470 research outputs found

    Micellar-polymer for enhanced oil recovery for Upper Assam Basin

    Get PDF
    One of the major enhanced oil recovery (EOR) processes is chemical flooding especially for the depleted reservoirs. Chemical flooding involves injection of various chemicals like surfactant, alkali, polymer etc. to the aqueous media. Bhogpara and Nahorkatiya are two depleted reservoirs of upper Assam basin where chemical flooding can be done to recover the trapped oil that cannot be recovered by conventional flooding process. Micellar-polymer (MP) flooding involves injection of micelle and polymer to the aqueous phase to reduce interfacial tension and polymer is added to control the mobility of the solution, which helps in increasing both displacement and volumetric sweep efficiency and thereby leads to enhanced oil recovery. This work represents the use of black liquor as micelle or surfactant that is a waste product of Nowgong Paper Mills, Jagiroad, Assam, which is more efficient than the synthetic surfactants. The present study examines the effect of MP flooding through the porous media of two depleted oil fields of upper Assam basin i.e. Bhogpara and Nahorkatiya for MP EOR. This work also compares the present MP flood with the earlier work done on surfactant (S) flooding. It was experimentally determined that the MP flood is more efficient EOR process for Bhogpara and Nahorkatiya reservoirs. The study will pertain to the comprehensive interfacial tension (IFT) study and the displacement mechanism in conventional core samples

    On spectra of Hermitian Randic matrix of second kind

    Full text link
    We propose the Hermitian Randi\'c matrix Rω(X)=(Rijω)R^\omega(X)=(R^\omega_{ij}), where ω=1+i32\omega=\frac{1+i \sqrt{3}}{2} and Rijω=1/didjR^\omega_{ij}={1}/{\sqrt{d_id_j}} if vivjv_iv_j is an unoriented edge, ω/didj{\omega}/{\sqrt{d_id_j}} if vivjv_i\rightarrow v_j, ω/didj{\overline{\omega}}/{\sqrt{d_id_j}} if vivjv_i\leftarrow v_j, and 0 otherwise. This appears to be more natural because of ω+ω=1\omega+\overline{\omega}=1 and ω=1|\omega|=1. In this paper, we investigate some features of this novel Hermitian matrix and study a few properties like positiveness, bipartiteness, edge-interlacing etc. We also compute the characteristic polynomial for this new matrix and obtain some upper and lower bounds for the eigenvalues and the energy of this matrix

    Racemic Resolution of some dl-Amino Acids using Aspergillus fumigatusl-Amino Acid Oxidase

    Get PDF
    The ability of Aspergillus fumigatus L-amino acid oxidase (L-aao) to cause the resolution of racemic mixtures of DL-amino acids was investigated with DL-alanine, DL-phenylalanine, DL-tyrosine, and DL-aspartic acid.A chiralcolumn,Crownpak CR?wasusedfortheanalysisof the amino acids. The enzyme was able to cause the resolution of the three DL-amino acids resulting in the production of optically pure D-alanine (100% resolution), D-phenylalanine (80.2%), and D-tyrosine (84.1%), respectively. The optically pure D-amino acids have many uses and thus can be exploited industrially. This is the first report of the use of A. fumigatus L-amino acid oxidase for racemic resolution of DL-amino acids

    Twórczość plastyczna jako forma wspierania rozwoju osób niewidomych i głuchoniewidomych

    Get PDF
    Twórczość plastyczna wydaje się być niedocenianym przez tyflopedagogów obszarem aktywności dzieci, młodzieży oraz dorosłych osób niewidomych i głuchoniewidomych. Tymczasem osoby te warto angażować w wiele form plastycznej kreacji, dodatkowo kierując się zasadą „im wcześniej, tym lepiej”. Tego typu doświadczenia mogą wspierać rozwój poznawczy, emocjonalny i społeczny osób z poważną dysfunkcją wzroku. Zostanie to wykazane na podstawie analizy literatury przedmiotu oraz poprzez przytoczenie studiów przypadków głuchoniewidomych uczestników plenerów rzeźbiarskich w Orońsku.Udostępnienie publikacji Wydawnictwa Uniwersytetu Łódzkiego finansowane w ramach projektu „Doskonałość naukowa kluczem do doskonałości kształcenia”. Projekt realizowany jest ze środków Europejskiego Funduszu Społecznego w ramach Programu Operacyjnego Wiedza Edukacja Rozwój; nr umowy: POWER.03.05.00-00-Z092/17-00

    Impact of physio-biochemical responses on amelioration of short-term storage and management of post-harvest seed quality of greengram (Vigna radiata)

    Get PDF
    The present study was carried out during winter (rabi) and rainy (kharif) seasons of 2021 and 2022 at Assam Agricultural University, Jorhat, Assam to address the significance of maintaining post-harvest seed quality and its management throughout the nation, and to promote the knowledge and create awareness among the farming communities and pulse growers at the national level in terms of the area with high rainfall and high relative humidity. The greengram [Vigna radiata (L.) R. Wilczek] variety (SGC-16) seeds were stored in 4 different types of packaging materials, viz. jute bag, polylined jute bags; HDPE (High Density Polyethylene) interwoven bags; and 700-gauze polythene bags and treated with treatment combination of emamectin benzoate (40 mg/kg) (chemical based); 5 ml/kg neem oil (plant based); 3 g/kg black pepper (recommended practise for the state); and 3 g/kg silica gel (desiccants). With an increase in storage time, a gradual decline in seed quality parameters such as viability, germination, seedling length, seedling dry weight, Seed vigour index-I, Seed vigour index-II, germination index value, field emergence, and chlorophyll content was observed. Variations for biochemical indicators of seed quality were also recorded. The seed germination above Indian Minimum Seed Certification Standard (IMSCS) level was maintained by all treatments up to 120 days of storage. However, emamectin benzoate (40 mg/kg) along with 3 g/kg of silica gel in HDPE interwoven bags found to be best in keeping seed quality standards with lowest lipid peroxidation activity (0.36 g/gm) and highest in seeds stored in jute bag (0.68 g/gm)

    Solvent evaporation driven entrapment of magnetic nanoparticles in mesoporous frame for designing a highly efficient MRI contrast probe

    Get PDF
    The present work reports a novel strategy of assembling maghemite (?-Fe2O3) nanoparticles (NPs) in mesoporous silica host for developing a highly efficient MRI contrast probe. Shrinkage of hydrophobic environment due to the continuous evaporation of chloroform from Chloroform-in-Water emulsions pushes the hydrophobic ?-Fe2O3 NPs towards the hydrophobic pores of silica spheres resulting in a water soluble dense assembly structure. Mesoporous silica only with straight pores is found to be suitable for this particular entrapment process, while with curved and twisted pores, NPs are found to be seated on the surface only. So-developed assembly system has retained the superparamagnetic behaviour of its comprising NPs and exhibited high colloidal stability and biocompatibility. A significant enhancement in MRI transverse relaxivity to 386.2?mM?1?s?1 from 191.8?mM?1?s?1 of isolated primary ?-Fe2O3 NPs, has been obtained due to the strong magnetic field generated by the large number of NPs packed in the porous channels and consequent faster relaxation process. The fabrication strategy can be extended for the development of designed secondary nanostructures with new magnetic effects and physical properties

    Cloning and heterologous expression of a gene encoding lycopene-epsilon-cyclase, a precursor of lutein in tea (Camellia sinensis var assamica)

    Get PDF
    This report describes the cloning and expression of a gene lycopene epsilon cyclase, (LCYE) from Camellia sinensis var assamica which is a precursor of the carotenoid lutein in tea. The 1982 bp cDNA sequence with 1599 bp open reading frame of LCYE was identified from an SSH library constructed for quality trait in tea. 5’ and 3’ RACE (rapid-amplification of cDNA ends) was done to clone the full length cDNA of LCYE. Homology studies showed that the deduced amino acid sequence of LCYE gene had the highest sequence identity of up to 84% with Vitis vinefera. The cloned gene was successfully expressed in a PET based Escherichia coli expression system. The size of the expressed protein was 59615 Daltons. A suppression subtractive library was constructed using a quality clone H3111 (tester) and a garden series clone T3E3 (driver).Key words: Carotenoid, RACE, heterologous expression, lutein, tea

    Effect of Freezing Rate on Quality of Cryopreserved Goat Spermatozoa Using a Programmable Freezer

    Get PDF
    Abstract: A total of 45 ejaculates from nine Beetal bucks collected by artificial vagina, washed and extended i
    corecore