Effect of cadmium telluride quantum dots on the dielectric and electro-optical properties of ferroelectric liquid crystals

We present here the dielectric and electro-optical studies of cadmium telluride quantum dots (CdTe QDs) doped ferroelectric liquid crystals (FLCs). It has been observed that the doping of CdTe QDs not only induced a pronounced memory effect but also affected the physical parameters of FLC material (LAHS19). The modifications in the physical parameters and memory effect of LAHS19 are found to depend on the concentration ratio of CdTe QDs. The lower concentration of CdTe QDs (1–3 wt%) enhanced the values of spontaneous polarization and rotational viscosity of LAHS19 material but did not favor the memory effect, whereas a higher concentration of CdTe QDs (>5 wt%) degraded the alignment of LAHS19 material. The doping of ∼5 wt% of CdTe QDs is found to be the most suitable for achieving good memory effect without significantly affecting the material parameters

Electrically modulated photoluminescence in ferroelectric liquid crystal

Electrical modulation and switching of photoluminescence (PL) have been demonstrated in pure deformed helix ferroelectric liquid crystal (DHFLC) material. The PL intensity increases and peak position shifts towards lower wavelength above a threshold voltage which continues up to a saturation voltage. This is attributed to the helix unwinding phenomenon in the DHFLC on the application of an electric field. Moreover, the PL intensity could be switched between high intensity (field-on) and low intensity (field-off) positions. These studies would add a new dimension to ferroelectric liquid crystal's application in the area of optical devices.Comment: 4 figure

Evolution of excitation wavelength dependent photoluminescence in nano-CeO2 dispersed ferroelectric liquid crystals

The optical properties of nano-ceria (nano-CeO2) dispersed ferroelectric liquid crystals (FLCs) have been investigated by excitation wavelength dependent photoluminescence (PL) spectroscopy. The PL spectra of nano-ceria exhibited a strong excitation wavelength dependence in the 255-370 nm range. The red shift in the violet emission band of ceria i.e. from 368 nm to 396 nm with increasing excitation wavelength, has been attributed to the recombination of electrons trapped in the defect band and the deeply trapped holes in oxygen vacancies. This excitation wavelength dependence of ceria has noticeably been manifested in the PL response of FLC-CeO2 nanocomposites as well. PL emission recorded at an excitation wavelength where host and guest materials show intense emission, i.e. 340 nm, exhibits a quenching effect connected to the overlapping of emission and absorption bands of the host FLC and guest ceria NPs respectively. No blue/red shift in the spectral energy band was observed at 310 and 340 nm excitations. On the other hand, emission spectra at a lower excitation wavelength followed a reverse trend: an increase in the emission intensity, with a large blue shift in spectral energy band. The mechanisms involved in the changes of the PL spectrum of FLC-ceria nanocomposites with varying ceria concentration and excitation wavelengths are discussed in detail

An Approach for Feature extraction of Fabric using wavelet transform & defect detection using Genetic algorithm

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Highly sensitive bovine serum albumin biosensor based on liquid crystal

A highly sensitive liquid crystal (LC) based bovine serum albumin (BSA) protein biosensor is designed. A uniform homeotropic alignment of nematic LC was observed in BSA free substrate which changed into homogeneous in presence of BSA. The change in the LC orientation is found to depend strongly on BSA concentration. This change in the LC alignment is attributed to the modification in the surface conditions which is verified by contact angle measurements. We have detected an ultra low concentration (0.5 mu g/ml) of BSA. The present study demonstrates the utilization of LC in the realization of high sensitivity biosensors

Memory effect in weakly anchored surfaces of deformed helix ferroelectric liquid crystals

A wide-range memory effect in deformed helix ferroelectric liquid crystals (DHFLCs) has been investigated by electro-optical and textural methods. A comparative study has been performed on strongly and weakly anchored surfaces of DHFLC cells. The saturation voltage has been compared in both types of cells by studying the variation of tilt angle and spontaneous polarization with applied voltage. The long-lasting memory effect has been observed in untreated (weakly anchored) cells. It has been proposed that perfect memory in DHFLC cells without any surface treatment is due to the possibility of the absence of depolarization and ionic charges over the surfaces of the cells

Soil fertility as influenced by alternate sequential cropping systems to rice-rice (Oryza sativa L.) in Tunga Bhadra project area

A field experiment was carried out in farmers field near Agriculture Research Station, Siruguppa in Karnataka during kharif and rabi of 2014-15 to Study influence of alternate sequential copping systems to rice-rice (Oryza sativa L.) system on fertility status of soil in Tunga Bhadra Project (TBP) Area. The experimental site was medium deep black with soil pH (8.01), EC (0.54 dS m-1), available nitrogen (240.80 kg ha-1), P2O5 (22.90 kg ha-1) and K2O (347.49 kg ha-1). The experiment comprised of seven sequential cropping systems viz., T1: Rice-maize, T2: Rice-sorghum, T3: Rice-chickpea, T4: Rice-sesame, T5: Maize-chickpea, T6: Cotton-sesame and T7: Rice-rice. These treatments were laid out in completely randomized block design with three replications. The study revealed that significantly higher rice equivalent yield (REY) was recorded in cotton-sesame cropping system (13117 kg ha-1) compared to rest of the cropping systems. Significantly higher system productivity was recorded with maize-chickpea (35.94 REY kg ha-1 day-1) cropping system and it was significantly superior over existing rice-rice (26.89 REY kg ha-1day-1) cropping systems. Significantly higher available nitrogen (210.21 kg ha-1) and P2O5 (34.22 kgha-1) in soil was noticed with ricechickpea cropping system whereas significantly higher available K2O was obtained after the harvest of rice-rice cropping system (330.10 kg ha-1). The cotton-sesame and maize-chickpea crop sequences are more productive and sustainable as they improve the productivity and fertility status of soil when compared to other cropping sequences and can be a better option for the farmers of the Tunga Bhadra Project area, Karnataka

Stress induced hyperglycemia and the subsequent risk of type 2 diabetes in survivors of critical illness

OBJECTIVE: Stress induced hyperglycemia occurs in critically ill patients who have normal glucose tolerance following resolution of their acute illness. The objective was to evaluate the association between stress induced hyperglycemia and incident diabetes in survivors of critical illness. DESIGN: Retrospective cohort study. SETTING: All adult patients surviving admission to a public hospital intensive care unit (ICU) in South Australia between 2004 and 2011. PATIENTS: Stress induced hyperglycemia was defined as a blood glucose ≥ 11.1 mmol/L (200 mg/dL) within 24 hours of ICU admission. Prevalent diabetes was identified through ICD-10 coding or prior registration with the Australian National Diabetes Service Scheme (NDSS). Incident diabetes was identified as NDSS registration beyond 30 days after hospital discharge until July 2015. The predicted risk of developing diabetes was described as sub-hazard ratios using competing risk regression. Survival was assessed using Cox proportional hazards regression. MAIN RESULTS: Stress induced hyperglycemia was identified in 2,883 (17%) of 17,074 patients without diabetes. The incidence of type 2 diabetes following critical illness was 4.8% (821 of 17,074). The risk of diabetes in patients with stress induced hyperglycemia was approximately double that of those without (HR 1.91 (95% CI 1.62, 2.26), p<0.001) and was sustained regardless of age or severity of illness. CONCLUSIONS: Stress induced hyperglycemia identifies patients at subsequent risk of incident diabetes.Mark P. Plummer, Mark E. Finnis, Liza K. Phillips, Palash Kar, Shailesh Bihari, Vishwanath Biradar, Stewart Moodie, Michael Horowitz, Jonathan E. Shaw, Adam M. Dean

A study of hypertensive disorders of pregnancy and the fetal outcome in a tertiary care hospital: a prospective study

Background: Pregnancy induced hypertension is one of the major causes of feto maternal morbidity and mortality in pregnancy. The exact cause of PIH is unknown certain factors are known to increase the risk of PIH such as risk factor includes that young women with first pregnancy.Methods: The objective of this study was to assess the socio-demographic and clinico-pathological profile of the patients with hypertensive disorders of pregnancy and its associated fetal outcomes. A prospective study was conducted in department of obstetrics and gynecology Shri B. M. Patil Medical College, Hospital and Research Centre, BLDE (Deemed to be University), Vijayapura Karnataka from 15th July to 15th December 2018. All women admitted to labour ward with diagnosis of hypertensive disorders of pregnancy were included in the study after ruling out the exclusion criteria and thorough history, examination and laboratory evaluation were done and followed till delivery.Results: A total of 123 pregnant women with hypertensive disorder of pregnancy were enrolled in the study. Most of the participants were in the age group of 20 to 30 years. The PIH was seen mostly in primigravida, lower socioeconomic status and with lower educational levels. Emergency LSCS is the most common mode of delivery.Conclusions: The hypertensive disorder in pregnancy affects the majorly younger age group. It is most commonly seen in low socio-economic and uneducated population. Hence, there should be provided with proper antenatal care, early detection of hypertensive disorders for better feto-maternal outcome