Step Technique Research Articles

The Triple Layer Graft Protocol to Repair Esthetically Compromised Implants: Rationale, Technique, Indications, and Contraindications.

These two clinical case reports show the use of the Triple Layer Graft procedure along with the Decoronation procedure to help restore normal contour and height of tissue The procedure was highly effective at restoring the esthetics that the patients needed on their implants. Short and long term results along with the step by step technique are shown. Two patients of 33 and 25 years of age both had significant reduction in the height over their implants in the #7 and #10 locations. The first patient had the implants placed 15 years ago and the second patient had them done 5 years before our treatment. Current techniques to remedy esthetic issues created by malpositioned implants consist of soft and/or hard tissue grafting but tend to be utilized independently of each other in discrete procedures as opposed to being combined in one surgical protocol. The Triple Layer Graft (TLG) surgical protocol is novel in that it incorporates all three layers of grafting to address both soft and hard tissue deficits in one procedure done at one time after doing a decoronation technique. The TLG surgical and prosthetic protocol has been previously published by these authors, but this article will discuss the rationale along with the technique and indications and contraindications, illustrated via case reports. The authors will also report on the long-term results of this technique. The Triple Layer Graft TLG) in combination with the Decoronation technique is an effective method in managing mild as well as severe esthetic defects over the facial of previously placed implants. The Triple Layer Graft will allow implants that were previously removed in order to place a new implant along with ridge augmentation may be able to be saved. This is a wonderful procedure for the patient since the implant does not have to be removed and replaced.

Формирование двигательных действий у детей с расстройствами аутистического спектра на занятиях адаптивной физической культурой

<p style="text-align: justify;"><strong>Objectives. </strong>Ski training classes for children with autism spectrum disorders (ASD) help develop locomotor functions, develop physical qualities, strengthen health and compensate for the lack of motor activity. Adaptive physical education (APE) classes develop basic types of movements, including when moving on skis. Currently, in the practice of APE there are no methods that form motor actions in children with ASD by means of ski training. The author’s method of step-by-step formation of motor actions in ski training for children with ASD allows teaching the ability to move on skis in various ways.</p> <p style="text-align: justify;"><strong>Methods</strong>. The article presents the materials of an empirical study conducted in a group of 6 children with ASD aged 8—9 years. When teaching children motor skills in APE classes, the method of step-by-step formation of motor actions by means of ski training was used. Motor skills were assessed by the tests “Sliding step”, “Alternating two-step move”, “Simultaneous stepless move”. Diagnostics of the technique of performing ski moves was carried out by the method of expert assessment.</p> <p style="text-align: justify;"><strong>Results</strong>. The sliding step was mastered most successfully by children: 83% (n=5) of children mastered the sliding step technique. The correct technique for performing a simultaneous stepless and alternating two-step walk was mastered by 67% of children (n=4). The number of children capable of covering the distance using the alternating two-step walk and simultaneous stepless walk techniques increased from 1 to 5.</p> <p style="text-align: justify;"><strong>Conclusions. </strong>The presented results confirm the possibility of children with ASD mastering certain methods of skiing using a step-by-step method of forming motor actions. Application at each stage of non-verbal techniques, teaching methods (for example, action by demonstration), form the technique of ski moves in children. The proposed method was implemented in a guideline for the step-by-step teaching of motor actions in ski training for children with ASD. In the future, it is planned to develop a guideline for teaching the techniques of turns, ascents, and descents in ski training for children with ASD.</p>

Performance of R134a vapour compression refrigeration system by using Gr and Al2o3 hybrid nano lubricants

Nowadays, in many developing countries like India they are facing the shortage of energy. The Refrigeration system has become the major consumer of energy for many industrial as well as household applications. So, it is the need to enhance the energy efficiency of the refrigeration systems. Performance of the refrigeration system can be improved either by increasing the rate of heat absorption in evaporator or by reducing the compressor power. Use of efficient lubricant oil can help to remove the heat generated in the compression process which leads to less power consumption. Development in Nanotechnology makes it possible to develop a new class of lubricant called nanolubricant, in which nanoparticles are added in base lubricant oil to enhance the thermal properties. The two step technique with ultrasonic agitation force is used tosynthesise stable nanolubricant. The present study investigates the performance of an R-134a refrigerant vapour compression refrigeration system using nanolubricant with different volume concentrations (0.05%, 0.075%, 0.1% and 0.2%) of Graphene/Aluminium nanoparticles to mineral oil (MO) experimentally. The result shows maximum enhancement in COP approximately as 85% for 0.075 % volume fraction Nano lubricant as compared to base fluid. Use of nanolubricant saves approximately 27% compressor power.

Double Step Technique for Accurate Microwave High Attenuation Measurements

Double Step Technique for Accurate Microwave High Attenuation Measurements

Virtual body-fitted grid-based immersed boundary method for simulation of thermal flows with Dirichlet and Neumann boundary conditions

In this work, a virtual body-fitted grid-based immersed boundary method (IBM) combined with the thermal lattice Boltzmann flux solver (TLBFS) is proposed to efficiently simulate thermal flows with Dirichlet and Neumann boundary conditions. The method involves generating a virtual body-fitted grid along the immersed boundary and implementing the boundary conditions using a fractional step technique. In the prediction step, the finite-volume TLBFS is used to obtain the predicted flow field on the Eulerian mesh without considering the immersed boundary, while in the correction step, the correction process of the flow field is conducted on the virtual grid. Thus, the effect of the boundary is transferred to the fluid domain through the virtual grid indirectly. For Dirichlet boundary conditions, such as the no-slip condition and the specified temperature condition, the velocity and temperature corrections are considered unknowns and solved through a matrix system formed from enforcing the boundary conditions. As for the Neumann boundary condition, such as the specified heat flux condition, the temperatures at virtual layers inside the immersed body are regarded as unknowns and computed from those at virtual layers outside the wall according to the quadratic distribution. Several benchmark cases including natural, forced, and mixed convection problems are well simulated to validate the method. The numerical results are in good agreement with reference data, demonstrating the capacity of the present method to simulate thermal flows with Dirichlet and Neumann boundary conditions while requiring fewer Lagrangian points and achieving higher computational efficiency.

VE73 Pelvic lymph node dissection during robotic radical cystectomy. Step by step technique

VE73 Pelvic lymph node dissection during robotic radical cystectomy. Step by step technique

Making of an Indigenous and Efficient Powertrains for EV, HEV & FCEV’s

Rise in greenhouse gas emissions which is resulting into ozone layer depletion and global warming effect is alarming to control CO2 emissions by drastically reducing fossil fuel consumption from the vehicles. This need has already started trend towards extreme downsizing and down speeding of Internal Combustion Engines (ICE) for making them highly efficient. In addition to this use of after treatment devices viz. Diesel Oxidation Catalyst (DOC), Diesel Particulate Filter (DPF), Lean NOx Catalyst (LNT), Selective Catalytic Reduction (SCR) are helping to a great extent for meeting emission norms till Euro - VI for automotive sector, Tier–IV F and Stage V for Off Highway Power sector. However, to address present greenhouse effect along with exponential decay of fossil fuels, there is need to achieve CO2 emissions less than 100 g/km or to achieve practically zero carbon footprint using an alternate powertrain. Electrification is one of the promising solutions and which is three-fold in present situation. The first level of electrification comes in the form of Hybrid Electric Vehicle (HEV) technology followed by Battery Electric Vehicles and Fuel Cell Electric Vehicles as second and third level of electrification respectively. In all these technologies a common thread is running in the form of an efficient electric drive train. Several efforts have been taken to improve torque per unit ampere by use of efficient motor and motor control algorithms viz PMSM powered with FOC, by developing controls which take care of parametric variations and external force disturbances by use of back stepping techniques which are based on rotor resistance estimation by fuzzy logic, FOC techniques based on adaptive input-output feedback linearization, by shifting towards high voltage systems, by going for higher switching frequencies for inverters which uses silicon carbide based MOSFET switches, by exploring use of multilevel inverters for Total Harmonic Distortion (THD) control etc. Use of E Axle based powertrains in EV, HEV and FCEV offers additional complimentary benefits apart from technology options described above. E Axle based powertrains offers flexibility in generating three variants of vehicle using one electric drive train architecture viz. making EV, HEV & FCEV. Compactness, modularity, scalability, flexibility along with efficient cooling system management and control over active current losses due to use of bus bars are the implicit advantages of E Axle based powertrains. These advantages further get multiplies if we go for 3 in 1 (gearbox + Stator housing + Inverter) architectures which are predominantly used in independent suspension-based vehicles. Lot of efforts are going on to inherit this technology for rigid axle suspension based commercial vehicles. Research in this area is getting further extended to make 5 in 1 E Axles where there will addition of DC - DC converter and On-Board Charger (OBC) apart from components present in 3 in 1 configuration. Two major challenges need to be addressed and to be resolved while designing E Axle based powertrains by doing concurrent vehicle engineering. This is mainly due to increased unsprang weight that need to be handled by suspension system and exposed electric drive components to excitation loads coming from roads. Fig: Indigenously Developed E Axle Based Powertrain for Small Commercial VehiclesBy proper lay outing for effective vehicle mass distribution and required CG location which is essential from overall vehicle dynamics, more space can be offered by E Axle based powertrains for increasing battery energy density for getting more electric range in case of BEV’s. This add on space benefit extend help in packaging of hydrogen fuel cell integrated with power cells in case of FCEV’s. Thus, E Axle based powertrains proves to be modern and most efficient way of making EV, HEV & FCEV’s.

Adaptive fuzzy ABLF function fixed‐time tracking control method for nonlinear fault‐tolerant control systems with event triggering mechanism

SummaryAs the nonlinearities of many real physical controlled systems become stronger and stronger, they are difficult to be described by accurate mathematical models. For a class of nonlinear single‐input single‐output systems with all‐state constraints and actuator faults, an event‐triggered adaptive fuzzy ABLF function fixed‐time tracking control method is proposed. The asymmetric barrier Lyapunov function (ABLF) combined with backward step technique is used to ensure the boundedness of the closed‐loop system output. In order to solve the problem of limited bandwidth resources, this paper adopts the event trigger mechanism and fuzzy control technology to approximate the unknown function to ensure the convergence of the system in a fixed time. After theoretical analysis, it is proved that the tracking error of the system converges in the small neighborhood of the origin, and it still has good tracking performance when the actuator faults. Finally, by comparing the proposed method with the asymmetric barrier Lyapunov function, which verifies the effectiveness of the proposed method.

Lead-free methyl ammonium tin iodide perovskite thin film growth in single step via plasma enhanced chemical vapour deposition technique and its optoelectronic properties

In the present work, lead free methyl ammonium tin iodide (CH3NH3SnI3 or MASnI3) perovskite thin films have been deposited via single step plasma enhanced chemical vapour deposition (PECVD) technique. In our earlier work, we reported lead based methyl ammonium lead iodide (CH3NH3PbI3 or MAPbI3) perovskite thin film deposition in 2-step, using sputtering technique for the PbI2 thin films and PECVD technique for CH3NH3I (MAI) thin films. Similarly, CH3NH3SnI3 perovskite thin films are deposited in this work using PECVD technique in single step. Lead is substituted with tin due to its toxic behaviour, environmental and health related issues. CH3NH3SnI3 perovskite is doped n-type via changing the molar ratio of SnI2 and CH3NH3I. SnI2/CH3NH3I ratio is changed from 0.33 to 2 to study the n-type doping of CH3NH3SnI3 perovskite. Deposited CH3NH3SnI3 perovskite thin films are deposited over p-type silicon wafer to make n-type doped n-CH3NH3SnI3/p-Si heterojunction photodiode.

Application of residual network based on multispectral attention mechanism in stepped eddy current thermography defect detection

The stepped eddy current thermography nondestructive testing technique has a low and uneven temperature rise under weak excitation conditions, which brings great challenges to the quantitative analysis of defects in the inner wall of pressure vessels. To solve the above problems, this paper proposes a multi-spectral channel attention residual network model based on a Gramian angular difference field (GADF) for automatic detection and quantification. Firstly, the noise reduction and compression of temperature time series data are accomplished by singular value decomposition and piecewise aggregate approximation. Secondly, three infrared feature strategies commonly used for quantitative analysis were transformed by GADF and Gramian angular sum field (GASF) techniques to filter out the infrared feature data sets that contain the most defective feature information. Finally, the frequency domainization of the feature map is realized by embedding the multispectral channel attention in the residual network. The global dependencies and relevant essential features of infrared data are effectively captured, and the redundant feature information generated by deep learning feature maps is suppressed. The effectiveness of the model is verified by comparing several time-series models with advanced deep-learning models. The results show that the proposed model has excellent performance in terms of accuracy, stability, and generalization ability. Meanwhile, the model can effectively extract the defects in the region of uneven temperature rise.

Evaluation of post-surgical complications between "Rendez-vous" technique vs. standard care in patients with choledocholithiasis

"Rendez-vous" (RV) technique is a mixed-technique which uses both laparoscopic and endoscopic skills; however, the evidence is contradictory regarding the implementation of this technique or the 2-step sequential technique (endoscopic retrograde cholangiopancreatography [ERCP] followed by laparoscopic cholecystectomy [LC]) in the management of cholecysto-choledocholitiasis. To estimate the association between the implementation of RV technique and the presence of post-surgical complications as primary outcome, using as comparator the 2-step sequential technique. An observational, analytical, retrospective study was conducted, using as exposed cohort the medical records from patients with a diagnosis of cholelithiasis, cholecystitis, or mild biliary pancreatitis. The exposed cohort underwent RV technique, while the unexposed cohort were those which underwent two step technique. There was a lower post-surgical complication rate in the RV group (0%) compared with the 10.1% (p = 0.3617) in the control group. Also, RV technique showed a lesser hospitalization time (p = 0.0377) and a lesser post-surgical hospitalization time (p < 0.0001). RV technique is superior when compared with the 2-step sequential technique (ERCP followed by LC), based on a better surgical success rate, a fewer complications rate and less hospitalization time.

The Technique and Material Used to Join Transfers Affect the Accuracy and Final Fit of Implant-Supported Prostheses-In Vitro Study.

This study evaluated the linear dimensional change of polymerization of three materials and two techniques of the union of molding transfers for implant-supported prostheses used in the open-tray technique. A nylon maxilla-shaped matrix was made, two osseous integrated implants were installed, and, over these two, straight conical mini-pillars were installed. Open-tray impression transfers were attached to the mini-pillars, and a silicone guide was made to standardize the connections between the transfers. The samples were divided into six groups (n = 20): PA (Pattern Resin LS, chemically activated acrylic resin in the single step technique); DU (Durallay, chemically activated acrylic resin in the single step technique); BI (Protemp4, bisacrylic resin in the single step technique); PAC (Pattern Resin LS in sectioning and joining of segments technique); DUC (Durallay, in sectioning and joining of segments technique); and BIC (Protemp4, in sectioning and joining of segments technique). The linear dimensional change values that occurred among these transfers were measured in a profile projector (VB300; Starret) coupled to the Quadra Check device, with a resolution of 0.001 mm, performed by a single calibrated operator. Data were submitted to a two-way analysis of variance and Tukey's test (p < 0.01). Statistically significant mean values were found in all comparisons. The PA showed the lowest mean values (µm) of linear dimensional change, both in the single-step technique and in the sectioning and joining technique, in the following order: BI 255.73 (3.81), DU 173.75 (2.30), PA 95.97 (3.20), BIC 23.82 (1.71), DUC 20.85 (2.53), and PAC 13.27 (2.09). The single-step technique showed the worst results, regardless of the material. The sectioning and joining technique reduced the dimensional change in all materials, and the Pattern Resin LS showed the lowest shrinkage mean values, followed by Durallay and Protemp4.

Compilation of a Tool to Measure Financial Knowledge and Skills of Hospital Managers

Introduction: The hospitals, as the most important organization providing healthcare services, need efficient and effective management more than any other organization. Therefore، knowledge, skills, and capabilities of hospital managers should be given special attention، and one of these skills is financial knowledge and skill. Therefore، this research has been done with the aim of developing and validating a tool for measuring the knowledge and financial skills of hospital managers. Methods: The present combined study was conducted in 1401-1402. The research community included managers of educational and therapeutic hospitals, academic faculty members, and graduate students of accounting and financial management as financial experts (Delphi panel). Sampling started purposefully and continued until data saturation. To collect data, interviews, focused group discussions and questionnaires were used, and fuzzy Delphi and fuzzy AHP methods were used to analyze the data. Results: The important dimensions and components were determined according to the fuzzy Delphi method, including 8 dimensions and 23 indicators, and with the help of the AHP method, the weight of each dimension was determined. Then, 68 multiple choice questions related to each of the identified dimensions were designed based on interviews with experts. In the next step, through questionnaire and fuzzy Delphi technique, the opinion of experts was obtained about the questions raised, and finally 46 four-choice questions were compiled as a tool to measure the knowledge and financial skills of hospital managers. Conclusion: Hospitals are important parts of providing health services and considering the limited resources of the health sectors, proper allocation of resources, application of scientific management, correct and principled planning will be an important step in achieving the goals of the health system. A proper understanding of the principles of financial management and how to present financial information and how to share costs in hospitals help the managers of hospitals to have a dynamic picture of their activities and goals and to be able to make more informed decisions for the future.

Step by step technique of Stentless Florence Robotic Intracorporeal Neobladder (FloRIN), does the ureteral management influence functional outcomes?

Benefits and harms of avoid the sent placement during IntraCorporeal Neobladder configuration are still debated. Our objective was to describe the step-by-step technique of Florence intracorporeal neobladder (FloRIN) configuration performed with stentless procedure focusing on perioperative and mid-term functional outcomes. In this single institution prospective randomized 1:1 series all consecutive patients underwent Robot-Assisted Radical Cystectomy (RARC) and FloRIN reconfiguration from January 2021 to March 2021 were enrolled. Functional perioperative and mid-term outcomes were gathered. Postoperative complications were graded according to Clavien-Dindo classification and divided in early (<30 days from discharge) and delayed (>30 days). Overall, 10 patients were included in the analysis. Of these, the 50.0% was treated with Stentless FloRIN. In terms of baseline features, no differences were recorded between the two groups. Median age was 65 and 66 years while median BMI was 27 and 25 in the stentless and in the stent group, respectively. Concerning intraoperative variables, no intraoperative complications as well as open conversion occurred among both groups. As regard introperative features, a shorter console time was associated with stentless procedure (331 min vs 365 min). In terms of perioperative outcomes, canalization and time to drainage removal didn't differ between groups while length of hospital stay was significantly lower in stentless group 10 days versus 14 days. Early and delayed postoperative complication rate was not influenced by the ureteral management at a preliminary assessment with comparable rates of Clavien Dindo ⩾ 3a between the two groups. Mid-term functional outcomes did not differ between groups in terms of kidney function loss. FloRIN with Stentless technique showed functional and perioperative preliminary outcomes comparable with the standard ureteral management strategy. Further series with longer functional follow-up assessment will be needed to confirm our preliminary results.

Combined Decompression of Pudendal and Inferior Cluneal Nerves for Entrapment Neuralgias Using Transperitoneal Robotic Laparoscopy: Feasibility and Our Four-Step Technique

Objective: To demonstrate the feasibility of a combined decompression of pudendal and inferior cluneal nerves for entrapment syndrome using a transperitoneal robotic laparoscopy. DesignDemonstration of our 4 steps technique with narrated video footage. SettingPudendal and inferior cluneal neuralgias caused by an entrapment syndrome are both responsible for perineal pain (1). Although more precise data are lacking, these two neuralgias are frequently associated. Failure of surgical pudendal nerve decompression in the early 2000 has driven to discover the entity of a potential entrapment syndrome of the posterior cutaneous nerve of the tight and its inferior cluneal branches between the ischium bone and the sacrotuberous ligament (2). The corresponding neuralgia is responsible for a neuropathic pain to a more posterior part of the perineum and the thigh, without any neuro-vegetative symptom. In case of failure of medical treatment, surgery can be proposed using an invasive open trans-gluteal approach as a standard treatment (3-5). InterventionsTransperitoneal robotic laparoscopy for a mini-invasive releasing of both pudendal and inferior cluneal nerves, following a 4 steps technique:1. Opening of the peritoneum between external iliac vessels and umbilical ligament2. Dissection of the internal iliac and pudendal arteries up to the pudendal nerve3. Section of sacrospinous ligament and release of pudendal nerve4. Section of sacrotuberous ligament and release of inferior cluneal nerve. ConclusionPreviously, pudendal and inferior cluneal neuralgias have been managed with an invasive open trans-gluteal surgery. Here, we demonstrate the feasibility of a mini-invasive transperitoneal robotic laparoscopy, with a standardized 4 steps surgical technique.

Utilizing Deep Learning Techniques for the Classification of Spoken Languages in India

In Western countries, speech-recognition applications are accepted. In East Asia, it isn't as common. The complexity of the language might be one of the main reasons for this latency. Furthermore, multilingual nations such as India must be considered in order to achieve language recognition (words and phrases) utilizing speech signals. In the last decade, experts have been clamoring for more study on speech. In the initial part of the pre-processing step, a pitch and audio feature extraction technique were used, followed by a deep learning classification method, to properly identify the spoken language. Various feature extraction approaches will be discussed in this review, along with their advantages and disadvantages. Also discussed were the distinctions between various machine learning and deep learning approaches. Finally, it will point the way for future study in Indian spoken language recognition, as well as AI technology.

An Experimental Study on the Effectiveness of the Backward-Facing Step Technique on Small-Scale Horizontal-Axis Wind Turbine Rotor Blades

The aim of this research work was to explore how modifying the design of small-scale HAWT rotor blades through the backward-facing step technique affects their efficiency under varying wind speeds. The study involved altering step parameters such as location, length, and depth to create four distinct stepped blade shapes and enhance the aerodynamic performance of a rotor with a diameter of 280 mm. A specific blade profile, NREL S822, was selected to meet both aerodynamic and structural criteria. The rotor models were examined at a Reynolds number of 4.7 × 104 for wind speeds between 8.5 and 15.5 m/s and tip-speed ratios between 2 and 5. The experimental results indicated that for certain geometric step parameter values, the efficiency of the rotor model (B3) increased by approximately 47% compared to the base model (B1), particularly for tip-speed ratios lower than around 3.2. However, beyond this point, the rotor efficiency dropped significantly, reaching approximately 60% in one case. Additionally, a hybrid rotor model (B6) was generated by combining the shape of the rotor model (B4) with the most efficient rotor model from the literature, generated using the leading-edge wavy shape technique. This hybrid rotor model enhanced rotor efficiency for specific values of tip-speed ratio and also ensured its smoother operation. Overall, the rotor model (B2), distinguished by smaller step parameter values and a shift as well as broadening of the power coefficient curve towards lower tip-speed ratio values, exhibited a higher peak power coefficient, approximately 1.4% greater than the base rotor (B1). This increase occurred at a lower tip-speed ratio, allowing the rotor to operate with higher efficiency across a broader range of tip-speed ratios.

Proof of Principle of the Lunar Soil Volatile Measuring Instrument on Chang’ e-7: In Situ N Isotopic Analysis of Lunar Soil

The nitrogen isotopic compositions of lunar soil have important implications for the sources of lunar volatiles and even the evolution of the moon. At present, the research on the lunar nitrogen isotopic compositions is mainly based on the lunar meteorites and the samples brought back by the Apollo and Luna missions. However, volatiles adsorbed on the surface of the lunar soil may be lost due to changes in temperature and pressure, as well as vibration and shock effects when the sample is returned. At the same time, in the case of low N content in the sample, since N is the main component of the earth’s atmosphere, it is easily affected by the atmosphere during the analysis process. Therefore, in situ nitrogen isotopic analysis of lunar soil on orbit is necessary to avoid the problems mentioned above and is one of the primary science goals for the Lunar Soil Volatile Measuring instrument on Chang’e-7 spacecraft. After the nitrogen purification procedure, the volatiles in lunar soil that are released through single-step or stepped heating techniques diffuse to the quadrupole mass spectrometer to obtain the N contents and isotopic compositions of the lunar soil. This paper introduces the ground test for N isotopic analysis of lunar soil in orbit according to the Lunar Soil Volatile Measuring Instrument. After long-term repeated measurements, the background and CO-corrected Air-STD 14N/15N ratio is 268.986 ± 4.310 (1SD, n = 35), and the overall reproducibility of measurements is 1.6%. The accuracy of N isotopic compositions is calculated to be better than 5%, which can distinguish different sources of N components in lunar soil.

Chemical Reaction Models in Synthetic Promoter Design in Bacteria.

We discuss the formalism of chemical reaction networks (CRNs) as a computer-aided design interface for using formal methods in engineering living technologies. We set out by reviewing formal methods within a broader view of synthetic biology. Based on published results, we illustrate, step by step, how mathematical and computational techniques on CRNs can be used to study the structural and dynamic properties of the designed systems. As a case study, we use an E. coli two-component system that relays the external inorganic phosphate concentration signal to genetic components. We show how CRN models can scan and explore phenotypic regimes of synthetic promoters with varying detection thresholds, thereby providing a means for fine-tuning the promoter strength to match the specification.

An immersed boundary velocity correction method combined with virtual body-fitted grid for simulation of incompressible flows

In this work, a virtual body-fitted grid is introduced into the velocity correction-based immersed boundary method (IBM) to simulate incompressible flows. The impact of the immersed boundary is indirectly transmitted to the flow field via a virtual body-fitted grid. In this method, the fractional step technique consisting of the predictor and the corrector is adopted. The prediction step is executed on the Eulerian mesh, and the correction step is done on the virtual grid to fulfill the no-slip boundary condition. After the correction step, the corrected velocity field on the virtual grid is then assigned to that on the Eulerian mesh to update the flow field. Being able to adjust the grid spacing flexibly, the virtual body-fitted grid alleviates the shortcomings of the conventional IBM that uses the smooth Dirac delta function to associate Lagrangian points with their surrounding Eulerian points. As a result, the present method is easy to apply to non-uniform Cartesian grids, which is inapplicable to the conventional IBM with the smooth Dirac delta function. Numerical experiments concerning flow past a circular cylinder and a NACA0012 airfoil demonstrate the advantages of the present method, i.e., fewer Lagrangian points are required to avoid the streamline penetration of boundary and the range of “diffuse interface” can be narrowed by reducing the normal grid spacing of the virtual body-fitted grid to improve numerical results on a coarse mesh. In addition, an accuracy assessment on the decaying vortex problem reveals that the present IBM has a second-order accuracy.