Oc Values Research Articles

The off-site transport of pesticide loads from two land uses in relation to hydrological events in the Mt. Lofty Ranges, South Australia

Abstract In the Mediterranean climate of this study the growing period (and hence spraying period) for horticultural crops usually occurs from late spring to summer (i.e. October–March). However, runoff predominantly occurs in winter (late April–October) since there is insufficient rain in the spring and summer period for runoff to occur. It is therefore important to establish the runoff potential of pesticide, despite the long contact time with soil. We studied the distribution of the loads transported during individual runoff events, and the proportion of total annual load transported in each event over three seasons. Some insecticides and fungicides (pirimicarb, procymidone, carbaryl, fenarimol and penconazole) transported off-site from and apple and cherry orchard over a period of 30 months showed a strong association between peak pesticide load and peak flow during individual flow events. Others (particularly chlorpyrifos) however showed no obvious relationship between flow and load transported off-site. Throughout the year certain pesticides demonstrated behaviour characteristic of those chemicals that move in the first flush of drainage water in the season. This was particularly evident for pirimicarb, bupirimate, carbaryl and fenarimol, which all have K OC values K OC values ≥1500 L/kg. Generally, the total amount of pesticide moving off-site from both orchards was R 2 = 0.48, n = 26). The results from this study have implications for the development of management strategies to minimise pesticide transport to waterways.

Development of DA-type polymers with phthalimide derivatives as electron withdrawing units and a promising strategy for the enhancement of photovoltaic properties

We report on two push–pull type polymer semiconductors involving phthalimide derivatives as electron withdrawing units. The solubility and energy level of phthalimide could be easily controlled by introducing various functional groups in its nitrogen site. Additionally, the V OC value of polymer semiconductor materials with phthalimide as an electron withdrawing unit could be efficiently enhanced because of the low HOMO energy level of phthalimide. Nevertheless, there are just a few of studies regarding the use of phthalimide in OPVs. In this study, we synthesized two photovoltaic polymer materials based on phthalimide with high V OC value, PFTPT and PCTPT. Between the two polymers, PCTPT/PC 71BM-based photovoltaic cell afforded the best PCE value of 1.4% ( V OC=0.94 V, J SC=4.41 mA/cm 2, FF=0.33) under 100 mW/cm 2 irradiation. In addition, a promising strategy for the development of high performance photovoltaic polymers with phthalimide derivatives as electron withdrawing units was investigated.

Sorption of organic contaminants by Oxford Clay and Mercia Mudstone landfill liners

Abstract This study provides an evaluation of the sorption capacity of two contrasting mineral liners or barriers widely used in the UK for a range of organic contaminants of varying hydrophobicity commonly found in landfill leachate. Batch tests (involving toluene, trichlorobenzene, trichloroethene and naphthalene) showed that the sorption capacity of Oxford Clay was not only significantly greater than that of Mercia Mudstone, but was also greater than the sorption capacity of many soils or clays reported in the literature. The organic carbon normalized sorption coefficients ( K oc ) for Mercia Mudstone were comparable with both published and empirically derived K oc values, but the K oc for Oxford Clay was underestimated by literature values by several orders of magnitude. Retardation of these contaminants by Oxford Clay was also under-predicted by estimates based solely on organic carbon content. Amorphous organic matter (the main component of the organic matter in the Oxford Clay as characterized using ‘coal petrography’ methods) was believed to be responsible for the elevated sorption capacity of the Oxford Clay liner. Sorption coefficients were reduced in the presence of dissolved organic carbon in leachate, suggesting that published K oc values derived in synthetic groundwater may overestimate the sorption capacity in landfill scenarios. Sorption coefficients and K oc – K ow correlations determined in this study can be used for modelling organic contaminant sorption in Oxford Clay and Mercia Mudstone liners as part of landfill risk assessments in the absence of site-specific data, in particular for Oxford Clay, for which published correlations were shown to be too conservative. For other types of clay liner material, the cautious approach would be to determine site-specific sorption coefficients following characterization of the organic carbon. Further research is needed into the effects of leachate dissolved organic carbon and the composition of clay liner organic carbon on sorption of hydrophobic organic compounds.

P2-300 Effects of antihypertensive drug treatments on bone turnover in elderly men: a cross-sectional analysis of the Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) study

IntroductionPrevious studies have found that some antihypertensive drugs may lower fracture risk. However, the impact of antihypertensive drugs on bone metabolism is not entirely clear. We examined how antihypertensive drugs...

Laser fired contacts applied to the rear surface of heterojunction silicon solar cells

In this work, we fabricate heterojunction silicon solar cells on p-type substrates whose rear surface configuration is based on dielectric passivation and laser fired contacts (LFC cells). This is an alternative to boron-doped amorphous silicon film, with which we also fabricate solar cells for direct comparison (HJ cells). As substrates, 3.5 and 0.8 Ω cm p-type double-side polished FZ c-Si wafers are used. Regarding surface passivation for highly doped substrates, LFC configuration has some advantage due to the higher difficulty in creating an efficient amorphous back surface field. Additionally, those substrates are also more advantageous in terms of carrier injection when the rear surface is locally contacted. Thus LFC cells made on 0.8 Ω cm substrates reach V oc values up to 680 mV, in the same range as that of their HJ cell counterpart, with better FF demonstrating that LFC configuration is a feasible alternative for highly doped substrates. Focusing on the impact of the distance between rear contacts on cell performance, we found a trade-off between open circuit voltage V oc and fill factor FF. Finally electroluminescence characterization and the dependence of V oc on pitch, modeled by Fischer's equation, indicate that the depassivated area due to the laser processing of the contacts is bigger than the contacted area.

Effect of structural composition of humic acids on the sorption of a branched nonylphenol isomer

By using dialysis equilibrium experiments, the sorption of a branched nonylphenol isomer [4-(1-ethyl-1,3-dimethylpentyl)-phenol] (NP111) on various humic acids (HAs) isolated from river sediments and two reference HAs was studied. The HAs were characterized by solid-state 13C direct polarization/magic angle spinning nuclear magnetic resonance ( 13C DP/MAS NMR) spectroscopy. Sorption isotherms of NP111 on HAs were described by a linear model. The organic carbon-normalized sorption coefficient ( K OC) ranged from 2.3 × 10 3 to 1.5 × 10 4 L kg −1. Interestingly, a clear correlation between K OC value and alkyl C content was observed, indicating that the aliphaticity of HAs markedly dominates the sorption of NP111. These new mechanistic insights about the NP111 sorption indicate that the fate of nonylphenols in soil or sediment depends not only on the content of HA, but also on its structural composition.

Characterization of PM10 and PM2.5 source profiles for resuspended road dust collected using mobile sampling methodology

Abstract A new sampling method using a mobile sampling system was developed to sample resuspended road dust on a paved road. To calculate the net mass concentration of resuspended road dust in the dust sample collected behind the front tire of the mobile sampling system, a background subtraction method was employed. The ratio of the PM 2.5 concentration to the PM 10 concentration in resuspended road dust ranged from 0.25 to 0.40, depending upon the sampling sites, which appears to be a function of traffic characteristics, land use, and so forth. The results of chemical analysis of PM samples demonstrated that specific source profiles for resuspended road dust exist according to sampling sites as well as particle size range. It is likely that, particularly in the case of Al, Ca, Fe, and OC, there exists a relatively small or approximately equal magnitude of dependence of sampling sites on the mass percentage of elements in the sampled PM compared with that of the particle size range. In view of the dependence of the Zn mass percentage and Cu/Sb on the average hourly traffic, it is clear that as traffic volume increases, tire wear and brake wear increase, and, accordingly, the amount of tire wear dust and brake wear dust deposited on paved roads increases. It turned out that OC and EC values do not change appreciably with the average hourly traffic. Nonetheless, it was noted that the OC values of PM coarse are two or three times larger than those of PM fine, showing a clear dependence of OC on the particle size range. In the case of EC, however, no clear dependence of EC on the particle size range was found.

Impact of De-Ashing Humic Acid and Humin on Organic Matter Structural Properties and Sorption Mechanisms of Phenanthrene

Organic matter-mineral interactions greatly affect the fate of hydrophobic organic compounds (HOCs) in the environment. In the present study, the impact of organic matter-mineral interaction on sorption of phenanthrene (PHE) by the original and de-ashed humic acids (HAs) and humin (HM) was examined. After de-ashing treatment, the overall polarity of organic matter in HAs and HM consistently decreased. Differently, the surface polarity of HAs increased but that of HM decreased. No correlation between K(oc) values of PHE by all tested sorbents and their bulk polarity was observed due to inaccessibility of a portion of interior sorption domains. The inaccessibility of interior sorption domains in HAs and HM was partly due to the crystalline structure in organic matter as indicated by differential scanning calorimetric (DSC) and ¹³C NMR data and the interference from minerals. A good correlation between surface polarity of the original and de-ashed HAs and HMs and their K(oc) values for PHE indicated its importance in HOC sorption. Dissimilar changes in surface polarity of HAs and HM after de-ashing treatment can be ascribed to the distinct interactions between organic matter and minerals. The solid-state ¹³C NMR, XPS, and elemental composition data of all tested sorbents revealed that a larger fraction of O atoms in HAs were involved in organic matter-mineral interaction as compared to HM. Results of this work highlight the importance of soil organic matter (SOM)-mineral interactions, surface polarity, and microscaled domain arrangement of SOM in HOC sorption.

Sorption of chlorinated solvents and degradation products on natural clayey tills

The sorption of chlorinated solvents and degradation products on seven natural clayey till samples from three contaminated sites was investigated by laboratory batch experiments in order to obtain reliable sorption coefficients ( K d values). The sorption isotherms for all compounds were nearly linear, but fitted by Freundlich isotherms slightly better over the entire concentration range. For chloroethylenes, tetrachloroethylene (PCE) was most strongly sorbed to the clayey till samples ( K d = 0.84–2.45 L kg −1), followed by trichloroethylene (TCE, K d = 0.62–0.96 L kg −1), cis-dichloroethylene (cis-DCE, K d = 0.17–0.82 L kg −1) and vinyl chloride (VC, K d = 0.12–0.36 L kg −1). For chloroethanes, 1,1,1-trichloroethane (1,1,1-TCA) was most strongly sorbed ( K d = 0.2–0.45 L kg −1), followed by 1,1-dichloroethane (1,1-DCA, K d = 0.16–0.24 L kg −1) and chloroethane (CA, K d = 0.12–0.18 L kg −1). This is consistent with the order of hydrophobicity of the compounds. The octanol–water coefficient (log K ow ) correlated slightly better with log K d values than log K oc values indicating that the K d values may be independent of the actual organic carbon content ( f oc ). The estimated log K oc or log K d for chlorinated solvents and degradation products determined by regression of data in this study were significantly higher than values determined by previously published empirical relationships. The site specific K d values as well as the new empirical relationship compared well with calculations on water and soil core concentration for cis-DCE and VC from the Rugårdsvej site. In conclusion, this study with a wide range of chlorinated ethenes and ethanes – in line with previous studies on PCE and TCE – suggest that sorption in clayey tills could be higher than typically expected.

Sorption of bisphenol A, 17α-ethinyl estradiol and phenanthrene on thermally and hydrothermally produced biochars

Thermal and hydrothermal biochars were characterized, and adsorption of bisphenol A (BPA), 17α-ethinyl estradiol (EE2) and phenanthrene (Phen) was determined to investigate the sorption characteristic difference between the two types of biochars. Thermal biochars were composed mostly of aromatic moieties, with low H/C and O/C ratios as compared to hydrothermal ones having diverse functional groups. Single-point organic carbon-normalized distribution coefficients (log K OC) of EE2 and BPA of hydrothermal biochars were higher than thermal biochars, while Phen log K OC values were comparable among them. X-ray diffraction and solid state nuclear magnetic resonance results suggested that hydrothermal biochars consisted of more amorphous aliphatic-C, possibly being responsible for their high sorption capacity of Phen. This study demonstrated that hydrothermal biochars could adsorb a wider spectrum of both polar and nonpolar organic contaminants than thermally produced biochars, suggesting that hydrothermal biochar derived from poultry and animal waste is a potential sorbent for agricultural and environmental applications.

Short-term secondary organic carbon estimations with a modified OC/EC primary ratio method at a suburban site in Madrid (Spain)

A time series of more than two years of continuous measurements of EC, OC and TC obtained with a Rupprecht and Patashnick (R&P) thermal analyzer at a suburban site in Madrid has been evaluated in this work. Correction factors obtained from intercomparison exercises with thermo-optical methods were applied to the original measurements. Corrected OC and EC mean values are 3.7 and 1.3 μg m−3 respectively. The highest individual values have been recorded in winter. No seasonal variation has been observed in OC, whereas a slight decrease of EC is observed in summer, leading to higher OC/EC ratios. The mean value of the OC/EC ratio is 4.9. Daily patterns show maximum EC and OC associated to traffic rush hours, with a delay of the OC peak related to the formation of SOC. Daily oscillation is more pronounced in winter. Hourly estimations of SOC production have been obtained by the primary OC/EC ratio approach, after discounting the OC, EC background contamination. A mean primary ratio value of 0.59 has been used for SOC short-term estimations throughout the entire time period. As expected, the highest SOC production is observed in summer, related to the increasing in photochemical activity, which also influences daily patterns and the time of the daily SOC maximum. In summer the daily SOC production ranges from 80 to 92%, whereas in the winter months it varies from 70 to 84%. These SOC estimations do not discount primary biogenic or natural contributions to OC and are therefore maximum values.

Comparison of surface passivation of crystalline silicon by a-Si:H with and without atomic hydrogen treatment using hot-wire chemical vapor deposition

We compared surface passivation of c-Si by a-Si:H with and without atomic hydrogen treatment prior to a-Si:H deposition. The atomic hydrogen is produced by hot-wire chemical vapor deposition (HWCVD). For this purpose, we deposited a-Si:H layers onto both sides of n-type FZ c-Si wafers and measured the minority carrier effective lifetime and implied V OC for different H treatment times ranging from 5 s to 30 s prior to a-Si:H deposition. We found that increasing hydrogen treatment times led to lower effective lifetimes and implied V OC values for the used conditions. The treatments have been performed in a new virgin chamber to exclude Si deposition from the chamber walls. Our results show that a short atomic hydrogen pretreatment is already detrimental for the passivation quality which might be due to the creation of defects in the c-Si. AFM measurements do not show any change in the surface roughness of the different samples.

Controlling side-chain density of electron donating polymers for improving their packing structure and photovoltaic performance

A simple and efficient approach of controlling the side-chain density in the electron donating polymers has been demonstrated to tune their 3-D packing structure and HOMO level, which increases the hole mobility and V(oc) values, thus improving the solar cell performance.

Planar and textured heterojunction organic photovoltaics based on chloroindium phthalocyanine (ClInPc) versus titanyl phthalocyanine (TiOPc) donor layers

Planar and textured heterojunction solar cells (OPVs) are reported for vacuum deposited chloroindium phthalocyanine (ClInPc)/C 60 heterojunctions, and their response compared to previously explored OPVs based on titanyl phthalocyanine (TiOPc)/C 60 heterojunctions. As for TiOPc/C 60 OPVs, the photoelectrical activity of ClInPc/C 60 OPVs extends well into the near infrared, with good activity out to ca. 900 nm. As-deposited ClInPc films (Phase I) produce open-circuit photopotentials, V OC as high as ca. 0.8 V (Phase I form of ClInPc), ca. 0.15 V larger than previously observed for Phase I TiOPc/C 60 OPVs. The offsets in frontier orbital energies ( E HOMO Pc – E LUMO C 60 ) revealed by UV-photoemission studies (UPS) are slightly smaller for ClInPc/C 60 versus TiOPc/C 60 heterojunctions, and the interface dipole contribution (shift in local vacuum level) to these offsets is in the opposite direction for ClInPc/C 60 versus TiOPc/C 60 heterojunctions, or missing altogether, suggesting differences in molecular interaction at the Pc/C 60 interface. Higher V OC values are correlated with lower reverse saturation currents, J o , for ClInPc/C 60, versus other Pc or pentacene/C 60 heterojunctions, suggesting weak intermolecular interactions at the ClInPc/C 60 interface and large barriers to dark charge injection. Solvent annealing of the ClInPc films enhances the near-IR response, and textures the Pc film, enhancing the Pc/C 60 interfacial contact area and the short-circuit photocurrent, J SC . J SC under AM 1.5 illumination conditions was estimated by integration of the incident photon current efficiency (IPCE) response, to compare relative power conversion efficiencies for the two different device types. The estimated efficiency of Phase I ClInPc/C 60 OPVs is ca. 2.6%. The estimated AM 1.5 efficiency of ClInPc/C 60 OPVs with solvent annealed Pc layers is estimated to be ca. 3.3%, arising from the extensive texturing achieved of the Pc layer, which nearly doubles J SC for the Phase II versus Phase I Pc films.

Occurrence of polycyclic musks in wastewater and receiving water bodies and fate during wastewater treatment

The occurrence of cashmerane (DPMI), celestolide, phantolide, traesolide (ATII), galaxolide (HHCB) and tonalide (AHTN) in sewage and surface waters and their fate during wastewater treatment and anaerobic sludge digestion is investigated. AHTN and HHCB are the most important representatives and influent concentrations of 0.41–1.8 and 0.9–13 μg L −1 are observed. DPMI is detected in influent and effluent samples but in notably lower concentrations than AHTN and HHCB. Major sources of polycyclic musks are households, whereas industrial emitters seem to be of minor importance. This conclusion is supported by the analysis of selected industrial wastewaters (metal, textile and paper industry). Specific emissions of 0.36 ± 0.19 and 1.6 ± 1.0 mg cap −1 d −1 for AHTN and HHCB are calculated. Overall removal efficiencies between approx 50% and more than 95% are observed during biological wastewater treatment and removal with the excess sludge is the major removal pathway. Log K D values of 3.73–4.3 for AHTN, 3.87–4.34 for HHCB and 2.42–3.22 for DPMI are observed in secondary sludge. During sludge digestion no or only slight removal occurred. Mean polycyclic musk concentrations in digested sludge amounted to 1.9 ± 0.9 (AHTN), 14.2 ± 5.8 (HHCB), 0.8 ± 0.4 (ATII) and 0.2 ± 0.09 (DPMI) mg kg −1 dry matter. In the receiving water systems a comparable distribution as during wastewater treatment is observed. AHTN, HHCB and DPMI are detected in surface waters (ND (not detected) – < 0.04, ND – 0.32 and ND – 0.02 μg L −1) as well as AHTN and HHCB in sediments (ND – 20, ND – 120 μg kg −1). For HHCB an apparent K OC value of 4.1–4.4 is calculated for sediments. Major source for polycyclic musks in surface waters are discharges from wastewater treatment plants. For HHCB and DPMI 100% of the load observed in the sampled surface waters derive from discharges of treated wastewater.

Efficient Synthetic Access to Cationic Dendrons and Their Application for ZnO Nanoparticles Surface Functionalization: New Building Blocks for Dye-Sensitized Solar Cells

A new concept for the efficient synthesis of cationic dendrons, 4-tert-butyl-1-(3-(3,4-dihydroxybenzamido)benzyl)pyridinium bromide (17), 1,1'-(5-(3,4-dihydroxybenzamido)-1,3-phenylene)bis(methylene)bis(4-tert-butylpyridinium) bromide (18), N1,N7-bis(3-(4-tert-butyl-pyridium-methyl)phenyl)-4-(3-(3-(4-tert-butyl-pyridinium-methyl)phenyl-amino)-3-oxopropyl)-4-(3,4-dihydroxybenzamido)heptanediamide tribromide (19), and N1,N7-bis(3,5-bis(4-tert-butyl-pyridium-methyl)phenyl)-4-(3-(3,5-bis(4-tert-butyl-pyridinium-methyl)phenylamino)-3-oxopropyl)-4-(3,4-dihydroxybenzamido)heptanediamide hexabromide (20), and their facile binding to zinc oxide (ZnO) nanostructures is introduced. Dendrons containing highly reactive benzylic bromides reacted readily with 4-tert-butyl-pyridine and resulted in cationic dendrons. Furthermore, these permanently positively charged dendrons were equipped with a catechol anchor group. This enabled ZnO surface functionalization by simple immersion. The adsorption of 17, 18, 19, and 20 on the colloidal nanoparticles was monitored by Langmuir isotherms. The highest obtained experimental loadings correspond to 99.5%, 98.6%, 99.1%, and 42.5% of the particle surface for 17, 18, 19, and 20, respectively. These results indicate insufficient adsorption of the largest molecule 20 leading to reduced colloidal stability of the nanoparticles, while an enhanced stability after grafting with 17, 18, and 19 was observed. Mesoporous films suitable for the use as electrodes in dye-sensitized solar cells (DSSCs) were prepared. Subsequently, the films were functionalized with 18, 19, or 20 and sensitized with zinc-5,15-bis-[2',6'-bis-{2'',2''-bis-(carboxy)-ethyl}-methyl-4'-tert-butyl-pheny]-10,20-bis-(4'-tert-butylphenyl)porphyrin-octasodium-salt. UV-vis absorption spectra confirmed that 18, 19, and 20 are suitable for the stable electrostatic attachment of the dye. Current-voltage characteristics of complete cells demonstrated that increasing positive functionalization of the ZnO surface leads to decreased open circuit voltages (V(oc)). All V(oc) values were around 0.4 V with a maximum for the 18 functionalized ZnO film of 0.45 V. The maximum cell efficiency obtained (0.31%) is rather high, considering the narrow spectral absorption of the dye and the rather thin ZnO films used. Finally, incident photon to current efficiency (IPCE) measurements confirmed photoinduced electron injection from the dye. These features are important assets for applications in particle technology and even facilitated advanced devices like a supramolecular DSSC complete with a subsequent layer of negatively charged porphyrins.

Synthesis and characterization of low-bandgap copolymers based on dihexyl-2 H-benzimidazole and terthiophene

A series of new semiconducting polymers with 3-(hexyloxy)thiophene, 2,2-dihexyl-2 H-benzimidazole ( HBI) and thiophene units was synthesized using Stille polymerization. These random copolymers show good solubility at room temperature in organic solvents owing to the long alkyl chain in new acceptor, 2,2-dihexyl-2 H-benzimidazole. In HBI, the sulfur at 2-position of 2,1,3-benzothiadiazole ( BT) unit was replaced with the carbon to make a highly soluble electron deficient moiety while keeping the 1,2-quinoid form of BT unit. The spectra of the solid films show absorption bands with maximum peaks at about 408–526 nm and the absorption onsets at 550–692 nm, corresponding to band gaps of 1.79–2.25 eV. The onset wavelengths of the absorption spectra in thin films exhibit a gradual red-shift with decreased amount of dihexyl-2 H-benzimidazol unit, that is, from 550 nm with PHOTDTHBI-9 to 692 nm with PHOTDTHBI-1. Under white light illumination (AM 1.5 G, 100 mW/cm 2), the device with PHOTDTHBI-3:PCBM blend demonstrated a V OC value of 0.36 V, a J SC value of 1.20 mA/cm 2, and a FF of 0.37, leading to the efficiency of 0.16%.

Evaluation of Bone Bruises and Associated Cartilage in Anterior Cruciate Ligament–Injured and –Reconstructed Knees Using Quantitative T 1ρ Magnetic Resonance Imaging: 1-Year Cohort Study

To quantitate bone marrow edema-like lesions (BMELs) and the radiologic properties of cartilage in knees with acute anterior cruciate ligament (ACL) injuries using T(1ρ) magnetic resonance imaging over a 1-year period. Nine patients with ACL injuries were studied. Magnetic resonance imaging scans were acquired within 8 weeks of the injury, after which ACL reconstruction surgery was performed. Images were then acquired 0.5, 6, and 12 months after reconstructions. The volume and signal intensity of BMELs were quantified at baseline and follow-up examinations. T(1ρ) values were quantified in cartilage overlying the BMEL (OC) and compared with surrounding cartilage at all time points. BMELs were most commonly found in the lateral tibia and lateral femoral condyle. Nearly 50% of BMELs resolved over a 1-year period. The T(1ρ) values of the OC in the lateral tibia, medial tibia, and medial femoral condyle were elevated compared with respective regions in surrounding cartilage at all time points; the difference was significant only in the lateral tibia (P < .05). The opposite results were found in the lateral femoral condyle. For the medial tibia and medial femoral condyle, none of the time periods was significantly different. The percent increase in T(1ρ) values of OC in the lateral tibia was significantly correlated with BMEL volume (r = 0.74, P < .05). At 1 year, the OC in the lateral tibia, medial tibia, and medial femoral condyle showed increased T(1ρ) values despite improvement of BMEL. In patients after ACL tear and reconstruction, (1) the cartilage overlying BMEL in the lateral tibia experiences persistent T(1ρ) signal changes immediately after acute injuries and at 1-year follow-up despite BMEL improvement, (2) the superficial layers of the overlying cartilage show greater matrix damage than the deep layers, and (3) the volume of the BMEL may predict the severity of the overlying matrix's damage in the lateral tibia. T(1ρ) is capable of quantitatively and noninvasively monitoring this damage and detecting early cartilage changes in the lateral tibia over time. Level IV, therapeutic case series.

Occurrence of priority hazardous PAHs in water, suspended particulate matter, sediment and common eels ( Anguilla anguilla) in the urban stretch of the River Tiber (Italy)

This study investigated the occurrence of polycyclic aromatic hydrocarbons (PAHs) in water, suspended particulate matter (SPM), bed sediment and common eels ( Anguilla anguilla) in the urban stretch of the River Tiber (Italy). The selected PAHs, fluoranthene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, benzo(g,h,i)perylene, indeno(1,2,3-cd)pyrene, belong to the EC priority list of dangerous substances. SPM was found to be the most polluted compartment, with values ranging from 1663.1 to 15472.9 ng g −1 (Σ 6PAHs), followed by sediment samples, from 157.8 to 271.6 ng g −1 and by aqueous samples, from 23.9 to 72.0 ng L −1. The distribution coefficient ( K d) showed a good correlation with particle organic carbon (OC) content, while K oc values experimentally measured for sediment/SPM deviated from those predicted by K ow, implying that for very hydrophobic compounds, K ow alone may not be an appropriate descriptor of all the thermodynamic forces involved in their sorption to aquatic particles. Some selected PAH ratios indicated that PAHs in the River Tiber come mainly from pyrolitic sources and vehicular traffic. Concentrations of individual PAHs in muscles of common eels varied from 0.8 to 7.0 ng g −1 wet wt. and the calculated toxicity equivalent concentration (TEQ, 1.8 ng g −1 wet wt.) of total PAHs fell below the recommended screening value (SV) in US EPA guidelines, suggesting no concern for human consumption.

Post annealing effect of flexible polymer solar cells to improve their electrical properties

Flexible polymer solar cells with an ITO/PEDOT/P3HT:PCBM/Al structure were fabricated using regioregular poly(3-hexylthiophene) (P3TH) polymer:(6,6)-phenyl C61-butyric acid methyl ester (PCBM) fullerene polymer as the photovoltaic (PV) bulk hetero-junction layer. The P3HT and PCBM used as the electron donor and electron acceptor materials were spin cast on indium tin oxide (ITO) coated polyethylene naphthalate (PEN) substrates. The optimum mixing concentration ratio of the P3HT:PCBM PV layer was found to be 4:4 wt.%, at which the maximum short circuit current density (J SC), open circuit voltage (V OC), fill factor (FF) and power conversion efficiency (PCE) values were about 3.8 mA/cm 2, 427 mV, 36.6% and 0.66%, respectively. To investigate the effects of the post annealing treatment, the as-prepared flexible polymer solar cells were post annealed at temperatures ranging from 150 °C to 180 °C for 5 min. The J SC and V OC values increased with increasing post annealing temperature from 150 °C to 170 °C, which may be due to the improvement of the light absorption coefficient of P3HT and improved ohmic contact between the PV layer and Al electrode film. The maximum J SC, V OC, FF and PCE values of the flexible polymer solar cell, which was post annealed at 170 °C for 5 min, were found to be about 4.3 mA/cm 2, 616 mV, 32.6% and 0.86%, respectively.