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Fiber Bragg grating sensors (FBG) were embedded into the CF/PPS laminates to demonstrate the monitoring of the press forming of the L-shaped CFRTPs (Carbon Fiber Reinforced Thermoplastics). In-plane strain of the flexion represented a unique change from contact with the flat plate to position of bottom dead center. Residual strains along the FBG are able to evaluate directly, which is mainly caused by cooling part of the press forming process. Moreover a non-axisymmetric strain in the FBG was evaluated at the flexion. Fiber-optic sensing probably become beneficent technology to improve a press forming process of CFRTPs. [ABSTRACT FROM AUTHOR]

Dimpling in the face sheets of honeycomb sandwich structures due to mismatch in the thermal expansion coefficient of the constituent materials, with emphasis on its monitoring and assessment, was studied by utilizing embedded distributed fiber optic sensors. Strain distributions along optical fibers embedded in the face sheet of the sandwich structures were monitored during manufacturing. Based on finite element analysis results, the strain data was interpreted and dimpling monitoring capability was discussed. Simple analytical model to predict the dimple profile and thus assess the dimpling condition from the strain data was also presented and evaluated. [ABSTRACT FROM AUTHOR]

To examine the relevance of concentration of benzalkonium chloride (BAK) on the cornea, we investigated the effects of latanoprost containing BAK alone and in combination with other antiglaucoma drug classes on corneal epithelium in vitro in a cultured rabbit corneal cell line (SIRC) and in vivo , using a corneal resistance device (CRD). [ In vitro ] staten's seruminstitut rabbit corneal cells were exposed to 0.005% latanoprost for 30 s, followed by either phosphate buffered saline (control), 0.1% brimonidine, 0.5% timolol, 1% dorzolamide, or 1% brinzolamide. The number of viable cells was counted at 8, 15, and 30 min. [ In vivo ] Albino rabbits were administered one drop of 0.005% latanoprost, followed 5 min later by one drop of an agent from the in vitro trial. This was repeated every 15 min for a total of three times. The change in corneal barrier function was assessed by measuring the corneal resistance at 2 and 30 min after the final administration. [ In vitro ] At 8 min, the viable cell count in the latanoprost+dorzolamide group was significantly lower than in the control group. At 15 and 30 min, all treatment groups, except the latanoprost+brimonidine group, demonstrated significantly lower viable cell counts than the control group. [ In vivo ] At 2 min after the final eye drop, the latanoprost+timolol group and the latanoprost+brinzolamide group demonstrated significantly lower corneal resistance than did the latanoprost+brimonidine group. No significant difference was observed between the agents at 30 min. In conclusion, when combining latanoprost containing benzalkonium chloride with other classes of antiglaucoma drugs, brimonidine may cause the least corneal damage, and the number of drug administrations may be an important factor. [ABSTRACT FROM AUTHOR]

Highlights: [•] Concentrations of PCDDs/DFs and co-PCBs in some media from crematories were measured as a Japanese follow-up investigation. [•] Dioxin emission factors via flue gas for 2007 were significantly lower than those for 1999. [•] The implementation of dioxin emission standards in Japan has been successful in reducing dioxin emissions from crematoriums. [•] TEQ concentrations of dioxins in bottom ash (mainly bone) were very low and ranged from 0 to 0.042ng-TEQg−1. [•] Fly ash from some facilities with a heat exchanger contained higher dioxins, because of secondary formation of dioxins. [Copyright &y& Elsevier]

Abstract: The authors and Hitachi Cable, Ltd. have recently developed small-diameter optical fiber and its fiber Bragg grating (FBG) sensor for embedment inside a lamina of composite laminates without strength reduction. The outside diameters of the cladding and polyimide coating are 40 and 52μm, respectively. First, a brief summary is presented for applications of small-diameter FBG sensors to damage monitoring in composite structures. Then, we propose a new damage detection system for quantitative evaluation of delamination length in CFRP laminates using Lamb wave sensing. In this system, a piezo-ceramic actuator generates Lamb waves in a CFRP laminate. After the waves propagate in the laminate, transmitted waves are received by an FBG sensor attached on or embedded in the laminate using a newly developed high-speed optical wavelength interrogation system. This system was applied to detect interlaminar delamination in CFRP cross-ply laminates. When the Lamb waves passed through the delamination, the amplitude decreased and a new wave mode appeared. These phenomena could be well simulated using a finite element analysis. From the changes in the amplitude ratio and the arrival time of the new mode depending on the delamination length, it was found that this system could evaluate the delamination length quantitatively. Furthermore, small-diameter FBG sensors were embedded in a double-lap type coupon specimen, and the debonding progress could be evaluated using the wavelet transform. [Copyright &y& Elsevier]

Transverse cracking behavior in high temperature bismaleimide-based carbon fiber reinforced plastics (CFRP) laminates under fatigue loading was observed. Three types of cross-ply laminate, [0/902/0], [02/903/02] and [02/904/02], were tested to study the effect of ply thickness. Damage observation was conducted using two methods. Optical microscopy and soft X-ray radiography were used for edge and internal damage observation, respectively. Variational approach was used to derive the energy release rate associated with transverse cracking. Multiplication of transverse cracks was modeled based on modified Paris-law approach. [Copyright &y& Elsevier]

First, a methodology for observation and modeling of microscopic damage evolution in quasi-isotropic composite laminates is presented. Based on the damage observation using both an optical microscope and a soft X-ray radiography, a damage mechanics analysis is conducted to formulate the stiffness change due to transverse cracking. Then, both energy and stress criteria are combined to provide a valid procedure to predict the transverse crack evolution. The theoretical prediction is found to agree well with the experimental results for the transverse crack density as a function of strain as well as stress–strain curves. Then, another methodology is introduced using two kinds of embedded optical fiber sensors to detect and monitor the transverse crack evolution in composite laminates. One is plastic optical fibers (POF), where the loss in optical power is generated by local deformation of POF due to transverse cracking. The other is fiber Bragg grating (FBG) sensors, where the local strain distribution within the FBG gage length due to transverse cracking alters the power spectrum of the light reflected from the FBG sensors. Embedded optical fiber sensors are found to be a powerful method to detect and monitor the transverse crack evolution in composite laminates. [Copyright &y& Elsevier]

Microscopic damage behavior in quasi-isotropic CFRP laminates with interlaminar-toughened layers under tensile fatigue loading is investigated. Damage observation is conducted using an optical microscope and soft X-ray radiography. The material used is CFRP with interlaminar-toughened layers, T800H/3900-2. The laminate configurations are quasi-isotropic [45/0/−45/90]s, [0/45/−45/90]s and [45/−45/0/90]s to discuss the effect of stacking sequence on microscopic fatigue damages. A damage mechanics analysis is used to obtain the energy release rate for transverse cracking which is correlated to the transverse crack density growth rate. The modified Paris-law analysis proves to be valid for characterization of transverse crack multiplication when the effect of other damage is small. [Copyright &y& Elsevier]

Prediction of the residual state of sandwich structures after impact or indentation loading is important for estimation of their residual properties and for damage detection purposes. An extended foam material model, that takes into account the degradation of elastic modulus during compression and the changed tensile response after compressive damage of the foam material, was constructed based on the Crushable foam material available in ABAQUS. The model was validated by foam core sandwich beam indentation simulation and comparison with experimental data. The extended model could predict the indentation loading and unloading response accurately and provided improved predictions of the residual state. [ABSTRACT FROM AUTHOR]

Our previous study proposed a hierarchical sensing–healing system combining a microvascular self-healing material and a fluid distribution system with local pressure monitoring. This study demonstrated the hierarchical system in a structural composite element. First, the overview of the system was given for the sake of the completeness and the technical merits were discussed. Next, double cantilever beam (DCB) tests were conducted to confirm the system’s feasibility. Finally, the sensing/healing performance was evaluated using a compression after impact (CAI) test of a composite stiffened panel. Even though further optimization of the healing resin and the microvascular channel network is necessary, the hierarchical system restored the structural stability of the damaged panel and recovered the degraded strength, confirming the high potential of the hierarchical system under practical conditions. [ABSTRACT FROM AUTHOR]

Carbon fiber reinforced plastic (CFRP) pipes are key structural elements for observation satellites. Significant radial tensile stress, however, is induced in thick-walled CFRP pipes during curing, leading to premature delamination failure and performance degradation. This study proposes a residual stress-reduction method to develop a thick-walled, crack-free CFRP pipe. We began by addressing the effect of stacking sequence on residual stress using theoretical and numerical analyses. The result led us to a novel stress-reduction method where circumferentially stiff 90° layers are gathered close to the inner surface. Two pipes were then manufactured: asymmetric and symmetric lay-ups. The radial strain development was evaluated using our fiber-optic-based monitoring system to confirm the effectiveness of the method. Finally, a thick-walled pipe was fabricated. No failure was observed during curing, successfully demonstrating a thick-walled, crack-free CFRP pipe. Additionally, a low-temperature test was conducted, and the pipe endured down to −120 °C, demonstrating a 140 °C lower operation temperature than that of a conventional symmetric pipe, which is highly beneficial for space applications. [ABSTRACT FROM AUTHOR]

Abstract: An activated carbon (AC) containing a high concentration (374mgg−1) of Fe was prepared by carbonization of an ion-exchange resin. To examine its chemical reactivity as a catalyst to decompose 2,2′,4,4′,5,5′-hexachlorobiphenyl (PCB-153), the decomposition parameters of temperature and time were varied under air or N2. Decomposition at 350°C was achieved within 15min under air and 30min under N2, and the efficiency of PCB-153 decomposition was 99.7% and 98.0%, respectively. An analysis of inorganic chloride ions revealed that PCB-153 was mineralized effectively during the decomposition. The Brunauer–Emmett–Teller (BET) surface area and pore volume of the AC were measured to assess the adsorption capacity before and after the decomposition. The differences between decomposition under air and N2 reflected the differences in the BET surface and pore volume measurements. A decomposition pathway was postulated, and the reactive characteristics of chlorine atoms loaded on the benzene rings followed the order of para > meta > ortho, which agrees with the calculated results from a density functional theory study. [Copyright &y& Elsevier]

Abstract: This study examined the effects of multi-walled carbon nanotube (CNT) dispersion on stress–strain behaviors of poly-ether–ether–ketone (PEEK) at room temperature. Tensile test specimens containing 9wt.% and 15wt.% of CNT were fabricated using injection molding. Results of focused ion beam (FIB) observations show that many CNTs in the CNT/PEEK composite are aligned longitudinally. Although the PEEK stress–strain behavior is almost linear up to 1.5% strain, the stress–strain curves of CNT/PEEK composites exhibit considerable nonlinear and hysteretic behaviors from extremely low strain (<0.1%) under both tensile and compressive loading. The experimental results suggest that the viscoelastic deformation effects on nonlinear and hysteresis behaviors are not strong below 1.5% strain. Presumably, the slippage at the CNT–PEEK interface occurs with increasing applied stress because of poor interfacial load-transfer capability. [ABSTRACT FROM AUTHOR]

Abstract: In this study, poly(ether ether ketone)/carbon nanotubes (CNTs) composites were fabricated by using multi-walled carbon nanotubes (MWNTs) as fillers. Tensile properties of nanocomposites at below and above the glass transition temperature of pure poly(ether ether ketone) (around 145°C) were studied. At room temperature, the addition of 15wt% MWNTs increased the tensile modulus (at 0.1–0.3% strain) by 89% and the yield stress by 19%. Above the glass transition temperature, they increased by 163% and 42%, respectively. The experimental results showed that the reinforcement of MWNTs is effective for poly(ether ether ketone), and is more effective at high temperature than at room temperature. Dynamic mechanical thermal analyzer results showed an increase in storage modulus with increasing MWNTs loading fraction at both below and above the glass transition temperature. Scanning electron microscope and transmission electron microscope images showed that the MWNTs were well dispersed in the polymer matrix. The information regarding composite deformation mechanisms was provided by in situ transmission electron microscopy studies, and also interfacial bonding between the carbon nanotubes and polymer matrix was qualitatively studied. [Copyright &y& Elsevier]

Abstract: We investigated the reactivity between modified activated carbon and pentachlorobenzene (P5CBz) to better understand how the nature of activated carbon affects the decomposition of chlorinated aromatics. To modify and control the overall characteristics, activated carbon was treated with either nitric acid or hydrogen peroxide. According to ESR, the number of free radicals on the activated carbon was found to increase in response to a treatment in 70% nitric acid at 70°C for 24h. Additionally, certain functional groups, such as carboxyl and hydroxyl groups, are believed to have formed on the surface of the activated carbon as indicated by the results of FT-IR and XPS. The catalytic decomposition experiments involving P5CBz were conducted using a pulse-type, packed-bed reactor. Using the activated carbon that was previously treated with nitric acid for 24h, P5CBz molecules were completely decomposed at a temperature of 350°C, irrespective of either an air or nitrogen atmosphere. The mechanism of decomposition of P5CBz depends on the kind of oxygen functional group and free radicals present. [Copyright &y& Elsevier]

Abstract: This paper proposes a numerical simulation of interlaminar damage propagation in FRP laminates under transverse loading, using the finite element method. First, we conducted drop-weight impact tests on CFRP cross-ply laminates. A ply crack was generated at the center of the lowermost ply, and then a butterfly-shaped interlaminar delamination was propagated at the 90/0 ply interface. Based on these experimental observations, we present a numerical simulation of interlaminar damage propagation, using a cohesive zone model to address the energy-based criterion for damage propagation. This simulation can address the interlaminar delamination with high accuracy by locating a fine mesh near the damage process zone, while maintaining computational efficiency with the use of automatic mesh generation. The simulated results of interlaminar delamination agreed well with the experiment results. Moreover, we demonstrated that the proposed method reduces the computational cost of the simulation. [Copyright &y& Elsevier]

Abstract: The process of destroying polychlorinated biphenyls (PCBs) generates exhaust gases that contain low quantities of PCBs, which cannot be disposed of easily. Activated carbon (AC) can be used to adsorb residual PCBs after disposal of high-level PCBs. We examined the chemical reactivity of AC-supported iron as a catalyst to decompose PCB-153, and varied three decomposition parameters (temperature, time and iron concentration) under an atmosphere of either air or N2. We measured the Brunauer–Emmett–Teller (BET) surface area and pore volume of AC to assess the adsorption capacity of AC before and after decomposition. At low temperatures the adsorption process was more important than the decomposition process. The decomposition process was completed within 30 and 60min under air and N2, respectively. The efficiency of PCB-153 decomposition at 350°C for 120min was ∼100.0% and 97.1% under air and N2, respectively. Analysis of inorganic chloride ions revealed that PCB-153 was effectively destroyed during decomposition. The differences between decomposition under air and N2 reflected differences in BET surface and pore volume. [Copyright &y& Elsevier]

Abstract: This paper examines the stress distribution around a fiber break in alumina fiber-reinforced aluminum matrix (Al2O3/Al) composites using finite element analysis and predicts their tensile strengths using tensile failure simulations. In particular, we discuss the effect of matrix hardening on the tensile failure of the Al2O3/Al composites. First, we clarify the differences in the stress distribution around a fiber break between an elastic–perfect plastic matrix and an elastic–plastic hardening matrix using finite element analysis. Second, the procedures for simulating fiber damage evolution in the Al2O3/Al composites are presented. The simulation incorporates the analytical solution to the stress distribution of a broken fiber in the spring element model for the stress analysis of the whole composite. Finally, we conduct Monte Carlo simulations of fiber damage evolution to predict the tensile strength of the Al2O3/Al composites. Coupled with a size-scaling analysis, the simulated results express the size effect on the strengths of the composites seen in experimental results. [Copyright &y& Elsevier]

Thermal fatigue tests were conducted on high temperature resistant carbon fiber reinforced plastics cross-ply laminates to evaluate microscopic damage progress which affects macroscopic mechanical behavior of the laminates. Materials system used were thermoplastic polyetheretherketone based, AS4/PEEK and thermoset bismaleimide based, G40-800/5260. Several types of laminate configuration were used to clarify the effect of ply thickness on microscopic damage progress. Microscopic damages were observed using optical microscopy and soft X-ray radiography. Energy release rate associated with transverse cracking was calculated using variational analysis. The modified Paris law was used to predict transverse cracking. From comparison to mechanical fatigue test results, it is clarified that transverse crack accumulation rate was larger under thermal fatigue loading at same energy release rate range due to the dependence of the fracture toughness on temperature. [Copyright &y& Elsevier]

Though some researchers have already reported polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) concentration in flue gas at inlet and outlet of wet scrubber (WS) in municipal solid waste incinerator (MSWI), there are few investigations about scrubbing water, suspended solid (SS) in scrubbing water and sludge. In order to understand the behavior of PCDD/Fs in WS and to make clear the effect of the residence time of scrubbing water in WS on the PCDD/Fs concentrations in scrubbing water and at the outlet gas of WS, PCDD/Fs, polychlorinated biphenyls (PCBs), chlorobenzenes (CBzs) and chlorophenols (CPs) concentrations in various media around WS were investigated at two MSWIs. PCDD/Fs concentration in flue gas at outlet of WS was higher than that at inlet of WS in both MSWIs. In WS A, it was observed that the homologue profiles changed considerably and the concentration of higher chlorinated compounds such as H7CDD/Fs and O8CDD/F increased remarkably at outlet gas of WS A. Only CPs were transferred from flue gas to scrubbing water in both WSs. As for scrubbing water, a large amount of their chlorinated aromatic compounds was detected in SS particles. According to the results, it was found that not only flue gas conditions but also operational and structural conditions in WS had great influence on minimizing the memory of chlorinated aromatic compounds in WS. [Copyright &y& Elsevier]

The organic contaminants in municipal solid waste incineration (MSWI) fly ash, including chlorinated aromatic compounds and polycyclic aromatic hydrocarbons, have high toxicity and a potential negative impact on the environment. An effective and low energy consumption technique to remove the organic contaminants from MSWI fly ash is required urgently. Organic contaminants, such as chlorobenzenes (CBzs), in MSWI fly ash are known to become enriched in the unburnt carbon (UC) fraction. It is proposed that removal of UC from fly ash will result in the effective removal of most organic micropollutants. In this research, we use a technique of surfactant-assisted column flotation to decontaminate MSWI fly ash by removal of the CBzs-enriched UC from MSWI fly ash. We find that 39.8% of CBzs can be removed from fresh MSWI fly ash with 61.7% UC removal efficiency, whereas only 33.2% of CBzs can be removed from weathered MSWI fly ash with a low UC removal efficiency of 33.7%. By adding a mixture of two kinds of surfactants: sorbitan mono-oleate and polyoxyethylene (20) sorbitan mono-oleate to the weathered fly ash, 47.0% of CBzs were removed at the hydrophile lipophile balance value of 13.5, while the UC removal efficiency increased to 49.0%. The results show that surfactants can enhance CBzs and UC removal efficiencies during the column flotation process. Higher CBzs and UC removal efficiencies can be expected by further optimizing the conditions of surfactant-assisted column flotation. [Copyright &y& Elsevier]

Unburned carbon (UC) is the major source of organic contaminants in municipal solid waste (MSW) fly ash. So most organic contaminants can be removed by the removal of the UC from the MSW fly ash. In this paper, we first used a technique of column flotation to remove UC from MSW fly ash. The influences of column flotation parameters on the recovery efficiency of UC were systematically studied. It was found that the UC recovery efficiency was greatly influenced by the gas flow rate, pH value, collector kerosene''s concentration and the types of fly ash. By optimizing the above parameters, we have successfully removed 61.2% of the UC from MSW fly ash having 5.24% UC content. The removal mechanism was well accounted for the kinetic theory of column flotation and surface-chemistry theory. The results indicate that the column flotation technique is effective in removing the UC from MSW fly ash, and show that there is a strong possibility for practical application of this technique in removing the organic contaminants from MSW fly ash. [Copyright &y& Elsevier]

One of the difficulties in composite structural application is joining components. A T-joint is a critical component in aircraft structures that transfers loads between vertical and horizontal panels. However, in T-joints, a critical concern is that cracks occur in the deltoid and immediately propagate along the flange-skin interface. Therefore, introducing crack arrest features at the flange-skin interface is effective in improving the damage tolerance of T-joints. This study begins by investigating the crack propagation mode at the flange-skin interface using finite element analysis and then proposes an appropriate crack arresting mechanism using interlocking fiber features that we have been studying. The effectiveness of the crack arrester in T-joints is evaluated by pull-up tests. The specimens with the arrester showed totally different failure progress and much higher energy absorption capability as compared to the specimens without the arrester. Some important findings on the efficient arrester arrangement and configuration were also obtained. [ABSTRACT FROM AUTHOR]

The decomposition efficiency of polychlorinated biphenyls (PCBs) was determined using elemental iron (Fe) and three iron (hydr)oxides, i.e., α-Fe 2 O 3 , Fe 3 O 4 , and α-FeOOH, as catalysts. The experiments were performed using four distinct PCB congeners (PCB-209, PCB-153, and the coplanar PCB-167 and PCB-77) at temperatures ranging from 180 °C to 380 °C and under an inert, oxidizing or reducing atmosphere composed of N 2 , N 2 + O 2 , or N 2 + H 2 . From these three options N 2 showed to provide the best reaction atmosphere. Among the iron compounds tested, Fe 3 O 4 showed the highest activity for decomposing PCBs. The decomposition efficiencies of PCB-209, PCB-167, PCB-153, and PCB-77 by Fe 3 O 4 in an N 2 atmosphere at 230 °C were 88.5%, 82.5%, 69.9%, and 66.4%, respectively. Other inorganic chlorine (Cl) products which were measured by the amount of inorganic Cl ions represented 82.5% and 76.1% of the reaction products, showing that ring cleavage of PCBs was the main elimination process. Moreover, the dechlorination did not require a particular hydrogen donor. We used X-ray photoelectron spectroscopy to analyze the elemental distribution at the catalyst’s surface. The O/Fe ratio influenced upon the decomposition efficiency of PCBs: the lower this ratio, the higher the decomposition efficiency. X-ray absorption near edge structure spectra showed that α-Fe 2 O 3 effectively worked as a catalyst, while Fe 3 O 4 and α-FeOOH were consumed as reactants, as their final state is different from their initial state. Finally, a decomposition pathway was postulated in which the Cl atoms in ortho -positions were more difficult to eliminate than those in the para - or meta -positions. [ABSTRACT FROM AUTHOR]

Abstract: This study examined the nanoscopic damage progression of aligned multi-walled carbon nanotubes (CNT)/epoxy composites under tensile loading using transmission electron microscopy (TEM). Aligned CNT/epoxy composite films (30μm thickness) were processed using a forest-drawn aligned CNT sheet and hot-melt prepreg method. Four film specimens, respectively subjected to tensile stress of 0MPa, 45MPa, 95MPa and 110MPa, were prepared. After tensile loading, each specimen was machined until the thickness became about 100nm using a focused ion beam milling machine (FIB) for TEM observations. Damage of three kinds, i.e. CNT break derived from the disordered CNT structures around metallic catalyst, sword-in-sheath type CNT break, and several patterns of interfacial debonding, was observed clearly. The broken CNTs and interfacial debonding per unit area were counted from TEM photographs. Results show that broken CNTs and interface debonding increased considerably at 95–110MPa, which suggests multiple fracture of CNT under tensile loading. The CNT length at the failure stress (110MPa) was approximately 45μm. Estimated values from the strength of CNTs resemble those from macroscopic stress–strain behavior. [Copyright &y& Elsevier]

Abstract: This paper presents a proposal of a simple and easy method to evaluate the interfacial shear strength (IFSS) of CNT-dispersed polymer composites. An individual multi-wall carbon nanotube (MWNT) was pulled out from a MWNT-dispersed/PEEK composite using a nano-pullout testing system installed in an SEM. The tensile load was measured using the elastic deformation of an AFM cantilever. The pull-out length was controlled by making a through-thickness hole near the specimen edge using a focused ion beam (FIB) system. The IFSS of a MWNT/PEEK composite was measured as 3.5–14MPa, which agrees with the IFSS estimated from the macroscopic stress–strain behavior of the MWNT/PEEK composites. [Copyright &y& Elsevier]

Abstract: We investigated whether polychlorinated biphenyls (PCBs) and water could be simultaneously removed from river sediment by solvent extraction using liquefied dimethyl ether (DME) as the extractant. DME exists in a gaseous state at normal temperature and pressure and can dissolve organic substances and some amount of water; therefore, liquefied DME under moderate pressure (0.6–0.8MPa) at room temperature can be effectively used to extract PCBs and water from contaminated sediment, and it can be recovered from the extract and reused easily. First, we evaluated the PCB and water extraction characteristics of DME from contaminated sediment. We found that 99% of PCBs and 97% of water were simultaneously extracted from the sediment using liquefied DME at an extraction time of 4320s and a liquefied DME/sediment ratio of 60mLg−1. The extraction rate of PCBs and water was expressed in terms of a pseudo-first-order reaction rate. Second, we estimated the amount of DME that was recovered after extraction. We found that 91–92% of DME could be recovered. In other words, approximately 5–10% of DME was lost during extraction and recovery. It is necessary to optimize this process in order to recover DME efficiently. The extraction efficiency of the recovered DME is similar to that of the pure DME. From the results, we conclude that solvent extraction using liquefied DME is suitable for extracting PCBs and water from contaminated sediment. [Copyright &y& Elsevier]

Abstract: In this study, we propose a “washing–calcination–conversion of washed fly ash into cement material with bottom ash” (WCCB) system to reduce the amount of fly ash that must be specially treated so it can be used as raw cement material. Calcium hydroxide (Ca(OH)2) is widely used in air-pollution control devices of incinerators while sodium bicarbonate (NaHCO3) is not. We conducted single-, double-, and triple-washing experiments to compare the washing characteristics of two types of fly ash. Unlike NaHCO3 fly ash, Ca(OH)2 fly ash has almost twice as much washed residue and almost 2.5 times more chlorine after the same washing procedure. After washing once, the washing frequency is also important for NaHCO3 fly ash, while the mixing time and liquid/solid ratio are more critical for Ca(OH)2 fly ash. The use of NaHCO3 is more suitable for the WCCB system. [Copyright &y& Elsevier]

Only limited information on the chemical forms of copper in municipal solid waste incinerator (MSWI) fly ash is available in the literature. Therefore, we performed in situ X-ray absorption near-edge spectroscopy (XANES) experiments involving two types of real fly ash to confirm the behavior of copper in fly ash at secondary formation temperatures for polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). CuCl2 ·3Cu(OH)2 was detected in both fly ash types before heating experiments. Cupric compounds in real fly ash were reduced to cuprous compounds or elemental copper at approximately 200°C. The changes in the Cu XANES spectra observed for the two fly ash samples were similar to those observed previously. We also examined the behavior of copper in model fly ash using SiO2 to investigate the effect of supporting materials and copper content in fly ash on the dynamic changes of copper and amount of dioxins generated. There was little difference between the use of boron nitride (BN) and SiO2 as a supporting material. The formation mechanisms of PCDDs and PCDFs in both of the model fly ash types were basically the same. Thus, we conclude that the dynamic change of copper in MSWI fly ash during heating is a commonly observed feature, and no simple relationship between the composition of fly ash and the amount of PCDD/PCDF generated or dynamic change of copper is apparent. The dynamic change of copper explained the generated amount and homologue distribution of PCDDs and PCDFs. [Copyright &y& Elsevier]

Abstract: Dioxin concentrations from municipal waste incinerators in Japan and elsewhere often show low concentrations that comply with legal limits (in this paper, the term “dioxin” designates WHO-TEQ: PCDD/Fs+dioxin-like PCB). However, such data is usually generated under normal steady state operational conditions, and there has been little investigation of releases occurring during startup and shutdown. It is important, therefore, to ascertain quantitatively emissions in an unsteady state (startup and shutdown) in order to correctly evaluate the relationship between emissions from a facility and the surrounding environment. The present study aimed to examine dioxin emissions of a continuously operated incinerator at startup and shutdown, and estimating the time period of greatest emission, and the processes causing dioxin generation. The startup process was divided into five stages and the shutdown into two; at each stage, dioxins in the flue gas were measured at the boiler outlet and the stack. From the concentration of dioxins and the flue gas volume at each stage, the amount of dioxins at startup and shutdown were calculated, and these were compared with that under steady state conditions. Dioxin concentration at the stack under steady state conditions was a very low level, while those at startup and shutdown were higher. In the case where dioxin concentration under a steady state is a low level like in this study, it is indicated that the total annual dioxin emission from a facility could be attributed to the startup periods. [Copyright &y& Elsevier]

Abstract: A limited amount of information exists regarding the relationship between the chemical form of copper and the formation of chlorinated aromatics in fly ash. To understand the effects of the various forms of copper on the formation of chlorinated aromatics in real fly ash, we determined the chemical forms of copper present in various types of real fly ash using X-ray absorption near edge structure (XANES) and evaluated the relationship between the chemical forms of copper and the formation of chlorinated aromatics. Copper chloride hydroxide (CuCl2 ·3Cu(OH)2) and cuprous chloride (CuCl) were the predominant copper species found in real fly ash. Although pure cupric chloride (CuCl2) is known to be the most active catalyst for the formation of chlorinated aromatics under experimental conditions with synthetic fly ash, CuCl2 was not found in every real fly ash sample. The amount of copper chloride hydroxide was positively correlated with the formation of chlorinated aromatics in real fly ash and is, consequently, considered to be one of the key species involved in the formation of chlorinated aromatics. [Copyright &y& Elsevier]

Mitochondrial DNA 5178 adenine/cytosine (mt5178 A/C) polymorphism is one of the longevity-associated mitochondrial DNA polymorphisms. The frequency of the mt5178A genotype is significantly higher in Japanese centenarians than in the general population. We previously reported that serum high-density lipoprotein cholesterol levels were significantly higher in men with mt5178A than in those with mt5178C. However, this significant difference disappeared after adjusting for drinking frequency. To investigate the interaction between mt5178 A/C polymorphism and habitual drinking on serum lipid levels, we performed an association study in 321 healthy middle-aged Japanese men. Interaction between mt5178 A/C polymorphism and daily drinking on serum triglyceride (TG) levels was observed (P=0.019). Moreover, interaction between mt5178 A/C polymorphism and cigarette consumption on serum TG levels was also observed (P=0.022). Multiple regression analysis showed that, in men with mt5178A, daily drinking decreased TG levels (P=0.025), and cigarette consumption increased TG levels (P<0.001), while in men with mt5178C, the effects of daily drinking and cigarette consumption on TG levels were unclear. No interaction was observed on other lipid levels. Longevity-associated mitochondrial DNA 5178 A/C polymorphism thus influences the effects of daily drinking and cigarette consumption on TG levels in middle-aged Japanese men. [Copyright &y& Elsevier]

Mitochondrial DNA 5178 adenine/cytosine (mt5178 A/C) polymorphism was reported to be associated with longevity and susceptibility to adult-onset diseases in Japanese. To examine whether mt5178 A/C genotypes are associated with serum protein fraction profiles, we genotyped 461 healthy Japanese individuals, and studied the relationship of mt5178 A/C genotypes to both proportion and levels of serum protein fraction. The mt5178 A/C was genotyped using polymerase chain reaction-restriction fragment length polymorphism method. The alpha-1, alpha-2, and beta globulin proportions in females carrying mt5178A were significantly higher than those in females carrying mt5178C (P=0.002, 0.006, and 0.008, respectively). Moreover, the alpha-1, alpha-2, and beta globulin levels in females carrying mt5178A were significantly higher than those in females carrying mt5178C (P=0.001, 0.002, 0.018, respectively). This difference in globulin fraction level between the two genotypes was more evident in premenopausal females than in postmenopausal females. However, no such difference was found in males. These results provide the first evidence that the mt5178 A/C polymorphism may influence the serum protein fraction levels of the healthy Japanese women. [Copyright &y& Elsevier]

Small-diameter fiber Bragg grating (FBG) sensors, of outside diameter 52 μm, have been developed by the authors and Hitachi Cable Ltd. for embedding inside a laminate without deterioration of the mechanical properties of the composite laminate. In this research, the small-diameter FBG sensor was embedded in the 0° ply of a CFRP cross-ply laminate for the detection of transverse cracks in the 90° ply. The reflection spectra from the FBG sensor were obtained at various tensile stresses. As a result of damage, the spectrum became broad and had some peaks with increase in the transverse crack density. Furthermore, theoretical calculation reproduced the change in the spectrum very well. These results show that small-diameter FBG sensors have the potential to detect the occurrence of transverse cracks through the change in the form of the spectrum, and to evaluate the transverse crack density quantitatively by the spectrum width. [Copyright &y& Elsevier]