Varying Time Durations Research Articles

Machine learning predictive model for dynamic response of rising bubbles impacting on a horizontal wall

The integrated behavior of the fluid flow, encompassing variation of some specific response, has received more attention than mere examination of velocity and pressure distributions. A machine learning framework is introduced for the first time to elucidate and predict the complex fluid dynamic responses across varying time scales. For the same class of fluid processes, the dynamic response curves with varying time durations can be defined in terms of time scales and curve shapes. The former is predicted by a single-objective regression model, and the curves are normalized and recovered using time scaling and uniform interpolation. The latter are downscaled by Principal Component Analysis (PCA) and then predicted by a multi-objective regression model. As a novel application, this framework is employed to analyze small bubbles in a Newtonian fluid as they impact a horizontal wall, predicting the velocity, aspect ratio, and position dynamic response of the bubbles. Both Random Forest and Gaussian Process models, based on PCA-driven data processing, exhibit remarkable accuracy in describing and predicting complex dynamics of rising bubbles. Notably, PCA's principal components demonstrate independence and are set through rigorous cross-validation of the training set, rather than dependence on the Cumulative Variance Explained (CVE) values. Furthermore, our framework adeptly extends to predict the complex behavior of multiple bubble bounces by concatenating individual bounce predictions with high efficiency and precision. The proposed framework proves to be a catalyst for comprehending the dynamic response of fluids.

Swelling kinetics of mixtures of soybean phosphatidylcholine and glycerol dioleate

Lipid-based drug delivery systems offer the potential to enhance bioavailability, reduce dosing frequency, and improve patient adherence. In aqueous environment, initially dry lipid depots take up water and form liquid crystalline phases. Variation of lipid composition, depot size and hydration-induced phase transitions will plausibly affect the diffusion in and out of the depot. Lipid depots of soybean phosphatidylcholine (SPC) and glycerol dioleate (GDO) mixtures were hydrated for varying time durations in a phosphate-buffered saline (PBS) buffer and then analyzed with Karl Fischer titration, magnetic resonance imaging (MRI) and gravimetrically. Mathematical modeling of the swelling process using diffusion equations, was used to estimate the parameters of diffusion. Both composition of lipid mixture and depot size affect swelling kinetics… The diffusion parameters obtained in Karl Fischer titration and MRI (with temporal and spatial resolution respectively) are in good agreement. Remarkably, the MRI results show a gradient of water content within the depot even after the end of diffusion process. Apparently contradicting the first Fick’s law in its classical form, these results find an explanation using the generalized Fick’s law that considers the gradient of chemical potential rather than concentration as the driving force of diffusion.

Extraction of <i>trans</i>-Anethole from Star Anise (<i>Illicium verum</i>) Using Combination of Microwave, Ultrasonic, and Enzyme Assisted Methods and Evaluation of Their Antibacterial Activity

This study examines the efficiency of non-conventional extraction methods to obtain trans-anethole from Illicium verum using single and combination extraction techniques: microwave assisted extraction (MAE), ultrasound-assisted extraction (UAE), and enzyme assisted extraction (EAE) employing lipase from Aspergillus oryzae. All extraction methods were conducted using 96% ethanol (1:5 w/v) with varying time durations. The resulting product was an oleoresin, subsequently analyzed and separated using thin liquid chromatography (TLC) and column chromatography employing a solvent mixture of toluene and ethyl acetate in a 9:1 ratio and identified via gas chromatography-mass spectra (GC-MS). The results revealed that trans-anethole yields from a single extraction method were 30.76% (MAE), 41.05% (UAE), and 40.90% (EAE). The combination of extraction methods, such as MAE-UAE, MAE-EAE, and UAE-EAE, produced trans-anethole yields of approximately 42.73%, 52.80%, and 45.02% respectively, surpassing the yields of the single extraction method. Notably, the triple extraction method of MAE-UAE-EAE yielded the highest trans-anethole content at 56.00%. Antibacterial testing against Staphylococcus aureus was performed on all samples. The trans-anethole demonstrating the highest inhibitory effect was obtained from the double extraction method, particularly the combination of UAE-EAE. These results underscore the synergistic efficiency of combining microwave, ultrasound, and enzymatic extraction methods, highlighting their superior efficacy in obtaining trans-anethole.

PO-01-126 SEXUAL DIMORPHISM AND CARDIAC ARRHYTHMIAS IN A MOUSE MODEL OF FRIEDREICH'S ATAXIA: WHAT DO WE KNOW?

Friedreich ataxia (FA) is a monogenic recessive disorder caused by the reduction of the mitochondrial protein, frataxin (FXN). Despite neurological deficits place patients with FA in the wheelchairs, most patients die from lethal cardiomyopathy in their 40s. FA patients develop progressive cardiac disease with characteristics similar to primary hypertrophic cardiomyopathy but with more progressive cardiac fibrosis, both diastolic and systolic dysfunction, and arrhythmias. However, the mechanisms leading to cardiomyopathy and arrhythmias in FA patients are poorly understood. To characterize electrical signal propagation and cardiac function in a mouse model which imitates the late-stage cardiomyopathy in FA patients. Cardiac-specific McK-Cre FXN knockout (FXN cKO) mice were used as a model of severe cardiomyopathy which is characteristic for the late-stage of FA. Due to premature death, animals of either sex at 8-weeks of age were used to assess cardiac function in-vivo by echocardiography and surface electrocardiogram (ECG). We found that FXN cKO mice developed idiosyncratic arrhythmias with varying time durations for beat-to-beat (RR) intervals and heart rate variability (HRV) parameters such as root mean squared successive differences (RMSSD, p<0.0358), revealing increased vagal activity. Mice presented extended P-wave (p<0.0113) and QTc intervals (>150 ms, p<0.0015), suggesting impaired atrial and left-ventricular function, resembling human patients. HRV frequency parameters showed increased low-frequency (0.023), high-frequency (p<0.264) and total (p<0.0326) power. Non-linear parameters showed varying short-term variation (SD1, p<0.019), increased long-term variation (SD2, p<0.0017) and ellipse area values (S, p<0.0074). Poincare plots of FXN cKO males included multiple clustering of RR and RR+1 identities while females generally sustained a single clustered ellipse (area, p<0.028). Similarly, QTc intervals were increased mostly in FXN cKO males. Contractile dysfunction was also more severe in FXN cKO males as evident by reduction in left ventricular fractional shortening, ejection fraction, stroke volume and cardiac output. Our study revealed sexual dimorphism and significant impairment in electrical and contractile function in FXN cKO males compared to females. A detailed characterization of impaired electrical signals in FA hearts will build a platform for drug testing to treat lethal cardiomyopathy in FA.

Understanding of low-carbon steel marine corrosion through simulation in artificial seawater

&lt;abstract&gt; &lt;p&gt;The current laboratory experiments investigated the corrosion resistance of carbon steel in artificial seawater (ASW) using the steel coupons hanging on a closed glass reactor of ASW with volume-to-specimen area ratios ranging from 0.20 to 0.40 mL/mm&lt;sup&gt;2&lt;/sup&gt;. These coupons were immersed in ASW for varying time durations (7 and 14 d) at room temperature without agitation. Further, the corrosion rates based on the weight loss and electrochemical analytical method were determined. Following exposure to carbon steel for 7 and 14 d, corrosion rates were 0.2780 &lt;italic&gt;mmpy&lt;/italic&gt; and 0.3092 &lt;italic&gt;mmpy&lt;/italic&gt;, respectively. The surfaces appeared to be not protected by oxides based on this result. The electrochemical impedance spectrometer in potentiostatic/galvanostatic mode, in conjunction with EDX analysis, predicted the evolution of oxygen reduction. The 7th-day immersion sample had a higher oxygen content, and the 14th-day immersion sample had a slightly lower oxygen content. Methods of X-ray diffraction (XRD) and scanning electron microscopy (SEM) characterized the surface morphology and composition of their corrosion product. Corrosion products derived from rust minerals hematite, lepidocrocite and magnetite appeared to cover the carbon steel surface after exposure. This result can get insight into the corrosion behavior of low-carbon steel used in marine environments.&lt;/p&gt; &lt;/abstract&gt;

Understanding the Role of Directional Texture in Tribofilm Evolution

Abstract This paper reports a study of the evolution of directional texture and its role in the manipulation of tribofilm layers under boundary lubrication (BL). The use of surface protective tribofilms/lubricant chemistries along with the use of textured surfaces has gained significant attention as an effective BL strategy to provide advanced lubrication. However, the evolution of surface texture in the direction of motion under continuous asperity-to-asperity contact remains unexplored, especially in correlation with the tribofilm properties on textured surfaces. Mechanical polishing using SiC abrasive paper was used to generate directional and concentric surface texture on 52100 steel discs. Tribological tests of varying time durations were performed using MoS2-based lubricant to systematically study the evolution of texture and tribofilm using a pin-on-disc rotational setup. A laser microscope was used for areal texture characterization while tribofilm was characterized using SEM/EDS, Raman, and FIB/TEM. The results show that directional texture manipulates the early onset and tribo-chemical reactions and the delivery of lubricant tribofilm on the asperities during the evolution process.

Wettability of thermoplastic and thermoset polymers with carbon nanotube grafted carbon fiber

In this experimental study the wetting behavior of unsized and carbon nanotube (CNT) grafted carbon fibers is assessed with various polymers. Thermoset epoxy and two thermoplastics (polypropylene and polycarbonate) are tested. Sessile drop method and drop-on-fiber method are employed to quantify the wettability of various fiber/polymer combinations. Contact angle measurements based on the above two methods give insights into the effectiveness of various polymers to wet different types of carbon fiber fabrics and single fiber filaments. Moreover, the effect of CNT length and density on the wettability of carbon fibers is ascertained by synthesizing nanotubes on the fiber surface for varying time durations (10–30 min). CNT grafting reduces the contact angle of the polymer drop with carbon fiber; however, too much growth of nanotubes on the fiber surface leads to improper impregnation of the polymer into the carbon fabric. While polypropylene shows better wetting characteristics with unsized and CNT grafted carbon fibers, polycarbonate shows poor wettability.

A scalable approach for functionalization of TiO2 nanotube arrays with g-C3N4 for enhanced photo-electrochemical performance

Graphitic carbon nitride (g-C3N4) has manifested itself as an effective counterpart of titanium di-oxide (TiO2) to extend its photoactivity in the visible range. In this work, g-C3N4 functionalized TiO2 nanotubes were synthesized by electrodeposition of g-C3N4 in bulk on TiO2 nanotubes from a continuously rotating organic suspension at a moderate voltage (∼90 V). Additionally, samples with varying time durations were also synthesized to examine the effect of electrodeposition time on the performance of g-C3N4 functionalized TiO2 nanotubes. Photo-electrochemical measurements demonstrated strong light induced activity, with a photocurrent density of 0.14 mA/cm2 at 1 V vs Ag/AgCl in 1 M Na2SO4 electrolyte. Maximum photoresponse for g-C3N4 functionalized TiO2 nanotubes was upto 4 factors higher than bare TiO2 nanotubes. The crystallinity, morphology and chemical compositions were investigated by XRD, FESEM and XPS respectively. Further, the optical absorption edge, chemical bonds and defects states were evaluated by UV–visible, Raman, FTIR, PL and EPR spectroscopy. The properties of g-C3N4/TiO2 system were correlated with the photocurrent behaviour and a mechanism of the probable role of vacancies and defects in their photo induced activity has been proposed. The study has established a simple and scalable scheme for the functionalization of TiO2 nanotube with g-C3N4 to achieve enhanced photo-electrochemical properties.

Ductility effect on clinching joint strength in lap-shear configuration loading

Clinching is a mechanical sheet metal joining method in which the sheets are geometrically interlocked using, punch and die, tools without any consumables. In this work, to improve the clinching joint strength in lap shear configuration, the base sheet material is heat-treated in a furnace over varying time durations and temperatures to improve the ductility. Ductility is the prime factor in deciding the amount of cold roll bonding (CRB). This CRB helps during the joining of heat-treated sample to eliminating the gap at the “S” interlock and increase in friction, otherwise the gap would be present in the untreated material. This elimination of gap and higher friction is necessary for the identified belt friction mechanism operating at the lap shear configuration to produce higher joint strength. These causes are confirmed by examining SEM images of the cross sections of the joint and fractography of the failed joint interface. The joints so formed are tested for its strength in monotonic lap-shear configuration loading. Experimentally it is observed that the heat-treatment of base sheets improves the strength in this configuration by more than 50% compared to the untreated material.

Characterization of High Temperature Calibration Bath through Stability and Uniformity Tests with Data Acquisition using Standard Platinum Resistance Thermometer and Precision Multimeter

Calibration is one area in measurement where our country is still in the process of improvement. The absence of confirmed approaches and actions for identifying the features of calibration baths by numerous laboratories disallowed them to assess more the finest measurement ability and develop their accurateness. In recent advances in technology, there is now a way of providing the best measurement capability in temperature calibration by providing validated methods in characterizing calibration baths that contributes to the uncertainty of measurement of the calibrated thermometer and is therefore important to measure the extent of its contribution to the final uncertainty. This study adapted the process from obtainable and current methods. Platinum Resistance Thermometer (PRT-Isotech) and Standard Platinum Resistance Thermometer (SPRT-Hart) which are interfaced to Precision Digital Multimeters were used for measurements. Quite a few measurements were made at varying time durations implemented on several known positions in an orderly measurement form which enclosed the whole workspace. The uniformities and stabilities of the calibration bath were computed by getting the range of the Minimum Difference with the Maximum Difference taken at every established temperature point. Outcomes of measurements exhibited that the calibration bath stability at every temperature setting are steadier at lesser temperatures and have a tendency to rise as the temperature approaches 250oC. The liquid bath was further unvarying at lesser temperatures. The variances found were insignificantly distributed since the Standard Deviation ranged only from 0.005 to 0.013.

Evaluation of self-healing properties of inhibitor loaded nanoclay-based anticorrosive coatings on magnesium alloy AZ91D

This study emphasizes on the evaluation and comparison of the anticorrosive properties of sol–gel coatings with and without inhibitor loaded nanocontainers. In this case, naturally available clay nanotubes (halloysite) were loaded with cationic corrosion inhibitors Ce3+/Zr4+. These nanocontainers were dispersed in hybrid organic–inorganic sol–gel matrix sol. Coating was applied on magnesium alloy AZ91D using the sols containing modified and unmodified nanocontainers employing the dip coating method and cured at 130 °C for 1 h in air. Corrosion resistance of coated/uncoated substrates were analyzed using electrochemical impedance spectroscopy, potentiodynamic polarization and weight loss measurements after exposure to 3.5 wt% NaCl solution for varying time durations between 24 h to 120 h. Self-healing ability of coatings was evaluated by micro-Raman spectroscopy after 120 h exposure to 3.5 wt% NaCl solution. Coatings generated after dispersion of corrosion inhibitor loaded clay in hybrid sol–gel matrix have shown more promising corrosion resistance when compared to just the sol–gel matrix coatings, after prolonged exposure to corrosive environment.

Montmorillonite nanoclay-based self-healing coatings on AA 2024-T4

Cation-exchanged montmorillonite (MMT), which is an aluminum-pillared clay, was dispersed into an organic–inorganic hybrid silica matrix sol. Cationic inhibitors Ce3+/Zr4+ were introduced into montmorillonite by two methods, namely (1) physical mixing of MMT with the inhibitor solutions and (2) physical mixing for short durations and evacuation of the mixture of MMT and inhibitor solutions. Coatings using these sols were deposited on aluminum alloy AA 2024-T4 substrates, by the dip coating technique followed by thermal curing at 130°C for 1 h. TEM, BET, and XRD analyses were carried out for the inhibitor-modified montmorillonite powders. Potentiodynamic polarization and electrochemical impedance spectroscopic analyses were carried out on uncoated and coated substrates to evaluate the corrosion protection property after exposure to 3.5 wt% NaCl for varying time durations, up to 120 h. Self-healing ability was evaluated using SVET analysis by creating an artificial scribe on the surface and exposure to 3.5 wt% NaCl. Elemental mapping was carried out on scribed substrates before and after exposure to 5 wt% salt fog. Sols containing montmorillonite intercalated with cationic inhibitors when deposited on AA 2024-T4 substrates exhibited low corrosion currents after a prolonged duration of exposure to corrosion medium.

Development of calcium titanium oxide coated silicon solar cells for enhanced voltage generation capacity

Abstract Depletion of fossil fuel based energy sources drive the present scenario towards development of solar based alternative energy. Polycrystalline silicon solar cells are preferred due to low cost and abundant availability. However, the power conversion efficiency of polycrystalline silicon is lesser compared to monocrystalline one. The present study aims at analyzing the effect of calcium titanium oxide (CaTiO3) antireflection (AR) coating on the power conversion of polycrystalline solar cells. CaTiO3 offers unique characteristics, such as non-radioactive and non-magnetic orthorhombic biaxial structure with bulk density of 3.91 g/cm3. CaTiO3 film deposition on the solar cell substrate has been carried out using Radio Frequency (RF) magnetron sputter coating technique under varying time durations (10 min to 45 min). Morphological studies proved the formation of CaTiO3 layer and respective elemental percentages on the coated substrate. Open circuit voltage studies were conducted on bare and coated silicon solar substrates under open and controlled atmospheric conditions. CaTiO3 coated on a solar cell substrate in a deposition time of 30 min showed 8.76 % improvement in the cell voltage compared to the bare solar cell.

Self-healing ability of nanoclay-based hybrid sol-gel coatings on magnesium alloy AZ91D

The main objective of the study was to investigate the effect of loading cationic corrosion inhibitors into halloysite nanotubes on the corrosion resistance of self-healing coatings derived from these materials. For this purpose, corrosion inhibitors Ce3+/Zr4+ were encapsulated into halloysite clay nanotubes. The encapsulated nanotubes were dispersed into a hybrid silica sol-gel matrix and deposited on magnesium alloy AZ91D substrates by dip coating method. The coatings were cured at 130°C for 1h in air. The bare, matrix sol coated and self-healing sol coated substrates were evaluated for their self-healing and corrosion protection abilities using weight loss experiments, potentiodynamic polarization and electrochemical impedance spectroscopy measurements after immersion in 3.5% NaCl solution for varying time durations between 1h to 24h. These results were further corroborated with those obtained from scanning vibrating electrode technique. The self-healing property and the promising nature of cationic corrosion inhibitor loaded halloysite nanotube based corrosion protection coatings on AZ91D substrates could be confirmed from the present investigations.

Induction of giant cells by the synthetic food colorants viz. lemon yellow and orange red.

Cytotoxicity and giant cell formation induced by lemon yellow and orange red synthetic food colorants were evaluated in the present study. The aqueous solutions of both the dye solutions were tested for cytotoxicity using Allium cepa assay. Frequency of giant cells were determined after treating the root tips with different concentrations of both food colorant solutions viz., 0.005, 0.01, 0.05, 0.1% for varying time durations (1/2, 1, 2, 3h). These colorants may cause giant cell formation primarily by interfering with the normal course of mitosis. Giant cells showing multiple aberrations viz. bridged and binucleate condition, cellular fragmentation, nuclear lesion, double and multiple nuclear lesions, double nuclear peaks and cellular breakage, elongated nucleus, nuclear budding, hyperchromasia, micronucleus, nuclear erosion, pulverized nucleus etc. were induced in root tips treated with both of the colorants. The synthetic food colorant treated cells showed inhibition of cell division and induction of giant cells. A dose dependant decrease in the mitotic index [88.20% (c(-ve), 3h) to 81.54% (Lx4, 3h) and 88.20% (c(-ve), 3h) to 73.17% (Ox4, 3h)] was observed. All mitotic phases show significant induction of giant cells when treated with both food colorants. Interphase stage shows higher percentage of giant cells, whereas in cytokinesis it was negligible. The orange red food colorant is observed to be more toxic because it recorded higher percentage of giant cell induction when compared with lemon yellow [27.93% (Lx4, 3h) and 28.07% (Ox4, 3h)].

Toxicological evaluation of polar and nonpolar components of Isodon coetsa (Lamiaceae)

Isodon coetsa (Buch.-Ham. ex D.Don) Kudo, a perennial herb used in traditional Chinese folk medicines as an antibacterial, antiinflammatory, and antitumour agent, was subjected to toxicity analysis. Cytotoxic screening using the Allium L. assay was done with extracts containing polar and nonpolar compounds as well as with polar compounds alone. Root tips were treated with different concentrations of both the extracts, 0.005%, 0.01%, 0.05%, and 0.1%, for varying time durations (30 min, 1 h, 2 h, and 3 h). Extremely significant levels of chromosome abnormality (P < 0.001) were observed with the extracts when compared with the positive control (0.01% methyl parathion), but the extract with polar and nonpolar compounds showed higher abnormality percentage. Not much variation was observed in the mitotic index when compared to the negative control (distilled water). Studies revealed many clastogenic and nonclastogenic abnormalities. The major abnormalities included chromosome fragments, stickiness, ring chromosomes, chromosome bridges, pulverization, binucleate cell, micronucleus, ball metaphase, chromosome laggards, and shift in microtubule organizing center. The results showed that the nonpolar components possessed more clastogenic activity, which can be specifically targeted in order to destroy cancer cells. The toxic activity of extracts also suggests the need of judicious use of I. coetsa in folk medicines.

Experimental Studies on the Superplastic Forming of Square Shaped Components and Diffusion Bonding Characteristics of Ti–6Al–4V Alloy

Superplasticity is the ability of a polycrystalline material to exhibit, in a relatively isotropic manner, large elongations when deformed in tension. This property is exploited during superplastic forming in the fabrication of complex-shaped components which are otherwise technically difficult or economically costly to form by conventional methods. The ability of some titanium alloys to undergo superplastic deformation coupled with their diffusion bonding capability provides excellent opportunities to fabricate intricate parts resulting in significant cost and weight savings, particularly in the manufacture of aerospace structures. In the present work, experimental studies on the superplastic forming of square shaped components from titanium alloy Ti–6Al–4V sheets of 2 mm thickness that are commonly used in aerospace structural applications are reported. Superplastic forming of suitably sized blanks was carried out at temperatures of 1,148 K (875 °C), 1,173 K (900 °C) and 1,200 K (927 °C) using constant argon gas pressures of 1, 1.4 and 1.8 MPa. The formed components were characterized for their thickness distribution, mechanical and metallurgical properties. Diffusion bonding characteristics of the alloy sheet of 1 mm thickness were investigated for varying time durations at different temperatures and 4 MPa stress under an argon atmosphere and lap shear strength values of the joints are reported. Efforts were then made to carry out diffusion bonding concurrent with superplastic forming (SPF/DB). For these experiments, two sheets of 1 mm thickness each were superplastically formed into square components of size 80 mm square and 60 mm deep with an initial forming cycle followed by a diffusion bonding cycle by subjecting the component to a static pressure (higher than the forming pressure) for a specified period of time, which ensured good bonding between the two sheets. The components formed by the SPF/DB process were compared with those formed from the monolithic 2 mm sheet and the results are presented.

C-mitotic effect of aqueous extracts of Isodon coetsa (Buch.-Ham. ex D. Don) Kudo (Lamiaceae)

Isodon coetsa (Buch.-Ham. ex D. Don) Kudo (Lamiaceae) belongs to a genus typified for the presence of bioactive ent-kaurane diterpenoids and have been used in traditional Chinese folk medicine as antibacterial, antiinflammatory and antitumour agents for a long time. The aqueous leaf extracts were tested for cytotoxicity screening using Allium cepa assay due to its biological activity. Root tips were treated with different concentrations of the extract viz., 0.005 %, 0.01 %, 0.05 %, 0.1 % for varying time durations (½ h, 1 h, 2 h, 3 h). Increase in mitotic index was observed in all treatments. High frequency of aberrations viz., C-metaphase, polyploidy, cytostasis and vagrant chromosomes were observed in treated root tips, which revealed the C-mitotic effect in the extract. The plant extracts show severe as well as partial C-mitotic activity which was time and concentration independent. C-mitotic activity was found to be prominent during 1 h treatment at all concentrations which may be due to the cytostatic effect. Higher duration treatments at all concentration revealed a decrease probably due to the cytotoxic effect during prolonged exposure. Induction of polyploidy was observed at all treatments, which do not show any correlation either with concentration or time, probably due to the metabolic imbalance of the treated cells. Thus, it is concluded that Isodon coetsa leaf extracts possess C-mitotic activity which can be the effect of the presence of a colchicine like compound in it.

An investigation of a TiAlO based refractory slurry face coat system for the investment casting of Ti–Al alloys

The investment casting process offers great freedom of design with the economic advantage of near net shape production and has been widely used to process TiAl alloys. An investigation was undertaken to develop stable and cheap refractory slurry systems, suitable for use as a face coat in the investment casting of titanium aluminides. A TiO2–Al2O3 (TiAlO) based face coat slurry was investigated and compared with a traditional yttria based face coat slurry. After sintering, the chemical inertness of the manufactured shells in contact with molten TiAl alloys was tested by simulating the casting process using a flash re-melting test, in which sample shells were in contact with titanium aluminides at given temperatures for varying time durations and subsequently re-solidified. Compared with yttria, the TiAlO face coat had relatively lower chemical inertness against molten alloys, forming a thick hardened layer at the metal/shell interface with massive interaction products along grain boundaries. The reaction also changed the wetting behaviour of the TiAl on the TiAlO face coat with the contact angle decreasing as a function of interaction time.

In vitro anthelmintic efficacy of Carex baccans (Cyperaceae): ultrastructural, histochemical and biochemical alterations in the cestode, Raillietina echinobothrida

The aqueous juice of the root extract of Carex baccans (Family: Cyperaceae) is used as an anthelmintic in Meghalaya, India. The present investigation was carried out to evaluate the extent of ultrastructural, histochemical and biochemical alterations caused by the plant derived component(s) on Raillietina echinobothrida, a cestode parasite of domestic fowl. Live tapeworms, collected from the freshly slaughtered host, were exposed to different concentrations of the crude ethanolic root extract of C. baccans for varying time durations. The treated parasites revealed complete inactivation and flaccid paralysis leading to death; they were processed for ultrastructural, histochemical and biochemical observations, as soon as paralysis set in. Compared to controls, the treated parasites showed extensive distortion and destruction of the surface fine topography of the tegument, erosion of microtriches, disruption of muscle layers, intense vacuolization of tegumental and subtegumental layers, swelling and vacuolization of mitochondria and a significantly reduced activity of tegumental enzymes like AcPase and AlkPase. Phytochemicals from the root of C. baccans seem to be effective against soft-bodied cestode parasites and need to be characterized and identified.