bluuebunny/crossref_metadata_2025 huggingface dataset:
Neurosteroids and Epileptogenesis
Authors: Biagini G. , Rustichelli C. , Curia G. , Vinet J. , Lucchi C. , Pugnaghi M. , Meletti S.
Published: June 2013

Epileptogenesis is defined as the latent period at the end of which spontaneous recurrent seizures occur. This concept has been recently re‐evaluated to include exacerbation of clinically‐manifested epilepsy. Thus, in patients affected by pharmacoresistant seizures, the progression toward a worse condition may be viewed as the result of a durable epileptogenic process. However, the mechanism potentially responsible for this progression remains unclear. Neuroinflammation has been consistently detected both in the latent period and in the chronic phase of epilepsy, especially when brain damage is present. This phenomenon is accompanied by glial cell reaction, leading to gliosis. We have previously described rats presenting an increased expression of the cytochrome P450 cholesterol side‐chain cleavage (P450scc) enzyme, during the latent period, in glial cells of the hippocampus. The P450scc enzyme is critically involved in the synthesis of neurosteroids and its up‐regulation is associated with a delayed appearance of spontaneous recurrent seizures in rats that experienced status epilepticus induced by pilocarpine. Moreover, by decreasing the synthesis of neurosteroids able to promote inhibition, such as allopregnanolone, through the administration of the 5α‐reductase blocker finasteride, it is possible to terminate the latent period in pilocarpine‐treated rats. Finasteride was also found to promote seizures in the chronic period of epileptic rats, suggesting that neurosteroids are continuously produced to counteract seizures. In humans, exacerbation of epilepsy has been also described in patients occasionally exposed to finasteride. Overall, these findings suggest a major role of neurosteroids in the progression of epilepsy and a possible antiepileptogenic role of allopregnanolone and cognate molecules.
Sex differences in objective measures of sleep in post‐traumatic stress disorder and healthy control subjects
Authors: Richards Anne , Metzler Thomas J. , Ruoff Leslie M. , Inslicht Sabra S. , Rao Madhu , Talbot Lisa S. , Neylan Thomas C.
Published: June 2013

A growing literature shows prominent sex effects for risk for post‐traumatic stress disorder and associated medical comorbid burden. Previous research indicates that post‐traumatic stress disorder is associated with reduced slow wave sleep, which may have implications for overall health, and abnormalities in rapid eye movement sleep, which have been implicated in specific post‐traumatic stress disorder symptoms, but most research has been conducted in male subjects. We therefore sought to compare objective measures of sleep in male and female post‐traumatic stress disorder subjects with age‐ and sex‐matched control subjects. We used a cross‐sectional, 2 × 2 design (post‐traumatic stress disorder/control × female/male) involving83 medically healthy, non‐medicated adults aged 19–39 years in the inpatient sleep laboratory. Visual electroencephalographic analysis demonstrated that post‐traumatic stress disorder was associated with lower slow wave sleep duration (F(3,82) = 7.63, P = 0.007) and slow wave sleep percentage (F(3,82) = 6.11, P = 0.016). There was also a group × sex interaction effect for rapid eye movement sleep duration (F(3,82) = 4.08, P = 0.047) and rapid eye movement sleep percentage (F(3,82) = 4.30, P = 0.041), explained by greater rapid eye movement sleep in post‐traumatic stress disorder females compared to control females, a difference not seen in male subjects. Quantitative electroencephalography analysis demonstrated that post‐traumatic stress disorder was associated with lower energy in the delta spectrum (F(3,82) = 6.79, P = 0.011) in non‐rapid eye movement sleep. Slow wave sleep and delta findings were more pronounced in males. Removal of post‐traumatic stress disorder subjects with comorbid major depressive disorder, who had greater post‐traumatic stress disorder severity, strengthened delta effects but reduced rapid eye movement effects to non‐significance. These findings support previous evidence that post‐traumatic stress disorder is associated with impairment in the homeostatic function of sleep, especially in men with the disorder. These findings suggest that group × sex interaction effects on rapid eye movement may occur with more severe post‐traumatic stress disorder or with post‐traumatic stress disorder comorbid with major depressive disorder.
An integrative view of phylogenetic comparative methods: connections to population genetics, community ecology, and paleobiology
Authors: Pennell Matthew W. , Harmon Luke J.
Published: June 2013

Recent innovations in phylogenetic comparative methods (PCMs) have spurred a renaissance of research into the causes and consequences of large‐scale patterns of biodiversity. In this paper, we review these advances. We also highlight the potential of comparative methods to integrate across fields and focus on three examples where such integration might be particularly valuable: quantitative genetics, community ecology, and paleobiology. We argue that PCMs will continue to be a key set of tools in evolutionary biology, shedding new light on how evolutionary processes have shaped patterns of biodiversity through deep time.
Low Back Pain in a Natural Disaster
Authors: Angeletti Chiara , Guetti Cristiana , Ursini Maria L. , Taylor Robert , Papola Roberta , Petrucci Emiliano , Ciccozzi Alessandra , Paladini Antonella , Marinangeli Franco , Pergolizzi Joseph , Varrassi Giustino
Published: June 2013

Low back pain is usually self‐limited. The transition from acute to chronic LBP is influenced by physical and psychological factors. Identification of all contributing factors, in a mass emergency setting, differentiating primary and secondary life‐threatening forms of LBP, is the best approach for success. Aims of the present report were to estimate the prevalence of LBP in population afferent to four advanced medical presidiums (AMPs) during postseismic emergency period and to evaluate frequency of use, types of pain killers administered to patients and short‐term efficacy of them.

Methods

Study was carried out in four AMPs during the first 5 weeks after the earthquake. Site, type of eventual trauma, pain intensity during LBP episode by Verbal Numerical Rating Scale (vNRS) were registered. Diagnosis of primary or secondary LBP was made on the basis of clinical features and therapeutic treatment was also analyzed.

Results

The prevalence of acute LBP was 4.9% (95%, IC 3.7 to 6.4), among 958 first accesses to AMP, representing 14.1% (95%, IC 10.8 to 18.3) of cases on the total of 322 patients treated for all pain conditions. Episodes of relapsed LBP in chronic pre‐existing LBP represented the 40% (n = 19) of cases, while the first episode was present in 60% of patients (n = 28). Pain treatment was effective with a significant reduction in vNRS in short term evaluation.

Conclusions

The emotional stress induced by natural disaster tends to heighten norepinephrine and sympathetic nervous system activity, which may further amplify nociception through peripheral or central mechanisms that result in consistent prevalence of primary NSLBP and become potential risk factor for pain chronicization.
Music, perceived arousal, and intensity: Psychophysiological reactions to Chopin's “Tristesse”
Authors: Mikutta Christian Alexander , Schwab Simon , Niederhauser Sandra , Wuermle Othmar , Strik Werner , Altorfer Andreas
Published: June 2013

The present study investigates the relation of perceived arousal (continuous self‐rating), autonomic nervous system activity (heart rate, heart rate variability) and musical characteristics (sound intensity, musical rhythm) upon listening to a complex musical piece. Twenty amateur musicians listened to two performances of Chopin's “Tristesse” with different rhythmic shapes. Besides conventional statistical methods for analyzing psychophysiological reactions (heart rate, respiration rate) and musical variables, semblance analysis was used. Perceived arousal correlated strongly with sound intensity; heart rate showed only a partial response to changes in sound intensity. Larger changes in heart rate were caused by the version with more rhythmic tension. The low‐/high‐frequency ratio of heart rate variability increased—whereas the high frequency component decreased—during music listening. We conclude that autonomic nervous system activity can be modulated not only by sound intensity but also by the interpreter's use of rhythmic tension. Semblance analysis enables us to track the subtle correlations between musical and physiological variables.
The dissociation between theP3a event‐related potential and behavioral distraction
Authors: Wetzel Nicole , Schröger Erich , Widmann Andreas
Published: June 2013

Unexpected novel sounds can capture our attention and impair performance. Recent behavioral research revealed that only novel sounds that provided target‐related (but not task‐related) information impaired performance. This poses the question of the automaticity of novelty processing and its expression at the behavioral level. In an auditory‐visual oddball paradigm, the informational content of sounds regarding the time and probability of target occurrence was varied. Independent from the informational content, novel, and deviant sounds elicited theP3a, anERP‐component related to novelty processing. In contrast, impaired performance was only observed if target‐related information was provided. Results indicate that distractor sounds are automatically evaluated as potentially significant, but that the consequences for behavior depend on further processes such as the processing of the given information.
Invasion status and risk assessment for Salvia tiliifolia, a recently recognised introduction to China
Authors: Hu G X , Xiang C L , Liu E D
Published: June 2013

This study corrected the misidentification of an alien species, Salvia tiliifolia, which had been incorrectly identified as S. dugesii (a synonym of S. melissodora) in China. The distribution of S. tiliifolia in China was surveyed and it was inferred that it was probably introduced into Kunming, Yunnan in the 1990s and then spread to adjacent counties of Yunnan and south‐western Sichuan Province. The Australian weed risk assessment (WRA) was used to evaluate its invasive status. To determine the validity of Australian WRA in China, another 25 exotics representing casual alien plants, naturalised plants and invasive plants were tested. The Australian WRA was validated as a legitimate approach in China. Salvia tiliifolia scored 14, falling into the category of invasive plants. While the distribution of S. tiliifolia is currently restricted to Yunnan and a small part of Sichuan and the species has not displayed an adverse impact on local environments yet, the WRA results indicated that the species was a high risk plant. It was recommended that local land managers should monitor this species and take measures to stop its continuing expansion or eradicate it if possible.
Boron nitride growth on metal foil using solid sources
Authors: Suzuki Satoru , Molto Pallares Roger , Orofeo Carlo M. , Hibino Hiroki
Published: June 2013

Large-area, atomically thin hexagonal boron nitride (h-BN) thin films were grown simply by annealing in a vacuum from solid sources deposited on Ni or Co foils. Either a sputter-deposited amorphous boron nitride film or a spin-coated borane ammonia film can be used as the B and N source. The h-BN films were formed on the back surface of the metal foil following diffusion of B and N atoms through the foil of ∼20 μm-thick, although N is almost completely insoluble in these metals. The atomically thin h-BN film largely prevented the foil from oxidizing. The h-BN film formation was found to be restricted by the provision of N atoms. The authors propose that the mass transport of N atoms in the foil and on the back surface of the foil is dominated by grain boundary diffusion and surface migration.
FusionArc optimization: A hybrid volumetric modulated arc therapy (VMAT) and intensity modulated radiation therapy (IMRT) planning strategy
Authors: Matuszak Martha M. , Steers Jennifer M. , Long Troy , McShan Daniel L. , Fraass Benedick A. , Edwin Romeijn H. , Ten Haken Randall K.
Published: June 2013

Purpose:

To introduce a hybrid volumetric modulated arc therapy/intensity modulated radiation therapy (VMAT/IMRT) optimization strategy called FusionArc that combines the delivery efficiency of single‐arc VMAT with the potentially desirable intensity modulation possible with IMRT.

Methods:

A beamlet‐based inverse planning system was enhanced to combine the advantages of VMAT and IMRT into one comprehensive technique. In the hybrid strategy, baseline single‐arc VMAT plans are optimized and then the current cost function gradients with respect to the beamlets are used to define a metric for predicting which beam angles would benefit from further intensity modulation. Beams with the highest metric values (called the gradient factor) are converted from VMAT apertures to IMRT fluence, and the optimization proceeds with the mixed variable set until convergence or until additional beams are selected for conversion. One phantom and two clinical cases were used to validate the gradient factor and characterize the FusionArc strategy. Comparisons were made between standard IMRT, single‐arc VMAT, and FusionArc plans with one to five IMRT/hybrid beams.

Results:

The gradient factor was found to be highly predictive of the VMAT angles that would benefit plan quality the most from beam modulation. Over the three cases studied, a FusionArc plan with three converted beams achieved superior dosimetric quality with reductions in final cost ranging from 26.4% to 48.1% compared to single‐arc VMAT. Additionally, the three beam FusionArc plans required 22.4%–43.7% fewer MU/Gy than a seven beam IMRT plan. While the FusionArc plans with five converted beams offer larger reductions in final cost—32.9%–55.2% compared to single‐arc VMAT—the decrease in MU/Gy compared to IMRT was noticeably smaller at 12.2%–18.5%, when compared to IMRT.

Conclusions:

A hybrid VMAT/IMRT strategy was implemented to find a high quality compromise between gantry‐angle and intensity‐based degrees of freedom. This optimization method will allow patients to be simultaneously planned for dosimetric quality and delivery efficiency without switching between delivery techniques. Example phantom and clinical cases suggest that the conversion of only three VMAT segments to modulated beams may result in a good combination of quality and efficiency.
Complete Genome Sequence of Early Passaged Human Herpesvirus 6A (GS Strain) Isolated from North America
Authors: Gravel Annie , Ablashi Dharam , Flamand Louis
Published: June 2013

The genome sequence of the original human herpesvirus 6A (HHV-6A) (GS isolate) has never been determined. DNA from a very low passage (<5 times) HHV-6A GS stock was isolated and sequenced, making it the first HHV-6A of U.S. origin to be fully sequenced. Such a sequence will be helpful for comparative analysis with other HHV-6A strains, including the U1102 strain isolated from Uganda.
Draft Genome Sequence of Arthrobacter gangotriensis Strain Lz1y
T
, Isolated from a Penguin Rookery Soil Sample Collected in Antarctica, near the Indian Station Dakshin Gangotri
Authors: Shivaji Sisinthy , Ara Sreenivas , Bandi Sunil , Singh Aditya , Kumar Pinnaka Anil
Published: June 2013

We report here the 4.3-Mb genome of
Arthrobacter gangotriensis
strain Lz1y
T
, isolated from a penguin rookery soil sample collected in Antarctica, near the Indian station Dakshin Gangotri.
Necrotising fasciitis of the thigh
Authors: Haemers K , Peters R , Braak S , Wesseling F
Published: June 2013

Necrotising fasciitis (NF) is an extremely virulent form of infectious fasciitis. It affects skin, subcutaneous fat and superficial and deep muscular fascia by rapidly progressive necrosis. Expeditious diagnosis and radical debridement is necessary to prevent the onset of sepsis, multisystem organ failure and possible death. Perforated rectal cancer resulting in NF can spread to the perineum and genitals known as Fournier gangrene. This case describes an unusual case of NF of the right thigh as first presentation highly suggestive for rectal cancer.
The reversible cerebral vasoconstriction syndrome in association with venlafaxine and methenamine
Authors: Davies G , Wilson H , Wilhelm T , Bowler J
Published: June 2013

The reversible cerebral vasoconstriction syndrome (RCVS) is characterised by thunderclap headache and multifocal vasoconstriction of cerebral arteries on angiography. It is often drug induced, but it can occur postpartum, and as a result of a number of other precipitants. To make the diagnosis, it is necessary to exclude other causes of severe headache (such as aneurysmal subarachnoid haemorrhage, carotid dissection and primary angiitis of the central nervous system). However, it is also important to show that the vasoconstriction has resolved with repeat angiography at the 3-month stage. Here we report two cases of RCVS in association with venlafaxine and the urinary antiseptic, methenamine. Serotonin–norepinephrine reuptake inhibitors have recently been reported as a possible precipitant, but this is the first report to implicate methenamine. Although RCVS is relatively uncommon, it should be considered in the differential of those presenting with thunderclap headache.
Educational agenda for diagnostic error reduction
Authors: Trowbridge Robert L , Dhaliwal Gurpreet , Cosby Karen S
Published: June 2013

Diagnostic errors are a major patient safety concern. Although the majority of diagnostic errors are partially attributable to cognitive mistakes, the most effective means of improving clinician cognition in order to achieve gains in diagnostic reliability are unclear. We propose a tripartite educational agenda for improving diagnostic performance among students, residents and practising physicians. This agenda includes strengthening the metacognitive abilities of clinicians, fostering intuitive reasoning and increasing awareness of the role of systems in the diagnostic process. The evidence supporting initiatives in each of these realms is reviewed and a course of future implementation and study is proposed. The barriers to designing and implementing this agenda are substantial and include limited evidence supporting these initiatives and the challenges of changing the practice patterns of practising physicians. Implementation will need to be accompanied by rigorous evaluation.
Will Decision-Support Systems Be Widely Used for the Management of Plant Diseases?
Authors: Shtienberg Dani
Published: June 2013

Decision-support systems (DSSs) are interactive computer-based systems that help decision makers solve unstructured problems under complex, uncertain conditions. Experimental use of DSSs has resulted in improved disease suppression and lowered risks of crop damage. In many cases, it has also led to the use of smaller quantities of active substances, as compared with standard spraying practices. Hundreds of DSSs have been developed over the years and are readily available and affordable. However, most farm managers do not use them as part of their integrated pest management (IPM) practices. Since the mid-1980s, the author of this paper, together with numerous colleagues, has developed DSSs and decision rules for the management of diseases in a variety of crops, including extensive crops, such as wheat, sunflower, and pea; semi-intensive crops, such as pear, chickpea, cotton, and tarragon; and intensive crops, such as tomato, potato, cucumber, sweet pepper, carrot, and grapevine. Some of these systems were used widely, but others were not. This experience may allow us to draw general conclusions regarding the use of DSSs and decision rules. Possible explanations for the widely varying acceptance rates are presented, and the effects of anticipated changes in the agribusiness sector on the future use of DSSs are discussed.
Experimental Measures of Pathogen Competition and Relative Fitness
Authors: Zhan Jiasui , McDonald Bruce A.
Published: June 2013

Competition among pathogen strains for limited host resources can have a profound effect on pathogen evolution. A better understanding of the principles and consequences of competition can be useful in designing more sustainable disease management strategies. The competitive ability and relative fitness of a pathogen strain are determined by its intrinsic biological properties, the resistance and heterogeneity of the corresponding host population, the population density and genetic relatedness of the competing strains, and the physical environment. Competitive ability can be inferred indirectly from fitness components, such as basic reproduction rate or transmission rate. However, pathogen strains that exhibit higher fitness components when they infect a host alone may not exhibit a competitive advantage when they co-infect the same host. The most comprehensive measures of competitive ability and relative fitness come from calculating selection coefficients in a mixed infection in a field setting. Mark-release-recapture experiments can be used to estimate fitness costs associated with unnecessary virulence and fungicide resistance.
(Invited) Metal Oxide Nano Film Characterization for CMP Optimization
Authors: Basim G. Bahar , Karagoz Ayse , Ozdemir Zeynep
Published: June 2013

This paper focuses on the planarization of metallic films in microelectronics manufacturing by CMP through investigation of metal oxide thin films forming as a result of the chemical component of the process. Tungsten planarization is discussed as a model to establish the role of metal oxide nano-films in achieving material removal through their formation characteristics during polishing. The findings indicate a protective oxide film formation on tungsten, which tends to nucleate at high concentrations of oxidizers and enables material removal through the interaction of nano-particles in the slurry with the surface oxide hillocks.
Metal Clearing Process Control in Metal CMP
Authors: Xu Kun , Carlsson Ingemar , Liu Tzu-Yu , Shen Shih-Haur , Swedek Bogdan , Wang You , Xia Xinyun , Bennett Doyle , Tu Wen-Chiang , Karuppiah Lakshmanan
Published: June 2013

Metal clearing in chemical mechanical polishing was conducted using a fixed polishing recipe, with polish pressures tuned based upon blanket metal film’s bulk removal uniformity. A fixed recipe cannot count for incoming film’s non-uniformity, pattern lay out impact, and consumable life induced process drift. Consequently, a fixed recipe used in metal clearing step can result in poor within wafer Rs range on patterned wafers. This paper described Within Wafer (WIW) clearing uniformity and topography uniformity was improved via a novel metal clearing process control, and was adaptive to consumable and hardware’s variations.
Electrochemical Characterizations and CMP Performance of Ru Slurry
Authors: Shi Tom Xiaobo , Henry James , Schlueter James
Published: June 2013

Currently, the manufacture of integrated circuits and fabrication of electronic devices requires the use of various types of chemical mechanical polishing compositions to selectively remove different metal, barrier, dielectric, low-k, ultra-low-k and other films at desirable rates to achieve the global planarization goal on the surfaces of patterned wafers. For more advanced node processing and applications, the copper metal lines are getting thinner and narrower, which leads to increased resistivity and causes electrical signal loss in the interconnection lines of the fabricated electronic devices. Therefore, new barrier layer materials other than Ta, TaN, Ti and TiN have been introduced in order to reduce the electrical signal loss beyond 20nm node applications. Ruthenium (Ru) has been used and tested as one of the new promising barrier layer materials. The introduction of Ru as a new barrier layer further complicates electrochemical and chemical reactions involved in a barrier chemical mechanical planarization process. Our studies focused on discovering the effects of key chemical components used in the CMP polishing compositions for polishing copper/ruthenium films and the effects of such polishing compositions on corrosion current, open circuit potential, galvanic corrosion and AC impedance on both ruthenium and copper films. The chemical mechanical polish results are reported together with these electrochemical studies. Using electrochemical studies, the effects of corrosion inhibitors on galvanic corrosion behavior at the Cu/Ru interface enables a more effective selection of suitable corrosion inhibitors for polishing Cu/Ru films.
Studies on Slurry Design Fundamentals for Advanced CMP Applications
Authors: Basim G. Bahar , Karagoz Ayse , Ozdemir Zeynep , Vakarelski Ivan U. , Chen Long
Published: June 2013

New developments and device performance requirements in microelectronics industry add to the challenges in chemical mechanical planarization (CMP) process. One of the recently introduced materials is germanium which enables improved performance through better channel mobility in shallow trench isolation (STI) applications. This paper reports on the slurry design alternatives for Ge CMP with surfactant mediation to improve on the silica/germanium selectivity using colloidal silica slurry. In addition to the standard CMP tests to evaluate the material removal rates, atomic force microscopy (AFM) based wear tests were also conducted to evaluate single particle-surface interaction of the polishing system. Furthermore, nature of the surface oxide film of germanium was studied through contact angle measurements and surface roughness tested by AFM. It was observed that the CMP selectivity of the silica/germanium system and defectivity control were possible with a reasonable material removal rate value by using self-assembled structures of cationic surfactants.
Chemical Mechanical Polishing for Extreme Ultraviolet Lithography Mask Substrates
Authors: Amanapu Hari Prasad , Lagudu Uma Rames , Teki Ranganath , John-Kadaksham Arun , Babu Suryadevara V.
Published: June 2013

We describe the effectiveness of depositing an amorphous silicon thin film to cover the existing defects on the surface of extreme ultraviolet (EUV) lithography mask substrates and then polishing the film using abrasive-free liquids. Preliminary investigations on a-silicon coated Si wafers showed that the surface roughness and removal rates (RRs) are largely dependent on the polishing pressure. Higher polishing pressures led to higher removal rates and surface roughness while a lower polishing pressure of 0.5 psi led to negligible RRs but achieved a surface roughness of ~0.1 nm RMS (root-mean square). A two-step CMP process, consisting of polishing at 1 psi followed by polishing at 0.5 psi on an IC-1000 pad gave acceptable surface roughness (~0.1 nm) as well as adequate material removal. The same polishing conditions when transferred to a-silicon films deposited on 6”x6”x0.25” quartz EUV substrates also resulted in a RMS surface roughness of ~0.1 nm.
Precision, Damage-Free Etching by Electron-Enhanced Reactions: Results and Simulations
Authors: Gillis H.P. , Anz Samir J. , Han Si-Ping , Su Julius , Goddard William A.
Published: June 2013

Ion-enhanced dry etch methods inflict "etch process damage" through surface ion bombardment. These inherent limitations in conventional dry etch methods create potential roadblocks to achieving device properties necessary for scaling below 32 nm. We describe an alternative dry etch method in which electrons with energies below about 100 eV stimulate precision etching of features as small as 20 nm without damage. This Low Energy Electron Enhanced Etching (LE4) method also gives atomically smooth etched surfaces, very high selectivity between materials, and maintains stoichiometry of compound materials. LE4 etches low K dielectric materials with no loss of carbon, and gives Line Width Roughness (LWR) values dramatically smaller than achieved by ion-enhanced etching. We have developed the Electron Force Field (eFF) method to describe electron dynamics in highly excited electronic states, and use it to show preferential bond breaking and product desorption after electronic excitation of the sample surface.
Surface Conduction Mechanism in AlGaN/GaN High Electron Mobility Transistors with Pre-Gate Treatment
Authors: Cheng Chun-Hu , Chang Tsu , Liao Sheng Yu , Ho Wei Der , Shiau Yen Cen , Chang Tsu , Sen Jen Shu
Published: June 2013

From our study, we performed an oxygen-plasma pre-gate treatment on AlGaN/GaN HEMT deivce and found that Schottky height lowering after oxygen treatment was ascribed to surface states in AlGaN barrier layer near gate region that might cause output impedance variation, output power degradation and reliability issue. The surface defect traps with a shallow trapping level near gate region are responsible for triggering the behavior of parasitic resistance change. Also, these shallow traps easily generate electron emission current via a trap-assisted process, which can contribute an additional gate leakage current. Thus, such process-induced defect issue may play an important role to affect transistor output characteristics, especially for RF characteristics such as cut-off frequency and RF power gain.
Feature Profile 2D and 3D Simulation with Etching, Deposition, and Implantation Processes
Authors: Moroz Paul , Moroz Daniel J
Published: June 2013

Interaction of plasmas with solid materials during materials processing involves many phenomena. In most cases, processes of etching, deposition, and implantation go on at the same time, and the final result depends on the balance between those processes. Here, the current approach and progress in feature profile simulations via FPS3D are presented. The FPS3D code provides a convenient environment for simulations of processing for any set of materials and fluxes, as well as for any surface and volume reactions. Moreover, the code can treat “recipes” with arbitrary number of steps, each step having its own set of fluxes. To properly compute effects of implantation, the code estimates penetration depths for all used gaseous species interacting with all used solid materials. We report here on the current status of FPS3D as well as on a supporting molecular dynamics code, MDSS, which is mainly used to prepare data for the input and chemistry files for FPS3D.
Microscopic Polarization Behavior and Thermodynamic Stability of TiS and Ti4C2S2 Inclusions in Stainless Steels
Authors: Shimahashi Naoya , Muto Izumi , Sugawara Yu , Hara Nobuyoshi
Published: June 2013

Microelectrochemical polarization, thermodynamic calculations, and Auger electron spectroscopy were performed to elucidate the predominant factor affecting the pit initiation resistance at sulfide and carbosulfide inclusions in stainless steels. The Ti-oxide enriched layers on the inclusions inhibit the dissolution of the TiS and Ti4C2S2 inclusions in the passive and trans-passive regions of stainless steels. While the MnS inclusion surfaces are covered by Mn-oxides, the corrosion resistance of Mn-oxides is not sufficient to prevent the inclusion dissolution and pit initiation. The oxide enriched surface layers on the sulfide and the carbosulfide inclusions greatly influence the pit initiation resistance at the inclusions.
Microelectrochemical Investigation of Pit Initiation and Selective Dissolution between MnS and Stainless Steel
Authors: Chiba Aya , Muto Izumi , Sugawara Yu , Hara Nobuyoshi
Published: June 2013

In a solution with Cl- ions, the trench at the MnS/steel boundary was found to be formed by the dissolution of the stainless steel as a precursor of pit initiation. The synergistic effect of the MnS dissolution products with Cl- ions caused dissolution on the stainless steel side of the boundary. The proposed pit initiation mechanism at the MnS inclusions is follows: 1) the dissolution of the stainless steel is caused by the synergistic effect of the MnS dissolution products with Cl- ions, which made the trench at the boundary; 2) the pits initiate in this trench because the trench is the occluded area, and the preferred site for pit initiation.
Investigation into the Effect of Spot Weld Electrode Life and Quality on the Corrosion Behavior of Galvanized Automotive Steel Using the Three-dimensional Scanning Vibrating Technique
Authors: Wilson Benjamin Paul , Searle Justin R. , Yliniemi Kirsi , Jones T. Bryan , Worsley David A. , McMurray H. Neil
Published: June 2013

The Three dimensional Scanning Vibrating Electrode Technique (3D SVET) – which allows the measurement of non-planar samples - has been used to investigate the effects that spot weld tip lifetime (i.e. number of welds produced by a tip between dressings) has on corrosion of spot welded steel. Cathodic activity is concentrated within the spot weld when weld tips are fresh (used for <10 welds) or aged (>1000 welds) whilst anodic activity is found on the spot weld perimeter. This is due to copper deposition within the weld and zinc enrichment around the spot weld as a result of the welding process.
Corrosion under Water-Repellent Coating
Authors: Akage Yuuichi , Saito Hiroyuki
Published: June 2013

A paint film or coating protects a metal substrate from corrosion.Since a water-repellent coating is hydrophobic, the coating mustserve as higher barrier than other conventional coatings. Weelectrochemically investigated the corrosion under water-repellentcoating. We found that water penetrates into water-repellentcoatings as well as conventional coatings and the metal substrate is corroded.
Evaluation of Zinc Rich Paint (ZRP) Efficiency on Mild Steel in Seashore Environment
Authors: Sofian Azizul Helmi , Noda Kazuhiko
Published: June 2013

Exposure to humidity and salinity in atmosphere will accelerate the corrosion process of steel. Corrosion of metallic surfaces can be reduced or controlled by addition of chemical compounds to corrodent. Zinc is one of the most important components for commercial application in the corrosion protection of steel, for which it is extensively employed to coat or galvanize ferrous metallic products. In this paper is focused with directly on efficiency of ZRP coating applied on steel substrate under NaCl solution as artificial seashore environment by using Open Circuit Potential (OCP) measurements and Electrochemical Impedance Spectroscopy (EIS).
Non-destructive Evaluation of a Corroded Metal Surface Using Terahertz Wave
Authors: Kariya Hidetaka , Sato Akihiro , Tanabe Tadao , Saito Kyosuke , Nishihara Katsuhiro , Taniyama Akira , Oyama Yutaka
Published: June 2013

In this paper, the possibility of utilizing characteristic absorption spectra in the terahertz (THz) frequency region for the non-destructive evaluation of a corroded metal surface coated with an insulator is discussed. The infrared activity of corrosion products in response to THz waves was characterized. The THz absorption spectra of Al(OH)3 and ZnCl2∙4Zn(OH)2 powders, which are typical corrosion products in Zn-Al alloy, were measured with a frequency tunable terahertz light source based on difference frequency generation from a GaP crystal. Characteristic absorption peaks were observed in both spectra. Subsequently, THz reflection imaging was conducted on a metal surface partially covered with these corrosion products and a coating. By using the characteristic absorption peaks of the corrosion products, the spatial distribution of these products was clearly obtained. From the results, it was shown that THz waves can be applied to the non-destructive evaluation of corroded metal surfaces coated with insulators.
Non-destructive Inspection of Copper Corrosion via Coherent Terahertz Light Source
Authors: Oyama Yutaka , Yamagata Takashi , Kariya Hidetaka , Tanabe Tadao , Saito Kyosuke
Published: June 2013

In order to investigate the infrared activities of corrosion products of copper in terahertz (THz) frequency band, THz absorption spectra of copper (I) oxide (Cu2O) and copper (II) oxide (CuO) powders are measured. In view of the practical application for non-destructive inspection of copper wire deterioration, THz reflectance spectra of copper conductive wires with and without oxidization were also measured. THz spectroscopy results have shown some clear specific absorption bands in 1-5THz region, and the THz reflection spectra have revealed clear reflection intensity difference at around 1.7THz band between corroded and not-corroded copper wires. It is also shown that the surrounding polyethylene (PE) of copper electric wire is very transparent for THz wave, thus non-destructive inspection of the corrosion status of copper wire surrounded by the invisible PE insulator can be possible by using THz wave.
Electrochemical Behavior of Ti-6Al-7Nb in Simulated Physiological Body Fluid Environment
Authors: Al-Mobarak Norah Abdulaziz , Al-Swayih Amal , Al-Rashoud F
Published: June 2013

The electrochemical behavior of Ti-6Al-7Nb was investigated, and compared with that of Ti–6Al–4V alloy, which is commonly used as implant material, particularly for dentistry, orthopaedic and osteosynthesis applications. The aim of present study was to evaluate their corrosion resistance in an artificial physiological conditions using Hank’s solution at 37◦C. This evaluation was carried out through the analysis of the potentiodynamic polarization (PD), and electrochemical impedance spectroscopy (EIS) tests. Very low current densities were obtained from the PD curves, indicating a typical passive behavior for two investigated alloys. The EIS results at open circuit potential and at different potential exhibited capacitive behavior (high corrosion resistance) with phase angles close to −90◦ and high impedance values at low and medium frequencies, which are indicative of the formation of a highly stable film on these alloys in the test solution. The resistance of TAN is slightly higher than that of TAV. This difference can be attributed to the alloying elements. For TAN, the formation of Nb2O5 oxide, which is chemically more stable and less soluble compared to V2O5 formed on the Ti–6Al–4V alloy, enhances resistance to dissolution of the surface film. Thus, it has been suggested that Ti–6Al–7Nb can be a better alternative to Ti–6Al–4V in simulated body fluid environment.
Microstructural Controls of a Titania Electrode for Dye-Sensitized Solar Cells
Authors: Nakamura Ayaka , Hyodo Takeo , Shimizu Y.
Published: June 2013

Dye-sensitized solar cells (DSSCs) have been fabricated by employing TiO2 nanotubes (TNTs) with large specific surface area (SSA) and submicron-sized macroporous (mp-)TiO2 powders. The SSA of TNT obtained was much larger than that of commercial TiO2 nanoparticles (P25, AEROXIDE®) and the photovoltaic performance of the DSSC with the TNT electrode was larger than that with the P25 electrode. The addition of P25 to the TNT electrode was ineffective in improving the performance, and further addition of In2O3 to the TNT electrode containing P25 led to larger improvement in photoenergy-conversion efficiency to η = 5.73%. This improvement in η is considered to arise from the enhancement of the electronic conduction among TiO2 particles by the mixing of In2O3. On the other hand, the photovoltaic performance of DSSCs with the mp-TiO2 electrodes was low, but the stacking of the mp-TiO2 film onto the P25 electrode was quite effective in improving the photovoltaic performance, probably because of the excellent light scattering properties of the mp-TiO2 film.
Effects of Annealing Pressure for Electrodeposited CuInSe2 Solar Cell
Authors: Chang Tsung Wei , Lee Wen Hsi , Su Yin Hsien
Published: June 2013

As-deposited CuInSe2 films by electrodeposition are generally amorphous. A better photoelectric conversion efficiency of solar cell device should be derived from crystallized CuInSe2 absorber layer, and also the schottky contact with the CdS layer. In this work, a high pressure atmosphere was applied during the heat treatment, which achieved level surface and better crystallization for CuInSe2 thin films. We optimized the atomic ratio of eletrodeposited CuInSe2 thin films, the parameters for annealing process and the fabrication of the entire device. Top view images from field-emission-scanning electron microscopy indicates well-defined grains of CuInSe2 films. Raman spectrum results of annealed CuInSe2 films show the presence of CuInSe2 phase, and no secondery phases such as Cu-Se were detected. Energy dispersive spectrometer analysis shows the composition atomic ratio of copper indium diselenide to be soichiometric. The measurement of solar simulater indicates an imrovement of conversion efficiency of CuInSe2 solar cell after employing the high pressure annealing process.
The Effect of TiO2 Microstructure and Introduction of Silver Nanoparticles on Conversion Efficiency of Sb2S3 Sensitized Semiconductor Solar Cells
Authors: Yoshioka Shohei , Mishima Takayoshi , Ihara Manabu
Published: June 2013

Sensitized semiconductor solar cells consisting of alternative heterojunction materials (TiO2/Sb2S3/CuSCN) are characterized by an extremely thin absorber that allows effective charge transportation due to reduction in recombination. In these cells, Sb2S3 exhibited both positive and negative effects; it generated photocarriers and protected the cell from leakage current, but also behaved as a recombination center and increased the ohmic resistance. CuSCN was the additional critical factor of a cell performance with porous TiO2. CuSCN deposited on top of the porous structure exhibited two effects: high ohmic resistance and control of effective Sb2S3 at pn junctions. To achieve maximization of photocarrier generation and minimization of recombination, silver nanoparticles, which express localized surface plasmons when illuminated, were then applied to Sb2S3 cells with compact TiO2. The results revealed improved photoabsorption without having to increase the amount of Sb2S3, and revealed an improved J
SC from 0.66 mA/cm2 to 1.88 mA/cm2.
Optical Management by Localized Surface Plasmon of Metal Nanoparticles and Application to a Solar Cell
Authors: Nam Kwanwoo , Hachimura Hironori , Ihara Manabu
Published: June 2013

For current-matching of multi-junction Si solar cells, localized surface plasmons (LSPs) of metal nanoparticles (MNPs) are considered as a new solution because MNPs can reflect or transmit light of specific wavelengths. To predict the LSP effect of MNP films in solar cells, we fabricated gold and silver nanoparticle films by spin-coating onto amorphous Si (a-Si) layer and investigated the optical properties of each film. Gold and silver nanoparticle films have the reflection peaks at 700 nm and 600 nm, respectively. Furthermore, we fabricated films by ink-jet printing to adjust the micro and nano-ordered structure and investigated the correlation between the morphology of the films and the optical properties. MNP films fabricated by ink-jet printing have a more balanced reflection and absorption effect compared to films fabricated by spin-coating. Furthermore, we considered appropriate application in multi-junction solar cells using our measured characteristics of the MNP films.
Electrodeposition of In-S based Buffer Layers for High Efficiency Cu(In,Ga)Se2 based Solar Cells
Authors: Chassaing Elisabeth , Naghavi Negar , Galanti Serena , Renou Gilles , Soro Moussa , Bouttemy Muriel , Etcheberry Arnaud , Lincot Daniel
Published: June 2013

Soft chemical processes such as screen printing, sol-gel, electrochemical or chemical bath-deposition, enable low cost and easily scalable processes for thin layer solar cells. For the CIGSe based solar cells, with the standard Mo/Cu(In,Ga)Se2/CdS/i-ZnO/n+-ZnO structure, all layers of the p-n heterojunction and the transparent conductive oxide window can be grown by aqueous solution processes. In this work we focus on the electrochemical investigation of In-S layers. XPS analyses show the presence of both S and O. Conversion efficiencies of complete devices up to 14 % are obtained.
Optical Property of Random Inverted-Pyramid Textures on Si Surface by Etching with N-Fluoropyridinium Salts
Authors: Otani Masaki , Uchikoshi Junichi , Tsukamoto Kentaro , Hirano Toshinori , Nagai Takabumi , Adachi Kenji , Kawai Kentaro , Arima Kenta , Morita Mizuho
Published: June 2013

We have proposed a new photo-etching method to form Si surface textures with N-fluoropyridinium salts. Si is etched by applying N-fluoropyridinium salts to its surface and exposing the surface to light. Etching depth increases with light intensity. We have formed random inverted-pyramid textures on a Si surface by controlling the light intensity at a constant temperature.
EC-STM Study of Two-Dimensional Complex Adlayer Directly Formed on Au(111)
Authors: Yoshimoto Soichiro , Nishiyama Katsuhiko
Published: June 2013

Redox-active adlayers consisting of 4',4''''-(1,4-phenylene)bis(2,2':6',2''-terpyridine) ligand and Co2+ and/or Fe2+, were prepared on a Au(111) surface by a stepwise coordination method. The obtained adlayers produced a well-defined, stable redox wave associated with Co2+ and/or Fe2+ coordinated to 4',4''''-(1,4-phenylene)bis(2,2':6',2''-terpyridine). It was found that the ability to coordinate with PTPy adlayer formed on Au(111) was clearly dependent on the metal ions.
Surface Morphology and Stress in Electrodeposited Copper Nanofilms
Authors: O'Grady Michael , Lenihan Catherine , Buckley Denis Noel
Published: June 2013

In-situ stress measurements and in-situ AFM imaging were employed to studystress evolution during the electrodeposition of copper nanofilms from acidiccopper sulphate electrolyte, at overpotentials of 125–200 mV and to comparethe observed stress and morphology changes with theoretical predictions. Asthe films grew, tensile stress initially increased, corresponding to graincoalescence as observed by AFM, and reached a plateau value when significantGB volume had occurred. The time evolution of stress was examined duringinterruption of deposition. Generally, when deposition was interrupted, tensilestress decreased as predicted by Chason's model13 for low mobility deposits. Atall potentials, upon resuming deposition stress recovered to its pre-interruptedstate. Stress increased with increasing overpotential as expected from theory.Cl- was found to directly reduce stress and resulted in a rougher surface thanwas observed without additives.
Application of Artificial Neural Networks to Predict Chemical Composition of Electrodeposited Nanocrystalline Ni-Mo Thin Films
Authors: Allahyarzadeh Mohammad Hosein , Ashrafi Ali , Shahrabi Taghi , Seddighian A , Aliofkhazraei Mahmoud , Sabour Rouhaghdam Alireza
Published: June 2013

Present research represents the application of artificial neural networks to predict the chemical composition of electrodeposited Ni-Mo thin films. Artificial neural networks commonly are utilized as a prediction tools so that these networks could approximately find kind of logic relationships between inputs and target; they fitted appropriate coefficient and weighting factors to the inputs which are proportional to their importance. In order to evaluate the model developed, three experimental results were compared with the predicted ones. However, more data are required to train more reliable prediction models, presents study revealed an acceptable error less than 1% between predicted values and experimental data. The Ni-Mo thin films also were conducted from citrate-ammonia deposition bath. Microstructure, morphology and chemical composition of deposited films was studied using scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis.