An investigation on characterization of bio-composites

This research work describes the characterization and fabrication of bio-composites as artificial bone implant materials. The fractured bone can be repaired or replaced by artificial bone materials. Many implant materials has been made in the last three decades made of metals alloys ceramics polymers etc. The main problem with the metallic bone implants is the stress shielding and bone regeneration. Polymeric bone implants may overcome these difficulties. This article presents the processing techniques and experimental results of two different bio-composites viz. Hydroxyapatite (HAp)/High density polyethylene (HDPE) bio-composite by micro-injection molding and compression molding technology and Hydroxyapatite (HAp)/High molecular high density polyethylene (HMHDPE) bio-composite by compression molding technology. The initial materials HAp was synthesized by wet chemical precipitation technique, mixed with HDPE granules at 180 0C in a micro-compounder and also mixed with HMHDPE in a twin screw extruder at 220 0C, followed by micro-injection and compression molding and compression molding. Testing of different mechanical properties like tensile, compressive, flexural, impact and two body abrasion wear has been carried out. The experimental result provided shows a good mechanical behavior. An artificial neural network (ANN) model and a fuzzy logic (FL) model have been presented, for the prediction of abrasion wear amount of the fabricated bio-composites. Two body abrasive wear testing has done as per the full factorial design approach as well as it helps to construct the fuzzy prediction model based on Mamdani method. 75% of the response data used for training and 25% data used for testing of the artificial neural network (ANN) prediction methodology. The predicted results are in good (for testing) arrangement with the experimental data with an absolute average percentage error of 0.3470 and 1.8224 for ANN and 4.4542 and 2.7104 for fuzzy logic. It was found that both the fuzzy and ANN model are able to predict the abrasion wear rate in operating conditions with a very high degree of accuracy

A new strategy for improvement of tamarind seed based chicken diet after microbial detannification and assessment of its safety aspects

Tamarind seed, an abundant agricultural waste, contains a large amount of naturally occurring anti-nutrient, tannin. This study aimed at evaluating the detannification efficiency of tannase producing Bacillus subtilis PAB2 in comparison with enzymatic and conventional physical techniques, and assessment of its health promoting effect in chicken model. Microbial fermentation resulted in lowering of 80.8% tannin, whereas enzymatic and physical treatment removed only 48 and 28.6%, respectively. To assess the health beneficial effects, experimental schedule for poultry chicken model was designed viz., (T1) commercial food, (T2) T1+tamarind seeds, (T3) T1+enzymatic detannified seeds and (T4) T1+ fermented seeds. It was found that physiological indices of chicken in T4 group improved more than T2, but those were comparable with T1 and T3. The level of total plasma protein, albumin and other haematological parameters also significantly (P<0.05) improved in T4 more than T2. The quantities of small intestinal indicator microbes like Escherichia coli, Clostridium perfringens and Yeast sp. in T4 group increased more than T2. Thus, fermentation led to quality improvement of raw tamarind seed which suggested its employment as an alternative feedstock for poultry chicken

Effect of microbial load on the condition index of the edible oyster, Saccostrea cucullata in the Sundarbans, India

The effect of microbial load on the condition Index of the edible oyster, Saccostrea cucullata were analysed on monthly basis during 2010 and 2011 from the three different stations (Namkhana, Frasergaunge and Sajnekhali) of Indian Sundarbans. The results showed significant variation with respect to microbial load between stations and seasons, which is reflected in the tissue of edible oyster. Significant positive correlations were observed between microbial load of the ambient environment and the tissue system of oyster. The Condition Index of the oyster species also exhibited negative correlation with the microbial load of oyster tissue, which confirms the negative stress induced by microbes on the growth and survival of the species

Thermodynamic and kinetic characteristics of an a-amylase from Bacillus licheniformis SKB4

An amylolytic bacterial strain, Bacillus licheniformis SKB4 produced maximum amylase at pH 6.5 at 42 °C, and at late stationary phase (24 h) of growth. Starch and peptone were found the best supporting carbon and nitrogen source with C:N ratio of 1:2 for amylase production. The purified enzyme was non-responsive to most of the metal ions except K+ and Mg++ (1.0 mM). The enzyme was stable and active at pH 6.5. The enzyme showed optimum temperature at 90 °C with 10 min of half life (t½) at 100 °C. The Q10 of the enzyme was 1.0. The thermodynamic principles like activation energy, free energy for substrate binding and transition state of the enzyme were found 31.53, 5.53 and -17.4 KJ/Mol of starch, respectively. The kinetic constant like Vmax, Km, K catand catalytic efficiency (Kcat/Km)for starch were found to be 1.04 μmol mg-1 min-1, 6.2 mg ml-1,2 × 103 S-1 and 3.22 × 102 ml mg-1 S-1,respectively. All these findings suggested that this amylase has unique characteristics for starch hydrolysis in respect to thermostability and kinetic properties

Ethnic Preparation of Haria, a Rice-Based Fermented Beverage, in the Province of Lateritic West Bengal, India

Haria is a rice-based fermented beverage that is popular among tribal and low income people in lateritic West Bengal and East-Central India. The principal ingredient of this beverage is low grade boiled rice (Oryza sativa L.), which is mixed with a traditional starter, called bakhar, and fermented within a heat-sterilized earthen pot for 3-4 days. The main aim of this study was to investigate the ethnobotanical importance and traditional process of haria preparation. The method adopted for this study was based on interactive questionnaires and laboratory experiments. It was found that the pH decreased during the course of fermentation with increased titratable acidity of 1.42%. The alcohol content was 2-3% (v/v) in the consumable beverages. This documentation will be useful for further exploitation of haria as a health drink

Field Induced Single Ion Magnetic Behaviour in Square-Pyramidal Cobalt(II) Complexes with Easy-Plane Magnetic Anisotropy

Two penta-coordinate CoII complexes with formulae [Co(14-TMC)Cl](BF4) (1, 14-TMC = 1,4,8,11-Tetramethyl-1,4,8,11-tetraazacyclotetradecane) and [Co(12-TBC)Cl](ClO4)&middot;(MeCN) (2, 12-TBC = 1,4,7,10-Tetrabenzyl-1,4,7,10-tetraazacyclododecane) were synthesized and characterized. Structural analysis revealed that ligand coordinates to the CoII centre in a tetradentate fashion and the fifth position is occupied by chloride ion and the geometries around CoII centres are best described as distorted square pyramidal. Detailed magnetic measurements disclose the presence of significant easy-plane magnetic anisotropy and field induced slow magnetic relaxation behaviours of the studied complexes. More insight into the magnetic anisotropy has been given using ab initio theory calculations, which agree well with the experimental values and further confirmed the easy-plane magnetic anisotropy

Predictive modeling and machining performance optimization during drilling of polymer nanocomposites reinforced by graphene oxide/carbon fiber

This paper explores the parametric appraisal and machining performance optimization during drilling of polymer nanocomposites reinforced by graphene oxide/-carbon fiber. The consequences of drilling parameters like cutting velocity, feed, and weight % of graphene oxide on machining responses, namely surface roughness, thrust force, torque, delamination (In/Out) has been investigated. An integrated approach of a Combined Quality Loss concept, Weighted Principal Component Analysis (WPCA), and Taguchi theory is proposed for the evaluation of drilling efficiency. Response surface methodology was employed for drilling of samples using the titanium aluminum nitride tool. WPCA is used for aggregation of multi-response into a single objective function. Analysis of variance reveals that cutting velocity is the most influential factor trailed by feed and weight % of graphene oxide. The proposed approach predicts the outcomes of the developed model for an optimal set of parameters. It has been validated by a confirmatory test, which shows a satisfactory agreement with the actual data. The lower feed plays a vital role in surface finishing. At lower feed, the development of the defect and cracks are found less with an improved surface finish. The proposed module demonstrates the feasibility of controlling quality and productivity factors

Field Induced Slow Magnetic Relaxation in a Non Kramers Tb(III) Based Single Chain Magnet

Herein, we report a novel Tb(III) single chain magnet with the chemical formulae [Tb(&#956;-OH2)(phen)(&#956;-OH)(nb)2]n by using 4-nitrobenzoic acid (Hnb) and 1,10-phenanthroline (phen) as ligand system. The single-crystal X-ray diffraction reveals that 4-nitrobenzoic acid acts as a monodentate ligand, water and hydroxyl ions are the bridging ligand and the phen serves as a bidentate chelating ligand. The static magnetic susceptibility measurement (from 2 K to 300 K) shows ferromagnetic interaction at very low temperature (below 6 K). The alternating current (AC) susceptibility data of the complex show temperature and frequency dependence under an applied 2000 Oe DC (direct current) field. The phen moiety behaves as an antenna and enables the complex to show the green light fluorescence emission by absorption-energy transfer-emission mechanism. To calculate the exchange interaction, broken symmetry density functional theory (BS-DFT) calculations have been performed on a model compound which also reveals weak ferromagnetic interaction. Ab initio calculations reveals the anisotropic nature (gz = 15.8, gy, gy = 0) of the metal centre and the quasi doublet nature of ground state with small energy gap and that is well separated from the next excited energy state

Swarm intelligence integrated approach for experimental investigation in milling of multiwall carbon nanotube/polymer nanocomposites

In manufacturing industries, the selection of machine parameters is a very complicated task in a time-bound manner. The process parameters play a primary role in confirming the quality, low cost of manufacturing, high productivity, and provide the source for sustainable machining. This paper explores the milling behavior of MWCNT/epoxy nanocomposites to attain the parametric conditions having lower surface roughness (Ra) and higher materials removal rate (MRR). Milling is considered as an indispensable process employed to acquire highly accurate and precise slots. Particle swarm optimization (PSO) is very trendy among the nature-stimulated metaheuristic method used for the optimization of varying constraints. This article uses the non-dominated PSO algorithm to optimize the milling parameters, namely, MWCNT weight% (Wt.), spindle speed (N), feed rate (F), and depth of cut (D). The first setting confirmatory test demonstrates the value of Ra and MRR that are found as 1.62 µm and 5.69 mm3/min, respectively and for the second set, the obtained values of Ra and MRR are 3.74 µm and 22.83 mm3/min respectively. The Pareto set allows the manufacturer to determine the optimal setting depending on their application need. The outcomes of the proposed algorithm offer new criteria to control the milling parameters for high efficiency