Effect of substrate and fermentation conditions on pectinase and cellulase production by <Emphasis Type="Italic">Aspergillus niger</Emphasis> NCIM 548 in submerged (SmF) and solid state fermentation (SSF)

The present study deals with the optimization of substrate and fermentation conditions for the production of both pectinase and cellulase by Aspergillus niger NCIM 548 under same fermentation conditions in submerged fermentation (SmF) and solid state fementation (SSF) using a central composite face centered design of response surface methodology (RSM). As per statistical design, the optimum conditions for maximum production of pectinase (1.64 U/mL in SmF and 179.83 U/g in SSF) and cellulase (0.36 U/mL in SmF and 10.81 U/g in SSF) were, time 126 h, pH 4.6, and carbon source concentration 65 g/L in SmF and were time 156 h, pH 4.80, and moisture content 65% in SSF. The response surface modeling was applied effectively to optimize the production of both pectinase and cellulase by A. niger under same fermentation conditions to make the process cost-effective in both submerged and solid state fermentation using agro industrial wastes as substrate.     

Performance analysis of induced draft cooling tower integrated with rotary silica gel mesh

A humid environment decreases the performance of induced draft counter flow cooling towers (IDCFCT) normally used in power plants and process industries. The primary objective of this study is to experimentally analyze the effect of using rotary silica gel mesh (RSGM) on the performance of IDCFCT. Experimental setups of IDCFCT with and without RSGM have been designed and fabricated to perform the comparative analysis. The performance of both cooling towers (CTs) in terms of output temperature, relative humidity of air, range, approach, and effectiveness at different air velocities has been investigated. The results indicate that the outlet air temperature of IDCFCT integrated with the RSGM wheel is 0.5–1.5°C higher than the IDCFCT without the RSGM wheel. IDCFCT with RSGM wheel shows maximum effectiveness of 0.67 at an air velocity of 1.5 m/s and inlet water temperature of 55°C; whereas, for IDCFCT without RSGM wheel, it is only 0.54. In terms of efficiency, RSGM wheel integrated IDCFCT shows an improvement of 24% compared to IDCFCT without RSGM wheel. It has been observed that RSGM-integrated IDCFCT also helps to save water up to 431.7 kg/h at an air velocity of 1 m/s with a water inlet temperature of 35°C. Moreover, the advantage of integrating the RSGM wheel with IDCFCT has been further corroborated in terms of the reduction in the height of the CT obtained with the help of a thermodynamic model.     

A new synthesis route of ammonia production through hydrolysis of metal – Nitrides

Recently ammonia has emerged as a potential hydrogen storage material because it contains 17.8 wt% hydrogen. Here, we propose a new synthesis route of ammonia production using hydrolysis of nitrides, which is based on the conversion technique using thermal energy, solar heat or exhaust heat to form NH₃ directly. Lithium metal has been tested as a starting material for the above purpose. We present the detailed results on room temperature nitridation of lithium metal, it is found that the nitridation properties are strongly affected by the surface state of lithium metal. The ammonia synthesis via hydrolysis of lithium nitride succeeds and it is strongly dependent on the reaction rate and temperature.     

Analysis of Fluopicolide and Propamocarb Residues on Tomato and Soil Using QuEChERS Sample Preparation Method in Combination with GLC and GCMS

Persistence of fluopicolide and propamocarb in tomato was studied following three applications of a combination formulation of Infinito 68.75 SC (fluopicolide 6.25 %?+?propamocarb 62.5 %) at 1500 and 3000 mL ha^?1 by 7 days interval, starting the spray at fruit development stage. QuEChERS method included extraction of sample with ethyl acetate and cleanup of dispersive solid-phase extraction was used for the determination of fluopicolide and propamocarb residues on tomato and soil. Residues of fluopicolide and propamocarb in tomato were estimated by gas–liquid chromatography and gas chromatograph–mass spectrometry, respectively. Half-lives for fluopicolide were found to be 2.58 and 2.31 days, whereas for propamocarb these values were observed to be 1.49 and 2.08 days at single and double the application rates, respectively. Residues of fluopicolide dissipated below its limit of quantification (LOQ) of 0.01 mg kg^?1 after 7 and 10 days at single and double the application dosage, respectively. Similarly, residues of propamocarb took 5 and 7 days to reach LOQ of 0.10 mg kg^?1, at single and double dosages, respectively. Soil samples collected after 15 days of the last application did not show the presence of fluopicolide and propamocarb at their detection limit of 0.01 and 0.10 mg kg^?1, respectively. The initial deposit of residues of propamocarb and fluopicolide for both the dosages were below the prescribed codex maximum residue limit values of 2 and 1 mg kg^?1, respectively. Therefore, a 1-day waiting period was suggested to reduce human health risks before consumption of tomato fruits.     

Studies on the solubility of hydrogen in molten Pb83Li17 eutectic alloy

Lead–lithium eutectic (Pb₈₇Li₁₇) alloy is a candidate material to be used as a secondary tritium breeder, neutron multiplier and heat transfer agent in the fusion reactor. The tritium thus produced in the alloy may be soluble or appear as a new phase of lithium-tritides and/or lead-tritides, which eventually affect the performance of Pb₈₃Li₁₇ eutectic. Therefore, solubility of tritium in the alloy at the operating conditions of the fusion reactor is a subject matter of investigation. Tritium being the isotope of hydrogen behaves more or less similar to the hydrogen. In the present investigation the solubility of hydrogen in the Pb₈₃Li₁₇ has been investigated as a function of temperature and pressure. It was found that, hydrogen solubility in the Pb₈₇Li₁₇ alloy is almost constant above 350 °C. Hydrogen solubility increases with increase of temperature up to 400 °C. Hydrogen solubility is 120 ppm at 400 °C and 800 Torr hydrogen pressure. The solubility decreases on further rise in temperature from 400 °C. However, at all the temperatures hydrogen solubility increased with increase of partial pressure of hydrogen.     

Effect of nickel addition on the solubility of hydrogen in tantalum

A study of isothermal as well as isobaric P–C–T equilibrium measurements has been investigated for the solubility of hydrogen in tantalum and its alloys with nickel (1.7 and 4.9 atom % Ni) in the temperature range of 673–873 K and hydrogen pressure range of 0.60–1.20 atmospheres. The alloys were prepared by arc melting in an inert atmosphere. The dissolved hydrogen was within the solid solubility range corresponding to the temperature and followed the Sievert's law. The hydrogen solubility in tantalum decreased on the addition of nickel as an alloying element. The change in enthalpy and the change in entropy of solution for hydrogen in the tantalum metal and its alloys were calculated. The heat of reaction for hydrogen solution in all the samples was exothermic. The enthalpy of solution for hydrogen in the tantalum matrix increases on the addition of Ni as an alloying element.     

A review on synthesis and characterization of commercially available natural fibers: Part II

Increasing environmental concerns, along with the potential declination of the crude worldwide reserves, have made the human beings to utilize more regenerable resources to substitute for the design and development of more new products. This has made us to use the synthetic and natural fibers to develop innovative products. However, more eco-friendly properties of natural fibers have made them to be preferable over the synthetic fibers. To make efficient use of these fibers, it is essential to know the behavioral characteristics of these fibers. So, in this review II paper, an effort has been made to discuss the various characterization analysis studies, like Fourier transform-infrared spectra spectral analysis, X-ray and thermogravimetric methods carried out by various researchers.     

Overall thermal energy and exergy analysis of hybrid photovoltaic thermal array

In this paper, overall thermal energy and exergy analysis has been carried out for different configurations of hybrid photovoltaic thermal (PVT) array. The hybrid PVT array (10.08 m × 2.16 m) is a series and parallel combinations of 36 numbers of PV modules. A one-dimensional transient model for hybrid PVT array has been developed using basic heat transfer equations. On the basis of this transient model, an attempt has been made to select an appropriate hybrid PVT array for different climatic conditions (Bangalore, Jodhpur, New Delhi, and Srinagar) of India. On the basis of high grade energy (i.e. overall exergy gain), case-III has been selected as the most appropriate configuration because overall exergy for case-III is 12.9% higher than case-II. The overall thermal energy and exergy gain for Bangalore is 4.54 × 10⁴ kW h and 2.07 × 10⁴ kW h respectively which is highest in comparison to the other cities.     

Meteorologically efficient commissioning of salt gradient solar pond

Salt gradient solar pond has thermal performance parameters as rate of warm-up, highest achievable temperature, and cumulative heat collection. All these are strongly influenced by the meteorology. Consequently, specific to the meteorology of a geographic location, there is a best starting day for the as pond defined by Singh et al. [1]. The present work has done rigorous analysis of influence of meteorology on pond??s thermal performance. It is found that the starting day has strong influence in initial stage of pond warm-up; however the effect diminishes in long-term. Finally pond started on any day of the year acquires same highest temperature. It is also found that in order to retrieve maximum heat, waiting for the best starting day to commission a pond is not judicious, rather it is always more beneficial commission the pond at the earliest possible day. This finding is of practical significance while planning to put a pond in operation.