Drop Formation and Impaction on the Plant

1988 ◽  
Vol 2 (1) ◽  
pp. 82-87 ◽  
Author(s):  
Donald L. Reichard
Keyword(s):  
High Speed ◽  
Target Surface ◽  
Drop Formation ◽  
Droplet Generator ◽  
Micro Structure ◽  
Uniform Size ◽  
Leaf Surfaces ◽  
Spray Droplets ◽  
Before And After ◽  
Water Drops

The effect of variables that influence the retention of spray droplets impacting on leaf surfaces was studied, using a uniform-size droplet generator to produce drops ranging from 63 to 545 μm diam. To observe the impaction of spray droplets more easily and to measure their velocity before and after impaction, high-speed motion photography (6000 frames/sec) was used. Rebound of spray droplets depends on the micro-structure of the target surface. Leaf surfaces of several crops and weeds reflected 63 to 545 μm diam water drops traveling at velocities less than velocities of drops delivered by popular nozzles at commonly used spray pressures. If the concentration is high enough, some surfactants can reduce the rebound of drops. With one surfactant, its concentration had to be much greater than the critical micelle concentration to reduce reflection of spray drops.

A Piezoelectric Droplet Generating Device for Experiment in Successive Droplets Impacting Onto Solid Surface

2018 ◽  
Author(s):  
Jianxin Li ◽  
Huang Zhang ◽  
Yuzheng Li ◽  
Qianfeng Liu ◽  
Hanliang Bo
Keyword(s):  
Solid Surface ◽  
High Speed ◽  
Experimental Studies ◽  
Structure Design ◽  
Nozzle Diameter ◽  
Signal Frequency ◽  
Duty Ratio ◽  
Droplet Generator ◽  
Uniform Size ◽  
Drop On Demand

The outcomes of successive droplets impacting onto solid surface of the steam separator in a nuclear power system’s steam generator has a strong effect on the separating efficiency. Due to amounts of influencing factors, experimental research is an important method to study the phenomena of droplet-wall collision. However, because it is hard to generator continuous droplets with controllable uniform size and frequency, experimental studies about successive droplets impacting on solid surface are relative limited. In this study, a novel drop-on-demand (DOD) droplet generator is designed and fabricated based on piezoelectric ceramics, in which successive droplets with a uniform diameter can be generated. Firstly, the structure design of the DOD droplet generator, the setup of the control system and working principle are described in detail in this paper. Then the droplet generating performance of the device under different signal frequency fs, signal amplitude U, duty ratio Dr, and nozzle diameter Dn are investigated experimentally using a high-speed camera at 4000 fps. Finally, the influence of the signal frequency fs, voltage U, duty ratio Dr and nozzle diameter Dn on the diameter of droplet Dd is discussed. A test of successive droplets generated by the device impacting on an aluminum plate is conducted.

Experimental Investigation on Newtonian Drop Formation in Different Continuous Phase Fluids

2018 ◽  
Author(s):  
Ashkan Nazari ◽  
Arash Nazari
Keyword(s):  
High Speed ◽  
Water Drop ◽  
Continuous Phase ◽  
Drop Formation ◽  
Formation Water ◽  
Bulk Fluid ◽  
Flow Rates ◽  
Matlab Code ◽  
Water Drops ◽  
Surface Tension Forces

In this work, formation water drops as a Newtonian fluid in different bulk fluids are investigated. A MATLAB code has been developed to process the images taken via a high speed camera in the lab to measure the contact angle of drop, as well as the drop’s diameter and volume at different stages of formation. It is found that the water drop shows similar behavior when they shaped in the liquid phase bulk fluid with different properties while the drop formation’s behavior is substantially different when water drops are formed in the gas bulk fluid. In addition, it is tried to predict the frequency of drop formation at different flow rates with regard to the inertial and surface tension forces applied to the dispread fluid.

Fem Simulation of Micro-Rotating-Structures and Their Applications in Measurement of Residual Stresses in Thin Films

1997 ◽  
Vol 505 ◽  
Author(s):  
Xin Zhang ◽  
Tong-Yi Zhang ◽  
Yitshak Zohar
Keyword(s):  
Thin Films ◽  
Residual Stresses ◽  
Fem Simulation ◽  
Sensitivity Factor ◽  
Local Measurement ◽  
Micro Structure ◽  
Micro Raman Spectroscopy ◽  
Before And After ◽  
Polysilicon Films ◽  
Simulation Results

ABSTRACTFEM simulation of micro-rotating-structures was performed for local measurement of residual stresses in thin films. A sensitivity factor is introduced, studied and tabulated from the simulation results. The residual stress can be evaluated from the rotating deflection, the lengths of rotating and fixed beams, and the sensitivity factor. The micro-structure technique was applied to measure residual stresses in both silicon nitride and polysilicon thin films, before and after rapid thermal annealing (RTA), and further confirmed by wafer curvature method. Residual stresses in polysilicon films at different RTA stages were also characterized by micro-Raman spectroscopy (MRS). The experimental results indicate that micro-rotating-structures indeed have the ability to measure spatially and locally residual stresses in MEMS thin films with appropriate sensitivities.

scholarly journals High-Speed Dynamic Projection Mapping onto Human Arm with Realistic Skin Deformation

2021 ◽  
Vol 11 (9) ◽  
pp. 3753
Author(s):  
Hao-Lun Peng ◽  
Yoshihiro Watanabe
Keyword(s):  
User Interfaces ◽  
High Speed ◽  
Target Surface ◽  
Human Vision ◽  
Surface Model ◽  
Projection Mapping ◽  
Skin Deformation ◽  
Human Arm ◽  
Conventional Methods ◽  
Joint Tracking

Dynamic projection mapping for a moving object according to its position and shape is fundamental for augmented reality to resemble changes on a target surface. For instance, augmenting the human arm surface via dynamic projection mapping can enhance applications in fashion, user interfaces, prototyping, education, medical assistance, and other fields. For such applications, however, conventional methods neglect skin deformation and have a high latency between motion and projection, causing noticeable misalignment between the target arm surface and projected images. These problems degrade the user experience and limit the development of more applications. We propose a system for high-speed dynamic projection mapping onto a rapidly moving human arm with realistic skin deformation. With the developed system, the user does not perceive any misalignment between the arm surface and projected images. First, we combine a state-of-the-art parametric deformable surface model with efficient regression-based accuracy compensation to represent skin deformation. Through compensation, we modify the texture coordinates to achieve fast and accurate image generation for projection mapping based on joint tracking. Second, we develop a high-speed system that provides a latency between motion and projection below 10 ms, which is generally imperceptible by human vision. Compared with conventional methods, the proposed system provides more realistic experiences and increases the applicability of dynamic projection mapping.

scholarly journals Cognitive Vocal Program applied to individuals with signals presbylarynx: preliminary results

CoDAS ◽  
2014 ◽  
Vol 26 (6) ◽  
pp. 503-508 ◽  
Author(s):  
Katia Nemr ◽  
Glaucia Verena Sampaio de Souza ◽  
Marcia Simões-Zenari ◽  
Domingos Hiroshi Tsuji ◽  
Adriana Hachiya ◽  
...  
Keyword(s):  
High Speed ◽  
Vocal Production ◽  
Maximum Phonation Time ◽  
Preliminary Results ◽  
Perceptual Evaluation ◽  
Articulatory Movements ◽  
Before And After ◽  
Screening Protocol ◽  
Program Intervention ◽  
Vocal Quality

PURPOSE: To propose and verify the feasibility of a vocal program intervention in patients with presbylarynx signs with or without vocal complaints. METHOD: Among 20 elder participants of the current research, 3 female patients with median age of 67 years were chosen for the pilot study. Laryngological examination, vocal recording with CAPE-V (Consensus Auditory-Perceptual Evaluation of Voice) protocol, and Screening Protocol of Risk of Dysphonia (SPRD) were conducted before and after the program intervention. They joined the Cognitive Vocal Program for presbyphonia based on the genetic epistemology by Jean Piaget associated with vocal techniques based on scientific literature. This program is structured with six sessions and each one of them is focused in different aspects of vocal production. RESULTS: After the program intervention, some aspects such as loudness, coordination between breathing and speaking, accuracy in articulatory movements, jitter, and harmonics-to-noise ratio improved with parameters within the expected range for the age group. Three female participants were observed for better vocal quality, higher fundamental frequency, and better maximum phonation time. In two cases, tension related to loudness elevation and better scores on SPRD was observed. Using by high-speed laryngeal image, we also observed reduction of presbylarynx signs, and remarkable improvement in glottis closure competence and mucosal wave movement of the patients with and without vocal complaints. CONCLUSION: The preliminary results suggest encouraging prospects for the proposal with improvement in the aspects analyzed. This program was well designed and did not require any further adjustments.

scholarly journals Impact of cleaning regimes on dental water unit contamination

2011 ◽  
Vol 9 (4) ◽  
pp. 647-652 ◽  
Author(s):  
Soad A. Abdallah ◽  
Ahmed I. Khalil
Keyword(s):  
High Speed ◽  
Tap Water ◽  
Daily Basis ◽  
Dental Chair ◽  
Dental Clinics ◽  
Significant Difference ◽  
Before And After ◽  
Hand Piece ◽  
Viable Bacteria ◽  
Dental Unit Waterlines

Microorganisms that have been identified in dental unit waterlines (DUWLs) are of concern because they can cause infections, especially in immunocompromised patients. This study aimed to assess the incidence of microbial contamination in DUWLs before and after intervention to reduce contamination, and to investigate the presence of coliforms, Escherichia coli and Pseudomonas aeruginosa. Water samples were collected aseptically from the waterlines. The high-speed hand-piece and dental chair units were served by one distillation apparatus, which was fed by the potable tap water of four dental clinics. Different interventions were used: chlorination, flushing before clinics and between patients, draining at the end of the day, and freshly distilled water on a daily basis. There was a significant difference between the level of contamination in the high-speed hand-piece (1.5–2.7 log CFU/ml) and dental chair unit water (2.0–3.5 log CFU/ml). Coliforms (0.9%) E. coli (0.9%) and Pseudomonas (1.8%) were detected during 2008. This study indicates the need to monitor water quality regularly and prevent stagnation in DUWLs to reduce the number of viable bacteria to <100 CFU/ml. We recommend flushing the DUWL for 2 min before the first patient and for 10–20 s between patients, flushing the dental unit at the end of the day and draining it overnight to reduce the development of biofilms, and chlorination of the DUWLs.

scholarly journals Musculoskeletal Outcomes from Chronic High-Speed, High-Impulse Resistance Exercise

2018 ◽  
Vol 39 (10) ◽  
pp. 791-801 ◽  
Author(s):  
John Caruso ◽  
Michael Voor ◽  
Jason Jaggers ◽  
T. Symons ◽  
Jeremy Stith ◽  
...  
Keyword(s):  
Mechanical Loading ◽  
High Speed ◽  
Type I Collagen ◽  
Training Session ◽  
Knee Extension ◽  
Type I ◽  
Before And After ◽  
Force Peak ◽  
Blood Marker ◽  
Hip Extension

AbstractWhile bones and muscles adapt to mechanical loading, it appears that very specific types of stimuli must be applied to achieve osteogenesis. Our study assessed musculoskeletal outcomes to 30 training sessions on an Inertial Exercise Trainer (Newnan, GA). Subjects (n=13) performed workouts with their left leg, while their right served as an untreated control. Workouts entailed three 60-s sets each of knee extension, hip extension and calf press exercises, separated by 90-s rests. Before and after the 30 training sessions, subjects underwent strength tests (knee and ankle extensors of both legs), DEXA scans (hip, knee and ankles of both legs), and blood draws. After 30 training sessions 2×2 ANOVAs showed left leg peak torques rose significantly. 2×2 ANCOVAs, with bone scan area as a covariate, showed significant left leg calcaneal bone mineral content (+29%) and density (+33%) increases after 30 training sessions. A significant decline in C-terminal telopeptides of type I collagen, a blood marker of bone resorption, also occurred after 30 training sessions. The Inertial Exercise Trainer’s large volume of training session repetitions elicited high peak force, peak acceleration and impulses that likely provided a mechanical loading stimulus that evoked calcaneal accretion.

Research on the Characteristic of Diesel Elastic-Plate Impingement Spray

2012 ◽  
Vol 433-440 ◽  
pp. 116-122
Author(s):  
Chang Yuan Wang ◽  
Fu Shui Liu ◽  
Xiang Rong Li
Keyword(s):  
Experimental Research ◽  
Elastic Plate ◽  
High Speed ◽  
Incident Angle ◽  
Injection Pressure ◽  
High Speed Photography ◽  
Research Results ◽  
Free Jet ◽  
Constant Volume Chamber ◽  
Spray Droplets

A series of experimental research results on the characteristic of diesel elastic-plate impingement spray using High Speed Photography camera are presented in this paper. The experiments were carried out in a constant volume chamber specially designed, which can hold a high ambiance pressure. The special fixed device was designed so that the elastic-plate can be fixed on the spray path, meanwhile the spray incident angle and height can be changed. The free jet spray and elastic-plate impingement spray was compared under the same experimental condition including different injection pressure and different background pressure. Experimental research showed that impingement spray droplets diffuse more quickly than free jet spray.

Granulation of Extruded Plastic Wires: Influence of Tool Coating Properties and Tool Geometry on Cutting Forces and Tool Wear

2016 ◽  
Vol 1140 ◽  
pp. 181-188
Author(s):  
Macario Cardone ◽  
Matthias Putz ◽  
Gerhard Schmidt ◽  
Martin Dix ◽  
Jürgen Friedrich ◽  
...  
Keyword(s):  
High Speed ◽  
High Speed Steel ◽  
Polyamide 6 ◽  
Machining Process ◽  
Test Facility ◽  
Tool Geometry ◽  
Coated Tools ◽  
Tool Coating ◽  
Before And After ◽  
Wear Evaluation

Granulators are widely used to reduce reinforced and unreinforced plastic strands in small pieces. The tools implemented in this machining process are mainly made of high-speed steel. This work investigates diverse PVD hard thin coatings with the aim of improving tool life and efficiency in granulation technology. A test facility reproducing the main features of a real granulator has been designed and assembled. The machined strand materials are ABS plastic and fibreglass-reinforced polyamide 6, while the tested PVD films are CrN, TiCN, TiAlN and two different diamond-like carbon coatings. The wear evaluation of all coated tools has been done via structured light projection, together with a scanning electron microscopy-based analysis, before and after their implementation on the test facility. Furthermore, a suitable 2D finite element modelling of the machining process has been realized.

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