bluuebunny/crossref_metadata_2025 huggingface dataset:
Residual Weed Control with Imazapic, Diclosulam, and Flumioxazin in Southeastern Peanut (Arachis hypogaea)
Authors: Grey T. L. , Bridges D. C. , Prostko E. P. , Eastin E. F. , Johnson W. C. , Vencill W. K. , Brecke B. J. , MacDonald G. E. , Ducar J. A. Tredaway , Everest J. W. , Wehtje G. R. , Wilcut J. W.
Published: April 2010

Imazapic, diclosulam, and flumioxazin have been registered for use in peanut since 1996. These herbicides provide substantial residual control of broadleaf weeds in peanut. A comprehensive review was conducted for these residual herbicides to determine their role in future weed control systems in peanuts. Weed control data for research from over 100 experiments conducted from 1990–2000 by Georgia, Florida, and Auburn Universities and USDA-ARS scientists were compiled. Residual herbicide systems evaluated were imazapic postemergence (POST) at 71 g ai/ha, flumioxazin preemergence (PRE) at 70, 87, and 104 g ai/ha, diclosulam preplant incorporated (PPI) and PRE at 18 and 26 g ai/ha, and paraquat plus bentazon early POST (EPOST). Other treatments included the residual herbicides used in combination with paraquat plus bentazon EPOST, for a total of 17 treatments. Regionally important weeds were selected and included: sicklepod, Florida beggarweed, purple and yellow nut-sedge, Ipomoea morningglory species, and smallflower morningglory. Sicklepod control with imazapic alone was 86% (50 tests), 73% (25 tests) with paraquat plus bentazon, and 63% or less with diclosulam and flumioxazin regardless of rate. Florida beggarweed control was 90% (29 tests) with flumioxazin (104 g/ha PRE); 78% (50 tests) with diclosulam 26 g/ha PPI; 72% (72 tests) with imazapic; and 70% (40 tests) with paraquat plus bentazon. Purple and yellow nutsedge control was 90% with imazapic. Yellow nutsedge control was 78% (18 tests) with diclosulam (26 g/ha PRE) and less than 69% with flumioxazin and paraquat plus bentazon. Paraquat plus bentazon increased weed control over residual herbicides alone.
Impact of Application Rate and Treatment Interval on the Efficacy of Pyraclostrobin in Fungicide Programs for the Control of Early Leaf Spot and Southern Stem Rot on Peanut1
Authors: Hagan A. K. , Campbell H. L. , Bowen K. L. , Wells L.
Published: April 2010

In 1999, 2000, and 2001, efficacy of the strobilurin fungicide pyraclostrobin (Headline F500) for the control of early leaf spot and southern stem rot was compared to that of standard fungicide programs on peanut cv. Georgia Green produced under irrigation. When applied at 2 wk intervals in 1999 and 2001, programs that included pyraclostrobin at rates ranging from 0.08 to 0.22 kg ai/ha gave better control of early leaf spot than the recommended season-long chlorothalonil program and were at least as efficacious against this disease as tebuconazole and azoxystrobin. The level of early leaf spot control provided by 0.08 to 0.16 kg ai/ha of pyraclostrobin applied every 3 wk and by chlorothalonil at the recommended 2 wk interval was similar. In all 3 yr, incidence of southern stem rot on peanut treated with pyraclostrobin alone, tank-mixed with flutolanil, or alternated with tebuconazole was significantly below damage levels recorded in plots treated with chlorothalonil alone and was usually comparable to the level of disease control obtained with recommended tebuconazole, flutolanil, or azoxystrobin programs. Compared to chlorothalonil alone, yields of the pyraclostrobin-treated peanuts were significantly greater in 2000 and 2001 and generally did not significantly differ from those yields recorded with the tebuconazole, flutolanil, or azoxystrobin programs. While pyraclostrobin often gave similar southern stem rot control over a range of treatment intervals, the most consistent yield gains were obtained when this fungicide was applied every 2 wk.
Response of Strip-Tilled Peanut to Broiler Litter, Starter Fertilizers, and Fungicide in an Irrigated Cropping System
Authors: Gascho G. J. , Brenneman T. B.
Published: April 2010

Peanut (Arachis hypogaea L.) production in the Southern Coastal Plain of the U.S. is being impacted by increased use of broiler litter and by conservation tillage. There are no studies on the use of broiler litter for peanut grown in strip tillage and very little information on the use of starter fertilizers. Runner-type peanut was included in a 3 yr, double-cropped, irrigated rotation to determine the effects of broiler litter rates and starter fertilizers on disease development, pod yield, market grade, and gross economic value of runner market type peanut. Broiler litter rates of 0, 4.5, 9.0, and 13.5 Mg/ha were applied to the soil surface without incorporation prior to seeding. Within each broiler litter rate there were three starter fertilizer regimes (none, 93 L10–34–0/ha, and 93 L 12–22–5/ha) each with and without flutolanil {N-[3-(1-methylethoxy) phenyl]-2-(trifluoromethyl) benzamide}applied twice at 1.12 kg ai/ha/application. Over 4 yr, broiler Utter either decreased or did not affect pod yield, market grade, or gross economic value of peanut. Southern stem rot (Sclerotium rolfsii) incidence was not affected by broiler litter, but Rhizotonia limb rot (Rhizoctonia solani, AG-4) incidence increased with broiler litter rate, possibly accounting for some of the decreases in production variables. Broiler litter application was neither an agronomic nor economic best management practice for peanut in this strip-tilled study. Flutolanil increased pod yield, market grade, and gross economic value of peanut regardless of broiler litter rate by decreasing the incidence of southern stem rot and Rhizotonia limb rot. Starter fertilizer had little effect on any of the measured parameters.
Processing Costs and Derived Demand for Screened Versus Unscreened Farmer Stock Peanuts1
Authors: Lamb M. C. , Blankenship P. D. , Whitaker T. B. , Dorner J. W.
Published: April 2010

Screening of farmer stock peanuts separates smaller, lower value pods from larger, higher value pods by mechanical separation. The returns to screening farmer stock peanuts depend on prescreened peanut quality. The purpose of this research was to examine the post-harvest processing costs and the resulting derived demand schedules between screened and unscreened lots. Screening increased value by $19.79/Mg in screened versus unscreened lots. Due to the removal of peanuts during the screening process, the farmer stock lot value and total value of 45 paired farmer stock lots comparing screened versus unscreened lots differed by only $2.45 (0.10%) and $109.98 (0.98%), respectively. Thus, the total purchase cost to shellers for screened lots is not significantly different from unscreened lots. Differences in shelled stock values on a per ton, per lot, and total basis were $38.86, $17.29, and $704.01, respectively, where processing cost differences were assumed to be zero. However, 16 shelled stock lots (20,287 kg) were rejected due to aflatoxin > 15 ppb in the unscreened peanuts compared to five rejected lots (5265 kg) in the screened peanuts. Estimates for blanching cost and product loss due to shrink and disappearance were applied to the unscreened and screened lots, respectively. For farmer stock lots in which at least one shelled stock lot was rejected, the added processing costs per Mg equate to $349.54 and $153.43 in the unscreened and screened lots, respectively. Deducting the added processing cost from the loan value ($677.73/Mg) resulted in net farmer stock values per Mg of $328.19 and $524.30 in the unscreened and screened lots, respectively. Thus, screening peanuts improved shelled stock peanut quality by reducing rejected lots and processing costs.
Narrow-Sense Heritability of Selected Sensory Descriptors in Virginia-Type Peanut (Arachis hypogaea L.)1
Authors: Isleib T. G. , Pattee H. E. , Giesbrecht F. G.
Published: April 2010

The sweet, bitter and roasted peanut attributes of roasted peanut (Arachis hypogaea L.) flavor have been shown to be heritable traits. Previous research has estimated broad-sense heritability (H) and breeding values of numerous peanut cultivars and breeding lines for these attributes, but no study has estimated narrow-sense heritability (h2) in a specific population derived through hybridization and inbreeding. A population of 120 F3-derived families was developed without selection from the cross of NC 7/NC Ac 18431, a virginia-type line identified in 1990 as having a good flavor profile. The parents and F3:5 families were grown at two locations in North Carolina in 1995. SMK samples from each plot were roasted, ground to paste, tasted by a sensory panel, and scored for roasted peanut, sweet, bitter and astringent attributes. Additive and nonadditive genetic variances were estimated by equating variances among F2-derived families and among F3-derived families within F2-derived families to genetic covariances among inbred relatives. Regardless of whether the genetic model included dominance or additive-by-additive epistasis, the estimates of additive genetic variance for flavor attributes were small compared to those for nonadditive genetic variance. Narrow-sense heritability in the F2 generation was estimated at 0 for roasted peanut and astringent, 0.02 to 0.04 for sweet, and 0.01 to 0.03 for bitter, depending on the model used. Because of the low values of h2, which are specific to this population, gain from selection in early generations is expected to be limited within this population. Selection in this population should be practiced in late generations. Other parents have been identified whose crosses should produce greater improvement in sensory quality than can be expected from the NC 7 / NC Ac 18431 population.
Physical Properties of Muffins Containing Peanut Flour and Peanut Butter
Authors: Hinds M. J.
Published: April 2010

Recent studies have reported that frequent peanut consumption may have positive effects on blood lipid profiles. This role of peanuts as a potential functional food is due mainly to its lipid composition. Consumers are demanding convenient and health-improving meal items, and sales of muffins have increased. Thus, muffins may serve as an excellent carrier to deliver the health benefits of peanuts. Previous studies on peanut utilization in muffins focused on increasing protein content by using defatted peanut materials. However, the potential functionality of peanut lipid suggests the need to investigate its inclusion in muffins. In this study, response surface methodology (RSM) was used to evaluate the effects of replacing wheat flour by partially defatted (12% fat, d.b.) peanut flour (PF, at 0, 40, 80%), and the addition of peanut butter (PB, at 0, 21.5, 35.4%, wt of dry ingredients) on physical properties of muffins. Experimental muffins containing 0% PF + 0% PB, and commercial banana-walnut muffins were used as controls. Replacement of wheat flour by PF or addition of PB significantly (P < 0.05) increased tenderness of the muffins. Peanut butter was the major factor decreasing muffin volume when formulations contained > 20% PB. As PF% was increased, the outer surface of muffins became more browner, whereas increased PB gave rise to a more intense hue. Internal crumb color became darker and more intense brown as both PF and PB were increased. RSM predicted that formulations ranging from 0% PF + 32% PB through 30% PF + 15% PB to 61% PF + 0% PB would have optimum texture and volume. Findings indicate the potential for production of good quality muffins containing up to 32% wt of peanut materials per weight of total ingredients, and < 18% peanut lipid in the baked products.
Sanitation, Water and Health
Authors: Rautanen Sanna Leena , Luonsi Antero , Nygard Henry , Vuorinen Heikki S. , Rajala Riikka P.
Published: April 2010

This article focuses on sanitation, health and hygiene as themes of the 5th IWHA conference 2007. It investigates how understanding of the key concepts and the links between health, water and sanitation have changed over time. It identifies some of the key drivers that prompted these changes. The history of sanitation and hygiene is the history of epidemiology, medicine and public health, as well as the history of industrialisation, urbanisation and related urban misery. Since the first urban settlements appeared sanitation has also been linked to drainage and flood management. The conference papers and presentations discussed in this theme article provide insights into sanitation, health, water and urban development, including such specific themes as flood and rainwater management. The article initially focuses on early civilisations, then on health, broadening the scope to questions relating to economics and institutions in an attempt to identify a range of other drivers.
Water, Food and the Economy
Authors: Vinnari E.M. , Frederiksen H.
Published: April 2010

Water and the economy have always been engaged in a two-way interaction. Almost all the great civilisations in the world formed around water, which has been essential not only for supplying drinking water but also for sustaining agriculture, energy production, trade and transport - the foundations of economically and culturally thriving societies. This article presents and discusses the papers presented at the 5th IWHA Conference under the theme 'Water, Food and the Economy'. The papers and presentations were specific to food security; land and water resources management and policy; the economic significance of watercourses in energy production, transport and economic development; the intertwined nature of water infrastructure projects and politics; and the management of extreme weather phenomena. The article closes with a few remarks regarding the theme papers and topics within this area that should receive greater attention in future efforts.
Water and the City
Authors: Katko Tapio S. , Juuti P.S. , Tempelhoff J.
Published: April 2010

The growth and development of urban spaces in all parts of the world is an outstanding feature of modern history. Apart from being notable growth generators of economies, cities have also been localities where the poorest of the poor congregate seeking the opportunity to make a living. Another outstanding feature of cities has been the growth and development of their comprehensive water infrastructure. The theme included eleven sessions with 37 presented papers and one Round Table Panel with five presentations that were regrouped for synthesis under the following categories: water and urban landscape, ancient urban water, managing urban water systems (technological breakthroughs, integration and regionalisation, flood control, policy and politics, challenges in developing and transition economies, sanitary and environmental education) and water privatisation. By 2007 more than a half of the world's population were living in urban areas; urban growth is fastest in the third world. Thus, the theme will only grow in importance in the future. Several presentations showed that decisions on water resources and services are to a large extent public by nature. The paradigm shift under way towards more efficient water use is limiting the growth of water use. The use of traditional technologies should also be considered when striving towards sustainability. Finally, understanding their pasts is a basic requirement for any sound strategic and visionary planning of preferable futures for cities.
Morphological Homonymy in the Qur'anic Text: A Semantic Overview
Authors: Arar Mahdi
Published: April 2010

This study discusses the presence of two different type of homonyms, al-mushtarak al-ṣarfī and al-mushtarak al-lafẓī, in the Qur'an and distinguishes these from other kinds of homonyms. Al-Mushtarak al-ṣarfī relates to the field of morphology, whereas al-mushtarak al-lafẓī belongs to the lexicographical facet of language. The article then goes on to discuss homonymy in terms of alternative forms, derived forms, and the effect of morphological features such al-iʿlāl (‘defectiveness in verbs and nouns’), al-ibdāl (‘substitution’), al-ḥadhf (‘omission’), and al-jamʿ (‘combination’), as well as the multiplicity in meanings of some prefixes and suffixes.
Synthesis and Physico-Chemical Properties of New Tetraethylammonium-Based Amino Acid Chiral Ionic Liquids
Authors: Rahman Mohd Basyaruddin Abdul , Jumbri Khairulazhar , Basri Mahiran , Abdulmalek Emilia , Sirat Kamaliah , Salleh Abu Bakar
Published: April 2010

This paper reports the synthesis of a series of new tetraethylammonium-based amino acid chiral ionic liquids (CILs). Their physico-chemical properties, including melting point, thermal stability, viscosity and ionic conductivity, have been comprehensively studied. The obtained results indicated that the decomposition for these salts proceeds in one step and the temperature of decomposition (Tonset) is in the range of 168–210 °C. Several new CILs prepared in this work showed high ionic conductivity compared to the amino acid ionic liquids (AAILs) found in the literature.
Laser Photoacoustic Detection of CO2 in Old Disc Tree-Rings
Authors: Ageev Boris , Ponomarev Yurii , Sapozhnikova Valeria
Published: April 2010

A homemade CO2–laser photoacoustic spectrometer has been used for monitoring CO2 in gas samples extracted under vacuum from the wood of old spruce disc tree-rings for a ~60 year series. The experimental results show that (1) the CO2 concentration exhibits annual trends correlated with an increase in atmospheric CO2 in a number of cases; (2) at the time when the annual CO2 trend changes from positive to negative, the annual tree-ring stable carbon isotope ratios (δ13C) of CO2 change as well; (3) the disc tree-ring widths are observed to decrease in most cases where the annual CO2 increased; (4) simultaneously with the annual CO2 variation, annual H2O distribution was detected in gas samples of the wood tree-rings of one spruce disc. The observed patterns of the annual CO2 distribution in the disc tree-rings are assumed to be the evidence of the impact of the atmospheric CO2 increase. In other words, a change in the concentration gradient between the stem and the atmospheric CO2 may lead to a gradual CO2 accumulation in the stem because of a decrease in the diffusion rate and to a change in the tree parameters.
Implications of the Nucleocapsid and the Microenvironment in Retroviral Reverse Transcription
Authors: Mougel Marylène , Cimarelli Andrea , Darlix Jean-Luc
Published: April 2010

This mini-review summarizes the process of reverse-transcription, an obligatory step in retrovirus replication during which the retroviral RNA/DNA-dependent DNA polymerase (RT) copies the single-stranded genomic RNA to generate the double-stranded viral DNA while degrading the genomic RNA via its associated RNase H activity. The hybridization of complementary viral sequences by the nucleocapsid protein (NC) receives a special focus, since it acts to chaperone the strand transfers obligatory for synthesis of the complete viral DNA and flanking long terminal repeats (LTR). Since the physiological microenvironment can impact on reverse-transcription, this mini-review also focuses on factors present in the intra-cellular or extra-cellular milieu that can drastically influence both the timing and the activity of reverse-transcription and hence virus infectivity.
Microwave Assisted Synthesis of Yb:Y2O3 Based Materials for Laser Source Application
Authors: Costa Anna Luisa , Serantoni Marina , Blosi Magda , Mercadelli Elisa , Esposito Laura , Piancastelli Andreana , Sanson Alessandra
Published: April 2010

Yb:Y2O3 submicrometric particles were synthesized through co‐precipitation of Yb and Y nitrate in water. Microwave heating and controlled release of ammonia through urea decomposition at reaction temperature leaded to the formation of disaggregated, monosized spherical particles of carbo‐hydroxy‐nitrate precursors. Pure crystalline Yb:Y2O3 powder that preserved the described morphology was obtained after calcination in air at 800 °C for 30 min. This powder mixed with commercial alumina powder was used to produce transparent Yb:YAG ceramics. Improved properties in terms of powder morphology and reactivity were presented in comparison with powders obtained by traditional heating.
The Precipitation Behavior of Superalloy ATI Allvac 718Plus
Authors: Zickler Gerald A. , Radis Rene , Schnitzer Ronald , Kozeschnik Ernst , Stockinger Martin , Leitner Harald
Published: April 2010

ATI Allvac 718Plus is a novel nickel‐based superalloy, which was designed for heavy‐duty applications in aerospace gas turbines. The precipitation kinetics of the intermetallicδ(Ni3Nb) andγ′(Ni3(Al,Ti)) phases in this alloy are of scientific as well as technological interest because of their significant influence on the mechanical properties. Important parameters like grain size are controlled by coarseδprecipitates located at grain boundaries, whereas smallγ′precipitates are responsible for strengthening by precipitation hardening. In the present study, the microstructure is investigated by three‐dimensional atom probe tomography and simulated by computer modeling using the thermo‐kinetic software MatCalc. The results of numerical simulations and experimental data are compared and critically discussed. It is shown that the chemical compositions of the phases change during isothermal aging, and the precipitation kinetics ofδandγ′phases interact with each other as shown in a time temperature precipitation (TTP) plot. The TTP plot shows C‐shaped curves with characteristic discontinuities in the temperature range, where simultaneous and concurrent precipitation of theδandγ′phases occurs. This leads to a competition in the diffusion of Nb and Al, which are partly present in both phases. Thus, the present study gives important information on heat treatments for ATI Allvac 718Plus in order to achieve the desired microstructure and mechanical properties.
Modeling of Coating Process, Phase Changes, and Damage of Plasma Sprayed Thermal Barrier Coatings on Ni‐Base Superalloys
Authors: Beck Tilmann , Białas Marcin , Bednarz Piotr , Singheiser Lorenz , Bobzin Kirsten , Bagcivan Nazlim , Parkot Daniel , Kashko Tatyana , Petković Ivica , Hallstedt Bengt , Nemna Sergey , Schneider Jochen M.
Published: April 2010

The paper gives an overview on the modeling activities on plasma sprayed thermal barrier coating in the frame of TFB 63. In the first part, through‐process modeling of the APS deposition of a ZrO2 based TBC is described. Starting from simulation of the plasma jet, heat transfer into the powder particles, particle melting, particle impact on the substrate surface, and solidification is simulated. A homogenization method is introduced to describe the mechanical properties of the resulting TBC. The second part shows simulation of interdiffusion and phase transformations of MCrAlY and intermetallic oxidation protection coatings on several cast Ni‐base alloy substrates. Finally, FEM‐based damage simulation of oxidation protection coatings by transversal fatigue cracks during thermomechanical fatigue loading as well as by delamination of the TBC during thermocyclic loading is discussed.
Recrystallization Modeling of AA8XXX Alloys with Cellular Automata Considering Recovering Kinetics
Authors: Schäfer Carmen , Pomana Gerda , Mohles Volker , Gottstein Günter , Engler Olaf , Hirsch Jürgen
Published: April 2010

A through‐process modeling scheme for the prediction of recrystallization textures and microstructures after final annealing, subsequent to cold rolling is proposed and applied to a commercial AlFeSi alloy. The heart of the setup is a cellular automaton for modeling of recrystallization which considers changes in dislocation density by recovery and changes in Zener and solute drag due to microchemistry evolution. However, recrystallization is the crucial point in the whole setup, since it leads to significant changes in microstructure and texture. The simulated results are compared to experiments.
Methodology for Thermomechanical Simulation and Validation of Mechanical Weld‐Seam Properties
Authors: Bleck Wolfgans , Reisgen Uwe , Mokrov Oleg , Rossiter Eduardo , Rieger Thomas
Published: April 2010

A simulation and validation of the mechanical properties in submerged‐arc‐weld seams is presented, which combines numerical simulation of the thermal cycle in the weld using the SimWeld software with an annealing and testing procedure. The weld‐seam geometry and thermal profile near the weld seam can be computed based on the simulation of an equivalent heat source describing the energy input and distribution in the weld seam. Defined temperature–time cycles are imposed on tensile specimens allowing for annealing experiments with fast cooling rates. The direct evaluation of welded structures and the simple generation of input data for mechanical simulations in FE software packages are possible.
Modeling the Porosity Formation in Austenitic SGI Castings by Using a Physics‐Based Material Model
Authors: Pustal B. , Hallstedt B. , Schäfer W. , Bartels C. , Subasic E. , Siebert H. , Schneider J. M. , Bührig‐Polaczek A.
Published: April 2010

On solidification, microsegregations build up in solid phases due to changes in solid concentrations with temperature. Diffusion, which is a kinetic process, usually reduces the occurrence of microsegregations. This work is aimed at modeling such kinetic effects on the solidification of austenitic cast iron, using a holistic approach. For this purpose, a microsegregation model is developed and validated. Moreover, this model is directly coupled to a commercial process‐simulation tool and thermodynamic software. A series of GJSA‐XNiCr 20‐2 clamp‐rings is cast by varying the inoculation state and the number of feeders. The composition of this cast alloy is analyzed and the microstructure characterized to provide input data for the microsegregation model. In order to validate the software, cooling curves are recorded; differential thermal analysis, electron dispersive X‐ray analysis and electron probe micro analysis are carried out. Furthermore, the porosity within the casting is analyzed by X‐ray. By performing coupled simulations, the different cooling characteristics within the casting lead to pronounced differences in phase fractions and solidification temperatures which are due to dendrite arm coarsening. The hot spot effect below the feeders is assisted by a shift towards lower solidification temperatures over the solidification time. This shift is a result of the local cooling characteristics, which can only be predicted when process simulation is directly coupled with material simulation. The porosity predictions and the porosity analysis exhibit good agreement. A comparison between experimental and virtual cooling curves closes, implying that the novel coupling concept and its implementation are valid.
Fabrication and Drug Delivery of Ultrathin Mesoporous Bioactive Glass Hollow Fibers
Authors: Hong Youliang , Chen Xuesi , Jing Xiabin , Fan Hongsong , Gu Zhongwei , Zhang Xingdong
Published: April 2010

Ultrathin mesoporous bioactive glass hollow fibers (MBGHFs) fabricated using an electrospinning technique and combined with a phase‐separation‐induced agent, poly(ethylene oxide) (PEO), are described. The rapid solvent evaporation during electrospinning and the PEO‐induced phase separation process demonstrated play vital roles in the formation of ultrathin bioactive glass fibers with hollow cores and mesoporous walls. Immersing the MBGHFs in simulated body fluid rapidly results in the development of a layer of enamel‐like apatite mesocrystals at the fiber surfaces and apatite nanocrystals inside the hollow cores. Drug loading and release experiments indicate that the drug loading capacity and drug release behavior of the MBGHFs strongly depends on the fiber length. MBGHFs with fiber length >50 µm can become excellent carriers for drug delivery. The shortening of the fiber length reduces drug loading amounts and accelerates drug release. The MBGHFs reported here with sophisticated structure, high bioactivity, and good drug delivery capability can be a promising scaffold for hard tissue repair and wound healing when organized into 3D macroporous membranes.
Investigations on the Structural Damage in Human Erythrocytes Exposed to Silver, Gold, and Platinum Nanoparticles
Authors: Asharani P. V. , Sethu Swaminathan , Vadukumpully Sajini , Zhong Shaoping , Lim Chwee Teck , Hande M. Prakash , Valiyaveettil Suresh
Published: April 2010

Human erythrocytes or red blood cells (RBCs), which constitute 99% of blood cells, perform an important function of oxygen transport and can be exposed to nanoparticles (NPs) entering into the human body during therapeutical applications involving such NPs. Hence, the haemocompatibility of the Ag, Au, and Pt NPs on human RBCs is investigated. The parameters monitored include haemolysis, haemagglutination, erythrocyte sedimentation rate, membrane topography, and lipid peroxidation. The findings suggest that platinum and gold NPs are haemocompatible compared to Ag NPs. Erythrocytes exhibit significant lysis, haemagglutination, membrane damage, detrimental morphological variation, and cytoskeletal distortions following exposure to Ag NPs at a concentration of 100 µg mL−1. Exposure of Ag+ to RBCs shows no lysis or deterioration, implying that the observed toxicity is solely due to NPs. The haemolyzed erythrocyte fraction has the ability to induce DNA damage in nucleated cells. Additionally, multiple pits and depressions are observed on RBC membrane following exposure to Ag NPs (50 µg mL−1 onwards). Hence, it is apparent that Ag NPs exhibit toxicity on RBCs and on other cells that are exposed to NP‐mediated haemolyzed fractions.
Effect of Carbon Chain Length in the Substituent of PCBM‐like Molecules on Their Photovoltaic Properties
Authors: Zhao Guangjin , He Youjun , Xu Zheng , Hou Jianhui , Zhang Maojie , Min Jie , Chen Hsiang‐Yu , Ye Mingfu , Hong Ziruo , Yang Yang , Li Yongfang
Published: April 2010

A series of [6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM)‐like fullerene derivatives with the butyl chain in PCBM changing from 3 to 7 carbon atoms, respectively (F1–F5), are designed and synthesized to investigate the relationship between photovoltaic properties and the molecular structure of fullerene derivative acceptors. F2 with a butyl chain is PCBM itself for comparison. Electrochemical, optical, electron mobility, morphology, and photovoltaic properties of the molecules are characterized, and the effect of the alkyl chain length on their properties is investigated. Although there is little difference in the absorption spectra and LUMO energy levels of F1–F5, an interesting effect of the alkyl chain length on the photovoltaic properties is observed. For the polymer solar cells (PSCs) based on P3HT as donor and F1–F5, respectively, as acceptors, the photovoltaic behavior of the P3HT/F1 and P3HT/F4 systems are similar to or a little better than that of the P3HT/PCBM device with power conversion efficiencies (PCEs) above 3.5%, while the performances of P3HT/F3 and P3HT/F5‐based solar cells are poorer, with PCE values below 3.0%. The phenomenon is explained by the effect of the alkyl chain length on the absorption spectra, fluorescence quenching degree, electron mobility, and morphology of the P3HT/F1–F5 (1:1, w/w) blend films.
Effect of the Molecular Size of Analytes on Polydiacetylene Chromism
Authors: Seo Donghwan , Kim Jinsang
Published: April 2010

The pH chromism of polydiacetylenes (PDAs) is examined with respect to the molecular size and acidity of acid analytes, along with the alkyl spacer length of primary‐amine‐functionalized diacetylene (DA) lipids. pH turns out to be an important parameter to charge amine headgroups of PDA but a change in pH does not necessarily result in a PDA color change. The molecular size of acid analytes is identified as another factor that can produce a configurational change in PDA amine headgroups, followed by perturbation of the ene–yne conjugated backbone. In addition, the length of a flexible alkyl spacer between the amine headgroup and the amide group of the diacetylene lipids is found to strongly affect the degree of PDA chromatic transition. The longer alkyl spacer shows a smaller chromatic transition from blue to red phase. The alkyl spacer seems to provide a certain degree of freedom to the amine headgroup, thus decreasing the transfer of headgroup steric effects to the PDA backbone. These correlations found for PDA chromism are applied to the development of a system that colorimetrically detects diethyl phosphate (DEP), a degraded nerve agent simulant. PDA liposomes show a selective chromatic transition upon binding with DEP compared to other acid analytes.
Goldnanopartikel‐Fluorophor‐Komplexe: empfindliche, selektive “Nasen” für die Biosensorik
Authors: Bunz Uwe H. F. , Rotello Vincent M.
Published: April 2010

Goldnanopartikel (Gold‐NPs) löschen die Fluoreszenz adsorbierter Fluorophore. Sobald solche Komplexe durch einen Analyten gespalten werden, beobachtet man ein “Anschalten” der Fluoreszenz. Durch eine sorgfältige Auswahl von funktionalisiertem NP und Fluorophor lassen sich Komplexe mit differentiellem Ansprechverhalten auf Analyte erhalten, was zu vielseitigen und dennoch einfachen Array‐basierten Sensorplattformen führt. Mithilfe dieser Methode können wir Proteine in Pufferlösungen und im Blutserum identifizieren, zwischen unterschiedlichen Bakterienspezies und ‐stämmen differenzieren und gesunde, karzinöse und metastatische Human‐ und Mauszellen voneinander unterscheiden.
Self‐Assembly of Coiled Coils in Synthetic Biology: Inspiration and Progress
Authors: Robson Marsden Hana , Kros Alexander
Published: April 2010

Biological self‐assembly is very complex and results in highly functional materials. In effect, it takes a bottom‐up approach using biomolecular building blocks of precisely defined shape, size, hydrophobicity, and spatial distribution of functionality. Inspired by, and drawing lessons from self‐assembly processes in nature, scientists are learning how to control the balance of many small forces to increase the complexity and functionality of self‐assembled nanomaterials. The coiled‐coil motif, a multipurpose building block commonly found in nature, has great potential in synthetic biology. In this review we examine the roles that the coiled‐coil peptide motif plays in self‐assembly in nature, and then summarize the advances that this has inspired in the creation of functional units, assemblies, and systems.
Gold Nanoparticle–Fluorophore Complexes: Sensitive and Discerning “Noses” for Biosystems Sensing
Authors: Bunz Uwe H. F. , Rotello Vincent M.
Published: April 2010

Gold nanoparticles (NPs) efficiently quench adsorbed fluorophores. Upon disruption of such complexes by an analyte, fluorescence turn‐on is observed. By judicious choice of the functionalized NP and the fluorophore, these complexes display different responses to analytes, thus leading to versatile yet simple array‐based sensor platforms. Using this strategy, we can identify proteins in buffer and serum, distinguish between both different species and different strains of bacteria, and differentiate between healthy, cancerous, and metastatic human and murine cells.
Chiral iridium(I) bis(NHC) complexes as catalysts for asymmetric transfer hydrogenation
Authors: Diez Claus , Nagel Ulrich
Published: April 2010

The common use of NHC complexes in transition‐metal mediated C–C coupling and metathesis reactions in recent decades has established N‐heterocyclic carbenes as a new class of ligand for catalysis. The field of asymmetric catalysis with complexes bearing NHC‐containing chiral ligands is dominated by mixed carbene/oxazoline or carbene/phosphane chelating ligands. In contrast, applications of complexes with chiral, chelating bis(NHC) ligands are rare. In the present work new chiral iridium(I) bis(NHC) complexes and their application in the asymmetric transfer hydrogenation of ketones are described. A series of chiral bis(azolium) salts have been prepared following a synthetic pathway, starting from L‐valinol and the modular buildup allows the structural variation of the ligand precursors. The iridium complexes were formed via a one‐pot transmetallation procedure. The prepared complexes were applied as catalysts in the asymmetric transfer hydrogenation of various prochiral ketones, affording the corresponding chiral alcohols in high yields and moderate to good enantioselectivities of up to 68%. The enantioselectivities of the catalysts were strongly affected by the various, terminal N‐substituents of the chelating bis(NHC) ligands. The results presented in this work indicate the potential of bis‐carbenes as stereodirecting ligands for asymmetric catalysis and are offering a base for further developments. Copyright © 2010 John Wiley & Sons, Ltd.
A novel method of modifying poly(ethylene terephthalate) fabric using supercritical carbon dioxide
Authors: Ma Wen‐Xiao , Zhao Chuan , Okubayashi Satoko , Tabata Isao , Hisada Kenji , Hori Teruo
Published: April 2010

For the modification of poly(ethylene terephthalate) (PET) fabric, a type of epoxy compound, glycerol polyglycidyl ether (GPE), was impregnated as a cross‐linking agent into PET fabric by means of supercritical carbon dioxide (scCO2), then, a series of immobilization processes were implemented, including the pad‐dry‐cure process and the solution process to finish the GPE‐PET fabric with natural functional agents (sericin, collagen, or chitosan). Chloroform was found to be an effective cosolvent, as evidenced by the mass transfer of GPE to PET during the treatment with scCO2. Chemical analyses by X‐ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy showed that GPE can penetrate the surface of the PET fabric in scCO2 pretreatment process, and natural functional agents (sericin, collagen, or chitosan) can also be immobilized on the surface of the GPE‐PET fabric especially for the method of pad‐dry‐cure. The nitrogen content in the modified PET fabrics was calculated accurately and confirmed by combustion analysis. The modified PET fabric displayed improvements in surface wettability, moisturization efficiency, and antibacterial characteristics against S. aureus, which demonstrated that the feasibility of this design for immobilizing natural functional agents (sericin, collagen, or chitosan) onto the surface of the PET fabric. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Removal of phenol from aqueous solutions by adsorption onto polymeric adsorbents
Authors: Hararah Muhanned A. , Ibrahim Khalid A. , Al‐Muhtaseb Ala'a H. , Yousef Rushdi I. , Abu‐Surrah Adnan , Qatatsheh Ala'a
Published: April 2010

Phenolic compounds are one of the most representative pollutants in industrial wastewater, and efficient removals of them have attracted significant concerns. In this study, several commercial and new synthetic polymers (acrylonitrile, 1,3‐butadiene, and styrene copolymer (ABS), styrene, acrylonitrile copolymer (SAN), poly(vinyl chloride) (PVC), poly(methyl methacrylate) (PMMA), poly(tert‐butyl acrylate) (ptBA)) with special functionalities were evaluated for their ability to remove phenol from an aqueous solution. Equilibrium studies were conducted in the range of 20–100 mg/L initial phenol concentrations, 3–11 pH solutions, and a temperature range of 25–65°C. The results showed that (styrene, 1,3‐butadiene) copolymer (SAN) gave the best adsorption capacity among all of the polymers tested. The solution temperature, phenol concentration, and agitation rate played a significant role in influencing the capacity of the adsorbents toward phenol molecules. An increase in solution temperature led to a significant increase in the adsorption capacity of SAN. The percentage of adsorption decreased when initial concentration of phenol increased. However, the percentage removal of phenol was observed to increase with agitation. Removal of phenol using polymeric microbeads is difficult to investigate under high and low pH values because it requires a lot of acid or base to adjust the pH values in the adsorption media. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Thermo‐electric‐visco‐elastic material
Authors: Ezzat M. A. , Zakaria M. , El‐Bary A. A.
Published: April 2010

In this work, we introduce the Seebeck effect in Ohm's law and Thomson heating effect in generalized Fourier's law, to the equations of the linear theory of electro‐magneto‐thermoviscoelasticity, allowing the second sound effects. A normal mode analysis is used. The resulting formulation is applied to a problem of a rotating thick plate subject to heat on parts of the upper and lower surfaces of the plate that varies exponentially with time. The exact formulas of temperature, displacement, stresses, electric field, magnetic field, and current density are obtained. The considered variables are presented graphically and discussions are made. Seebeck and Peltier effects on thermoelectric viscoelastic material are studied. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
A novel method for controlling the sublayer microstructure of an ultrafiltration membrane: The preparation of the PSF–Fe3O4 ultrafiltration membrane in a parallel magnetic field
Authors: Huang Zheng‐Qing , Chen Long , Chen Kun , Zhang Zhi , Xu Hong‐Tao
Published: April 2010

It is very important to control the substructure of a membrane prepared by the phase inversion process. This article reports a novel method to control the substructure of ultrafiltration (UF) membrane by the combined effect of a magnetic filler and a parallel magnetic field. A series of polysulfone (PSF)–ferrosoferric oxide (Fe3O4) UF membranes with different amounts of Fe3O4 were prepared in a parallel magnetic field from suspensions, using the phase inversion process. The suspensions consisted of PSF, N,N‐dimethylacetamide, poly(vinylpyrrolidone), and Fe3O4. Magnetic Fe3O4 particles in a casting solution are expected to arrange along the direction of a magnetic field during the membrane formation. This kind of oriented arrangement can gradually change the cross‐sectional microstructure of a membrane from normal finger‐like macrovoids perpendicular to the membrane surface into macrovoids parallel to the membrane surface, with increasing Fe3O4 content. As a result, a novel membrane with “lamellar macrovoids” (parallel to the membrane surface) in the sublayer was prepared as the Fe3O4 content reached 70 wt %. Furthermore, the membrane with 70 wt % Fe3O4 not only had the best flux and rejection but also had a good antipressure ability. The formation mechanism of novel microstructure of the sublayer in the UF membrane is also discussed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Constructing an abstract model for ladder diagram diagnosis using Petri nets
Authors: Tsai Jui‐I , Teng Ching‐Cheng
Published: April 2010

This paper proposes a method for constructing an abstract model for analyzing and diagnosing electrical circuit ladder diagrams (LDs) using Petri nets, and also supporting network‐based monitoring and supervision. This approach converts normal open (NO) and normal close (NC) contacts in the LD into Petri net transitions, and converts devices (e.g. relay coils) in the LD into Petri net places. This study introduces the concepts of composite transitions, composite places, and relevant state to reduce complexity and increase readability of Petri nets for constructing abstract models. The current study constructing diagnosis of fault modeling, introduces simple matrix manipulation and the difference output vector (DOV) to determine the faulty area for diagnosis in the ladder diagram. An LD controller example demonstrates the usable approach. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Control of Relative Direction and Amplitude in Extension/Contraction Motions of Molecular Strands Induced by Ion Binding
Authors: Stadler Adrian‐Mihail , Ramírez Juan , Lehn Jean‐Marie
Published: April 2010

The shape of ligand strands composed of six‐membered aza‐heterocycles (het) connected at the α and α′ positions by hydrazone (hyz) units is determined in a predictable fashion by the nature of the heterocyclic groups (pyridine, pyrimidine, pyrazine etc.), and covers the range from extended linear to compact helical structures. The binding of metal ions to the coordination subunits, defined by the het‐hyz sequences, leads to marked shape changes by inter‐converting bent and linear conformations of the subunits, thus inducing relative motions of strand domains either in the same (con‐sense, “twirling”) or in opposite (dis‐sense, “flapping”) directions. The amplitude of the motion induced by metal‐ion binding and release and the relative directions of the formal motions can be controlled by the nature of the heterocyclic units. Thus, motions around a central 4,6‐disubstituted pyrimidine are dis‐sense motions, whereas there are con‐sense motions around a central 2,5‐disubstituted pyrazine unit, as illustrated by model ligands 1 and 2, respectively. The more extended helical 3 and undulating (zigzag shape) 4 ligands undergo larger‐amplitude motions combining the relative displacements displayed by 1 and 2. Ligands 3 and 4 form linear tetranuclear PbII and ZnII complexes, thus producing an extension motion. The same holds for [Ru(4)(terpy)4](PF6)8 (terpy=terpyridine). Reversible acid–base‐triggered molecular motions have been generated with [Zn4(4)(OTf)8] (TfOH=triflic acid).
Room‐Temperature, Ligand‐ and Base‐Free Heck Reactions of Aryl Diazonium Salts at Low Palladium Loading: Sustainable Preparation of Substituted Stilbene Derivatives
Authors: Felpin François‐Xavier , Miqueu Karinne , Sotiropoulos Jean‐Marc , Fouquet Eric , Ibarguren Oier , Laudien Julia
Published: April 2010

The Pd(OAc)2‐catalyzed Heck reaction of aryl diazonium salts with 2‐arylacrylates led to cis‐stilbenes with good to excellent stereoselectivity. The environmentally friendly protocol developed in this work features low palladium loading in technical‐grade methanol at room temperature under base‐, additive‐, and ligand‐free conditions. The same protocol applied to simple Heck coupling of aryl diazonium salts with methyl acrylate allows astonishingly low palladium loading, down to 0.005 mol %. The stereoselectivity experimentally observed for the synthesis of cis‐stilbenes has been rationalized by DFT calculations. Moreover, the role of methanol in promoting the reaction has been clarified by a computational study.