Wyniki wyszukiwania

1

Trichodinid ectoparasites [Ciliophora, Peritrichia] from the tiger puffer Takifugu rubripes in the Yellow Sea, with revision of Trichodina jadranica Raabe, 1958

100%

Hu K.

Acta Protozoologica

|

2007

|

tom 46

|

nr 4

311-324

2

Simulated ammonia nitrogen wastewater treated with spent mushroom compost in a laboratory bioreactor

51%

Yang Y., Liang W., Hu K.

Polish Journal of Environmental Studies

|

2016

|

tom 25

|

nr 5

The simulated ammonia nitrogen wastewater was treated with spent mushroom compost (SMC) in a laboratory bioreactor (LBR), and shifts in microbial diversity in LBR were conducted by polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE). We found that the removal efficiencies of NH4+-N and COD reached 73.4% and 61.7%, respectively, and that simultaneous nitrification and denitrification (SND) was observed during the process of NH4+-N removal. In addition, we observed that there were no obvious changes in microbial diversity shifts, and that the predominant four isolates were identified as Flavobacterium johnsoniae, Sphinbacterium multivorum, Comamonas sp., and Rhizobium sp., which functioned together and played a critical role in treating simulated ammonia nitrogen wastewater in LBR. Overall, SMC could provide both carbon sources and indigenous functional microorganisms for nitrogen removal, indicating that SMC has potential for wastewater treatment.

3

High-speed catamaran's longitudinal motion attenuation with active hydrofoils

51%

Hu K., Ding Y., Wang H.

Polish Maritime Research

|

2018

|

tom 25

|

nr Special Issue S2

This paper mainly studies the longitudinal motion prediction method and control technology of high-speed catamaran using the active hydrofoils. To establish the longitudinal motion equations of the ship basing on the 2.5D theory. Using the CFD software to obtain the hydrodynamic data of the hydrofoil. Bring the hydrodynamic expression of hydrofoils into the longitudinal motion equations of the ship. Predicting the longitudinal motion of High-speed catamaran before and after added the hydrofoils. A specific catamaran has been predicted with this approach, the result indicates this approach is workable and this prediction approach provides the theoretical basis for assessing the stabilization ability of appendages and possess the engineering practical value

4

Numerical simulations of linearly stratified flow past submerged bodies

45%

Ma W., Li Y., Ding Y., Hu K., Lan L.

Polish Maritime Research

|

2018

|

tom 25

|

nr Special Issue S3

In this study, a methodology was presented to predict density stratified flows in the near-field of submerged bodies. The energy equation in temperature form was solved coupled with momentum and mass conservation equations. Linear stratification was achieved by the definition of the density as a function of temperature. At first, verifications were performed for the stratified flows passing a submerged horizontal circular cylinder, showing excellent agreement with available experimental data. The ability of the method to cope with variable density was demonstrated. Different turbulence models were used for different Re numbers and flow states. Based on the numerical methods proposed in this paper, the stratified flow was studied for the real scale benchmark DAPRA Suboff submarine. The approach used the VOF method for tracing the free surface. Turbulence was implemented with a k − ω based Detached Eddy Simulation (DES) approach. The effects of submarine speed, depth and density gradient on the free surface wave pattern were quantitatively analyzed. It was shown that, with the increasing of the speed of the submarine, the wavelength and wave height of the free surface wave were gradually increasing. The wave height of the free surface wave was gradually reduced as the submarine’s depth increased. Relative to the speed and submarine depth, the changes of the gradient density gradient have negligible effects on the free surface wave field

5

Nitrogen removal from piggery wastewater within a sequencing batch reactor using pseudomonas putida

45%

Yang Y., Chen F., Xie L., Xiong J., Hu K.

Polish Journal of Environmental Studies

|

2017

|

tom 26

|

nr 2

This work evaluates the efficiency of ammonium removal from piggery wastewater using a sequencing batch reactor (SBR) inoculated with a newly isolated strain of Pseudomonas putida HJH1. The strain HJH1 not only could survive and remove up to 72.4 mg/L NO₂⁻-N under aerobic conditions, but it also has good performance for simultaneous nitrification and denitrification (SND) with no nitrite accumulation. The SBR system was able to consistently remove: 1) 76.4-100% ammonium nitrogen and 71.4-100% COD from artificial wastewater in stage 1, and 2) 89.2-99.1% ammonium nitrogen and 82.4-100% COD from piggery wastewater in stage 2. During the whole operation, the strain HJH1 predominated in the SBR all the time to function together with other bacteria. Results indicated that the SBR system inoculated with Pseudomonas putida HJH1 can efficiently remove ammonium nitrogen from piggery wastewater, thereby having potential applications for future nitrogen removal.

6

Method of emergency collision avoidance for unmanned surface vehicle (USV) based on motion ability database

39%

Song L., Chen H., Xiong W., Dong Z., Mao P., Xiang Z., Hu K.

Polish Maritime Research

|

2019

|

tom 26

|

nr 2

The unmanned surface vehicles (USV) are required to perform a dynamic obstacle avoidance during fulfilling a task. This is essential for USV safety in case of an emergency and such action has been proved to be difficult. However, little research has been done in this area. This study proposes an emergency collision avoidance algorithm for unmanned surface vehicles (USVs) based on a motion ability database. The algorithm is aimed to address the inconsistency of the existing algorithm. It is proposed to avoid collision in emergency situations by sharp turning and treating the collision avoidance process as a part of the turning movement of USV. In addition, the rolling safety and effect of speed reduction during the collision avoidance process are considered. First, a USV motion ability database is established by numerical simulation. The database includes maximum rolling angle, velocity vector, position scalar, and steering time data during the turning process. In emergency collision avoidance planning, the expected steering angle is obtained based on the International Regulations for Preventing Collisions at Sea (COLREGs), and the solution space, with initial velocity and rudder angle taken as independent variables, is determined by combining the steering time and rolling angle data. On the basis of this solution space, the objective function is solved by the particle swarm optimization (PSO) algorithm, and the optimal initial velocity and rudder angle are obtained. The position data corresponding to this solution is the emergency collision avoidance trajectory. Then, the collision avoidance parameters were calculated based on the afore mentioned model of motion. With the use of MATLAB and Unity software, a semi-physical simulation platform was established to perform the avoidance simulation experiment under emergency situation. Results show the validity of the algorithm. Hence results of this research can be useful for performing intelligent collision avoidance operations of USV and other autonomous ships

7

Detrimental effects of testosterone on post-myocardial infarction remodeling in female rats

33%

Frantz S., Hu K., Widder J., Weckler B., Scheuermann H., Bauersachs J., Ertl G., Callies F., Allolio B.

Journal of Physiology and Pharmacology

|

2007

|

tom 58

|

nr 4

Clinical data suggest an association of increased serum androgens with cardiovascular mortality in females, but not in males. Therefore, we examined effects of chronic anabolic testosterone administration on left ventricular remodeling after myocardial infarction in female rats. Ovariectomized adult female rats were treated with placebo, supraphysiologic testosterone undecanoate (T), estradiol (E2), or T+E2. Two weeks after ovarcectomy, animals underwent sham-operation or coronary artery ligation. Left ventricular remodeling and function were assessed by echocardiography and hemodynamic investigation. In sham operated animals T administration increased serum T levels and led to cardiac hypertrophy, with an increase in the ß/alpha-MHC-ratio and in IGF-1 expression. After coronary artery ligation, infarct size and mortality were similar among the groups. T treatment aggravated left ventricular hypertrophy and chamber dilatation (end-diastolic diameter, E2 vs. T vs. E2+T, 8.6 ± 0.6 vs. 9.9 ± 0.3 vs. 9.8 ± 0.3 mm, p<0.05) and reduced fractional shortening 8 weeks after myocardial infarction. Extracellular matrix remodeling was not altered by hormonal treatment. In conclusion, chronic anabolic T treatment causes myocardial hypertrophy under basal conditions and adversely affects left ventricular remodeling following myocardial infarction in female rats.

Ograniczanie wyników

Trichodinid ectoparasites [Ciliophora, Peritrichia] from the tiger puffer Takifugu rubripes in the Yellow Sea, with revision of Trichodina jadranica Raabe, 1958

Simulated ammonia nitrogen wastewater treated with spent mushroom compost in a laboratory bioreactor

High-speed catamaran's longitudinal motion attenuation with active hydrofoils

Numerical simulations of linearly stratified flow past submerged bodies

Nitrogen removal from piggery wastewater within a sequencing batch reactor using pseudomonas putida

Method of emergency collision avoidance for unmanned surface vehicle (USV) based on motion ability database

Detrimental effects of testosterone on post-myocardial infarction remodeling in female rats