Microencapsulation of n-tetradecane with poly (methyl methacrylate-co-methacrylic acid) shell by seeded emulsion polymerisation and its thermal energy storage characteristics.

This study aims to enhance the latent heat storage properties of the microcapsules by altering the amount of crosslinking agent from 3 to 20%w/w, the core-to-shell ratio from 1:1 to 2:1, and the amount of initiator from 1 to 3%. The phase change material n-tetradecane (C-14) was microencapsulated by using poly (methyl methacrylate -co- methacrylic acid) as a shell material through an oil by water-seeded emulsion polymerisation technique. The structural, morphological, and thermal properties of microcapsules were evaluated by using Fourier transform infrared spectroscopy, optical microscopy, scanning electron microscopy, differential scanning calorimetry analysis, and thermogravimetric analysis. The average particle size of the microcapsules ranges from 01 to 15 µm. The results showed that the microcapsules have a higher melting enthalpy value of 127.3 ± 0.06 J/g with a microencapsulation efficiency of 66.72% when a 20% w/w crosslinker was used. The thermal stability of the phase change material (PCM) was increased by ∼30 ± 2 °C by encapsulation.

Pasting, viscoelastic and rheological characterization of gluten free (cereals, legume and underutilized) flours with reference to wheat flour.

In this study, the rheological properties of dough prepared from gluten free flours (rice, sorghum, moong, water chestnut and unripe banana) and wheat dough were determined. Pasting properties and viscoelastic properties were analyzed using rheometer and dough rheology experiment was performed on texture analyzer. Water chestnut flour exhibited highest peak viscocity (22.6 Pa s), trough viscosity (12.1), breakdown viscosity (10.5 Pa s) and final viscosity (14.92 Pa s) than others while unripe banana flour showed highest setback viscosity (4.54 Pa s). Pasting temperature was found to be highest for sorghum followed by wheat and others. The highest elastic (G') and loss (G″) module were obtained for moong flour. Wheat and gluten free flours were found to exhibit thixotropic effect. Moong flour dough was found to be the stickiest (dough stickiness 57.83 g) followed by WCF, UBF, wheat, rice and sorghum. Similar trend was observed for dough strength. These flours can be proved as key materials for the gluten-free products market and can provide additional inexpensive advantage to the food processing industry.

Seroprevalence of dengue in a rural and an urbanized village: A pilot study from rural western India.

BACKGROUND & OBJECTIVES: Dengue is highly prevalent in tropical and subtropical regions. The prevalence of dengue is influenced by number of factors, i.e. host, vector, virus and environmental conditions including urbanization and population density. A cross sectional study was undertaken to determine the seroprevalence of dengue in two selected villages that differed in the level of their urbanization and population density. METHODS: Two villages with demographically well-defined populations close to Pune, a metropolitan city of western India, were selected for the study. Age stratified serosurvey was carried out during February to May 2011 in the two villages-a rural village A, located 6 km from the national highway with a population density of 159/km2 ; and an urbanized village B, located along the highway with a population density of 779/km2 . Assuming a low seroposi- tivity of 10%, 702 serum samples were collected from village A. Sample size for village B was calculated on the basis of seropositivity obtained in village A, and 153 samples were collected. Serum samples were tested for the presence of dengue virus (DENV)-specific IgG. Simple proportional analyses were used to calculate and compare the seroprevalence. RESULTS: Of the 702 samples collected from village A, 42.8% were found positive for anti-DENV IgG. A significantly higher seropositivity for DENV (58.8%) was found in village B. In village A, there was an age dependent increase in seroprevalence; whereas, in village B, there was a steep increase from 17% positivity in 0-10 yr age group to 72% in the 11-20 yr age group. The seroprevalence was almost similar in the older age groups. INTERPRETATION & CONCLUSION: The observations suggested that prevalence of dengue is probably associated with urbanization and host population density. Areas that are in the process of urbanization needs to be monitored for prevalence of dengue and its vector, and appropriate vector control measures may be implemented.

Design and synthesis of bio-based UV curable PU acrylate resin from itaconic acid for coating applications.

UV curable PUA resin was successfully synthesized from polyol based on sustainable resource originated from itaconic acid (IA), isophorone diisocyanate (IPDI) and 2-hydroxyethyl methacrylate (HEMA). A polyol was synthesized by condensation reaction of IA with 16-hexanediol in the presence of p-Toluenesulfonic acid (pTSA). The synthesized PUA resin was characterized for its structural elucidation by using Fourier Transform Infrared Spectrophotometer (FTIR), 1H and 13C NMR spectroscopy. The synthesized UV curable PUA resin was incorporated in varying concentrations in conventional PUA coating system. The effects of varying concentration of synthesized UV curable PUA resin on rheology, crystallinity, thermal and coating properties were evaluated. The rheological behavior of the resins were evaluated at variable stress and result showed decrease in viscosity of resin as concentration of synthesized UV curable PUA resin increases in conventional PUA resin. The cured coatings have been evaluated for glass transition temperature (Tg) and thermal behavior by differential scanning calorimeter and thermogravimetric analysis respectively. The degree of crystallinity of the coatings was determined from X-ray diffraction patterns using the PFM program. It was found that increase in the mass proportion of IA based PUA in coatings, the coating becomes more rigid and crystalline. The synthesized UV curable PUA coatings showed interesting mechanical, chemical, solvent and thermal properties as compared to the conventional PUA. Further, cured coatings were also evaluated for gel content and water absorption.

Synthesis of titanium dioxide by ultrasound assisted sol-gel technique: effect of calcination and sonication time.

Nanostructured titanium dioxide has been synthesized using both conventional and ultrasound assisted sol-gel technique with an objective of understanding the role of cavitational effects in the synthesis process. The experiments were conducted at a constant calcination temperature of 750 °C and the calcination time was varied from 30 min to 3 h to study the effect of calcination time on the properties of the synthesized TiO2. The TiO2 specimens were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The influence of the sonication time on the phase transformation process from anatase to rutile and also on the crystallite size and percentage crystallinity of the synthesized TiO2 has also been investigated. It was observed that 100% phase transformation occurred after 3 h of calcination for the ultrasound assisted sol-gel synthesized TiO2. The study on the phase transformation via variation of sonication time yielded interesting results. It was observed that as the sonication time increased, an initial increase in the rutile content is obtained and beyond optimum sonication time, the rutile content decreased. In general, the ultrasound assisted process results in synthesis of TiO2 material with higher rutile content as compared to the conventional sol-gel process.

Preparation of nano cellulose fibers and its application in kappa-carrageenan based film.

Bio-based nanocomposite films were successfully developed using nanofibrillated cellulose (NFC) as the reinforcing phase and kappa-carrageenan (KCRG) as the matrix. NFC was successfully synthesis from short stable cotton fibers by chemo-mechanical process. The bionanocomposites were prepared by incorporating 0.1, 0.2, 0.3, 0.4, 0.5, and 1wt% of the NFC into a KCRG matrix using a solution casting method there characterization was done in terms of thermal properties (DSC), morphology (SEM), water vapor transmission rate (WVTR), oxygen transmission rate (OTR), X-ray diffractograms (XRD), and tensile properties. The main conclusion arising from the analysis of the result is that the bionanocomposites containing 0.4wt% of NFC exhibited the highest enhancement in tensile strength it is almost 44% improvement. WVTR and OTR results showed improvement of all nanocomposite film compare to control KCRG film.

Synthesis of nano cellulose fibers and effect on thermoplastics starch based films.

Starch based films limit their application due to highly hydrophilic nature and poor mechanical properties. This problem was sought to be overcome by forming a nanocomposite of Thermoplastic starch (TPS) and Nano-Cellulose fibers (NCF). NCF was successfully synthesised from short stable cotton fibres by a chemo-mechanical process. TPS/NCF composite films were prepared by solution casting method, and their characterizations were done in terms of differential scanning calorimeter (DSC), morphology (SEM), water vapor permeability (WVTR), oxygen transmission rate (OTR), X-ray diffractograms, light transmittance and tensile properties. At very low concentration of NCF filled TPS composite film showed improvement in properties. The 0.4 t% NCF loaded TPS films showed 46.10% improved tensile strength than by base polymer film, beyond that 0.5 t% concentration tensile strength starts to deteriorate. WVTR and OTR results showed improved water vapor barrier property of TPS matrix. The DSC thermograms of TPS and composite films did not show any significant effect on the melting point of composite film to the base polymer TPS.

Synthesis of zirconium dioxide by ultrasound assisted precipitation: effect of calcination temperature.

Nanostructured zirconium dioxide was synthesized from zirconyl nitrate using both conventional and ultrasound assisted precipitation in alkaline medium. The synthesized samples were calcinated at temperatures ranging from 400°C to 900°C in steps of 100°C. The ZrO(2) specimens were characterized using X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The thermal characteristics of the samples were studied via Differential Scanning Calorimetry-Thermo-Gravimetry Analysis (DSC-TGA). The influence of the calcination temperature on the phase transformation process from monoclinic to tetragonal to cubic zirconia and its consequent effect on the crystallite size and % crystallinity of the synthesized ZrO(2) was studied and interpreted. It was observed that the ultrasound assisted technique helped to hasten to the phase transformation and also at some point resulted in phase stabilization of the synthesized zirconia.

An uncommon presentation of an inflammatory gingival enlargement--responding to non-surgical periodontal therapy.

BACKGROUND: The various clinical manifestations of inflammatory gingival enlargement reported are more or less similar regardless of the underlying aetiological factors. Unusual presentation and unknown aetiology pose a diagnostic challenge for a periodontist. METHODS: A 34-year-old Indian woman presented with the complaint of gum swelling that was sessile, lobulated, soft in consistency and bluish red in colour with ulcerated surface in some region, which was covered by the necrotic slough. This type of enlargement was unusual and some underlying systemic pathology was suspected. But a written consultation from her physician confirmed her systemic health, which was based on clinical, radiological and haematological investigations. Histopathological examination confirmed the diagnosis of inflammatory gingival enlargement. Patient was treated with oral hygiene instructions, scaling and root planning. RESULT: Within a month of conventional periodontal therapy, gum enlargement reduced markedly and patient was put on oral hygiene maintenance programme. CONCLUSION: Periodontal therapy is diagnosis-driven and, to the extent possible, should address all the possible factors that impact development and progression of diseases that may affect periodontal tissue. In plaque-induced periodontal diseases, non-surgical periodontal therapy is still a gold standard among all the therapies available.

Synthesis of titanium dioxide by ultrasound assisted sol-gel technique: effect of amplitude (power density) variation.

Titanium dioxide was successfully synthesized by utilizing sol-gel technique modified by incorporation of ultrasound as a reaction aid. The effect of amplitude of irradiation (power input varied from 19.9 to 80.8 W) on % Rutile, % yield, % crystallinity, crystallite size and morphological (scanning electron microscopy) properties of the obtained nano-TiO(2) was studied. Calcination temperatures of all the samples were kept constant at 750 degrees C. With increasing ultrasonic irradiation amplitude it is observed that the values of % Rutile (after calcination) increased and reached a peak value after which further increase in amplitude resulted in a decrease in the % Rutile. A similar trend was observed in the case of % crystallinity and % yield of the reaction. On the basis of these results an optimum operating ultrasonic irradiation amplitude for the reaction has been suitably established.

Phase transformation of nanostructured titanium dioxide from anatase-to-rutile via combined ultrasound assisted sol-gel technique.

An effort was made to synthesize nanostructured TiO(2) via sol-gel technique to obtain a 100% rutile polymorph of nanostructured TiO(2). The sol-gel synthesis technique was suitably modified by incorporating ultrasound to study the effect of cavitation on the phase transformation, crystallite size, crystallinity and morphological (scanning electron microscopy) properties of the obtained nano-TiO(2). It was observed that using ultrasound, yield of the nano-TiO(2) was improved from 86.35% to 95.078%. The phase transformation of anatase-to-rutile of TiO(2) was studied for both (ultrasound assisted and conventional) the processes. Complete phase transformation of the TiO(2) was observed as expected with and without the use of ultrasound but the marked reduction in the required calcination temperature for obtaining 100% phase transformation with ultrasound was the major achievement in the present study, leading to 70% energy savings during calcination.