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1.
Chemosphere ; 322: 138078, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36754302

RESUMEN

Conventional homogeneous-based catalyzed transesterification for the production of biodiesel can be replaced with a membrane reactor that has an immobilized heterogeneous catalyst. Combining reaction with separation while utilizing membranes with a certain pore size might boost conversion process. this investigation to study the effectiveness of membrane reactor in combination with heterogeneous green nano catalysis of MnO2. Techniques such as XRD, EDX, FTIR, SEM, and TGA were used to characterize the synthesized MnO2 nano catalyst. The highest conversion of around 94% Trachyspermum ammi oil was obtained by MnO2. The optimum process variables for maximum conversion were catalyst loading of 0.26 (wt.%), 8:1 M ratio, 90 °C reaction temperature, and time 120 min. The green nano catalyst of MnO2 was reusable up to five cycles with minimum loss in conversion rate of about 75% in the fifth cycle. Nuclear magnetic resonance validated the synthesis of methyl esters. It was concluded that membrane reactor a promising technique to efficiently transesterify triglycerides into methyl esters and enable process intensification uses MnO2 as a catalyst.


Asunto(s)
Ammi , Óxidos , Compuestos de Manganeso , Biocombustibles , Esterificación , Ésteres , Aceites de Plantas
2.
Chemosphere ; 319: 137994, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36720415

RESUMEN

Better processing techniques must be utilized widely due to the rising demand for honey. The most common honey processing techniques are applied to melissopalynomorphs to check the quality and quantity of valuable honey using microporous ultrafiltration membranes. It is essential to have the ability to selectively filter out sugars from honey using ultrafiltration. This study authenticated 24 honey samples using membrane reactors ultrafiltration protocol to describe the pollen spectrum of dominant vegetation. The purpose of this study was also to explore nutritional benefits as well as the active phytochemical constituents of honey samples. Honey samples were collected and labeled Acacia, Eucalyptus, and Ziziphus species based on plant resources provided by local beekeepers. A variety of honeybee flora was collected around the apiaries between 2020 and 2021. Honey analysis revealed that the pollen extraction of 24 bee foraging species belonging to 14 families. The honey membrane technology verified the identities of honey and nectar sources. Also, pollen identified using honey ultrafiltration membranes revealed dominant resources: Acacia spp. (69%), Eucalyptus spp. (52%) and Ziziphus spp. Honey filtration using a membrane technology classified 14 samples as unifloral, represented by six dominant pollen types. The absolute pollen count in the honey sample revealed that 58.33% (n = 14) belong to Maurizio's class I. Scanning ultrasculpturing showed diverse exine patterns: reticulate, psilate, scabrate-verrucate, scabrate-gemmate, granulate, perforate, microechinate, microreticulate, and regulate to fossulate for correct identification of honey pollen types. Honey ultrafiltration should be utilized to validate the botanical sources of honey and trace their biogeographic authenticity. Thus, it is imperative to look at the alternative useful method to identify the botanical origin of filtered honey. It is critical to separate honey from adulteration by a standardized protocol. Membrane technology has yielded significant outcomes in the purification of honey.


Asunto(s)
Eucalyptus , Miel , Abejas , Animales , Miel/análisis , Polen/química , Plantas , Néctar de las Plantas , Eucalyptus/química
3.
Chemosphere ; 314: 137604, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36574789

RESUMEN

Depletion of non-renewable fuel has obliged researchers to seek out sustainable and environmentally friendly alternatives. Membranes have proven to be an effective technique in biofuel production for reaction, purification, and separation, with the ability to use both porous and non-porous membranes. It is demonstrated that a membrane-based sustainable and green production can result in a high degree of process intensification, whereas the recovery and repurposing of catalysts and alcohol are anticipated to increase the process economics. Therefore, in this study sustainable biodiesel was synthesized from inedible seed oil (37 wt%) of Cordia myxa using a membrane reactor. Transesterification was catalyzed by heterogenous nano-catalyst of indium oxide prepared with leaf extract of Boerhavia diffusa. Highest biodiesel yield of 95 wt% was achieved at methanol to oil molar ratio of 7:1, catalyst load 0.8 wt%, temperature 82.5 °C and time 180 min In2O3 nanoparticles exhibited reusability up to five successive transesterification rounds. The production of methyl esters was confirmed using Fourier-transform infrared spectroscopy and Nuclear Magnetic Resonance. The predominant fatty acid methyl ester detected in the biodiesel was 5, 8-octadecenoic acid. Biodiesel fuel qualities were determined to be comparable to worldwide ASTM D-6571 and EN-14214 standards. Finally, it was concluded that membrane technology can result in a highly intensified reaction process while efficient recovery of both nano catalysts and methanol increases the economics of transesterification and lead to sustainable production.


Asunto(s)
Cordia , Nanopartículas , Aceites de Plantas/química , Metanol , Biocombustibles , Biomasa , Esterificación , Catálisis , Etanol , Ácidos Grasos/química
4.
Chemosphere ; 305: 135335, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35724723

RESUMEN

Membrane technology has been adopted as a prospective and promising alternative to the standard technology used for biodiesel production since the time when it had some limitations. During this research project, the inedible seed oil generating feedstock known as Saussurea heteromalla was put through a biodiesel production process that utilized membrane technology with an effort to increase the yield of methyl ester. The transesterification process was mediated by zirconium oxide nanoparticles that were generated using an aqueous extract of Portulaca oleracea leaf. With an oil to methanol ratio of 1:9, a catalyst concentration of 0.88 (wt. %), temperature of 87 °C, and reaction time of 180 min, the highest possible biodiesel yield of 93% was achieved. The findings of the catalyst characterization demonstrated the purity of the zirconium oxide nano particles and their nanoscale nature with average particle size of 31 nm. Using gas chromatography and mass spectrometry (GC/MS), an examination of biodiesel revealed the presence of four different peaks of methyl esters. Using Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance, we were able to verify that the production of methyl esters in the biodiesel sample was successful (NMR). Zerconium oxide nanoparticles were found reusable up to five consecutive cycles of transesterification. The fuel-related properties of methyl ester have been determined and are in line with the requirements of the international standards ASTM D-6571 and EN 14214. In the course of our ongoing research, we made use of membrane technology, which led to the production of biodiesel from the seed oil of Saussurea heteromalla that was better for the environment, more cost effective, and produced in greater quantities.


Asunto(s)
Biocombustibles , Saussurea , Biocombustibles/análisis , Catálisis , Esterificación , Ésteres/química , Aceites de Plantas/química
5.
Chemosphere ; 303(Pt 2): 135138, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35636597

RESUMEN

Green nano-technology together with the availability of eco-friendly and alternative sources are the promising candidates to combat environment deteriorations and energy clutches globally. The current work focuses on the synthesis and application of newly synthesized nano catalyst of Iodine doped Potassium oxide I (K2O) for producing sustainable biodiesel from novel non-edible seed oils of Coronopus didymus L. using membrane based contactor to avoid emulsification and phase separation issues. Highest biodiesel yield (97.03%) was obtained under optimum conditions of 12:1 methanol to oil ratio, reaction temperature of 65 °C for 150 min with the 1.0 wt% catalyst concentration. The lately synthesized, environment friendly and recyclable Iodine doped Potassium oxide K (IO)2 catalyst was synthesized via chemical method followed by characterization via advanced techniques including EDX, XRD, FTIR and SEM analysis. The catalyst was proved to be stable and efficient with the reusability of five times in transesterification reaction. These analysis have reported the sustainability, stability and good quality of biodiesel from seed oil of Coronopus didymus L. using efficient Iodine doped potassium oxide catalyst. Thus, non-edible, environment friendly and novel Coronopus didymus L. seeds and their extracted oil along with Iodine doped potassium oxide catalyst seems to be highly affective, sustainable and better alternative source to the future biodiesel industry. Also, by altering the reaction equilibrium and lowering the purification phases of the process, these studies show the potential of coupling transesterification and a membrane contactor.


Asunto(s)
Biocombustibles , Yodo , Biocombustibles/análisis , Catálisis , Esterificación , Yoduros , Óxidos , Aceites de Plantas/química , Compuestos de Potasio
6.
Langmuir ; 37(46): 13767-13777, 2021 11 23.
Artículo en Inglés | MEDLINE | ID: mdl-34753286

RESUMEN

Microemulsified gels (µEGs) with fascinating functions have become indispensable as topical drug delivery systems due to their structural flexibility, high stability, and facile manufacturing process. Topical administration is an attractive alternative to traditional methods because of advantages such as noninvasive administration, bypassing first-pass metabolism, and improving patient compliance. In this article, we report on the new formulations of microemulsion-based gels suitable for topical pharmaceutical applications using biocompatible and ecological ingredients. For this, two biocompatible µE formulations comprising clove oil/Brij-35/water/ethanol (formulation A) and clove oil/Brij-35/water/1-propanol (formulation B) were developed to encapsulate and improve the load of an antimycotic drug, Clotrimazole (CTZ), and further gelatinized to control the release of CTZ through skin barriers. By delimiting the pseudo-ternary phase diagram, optimum µE formulations with clove oil (∼15%) and Brij-35 (∼30%) were developed, keeping constant surfactant/co-surfactant ratio (1:1), to upheld 2.0 wt % CTZ. The as-developed formulations were further converted into smart gels by adding 2.0 wt % carboxymethyl cellulose (CMC) as a cross-linker to adhere to the controlled release of CTZ through complex skin barriers. Electron micrographs show a fine, monodispersed collection of CTZ-µE nanodroplets (∼60 nm), which did not coalesce even after gelation, forming spherical CTZ-µEG (∼90 nm). However, the maturity of CTZ nanodroplets observed by dynamic light scattering suggests the affinity of CTZ for the nonpolar microenvironment, which was further supported by the peak-to-peak correlation of Fourier transform infrared (FTIR) analysis and fluorescence measurement. In addition, HPLC analysis showed that the in vitro permeation release of CTZ-µEG from rabbit skin in the ethanolic phosphate buffer (pH = 7.4) was significantly increased by >98% within 6.0 h. This indicates the sustained release of CTZ in µEBG and the improvement in transdermal therapeutic efficacy of CTZ over its traditional topical formulations.


Asunto(s)
Clotrimazol , Aceite de Clavo , Administración Cutánea , Animales , Sistemas de Liberación de Medicamentos , Emulsiones , Geles , Conejos
7.
Eur J Nucl Med Mol Imaging ; 35(6): 1056-64, 2008 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-18228018

RESUMEN

PURPOSE: The uptake of (99m)Tc-UBI (29-41) was evaluated at sites of bacterial infections in rabbits before and after treatment with ciprofloxacin. METHODS: Staphylococcus aureus susceptible to ciprofloxacin was used to induce a focal infection in each rabbit of group 1 (G1), group 2 (G2), and group 3 (G3) with 2 x 10(4), 2 x 10(6), and 2 x 10(8) colony forming units (CFU), respectively. After 24 h, images of infected thighs (target: T) and contralateral thighs (nontarget: NT) were acquired. Animals then received ciprofloxacin intramuscularly for 5 days followed by imaging on the third and fifth days. The control group 4 (G4) was imaged at days 1, 3, and 5 under the same acquisition parameters. Group 5 (G5) was employed to study biodistribution of the peptide. RESULTS: Increases in (T/NT) ratios in G1, G2, and G3 were observed from 5 min onwards with maximum values at 60 min. G3 revealed the highest accumulation of the peptide. Growth of the same strain of S. aureus on blood agar medium was visualized after fine needle aspiration. After ciprofloxacin treatment, the images for G1-G3 resulted in significantly decreased (P < 0.05) T/NT values on the third and fifth days that correlated with reduction in number of viable bacteria. No significant difference (P < 0.05) in left to right thigh ratios in the control group (G4) was observed. Biodistribution of the peptide showed rapid removal of tracer from circulation through the kidneys. CONCLUSIONS: ( 99m ) Tc-UBI (29-41) accumulation directly correlates with the number of viable bacteria. This infection localization agent can be utilized for monitoring efficacy and duration of antibiotic treatment.


Asunto(s)
Ciprofloxacina/uso terapéutico , Miositis/diagnóstico por imagen , Miositis/metabolismo , Compuestos de Organotecnecio/farmacocinética , Fragmentos de Péptidos/farmacocinética , Infecciones Estafilocócicas/diagnóstico por imagen , Infecciones Estafilocócicas/metabolismo , Animales , Antiinfecciosos/uso terapéutico , Tasa de Depuración Metabólica , Miositis/tratamiento farmacológico , Especificidad de Órganos , Conejos , Cintigrafía , Radiofármacos/farmacocinética , Infecciones Estafilocócicas/tratamiento farmacológico , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/metabolismo , Muslo/diagnóstico por imagen , Distribución Tisular , Resultado del Tratamiento
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