Extraction of chemical information of suspensions using radiative transfer theory to remove multiple scattering effects : application to a model two-component system

An approach for removing multiple light scattering effects using the radiative transfer theory (RTE) in order to improve the performance of multivariate calibration models is proposed. This approach is then applied to the problem of building calibration models for predicting the concentration of a scattering (particulate) component. Application of this approach to a simulated four component system showed that it will lead to calibration models which perform appreciably better than when empirically scatter corrected measurements of diffuse transmittance (Td) or reflectance (Rd) are used. The validity of the method was also tested experimentally using a two-component (Polystyrene-water) system. While the proposed method led to a model that performed better than that built using Rd, its performance was worse compared to when Td measurements were used. Analysis indicates that this is because the model built using Td benefits from the strong secondary correlation between particle concentration and pathlength travelled by the photons which occurs due to the system containing only two components. On the other hand, the model arising from the proposed methodology uses essentially only the chemical (polystyrene) signal. Thus this approach can be expected to work better in multi-component systems where the pathlength correlation would not exist

Full correction of scattering effects by using the radiative transfer theory for improved quantitative analysis of absorbing species in suspensions

Sample-to-sample photon path length variations that arise due to multiple scattering can be removed by decoupling absorption and scattering effects by using the radiative transfer theory, with a suitable set of measurements. For samples where particles both scatter and absorb light, the extracted bulk absorption spectrum is not completely free from nonlinear particle effects, since it is related to the absorption cross-section of particles that changes nonlinearly with particle size and shape. For the quantitative analysis of absorbing-only (i.e., nonscattering) species present in a matrix that contains a particulate species that absorbs and scatters light, a method to eliminate particle effects completely is proposed here, which utilizes the particle size information contained in the bulk scattering coefficient extracted by using the Mie theory to carry out an additional correction step to remove particle effects from bulk absorption spectra. This should result in spectra that are equivalent to spectra collected with only the liquid species in the mixture. Such an approach has the potential to significantly reduce the number of calibration samples as well as improve calibration performance. The proposed method was tested with both simulated and experimental data from a four-component model system

Understanding Learning Style Variations among Undergraduate Students

A study was conducted in Vellore district of Tamil Nadu state to understand the learning styles of students. The term learning style refers to the way or method or approach by which a student learns. The study explored the possible learning style variations among agricultural, horticultural, engineering and arts & science students and their association with academic achievement. One hundred and twelve students were randomly selected from the four streams and their learning styles were analyzed. In the agricultural and horticultural streams, a majority of the students were auditory learners. They were also found to be predominantly unimodal learners. Overall, it was found that majority of the students were visual learners followed by auditory and kinesthetic style. The highest percentage of kinesthetic learners was found among engineering students. Trimodal learners scored the highest mean percentage of marks. The influence of learning styles on the academic achievements of the students did not show a significant relationship

Inference of moisture content in unsaturated media using ultrasonics

A study is reported which investigates the use of commercial ultrasonics to determine moisture content in geologic and similar materials. Transmission experiments were performed on two of the limiting extremes found in these types of media. In one, tests were made on moistened sand. In the other, fractured media were experimentally simulated with a stack of ceramic tiles with gaps filled with and without water. A simple theoretical model has been developed to estimate velocities and transmitted amplitudes through the tile system, and calculations from this model are compared to the experimental data. It appears that ultrasonics are more sensitive to moisture content in systems where the amount of granular materials is small compared to consolidated media

DESIGN OF COMPACT PRINTED RECTANGULAR MONOPOLE ANTENNA AND U- SHAPED MONOPOLE ANTENNA FOR L-BAND AND S-BAND APPLICATIONS

In this paper we have investigated printed monopole antennas, which is basically a printed micro strip antenna with etched ground plane for multi-band applications. In particular we have fabricated and tested printed monopole antennas for L-band and S-band applications. Printed rectangular monopole antennas are studied first for L-band applications. In high performance aircraft, spacecraft, satellite, missile and consumer electronics applications, where weight, cost, performance, ease of installation, and aerodynamic profile are constraints, low profile antennas may be required. Presently there are many other government and commercial applications, such as mobile radio and wireless communications that have similar specification. To meet these requirements, micro strip patch antennas can be used. These antennas are low profile, conformable to planar and non planar surfaces, simple and inexpensive to manufacture. In this thesis mainly we have designed Rectangular printed monopole antenna and U-shape Printed monopole antennas for L-band and S-bands applications. The final structures are presented in this report after doing an extensive simulation study and analysis and presented relevant results

Environmental Management: A study of Manufacturing Units working in the Gujarat State

People of India are lucky in the richness of natural resources and diversity of living resources. Uniqueness of our planet earth is the most exiting fact. Earth is the only planet that can support life. The earth is gifted with thousands of rivers that supplies sweet water to quench out thirst, an atmosphere that supplies oxygen for our survival, a natural ozone umbrella that protects us from dangerous ultra violet rays, a green carpet of vegetation that recycles the waste gases like carbon dioxide to oxygen, a large number of attractions like rainbows, lightening and thunders. There are three types of environments including, atmosphere, hydrosphere and biosphere. The nature itself keeps balance among these three layers. Biological wealth on the land includes vegetation, animals, birds, and insects, which are interdependent. The environment in all its facets of biological diversity, the air, soil water, and the forests constitute the essential life support system on which we depend. The main and foremost aims of environment are to study of nature ‘Environment is the sum of all social, economical, biological factors which constitutes the surroundings of man, who is both creator and moulder’. In India, industrial sector plays major role in creation environmental imbalance. Researcher selects this area particularly to study environmental problems in Gujarat State. Samples are selected from five main area of cement, pharmaceutical, textile, chemical VI and fertilizer. Rational of this sample is that Gujarat Industrial Economy majority dependent on these industries. This study has significant utility for decision making authority, industry, academician and researcher