A fluid-driven soft robotic fish inspired by fish muscle architecture

Artificial fish-like robots developed to date often focus on the external morphology of fish and have rarely addressed the contribution of the structure and morphology of biological muscle. However, biological studies have proven that fish utilize the contraction of muscle fibers to drive the protective flexible connective tissue to swim. This paper introduces a pneumatic silicone structure prototype inspired by the red muscle system of fish and applies it to the fish-like robot named Flexi-Tuna. The key innovation is to make the fluid-driven units simulate the red muscle fiber bundles of fish and embed them into a flexible tuna-like matrix. The driving units act as muscle fibers to generate active contraction force, and the flexible matrix as connective tissue to generate passive deformation. Applying alternant pressure to the driving units can produce a bending moment, causing the tail to swing. As a result, the structural design of Flexi-Tuna has excellent bearing capacity compared with the traditional cavity-type and keeps the body smooth. On this basis, a general method is proposed for modeling the fish-like robot based on the independent analysis of the active and passive body, providing a foundation for Flexi-Tuna’s size design. Followed by the robot’s static and underwater dynamic tests, we used finite element static analysis and fluid numerical simulation to compare the results. The experimental results showed that the maximum swing angle of the tuna-like robot reached 20°, and the maximum thrust reached 0.185 N at the optimum frequency of 3.5 Hz. In this study, we designed a unique system that matches the functional level of biological muscles. As a result, we realized the application of fluid-driven artificial muscle to bionic fish and expanded new ideas for the structural design of flexible bionic fish.

IR 4.0 Technologies Enable Breakthroughs in Upstream Production Operations

The fourth industrial revolution (IR 4.0) has brought about many exciting and game changing technological advancements in recent years that span across different industries. Our petroleum industry was no exception. In this paper, we will present realizations of IR 4.0's fruitful impact on multiple upstream production engineering and operation problems. The first IR 4.0 technology uses machine learning techniques to predict scale inhibition and design inhibition programs that arrest scale formation. Scale formation is a common oilfield problem that consumes a lot of expense from operators. The machine learning method has shown its ability to curtail such expenses and manage risks associated with scale formation. The second technology is modeling the reliability of downhole Inflow Control Valves (ICVs) and predicting their failure. The technology is based on advanced big data analytics and uses automated statistical techniques to achieve the method objectives. This technology provides production engineers with an analytical decision-making model to predict ICVs failures and suggest the optimum frequency for stroking or cycling of the downhole valves as a preventive maintenance practice. The third IR 4.0 technology is the automated well integrity risk ranking. This particular technology uses smart interfaces and advanced computation algorithms applied on big data to assign (or weigh) risks of a well in terms of well integrity. This intelligent integrity ranking or classification shifts focus to wells prone to integrity failures more than the healthy ones. In addition, the method helps optimize integrity surveillance resources and prevents the obvious setbacks from a well integrity issue. The paper will explain detailed methodologies of all three IR 4.0 technologies and outline expected results from field implementation of those technologies.

Methodology of the selection of effective dipping and control over the filling depth of open-textured construction materials

It is determined that for the combination of the dipping process with the ultrasound control it is necessary to carry out the optimization of the filling speed and the precision of control over the dipping depth, to determine the optimum frequency of the ultrasound emission which satisfies the speed and the dipping measurement precision of the sample with the hydrophobic agent. On the basis of the performed multiobjective optimization, experimental results for the dipping and the control over the dipping stage of porous materials by the solution in the uniform acoustic field alignment charts are received for the selection of the rational frequency of ultrasound fluctuations which allow regulating and/or optimizing dipping and control processes over the material filling depth subject to customer tasks. The selection methodology of effective values of parameters of the acoustic field providing the combination of filling processes and the control over the depth of the dipped material filling is well-reasoned.

Effectiveness of K2siO3 on growth and physio-biochemical changes of banana seedlings grown under tropical climate as influenced by application frequency

Slow growth rate of tissue-cultured banana seedling’s performance and high post-transplanting mortality rate are commonly due to low rate mineral content in the soil, climate change and soil-borne disease. This study aimed to evaluate the effects of potassium silicate (K2SiO3) on growth, physio-biochemical changes on Berangan banana seedlings grown under tropical climate conditions. The experiment was conducted under a rain shelter and all treatments were arranged in a randomized complete block (RCBD) design. The plants were soil drenched with K2SiO3 at constant 0.0901 M by 25 mL/plant after two weeks of transplanting with different frequencies application: 0-day interval (DI) served as control, 7 DI (12×), 15 DI (6×) and 30 DI (3×) throughout three months experimental period. Results showed that K2SiO3 (13% SiO2, 20% K2O) applied on healthy banana seedlings at 15 days interval significantly improved morphological growth trait (plant height, pseudo-stem diameter size, total leaf area, root length, and dry matter biomass) and physiological traits characters, but reduced proline and MDA content in plant tissues of banana. Hence, the results confirmed that each banana seedlings that received K2SiO3 at optimum frequency rate (15DI) had successfully enhanced the growth performance with better quality of Berangan banana seedlings at commercial-scale production.

Breakthrough Enhanced Oil Recovery Technology with Low Cost & Fast Yield on Pilot Test of Vibroseismic EOR Technology in Tempino Field, Sumatera, Indonesia

Enhanced Oil Recovery (EOR) is a tertiary recovery which requires relatively a high cost of CAPEX and OPEX. The current EOR technique is generally stand alone and injected into single reservoir layer without contributing to the other layers (unconnected reservoir layer). For this reason, a breakthrough of low cost EOR technology (CAPEX & OPEX) is needed, especially since oil prices tend to fall low. Vibroseismic EOR is one of the EOR methods (categorized as mechanical EOR) that is inexpensive, fast response / yield, high mobility (can be moved to another place), environmentally friendly, and could be combined with the waterflood method or other EOR methods to get more effective and optimal result. However, the research & implementation on Vibroseismic EOR are still limited. The paper describes the pilot test of Vibroseismic EOR technology in Tempino Field. The initial stage is to select the suitable field for implementation Vibroseismic EOR. Then, the rock & fluid properties of the selected field are tested and examined by vibration and stimulation in the laboratory to obtain optimum frequency of 20 Hz S waves (circular / transverse) and 35 Hz P waves (longitudinal). The field scale-up process is carried out by measuring or testing field parameters called Vibroseis Field Parameter Test (VFP Test). VFP Test results get the optimum frequency of S and P waves of 20 Hz using 3 trucks and drive level 70% with amplitude value up to 0.024 rms (root mean square). Through the EOR vibroseismic method, the truck is the source of vibrations on the surface will generate acoustic waves propagating through the rock (subsurface) throughout the reservoir layer within the wave penetration range, generally reaching a depth of 6500 ft depending on the amplitude / power source of vibration, thickness of weathered layer, and rock type. The waves that reach the reservoir will affect the rock & fluids properties. The pilot test results on production wells showed a positive response within 1 month after vibration, especially those around the existing injection wells which the permeability was relatively good. The increased production accumulative of 10 (ten) monitoring production wells about 8% and withhold declining rate up to 20% from base case. Oil drainage around production wells and drainage direction are confirmed by changes in hydrocarbon saturation maps through passive seismic techniques measured before, during, and after vibration. The results of this pilot test show that Vibroseismic EOR technology is very promising to be developed to the full-scale stage and implemented in other areas.

Simulation of Single Channel Magnetic Induction Tomography for Meningitis Detection By Using COMSOL Multiphysics

Meningitis is a inflammation of the meninges and the most common central nervous system (CNS) due to bacterial infection. Numbers of children who have bacterial meningitis are still high in recent 15 years regardless of the availability of newer antibiotics and preventive strategies. This research focuses on simulation using COMSOL Multiphysics on the design and development of magnetic induction tomography (MIT) system that emphasizes on a single channel rotatable of brain tissue imaging. The purpose of this simulation is to test the capability of the developed MIT system in detecting the change in conductivity and to identify the suitable transmitter-receiver pair and the optimum frequency based on phase shift measurement technique for detecting the conductivity property distribution of brain tissues. The obtained result verified that the performance of the square coil with 12 number of turns (5Tx-12Rx) with 10MHz frequency has been identified as the suitable transmitter-receiver pair and the optimum frequency for detecting the conductivity property distribution of brain tissues.

Effect of pulsating disintegrating airflow on electric arc depositing

To limit the losses in sprayed metal in the process of electric arc deposition, the disintegrating airflow is pulsated. In this work, the effect of changing the pulsation frequency was studied on the process performance, mainly, the efficiency of metal removal and rate of deposition. Additionally, the bonding strength of the resulting sprayed metal was evaluated at different pulsation frequencies. The application of air pulsations increases the productivity and efficiency of sprayed material by increasing the efficiency of material used up to 30% and enhancing the rate of deposition up to 32%, at a frequency range 70–80 Hz. Moreover, at the optimum frequency of air pulsations, the bond strength increased up to 69%, measured by Steffensen’s dowel method. The results found in this work will allow for more rational usage of the electrical arc energy and material.

Novel Hollow Octagonal Core Photonic Crystal Fiber (PCF) based Cholesterol Sensor

Cholesterol, also known as the pulpy fat of human body, may cause the body vulnerable to heart malady by filling blood-vessel with fatty substances. This urges a precise, simple, and effective method of cholesterol detection. Considering this, a novel hollow equilateral-octagon core PCF model has been presented as a cholesterol sensor. The sensor is modeled and simulated using finite element method (FEM). Multiple performance metrics suggests the effectiveness of the proposed sensor model. The relative sensitivity attained for the model is 92.34% at optimum frequency (OF), 3.6THz. Besides, the model shows ultra-lower confinement loss of 3.77×10− 18cm−1 at OF along with standard values for other performance metrics. In addition, the feasible implementation of the model by exercising existing fabrication strategies ensures the practicability of the proposed sensor.

Optimum design for a novel inerter-based vibration absorber with an amplified inertance and grounded stiffness for enhanced vibration control

This article presents the results of the study of a novel inerter-based vibration absorber with an amplified inertance mechanism and grounded stiffness, to control excessive vibrational movements of an excited primary structure. The inerter vibration absorber used in this study acts as a passive tuned inerter damper. An undamped primary structure model with a single degree of freedom controlled by the proposed inerter vibration absorber is developed and used to derive the equations of motion of the coupled system. The optimum frequency ratio and the optimum damping ratio of inerter vibration absorber are found using the fixed point theory for harmonic force-excited primary structures. Then, the optimum grounded stiffness ratio is deduced. Based on the inclusion of an amplified inertance mechanism, it is found that for given inertance mass ratio, the change in the amplification ratio results in three cases for the optimum grounded stiffness ratio, that is, negative, zero, and positive. From these three cases of grounded stiffness, the inerter vibration absorber with positive grounded stiffness has demonstrated the best control performance. Under optimum parameters, the results indicate that the inerter vibration absorber in this article outperforms some existing inerter vibration absorbers under the harmonic excitation, in terms of decreases in the peak vibration response of the primary system and widens the suppression bandwidth. Finally, the further comparison among the inerter vibration absorber under random (white noise) excitation also shows that the model in this article is superior to other inerter vibration absorbers in terms of smallest mean square response and smallest variance of the time history of the primary system.