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1.
J Environ Manage ; 299: 113591, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34455350

RESUMO

An annular bioreactor (ABR) with wide gap was used for PHB production from Ralstonia eutropha. Hydrodynamic studies demonstrated the uniform distribution of fluid in the ABR due to the Taylor-Couette flow. Thereafter, the ABR was operated at different agitation and sparging rates to study its effect on R. eutropha growth and PHB production. The ABR operated at 500 rpm with air sparge rate of 0.8 vvm yielded a maximum PHB concentration of 14.89 g/L, which was nearly 1.4 times that obtained using a conventional stirred-tank bioreactor (STBR). Furthermore, performances of the bioreactors were compared by operating the reactors under fed-batch mode. At the end of 90 h of operation, the ABR resulted in a very high PHB production of 70.8 g/L. But STBR resulted in a low PHB concentration of 44.2 g/L. The superior performance was due to enhanced oxygen and nutrient mass transfer in the ABR.


Assuntos
Cupriavidus necator , Reatores Biológicos , Galactanos , Hidroxibutiratos , Mananas , Extratos Vegetais , Gomas Vegetais , Poliésteres
2.
Chemosphere ; 284: 131371, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34323807

RESUMO

The rapid depletion of crude-oil resource which sustains a conventional petroleum refinery together with its environmental impact has led to the search for more sustainable alternatives. In this context, biorefinery serves to fulfil the aim by utilizing waste resources. Hence, this study focused on techno-economic assessment of PHB production at large scale from waste carob pods in a closed-loop biorefinery setup. Firstly, the use of pure sugars in SC1 was shifted to use of carob pods as feedstock in SC2, upgradation of stirred tank bioreactor with novel annular gap bioreactor in SC3 and replacing the conventional centrifugation process with the upcoming ceramic membrane separation process in SC4. An Aspen plus™ flowsheet was developed by including the aforementioned novel strategies for PHB production. The effectiveness of PHB production under various scenarios was evaluated based on its pay-out period and turnover accumulated at the end of 7th year of a PHB plant operation. Instead of pure sugars as the feedstock (SC1), carob pod extract (SC2) reduced the pay-out period from 12.6 to 6.8 years. Likewise, switching onto ABR from the conventional STBR further decreased the pay-out period to 4.8 years. Finally, the use of ceramic membranes (SC4) instead of centrifugation resulted in a similar pay-out period of 4.8 years with increased turnover of about 1.4 billion USD. Thus, the use of carob pods along with an improved PHB titre in ABR and incorporation of affordable ceramic membrane technology for PHB rich biomass separation resulted in a highly cost-effective PHB production strategy.


Assuntos
Reatores Biológicos , Hidroxibutiratos , Biomassa , Análise Custo-Benefício , Açúcares
3.
Int J MCH AIDS ; 9(3): 411-420, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33163290

RESUMO

Background and Objectives: The purpose of this study was to analyze trends in HIV prevalence and risk factors associated with HIV infection among pregnant women attending antenatal clinics in Odisha State, India. Methods: Data were from the HIV Sentinel Surveillance (HSS) among pregnant women, a descriptive cross-sectional study using consecutive sampling method and conducted in India. Data and samples were collected from pregnant women attending select antenatal clinics that act as designated sentinel sites in Odisha State, India, during the three months surveillance period and in three surveillance years: 2013, 2015, and 2017. All eligible pregnant women aged between 15 and 49 years, attending the sentinel sites for the first time during the surveillance period, were included. Information on their socio-demographic characteristics and blood samples were also collected. Results: In total, 38,384 eligible pregnant women were included in the survey. Of these, 107 women were HIV positive, with an overall prevalence of 0.28%. HIV prevalence indicated a stabilizing trend between 2013 and 2017. However, pregnant women whose spouses were non-agricultural laborers, truck drivers, or migrants were significantly at higher risk of being infected. Likewise, HIV prevalence significantly increased over the years among pregnant women whose spouses were in the service sector (government or private). District-wise fluctuations in HIV prevalence was observed, with the district of Cuttack recording the highest prevalence among the districts. Conclusion and Global Health Implications: Women who are spouses of non-agricultural laborers, truck drivers or migrants need focused interventions, such as creating awareness on HIV and its prevention. Migration, due to poverty and its impact on sexually transmitted diseases among migrants from low and middle-income countries, have been documented globally. Single male migrant specific interventions are recommended to halt the disease progression among pregnant women and general population in Odisha, India.

5.
Bioresour Technol ; 307: 123247, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32234592

RESUMO

A novel closed-loop biorefinery model using carob pods as the feed material was developed for PHB production. The carob pods were delignified, and as the second step, sugars present in the delignified carob pods were extracted using water. Ralstonia eutropha and Bacillus megaterium were cultivated on the carob pod extract and its performance was evaluated using Taguchi experimental design. R. eutropha outperformed the B. megaterium in terms of its capability to grow at a maximum initial sugar concentration of 40 g L-1 with a maximum PHB production of 12.2 g L-1. Finally, the concentrated lignin from the first step was diluted with different proportion of chloroform to extract PHB from the bacterial biomass. The PHB yield and purity obtained were more than 90% respectively using either R. eutropha or B. megaterium. Properties of the PHB produced in this study were examined to establish its application potential.


Assuntos
Cupriavidus necator , Lignina , Galactanos , Hidroxibutiratos , Mananas , Gomas Vegetais , Poliésteres , Açúcares
6.
Int J Biol Macromol ; 154: 866-877, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32201206

RESUMO

Polyhydroxybutyrate (PHB) is a natural polyester of microbial origin and is an excellent substitute for petroleum-based food packaging materials. However, moderate mechanical, thermal and barrier properties limit utilization of PHB for commercial food packaging applications. In order to overcome these drawbacks, the present study evaluated the solution casting method for the preparation of PHB nanocomposite by incorporating various concentration (0-1.3 wt%) of graphene nanoplatelets (Gr-NPs). The prepared nanocomposites were tested for their morphology, mechanical, thermal, barrier, cytotoxicity and biodegradable properties. A Gr-NPs concentration of 0.7 wt% was found to be optimum without any agglomeration. In comparison with pristine PHB, the PHB/Gr-NPs nanocomposite showed a higher melting point (by 10 °C), thermal stability (by 10 °C), tensile strength (by 2 times) along with 3 and 2 times reduction in oxygen and water vapour permeability, respectively. The penetration of UV and visible light was greatly reduced with the addition of Gr-NPs. Furthermore, cytotoxic effect of the prepared nanocomposite was found to be statistically insignificant in comparison with the pristine PHB. A four-fold increase in the shelf life was demonstrated by a simulation study conducted using moisture and oxygen-sensitive food items (potato chips and milk product).


Assuntos
Embalagem de Alimentos , Grafite/química , Hidroxibutiratos/química , Nanocompostos/química , Oxigênio/química , Permeabilidade , Resistência à Tração , Água/química
8.
J Environ Manage ; 250: 109401, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31472375

RESUMO

This study evaluated a novel shortcut nitrogen removal method using a mixed consortium of microalgae, enriched ammonia oxidizing bacteria (AOB) and methanol utilizing denitrifier (MUD) in a photo-sequencing batch reactor (PSBR) for treating ammonium rich wastewater (ARWW). Alternating light and dark periods were followed to obtain complete biological nitrogen removal (BNR) without any external aeration and with the addition of methanol as the sole carbon source, respectively. The results showed that influent NH4+ was oxidized to NO2- by AOB during the light periods at a rate of 8.09 mg NH4+-N L-1h-1. Subsequently, NO2- was completely reduced during the dark period due to the action of MUD in presence of methanol. The high activities of ammonia monooxygenase (AMO) and nitrite reductase (NIR) enzymes revealed the strong role of AOB and MUD for achieving shortcut nitrogen removal from the wastewater. The reduced activities of nitrate reductase (NR) and nitrite oxidoreductase (NOR) at a high concentration of DO, NH4+ and NO2-in the system further confirmed the nitrogen removal pathway involved in the process. The biomass produced from these experiments showed good settling properties with a maximum sedimentation rate of 0.7-1.8 m h-1, a maximum sludge volume index (SVI) of 193 ml g-1- 256 ml g-1and floc size of 0.2-1.2 mm. In order to describe the growth and interaction among the algae, AOB and MUD for nitrogen removal in the system, the experimental results were fitted to four metabolic models, which revealed best fit of the experimental data due to the models based on algae-AOB and algae-AOB-MUD activities than with the other two models.


Assuntos
Desnitrificação , Nitrogênio , Amônia , Bactérias , Reatores Biológicos , Nitritos , Esgotos
9.
Front Chem ; 7: 474, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31355179

RESUMO

Prostate Cancer (PCa) is the most frequently diagnosed cancer in men in their late '50s. PCa growth is mainly due to the activation of the androgen receptor by androgens. The treatment for PCa may involve surgery, hormonal therapy, and oral chemotherapeutic drugs. A structural based molecular docking approach revealed the findings of (E)-N'-((1-chloro-3,4-dihydronaphthalen-2-yl)methylene)benzohydrazide derivatives, where the possible binding modes of the compounds with protein (PDB ID: 3V49) are shown. The compounds (6a-k) were synthesized and characterized by using conventional methods. The compounds, 6g, 6j, and 6k were reconfirmed through single crystal X-ray diffraction (XRD). Further, the compounds (6a-k) and standard drug were evaluated against human prostate cancer cell lines, LNCaP and PC-3 and the non-cancerous cell line, 3T3. Among these compounds, 6g and 6j showed higher cytotoxicity, and 6g exhibited dose-dependent activity and reduced cell viability. The mechanism of action was observed through the induced apoptosis and was further confirmed by western blot and ELISA. Molecular dynamics simulation studies were carried out to calculate the interaction and the stability of the protein-ligand complex in motion. ADME properties were predicted for all the tested compounds. These findings may give vital information for further development.

10.
Int J Telemed Appl ; 2019: 5903106, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31186627

RESUMO

Background: Stroke is a leading cause of disability and requires continued care after hospital discharge. Mobile-based interventions are suitable to reduce the cost of stroke rehabilitation and facilitate self-management among stroke survivors. However, before attempting to use mobile-based home exercise program, it is crucial to recognize the readiness of stroke survivors and their caregivers to opt for such interventions. Objective: To assess the acceptability and attitude towards a mobile-based home exercise program among stroke survivors and their primary caregivers. Methods: A cross-sectional study was conducted among 102 participants to understand their attitude and acceptability towards mobile-based home exercise program. A validated 10-item questionnaire was adapted for the study. The questions which assessed the attitude were rated on a three-point Likert scale, with three denoting agree and one denoting disagree. The acceptability was assessed by their willingness to opt for a mobile-based home program services. A Chi-square analysis and cross-tabulation were performed to test differences between caregivers and patients. A logistic regression was performed to determine the effects of age, gender, and mobile phone on acceptability. Results: Ninety-two percent of caregivers and 90% of patients showed willingness to opt for mobile-based intervention. Majority of the participants showed a positive attitude towards this mode of treatment. There was no difference in the attitude noted among caregivers and patients (p>0.05) towards mobile-based intervention. Conclusion: The stroke survivors and caregivers welcomed the concept of mobile-based home exercise program even in a low-resource settings, but further studies to understand treatment and cost-effectiveness of this technology among the stroke survivors would lead to better implementation.

11.
Eur J Med Chem ; 168: 1-10, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30798049

RESUMO

Structural based molecular docking approach revealed the findings of 2-(phenoxymethyl) -5-phenyl-1,3,4-oxadiazole derivatives. The compounds (7a-o) were synthesized and characterized well by using conventional methods. The compounds, 7b and 7m were reconfirmed through single crystal XRD analysis. The synthesized compounds (7a-o) were evaluated their antiproliferative activities against MCF-7 and MDA-MB-453. Furthermore, Lipinski's rule of five and pharmacokinetic properties were predicted for the test compounds. These results demonstrate that the compounds 7b and 7d exhibit more potent cytotoxicity and 7d exhibits dose-dependent activity and reduced cell viability. Further, the mechanism of action for the induced apoptosis was observed through morphological changes and western blotting analysis. These findings may furnish the lead for further development.


Assuntos
Antineoplásicos/farmacologia , Desenho de Fármacos , Oxidiazóis/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Modelos Moleculares , Estrutura Molecular , Oxidiazóis/síntese química , Oxidiazóis/química , Relação Estrutura-Atividade
12.
Heliyon ; 4(11): e00950, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30839844

RESUMO

We have realized for the first time the multibreather vector multi-solitons supporting collision dynamics with many interaction effects (namely reflection, attraction, beating, etc., effects) associated with the coupled nonlinear Schrödinger family equations having multiple applications. Such effects can be suppressed or enhanced by using the soliton parameters. Here each colliding multibreather vector one-soliton is composed with many soliton and antisoliton parts. Our solutions have freedom to control the number of soliton and antisoliton parts used to compose a vector one-soliton with a definite breathing length. It is also interesting to observe that the breathing maps associated with the obtained solutions depend on their free parameters and also the system parameters. All such investigations help us to realize different breathing mechanisms (namely pedaling, toggling, symmetric compression, symmetric elongation, asymmetric compression, asymmetric elongation, etc.) supported by the colliding one-solitons. An existing breathing mechanism of a given vector breather one-soliton can be suppressed or switched into another mechanism by tuning certain parameters appropriately. Because of such features we believe that this kind of study will further give impetus on the Lindner-Fedyanin system in the continuum limit, and find the potential applications in fiber coupler and also in Bose-Einstein condensates.

13.
3 Biotech ; 7(1): 37, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28439813

RESUMO

This study investigated simultaneous heavy metals removal and anthracene biodegradation by Rhodococcus opacus at different initial anthracene concentrations in the range 50-200 mg L-1. The heavy metals tested were Fe(III), Cu(II), Zn(II), Cd(II), Ni(II), and Pb(II) at 10 mg L-1 initial concentration: The organism was found to be well capable of removing the heavy metals along with high anthracene biodegradation efficiency. However, anthracene biodegradation rate by the organism was reduced due to these heavy metals. In addition, the heavy metals effect on R. opacus biomass growth followed the order: Cd > Ni > Pb > Cu > Zn > Fe. The total time to anthracene biodegradation increased from 144 to 216 h in the presence of Fe, Zn, Cu, or Pb, and it was up to 240 h in the presence of Cd or Ni. Compared with 70.2% (w/w) lipid accumulation by the bacterium in the absence of these heavy metals, a significant decline in the same was observed in the presence of the different heavy metals. These values were 41.2, 44.1, 52.1, 54.1, 58.6, and 63.1% (w/w) for Cd, Ni, Pb, Cu, Zn, and Fe, respectively. Field emission scanning electron microscopy integrated with energy dispersive X-ray spectroscopy and transmission electron microscopy of the biomass grown in the presence and absence of these heavy metals further confirmed a change in morphology of the bacterium due to the heavy metals. Fourier transmission infrared spectroscopy spectra of the biomass obtained during its growth in the presence and absence of the heavy metals confirmed the involvement of N-H, C-H bend, -CH2-(C=O), C-N stretch, C-H and O-H bending, and -C-Cl groups on the biomass for heavy metal uptake by the bacterium.

14.
Int J Phytoremediation ; 19(11): 1007-1016, 2017 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-28436682

RESUMO

Discharge of wastewater from electroplating and leather industries is a major concern for the environment due to the presence of toxic Cr6+ and other ions, such as sulfate, nitrate, phosphate, etc. This study evaluated the potential of Tradescantia pallida, a plant species known for its Cr bioaccumulation, for the simultaneous removal of Cr6+, SO42-, NO3-, and PO43-. The effect of different co-ions on Cr6+ removal by T. pallida was examined following the Plackett-Burman design of experiments carried out under batch hydroponics conditions. The results revealed a maximum removal of 84% Cr6+, 87% SO42-, 94% NO3- and 100% PO43- without any phytotoxic effect on the plant for an initial Cr6+ concentration in the range 5-20 mg L-1. SO42- and NO3- enhanced Cr uptake at a high initial Cr concentration (20 mg L-1), whereas PO43- did not affect Cr uptake both at high and low initial Cr concentrations. The Cr6+ removal kinetics in the presence of different ions was well described by the pseudo-second-order kinetic model which revealed that both biosorption and bioaccumulation of the metal played an important role in Cr6+ removal. Increase in the total carbohydrate and protein content of the plant following Cr6+ and co-ions exposure indicated a good tolerance of the plant toward Cr6+ toxicity. Furthermore, enhancement in the lipid peroxidation and catalase activity in T. pallida upon Cr6+ exposure revealed a maximum stress-induced condition in the plant. Overall, this study demonstrated a very good potential of the plant T. pallida for Cr6+ removal from wastewater even in the presence of co-ions.


Assuntos
Biodegradação Ambiental , Cromo , Tradescantia , Águas Residuárias , Poluentes Químicos da Água , Cromo/metabolismo , Galvanoplastia , Íons , Cinética , Peroxidação de Lipídeos , Oxirredução , Tradescantia/metabolismo , Poluentes Químicos da Água/metabolismo
15.
Bioresour Technol ; 192: 494-500, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26081625

RESUMO

Sulfate reduction by carbon monoxide (CO) utilizing anaerobic biomass from a large scale upflow anaerobic sludge blanket reactor was studied. Anaerobic mixed microbial consortia from five different sources were initially examined for their biological CO conversion potential. Among the different biomass, the biomass from an upflow anaerobic sludge blanket reactor treating domestic wastewater, located in Kavoor, Karnataka, India, showed a maximum CO conversion efficiency. The effect of three main culture parameters, i.e. inoculum volume, initial CO concentration and temperature on simultaneous CO conversion and sulfate reduction was assessed employing the Taguchi experimental design technique. A maximum CO conversion of 85.62% and a maximum sulfate reduction of 50.65% were achieved. Furthermore, the experimental data was fitted to substrate inhibition models reported in the literature. Among the different models, Monods and Haldane kinetic models were found most suitable to describe the kinetics of biomass growth and CO removal by the anaerobic biomass.


Assuntos
Acinetobacter/metabolismo , Monóxido de Carbono/metabolismo , Modelos Biológicos , Esgotos/microbiologia , Sulfatos/metabolismo , Poluentes Químicos da Água/metabolismo , Reatores Biológicos/microbiologia , Simulação por Computador , Oxirredução , Sulfatos/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos
16.
Appl Biochem Biotechnol ; 175(8): 3863-74, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25725800

RESUMO

In this study, Nostoc muscorum, a native cyanobacterial species isolated from a coal mining site, was employed to remove Cu(II), Zn(II), Pb(II) and Cd(II) from aqueous solution containing these metals in the mixture. In this multicomponent study, carried out as per the statistically valid Plackett-Burman design of experiments, the results revealed a maximum removal of both Pb(II) (96.3 %) and Cu(II) (96.42 %) followed by Cd(II) (80.04 %) and Zn(II) (71.3 %) at the end of the 60-h culture period. Further, the removal of these metals was attributed to both passive biosorption and accumulation by the actively growing N. muscorum biomass. Besides, the specific removal rate of these metals by N. muscorum was negatively correlated to its specific growth rate. For a better understanding of the effect of these metals on each other's removal by the cyanobacteria, the results were statistically analyzed in the form of analysis of variance (ANOVA) and Student's t test. ANOVA of the metal bioremoval revealed that the main (individual) effect due to the metals was highly significant (P value <0.05) on each other's removal. Student's t test results revealed that both Zn(II) and Pb(II) strongly inhibited both Cu(II) removal (P value <0.01) and Cd(II) removal (P value <0.02). All these results not only demonstrated a very good potential of the cyanobacteria in the bioremoval of these metals but also the effect of individual metals on each other's removal in the multicomponent system.


Assuntos
Cádmio/isolamento & purificação , Metais Pesados/isolamento & purificação , Nostoc muscorum/metabolismo , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Biodegradação Ambiental , Cádmio/química , Cádmio/toxicidade , Concentração de Íons de Hidrogênio , Cinética , Metais Pesados/química , Metais Pesados/toxicidade , Nostoc muscorum/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/toxicidade
17.
Artigo em Inglês | MEDLINE | ID: mdl-26764780

RESUMO

We find a dark component guiding the practically interesting bright-bright vector one-soliton to two different parametric domains giving rise to different physical situations by constructing a more general form of three-component dark-bright-bright mixed vector one-soliton solution of the generalized Manakov model with nine free real parameters. Moreover our main investigation of the collision dynamics of such mixed vector solitons by constructing the multisoliton solution of the generalized Manakov model with the help of Hirota technique reveals that the dark-bright-bright vector two-soliton supports energy-exchange collision dynamics. In particular the dark component preserves its initial form and the energy-exchange collision property of the bright-bright vector two-soliton solution of the Manakov model during collision. In addition the interactions between bound state dark-bright-bright vector solitons reveal oscillations in their amplitudes. A similar kind of breathing effect was also experimentally observed in the Bose-Einstein condensates. Some possible ways are theoretically suggested not only to control this breathing effect but also to manage the beating, bouncing, jumping, and attraction effects in the collision dynamics of dark-bright-bright vector solitons. The role of multiple free parameters in our solution is examined to define polarization vector, envelope speed, envelope width, envelope amplitude, grayness, and complex modulation of our solution. It is interesting to note that the polarization vector of our mixed vector one-soliton evolves in sphere or hyperboloid depending upon the initial parametric choices.

18.
Acta Crystallogr Sect E Struct Rep Online ; 70(Pt 9): 127-9, 2014 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-25309159

RESUMO

In the title compound, C30H28N2O6, the pyran ring adopts a slightly distorted half-chair conformation and the pyrone ring adopts an envelope conformation, with the C atom bearing the carboxyl-ate group as the flap. The pyrazole ring [maximum deviation = 0.002 (2) Å] forms a dihedral angle of 13.2 (1)° with the attached benzene ring. The near-planar atoms of the pyran ring and the pyrazole ring are close to coplanar, the dihedral angles between their mean planes being 6.4 (1)°. The dihedral angle between the pyrone ring and the benzene ring of the chromene unit is 10.7 (1)°. The mol-ecular conformation is stabilized by an intra-molecular C-H⋯O hydrogen bond, which generates an S(6) ring motif. In the crystal, C-H⋯O inter-actions generate supra-molecular chains propagating in [100] and these are connected into double layers that stack along the c-axis direction by weak π-π inter-actions between pyrazole rings [centroid-centroid distance = 3.801 (1) Å].

19.
Artigo em Inglês | MEDLINE | ID: mdl-25215794

RESUMO

We have constructed a dark-bright N-soliton solution with 4N+3 real parameters for the physically interesting system of mixed coupled nonlinear Schrödinger equations. Using this as well as an asymptotic analysis we have investigated the interaction between dark-bright vector solitons. Each colliding dark-bright one-soliton at the asymptotic limits includes more coupling parameters not only in the polarization vector but also in the amplitude part. Our present solution generalizes the dark-bright soliton in the literature with parametric constraints. By exploiting the role of such coupling parameters we are able to control certain interaction effects, namely beating, breathing, bouncing, attraction, jumping, etc., without affecting other soliton parameters. Particularly, the results of the interactions between the bound state dark-bright vector solitons reveal oscillations in their amplitudes under certain parametric choices. A similar kind of effect was also observed experimentally in the BECs. We have also characterized the solutions with complicated structure and nonobvious wrinkle to define polarization vector, envelope speed, envelope width, envelope amplitude, grayness, and complex modulation. It is interesting to identify that the polarization vector of the dark-bright one-soliton evolves on a spherical surface instead of a hyperboloid surface as in the bright-bright case of the mixed coupled nonlinear Schrödinger equations.


Assuntos
Modelos Teóricos , Teoria Quântica , Movimento (Física) , Dinâmica não Linear
20.
Acta Crystallogr Sect E Struct Rep Online ; 69(Pt 4): o562-3, 2013 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-23634100

RESUMO

In the title compound, C18H17NO3S, the seven-membered thia-zepine ring adopts a slightly distorted sofa conformation. The dihedral angle between the mean plane of the benzothia-zepine ring system and the benzene ring is 5.9 (1)°. The mol-ecular conformation is stabilized by an intra-molecular C-H⋯S hydrogen bond, which generates an S(7) ring motif. In the crystal, N-H⋯O and C-H⋯O hydrogen bonds link inversion-related mol-ecules into dimers, incorporating R 1 (2)(6) and R 2 (2)(8) ring motifs; the acceptor O atom is bifurcated. These dimers are further linked by C-H⋯O hydrogen bonds, forming supra-molecular tapes running along the a axis. These are connected into the three-dimensional architecture by C-H⋯π inter-actions.

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