Optimal position of thermal fog nozzles for multicopter drones

2021 ◽  
Vol 3 (4) ◽  
Keyword(s):  
Optimal Position

Analysis of field uniformity and quantitative evaluation of subsurface pitting corrosion in conductors via GPEC

2020 ◽  
Vol 64 (1-4) ◽  
pp. 19-29
Author(s):  
Shuting Ren ◽  
Yong Li ◽  
Bei Yan ◽  
Jinhua Hu ◽  
Ilham Mukriz Zainal Abidin ◽  
...  
Keyword(s):  
Quantitative Evaluation ◽  
Eddy Current ◽  
Pitting Corrosion ◽  
Gradient Field ◽  
Uniform Field ◽  
Eddy Current Method ◽  
Optimal Position ◽  
Pulsed Eddy Current ◽  
Field Uniformity ◽  
Processing Algorithms

Structures of nonmagnetic materials are broadly used in engineering fields such as aerospace, energy, etc. Due to corrosive and hostile environments, they are vulnerable to the Subsurface Pitting Corrosion (SPC) leading to structural failure. Therefore, it is imperative to conduct periodical inspection and comprehensive evaluation of SPC using reliable nondestructive evaluation techniques. Extended from the conventional Pulsed eddy current method (PEC), Gradient-field Pulsed Eddy Current technique (GPEC) has been proposed and found to be advantageous over PEC in terms of enhanced inspection sensitivity and accuracy in evaluation and imaging of subsurface defects in nonmagnetic conductors. In this paper two GPEC probes for uniform field excitation are intensively analyzed and compared. Their capabilities in SPC evaluation and imaging are explored through simulations and experiments. The optimal position for deployment of the magnetic field sensor is determined by scrutinizing the field uniformity and inspection sensitivity to SPC based on finite element simulations. After the optimal probe structure is chosen, quantitative evaluation and imaging of SPC are investigated. Signal/image processing algorithms for SPC evaluation are proposed. Through simulations and experiments, it has been found that the T-shaped probe together with the proposed processing algorithms is advantageous and preferable for profile recognition and depth evaluation of SPC.

scholarly journals Predicting the Characteristics of Defect Transitions on Curved Surfaces

Soft Matter ◽  
2021 ◽  
Author(s):  
Siddhansh Agarwal ◽  
Sascha Hilgenfeldt
Keyword(s):  
Critical Size ◽  
Complex Function ◽  
Lattice Defects ◽  
Curved Surfaces ◽  
Simple Condition ◽  
Shape Parameters ◽  
Optimal Position

The energetically optimal position of lattice defects on intrinsically curved surfaces is a complex function of shape parameters. For open surfaces, a simple condition predicts the critical size for which...

scholarly journals Impaired eIF5A function causes a Mendelian disorder that is partially rescued in model systems by spermidine

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Víctor Faundes ◽  
Martin D. Jennings ◽  
Siobhan Crilly ◽  
Sarah Legraie ◽  
Sarah E. Withers ◽  
...  
Keyword(s):  
De Novo ◽  
Model Systems ◽  
Yeast Growth ◽  
Related Disorder ◽  
Optimal Position ◽  
Human Phenotype ◽  
Mendelian Disorder ◽  
Growth Defects ◽  
Polysome Profiling

AbstractThe structure of proline prevents it from adopting an optimal position for rapid protein synthesis. Poly-proline-tract (PPT) associated ribosomal stalling is resolved by highly conserved eIF5A, the only protein to contain the amino acid hypusine. We show that de novo heterozygous EIF5A variants cause a disorder characterized by variable combinations of developmental delay, microcephaly, micrognathia and dysmorphism. Yeast growth assays, polysome profiling, total/hypusinated eIF5A levels and PPT-reporters studies reveal that the variants impair eIF5A function, reduce eIF5A-ribosome interactions and impair the synthesis of PPT-containing proteins. Supplementation with 1 mM spermidine partially corrects the yeast growth defects, improves the polysome profiles and restores expression of PPT reporters. In zebrafish, knockdown eif5a partly recapitulates the human phenotype that can be rescued with 1 µM spermidine supplementation. In summary, we uncover the role of eIF5A in human development and disease, demonstrate the mechanistic complexity of EIF5A-related disorder and raise possibilities for its treatment.

scholarly journals Optimization of Dynamic Task Location within a Manipulator’s Workspace for the Utilization of the Minimum Required Joint Torques

Electronics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 288
Author(s):  
Adam Wolniakowski ◽  
Charalampos Valsamos ◽  
Kanstantsin Miatliuk ◽  
Vassilis Moulianitis ◽  
Nikos Aspragathos
Keyword(s):  
High Performance ◽  
Human Robot Interaction ◽  
Optimal Position ◽  
End Effector ◽  
Joint Torques ◽  
Dynamic Task ◽  
Arbitrary Position ◽  
Simulation Results ◽  
Set Up ◽  
Task Placement

The determination of the optimal position of a robotic task within a manipulator’s workspace is crucial for the manipulator to achieve high performance regarding selected aspects of its operation. In this paper, a method for determining the optimal task placement for a serial manipulator is presented, so that the required joint torques are minimized. The task considered comprises the exercise of a given force in a given direction along a 3D path followed by the end effector. Given that many such tasks are usually conducted by human workers and as such the utilized trajectories are quite complex to model, a Human Robot Interaction (HRI) approach was chosen to define the task, where the robot is taught the task trajectory by a human operator. Furthermore, the presented method considers the singular free paths of the manipulator’s end-effector motion in the configuration space. Simulation results are utilized to set up a physical execution of the task in the optimal derived position within a UR-3 manipulator’s workspace. For reference the task is also placed at an arbitrary “bad” location in order to validate the simulation results. Experimental results verify that the positioning of the task at the optimal location derived by the presented method allows for the task execution with minimum joint torques as opposed to the arbitrary position.

scholarly journals Optimal Location of Energy Dissipation Box in Long Distance and High Drop Gravitational Water Supply System

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 461
Author(s):  
Weixiang Ni ◽  
Jian Zhang ◽  
Sheng Chen
Keyword(s):  
Energy Dissipation ◽  
Water Supply ◽  
Water Level ◽  
Pressure Head ◽  
Optimal Location ◽  
Water Supply Systems ◽  
Protective Effects ◽  
Long Distance ◽  
Optimal Position ◽  
Gravitational Flow

In the long-distance and high-drop gravitational water supply systems, the water level difference between the upstream and downstream is large. Thus, it is necessary to ensure energy dissipation and pressure head reduction to reduce the pipeline pressure head. The energy dissipation box is a new type of energy dissipation and pressure head reduction device, which is widely used in the gravitational flow transition systems. At present, there is still a dearth of systematic knowledge about the performance of energy dissipation boxes. In this paper, a relationship between the location of the energy dissipation box and the pressure head amplitude is established, a theoretical optimal location equation of the energy dissipation box is derived, and numerical simulations using an engineering example are carried out for verification. The protective effects of an energy dissipation box placed at the theoretical optimal location and an upstream location are compared. The results indicate that for the same valve action time, the optimal position allows effectively reducing the total volume of energy dissipation box. The oscillation amplitudes of the water level in the box and the pressure head behind the box are markedly reduced. Under the condition that the water level oscillation of the energy dissipation box is almost the same, the optimal location offers better pressure head reduction protection performance than the upstream location.

scholarly journals Effect of electromagnetic-navigated shunt placement on failure rates: a prospective multicenter study

2010 ◽  
Vol 113 (6) ◽  
pp. 1273-1278 ◽  
Author(s):  
Caroline Hayhurst ◽  
Tjemme Beems ◽  
Michael D. Jenkinson ◽  
Patricia Byrne ◽  
Simon Clark ◽  
...  
Keyword(s):  
Revision Rate ◽  
Shunt Revision ◽  
Standard Group ◽  
Fisher Exact Test ◽  
Anatomical Landmarks ◽  
Failure Rates ◽  
Shunt Failure ◽  
Catheter Position ◽  
Optimal Position ◽  
Shunt Placement

Object As many as 40% of shunts fail in the first year, mainly due to proximal obstruction. The role of catheter position on failure rates has not been clearly demonstrated. The authors conducted a prospective cohort study of navigated shunt placement compared with standard blind shunt placement at 3 European centers to assess the effect on shunt failure rates. Methods All adult and pediatric patients undergoing de novo ventriculoperitoneal shunt placement were included (patients with slit ventricles were excluded). The first cohort underwent standard shunt placement using anatomical landmarks. All centers subsequently adopted electromagnetic (EM) navigation for routine shunt placements, forming the second cohort. Catheter position was graded on postoperative CT in both groups using a 3-point scale developed for this study: (1) optimal position free-floating in CSF; (2) touching choroid or ventricular wall; or (3) intraparenchymal. Episodes and type of shunt revision were recorded. Early shunt failure was defined as that occurring within 30 days of surgery. Patients with shunts were followed-up for 12 months in the standard group, for a median of 6 months in the EM-navigated group, or until shunt failure. Results A total of 75 patients were included in the study, 41 with standard shunts and 34 with EM-navigated shunts. Seventy-four percent of navigated shunts were Grade 1 compared with 37% of the standard shunts (p = 0.001, chi-square test). There were no Grade 3 placements in the navigated group, but 8 in the standard group, and 75% of these failed. Early shunt failure occurred in 9 patients in the standard group and in 2 in the navigated group, reducing the early revision rate from 22 to 5.9% (p = 0.048, Fisher exact test). Early shunt failures were due to proximal obstruction in 78% of standard shunts (7 of 9) and in 50% of EM-navigated shunts (1 of 2). Conclusions Noninvasive EM image guidance in shunt surgery reduces poor shunt placement, resulting in a significant decrease in the early shunt revision rate.

The Determination of the Three-Point Support Design of Machine Tool Based on iSIGHT

2014 ◽  
Vol 607 ◽  
pp. 342-345
Author(s):  
Sheng Hui Zhao ◽  
Xiao Chuang Zhu ◽  
Da Wei Zhang
Keyword(s):  
Machine Tool ◽  
High Precision ◽  
Multidisciplinary Optimization ◽  
Joint Surface ◽  
Objective Functions ◽  
Multi Objective Optimization ◽  
Support Design ◽  
Optimal Position ◽  
Point Support

In order to meet the requirements of high-precision machine tool, it has been an important factor to select an appropriate way to support the bed. By building a multidisciplinary optimization (MDO) process based on iSIGHT, this article select the deformation difference of the guides and the deformation difference of the joint surface between column and bed of the machine tool as the objective functions, and then conduct a multi-objective optimization (MOO) of the positional parameters of the three-point support. Eventually the optimization result is given and the optimal position of the three-point support is determined.

An approach to bilateral bone-anchored hearing aid surgery in children: contralateral placement of sleeper fixture

2008 ◽  
Vol 123 (5) ◽  
pp. 555-557 ◽  
Author(s):  
J M Bernstein ◽  
P Z Sheehan
Keyword(s):  
Hearing Loss ◽  
Hearing Aids ◽  
Conductive Hearing Loss ◽  
Hearing Aid ◽  
Contralateral Side ◽  
Two Stage ◽  
Calvarial Bone ◽  
Optimal Position ◽  
Bone Anchored Hearing Aid ◽  
Conductive Hearing

AbstractObjective:Bone-anchored hearing aid surgery in younger children is a two-stage procedure, with a titanium fixture being allowed to osseointegrate for several months before an abutment is fitted through a skin graft. In the first procedure, it has been usual to place a reserve or sleeper fixture approximately 5 mm from the primary fixture as a backup in case the primary fixture fails to osseointegrate. This ipsilateral sleeper fixture is expensive, is often not used, and is placed in thinner calvarial bone where it is less likely to osseointegrate successfully. The authors have implanted the sleeper fixture on the contralateral side, with the additional objective of reducing the number of procedures for bilateral bone-anchored hearing aid implantation, providing a cost-effective use for the sleeper.Methods:The authors implanted the bone-anchored hearing aid sleeper fixture in the contralateral temporal bone instead of on the ipsilateral side in seven successive paediatric cases with bilateral conductive hearing loss requiring two-stage bone-anchored hearing aids, treated at the Royal Manchester Children's Hospital, UK.Results:The seven patients ranged in age from five to 15 years, with a mean age of 10 years; in addition, a 20-year-old with learning disability was also treated. In each case, the contralateral sleeper fixture was not needed as a backup fixture, but was used in four patients (57 per cent) as the basis for a second-side bone-anchored hearing aid.Conclusions:In children with bilateral conductive hearing loss, in whom a bilateral bone-anchored hearing aid is being considered and the second side is to be operated upon at a later date, we recommend placing the sleeper fixture on the contralateral side at the time of primary first-side surgery. Our technique provides a sleeper fixture located in an optimal position, where it also offers the option of use for a second-side bone-anchored hearing aid and reduces the number of procedures needed.

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