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An open-atmosphere, unconfined setup comprising a novel multiple inverse-diffusion flame (m-IDF) burner modified with extended precursor tubes is employed to synthesize graphene on substrates. Growth conditions of mono-, bi-, and few-layer graphene (MLG, BLG, and FLG, respectively) are investigated, with systematic variation of parameters such as substrate temperature, methane-to-hydrogen volume flow rate ratio ( J CH 4 : J H 2 ), growth duration, post-flame flow profiles, substrate material, precursor species (e.g., CH4, C2H2, C2H4), and in-situ post-growth hydrogen annealing. Graphene growth on copper is observed for a wide range of temperatures from 850 °C to 1000 °C, with high-quality BLG created at a substrate temperature of 1000 °C with J CH 4 : J H 2 of 1:100 for 5 min growth duration. A sequential in-situ post-growth hydrogen annealing treatment, where the hydrocarbon precursor flow is terminated but the hydrogen m-IDFs are maintained, is found to be effective for etching adlayers of graphene. As such, BLG is reduced to MLG by increasing the post-growth hydrogen annealing duration at 1000 °C to 10 min. In-situ gas-phase Raman measurements characterize the evolution of the gas-phase precursor species in the synthesis flow field. CH2 is determined to be the main gas-phase carbon species needed near the substrate to form graphene in our flame synthesis system.

Cigarette smoking is a risk factor for developing nonmuscle invasive bladder cancer, and continued smoking exposure after diagnosis may increase the likelihood of adverse clinical outcomes. We compare self-reported vs biochemically verified nicotine exposure to determine the accuracy of self-report among recently diagnosed nonmuscle invasive bladder cancer patients.This cross-sectional analysis consisted of 517 nonmuscle invasive bladder cancer patients who contributed a urine or saliva specimen the same day as self-reporting their smoking, use of e-cigarettes, nicotine replacement therapy and whether they lived with a smoker. Cotinine, the primary metabolite of nicotine, was used as an objective biomarker of recent nicotine exposure.The prevalence of high, low and no cotinine exposure was 13%, 54% and 33%, respectively. Overall, 7.3% of patients (38/517) reported being a current cigarette smoker, while 13% (65/517) had cotinine levels consistent with active smoking exposure. Of these 65 patients 27 denied current smoking, resulting in a sensitivity of self-reported current smoking of 58%. After considering other sources of nicotine exposure such as e-cigarettes, cigars, nicotine replacement therapy and living with a smoker, the sensitivity was higher, at 82%. Nearly all patients with low cotinine denied any smoking-related exposure.Our findings suggest either biochemical verification with cotinine or additional questions about other sources of nicotine are needed to accurately identify nonmuscle invasive bladder cancer patients who have smoking-related exposures. Accurate classification of active and passive smoking exposure is essential to allow clinicians to advise cessation and help researchers estimate the association between post-diagnosis smoking-related exposure and nonmuscle invasive bladder cancer recurrence risk.

Amaranthus palmeri is a troublesome weed which is growing in importance worldwide. It causes serious competition in many crops. A. palmeri was introduced into Turkey 4–5 years ago and appears to adapt to different environmental conditions. Monoculture cropping systems and repeated use of the same herbicides have led to development of herbicide resistance in A. palmeri to several active ingredients including glyphosate, in USA and in South America. This study was conducted to investigate the evolution of glyphosate resistance in A. palmeri in Turkey. Seeds of 21 A. palmeri populations were collected in Turkish citrus fields where control problems with glyphosate were reported. A potentially glyphosate susceptible A. palmeri population was collected from a maize field (GS1 biotype). Seeds of putatively resistant and potentially susceptible (GS) biotypes were germinated and transplanted into large pots, and then allowed to grow in separate greenhouse chambers to obtain F2 generations. After carrying out a preliminary test experiment to exclude the most susceptible populations, a dose-response experiment was conducted in which glyphosate was applied at the 3–4 true leaf stage at 0, 332.5, 665, 1330, 2660, 5320, 10,640 and 21,280 g a.i. ha−1. Plants were harvested 21 days after treatment and dry weight was determined. Glyphosate applied at the recommended rate (1330 g a.i ha−1) controlled GS A. palmeri biotypes by more than 95% while controlling the GR biotypes at about 45%. Among those biotypes, GR1 and GR2 biotypes were confirmed to have an incipient resistance to glyphosate. The effect of glyphosate on shikimic acid accumulation was determined. Results showed that the GS2 biotype accumulated 3.1 and 1.56 times more shikimic acid than GR2 and GR1 biotypes which demonstrates that there is a lower accumulation of shikimic acid in the alleged resistant biotypes than in GS1. These findings demonstrate some increased tolerance of A. palmeri biotypes to glyphosate, which reinforces the need to implement integrated weed management to control this invasive plant in Turkey.

This paper reports the application of silicon bipolar junction transistor (BJT) modeling techniques to the modeling of dynamic behavior of high-voltage 4H-SiC BJTs, and the experimental validation thereof. High-voltage silicon BJTs are impractical due to their low current gain that requires a bulky base driver. Emergence of high-voltage 4H-SiC vertical NPN BJTs with a tenfold higher gain enables the application of efficient drivers, with ratings close to those of IGBTs. This paper demonstrates the advantages offered by 4H-SiC BJTs by means of wide-scale measurements at 800 V and 10 A in a range of temperatures up to 175 °C and adjusted base driver switching rates. This paper shows that the turn- off storage delay in the SiC BJT is two orders of magnitude lower than that of the silicon device. It also shows that the turn- on switching transients of SiC device are by an order of magnitude and the turn- off transients are by two orders of magnitude faster than that of its silicon counterpart, resulting in a tenfold reduction of the switching energy. It also demonstrates the temperature dependence of switching transients of the silicon BJT, and the relative temperature-invariance of the SiC device's performance. This paper concludes with validation of the transient models for the 4H-SiC NPN BJT, showing that the model is sufficiently accurate for transient switching and loss calculations.

In this paper, the properties of crosstalk on SiC planar MOSFET, SiC symmetrical double-trench MOSFET and SiC asymmetrical double-trench MOSFET is investigated on a half-bridge topology, to enable analysis of the impact of temperature, drain-source transition speed and gate resistance on the severity of the shoot-through current and induced gate voltage. The experimental measurements, performed on a wide range of temperatures and switching rates, show that the two selected symmetrical and asymmetrical double-trench MOSFETs exhibit higher induced gate voltage during crosstalk with the same external gate resistance compared with the planar SiC MOSFET, yielding a higher shoot-through current. Therefore, in continuous initiation of intentional crosstalk, the two double-trench MOSFETs experience more temperature rise, especially for symmetrical one which leads the device to verge of failure within minutes while the temperature rise in other two devices is significantly lower. The different trends of shoot-through current with temperature on DUTs reveals that they are dominated by different mechanisms, i.e., influenced by threshold voltage and inversion layer carriers' mobility. A model is developed for prediction of shoot-through current during crosstalk which is validated for the 3 device structures. The comparison of the modelled results with the measurement proves its capability to predict the crosstalk behaviour.

Double-pulse testing is widely used in the power-electronics industry for rapid evaluation of power devices. These tests aim to allow observation of how a power device under test (DUT) would behave in real-world continuous-mode operation, without having to operate a full converter. It is well known that several device parameters are temperature-dependent, and for full accuracy, in the double-pulse test the temperature of the DUT must be controlled such that it matches the temperature(s) expected in real-world operation. Further and more challenging complications arise if a GaN (Gallium nitride) transistor is being tested, as these suffer from electron/hole trapping between different layers of the device (e.g., p‑GaN, GaN, AlGaN), which can modulate the gate voltage threshold (V TH ) up or down, and give rise to the phenomenon known as dynamic R dson . This paper reviews the factors that give rise to these dynamic effects in the two main families of normally-off p‑gate GaN power transistors: Schottky-gate and ohmic-gate. Experiments performed with a 400 V, 2 kW-rated converter, whose power devices are mounted on a daughter-board so they can be interchanged without affecting the power board, demonstrate the types and levels of discrepancy to be expected between double-pulse testing and continuous-mode operation. Modification of the double-pulse test to an N-pulse test is proposed, and it is shown that this new test method can reproduce the waveforms seen during continuous operation.

Using a rapid, open-atmosphere flame synthesis technique, iron-oxide nanoparticles (α-Fe2O3) and nanocrystals (γ-Fe2O3) and carbon nanotubes (CNTs) are grown directly on stainless steel substrates. Multiple inverse-diffusion flames provide both oxide species (H2O and CO2) and carbon species (CH4, CO, C2H2), at elevated temperature, conducive for the growths of iron-oxide nanoparticles/nanocrystals and CNTs. The growth of α-Fe2O3 nanoparticles occurs at 500 °C. At a temperature of 850 °C, the growth of CNTs occurs on type 304 stainless steel, while γ-Fe2O nanocrystal films are grown on 304 L and 316 L stainless steels with relatively lower innate carbon content. Interestingly, a temperature-step process, where 304 stainless steel substrate is initially at 500 °C and then increased to 850 °C, distinctly converts the “seed” α-Fe2O3 nanoparticles into larger γ-Fe2O3 nanocrystals, with some scattered CNTs. Strategically time-varied local conditions should produce different compositional ratios of iron-oxide/CNT hybrid films, as well as targeted functionally-graded nanostructures and nanocomposites.

There are several reconstructive procedures in foot and ankle surgery wherein structural grafts are needed to fill defects, restore height, and maintain correction while providing an osteoconductive environment until fusion occurs. Traditionally used autografts and allografts have their disadvantages and limitations. Porous tantalum, with stiffness similar to bone and its biocompatibility, can be a viable option in foot and ankle reconstructive procedures.

In situ thermal treatment (ISTT) technologies have been applied at sites impacted by non-aqueous phase liquids (NAPLs). There is a need to establish expectations for the treatment of semi-volatile NAPLs, including those consisting primarily of polycyclic aromatic hydrocarbons (PAHs), and the potential benefits and limitations of partial NAPL removal. A series of laboratory experiments was conducted to investigate NAPL removal and soil concentrations during the heating of creosote-impacted sand, as well as aqueous concentrations during post-heating dissolution. The results showed co-boiling near the water boiling temperature due to the low volatility of most creosote components, with limited decreases in NAPL saturation (from 30% to 21% of the pore space). Decreases in soil concentration were more substantial than decreases in NAPL saturation (by a factor of 2–180), with greater removal for higher-volatility components at higher treatment temperatures. Results of the dissolution experiments showed mixed results, with decreases in the aqueous concentrations for 12 of 15 components, but increases in aqueous concentrations for phenanthrene , fluoranthene and pyrene after heating to 205 °C or 320 °C. Overall, the results illustrate the utility of bench-scale treatability tests in helping to establish ISTT goals and expectations.

Active gate driving of power devices seeks to shape switching trajectories via the gate, for example, to reduce EMI without degrading efficiency. To this end, driver ICs with integrated arbitrary waveform generators have been used to achieve complex gate signals. This article describes, for the first time, the implementation details of a digitally programmable arbitrary waveform gate driver capable of a 10-GHz waypoint rate, including comprehensive design considerations for critical high-speed subsystems that codify the tradeoff in flexibility, speed, and area. The design, which is taped out in a 180-nm high-voltage CMOS process, utilizes buffers that switch up to ten times in a single clock cycle to overcome the limited achievable clock speed of high-voltage silicon integrated circuits and a fully digital architecture to provide robustness under high slew rates of the ground rail. The driver IC has networks of 100-ps delay elements that are configured prior to a switching transient, to selectively control an array of fast, parallel-connected drivers with different output impedances. Key to the high timing resolution are high-speed asynchronous circuits for memory readout, output buffering, and pulse generation. The driver IC is experimentally evaluated to have a 100-ps resolution and to operate reliably in a 400-V gallium nitride (GaN) bridge leg, under ground-rail voltage slew rates peaking at over 100 V/ns. Design rules are provided to obtain an architecture with the least area for a given set of timing and impedance resolution requirements. The reported design methods enable complex driving waveforms to be applied during nanosecond-scale transients of GaN power devices and demonstrate how digitally programmable active gate drivers for GaN power FETs can be designed to meet a given set of application requirements.

The material properties of GaN enable high-voltage devices to be manufactured in very small packages. This reduces device footprint and parasitics. However, it also increases thermal impedances which makes thermal management increasingly challenging, negatively affecting reliability. One way to increase reliability is to monitor device junction temperature, and subsequently modify converter operation to hold the temperature in safe bounds. This paper demonstrates a method of sensing the instantaneous junction temperature of GaN power devices, using a low-cost capacitive E-field probe and analogue circuitry. For the first time, the use of the extremely fast turn-on dv/dt of GaN devices to determine instantaneous junction temperature is reported. The dependency of the sensor output on load current is shown, and a circuit demonstrated that provides an alert for temperatures above a chosen threshold. The circuit detail, operation, response times, and alternative approaches to take care of the dependency on load current are presented, with a view to helping designers to develop integrated and discrete temperature sensing methods for GaN devices. This new temperature sensing technique could be integrated into a smart power module or added to large power devices as an auxiliary circuit.

Wide-bandgap (WBG) cascodes combine the advantages of gate drivability and reliability of silicon MOSFETs with the conversion efficiency of WBG devices. In cascodes, a low voltage silicon MOSFET drives a vertical SiC JFET or a lateral GaN HEMT. This paper will present the first systematic comparison of the WBG cascodes considering static & dynamic performance, 3 rd quadrant operation and avalanche ruggedness, as well as the temperature sensitivities. The results show that the GaN cascode outperforms the SiC cascode in switching performance, however, demonstrates is more temperature sensitive at on-state. A model is developed to predict the dI DS /dt and its derivative against R G . Whilst turn-ON dI DS /dt and dV DS /dt have positive temperature coefficients in the SiC cascode and negative coefficients in the GaN cascode, the SiC cascode is more avalanche rugged, whereas the GaN cascode is incapable of unclamped inductive switching.

5-Aza-2'-deoxycytidine (5-aza-dC) is a nucleoside analogue with cytotoxic and DNA demethylating effects. Here we show that 5-aza-dC induces the proteasomal degradation of free (non-chromatin bound) DNMT1 through a mechanism which is dependent on DNA synthesis and the targeting of incorporated 5-aza-dC residues by DNMT1 itself. Thus, 5-aza-dC induces Dnmt1 degradation in wild-type mouse ES cells, but not in Dnmt [3a(-/-), 3b(-/-)] mouse ES cells which express Dnmt1 but lack DNA methylation (< 0.7% of CpG methylated) and contain few hemi-methylated CpG sites, these being the preferred substrates for Dnmt1. We suggest that adducts formed between DNMT1 and 5-aza-dC molecules in DNA induce a ubiquitin-E3 ligase activity which preferentially targets free DNMT1 molecules for degradation by the proteasome. The proteasome inhibitor MG132 prevents DNMT1 degradation and reduces hypomethylation induced by 5-aza-dC.

Per- and polyfluoroalkyl substances (PFAS) are manmade, fluorinated organic chemicals which have been identified as persistent organic pollutants. PFAS have surface active properties that have made them suitable for applications in oil- and water-resistant products, as well as many firefighting foams. No on-site remediation strategies exist to treat PFAS impacted soils. Mechanochemical remediation of PFOS- and PFOA-amended sand via a planetary ball mill was studied. The effect of sand mass, KOH as a co-milling reagent, and water saturation on the degradation of PFOA and PFOS was evaluated. By 4 h of milling concentrations were reduced by up to 98% for PFOS-amended dry sand and 99% for PFOA-amended dry sand without the addition of a co-milling reagent. Water saturation was determined to be a significant hindrance on the mechanochemical destruction of PFOS and PFOA. A maximum of 89% of fluoride was recovered from PFOS-amended sand when KOH was used as a co-milling reagent. It is hypothesized that reactive particles generated from the fracture of sand grains react with PFAS molecules to initiate destruction, which can result in full defluorination. Milling experiments were also conducted on soils from a Canadian firefighting training area (FFTA), demonstrating that PFOS concentrations can be reduced by up to 96% in site soils. For the first time, ball milling for the remediation of PFAS in environmental media has been demonstrated using amended sand and legacy soils from a FFTA.

Heterotropic allosteric activation of protein function, in which binding of one ligand thermodynamically activates the binding of another, different ligand or substrate, is a fundamental control mechanism in metabolism and as such has been a long-aspired capability in protein design. Here we show that greatly increasing the magnitude of a protein’s net charge using surface supercharging transforms that protein into an allosteric ligand- and counterion-gated conformational molecular switch. To demonstrate this we first modified the designed helical bundle hemoprotein H4, creating a highly charged protein which both unfolds reversibly at low ionic strength and undergoes the ligand-induced folding transition commonly observed in signal transduction by intrinsically disordered proteins in biology. As a result of the high surface-charge density, ligand binding to this protein is allosterically activated up to 1,300-fold by low concentrations of divalent cations and the polyamine spermine. To extend this process further using a natural protein, we similarly modified Escherichia coli cytochrome b(562) and the resulting protein behaves in a like manner. These simple model systems not only establish a set of general engineering principles which can be used to convert natural and designed soluble proteins into allosteric molecular switches useful in biodesign, sensing, and synthetic biology, the behavior we have demonstrated––functional activation of supercharged intrinsically disordered proteins by low concentrations of multivalent ions––may be a control mechanism utilized by Nature which has yet to be appreciated.

Symposium on the Banning of Herbicides -- 2019 -- New Orleans, LA WOS: 000530868100006 Hazelnut (Corylus avellana L.) is a native shrub on the steep slopes of the mountains and on the plains in the Black Sea coast of Turkey. Turkey is the world's largest hazelnut producer and exporter, followed by Italy, Spain, the United States, and Greece. Within the scope of this project, a number of surveys were conducted in Turkey to understand the impact of a glyphosate ban on hazelnut production and the economy. Sixty farm surveys were conducted within the Black Sea region, and those data were used as primary information sources. Databases of institutions, theses, academic reports, and published articles were used as secondary data sources to determine the possible effects of a glyphosate ban on Turkish hazelnut production and economy. One of the most important findings of the study was that agricultural business and employment sustained by hazelnut production constitute a significant part of the rural economy. Tillage and mechanical strategies remain as the most sustainable alternative methods for controlling weeds. A potential glyphosate restriction may increase the demand for labor due to a higher need for mechanical strategies. The cost of these alternative methods are 80% more compared with glyphosate weed control systems. The benefit-cost model predicted that, in the case of no glyphosate use, total hazelnut production would decrease by 12% to 21% due to inefficient weed control. A glyphosate ban would result in a reduction in Turkish gross domestic product. Yearly, an average of US$2 billion in revenue is obtained from hazelnut exports, and this number corresponds to 1.37% of Turkey's annual export value. The glyphosate ban would cause a US$240 to US$420 million loss in hazelnut export value and reduce production by 66 to 115 million kg. Global demand for hazelnut is believed to be on the increase, and world production depends largely on Turkey. Weed Sci Soc Amer, IInt Weed Sci Soc Bayer Agriculture BVBA, Brussels-Belgium Funding for this research was provided by Bayer Agriculture BVBA, Brussels-Belgium. No conflicts of interest have been declared.

Tungsten-oxide nanowires are synthesized directly from the surface of tungsten substrate probes inserted into counter-flow diffusion-flames to correlate as-formed morphologies with local conditions because of the quasi-one-dimensionality of the flow field. Computational simulations aid in designing the flame structure for the experiments with respect to relevant chemical species and temperature. The tungsten substrates are inserted into the flame structure on either the air side or fuel side of the flame reaction zone, permitting evaluation of the roles of H2O (or CO2) versus O2, which serve as reactant species in the growth of the resulting tungsten-oxide nanostructures. Furthermore, methane flames are compared with hydrogen flames, which only have H2O (and no CO2) as product species. The temperature profiles of the methane and hydrogen flames are purposefully matched to compare the effect of chemical species produced by the flame which serve as reactants for nanostructure growth. Single-crystalline, well-vertically-aligned, and dense WO2.9 nanowires (diameters of 20–50 nm, lengths of > 10 µm, and coverage density of 109–1010 cm−2) are obtained at a gas-phase temperature of 1720 K on the air-side of the methane flame. Comparisons among the probed locations and flame species indicate that the CO2 route is a heterogeneous one that helps in seeding the growth of nanowires at the nucleation stage, with subsequent vapor–solid growth occurring from other routes. Probing on the fuel side of the hydrogen flame isolates the H2O route and confirms that it is able to produce tungsten-oxide nanowires, albeit at a very reduced rate and yield. Moreover, given the thermodynamic unfavorability of H2O reaction with W to form gaseous W/O species, a self-photocatalytic mechanism is proposed where H2O decomposes to reactive OH on the surface of WOx, facilitating production of volatile W/O species for continued growth by the vapor–solid mechanism for the tungsten-oxide nanowires. The effect of gas-phase temperatures of 1280, 1500, and 1720 K are examined, with increasing temperatures corresponding to higher yield density because of increased nucleation and augmented formation of volatile W/O compounds.

TO THE EDITOR: In prostate-cancer patients investigated with 18F‐DCFPyL, a second-generation 18F‐labeled prostate-specific membrane antigen ligand, Jansen et al. have recently validated the image-based tumor‐to‐blood ratio (TBR) as an optimal trade‐off between a reliable surrogate for the

Micropapillary urothelial carcinoma (MPUC) is a rare but an aggressive variant of urothelial carcinoma. MPUC has been shown to commonly exhibit ERBB2 amplification and HER2 protein overexpression, but the frequency and distribution of these findings within micropapillary (MP) and not otherwise specified (NOS) components of tumors with mixed histology have not been addressed. Therefore, we evaluated ERBB2 amplification and HER2 expression in 43 MPUC cases by fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC). Of the 35 tumors containing both MP and NOS components, ERBB2 amplification was present in both the MP and NOS components of 12 tumors (34.3%), in only the MP component of 11 tumors (31.4%), and exclusively in the NOS component of 4 tumors (11.4%). HER2 protein overexpression was significantly more commonly present in the MP component compared to the NOS component within the same tumor (68.6% versus 34.3%, P = .012). Overall, there was a moderately positive correlation between HER2 protein expression and ERBB2 amplification in both MP (ρ = 0.59, P < .001) and NOS (ρ = 0.70, P < .001) components. All MP/NOS areas with IHC score 3+ and none of MP/NOS areas with IHC score 0 were associated with ERBB2 amplification. We conclude that ERBB2 amplification and HER2 overexpression are preferentially but not exclusively identified in the MP component compared to the NOS component within the same tumor. Our findings identify the presence of intratumoral heterogeneity of ERBB2 amplification and HER2 expression in MPUC and provide grounds for further investigation into the mechanisms underlying the development of MPUC.

Wide-bandgap (WBG) based cascode devices combine the advantages of the gate driveability and reliability of silicon MOSFETs with the power conversion efficiency and switching rate of wide bandgap devices. A low voltage (rated at ~20–30 V) silicon MOSFET drives a vertical JFET for the SiC cascode whereas for the GaN cascode, it drives a lateral GaN HEMT. This paper presents the first systematic comparison of the WBG discrete and module cascodes considering conduction losses, 3rd quadrant operation, switching performance, unclamped switching performance, spontaneous switchings, crosstalk as well as the temperature sensitivities. The results show that the GaN cascode outperforms the SiC cascode considerably in switching performance, however, demonstrates higher conduction losses with more temperature sensitivity in GaN. In this paper, it is also shown experimentally and theoretically that the switching rate in the GaN cascode is more sensitive to the gate resistance compared to the SiC cascode. While turn-ON dIDS/dt and dVDS/dt have positive temperature coefficients in the SiC cascode and negative coefficients in the GaN cascode, the SiC cascode is shown to be more UIS rugged, whereas the GaN cascode is incapable of unclamped inductive switching. The impact of unwanted switching on both GaN and SiC cascodes are also shown, indicating that there is a range of optimum gate resistances where un-wanted turn-on and turn-off switchings can be avoided, with the GaN cascode experiencing a higher crosstalk-induced gate voltage due to its higher switching rates.

Nanoparticulate (3–10 nm) TiO2 polymorphs, i.e., rutile, anatase, and srilankite (also known as TiO2-II or α-PbO2-type TiO2) phases are produced via low-pressure (e.g., 20 torr) flame synthesis at temperatures ranging from 1560K to 2650K, with burner flow velocities varying from 150 to 300 cm/s, using titanium tetra-isopropoxide (TTIP) as precursor. Interestingly, added carbon (i.e., ethylene) in the feed stream produces nanoparticles of the generally characteristic low-temperature high-pressure metastable srilankite phase. The as-synthesized nanopowder is composed of either rutile or srilankite phase, with composition dependent on particle residence time in the flow field. Under the same conditions, feed gas without carbon, e.g., hydrogen, yields anatase phase TiO2. Post heat treatment up to 773K in thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) highlights the thermal stability of the samples, while x-ray photoelectron spectroscopy (XPS) indicates the presence of carbon, with absences of Ti3+, Ti–C, and nitrogen. Microscopy reveals morphology on both the micrometer scale (scanning electron microscopy, SEM) and nanometer scale (transmission electron microscopy, TEM), while x-ray diffraction (XRD) and selected area electron diffraction (SAED) confirm polymorph variation under different synthesis conditions. CHN analysis determines that the synthesized srilankite contains a greater weight percentage of carbon than does anatase. Excess carbon doped into the lattice during low-pressure flame synthesis seems to be the key in stabilizing the high-pressure srilankite phase for such nanoparticles.

Field experiments were conducted in 2008 and 2010 to determine crop tolerance and weed control efficacy of the POST herbicides bentazon, flumioxazin, and oxyfluorfen applied to direct-seeded dry bulb onions on organic soil. Postemergence application of oxyfluorfen at 0.071 kg ai ha−1resulted in less than 20% onion injury when applied at the 2 and 4 onion leaf stages and provided good control of ladysthumb and common lambsquarters. Oxyfluorfen EC caused slightly higher visual injury than oxyfluorfen SC, but there was no difference in onion yield among the treatments. Application of flumioxazin at 0.036 of 0.072 kg ai ha−1alone or in combination with pendimethalin ACS resulted in minimal onion injury and no yield reduction. Combining flumioxazin in a tank mix with pendimethalin EC, dimethenamid-P EC, orS-metolachlor EC resulted in significant onion injury and yield reduction. Flumioxazin plusS-metolachlor, dimethenamid-P, or pendimethalin improved ladysthumb control in one of two years. Bentazon applied at 0.56 kg ai ha−1produced moderate onion injury and did not control yellow nutsedge adequately. Bentazon applied at 1.12 kg ai ha−1provided good control of yellow nutsedge but caused serious onion injury and yield loss.

To address the challenge of trichloroethene (TCE) remediation in low permeability zone, an inexpensive Cu–Ni bimetallic cathode was proposed in electrokinetic (EK) remediation system to couple electrokinetic migration with in situ electrochemical hydrodechlorination. Aqueous phase TCE was originally added into the anolyte so that breakthrough curves through the low permeability porous soil compartment could be obtained to better understand TCE migration driven by electroosmosis flow using different cathodes. The Cu–Ni cathode resulted in more TCE migration of 7.64 mg compared to that of 5.99 mg with Ni and 4.22 mg with mixed metal oxide (MMO) cathode, suggesting that the Cu–Ni cathode was capable of driving more TCE flux out of the contaminated soil. With the Cu–Ni cathode, 98.4% of TCE flux that reached the cathode was electrochemically reduced on the cathode, which was much higher than that with MMO cathode (77.9%) or Ni cathode (59.6%). TCE mass that was transported by electroosmosis flow increased from 2.04 to 6.68 mg when the voltage gradient increased from 1 to 4 V cm−1, with the normalized energy consumption increasing from 0.06 to 0.16 kWh kg−1 per unit water movement, and from 0.54 to 2.55 kWh g−1 per unit TCE transport. For TCE that did reach the cathode compartment, > 98% degradation maintained at the Cu–Ni cathode with various voltage gradients. The coupled electrokinetic and electrochemical hydrodechlorination technology appears to be a promising strategy for the remediation of low permeability porous media.

The germination of Clostridium tyrobutyricum spores; the growth of vegetative cells of C. tyrobutyricum ; and the growth of four cultures each of lactobacilli, coliform bacteria, and cheese starter cultures were studied in culture media containing various levels of lysozyme. Lysozyme was found to inhibit vegetative growth of both isolates (BZ15 and C611) of C. tyrobutyricum at concentrations equal to and greater than 250 units/ml. Spore germination was stimulated by lysozyme with maximum stimulation at 250 units/ml. This effect was more evident with the slower germinating strain, C611. One Lactobacillus isolate was not affected by lysozyme while the other three isolates were inhibited by 500 to 1000 units/ml of lysozyme, but were not affected by lower concentrations. The activity of the four starter cultures was not affected by lysozyme concentrations of up to 2500 units/ml. Growth of three coliform isolates was inhibited by 1000 units/ml of lysozyme, but was not significantly affected by lower concentrations of the enzyme. Growth of the fourth coliform isolate was stimulated by lysozyme at all the concentrations used in the experiments.

Effective methods are needed to fabricate the next generation of high-performance graphene-reinforced polymer matrix composites (G-PMCs). In this work, a versatile and fundamental process is demonstrated to produce high-quality graphene-polymethylmethacrylate (G-PMMA) composites via in situ shear exfoliation of well-crystallized graphite particles loaded in highly-viscous liquid PMMA/acetone solutions into graphene nanoflakes using a concentric-cylinder shearing device. Unlike other methods where graphene is added externally to the polymer and mixed, our technique is a single step process where as-exfoliated graphene can bond directly with the polymer with no contamination/handling. The setup also allows for the investigation of the rheology of exfoliation and dispersion, providing process understanding in the attainment of the subsequently heat injection-molded and solidified G-PMC, essential for future manufacturing scalability, optimization, and repeatability. High PMMA/acetone concentration correlates to high mixture viscosity, which at large strain rates results in very-high shear stresses, producing a large number of mechanically-exfoliated flakes, as confirmed by liquid-phase UV–visible spectral analysis. Raman spectroscopy and other imaging evince that single- and bi-layer graphene are readily achieved. Nevertheless, a limit is reached at high mixtures viscosities where the process becomes unstable as non-Newtonian fluid behavior (e.g. viscoelastic) dominates the system. Characterization of microstructure, morphology, and properties of this new class of nanostructured composites reveals interesting trends. Observations by transmission electron microscopy, scanning electron microscopy, and helium ion microscopy of the manufactured G-PMCs show uniform distributions of unadulterated, well-bonded, discontinuous, graphene nanoflakes in a PMMA matrix, which enhances stiffness and strength via a load-transfer mechanism. Elastic modulus of 5.193 GPa and hardness of 0.265 GPa are achieved through processing at 0.7 g ml−1 of acetone/PMMA for 1% wt. starting graphite loading when injected into a sample mold at 200 °C. Mechanical properties exhibit 31% and 28.6% enhancement in elastic modulus and hardness, respectively, as measured by nano-indentation.

Kaya Altop, Emine/0000-0002-0987-9352 WOS: 000367410500002 Weeds limit hazelnut productivity through competition and interference. Field experiments were conducted from spring 2010 through 2013 to evaluate string trimming alone or combined with herbicides in hazelnut orchards to control mugwort (Artemisia vulgaris L.), purple nutsedge (Cyperus rotundus L), and burning nettle (Urtica urens L.). Treatments were mowing with a string trimmer (ST) alone, or ST followed by glyphosate, glyphosate + diflufenican, and glyphosate + carfentrazone-ethyl. These combinations also were applied with pendimethalin and oxyfluorfen as pre-emergence applications. The experiments were conducted in Fatsa-Ordu, Turkey, on a sandy clay soil with multi-stemmed trees (ocak). The combination treatments improved weed control compared to ST alone. Glyphosate plus carfentrazone-ethyl application 15 days after ST was the most effective treatment for control of these weeds. This combination was more effective in reducing seed bank reserves of A. vulgaris, C rotundus and U. urens than herbicides applied alone or in mixtures throughout all seasons. Hazelnut yield was not significantly affected by herbicide treatments in 2010 or 2011. Hazelnut yield increased during the latter half of the experimental period, in 2012 and 2013. In a mixed population of A. vulgaris, C. rotundus and U. urens, 89 plants per m(2) caused 12.1% yield loss. When the density increased to 256 plants per m2, yield losses increased to 29.7%. Hazelnut treated with ST followed by glyphosate plus carfentrazone-ethyl had the highest financial return. Post-emergence weed management systems in hazelnut should include ST followed by glyphosate plus carfentrazone-ethyl applications for maximum returns. (C) 2015 Elsevier Ltd. All rights reserved.

This research demonstrates a general approach to produce graphene enhanced polymer matrix composites (G-PMCs) using in situ shear exfoliation of mined graphite directly within molten thermoplastic polymer. It is found that shear exfoliation of 35 wt % graphite within polyetheretherketone (PEEK) after multipass processing creates graphene nanoflakes (GNFs) that are uniformly distributed and bonded to PEEK, resulting in a nearly 400% increase in tensile modulus. Morphology images show surface crystallization of PEEK on GNF surfaces, very good planar adhesion, and size reduction of GNFs in both the c-axis direction and in diameter due to fracture across the basal plane. Spectroscopic analysis from Raman and XPS spectra indicate in-situ formation of chemical bonding between created GNFs and PEEK. This shear exfoliation melt-mixing method allows high GNF concentration, intimate particle-matrix interaction, in situ functionalization, and provides a platform changing technology for lightweight, stiff PMCs with low raw materials costs, tunable properties, and simple part fabrication methods.

Active gate driving, where the gate signal is actively profiled, has been shown to reduce EMI, overshoot, and switching loss, in silicon power converters. Recently, much faster gate drivers with the ability to profile at a 100 ps resolution have been reported, which has opened up the possibility of actively driving emerging wide-bandgap devices. This could allow Gallium Nitride (GaN) and Silicon Carbide (SiC) FETs to be switched faster than is currently possible, as unwanted switching features such as current ringing at turn-on could be eliminated. However, these drivers have previously only been demonstrated with preprogrammed gate profiles that have been optimized at certain operating conditions, whereas converters typically operate in a range of conditions. In this paper, some limitations of using fixed gate profiles on GaN FETs are reported for the first time, and a new method of profile adaptation is demonstrated. First, the gate profiles in a 400 V GaN bridge‑ leg are optimized to minimize current ringing at turn-on for a given load current. Then, the load current is varied, showing that the gate signal profile remains close to optimal for ±20% changes in current. Also, over a larger range of at least ±35%, the profiled waveform performs better than a non-profiled gate waveform. It is then demonstrated that by slightly reducing the driver’s internal clock frequency with increasing load current, the profile is re-optimized for new load currents. It is concluded that driver clock frequency adaptation may be a means of adapting gate profiles to load current variation and possibly also to temperature variation.

Perinatal exposure of rats and mice to the typically reported 4mg/g bd wt dose of monosodium glutamate (MSG) results in a complete block in GH secretion as well as obesity, growth retardation and a profound suppression of several cytochrome P450s, including CYP2C11, the predominant male-specific isoform - all irreversible effects. In contrast, we have found that a lower dose of the food additive, 2mg/g bd wt on alternate days for the first 9 days of life results in a transient neonatal depletion of plasma GH, a subsequent permanent overexpression of CYP2C11 as well as subnormal (mini) GH pulse amplitudes in an otherwise normal adult masculine episodic GH profile. The overexpressed CYP2C11 was characterized by a 250% increase in mRNA, but only a 40 to 50% increase in CYP2C11 protein and its catalytic activity. Using freshly isolated hepatocytes as well as primary cultures exposed to the masculine-like episodic GH profile, we observed normal induction, activation, nuclear translocation and binding to the CYP2C11 promoter of the GH-dependent signal transducers required for CYP2C11 transcription. The disproportionately lower expression levels of CYP2C11 protein were associated with dramatically high expression levels of an aberrant, presumably nontranslated CYP2C11 mRNA, a 200% increase in CYP2C11 ubiquitination and a 70–80% decline in miRNAs associated, at normal levels, with a suppression of CYP2C expression. Whereas the GH-responsiveness of CYP2C7 and CYP2C6 as well as albumin was normal in the MSG-derived hepatocytes, the abnormal expression of CYP2C11 was permanent and irreversible.

With switching transients as fast as 100 V/ns and a low threshold voltage of 1-2 V, GaN FETs in bridge-leg topologies are potentially vulnerable to crosstalk and the resultant unwanted partial turn-on, noise interference, and increased losses. Constant-strength gate drivers for GaN FETs limit switching speed to suppress crosstalk. In this work, active gate driving is shown to permit faster switching, whilst still suppressing crosstalk. This is demonstrated in a GaN FET bridge-leg converter. The control device transients are shaped to reduce crosstalk, whilst the synchronous device's gate impedance is actively varied to increase its immunity to crosstalk. This is carried out using two 6.7-GHz active gate drivers that can dynamically vary their output resistance from 0.12 Ω to 64 Ω every 150 ps during the sub-10-ns switching transients. It is demonstrated that unwanted turn-on is suppressed without incurring undershoot and oscillation in the gate, that negative spurious gate voltages can be greatly reduced, and that oscillations in the transient drain current are damped, without incurring additional loss.

Kaya Altop, Emine/0000-0002-0987-9352 WOS: 000415071600016 Use of reduced and no-tillage systems has increased in recent years due to concerns for ecological and economic sustainability of agricultural production. Effective weed control is a serious concern in reduced tillage production. This study was conducted to investigate weed control practices in reduced and no-till maize production. The most effective timing of glyphosate application, either before or after sowing, was investigated in combination with pre-emergence application of acetochlor (840 g a.i/L), post-emergence application of foramsulfuron (22.5 g a.i/L), and two hoeing treatments. The treatments were maintained on the same plots during 2011 and 2012 to evaluate the cumulative effects of the treatments. Main plot treatments consisted of four timings of glyphosate application: 20 or 10 days before sowing, day of sowing, 5 days after sowing, and an untreated control. Sub-plot treatments were: pre- plus post-emergence herbicides, pre-emergence herbicide plus rotary hoeing, post-emergence herbicide plus rotary hoeing, and post-emergence herbicide plus two hoeing treatments (rotary and lister hoe). In the main plots, the lowest weed biomass was produced in glyphosate treatments at sowing and 5 days after sowing; the highest biomass was produced in control plots and in the plots with glyphosate treatments 20 days before sowing. In the sub-plots, the greatest weed biomass was produced in plots with two hoeing treatments (rotary and lister hoe). Glyphosate treatments at sowing and post-emergence herbicide treatment combinations produced the best weed control. Economic analysis revealed that pre-sowing, non-selective herbicide treatments provided a slight increase in net profit. Mechanical hoeing decreased net income due to increased production costs. The highest income was obtained from the pre-emergence plus post-emergence herbicide treatment combinations with no glyphosate. Turkish Ministry of Food Agriculture and LivestockGida Tarim Ve Hayvancilik Bakanligi [TAGEM/BS-10/07-03/04-01] This project was funded by a grant provided by Turkish Ministry of Food Agriculture and Livestock (TAGEM/BS-10/07-03/04-01).

Source at https://doi.org/10.1002/ece3.2579. The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.

Interactions between polycrystalline yttria (Y 2 O 3 ) and graphitic carbon during high-pressure high-temperature processing can take two main forms: (i) major carbon ingress into fractured grain boundaries of Y 2 O 3 by an infiltration mechanism, and (ii) minor carbon ingress into intact grain boundaries of Y 2 O 3 by a diffusion mechanism. In the latter case, when grain coarsening occurs, excess carbon particles form at grain boundaries, since there is little or no solubility of carbon in the Y 2 O 3 grains themselves, irrespective of crystal structure. Segregation of carbon to grain boundaries can reduce grain-boundary strength. For example, high-purity fine-grained Y 2 O 3 , which is originally characterized by transgranular fracture, displays intergranular fracture after carbon ingress into it.

We proposed to determine whether, like other sexual dimorphisms, drug metabolism is permanently imprinted by perinatal hormones, resulting in its irreversible sex-dependent expression. We treated newborn male rats with monosodium glutamate (MSG), a total growth hormone (GH) blocker, and, using cultured hepatocytes, examined expression of adult CYP2C11, the predominant cytochrome-P450 expressed only in males, as well as the signal transduction pathway by which episodic GH solely regulates the isoform's expression. In addition, adolescent hypophysectomized (hypox) male rats served as controls in which GH was eliminated after the critical imprinting period. Whereas renaturalization of the masculine episodic GH profile restored normal male-like levels of CYP2C11, as well as CYP2C12, in hepatocytes from hypox rats, the cells derived from the MSG-treated rats were completely unresponsive. Moreover, GH exposure of hepatocytes from hypox rats resulted in normal induction, activation, nuclear translocation, and binding to the CYP2C11 promoter of the signal transducers mediating GH regulation of CYP2C11 expression, which dramatically contrasted with the complete unresponsiveness of the MSG-derived hepatocytes, also associated with hypermethylation of GH-response elements in the CYP2C11 promoter. Lastly, neonatal MSG treatment had no adverse effect on postnatal and adult testosterone levels. The results demonstrate that the sexually dimorphic expression of CYP2C11 is irreversibly imprinted shortly after birth by a hormone other than the customary testosterone, but likely by GH.—Das, R. K., Banerjee, S., Shapiro, B. H. Irreversible perinatal imprinting of adult expression of the principal sex-dependent drug-metabolizing enzyme CYP2C11.

Silicon carbide (SiC) switching power devices (MOSFETs, JFETs) of 1200 V rating are now commercially available, and in conjunction with SiC diodes, they offer substantially reduced switching losses relative to silicon (Si) insulated gate bipolar transistors (IGBTs) paired with fast-recovery diodes. Low-voltage industrial variable-speed drives are a key application for 1200 V devices, and there is great interest in the replacement of the Si IGBTs and diodes that presently dominate in this application with SiC-based devices. However, much of the performance benefit of SiC-based devices is due to their increased switching speeds ( di/dt, dv/ dt), which raises the issues of increased electromagnetic interference (EMI) generation and detrimental effects on the reliability of inverter-fed electrical machines. In this paper, the tradeoff between switching losses and the high-frequency spectral amplitude of the device switching waveforms is quantified experimentally for all-Si, Si-SiC, and all-SiC device combinations. While exploiting the full switching-speed capability of SiC-based devices results in significantly increased EMI generation, the all-SiC combination provides a 70% reduction in switching losses relative to all-Si when operated at comparable dv/dt. It is also shown that the loss-EMI tradeoff obtained with the Si-SiC device combination can be significantly improved by driving the IGBT with a modified gate voltage profile.

Safranines hold great promise as artificial flavin-like electron transfer cofactors with tunable properties. We have previously reported the stepwise synthesis of a safranine analogue, p-methoxy safranine. We now report an improved synthetic pathway which enables the synthesis of safranine analogues containing electron donating phenyl substituents. Low potential safranine analogues were synthesized that extend the range of two electron midpoint reduction potentials to 249 mV, or 11.4 kcal/mol. NMR analysis of the safranine series demonstrates that the 15N chemical shift at the N(5) position correlates with the two-electron reduction midpoint potential.

Multi-walled and single-walled carbon nanotubes (CNTs) and few-layer graphene (FLG) are grown directly on spinel powders using flame synthesis. CNT and FLG growth occurs via the decomposition of flame-generated carbon precursors (e.g., CO, C2H2, and CH4) over nanoparticles (i.e., Ni, Co, Fe, and Cu) reduced from the solid oxide. The growth of CNTs is investigated on NiAl2O4, CoAl2O4, and ZnFe2O4, using counterflow diffusion flame and multiple inverse-diffusion flames (m-IDFs), while the growth of FLG is investigated on CuFe2O4 using m-IDFs. As shown by analytical electron microscopy techniques, Raman spectroscopy, and X-ray diffraction, substrate temperature and spinel composition play critical roles in the growth of both CNTs and FLG.

Experiments were conducted to test a new herbicide for posttransplant application in Christmas trees. A premix containing 68.6% hexazinone and 6.5% sulfometuron-methyl was applied at 3.0, 4.5, 6.0, 7.5, and 9.0 oz/acre plus 0.25% v/v nonionic surfactant (NIS) to recently transplanted fraser fir (Abies fraseri) Christmas trees and trees transplanted for 1 year in Spring 2008. The treatments were repeated on the same plots in 2009 and 2010. At Gobles, MI, trees treated with 7.5 oz/acre of hexazinone plus sulfometuron had increased stem diameter, after one growing season, and trees treated with 9.0 oz/acre had reduced leader length the second year. After 3 years, fraser fir trees treated with hexazinone plus sulfometuron at 9.0 oz/acre had reduced tree height. Stem diameter, leader length, and number of leader buds were not statistically different from the untreated control. At Horton, MI, trees treated with 9.0 oz/acre of hexazinone plus sulfometuron had reduced leader length after 1, 2, and 3 years. After 3 years, trees treated with hexazinone plus sulfometuron at 6.0, 7.5, and 9.0 oz/acre were shorter than the untreated controls. There were no differences from the untreated trees in stem diameter of trees treated with hexazinone plus sulfometuron after 3 years.

Using open-atmosphere flame synthesis, graphene films and carbon nanotubes (CNTs) are grown directly on nickel and nickel-alloy substrates. The gas-flow input CH 4 to H 2 ratio (1:10) is held constant. For nickel, copper–nickel, and Inconel, few-layer graphene (FLG) grows at 850 °C. Transitional growth from FLG to CNTs is observed on nickel, copper–nickel, and Inconel, as the substrate temperature is decreased to 500 °C. CNT growth is found for nitinol at 500 °C; however, graphene growth is not observed for nitinol at elevated temperatures for the examined experimental conditions.

Asparagus (Asparagus officinalis) is a perennial crop that has a 12- to 20-year production life in the field. Herbicides are applied in the spring each year and again after final harvest in early summer. Asparagus yield declines with age, and herbicides may contribute to yield decline. An experiment was established in 2004 and maintained for seven years with the same herbicide treatments applied each spring to determine herbicide effects on marketable spear yield. Spring-applied diuron, metribuzin, terbacil, sulfentrazone, halosulfuron, mesotrione, and clomazone had no adverse effect on yield or quality over the seven years of the experiment. Flumioxazin reduced yearly average marketable yield compared with standard treatments, and some spears developed lesions early in the season after rainfall. Asparagus yield from most treatments declined more than 50% from 2004 to 2010.

Graphene films are grown in open-atmosphere on metal substrates using a multiple inverse-diffusion flame burner with methane as fuel. Substrate material (i.e. copper, nickel, cobalt, iron, and copper–nickel alloy), along with its temperature and hydrogen treatment, strongly impacts the quality and uniformity of the graphene films. The growth of few-layer graphene (FLG) occurs in the temperature range 750–950 °C for copper and 600–850 °C for nickel and cobalt. For iron, the growth of graphene is not exclusively observed. The variation of graphene quality for different substrates is believed to be due primarily to the difference in carbon solubility between the metals.