高速检测条件下缺陷钢轨涡流效应的仿真

由于高速漏磁检测下速度效应的存在,检测信号会发生畸变。根据漏磁检测中速度效应的基本原理可知,速度感应产生的涡流是直接影响漏磁检测信号的因素之一,而且其大小同速度及磁场强度成正比。因此文章根据高速检测的这一特点,建立了新的高速检测模型,对一系列运行在不同速度下有缺陷的钢轨模型进行了有限元仿真,并将该模型下的检测信号与经典漏磁模型的检测信号对比,进一步认识了涡流效应对检测信号的影响。

Transforaminal Percutaneous Endoscopic Discectomy using Transforaminal Endoscopic Spine System technique: Pitfalls that a beginner should avoid

Transforaminal Percutaneous Endoscopic Discectomy(TPED) is a minimally invasive technique mainly used for the treatment of lumbar disc herniation from a lateral approach. Performed under local anesthesia, TPED has been proven to be a safe and effective technique which has been also associated with shorter rehabilitation period, reduced blood loss, trauma, and scar tissue compared to conventional procedures. However, the procedure should be performed by a spine surgeon experienced in the specific technique and capable of recognizing or avoiding various challenging conditions. In this review, pitfalls that a novice surgeon has to be mindful of, are reported and analyzed.

湿式氧化用于染料废水脱色:过去20年回顾（英文）

Wet air oxidation(WAO), a liquid phase reaction between organic materials in water and oxygen, is one of the most economical and technologically viable advanced oxidation processes for wastewater treatment, particularly toxic and high organic content wastewater. WAO is the liquid phase oxidation of organics or oxidizable inorganic components at elevated temperatures(125–320 °C) and pressures(0.5–20 MPa) using gaseous oxygen(or air) as oxidant. In the past two decades, the WAO process was widely studied and applied in the treatment of dye wastewater. Compared to conventional WAO, catalytic WAO processes have higher efficiency and use moderate reaction conditions. The catalysts included homogenous and heterogeneous types. The key points that need to be solved are recycling of homogenous catalysts and better stability of heterogeneous catalysts. In the present review, the technological processes are first introduced, then some research history and hotspots of WAO research are presented, and finally, its application in the treatment of dye wastewater in the past two decades is summarized to reveal the impressive changes in modes, trends, and conditions used. The application includes model pollutant studies and wastewater tests.

Effects of laparoscopic cholecystectomy on lung function:A systematic review

AIM: To present and integrate findings of studies investigating the effects of laparoscopic cholecystectomy on various aspects of lung function.

Wireless endoscopy in 2020:Will it still be a capsule?

Currently,the major problem of all existing commercial capsule devices is the lack of control of movement.In the future,with an interface application,the clinician will be able to stop and direct the device into points of interest for detailed inspection/diagnosis,and therapy delivery.This editorial presents current commerciallyavailable new designs,European projects and delivery capsule and gives an overview of the progress required and progress that will be achieved-according to the opinion of the authors- in the next 5 year leading to 2020.

Complex knee injuries treated in acute phase: Long-term results using Ligament Augmentation and Reconstruction System artificial ligament

AIM To present the long-term results of complex knee injuries, treated early using the Ligament Augmentation and Reconstruction System(LARS) artificial ligament to reconstruct posterior cruciate ligament(PCL).METHODS From September 1997 to June 2010, thirty-eight complex knee injuries were treated, where early arthroscopic PCL reconstructions were undergone, using the LARS(Surgical Implants and Devices, Arc-sur-Tille, France) artificial ligament. Exclusion criteria were: Late(> 4 wk) reconstruction, open technique, isolated PCL reconstruction, knee degenerative disease, combinedfracture or vascular injury and use of allograft or autograft for PCL reconstruction. Clinical and functional outcomes were assessed with IKDC Subjective Knee Form, KOS-ADLS questionnaire, Lysholm scale and SF-12 Health Survey. Posterior displacement(PD) was measured with the Telos Stress Device. RESULTS Seven patients were excluded; two because of coexisting knee osteoarthritis and the remaining five because of failure to attend the final follow-up. The sample consisted of 31 patients with mean age at the time of reconstruction 33.2 ± 12.5 years(range 17-61). The postoperative follow-up was on average 9.27 ± 4.27 years(range 5-18). The mean average IKDC and KOS scores were 79.32 ± 17.1 and 88.1 ± 12.47% respectively. Average PD was 3.61 ± 2.15 mm compared to 0.91 ± 1.17 mm in the uninjured knees(one with grade 1+ and two with grade 2 +). Dial test was found positive in one patient, whereas the quadriceps active drawer test was positive in three patients. None was tested positive on the reverse-pivot shift test. The range of motion(ROM) was normal in thirty knees, in comparison with the contralateral one. There was no extension deficit. Osteoarthritic changes were found in three knees(9.6%).CONCLUSION Early treatment of complex knee injuries, using LARS artificial ligament for PCL reconstruction sufficiently reduces posterior tibia displacement and provides satisfactory long-term functional outcomes.

Design of a Prototype EHD Air Pump for Electronic Chip Cooling Applications

This paper presents the design,optimization and fabrication of an EHD air pump intended for high-power electronic chip cooling applications.Suitable high-voltage electrode configurations were selected and studied,in terms of the characteristics of the generated electric field,which play an important role in ionic wind flow.For this purpose,dedicated software is used to implement finite element analysis.Critical design parameters,such as the electric field intensity,wind velocity,current flow and power consumption are investigated.Two different laboratory prototypes are fabricated and their performances experimentally assessed.This procedure leads to the fabrication of a final prototype,which is then tested as a replacement of a typical fan for cooling a high power density electronic chip.To assist towards that end,an experimental thermal testing setup is designed and constructed to simulate the size of a personal computer’s CPU core of variable power.The parametric study leads to the fabrication of experimental single-stage EHD pumps,the optimal design of which is capable of delivering an air flow of 51 CFM with an operating voltage of 10.5 kV.Finally,the theoretical and experimental results are evaluated and potential applications are proposed.

Evaluation of La AlO_3 as top coat material for thermal barrier coatings

Perovskite is a versatile group of oxide materials allowing their properties to be tailored by composition towards specific requirements. La Al O3 was prepared to study and report its properties in the context of its potential in thermal barrier coatings（TBCs） technology. A citric acid method was used for synthesis and the perovskite structure was confirmed using XRD and FT-IR. Viscosity of the solution precursor was checked as well as the particle size by laser particle size analysis. Densification behavior of the material was followed by conventional sintering and by spark plasma sintering. Apparent porosity by the Archimedes method, thermal conductivity and thermal expansion coefficient were studied. Mechanical and fracture properties were measured at elevated temperatures up to 1300 ℃ For samples sintered at 1200-1400 ℃, coefficient of thermal expansion ranged from 5.5×10^-6 to 6.5×10^-6 K^-1 and thermal conductivity ranged between 2.2 and 3.4 W/（m？K）. Elastic modulus and ultimate stress were measured at 1000-1300 ℃, while by micro-indentation, fracture toughness was found to be 3 MPa·m1/2. As the sintering temperature increased from 1200 to 1500 ℃, significant densification from 3.21 to 5.81 g/cm^3 was found, indicating that material annealing should be made at least at 1400 ℃. Under this condition, negligible dimensional change in phase transition temperature of La Al O3 from the rhombohedral（R3 c） to the ideal cubic（Pm3 m） is found. Data reported in this work can be useful for comparing the mechanical and fracture behaviours of different TBCs developed involving La Al O3 as well as input for numerical simulations.

Organizational commitment and turnover intention among rural nurses in the Philippines: Implications for nursing management

Objectives:The unrelenting migration trend of Filipino nurses to other countries has threatened the quality of patient care services in the country.This study explored the extent of nurses'organizational commitment and turnover intention in the Philippines.Furthermore,predictors of nurses'organizational commitment and turnover intention were identified.Methods:A cross-sectional research design was adopted for this study.Two hundred nurses from nine rural hospitals in the Central Philippines were asked to participate in the study and 166 nurses responded(an 83%response rate).Two standardized instruments were used:the Organizational Commitment Questionnaire and the Six-item Turnover Intention Inventory Scale.Results:Findings revealed that Philippine nurses were moderately committed(3.13±0.24)to and were undecided(2.42±0.67)whether or not to leave their organization.Nurses'age(P=0.006),gender,(t=-2.25,P=0.026),education(t=2.38,P<0.001),rank(t=4.38,P<0.001),and work experience(t=2.18,P=0.031)correlated significantly with organizational commitment,while nurses'age(P=0.028)and education(t=1.99,P=0.048)correlated significantly with turnover intention.An inverse relationship was identified between the organizational commitment and turnover intention(r=-0.22,P=0.005).Conclusion:The findings of this study highlight the need for formulation and implementation of interventions to promote life-long commitment in nurses and to reduce turnover rates.

Open-Type Ferry Safety System Design for Using LNG Fuel

In this feasibility study, we investigate the viability of using Liquefied Natural Gas （LNG） fuel in an open type Ro-Ro passenger ferry and the associated potential challenges with regard to the vessel safety systems. We recommend an appropriate methodology for converting existing ships to run on LNG fuel, discuss all the necessary modifications to the ship’s safety systems, and also evaluate the relevant ship evacuation procedures. We outline the basic requirements with which the ship already complies for each safety system and analyze the additional restrictions that must be taken into consideration for the use of LNG fuel. Appropriate actions are recommended. Furthermore, we carry out a hazard identification study. Overall, we clearly demonstrate the technical feasibility of the investigated scenario. Minimal modifications to the ship’s safety systems are required to comply with existing safety rules for this specific type of ship.

A Study of the Enzymatic Hydrolysis of Fish Frames Using Model Systems

A model system was employed to study the operating conditions and primary parameters of enzymic hydrolysis of cod proteins. Pancreatin, papain, and bromelain were used to hydrolyse minced cod fillets under controlled conditions and with the rate of hydrolysis being continually monitored via both the pH-stat and TNBS method. The two methods were compared and evaluated. The rate of protein solubilisation was plotted against the degree of hydrolysis (DH). Dry fish protein hydrolysate (FPH) powders having short, medium and high degrees of hydrolysis (DH of approximately 8%, 11% and 16% respectively) were produced and analysed for their molecular weight distribution, using size exclusion chromatography. Almost complete protein solubilisation (75 g soluble protein per kg hydrolysis solution) could be achieved within an hour, at 40oC, at 1% enzyme/substrate ratio (w/w) with papain and bromelain. The pH-stat was found capable of continuously following the rate of hydrolysis but only at low DH. The TNBS could be accurately used even at high DH to estimate the percentage of the peptide bonds cleaved, but required chemical analysis of withdrawn samples.

Potential of acoustic emissions from three point bending tests as rock failure precursors

Development of failure in brittle materials is associated with microcracks,which release energy in the form of elastic waves called acoustic emissions. This paper presents results from acoustic emission measurements obtained during three point bending tests on Nestos marble under laboratory conditions.Acoustic emission activity was monitored using piezoelectric acoustic emission sensors,and the potential for accurate prediction of rock damage based on acoustic emission data was investigated. Damage localization was determined based on acoustic emissions generated from the critically stressed region as scattered events at stresses below and close to the strength of the material.

Cortisol levels and serum antioxidant status following chemotherapy

Chemotherapy results in increased free radical formation and depletion of tissue antioxidants. Moreover, patients receiving chemotherapy are under emotional stress, which is also accompanied by low antioxidant levels. In the present study, we measured cortisol, the main stress hormone, and total antioxidant capacity (TAC) in serum of 51 cancer patients during chemotherapy. Antioxidant activity was estimated by measuring the influence of serum in oxidation of ABTS (2,2'-azino-bis (3-ethylbenz-thiazoline-6-sulfonic acid to ABTS+ by methmyoglobin (Antioxidant kit of Cayman). Serum cortisol was measured using an ELISA colorimetric assay. Serum TAC was significantly decreased (75% decrease compared to normal levels, p = 0.001) in all patients during chemotherapy, while blood cortisol concentration was increased by 10%, (p = 0.044). Lower antioxidant levels and higher cortisol concentration were detected in patients receiving chemotherapeutic drugs daily, compared to the ones receiving chemotherapy once a week. A difference between sexes was observed with male patients presenting lower antioxidant status and higher cortisol levels than females. A significant and persistent decrease in antioxidant capacity accompanied by increased cortisol concentration was observed in all patients during chemotherapy. This fact, which is probably generated by biological and emotional stress, increases the probability of harmful side effects and organism weakening and needs to be considered during patients’ treatment.

Removal of Turbidity and COD from a Synthetic Water Sample by Coagulation

The main objective of this research was to study the removal of turbidity and COD （chemical oxygen demand） from a synthetic water sample. The water sample was treated chemically by coagulation. Two inorganic coagulants were used, ferric chloride and the double salt potassium-aluminium sulphate. The optimum coagulant dosage and working pH were examined. The results for ferric chloride as coagulant showed that the maximum removal efficiency （%） of COD was achieved at pH 6 with a dosage of 100 mg-L-1 and the maximum removal efficiency （%） of turbidity at pH 5 with a dosage of 500 mg.L-1. For double salt, as coagulant, the maximum removal efficiencies （%） of COD and turbidity were achieved at pH 6 with a dosage of 3,500 mg.L-1. An extensive comparison with results from previous studies was also described in this research.

Adaptive load forecasting of the Hellenic electric grid

Designers are required to plan for future expansion and also to estimate the grid's future utilization. This means that an effective modeling and forecasting technique, which will use efficiently the information contained in the available data, is required, so that important data properties can be extracted and projected into the future. This study proposes an adaptive method based on the multi-model partitioning algorithm (MMPA), for short-term electricity load forecasting using real data. The grid's utilization is initially modeled using a multiplicative seasonal ARIMA (autoregressive integrated moving average) model. The proposed method uses past data to learn and model the normal periodic behavior of the electric grid. Either ARMA (autoregressive moving average) or state-space models can be used for the load pattern modeling. Load anomalies such as unexpected peaks that may appear during the summer or unexpected faults (blackouts) are also modeled. If the load pattern does not match the normal be-havior of the load, an anomaly is detected and, furthermore, when the pattern matches a known case of anomaly, the type of anomaly is identified. Real data were used and real cases were tested based on the measurement loads of the Hellenic Public Power Cooperation S.A., Athens, Greece. The applied adaptive multi-model filtering algorithm identifies successfully both normal periodic behavior and any unusual activity of the electric grid. The performance of the proposed method is also compared to that produced by the ARIMA model.

Transfer of Heavy Metal Contaminants from Animal Feed to Animal Products

Study was conducted to assess the possible transfer of heavy metals from livestock feeds to animal products. In experiment-l, samples （n = 503） collected from conventional farms in Central Greece were analysed for heavy metal Copper （Cu）, Zinc （Zn）, Cadmium （Cd）, Lead （Pb）, Nickel （Ni） and Chromium （Cr） contents in muscle tissues, livers, kidneys, excremental and basic mixtures in livestock such as cows and sheep. Results showed that transfer of heavy metal contaminants from feed to animal products fluctuated below the permissible risk levels. In experiment 2, samples （n = 440） of feedstuffs used in different feeding regimens and seasons at different livestock farms [sheep （n = 140）, dairy cows （n = 180）, pigs （n = 120）] were collected. Results showed that relatively high concentration of Cu in the excrements of pigs （155 ＋ 9.13） and Zn in the excrements of sheep （144.56 ＋ 5.78） are explained by the use of Cu in the diet of developing piglets and sheep. Ovine showed higher concentration ofNi, Cr, and Pb in their excrements, while, the concentration of heavy metals in forages was under the allowed range to the EU legislation.

Automated Building Block Extraction and Building Density Classification Using Aerial Imagery and LiDAR Data

This paper examines the utility of high-resolution airborne RGB orthophotos and LiDAR data for mapping residential land uses within the spatial limits of suburb of Athens, Greece. Modem remote sensors deliver ample information from the AOI （area of interest） for the estimation of 2D indicators or with the inclusion of elevation data 3D indicators for the classification of urban land. In this research, two of these indicators, BCR （building coverage ratio） and FAR （floor area ratio） are automatically evaluated. In the pre-processing step, the low resolution elevation data are fused with the high resolution optical data through a mean-shift based discontinuity preserving smoothing algorithm. The outcome is an nDSM （normalized digital surface model） comprised of upsampled elevation data with considerable improvement regarding region filling and ＂straightness＂ of elevation discontinuities. Following this step, a MFNN （multilayer feedforward neural network） is used to classify all pixels of the AOI into building or non-building categories. The information derived from the BCR and FAR building indicators, adapted to landscape characteristics of the test area is used to propose two new indices and an automatic post-classification based on the density of buildings.

Global Production Estimation of Rare Earth Elements and Their Environmental Impacts on Soils

Due to high demand and limited availability of rare earth elements (REEs), Europe is unable to meet its industrial needs, especially High Tech needs, today for the manufacturing sector. Therefore, the EU has included them in the group of 14 critical minerals. China currently controls completely the mining activity, the enrichment technologies and metallurgy, and end-metal products of rare earths, resulting both Europe and the U.S.A. in full industrial dependency. The exploitation and wide use of REEs in fertilizers have led to accumulation of these elements in soils, resulting in an agriculture field pollution, which affects directly the soil microfauna with a toxic potential effect.

Electro-Hydrodynamic(EHD) Thrust Analysis in Wire-Cylinder Electrode Arrangement

The thrust generation by electro-hydrodynamic （EHD） effect has been studied for a wire-cylinder arrangement under high DC voltage. Series of measurements have been conducted in order to determine the relationship between generated thrust and corona discharge current, as well as its dependence on geometrical characteristics of the electrodes, e.g. electrode gap, wire and cylinder radii. The experimental investigation has shown a linear relationship between the generated thrust and the discharge current, while parametric analysis showed that increased electrode gap and emitter radius reduces the thrust. On the other hand, large gaps favor the thrust per unit power ratio.