Search

Construction waste materials are resources misplaced. Trading them across different jurisdictions is an innovative way to reuse or recycle the materials, which in turn obtains “cleaner production” in the construction sector. It can achieve a win-win situation between the demand and supply sides, but several hurdles must be overcome first. A particular hurdle is that demand and supply of such materials arises sporadically in discrete sites, thereby matching the two sides is not always opportune. We find parallels in the energy sector, where smart grids have been developed to store power generated sporadically by small producers and distribute it to individual users based on their (erratic) needs. Learning from smart grids, this research aims to shed light on innovative institutional arrangements promoting the development of an effective cross-jurisdictional construction waste material trading market. Underpinning this research is a mixed-method approach including cross-sectoral learning and a case study encompassing a series of site visits and semi-structured interviews in China’s Greater Bay Area. By comparing the commonalities between electricity and construction waste in terms of production, market, transmission, distribution, and consumption, we elaborate smart grid innovations and their possible applications to construction waste materials trading. Our research contributes to the body of knowledge on waste management, the circular economy, and the sharing economy. It will help establish a cross-jurisdictional waste material trading market in the Greater Bay Area. It also provides useful references to other regions in searching solutions for waste trading/sharing.

Construction and demolition (C&D) waste recycling constitutes an indispensable component in the overall waste management strategy. Unlike the traditional recycling approaches whereby C&D waste is transported to off-site facilities for treatment, construction managers are actively exploring the possibility of on-site recycling where C&D waste is treated directly at source. This study reports the barriers and facilitators of implementing on-site C&D waste recycling by contextualizing it in Hong Kong. It does so by adopting a mixed-method approach combining case study, site visits, and interviews. It is discovered that the barriers include (1) site space constraints, (2) narrow window of opportunity to trade recycled products, (3) vulnerable business case, (4) lack of support from off-site recycling, and (5) lack of government policy support. A series of facilitating measures are also proposed, including (1) developing customized on-site recycling equipment, (2) establishing a demand-supply information-sharing platform, (3) developing more thriving off-site recycling, and (4) providing more government support. This study probes into the real-life on- and off-site waste recycling practices in Hong Kong's prominent C&D management system. It can also provide useful references for others in developing their own C&D waste recycling strategies by rationally deploying on- and off-site recycling., Graphical abstract Unlabelled Image, Highlights • Identified five major barriers to on-site C&D waste recycling in Hong Kong; • Developed four facilitators to promote on-site C&D waste recycling in Hong Kong; • The facilitators discussed may serve as useful reference for other economies.

An overview of advances and progress on the KSTAR plasma control improvement is given. The enhancement of the KSTAR plasma control system (PCS) continues in order to enable implementations of more sophisticated control algorithms and capabilities of integrated controls on magnets, gas, heating and off-normal event handling. Features and functionalities on the generic magnetic controls, kinetic controls and new fault scheme design are added for the operation space expansion, mainly regarding recent achievements of high plasma current up to 1.1 MA for 10 s, high-performance long pulse up to 90 s, and discharges relevant to ITER research. Technical challenges and prospective upgrades in the near future are described.

We develop the compact NMR/MRI device using high temperature superconducting (HTS) wires with the persistent current mode operating. So, the joint techniques between 2G wires are very important issue and many studies have been carried out. Recently, the K JOINS, Inc. has developed successfully the high performance superconducting joints between 2G wires by partial melting diffusion and oxygenation annealing process [1]. In this study, the current bypassing properties in a loop-shaped 2G wire are measured experimentally to develop the permanent current switch (PSC). The current bypassing properties of loop-shaped test coil wound with 2G wire (GdBCO) are evaluated by measured the self-magnetic field due to bypassed current by Hall sensors. The strain gauge was used as heater for persistent current switch, and thermal properties against various thermal inputs were investigated experimentally.

Effect of Cu and powder mixing with Cu-free (Nd, Dy)-Fe-B jet-milled powder on the magnetic properties of sintered magnets was investigated. The coercivity of a magnet prepared from the Cu-free (Nd, Dy)-Fe-B powder was about 10 kOe even though the alloy powder already contained some Dy (3.5 wt%). When small copper powder was blended, however, the coercivity of the magnet increased almost 100%, exhibiting about 20 kOe. On the contrary, the coercivity enhancement was moderate, about 4 kOe, when dysprosium content in the sintered magnet was simply increased to 4.9 wt% by the addition of small 3 powder.

s: Phase Contrast MR Angiography(PC MRA) is excellent MRA technique for measuring the velocity ofvessels in the human body. PC MRA need to at least four images for angiogram reconstruction and it caused longerscan time. Therefore, we used keyhole imaging combined PC MRA to reduce the scan time. However, keyhole imag-ing can lead the erroneous effects as loss of phase information or frequency discontinuous. In this study, we appliedthe keyhole imaging combined 2D PC MRA for improving the temporal resolution and also measured the velocityto evaluate the accuracy of phase information. We used 0.32T MRI scanner(Magfinder II, Scimedix, Korea). Usingthe 2D PC MRA pulse sequence, the vascular images for a human brain targeted on the Superior Sagittal Sinus(SSS)were obtained. We applied tukey window function for keyhole images to minimize the ringing artifact and erroneousfactors that are induced frequency discontinuous and phase information loss. We also applied zero-padded algorithmto peripheral missing k-space lines to compare keyhole imaging results and the artifact power(AP) value was mea-sured on the complex difference images to validate the image quality. Consider as based on our results, heavy imagedistortions and artifacts were shown until using at least 50% keyhole factor. Using above the 50% keyhole factorsare shown well reconstructed and matched for magnitude images and velocity information measurements. In con-clusion, we confirmed the image quality and velocity information of keyhole technique combined 2D PC MRA. Espe-cially, measured velocity information through the keyhole imaging combination was similar to the velocity informationof full sampled k-space image despite of frequency discontinuous and phase information loss in the keyhole imagingreconstruction process. Consequently, the keyhole imaging combined 2D PC MRA will give some clinical usefulnessand advantages as improving the temporal resolution and measuring the velocity information via selecting the appro-priate keyhole factor at low tesla MRI system.Key words: keyhole imaging, PC MRA, velocity measurement, zero-padding

In order to improve the remanence of (Nd, Dy)-Fe-B sintered magnets, we investigated the influence of compaction conditions such as packing density, applied field and green density on the magnetic properties. While the remanence decreased with increasing the packing density and green density, it increased with the increase of the applied field. In addition, XRD analysis revealed that the remanence was enhanced as the degree of powder alignment was improved. The green density was more influential on the remanence than the packing density and applied field.

s: Parallel imaging technique can provide several advantages for a multitude of MRI applications. Especially,in SENSE technique, sensitivity maps were always required in order to determine the reconstruction matrix, there-fore, a number of difference approaches using sensitivity information from coils have been demonstrated to improveof image quality. Moreover, many filtering methods were proposed such as adaptive matched filter and nonlinear dif-fusion technique to optimize the suppression of background noise and to improve of image quality. In this study, weperformed SENSE reconstruction using computer simulations to confirm the most suitable method for the feasibilityof filtering effect and according to changing order of polynomial fit that were applied on variation of spatial resolutionof sensitivity map. The image was obtained at 0.32T(Magfinder II, Genpia, Korea) MRI system using spin-echo pulsesequence(TR/TE = 500/20 ms, FOV = 300 mm, matrix = 128×128, thickness = 8 mm). For the simulation, obtainedimage was multiplied with four linear-array coil sensitivities which were formed of 2D-gaussian distribution and theimage was complex white gaussian noise was added. Image processing was separated to apply two methods whichwere polynomial fitting and filtering according to spatial resolution of sensitivity map and each coil image was sub-sampled corresponding to reduction factor(r-factor) of 2 and 4. The results were compared to mean value of geometyfactor(g-factor) and artifact power(AP) according to r-factor 2 and 4. Our results were represented while changingof spatial resolution of sensitivity map and r-factor, polynomial fit methods were represented the better results com-pared with general filtering methods. Although our result had limitation of computer simulation study instead ofapplying to experiment and coil geometric array such as linear, our method may be useful for determination of optimalsensitivity map in a linear coil array.Key words: SENSE, sensitivity map, polynomial fitting, low pass filtering, spatial resolution

In order to increase the coercivity of (Nd, Dy)-Fe-B sintered magnets without much reduction of remanence, small amount of Dy compounds such as and was mixed with (Nd, Dy)-Fe-B powder. After mixing, the coercivity of (Nd, Dy)-Fe-B sintered magnets apparently increased with the increase of Dy compound in the mixture. Addition of was more effective than for the improvement of coercivity. Reduction of the remanence by the addition of Dy compound, however, was larger than expected mostly due to unresolved coarse Dy compound in the magnet. EPMA analysis revealed that Dy was diffused throughout the grains in the magnet mixed with whereas Dy was rather concentrated around grain boundaries in the magnet mixed with .

Ring forging process is more appropriate for high-length and thin walled ring, because it utilizes the forging press and hence does not require heavy-duty ring rolling mill. Although ring forging process is very simple and economic for facilities, the process is not efficient because of multi-forging-step and low material utilization. An effective ring forging process is developed using a hollow ingot. When a hollow ingot is used with a workpiece, the ingot can be forged into a final ring without multi-stage pre-forging process, such as, cogging, upsetting, and piercing, etc.. Finally it has advantages of the material utilization and process improvement because a few reheating and forging process are not necessary to make workpiece for ring forging. The important design variables are the applied plastic deformation energy to eliminate cast structure and make uniform properties. In this study, the mechanical properties after forging of hollow cast ingot were investigated from the experiment using circumferential sectional model. Also, the effects of process variables were studied by FEM simulation on the basis of thermo-visco-plastic constitutive equation. Applied strain is different at each position in length direction because diameter of hollow ingot is different in length direction. The different strain distribution become into a narrow gap by additional plastic deformation during diameter extension process.

Thermal energy control is a important factor to control properties of large sized product in ingot-forging. Good control of thermal energy helps to increase characteristics and eliminate defects of large cast-forged part, such as large sized forged shell. We have studied about not only large size ring forging process and after heat treatment process by FEM simulation. Changes of temperature and microstructure for forged shell were predicted according to different heat treatment conditions. Therefore, we can choose the proper heat treatment condition by FEA. The sectional properties confirmed by practical experiment and evaluation have presented possibilities of process design by computational analysis.

Transport and magnetization of MgIn 2− x Mn x O 4 polycrystalline pellets (0 x 2 O 4 with Mn results in an increase in electrical resistivity and a decrease in electron concentration. The electrical resistivity increases with decreasing temperature throughout the temperature range and variable-range hopping is observed at low temperatures. The diamagnetic pure MgIn 2 O 4 changes to paramagnetic after doping. The paramagnetism of the doped samples obeys the Curie–Weiss law. The magnetic-field dependence of the magnetization of the doped samples can be well described by the Brillouin function.

In this paper, we analyze the performance of random spreading code-division multiple-access (CDMA) systems with a multicarrier in asynchronous uplink channels. We first derive the probability density function (pdf) of the multiple-access interference (MAI) plus noise and then extend the results to orthogonal frequency division multiplexing (OFDM) with intercarrier interference (ICI) that is caused by a frequency offset. We obtain the pdf of the MAI and the ICI plus noise under Rayleigh and frequency-selective fading as a function of the number of users and the spreading factor, as well as the number of subcarriers and the frequency offset. The bit-error-rate (BER) analysis shows that the power penalty from the frequency offset increases with the system loading. We develop the Gaussian approximation that provides an accurate estimation of the BER with reduced computational complexity comparing to the direct calculations using the pdf.

Gastrodia elata has been cultivated using mycorrizal fungi including Armillaria mellea as an energy source (myco-hetrotrophy) because it is aphyllous and achlorophyllous archid. But the yields of G. elata have been recently decreased owing to the degeneration of spawn tuber arised from successive asexual reproduction. Therefore, this study was carried out to solve this degeneration by seed germination, namely sexual reproduction. The seed germination of G. elata was excellent on the fallen leaves medium of oak tree. The fruetification rate of the capsule of G. elata by artificial pollination was 94.1% and better than natural pollination. The living weight of capsules of G. elata suitable for seeds germination was above 31 mg. The middle-matured seeds and matured seeds of capules were largely germinated, while the immatured seeds was small germinated. The storage temperature of the cropped capsules suitable for a favorable seed germination was and the storage period of it was one month.

Background and Purpose— Experimental evidence has indicated the benefits of simvastatin for the treatment of subarachnoid hemorrhage. Two randomized placebo-controlled pilot trials that used the highest clinically approved dose of simvastatin (80 mg daily) gave positive results despite the fact that a lower dose of simvastatin (40 mg daily) did not improve clinical outcomes. We hypothesized that a high dose of 80 mg of simvastatin daily for 3 weeks would reduce the incidence of delayed ischemic deficits after subarachnoid hemorrhage compared with a lower dose (40 mg of simvastatin daily) and lead to improved clinical outcomes. Methods— The study design was a randomized controlled double-blinded clinical trial. Patients with aneurysmal subarachnoid hemorrhage (presenting within 96 hours of the ictus) from 6 neurosurgical centers were recruited for 3 years. The primary outcome measure was the presence of delayed ischemic deficits, and secondary outcome measures included a modified Rankin disability score at 3 months and an analysis of cost-effectiveness. Results— No difference was observed between the groups treated with the higher dose or the lower dose of simvastatin in the incidence of delayed ischemic deficits (27% versus 24%; odds ratio, 1.2; 95% confidence interval, 0.7–2.0; P =0.586) or in the rate of favorable outcomes (modified Rankin Scale score, 0–2) at 3 months (73% versus 72%; odds ratio, 1.1; 95% confidence interval, 0.6–1.9; P =0.770). Conclusions— High-dose simvastatin treatment should not be prescribed routinely for aneurysmal subarachnoid hemorrhage. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT01077206.

The Karhunen–Loeve Galerkin procedure is a type of Galerkin methods that employs the empirical eigenfunctions of the Karhunen–Loeve decomposition as basis functions. This technique can reduce nonlinear partial differential equations to sets of minimal number of ordinary differential equations by limiting the solution space to the smallest linear subspace that is sufficient to describe the observed phenomena. Previously [1] , it has been shown that one dimensional Burgers equation is reduced to a low dimensional model by this method, which is employed to solve boundary optimal control problems very efficiently. The present paper demonstrates that the Karhunen–Loeve Galerkin procedure can be extended to solve problems of the boundary optimal control of multidimensional Navier–Stokes equations. Since the reduction of modes in the multidimensional case is much larger than that in the one dimensional case, the present technique is found to be more powerful when applied to the control problems of the Navier–Stokes equation than those of the Burgers equation.

The Burgers equation is a simple one-dimensional model of the Navier-Stokes equation. In the present paper, we suggest an efficient method of solving optimal boundary control problems of the Burgers equation, which is practical as well as mathematically rigorous. Our eventual purpose is to extend this technique to the control problems of viscous fluid flows. The present method is based on the Karhunen-Loeve decomposition which is a technique of obtaining empirical eigenfunctions from the experimental or numerical data of a system. Employing these empirical eigenfunctions as basis functions of a Galerkin procedure, one can a priori limit the function space considered to the smallest linear subspace that is sufficient to describe the observed phenomena, and consequently reduce the Burgers equation to a set of ordinary differential equations with a minimum degree of freedom. The resulting low-dimensional model of Burgers equation is shown to simulate the original system almost exactly. The present algorithm is well suited for the problems of control or optimization, where one has to solve the governing equation repeatedly but one can also estimate the approximate solution space based on the range of control variables. The present method of solving boundary control problems of Burgers equation employing the lowdimensional model obtained by the Karhunen-Loeve Galerkin procedure is found to yield accurate results in a very efficient way, when the minimization of the objective function is performed using a conjugate gradient method.

The variety of isotopes in cosmic rays allows us to study different aspects of the processes that cosmic rays undergo between the time they are produced and the time of their arrival in the heliosphere. In this paper, we present measurements of the isotopic ratios [superscript 2]H/[superscript 4]He, [superscript 3]He/[superscript 4]He, [superscript 6]Li/[superscript 7]Li, [superscript 7]Be/([superscript 9]Be+[superscript 10]Be), and [superscript 10]B/[superscript 11]B in the range 0.2-1.4 GeV of kinetic energy per nucleon. The measurements are based on the data collected by the Alpha Magnetic Spectrometer, AMS-01, during the STS-91 flight in 1998 June., United States. Dept. of Energy, Massachusetts Institute of Technology

The Alpha Magnetic Spectrometer (AMS) was flown on the space shuttle Discovery during flight STS-91 (June 1998) in a 51.7 deg orbit at altitudes between 320 and 390 km. A search for antihelium nuclei in the rigidity range 1–140 GV was performed. No antihelium nuclei were detected at any rigidity. An upper limit on the flux ratio of antihelium to helium of < 1.1×10^−6 was obtained. The high energy proton, electron, positron, helium, antiproton and deuterium spectra were accurately measured. For each particle and nuclei two distinct spectra were observed: a higher energy spectrum and a substantial second spectrum. Positrons in the second spectrum were found to be much more abundant than electrons. Tracing particles from the second spectra shows that most of them travel for an extended period of time in the geomagnetic field, and that the positive particles (p and e+) and negative ones (e−) originate from two complementary geographic regions. The second helium spectrum flux over the energy range 0.1–1.2 GeV/nucleon was measured to be (6.3 ± 0.9) × 10^−3(m^2 s sr)^−1. Over 90 percent of the helium flux was determined to be 3He at the 90% confidence level

Numerical simulations and a mean-field analysis of a sandpile model of earthquake aftershocks in 1d, 2d and 3d euclidean lattices determine that the average stress decays in a punctuated fashion after a main shock, with events occurring at characteristic times increasing as a geometrical series with a well-defined multiplicative factor which is a function of the stress corrosion exponent, the stress drop ratio and the degree of dissipation. These results are independent of the discrete nature of the lattice and stem from the interplay between the threshold dynamics and the power law stress relaxation., 5 pages, 6 figures (revtex)