bluuebunny/crossref_metadata_2025 huggingface dataset:
Stability and predictive utility, over 3 years, of the illness beliefs of individuals recently diagnosed with Type 2 diabetes mellitus
Authors: Skinner T. C. , Khunti K. , Carey M. E. , Dallosso H. , Heller S. , Davies M. J.
Published: May 2014

Aim

To determine the stability of beliefs of patients with Type 2 diabetes about their diabetes over 3 years, following diagnosis.

Methods

Data were collected as part of a multicentre cluster randomized controlled trial of a 6‐h self‐management programme, across 207 general practices in the UK. Participants in the original trial were eligible for follow‐up with biomedical data (HbA1c levels, blood pressure, weight, blood lipid levels) collected at the practice, and questionnaire data collected by postal distribution and return. Psychological outcome measures were depression (Hospital Anxiety and Depression Scale) and diabetes distress (Problem Areas in Diabetes scale). Illness beliefs were assessed using the Illness Perceptions Questionnaire‐Revised and the Diabetes Illness Representations Questionnaire scales.

Results

At 3‐year follow‐up, all post‐intervention differences in illness beliefs between the intervention and the control group remained significant, with perceptions of the duration of diabetes, seriousness of diabetes and perceived impact of diabetes unchanged over the course of the 3‐year follow‐up. The control group reported a greater understanding of diabetes during the follow‐up, and the intervention group reported decreased responsibility for diabetes outcomes during the follow‐up. After controlling for 4‐month levels of distress and depression, the perceived impact of diabetes at 4 months remained a significant predictor of distress and depression at 3‐year follow‐up.

Conclusions

Peoples' beliefs about diabetes are formed quickly after diagnosis, and thereafter seem to be relatively stable over extended follow‐up. These early illness beliefs are predictive of later psychological distress, and emphasize the importance of initial context and provision of diabetes care in shaping participants' future well‐being.
Morphology of sensory papillae on the feeding proboscis of cone snails (Mollusca, Gastropoda)
Authors: James David , Prator Cecilia A. , Martin Gary G. , Schulz Joseph R.
Published: May 2014

Cone snails, predatory marine gastropods, have developed a specialized prey capture method in which a long, distensible proboscis is used to identify prey and inject venom via a hydraulically propelled hollow radular tooth. Using brightfield, epifluorescence, confocal, and transmission and scanning electron microscopy, we describe the morphology of ciliated sensory structures concentrated on the tip of the proboscis. The number and morphology of these sensory papillae are linked to the type of preferred prey: cone snails feeding on worms and mollusks have short, cone or finger‐shaped papillae, whereas fish‐hunting cone snails have long tubular papillae in addition to short conical papillae. Sensory papillae are well positioned to provide information necessary to locate, identify, and dispatch prey. Proboscis tips and their sensory papillae regenerated within 10 d following experimental ablation, and snails with regenerated proboscis tips were able to locate and envenomate prey. The remarkable intrageneric variation found in the morphology of these sensory structures is probably linked to the specialized prey that cone snail species have evolved to hunt.
Understanding health care delivery as a complex system
Authors: Sturmberg Joachim , Lanham Holly J.
Published: May 2014

Rationale, aims and objectives

The concept of emergence offers a new way of thinking about multimorbidity and chronic disease.

Results and conclusions

Multimorbidity and chronic disease are the end results of ongoing perturbations and interconnected activities of simpler substructures that collectively constitute the complex adaptive superstructure known as us, the person or patient. Medical interventions cause perturbations of many different subsystems within the patient, hence they are not limited to the person's bodily function, but also affect his general health perception and his interactions with his external environments. Changes in these domains inevitably have consequences on body function, and close the feedback loop of illness/disease, recovery and regained health.
Individual and contextual determinants of innovative work behaviour: Proactive goal generation matters
Authors: Montani Francesco , Odoardi Carlo , Battistelli Adalgisa
Published: May 2014

This study examines the extent to which proactive goal generation is a self‐regulatory mechanism that explains how individual and contextual factors influence employee innovative work behaviour. Specifically, it is proposed that learning goal orientation (LGO), psychological climate for innovation, and task variety positively and indirectly influence innovative behaviour via proactive goal generation activities, namely envisioning and planning. Additionally, LGO is expected to positively moderate the planning–innovation link. Based on data collected at two points in time on a sample of 107 employees from 12 small Italian enterprises, we found that envisioning and planning mediated the positive impact of LGO, psychological climate for innovation, and task variety on innovative behaviour. Furthermore, the relationship between planning and innovative behaviour was stronger when LGO was higher. Theoretical and managerial implications of these findings are discussed.

Practitioner points

Individual engagement in proactive goal‐regulatory activities is an important driver of workplace innovative behaviour. It is hence worthwhile for managers to provide employees with practical tools and guidelines to develop their proactive goal‐setting and goal‐planning skills.

Learning goal orientation, psychological climate for innovation, and task variety indirectly shape innovative work behaviour by affecting envisioning and planning processes. In order to increase employees' motivation to engage in proactive goal generation tasks, managers should thus promote the development of a change‐oriented work environment, ensure an adequate amount of variety in the execution of work activities, and retain and develop a learning‐oriented workforce.

Learning goal orientation is a boundary condition associated with planning's effects on innovative behaviour. Managers should hence emphasize skill development and the use of flexible approaches in the execution of plans and tasks.
Impacts of altered precipitation, nitrogen deposition and plant competition on a Mediterranean seed bank
Authors: Ochoa‐Hueso Raúl , Manrique Esteban
Published: May 2014

Questions

Do increased nitrogen (N) fertilization, altered water supply and increased competition by a nitrophilous plant species alter the establishment of the plant community developed from the soil seed bank present in a semi‐arid Mediterranean ecosystem under greenhouse conditions? Does the nitrophilous plant respond in the same way to N addition under field conditions?

Location

The kermes oak/rosemary shrubland in the Nature Reserve El Regajal‐Mar de Ontígola, central Spain.

Methods

In September 2008, native soil seed bank was collected in open areas dominated by rosemary shrubs. Seeds of the nitrophilous Diplotaxis siifolia were collected in early summer 2008. Pots with aliquots of soil were distributed among eight treatments, which resulted from combinations of two levels of N fertilization, water supply and density of D. siifolia in the seed bank. The plant community was left to grow for 3 mo, when chlorophyll fluorescence measurements and harvests were made. In summer 2008, the soil seed bank density of 0 and 50 kg N·ha−1·yr−1 plots was also manipulated in the field by broadcasting seeds to a density of 8000 D. siifolia seeds·m−2.

Results

Increased N and competition tended to reduce soil water content in ‘high water’ pots. High water and N fertilization increased total above‐ and below‐ground plant biomass production. Nitrogen fertilization reduced plant root:shoot ratio, had a negative effect on plant richness and, coupled with ‘high competition’ and ‘high water’, reduced forb biomass productivity. The competition treatment decreased chlorophyll fluorescence in grasses. Under field conditions, N fertilization increased D. siifolia density and this effect was dependent on soil phosphorus availability.

Conclusions

Our results show that nitrophilous plant species such as D. siifolia can be a threat to local plant communities in the context of increased N deposition and altered precipitation events. In particular, local plant communities from semi‐arid Mediterranean climates, and especially the forb element, may suffer more from competition in highly polluted and invaded sites during unusually wet years. Finally, we predict a future increase in the relative dominance of these species in semi‐arid Mediterranean environments where forb species typically adapted to low‐nutrient environments will fail to successfully compete with weeds.
Let's Get Messi? Top‐Scorer Productivity in the European Champions League
Authors: Fry Tim R. L. , Galanos Guillaume , Posso Alberto
Published: May 2014

Getting a player like Lionel Messi in the squad would seem like a dream come true for a professional football manager, but is it always best to have top‐quality players? We study the determinants of top goal‐scorers’ productivity in the UEFA Champions League. We find evidence of a concave relationship between age and productivity and uncover an inverted‐U relationship between performance and minutes played. Finally, we find a positive effect on height, being left footed and being a striker on the probability of scoring a goal. The results have important implications for managers both in looking to sign on new players and to maximise their potential during a competitive match.
Competition Between Exclusive Religions: The Counter‐Reformation As Entry Deterrence
Authors: Ferrero Mario
Published: May 2014

This article sets forth a theory of competition between exclusive religions as an entry deterrence game, in which the incumbent may find it profitable not to accommodate but to deter the competitor's entry by precommitting to sufficient capacity expansion in the event of entry. If entry costs are high enough, deterrence is optimal and the incumbent remains a monopolist, although the entry threat distorts its effort upward. The model is then applied to the Catholic Church's reaction to the Protestant Reformation. It is argued that the model provides a better fit to the historical data of the Counter‐Reformation than the price‐cutting model proposed by economists Ekelund, Hébert and Tollison (, ).
Comparison of the Sysmex XT‐2000iV and microscopic bone marrow differential counts in Wistar rats treated with cyclophosphamide, erythropoietin, or serial phlebotomy
Authors: Criswell Kay A. , Bock Jeffrey H. , Wildeboer Samantha E. , Johnson Kjell , Giovanelli Richard P.
Published: May 2014

Background

In a previous study, it was demonstrated that bone marrow analysis using the Sysmex XT‐2000iV hematology analyzer produced differential counts in untreated rats that were comparable to microscopic differential counts.

Objective

The aim of this study was to modulate hematopoiesis in rats in vivo either through pharmacologic treatment or serial phlebotomy, and to determine whether the Sysmex XT‐2000iV could accurately analyze bone marrow quantitative changes when compared with results obtained by microscopy.

Methods

Rats were treated once with 0, 5, 20, and 40 mg/kg cyclophosphamide (CP), 0, 50, 100 IU/kg erythropoietin (EPO) on 4 consecutive days, or serial phlebotomy of 1–2 mL of blood for 4 days. Modulation of hematopoietic populations in bone marrow was evaluated using the Sysmex XT‐2000iV hematology analyzer, and compared with microscopic differential counts.

Results

Correlation coefficients between M:E ratios determined by Sysmex and the microscopic method were 0.94, 0.96, and 0.98 for CP, EPO, or serial phlebotomy treatments, respectively. Mean concordance correlation coefficients for M:E demonstrated method agreement of 0.63, 0.92, and 0.85 for the 3 treatments. Quantitative automated and microscopic bone marrow differential counts were within the expected 95% confidence intervals for CP, EPO or serial phlebotomy.

Conclusions

The Sysmex XT‐2000iV provides quantitative bone marrow differential counts of bone marrow cell series in rats with treatment‐induced changes which are comparable to microscopic differential counts. Reliable automatic bone marrow differential counting allows increased throughput, sensitivity, reproducibility, and enhanced interpretation of bone marrow evaluation in rodent preclinical studies.
Flow Pulsation and Geometry Effects on Mixing of Two Miscible Fluids in Microchannels
Authors: Ammar Houssein , Ould el Moctar Ahmed , Garnier Bertrand , Peerhossaini Hassan
Published: May 2014

Many microfluidic applications involve chemical reactions. Most often, the flow is predominantly laminar, and without active or passive mixing enhancement the reaction time can be extremely long compared to the residence time. In this work we demonstrate the merits of the combination of flow pulsation and geometrical characteristics in enhancing mixing efficiency in microchannels. Mixing was studied by introducing a mixing index based on the gray level observed in a heterogeneous flow of pure water and water colored by rhodamine B. The effects of the injection geometry at the microchannel inlet and the use of pulsed flows with average Reynolds numbers between 0.8 and 2 were studied experimentally and numerically. It appeared that the mixing index increases with the nondimensional residence time (τ), which is inversely proportional to the Reynolds number. In addition, we show that the mixing efficiency depends strongly on the geometry of the intersection between the two fluids. Better mixing was achieved with sharp corners (arrowhead and T intersections) in all cases investigated. In pulsed flow, the mixing efficiency is shown to depend strongly on the ratio (β) between the peak amplitude and the mean flow rate. Optimal conditions for mixing in the microchannels are summarized as a function of Reynolds number Re, the ratio β, and the geometries.
Infective endocarditis caused byStreptococcus gallolyticussubspeciespasteurianusand colon cancer
Authors: Takamura Noriko , Kenzaka Tsuneaki , Minami Kensuke , Matsumura Masami
Published: May 2014

A 56-year-old man presented to our department with a 2-month history of fever and chills. He had received a mitral valvuloplasty 3 years ago. He had been administered levofloxacin for 2 months. We discontinued levofloxacin and repeated the blood cultures. Bacterial blood cultures were positive and transoesophageal echocardiography revealed vegetation attached to the posterior mitral leaflet. We started the patient on intravenous antibiotic therapy for infectious endocarditis byStreptococcus gallolyticussubspeciespasteurianus. A colonoscopic screening revealed adenomatoid intracellular carcinoma. Previous studies have reported a weak association between colorectal cancer andStreptococcus bovisbiotype II/2, which includesS gallolyticussubspeciespasteurianus; however, the rate is notably higher than the rate of colorectal cancer as indicated by positive faecal occult-blood test results. We conclude that colonoscopies should be routine while scanning for colorectal cancer in all patients withS bovisbacteraemia, regardless of the subspecies.
A free boundary problem modeling electrostatic MEMS: II. Nonlinear bending effects
Authors: Laurençot Philippe , Walker Christoph
Published: May 2014

Well-posedness of a free boundary problem for electrostatic microelectromechanical systems (MEMS) is investigated when nonlinear bending effects are taken into account. The model describes the evolution of the deflection of an electrically conductive elastic plate suspended above a fixed ground plate together with the electrostatic potential in the free domain between the two plates. The electrostatic potential is harmonic in that domain and its values are held fixed along each plate. The equation for the elastic plate deflection is a parabolic quasilinear fourth-order equation, which is coupled to the gradient trace of the electrostatic potential on the elastic plate.
Robust error estimates in weak norms for advection dominated transport problems with rough data
Authors: Burman Erik
Published: May 2014

We consider transient convection–diffusion equations with a velocity vector field with multiscale character and rough data. We assume that the velocity field has two scales, a coarse scale with slow spatial variation, which is responsible for advective transport and a fine scale with small amplitude that contributes to the mixing. For this problem we consider the estimation of filtered error quantities for solutions computed using a finite element method with symmetric stabilization. A posteriori error estimates and a priori error estimates are derived using the multiscale decomposition of the advective velocity to improve stability. All estimates are independent both of the Péclet number and of the regularity of the exact solution.
AN INTERACTIVE COMPUTER FRAMEWORK FOR LEARNING GENETICS
Authors: YANG XIAOLI , CAI YIFAN , TSENG CHARLES
Published: May 2014

To enhance the effectiveness of learning genetics, we have developed a series of individual computer programs integrating interactivity with animated processes. It was noted that, although the content of the programs varied, the programs all contained a number of common features, including the ability to display text and images, present animated content, and interact with the user. These common features led us to the development of an innovative and unified framework of integrated functions for modeling and simulations. The framework, named "GeneAct" was developed to standardize and accelerate the development of the computer based genetics learning programs and was used as the application programming interface (API). The API allows the content to be imbued with rich text (text with multi-formats), static images, and animations; and it also allows the program to be interactive.
Toward the Directed Self-Assembly of Engineered Tissues
Authors: Varner Victor D. , Nelson Celeste M.
Published: May 2014

Using scaffold-based approaches, tissue engineers have made bold steps toward creating replacement tissues in the laboratory. However, many of these engineered constructs do not fully match the functional properties of their native counterparts. This is partially due to our limited quantitative understanding of the growth and remodeling processes that alter the architecture of engineered tissues, both in culture and after implantation. Here, we consider the mechanisms by which physical cues direct this adaptive response. In particular, we highlight recent experimental and computational studies that characterize quantitatively the mechanics of growth and remodeling in tissue constructs. These advances, from fields as diverse as soft tissue biomechanics and developmental biology, can be used to design new tissue engineering approaches that direct the self-assembly of engineered tissues.
Effects of Electrolytes on the Photoelectric Properties of TiO2-Based Dye-Sensitized Solar Cells
Authors: Shang Mingwei , Liu Benjamin , Dong Zhenhua , Dong Zhenyu , Sun Qiong , Dong Lifeng
Published: May 2014

During the past two decades, unique photoelectric properties of TiO2 have attracted a lot of interest in the research of dye-sensitized solar cells (DSSCs); however, the use of a proper type of electrolyte is a decisive limitation correlating to the final performance of this kind photovoltaic device. This paper is focused on analyzing the effects of different electrolytes on the cell performance in order to improve the photoelectric properties of TiO2-based DSSCs. Specifically, for the cell fabrication, the iodine-based electrolyte, sulfur-based electrolyte and inorganic solid-state electrolyte CsSnI2.95F0.05 are selected to couple with TiO2 nanorod arrays respectively. Their final photovoltaic properties including j-V characteristics and impedance spectroscopy are measured correspondingly. The cell composing of CsSnI2.95F0.05 shows the highest conversion efficiency around 8.9%, which is much higher than those cells fabricated with the other two kinds of electrolytes.
(Invited) Atomic Layer Deposition of HfO2 Using HF Etched Thermal and RTP SiO2 as Interfacial Layers
Authors: Han Lei , Chen Zhi David
Published: May 2014

Atomic Layer Deposition (ALD) of HfO2 on Si substrates requires an interfacial oxide layer, which should be full of hydroxyl groups (-OH groups) or hydrophilic. Chemical oxide grown by SC1 solution is widely used as an ideal interfacial layer. It was reported that thermal SiO2 and RTP SiO2 are not good as interfacial layers because they are lack of OH groups. In this research, we found that diluted HF etching of thermal SiO2 and RTP SiO2 could create hydrophilic surfaces, which could be used as interfacial layers for ALD of HfO2. The electrical properties of the HfO2 grown on etched thermal and RTP SiO2 is not significantly degraded comparing to the HfO2 grown on chemical oxide.
(Invited) Modeling the Influence of Interface Traps on the Transfer Characteristics of InAs Tunnel-FETs and MOSFETs
Authors: Pala Marco , Esseni David
Published: May 2014

We present a numerical study based on a full quantum transport model to investigate the effects of interface traps in nanowire InAs Tunnel-FETs and MOSFETs by varying the trap energy level, its position and the working temperature. Our 3-D self-consistent simulations show that in Tunnel-FETs even a single trap can deteriorate the inverse subthreshold slope of a nanowire InAs Tunnel-FET; shallow traps have the largest impact on subthreshold slopes; and the inelastic phonon-assisted tunneling through interface traps results in a temperature dependence of the Tunnel-FET characteristics. The effect of traps on the MOSFET characteristics is less dramatic and mainly limited on a degradation of the voltage swing which can be effectively countered out by an aggressive oxide thickness scaling. Finally, we present a comparative analysis of the impact of interface traps on the performance variability of nanowire InAs Tunnel-FETs and MOSFETs by considering several random distributions of traps.
(Invited) Resistive Switching and Current Status of HfO2-based RRAM
Authors: Walczyk Christian , Sowinska Malgorzata , Walczyk Damian , Calka Pauline , Schroeder Thomas
Published: May 2014

The integration of embedded non-volatile memory (eNVM) devices in a Si CMOSmanufacturing process requires to identify cost-effective process flow strategies and Si-CMOS compatible materials. Hafnium dioxide (HfO2) is a promising dielectric for future Resistive Random-Access Memory (RRAM) applications. Following the “More than Moore” (MtM) approach, the advantage is given by the fact that the back-end-of-line(BEOL) integration of HfO2-based metal-insulator-metal (MIM) memory cells allows acost-effective realization of embedded RRAMs. However, it still remains difficult in HfO2-based RRAM to further reduce energy dissipation and in addition to increasereliability for system-on-chip (SoC) applications. Hence, a detailed understanding of the atomic-scale mechanism and the identification of the material changes within the insulator are necessary. To address this issue, RRAM integration aspects were accompanied by fundamental materials research studies. First, non-destructive and in-operando Hard X-ray Photoelectron Spectroscopy (HAXPES) was performed to correlate the resistive switching effect with materials modifications at the Ti/HfO2 interface. The fundamental materials research insights were then transferred to integrated 1T1R devices in 4 kbit RRAM test arrays.
Novel Poly Gate Shaping by Wet Etch Process in 2xnm NAND Flash Device and Beyond
Authors: Liao Yu-Mei , Tai Hsin , Liu Wei-Ting , Chang Hsien-Min , Peng Wen-Chuan , Ying Tzung-Hua , Tang Ching-Hsuan , Yang Chia-Cheng
Published: May 2014

With Moore’s law, critical dimensions (CD) become smaller and smaller, and CD control becomes a task of process developing and wafer fabrication. Gate shrinkage by wet process is one choice of non-lithography techniques to meet smaller CD requirements. In this paper, the polysilicon shrinkage amount can be adjusted by ionic surfactant ratio in TMAH (Tetra methyl ammonium hydroxide) and polysilicon with different phosphorous dopant dosage and thermal budget.
Novel Clean Concept of Advanced Patterning Film (Amorphous Carbon) for Beyond 2xnm Generation Self-Aligned Double-Patterning (SADP) Process
Authors: Tai Hsin , Liao Yu-Mei , Liu Wei-Ting , Peng Wen-Chuan , Ying Tzung-Hua
Published: May 2014

Advanced Patterning Film (APF, Amorphous Carbon) is newly developed hard mask material by APPLIED MATERIALS, Inc. for fine pattern definition, especially used in ArF immersion process. Amorphous carbon is one candidate of core materials of Self-Aligned Double-Pattering (SADP) process, but it is usually suggested not to use wet clean process after pattern definition due to moisture absorption of APF. We successfully demonstrate better amorphous carbon surface clean performance without any film damaged. Line edge roughness (LER) is improved from 3.03nm to 2.48nm (18.2%) and without pattern even-odd space issue beyond 2xnm generation.
(Invited) Reducing EOT and Interface Trap Densities of High-k/III-V Gate Stacks
Authors: Chobpattana Varistha , Mates Thomas , Mitchell William , Zhang Jack , Stemmer Susanne
Published: May 2014

We report on in-situ surface preparation methods prior to atomic layer deposition (ALD) of gate dielectrics on In0.53Ga0.47As, and investigate their influence on the ability to scale the equivalent oxide thickness (EOT) and to reduce interface trap densities (Dit
). The surface treatments employed here consist of in-situ cleaning involving alternating cycles of nitrogen plasma and trimethylaluminum (TMA) pulses prior to ALD of different dielectrics (1,2). We demonstrate metal-oxide-semiconductor capacitors with HfO2 dielectrics and low Dit
(in the mid 1012 cm-2 eV-1 range) that can be scaled to sub-nm EOT. Accumulation capacitances exceed 3 µF/cm2 at 1 MHz on n-type In0.53Ga0.47As. Complementary studies of interface chemistry and surface morphology using transmission electron microscopy, x-ray photoelectron spectroscopy, and secondary ion mass spectrometry as a function of surface cleaning parameters are presented and elucidate the mechanisms by which these novel surface preparation methods allow for reducing both Dit
and EOT.
(Invited) High Brightness, Large Scale GaN Based Light-Emitting Diode Grown on 8-Inch Si Substrate
Authors: Lee Seung-Jae , Park Hyung-Jo , Park Jun-Beom , Jeon Dae-Woo , Baek Jong Hyeob , Li Hongwei , Krishnan Balakrishnan , Su Jie , Paranjpe Ajit , Lee Dong S.
Published: May 2014

A crack-free, uniform InGaN/GaN light-emitting diode (LED) structure with strain-engineered buffer layer was grown on an 8-inch diameter Si(111) substrate. The full width at half maximum (FWHM) of (002) and (102) ω-scan is 280 and 420 arcsec, respectively. For LED on 8-inch Si, multiple quantum well (MQW) photoluminescence (PL) wavelength uniformity of 0.55% (2.4 nm) has been achieved by using proper curvature engineered wafer carrier. We demonstrated high brightness 1 x 1 mm2 LED devices utilizing vertical chip process then evaluated their device properties. The electro-optical characteristics of the fabricated vertical LED (VLED) shows around 1 W light output power at 1 A injection current with operating voltage of 4.0 V.
Enhancement of AlGaN/GaN High Electron Mobility Transistor Off-State Drain Breakdown Voltage via Backside Proton Irradiation
Authors: Li Shun , Hwang Ya-Hsi , Hsieh Yueh-Ling , Ren Fan , Pearton Stephen J. , Patrick Erin , Law Mark E
Published: May 2014

Proton irradiations from the backside of the AlGaN/GaN high electron mobility transistors (HEMTs) were employed to enhance its off-state drain breakdown voltage. Via holes were fabricated directly under the active area of the HEMTs by etching through the Si substrate for the backside irradiations. The steep drop at the end of proton energy loss profile allows radiation-induced defects to be placed at precise locations within the AlGaN/GaN HEMT structure. Neither degradation of drain current nor enhancement of off-state drain voltage breakdown voltage was observed for the HEMTs irradiated with the proton energy of 225 or 275 keV, for which the defects were put in the GaN buffer. HEMTs with defects placed in the two dimensional electron gas (2DEG) channel region and the AlGaN barrier, using 330 or 340 keV irradiations, not only showed degradations on drain current and extrinsic transconductance but also demonstrated improvements of the off-state drain breakdown voltage.
(Invited) High Temperature Wireless Smart Sensor Technology Based on Silicon Carbide Electronics
Authors: Hunter Gary W. , Scardelletti M. C. , Ponchak G. E. , Beheim G. M. , Mackey J. A. , Spry D. J. , Meredith R. D. , Dynys F. W. , Neudeck P G , Jordan J. L. , Chen L. Y. , Harsh K. , Zorman Christian A.
Published: May 2014

Smart Sensor Systems that can operate at high temperatures are required for a range of aerospace applications including propulsion systems. This paper discusses the development and demonstration of the components of a high temperature Smart Sensor System that includes a sensor, electronics, wireless communication, and power scavenging. In particular, a wireless pressure sensor system was demonstrated at 475°C with a notable amount of the power provided by power scavenging at elevated temperatures. This wireless pressure sensor system included a sensor, electronics, and wireless communication components integrated onto a single alumina substrate. High temperature wireless signal transmission at a distance of 1 meter using this approach was demonstrated at 475º C from 70-100 psi for more than one hour. This demonstration of multiple Smart Sensor System components is considered a foundation for the development of high temperature Smart Sensor Systems for use in harsh environments.
(Invited) Effect of Annealing on Electronic Carrier Transport Properties of Gamma-Irradiated AlGaN/GaN High Electron Mobility Transistors
Authors: Yadav Anupama , Schwarz Casey , Shatkhin Max , Wang Luther , Flitsiyan Elena , Chernyak Leonid , Liu Lu , Hwang Y.H. , Ren Fan , Pearton Stephen J. , Lubomirsky Igor
Published: May 2014

AlGaN/GaN High Electron Mobility Transistors were irradiated with 60Co gamma-ray doses from 100 Gy up to a maximum dose of 1000 Gy. After irradiation, the devices were annealed at 200˚ C for 25 minutes. Annealing of the gamma irradiated transistors show that partial recovery of device performance is possible at this temperature. The impact of irradiation and annealing on minority carrier diffusion length and activation energy were monitored through the use of the Electron Beam Induced Current method. Impact on transfer, gate, and drain characteristics were analyzed through current-voltage measurements.
Effect of Proton Irradiation on DC Performance and Reliability of Circular-Shaped AlGaN/GaN High Electron Mobility Transistors
Authors: Xi Y. Y. , Hwang Ya-Hsi , Hsieh Yueh-Ling , Li Shun , Ren Fan , Pearton Stephen J. , Patrick Erin , Law Mark E , Yang Gwangseok , Kim Hong-Yeol , Kim Jihyun , Baca Albert G. , Allerman Andrew A. , Sanchez Carlos
Published: May 2014

The effect of 5 MeV proton irradiation on DC performance and reliability of circular-shaped AlGaN/GaN high electron mobility transistors were investigated. The drain saturation current (IDSS) reduced 12.5% and the sheet resistance increased 9.2% after irradiation with a dose of 2×1014 1/cm2. Threshold voltage shifted more positively with a dose of 2×1014 1/cm2 compared to 2×1013 /cm2. Besides, the breakdown voltage improved 39.8% after irradiation with dose of 2×1014 1/cm2. Simulation was done and the peak electric field at the drain side of the gate edge was found to be reduced after irradiation. The defects generated after irradiation at the AlGaN/GaN interface create a virtual gate and thus reduce the electric field. Gate lag measurement was performed to characterize the defects. The current dispersion of DC to high frequency indicates the defects had been generated after irradiation, which is in agreement with the simulation data.
Optically Allowed Photoluminescence from a Direct-Gap Si-Ge Superstructure on Si0.4Ge0.6
Authors: Lockwood David J. , Rowell Nelson L. , Gouyé Adrien , Favre Luc , Ronda Antoine , Berbezier Isabelle
Published: May 2014

Both Si and Ge possess an indirect band gap, which makes them very inefficient light emitters, and band gap engineering has been proposed as a way to overcome this limitation. According to the theoretical work of M. d’Avezac et al. (Phys. Rev. Lett. 108, 027401 (2012)), a SiGe2Si2Ge2SiGen superstructure on Si0.4Ge0.6 should have a direct and dipole-allowed gap of 0.863 eV. Here we report on the growth of such a structure and its optical properties. Two similar samples were prepared by molecular-beam and solid-phase epitaxy. Photoluminescence (PL) spectra were obtained at low temperatures (6-25 K) with excitation at 405 and 458 nm. A strong low-energy PL quadruplet is seen, with peaks near 729, 758, 792 and 823 meV at 6 K, together with a much weaker peak at 871 MeV. The weak peak at 871 meV is assigned to the dipole-allowed direct-gap transition expected in the superstructure.
(Invited) Ballistic Hot Electron Effects in Nanosilicon Dots and Their Photonic Applications
Authors: Koshida Nobuyoshi , Ikegami Naokatsu , Kojima Akira , Mentek Romain , Suda Ryutaro , Yagi Mamiko , Shirakashi Junichi , Gelloz Bernard , Mori Nobuya
Published: May 2014

The physical property of nanocrystalline silicon (nc-Si) dots as a confined wide-gap material relates not only to photonics, but also to electronics. As supported experimentally and theoretically, the electronic structure with discrete levels significantly enhances the impact ionization rate, and then internal electron avalanche occurs at the early stage of photo-excitation or injection. The nc-Si diode, on the other hand, acts as a planar cold cathode which emits ballistic hot electrons. In addition to the use in vacuum, the device is available for the operation in solutions. In vacuum active-matrix nc-Si electron emitter array has been developed for massively parallel electron beam direct-write lithography. Another application scheme in solutions provides alternative thin films deposition of Si, Ge, and SiGe, in which the nc-Si emitter supplies highly reducing electrons. Recent advancements of these studies are discussed.
(Invited) Narrow Linewidth, Highly Efficient, and Integrated Light Emitting Diodes Based on Ge Quantum Dots in Optical Microcavities
Authors: Xu Xuejun , Maruizumi Takuya , Shiraki Yasuhiro
Published: May 2014

Room-temperature current-injected light emitting diodes with well-resolved and narrow emission peaks are demonstrated based on Ge self-assembled quantum dots embedded in optical microcavities, including photonic crystal cavities and microdisks. By using modified L3-type photonic crystal cavities, sharp resonant peaks with Q-factor over 800 are observed in the electroluminescence spectra around wavelength of 1.3 µm. Measurable output power on the level of pico-Watt is obtained under 3 mA injected current. In order to realize integration with other on-chip photonic devices, waveguide-coupled microdisk light emitting diodes are also demonstrated. Light emission is successfully coupled from the microdisk to waveguide. Sharp resonant peaks with Q-factor over 5000 are realized. As a further step to enhance the light emission efficiency of Ge quantum dots, n-type delta-doping at Ge/Si interfaces is performed and up to 3 times enhancement of emission intensity is obtained due to extra supply of extrinsic electrons.
(Invited) Transport and Electroluminescence Properties of Size-Controlled Silicon Nanocrystals Embedded in SiO2 Matrix Following the Superlattice Approach
Authors: López-Vidrier Julià , Berencén Yonder , López-Conesa Lluís , Blázquez Oriol , Ramírez Joan Manel , Estradé Sònia , Peiró Francesca , Hernández Sergi , Garrido Blas
Published: May 2014

We report a throrough analysis of the electrical and optical properties of silicon nanocrystals (Si-NCs)/SiO2 superlattices (SL), deposited on Si substrate by means of plasma-enhanced chemical-vapor deposition. A post-deposition annealing treatment was performed to induce phase separation and, therefore, precipitate the Si excess in the form of Si NCs. An excellent size control is reached by the limited thickness of the silicon rich layer of the SL. A discussion on the NC size effect on the injection and transport (electrical), and on absorption and electroluminiscence (electro-optical) is presented. An strong correlation between charge transport and electroluminescence is revealed. This work demonstrates that Si-NCs are a promising photovoltaic and luminescent material system; especially in the case of a SL-based material.
(Invited) Photoluminescence Enhancement of a Silicon Nanocrystal Plane Positioned in the Near-Field of a Silicon Nanowire
Authors: Kallel Houssem , Wiecha Peter , Zhao Yu , Arbouet Arnaud , Carrada Marzia , Ben Assayag Gérard , Periwal Priyanka , Baron Thierry , Normand Pascal , Chehaidar Abdallah , Paillard Vincent
Published: May 2014

Semiconductor nanowires have an excellent ability to trap, guide, scatter or absorb light thanks to the presence of specific resonant optical modes. The electromagnetic field-enhancement associated to such effects can be used to modify the luminescence of emitters positioned in the vicinity of the nanowire, as to plasmonic nano-antennas. We show that the photoluminescence of silicon nanocrystals embedded in silica can be enhanced by a factor of about 3 in the presence of a silicon nanowire on the silica surface. This could be the basis of a promising CMOS-compatible process to improve silicon-based light emitting devices. 2D maps of the nanocrystal photoluminescence exhibit different behaviors as function of laser polarization and can be related to the electric field intensity distribution in the nanowire near-field, where the Si-NCs layer is located. Preliminary results of nonlinear optics for imaging the local electric field are presented.
(Invited) Development of Novel Three-Dimensional Structuring of Integrated Circuits by Using Low Temperature Direct Bonding for CMOS Image Sensors
Authors: Goto Masahide , Hagiwara Kei , Iguchi Yoshinori , Ohtake Hiroshi , Saraya Takuya , Higurashi Eiji , Toshiyoshi Hiroshi , Hiramoto Toshiro
Published: May 2014

We have developed a novel 3D structuring technology of ICs by using low temperature direct bonding for stacked CMOS image sensors. Apart from conventional 3D stacking technique by using through silicon vias (TSVs), our fabrication process with hybrid bonding of Au/SiO2 can directly connect individual FETs, thereby making it suitable for ultra-high-density integration of ICs within an image sensor pixel area of less than a few μm2. We have demonstrated successful operation of a 3D CMOS inverter bonded through 3-μm-diameter Au electrodes and a ring oscillator of 101 stages to show the feasibility of a novel 3D integration toward high-density ICs.
Effect of Using Ethanol as the Oxygen Source on the Growth and Dielectric Behavior of Atomic Layer Deposited Hafnium Oxide
Authors: Selvaraj Sathees Kannan , Colon Albert , Rossero Jorge Iván , Shi Junxia , Takoudis Christos G
Published: May 2014

Use of common atomic layer deposition (ALD) oxygen sources such as oxygen, ozone or water often causes uncontrolled oxidation of the silicon surface by diffusion through the growing HfO2 film during the ALD process. This results in thick interfacial layer (IL) that is detrimental to future transistor scaling if further thinning of the IL is desired. In order to minimize the uncontrolled oxidation at the interface, we explored the use of ethanol as the ALD oxygen source in the ALD HfO2 process. The effect of using ethanol on the growth, composition and electrical behavior of ALD HfO2 films was studied and compared against films prepared using water based ALD process. Ethanol showed good reactivity with the hafnium precursor tetrakis(diethylamino)hafnium and displayed typical ALD growth behavior of linear film growth within a wide ALD process temperature window (200-280 °C). The ethanol based ALD process exhibited HfO2 growth rate of 0.05 nm/cycle which was less than 0.15 nm/cycle obtained when water was used as the ALD oxygen source. X-ray photoelectron spectroscopy (XPS) showed the deposition of stoichiometric HfO2 with trace amount of carbon in the film. SiO2 interfacial layer was not observed in as-deposited samples, whereas annealed samples showed SiO2 XPS features. Films prepared using the ethanol based ALD process showed comparable dielectric performance to that of water based ALD process films and displayed well behaved C-V and I-V curves with as-deposited (ethanol) HfO2 samples showing the lowest leakage current density of 5 x 10-8 A/cm2 at 1 V gate bias.
(Invited) Metrology for 3D Integration
Authors: Allen Richard A , Vartanian Victor , Read David , Baylies Winthrop
Published: May 2014

Three-dimensional stacked integrated circuit (3DS-IC) fabrication requires complex technologies such as high-aspect ratio through-silicon vias (TSVs), wafer thinning, thin wafer handling and processing, and bonding of thin wafers with complex patterned surfaces. Each of these new fabrication steps is associated with metrology challenges. The SEMI 3DS-IC Committee is developing a set of guides to assist the 3DS-IC community in addressing these challenges by identifying metrology solutions. In this paper we provide an overview of the metrology needs for 3DS-IC, identify metrology solutions, and provide examples from SEMI standards describing methods for characterizing the quality and strength of bonds between wafers.
Photoresist Derived Carbon Films as High Capacity Anodes for Lithium Ion Battery
Authors: Kakunuri Manohar , Sharma Chandra Shekhar
Published: May 2014

An epoxy based negative photoresist (SU-8) was spin coated on stainless steel (SS) wafer followed by two step pyrolysis in inert atmosphere to yield dense carbon films to be used as anode for lithium (Li) ion battery. The selection of SS wafer as a substrate was in accordance with commercial Li ion battery architecture. Cyclic voltammogram confirms the passive layer formation by electrolyte decomposition in the initial cycle. Galvanostatic charge discharge experiments performed at 0.1 C rate within 0.01-3 V confirms the reversible intercalation of Li ions and shows higher gravimetric reversible capacity for these photoresist derived carbon films on SS wafer substrate than graphite (400 mAh/g vs. 372 mAh/g for graphite). This high reversible capacity may be attributed to high disorderness in photoresist derived carbon as characterized by x-ray diffraction and Raman spectroscopy.
Molecules in Circuits: A New Type of Microelectronics?
Authors: McCreery Richard Louis , Bergren Adam , Nagy Sayed , Yan Haijun , Bayat Akhtar , Kondratenko Mykola
Published: May 2014

We use surface chemistry, spectroscopy, and conjugated organic molecules to make “molecular junctions” consisting of a single layer of molecules a few nanometers thick between conducting carbon and copper electrodes, then we study the behavior of molecules as circuit elements. The primary goal is to design and build functional molecular electronic components to greatly enhance the already powerful world of silicon microelectronics.
Simultaneous Gastric and Duodenal Erosions due to Adjustable Gastric Banding for Morbid Obesity
Authors: Manatakis Dimitrios K. , Terzis Ioannis , Kyriazanos Ioannis D. , Dontas Ioannis D. , Stoidis Christos N. , Stamos Nikolaos , Davides Demetrios
Published: May 2014

Erosion is an uncommon but feared late complication of adjustable gastric banding for morbid obesity. A high index of clinical suspicion is required, since symptoms are usually vague and nonspecific. Diagnosis is confirmed on upper gastrointestinal endoscopy and band removal is the mainstay of treatment, with band revision or conversion to other bariatric modalities at a later stage. Duodenal erosion is a much rarer complication, caused by the connection tubing of the band. We present our experience with a case of simultaneous gastric and duodenal erosions, managed by laparoscopic explantation of the band, primary suture repair of the duodenum, and omentopexy.
Modeling and Analysis of Mobility Management in Mobile Communication Networks
Authors: Baek Woon Min , Yoon Ji Hyun , Kim Chesoong
Published: May 2014

Many strategies have been proposed to reduce the mobility management cost in mobile communication networks. This paper studies the zone-based registration methods that have been adopted by most mobile communication networks. We focus on two special zone-based registration methods, called two-zone registration (2Z) and two-zone registration with implicit registration by outgoing calls (2Zi). We provide a new mathematical model to analyze the exact performance of 2Zand 2Zi. We also present various numerical results, to compare the performance of 2Ziwith those of 2Zand one-zone registration (1Z), and show that 2Ziis superior to 2Zas well as 1Zin most cases.
Applying Data Clustering Feature to Speed Up Ant Colony Optimization
Authors: Pang Chao-Yang , Hu Ben-Qiong , Zhang Jie , Hu Wei , Shan Zheng-Chao
Published: May 2014

Ant colony optimization (ACO) is often used to solve optimization problems, such as traveling salesman problem (TSP). When it is applied to TSP, its runtime is proportional to the squared size of problemNso as to look less efficient. The following statistical feature is observed during the authors’ long-term gene data analysis using ACO: when the data sizeNbecomes big, local clustering appears frequently. That is, some data cluster tightly in a small area and form a class, and the correlation between different classes is weak. And this feature makes the idea of divide and rule feasible for the estimate of solution of TSP. In this paper an improved ACO algorithm is presented, which firstly divided all data into local clusters and calculated small TSP routes and then assembled a big TSP route with them. Simulation shows that the presented method improves the running speed of ACO by 200 factors under the condition that data set holds feature of local clustering.
Existence and Uniqueness of Solution for Perturbed Nonautonomous Systems with Nonuniform Exponential Dichotomy
Authors: Xia Yong-Hui , Yuan Xiaoqing , Kou Kit Ian , Wong Patricia J. Y.
Published: May 2014

Nonuniform exponential dichotomy has been investigated extensively. The essential condition of these previous results is based on the assumption that the nonlinear term satisfies|f(t,x)|≤μe−ε|t|. However, this condition is very restricted. There are few functions satisfying|f(t,x)|≤μe−ε|t|. In some sense, this assumption is not reasonable enough. More suitable assumption should be|f(t,x)|≤μ. To the best of the authors' knowledge, there is no paper considering the existence and uniqueness of solution to the perturbed nonautonomous system with a relatively conservative assumption|f(t,x)|≤μ. In this paper, we prove that if the nonlinear term is bounded, the perturbed nonautonomous system with nonuniform exponential dichotomy has a unique solution. The technique employed to prove Theorem 4 is the highlight of this paper.