scholarly journals Semi-Automatic Lab-on-PCB System for Agarose Gel Preparation and Electrophoresis for Biomedical Applications

Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1071
Author(s):  
Jesús David Urbano-Gámez ◽  
Francisco Perdigones ◽  
José Manuel Quero
Keyword(s):  
Biomedical Applications ◽  
Negative Temperature Coefficient ◽  
Mixing Time ◽  
Dna Amplification ◽  
Negative Temperature ◽  
Agarose Gel ◽  
Curing Time ◽  
Conductivity Sensor ◽  
Ntc Thermistor ◽  
Gel Preparation

In this paper, a prototype of a semi-automatic lab-on-PCB for agarose gel preparation and electrophoresis is developed. The dimensions of the device are 38 × 34 mm2 and it includes a conductivity sensor for detecting the TAE buffer (Tris-acetate-EDTA buffer), a microheater for increasing the solubility of the agarose, a negative temperature coefficient (NTC) thermistor for controlling the temperature, a light dependent resistor (LDR) sensor for measuring the transparency of the mixture, and two electrodes for performing the electrophoresis. The agarose preparation functions are governed by a microcontroller. The device requires a PMMA structure to define the wells of the agarose gel, and to release the electrodes from the agarose. The maximum voltage and current that the system requires are 40 V to perform the electrophoresis, and 1 A for activating the microheater. The chosen temperature for mixing is 80 ∘C, with a mixing time of 10 min. In addition, the curing time is about 30 min. This device is intended to be integrated as a part of a larger lab-on-PCB system for DNA amplification and detection. However, it can be used to migrate DNA amplified in conventional thermocyclers. Moreover, the device can be modified for preparing larger agarose gels and performing electrophoresis.

scholarly journals Automatic Lab on PCB System for Agarose Gel Preparation and Electrophoresis for Biomedical Applications

2021 ◽  
Author(s):  
Jesús David Urbano-Gámez ◽  
Francisco Perdigones ◽  
José Manuel Quero
Keyword(s):  
Biomedical Applications ◽  
Mixing Time ◽  
Dna Amplification ◽  
Agarose Gel ◽  
Curing Time ◽  
Agarose Gels ◽  
Conductivity Sensor ◽  
Ntc Thermistor ◽  
Gel Preparation ◽  
Maximum Voltage

In this paper, a prototype of an automatic lab on PCB for agarose preparation and electrophoresis is developed. The dimensions of the device are 38×34 mm2 and includes a conductivity sensor for detecting the TAE buffer (Tris-Acetate-EDTA buffer), a microheater for mixing, a NTC thermistor for controlling the temperature, a LDR sensor for measuring the transparency of the mixture, and two electrodes for performing the electrophoresis. The agarose preparation functions are governed by a microcontroller. The device requires a PMMA structure to define the wells of the agarose gel, and to release the electrodes from the agarose. The maximum voltage and current that the system requires are 40 V to perform the electrophoresis, and 1 A for activating the microheater. The chosen temperature for mixing is 80ºC, with a mixing time of 10 min. In addition, the curing time is about 30 min. This device is intended to be integrated as a part of a larger lab on PCB system for DNA amplification and detection. However, it can be used to migrate DNA amplified in conventional thermocyclers. Moreover, the device can be modified for preparing larger agarose gels and performing electrophoresis in an automatic manner.

scholarly journals Development of Auto Thermal Control Device For Space Air - Conditioning

2021 ◽  
pp. 193-204
Author(s):  
Akinde Olusola Kunle ◽  
Maduako Kingsley Obinna ◽  
Akande, Kunle Akinyinka ◽  
Adeaga Oyetunde Adeoye
Keyword(s):  
Temperature Coefficient ◽  
Room Temperature ◽  
Negative Temperature Coefficient ◽  
Negative Temperature ◽  
Thermal Control ◽  
Positive Temperature Coefficient ◽  
Control Device ◽  
Thermal Source ◽  
Positive Temperature ◽  
Ntc Thermistor

Auto Thermal Control device is an electronic based device which employs the application of temperature sensors to controlling household appliances without human interference directly. In this work, thermal source is used to regulate electrical fan and room heater depending on ambient temperature. The room heater, which is adjusted to a set temperature, switches ‘ON’ when the temperature of a room is low (cold). While the same is switches ‘OFF’ with increase in the room temperature. This triggers ‘ON’ an electric fan at different speeds, and thus cools the room. A temperature sensor, tthermistor, monitors change in room temperature. Two types of thermistor exists: Positive Temperature Coefficient, PTC. An increasee in the resistance of PTC results in increasee in temperature). In the Negative Temperature Coefficient, NTC; a decreasee in resistance yields to temperature increase. This article explored a NTC thermistor. The design could be a ready product in the market of the developing nation where environmental automation is yet fully deployed.

FABRICATION AND CHARACTERIZATION OF Ni–Mn–Si–Al–O NTC THERMISTOR AND ITS APPLICATION AS TEMPERATURE WIRE SENSOR

2013 ◽  
Vol 06 (04) ◽  
pp. 1350039 ◽  
Author(s):  
SEN LIANG ◽  
XIAO ZHANG ◽  
HAIBO LI ◽  
MIN LUO ◽  
JIN LI ◽  
...  
Keyword(s):  
Room Temperature ◽  
Negative Temperature Coefficient ◽  
Negative Temperature ◽  
Absolute Temperature ◽  
Oxide Ceramic ◽  
Reaction Route ◽  
Ntc Thermistor ◽  
Fabrication And Characterization ◽  
Ceramic Compounds

A series of Al 2 O 3 substituted manganese oxide ceramic compounds, Ni 0.6 Si 0.2 Mn 2.2-x Al x O 4(0 ≤ x ≤ 0.6), were prepared by solid-state reaction route. The phase composition, microstructure, and electrical properties of compounds were studied. The results revealed that all the compounds were composed of cubic spinel structure without any other oxides. Besides they exhibited a linear relationship between logarithm of electrical resistivity (ln ρ) and reciprocal of absolute temperature (1/T) over a temperature ranging from room temperature to 300°C, which indicated a negative temperature coefficient (NTC) characteristic. The B25/85 constant was found to increase with the increase of Al 2 O 3 content. The B25/85 values of the NTC Ni 0.6 Si 0.2 Mn 2.2-x Al x O 4 thermistors for x = 0,0.1,0.2,0.3,0.4, and 0.6 were 4581, 4612, 4680, 4875, and 5089 K, respectively. Finally, a new method to produce one meter long continuous fire wire sensors was also proposed.

scholarly journals Response characteristics of a negative temperature coefficient thermistor

2020 ◽  
Vol 1 ◽  
pp. 17-22
Author(s):  
Sunday F. Iyere ◽  
Bernard O. A. Ozigi ◽  
Joseph K. Yeboah
Keyword(s):  
Temperature Coefficient ◽  
Negative Temperature Coefficient ◽  
Negative Temperature ◽  
Control Device ◽  
Response Curves ◽  
Temperature Changes ◽  
Response Characteristics ◽  
Ntc Thermistor ◽  
And Control ◽  
Measurement And Control

This article focuses on the thermistor as a device that is widely used for temperature measurement and control in most electrical and electronic devices and appliances. The research is based on the type of thermistor used in photocopiers with particular reference to Minolta Bizhub (model-210) photocopier. The resistance and temperature were recorded by the application of conventional heat to deduce the response curves of resistance versus temperature and resistance/time. Results obtained from the characteristics show that the thermistor employed in the photocopier is a negative temperature coefficient (NTC) device. Also, there was a time variation in the response of the thermistor resistance to temperature changes, which indicates that the thermistor under test functions as a temperature control device. The shape of resistance versus temperature curve appeared to be similar to that of a typical NTC thermistor characteristics.

Material Design for High Strength NTC Thermistor Ceramics

2007 ◽  
Vol 350 ◽  
pp. 229-232 ◽  
Author(s):  
Tadamasa Miura ◽  
Akinori Nakayama ◽  
Hideaki Niimi ◽  
Hiroshi Tamura
Keyword(s):  
Compressive Stress ◽  
Negative Temperature Coefficient ◽  
Stress Measurement ◽  
Spinel Phase ◽  
High Strength ◽  
Material Design ◽  
Negative Temperature ◽  
Ntc Thermistor ◽  
Typical Composition ◽  
Salt Phase

Various factors were investigated to decide the mechanical properties of (Mn1–xNix)3O4 ceramics, that are typical composition systems of NTC (negative temperature coefficient) thermistors. The strength of NTC thermistor ceramics can be improved by designing the material so that the compressive stress may remain at the surface of the ceramics. At high temperature, the thermal expansion coefficient of a rock salt phase segregated internally ceramic increases over that of the spinel phase, further, on the surface of the ceramics, this compressive stress remains below room temperature. Moreover, it was confirmed that the stress analysis result by the FEM corresponded well with the stress measurement result on the surface of the ceramics measured by μ -XRD.

Structural, optical and electrical properties of thermal evaporated nano sized In2Te3 thin films

2018 ◽  
Vol 1 (1) ◽  
pp. 21-25
Author(s):  
R Revathi ◽  
R Karunathan
Keyword(s):  
Thin Films ◽  
Negative Temperature Coefficient ◽  
Thermal Evaporation ◽  
Structural Parameters ◽  
Negative Temperature ◽  
Resistivity Measurements ◽  
Allowed Transition ◽  
Evaporation Technique ◽  
Indium Telluride ◽  
Made In

Indium Telluride thin films were prepared by thermal evaporation technique. Films were annealed at 573K under vacuum for an hour. Both as-deposited and annealed films were used for characterization. The structural parameters were discussed on the basis of annealing effect for a film of thickness 1500 Å. Optical analysis was carried out on films of different thicknesses for both as - deposited and annealed samples. Both the as- deposited and annealed films exhibit direct and allowed transition. Electrical resistivity measurements were made in the temperature range of 303-473 K using Four-probe method. The calculated resistivity value is of the order of 10-6 ohm meter. The activation energy value decreases with increasing film thickness. The negative temperature coefficient indicates the semiconducting nature of the film.

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