bluuebunny/crossref_metadata_2025 huggingface dataset:
Integrated Coordinated Optimization Control of Automatic Generation Control and Automatic Voltage Control in Regional Power Grids
Authors: Lu Qiu-Yu , Hu Wei , Zheng Le , Min Yong , Li Miao , Li Xiao-Ping , Ge Wei-Chun , Wang Zhi-Ming
Published: September 2012

Automatic Generation Control (AGC) and Automatic Voltage Control (AVC) are key approaches to frequency and voltage regulation in power systems. However, based on the assumption of decoupling of active and reactive power control, the existing AGC and AVC systems work independently without any coordination. In this paper, a concept and method of hybrid control is introduced to set up an Integrated Coordinated Optimization Control (ICOC) system for AGC and AVC. Concerning the diversity of control devices and the characteristics of discrete control interaction with a continuously operating power system, the ICOC system is designed in a hierarchical structure and driven by security, quality and economic events, consequently reducing optimization complexity and realizing multi-target quasi-optimization. In addition, an innovative model of Loss Minimization Control (LMC) taking into consideration active and reactive power regulation is proposed to achieve a substantial reduction in network losses and a cross iterative method for AGC and AVC instructions is also presented to decrease negative interference between control systems. The ICOC system has already been put into practice in some provincial regional power grids in China. Open-looping operation tests have proved the validity of the presented control strategies.
Recognizing Vertical and Lateral Variability in Terrestrial Landscapes: A Case Study from the Paleosols of the Late Pennsylvanian Casselman Formation (Conemaugh Group) Southeast Ohio, USA
Authors: Catena Angeline , Hembree Daniel
Published: September 2012

The Upper Pennsylvanian Casselman Formation of southeastern Ohio contains four distinct paleosol types that formed in alluvial systems within the distal Appalachian foreland basin. The properties of these paleosols as well as their small-scale lateral and vertical variations were studied to interpret the paleoenvironmental and paleoecological conditions within the alluvial settings in which they formed. The ichnofossils and pedogenic features preserved within the paleosols of the Casselman Formation record the local climactic, hydrologic, biotic, and topographic changes that occurred in the region during the Late Pennsylvanian. The four paleosols types of the Casselman Formation are interpreted as Alfisols (Type A, Type D), Vertisols (Type B), and Inceptisols (Type D). The four paleosol types indicate different degrees of changes in local moisture regimes including water table fluctuations due to seasonal precipitation and flooding events. The assemblages of ichnofossils within the paleosol types were produced by both soil arthropods and a diverse array of plants that formed part of the different soil ecosystems present within the alluvial environment. Although regional-scale studies are important for understanding the Late Pennsylvanian world, small-scale studies are also necessary to fully understand the local pedogenic, paleoenvironmental, and paleoecologic consequences of global scale changes in paleoclimate and paleogeography.
A Coupling Kinetics Model for Pollutant Release and Transport in the Process of Landfill Settlement
Authors: Zhao Ying , Xue Qiang , Liu Lei
Published: September 2012

A coupling kinetics model is developed to simulate the release and transport of landfill leachate pollutants in a deformable municipal solid waste landfill by taking into account of landfill settlement, seepage of leachate water, hydrolyse of insoluble and degradable organic pollutants in solid phase, biodegradation of soluble and degradable organic pollutants in solid phase and aqueous one, growth of aerobic and anaerobic microorganism, and consumption of dissolved oxygen. The release and transport of organic pollutants and microorganisms in landfills in the process of landfill settlement was simulated by considering no hydraulic effect. Simulation results demonstrated that the interaction between landfill settlement and the release, transport and biodegradation of landfill leachate pollutants was significant. Porosity and saturated hydraulic conductivity were not constants because of the landfill settlement, which affected the release, transport and biodegradation of landfill leachate pollutants, and furthermore acted on the landfill settlement. The simulation results accorded with the practical situation, which preliminarily verified the reliability of the mathematical model and the numerical program in this paper.
Molecular Mechanisms of Cardiotoxicity Induced by ErbB Receptor Inhibitor Cancer Therapeutics
Authors: Hervent Anne-Sophie , De Keulenaer Gilles W.
Published: September 2012

The introduction of the so-called “targeted therapies”, particularly those drugs that inhibit the activity of tyrosine kinases, has represented a remarkable progress in the treatment of cancer. Although these drugs improve survival rates in cancer, significant cardiotoxicity, manifesting as left vertricular dysfunction and/or heart failure, has emerged. The ErbB receptor tyrosine kinases are being pursued as therapeutic targets because of their important roles in normal physiology and in cancer. Besides the fact that the ErbB receptors are indispensable during development and in normal adult physiology, epidermal growth factor (EGFR) and ErbB2 in particular have been implicated in the development of many human cancers. This review focuses on the rationale for targeting members of ErbB receptor family and numerous agents that are in use for inhibiting the pathway. We summarize the current knowledge on the physiological role of ErbB signaling in the ventricle and on structural aspects of ErbB receptor activation in cancer and cardiac cells. We examine the underlying mechanisms that result in on-target or off-target cardiotoxicities of ErbB inhibitors, which can influence the design of future anticancer therapies.
Anti-Inflammatory and Analgesic Activities of a Novel Biflavonoid from Shells of Camellia oleifera
Authors: Ye Yong , Guo Ya , Luo Yue-Ting
Published: September 2012

Shells are by-products of oil production from Camellia oleifera which have not been harnessed effectively. The purpose of this research is to isolate flavonoid from shells of Camellia oleifera and evaluate its anti-inflammatory and analgesic effects. The flavonoid was identified as bimolecular kaempferol structure by UV, MS, 1H NMR and 13C NMR spectra, which is a new biflavonoid and first found in Camellia oleifera. It showed dose-dependent anti-inflammatory activity by carrageenin-induced paw oedema in rats and croton oil induced ear inflammation in mice, and analgesic activity by hot plate test and acetic acid induced writhing. The mechanism of anti-inflammation of biflavonoid is related to both bradykinin and prostaglandins synthesis inhibition. The biflavonoid showed both central and peripheral analgesic effects different from aspirin, inhibition of the synthesis or action of prostaglandins may contribute to analgesic effect of biflavonoid. The biflavonoid significantly decreased malonaldehyde (MDA) and increased superoxidase dismutase (SOD) and Glutathione peroxidase (GSH-Px) activity in serum (p < 0.01), revealed strong free radical scavenging activity in vivo. It indicates the biflavonoid can control inflammation and pain by eliminating free radical so as to inhibit the mediators and decrease the prostaglandins. The biflavonoid can be used as a prospective medicine for inflammation and pain.
Influence of the Polyvinyl Pyrrolidone Concentration on Particle Size and Dispersion of ZnS Nanoparticles Synthesized by Microwave Irradiation
Authors: Soltani Nayereh , Saion Elias , Erfani Maryam , Rezaee Khadijeh , Bahmanrokh Ghazaleh , Drummen Gregor P. C. , Bahrami Afarin , Hussein Mohd Zobir
Published: September 2012

Zinc sulfide semiconductor nanoparticles were synthesized in an aqueous solution of polyvinyl pyrrolidone via a simple microwave irradiation method. The effect of the polymer concentration and the type of sulfur source on the particle size and dispersion of the final ZnS nanoparticle product was carefully examined. Microwave heating generally occurs by two main mechanisms: dipolar polarization of water and ionic conduction of precursors. The introduction of the polymer affects the heating rate by restriction of the rotational motion of dipole molecules and immobilization of ions. Consequently, our results show that the presence of the polymer strongly affects the nucleation and growth rates of the ZnS nanoparticles and therefore determines the average particle size and the dispersion. Moreover, we found that PVP adsorbed on the surface of the ZnS nanoparticles by interaction of the C–N and C=O with the nanoparticle’s surface, thereby affording protection from agglomeration by steric hindrance. Generally, with increasing PVP concentration, mono-dispersed colloidal solutions were obtained and at the optimal PVP concentration (5%), sufficiently small size and narrow size distributions were obtained from both sodium sulfide and thioacetamide sulfur sources. Finally, the sulfur source directly influences the reaction mechanism and the final particle morphology, as well as the average size.
Study of Morphological Changes in MgH2 Destabilized LiBH4 Systems Using Computed X-ray Microtomography
Authors: Dobbins Tabbetha , NaraseGowda Shathabish , Butler Leslie G.
Published: September 2012

The objective of this study was to apply three-dimensional x-ray microtomographic imaging to understanding morphologies in the diphasic destabilized hydride system: MgH2 and LiBH4. Each of the single phase hydrides as well as two-phase mixtures at LiBH4:MgH2 ratios of 1:3, 1:1, and 2:1 were prepared by high energy ball milling for 5 minutes (with and without 4 mol % TiCl3 catalyst additions). Samples were imaged using computed microtomography in order to (i) establish measurement conditions leading to maximum absorption contrast between the two phases and (ii) determine interfacial volume. The optimal energy for measurement was determined to be 15 keV (having 18% transmission for the MgH2 phase and above 90% transmission for the LiBH4 phase). This work also focused on the determination of interfacial volume. Results showed that interfacial volume for each of the single phase systems, LiBH4 and MgH2, did not change much with catalysis using 4 mol % TiCl3. However, for the mixed composite system, interphase boundary volume was always higher in the catalyzed system; increasing from 15% to 33% in the 1:3 system, from 11% to 20% in the 1:1 system, and 2% to 14% in the 2:1 system. The parameters studied are expected to govern mass transport (i.e., diffusion) and ultimately lead to microstructure-based improvements on H2 desorption and uptake rates.
Effects of Cultivar and Process Variables on Dynamic-Mechanical and Sensorial Behavior of Value-Added Grape-Based Smoothies
Authors: Baiano Antonietta , Mastromatteo Marcella , Del Nobile Matteo Alessandro
Published: September 2012

The effects of either cooking temperature (45, 80, and 100 °C) or inclusion of seed particles on the dynamic-mechanical and sensorial properties of value-added Crimson seedless, Black Pearl, or Baresana grape-based smoothies were studied. The inclusion of seed particles resulted in significant increases of the phenolic content, both in Black Pearl and Baresana, but it did not affect in a negative way the sensorial characteristics of smoothies whereas it caused an increase of the viscoelastic behavior of Black Pearl and a slight decrease in Baresana grape-based smoothies. In particular, the investigated rheological parameters were the loss and storage modulus. Moreover, the loss tangent value (the ratio between loss and storage modulus) remained unchanged, indicating a pseudoplastic behavior of all samples, independent on the process conditions. The smoothies produced from Crimson grapes at the intermediate temperature (80 °C) showed sensorial and rheological characteristics similar to those manufactured at 45 °C and better than those manufactured at 100 °C.
Synthesis and Anticancer Activity of Di(3-thienyl)methanol and Di(3-thienyl)methane
Authors: Kaushik Nagendra Kumar , Kim Hong Seon , Chae Young June , Lee Young Nam , Kwon Gi-Chung , Choi Eun Ha , Kim In Tae
Published: September 2012

Di(3-thienyl)methanol (2) and di(3-thienyl)methane (3) have been synthesized and screened against the T98G (brain cancer) cell line. Treatment induced cell death (MTT and macro-colony assay), growth inhibition, cytogenetic damage (micronuclei formation), were studied as cellular response parameters. Treatment with the compounds enhanced growth inhibition and cell death in a concentration dependent manner in both T98G and HEK (normal) cell lines. At higher concentrations (>20 µg/mL) the cytotoxic effects of the compounds were highly significant. The effect on clonogenic capacity and micronuclei formation observed after treatment of cells. Amongst the compounds, compound 2 exhibited potent activity against T98G brain cancer cells. Despite potent in vitro activity, both compounds exhibited less cytotoxicity against normal human HEK cells at all effective concentrations.
The Detection of Patients at Risk of Gastrointestinal Toxicity during Pelvic Radiotherapy by Electronic Nose and FAIMS: A Pilot Study
Authors: Covington James A. , Wedlake Linda , Andreyev Jervoise , Ouaret Nathalie , Thomas Matthew G. , Nwokolo Chuka U. , Bardhan Karna D. , Arasaradnam Ramesh P.
Published: September 2012

It is well known that the electronic nose can be used to identify differences between human health and disease for a range of disorders. We present a pilot study to investigate if the electronic nose and a newer technology, FAIMS (Field Asymmetric Ion Mobility Spectrometry), can be used to identify and help inform the treatment pathway for patients receiving pelvic radiotherapy, which frequently causes gastrointestinal side-effects, severe in some. From a larger group, 23 radiotherapy patients were selected where half had the highest levels of toxicity and the others the lowest. Stool samples were obtained before and four weeks after radiotherapy and the volatiles and gases emitted analysed by both methods; these chemicals are products of fermentation caused by gut microflora. Principal component analysis of the electronic nose data and wavelet transform followed by Fisher discriminant analysis of FAIMS data indicated that it was possible to separate patients after treatment by their toxicity levels. More interestingly, differences were also identified in their pre-treatment samples. We believe these patterns arise from differences in gut microflora where some combinations of bacteria result to give this olfactory signature. In the future our approach may result in a technique that will help identify patients at “high risk” even before radiation treatment is started.
Cu2O and Au/Cu2O Particles: Surface Properties and Applications in Glucose Sensing
Authors: Won Yu-Ho , Stanciu Lia A.
Published: September 2012

In this work we investigated the surface and facet-dependent catalytic properties of metal oxide particles as well as noble metal/metal oxide heterogeneous structures, with cuprous oxide (Cu2O) and Au/Cu2O being selected as model systems. As an example of application, we explored the potential of these materials in developing electrocatalytic devices. Cu2O particles were synthesized in various shapes, then used for testing their morphology-dependent electrochemical properties applied to the detection of glucose. While we did not attempt to obtain the best detection limit reported to date, the octahedral and hexapod Cu2O particles showed reasonable detection limits of 0.51 and 0.60 mM, respectively, which are physiologically relevant concentrations. However, detection limit seems to be less affected by particle shapes than sensitivity. Heterogeneous systems where Au NPs were deposited on the surface of Cu2O particles were also tested with similar results in terms of the effect of surface orientation.
On Increasing Network Lifetime in Body Area Networks Using Global Routing with Energy Consumption Balancing
Authors: Tsouri Gill R. , Prieto Alvaro , Argade Nikhil
Published: September 2012

Global routing protocols in wireless body area networks are considered. Global routing is augmented with a novel link cost function designed to balance energy consumption across the network. The result is a substantial increase in network lifetime at the expense of a marginal increase in energy per bit. Network maintenance requirements are reduced as well, since balancing energy consumption means all batteries need to be serviced at the same time and less frequently. The proposed routing protocol is evaluated using a hardware experimental setup comprising multiple nodes and an access point. The setup is used to assess network architectures, including an on-body access point and an off-body access point with varying number of antennas. Real-time experiments are conducted in indoor environments to assess performance gains. In addition, the setup is used to record channel attenuation data which are then processed in extensive computer simulations providing insight on the effect of protocol parameters on performance. Results demonstrate efficient balancing of energy consumption across all nodes, an average increase of up to 40% in network lifetime corresponding to a modest average increase of 0.4 dB in energy per bit, and a cutoff effect on required transmission power to achieve reliable connectivity.
A Low Cost Matching Motion Estimation Sensor Based on the NIOS II Microprocessor
Authors: González Diego , Botella Guillermo , Meyer-Baese Uwe , García Carlos , Sanz Concepción , Prieto-Matías Manuel , Tirado Francisco
Published: September 2012

This work presents the implementation of a matching-based motion estimation sensor on a Field Programmable Gate Array (FPGA) and NIOS II microprocessor applying a C to Hardware (C2H) acceleration paradigm. The design, which involves several matching algorithms, is mapped using Very Large Scale Integration (VLSI) technology. These algorithms, as well as the hardware implementation, are presented here together with an extensive analysis of the resources needed and the throughput obtained. The developed low-cost system is practical for real-time throughput and reduced power consumption and is useful in robotic applications, such as tracking, navigation using an unmanned vehicle, or as part of a more complex system.
A Digitalized Silicon Microgyroscope Based on Embedded FPGA
Authors: Xia Dunzhu , Yu Cheng , Wang Yuliang
Published: September 2012

This paper presents a novel digital miniaturization method for a prototype silicon micro-gyroscope (SMG) with the symmetrical and decoupled structure. The schematic blocks of the overall system consist of high precision analog front-end interface, high-speed 18-bit analog to digital convertor, a high-performance core Field Programmable Gate Array (FPGA) chip and other peripherals such as high-speed serial ports for transmitting data. In drive mode, the closed-loop drive circuit are implemented by automatic gain control (AGC) loop and software phase-locked loop (SPLL) based on the Coordinated Rotation Digital Computer (CORDIC) algorithm. Meanwhile, the sense demodulation module based on varying step least mean square demodulation (LMSD) are addressed in detail. All kinds of algorithms are simulated by Simulink and DSPbuilder tools, which is in good agreement with the theoretical design. The experimental results have fully demonstrated the stability and flexibility of the system.
Non-Parametric Bayesian Human Motion Recognition Using a Single MEMS Tri-Axial Accelerometer
Authors: Ahmed M. Ejaz , Song Ju Bin
Published: September 2012

In this paper, we propose a non-parametric clustering method to recognize the number of human motions using features which are obtained from a single microelectromechanical system (MEMS) accelerometer. Since the number of human motions under consideration is not known a priori and because of the unsupervised nature of the proposed technique, there is no need to collect training data for the human motions. The infinite Gaussian mixture model (IGMM) and collapsed Gibbs sampler are adopted to cluster the human motions using extracted features. From the experimental results, we show that the unanticipated human motions are detected and recognized with significant accuracy, as compared with the parametric Fuzzy C-Mean (FCM) technique, the unsupervised K-means algorithm, and the non-parametric mean-shift method.
Is Sustainablity Possible in Protected Areas in Mexico? Deer as an Example of a Renewable Resource
Authors: Gallina Sonia
Published: September 2012

In 2000, Mexico’s National Commission of Protected Areas (CONANP) was created to encourage the protection, management and restoration of natural and cultural resources and their conservation. Protected areas were recently increased by more than 3 million hectares, for a current total of more than 25 million hectares, corresponding to 174 protected areas that cover 12.90% of the country’s surface area. The information obtained by research helps us understand both biodiversity and ecological processes, as well as the social and economic phenomena that influence the use of ecosystems. In Mexico there are four species of deer: white-tailed deer, mule deer, red brocket and brown brocket. These ungulates have been an important part of the diet of indigenous people and rural communities, and represent an important resource for sport and trophy hunting. We found the best deer populations in protected areas; these can therefore maintain the gene pool and serve as source populations for other areas. These populations are also useful from a research perspective. People living in some protected areas continue to use natural resources such as deer, and also receive economic inputs to develop ecotourism programs, and support from the government for the environmental services derived from conserving biodiversity.
Sustainability Features of Nuclear Fuel Cycle Options
Authors: Passerini Stefano , Kazimi Mujid
Published: September 2012

The nuclear fuel cycle is the series of stages that nuclear fuel materials go through in a cradle to grave framework. The Once Through Cycle (OTC) is the current fuel cycle implemented in the United States; in which an appropriate form of the fuel is irradiated through a nuclear reactor only once before it is disposed of as waste. The discharged fuel contains materials that can be suitable for use as fuel. Thus, different types of fuel recycling technologies may be introduced in order to more fully utilize the energy potential of the fuel, or reduce the environmental impacts and proliferation concerns about the discarded fuel materials. Nuclear fuel cycle systems analysis is applied in this paper to attain a better understanding of the strengths and weaknesses of fuel cycle alternatives. Through the use of the nuclear fuel cycle analysis code CAFCA (Code for Advanced Fuel Cycle Analysis), the impact of a number of recycling technologies and the associated fuel cycle options is explored in the context of the U.S. energy scenario over 100 years. Particular focus is given to the quantification of Uranium utilization, the amount of Transuranic Material (TRU) generated and the economics of the different options compared to the base-line case, the OTC option. It is concluded that LWRs and the OTC are likely to dominate the nuclear energy supply system for the period considered due to limitations on availability of TRU to initiate recycling technologies. While the introduction of U-235 initiated fast reactors can accelerate their penetration of the nuclear energy system, their higher capital cost may lead to continued preference for the LWR-OTC cycle.
¿Primos o hermanos? Nacionalismo, integralismo y humanismo cristiano en la Argentina de los años sesenta
Authors: Zanca José A.
Published: September 2012

Les études consacrées à l'histoire du catholicisme argentin pendant le XXe siècle reposent sur l’idée selon laquelle il existerait une continuité «structurelle» allant de la Première Guerre mondiale aux années quatre-vingt. Cette continuité renverrait, d’une part, à la formation d'une identité profonde et intransigeante qui aurait catégoriquement rejeté la modernité et, d’autre part, à la diffusion dès les années trente du «mythe de la nation catholique». Dans ces études, Vatican II est considéré comme un «réarrangement» plutôt que comme un changement radical. Cet article revient donc sur ces théories, en y incorporant la tradition de l'humanisme chrétien afin de relier les évolutions du catholicisme avec le processus plus large de sécularisation sociale qui touche les sociétés contemporaines. En ce sens, cette étude interprète l'humanisme chrétien comme un «agent interne» de sécularisation, dans la mesure où ses pratiques et son discours ont progressivement diminué le pouvoir de l'autorité dans la culture religieuse.
Urinary 1-Hydroxypyrene as a Biomarker to Carcinogenic Polycyclic Aromatic Hydrocarbon Exposure
Authors: Ifegwu Clinton , Osunjaye Kayode , Fashogbon Folasade , Oke Kolawole , Adeniyi Afolabi , Anyakora Chimezie
Published: September 2012

In order to capture the extent of exposure to polycyclic aromatic hydrocarbons (PAHs), various biomarkers have been employed. The biomarkers employed for PAHs include PAHs genetoxic end points in lymphocytes, urinary metabolites, PAH-DNA adducts, and PAH-Protein adducts. Of these, excretory 1-hydroxypyene, a metabolite of pyrene, has been used extensively as a biological monitoring indicator of exposure to PAHs. This study attempts to assess the level of this biomarker in the body fluid of 68 exposed subjects using high performance liquid chromatography HPLC. The subjects screened included auto mechanics, drivers, and fuel attendants. 1-hydroxypyrene was extracted from the urine of the subjects using solid phase extraction method. The HPLC analysis was done in isocratic mode using water:methanol (12:88 v/v) mobile phase. The stationary phase was XBridge C18 (150 × 4.6 mm) 5 μm column. The wavelength was 250 nm at a flow rate of 1.2 mL/min. The oven temperature was 30 °C and the injection volume was 20 μL. The run time was 3 minutes. The level of urinary 1-hydroxypyrene detected varied for the different categories of occupation studied. About 27% of sampled fuel attendants and 22% of auto mechanics had detectable 1-hydroxypyrene in their urine samples. There was no detectable 1-hydroxypyene in the urine samples of commercial drivers or in the urine samples of students used as controls. The results of this study showed that fuel attendants and auto mechanics have significant exposures to PAHs. So far, there is no established benchmark for level of PAHs in urine, but our findings indicate the possibility of future cancer cases in this population as a result of their occupational exposure. The study was not able to link the level of 1-hydroxypyene with the smoking habits of the subjects.
Impact of Serum Estradiol on Biomarkers of Oxidative Stress in Polycystic Ovary Syndrome and Ovulatory Women
Authors: Block-Abraham Dana M. , Ke Raymond W. , Bloomer Richard J.
Published: September 2012

Background

Estrogens are thought to possess antioxidant properties in vivo, with estradiol being the most biologically active and available. Unlike ovulatory women, those with polycystic ovary syndrome (PCOS) have a relative steady-state serum estradiol concentration across a typical month. To better understand the antioxidant role of serum estradiol in premenopausal women, we evaluated biomarkers of oxidative stress at two time points in both ovulatory and anovulatory cycles (ie, women with PCOS).

Methods

A total of 16 women (7 PCOS, 9 ovulatory) completed this study. Ovulatory women were tested on cycle day 3, and again on cycle day 21. Women with PCOS were tested at a random time and returned to the clinic 14 days later. At each visit, blood was collected for determination of malondialdehyde (MDA), hydrogen peroxide (H2O2) and Trolox Equivalent Antioxidant Capacity (TEAC). Estradiol, progesterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were also measured.

Results

There were no significant differences observed in any oxidative stress biomarker between ovulatory and PCOS women. Estradiol levels were positively correlated with TEAC in women with PCOS (r = 0.57; P = 0.03), but not in ovulatory women. While not statistically significant, negative correlations were noted between estradiol and MDA and estradiol and H2O2 in women with PCOS but not in ovulatory subjects.

Conclusions

Our data indicate that oxidative stress biomarkers do not differ between PCOS and ovulatory women. The changing estrogen level that occurs throughout ovulatory cycles does not appear to impact overall oxidative status when compared to the relative steady-state estradiol levels in PCOS subjects in our study. Furthermore, estradiol may be associated with antioxidant status and biomarkers of oxidative stress in women with PCOS but not in those with regular menstrual cycles.
Influence of a Carrington-like event on the atmospheric chemistry, temperature and dynamics
Authors: Calisto M. , Verronen P. T. , Rozanov E. , Peter T.
Published: September 2012

Abstract. We have modeled the atmospheric impact of a major solar energetic particle event similar in intensity to what is thought of the Carrington Event of 1–2 September 1859. Ionization rates for the August 1972 solar proton event, which had an energy spectrum comparable to the Carrington Event, were scaled up in proportion to the fluence estimated for both events. We have assumed such an event to take place in the year 2020 in order to investigate the impact on the modern, near future atmosphere. Effects on atmospheric chemistry, temperature and dynamics were investigated using the 3-D Chemistry Climate Model SOCOL v2.0. We find significant responses of NOx, HOx, ozone, temperature and zonal wind. Ozone and NOx have in common an unusually strong and long-lived response to this solar proton event. The model suggests a 3-fold increase of NOx generated in the upper stratosphere lasting until the end of November, and an up to 10-fold increase in upper mesospheric HOx. Due to the NOx and HOx enhancements, ozone reduces by up to 60–80% in the mesosphere during the days after the event, and by up to 20–40% in the middle stratosphere lasting for several months after the event. Total ozone is reduced by up to 20 DU in the Northern Hemisphere and up to 10 DU in the Southern Hemisphere. Free tropospheric and surface air temperatures show a significant cooling of more than 3 K and zonal winds change significantly by 3–5 m s−1 in the UTLS region. In conclusion, a solar proton event, if it took place in the near future with an intensity similar to that ascribed to of the Carrington Event of 1859, must be expected to have a major impact on atmospheric composition throughout the middle atmosphere, resulting in significant and persistent decrease in total ozone.
The formation of SOA and chemical tracer compounds from the photooxidation of naphthalene and its methyl analogs in the presence and absence of nitrogen oxides
Authors: Kleindienst T. E. , Jaoui M. , Lewandowski M. , Offenberg J. H. , Docherty K. S.
Published: September 2012

Abstract. Laboratory smog chamber experiments have been carried out to investigate secondary organic aerosol (SOA) formation from the photooxidation of naphthalene and its methyl analogs, 1- and 2-methylnaphthalene (1-MN and 2-MN, respectively). Laboratory smog chamber irradiations were conducted in a flow mode to ensure adequate collection of the aerosol at reasonably low reactant concentrations and in the presence and absence of nitrogen oxides. Phthalic acid and methyl analogs were identified following BSTFA derivatization of the aerosol extract. These compounds were examined to determine whether they could serve as reasonable molecular tracers to estimate the contributions of these precursors to ambient PM2.5. Measurements were also made to determine aerosol parameters from secondary organic aerosol from naphthalene, 1-MN, and 2-MN. A mass fraction approach was used to establish factors which could be applied to phthalic acid concentrations in ambient aerosols, assuming a negligible contribution from primary sources. Phthalic anhydride uptake (and hydrolysis) was tested and found to represent a moderate filter artifact in filter measurements with and without in-line denuders. This study provided the opportunity to examine differences using authentic standards for phthalic acid compared to surrogate standards. While the mass fraction based on a surrogate compounds was somewhat lower, the differences are largely unimportant. For naphthalene, mass fractions of 0.0199 (recommended for ambient samples) and 0.0206 were determined in the presence and absence of nitrogen oxides, respectively, based on phthalic acid standards. The mass fractions determined from the laboratory data were applied to ambient samples where phthalic acid was found and expressed "as naphthalene" since phthalic acid was found to be produced in the particle phase from other methylnaphthalenes. The mass fraction values were applied to samples taken during the 2005 SOAR Study in Riverside, CA and 2010 CalNex Study in Pasadena. In both studies an undetermined isomer of methylphthalic acid was detected in addition to phthalic acid. Laboratory experiment retention times and mass spectra suggest that the major precursor for this compound is 2-MN. For the CalNex Study, SOC values for the 2-ring precursor PAHs (as naphthalene) were found to range from below the detection limit to 20 ngC m−3 which with the laboratory mass fraction data suggests an upper limit of approximately 1 μg m−3 for SOA due to 2-ring PAHs. Temporal data over the course of the one-month CalNex study suggest that primary sources of phthalic acid were probably negligible during this study period. However, the values must still be considered upper limits given a potential hydrolysis reaction or uptake of phthalic anhydride (subsequently hydrolyzed) onto the collection media.
Impact of forest fires, biogenic emissions and high temperatures on the elevated Eastern Mediterranean ozone levels during the hot summer of 2007
Authors: Hodnebrog Ø. , Solberg S. , Stordal F. , Svendby T. M. , Simpson D. , Gauss M. , Hilboll A. , Pfister G. G. , Turquety S. , Richter A. , Burrows J. P. , Denier van der Gon H. A. C.
Published: September 2012

Abstract. The hot summer of 2007 in southeast Europe has been studied using two regional atmospheric chemistry models; WRF-Chem and EMEP MSC-W. The region was struck by three heat waves and a number of forest fire episodes, greatly affecting air pollution levels. We have focused on ozone and its precursors using state-of-the-art inventories for anthropogenic, biogenic and forest fire emissions. The models have been evaluated against measurement data, and processes leading to ozone formation have been quantified. Heat wave episodes are projected to occur more frequently in a future climate, and therefore this study also makes a contribution to climate change impact research. The plume from the Greek forest fires in August 2007 is clearly seen in satellite observations of CO and NO2 columns, showing extreme levels of CO in and downwind of the fires. Model simulations reflect the location and influence of the fires relatively well, but the modelled magnitude of CO in the plume core is too low. Most likely, this is caused by underestimation of CO in the emission inventories, suggesting that the CO/NOx ratios of fire emissions should be re-assessed. Moreover, higher maximum values are seen in WRF-Chem than in EMEP MSC-W, presumably due to differences in plume rise altitudes as the first model emits a larger fraction of the fire emissions in the lowermost model layer. The model results are also in fairly good agreement with surface ozone measurements. Biogenic VOC emissions reacting with anthropogenic NOx emissions are calculated to contribute significantly to the levels of ozone in the region, but the magnitude and geographical distribution depend strongly on the model and biogenic emission module used. During the July and August heat waves, ozone levels increased substantially due to a combination of forest fire emissions and the effect of high temperatures. We found that the largest temperature impact on ozone was through the temperature dependence of the biogenic emissions, closely followed by the effect of reduced dry deposition caused by closing of the plants' stomata at very high temperatures. The impact of high temperatures on the ozone chemistry was much lower. The results suggest that forest fire emissions, and the temperature effect on biogenic emissions and dry deposition, will potentially lead to substantial ozone increases in a warmer climate.
Modeling postfire water erosion mitigation strategies
Authors: Rulli M. C. , Offeddu L. , Santini M.
Published: September 2012

Abstract. Severe wildfires are often followed by significant increase in runoff and erosion, due to vegetation damages and changes in physical and chemical soil properties. Peak flows and sediment yields can increase up to two orders of magnitude becoming dangerous for human lives and ecosystem, especially in the wildland-urban interface. Watershed post fire rehabilitation measures are usually used to mitigate the effects of fire on runoff and erosion, by protecting soil from splash and shear stress detachment and enhancing its infiltration capacity. Modeling post fire erosion and erosion mitigation strategies can be useful in selecting the effectiveness of rehabilitation method. In this paper a distributed model based on Revised Universal Soil Loss Equation (RUSLE), properly parameterized for a Mediterranean basin located in Sardinia, is used to determine soil losses for six different scenarios describing both natural and post-fire basin condition, the last accounting also for the single and combined effect of different erosion mitigation measures. Fire effect on vegetation and soil properties have been mimed by changing soil drainage capacity and organic matter content, and RUSLE factors related to soil cover and protection measures. Model results show for the analyzed rehabilitation treatments their effect in reducing the amount of soil losses with the peculiar characteristics of the spatial distribution of such changes.
Instabilities on Alpine temperate glaciers: new insights arising from the numerical modelling of Allalingletscher (Valais, Switzerland)
Authors: Faillettaz J. , Funk M. , Sornette D.
Published: September 2012

Abstract. The processes leading to a glacier instability depend on the thermal properties of the contact between the glacier and its bedrock. Assessing the stability of temperate glacier (i.e. the glacier can slide on its bedrock) remains problematic. In order to scrutinize in more detail the processes governing such "sliding" instabilities, a numerical model designed to investigate gravitational instabilities in heterogeneous media was further developed to account for the presence of water at the interface between the bedrock and the glacier for Allalingletscher. This model made it possible to account for various geometric configurations, interaction between sliding and tension cracking and water flow at the bedrock. We could show that both a critical geometrical configuration of the glacier tongue and the existence of a distributed subglacial drainage network were the main causes of the Allalingletscher catastrophic break-off. Moreover, the analysis of the modelling results diagnosed the phenomenon of recoupling of the glacier to its bed followed by a pulse of subglacial water flow as a potential new precursory sign of the final break-off in 1965. This model casts a gleam of hope for a better understanding of the ultimate rupture process resulting from such glacier sliding instabilities.
Manifestation of two meddies in altimetry and sea-surface temperature
Authors: Bashmachnikov I. , Boutov D. , Dias J.
Published: September 2012

Abstract. Two meddies were identified in the Iberian Basin using shipboard ADCP (Meddy 1) and ARGO float (Meddy 2) in contrasting background conditions. Meddy 1 was observed while interacting with the Azores current (AzC) while Meddy 2 was observed rather far north from the AzC jet, in much calmer dynamical background. In both cases the meddies produced a clear anticyclonic surface signal, detectable in altimetry as well as in sea-surface temperature (SST). Analysis of the in-situ observations of the dynamic signal over Meddy 1 showed that the signal, generated by the moving meddy, dominated the AzC dynamics at least up to the base of the seasonal thermocline even at the late stages of its interaction with the jet. The center of rotation of the surface signal was shifted south-westward from the axis of the meddy by about 18 km, and its dynamic radius was 2 times bigger than that of the meddy. The SST anomalies in the core of the surface signals were negative in contrast to the positive SST anomalies in surface anticyclones generated by meandering surface currents. The later difference gives ground for identification of meddies (as well as other sub-surface anticyclones) using coupled altimetry – SST remote sensing data. An identification of Meddy 1 previous to the shipboard ADCP measurements was the first successful experience. At the same time, SST anomalies over both meddies were rather weak, often unstable and statistically significant only over periods of months.
A minimal, statistical model for the surface albedo of Vestfonna ice cap, Svalbard
Authors: Möller M.
Published: September 2012

Abstract. The ice cap Vestfonna is located in northeastern Svalbard and forms one of the largest ice bodies of the Eurasian Arctic. Its surface albedo plays a key role in the understanding and modelling of its energy and mass balance. The principle governing factors for albedo evolution, i.e. precipitation and air temperature and therewith snow depth and melt duration, were found to vary almost exclusively with terrain elevation throughout the ice cap. Hence, surface albedo can be expected to develop a comparable pattern. A new statistical model is presented that estimates this mean altitudinal albedo profile of the ice cap on the basis of a minimal set of meteorological variables on a monthly resolution. Model calculations are based on a sigmoid function of the artificial quantity rain-snow ratio and a linear function of cumulative snowfall and cumulative positive degree days. Surface albedo fields of the MODIS snow product MOD10A1 from the period March to October in the years 2001–2008 serve as a basis for both calibration and cross-validation of the model. The meteorological model input covers the period September 2000 until October 2008 and is based on ERA-Interim data of a grid point located close to the ice cap. The albedo model shows a good performance. The root mean square error between observed and modelled albedo values along the altitudinal profile is 0.057±0.028 (mean ± one standard deviation). The area weighted mean even reduces to a value of 0.054. Distinctly higher deviations (0.07–0.09) are only present throughout the very lowest and uppermost parts of the ice cap that are either small in area or hardly affected by surface melt. Thus, the new, minimal, statistical albedo model presented in this study is found to reproduce the albedo evolution on Vestfonna ice cap on a high level of accuracy and is thus suggested to be fully suitable for further application in broader energy or mass-balance studies of the ice cap.
Improving Indoor Air Quality by Using the New Generation of Corrugated Cardboard-Based Filters
Authors: Candiani Gabriele , Del Curto Barbara , Cigada Alberto
Published: September 2012

Purpose

Indoor Air Quality (IAQ) is strictly affected by the concentration of Total suspended particulate matter (TSP). Air filtration is by far the most feasible suggestion to improve IAQ. Unfortunately, highly effective HEPA filters also have a few major weaknesses that have hindered their widespread use. There is therefore a renewed interest in developing novel, cost-effective filtration systems. We have recently reported the development of cardboard-based filters for bacterial removal that were further implemented and tested herein.

Methods

A parallelepiped filter manufactured by aligning strips of corrugated cardboard and surrounded by a cardboard frame was specifically designed with an internal pocket holding a partially cut antistatic pleated fabric (HP). This filter, together with its parent version (CTRL) and a commercially sourced specimen (CAF), were assessed comparatively in a longtime test to assess their effectiveness on TSP removal.

Results

We found that the TSP abatement efficiency (E%) of the HP filter was relatively high and invariable over the 93 days of test and the pressure drop (PD%) decrease because of filter clogging was moderate. Most important, the HP filter was the most effective if assessed in terms of overall yield (Y%) and its performance was quite constant over the entire period considered.

Conclusions

This work disclosed this novel class of corrugated cardboard-based filters as promising tools to ameliorate IAQ in light of their good TSP removal properties that endure over time. Moreover, cardboard is a lightweight, inexpensive, and eco-friendly material and corrugated cardboard-based air filters are very easy to shape and mount on and/or replace in existing ventilation systems
Fullerene C60 Nanotubes Fabricated with Light Irradiation as a Critical Influence Factor
Authors: Qu Yongtao , Yu Wenwen , Niu Nana , Liang Shaocen , Li Guibao , Piao Guangzhe
Published: September 2012

Crystalline fullerene C60 nanotubes were prepared simply via liquid-liquid interfacial precipitation using the mixture of C60-saturated pyridine and isopropyl alcohol. C60-saturated pyridine solution was exposed to visible light to promote the growth of fullerene C60 nanotubes. The average diameters of the fullerene particles in C60-pyridine colloid solution after irradiation were characterized by dynamic light scattering. After light irradiation, an outer separated layer of pyridine surrounds the fullerene particles because of the charge transfer complexes formation. The mean ratios of inner diameter to outer diameter of fullerene C60 nanotubes fabricated at different irradiation time and wavelength were given in this paper for the first time. On the basis of the relationship between the average diameters of the fullerene particles in C60-pyridine colloid solution and the mean ratio of inner diameter to outer diameter of FNTs fabricated after irradiation, outer separated layer of pyridine surrounding the fullerene particles was supposed to play an important role in the formation process of fullerene C60 nanotubes.