DEVELOPMENT OF GROWTH MODELS FOR ELECTRONICS HARDWARE AND SOFTWARE COMPONENTS

ABSTRACT Now a days information technology plays an important role in all field

Preparation and properties of thin silicon nitride films

373-377<span style="font-size:14.0pt;line-height: 115%;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" color:black;mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:="" hi"="" lang="EN-IN">Very thin thermal silicon nitride films have been prepared using an indigenously developed nitridation reactor. Growth kinetics of the films have been studied for different pressure conditions in the temperature range 850-1100°C for different time periods. Optical and electrical properties have been studied The values of refractive index, resistivity and dielectric constant of the films have been measured and are found to be 1.95 , 8×1014 ohm-cm and 5.6, respectively.</span

Structural and Photoluminescence Studies of (Cu, Al) Co-doped ZnO Nanoparticles

International audiencePristine and co-doped ZnO with doping of Cu and Al nano particles have been successfully synthesized by chemical co-precipitation method without using any capping agent and annealed in air ambient at 500 0 C for one hour. Here, the Al concentration is fixed at 5 mol percent and copper concentration is increasing from 1 to 5 mol percent. The Crystallanity, structure and crystallite size of pure and co-doped ZnO nano particles are determined by X-ray diffraction (XRD) in range from 20 0 to 80 0. XRD pattern reveals that the samples possess hexagonal wurtzite structure of ZnO and the estimated particle size of pure and co-doped ZnO nano particles is 20-22nm. Morphological and compositional analysis is done by SEM and EDS. Photoluminescence studies reveals the origin of PL emission in the visible region. PL spectrum shows the blue emission peaks appeared at 435, 448 and 468 nm and green emission peak at 536 nm. Introduction. ZnO is a promising (II-V) semi conductor with wide direct band gap (3.32 eV) and large binding energy (60 MeV). It have attracted a lot of attention due to its significant properties such as room temperature luminescence, good transparency and high electron mobility. Also, it has practical applications in various fields such as solar cells, light emitting diodes, gas sensors, etc. Preferentially ZnO is in the hexagonal wurtzite structure[1-3]. Electronic structure, optical and electrical properties of the host lattice ZnO can be varied by adding of different type of metal ions such as Ca, Al, Mg, Ni and Fe[4-10]. The magnetic properties of ZnO also tuned by doping of metal ions such as Co, N, Ru and Cu[11-13]. There are different methods for the synthesis of ZnO nano particles such as solution combustion method [14], vapor phase oxidation[15], chemical vapor deposition, sol-gel[16], chemical co-precipitation method[17-19]. Among these methods chemical co-precipitation method is used for the preparation of large quantity of pure and doped ZnO nano particles because it is simple, cost effective and high yield rate. The structural, compositional and optical properties of the synthesized nano particles are presented

Design and Development of an Inexpensive Temperature Controller for an Infant Incubator

ABSTRACT: Neonatal Intensive Care Unit (NICU) is used for better temperature measurement, isolation from infection, specialized feeding to infants and to prevent hypothermia and hyperthermia. The NICU or incubator consists of a servo control system including temperature sensor to regulate incubator air temperature. Among the number of temperature sensors like thermocouples, thermistors, Mercury thermometers, digital temperature sensor (DTS), etc, DTS gives accurate results over analog temperature sensors. The objective of the work is to interface Programmable ADT7410 DTS to PIC18F8720 Microcontroller to monitor the infants body temperature. This sensor measures temperature with accuracy, high resolution and fast conversion. ADT7410 is a MEM based digital sensor, which is Programmable for High, Low and critical temperature limits. It also includes on-chip oscillator, Sigma-Delta modulator, temperature registers and interrupt pins. PIC microcontroller is used as core of servo control system to read and write temperature from sensor using I2C protocol, and to control peripherals like radiant warmer, buzzer, Relays and display the result on LCD monitor. The software program is written in C language and compiled to generate Hex file. The step by step process of the system is explained using flowchart

Data acquisition system using Matlab for deep level transient spectroscopy studies

204-209A microcontroller (AT89S8252) based data acquisition system has been developed for acquiring and processing the data from a home built deep level transient spectroscopy (DLTS)system. User friendly menu driven software has been developed in Matlab for selection of different DLTS measurement modes, data acquisition modes, channels (four channels) selection and number of data points on a single transient. It can be operated in two data acquisition modes namely scan mode and continuous mode. The scan mode is used to perform online analysis and continuous mode for offline data analysis. The developed software is also useful to operate the DLTS system in any one of the two operating modes namely boxcar mode or high resolution mode. The versatility of the data acquisition system is that the software developed can be used to obtain I-V characteristics using commercially available source meters. The paper also deals with the different wavelet decomposition methods for DLTS data acquisition and processing

A general purpose computer-based data acquisition system and temperature controller

117-120<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">The design and operational details of a general purpose computer based data acquisition system (DAS) and temperature controller are given. The DAS consists of a 12-bit analog to digital converter (25 µs convertion time), two 12-bit digital to analog converters having fast settling time (500 ns), control circuit and Thermocouple Signal Conditioner (2B50). The software which is user friendly menu driven has been developed in Turbo-Basic. The data acquired is stored in the hard disk and can also be displayed on the monitor. The algorithms for data acquisition and temperature control are presented. The temperature in the range 77-400 K can be controlled with an accuracy of ± 0.1 K. Because of its simplicity and versatality, the system is best suited for upgrading the existing instruments like NMR spectrometers, EPR spectrometer, etc. where data acquisition and temperature control are involved.</span

Investigations on structural and optical properties of co-doped (Ag, Co) ZnO nanoparticles

Undoped and co-doped (Ag, Co) ZnO powders were synthesized by chemical co-precipitation method without using any capping agent. The X-ray diffraction results indicate that the undoped and co-doped ZnO powders have pure hexagonal structure and are consisting of nanosized single-crystalline particles. The size of the nanoparticles increases with increasing Ag concentration from 1 to 5 mol% as compared to that of undoped ZnO. The presence of substitution dopants of Ag and Co in the ZnO host material was confirmed by the Energy dispersive analysis of X-rays (EDAX). Optical absorption measurements indicate blue shift and red-shift in the absorption band edge upon doping concentration of Ag and blue emission was observed by photoluminescence (PL) studies

Doping effect of Ag+, Mn2+ ions on Structural and Optical Properties of ZnO nanoparticles

Pure ZnO and co-doped (Mn, Ag) ZnO nanoparticles have been successfully prepared by chemical co-precipitation method without using a capping agent. X-ray diffraction (XRD) studies confirms the presence of wurtzite (hexagonal) crystal structure similar to undoped ZnO, suggesting that doped Mn, Ag ions are substituted to the regular Zn sites. The morphology of the samples were studied by scanning electron microscopy (SEM). The chemical composition of pure and co-doped ZnO nanoparticles were characterized by energy dispersive X-ray analysis spectroscopy (EDAX). Optical absorption properties were determined by UV-vis Diffuse Reflectance Spectrophotometer. The incorporation of Ag+, Mn2+ in the place of Zn2+ provoked to decrease the size of nanocrystals as compared to pure ZnO. Optical absorption measurements indicates blue shift in the absorption band edge upon Ag, Mn ions doped ZnO nanoparticles