Evaluation of Nigerian Source of Kaolin as a Raw Material for Mullite Synthesis

In the present study, a new source of kaolinitic clay (Al2O3.2SiO2.2H2O) collected from Abule Onikosin Road in Abeokuta area of Ogun State, Nigeria was first processed to remove the stony materials adhered to its surface and subsequently characterized with respect to its chemical analysis, TG-DTA, particle size spectrum and identification of mineralogical phases by XRD technique. The identified endothermic peak at 516.39oC for dehydroxylation in the DTA curve and observed deformed XRD profile confirm that the clay belongs to disordered kaolinitic clay. The high SiO2 content (59.26 wt%) compared to theoretical value (46.54 wt%) of well-ordered kaolinite is due to excess silica and this has been revealed in XRD pattern as quartz peak. The compact samples of this processed clay powder on heating in the temperature range of 1400-1600oC resulted almost densified and impervious sample at 1600oC. The densification occurred by viscous flow mechanism. Silica together with impurity oxides (Fe2O3, TiO2) in the clay forms glassy phase in the above temperature range and that accompany the formation of mullite (3Al2O3.2SiO2) crystals. The XRD and FESEM studies conducted on heated samples revealed the formation of mullite needle, the amount and aspect ratio of which increases with increase in heating temperature. The EDAX studies confirm the presence of Al, Si, O as major elements which also support mullite formation in the heated compact samples. This new sources of kaolinitic clay identified in Nigeria is found to be suitable for mullite synthesis and it is advantageous due to its low temperature mullitization unique microstructure

Effects of SiO(2) and TiO(2) fillers on thermal and dielectric properties of eco-friendly bismuth glass microcomposites of plasma display panels

The effects of SiO(2) (amorphous) and TiO(2) (crystalline, rutile) fillers on softening point (T (s)), glass transition temperature (T (g)), coefficient of thermal expansion (CTE), and dielectric constant (E >) of zinc bismuth borate, ZnO-Bi(2)O(3)-B(2)O(3) (ZBIB) glass microcomposites have been investigated with a view to its use as the white back (rear glass dielectric layer) of plasma display panels (PDPs). The experimentally measured properties have also been compared with those of theoretically predicted values. Both the experimental and theoretical trends of these properties with added filler contents correlate very well. The interaction of fillers with glass which occurred during sintering at 560A degrees C has also been monitored by XRD and FTIR spectroscopic analyses. The microstructures and distribution of fillers in the glass matrix have been analyzed by SEM images. It is observed that the fillers have partially dissolved in the glass at the firing temperature leaving some unreacted filler as residue which results in ceramic-glass microcomposites. In consideration of the desired properties of white back of PDPs, the addition of TiO(2) filler to ZBIB glass is found to be more preferable than SiO(2) filler. The addition of 10 wt% TiO(2) filler yielded T (s), T (g), CTE and E > values of 560A degrees C, 480A degrees C, 82 x 10(-7)/K and 14 center dot 6 which are found to meet the desired values of < 580A degrees C, < 500A degrees C, < 83 x 10(-7)/K and < 15, respectively with respect to use of PD200 glass as substrate in PDP technology

MONOSODIUM GLUTAMATE POTENTIATES THE CONTRACTION OF THE VISCERAL SMOOTH MUSCLE OF DUODENUM BY AUGMENTING THE ACTIVITY OF INTRINSIC CHOLINERGIC EFFERENTS, INDUCING OXIDATIVE STRESS AND PROLIFERATING SMOOTH MUSCLE CELLS

Objective: The objective of the present study was to examine the effects of monosodium glutamate (MSG) on the contraction of visceral smooth muscle (VSM) of the duodenum in a rat model to understand the MSG-induced impairment of the function of the small intestine. Methods: Male albino rats of Charles Foster strain were exposed with MSG at three different dosages (632, 1264, and 2528 mg/kg BW/day) for 30-day duration. The records of the contraction of the duodenum were achieved with isotonic transducer (IT-2245) coupled with RMS-Polyrite D by our standard laboratory protocol. Results: We have observed potentiation of contraction of duodenum ex vivo dose-dependently in MSG exposed groups of rats compared to control. Furthermore, the enzymatic activity of acetylcholinesterase (AChE) in VSM tissue homogenate and expression of AChE protein in fixed duodenal muscle cell layers have been decreased in a dosage response manner comparing to control rats. We have found a significant decrease in the activities of some antioxidant enzymes such as Cu-Zn superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione-s-transferase, and increase in the level of malondialdehyde in MSG exposed VSM tissue homogenate of the duodenum. We have also observed thickening of muscularis externa layer and increase in the number of muscle cells in circular and longitudinal muscle layers of the duodenal wall in transverse duodenal wall sections stained with eosin-hematoxylin. Conclusion: MSG potentiates the contraction of VSM of duodenum by augmenting the activity of intrinsic cholinergic efferents predominantly, and inducing oxidative stress and proliferating smooth muscle cells

Influence of combined Al(2)O(3)-SiO(2) filler on thermal and dielectric properties of barium zinc borate glass microcomposites for barrier ribs of plasma display panels

The co-effects of Al(2)O(3)-SiO(2) filler to an extent of 25 wt.% on thermal (softening point and coefficient of thermal expansion) and dielectric constant of lead free BaO-ZnO-B(2)O(3)-SiO(2)-Li(2)O-Na(2)O (BZBSLN) glasses have been explored with a view to use as barrier ribs of plasma display panels (PDPs). The interaction of fillers with glass occurred during firing (570 degrees C) has also been investigated by XRD, SEM micrograph and FTIR spectroscopy analyses. The fillers have been found to be partially dissolved in the glass at the firing temperature leaving some unreacted residual filler which result in ceramic-glass microcomposites. All the properties are found to follow the same experimental and theoretical trends, and regulate by the covalent character as well as the optical basicity of microcomposites. Addition of combined filler found to be yielded the required properties and meeting the criteria for barrier rib application

Comparison of Maternal and Foetal Outcome between Normal and Abnormal Amniotic Fluid Index in the Third Trimester of Pregnancy - A Longitudinal Analytical Study in A Tertiary Level Medical College of Suburban West Bengal, India

Background: Amniotic fluid (AF) is the protective liquid present in the amniotic sac of a gravid uterus. Amniotic fluid has nutritive, protective and diagnostic functions. Amniotic Fluid Index (AFI) is most popular and reliable method for quantifying amniotic fluid, till date. AFI is one of the major parameters of foetal biophysical profile (BPP) that can predict perinatal and maternal outcomes. Periodical scanning of foetus is utmost essential during antenatal visits, especially in high-risk pregnancies, but there is no definite standard protocol regarding its frequency.Methods: This study was conducted in the department of Obstetrics & Gynaecology, College of Medicine & JNM Hospital, Kalyani, Nadia, India. This longitudinal analytical study included 356 patients, among whom 151 (42.4%) were in oligohydramnios group, 174 (48.9%) in normal group and 31 (8.7%) in polyhydramnios group.Results: The data revealed oligohydramnios was strongly associated with caesarean section (p = 0.0010). In oligohydramnios group, IUGR was found in 37 (24.5%) patients (p = 0.0297). Meconium-stained liquor was almost similar in all three categories i.e. 15 (10.0%) in oligohydramnios group, 18 (10.3%) in normal group and 5 (16.1%) in polyhydramnios group, respectively. There was higher SNCU admission among babies delivered by mothers with oligohydramnios (p = 0.0369). There was no statistically significant difference in 1 and 5 minutes APGAR scores among normal and abnormal AFI groups. Conclusions: It was inferred that LSCS, IUGR baby and SNCU admission rates were more in oligohydramnios group compared to other categories. The perinatal death was 3.3% with oligohydramnios compared to 1.7% with normal liqour. The results from this study emphasize on the importance of AFI among the various means of antepartum surveillance and predictors of foetal outcome. Keywords: Oligohydramnios, Polyhydramnios, Foetal Outcome, IUGR, AF

High Strength Porous Ceramic Tile from Inorganic Wastes and Other Ceramic Minerals

The effect of iron and steel slag and fly ash additions on the physicomechanical properties, phase, and microstructure of normal porcelain compositions replacing quartz in full and feldspar in part was investigated. Two compositions, varying the amount of slag and fly ash, were prepared and the compacts made out of them were heated in the temperature range of 1100–1180 °C. Both porous and vitrified samples were obtained. The samples heated at 1150 C resulted in 7–9 % water absorption, lower shrinkage (56 %) and superior flexural strength (50–58 MPa) from both compositions. The highly porous sample heated at 1100 °C resulted in 16–18 % water absorption, around 40 MPa flexural strength and shrinkage in the range of 2–3 %. It was interesting to observe that the vitrified samples offered lower flexural strength (40–50 MPa) than the porous samples heated at 1150 °C. These properties were correlated with phase and microstructural observations. Anorthite crystals were present as a major phase in both and the microstructure was highly crystalline

Phase and microstructural evolution in quartz-free porcelain tile compositions

In the present investigation, three quartz-free porcelain compositions were prepared where quartz was fully substituted by fly ash (VPF 1) and feldspar was partly substituted by blast furnace slag (VPF 2) and basic oxygen furnace slag (VPF 3). A quartz-containing porcelain (VPQ) was also considered to compare the results with quartz-free porcelain bodies. Phase transformation and mass loss of the prepared batches were measured up to 1150 degrees C by simultaneous thermogravimetric and differential thermal analysis (TG-DTA). Endothermic peaks in the range of 519.27-539.01 degrees C were mainly due to dehydroxylation of kaolin. Exothermic peaks in the range of 814.01-1060.55 degrees C were attributed to mullite crystallization. No major difference was found in TG-DTA data of quartz-containing sample. Fabricated green samples were heated in the temperature range of 1100-1280 degrees C based on the softening point (PCE values) of the experimental bodies. Physico-mechanical properties, phase, and microstructure of the heated samples were evaluated by standard techniques. Early vitrification was observed in the case of VPF 1 and VPF 3. Quartz-containing body (VPQ) was vitrified at 1280 degrees C. X-ray diffraction (XRD), field emission scanning electron microscopic (FESEM), and energy dispersive X-ray analysis (EDAX) studies confirmed the presence of quartz (SiO2) and mullite (3Al(2)O(3 center dot)2SiO(2)) in VPF 1 while quartz, mullite, and anorthite (CaO center dot Al2O3 center dot 2SiO(2)) were observed in VPF 2 and VPF 3. Alumina-enriched slag used in this study was contributed towards anorthite crystal formation. In quartz-containing body, major phases were found to be quartz and mullite

An explorative study to enable environmentally conscious manufacturing for an industrial gearbox manufacturing organization

In recent years, environmentally conscious manufacturing (ECM) has become an important aspect and proactive approach for majority of the manufacturing organizations in India. The reason is that ECM not only helps to produce environment friendly, but also helps to make money by reducing cost or achieving competitive advantage. Industrial gearbox manufacturing organizations have significant environmental impacts as industrial gearbox manufacturing involves several steps which use valuable resources and pollute the environment. Hence, this paper presents an explorative environmental study of an Indian industrial gearbox manufacturing organization. The objective of the current paper is (i) to identify the environmental problems and environmentally conscious manufacturing indicators (ECMI), (ii) to find out the root causes of these problems and (iii) to solve the root causes based on the available state-of-the-art literature. This research work not only reviews the efficient environment friendly manufacturing techniques, but also helps the organization to become eco-efficient by producing environment friendly while making money. First ECMIs selected from literature review, are validated through process mapping. Then these indicators are prioritized using analytic hierarchy process (AHP) to find out the critical environmentally conscious manufacturing indicators (CECMI). The sources of CECMIs are identified using either data envelopment analysis (DEA) or direct observation of the available database. Finally, some possible solutions are also addressed in this paper