The encapsulation of model oil in Ca-alginate beads using high oil loading was studied. It was found that the alginate concentration, oil volume fraction and alginate type each have a significant ...influence on the encapsulation efficiency and on bead properties. The alginate-oil emulsion, comprising an oil loading up to 30vol% and 25g/L of high G alginate solution (equivalent to an oil-to-wall weight ratio of up to 15g/g), was found to be stable and resulted in an encapsulation efficiency of 90% before drying. The oil-loaded, wet beads were spherical. The encapsulation efficiency was dependent on the degree of cross-linking at the surface of the extruded emulsion droplet as well as on the emulsion stability. The oil extraction profile of dried beads may be related to the structural properties of the beads, which are dependent on both the drying method and the oil loading. The overall encapsulation efficiency after freeze-drying and oven-drying were 90% and 79%, respectively, with an oil content of over 85wt% for both types of dried beads. The freeze-dried beads were non-oily and free flowing, whereas the oven-dried beads were oily and sticky. The results of this work are compared to those in the literature, and the merits and the drawbacks associated with different methods are discussed.
The generation of palm oil mill effluent (POME) alongside with the production of crude palm oil has created environmental issue for the palm oil mill industry in Malaysia due to its polluting ...characteristics. POME with its high organic content is a source with great potential for biogas production. However, POME is commonly treated using open ponding system just to comply with government regulation without capturing biogas released from the process. Biogas generated from anaerobic digestion of POME can replace palm kernel shell and mesocarp fiber which has higher economic value as boiler fuel; upgraded to be used in gas engine for power generation. It is estimated that net profit of RM 3.8 million per year can be obtained in a palm oil mill with processing capacity of 60tonnes/hr from electricity generation using biogas produced from POME treatment. This review paper will elaborate on the potential of POME as a source of renewable energy and the challenges faced by the palm oil mills in Malaysia which deters the development of biogas plants in the mill.
Oil-in-water (O/W) Pickering emulsions stabilized by food-grade particles have gained increasing research attention recently. The aim of the present study was to investigate the effects of chitosan ...concentration and environmental factors i.e., ionic strength, temperature, and pH on the physical stability of the emulsions stabilized by self-aggregated chitosan particles. The emulsions were prepared using a high speed homogenizer and their coalescence, creaming, and flocculation stability was evaluated. Increasing the chitosan concentration from 0.01 to 0.3% w/v was found to enhance the coalescence and creaming stability. Similar results were obtained with the addition of NaCl from 100 to 500 mM. The emulsions were also highly stable at pH 7 and above. Reducing the pH was found to promote droplets coalescence and creaming, with demulsification occurring at pH 2. The emulsions were stable at and below 50 °C. Increasing the temperature was found to promote droplets coalescence and creaming. The improvement in the emulsion stability could be attributed to the aggregation of particles at the O/W interface and the formation of chitosan networks in the continuous phase, thus limiting droplet–droplet interactions. In conclusion, the physical stability of Pickering emulsions stabilized by chitosan particles was found to be responsive to environmental stimuli. This feature could be exploited in the development of stimulus-responsive emulsions for food or pharmaceutical applications.
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•Chitosan particles were responsive to pH, ionic strength, and temperature.•Pickering emulsions stabilized by chitosan particles were formed.•Chitosan concentration, pH, salt, and temperature affected emulsion stability.•Opportunity for the development of stimulus-responsive emulsions.
SUMMARY
The Hunga Tonga-Hunga Ha'apai volcano eruption resulted in propagation of tsunamis globally. Atmospheric pressure disturbances and tsunamis were recorded in Lingding Bay, China, situated more ...than 9000 km from the volcano. We studied the features of tsunamis in Lingding Bay and its surrounding areas by using records from tide gauges and meteorological stations. Lamb waves were observed in the bay approximately 8, 44 and 80 hr after the volcanic eruption. The first and second tsunami waves arrived approximately 11 and 45–47 hr following the eruption, respectively, indicating consistency with the arrival time of Lamb waves. In addition, wavelet and Fourier analyses were applied to the sea level records to investigate the frequency characteristics. The ratio of the tsunami spectra to the background spectra for two tsunami waves was calculated as the source spectra. The source spectra of two tsunami waves were mostly of the same shape, with dominant periods of ∼17 and ∼46 min. Our results provide information for theoretical investigation of the Tonga tsunami event. More efforts should be devoted to relevant research on the generating mechanism and early warning of tsunamis from non-seismic origins.
The recent developments of nanostructured WO3 thin films synthesized through the electrochemical route of electrochemical anodization and cathodic electrodeposition for the application in ...photoelectrochemical (PEC) water splitting are reviewed. The key fundamental reaction mechanisms of electrochemical anodization and cathodic electrodeposition methods for synthesizing nanostructured WO3 thin films are explained. In addition, the effects of metal oxide precursors, electrode substrates, applied potentials and current densities, and annealing temperatures on size, composition, and thickness of the electrochemically synthesized nanostructured WO3 thin films are elucidated in detail. Finally, a summary is given for the general evaluation practices used to calculate the energy conversion efficiency of nanostructured WO3 thin films and a recommendation is provided to standardize the presentation of research results in the field to allow for easy comparison of reported PEC efficiencies in the near future.
It′s all a matter of e: The synthesis of nanostructured WO3 to be used for photochemical water splitting using various electrochemical routes is reviewed. Key fundamental reaction mechanisms and various effects of synthesis methods and approaches on physical, chemical, optical, and photoelectrochemical properties of nanostructured WO3 are explained. Also, a summary of the current evaluation practices on the energy conversion efficiency of nanostructured WO3 is provided.
Structured lipid is a type of modified form of lipid that is "fabricated" with the purpose to improve the nutritional and functional properties of conventional fats and oils derived from animal and ...plant sources. Such healthier choice of lipid received escalating attention from the public for its capability to manage the rising prevalence of metabolic syndrome. Of which, medium-chain triacylglycerol (MCT) and medium-and long-chain triacylglycerol (MLCT) are the few examples of the "new generation" custom-made healthful lipids which are mainly composed of medium chain fatty acid (MCFA). MCT is made up exclusively of MCFA whereas MLCT contains a mixture of MCFA and long chain fatty acid (LCFA), respectively. Attributed by the unique metabolism of MCFA which is rapidly metabolized by the body, MCFA and MCT showed to acquire multiple physiological and functional properties in managing and reversing certain health disorders. Several chemically or enzymatically oils and fats modification processes catalyzed by a biological or chemical catalyst such as acidolysis, interesterification and esterification are adopted to synthesis MCT and MLCT. With their purported health benefits, MCT and MLCT are widely being used as nutraceutical in food and pharmaceutical sectors. This article aims to provide a comprehensive review on MCT and MLCT, with an emphasis on the basic understanding of its structures, properties, unique metabolism; the current status of the touted health benefits; latest routes of production; its up-to-date applications in the different food systems; relevant patents filed and its drawbacks
Although the traits emerged in a mass gathering are often non-deliberative, the act of mass impulse may lead to irrevocable crowd disasters. The two-fold increase of carnage in crowd since the past ...two decades has spurred significant advances in the field of computer vision, towards effective and proactive crowd surveillance. Computer vision studies related to crowd are observed to resonate with the understanding of the emergent behavior in physics (complex systems) and biology (animal swarm). These studies, which are inspired by biology and physics, share surprisingly common insights, and interesting contradictions. However, this aspect of discussion has not been fully explored. Therefore, this survey provides the readers with a review of the state-of-the-art methods in crowd behavior analysis from the physics and biologically inspired perspectives. We provide insights and comprehensive discussions for a broader understanding of the underlying prospect of blending physics and biology studies in computer vision.
•Review crowd behavior studies in computer vision from physics and biology outlooks.•Overview of the key attributes of crowd from the perspectives of the two sciences.•General attributes of crowd: decentralized, collective motion, emergent behavior.•Contradicting attributes of crowd: thinking/non-thinking, bias/non-bias.•Discuss sample applications of crowd based on attributes and benchmarked datasets.
The shape diagram reveals a clear operating region and the process limits within which spherical ca-alginate beads could be formed.
The aim of this work was to develop prediction models for shape and ...size of ca-alginate macrobeads produced through extrusion–dripping method. The relationship between the process variables on the shape and size of the alginate drops before and after gelation was established with the aid of image analysis. The results show that a critical Ohnersorge number (
Oh)
>
0.24 was required to form spherical beads. The shape transition of ca-alginate beads could be typically distinguished into three phases along the collecting distance and it was affected by the combined influence of the solution properties, the collecting distance and the drop size. Mathematical equations and a master shape diagram were developed to reveal a clear operating region and the overall process limits within which spherical ca-alginate beads could be formed. In terms of bead size, the overall size correction factor (
K) which accounted for the liquid loss factor (
k
LF
) and the shrinkage factor (
k
SF
), varied between 0.73 and 0.85 under the experimental conditions. The size prediction model correlated well with the experimental data. The approach and the outcome could be used as a model to develop prediction tools for similar bead production systems.
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