Production of biohydrogen has the potential to be a renewable alternative to current technologies. There are varieties of technologies for biological hydrogen production mechanisms including ...biophotolysis, photo fermentation, dark fermentation and hybrid biohydrogen production by electrochemical processes. In these studies, a review on the recent developments of biohydrogen production is presented. First, the theoretical principles of biophotolysis by cyanobacteria and green micro algae, as well as direct and indirect of biophotolysis process on hydrogen production are described. Secondly, practical aspects and fundamental of biological hydrogen production processes by photo and dark fermentation are reviewed. This work also involved comparison of the maximum H2 yield, bacterial strains, operating condition, suitable substrates, and mathematical models for fermentative hydrogen production. A new hybrid biological hydrogen production processes by using the electrochemical process is then proposed. This study can also be used to improve the basic and current knowledge about the performance of the biophotolysis, fermentative and electrochemical process in producing hydrogen gas as the alternate fuel.
This paper intends to review the state of the art of new generation nanomaterials – carbon nanotubes (CNTs), graphene, zeolites, aquaporin (AQP) for water desalination. The major applications of ...these nanomaterials in water desalination are critically discussed based on their functions in different types of processes. In addition, the potential impact of these nanomaterials on human health and ecosystem as well as its potential interference with treatment processes was also briefly discussed. It can be seen that the use of these advanced materials in membranes for reverse osmosis, membrane distillation, forward osmosis, pervaporation, and electrodialysis, formed the bulk of the reported works in the literature. Apart from that, these nanomaterials also have been reported to be utilized as adsorbents, supercapacitor, and capacitive deionization (CDI) for desalination purpose. However there has been very limited works reported on the environmental impact of these nanomaterials. Future works should focus on the process that would have the best potential to be cost-effectively commercialized at industrial scale which, based on this review, looks to be the CDI technology.
•Overview of recent advanced nanomaterials - carbon nanotubes, graphene, zeolites, and aquaporin for various water desalination technologies.•Major applications of these nanomaterials in water desalination are critically reviewed based on their functions in unit operation processes.
This book is the first to comprehensively explore elasticity imaging and examines recent, important developments in asymptotic imaging, modeling, and analysis of deterministic and stochastic elastic ...wave propagation phenomena. It derives the best possible functional images for small inclusions and cracks within the context of stability and resolution, and introduces a topological derivative–based imaging framework for detecting elastic inclusions in the time-harmonic regime. For imaging extended elastic inclusions, accurate optimal control methodologies are designed and the effects of uncertainties of the geometric or physical parameters on stability and resolution properties are evaluated. In particular, the book shows how localized damage to a mechanical structure affects its dynamic characteristics, and how measured eigenparameters are linked to elastic inclusion or crack location, orientation, and size. Demonstrating a novel method for identifying, locating, and estimating inclusions and cracks in elastic structures, the book opens possibilities for a mathematical and numerical framework for elasticity imaging of nanoparticles and cellular structures.
Persistent organic pollutants (POPs) are carbon-based chemical substances that are resistant to environmental degradation and may not be completely removed through treatment processes. Their ...persistence can contribute to adverse health impacts on wild-life and human beings. Thus, the solar photocatalysis process has received increasing attention due to its great potential as a green and eco-friendly process for the elimination of POPs to increase the security of clean water. In this context, ZnO nanostructures have been shown to be prominent photocatalyst candidates to be used in photodegradation owing to the facts that they are low-cost, non-toxic and more efficient in the absorption across a large fraction of the solar spectrum compared to TiO2. There are several aspects, however, need to be taken into consideration for further development. The purpose of this paper is to review the photo-degradation mechanisms of POPs and the recent progress in ZnO nanostructured fabrication methods including doping, heterojunction and modification techniques as well as improvements of ZnO as a photocatalyst. The second objective of this review is to evaluate the immobilization of photocatalyst and suspension systems while looking into their future challenges and prospects.
We aim to present a new scheme for high-dimensional atomic microscopy via double electromagnetically induced transparency in a four-level tripod system. For atom–field interaction, we construct a ...spatially dependent field by superimposing three standing-wave fields (SWFs) in 3D-atom localization. We achieve a high precision and high spatial resolution of an atom localization by appropriately adjusting the system variables such as field intensities and phase shifts. We also see the impact of Doppler shift and show that it dramatically deteriorates the precision of spatial information on 3D-atom localization. We believe that our suggested scheme opens up a fascinating way to improve the atom localization that supplies some practical applications in atom nanolithography, and Bose–Einstein condensation.
In this study, two biomass-based adsorbents were used as new precursors for optimizing synthesis conditions of a cost-effective powdered activated carbon (PAC). The PAC removed dyes from an aqueous ...solution using carbonization and activation by KOH, NaOH, and H
SO
. The optimum synthesis, activation temperature, time and impregnation ratio, removal rate, and uptake capacity were determined. The optimum PAC was analyzed and characterized using Fourier-transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), a field emission scanning electron microscope (FESEM), Zeta potential, and Raman spectroscopy. Morphological studies showed single-layered planes with highly porous surfaces, especially PAC activated by NaOH and H
SO
. The results showed that the experimental data were well-fitted with a pseudo-second-order model. Based on Langmuir isotherm, the maximum adsorption capacity for removing methylene blue (MB) was 769.23 mg g
and 458.43 mg g
for congo red (CR). Based on the isotherm models, more than one mechanism was involved in the adsorption process, monolayer for the anionic dye and multilayer for the cationic dye. Elovich and intraparticle diffusion kinetic models showed that rubber seed shells (RSS) has higher α values with a greater tendency to adsorb dyes compared to rubber seed (RS). A thermodynamic study showed that both dyes' adsorption process was spontaneous and exothermic due to the negative values of the enthalpy (ΔH) and Gibbs free energy (ΔG). The change in removal efficiency of adsorbent for regeneration study was observed in the seventh cycles, with a 3% decline in the CR and 2% decline in MB removal performance. This study showed that the presence of functional groups and active sites on the produced adsorbent (hydroxyl, alkoxy, carboxyl, and π - π) contributed to its considerable affinity for adsorption in dye removal. Therefore, the optimum PAC can serve as efficient and cost-effective adsorbents to remove dyes from industrial wastewater.
An objective method was developed to detect local cells of the Siberian high (SH) over the Middle East, and mean sea level pressure (SLP) data from the National Centers for Environmental ...Prediction/National Center for Atmospheric Research reanalysis dataset were used to specify the centers of local SH cells and associated ridges. The results indicated that approximately 25.8% of winter SH cells influence the Middle East, and this influence diminishes from December to February. Synoptically, the area between the Black and Caspian Seas represents a remote area for sensing the influences of the SH on the Middle East. Although the SH is considered a shallow system, the variability of the effectiveness of the SH throughout the Middle East was estimated from the integration of atmospheric systems at the whole‐atmosphere scale (from the surface to 200 hPa). Further, this study demonstrated that the westward extension of the SH over the Middle East is associated with weak cyclogenesis in the area between the Black and Caspian Seas; that is, the atmospheric systems are favourable for strengthening the upper‐layer ridge in this area. However, the eastward retreat of the SH extension from the Middle East is associated with strong cyclogenesis in the area between the Black and Caspian Seas; that is, the atmospheric systems are unfavourable for strengthening the upper‐layer ridge in this area. This study revealed the importance of the SH in the generation of the pressure gradient over the Arabian Peninsula and the associated development of dust storms and the Red Sea Trough.
The results indicated that approximately 25.8% of the winter the Siberian high (SH) cells influenced the Middle East, and this influence decreased from December to February. Synoptically, the area between the Black and Caspian seas represents a remote area for sensing the influences of the SH on the Middle East.
For sessile marine invertebrates with complex life cycles, habitat choice is directed by the larval phase. Defining which habitat-linked cues are implicated in sessile invertebrate larval settlement ...has largely concentrated on chemical cues which are thought to signal optimal habitat. There has been less effort establishing physical settlement cues, including the role of surface microtopography. This laboratory based study tested whether surface microtopography alone (without chemical cues) plays an important contributing role in the settlement of larvae of coral reef sessile invertebrates. We measured settlement to tiles, engineered with surface microtopography (holes) that closely matched the sizes (width) of larvae of a range of corals and sponges, in addition to surfaces with holes that were markedly larger than larvae. Larvae from two species of scleractinian corals (Acropora millepora and Ctenactis crassa) and three species of coral reef sponges (Luffariella variabilis, Carteriospongia foliascens and Ircinia sp.,) were used in experiments. L. variabilis, A. millepora and C. crassa showed markedly higher settlement to surface microtopography that closely matched their larval width. C. foliascens and Ircinia sp., showed no specificity to surface microtopography, settling just as often to microtopography as to flat surfaces. The findings of this study question the sole reliance on chemical based larval settlement cues, previously established for some coral and sponge species, and demonstrate that specific physical cues (surface complexity) can also play an important role in larval settlement of coral reef sessile invertebrates.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Epilepsy is a serious neurological disorder that affects around 50 million people worldwide. Almost 30% of epileptic patients suffer from pharmacoresistance, which is associated with social ...isolation, dependent behaviour, low marriage rates, unemployment, psychological issues and reduced quality of life. Currently available antiepileptic drugs have a limited efficacy, and their negative properties limit their use and cause difficulties in patient management. Antiepileptic drugs can provide only symptomatic relief as these drugs suppress seizures but do not have ability to cure epileptogenesis. The long term use of antiepileptic drugs is limited due to their adverse effects, withdrawal symptoms, deleterious interactions with other drugs and economic burden, especially in developing countries. Furthermore, some of the available antiepileptic drugs may even potentiate certain type of seizures. Several in vivo and in vitro animal models have been proposed and many new antiepileptic drugs have been marketed recently, but large numbers of patients are still pharmacoresistant. This review will highlight the difficulties in treatment and management of epilepsy and the limitations of available antiepileptic drugs and animal seizure models.
Hyperparameter tuning is an important process to maximize the performance of any neural network model. This present study proposed the factorial design of experiment for screening and response ...surface methodology to optimize the hyperparameter of two artificial neural network algorithms. Feed-forward neural network (FFNN) and radial basis function neural network (RBFNN) are applied to predict the permeate flux of palm oil mill effluent. Permeate pump and transmembrane pressure of the submerge membrane bioreactor system are the input variables. Six hyperparameters of the FFNN model including four numerical factors (neuron numbers, learning rate, momentum, and epoch numbers) and two categorical factors (training and activation function) are used in hyperparameter optimization. RBFNN includes two numerical factors such as a number of neurons and spreads. The conventional method (one-variable-at-a-time) is compared in terms of optimization processing time and the accuracy of the model. The result indicates that the optimal hyperparameters obtained by the proposed approach produce good accuracy with a smaller generalization error. The simulation results show an improvement of more than 65% of training performance, with less repetition and processing time. This proposed methodology can be utilized for any type of neural network application to find the optimum levels of different parameters.
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