Preparation and characterization of polyethylene-based hybrid particles by an environmentally-friendly and aqueous solvent evaporation method

The present paper reports preparation procedure and characterization of micrometer-sized polyethylene (PE)-based hybrid particles containing various amounts of Mg(OH)2 powder treated with different amounts of methylhydrogen polysiloxane (MHS). The PE-based hybrid particles were fabricated by an environmentally-friendly and aqueous solvent evaporation method by employing different kinds of surfactants. The shape, microstructure and other properties of the resultant PE-based hybrid particles were dependent markedly on the changes in composition of raw materials, especially for the amount of MHS used for the treatment of Mg(OH)2 and the kind of surfactant. The particles fabricated by using 1 wt% MHS-treated Mg(OH)2 (ST-1) powder and polyoxyethylene (10) octylphenyl ether (Triton X-100) as a surfactant showed spherical shape and their primary particle sizes were about 4--10 μm, irrespective of the additive amount of ST-1 powder. These particles showed superior properties in terms of the actual content of MHS-treated Mg(OH)2 powder incorporated inside the hybrid particles, particle size distribution and particle shape, in comparison with other particles fabricated by using 5 wt% MHS-treated Mg(OH)2 (ST-5) powder and polyoxyethylene (8) octylphenyl ether (Triton X-114) as a surfactant. This is due to good affinity (average contact angle was 19.4°) between the ST-1 powder and the aqueous phase, i.e. a continuous phase, dissolving Triton X-100. Furthermore, a composite fabricated by employing these PE-based hybrid particles showed uniform and homogeneous distribution of ST-1 powder in the PE matrix

Dielectric barrier discharge plasma microbubble reactor for pretreatment of lignocellulosic biomass

A novel lignocellulosic biomass pretreatment reactor has been designed and tested to investigate pretreatment efficacy of miscanthus grass. The reactor was designed to optimize the transfer of highly oxidative species produced by dielectric barrier discharge plasma to the liquid phase immediately after generation, by arranging close proximity of the plasma to the gas‐liquid interface of microbubbles. The reactor produced a range of reactive oxygen species and reactive nitrogen species, and the rate of production depended on the power source duty cycle and the temperature of the plasma. Ozone and other oxidative species were dispersed efficiently using energy efficient microbubbles produced by fluidic oscillations. A 5% (w/w) miscanthus suspension pretreated for 3 h at 10% duty cycle yielded 0.5% acid soluble lignin release and 26% sugar release post hydrolysis with accelerated pretreatment toward the latter stages of the treatment demonstrating the potential of this approach as an alternative pretreatment method

Continuous Membrane Emulsification with Pulsed (Oscillatory) Flow

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Industrial and Engineering Chemistry Research, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see: http://dx.doi.org/10.1021/ie3020457Tubular micrometer pore sized sieve type membranes with internal diameter of 14 mm and length of 60 mm containing uniform pores of diameter 10 and 20 μm were used to generate emulsions of sunflower oil dispersed in water and stabilized by Tween 20 using oscillatory flow of the continuous phase. Drop diameters between 30 and 300 μm could be produced, in a controllable way and with span values of down to 0.4. By using pulsed flow it was possible to provide dispersed phase concentrations of up to 45% v/v in a single pass over the membrane, that is, without the need to recirculate the continuous phase through the membrane tube. It was possible to correlate the drop size produced with the shear conditions at the membrane surface using the wave shear stress equation. The oscillatory Reynolds number indicated flow varying from laminar to substantially turbulent, but the change in flow conditions did not show a notable influence on the drop diameters produced, over what is predicted by the varying wall shear stress applied to the wave equation. However, the 20 μm pore sized sieve type membrane appeared to allow the passage of the pressure pulse through the membrane pores, under certain operating conditions, which did lead to finer drop sizes produced than would be predicted. These through-membrane pulsations could be suppressed by changes in operating conditions: a higher dispersed phase injection rate or more viscous continuous phase, and they did not occur under similar operating conditions used with the 10 μm pore sized sieve type of membrane. Generating emulsions of this size using pulsed continuous phase flow provides opportunities for combining drop generation at high dispersed phase concentration, by membrane emulsification, with downstream processing such as reaction in plug flow reactors

カキ結果枝の乾物蓄積量と生理落果との関係(農学部門)

カキの果実, 新梢, 葉及び2年生枝の乾物重並びに葉面積を推定する単回帰式を求めた。その結果, 果実乾物重は(横径)^2×縦径, 新梢乾物重は新梢長×(新梢中央部の直径)^2,葉乾物重及び葉面積は葉身長×葉幅長, 2年生枝乾物重は枝長×(枝中央部の直径)^2を説明変数とすることにより, 高い相関係数が得られた。この単回帰式を用い, 結果枝の新梢, 葉及び果実の乾物重を非破壊的に推定し, 結果枝の乾物蓄積量と生理落果との関係を調べた。その結果, 落果の認められる結果枝は落果の認められない結果枝に比べ, 結果枝乾物重, 枝葉乾物重の値が高く, 果実乾物増加量, 果実への乾物分配率が低かった。このことにより, 結果枝の乾物蓄積量が高い値を示しても, 果実への乾物分配率が低ければ落果と関係することが明らかとなった。また, 枝葉乾物重が高い値を示すとき, 果実乾物増加量が低い値を示すことから, 果実と枝葉間に同化産物の競合関係の存在することが実証された。Single regression equations were determined for estimating the dry weight of fruit, new shoot, leaf and 2 year old blanch and the leaf area in Japanese persimmon (Diospyros kaki Thunb.) As the results, correlation coefficients of all equations were strong enough to estimate the dry weight of fruit, shoot, leaf and 2 year old blanch and the leaf area, by using. (fruit width)^2×fruit length, shoot length×(shoot diameter at half length)^2,leaf length×leaf width, branch length×(branch diameter at half length)^2 and leaf length×leaf width for predictor variables respectively. These data of predictor variables were collected weekly from 16 May from "dropping" bearing shoot that early fruit drop occurred in several weeks after pollination and "control" bearing shoot that early fruit drop did not occur. Furthermore, the relationship between early fruit drop and accumulated dry matter of bearing shoot which was estimated by using above regression equation was investigated. Dry weight of bearing shoot (fruit+shoot+leaf) and of vegetative organ (shoot+leaf) were significantly higher value in "dropping" than in "control". In addition, dry weight increase of fruit and distribution ratio of dry weight increase into fruit were significantly higher value in "control" than in "dropping". The results showed that lower distribution ratio of dry weight increase into fruit, whereas higher value of dry weight of bearing shoot, were apparently related to early fruit drop and that there were severe competition of asimilate between fruit and vegetative organ

Formulation, stabilisation and encapsulation of bacteriophage for phage therapy

Against a backdrop of global antibiotic resistance and increasing awareness of the importance of the human microbiota, there has been resurgent interest in the potential use of bacteriophages for therapeutic purposes, known as phage therapy. A number of phage therapy phase I and II clinical trials have concluded, and shown phages don’t present significant adverse safety concerns. These clinical trials used simple phage suspensions without any formulation and phage stability was of secondary concern. Phages have a limited stability in solution, and undergo a significant drop in phage titre during processing and storage which is unacceptable if phages are to become regulated pharmaceuticals, where stable dosage and well defined pharmacokinetics and pharmacodynamics are de rigueur. Animal studies have shown that the efficacy of phage therapy outcomes depend on the phage concentration (i.e. the dose) delivered at the site of infection, and their ability to target and kill bacteria, arresting bacterial growth and clearing the infection. In addition, in vitro and animal studies have shown the importance of using phage cocktails rather than single phage preparations to achieve better therapy outcomes. The in vivo reduction of phage concentration due to interactions with host antibodies or other clearance mechanisms may necessitate repeated dosing of phages, or sustained release approaches. Modelling of phage-bacterium population dynamics reinforces these points. Surprisingly little attention has been devoted to the effect of formulation on phage therapy outcomes, given the need for phage cocktails, where each phage within a cocktail may require significantly different formulation to retain a high enough infective dose. This review firstly looks at the clinical needs and challenges (informed through a review of key animal studies evaluating phage therapy) associated with treatment of acute and chronic infections and the drivers for phage encapsulation. An important driver for formulation and encapsulation is shelf life and storage of phage to ensure reproducible dosages. Other drivers include formulation of phage for encapsulation in micro- and nanoparticles for effective delivery, encapsulation in stimuli responsive systems for triggered controlled or sustained release at the targeted site of infection. Encapsulation of phage (e.g. in liposomes) may also be used to increase the circulation time of phage for treating systemic infections, for prophylactic treatment or to treat intracellular infections. We then proceed to document approaches used in the published literature on the formulation and stabilisation of phage for storage and encapsulation of bacteriophage in micro- and nanostructured materials using freeze drying (lyophilization), spray drying, in emulsions e.g. ointments, polymeric microparticles, nanoparticles and liposomes. As phage therapy moves forward towards Phase III clinical trials, the review concludes by looking at promising new approaches for micro- and nanoencapsulation of phages and how these may address gaps in the field