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We developed an improved hexagonal wurtzite ZnO and ZnO/C microflowers through the facile hydrothermal technique. The obtained nanostructures were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Energy-dispersive X-ray spectroscopy (EDX) and UV–visible diffuse reflectance spectroscopy (UV–Vis DRS). The formation of flower-like material is confirmed using SEM and TEM analysis with an average diameter of about 2 µm composed of several plate-like nanostructures. The optical analysis results show that the presence of carbon particles with ZnO structures has significantly increased the light absorption ability of nanocomposite. The photocatalytic degradation ability of prepared nanostructures was examined using methylene blue as a model pollutant. The obtained results show that the photocatalytic degradation ability of ZnO/C nanostructures is approximately two times higher than the pristine ZnO microflowers. Based on the investigation, an enhancement of the photocatalytic ability of ZnO/C nanocomposite is achieved due to the synergistic effect between carbon particles and flower-like ZnO nanostructures.

The effect of g-C3N4 on the structural, optical, and photocatalytic properties of ZnO microcrystals under hydrothermal conditions was investigated in this research. The addition of g-C3N4 changed not only the phase composition, but also affect the growth of ZnO crystals, changing the lattice parameter and the transformation of hexagonal cylinder-like twinned ZnO microcrystals (1–2 μm length and 0.5–1 μm diameter) to g-C3N4 amalgamated rice-like ZnO nanostructure (500 nm length and 100 diameter) with type II heterojunction. The optical bandgap was found to be 3.27 and 3.21 eV for pristine ZnO and g-C3N4@ZnO, respectively. Owing to the narrow bandgap (2.7 eV) of g-C3N4, a red shift towards the visible region in optical absorption and a substantial reduction in the optical bandgap was observed for g-C3N4@ZnO heterostructure. Besides, it is also found that g-C3N4@ZnO has significantly higher photocatalytic effect (93 %) on RhB dye degradation than pristine ZnO (70 %) and g-C3N4 (68 %), because it produce a large number of reactive species (·OH and O2•− radicals) by hold-up the recombination of charge carriers via type II heterojunction. This research may be one of the most realistic approaches to developing effective photocatalysts for environmental remediation.

In this study, we synthesized the visible-light-driven photocatalytic activity of CdO nanowires and g-C3N4/CdO hybrid nanostructure by the hydrothermal method. X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectrometry, and UV–Vis diffuse reflectance spectroscopy studies were carried out to compare the structural, morphological, and optical properties of CdO nanowires and g-C3N4/CdO hybrid nanostructure. Also, we investigated how CdO nanowires and g-C3N4/CdO hybrid nanostructure function as photocatalysts in the photocatalytic oxidation of RhB under visible light illumination, which revealed that g-C3N4/CdO hybrid nanostructure exhibits better photocatalytic oxidation on RhB than CdO nanowires with the first-order degradation kinetics. The prepared g-C3N4/CdO hybrid nanostructure can provide hybridized conduction band or valence band, which facilitates better charge transport and reduces recombination electron-hole charge carriers leading to higher photocatalytic performance. Hence, making hybrid nanostructures such as g-C3N4/CdO can be a potential approach to develop effective photocatalysts for treating effluents discharged from textile and dyeing industries.

We report the synthesis of silver-integrated silica nanostructures using rice hulls and silver chloride through a facile thermal combustion process. The formation of mesoporous silica nanomatrix embedded with silver nanoparticles (SiO2:Ag 5 wt% and SiO2:Ag 10 wt%) was confirmed by XRD, FTIR, EDX, BET, and TEM analysis. Also, the obtained results from the above studies revealed that the concentration of silver ions significantly increases the particle size and number of silver nanoparticles formed in the silica matrix. The electrochemical performance was studied using silver-integrated silica nanostructures as a working electrode in KOH electrolyte. The maximum specific capacitance of SiO2:Ag 5 wt%- and SiO2:Ag 10 wt%-coated electrode was found to be 517 and 580 F/g at current density of 1 A/g. It was also found that SiO2:Ag 10 wt% electrode exhibit an excellent stability with the capacitance retention of 94% than SiO2:Ag 5 wt% (capacitance retention of 85%) after 1000 cycles at a current density of 1 A/g. These results may be attributed to the inherent characteristic of more silver nanoparticles present in the silica nanomatrix in SiO2:Ag 10 wt%. The intrinsic characteristic of rice hull-derived silica nanostructures such as high surface area and mesoporous structure along with the advantage of silver nanoparticles (conductivity) can facilitate the Faradic redox processes at electrode surface which are responsible for the supercapacitive behavior of the prepared silver-integrated silica nanostructures.

Mandible is the only mobile facial jaw bone and it aides in various functions such as phonation and mastication. Therefore, management of mandible fracture becomes inevitable due to its functional and anatomical importance. Fracture fixation methods and techniques have steadily evolved with various osteosynthesis systems. In this article, we discuss the management of mandible fracture using a newly designed two-dimensional (2D) hybrid V-shaped plate. In this paper, we have evaluated the efficacy of the newly developed 2D V-shaped locking plate in the management of mandibular fractures. We have assessed 12 cases of different mandibular fractures ranging from symphysis, parasymphysis, angle and subcondylar region. Treatment outcome was assessed both clinically and radiologically at regular intervals with various intraoperative and postoperative parameters. Results of this study suggest that fixation of mandible fracture with the 2D hybrid V-shaped plate facilitates anatomic reduction and functional stability and carries a low morbidity and infection rate. The 2D anatomic hybrid V-shaped plate can be a suitable alternative to conventional miniplate and 3D plates as it offers satisfactory anatomic reduction and functional stability. Positioning the plate in relation to the mental nerve and plate adaptation along the angle region are much easier.

The objective of this study is to analyse the movement of nitrates and dissolved oxygen under the effect of denitrification in a fracture–matrix (F–M) system with skin formation. An implicit finite difference scheme is developed to model the coupled nonlinear partial differential equations. A varying grid is considered at the fracture–skin interface to handle the mass transfer from the fracture to the skin. Bacterial growth is taken into account in the fracture. The growth is affected by the presence of electron donor and electron acceptor. Sensitivity analysis is performed for various fluid flow velocities, skin diffusion coefficients, facture dispersion coefficients, skin porosities (S-P), fracture apertures and rock–matrix (R–M) porosities. Outcomes of this study indicate that the occurrence of skin enriches the transport of nitrates as compared to the absence of skin when denitrification process exists in the system. The low fluid velocity (0.5 m/day) reduces the transport of nitrates to a distance of 5 m, whereas a high fluid velocity (5.0 m/day) triggers up to a distance of 30 m from the fracture inlet. The higher skin diffusion coefficient enhances the migration of nitrates and dissolved oxygen compared to the lower skin diffusion coefficients. The fracture aperture variation from 100 to 500 μm increases the movement of nitrates and dissolved oxygen in fracture from 4 to 10 m, respectively. The variation of S-P from 25 to 75% also follows the same trend. Variation in R–M porosity has an insignificant effect on the movement of nitrates and dissolved oxygen.

Certain materials that are used in industries to manufacture parts, components and sub-assemblies are difficult to machine using traditional machining processes. Abrasive water jet machining is a viable solution to such a problem, and its use is sought where precision is the requirement. The process involves many input controllable parameters that influence the performance characteristics of the process such as MRR, surface finish and kerf width. Inconel-625 is one such hard-to-machine material that finds many applications in industries. The objective of the present work is set to ascertain experimentally the influence of three input parameters on the three responses mentioned above through ANOVA. WASPAS and MOORA are two powerful techniques that are used for multi-objective optimization, and the ranks of both the MCDM methods were observed to be same. Traverse speed and abrasive mass flow rate are proven to be statistically significant on MRR and surface finish, whereas standoff distance along with the above two parameters is also significant on the response kerf width. Machined surface morphology is studied using scanning electron microscopy. From the SEM morphology, it was confirmed that the higher abrasive flow rate obtained rough surface finish.

Understanding the heat transfer mechanism in the subsurface is essential for designing geothermal heat extraction system as well as oil extraction system in petroleum reservoirs. Due to the inherent variability in thermal diffusivity in the rock matrix–fracture system, this interface can either act as a source or sink for temperature. The main objective of this study is to investigate the influence of considering the heat transfer term either as a source or a sink at the fissure–matrix interface while describing the spatial and temporal distribution of temperature in a fractured reservoir at the scale of a single fissure. A numerical model is developed using implicit finite difference method to forecast the spatial and temporal propagation of the thermal front and to analyse the sensitivity of various coupling terms at the fissure–matrix interface. Following the numerical treatment, the velocity of thermal front as well as the degree of thermal dispersion encountered within the high-permeable fissure was computed using the method of spatial moments (first and second, respectively). Numerical results indicate that the mobile fluids within the fissure could reflect the exchange of stored heat energy from the rock-matrix quite efficiently for the cases with the heat gain term in the fissure equation. An enhanced mixing effect was observed for the cases having an explicit heat loss term for the matrix in the absence of any source/sink in the fissure equation. However, the thermal mixing regime remained insignificant for the cases having an explicit heat gain term in the fissure.

Discrete groundwater level datasets are interpolated often using kriging group of models to produce a spatially continuous groundwater level map. There is always some level of uncertainty associated with different interpolation methods. Therefore, we developed a new trend function with the mean groundwater level as a drift variable in the regression kriging approach to predict the groundwater levels at the unvisited locations. Groundwater level data for 29 observation wells in Adyar River Basin were used to assess the performance of the developed regression kriging models. The cross-validation results shows that the proposed regression kriging method in the spatial domain outperforms other physical and kriging-based methods with R2 values of 0.96 and 0.98 during pre-monsoon and post-monsoon seasons, respectively.

Studies on mass transfer and transport of dissolved contaminants through heterogeneous hydrogeology rely on realistic expressions of their functional parameters. Hydrodynamic dispersion is one such parameter inheriting significant ambiguities in its estimation when subjected to heterogeneous flow conditions. In this study, a numerical model has been developed to explicitly evaluate the variability of dispersion coefficient on time-based and space-based scales for simulating contaminant transport mechanism in saturated porous media under nonlinear sorption mass transfer. Four types of inlet (solute source) conditions, viz., constant continuous, pulsating, exponentially decaying and sinusoidal varying were considered, and the resulting concentration profiles were compared. The governing partial differential equations were solved using an implicit finite difference technique. The results from sensitivity analysis suggest that the magnitude of the fluid velocity was influenced by the type of dispersion coefficient for different inlet boundary conditions. However, sorption partition coefficients and porosities were generally insensitive to the nature of dispersion under these boundary conditions. When time-dependent dispersion coefficient was adopted, an asymptotic increase in retained solute mass was observed for increased fluid velocity irrespective of the boundary conditions. The behavior of the concentration profile obtained using distance-dependent dispersion coefficient was unique when sinusoidal decaying solute boundary condition was used. The study rightly emphasizes the need for simultaneously updating mass transfer and transport parameters while accounting for the variation in solute inlet conditions.

Supercapacitors are emerged as leading energy storage device and developing new electrode materials for supercapacitors has received much scientific interest from the researchers. In this study, we have synthesized tin oxide-decorated amorphous silica (SnO2@RH-SiO2) nanostructures using rice husk template as a silica source via simple microwave combustion method for supercapacitor applications. XRD, FT-IR, and EDX studies obviously characterize that silica is present in amorphous form along with crystalline SnO2 having a rutile tetragonal structure in the prepared SnO2@RH-SiO2 sample. Further, TEM observation indicates that prepared sample is consisting of amorphous silica nanospheres decorated with agglomerated tin oxide nanoparticles having size of 5–10 nm. Cyclic voltammetry and galvanostatic charge/discharge studies characterize the supercapacitive behavior of working electrode fabricated from prepared SnO2@RH-SiO2 nanostructure. The specific capacitances of SnO2@RH-SiO2 nanostructure are about 448, 330, 275, 240, 225, and 200 F/g with the current density value of 1, 2, 4, 6, 8, and 10 A/g, respectively. The presence SnO2 species in SnO2@RH-SiO2 nanostructure can provide reactive surfaces for the adsorption/desorption charges and it facilitates the charge storage at the surface of sample. The above results suggested that the prepared SnO2@RH-SiO2 nanostructure has potential application for making electrochemical supercapacitors.

The present work investigates the ability of robust biochar from Gracilaria Rhodophyta red weeds collected from the deep sea waters of the Bay of Bengal, for sequential removal of silver and Brilliant Green (BG) dye from contaminated water. The impacting operating parameters viz contact time, the dosage of biochar, pH, and initial Ag+ concentration are optimized using 24 factorial central composite design (CCD)-based statistical modeling. The analysis of variance (ANOVA) projected an excellent history match of model data with experimental through high correlation coefficients. The sequential batch adsorption studies performed at a temperature of 303 K projected an uptake of 4.7 mg/g and 17.8 mg/g at the optimal operating conditions of pH 5–7 and 6, biochar dosage 1.0 and 0.5 g/100 mL, initial concentration 50 mg Ag+ ions and 100 mg BG dye per liter, and operating time 45 and 60 min, respectively, for Ag+ ions and BG dye. Further, the surface morphology, elemental compositions, functional groups, depositional, and structural characteristics of the biochar analyzed using FESEM, EDX, FTIR, BET, and XRD respectively confirmed its ability to successfully treating the contaminants. Moreover, the isothermal, thermodynamic, and kinetic analysis established the Langmuir model-based mono-layered homogeneous physisorption of Ag+ and BG dye with pseudo-second-order depositional characteristics at the solid-solution interface. The biochar is regenerative enough and could remove substantial amounts of Ag+ and BG dye from industrial contaminated water bodies. Moreover, the present work aids in promoting seaweed harvesting as an alternate occupation for littoral fisher societies.

We report the synthesis of hydroxyapatite (HAp)-based antibacterial biomaterials using a mussel shell as a calcium source and by the integration of silver ions via a wet precipitation method. The silver doping at 2 mol% can provide silver-doped carbonated HAp while at 10 mol% can offer silver-doped carbonated HAp/silver oxide nanocomposite. The synthesized Ag-integrated samples exhibit the H (263–903Mpa) and E (0.96–3.31GPa) almost similar to cancellous bone with good antibacterial inhibition on S. aureus (15 ± 02 mm) and E. coli (26 ± 02 mm) growth. Hence, they can be a potential precursor to make bone fillers for the treatment of bone infections.

For the comfortable and luxurious living of human beings, lakhs of products are beings produced daily and are increasing in number rapidly, using innovative technologies. So is the increasing demand for different materials to possess required properties, many a time contradicting ones like light weight and high strength. This necessity for new material with unconventional properties has paved the way to the emergence and development of materials—Metal Matrix Composites (MMC). Materials that possess required properties like high wear and corrosion resistance, good toughness, strength etc., in their fibrous form are conveniently reinforced with base metal matrix to produce MMC. Many such composites are developed for various applications, like in aerospace, automobile, and electronic systems. Development of such new composites posed different challenges in the form of their machinability, formability etc. Various research works attempted to optimize process parameters and develop mathematical models for predicting the machinability. MMCs can be prepared using different processes like Powder Metallurgy, Spray Deposition Method, stir casting, squeeze casting, and electroplating. Different works on MMCs used different production methods. Joining of MMCs is another area where some research is carried out. Some other works used different base materials and reinforcements to obtain needed properties for specific applications. Hence in this context, it is thought apt to consolidate work that is carried out during the last two decades. In this review work, the turn of events, use, and future capability of Al-MMCs in different mechanical and business applications are examined, together with the current difficulties frustrating their full market entrance.

Aluminum-based metal matrix composites are evolving rapidly to cater to the specific needs of the industry. Al 5052 is an alloy of aluminum that possesses high strength and corrosion resistance. It is readily weldable, light in weight, and gives smooth surface finish. The present work target is to improve the mechanical and wear properties of Al 5052 through the addition of reinforcements, silicon carbide (SiC), and titanium carbide (TiC). Stir casting method was utilized for the fabrication of the above hybrid composites by varying the proportion of reinforcements. The first specimen, SP1, is fabricated with 7.5% SiC and 2.5% TiC; the second one, SP2, with 5% SiC and 5% TiC; and the third one, SP3, with 2.5% SiC and 7.5% TiC. Hardness, tensile strength, and wear properties of the above three specimens have been determined using Brinell Hardness tester, Universal Testing Machine (UTM), and Pin-on-Disk wear testing machine, respectively. SP3 has been evaluated to be the better one with regard to improving hardness and tensile strength and recording less wear compared to SP1 and SP2.

We report a facile and inexpensive method to prepare zinc oxide nanoparticles with different particle size and shape using Achyranthes aspera and Couroupita guianensis leaf extracts as the reducing agent and zinc nitrate as a precursor. The prepared zinc oxide nanoparticles were analyzed by various characterization methods and obtained results evidently revealed that crystalline parameter, purity, optical absorption, band gap, particle size and shape of the ZnO nanoparticles significantly influenced by the type of leaf extract used as reducing agent. Further, photocatlytic activity study obviously demonstrates that prepared samples exhibits superior photocatlytic activity for the degradation of methylene blue dye by creating superoxide anion radicals and OH radicals under photonic irradiation. Hence, prepared zinc oxide nanoparticles by plant extract mediated synthesis can be applied as a photocatlyst for the possible waste water treatment in textile industry.

We report the facile synthesis of zinc oxide (ZnO) nanostructures with different sizes and morphologies by a rapid microwave assisted synthesis using ethylenediaminetetraacetic acid (EDTA) and/or trisodium citrate as chelating agents and their characterization. The obtained ZnO nanostructures having hexagonal Wurtzite structure with different morphologies. With the aid of EDTA and/or trisodium citrate, flowers, flakes, solid spheres and porous spheres were obtained by controlling the crystal growth habit and the concentration of ZnO growth units under microwave irradiation. The optical behaviour was analyzed using UV–Vis spectroscopic technique which indicates that the prepared ZnO nanostructures exhibit band gap between 3.27 and 3.37 eV due to potential fluctuations in electronic band structure of ZnO owing to surface-related defects and/or adsorbed species.

To evaluate the application of extended nasolabial flap versus buccal fat pad graft in the surgical management of oral submucous fibrosis.This prospective study was carried out in the Department of Oral and Maxillofacial Surgery, Tamil Nadu Government Dental College and Hospital, Chennai.A total of 8 patients (6 men and 2 women) with age range from 21 to 65 years were selected for study. These 8 patients were randomly divided into two groups of four namely group 1 and group 2. In group 1 patients, reconstruction was planned with extended nasolabial flaps and in group 2 patients, reconstruction was planned with buccal fat pad graft respectively.PairedThe mean preoperative mouth opening in group 1 was 8.5 mm and in group 2 was 11.75 mm. The mean increase in group 1 after one year of postoperative period was 21.50 mm and in group 2 was 24.75 mm.In the present study, buccal fat pad graft proved to give better results as the interposition material as it has good patient acceptance, rapid epithelization, minimal donor site morbidity and minimal intra and postoperative complications.

A one-dimensional numerical model is developed to simulate the nitrogen species in wastewater-applied agricultural field to investigate the effect of various isotherms of ammonium nitrogen and nitrate nitrogen. Results suggest that the ammonium nitrogen concentration reaches up to the depth of 40, 25 and 16 cm due to the linear, Freundlich and Langmuir isotherms of ammonium nitrogen, which is corresponding to the reduction in migration depth up to 37% by Freundlich isotherm and 55% by Langmuir isotherm as compared with linear isotherm. Similarly, the peak concentration of 25, 15 and 12 mg/l of nitrate nitrogen is observed during linear, Freundlich and Langmuir isotherms of NH4–N, respectively. Further, the results show that 4% peak concentration reduction is experienced for NO3–N due to the linear NH4–N sorption alone, 7% peak reduction is observed for NO3–N concentration by Freundlich NH4–N sorption alone, and 12.5% peak reduction is monitored for NO3–N concentration due to Langmuir NH4–N sorption alone compared with the combination of Freundlich NO3–N sorption. The numerical results suggest that the combination of Langmuir isotherm of NH4–N and Freundlich isotherm of NO3–N is identified as a best combination of isotherm scenario, which mitigates the NO3–N contamination in groundwater resources.

The transport of nitrogen coming from wastewater applied agricultural field is a major problem in assessing the vulnerability of groundwater contamination. In this study, laboratory column experiments are conducted in order to simulate the paddy, groundnut and wheat irrigation with wastewater. The experiments are carried out with high clay content (≈35%) soil from Kancheepuram, Tamilnadu and low clay (≈9%) soil from Ludhiana, Punjab, India. Furthermore, a numerical model and HYDRUS-1D model are developed to simulate the experimental results. The experimental results show that there is no effluent collected at the bottom of the column during groundnut irrigation in Kancheepuram soil and effluent collected except during first irrigation in the case of wheat irrigation in Ludhiana soil. The experimental and numerical results illustrate that when 50 mg/l of ammonium and 20 mg/l of nitrate nitrogen applied during paddy irrigation, the peak nitrate nitrogen concentration of 50 mg/l is arrived after 10 days in Kancheepuram soil due to low permeability and relatively less background soil nitrogen. But in the case of Ludhiana soil with 94 mg/l of total nitrogen applied during paddy irrigation, the peak nitrate nitrogen concentration of 1,620 mg/l is observed at first day due to high permeability and high soil background nitrogen concentration. Additionally, the model results show that the application of high nitrogen content wastewater for irrigation in Ludhiana soil will affect the groundwater quality even when the groundwater table is deep as compared with Kancheepuram soil.

A numerical model has been developed in this study for analysing the influence of Sips sorption isotherm on the contaminant transport mechanism in a coupled fracture matrix system. The implicit finite difference numerical technique has been used to solve the coupled non-linear governing equations. A varying grid is adopted at the fracture and rock matrix interface to capture the mass transfer at the interface. A constant continuous source of contaminants is assumed at the inlet of the fracture and the fracture is assumed to be saturated. Results suggest that the magnitude of the Sip’s equilibrium constant in the fracture is extremely sensitive in deciding the resultant transport behaviour within the high permeable fracture. The magnitude of the Sip’s model exponent within the high permeable fracture is highly sensitive in deciding the timing of zero concentration (exhaustion) within the high permeable fracture.

This paper deals with the fuzzy set-valued functions of real variables on time scale whose values are normal, convex, upper semicontinuous and compactly supported fuzzy sets in $$\mathbb {R}^{n}$$Rn. We introduce and study the fundamental properties of new class of derivative called generalized delta derivative ($$\Delta _{g}$$Δg-derivative) and generalized delta integral ($$\Delta _{g}$$Δg-integral) for such fuzzy functions.

Information on the viscosity of Pickering emulsion is required for their successful application in upstream oil and gas industry to understand their stability at extreme environment. In this work, anovel formulation of oil-in-water (o/w) Pickering emulsion stabilized using nanoparticle-surfactant-polymer (polyacrylamide) system as formulated in our earlier work (Sharma et al., Journal of Industrial and Engineering Chemistry, 2014) is investigated for rheological stability at high pressure and high temperature (HPHT) conditions using a controlled-strain rheometer. The nanoparticle (SiO2and clay) concentration is varied from 1.0 to 5.0 wt%. The results are compared with the rheological behavior of simple o/w emulsion stabilized by surfactant-polymer system. Both the emulsions exhibit non-Newtonian shear thinning behavior. A positive shift in this behavior is observed for surfactant-polymer stabilized emulsion at high pressure conditions. Yield stress is observed to increase with pressure for surfactant-polymer emulsion. In addition, increase in temperature has an adverse effect on the viscosity of emulsion stabilized by surfactant-polymer system. In case of nanoparticle-surfactant-polymer stabilized o/w emulsion system, the viscosity and yield stress are predominantly constant for varying pressure and temperature conditions. The viscosity data for both o/w emulsion systems are fitted by the Herschel-Bulkley model and found to be satisfactory. In general, the study indicates that the Pickering emulsion stabilized by nanoparticle-surfactant-polymer system shows improved and stable rheological properties as compared to conventional emulsion stabilized by surfactant-polymer system indicating their successful application for HPHT environment in upstream oil and gas industry. � 2014 The Korean Society of Rheology and Springer.

The pesticides applied on the soil surface can be transported vertically downwards through the unsaturated porous system and lead to groundwater contamination. Proper agricultural management practices such as selection of appropriate irrigation techniques, choosing proper irrigation rates, and application of optimum pesticide dosages are necessary to prevent leaching of pesticides to greater depths thus preventing groundwater contamination. A simulation study is conducted based on the one-dimensional numerical model considering Richard’s equation for unsaturated water flow and solute transport which takes into account the effect of both adsorption and biodegradation with inhibitory effect to understand pesticide transport in an unsaturated porous medium. The study addresses the influence of irrigation rate, type of irrigation, and pesticide dosage on soil moisture and pesticide concentration distribution. The numerical results suggest that higher water application rates can carry the pesticides to greater depths. Pulsed irrigation can slightly reduce water losses through the root zone when compared to continuous irrigation. The comparison of the wetting patterns and the pesticide distribution obtained in continuous and pulsed irrigation helps to decide the use of a particular irrigation strategy in order to achieve suitable goals. In addition, the results from this study bring out better understanding of the effect of pesticide concentration and dosage on the resultant pesticide distribution in the unsaturated zone and the pesticide potential to cause groundwater contamination. The better analysis of outputs from this study can help in improving and designing better agricultural management strategies, carrying out risk assessment and bioremediation studies.

In this paper we obtain a necessary and sufficient condition for the existence of at least one Ψ-bounded solution and also obtained sufficient conditions for Ψ-(uniform) stability of the Kronecker product system associated with the matrix Lyapunov system X′(t)=A(t)X(t)+X(t)B(t)+F(t).

Diet is now one of the well established means in the management of diabetes. Bitter gourd and spent turmeric at 10% level were tested for their efficacy on glycosaminoglycan metabolism in various tissues viz., liver, spleen, lungs, heart and testis in control, diabetic and treated rats. The glycosaminoglycans (GAGs) were isolated from defatted and dried tissues. The contents of sulfated GAGs decreased in all the tissues and the decrease was more prominent in heart and testis. In the isolated GAGs, contents of total sugar, amino sugar, uronic acid and sulfate were studied. Decrease in total sugar content was maximum in testis. Amino sugar content decreased considerably in testis (38%) and lungs (15%). The content of uronic acid also decreased in testis (33%) besides heart (29%) and liver (25%). Sulfate groups in GAGs perform pivotal functions in many biological events and decrease in sulfate content was significant in heart (40%), testis (37%) and liver (37%). GAGs profile on the cellulose acetate electrophoresis revealed that heparan sulfate (HS), hyaluronic acid (HA) and chondroitin sulfate/dermatan sulfate (CS/DS) were present in liver, spleen and lungs. HS, CS were present in heart, DS/CS was observed in testis. The observed beneficial effects in GAGs metabolism during diabetes may be due to the presence of high amounts of dietary fibres present in bitter gourd and spent turmeric, besides, possible presence of bioactive compounds in one or both of them.

Bitter gourd (Momordica charantia), a commonly consumed vegetable is used as an adjunct in the management of diabetes mellitus. A study was carried out to examine the effect of edible portion of bitter gourd at 10% level in the diet in streptozotocin induced diabetic rats. To evaluate the glycaemic control of bitter gourd during diabetes, diet intake, gain in body weight, water intake, urine sugar, urine volume, glomerular filtration rate and fasting blood glucose profiles were monitored. Water consumption, urine volume and urine sugar were significantly higher in diabetic controls compared to normal rats and bitter gourd feeding alleviated this rise during diabetes by about 30%. Renal hypertrophy was higher in diabetic controls and bitter gourd supplementation, partially, but effectively prevented it (38%) during diabetes. Increased glomerular filtration rate in diabetes was significantly reduced (27%) by bitter gourd. An amelioration of about 30% in fasting blood glucose was observed with bitter gourd feeding in diabetic rats. These results clearly provided experimental evidence that dried bitter gourd powder in the diet at 10% level improved diabetic status signifying its beneficial effect during diabetes.

The role of intraseasonal oscillations (ISOs) in modulating synoptic and interannual variations of surface winds over the Indian monsoon region is studied using daily averaged National Centers for Environmental Prediction/National Centre for Atmospheric Research (NCEP/NCAR) reanalyses for the period 1987-1996. Two dominant ISOs are found in all years, with a period between 30-60 days and 10-20 days respectively. Although the ISOs themselves explain only about 10-25% of the daily variance, the spatial structure of variance of the ISOs is found to be nearly identical to that of high frequency activity (synoptic disturbances), indicating a significant control by the ISOs in determining the synoptic variations. Zonal and meridional propagation characteristics of the two modes and their interannual variability are studied in detail. The synoptic structure of the 30-60 day mode is similar in all years and is shown to be intimately related to the strong ('active') or weak ('break') phases of the Indian summer monsoon circulation. The peak (trough) phase of the mode in the north Bay of Bengal corresponds to the 'active' ('break') phase of monsoon strengthening (weakening) the entire large scale monsoon circulation. The ISOs modulate synoptic activity through the intensification or weakening of the large scale monsoon flow (monsoon trough). The peak wind anomalies associated with these ISOs could be as large as 30% of the seasonal mean winds in many regions. The vorticity pattern associated with the 30-60 day mode has a bi-modal meridional structure similar to the one associated with the seasonal mean winds but with a smaller meridional scale. The spatial structure of the 30-60 day mode is consistent with fluctuations of the tropical convergence zone (TCZ) between one continental and an equatorial Indian Ocean position. The 10-20 day mode has maximum amplitude in the north Bay of Bengal, where it is comparable to that of the 30-60 day mode. Elsewhere in the Indian Ocean, this mode is almost always weaker than the 30-60 day mode. In the Bay of Bengal region, the wind curl anomalies associated with the peak phases of the ISOs could be as large as 50% of the seasonal mean wind curl. Hence, ISOs in this region could drive significant ISOs in the ocean and might influence the seasonal mean currents in the Bay. On the interannual time scale, the NCEP/NCAR reanalysed wind stress is compared with the Florida State University monthly mean stress. The seasonal mean stress as well as interannual standard deviation of monthly stress from the two analyses agree well, indicating absence of any serious systematic bias in the NCEP/NCAR reanalysed winds. It is also found that the composite structure of the 30-60 day mode is strikingly similar to the dominant mode of interannual variability of the seasonal mean winds indicating a strong link between the ISOs and the seasonal mean. The ISO influences the seasonal mean and its interannual variability either through increased/decreased residence time of the TCZ in the continental position or through occurrence of stronger/weaker active/break spells. Thus, the ISOs seem to modulate all variability in this region from synoptic to interannual scales.

The modulation of apolipoprotein B synthesis and secretion by fatty acids in rat hepatocytes was studied. Maximum apolipoprotein B production was obtained in the case of oleic acid followed by linoleic, stearic and palmitic/linolenic acid when compared to control which was not supplemented with any fatty acids. Oleic acid was found to exert a concentration dependent increase in the secretion of [3H] apolipoprotein B into the medium while that associated with the cell layer was not affected. Pulse chase experiments in the presence of oleic acid showed that it caused an increase in the secretion of apolipoprotein B into the medium.14C-acetate incorporation into cholesterol and cholesteryl ester associated with the cell layer and secreted very low density lipoproteins also showed an increase in the presence of oleic acid indicating an increase in cholesterogenesis. The effect of oleic acid on [3H] apolipoprotein B and very low density lipoproteins secretion appeared to be mediated through cholesterol as (i) ketoconazole, an inhibitor of cholesterol synthesis caused significant reduction in the stimulatory effect of oleic acid on apolipoprotein secretion and (ii) mevinolin, another inhibitor of cholesterol synthesis also reversed the stimulatory effect of oleic acid on apolipoprotein B secretion. These results indicated that oleic acid may influence apolipoprotein B synthesis and secretion in hepatocytes probably by affecting cholesterol/cholesteryl ester formation which may be a critical component in the secretion of apolipoprotein B as lipoproteins

Acanthamoeba sp. is a free-living amoeba known to cause chronic central nervous system infection or eye infection in humans. Many cases remain undetected for want of a good detection system. We report for the first time a rapid staining method to facilitate the identification of Acanthamoeba sp. using the modified Field's staining technique. A. castellanii, which was used in the present experiment, is maintained in our laboratory in mycological peptone medium (Gibco). The cultures were pooled together and smears were made on glass slides for staining purposes. Different types of stains such as Field's stain, modified Field's stain, Wright's stain, Giemsa stain, Ziehl-Neelsen stain, and trichrome stain were used to determine the best stain for the identification of this amoeba. The concentration of various stains and the duration of staining were varied to provide the best color and contrast for each stain. Acanthamoeba was also obtained from the brain of experimentally infected mice and was stained with various stains as mentioned above to determine the best stain for use in identifying the presence of this parasite in experimentally infected animals. The modified Field's stain gives a very good color contrast as compared with other stains. Furthermore, it takes only 20 s to be carried out using the least number of reagents, making it suitable for both laboratory and field use.

The present study investigated whether people working closely with animals were at higher risk of getting infected with Blastocystis hominis. The prevalence of the parasite was determined in two population groups, i.e., animal handlers and normal healthy individuals who did not work with animals. In all, 105 stool samples were collected from animal handlers from 2 local research institutions, a local zoo, and a local abattoir and 163 stool samples were collected from normal healthy individuals residing in high-rise flats in the city. The in vitro culture method used in the study detected that 41% of 105 animal handlers and 17% of 163 flat-dwellers in the city were positive for Blastocystis. This statistically significant finding (P = 0.0000313) shows that people who work closely with animals do stand at risk of acquiring Blastocystis infection.

An α-D-galactose-specific lectin from the seeds of jack fruit (Artocarpus integra) has been isolated in pure form by affinity chromatography on immobilised guar gum (a galactomannan). The lectin is shown to be a glycoprotein containing 3% carbohydrate and having a molecular weight of 39,500 as determined by gel filtration. Sodium dodecyl sulphate gel electrophoresis revealed a single polypeptide of 10,500 dalton, indicating that the native lectin is a tetrarner of identical subunits. The hemagglutinating activity of the lectin towards erythrocytes of all blood groups is found to be the same.

The interaction of the oligopeptides Ala-Gln-GIn-Leu-Ala-Gly-OH and Gln-Leu-Ala-Gly-OMe corresponding, respectively, to the sequence 53–58 and 55–58 oflac repressor protein with four polynucleotides was studied. The two peptides did not interact with poly dA. poly dT, poly d(A-T)·poly d(A-T) or poly d(A-G)·poly d(C-T). But they interacted in a characteristic way with poly d(A-C). poly d (G-T), the sequences of which are in abundance in thelac operator region. Both the peptides stabilised the melting of poly d (A-C). poly d (G-T) at a peptide to nucleotide ratio (P/N) of 4; at lower ratios, they destabilised the DNA slightly. The circular dichroism of the alternating polynucleotide with CAC/GTG sequences was perturbed by both the oligopeptides. The hexapeptide at a P/N of 4 caused the transformation of the B-form circular dichroism spectrum to a new state, characterised by strong 220 and 240 nm bands, and a rather weak long wavelength spectrum.