scholarly journals Robust Tracking of a Cost-Effective Micro-Stereolithography System Based on a Compliant Nanomanipulator

Micromachines ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 785 ◽  
Author(s):  
Yue Cao ◽  
Zhen Zhang
Keyword(s):  
Control Strategy ◽  
Light Emitting Diode ◽  
Tracking Error ◽  
Cost Effective ◽  
Laser Source ◽  
Feature Size ◽  
Single Digit ◽  
Motion System ◽  
Closed Pattern ◽  
The Right

Micro-stereolithography (MSL) has emerged as a promising and challenging technique in micro-/nano-scale additive manufacturing. Besides the requirement of the light source, the motion system requires ultra-high-precision tracking capability to reach the right location for every solidification event. To achieve single-digit micron feature size of the fabrication, we propose a robust control strategy to support a self-developed cost-effective MSL prototype based on a compliant nanomanipulator and a blue light-emitting diode (LED) module. In particular, the nonlinearity and parameter-variation of the compliant manipulator are dealt with by a robust radial basis function (RBF)-based neural network, and the repetitive control (RC) is innovatively integrated with RBF to improve the tracking performance of a closed pattern. Various simulations and real-time experiments are conducted to validate the proposed control strategy. The fabrication of a closed pattern will not begin by turning on the laser source until the tracking error reaches submicrons, and the fabrication results demonstrate that the cost-effective MSL system is capable of fabricating 2.5 µm feature size in a 0.5 mm working range.

scholarly journals A Supervisory Control Strategy for Improving Energy Efficiency of Artificial Lighting Systems in Greenhouses

Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 202
Author(s):  
Gianluca Serale ◽  
Luca Gnoli ◽  
Emanuele Giraudo ◽  
Enrico Fabrizio
Keyword(s):  
Control Strategy ◽  
Light Emitting Diode ◽  
Cost Savings ◽  
Energy Performance ◽  
Lighting System ◽  
Light Emitting ◽  
Artificial Lighting ◽  
Lighting Control ◽  
Lighting Systems ◽  
Power Densities

Artificial lighting systems are used in commercial greenhouses to ensure year-round yields. Current Light Emitting Diode (LED) technologies improved the system efficiency. Nevertheless, having artificial lighting systems extended for hectares with power densities over 50W/m2 causes energy and power demand of greenhouses to be really significant. The present paper introduces an innovative supervisory and predictive control strategy to optimize the energy performance of the artificial lights of greenhouses. The controller has been implemented in a multi-span plastic greenhouse located in North Italy. The proposed control strategy has been tested on a greenhouse of 1 hectare with a lighting system with a nominal power density of 50 Wm−2 requiring an overall power supply of 1 MW for a period of 80 days. The results have been compared with the data coming from another greenhouse of 1 hectare in the same conditions implementing a state-of-the-art strategy for artificial lighting control. Results outlines that potential 19.4% cost savings are achievable. Moreover, the algorithm can be used to transform the greenhouse in a viable source of energy flexibility for grid reliability.

scholarly journals Clinical Evaluation of Bracket Bonding Using Two Different Polymerization Sources

2008 ◽  
Vol 78 (5) ◽  
pp. 922-925 ◽  
Author(s):  
Nikolaos S. Koupis ◽  
Theodore Eliades ◽  
Athanasios E. Athanasiou
Keyword(s):  
Failure Rate ◽  
Orthodontic Treatment ◽  
Light Emitting Diode ◽  
Rank Test ◽  
Dental Arch ◽  
Halogen Lamp ◽  
Failure Rates ◽  
Bond Failure ◽  
Significant Difference ◽  
The Right

Abstract Objective: To comparatively assess clinical failure rate of brackets cured with two different photopolymerization sources after nine months of orthodontic treatment. Materials and Methods: The sample of this study comprised 30 patients who received comprehensive orthodontic treatment by means of fixed appliances. Using the same adhesive, 600 stainless steel brackets were directly bonded and light cured for 10 seconds with the light-emitting diode (LED) lamp or for 20 seconds with the conventional halogen lamp. A split-mouth design randomly alternated from patient to patient was applied. Failure rates were recorded for nine months and analyzed with Pearson χ2 test, and log-rank test at α = .05 level of significance. Results: The overall failure rate recorded with the halogen unit (3.33%) was not significantly different from the failure rate for the LED lamp (5.00%). Significantly more failures were found in boys compared with girls, in the mandibular dental arch compared with the maxillary arch, and in posterior segments compared with anterior segments. However, no significant difference was found between the right and left segments. Conclusion: Both light-curing units showed sufficiently low bond failure rates. LED curing units are an advantageous alternative to conventional halogen sources in orthodontics because they enable a reduced chair-time bonding procedure without significantly affecting bond failure rate.

scholarly journals ERP benefits capability framework: orchestration theory perspective

2018 ◽  
Vol 24 (1) ◽  
pp. 266-294 ◽  
Author(s):  
Amgad Badewi ◽  
Essam Shehab ◽  
Jing Zeng ◽  
Mostafa Mohamad
Keyword(s):  
Cost Effective ◽  
Organizational Capabilities ◽  
Erp Implementation ◽  
Content Type ◽  
Quantitative Studies ◽  
Financial Perspective ◽  
Complementary Resources ◽  
Benefits Realization ◽  
Research Questions ◽  
The Right

Purpose The purpose of this paper is to answer two research questions: what are the ERP resources and organizational complementary resources (OCRs) required to achieve each group of benefits? And on the basis of its resources, when should an organization invest more in ERP resources and/or OCRs so that the potential value of its ERP is realised? Design/methodology/approach Studying 12 organizations in different countries and validating the results with 8 consultants. Findings ERP benefits realization capability framework is developed; it shows that each group of benefits requires ERP resources (classified into features, attached technologies and information technology department competences) and OCRs (classified into practices, attitudes, culture, skills and organizational characteristics) and that leaping ahead to gain innovation benefits before being mature enough in realising a firm’s planning and automation capabilities could be a waste of time and effort. Research limitations/implications It is qualitative study. It needs to be backed by quantitative studies to test the results. Practical implications Although the “P” in ERP stands for planning, many academics and practitioners still believe that ERP applies to automation only. This research spotlights that the ability to invest in ERP can increase the innovation and planning capabilities of the organization only if it is extended and grown at the right time and if it is supported by OCRs. It is not cost effective to push an organization to achieve all the benefits at the same time; rather, it is clear that an organization would not be able to enjoy a higher level of benefits until it achieves a significant number of lower-level benefits. Thus, investing in higher-level benefit assets directly after an ERP implementation, when there are no organizational capabilities available to use these assets, could be inefficient. Moreover, it could be stressful to users when they see plenty of new ERP resources without the ability to use them. Although it could be of slight benefit to introduce, for example, business intelligence to employees in the “stabilizing period” (Badewi et al., 2013), from the financial perspective, it is a waste of money since the benefits would not be realised as expected. Therefore, orchestrating ERP assets with the development of organizational capabilities is important for achieving the greatest effectiveness and efficiency of the resources available to the organization. This research can be used as a benchmark for designing the various blueprints required to achieve different groups of benefits from ERP investments. Originality/value This research addresses two novel questions: RQ1: what are the ERP resources and OCRs required to achieve the different kinds of ERP benefits? RQ2: when, and on what basis, should an organization deploy more resources to leverage the ERP business value?

CRITICAL REVIEW OF EMULSION STABILITY AND CHARACTERIZATION TECHNIQUES IN OIL PROCESSING

2021 ◽  
pp. 1-36
Author(s):  
Vahideh Angardi ◽  
Ali Ettehadi ◽  
Özgün Yücel
Keyword(s):  
Separation Efficiency ◽  
Petroleum Industry ◽  
Cost Effective ◽  
Downstream Processing ◽  
Physical Factors ◽  
Comprehensive Review ◽  
Factors Affecting ◽  
Mathematical Explanations ◽  
The Stability ◽  
The Right

Abstract Effective separation of water and oil dispersions is considered a critical step in the determination of technical and economic success in the petroleum industry over the years. Moreover, a deeper understanding of the emulsification process and different affected parameters is essential for cost-effective oil production, transportation, and downstream processing. Numerous studies conducted on the concept of dispersion characterization indicate the importance of this concept, which deserves attention by the scientific community. Therefore, a comprehensive review study with critical analysis on significant concepts will help readers follow them easily. This study is a comprehensive review of the concept of dispersion characterization and conducted studies recently published. The main purposes of this review are to 1) Highlight flaws, 2) Outline gaps and weaknesses, 3) Address conflicts, 4) Prevent duplication of effort, 5) List factors affecting dispersion. It was found that the separation efficiency and stability of dispersions are affected by different chemical and physical factors. Factors affecting the stability of the emulsions have been studied in detail and will help to look for the right action to ensure stable emulsions. In addition, methods of ensuring stability, especially coalescence are highlighted, and coalescence mathematical explanations of phenomena are presented.

Effect of Double Hole-Transporting Structure on Color Purity of Blue Organic Light-Emitting Diodes (BOLED)

2013 ◽  
Vol 311 ◽  
pp. 424-429
Author(s):  
Kan Lin Chen ◽  
Chien Jung Huang ◽  
Zong Jin Wu ◽  
Chih Chieh Kang ◽  
Wen Ray Chen ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Organic Light Emitting Diodes ◽  
Blue Color ◽  
Color Purity ◽  
Television System ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
Hole Transporting ◽  
The Right

A blue organic light-emitting diode (OLED) with a double hole-transporting (DHT) structure has been developed. The blue color purity was improved by modulation the thickness of CBP layer. When the thicknesses of left CBP and right CBP are respectively 8 nm and 2 nm, the more pure blue coordinates are (0.155, 0.079), which are very close to the blue coordinates of the national television system committee (NTSC) standard (0.14, 0.08). Furthermore the current density, brightness and the luminous efficiency of device with the left CBP of 8 nm and the right CBP of 2 nm are respectively 144.7 mA/cm2, 1065 cd/m2 and 0.93 cd/A.

scholarly journals Improvement of the Impact Properties of Composite Laminates by Means of Nano-Modification of the Matrix—A Review

2018 ◽  
Vol 8 (12) ◽  
pp. 2406 ◽  
Author(s):  
Hamed Saghafi ◽  
Mohamad Fotouhi ◽  
Giangiacomo Minak
Keyword(s):  
Composite Laminates ◽  
Cost Effective ◽  
Careful Consideration ◽  
Impact Performance ◽  
Compression After Impact ◽  
The Matrix ◽  
The Right ◽  
2D And 3D ◽  
The Impact ◽  
Selection Of

This paper reviews recent works on the application of nanofibers and nanoparticle reinforcements to enhance the interlaminar fracture toughness, to reduce the impact induced damage and to improve the compression after impact performance of fiber reinforced composites with brittle thermosetting resins. The nanofibers have been mainly used as mats embedded between plies of laminated composites, whereas the nanoparticles have been used in 0D, 1D, 2D, and 3D dimensional patterns to reinforce the matrix and consequently the composite. The reinforcement mechanisms are presented, and a comparison is done between the different papers in the literature. This review shows that in order to have an efficient reinforcement effect, careful consideration is required in the manufacturing, materials selection and reinforcement content and percentage. The selection of the right parameters can provide a tough and impact resistant composite with cost effective reinforcements.

Position Domain PD Control for Contour Tracking

2010 ◽  
Author(s):  
P. R. Ouyang ◽  
Truong Dam
Keyword(s):  
Motion Tracking ◽  
Control Method ◽  
Tracking Error ◽  
Original System ◽  
Contour Tracking ◽  
Pd Control ◽  
Tracking Errors ◽  
Motion System ◽  
Common Control ◽  
The Time Domain

For multi-axis motion control applications, contour tracking is one of the most common control problems encountered by industrial manipulators and robots. In this paper, a position domain PD control method is proposed for the purpose of improving the contour tracking performance. To develop the new control method, the multi-axis motion system is viewed as a master-slave motion system where the master motion is sampled equidistantly and used as an independent variable, while the slave motions are described as functions of the master motion according to the contour tracking requirements. The dynamic model of the multi-axis motion system is developed in the position domain based on the master motion by transforming the original system dynamic equations from the time domain to the position domain. In this control methodology, the master motion will yield zero tracking error for the position as it is used as reference, and only the slave motion tracking errors will affect the final contour tracking errors. The proposed position domain PD controller is successfully examined in a Cartesian robotic system for linear motion tracking and circular contour tracking.

Cable Thru Downhole Insert Safety Valve: A New Paradigm

2021 ◽  
Author(s):  
Kuswanto Kuswanto ◽  
Oka Fabian ◽  
Orient B Samuel ◽  
Mohd Yuzmanizeil B Yaakub ◽  
Chua Hing Leong ◽  
...  
Keyword(s):  
Safety Valve ◽  
Cost Effective ◽  
Submersible Pump ◽  
New Paradigm ◽  
Reservoir Properties ◽  
Technology Application ◽  
Artificial Lift ◽  
Water Cut ◽  
The Right ◽  
Gas Lift

Abstract The B Field is located in the South China Sea, about 45 KM offshore Sarawak, Malaysia, in a water depth approximately 230 ft. Its structure is generally regarded as a gentle rollover anticline with collapsed crest resulting from growth faulting. The reservoirs were deposited in a coastal to shallow marine with some channels observed. Multiple stacked reservoirs consist of a series of very thick stacked alternating sandstone and minor shale layers with differing reservoir properties. The shallow zones are unconsolidated, and the wells were completed with internal gravel packs. Wells in B Field mostly were completed in multi-layered reservoirs as dual strings with SSDs and meant to produce as a commingled production. The well BX is located within B Field and designed as oil producer well with a conventional tubing jointedElectrical Submersible Pump (ESP) system which was installed back in 2008. Refer to figure 1, the initial completion schematic is 3-1/2″ single string that consist of the single production packer, gas lift mandrel, tubing retrievable Surface Controlled Subsurface Safety Valve (SCSSV) and ESP. The production packers equipped with the feed thru design to accommodate the ESP cable and the gas vent valve as part of the ESP completion design. The gas lift mandrel was installed in the completion string as a backup artificial lift method to receive the gas lift and orifice valve in the event of the conventional ESP failed. Hence the well still able to produce by introducing the gas thru the annulus to activate the gas lift valve. Eventually throughout the end of the the field life, the well would depend on the ESP system for the primary lifting method due to gas lift depth limitation and the gas supply. The conventional ESP failed after seven years of operation which is above the average ESP lifetime. The well last produced at a flow rate with 28 % water cut, however the well is not at the end of the field life. Based on the economical study with the right technology and cost efficient approach, the well still economicaly profitable. The Thru Tubing (TT) ESP technology is approached as cost effective solution compare to fully well workover. Despite a couple of operational challenges, for example, setting the cable hanger, maintaining downhole barrier requirement, the Thru Tubing Electrical Submersible Pump Cable Deployed (TTESP CD) and Cable Thru Insert Safety Valve (CT-ISV) was successfully installed. Several post-installation findings have uncovered some problems which are requiring some additional technical and operation improvement for future similar applications. This paper will highlight the deployment of the Cable Thru Insert Safety Valve (CT-ISV) that was successfully installed as pilot, which is the first application in the world, and also highlights the success, lesson learnt and improvement for future requirement for the CT-ISV application as one of the solution for retrofitting completion application without jeopardizing the well integrity. This achievement is collaboration between Company and service partner as the technology and deployment under the proprietary scope. Further technology application, the replication of this insert safety valve was conducted and successfully deployed on other three wells.

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