoir pressure and H2O on pre-eruptive melt accumulation and migration. We selected granodiorite, tonalite, and rhyolite in the Dehailonggang volcanic–plutonic complex to investigate the volcanic–plutonic connection and constraints of reservoir pressure and H2O on the pre-eruptive melt accumulation and migration in water-rich systems. Granodiorite, tonalite, and rhyolite exhibit temporal–spatial similarities (247 Ma) and the same magmatic origin consisting of ca. 75–80% enriched mantle materials mixed with ca. 20–25% lower crustal materials. TESCAN integrated mineral analyzer (TIMA) shows that both granodiorite and tonalite display a typical cumulate texture. The bulk–rock compositional complementary of the granodiorite, tonalite, and rhyolite, coupled with in situ geochemical signatures of feldspars and zircons, feldspar CSD, and rhyolite–MELTS modeling, indicate that (1) the granodiorite represents the crystal cumulate formed after crystal–melt phase separation of the original mush (OM) in the magma reservoir; (2) the interstitial melt of the OM was extracted, migrated, and ultimately erupted as the rhyolite; (3) the tonalite serves as an intermediate product resulting from the phase separation from the OM to the rhyolite. Rhyolite–MELTS modeling reveals that in water-rich environments, an increase in reservoir pressure (prior to reaching overpressure threshold) can lead to a reduction in melt viscosity. This, in turn, accelerates mechanical compaction and phase separation processes, ultimately shortening the pre-eruptive melt aggregation timescale. In contrast, it is noteworthy that H2O has a relatively minor influence on phase separation in such water-rich systems (> 4 wt. %). This study demonstrates the volcanic–plutonic genetic coupling and highlights the significance of reservoir pressure in controlling the dynamics of pre-eruptive melt within water-rich systems. [ABSTRACT FROM AUTHOR]

In this study, an ultra-high-precision pneumatic force servo system (UPFSS) is proposed. On the one hand, a novel air-floating pneumatic cylinder (AFPC) with an air-floating piston capable of independent air supply and exhaust is developed for this system, and its special flow channel design allows the air-floating piston to be suspended in the cylinder without being constrained by the pressure in the chambers. The friction force of the AFPC is less than 0.0049 N. On the other hand, a leakage chamber is constructed to simulate the clearance between the air-floating piston and the cylinder wall, and a fuzzy proportional integral (FPI)-based pressure control system (PCS) is designed for the simulated leakage chamber. Furthermore, a novel particle swarm optimization algorithm integrating Gaussian mutation and fuzzy theory (IGF-PSO) is presented. After testing, the IGF-PSO algorithm is found to have outstanding optimization performance. Then, the parameters of the FPI controller are optimized through the IGFPSO algorithm. Experimental comparisons reveal that the steady-state error achieved by the parameter-optimized pressure controller in response to the leakage condition is about 38 % smaller than that achieved by the pressure controller with parameters obtained using the trial-and-error method. Finally, the UPFSS is tested by using the optimized PCS to supply compressed air to the chamber of the AFPC. The results show that the UPFSS achieves a steady-state error of no more than 0.0279 N in the continuous step response within the range of 240 N. • A novel high-performance PSO with Gaussian mutation and fuzzy theory is proposed. • A novel air-floating cylinder with friction force of less than 0.0049 N is developed. • An ultra-high-precision pneumatic force servo system is obtained through optimization. [ABSTRACT FROM AUTHOR]

The electro-pneumatic braking system with ON/OFF solenoid valves has been widely used in trains due to its advantages and superiority. The undesirable impact of the thermal effect on the electro-pneumatic braking system leads to frequent valve switching, degradation of the pressure tracking performance and sometimes instability. This article presents an adaptive model predictive control approach to solve the pressure control problem under temperature uncertainty based on a switched unscented Kalman filter. First, a nonlinear switched dynamical model with the uncertain temperature parameter is derived for the electro-pneumatic braking system by comprehensively integrating its nonlinear, discontinuous dynamics and thermal effect. Using a switched unscented Kalman filter on the presented model of the system, the temperature parameter is accurately estimated to improve the model's accuracy. Based on the corrected system model and the designed adaptive model predictive control method, the pressure tracking performance and the valves' switchings of the electro-pneumatic braking system are improved, and the stability is guaranteed. The simulations and the experiments conducted for a braking system prototype confirm the performance validity of the proposed method. • A switched UKF is designed to account for the hybrid characteristics of the braking system. • An adaptive hybrid MPC is proposed to achieve optimal pressure tracking performance while minimizing the number of valve switches. • The stability of the closed-loop system is rigorously analyzed using Lyapunov theory. [ABSTRACT FROM AUTHOR]

Among various motor-controlled hydraulic cylinder (MCC) topologies, the two-motor-two-pump (2M2P) MCC distinguishes itself through several notable advantages, including precise cylinder pressure control and eliminating mode switch oscillations. Nevertheless, there are challenges remaining in fully realizing its operations across four quadrants and establishing an effective load-holding function within these operations. This study bridges this gap by implementing a 2M2P MCC prototype on a laboratory knuckle boom crane, enabling operation across all four quadrants. Experimental results indicate that position tracking errors remain within ±2.5 mm across three cases, which is well below 1% of the total cylinder travels in the experiments. Furthermore, smooth intersection of cylinder-bore-side and rod-side pressures is observed during transitions between quadrants. In conclusion, the proposed 2M2P MCC demonstrates seamless operation throughout all quadrants, with the load-holding function smoothly activating and deactivating in all four quadrants. [ABSTRACT FROM AUTHOR]

Copyright of Cotton Textile Technology is the property of Cotton Textile Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article presents a series of cases transformed in methods, which can be used to reduce and control the losses of energy at water transportation through pipes and fire extinguishing equipment. [ABSTRACT FROM AUTHOR]

This paper presents a pressure management technique for the reduction of leaks considering as a case study a branched water distribution system. The proposed technique is based on the detection and location of the leak using a genetic algorithm (GA) and pressure control using a Linear Quadratic Regulator (LQR). The validation of the proposed method uses measured pressure and flow data from a laboratory-scale water distribution system and its dynamic model. [ABSTRACT FROM AUTHOR]

The friction pair gap affects not only the temperature increase of the multi-disc wet clutch, but also the efficiency of the helicopter transmission system. Consequently, a rotational–axial engagement and disengagement-coupled kinetic model of a wet multi-disc clutch considering asperity contact, hydrodynamic lubrication, spline resistance, and a separating spring model are developed in this paper. The effects of operating conditions on the dynamic characteristics of the wet clutch are investigated. Further, the gap deviation coefficient is proposed to characterize the dynamic behavior of the friction pair gap. As the control oil pressure increases from 1.3 MPa to 1.7 MPa, the gap deviation coefficient increases by 8.6%. Moreover, as the rotation speed increases from 888 rpm to 2488 rpm and the lubricant oil temperature increases from 25 °C to 85 °C, the gap deviation coefficient decreases by 1.1% and 4.44%, respectively. Therefore, an appropriate increase in lubricant oil temperature and rotation speed can facilitate the friction pair gap to be more uniform. These results are useful for the development of optimal control strategies for aviation wet clutch systems. [ABSTRACT FROM AUTHOR]

Copyright of Smart Rail Transit is the property of Smart Rail Transit Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Glaucoma is identified by the loss of retinal ganglion cells (RGCs). The primary approach to managing glaucoma is to control intraocular pressure (IOP). Lately, there has been an increasing focus on neuroprotective therapies for glaucoma because of the limited effectiveness of standard methods in reducing IOP and preventing ongoing vision deterioration in certain glaucoma patients. Various drug-based techniques with neuroprotective properties have demonstrated the ability to decrease the mortality of retinal ganglion cells. This study will analyze the currently recommended drug-based techniques for neuroprotection in the prospective treatment of glaucoma. [ABSTRACT FROM AUTHOR]

This article addresses the high-performance pressure control of a pneumatic actuator that incorporates an air-bearing piston and an eddy current damper (ECD). After optimizing the pneumatic actuator, achieving precise pressure control relies on maintaining an accurate and stable airflow through the control valve. A terminal sliding mode adaptive control method (TSMAC) is proposed, proficiently integrating considerations for dead zone nonlinearities in the proportional valve and the effects of unmodeled disturbances in the pneumatic actuator. Using the opening area of the proportional valve as the input to the pneumatic system greatly simplifies the control process and reduces the workload required for valve parameter calibration. The Lyapunov-based stability analysis demonstrates that excellent asymptotic output tracking can be achieved with low steady-state error simply by knowing the boundaries of the valve opening area. The control effect of the proposed control strategy is compared with an adaptive backstepping sliding mode control method based on a linearly fitted proportional valve model on an established constant pressure control test bench. Experimental results under various loads and operating conditions illustrate the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

Background: To avoid cortical compression, several implant systems have included in the protocol dedicated drills aimed at widening the cortical region of osteotomy. However, the manual execution of this operation does not guarantee the necessary precision. Hence, the present study aimed to determine the optimal size of the recipient site at the level of the alveolar crest in relation to the size of the coronal region of the implant to achieve the best healing result. Materials and methods: Blades of different diameters were incorporated into the coronal part of the implant to prepare the cortical region of the mandibular alveolar bone crest in different dimensions in relation to the collar of the implant. The differences in diameter of the blades in relation to the collar of the implant were as follows: one control group, -175 μm, and three test groups, 0 μm, + 50 μm, or + 200 μm. Results: The marginal bone loss (MBL) at the buccal aspect was 0.7 mm, 0.5 mm, 0.2 mm, and 0.7 mm in the − 175 μm, 0.0 μm, + 50 μm, + 200 μm groups, respectively. The differences were statistically significant between group + 50 μm and control group − 175 μm (p = 0.019), and between + 50 μm and + 200 μm (p < 0.01) groups. The level of osseointegration at the buccal aspect was more coronally located in the test groups than in the control group, whereas the bone-to-implant contact percentage was higher in the + 50 μm and + 200 μm groups. However, these differences were not statistically significant. Conclusions: The lowest bone crest resorption and highest levels of osseointegration were observed in the 0.0 μm and + 50 μm groups. The cortical region where the blades had performed their cutting action showed regular healing with perfect hard and soft tissues sealing in all the groups. Cortical blades gathered bone particles, particularly in the + 200 μm group, which were incorporated into the newly formed bone. The results from the present experiment provide support to the use of blades that produce a marginal gap of 50 μm after implant insertion. [ABSTRACT FROM AUTHOR]

The pyrolysis of low alkanes (in the following short "pyrolysis") has already been investigated during the 1960s. However, none of the reactor systems used at the time are capable of continuous operation. Therefore, the Karlsruhe Institute of Technology has intensified the development of the promising liquid metal bubble column technology in recent years, which is capable of continuous operation. Various key aspects have been addressed, such as scale‐up and the pyrolysis of high‐caloric natural gas. Herein, further developments for a pilot scale system have been investigated, which concern increased throughput and long‐term operation capabilities. Careful evaluation of the impact of according measures has been done, which shows that the achieved scale‐up has only negligible effects on the pyrolysis outcome. The effects of the scale‐up on residence times are negligible. The bubble formation behavior depends on the throughput and the characteristics of the orifice. Wall effects are marginal. Fundamental minimization of weeping could not be confirmed. Reactor pre‐chambers in combination with tin collection chambers are recommended for further scale‐up. An increase in the volume flow should be examined. In terms of long‐term operation , head as well as feed pressure control is recommended. [ABSTRACT FROM AUTHOR]