scholarly journals AUTOMATED DIMENSIONING OF ASSEMBLY STRUCTURES OF MACHINE TOOLS BY USING COMPENSATORS

2020 ◽  
Vol 1 ◽  
pp. 503
Author(s):  
Angel Lengerov ◽  
Silviya Salapateva
Keyword(s):  
Machine Tools ◽  
Initial Conditions ◽  
Cost Effective ◽  
Initial Link ◽  
Set Size ◽  
Nominal Size ◽  
Different Dimensions ◽  
Functional Purpose ◽  
Nominal Dimension

The article presents the results of the obtained dependencies for determination of the dimensions and the number of compensators in assembling units of machine tools. An algorithm for automated dimensioning with non-adjustable compensators has been developed.The non-adjustable compensators are parts that are pre-fabricated with different dimensions. In the assembly process, that one is used providing the set size of the initial link in the particular configuration of the constituent links. The initial conditions for dimensioning the compensator are the results of the constructive design of the assembly with CAD products. As a result of this design, the nominal dimensions of all the parts of structural consideration are determined and under the condition to achieve the nominal size of the initial link. The tolerances and limiting dimensions of the parts, excluding those of the compensator, are chosen by the designer-constructor according to the functional purpose of the parts and the technological capabilities of the methods for their manufacture. This does not require limitations of the dimensional analysis but functional and cost-effective accuracy of the parts is taken into account. Dimensioning is done by applying a series of procedures, which are discussed in detail in the paper and the number of compensators by groups is determined. Based on the applied procedures is proposed an algorithm for sizing the units of machine with non-adjustable compensators. The tolerance for manufacturing the compensators shall be symmetrical in relation to the nominal dimension. On the basis of the dependencies obtained for the dimensions and the distribution of the compensators in groups, an algorithm and software for automated dimensioning of the structures with non-adjustable compensators can be created.  

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 A thermo-mechanical machining method for improving the accuracy and stability of the geometric shape of long low-rigidity shafts

2021 ◽  
Author(s):  
Antoni Świć ◽  
Arkadiusz Gola ◽  
Łukasz Sobaszek ◽  
Natalia Šmidová
Keyword(s):  
Heat Treatment ◽  
Cross Section ◽  
Mechanical Treatment ◽  
Geometric Shape ◽  
Different Dimensions ◽  
Thermo Mechanical Treatment ◽  
Mechanical Machining ◽  
Simultaneous Heat ◽  
Accuracy And Stability

AbstractThe article presents a new thermo-mechanical machining method for the manufacture of long low-rigidity shafts which combines straightening and heat treatment operations. A fixture for thermo-mechanical treatment of long low-rigidity shafts was designed and used in tests which involved axial straightening of shafts combined with a quenching operation (performed to increase the corrosion resistance of the steel used as stock material). The study showed that an analysis of the initial deflections of semi-finished shafts of different dimensions and determination of the maximum corrective deflection in the device could be used as a basis for performing axial straightening of shaft workpieces with simultaneous heat treatment and correction of the initial deflection of the workpiece. The deflection is corrected by stretching the fibers of the stock material, at any cross-section of the shaft, up to the yield point and generating residual stresses symmetrical to the axis of the workpiece. These processes allow to increase the accuracy and stability of the geometric shape of the shaft.

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.

Finite element modeling of surge propagation and an application to the Hay River, N.W.T.

1992 ◽  
Vol 19 (3) ◽  
pp. 454-462 ◽  
Author(s):  
F. E. Hicks ◽  
P. M. Steffler ◽  
R. Gerard
Keyword(s):  
Finite Element ◽  
Channel Flow ◽  
Open Channel ◽  
Initial Conditions ◽  
Open Channel Flow ◽  
Kinematic Wave ◽  
Finite Element Scheme ◽  
Flow Problems ◽  
Ice Jam

This paper describes the application of the characteristic-dissipative-Galerkin method to steady and unsteady open channel flow problems. The robust performance of this new finite element scheme is demonstrated in modeling the propagation of ice jam release surges over a 500 km reach of the Hay River in Alberta and Northwest Territories. This demonstration includes the automatic determination of steady flow profiles through supercritical–subcritical transitions, establishing the initial conditions for the unsteady flow analyses. The ice jam releases create a dambreak type of problem which begins as a very dynamic situation then develops into an essentially kinematic wave problem as the disturbance propagated downstream. The characteristic-dissipative-Galerkin scheme provided stable solutions not only for the extremes of dynamic and kinematic wave conditions, but also through the transition between the two. Key words: open channel flow, finite element method, dam break, surge propagation.

Quantum Dots as Components of Electrochemical Sensing Platforms for the Detection of Environmental and Food Pollutants: a Review

2017 ◽  
Vol 100 (4) ◽  
pp. 950-961 ◽  
Author(s):  
María Pedrero ◽  
Susana Campuzano ◽  
José M Pingarrón
Keyword(s):  
Quantum Dots ◽  
Signal Amplification ◽  
Cost Effective ◽  
Ease Of Use ◽  
Electrochemical Sensing ◽  
Multiplexed Detection ◽  
Sensing Platforms ◽  
Target Analytes

Abstract The determination of organic and inorganic environmental and food pollutants is a key matter of concern in analytical chemistry due to their effects as a serious threat to human health. Focusing on this issue, several methodologies involving the use of nanostructured electrochemical platforms have been recently reported in the literature. Among these methods, those employing the use of quantum dots (QDs) stand out because of features such as signal amplification, good reproducibility and selectivity, and the possibility for multiplexed detection, and because they preserve the outstanding characteristics of electrochemical methodologies with respect to simplicity, ease-of-use, and cost-effective instrumentation. This review describes recent electrochemical strategies, in which design QDs play a key role, for the determination of pollutants in food and environmental samples. The particular role of QDs in the reported methodologies, their preparation, and the electrochemical platform design, as well as the advantages that QDs provide in the analysis of target analytes, are critically discussed.

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