A simple, low cost and robust method for measurement of the zero-crossing temperature of an ultralow expansion cavity

2019 ◽  
Vol 52 (45) ◽  
pp. 455104
Author(s):  
Chenhao Wang ◽  
Zhonghua Ji ◽  
Ting Gong ◽  
Dianqiang Su ◽  
Yanting Zhao ◽  
...  
Keyword(s):  
Low Cost ◽  
2018 ◽  
Vol 5 (10) ◽  
pp. 181359 ◽  
Author(s):  
Samah Abo El Abass ◽  
Heba Elmansi

A green, sensitive and cost-effective method is introduced in this research for the determination of bambuterol and its main degradation product, terbutaline, simultaneously, relying on the synchronous spectrofluorimetric technique. First derivative synchronous spectrofluorimetric amplitude is measured at Δ λ = 20 nm, so bambuterol can be quantitated at 260 nm, and terbutaline can be measured at 290 nm, each at the zero crossing point of the other. The amplitude–concentration plots were linear over the concentration ranges of 0.2–6.0 µg ml −1 and 0.2–4.0 µg ml −1 for both bambuterol and terbutaline, respectively. Official guidelines were followed to calculate the validation parameters of the proposed method. The low values of limits of detection of 0.023, 0.056 µg ml −1 and limits of quantitation of 0.071, 0.169 µg ml −1 for bambuterol and terbutaline, respectively, point to the sensitivity of the method. Bambuterol is a prodrug for terbutaline, and the latter is considered its degradation product so the established method could be regarded as a stability-indicating one. Moreover, the proposed method was used for the analysis of bambuterol and terbutaline in their single ingredient preparations and the results revealed statistical agreement with the reference method. The suggested method, being a simple and low-cost procedure, is superior to the previously published methods which need more sophisticated techniques, longer analysis time and highly toxic solvents and reagents. It could be considered as an eco-friendly analytical procedure.


2021 ◽  
Vol 41 ◽  
pp. 102935
Author(s):  
John Severino ◽  
Rhys Jacob ◽  
Martin Belusko ◽  
Ming Liu ◽  
Frank Bruno

Author(s):  
N. Dehaese ◽  
S. Bourdel ◽  
H. Barthelemy ◽  
Y. Bachelet ◽  
G. Bas
Keyword(s):  
Low Cost ◽  

2020 ◽  
Vol 4 (2) ◽  
pp. 12-18
Author(s):  
Millena Almeida Monsores ◽  
Mikaelly Pereira Caet ◽  
Anna Karolina Mouzer Machado ◽  
Marina Cardoso Nemitz ◽  
Vítor Todeschini ◽  
...  

The present work describes a first-order derivative spectrophotometric (1D-UV) method for determination of dropropizine in commercial oral solutions. The method was developed using ecologically correct solvents and validated according to International Conference on Harmonization (ICH) recommendations. The response was linear in the concentration range of 6–24 μg/mL (r = 0.9997, n = 7) at wavelength 249 nm, which was the zero crossing point of excipient solutions. The detection and quantitation limits were 0.36 and 1.18 μg/mL, respectively. The method showed adequate precision, with a relative standard deviation values lower than 1.41%. Excellent values of accuracy were obtained, with a mean value of 99.44%. The method proved to be robust by a full factorial design evaluation. It is simple, it has low cost, and it has low use of polluting reagents. Minimum environmental hazards observed and the results obtained attest to the reliability of the proposed green method, showing to be specific, linear, precise, accurate and robust. Thus, the validated 1D-UV spectrophotometric method was successfully applied to the quantitative analysis of dropropizine in oral solutions dosage forms, helping to improve quality control and to assure therapeutic efficacy.


2019 ◽  
Author(s):  
Ramon Pires ◽  
Anderson Rocha ◽  
Jacques Wainer

Diabetic Retinopathy is the leading cause of blindness in working- age adults. This work aims at enhancing lesion detection, reinforcing referral decisions, and integrating our solutions with low-cost retinal imaging devices. For lesion detection, we proposed a novel coding technique robust to any kind oflesion. For referral decisions, we designed a robust method that does not rely upon lesion detection, proposed an effective data-driven model that significantly improves the performance, designed an accountable model that produces a re- liable response and enables pixel-based importance comprehension, and create local descriptors that are encoded into a rich mid-level representation. Our work has invaluable impacts both in biomedical and technical contexts.


Electronics ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 1456
Author(s):  
Yannis L. Karnavas ◽  
Anestis S. Topalidis ◽  
Maria Drakaki

The ongoing technological advancements of brushless DC motors (BLDCMs) have found a wide range of applications. For instance, ground-based electric vehicles, aerial drones and underwater scooters have already adopted high-performance BLDCMs. Nevertheless their adoption demands control systems to monitor torque, speed and other performance characteristics. Precise design structure and the particular motor functional characteristics are essential for the suitable configuration and implementation of an appropriate controller to suit a wide range of applications. Techniques which do not use Hall sensors should be used then. This paper deals with the analysis of hardware and software aspects during the development of such a microcontroller based and low cost speed controller for motors up to 500 W, along with its practical implementation. The sensorless method employed is based on the zero crossing point (ZCP) detection of the back-electromotive forces’ (back-EMF) differences, as the ZCPs of these quantities match to the time points at which the commutation sequence changes. Additionally, the study presents hardware and software details through calculations, figures, flowcharts and code, providing an insight of the practical issues that may arise in such a low cost prototype. Finally, results obtained by experiments validate the presented hardware/software architecture of the controller.


2010 ◽  
Vol 19 (4) ◽  
pp. 045017 ◽  
Author(s):  
Daniel Guyomar ◽  
Mickaël Lallart ◽  
Kaixiang Li ◽  
Jean-Yves Gauthier ◽  
Thomas Monnier

Author(s):  
Jing Yu ◽  
Xiongzhu Bu ◽  
Chao Xiang ◽  
Bo Yang

Concerning on the problem of low measuring precision of the current micro-inertial sensors, a novel attitude measurement method is proposed to dismiss the drift for remarkable attitude error. According to the output of the onboard three-axis magnetic sensor in the process of projectile flight, a low-cost attitude detection system is designed by using the intersection ratio of the sensor. First, the output model of the onboard three-axis magnetic sensor is established. The mathematical relationship between the characteristic ratio of magnetic sensor output and the pitch angle is then derived. Then, the solution and correction algorithm of the attitude angles are studied. Finally, the effectiveness of the attitude measurement method has been validated by carrying out the semi-physical experiments. The experimental results indicate that the error of attitude angles is within ±1° and the attitude angle error of the combined magnetic sensors is not cumulative. Meanwhile, the geomagnetic field strength is dispensable during the whole calculation process. Compared with the “Zero Crossing Method”, the proposed method has shown a nearly two-times higher accuracy and has no limitation of “MAGSONDE window”. What is more, this method proves to be more simple and has a doubled update rate in attitude angle calculation.


2020 ◽  
Vol 10 (6) ◽  
pp. 6515-6520
Author(s):  
B. M. Rija ◽  
M. K. Hussain ◽  
A. M. Vural

Power Factor (PF) correction is a major power quality function in electrical distribution systems. This paper proposes a low-cost Automatic Power Factor Correction (APFC) system to increase the PF of both lagging and leading single-phase loads. The Arduino Mega 2560 microcontroller was used to calculate the PF and activate the relays that connect the capacitor/inductor banks to the load in parallel. Thus, the required capacitive or inductive reactive power was produced by the APFC system by automatically connecting the capacitor/inductor banks to the load in parallel. The APFC system can also measure and display many electrical parameters of the load such as the rms voltage, the rms current, PF, and the real, reactive, and apparent power on an LCD display. Two zero-crossing detector circuits are used to find the phase angle difference between voltage and current waveforms of the load. The measurement ability of the APFC system was tested for resistive, inductive, and capacitive loads with two different sizes. The measurement results were compared with the measurements of a commercial digital power meter and a measurement error of less than 8.0% was observed. The PF correction ability of the APFC system was verified for inductive and capacitive loads with two different sizes. The experiments show that the PF increased to close to unity for both lagging and leading loads.


2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Ali A. Abdulla ◽  
Hui Liu ◽  
Norbert Stoll ◽  
Kerstin Thurow

A new robust method is proposed for multifloor navigation in distributed Life Science Laboratories. This method proposes a solution for many technical issues including (a) mapping and localization with ceiling landmarks and a StarGazer module for achieving an accurate and low cost multifloor navigation system, (b) a new method for path planning to navigate across multiple floor environments called backbone method and embedded transportation management system, (c) elevator environment handler with the necessary procedures to interact with the elevator presenting a new approach for elevator entry button and internal buttons detection, and (d) communication system to get an expandable network; this method utilizes a TCP/IP network for the communication. Many experiments in real Life Science Laboratories proved the efficient performance of the developed multifloor navigation system in life science environment.


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