FIELD INDUCED STUDIES IN CARBON NANOTUBES DOPED NEMATIC LIQUID CRYSTAL MIXTURE

Carbon nanotubes (CNTs) doped nematic liquid crystal (NLC) mixture of varying concentrations of CNTs in 0.0, 0.2 and0.5 wt./wt.% ratios have been prepared and studied. The effect of electric field on current behavior and optical propertiesin pure NLC and CNTs-NLC mixtures has been investigated. Dispersion of CNTs in NLC mixture increases the currentnearly 3 times. The lower concentration of CNTs leads to better optical response

Modified Entropy based Least Square Channel Estimation for OFDM and UFMC 5G Systems

The 5G network is anticipated to enable a sizable volume of wireless connections and mobile data traffic. A demand for several wireless communication is to attain greater spectrum, energy-efficiency, as well as quality of service (QoS) in terms of delay, dependability, and security. A developing technology for 5G wireless communication systems is massive multiple-input multiple-output (MMIMO). In MMIMO technology the main criteria for the transfer of information are multi carrier modulation (MCM) techniques for better spectral efficacy. It acts as a main part in the design of physical layer. In recent years orthogonal frequency division multiplexing (OFDM) MCM technique has played a vital role for the transmission of the information. But the main disadvantage of the OFDM system is the cyclic prefix that is added at the end of information. Because of this CP the symbol length also increases. To overcome the problem universal filtered multicarrier (UFMC) MCM technique is used. The other main criteria for the transmission of information are channel estimation (CE). 5G MMIMO systems require efficient CE technique to improve the performance of the system. For 5G MMIMO-UFMC systems, this research provides a modified entropy-based least square (MELS) CE approach. This research work is evaluated using MATLAB software. The performance analysis of UFMC and OFDM systems are done for MELS CE technique. The parameters such as bit error rate (BER) and mean square error (MSE) are analyzed for UFMC and OFDM systems. The results also prove that the proposed MELS CE technique performs better for UFMC 5G MMIMO system compared to OFDM 5G MMIMO system

OFDM: A Mathematical Review

Mathematical review of the Orthogonal Frequency Division Multiplexing is demonstrated in terms of Inter symbol interference, Multi carrier modulated system and cyclic prefix. Modeling of the mathematical equation of the Orthogonal Frequency Division Multiplexing, Inverse fast Fourier transform and fast Fourier transform is explained with the suitable example using MATLAB. Bit error rate performance of OFDM is also presented with the help of statistical computation

The study of clinical and endoscopic spectrum of upper gastrointestinal manifestations in HIV patients

Background: Opportunistic disorders are the most frequent GI complications of HIV infection and remain a major cause of morbidity and mortality in these patients. These disorders account for high prevalence of upper gastrointestinal symptoms such as dysphagia, odynophagia, retrosternal chest pain, abdominal pain and upper GI bleeding. Hence an attempt is being made to study clinical, endoscopic and biopsy changes in HIV patients with upper GI symptoms which helps us to make early diagnosis of upper GI disorders in HIV patients.Methods: HIV positive patients above 14 yrs diagnosed on the basis of recent NACO criteria having Upper G.I. symptoms, attending OPD of Department of Medicine admitted in Wards. All fifty three patients with upper G.I. symptoms were subjected to detail history, thorough clinical examination, routine and special investigations and Upper G.I Endoscopy.Results: Out of fifty three patients, nineteen (35.8%) cases had normal endoscopy. The most common finding was Antral Gastritis in fourteen (26.4%), followed by Candida esophagitis in twelve (22.6%), esophagitis in three (5.7%), candida esophagitis with antral gastritis in two (3.8%), duodenitis, varices and mass (ulcerated growth) in II part of Duodenum seen in one (1.9%) each.Conclusions: The evaluation of specific gastrointestinal complaints must be based on an assessment of degree of immunosuppression. With the progression of immunodeficiency, EGD becomes a useful diagnostic modality for the early diagnosis of these opportunistic infections and other inflammatory conditions

Study of anaemia in type 2 diabetes mellitus

Background: Anaemia is increasingly recognized entity in the patients with diabetes mellitus and constitutes an additional burden in patients. The prevalence of anaemia in the patients with diabetes is two or three times higher than in patients with comparable renal impairment and iron stores in the general population. As India is foreseen a diabetic capital of the world, it becomes imperative to recognize co-morbidities such as anaemia at the earliest. Hence this study is being conducted with the aim to determine the prevalence and various causes of anaemia in diabetics.Methods: After obtaining informed written consent, all diabetics patients were subjected to detailed history, through clinical examination and investigation with CBC, Renal function test including creatinine clearance. The difference of mean between anaemic and non anaemic diabetic patients was evaluated by unpaired student t test. Finally, correlation between the level of haemoglobin and index of renal damage (albumin-creatinine ratio) was accessed by Pearson correlation. Statistical software of SPSS 10 ver. and EXCEL (office 9) was used to analyse the data.Results: In the present study, nearly two third patients of type 2 diabetes mellitus were anaemic. The maximum number of anaemic patients with type 2 diabetes mellitus had microcytic hypochromic type of anaemia.Conclusions: It is therefore concluded that anaemia is a prevalent finding in patients with type 2 diabetes mellitus and represents significant unrecognised burden. The anaemia may be attributed to variable contribution of iron deficiency state and chronic inflammation as result of the disease itself

Comparing the number of attempts required for complete nuclear chop using calibrated and conventional phacotip

Background: Phacoemulsification is a state of art technique with a steep learning curve the configuration of the phacotip affects the efficacy and execution of the nuclear chopping techniques. Inadequate penetration of phacotip may result in partial thickness nuclear cleavage with residual posterior plane and over enthusiastic penetration may result in posterior capsule rupture. This may be avoided if some estimate can be made preoperatively of the depth of penetration required to achieve full thickness crack.Methods: A total of 60 eyes of 60 patients with age related cataract with grade 4.0 to 6.9 (LOCS III) fulfilling the inclusion and exclusion criteria were included in the study after written informed consent. They were divided into two groups A and B with 30 patients each randomly using envelope method and were operated using conventional and calibrated phacotips respectively and the number of attempts required to achieve complete nuclear chop was noted.Results: In group A, vertical chop was safely and effectively done is 23 patients in just one attempt while it took 2 attempts in 6 patients and 3 attempts in 1 patient. In group B, it took just one attempt in 26 patients while 2 attempts were required in 4 patients. The two groups were comparable (p value 0.453) and was found to be statistically significant.Conclusions: With the use of a calibrated phacotip, the surgeon already knows to what depth he has to penetrate the tip into the center of nucleus depending upon the grade of cataract which results in safe and effective chop in minimum attempts where as in the conventional phacotip, it is more of a blind process. Hence the calibrated phacotip has taken the guess work out of question

Electrooptic and Dielectric Studies in Cadmium Sulphide Nanorods/Ferroelectric Liquid Crystal Mixtures

We present the results based on the electrooptic and dielectric studies in cadmium sulphide (CdS) nanorods/ferroelectric liquid crystal mixtures. Doping of CdS nanorods increases the spontaneous polarization and response time, which due to large dipole-dipole interaction and increase in anchoring energies exists between nanorods and FLC molecules. Dielectric measurements revealed a decrease (~40% for 0.3% CdS in FLC) in permittivity and dielectric strength in doped sample cell than pure FLC mixture. A decrease in dc conductivity and relaxation frequency with doping concentration was also noticed. The preexponent factor and fractional exponent factor are found as predicated by existing theories