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International audience; This paper presents experimental and numerical results of the hybrid members with several encased steel profiles subjected to bending and shear. These results are compared with each other on the load-bearing capacity, the strain distribution, the stress distribution, the slip distribution, the crack pattern, the failure modes. These steel-concrete composite structural elements belong to the so-called “hybrid” structures which are neither reinforced concrete structure in the sense of Eurocode 2, nor steel-concrete composite structures in the sense of Eurocode 4. Currently, there is no design calculation guide of the resistance for this type of structure in international standards. Therefore, the comparison between numerical and experimental results is performed to point out the mechanism of the load transfer and failure taking place within the hybrid members subjected to bending and shear. It is the basis for calibrating the proposed design method for hybrid members reinforced by several steel profiles. The six hybrid member specimens were prepared and tested at the Structures Laboratory of INSA Rennes, France. The structural response of all hybrid members specimens were simulated by a full 3D finite element model using the Abaqus software. © 2018, Springer Nature Singapore Pte Ltd.

In this research, a low damping force shear-mode magneto-rheological (MR) damper that can replace conventional passive damper of a front-loading washing machine is designed and experimentally evaluated. In the design of the MR damper, required damping force, off-state friction force, size, and low cost of the MR damper are taken into account. Firstly, a suppression system for washing machines featuring MR dampers is proposed considering required damping force, available space, and cost of the system. Optimization of the proposed MR suspension system is then performed considering required damping force, off-state friction force, size, power consumption, and low cost of the MR damper. From the optimal results, simulated performance of the optimized MR damper is obtained and presented with discussions. A detailed design of the MR damper is then conducted, and a prototype MR damper is manufactured. In addition, experimental results on the prototype MR damper are obtained and compared with simulated ones. Finally, discussions on performance and application of the MR suspension system for front-loading washing machines are given.

Climate variability is contributing to water-scarcity problems in Kenya and to extreme flooding and drought in Vietnam. This paper compares diversity-based climate adaptation approaches in current land use in the Cam Xuyen district, Ha Tinh province, Central Vietnam and in the Kapingazi river watershed in Embu district, Eastern province, Kenya, in order to understand local responses to climate variability and examine the potential for policy support of diversity management by local people. Literature reviews and trend analysis of local time series of rainfall and temperature were combined with stakeholder interviews and workshops to identify technology and policy options for dealing with current and future climate variability. At all study sites, diversity in land use at farm level and along agriculture–forestry landscape gradients was a key strategy. Policy options to support such an approach could include legalization of agroforestry in Vietnam and a combination of regulations and incentive-based approa...

The TIGER-3 radar is being developed as an “all digital” radar with 20 integrated digital transceivers, each connected to a separate antenna. Using phased array antenna techniques, radiated power is steered towards a desired direction based on the relative phases within the array elements. This paper proposes an accurate phase measurement method to calibrate the phases of the radio output signals using Field Programmable Gate Array (FPGA) technology. The method sequentially measures the phase offset between the RF signal generated by each transceiver and a reference signal operated at the same frequency. Accordingly, the transceiver adjusts its phase in order to align to the reference phase. This results in accurately aligned phases of the RF output signals and with the further addition of appropriate phase offsets, digital beamforming (DBF) can be performed steering the beam in a desired direction. The proposed method is implemented on a Virtex-5 VFX70T device. Experimental results show that the calibration accuracy is of 0.153 degrees with 14 MHz operating frequency.

In this paper, we study the temperature field associated with the propagation of a fatigue crack in a very high cycle fatigue regime during ultrasonic fatigue testing. We use a Paris\textendashHertzberg crack growth law to compute the evolution of the crack and a perfectly elastic\textendashplastic constitutive law to compute the plastic dissipation per cycle at the tip of the crack. A thermomechanical finite element model is proposed to estimate the evolution of the temperature field during the crack propagation. Numerical results obtained agree fairly well with experimental results.

Ti-6Al-4V implants formed with a sintered porous surface for implant fixation by bone ingrowth were prepared with or without the addition of a thin surface layer of calcium phosphate (Ca-P) formed using a sol-gel coating technique over the porous surface. The implants were placed transversely across the tibiae of 17 rabbits. Implanted sites were allowed to heal for 2 weeks, after which specimens were retrieved for morphometric assessment using backscattered scanning electron microscopy and quantitative image analysis. Bone formation along the porous-structured implant surface, was measured in relation to the medial and lateral cortices as an indication of implant surface osteoconductivity. The Absolute Contact Length measurements of endosteal bone growth along the porous-surfaced zone were greater with the Ca-P-coated implants compared to the non-Ca-P-coated implants. The Ca-P-coated implants also displayed a trend towards a significant increase in the area of bone ingrowth (Bone Ingrowth Fraction). Finally, there was significantly greater bone-to-implant contact within the sinter neck regions of the Ca-P-coated implants.

Effects of growth conditions and buffer structures on crystal quality of 1.9-eV In

Virtual screening has proven very effective on grid infrastructures. Operating a dedicated virtual screening platform on grid/cloud resources requires optimizing the scheduling policy. We focus on finding platform scheduling policy for pilot-agent platform shared by many virtual screening users. They need a suitable scheduling algorithm at platform level to ensure a certain fairness between users. Optimal criterion used in our research is the stretch, a measure for user experience on the platform. From our latest research (Quang et al. 2013), simulation result and experimentation on real pilot agent platform showed that SPT policy is the best policy in 4 different existing scheduling policies (FIFO, SPT, LPT and Round Robin) for optimizing the stretch. However, research on real grid workload (Medernach 2005) showed that there are two types of grid user: normal users who submit frequently little jobs to grid and data challenge users who submit occasionally large number of jobs to grid. And SPT policy, in particularly, is not appropriate for data challenge user because they have to wait always normal user. In this paper, we proposed a new policy named SPT-SPT which uses multi-level queue scheduling technique for scheduling in pilot agent platform. In SPT-SPT policy, administrator creates two separate user groups in platform: Normal group and Data Challenge group. Each group has their own task queue in platform and SPT policy is applied on it. A parameter p (p Iµ [0,1]) is assigned to one task queue and 1-p for the other one. This parameter is the probability that task queue is chosen to send pilot agent their task. Simulation result showed that new policy is better than original SPT policy to optimize both group stretches. It improves user experience for Data Challenge group and do not impact very much for Normal group.

Using in vivo microdialysis in the frontal cortex of the freely moving rat we evaluated the effects of chronic treatment with the serotonin specific reuptake inhibitor (SSRI) fluoxetine in the presence and absence of the 5-HT1A/β-adrenergic antagonist (±)pindolol. Chronic vehicle treated animals produced no significant response to a challenge with fluoxetine (10 mg kg−1) on day 8 and 15. Alternatively, a significant (P

The resistance of an experimental sealer (KT-308) to bacterial ingress was assessed in six beagle dogs. In four mandibular premolars per dog, canals were prepared, filled with condensed gutta-percha and either KT-308 or Roth 801 cement (n = 24 roots), and the pulp chambers inoculated with plaque. Two additional premolars per dog were similarly root-filled, but not inoculated (n = 12 and 11, respectively). One incisor per dog was inoculated, but not root-filled (n = 6). Dogs were terminated after 6 months, and jaw blocks were retrieved and processed for light microscopic examination of the periapical tissues. Inflammation about the inoculated roots was significantly lower (p0.03) for KT-308 (17%) than Roth 801 cement (46%). Inflammation about the noninoculated roots did not differ significantly between KT-308 (8%) and Roth 801 cement (36%). This study demonstrated a better functional efficacy of KT-308 than of Roth 801 cement, and validated this in vivo model for assessment of root filling materials.

The Tri Auto ZX (J. Morita Co., Kyoto, Japan) is a cordless endodontic handpiece with a built-in apex locator that is programmed to reverse the direction of rotation when the file reaches a predetermined apical level or when torque becomes excessive.The purpose of this investigation was to examine the apical extent of rotary canal instrumentation and the ability to maintain apical constriction with the Tri Auto ZX at different automated settings.In 60 extracted teeth, canals were measured to the apical constriction, first visually and then electronically with the Tri Auto ZX; then they were instrumented with nickel titanium rotary files. For the instrumentation, the automatic apical reverse mechanism of the handpiece was set to 1, 1.5, or 2; these settings correspond to different distances from the apical foramen. Instrumentation was carried out apically until rotation was reversed by the automatic apical reverse function; the instrumented length was then measured, and the canal was filled with gutta-percha and sealer. The integrity of the apical constriction was assessed by exposing the apical 4 mm of the canal and observing the dentin-cementum junction. Paired t-tests were used to compare the visually measured length, the electronically measured length, and the instrumented length for each tooth.On average, the electronically measured length was 0.54 mm shorter than the visually measured length (p0.05). When the automatic apical reverse mechanism's setting was 1, the instrumented length was 0.1 mm shorter than the electronically measured length; when the setting was 1.5, the instrumented length was 0.36 mm shorter than the electronically measured length (p0.01). Results were inconsistent when the setting was 2.Instrumentation with the automatic apical reverse feature set at 1 consistently approximated the apical constriction; however, the constriction was frequently enlarged.

This paper presents a novel antenna impedance matching system used in the latest Australian SuperDARN class HF radar, at Buckland Park, South Australia. Earlier radar designs used an off-the-shelf log-periodic wideband antenna that is significantly easier to match over the SuperDARN frequency band, but expensive to buy and mount, and had limited capability for azimuthal beamforming. The newer TTFD antenna, used in many recent SuperDARN radars, offers improvement in these areas, but is in essence a narrow band antenna. It is capable of wideband operation at the cost of being difficult to match, frequency dependant, high-impedance and complex load. Previous TTFD matching transformers utilising toroids have been measured and evaluated for their suitability for the Buckland Park radar. A new system based on an LC matching network circuit has been devised to replace them. The design approach and results of the new matching circuit are detailed.

The TIGER-3 radar is being developed as an “all digital” radar with 20 integrated digital transceivers, each connected to a separate antenna. Accurate coordination of all 20 transceivers is essential for both generation of transmit signals and collection and merging of receive data to form a standard Su-perDARN data set. This paper proposes a clock synchronisation method to coordinate the operation of the entire system using Field Programmable Gate Array (FPGA) technology. The method is a co-operation between hardware and software to achieve the necessary clock quality and synchronisation requirements. It is extremely important that the clock signals are kept aligned in time within specified bounds. To achieve this a 125Mhz common master clock is sent from a clock controller to a clock buffer, which then distributes the signals to the transceivers. In turn, each transceiver sends back a clock signal which is a buffered version of the common clock in the same bundle. In order to synchronise clocks on the transceivers, phase delays of round-trip clock paths are measured on the clock controller board with the accuracy of 31.25ps. The measurement is performed by shifting the common clock phase at a resolution of 1/256 of the clock period until the return clock and the common clock are in phase. Once the measurement cycle is complete, each transceiver adjusts the phase of its clock as directed by the clock controller. Experimental results show that the phase noise of the transmit signal generated from the synchronised clocks at transceivers is less than −100 dBc/Hz, while the SNR of the transmit signal is ≈ 90 dB for the entire 8–20 MHz range.

Introduction. By 2013, approximately 15,000 MMT patients were being treated in Vietnam. The national goal is to have 80,000 patients on MMT by 2015. While increasing the number of patients, retaining patients on MMT is equally important. Methods. The Drop-out ratio was calculated and reasons for drop out identified based on program monitoring during 2011-2013. The cumulative number of patients included in this analysis was 6213 at 17 clinics in 6 provinces. Results. The rate of patient drop-out was less than 4% monthly in all clinics, but cumulatively up to 24% of patients enrolled in treatment dropped out the 3 year period. Reasons for drop included patients arrested by police (25%), moved to other clinics (4%), returned to rehabilitation (3%), and voluntarily stopping treatment (3%). The reason was unknown for a high proportion of loss to follow-up (55%). Conclusions. Drop-out is serious threat to the success of the MMT program in Vietnam. MMT clinic staff should provide education and counseling for patients to avoid illegal activities, arrest and interruption of MMT. Research should be conducted to understand the characteristics of drop-out patients and develop more effective interventions for improving retention.

Work in communities such as component-based development, model-driven engineering, and software architecture deal with quality assurance in different levels of design. Techniques such as component model, transformation, and architectural description language help to improve development costs, time and partially quality of systems. However, we argue that it is necessary to take a global and open approach for quality analysis by considering behavioral, deployment and non-functional qualities in the same design method. This paper presents our approach to building the architecture in RM-ODP's engineering viewpoint by using architectural figure concept with analysis tool. The concept is inspired from the software pattern and the software style but provides more capacities for quality properties analysis and for transformation of systems architecture.

Introduction. Since 2008, nine Methadone clinics have provided free clinical services in Hai Phong, Vietnam. In January 2014, the clinics began collecting a patient co-pay fee (USD $0.50 daily) to compensate for decreases in available funding. The following month, a survey measured patient satisfaction with component services and evaluated effects of the transition from free-service to a co-pay model. It also assessed patients' preferred fee collection schedules. Methods. All patients enrolled in the 9 clinics during February 19-21, 2014, were invited to participate and were given a short self-administrated, structured questionnaire. Participants completed and returned questionnaires into sealed boxes. Participation was voluntary and anonymous. Results. The response rate was 80% (2,227 participants). The proportion of patients answering "Satisfied" or "Very satisfied" to each service was as follows: reception (70.6%), medical examination (75.0%), counseling (76.9%), methadone dispensing (75.2%), security (67.9%) and sanitary condition (67.6%). The proportions of patients answering "Dissatisfied" or "Very dissatisfied" ranged from 5.9% (counseling) to 10.4% (security). 77.3% preferred to pay monthly, 15.9% quarterly, 1.9% semi-annually; 1.7% annually; and 3.1% other payment schedules. Conclusion. Results were used to recommend several service quality improvements for Methadone Maintenance Treatment Programs and to recommend a monthly fee collection schedule.

Introduction. Longer retention in drug abuse treatment is associated with better patient outcomes. This study is to evaluate the drop-out rates and the reasons for the early drop-out of patients in the SMART TA methadone maintenance treatment (MMT) clinics in Vietnam. Methods. Data from the monthly reports between 2011 and 2013 was collected from 17 clinics in 9 provinces for this retro-prospective data analysis. The number of drop-outs was calculated by using the number of patients who have ever enrolled into the program and total number of dropped out patients by the end of time period. The reasons for early drop-out were also analyzed. Results. A total of 1471 cumulative patients dropped out of the MMT program, indicating a drop-out rate of less than 4% per month per clinic. Among those who dropped out, 24% moved to other clinics, 9% died, and 67% dropped out completely. Reasons for permanent drop-out includes: returned to 06 centers (3%), arrested (25%), moved to other places (4%), other and unknown reasons (69%) Conclusion. Results of the study suggested that the rate of dropped out patients was low compared to other neighboring countries, and there is need to improve the loss to follow up.

We report pulse shaping experiments in the 20-fs range using a 512-element phase-only liquid crystal modulator array. The results demonstrate the potential for significantly improved spectral resolution compared to 128-element liquid crystal modulators previously used for pulse shaping. Furthermore, we show that subtle nonlinear spatial dispersion has a profound effect on replica pulses arising due to the pixellated nature of the liquid crystal modulator and may dramatically reduce their (already low) peak intensity.

Nd:YAG laser-induced modification of the root surface may inhibit development of external inflammatory resorption in replanted teeth. This study tested this hypothesis in vivo. The pulp chambers of six mandibular premolars in each of two dogs were accessed, inoculated with plaque, and sealed (Groups 1, 2). Two additional premolars in each dog were endodontically treated without inoculation (Groups 3, 4). After 2 weeks, teeth were hemisected and extracted. Each root had a 2 x 3 mm surface area denuded of cementum on the buccal and lingual surface. In Groups 1 (n = 12 roots) and 3 (n = 4), the denuded surfaces were wiped with 15% EDTA, coated with black ink, and irradiated with Nd:YAG laser (0.75 W, 15 pps, 300 microns tip, 20 s). In Groups 2 (n = 12) and 4 (n = 4), the surfaces were wiped with 15% EDTA, and rinsed with sterile saline for 20 s. Roots were replanted within 5 min. The dogs were perfusion-euthanised 10 weeks after replantation. Block specimens were removed, decalcified, embedded and horizontally sectioned (6 microns) at 180-microns intervals, resulting in 10 to 14 cross-sections of each root. From these, the middle five consecutive sections were stained with hematoxylin and eosin, and observed by light microscopy for occurrence of surface, inflammatory and replacement resorption on the denuded surfaces. No obvious differences were noted between the laser-irradiated and non-irradiated surfaces. Inflammatory resorption was frequent in Groups 1 and 2, and absent in Groups 3 and 4. Replacement resorption was minimal in Groups 1 and 2, and frequent in Groups 3 and 4. Differences between Groups 1 and 2, and between Groups 3 and 4 were not significant, whereas the differences between the two pairs of groups were statistically significant (chi-square and two-way ANOVA, P < 0.006). These results did not support the hypothesis, and questioned the clinical validity of the surface modification in Nd:YAG laser-irradiated dentin. Therefore, the clinical application of Nd:YAG laser to the root surfaces of replanted teeth is not warranted.

High luminance (brightness) thin-film phosphor materials have potential use in a variety of applications including heads-up, helmet-mounted, and electroluminescent displays, as well as in emerging flat-panel displays based on field emitter technology. Phosphor materials in thin film form offer several advantages over conventional powder phosphor screens. Since the film is nearly fully dense and in intimate contact with the underlying substrate, thin film phosphors transfer heat to the face plate much quicker than conventional, more porous, powder phosphor materials. This allows thin film phosphor screens to be driven at higher power levels, and therefore produce higher luminance, assuming the efficiency of the powder and film are the same. Fully dense phosphor films have smaller surface area, and will outgas less than conventional powder phosphor materials. Thin film phosphors have smaller grain sizes than conventional powder phosphor materials which will provide for smaller spot size, and thus, higher resolution. Furthermore, in applications such as field-emitter displays, powder phosphor particles can be physically dislodged from the screen due to the high electric fields produced by the large potential difference between the anode screen and gate electrode (or cathode), or dislodged by arcing which may occur if a powder particle protrudes significantly above the screen surface. Dislodged particles or damage produced by arcing could degrade display performance. Dense, thin-film phosphor materials which are well adhered to transparent substrates will provide much smoother surface morphologies, and should be able to withstand significantly higher electric field strength without arcing or screen degradation due to the dislocation of particles.

Phase imaging is used to compare near-field measurements with the corresponding far-field intensity distribution. A liquid-crystal device serves as a phase object that can be programmed as a variable grating. Real-time phase visualization then provides an avenue for direct optimization of complex phase gratings.

This paper elaborates on the idea, recently advanced by the authors, of using the scanning tunneling microscope (STM) in new experiments on laser frequency synthesis and laser rectification at optical frequencies. We first introduce the subject of harmonic generation and mixing of laser beams by the related tunneling device called ‘‘point contact diode.’’ Then, we present new quasistatic current–voltage characteristics of several STM junctions, emphasizing their nonlinear and rectifying aspects. The physical origin of the observed asymmetrical I–V curves is discussed. Finally, we describe the proposed rectification experiment which should result in an operationally meaningful definition of a tunneling time for electrons crossing an STM junction and we present some very preliminary results.

The adsorbate-induced reconstruction of the room-temperature Ni(110)-H surface has been resolved by scanning tunneling microscopy. The structure, known as ``streaky'' (1\ifmmode\times\else\texttimes\fi{}2) from LEED observations, is found to be primarily a (5\ifmmode\times\else\texttimes\fi{}2) Ni reconstruction with small domain size along the 〈001〉. Top-layer Ni atoms are paired long the 〈001〉 by a 0.5-A\r{} lateral displacement to form tetramers and every fifth 〈001〉 row is missing. The barrier height, measured simultaneously with a constant-current topograph, is found to be higher along the 〈001〉 missing rows.

Recent measurements of dc current-voltage characteristics of scanning-tunneling-microscope (STN) junctions have confirmed their expected high rectification property. We propose to exploit this property (i) to study rectification at infrared and optical frequencies and (ii) to arrive at a procedural definition of an electron tunneling time. We envisage focusing a laser beam of linearly polarized light onto a STM junction and detecting the dc bias induced across the junction by the alternating, asymmetrical tunnel current. The asymmetry may be of geometrical, material, and/or thermal origin. The dc rectified bias should vanish at sufficiently high laser frequency for fixed tip-to-surface distance or when withdrawing the tip away from the surface for fixed laser frequency. The average electron tunneling time is then one half of the inverse cutoff frequency observed in such a laser-rectification experiment. Similar experiments have already been conducted successfully with metal-whisker diodes and have resulted in the recent redefinition of the meter. The new opportunity offered by STM is the controllability of the junction and its microscopic size, entailing high responsivity. Additional possible laser-STM studies are proposed.