The Experts below are selected from a list of 143412 Experts worldwide ranked by ideXlab platform
Mirjana Minceva - One of the best experts on this subject based on the ideXlab platform.
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trapping multiple dual mode centrifugal partition chromatography for the separation of intermediately eluting components throughput maximization strategy
Journal of Chromatography A, 2017Co-Authors: Raena Morley, Mirjana MincevaAbstract:Trapping multiple dual mode centrifugal partition chromatography (trapping MDM CPC) is an alternative to isocratic pulse injections for the separation of intermediately-eluting components from complex mixtures using liquid-liquid chromatography. In this work, a throughput maximization strategy is developed and validated to investigate the full potential of trapping MDM CPC as a preparative technique. In the proposed approach, shake flask and stationary phase retention experiments are used to determine the maximum feed concentration and flow rate, respectively. A model-based parameter selection process combining a mathematical short-Cut Method and simulations based on the equilibrium cell model is used to obtain the column loading and step durations resulting in maximized process throughput. The proposed throughput maximization strategy is experimentally validated for the separation of a ternary model mixture of parabens. A preliminary comparison of trapping MDM CPC separation performance to that of stacked pulse injections is also made.
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trapping multiple dual mode centrifugal partition chromatography for the separation of intermediately eluting components operating parameter selection
Journal of Chromatography A, 2017Co-Authors: Johannes Goll, Raena Morley, Mirjana MincevaAbstract:Abstract The preparative separation of intermediately-eluting components in liquid-liquid chromatography is commonly performed with isocratic batch injections, a technique which often leads to low yield and/or purity as a result of peak overlap. Two-column trapping multiple dual mode centrifugal partition chromatography, an alternative discontinuous Method for the separation of a mixture into three product fractions (early-, intermediately-, and late-eluting components) at full recovery, is presented in this work. A mathematical shortCut Method based on equilibrium theory assumptions is derived for the determination of the key operating parameters (i.e., step durations and number of steps). The feasibility of the technique and the accompanying short-Cut Method is demonstrated by proof-of-concept experiments for the separation of two paraben model mixtures.
Raena Morley - One of the best experts on this subject based on the ideXlab platform.
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trapping multiple dual mode centrifugal partition chromatography for the separation of intermediately eluting components throughput maximization strategy
Journal of Chromatography A, 2017Co-Authors: Raena Morley, Mirjana MincevaAbstract:Trapping multiple dual mode centrifugal partition chromatography (trapping MDM CPC) is an alternative to isocratic pulse injections for the separation of intermediately-eluting components from complex mixtures using liquid-liquid chromatography. In this work, a throughput maximization strategy is developed and validated to investigate the full potential of trapping MDM CPC as a preparative technique. In the proposed approach, shake flask and stationary phase retention experiments are used to determine the maximum feed concentration and flow rate, respectively. A model-based parameter selection process combining a mathematical short-Cut Method and simulations based on the equilibrium cell model is used to obtain the column loading and step durations resulting in maximized process throughput. The proposed throughput maximization strategy is experimentally validated for the separation of a ternary model mixture of parabens. A preliminary comparison of trapping MDM CPC separation performance to that of stacked pulse injections is also made.
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trapping multiple dual mode centrifugal partition chromatography for the separation of intermediately eluting components operating parameter selection
Journal of Chromatography A, 2017Co-Authors: Johannes Goll, Raena Morley, Mirjana MincevaAbstract:Abstract The preparative separation of intermediately-eluting components in liquid-liquid chromatography is commonly performed with isocratic batch injections, a technique which often leads to low yield and/or purity as a result of peak overlap. Two-column trapping multiple dual mode centrifugal partition chromatography, an alternative discontinuous Method for the separation of a mixture into three product fractions (early-, intermediately-, and late-eluting components) at full recovery, is presented in this work. A mathematical shortCut Method based on equilibrium theory assumptions is derived for the determination of the key operating parameters (i.e., step durations and number of steps). The feasibility of the technique and the accompanying short-Cut Method is demonstrated by proof-of-concept experiments for the separation of two paraben model mixtures.
Akira Arimoto - One of the best experts on this subject based on the ideXlab platform.
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our experience with laparoscopic partial gastrectomy by the lift and Cut Method for gastric gastrointestinal stromal tumor with maximal preservation of the remnant stomach
Surgical Endoscopy and Other Interventional Techniques, 2017Co-Authors: Shintaro Okumura, Seiichiro Kanaya, Hisahiro Hosogi, Susumu Miura, Toshihiro Okada, Norihiro Shimoike, Shin Akagawa, Hironori Kawada, Akira ArimotoAbstract:Background Wedge resection is the most commonly used Method in laparoscopic partial gastrectomy for gastric gastrointestinal stromal tumor (GIST). However, this Method can involve inadvertent resection of additional gastric tissue and cause gastric deformation. To minimize the volume of resected gastric tissue, we have developed a laparoscopic partial gastrectomy with seromyotomy which we call the ‘lift-and-Cut Method’ for gastric GIST. Here, we report a case series of this surgery.
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our experience with laparoscopic partial gastrectomy by the lift and Cut Method for gastric gastrointestinal stromal tumor with maximal preservation of the remnant stomach
Surgical Endoscopy and Other Interventional Techniques, 2017Co-Authors: Shintaro Okumura, Seiichiro Kanaya, Hisahiro Hosogi, Susumu Miura, Toshihiro Okada, Norihiro Shimoike, Shin Akagawa, Hironori Kawada, Takeshi Ito, Akira ArimotoAbstract:Wedge resection is the most commonly used Method in laparoscopic partial gastrectomy for gastric gastrointestinal stromal tumor (GIST). However, this Method can involve inadvertent resection of additional gastric tissue and cause gastric deformation. To minimize the volume of resected gastric tissue, we have developed a laparoscopic partial gastrectomy with seromyotomy which we call the ‘lift-and-Cut Method’ for gastric GIST. Here, we report a case series of this surgery. First, the seromuscular layer around the tumor is Cut. Because the mucosa and submucosa are extensible, the tumor is lifted toward the abdominal cavity. After sufficient lifting, the gastric tissue under the tumor is Cut at the submucosal layer with a linear stapler (thus ‘lift-and-Cut Method’). Finally, the defect in the seromuscular layer is closed with a hand-sewn suture. From April 2011 to December 2015, 28 patients underwent laparoscopic partial gastrectomy by this Method at Osaka Red Cross Hospital. Average operation time was 126 min (range 65–302 min) and average blood loss was 10 ml (range 0–200 ml). No intraoperative complications including tumor rupture or postoperative complications regarded as Clavien–Dindo Grade II or higher occurred. All patients took sufficient solid diet at discharge. Median postoperative hospital stay was 7 days (range 5–21 days). On median follow-up of 26.6 months (range 6–54 months), no recurrence was reported. Laparoscopic partial gastrectomy by the lift-and-Cut Method is safe and simple, and widely applicable for gastric GIST.
Johannes Goll - One of the best experts on this subject based on the ideXlab platform.
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trapping multiple dual mode centrifugal partition chromatography for the separation of intermediately eluting components operating parameter selection
Journal of Chromatography A, 2017Co-Authors: Johannes Goll, Raena Morley, Mirjana MincevaAbstract:Abstract The preparative separation of intermediately-eluting components in liquid-liquid chromatography is commonly performed with isocratic batch injections, a technique which often leads to low yield and/or purity as a result of peak overlap. Two-column trapping multiple dual mode centrifugal partition chromatography, an alternative discontinuous Method for the separation of a mixture into three product fractions (early-, intermediately-, and late-eluting components) at full recovery, is presented in this work. A mathematical shortCut Method based on equilibrium theory assumptions is derived for the determination of the key operating parameters (i.e., step durations and number of steps). The feasibility of the technique and the accompanying short-Cut Method is demonstrated by proof-of-concept experiments for the separation of two paraben model mixtures.
X. Andy Sun - One of the best experts on this subject based on the ideXlab platform.
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Matrix minor reformulation and SOCP-based spatial branch-and-Cut Method for the AC optimal power flow problem
Mathematical Programming Computation, 2018Co-Authors: Burak Kocuk, Santanu S. Dey, X. Andy SunAbstract:Alternating current optimal power flow (AC OPF) is one of the most fundamental optimization problems in electrical power systems. It can be formulated as a semidefinite program (SDP) with rank constraints. Solving AC OPF, that is, obtaining near optimal primal solutions as well as high quality dual bounds for this non-convex program, presents a major computational challenge to today’s power industry for the real-time operation of large-scale power grids. In this paper, we propose a new technique for reformulation of the rank constraints using both principal and non-principal 2-by-2 minors of the involved Hermitian matrix variable and characterize all such minors into three types. We show the equivalence of these minor constraints to the physical constraints of voltage angle differences summing to zero over three- and four-cycles in the power network. We study second-order conic programming (SOCP) relaxations of this minor reformulation and propose strong Cutting planes, convex envelopes, and bound tightening techniques to strengthen the resulting SOCP relaxations. We then propose an SOCP-based spatial branch-and-Cut Method to obtain the global optimum of AC OPF. Extensive computational experiments show that the proposed algorithm significantly outperforms the state-of-the-art SDP-based OPF solver and on a simple personal computer is able to obtain on average a $$0.71\%$$ 0.71 % optimality gap in no more than 720 s for the most challenging power system instances in the literature.
