Energy Dispersive X-Ray Microanalysis in conjunction with Scanning Electron Micrography to establish nematodes as bioindicators in marine fish environment

Energy Dispersive X-Ray Microanalysis (EDXMA) has been used as the non-invasive technique on Indian helminthes to explore the role of nematode parasites as bioindicators in the marine ecosystem of Central West coast of India for the first time. The investigation incorporates assertions on the possible benefit of such technology to elucidate bioremediating prospects that could be helpful to establish helminth parasites as a tool representing Bioindicators. The accumulation of Sulphur and Iron were analysed from a raphidascaridoid roundworm, Rostellascaris spinicaudatum (Malhotra and Anas) parasitizing marine catfish, Arius maculatus from the Central west coast of India at Goa. Quantitatively, the cuticle on oral armature comprised as much as ten times more Sulphur than iron content in the roundworm under study. However, only Carbon and Oxygen were detected over caudal papillae, where no metals or other elements were recorded.

Antibiocorrosive Hybrid Materials with High Durability

We have developed novel antibiocorrosive multifunctional hybrid materials based on functionalizedperfluoroalkylmethacrylate copolymerswith epoxy groups in main chainsand selected biologically active compounds.The hybrids are transparent, showgood adhesion to various surfaces (plastic, wood),high viscoelastic recovery in scratch testing,low wear rates and glass transitions above 323 K. No phase separation is seen in scanning electron micrography. Enhanced mechanical strength and good abrasion resistance are advantages for uses of our protective and antibiocorrosive coatings in various applications including protection of cultural heritage.

Corrosion Improvement of 304L Stainless Steel by ZrSiN and ZrSi(N,O) Mono- and Double-Layers Prepared by Reactive Cathodic Arc Evaporation

Zr-based nitrides and oxynitrides were deposited by reactive cathodic arc evaporation in monolayer and double-layer structures with the aim of increasing the corrosion protection of 304L stainless steel (SS) in a biomedical aggressive environment. All coatings had a total thickness of 1.2 µm. Compared to the bare substrate, the surface roughness of the coated samples was higher, the presence of microdroplets being revealed by scanning electron micrography (SEM). The X-ray diffraction investigation of the ZrN phases revealed that the peaks shifted towards lower Bragg angles and the lattice constants increased as a result of Si and O2 inclusion in ZrN lattice, and of the ion bombardment characteristic of the cathodic arc method, augmented by the applied bias substrate. SS/ZrSiN/ZrSi(N,O) showed the best corrosion performance in an acidic environment (0.9% NaCl and 6% H2O2; pH = 4), which was ascribed to the blocking effect of the interfaces, which acted as a corrosion barrier for the electrolyte ingress. Moreover, the aforementioned bilayer had the highest amount of Si and O in the composition of the top layer, forming a stable passive layer with beneficial effects on corrosion protection.

Xanthan Matrix as Drug ZDelivery System

Here we present a new drug delivery system based on xanthan esterified with acrylic acid. This material served as a matrix for the incorporation of bioactive substances with antimicrobial and anti-inflammatory properties. The materials were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Nuclear Magnetic Resonance (NMR) and Scanning Electron Micrography (SEM). Mechanical strength tests showed a substantial improvement in the resilience and flexibility of the polymer matrix modified by esterification under conditions of mechanical stress. The release of bioactive substances from the basic matrix follows a Korsmeyer-Peppas type kinetics. The modified xanthan-based transport system was shown to be antimicrobially active with an inhibition rate of almost 100% on gram-positive and gram-negative bacteria. The obtained results recommend this biomaterial for the manufacture of transdermal drug delivery devices.

Optimising the Performance Of Crumb Rubber Modified Concrete

The issue of management of end of life tyre (EOLT) rubber or crumb rubber presents major social, environmental and economic challenges especially for Small Island Developing States (SIDS) such as Trinidad and Tobago. A successful measure in foreign jurisdictions is to utilize this waste material for civil construction as a substitute for natural aggregate however this strategy has not yet been applied in Trinidad and Tobago. Since the properties of concrete and the influence of additives are dependent on the source and chemical composition of the parent cement, research and scientific studies utilizing Trinidad Portland cement are necessary but lacking. This paper filled this information gap necessary to develop a rubberized Trinidad Portland Type IP concrete. Crumb rubber (0-10%) rubber was added to concrete as a replacement for fine aggregate using a water to cement ratio of 0.5 and cured over 3-28 days. Standard compressive strength, splitting tensile strength and slump tests were performed and the results statistically analysed. Microscopic features of adhesion and disruption characteristics were observed using Scanning Electron Micrography (SEM -EDS). Concrete mixtures using Trinidad Portland cement and crumb rubber at dosages 2 - 4 wt% resulted in a material with properties similar to the unmodified material with compressive strengths achieving the required specification of 20 MPa after 28 days. This study suggests that there is significant potential in valorising the concept of recycling tyre waste into modified crumb rubber concrete as a sustainable waste management option.

Kinetics of Transesterification of Croton megalocarpus Oil Using Alkaline Earth Catalysts with Conventional and Microwave Heating

Transesterification kinetics of Croton megalocarpus oil to produce fatty acid methyl esters (FAME) was studied using homogeneous NaOH and heterogeneous alkaline earth Nano MgO, MgO, Nano CaO, CaO, Reoxidized CaO, SrO, and BaO catalysts. Characteristic surface, bulk, and chemical properties of the heterogeneous catalysts were obtained which included surface area, pore properties, scanning electron micrography, X-ray diffraction, basic strength, and basicity. The catalyst porosity varied as Nano MgO > Nano CaO > MgO > CaO > CaO-RO > SrO > BaO and basicity as BaO > SrO > Nano CaO > CaO RO > CaO > Nano MgO > MgO. Catalysts NaOH, BaO, SrO, and Nano CaO gave a good FAME yield (>50%), and reaction order and rate constant have been reported for these catalysts, for both conventional heating and microwave irradiation. The overall reaction for NaOH was of 1st order for microwave irradiation with respect to triglyceride and of 2nd order with respect to triglyceride under conventional heating. For the heterogeneous catalysts, the overall reaction was of 3rd order, 2nd order with respect to triglyceride and 1st order with respect to methanol for both heating methods. Reaction rate constants for microwave irradiation were higher than those for conventional heating due to faster reaction rates under such heating. BaO was the most active heterogeneous catalyst, followed by SrO and Nano CaO, which was in accordance with their basicity.

A Novel Approach to Optimize Hot Melt Impregnation in Terms of Amorphization Efficiency

In this study, an innovative methodology to optimize amorphization during the hot melt impregnation (HMI) process was proposed. The novelty of this report revolves around the use of thermal analysis in combination with design of experiments (DoEs) to reduce residual crystallinity during the HMI process. As a model formulation, a mixture of ibuprofen (IBU) and Neusilin was used. The main aim of the study was to identify the critical process parameters of HMI and determine their optimal values to assure a robust impregnation process and possibly the highest possible amorphization rate of IBU. In order to realize this, a DoE approach was proposed based on a face-centered composite design involving three factors. The IBU/Neusilin ratio, the feeding rate, and the screw speed were considered as variables, while the residual crystallinity level of IBU, determined using differential scanning calorimetry (DSC), was measured as the response. Additionally, the stability of IBU under HMI was analyzed using high-performance liquid chromatography to estimate the extent of potential degradation. In order to verify the correctness of the DoE model, tested extrudates were manufactured by HMI and the obtained extrudates were thoroughly examined using scanning electron micrography, X-ray powder diffraction, and DSC.

Design of atrazine containing polysaccharide based slow release formulations to control environmental hazards

Atrazine is more reliable, flexible, effective and less expensive herbicide than any other available weed control approaches. However, easy leaching of atrazine is a matter of great environmental and health concern which limits its strong recommendation for practical applicability. Hence, controlled release formulations of atrazine, specially based on natural polysaccharide, are required for delivery and resolve the problems associated with conventional formulations. In the present work, slow release atrazine containing alginate-agar based bead formulations have been prepared and characterized by scanning electron micrography, Fourier transform infrared spectroscopy and swelling studies. The release of atrazine from the beads occurred through non-Fickian diffusion mechanism. The release of atrazine from the beads in the soil has been observed slower and lesser in soil as compared to the in vitro release. Besides providing the slow release of atrazine, these formulations after degradation may enhance the fertility of the soil.

Effects of Homogenization Treatment on Dispersoid Characteristics and Recrystallization Behavior in an Al-Zn-Mg-Cu-Zr Alloy

In the present research, a comprehensive study on the effect of the homogenization treatment on the characteristics of dispersoid and recrystallization behavior in an Al-Zn-Mg-Cu-Zr alloy has been conducted by means of optical micrography, scanning electron micrography and transmission electron micrography. The influence of three process parameters of the homogenization treatment, first stage holding temperature, holding time and heating rate, on the dispersoid characteristics has been throughly studied. The result shows that holding at 400°C for sufficient time is highly beneficial for obtaining fine and uniformly distributed Al3Zr particles. Compared with the high heating rate treatment, the slow one apparently leads to significantly smaller Al3Zr dispersoids, the dimension of the dispersoids decreases from 35 nm to 22 nm, and the number density of Al3Zr particle in the center of the grains increases from 13/μm2 to 35/μm2. The percentage of recrystallized grains of the alloy is found to be affected by dispersoid distribution.