Synergistic dynamics of light, photoperiod and chemical stimulants influences biomass and lipid productivity in Chlorella singularis (UUIND5) for biodiesel production

Kumar, Vinod,Kumar, Rajat,Rawat, Deepa,Nanda, Manisha The Korean Society for Applied Biological Chemistr 2018 Applied Biological Chemistry (Appl Biol Chem) Vol.61 No.1

Microalgae have emerged as a potential alternative for the production of many useful compounds like protein, carbohydrate and lipid. Lipid-rich microalgae are important and rich source for alternative energy production. In order to commercially utilize microalgae for energy production, the lipid productivity should be enhanced. Keeping in view the above-mentioned potentials of microalgae, in the present study, we have attempted to display the role of chemical stimulants and light in the growth and lipid production of the microalgae Chlorella singularis (UUIND5). During the present investigations, effect of varying photoperiods and different types of lights and chemical stimulants, viz. $CaCl_2$ and kinetin on growth rate and lipid production, was studied. The maximum growth rate recorded was $166{\pm}0.3mg/L/d$, when 0.80 g/l $CaCl_2$ and 0.5 mg/l kinetin were added to Bold's basal medium. C. singularis was then cultivated in this medium for 14 days under sunlight +LED (10-h sunlight + 14-h LED light) at photoperiod 24-h light/0-h dark. The maximum lipid yield 30.2% of dry wt. was obtained under sunlight +LED. Further, the gas chromatography analysis also showed the presence of fatty acid methyl esters (FAME). FAMEs profile was analyzed according to ASTM D6751 specification. Thus, it was concluded that sunlight +LED at 24-h light/0-h dark ($100{\mu}mol\;photons\;m^{-2}\;s^{-1}$) photoperiod with $CaCl_2$ and kinetin is an effective strategy to boost lipid productivity in C. singularis (UUIND5).

Synergistic dynamics of light, photoperiod and chemical stimulants influences biomass and lipid productivity in Chlorella singularis (UUIND5) for biodiesel production

Vinod Kumar,Rajat Kumar,Deepa Rawat,Manisha Nanda 한국응용생명화학회 2018 Applied Biological Chemistry (Appl Biol Chem) Vol.61 No.1

Microalgae have emerged as a potential alternative for the production of many useful compounds like protein, carbohydrate and lipid. Lipid-rich microalgae are important and rich source for alternative energy production. In order to commercially utilize microalgae for energy production, the lipid productivity should be enhanced. Keeping in view the above-mentioned potentials of microalgae, in the present study, we have attempted to display the role of chemical stimulants and light in the growth and lipid production of the microalgae Chlorella singularis (UUIND5). During the present investigations, effect of varying photoperiods and different types of lights and chemical stimulants, viz. CaCl2 and kinetin on growth rate and lipid production, was studied. The maximum growth rate recorded was 166 ± 0.3 mg/L/d, when 0.80 g/l CaCl2 and 0.5 mg/l kinetin were added to Bold’s basal medium. C. singularis was then cultivated in this medium for 14 days under sunlight ?LED (10-h sunlight ? 14-h LED light) at photoperiod 24-h light/0-h dark. The maximum lipid yield 30.2% of dry wt. was obtained under sunlight ?LED. Further, the gas chromatography analysis also showed the presence of fatty acid methyl esters (FAME). FAMEs profile was analyzed according to ASTM D6751 specification. Thus, it was concluded that sunlight ?LED at 24-h light/0-h dark (100 lmol photons m-2 s-1) photoperiod with CaCl2 and kinetin is an effective strategy to boost lipid productivity in C. singularis (UUIND5).

Effect of Addition of Silicon on the Microstructures and Bending Strength of Continuous Porous SiC-Si3N4 Composites

Paul, Rajat Kanti,Gain, Asit Kumar,Lee, Byong-Taek,Jang, Hee-Dong Wiley (Blackwell Publishing) 2006 JOURNAL OF THE AMERICAN CERAMIC SOCIETY - Vol.89 No.6

Impedance spectroscopy study of zinc oxide incorporated iron borate glass-ceramic

Ramteke Rajat,Kumari Kalpana,Bhattacharya Soumalya,Sharma Sanjeev Kumar,Rahman M.R. 한국물리학회 2021 Current Applied Physics Vol.22 No.-

Here, the effects of zinc oxide (ZnO) on impedance and dielectric properties of the ZnO incorporated iron borate (Fe3BO6) glass-ceramics were studied using impedance spectroscopy in a wide range of frequency (1 Hz – 1 MHz) and temperature (25 ◦C–250 ◦C). With ZnO addition, the ε′ and tanδ values were reduced significantly, the strength of the relaxation process also decreased, along with a decrease in conductivity. Activation energies associated with modulus and conductivity plots suggest that similar type of charge carriers was responsible for the relaxation and conduction processes. The analysis of both complex impedance and conductivity show the negative temperature coefficient of resistance (NTCR) behavior of the samples. The thermistor constant B-values of 5ZnO and 10ZnO were found to be 7223 and 7088 respectively. The study of the NTCR properties suggests a potential candidate for thermistor applications.

Comprehensive review on potential applications of microfluidization in food processing

Anit Kumar,Atul Dhiman,Rajat Suhag,Rachna Sehrawat,Ashutosh Upadhyay,David Julian McClements 한국식품과학회 2022 Food Science and Biotechnology Vol.31 No.1

Microfluidizer is one of the emerging processing technologies which has brought tremendous and desirable changes in food matrix. By generating high cavitation, shear, velocity impact and turbulent forces, microfluidizer brought structural modifications in food which led to significant improvements in physicochemical, functional, nutritional, rheological and sensory properties of food products without affecting their natural flavour. Reduction in particle size and thereby increase in surface area has brought these unique modifications. Microfluidization also improved bioavailability and bioaccessibility of bioactives by making them more exposed. Applications of microfluidizer includes stable emulsion/suspension formation, encapsulation, and nanoparticle production. It has also shown its preservation potential by inactivating enzymes and microbes thus improving food stability. The present review comprehensively discusses the working principle and effect of microfluidizer on dairy products, fruit juices, cereals, starches, egg yolk, emulsions, suspensions, and other novel products formulations. Microfluidization has opened a new channel for developing novel food ingredients non-thermally.

Shock wave attenuation using sandwiched structures made up of polymer foams and shear thickening fluid

Kehar Singh,Rajat Raj,Arun Kumar Rajagopal,Sachin Jalwal,Subrata Chakraborty 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.3

The present study experimentally investigates the shock wave attenuation performance of various sandwiched structures made up of different polymer foams (expanded polystyrene and polyurethane foam) with and without shear thickening fluid (STF). STF is a non-Newtonian fluid whose viscosity increases with increase in shear rate due to the formation of hydro clusters produced by the increased hydrodynamic forces acting between the interstitial spaces. Two layers of polymer foams have been considered for the shock protective material and the space between the layers is filled with shear thickening fluid. The shock wave is experimentally generated from a shock tube facility and is allowed to impinge on a target plate kept at 10 mm downstream to the shock tube end. It is seen that the protective material with polyurethane foam and shear thickening fluid (polyethylene glycol+silica nanoparticles) reduces the shock overpressure by nearly 35.51 %, whereas the protective material with only polyurethane foam (with the same thickness) reduces the shock overpressure by only 13.17 %. Similarly, the protective material with expanded polystyrene and shear thickening fluid reduces the shock overpressure by nearly 32.16 %, whereas the protective material with only expanded polystyrene (with the same thickness) reduces the shock overpressure by only 10.49 %. Hence, it is evident that the shear thickening fluid between the polymer foam layers greatly helps in shock wave attenuation.

Insights into the current status of bioactive value, postharvest processing opportunities and value addition of black carrot

Priyanka Thakur,Anika,Rajat Suhag,Atul Dhiman,Satish Kumar 한국식품과학회 2024 Food Science and Biotechnology Vol.33 No.4

Black carrots are a type of carrot that is naturally dark purple or black in color. They are a good source of antioxidants, vitamins, and minerals, and have been shown to have several health benefits, including reducing the risk of cancer, heart disease, and diabetes. This review article discusses the bioactive compounds present in black carrot, including anthocyanins, phenolic acids, carotenoids, and organic acids and sugars. It also compares the bioactive compounds and antioxidant capacity of black carrot with other carrot varieties. Furthermore, it discusses various postharvest processing methods, both conventional and novel, such as encapsulation, drying, and microbial decontamination, highlighting their effects on preserving and stabilizing the bioactive compounds. The review also emphasizes the incorporation of black carrot into different food products, including dairy items, beverages, and baked goods, and their impact on nutritional enhancement. The article provides knowledge on utilizing black carrot for improved nutritional and functional outcomes.

Banana Pseudostem Sap as a Biomordant for Dyeing of Silk with Celosia Flower

Shyam Barahapurkar,Roli Purwar,Rajat Kumar Baldua 한국섬유공학회 2020 Fibers and polymers Vol.21 No.9

This research paper is focused on the dyeing of silk fabrics with a natural dye extracted from Celosia flower andbanana pseudostem sap as a biomordant. The dyeing process was carried out by three different techniques i.e. pre-, post-, andsimultaneous mordanting method. The effect of dyeing process parameters namely mordant concentration, pH, andtemperature on the dye absorption and fastness properties of dyed silk fabric have been investigated for each dyeing method. Optimal values of dyeing process parameters have been categorized based on the highest value of dye absorption in terms ofK/S value. Optimum mordant concentration was found to be 18 % for all sets of dyeing methods. The optimum pH wasexamined to be 4.5, 4.0, and 4.0 and dyeing temperature was 70 °C, 70 °C, and 65 °C for the pre-, post-, and simultaneousmordanting dyeing methods, respectively. The color fastness to light, washing, and rubbing of dyed silk fabrics wasinvestigated. Fastness values of light and rubbing showed fair-to-good fastness level, whereas the color fastness to washingwas found to be good to very good. The antibacterial activity of the banana sap mordanted and simultaneously dyed silkfabrics was evaluated. The dyed silk fabric exhibited moderate antibacterial activity against gram-positive and gram-negativebacteria.

Critical Review of Flexible Pavement Performance Models

Ankit Gupta,Praveen Kumar,Rajat Rastogi 대한토목학회 2014 KSCE JOURNAL OF CIVIL ENGINEERING Vol.18 No.1

Maintenance and repair of the highway network system are major expenses in the state budget. For this reason various concerned organizations are pointing out the need for developing an intelligent and efficient pavement performance model that can prioritize pavement maintenance and rehabilitation works. Such models can forecast the remaining pavement service life and pavement rehabilitation needs, and can help in the formulation of pavement maintenance and strengthening programmes which will reduce the road agency and road user costs. The flexible pavement performance or deterioration models involve the complex interaction between vehicles and the environment, and the structure and surface of the pavement. Performance models relating to the pavement distress conditions like, cracking, raveling, potholing, and roughness are analyzed and developed by various researchers. But most of these models are found applicable to a particular set of traffic or environment conditions, thus highlighting the need of model(s) that can work in varied conditions satisfactorily. The paper presents a detailed review of various pavement performance models to examine the role of factors related to pavement materials, environmental conditions, type of traffic and volume of traffic, and to identify the limitations and gaps in the present knowledge on such models.

EBV reactivation mimicking a lymphoproliferative disorder associated with ruxolitinib therapy for myelofibrosis

Shruti Prem,David Loach,Jeffrey Lipton,Rajat Kumar,Vikas Gupta 대한혈액학회 2019 Blood Research Vol.54 No.4

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