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1.
Environ Monit Assess ; 196(5): 420, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38570413

RESUMO

Monitoring and protecting freshwater habitats are paramount for a sustainable water management perspective. This study investigated potentially toxic elements (PTEs) in the potamic water of the Anday Stream Basin (Türkiye), Black Sea Region, for a hydrological year (from May 2020 to April 2021). Among PTEs, the highest average values were recorded for sodium (Na) at 41.3 mg/L and the lowest for mercury (Hg) at 0.009 µg/L and noted under quality guidelines. The stream was found to be at the level of "Low Heavy Metal Pollution" and "Low Contamination" based on the ecotoxicological risk indices. The highest calculated hazard quotient (HQ) value of 1.21E-02 for Cd was noted in the children via the dermal pathway and the lowest of 6.91E-06 for Fe in adults via the ingestion pathway. Results revealed a higher hazard index (HI) value of 1.50E-02 for Cd to children and the lowest of 1.98E-05 for Fe to adults. As a result of applying agricultural risk indices, the stream showed sodium adsorption ratio values less than 6 and was found to be "Excellent" for agriculture. However, the sodium percentage values were less than 20 and found "Permissible" and the magnesium hazard > 50 and noted as "Unsuitable" for agriculture. Statistical analysis revealed that natural factors mainly attributed to PTE contamination of the Anday Stream Basin.


Assuntos
Mercúrio , Metais Pesados , Criança , Adulto , Humanos , Monitoramento Ambiental/métodos , Água/análise , Rios , Mar Negro , Turquia , Metais Pesados/análise , Mercúrio/análise , Medição de Risco , Sódio/análise , Cádmio/análise
2.
Technol Health Care ; 2023 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-37980581

RESUMO

BACKGROUND: Humeral fracture is a common long bone fracture in orthopedic clinical diagnosis and treatment. OBJECTIVE: To investigate the local temperature increase owing to changes in the specific absorption ratio (SAR) of the human body caused by humeral bone nails during magnetic resonance imaging (MRI). METHODS: A refined geometric model of the upper body was constructed via data segmentation and post-processing using the digital human image dataset. Finally, the geometric model was imported into COMSOL, a 3-T magnetic resonance coil was built, and the operating frequency (128 MHz) was set to analyze the SAR of the bone-nail pair and temperature changes. RESULTS: The analysis of the changes after bone-nail implantation under different tissue conditions revealed that the SAR and temperature after implantation and fixation were three times higher than those before, and the areas with abrupt changes in SAR and temperature were primarily concentrated in the bone-nail area. CONCLUSION: In MRI, metal implants can cause local elevation of the SAR near the implant in the human body, resulting in a temperature increase around the implant. Consequently, long-term scanning can damage the human body.

3.
Sensors (Basel) ; 23(5)2023 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-36904700

RESUMO

The dynamic range of an X-ray digital imaging system is very important when detecting objects with a high absorption ratio. In this paper, a ray source filter is used to filter the low-energy ray components which have no penetrating power to the high absorptivity object to reduce the X-ray integral intensity. This enables the effective imaging of the high absorptivity objects and avoids the image saturation of low absorptivity objects, thus achieving single exposure imaging of high absorption ratio objects. However, this method will reduce the image contrast and weaken the image structure information. Therefore, this paper proposes a contrast enhancement method for X-ray images based on Retinex. Firstly, based on Retinex theory, the multi-scale residual decomposition network decomposes the image into an illumination component and a reflection component. Then, the contrast of the illumination component is enhanced through the U-Net model with the global-local attention mechanism, and the reflection component is enhanced in detail using the anisotropic diffused residual dense network. Finally, the enhanced illumination component and the reflected component are fused. The results show that the proposed method can effectively enhance the contrast in X-ray single exposure images of the high absorption ratio objects, and can fully display the structure information of images on devices with low dynamic range.

4.
Nanotechnology ; 33(34)2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35512668

RESUMO

Radio frequency ablation and microwave hyperthermia are powerful tools for destroying dysfunctional biological tissues. However, wireless application of these techniques is hindered by their inability to focus the electromagnetic energy to small targets. The use of locally injected radio frequency- or microwave-absorbing nanomaterials can help to overcome this challenge by confining heat production to the injected region. Previous theoretical work suggests that high-aspect-ratio conducting nanomaterials, such as carbon nanotubes, offer powerful radio frequency and microwave absorption. While carbon nanotubes have been demonstrated as radiothermal agents, common solubilization methods may reduce their absorption efficiency, yielding undesirable nonspecific heating in the biological tissue background. In this manuscript, we hypothesize that pristine carbon nanotubes can act as efficient absorbers at radio frequencies, thus providing differential heating over the tissue background. Specifically, we use a sonication-free preparation technique to preserve both the high aspect ratio and local concentration of pristine carbon nanotubes. We validate the differential heating of these samples by 4.5-fold at 2 GHz compared to the heating of saline at a physiological concentration using infrared thermography. In addition, we successfully achieved local heating of pristine carbon nanotubes within a three-dimensional biological tissue phantom. Numerical simulations further aid in producing a temperature map within the phantom and confirming localized heating. Due to their significant differential and local heating, we believe that pristine carbon nanotubes may facilitate region-specific radio frequency ablation and microwave hyperthermia while keeping nonspecific heating to a low level in the normal tissue background.

5.
J Environ Manage ; 309: 114691, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-35168134

RESUMO

Groundwater irrigation has evolved the monocropping cultivation pattern to multi-cropping, especially in many arid/semi-arid tracts globally. Irrigation practices with the groundwater of poor quality can limit the selection of the crop, reduce crop yields and degrade the soil quality. The present study has been undertaken to identify the hydrogeochemical phenomena of groundwater systems in the south-western Birbhum district, India and to analyze groundwater suitability for irrigation during the pre-and post-monsoon cycles by adopting the Irrigation Water Quality Index (IWQI) using Multivariate Factor Analysis along with some traditional methods viz. sodium adsorption ratio, sodium percentage, magnesium hazards, residual sodium bicarbonate (RSBC) and carbonate (RSC), Wilcox's and USSL diagrams, permeability index and Kelly's index. The hydrogeochemical analysis revealed that chemical weathering and evaporation are predominant in the aquifer systems. Groundwater quality reflected soil salinity, sodicity and magnesium hazards risks and water toxicity to the sensitive plants at 0-46.4% of the post-monsoon samples and 0-38.4% of the pre-monsoon samples based on the individual traditional methods whereas about 97.73-98.88% of the total area was classified as moderate to severely unsuitable for irrigation during both seasons when integrated multiple parameters using the IWQI method. Prolonged use of such groundwater for irrigation is susceptible to causing moderate to severe infiltration problems at a greater extent of the study area. The study recommends adaptation of salinity, sodicity and RSC/RSBC reduction procedures (e.g., the use of acid and gypsum amendments in the irrigation lands and through water blending) and advanced irrigation practices (viz. drips, sprinklers and micro irrigations) to prevent soil degradation and increase crops productivity. Adopting Managed Aquifer Recharge procedures as well as rainwater harvesting in the areas bearing unsuitable water quality can dilute the ionic concentrations of the groundwater facies which in turn will improve the groundwater quality for irrigation.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , Monitoramento Ambiental , Sistemas de Informação Geográfica , Índia , Poluentes Químicos da Água/análise , Qualidade da Água , Abastecimento de Água
6.
Colloids Surf B Biointerfaces ; 205: 111846, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34015734

RESUMO

A simple and rapid colorimetric assay for determination of mercury(II) ion (Hg2+) in aqueous solutions was developed based on aggregation of gold/silver alloy nanocomposites (Au/Ag NCs). Au/Ag NCs were aggregated after the addition of Hg2+ and the positively charged amino acid, lysine. The different aggregation degrees of Au/Ag NCs is indicated by variations in the absorption spectra and accompanied by a color change from orange yellow to yellowish green. Under the optimal conditions, the shift of absorbance ratio (A650/A447) was proportional to Hg2+ concentrations in the range of 0.01-10.0 µM. The limit of detection is 4.8 nM. The proposed colorimetric assay was extremely specific for Hg2+ and other environmentally relevant metal ions did not interfere with the determination.


Assuntos
Mercúrio , Nanopartículas Metálicas , Nanocompostos , Colorimetria , Ouro , Ligas de Ouro , Íons , Lisina , Prata
7.
Heliyon ; 6(5): e03855, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32405546

RESUMO

A simple, accurate, precise and economical Q- Absorption Ratio spectrophotometric method was developed and validated for estimation of Anagliptin and Metformin HCl in synthetic mixture. Anagliptin and Metformin HCl showed an iso-absorptive point at 238 nm in distilled water. The second wavelength used was 233 nm which is λmax of Metformin HCl in distilled water. The concentration of the drugs was determined by using ratio of absorbance at iso-absorptive point (λ1 = 238 nm) and at the λmax of Metformin HCl (λ2 = 233 nm). This method is linear for both drugs; in range of 2-12 µg/mL at λ1 (R2 = 0.999) and at λ2 (R2 = 0.9998) for Anagliptin, and in the range of 5-30 µg/mL for Metformin HCl found at λ1 (R2 = 0.9995) and at λ2 (R2 = 0.9997). The % Recovery was 100.42-101.83 % of Anagliptin and 99.94-101.63 % of Metformin HCl by standard addition method. The LOD was found to be 0.201 µg/mL and 0.262 µg/mL for Anagliptin at λ1 and λ2 respectively. The LOD was found to be 0.320 µg/mL and 0.167 µg/mL for Metformin HCl at λ1 and λ2 respectively. The LOQ was found to be 0.610 µg/mL and 0.794 µg/mL for Anagliptin at λ1 and λ2 respectively. The LOQ was found to be 0.972 µg/mL and 0.506 µg/mL for Metformin HCl at λ1 and λ2 respectively. The method was found to be precise as % RSD was less than 2.00 in Repeatability, Interday and Intraday precision for Anagliptin and Metformin HCl. The % assay of analyte drugs in synthetic mixture was found to be 100.601% of Anagliptin and 100.206 % of Metformin HCl which showed good applicability of the developed method.

8.
Int J Numer Method Biomed Eng ; 36(3): e3318, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32017406

RESUMO

This paper investigates microneedle array electrodes for transcutaneous electrical nerve stimulation, and compares their performance with conventional surface electrodes. A three-dimensional model of tissue was developed for finite element multiphysics simulations. Investigations included current density in different depths of a tissue, space constant under electrodes, specific absorption ratio of tissue, selectivity of stimulation, temperature rise, and blood flow. Results showed that microneedle electrodes have up to 10% higher selectivity than the surface electrodes. Furthermore, it was found that stimulation using microneedle electrodes provides more robust current density at different tissue depths compared to the surface electrode stimulation. Microneedle electrodes showed enhanced stimulation parameters, particularly for targeting a specific nerve in a specific depth of a tissue.


Assuntos
Simulação por Computador , Eletrodos , Estimulação Elétrica Nervosa Transcutânea/métodos , Análise de Elementos Finitos , Humanos
9.
Environ Sci Pollut Res Int ; 26(32): 32902-32910, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31512136

RESUMO

The microalgae-based CO2 sequestration is considered to be an effective technique with great potential to cope with carbon emission. However, most researches are only focused on microalgae; the effects of physicochemical factors, which are carbon concentration, medium pH, and bubbling depth, on absorption and utilization of supplied CO2 in culture is less known. In order to understand and improve CO2 absorption in microalgae culture, the effects of these three factors were studied with different levels and combinations. Results revealed that when medium carbon concentration increased from 4.76 to 95.24 mmol/L, CO2 absorption ratio increased by about 12%, 10%, 12%, and 11% at medium depths of 10, 20, 40, and 80 cm, with the initial pH 10.6 to 9.7 by bubbling CO2, respectively. As bubbling depth increased from 10 to 80 cm, CO2 absorption ratio increased by about 25%, 22%, and 25% at carbon concentrations of 4.76, 9.52, and 95.24 mmol/L, with the initial pH 10.6 to 9.7 by bubbling CO2, respectively. In range of 10.6-7.0, pH had no significant effect on CO2 absorption ratio (P > 0.05) when carbon concentration is below 9.52 mmol/L, while above 9.52 mmol/L, pH had significant effect on CO2 absorption ratio (P < 0.05). It was found for the first time that the effect of pH on the CO2 absorption ratio was affected by carbon concentration. In addition, equilibrium pH, at which the CO2 partial pressure in the medium equals to that in the air, of medium with different carbon concentrations was also determined. Overall, in microalgae culture for CO2 sequestration, increasing CO2 bubbling depth and keeping higher carbon concentration and higher pH can improve CO2 absorption ratio, which will optimize the biofixation of CO2 by microalgae furthermore.


Assuntos
Dióxido de Carbono/química , Meios de Cultura/química , Microalgas/química , Biomassa , Sequestro de Carbono , Concentração de Íons de Hidrogênio , Porphyridium , Scenedesmus , Spirulina
10.
J Microsc ; 270(3): 335-342, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29437234

RESUMO

Quantum yield ratio (QA /QD ) and absorption ratio (KA /KD ) in all excitation wavelengths used between acceptor and donor are indispensable to quantitative fluorescence resonance energy transfer (FRET) measurement based on linearly unmixing excitation-emission spectra (ExEm-spFRET). We here describe an approach to simultaneously measure QA /QD and KA /KD values by linearly unmixing the excitation-emission spectra of at least two different donor-acceptor tandem constructs with unknown FRET efficiency. To measure the QA /QD and KA /KD values of Venus (V) to Cerulean (C), we used a wide-field fluorescence microscope to image living HepG2 cells separately expressing each of four different C-V tandem constructs at different emission wavelengths with 435 nm and 470 nm excitation respectively to obtain the corresponding excitation-emission spectrum (SDA ). Every SDA was linearly unmixed into the contributions (weights) of three excitation-emission spectra of donor (WD ) and acceptor (WA ) as well as donor-acceptor sensitisation (WS ). Plot of WS /WD versus WA /WD for the four C-V plasmids from at least 40 cells indicated a linear relationship with 1.865 of absolute intercept (QA /QD ) and 0.273 of the reciprocal of slope (KA /KD ), which was validated by quantitative FRET measurements adopting 1.865 of QA /QD and 0.273 of KA /KD for C32V, C5V, CVC and VCV constructs respectively in living HepG2 cells.

11.
Entropy (Basel) ; 20(9)2018 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-33265751

RESUMO

After the 2008 financial collapse, the now popular measure of implied systemic risk called the absorption ratio was introduced. This statistic measures how closely the economy's markets are coupled. The more closely financial markets are coupled the more susceptible they are to systemic collapse. A new alternative measure of financial market health, the implied information processing ratio or entropic efficiency of the economy, was derived using concepts from information theory. This new entropic measure can also be useful in predicting economic downturns and measuring systematic risk. In the current work, the relationship between these two ratios and types of risks are explored. Potential methods of the joint use of these different measures to optimally reduce systemic and systematic risk are introduced.

12.
J Chromatogr A ; 1523: 242-247, 2017 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-28818326

RESUMO

The design of a miniaturized LED-based UV-absorption detector was significantly improved for on-column nanoflow LC. The detector measures approximately 27mm×24mm×10mm and weighs only 30g. Detection limits down to the nanomolar range and linearity across 3 orders of magnitude were obtained using sodium anthraquinone-2-sulfonate as a test analyte. Using two miniaturized detectors, a dual-detector system was assembled containing 255nm and 275nm LEDs with only 216nL volume between the detectors A 100µm slit was used for on-column detection with a 150µm i.d. packed capillary column. Chromatographic separation of a phenol mixture was demonstrated using the dual-detector system, with each detector producing a unique chromatogram. Less than 6% variation in the ratios of absorbances measured at the two wavelengths for specific analytes was obtained across 3 orders of magnitude concentration, which demonstrates the potential of using absorption ratio measurements for target analyte detection. The dual-detector system was used for simple, but accurate, mobile phase flow rate measurement at the exit of the column. With a flow rate range from 200 to 2000nL/min, less than 3% variation was observed.


Assuntos
Técnicas de Química Analítica/instrumentação , Cromatografia Líquida/instrumentação , Indicadores e Reagentes , Limite de Detecção , Espectrofotometria Ultravioleta
13.
Plant Biol (Stuttg) ; 18(5): 835-41, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27263526

RESUMO

The present investigation evaluated the role of Stenotrophomonas maltophilia and its IAA-deficient mutant on soil health and plant growth under salinity stress in the presence of tryptophan. In the first phase, S. maltophilia isolated from roots of the halo- phytic herb, Cenchrus ciliaris was used as bio-inoculant on wheat grown in saline sodic soil. A field experiment was conducted at Soil Salinity Research Institute during 2010-2011. Treatments included seed inoculation with S. maltophilia with or without tryptophan; uninoculated untreated plants were taken as control. An aqueous solution of tryptophan was added to rhizosphere soil at 1 µg l(_1) after seed germination. Inoculation with S. maltophilia significantly increased soil organic matter, enhanced (20-30%) availability of P, K, Ca and NO3 -N and decreased Na content and electrical conductivity of rhizosphere soil. Plant height, fresh weight, proline and phytohormone content of leaves were increased 30-40% over the control. Activities of superoxide dismutase (SOD) and peroxidase (POD) were 40-50% higher than control. Addition of tryptophan further augmented (10-15%) growth parameters, whereas NO3 -N, P, K and Ca content, proline content and SOD and POD increased 20-30%. In a second phase, indoleacetic acid (IAA)-deficient mutants of S. maltophilia were constructed and evaluated for conversion of tryptophan to IAA at the University of Calgary, Canada, during 2013-2014. About 1800 trans-conjugants were constructed that were unable to produce IAA in the presence of tryptophan. The results suggest that tryptophan assisted S. maltophilia in the amelioration of salt stress, and that IAA played positive role in induction of salt tolerance.


Assuntos
Reguladores de Crescimento de Plantas/metabolismo , Microbiologia do Solo , Stenotrophomonas maltophilia/fisiologia , Triticum/microbiologia , Ácido Abscísico/metabolismo , Giberelinas/metabolismo , Ácidos Indolacéticos/metabolismo , Íons/análise , Íons/metabolismo , Mutagênese Insercional , Peroxidase , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/microbiologia , Folhas de Planta/fisiologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Raízes de Plantas/fisiologia , Rizosfera , Salinidade , Tolerância ao Sal , Sementes/crescimento & desenvolvimento , Sementes/microbiologia , Sementes/fisiologia , Solo/química , Stenotrophomonas maltophilia/genética , Superóxido Dismutase , Triticum/crescimento & desenvolvimento , Triticum/fisiologia
14.
Environ Sci Pollut Res Int ; 23(16): 15970-82, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27146530

RESUMO

The suitability of stormwater harvested from pervious pavement system (PPS) structures for reuse purposes was investigated in conditions where glyphosate-containing herbicides (GCH) are applied as part of PPS maintenance procedure. The experiment was based on the four-layered design previously described as detailed in CIRIA C582. Results indicated that the highest sodium absorption ratio (SAR) of 1.6 recorded in this study, was less than that at which loss of permeability begins to occur as well as deterioration of matrix structure. Furthermore, the maximum electrical conductivity (ECw) of 2990 µS cm(-1), recorded for 7200 mg L(-1) concentration (GCH) was slightly below the unstable classification range at which salinity problems related to water quality occur such that salts accumulate in the root zone to the extent that crop yields are adversely affected. However, GCH concentration of 720 mg L(-1) was within 'permissible' range while that of 72 mg L(-1) was within 'excellent' range. Current study raises some environmental concerns owing to the overall impact that GCH at concentrations above 72 mg L(-1) exerts on the net performance of the organic decomposers, heavy metal and hydrocarbon release from the system and thus, should be further investigated. However, effluent from all the test models including those dosed with high GCH concentration of 7200 mg L(-1) do not pose any threat in terms of infiltration or deterioration associated with salinity although, there are indications that high dosage of the herbicide could lead to an elevated electrical conductivity of the recycled water. Graphical abstract Impact of herbicide on irrigation water quality.


Assuntos
Monitoramento Ambiental , Herbicidas/análise , Reciclagem , Águas Residuárias/química , Poluentes Químicos da Água/análise , Abastecimento de Água/estatística & dados numéricos , Glicina/análogos & derivados , Hidrocarbonetos/análise , Metais Pesados/análise , Salinidade , Qualidade da Água , Glifosato
15.
Magn Reson Med ; 72(4): 1191-8, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24408149

RESUMO

PURPOSE: To determine the MR compatibility of common dental retainer wires at 7 Tesla in terms of potential RF heating and magnetic susceptibility effects. METHODS: Electromagnetic simulations and experimental results were compared for dental retainer wires placed in tissue-mimicking phantoms. Simulations were then performed for a human model with wire in place. Finally, image quality was assessed for different scanning protocols and wires. RESULTS: Simulations and experimental data in phantoms agreed well, with the length of the wire correlating to maximum heating in phantoms being approximately 47 mm. Even in this case, no substantial heating occurs when scanning within the specific absorption rate (SAR) guidelines for the head. Image distortions from the most ferromagnetic dental wire were not significant for any brain region. CONCLUSION: Dental retainer wires appear to be MR compatible at 7 Tesla.


Assuntos
Temperatura Corporal/efeitos da radiação , Encéfalo/fisiopatologia , Encéfalo/efeitos da radiação , Imageamento por Ressonância Magnética , Contenções Ortodônticas , Fios Ortodônticos , Absorção de Radiação , Contraindicações , Desenho de Equipamento , Análise de Falha de Equipamento , Humanos , Imagens de Fantasmas , Doses de Radiação , Ondas de Rádio/efeitos adversos
16.
Adv Pharm Bull ; 3(2): 447-51, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24312876

RESUMO

PURPOSE: Eperisone Hydrochloride (EPE) is a potent new generation antispasmodic drug which is used in the treatment of moderate to severe pain in combination with Paracetamol (PAR). Both drugs are available in tablet dosage form in combination with a dose of 50 mg for EPE and 325 mg PAR respectively. METHODS: The method is based upon Q-absorption ratio method for the simultaneous determination of the EPE and PAR. Absorption ratio method is used for the ratio of the absorption at two selected wavelength one of which is the iso-absorptive point and other being the λmax of one of the two components. EPE and PAR shows their iso-absorptive point at 260 nm in methanol, the second wavelength used is 249 nm which is the λmax of PAR in methanol. RESULTS: The linearity was obtained in the concentration range of 5-25 µg/mL for EPE and 2-10 µg/mL for PAR. The proposed method was effectively applied to tablet dosage form for estimation of both drugs. The accuracy and reproducibility results are close to 100% with 2% RSD. RESULTS of the analysis were validated statistically and found to be satisfactory. The results of proposed method have been validated as per ICH guidelines. CONCLUSION: A simple, precise and economical spectrophotometric method has been developed for the estimation of EPE and PAR in pharmaceutical formulation.

17.
Chemosphere ; 92(11): 1513-9, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23668963

RESUMO

This paper investigates the effect of using recycled fiber (RCF) in newsprint production on the effluent quality and its treatability using membrane operations for internal and external recycling and reuse. Increased chemical usage in RCF for deinking had significant impact on the silica and sodium content of the effluent which in turn limits the membrane's operation. Increasing the RCF content from 0% to 50% is estimated to increase the silica content from 4 to 119mgL(-1) and sodium content from 135 to 500mgL(-1). A process model was developed to calculate the impact of these excess chemicals on the greenhouse gas (GHG) emission and brine disposal for an integrated membrane plant design producing 4MLday(-1) of recycled water. As the ratio of RCF increased from 0% to 50% in the mill process, the operating pressure increased for nanofiltration (NF) and reverse osmosis (RO). Additionally, organics presence in the feed increased the NF operating pressure above the simulated value and reduced the silica removal efficiency by 15%. Incorporation of lime coagulation pretreatment was found to be essential to operate RO at high recoveries with relatively GHG emissions. Without pretreatment, as RCF content increased from 0% to 50%, RO recovery decreased from 80% to 22% and the expended GHG increased from 0.9 to 3.5kgCO2m(-3). Although the excess sodium concentration limits the brine disposal for irrigation purposes, a partial blending of the treated wastewater with other process streams resulted in the reduction of sodium absorption ratio by 20%.


Assuntos
Resíduos Industriais , Papel , Impressão , Gerenciamento de Resíduos/métodos , Compostos de Cálcio/química , Magnésio/química , Membranas Artificiais , Óxidos/química , Pressão , Águas Residuárias/química
18.
J Young Pharm ; 4(3): 157-63, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23112534

RESUMO

The aim of this study was to evaluate the influence of disintegration mechanism of various types of disintegrants on the absorption ratio (AR), wetting time (WT), and disintegration time (DT) of orodispersible tablets (ODTs). ODTs were prepared by direct compression using mannitol as filler and disintegrants selected from a range of swellable, osmotic, and porous disintegrants. Tablets formed were characterized for their water AR, WT, and DT. The porosity and mechanical strength of the tablets were also measured. Results show that the DT of formulated ODTs was directly related to the WT and was a function of the disintegration mechanism of the disintegrant used. The lowest WT and DT were observed for tablets formulated using the osmotic disintegrant sodium citrate and these tablets also showed the lowest AR and porosity. The wetting and disintegration of tablets containing the highly swellable disintegrant, sodium starch glycollate, was slowest despite their high water AR and high tablet porosity. Rapid wetting and disintegration of ODTs were therefore not necessarily related to the porosity of the tablets.

19.
J Adv Pharm Technol Res ; 2(4): 266-73, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22247895

RESUMO

The aim of this investigation was to develop fast dissolving tablet of cinnarizine. A combination of super disintegrants, i.e., sodium starch glycolate (SSG) and crosscarmellose sodium (CCS) were used along with camphor as a subliming material. An optimized concentration of camphor was added to aid the porosity of the tablet. A 3(2) full factorial design was applied to investigate the combined effect of two formulation variables: Amount of SSG and CCS. Infrared (IR) spectroscopy was performed to identify the physicochemical interaction between drug and polymer. IR spectroscopy showed that there is no interaction of drug with polymer. In the present study, direct compression was used to prepare the tablets. The powder mixtures were compressed into tablet using flat face multi punch tablet machine. Camphor was sublimed from the tablet by exposing the tablet to vacuum drier at 60°C for 12 hours. All the formulations were evaluated for their characteristics such as average weight, hardness, wetting time, friability, content uniformity, dispersion time (DT), and dissolution rate. An optimized tablet formulation (F 9) was found to have good hardness of 3.30 ± 0.10 kg/cm(2), wetting time of 42.33 ± 4.04 seconds, DT of 34.67 ± 1.53 seconds, and cumulative drug release of not less than 99% in 16 minutes.

20.
J Basic Clin Pharm ; 2(1): 53-61, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24826003

RESUMO

The objective of this study was to develop simple, precise, accurate and sensitive UV spectrophotometric methods for the simultaneous determination of ofloxacin (OFX) and flavoxate HCl (FLX) in pharmaceutical formulations. The first method is based on absorption ratio method, by formation of Q absorbance equation at 289 nm (λmax of OFX) and 322.4 nm (isoabsorptive point). The linearity range was found to be 1 to 30 µg/ml for FLX and OFX. In the method-II second derivative absorption at 311.4 nm for OFX (zero crossing for FLX) and at 246.2 nm for FLX (zero crossing for OFX) was used for the determination of the drugs and the linearity range was found to be 2 to 30 µg/ml for OFX and 2-75 µg /ml for FLX. The accuracy and precision of the methods were determined and validated statistically. Both the methods showed good reproducibility and recovery with % RSD less than 1.5%. Both the methods were found to be rapid, specific, precise and accurate and can be successfully applied for the routine analysis of OFX and FLX in combined dosage form.

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