Determination of cost-effective preventive maintenance schedule for a telecommunication software system

2003 ◽  
Vol 86 (7) ◽  
pp. 41-50
Author(s):  
Tadashi Dohi ◽  
Naoto Kaio ◽  
Shunji Osaki
Keyword(s):  
Preventive Maintenance ◽  
Cost Effective ◽  
Software System ◽  
Maintenance Schedule

scholarly journals Linear Sliding Stem Control Valve Hunting Analysis and Extrapolation of Valve Monitoring Features

2020 ◽  
Vol 9 (4) ◽  
pp. 1385-1389
Keyword(s):  
Preventive Maintenance ◽  
Control Valve ◽  
Cost Effective ◽  
Vital Role ◽  
Control Valves ◽  
Maintenance Schedule ◽  
Manual Intervention ◽  
Course Of Action ◽  
Plant Optimization ◽  
Maintenance Process

Control Valve is one of the major final control elements used in industries and plays a vital role in enhancing the productivity of a plant. Optimization of control valve depends on the effective preventive maintenance schedule. Control valves may be overhauled from the pipeline when there is a suspicion of fault. Almost 80% of the control valve maintenance relates to the diagnosis of valve in service to detect any abnormality. When a fault is identified the preventive maintenance process shifts to the breakdown maintenance process. During this process the control valve components are tested to determine the cause of the problem and to establish a corrective course of action. With the developments in microprocessor based control valve instruments along with their diagnostics capabilities has allowed engineers to simplify the maintenance activities. These digital devices can identify problems related with instrument air quality, leakage, supply pressure restriction, excessive friction, dead band, and calibration shift. Troubleshooting control valves after installing in the field is a tedious process as it is difficult to discriminate whether the problem is in the control valve or in the controller tuning. This article presents a novel method using sensors to identify the problems related with the control valve hunting, to pinpoint the source of error and present the performance results to end user. The objective of this research is to reduce manual intervention in troubleshooting of control valves and to enhance the predictive maintenance resulting in cost effective production.

Corncob Waste Based Adsorbent for Solid Phase Extraction of Tartrazine in Carbonated Drinks and Analytical Method using Ultra Performance Liquid Chromatography-Mass Spectrometry

2020 ◽  
Vol 16 (7) ◽  
pp. 924-932
Author(s):  
Yasmeen Mutlaq Ghazi Al Shamari ◽  
Saikh Mohammad Wabaidur ◽  
Abdulrahman Abdullah Alwarthan ◽  
Moonis Ali Khan ◽  
Masoom Raza Siddiqui
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Solid Phase Extraction ◽  
Solid Phase ◽  
Cost Effective ◽  
Ultra Performance Liquid Chromatography ◽  
Phase Extraction ◽  
Food Dye ◽  
Hyphenated Technique

Background : A new method has been developed for the determination of food dye tartrazine in soft drinks. Tartrazine is determined by hyphenated technique Ultra Performance Liquid Chromatography coupled with Mass spectrometry. The solid-phase extraction was used for the extraction of tartrazine. Methods: For the LC-MS analysis of tartrazine acetonitrile, water (80:20) was used as a mobile phase whereas, the C-18 column was selected as the stationary phase. The chromatographic run was allowed for 1 min. The adsorbent of the solid-phase extraction was synthesized from the waste corn cob. Results: Method found to be linear in the range of 0.1 mg L-1 - 10 mg L-1, limits of detection and quantitation were found to be 0.0165 mgL-1 and 0.055 mgL-1, respectively. Tartrazine, in the real sample, was found to be 20.39 mgL-1 and 83.26 mgL-1. Conclusion: The developed UPLC-MS method is rapid, simple, precise and can be used for the quantitative analysis of tartrazine. The solid-phase extraction also involves a cost-effective procedure for extraction as it does not involve the commercial cartridge.

scholarly journals Pitfalls in the Immunochemical Determination of β‑Lactam Antibiotics in Water

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 298
Author(s):  
Alexander Ecke ◽  
Rudolf J. Schneider
Keyword(s):  
Limit Of Detection ◽  
Cost Effective ◽  
Enzyme Linked Immunosorbent Assay ◽  
Degree Of Hydrolysis ◽  
Site Analysis ◽  
Antibody Recognition ◽  
Immunochemical Determination ◽  
Key Factor ◽  
Lactam Ring

Contamination of waters with pharmaceuticals is an alarming problem as it may support the evolution of antimicrobial resistance. Therefore, fast and cost-effective analytical methods for potential on-site analysis are desired in order to control the water quality and assure the safety of its use as a source of drinking water. Antibody-based methods, such as the enzyme-linked immunosorbent assay (ELISA), can be helpful in this regard but can also have certain pitfalls in store, depending on the analyte. As shown here for the class of β-lactam antibiotics, hydrolysis of the β‑lactam ring is a key factor in the immunochemical analysis as it influences antibody recognition. With the antibody used in this study, the limit of detection (LOD) in the immunoassay could be significantly reduced by hydrolysis for the five tested penicillins, with the lowest LOD for carbenicillin (0.2 nmol/L) and the greatest impact on penicillins G and V (reduction by 85%). In addition to enhanced quantification, our strategy also provides access to information about the degree of hydrolysis in water samples as shown for the most abundant penicillin amoxicillin.

scholarly journals Multivariate empirical mode decomposition–based structural damage localization using limited sensors

2021 ◽  
pp. 107754632110069
Author(s):  
Sandeep Sony ◽  
Ayan Sadhu
Keyword(s):  
Empirical Mode Decomposition ◽  
Structural Damage ◽  
Cost Effective ◽  
Threshold Value ◽  
Damage Localization ◽  
Time Frequency ◽  
Multivariate Empirical Mode Decomposition ◽  
Percentage Difference ◽  
Mode Decomposition

In this article, multivariate empirical mode decomposition is proposed for damage localization in structures using limited measurements. Multivariate empirical mode decomposition is first used to decompose the acceleration responses into their mono-component modal responses. The major contributing modal responses are then used to evaluate the modal energy for the respective modes. A damage localization feature is proposed by calculating the percentage difference in the modal energies of damaged and undamaged structures, followed by the determination of the threshold value of the feature. The feature of the specific sensor location exceeding the threshold value is finally used to identify the location of structural damage. The proposed method is validated using a suite of numerical and full-scale studies. The validation is further explored using various limited measurement cases for evaluating the feasibility of using a fewer number of sensors to enable cost-effective structural health monitoring. The results show the capability of the proposed method in identifying as minimal as 2% change in global modal parameters of structures, outperforming the existing time–frequency methods to delineate such minor global damage.

scholarly journals Immobilization-Free Electrochemical Sensor Coupled with a Graphene-Oxide-Based Aptasensor for Glycated Albumin Detection

Biosensors ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 85
Author(s):  
Wassa Waiwinya ◽  
Thitirat Putnin ◽  
Dechnarong Pimalai ◽  
Wireeya Chawjiraphan ◽  
Nuankanya Sathirapongsasuti ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Electrochemical Sensor ◽  
Detection Method ◽  
Limit Of Detection ◽  
Glycated Albumin ◽  
Cost Effective ◽  
Logarithmic Scale ◽  
Electrochemical Aptasensor ◽  
Alternative Approach

An immobilization-free electrochemical sensor coupled with a graphene oxide (GO)-based aptasensor was developed for glycated human serum albumin (GHSA) detection. The concentration of GHSA was monitored by measuring the electrochemical response of free GO and aptamer-bound GO in the presence of glycated albumin; their currents served as the analytical signals. The electrochemical aptasensor exhibited good performance with a base-10 logarithmic scale. The calibration curve was achieved in the range of 0.01–50 µg/mL. The limit of detection (LOD) was 8.70 ng/mL. The developed method was considered a one-drop measurement process because a fabrication step and the probe-immobilization process were not required. This simple sensor offers a cost-effective, rapid, and sensitive detection method, and could be an alternative approach for determination of GHSA levels.

scholarly journals Paper-based potentiometric sensing devices modified with chemically reduced graphene oxide (CRGO) for trace level determination of pholcodine (opiate derivative drug)

RSC Advances ◽  
2021 ◽  
Vol 11 (20) ◽  
pp. 12227-12234
Author(s):  
Hisham S. M. Abd-Rabboh ◽  
Abd El-Galil E. Amr ◽  
Elsayed A. Elsayed ◽  
Ahmed Y. A. Sayed ◽  
Ayman H. Kamel
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Cost Effective ◽  
Trace Level ◽  
Ion Sensing ◽  
Reduced Graphene ◽  
Chemically Reduced Graphene Oxide ◽  
Trace Level Determination ◽  
Analytical Device

Robust, reliable and cost-effective paper-based analytical device for potentiometric pholcodine (opiate derivative drug) ion sensing has been prepared and characterized.

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