Extraction of High-Value Chemicals from Plants for Technical and Medical Applications

Plants produce a variety of high-value chemicals (e.g., secondary metabolites) which have a plethora of biological activities, which may be utilised in many facets of industry (e.g., agrisciences, cosmetics, drugs, neutraceuticals, household products, etc.). Exposure to various different environments, as well as their treatment (e.g., exposure to chemicals), can influence the chemical makeup of these plants and, in turn, which chemicals will be prevalent within them. Essential oils (EOs) usually have complex compositions (>300 organic compounds, e.g., alkaloids, flavonoids, phenolic acids, saponins and terpenes) and are obtained from botanically defined plant raw materials by dry/steam distillation or a suitable mechanical process (without heating). In certain cases, an antioxidant may be added to the EO (EOs are produced by more than 17,500 species of plants, but only ca. 250 EOs are commercially available). The interesting bioactivity of the chemicals produced by plants renders them high in value, motivating investment in their production, extraction and analysis. Traditional methods for effectively extracting plant-derived biomolecules include cold pressing and hydro/steam distillation; newer methods include solvent/Soxhlet extractions and sustainable processes that reduce waste, decrease processing times and deliver competitive yields, examples of which include microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), subcritical water extraction (SWE) and supercritical CO₂ extraction (scCO₂). Once extracted, analytical techniques such as chromatography and mass spectrometry may be used to analyse the contents of the high-value extracts within a given feedstock. The bioactive components, which can be used in a variety of formulations and products (e.g., displaying anti-aging, antibacterial, anticancer, anti-depressive, antifungal, anti-inflammatory, antioxidant, antiparasitic, antiviral and anti-stress properties), are biorenewable high-value chemicals.     

Non-Newtonian blood flow with magnetic nanoparticles in a W-shaped stenosed arterial segment: A numerical study

Flow of blood, infused with magnetic nanoparticles, in a W-shaped stenosed human arterial segment is studied numerically using a realistic non-Newtonian blood rheology model. It is observed that the Newtonian model predicts less time to reach a steady state than the non-Newtonian blood rheology model. An increased drug retention time at the target site with an increase in nanoparticle concentration is predicted. Detailed simulations further reveal that the skin friction coefficient does not increase significantly with the increase in nanoparticle concentration. Hence, it is anticipated from our study that the infusion of drug-carrying nanoparticles in blood flow does not excessively enhance wall shear stress that may lead to arterial wall damage. An overall increase in heat transfer rates and wall shear stress at the stenosed section is seen with an increase in Reynolds number. The present study provides valuable information for designing computer-assisted drug delivery systems.     

The effect of systemic insecticides and nitrogen on oil-filling in developing seeds of toria (Brassica campestris cv. toria)

The systemic insecticides Metasystox and Temik reduced the oil content and increased the free fatty acid and phospholipid contents of the oil of toria seeds at early stages of their development. The oil level was, however, restored when the seeds were sown in soil supplied with nitrogen. At a later developmental stage (30 days after fertilisation), Temik increased, and Metasystox decreased the triacylglycerol content in the oil. Both insecticides increased the relative proportion of erucic acid in the oil, however this increase levelled off in the developing seeds when the toria crop was supplied with nitrogen fertiliser. In in-vivo studies, Metasystox at 10 μg ml^?1 was sufficient to lower the rate of [1-¹⁴C]acetate incorporation into lipids of developing seeds. The effect of Temik on lipid biosynthesis was not as pronounced as that of Metasystox.     

Performance Enhancement of Gaussian Minimum Shift Keying Using Optimum Phase Sampling Technique for Turbulent Free-Space Optical Communication

In this paper, analytical performances of Gaussian minimum shift keying (GMSK) are studied for free space optical communication system. Authors propose an innovative sampling technique called, optimum phase sampling technique to investigate the bit error performance of GMSK modulation. Subsequently, performances of GMSK like, bit error rate (BER), power spectral density, and adjacent carrier interference (ACI) have also been investigated and compared with other modulation techniques. Furthermore, return to zero (RZ) coding input bit stream prior to GMSK technique improves the ACI performance of GMSK. To end with, we present the improvement of degradation parameter (γ) in a tabular form through phase sampling technique. Moreover, both optimum phase sampling and narrow pulse shaping of RZ-GMSK obtains near optimal result of BER. The numerical results show, that the proposed phase sampled RZ-GMSK of 70% duty cycle at BT?=?0.6 has a degradation value of 0.979, which is comparable to GMSK at BT?=?∞. Moreover, the proposed RZ-GMSK achieves lower ACI value and has an error rate of 7?×?10^?7, which is lower than the GMSK of 1?×?10^?6 BER value.

     

Ameliorating effects of phosphorus,lime and animal manure on wheat yield and root cation exchange capacity in degraded alfisols of north-west himalayas

A field experiment over the two years was conducted to study the ameliorating effects of P, lime and animal manure on wheat (cv s-308) yield, root CEC and on economic doses of P. Phosphorus was applied as single superphosphate at the rate of 0, 13, 26, 39, 52, 65 and 78 kg P per ha; lime as CaCO₃ at 0 and 1 t/ha, and well cured animal manure at 0 and 8 t/ha. The application of P, to the extent of 65 kg/ha, increased the root CEC of wheat up to bloom stage only whereas nutrient concentration, uptake and; grain and straw yield were found to increase up to maturity. Similarly, addition of 8t/ha of animal manure resulted in a significant increase in root CEC up to bloom, nutrient concentration and uptake, vis-a-vis grain and straw yield of wheat were found to enhance up to maturity. However, the application of lime, though, increased the root CEC and nutrition of crop during both years, it did so in cases of wheat yield only during the first year of the experiment. Root CEC, particularly, at early growth stages, was very well correlated with N, P, K, Ca and Mg concentrations and uptake, and wheat yield at maturity. The economic dose of P for wheat in association with 8 t/ha of animal manure under the present conditions was found to be 39.4kg p/ha.     

Variation aware intuitive clock gating to mitigate on-chip power supply noise

With the advent of semiconductor process technology, both the dynamic and static power consumption have become major concerns for the circuit designers. Though clock gating (CG) is a potentially accomplished technique to minimise the dynamic power, it generally fails to cut down the static power dissipation. To address the same, we have unveiled a new CG scheme incorporating leakage control transistor, which simultaneously curbs the static and dynamic power along with the alleviation of power supply noise (PSN) in silicon chips by smartly controlling the current ramp (di/dt) and average current i(t): the main contributors to PSN. The proposed CG does not only save average, dynamic and static power by 84.34%, 90.33% and 66.73%, respectively, but also reduces PSN by 84.44% with respect to its non-gated counterpart when simulated using Cadence Virtuoso® for 90 nm Generic Process Design Kit at a switching frequency of 5 GHz and power supply voltage of 1.1 V.     

A study of lithium insertion into MnO2 containing TiS2 additive a battery material in aqueous LiOH solution

The electrochemical behavior and surface characterization of manganese dioxide (MnO₂) containing titanium disulphide (TiS₂) as a cathode in aqueous lithium hydroxide (LiOH) electrolyte battery have been investigated. The electrode reaction of MnO₂ in this electrolyte is shown to be lithium insertion rather than the usual protonation. MnO₂ shows acceptable rechargeability as the battery cathode. The influence of TiS₂ (1, 3 and 5 wt%) additive on the performance of MnO₂ as a cathode has been determined. The products formed on reduction of the cathode material have been characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), secondary ion mass spectrometry (SIMS), fourier transform infrared spectroscopy (IR) and transmission electron microscopy (TEM). It is found that the presence of TiS₂ to ≤3 wt% improves the discharge capacity of MnO₂. However, increasing the additive content above this amount causes a decrease in its discharge capacity.     

CFD analysis on flow and performance parameters estimation of solar updraft tower (SUT) plant varying its geometrical configurations

A 3D numerical model is developed to estimate and analyze the flow and performance parameters of solar updraft tower (SUT) plant. The effects of geometrical parameters, such as chimney height and collector roof angle are studied. A turbulent, renormalization group (RNG) k-ε model and discrete ordinates (DO) model is used to solve the governing equations. It is concluded that with an increase in collector roof angle, air velocity increases but air temperature decreases. There is 31% velocity enhancement when the chimney height is increased from 3 to 8 m. The overall, chimney and collector efficiencies and power output are estimated to be 0.00354%, 0.0465%, 81.4% and 0.255 W, respectively.     

Defluoridation behavior of nanostructured hydroxyapatite synthesized through an ultrasonic and microwave combined technique

The absorption performance of a nano-structured hydroxyapatite produced from a combined ultrasonic and microwave technique was examined for the removal of fluoride from contaminated water. The effect of physical and chemical parameters such as initial pH, contact time, initial fluoride concentration and temperature were investigated. The results indicated that the equilibrium adsorption data followed both the Langmuir and Freundlich isotherms, with a maximum monolayer adsorption capacity of 5.5mg/g at 298K. In addition, the kinetic studies have shown that the fluoride adsorption data followed a pseudo-second order model and that the intra-particle diffusion process played a significant role in determining the rate. The thermodynamic analysis also established that the adsorption process was endothermic and spontaneous. The initial and final fluoride loaded nano-hydroxyapatite samples were characterized using FESEM, TEM, XRD, FTIR and XPS methods. The analysis revealed that structural changes to the adsorbent had taken place.     

Prediction of throw in bench blasting using neural networks: an approach

Tailoring the muckpile shape and its fragmentation to the requirements of the excavating equipment in surface mines can significantly improve the efficiency and savings through increased production, machine life and reduced maintenance. Considering the various blast parameters together to predict the throw is subtle and can lead to wrong conclusions. In this paper, a different approach was followed to combine the representational power of multilayer neural networks and various machine learning techniques to predict the throw of a bench blast using the data from a limestone mine located in central India. Then, using various analysis techniques, the training parameters have been adjusted to reduce the cross-validation error and increase the accuracy. Here, four different architectures of neural networks have been trained by different techniques, and the best model has been selected. The different machine learning techniques have been implemented on the basis of accuracy of the output. The sensitivity analysis has been done to get the relative importance of the variables in prediction of the output.