scholarly journals Optimization of Fermentation Conditions for Carrageenase Production by Cellulophaga Species: A Comparative Study

Biology ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 971
Author(s):  
Md Musa Howlader ◽  
Jana Molz ◽  
Nico Sachse ◽  
Rando Tuvikene
Keyword(s):  
Enzymatic Degradation ◽  
Incubation Temperature ◽  
Optimization Method ◽  
Medium Composition ◽  
Sulphated Polysaccharides ◽  
Time Optimization ◽  
The One ◽  
Optimization Of Fermentation ◽  
Optimal Incubation ◽  
Optimal Medium

Carrageenases appear in various species of marine bacteria and are widely used for the degradation of carrageenans, the commercially significant sulphated polysaccharides. The carrageenase production ability of six different Cellulophaga species was identified, with ι-carrageenase being the most abundant carrageenolytic enzyme. C. algicola was the most potent strain, followed by C. fucicola and C. geojensis, whereas C. pacifica was the least effective carrageenase producer among the studied strains. The enzyme production was maximized using the one-factor-at-a-time optimization method. The optimal incubation temperature was identified as 25 °C and the incubation time was set as 48 h for all tested species. The optimal medium composition for Cellulophaga strains was determined as 30 g/L sea salt, 1.4 g/L furcellaran, and 3 g/L yeast extract. An ultrafiltered enzyme extracted from C. algicola had the highest activity at around 40 °C. The optimal pH for enzymatic degradation was determined as 7.8, and the enzyme was fairly stable at temperatures up to 40 °C.

An Enhanced One-Layer Passive Microfluidic Mixer With an Optimized Lateral Structure With the Dean Effect

2015 ◽  
Vol 137 (9) ◽  
Author(s):  
Teng Zhou ◽  
Yifan Xu ◽  
Zhenyu Liu ◽  
Sang Woo Joo
Keyword(s):  
Reynolds Number ◽  
Topology Optimization ◽  
Optimization Method ◽  
Mixing Efficiency ◽  
Boolean Operation ◽  
Microfluidic Mixer ◽  
Wide Range ◽  
The One ◽  
Lateral Structure ◽  
Topology Optimization Method

Topology optimization method is applied to a contraction–expansion structure, based on which a simplified lateral flow structure is generated using the Boolean operation. A new one-layer mixer is then designed by sequentially connecting this lateral structure and bent channels. The mixing efficiency is further optimized via iterations on key geometric parameters associated with the one-layer mixer designed. Numerical results indicate that the optimized mixer has better mixing efficiency than the conventional contraction–expansion mixer for a wide range of the Reynolds number.

Design rules for timber log reciprocal floors, based on mass optimization under stiffness constraint

2021 ◽  
pp. 095605992110416
Author(s):  
Pierre Latteur ◽  
Julien Geno ◽  
Marie Vandamme
Keyword(s):  
Parametric Design ◽  
Optimization Method ◽  
Equilibrium Equations ◽  
Design Rules ◽  
Stiffness Optimization ◽  
Structural Relevance ◽  
Reciprocal Structures ◽  
General Mass ◽  
The One ◽  
Robotic Tools

Building with raw timber allows to reduce the price of construction and to make it more competitive with respect to concrete or steel construction. For a few years now, the combination of parametric design and robotic tools make possible the fast and precise milling of timber logs for their accurate connection. However, the spans are quickly limited by the logs length. In this context, reciprocal structures are relevant, since they allow to build large spans structures with short beams. Finally, the architectural interest of reciprocal structures is not to prove. However, the choice of the most efficient reciprocal frame, as well as its structural relevance in terms of mass and stiffness is, most of the time, ruled by subjective considerations. This paper focuses on rectangular floors composed of reciprocal moduli and has three objectives: (1) to develop a general mass and stiffness optimization method for reciprocal floors, which is not only necessary to limit the price, but also to reduce their thickness, (2) to define design rules for reciprocal floors, in particular for the choice of the best engagement ratio, and (3) to compare the structural efficiency of reciprocal floors with the one of “traditional” floors with parallel logs. Coming from a dimensionless transformation of the equilibrium equations, the results of this article will thus give the designers keys to better design reciprocal structures, evaluate their structural performances and relevance, and justify their choices.

scholarly journals Jacob’s ladder Polemonium caeruleum L. and black salsify Sсorzonera hispanica L. in vitro culture

2018 ◽  
Vol 22 ◽  
pp. 216-221
Author(s):  
O. V. Bulko ◽  
L. G. Lioshina
Keyword(s):  
In Vitro Culture ◽  
Root Culture ◽  
Medium Composition ◽  
Cultivation Medium ◽  
Plant Cultivation ◽  
Regenerated Plants ◽  
Composition Modification ◽  
Jacob's Ladder ◽  
Optimal Medium

Aim. Micropropagation of Jacob’s ladder Polemonium caeruleum L. and black salsify Scorzonera hispanica L., obtaining root culture and regenerated plants. Methods. In vitro plant cultivation, medium composition modification for micropropagation, inoculation of explants with agrobacterial strains. Results. In vitro cultures of Jacob’s ladder and black salsify have been obtained, the optimal medium composition has been determined for the effective plants multiplication, rooting and growth, root cultures and regenerated plants of studied species have been obtained. Conclusions. Obtained technology of in vitro culture establishment of P. caeruleum and S. hispanica can be used for plants microclonal propagation so as root culture and regenerated plants acquiring due to the agrobacterial transformation – for further studies of secondary metabolism of these plants. Keywords: P. caeruleum L., S. hispanica L., micropropagation, phytohormones, root culture.

scholarly journals Optimization of an Economical Medium Composition For The Coculture of Clostridium Butyricum And Bacillus Coagulans

2021 ◽  
Author(s):  
Yonghong Li ◽  
Yun Wang ◽  
Yingying Liu ◽  
Xuan Li ◽  
Keke Li ◽  
...  
Keyword(s):  
Industrial Production ◽  
Fermentation Process ◽  
Bacillus Coagulans ◽  
Medium Composition ◽  
Clostridium Butyricum ◽  
Production Level ◽  
Beneficial Bacteria ◽  
Spore Yield ◽  
Viable Bacteria ◽  
Optimal Medium

Abstract Clostridium butyricum is a spore-forming probiotic existing in the intestines of humans and animals which can promote the enhancement of beneficial bacteria and maintain intestinal microecological balance. However, it is difficult to improve the production level of C. butyricum by conventional fermentation process. In this study, a co-fermentation process of C. butyricum DL-1 and Bacillus coagulans ZC2-1 was established to improve the viable counts and spore yield of C. butyricum, and the formula of coculture medium was optimized by flask fermentation. The results showed that the optimum medium composition is bran 10 g/L, corn steep powder 15 g/L, peptone 15 g/L, K2HPO4 1 g/L and MnSO4 0.5 g/L. Cultured stationarily in the optimal medium for 36 h, the number of viable bacteria of C. butyricum DL-1 reached 1.5×108 CFU/mL and the spore forming rate was 92.6%. The results revealed an economical and effective medium composition for the coculture of C. butyricum and B. coagulans. The co-fermentation process established in this study provides a new fermentation mode for the industrial production of other absolute anerobic bacteria.

A sintering burden blending model based on one-step optimization method and high-temperature characteristics of iron ore

2019 ◽  
Vol 116 (2) ◽  
pp. 211
Author(s):  
Shengli Wu ◽  
Xiaobo Zhai ◽  
Tiankai Song
Keyword(s):  
High Temperature ◽  
Iron Ore ◽  
Intelligent System ◽  
Quantitative Relationship ◽  
High Strength ◽  
Optimization Method ◽  
Temperature Characteristics ◽  
Positive Effects ◽  
One Step ◽  
The One

A sintering burden blending model is an intelligent system used to obtain the optimal blending proportions of burdens with minimal sintering burden cost. In this study, micro-sintering and sinter pot tests were first carried out to clarify the quantitative relationship between the shatter index (SI) of the sinter and high-temperature characteristics (HTCs) of the ore blends. The result shows that the lowest assimilation temperature (LAT) plays a dual role in SI, whereas the index of liquid phase fluidity (ILF) and compressive strength of the bonding phase (CSB) have positive effects on SI. The effect of the ILF is the largest. Based on the one-step optimization method, suitable ranges of room-temperature characteristics (RTCs) of ore blends, obtained relationship between sinter strength and HTCs of ore blends, sintering theory, and bisection and simplex algorithms, the proposed sintering burden blending model is established. The validation for the model shows that it is effective at utilizing iron ore resources, maintaining high strength of the sinter, while reducing burden costs.

PWM Dead Time Optimization Method for Automotive Multiphase DC/DC-Converters

2010 ◽  
Vol 25 (6) ◽  
pp. 1604-1614 ◽  
Author(s):  
Tomas Reiter ◽  
Dieter Polenov ◽  
Hartmut Pröbstle ◽  
Hans-Georg Herzog
Keyword(s):  
Dead Time ◽  
Optimization Method ◽  
Time Optimization

scholarly journals ADAPTIVE DISTRIBUTION OF A SWARM OF HETEROGENEOUS ROBOTS

2016 ◽  
Vol 56 (1) ◽  
pp. 67 ◽  
Author(s):  
Amanda Prorok ◽  
M. Ani Hsieh ◽  
Vijay Kumar
Keyword(s):  
Real Time ◽  
Large Scale ◽  
Optimization Problem ◽  
Optimization Method ◽  
Transition Rates ◽  
Trait Distribution ◽  
Time Optimization ◽  
Heterogeneous Robots ◽  
Real Time Optimization ◽  
Optimal Set

We present a method that distributes a swarm of heterogeneous robots among a set of tasks that require specialized capabilities in order to be completed. We model the system of heterogeneous robots as a community of species, where each species (robot type) is defined by the traits (capabilities) that it owns. Our method is based on a continuous abstraction of the swarm at a macroscopic level as we model robots switching between tasks. We formulate an optimization problem that produces an optimal set of transition rates for each species, so that the desired trait distribution is reached as quickly as possible. Since our method is based on the derivation of an analytical gradient, it is very efficient with respect to state-of-the-art methods. Building on this result, we propose a real-time optimization method that enables an online adaptation of transition rates. Our approach is well-suited for real-time applications that rely on online redistribution of large-scale robotic systems.

scholarly journals Spare Pose Graph Decomposition and Optimization for SLAM

2019 ◽  
Vol 256 ◽  
pp. 05003
Author(s):  
Tian Liu ◽  
Yongfu Chen ◽  
Zhiyong Jin ◽  
Kai Li ◽  
Zhenting Wang ◽  
...  
Keyword(s):  
Large Scale ◽  
Optimization Method ◽  
Single Chain ◽  
Original Graph ◽  
Time Consumption ◽  
Parallel Chain ◽  
Localization And Mapping ◽  
Graph Optimization ◽  
The One ◽  
Time Resource

The graph optimization has become the mainstream technology to solve the problems of SLAM (simultaneous localization and mapping). The pose graph in the graph based SLAM is consisted with a series of nodes and edges that connect the adjacent or related poses. With the widespread use of mobile robots, the scale of pose graph has rapidly increased. Therefore, optimizing a large-scale pose graph is the bottleneck of application of graph based SLAM. In this paper, we propose an optimization method basing on the decomposition of pose graph, of which we have noticed the sparsity. With the extraction of the Single-chain and the Parallel-chain, the pose graph is decomposed into many small subgraphs. Compared with directly processing the original graph, the speed of calculation is accelerated by separately optimizing the subgraph, which is because the computational complexity is increasing exponentially with the increase of the graph’s scale. This method we proposed is very suitable for the current multi-threaded framework adopted in the mainstream SLAM, which separately calculate the subgraph decomposed by our method, rather than the original optimization requiring a large block of time in once may cause CPU obstruction. At the end of the paper, our algorithm is validated with the open source dataset of the mobile robot, of which the result illustrates our algorithm can reduce the one-time resource consumption and the time consumption of the calculation with the same map-constructing accuracy.

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