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Production scheduling, which directly influences the completion time and throughput of workshops, has received extensive research. However, due to the high cost of real-world production verification, most literature did not verify the optimized scheduling scheme in real-world workshops. This paper studied the verification of scheduling schemes and environments, using a discrete event simulation (DES) platform. The aim of this study is to provide an efficient way to verify the correctness of scheduling environments established by programming languages and scheduling results obtained by intelligent algorithms. The system architecture of scheduling verification based on DES is established. The modelling approach via DES is proposed by designing parametric workshop generation, flexible production control, and real-time data processing. The popular distributed permutation flowshop scheduling problem is selected as a case study, where the optimal scheduling scheme obtained by a deep reinforcement learning algorithm is fed into the production simulation model in Plant Simulation software. The experiment results show that the proposed scheduling verification approach can validate the scheduling scheme and environment effectively. The utilization and Gantt charts clearly show the performance of scheduling schemes. This work can help to verify the scheduling schemes and programmed scheduling environment efficiently without costly real-world validation.

This paper presents a theoretical study on the developing forced convection heat transfer performance in a porous circular tube with asymmetric entrance temperature under LTNE condition. The Nusselt number is derived analytically, and its dependence on the pertinent parameters is investigated in details. It is found that the distribution characteristics of the Nusselt number with the circumstantial coordinate is determined predominantly by the asymmetric form of the entrance temperature function. Besides, the Nusselt number is strongly dependent on the values of the Peclet number, the Biot number, and the effective thermal conductivity ratio. The results obtained in this work are of benefit to further understand the thermal behavior of forced convection in a porous circular tube with asymmetric inlet temperature under LTNE condition. Meanwhile, the presented analytical solution can serve as a benchmark for calibrating numerical solutions of the studied problem.

In the present study, fully developed forced convection in tubes partially filled with composite metal foams (CMFs) is numerically investigated. In the CMF region, the Brinkman extended Darcy flow model and the local thermal non-equilibrium model are used to predict fluid and thermal transport. At the foam-foam interface in CMF, fluid temperature and solid energy are assumed to be continuous. At the foam-fluid interface, no-slip coupling conditions are used to couple flow and heat transfer of the foam and free regions. Governing equations are solved numerically with SIMPLE algorithm. Momentum and energy equations are discretized using the SGSD finite volume scheme for convective terms. Velocity distribution, temperature profile, the friction factor and Nusselt number in partially-filled CMF tubes are obtained. The results indicate that, porosity gradient has little effect on the friction factor at a low pore density, but the effect increases with increasing pore density. For the fixed pore density gradient, Nusselt number decreases with increasing porosity, and Nusselt number firstly increases sharply and then increases lineally with increasing Reynolds number. For the fixed material gradient, Nusselt number increases lineally with increasing Reynolds number.

In the present study, metal skeleton temperature, bubble growth, pool boiling curves, and the solid-liquid static contact angle of two-level gradient foams have been experimentally investigated in deionized water, aqueous surfactant solutions and polymeric additive solutions under atmospheric pressure. The surfactant is Triton X-100 and the polymeric additive is polyvinyl pyrrolidone. A two-level gradient foam sample is made by a uniform copper foam layer, a uniform nickel foam layer and a copper plate with the thickness of 2 mm. The pore densities of uniform foams are 5 PPI, 20 PPI and 40 PPI. The foam porosity is fixed as 0.98. The experimental results show that, foam layer position reversal has a great effect on pool boiling heat transfer of the gradient foam. The pool boiling heat transfer rate of the gradient nickel-copper foam increases with increasing bottom foam pore density. The temperature of corner skeleton on the upper surface of the gradient foam is higher than that of inner skeleton because of the heat flow from escaping bubbles by collision, cutting, stagnation, etc. The metal skeleton temperature is heavily affected by the additives of Triton X-100 and polyvinyl pyrrolidone due to the variations of the solid-liquid contact angles.

This paper investigates heat transfer performance and bubble behavior in gradient metal foam in saturated pure deionized water and n-heptanol solutions under pool boiling conditions. The gradient metal foam consists of a 40 PPI nickel foam layer with 4 mm thickness and a 10 PPI copper foam layer with 4 mm thickness; the foam porosity is 0.98. The experimental results show that n-heptanol increases the wettability of the copper surface and adversely affects the boiling heat transfer. At low heat flux, small departure bubbles attach onto the metal skeleton and then decrease in size. As heat flux increases, two common phenomena occur in the gradient foam: bubbles escape from the metal skeletons without cracking and bubbles separate into two smaller bubbles. When heat flux increases to 1 × 105 W m−2, two neighboring bubbles move upwards and are then sucked into the metal foam due to coalescence.

： The development of shale gas by injecting CO2 is complex, which results in the complicated dissolving process in porous formation. The components of underground formation are complicated and the non-uniform distribution greatly affects heat and mass transfer. In this study, the non-uniform porous media generated by quartet structure generation with dissolved solid, undissolved solid or immiscible phase is studied by lattice Boltzmann method, in which the flow, concentration and temperature fields are solved by Shan-Chen, mass transport and heat transfer lattice Boltzmann model, respectively. The results indicate that the reaction becomes further at the higher Damkohler number, while the diffusion becomes further at the higher Peclet number. The breakthrough time and the dissolution intersection points between the same solid distributions are affected by the solid dissolution rate non-uniformity. The breakthrough area is not affected by the vertical undissolved solid, but is considerably affected by the horizontal undissolved solid. But the breakthrough area is slightly affected by the vertical or horizontal immiscible gas, and the breakthrough time of the cases of immiscible gas is much more than those of undissolved solid.

Water jet impingement heat transfer is widely used in electronic component cooling, steelmaking, nuclear power plants and many other high heat transfer rate applications. This paper describes experiments with a jet from a moving nozzle impinging a surface using a stepping motor to control the nozzle. The effect of nozzle velocity on the heat transfer rates at different heat fluxes and flow rates are investigated. The experimental results show that a moving nozzle performs better than a fixed nozzle for reducing the maximum temperature difference of the heating surface and the average liquid film thickness, which results in steadier heat transfer rates and a more uniform temperature. Furthermore, a moving nozzle enhances the heat transfer in the convection by more than forty percent. Here, a higher nozzle velocity better enhances the heat transfer and temperature uniformity.

A numerical study on the solid–liquid phase change in open-cell metal foams is carried out by the phase field method originated from the Ginzburg–Landau theory. The Brinkman–Forchheimer extended Darcy equation and the local thermal non-equilibrium model are adopted to take natural convection and the heat transfer between metal foams and phase change materials (PCMs) into consideration, respectively. The result proves that the phase field model is reliable and effective in modeling metal foam enhanced phase change heat transfer in thermal energy storage. The effects of key parameters, such as Rayleigh number, porosity and pore density, on the melting and solidification process are investigated and it is found that they have great influence on the solid–liquid phase change. The phase field, flow field and temperature distributions in the melting and solidification process are obtained. Furthermore, kinetic undercooling in the solidification process is studied. It is concluded that heat conduction through the ligament of metal foams plays a dominant role in the solid–liquid phase change and kinetic undercooling effect is weakened as kinetic coefficient decreases.

Pool boiling heat transfer of gradient metal foams has been investigated in saturated pure deionized water and surfactant solutions at atmospheric pressure. Pore density gradients are from 5 PPI to 100 PPI, while the porosity remains at the fixed value of 0.98. The parametric study is performed by varying foam layer number and material. Alumina nanoparticle and surfactant (SDS and Triton X-100) effects on pool boiling heat transfer of gradient metal foams are also investigated. Images of nanoparticle-deposited foam fiber are captured by SEM. Bubble growth inside the gradient metal foams is captured by a high-speed camera. For no-nanoparticle-deposited gradient metal foams, pool boiling heat transfer in deionized water is heavily dependent on foam layer number and material gradient. For nanoparticle-deposited gradient metal foams, pool boiling heat transfer in surfactant solutions is dependent on surfactant concentrations and nanoparticle deposition condition on the metal skeletons. The visualization results show that departure bubble size first increases and then decreases in the gradient copper–nickel foam.

Near-field thermophotovoltaic devices are attractive energy conversion systems. In the present study, three-body near-field thermophotovoltaic systems are designed by introducing an intermediate modulator between thermal emitters and photovoltaic cells. The slab/grating emitter and modulator are made from Ga-doped ZnO, while the slab/grating cell is made from gallium antimonide. The scattering matrix method is used to calculate the radiative exchange between the emitter and the cell. The performances of three-body systems of slab-slab-slab/slab-slab-grating/ grating-grating-grating are investigated. The numerical results show that the output power of the three-slab system is significantly higher than that of the corresponding two-slab system. The output power improvement is attributed to the introduction of the modulator which enables the plasmon polaritons at two GZO surfaces to be coupled. The one-dimensional grating on the surface of the photovoltaic cell can serve as an anti-reflection pattern and improve the conversion efficiency and output power of the three-body system. Grating emitters and modulators can support hyperbolic modes and enhance the radiative heat flux of the whole system. The results prove that the three-body system can provide the possibility to improve the performance of a near-field thermophotovoltaic device.

In this paper, calcium nitrate and sodium nitrate are mixed in different molar ratios to form a cheap phase change material. The result shows that these binary mixtures all have exothermic peaks at around 220 °C, and the observed enthalpy increases with the NaNO 3 ratio. Further study indicates that although Ca(NO 3 ) 2 and NaNO 3 are mixed in different proportions, the mixture always first melts in the eutectic composition. Different Ca(NO 3 ) 2 and NaNO 3 ratio will lead to different amount of eutectic production, thereby resulting in different observed enthalpy. The sample with Ca(NO 3 ) 2 and NaNO 3 molar ratio of 3:7 shows the best heat storage performance. Specific heat capacity, compatibility and thermal conductivity are also measured in the paper. The cost of the 3:7 mixture is only about half of solar salt, but they have a similar latent heat storage capacity. Overall, this mixture shows a good application advantage.

As a new-type extending surface, metal foam owns great potential in next generation heat transfer technologies. Convective heat transfer performance in metal foams is numerically investigated based on the local thermal equilibrium (LTE) model and the local thermal non-equilibrium (LTNE) model. The solid–fluid temperature difference and relative deviation are put forward for quantifying LTNE effect. The effects of basic parameters on heat transfer are analysed in depth and the LTNE conditions in metal-foam tube for efficient heat exchangers are summarized. It is indicated that the relative deviation is a more suitable criterion for LTNE effect in metal foam than the solid–fluid temperature difference. The LTNE effect in metal foam is conspicuous for low porosity, large fluid–solid thermal conductivity difference, small duct size, low pore density, and low Reynolds number. Measures lowering proportion of local convective thermal resistance in total thermal resistance, or the ratio of thermal resistance of solid to that of fluid can weaken LTNE effect in metal foam. There is no necessary relationship between thermal performance of metal-foam heat exchangers and corresponding LTNE effect. Clarifying LTNE conditions in porous foams can lay a foundation for the demarcating criterion of LTE/LTNE models. This can also guide quick and accurate thermal design and verification of metal-foam heat exchangers.

Pool boiling heat transfer of metal foams with gradient pore densities has been investigated at atmospheric pressure in saturated deionized water. The gradient foams are made of two foam layers. The foam materials are copper and nickel. Pore densities of foam layers are from 5 PPI to 100 PPI, while the porosity remains the fixed value of 0.98. A parametric study is performed by varying the foam pore size and thickness. The effects of alumina nanoparticles and surfactant (SDS) on pool boiling heat transfer of gradient metal foams are also investigated in the present study. Images of foam fiber deposited by nanoparticles are captured by SEM. Compared to single-layer foams, gradient metal foams significantly enhance pool boiling heat transfer and the enhancement is heavily dependent on foam thickness and pore density gradient. The effects of SDS and nanoparticles on pool boiling heat transfer of gradient foams are dependent on concentrations.

Three new coordination polymers of Robson-type macrocycles, {[Cu2L1(bipy)]·(ClO4)2·CH3CN}∞ (1), {[Cu2L2(bipy)]·(ClO4)2·H2O}∞ (2) and {[Cu2L1(C8H4O4)]·(H2O)3}∞ (3) (where H2L1and H2L2 are the [2+2] condensation products of 1,3-diaminopropane with 2,6-diformyl-4-flurophenol and 2,6-diformyl-4-chlorophenol, respectively), have been synthesized and characterized. The magnetic susceptibility was measured for 1, 2 and 3 over the temperature range 2–300 K. The optimized magnetic data were J = −317.6 cm−1, j′ = 4.01 cm−1, ρ = 0.00031 with R = 8.5 × 10−39 for 1, J = −320.91 cm−1, j′ = 4.39 cm−1, ρ = 0.0013 with R = 1.8 × 10−39 for 2 and J = −221.01 cm−1, TIP = 0.00225, with R = 6 × 10−5 for 3.

The pool boiling heat transfer of deionized water on copper foams was experimentally studied under saturation conditions. Bubble growth behavior was captured by a high-speed camera. Two opposing factors, namely, surface area and bubble escaping resistance, governed the pool boiling heat transfer performance. The former dominated at large pore sizes, whereas the latter prevailed at small pore sizes. An experimental correlation was proposed for the heat transfer coefficient, which was applied at a porosity range of 0.9–0.98, pore density range of 5–40 PPI, and foam thickness of 5–7 mm. The bubble departure diameter and frequency of the high pore density (130 PPI) foam sample with V-shaped grooved arrays were further examined. The departure of the lotus-shaped bubble cluster caused by grooves was observed. Bubble cluster pulsation occurred at a high heat flux. The average departure diameter and frequency increased with the increase in heat flux. A typical bubble cluster pulsation period included four stages, namely, suction of the previous bubble cluster, fresh liquid supplement, liquid vaporization, and bubble cluster departure. The relationships between bubble cluster diameter and growth frequency were consistent in the boiling heat transfer performance of the three groove-arrayed foam surfaces.

Four symmetrical macrocyclic complexes, [Ni2L1(C6H4NO2)] (H2O)4 (1), [Cu4L1N3(ClO4)2(H2O)2]·[Cu2L1(ClO4)2(H2O)2 ]N3 (2), [Zn4L2 (H2O)2]·(ClO4)4 (3) and [Zn2L2(N3)2]CH3CN (4) (where H2L1 and H2L2 are the [2 + 2] condensation products of 2,6-diformyl-4-flurophenol with 1,3-diaminopropane and 1,4-diaminobutane, respectively), have been synthesized and characterized. The variable-temperature magnetisms of complexes 1 and 2 show that there are antiferromagnetic couplings between the two metal centers in both complexes, and the strongly electron-withdrawing fluorine groups in H2L weaken the antiferromagnetic exchange.

Pool boiling heat transfer of open-celled metal foam with V-shaped grooves for high pore densities has been investigated experimentally at atmospheric pressure in saturated deionized water. The foam materials are copper and nickel. The pore densities are 80 PPI, 100 PPI and 130 PPI, while the porosity and foam thickness remain the fixed values of 0.95 and 4 mm, respectively. The V-shaped grooves distributions are single-directional and crossing. The parametric study is performed by varying groove width and number. In the present study, the maximum heat flux is 1.47 × 10 6 W m −2 . Boiling patterns on foam surfaces are captured by a high speed camera. The results show that V-shaped groove significantly influences the pool boiling heat transfer performance of metal foam. Grooves’ effect heavily depends on their width, number, distribution and foam material, pore density.

The pool boiling heat transfer of trapezoid-shaped copper-foam fins has been investigated at atmospheric pressure in saturated deionized water. The pore densities of copper foams are 100 PPI and 130 PPI, respectively, while the porosity remains a fixed value of 0.95. The foam fins are single-directional and trapezoid-shaped. The parametric study is performed by varying the fin number, fin space, and fin thickness. The maximum heat flux is 1.47 × 106 W m−2 in the present study. Boiling patterns are captured by a high speed camera. The results show that the foam thickness significantly influences the pool boiling heat transfer performance, and its effect heavily depends on fin space and fin number.

In this paper, the authors analysed the impact of machine breakdowns in job shop scheduling problem with parallel machines. A mathematical model with the objective of minimizing the weighted value of makespan and early due date was established. An improved ant colony dynamic scheduling algorithm combined with elite strategy and max-min ant mechanism was designed. Simulation experiments were designed and numerical results verified the superiority of the proposed approach.

Pool boiling heat transfer on horizontal metallic foam surface with crossing and single-directional V-shaped groove was experimentally investigated at atmospheric pressure using deionized saturated water as the working liquid. Boiling patterns were captured using a high speed camera. The porosity of studied copper foam was fixed as 0.95. Thirty test samples categorized into three groups were studied. The influences of crossing V-shaped groove array configuration, single-directional groove width, and number on the heat transfer performance were examined respectively for the three groups in turn. The boiling process was governed by combinational interaction of three major factors of bubble escaping resistance, heat transfer surface area, and capillary force. The exhibited heat transfer performance of the metallic foam depended on whichever of the above factors dominated the boiling progress. Almost all V-shaped grooves could enhance the pool boiling heat transfer compared with foam surface without grooves. The optimal groove array configuration corresponding to highest heat transfer coefficient was connected to its groove volume ratio which was the very transition point for the behavior of the dominant factor. The optimal volume ratio for crossing groove array was 7.76% at pore density of 100 PPI and 5.84% at pore density of 130 PPI. The effect of groove number was heavily dependent on foam thickness. The optimal groove width of 2 mm was found for the three groove number values (1, 2, and 3). The boiling characteristics were illustrated with boiling patterns obtained from the high speed camera. The present study could aid enhanced boiling surface design of sintered porous surface.

In this study, pool boiling heat transfer performance of de-ionized water on horizontal plates sintered with copper fiber of various geometries was experimentally investigated under atmospheric pressure. Copper fiber felt with different structural parameters was proposed to provide artificial nucleate sites to improve heat transfer performance. A high-speed camera was used to photograph bubble growth processes. Pool boiling curves were obtained. Effects of fiber felt porosity and fiber diameter on the onset of nucleate boiling (ONB) and boiling heat transfer coefficient were investigated. It was revealed that copper fiber felt surfaces can reduce wall superheat at boiling incipience and exhibit significant enhancement of heat transfer compared with smooth surface. The influence of porosity on heat transfer performance for metal fiber felts was more sensitive than fiber diameter. A bubble with an average diameter of less than 0.3 mm was defined as a small-sized bubble (SSB) from visualization photograph by...

The current study investigated the saturated pool boiling heat transfer of deionized water with added surfactant on a horizontal metallic foam surface with V-shape grooves under atmospheric pressure. The influences of the groove configurations, sodium dodecyl sulfate (SDS) concentration, foam thickness, and thermal conductivity of foam material on heat transfer performance and bubble growth patterns were studied. SDS with concentrations of 100, 400, and 800 ppm was used as the surfactant. The foam porosity was fixed at 0.95. V-shape grooves with various widths and groove number were manufactured in the foam samples, with three pore densities of 20, 100, and 130 PPI. Results showed that the effects of the groove configuration, SDS concentration, and thickness on boiling heat transfer are heavily dependent on foam pore density. The counter-flow between the released bubbles and sucked liquid plays a significant role in heat transfer performance. The existence of sufficient grooves delays the critical heat flux (CHF), whereas SDS can achieve CHF earlier.

Purpose To determine the safety and radiation-enhancing effect of sodium glycididazole in laryngeal squamous cell carcinoma (stage T3-4,N0-3,M0) with conventional radiotherapy. Patients and methods Patients with locoregional advanced laryngeal cancer (stage T3-4,N0-3,M0) were included: group 1(control, n = 30)were not administered of sodium glycididazole; group 2 (test, n = 30) received sodium glycididazole at a dose of 700 mg/m2 intravenous infusion 30 minutes before radiotherapy three times a week. Surrogate end-points of efficacy were tumor and nodal size. Safety parameters were vomiting, nausea, mucositis, laryngeal edema, esophagus and skin reaction, dysphagia, dyspnea, neurological deficit. Patients were evaluated weekly during treatment for 7 weeks and thereafter monthly for 3 months. Results In the test, the overall response rate was 88.89% (95%CI, 71.00–97.00%) at 7 weeks and 92.59% (95%CI, 76.00 to 99.00%) at 1 month of follow-up. In the control, the overall response rate was 62.5% (95%CI, 41.00 to 81.00%) at 7 weeks and 58.33% (95%CI, 37.00 to 78.00%) at 1 month of follow-up. The short-term locoregional response rate was better in the test group at 7 weeks (p = 0.027) and at 1 month (p = 0.005) of follow-up. The test group had significantly more nausea and vomiting in weeks 1 (p = 0.047), 2 (p = 0.007), and 3 (p = 0.01) of treatment. Conclusions The study indicates sodium glycididazole is an effective radiation-enhancing agent that improves short-term locoregional control and is well tolerated in patients with locoregionally advanced laryngeal cancer.

V-doped LiFePO4/C cathode materials were prepared through a carbothermal reduction route. The microstructure was characterized by X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy. The electrochemical Li+ intercalation performances of V-doped LiFePO4/C were compared with those of undoped one through galvanostatic intermittent titration technique, cyclic voltamperometry, and electrochemical impedance spectrum. V-doped LiFePO4/C showed a high discharge capacity of ∼70 mAh g−1 at the rate of 20 C (3400 mA g−1) at room temperature. The significantly improved high-rate charge/discharge capacity is attributed to the increase of Li+ ion “effective” diffusion capability.

Based on the detailed laboratory experiments and theoretical analysis, a new three-layer model is proposed to predict the vertical velocity distribution in an open channel flow with submerged vegetation. The time averaged velocity and turbulence behaviour of a steady uniform flow with fully submerged artificial rigid vegetation was measured using a 3D Micro ADV, and the vertical distribution of velocity and Reynolds shear stress at different vegetation height, vegetation density and measuring positions were obtained. The results show that the velocity profile consists of three hydrodynamic regimes (i.e. the upper non-vegetated layer, the outer and bottom layer within vegetation); accordingly different methods had been adopted to describe the vertical velocity distribution. For the upper non-vegetated layer, a modified mixing length theory combined with the concept of ‘the new vegetation boundary layer’ was adopted, and an analytical model was presented to predict the vertical velocity distribution in this region. For the bottom layer within vegetation, the depth average velocity was obtained by numerically solving the momentum equations. For the upper layer within vegetation, the analytical solution was presented by expressing the shear stress as a formula fitted to the experimental data. Finally, the analytical predictions of the vertical velocity over the whole flow depth were compared with the results obtained by other researchers, and the good agreement proved that the three-layer model can be used to predict the velocity distribution of the open channel flow with submerged rigid vegetation.

The decision rules based on measurement uncertainty are given in ISO 14253-1, according to which only measurement uncertainty is considered in the three-dimensional measurement process, and the workpieces are simply accepted or rejected by measurement uncertainty. It can be seen that the decision rules don’t accord with the basic requirements of the improved GPS system because correlation uncertainty and specification uncertainty are not taken into account, which are existent actually in a GPS process. In order to solve this problem, this paper presents the decision rules based on total uncertainty, according to which the workpieces should be accepted or rejected by total uncertainty. The biggest difference between the two decision rules is whether correlation uncertainty and specification uncertainty have been taken into account. For a given GPS specification, the key of the decision rules based on total uncertainty is to calculate the compliance uncertainty of the corresponding GPS standard-chain. According to ISO 17450-2, a GPS process should be either in the default state or in the special state. Aiming at the two states, the calculation method for compliance uncertainty of a GPS standard-chain is given respectively. It enables us to generate compliance uncertainty on the verification of a GPS specification, which means the acceptance or refusal of a GPS characteristic can be conducted in a quantitative way. The example of flatness least-square assessment indicates that the veracity of assessment could be improved .

Technology forecasting plays a fatal role for enterprise survival and development. Technology maturity of thermostat is predicted with the TMMS and patent data algorithms. Radar plot is drawn to indicate the evolutionary potential for the further improvements of thermostat. It is pointed out that thermostat will be getting more dynamic and smaller with the help of radar plot. KEYWORD: radar plot; thermostat; technology forecasting

A Lagrangian approach is adopted to study the turbulent dispersion of spray droplets in the near-field of air-assisted orchard sprayers. In order to compute the mean and turbulent properties of the air flow generated by the moving sprayer, the generalised mass and momentum conservation equations, coupled with a k – e turbulence model, are solved numerically using finite volume methodology. These equations utilise a spatial-averaged porous medium model to take into account the effect of interactions between the air flow and crop. Airborne spray flux distributions have been calculated from ensemble-averaged particle trajectories predicted by two random-walk models (i.e. with and without temporal correlation). The results show that both stochastic models give reasonable agreement with measured drift profiles.

Experimental study of air natural convection in horizontally-positioned copper metallic foams with open cells was conducted. Temperature distributions on the heating surface were tested under different heating power for foam samples having different porosities and pore densities. The effects of porosity and pore density on the total thermal resistance of the foam sample were quantified. It is found that the porous surface can enhance the natural convection and reduce the thermal resistance by about 20% in comparison with a smooth surface. The surface area density and mass flow rate in natural convection are affected by porosity and pore density simultaneously. When the porosity is relative small (#x03B5; = 90%), there exits a critical value of the Gr number (turning point) for two pore densities (10ppi and 40ppi). When the Gr number is less than this critical value, the foam with a higher pore density has the lower total thermal resistance, whereas when the Gr number exceeds the turning point value, the opposite holds. If the porosity is increased to #x03B5; = 95%, the foam with a higher pore density has the lower thermal resistance in the whole experimental range. When the porosity and pore density is the same, the foam with smaller size has the higher thermal resistance in the whole experimental range. If the size is relatively small (100×100×50mm), for the two pore densities studied (20ppi and 80ppi), there exits a critical value of the Gr number (turning point). The foam with a lower porosity(#x03B5; = 90%) has the lower thermal resistance and the decrease is more obvious for the case of 80ppi.If the size is relatively big(100×100×80mm),there exists a critical value of the Gr number (turning point) only for the case of 10ppi. When the Gr number is less than this critical value, the foam with a higher porosity (#x03B5; = 95%) has the higher total thermal resistance, the opposite holds. While for the other two pore densities (20ppi and 40ppi), there is no turning point. The foam with a higher porosity (#x03B5; = 95%) has the higher total thermal resistance in the whole experimental range.

We report on measurements of the Young's modulus (Y) and internal friction (1/Q) in (TMTSF) 2 PF 6 at 5.5K as functions of electric field. No changes ( Δ Y/Y, Δ 1/Q −4 ) are observed at fields up to 100E T , the threshold for SDW depinning, in contrast to what is observed for many sliding charge-density-wave materials. A possible explanation is that we are not observing bulk depinning of the SDW.

We have measured the dependence of the CDW elastic depinning anomalies on frequency and uniaxial strain. The anomalies in shear and Young's moduli are approximately independent of frequency between 30Hz and 1kHz, falling rapidly above this. The shear modulus anomaly decreases rapidly when the strain exceeds ∼0.5%, where a second threshold electric field is observed.

This paper reports a novel suspended nanoscale solenoid metal inductor with inductance of several tens-nH for analog-circuit and radio-frequency application. The nanoscale inductors consist of three-dimensional aluminum or gold nanohelices, which are transformed from nanometer thick metal cantilevers by focused-ion-beam stress-introducing technology. For the inductor with a two-turn helix conductor, the inductance is measured to reach more than 20 nH while the structure size is less than 10 times 2 mum2. The quality factor is 1.4 at 100 MHz, and might increase to about several tens at Gigahertz. The inherent series resistance of the two-turn inductor is 10.6 Ohm.

Publisher Summary This chapter presents the Probabilistic Fracture Mechanics (PFM) method for making a reliability assessment on the draw bar of large-scale lock mitre gate of Three Gorges Project. The method provides a powerful tool for the design, manufacture, and flaw detection of the draw bar. The concepts of Goodman joint element have been extended to analyze 3-D contact problem between the pivot and the aperture of the draw bar. The sixteen node isoparametric contact elements, which have zero thickness, are used to simulate the mechanical behavior between contact surfaces with friction. The contact problem is nonlinear for boundary conditions, so the finite element analysis is carried out using a step-by-step incremental solution. In calculating procedure, the types of contact elements and reserve elements are changed, including relative sliding and possible separation after contact. Also the element matrixes are modified for these elements. A specific solution scheme called the wave frontal method is used effectively to solve the equations. Most of the failures reported in engineering structures are due to cyclic loading and they originate at geometric discontinuities, which are sites of high local stress gradients.