bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of Wind-Solar Hybrid Energy for Optimization and Design for Seawater Desalination System
Authors: Zhan Hao , Wang Shi Ming
Published: June 2014

China has long coastline and numerous islands, which contains ocean fishing, coastal aquaculture and development base of Marine resource and a state of coastal area. Conventional energy often can not be used in these islands, where fresh water resources is scarce, and often the quality of water does not conform to the hygiene standards. Transporting freshwater from land needs too high costs , and often may be affected by the weather. It’s a scientific and rational choice that utilizing the local rich resources of solar energy, wind energy and seawater resources to construct desalination station by using Wind-Solar Hybrid Energy, solve the problem of shortage of electric and water in these island areas and protect the ecological environment. In this paper, seawater desalination system by using Wind-Solar Hybrid Energy has being designed on the optimization and the economic benefit according to the wind, solar and water resources situation.
Research on Thermal Balance with Critical Density in the Zero-Range Process with many Defect Sites
Authors: Zeng Ren Fen
Published: June 2014

We introduce a one-dimensional Zero-Range Process (ZRP) with a defect site to describe the condensation. We concern the critical density in the ZRP. We also concern the critical density in the Zero-Range with many defect sites. by using the local coefficient ,we can get the critical density which is accord with theoretically critical density .
Thermodynamics Analysis and Mathematic Proof of the Error of the Equivalent Enthalpy Drop Partial Quantitative Method (EEDPQM)
Authors: Zhao Ming , Sun You Yuan , Liang Jun Yu , Shen Fa Rong , Sai Jun Cong , Xu Jian Qun
Published: June 2014

The economy of heat recovery system which changes due to the drain system is analyzed qualitative and calculated quantitative using Equivalent Enthalpy-drop Partial Quantitative Method (EEDPQM). By comparing with the results calculated by the Equivalent enthalpy-drop whole calculation method (EEDWCM) and the conventional heat balancing method (CHBM), this paper points out that the EEDPQM is a approximate calculation method when it is used to calculate the economy changes of heat recovery system due to the drain system. Then the EEDWCM is proved to be absolutely consistent with the CHBM, and in most cases the EEDPQM is consistent with the EEDWCM and CHBM while in some particular case (such as the changes of the drain system) it is not consistent and the expression of error item is given in this paper.
Influence of Flap Deflection Angle on Wind Turbine Airfoil with Trailing Edge Flaps
Authors: Jia Ya Lei , Han Zhong He , Li Fu You , Bai Ya Kai , Wang Ji Xuan
Published: June 2014

To improve the ability of capturing the wind energy of wind turbine and shorten the design period is of great importance to designing wind turbine blade. The article established S809 airfoil model with trailing edge flaps, The gap of the frontal subject and trailing edge flap adopt uniform gap structure, this structure will reduce the influence of the gap on aerodynamic characteristics.Using the k-ω Two equation turbulence model , the article calculated aerodynamic performance of S809 with 10% chord length trailing edge flaps under different deflecting angles. Results show that gap between the main body and trailing edge flap has little effect on airfoil aerodynamic performance, however, the deflection Angle of Trailing edge flap have great affect on airfoil aerodynamic performance, when deflection Angle of trailing edge flap is 14 ° degrees ,the lift-to-drag ratio is the largest.
Research on Mining Engineering with Dual Gradient High Inclination-Angle Fully Mechanized Mining Technology
Authors: Song Xin , Wang Li Min
Published: June 2014

In this paper, it will take in-depth research, site practical methods, and provide reasonable solutions to several key problems, such as conveyor and hydraulic support sliding；shearers badly sloped；the roof management of return airway when the working face lengthened；dealing with the upper corner gas；gangue fleeing；turn mining，which seriously affect production during high inclination-angle fully mechanized mining at 3# coal seam of the second mining section of ChengShan coal mine.
Study on Method for Building Horizontal Deformation Based on Material Properties and Coordinate Transposition
Authors: Lu Fu Min , Jiang Ting Yao
Published: June 2014

Considering the material property of the building,the building shows the tiny translation and rotation to the initiative period in a observation period, the paper derives minutely the formula that calculates horizontal deformation of the building by using the method of the coordinate transposition. It gives an example of calculation and draws some conclusions.
Application of Spline Function Based on Material Properties in the Deformation Analysis
Authors: Lu Fu Min , Jiang Ting Yao
Published: June 2014

Considering the material property of the soil body to the earthquake area and the situation that the law of the deformation of surface points in regions of active seismicity will vary before and after the occurrence of an earthquake, the paper discusses the method to erect a model of vertical deformation in regions of active seismicity using spline function. Finally, it verifies the effectiveness of the method using a simulating network. Some beneficial conclusions are obtained.
2D Numerical Analysis on Influence of Embankment’s Security and Stability Caused by Shield Tunneling
Authors: Zhong Xiao Chun , Ye Wen Long , Ren Yu Bin , Zhai Gao Yong , Chen Xue Dong
Published: June 2014

With the increasing cases of the soft foundation embankment driven by shield tunneling, study on the influence of embankment's security and stability caused by shield tunneling becomes a research focus. The calculated model considering tunnel face pressure and friction stress between shield shell and soil is established, and the influence on embankment's stability and security caused by tunnel depth, tunnel diameter, embankment slope ratio and shield additional pressure are analyzed. The results show: when shield gradually drives to the place at the ahead of slope toe to be about 7.5m, the influence on embankment's safety stability is the most unbeneficial; when the buried depth reaches 2.5 times of the diameter, the effect can be ignored.
Test Methods Research of Cracks in Ceramics Based on Genetic Algorithm
Authors: Liu Bing Xiang , Wang Feng Qin , Wu Xu Dong , Li Ying Xi
Published: June 2014

In order to improve the reliability of cracks in ceramics test, this paper puts forward a target adaptive segmentation method used by genetic algorithm and maximum-variance algorithm in all classes. This proposed method makes some appropriate improvements about crossover and mutation in genetic algorithm. Besides, the fitness function draws merits of maximum-variance algorithm in all classes and turns the best value in image segmentation into corresponding optimization problem. The simulation results of experiment shows the method proposed shortens the searching time and strengthens anti-noise property during image segmentation and improves recognition rate of cracks in ceramics.
Study on Direction for Land Reclamation Engineering in Limestone Mining Area — The Case of Limestone Mine Land in Tongyuanpu, Fengcheng
Authors: Bao Yu Xue
Published: June 2014

It is very difficult to have Land reclamation in the limestone mine.Based on the land reclamation principle and the actual economic situation of the project area geographical and geological characteristics,We are discussed land reclamation direction about of limestone areas , Improving the usage of the land reclamation type and economic value. Some reference is provided for land reclamation in other similar areas of limestone.
Environment Research with Progress of Bioremediations for Aquaculture Effluent
Authors: Mao Xin Yu , Shao Xiao Hou , Mao Jiang Qiang , Yin Chao , Wang Long , Sun Hao Bo , Tang Zhong Lin , Chang Ting Ting
Published: June 2014

Aquatic environment influences the quantity and quality of aquatic livings directly. In China, aquatic environment has been contaminated seriously as the rapid development of aquaculture industry. Bioremediation, mainly including efficient microbial agent method, immobilized microbe method, aquatic plant method, aquatic animal method and constructed wetlands method, can absorb and assimilate the organic and inorganic pollutants even toxic heavy metals in effluent, degrade them to innocuous substances through metabolism of microorganisms, aquatic plants or aquatic animals. Researches and demonstration showed that bioremediation could effectively decrease NH+4-N, NO−X-N, COD, SS generated by excess bait, fish manure, biological excrements and sediments, increase aquatic transparency, DO and stable pH value in aquaculture water. In future, theoretical researches should be enhanced on improvements of individual as well as integrated bioremediations which will contribute to sustainable development of aquaculture.
Environmental Study of the Design and Operation of the SCR Flue Gas Denitration Project
Authors: Cheng Yan Kun , Wang Li Xuan , Huo Peng
Published: June 2014

Describes the principle and process of application of (Selective catalytic reduction) SCR flue gas denitration technology application and process, boiler flue gas generated NOx and NH3 reduction in the role of a catalyst, generating no secondary pollution N2 and H2O, this paper layout and operation of the equipment on the SCR reactor, and the effect of flue gas denitrification were discussed deeply。
Environmental Pollution in China’s Urbanization Process and its Enlightenments
Authors: Han Ying
Published: June 2014

In recent years the haze weather indicates that China has faced serious environmental problems. In China, natural resources are relative scarce. After the reform and opening-up policies, China’s urbanization rate increased rapidly, but at the expense of the environment. Industrial pollution, municipal refuse, the pollution of cultivated land and food security, urban diseases emerge especially in China’s big cities. To coordinate the relationship between urbanization and the environment, the future should focus on investment in science and Technology and carry out reasonable city planning and layout in the progress of urbanization.
A Study of Remote Monitoring Fire Alarm System Based on Internet of Things
Authors: Hao Qi Lin , Yang Ping Xian , Wang Ming Jie , Ma Rui
Published: June 2014

In this paper, in order to achieve real-time remote monitoring of fire site, we designed a intelligent remote fire monitoring system based on ZigBee network and GPRS network. This system, used ZigBee and sensor to build data acquisition and short distance transmission network and combined with GPRS wireless data transmission and SMS alarm ,cooperates with the server and PC to build a remote monitoring scheme based on GRPS.
Combined Test of Capacity Regulating in 1100kV Controlled Shunt Reactor Valve-Control System
Authors: Lei Xi , Xu Gui Zhi , Xing Ke Zheng
Published: June 2014

As a flexible AC transmission system equipment, controlled shunt reactor is becoming increasingly important in the grid with the development of EHV / UHV transmission systems. Since currently rated voltage of controlled shunt reactor has developed to 1100kV, as its capacity control system, or valve-control system, stability and reliability test is very important. In this paper, the test circuit and method for the valve-control system in the laboratory or the test station for combined adjustment test is put forward. By adjustment of power supply and the device parameter, the valve-control system can put the voltage and current of the device to be the same as the on-set operation. Actual test of the world's first 1100kV controlled shunt reactor valve-control system shows that, the test method in this paper is correct and feasible, and the objective of assessment can be achieved.
Adaptive Fuzzy Sliding Mode Control for Brushless Double-Fed Wind Power Generation System
Authors: Shao Zong Kai , Duan Zhong Rong , Huang Guo Yong
Published: June 2014

For maximum wind power tracking, the adaptive fuzzy sliding mode control is designed based on the method of rotation speed feedback of brushless doubly-fed machine. The adaptive fuzzy system approaches the uncertainties of generation system. A nonlinear integrator sliding mode control strategy is proposed to track the speed of wind. The stability of closed-system is proved using Lyapunov’s method. Finally, the simulation studies are provided to confirm that the rotation speed of brushless doubly-fed machine can fast track the speed of wind. Then the maximum power-point tracking is gotten.
A New Method for Multi-Fault Diagnosis of Rotating Machinery Based on the Mixture Alpha Stable Distribution Model
Authors: Yu Gang , Kang Jian
Published: June 2014

As one of the most important type of machinery, rotating machinery may malfunction due to various reasons. Sometimes the fault is a single one, but sometimes it maybe in multi-fault condition, this paper mainly focus on the latter. First, the paper gives a brief introduction of the study on multi-fault, then it introduces the mixture of Alpha stable distribution model, besides, it gives the model parameters estimation algorithm in detail, at last we use the SOM net to complete pattern recognition. The results prove that this modeling method is effective in multi-fault diagnosis in rotating machinery.
Numerical Simulation on Stress Distribution of the Inclined Coal Seam under Different Pillar Width
Authors: Qi Jun De , Chai Jing , Zhang Jing Zhao
Published: June 2014

Numerical tests were conducted with six different pillar width to analyze the stress distribution of the inclined coal seam. The results show that, with the pillar width changes from 3m to 20m, the maximum stress surrounding tail entry of coal face 3506 is always gradually shift from down side to up side and the reasonable pillar width should be less than 7m.
Composite Nondestructive Testing Technology
Authors: Wang Hong Xun , Zhang Wei Fang , Liu Tian Jiao
Published: June 2014

The article introduces a variety of composite nondestructive testing technology which are new developed or commonly used in engineering in recent years, including the principle, detection range, characteristics and limitations. Make an outlook for the development directions of composite nondestructive testing technology.
Study on Light HVDC Converter and Harmonic Suppression of the Active Filter
Authors: Lv Si Qi
Published: June 2014

The key equipment of Light HVDC Technology is the converter and the filter. The main function of the converter is AC / DC conversion, which plays a vital role in converter station. The filter is also an important tool for harmonic suppression. Therefore, in this paper, the HVDC converter and the harmonic suppression are studied. Our paper discussed the advanced converter VSC which is currently being put into operation, its key technology--the MMC topology and the connection mode of VSC. Meanwhile, the production, effect and suppression of the harmonic are analyzed. Compared active power filter to the passive filter, finally, we chose the active filter as the research object. Successful experience of the HVDC Light project which has been put into operation or will be put into use showed that, the technology is in great progress and will be widely used.
Analysis and Research on Flight Mechanics with Air-Wake around Large Warship Decks
Authors: Li Xiang , Huang Sheng , Wang Chong
Published: June 2014

For large warships, aircrafts play an important role in the war. So during the development of large warships, the safety of the aircrafts takeoff and landing becomes the key technology, which requires the air-wake around large warship decks provide a safety environment for its busy work. However, for the warships with flush deck, superstructure is the main reason of causing air turbulence on the ship surface. At the same time, the states of motion also have an effect on air-wake such as pitch, rolling, etc. It will lead to air crash or inability of takeoff and landing if the air-wake around decks cannot meet the work requirements of the aircrafts. Therefore, the numerical simulation of air-wake around decks is very important for the development of large warships during the war.
Applied Mechanics in Moving Boundary Problems of One-Dimensional Non-Darcy Flow in Semi-Infinite Long Porous Media
Authors: Wang Jia Hang , Wang Lei , Zhou Duo Kai
Published: June 2014

Dimensionless mathematical models of the fluid flow in the semi-infinite long porous media with constant production pressure on the inner boundary conditions are built, which include the effect of threshold pressure gradient (TPG). The analytical solutions of these dimensionless mathematical models are derived through new definitions of dimensionless variables. Comparison curves of the dimensionless moving boundary under different values of dimensionless TPG are plotted from the proposed analytical solutions. For the case of constant production pressure, a maximum moving boundary exists, beyond which the fluid flow will not occur. The value of maximum boundary distance decreases with increasing TPG. However, the velocity of pressure propagation decreases with time. The larger the TPG is, the steeper the curve of pressure depression cone is and the shorter the distance of the pressure propagation is.
Applied Technology in Dynamics Study for Projecting Deployment of a New Anti-Riot Net
Authors: Li Yong Yuan , Fang Lei , Chen Hong Bo
Published: June 2014

In this paper, Dynamic analysis for the process of opening net is studied base on a new anti-riot device, focusing on the problem that dynamics modeling of fully compliant anti-riot net during the process, a new equivalent method is proposed. This method regards the anti-riot net as a variable drag coefficient rigid body, and regards four traction heads as a suppositional traction head, so the process of opening net can be transformed to the problem for movement of two rigid bodies, furthermore, the dynamic equations for the process of opening net was derived from this method. These equations are used to simulate the process of opening net; the simulation results are compared with test results to verify the practicability of the method.
An Information Retrieval Expansion Model Based on Wikipedia
Authors: Gan Li Xin , Tu Wei
Published: June 2014

Query expansion is one of the key technologies for improving precision and recall in information retrieval. In order to overcome limitations of single corpus, in this paper, semantic characteristics of Wikipedia corpus is combined with the standard corpus to extract more rich relationship between terms for construction of a steady Markov semantic network. Information of the entity pages and disambiguation pages in Wikipedia is comprehensively utilized to classify query terms to improve query classification accuracy. Related candidates with high quality can be used for query expansion according to semantic pruning. The proposal in our work is benefit to improve retrieval performance and to save search computational cost.
Cold-Start Emissions of an SI Engine Using Butanol/Gasoline Blends
Authors: Shi Mei Yu , Zhu Rong Fu , Li Jiang , Sun Yuan Tao
Published: June 2014

The influence of butanol/gasoline blends at low temperature for-7°C, on cold-start emissions of a spark-ignition engine was tested. In cold-start period of the engine, the efficiency of the engine was expected to be poor, and the air/fuel mixture would be leaner for the more butanol added. The experimental results showed that the engine could be stable with B10 and B30 in cold-start, and HC and CO emissions reduced more significantly with more butanol added.
Research on Information Processing with Release Method of Railway Freight Loading Information Based on Dynamic Planning Model
Authors: Hou Yi Meng , Zhang Qi
Published: June 2014

Freight loading information can not only limit the cargo volume from customers but also guide them to arrange their freight reasonably. This paper analyzed the factors influencing release of railway freight loading information, and established a freight loading information release model based on dynamic planning by setting the most important two indexes -- quantity of freight cars and equilibrium degree of freight cars as objective functions. The model was proved to be effective in balancing daily freight workload on the premise of satisfying customers’ requirements on cargo loadings. Thereby, the author thinks that reasonable release of freight loading information is effective and efficient in making more profits with limited resources.
Data Processing in Moving Boundary Problems of One-Dimensional Non-Darcy Flow in Semi-Infinite Porous Media
Authors: Jin Rong Rong , Wang Jia Hang
Published: June 2014

The paper establishes dimensionless mathematical models of the fluid flow in semi-infinite porous media with constant flow rate. Exact analytical solutions of these dimensionless mathematical models are derived by new definitions of dimensionless variables and Laplace transformation. Comparison curves of dimensionless moving boundary under different values of dimensionless Threshold Pressure Gradient (TPG) are plotted from newly proposed exact analytical solutions. An example is used to demonstrate pressure distribution in different positions with different TPG. It is shown that for the constant flow rate condition, the moving boundary extends to infinite in porous media with increasing production time. Steeper pressure curve is observed in larger TPG, which also exhibits greater pressure drop gradient and shorter pressure propagation distance at the same production time.
The Study of Tight Periodic Wavelet Frames and Wavelet Frame Packets and Applications
Authors: Chen Qing Jiang , Chai Yu Zhou , Cai Chuan Li
Published: June 2014

Information science focuses on understanding problems from the perspective of the stake holders involved and then applying information and other technologies as needed. A necessary and sufficient condition is identified in term of refinement masks for applying the unitary extension principle for periodic functions to construct tight wavelet frames. Then a theory on the approxi-mation order of truncated tight frame series is established, which facilitates construction of tight periodic wavelet frames with desirable approximation order. The pyramid decomposition scheme is derived based on the generalized multiresolution structure.
Engineering Research with Application of System Dynamics Model of Risk Identification in Railway Construction Project
Authors: Zhang Ling , Zhong Yan
Published: June 2014

Firstly, this paper compares the traditional risk identification methods and puts forward a point of view that system dynamics method is a supplement to the traditional risk identification methods. Secondly, we put the railway construction project schedule risk stage for research, establish a system dynamics model, use the software to identify causes of schedule risk in detail, and analyze the system self-regulating effect on schedule risk system. Finally, Using the Wuzhun railway data from Mount Huangshan to Wucaiwan to verify, we can prove the availability of system dynamics model in the railway construction project risk identification.
Research on Technology Industry Value Chain and its Properties
Authors: Jiao Yuan Yuan , Li Jian Hua
Published: June 2014

Constructing a model of the technological industry value chain by the use of Potter's value chain theory, to reveal the realization mechanism of the value added of technology industry value chain. Describes the characteristics of technology industry value chain, analysis of the causes of the ‘Valley of Death’ and ‘Darwin Sea’ produced, then give suggestions to resolve these problems.
Research on Management Engineering with Data Processing for Relationship between Equity Structures and Operating Performance — Take the Utilities Listed Companies as Example
Authors: Li Bing Jie , Niu Dong Xiao , Lu Yan , Xia Hua Li , Ding Wei Bin
Published: June 2014

Rational equity structure is the key to improve the operating performance. On the basis of the basic theory of international experts, the paper selects the data of utilities listed companies, and takes the principal component analysis and multiple linear regression model to build the index system of utilities for evaluating the operating performance after a series of data processing methods, at last, conducts the empirical analysis of the relationship between equity structure and operating performance. The results show that there is no significant correlation between the proportion of the state-owned restricted shares and the company's profitability; there is a positive correlation between the proportion of outstanding shares and the company’s profitability. Accordingly, the paper proposes some recommendations on management engineering at last to improve the company’s operating performance and the efficiency of management engineering.
Synthesis and Characterization of Fluorine-Doped Tin Oxide Nanocrystals Prepared by Sol-Gel Method
Authors: Tian Jun Qing , Shi Hai Ying , Zheng Wei
Published: June 2014

Fluorine-doped tin dioxide (FTO) nanocrystals were prepared with sol–gel method using SnCl4·5H2O and NH4F as precursor material. The FTO was characterized with X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Differential Thermal Analysis and Thermal Grativity (DTA-TG) and Infrared Radiation (IR) respectively. The electrical property was measured with Hall Effect Sensor. The result of XRD and SEM shows that FTO nanocrystal size is about 20 nm and the dimension of the grain is about 300 nm. IR spectrum analysis proves fluorine doping. The crystal phase transformation was discussed with DTA-TG curve. When the sintering temperature is 450°C, the sintering time is 60 min, and the molar ratio of F to Sn is 2:10, the sheet resistance of FTO film is 107Ω/□.
Preparation and Coagulation Performance of Polymeric Aluminum Zinc Ferric (PAZF) from Galvanized Aluminum Slag
Authors: Li Ming , Yu Yan Zhen , Guo Yu Zhong
Published: June 2014

A new inorganic coagulant polymeric aluminum zinc ferric (PAZF) was prepared using a galvanized aluminum slag as the main material. Coagulation performance was evaluated by jar test on printing and dyeing wastewater and landscape water treatment, and the optimum conditions for the two tested water samples were investigated to be coagulant dosage of 70 and 210 mg/L, pH value of 8.0 and 9.0, and settling time of 15 and 20 min. The removal of turbidity, chroma and COD for printing and dyeing wastewater treatment were 93.8%, 83.32% and 62.19% respectively with turbidity, TP and COD removal for landscape water treatment as 86.98%, 82.39% and 86.82%.
Separation and Acidic Solution Washing for Heavy Metals from Contaminated Soils
Authors: Chang Yi Kuo , Shu Yi Liang , Hsu I Yuang , Hong Zhen Wei
Published: June 2014

Contaminated soils in the environment remain being a significant issue during land application. Numerous methods have been suggested in recent years for remove, treating and beneficial uses of heavy metal-containing soils. In this research, the basic characteristics and the geochemistry of metals in the soils were studied, and which were subjected to percolation test. The results of experimental leaching tests of soils are subjected to model calculations. In addition, the separation processes, hydrocyclone treatment, is designed to separate coarse and fine-grained particles by high settling velocity of particles. The FLUENT flow simulations are help to demonstrate to liquid-solid flow and the simulation results are feedback to the hydrocyclone operation and design.
Attraction ofEpilachna dodecastigma(Coleoptera: Coccinellidae) toMomordica charantia(Cucurbitaceae) leaf volatiles
Authors: Sarkar Nupur , Mukherjee Abhishek , Barik Anandamay
Published: June 2014

Epilachna dodecastigma(Wiedemann) (Coleoptera: Coccinellidae) is an important herbivorous pest of bitter gourd,Momordica charantiaLinnaeus (Cucurbitaceae) plant in India and Bangladesh. Volatiles were collected from undamaged bitter gourd plants, and from plants 24 and 120 hours following the initiation of continuous adult female feeding damage, and subsequently identified and quantified by gas chromatography mass spectrometry and gas chromatography flame ionisation detector analyses. Of the 24 volatiles identified in the study, 22 were present in all three treatments (undamaged plants, 24 hours after feeding, and 120 hours after feeding), and all plants significantly increased emissions of these compounds following insect attack. In all plants, the compound 1-tridecanol was the most abundant, followed by phytol. Only two compounds were unique to insect damaged plants: methyl palmitate was characteristic of insect damaged plants, while nerolidol was only detected from plants 120 hours following insect attack, however neither of these insect-damage specific volatiles, when tested individually, elicited attraction in Y-shaped glass tube olfactometer bioassays.Epilachna dodecastigmashowed significant preference for the whole volatile blends from insect damaged plants compared with whole volatile blends from undamaged plants. Further, the insect elicited attraction to three individual synthetic compounds: geraniol, 1-tridecanol, and phytol, which had significantly higher emissions from insect damaged leaves compared with those from undamaged plants.
Medial Tibiofemoral-Joint Stiffness in Males and Females Across the Lifespan
Authors: Aronson Patricia , Rijke Arie , Hertel Jay , Ingersoll Christopher D.
Published: June 2014

Context:

Analyzing ligament stiffness between males and females at 3 maturational stages across the lifespan may provide insight into whether changes in ligament behavior with aging may contribute to joint laxity.

Objective:

To compare the stiffness of the medial structures of the tibiofemoral joint and the medial collateral ligament to determine if there are differences at 3 distinct ages and between the sexes.

Design:

Cross-sectional study.

Setting:

Laboratory.

Patients or Other Participants:

A total of 108 healthy and physically active volunteers with no previous knee surgery, no acute knee injury, and no use of exogenous hormones in the past 6 months participated. They were divided into 6 groups based on sex and age (8–10, 18–40, 50–75 years).

Main Outcome Measure(s):

Ligament stiffness of the tibiofemoral joint was measured with an arthrometer in 0° and 20° of tibiofemoral-joint flexion. The slope values of the force-strain line that represents stiffness of the medial tibiofemoral joint at 0° and the medial collateral ligament at 20° of flexion were obtained.

Results:

When height and mass were controlled, we found a main effect (P < .001) for age group: the 8- to 10-year olds were less stiff than both the 18- to 40- and the 50- to 75-year-old groups. No effects of sex or tibiofemoral-joint position on stiffness measures were noted when height and mass were included as covariates.

Conclusions:

Prepubescent medial tibiofemoral-joint stiffness was less than postpubescent knee stiffness. Medial tibiofemoral-joint stiffness was related to height and mass after puberty in men and women.
Plantar Loading During Cutting While Wearing a Rigid Carbon Fiber Insert
Authors: Queen Robin M. , Abbey Alicia N. , Verma Ravi , Butler Robert J. , Nunley James A.
Published: June 2014

Context

Stress fractures are one of the most common injuries in sports, accounting for approximately 10% of all overuse injuries. Treatment of fifth metatarsal stress fractures involves both surgical and nonsurgical interventions. Fifth metatarsal stress fractures are difficult to treat because of the risks of delayed union, nonunion, and recurrent injuries. Most of these injuries occur during agility tasks, such as those performed in soccer, basketball, and lacrosse.

Objective:

To examine the effect of a rigid carbon graphite footplate on plantar loading during 2 agility tasks.

Design:

 Crossover study.

Setting:

Laboratory.

Patients or Other Participants:

A total of 19 recreational male athletes with no history of lower extremity injury in the past 6 months and no previous metatarsal stress fractures were tested.

Main Outcome Measure(s):

 Seven 45° side-cut and crossover-cut tasks were completed in a shoe with or without a full-length rigid carbon plate. Testing order between the shoe conditions and the 2 cutting tasks was randomized. Plantar-loading data were recorded using instrumented insoles. Peak pressure, maximum force, force-time integral, and contact area beneath the total foot, the medial and lateral midfoot, and the medial, middle, and lateral forefoot were analyzed. A series of paired t tests was used to examine differences between the footwear conditions (carbon graphite footplate, shod) for both cutting tasks independently (α = .05).

Results:

During the side-cut task, the footplate increased total foot and lateral midfoot peak pressures while decreasing contact area and lateral midfoot force-time integral. During the crossover-cut task, the footplate increased total foot and lateral midfoot peak pressure and lateral forefoot force-time integral while decreasing total and lateral forefoot contact area.

Conclusions:

Although a rigid carbon graphite footplate altered some aspects of the plantar-pressure profile during cutting in uninjured participants, it was ineffective in reducing plantar loading beneath the fifth metatarsal.
On Global Dimensions of Tree Type Finite Dimensional Algebras
Authors: Hou Ruchen
Published: June 2014

A formula is provided to explicitly describe global dimensions of all kinds of tree type finite dimensional k-algebras for k an algebraic closed field. In particular, it is pointed out that if the underlying tree type quiver has n vertices, then the maximum global dimension is n – 1.
On a fractional Nirenberg problem, part I: blow up analysis and compactness of solutions
Authors: Jin Tianling , Li YanYan , Xiong Jingang
Published: June 2014

We prove some results on the existence and compactness of solutions of a fractional Nirenberg problem. The crucial ingredients of our proofs are the understanding of the blow up profiles and a Liouville theorem.
Quantum expanders and geometry of operator spaces
Authors: Pisier Gilles
Published: June 2014

We show that there are well separated families of quantum expanders with asymptotically the maximal cardinality allowed by a known upper bound. This has applications to the “growth” of certain operator spaces: It implies asymptotically sharp estimates for the growth of the multiplicity of

M_N

-spaces needed to represent (up to a constant

C>1

) the

M_N

-version of the

n

-dimensional operator Hilbert space

OH_n

as a direct sum of copies of

M_N

. We show that, when

C

is close to 1, this multiplicity grows as

\exp{\beta n N^2}

for some constant

\beta>0

. The main idea is to relate quantum expanders with “smooth” points on the matricial analogue of the Euclidean unit sphere. This generalizes to operator spaces a classical geometric result on

n

-dimensional Hilbert space (corresponding to N=1). In an appendix, we give a quick proof of an inequality (related to Hastings's previous work) on random unitary matrices that is crucial for this paper.
Almost sure global well-posedness for the radial nonlinear Schrödinger equation on the unit ball II: the 3d case
Authors: Bourgain Jean , Bulut Aynur
Published: June 2014

We extend the convergence method introduced in our works [8–10] for almost sure global well-posedness of Gibbs measure evolutions of the nonlinear Schrödinger (NLS) and nonlinear wave (NLW) equations on the unit ball in

\mathbb R^d

to the case of the three dimensional NLS. This is the first probabilistic global well-posedness result for NLS with supercritical data on the unit ball in

\mathbb R^3

. The initial data is taken as a Gaussian random process lying in the support of the Gibbs measure associated to the equation, and results are obtained almost surely with respect to this probability measure. The key tools used include a class of probabilistic
a priori
bounds for finite-dimensional projections of the equation and a delicate trilinear estimate on the nonlinearity, which – when combined with the invariance of the Gibbs measure – enables the
a priori
bounds to be enhanced to obtain convergence of the sequence of approximate solutions.
Assessment of Cardiac Dysfunction in the Intrauterine Growth-restricted Fetuses from Pre-eclamptic Mothers
Authors: Stamatian Florin , Caracostea Gabriela
Published: June 2014

Background

Although it is known that cardiac parameters have abnormal values in severely affected fetuses with intrauterine growth restriction (IUGR), recent research suggested that subclinical cardiac dysfunction may be present from the early stages of fetal deterioration. The identification and monitoring of cardiac dysfunction may be relevant for the management of these cases.

Materials and methods

In this prospective observational study, we evaluated 17 IUGR fetuses from nulliparous pregnant women diagnosed with pre-eclampsia. Cardiac structural assessment was performed using segmental sequential analysis. Cardiac function was assessed by conventional echocardiography and Tissue Doppler Imaging (TDI).

Results

Gestational age at admittance ranged between 24 and 30 weeks. A severe form of pre-eclampsia was diagnosed in 2 of 17 cases. Conventional cardiac examination showed low left and right ventricular diastolic filling with low E and A velocities, and increased myocardial performance indexes for both ventricles. Using TDI we observed decreased myocardial velocities and impaired contractility (demonstrated by low left and right diastolic velocities, as well as increased E’/A’ ratios).

Conclusion

Our study confirms the presence of early cardiac dysfunction in IUGR fetuses. Further studies are warranted to confirm the utility of TDI in obstetric ultrasound routine examination for monitoring fetal cardiac function in high-risk pregnancies.

How to cite this article

Caracostea G, Stamatian F. Assessment of Cardiac Dysfunction in the Intrauterine Growthrestricted Fetuses from Pre-eclamptic Mothers. Donald School J Ultrasound Obstet Gynecol 2014;8(2):123-127.
Neonatal Outcomes after Preconceptional Vaginal Micronized Progesterone Administration in Recurrent Pregnancy Loss: Five Years Prospective Study
Authors: Russu Manuela , Stănculescu Ruxandra , Păun Maria , Marin Jan Andi
Published: June 2014

Objectives

The objective of this prospective study was to analyze the effect of vaginal micronized progesterone (VMP) daily administrated in women with recurrent pregnancy loss, recurrent miscarriage, and/or preterm birth on neonatal outcomes.

Methods

In the treat group patients received 200 mg/day VMP (14 days/month, during the luteal phase) from preconception until completed 36 weeks of gestation. Women from the control group did not receive VPM treatment. Ultrasonographic examination was performed for gestational age confirmation, assessment of cervical length and congenital malformation screening in fetus.

Results

Compared with the control group, the women from the VMP group had a decreased time to conception, lower frequency of miscarriages and higher gestational age at delivery. Newborns from mothers treated with VPM had significantly higher birth weight than newborns from the control group of mothers (p = 0.022). The frequency of stillbirths and the need for oxygen supplementation and mechanical ventilation was lower in the newborns from treated group of mother compared with control group.

Conclusion

Vaginal micronized progesterone 200 mg/day from preconception to 36 weeks of gestation in women with recurrent pregnancy loss reduced the frequency of miscarriages, stillbirths, preterm births and neonatal morbidity.

How to cite this article

Russu M, Stănculescu R, Păun M, Marin JA. Neonatal Outcomes after Preconceptional Vaginal Micronized Progesterone Administration in Recurrent Pregnancy Loss: Five Years Prospective Study. Donald School J Ultrasound Obstet Gynecol 2014;8(2):128-133.
Lung Malformations: Prenatal Ultrasound Diagnosis and Obstetrical Management
Authors: Iliev Gheorghe , Dumitrascu Irina , Grigore Mihaela , Mihalceanu Elena , Scripcaru Daniela , Zoican Gabriela , Aprodu Gabriel , Bivoleanu Anca , Petrariu Andrei , Stamatin Maria
Published: June 2014

Purpose

We present our experience in prenatal diagnosis and obstetrical management of congenital lung malformations (CLM).

Materials and methods

The diagnosis of CLM was performed during routine second and third trimester fetal morphology assessment. The extent of the disease was established according to the type, localization and size of the pulmonary lesion and the presence of fetal complications (mediastinal shift, fetal hydrops, hydramnios). Termination of pregnancy (TOP) was indicated in cases associated with extrapulmonary anomalies, untreatable cases and fetal hydrops. After delivery a pulmonary X-ray and surgical examination was performed in all newborns.

Results

We diagnosed 15 cases with congenital lung malformations. Of these, 9 had congenital cystic adenomatoid malformation (CCAM). TOP was performed in 6 cases with CCAM. Three cases had a favorable pre/postnatal evolution. Bronchopulmonary sequestration (BPS) was diagnosed in 3 cases, all with favorable perinatal evolution. Right pulmonary agenesis was diagnosed in one case and the outcome was neonatal death. One case of congenital high airway obstruction syndrome was followed by TOP. One case of severe bilateral pulmonary hypoplasia (secondary to a severe bilateral hydrothorax) resulted in neonatal death.

Conclusion

Obstetrical management is established individually depending on the severity of the cases.

How to cite this article

Iliev G, Dumitrascu I, Grigore M, Mihalceanu E, Scripcaru D, Zoican G, Aprodu G, Bivoleanu A, Petrariu A, Stamatin M. Lung Malformations: Prenatal Ultrasound Diagnosis and Obstetrical Management. Donald School J Ultrasound Obstet Gynecol 2014;8(2):134-143.
Ultrasound Features of the Formation of the Maternal-Placental Complex in Cases of Hyperandrogenism as Observed during the First and Second Trimesters of Pregnancy
Authors: Olga Malysheva , Elena Toropkina , Luybov Agarkova , Irina Bukharina , Sergey Logvinov
Published: June 2014

An excess of maternal androgen adversely affects the implantation process and contributes to uterine circulatory disturbances and myometrium vessel sclerosis. Placental insufficiency is typically diagnosed at the end of the second trimester of pregnancy or at the beginning of the third trimester, when the treatment is not effective

Many researchers have attempted to use early sonographic diagnostics to identify placental failure in various pathological states. Nevertheless, the peculiarities of the formation of the fetal-placental complex during the first and second trimesters are still undefined. In this study, we traced the process of placental formation under conditions of excess maternal androgen using ultrasound and Dopplerometry. Morphological examinations of the ñhorion and placental tissue were undertaken to ñompare any changes.

Unfavorable chorion locations, heterogeneous chorion tissue structures, and marginal sinus dilatations were revealed by ultrasound. According to a Dopplerometric investigation, a statistically significant increase in peripheral vessel resistance in cases of hyperandrogenism was identified compared with healthy pregnancies. The negative influence of hyperandrogenism on placental formation was confirmed by morphological data (including the presence of immature decidual cells, defective villi that covered the epithelium, and the dissociative development of cotyledons).

How to cite this article

Olga M, Elena T, Luybov A, Irina B, Sergey L. Ultrasound Features of the Formation of the Maternalplacental Complex in Cases of Hyperandrogenism as Observed during the First and Second Trimesters of Pregnancy. Donald School J Ultrasound Obstet Gynecol 2014;8(2):149-154.
Fetal Origin of Adult Disease
Authors: Bora Rishabh , Bora Neharika Malhotra
Published: June 2014

Fetal origins of adult disease, a concept first popularized by Dr David Barker, has subsequently led to many studies which have provided the evidence that certain diseases do have links pointing to fetal origins—adverse influences early in development, and particularly during intrauterine life, can result in permanent changes in physiology and metabolism, which result in increased disease risk in adulthood.

Links that are well-established are—reduced birth weight and increased risk of coronary heart disease, hypertension and stroke in adulthood.

The concept of a fetal origin of adult disease have been extended well-beyond coronary heart disease and being a risk factor for coronary heart disease, and now includes investigations of the development of the central nervous system, early origins of adult mental health and cognitive function.

By understanding fetal origin of adult disease, health care professionals and policy makers will make this issue a high health care priority and implement preventive measures and treatment for those at higher risk for chronic diseases.

How to cite this article

Malhotra N, Malhotra J, Bora NM, Bora R, Malhotra K. Fetal Origin of Adult Disease. Donald School J Ultrasound Obstet Gynecol 2014;8(2):164-177.
Diagnostic Ultrasound Safety
Authors: Maeda Kazuo
Published: June 2014

Ultrasound bioeffect is discussed from its physical property, i.e. thermal effect by thermal index, mechanical effect by mechanical index, and by the output intensity of ultrasound. Generally, thermal and mechanical indices should be lower than 1 in obstetrical setting, and threshold output intensity of no bioeffect is lower than SPTA 240 mW/cm2 in pulse wave. Pulsed Doppler ultrasound thermal and mechanical indices should be also lower than 1, and should be carefully used it in 11 to 13+6 weeks of pregnancy. Real-time B-mode, transvaginal scan, pulsed Doppler, 3D and 4D ultrasound were separately discussed in the ultrasound safety. Generally diagnostic ultrasound is safe for the fetus and embryo, if thermal and mechanical indices are lower than 1, and ultrasound devices are safe, if it is used under official limitation, e.g. the output intensity is less than SPTA 10 mW/cm2 in Japan. The ultrasound user is responsible ultrasound safety, e.g. higher thermal and mechanical indices than 1 should be lowered to be lower than 1, controlling the device output intensity. The user should learn bioeffects of ultrasound and prudent use of ultrasound under the ALARA principle.

How to cite this article

Maeda K, Kurjak A. Diagnostic Ultrasound Safety. Donald School J Ultrasound Obstet Gynecol 2014;8(2):178-183.