bluuebunny/crossref_metadata_2025 huggingface dataset:
Knowledge creation and new product performance: the role of creativity
Authors: Chang Jung‐Jung , Hung Kuang‐Peng , Lin Ming‐Ji James
Published: March 2014

This research is concerned with how knowledge creation influences new product performance through creativity, which includes novelty and appropriateness. The following relationships are examined in our proposed model: (1) the influence of knowledge creation on new product performance; (2) the influence of novelty and appropriateness on new product performance; and (3) the influence of knowledge creation on novelty and appropriateness. A questionnaire was designed and mailed to the sampledTaiwanese manufacturing companies. The analysis results show that knowledge creation helps research and development personnel create novel and appropriate products, which in turn increase new product success. New product performance is affected by both novelty and appropriateness, the former of which has a greater influence. Through additional exploratory analyses, in which socialization, externalization, combination, and internalization are antecedents, we show that socialization's effect on new product performance is fully mediated by novelty and appropriateness, but internalization's influence is only partially mediated. Meantime, the influence of externalization on performance is fully mediated by novelty, but not by appropriateness. Combination has a direct influence on new product performance. Finally, this research provides theoretical and managerial implications based on these results.
Marginally Specified Priors for Non-Parametric Bayesian Estimation
Authors: Kessler David C. , Hoff Peter D. , Dunson David B.
Published: March 2014

Prior specification for non-parametric Bayesian inference involves the difficult task of quantifying prior knowledge about a parameter of high, often infinite, dimension. A statistician is unlikely to have informed opinions about all aspects of such a parameter but will have real information about functionals of the parameter, such as the population mean or variance. The paper proposes a new framework for non-parametric Bayes inference in which the prior distribution for a possibly infinite dimensional parameter is decomposed into two parts: an informative prior on a finite set of functionals, and a non-parametric conditional prior for the parameter given the functionals. Such priors can be easily constructed from standard non-parametric prior distributions in common use and inherit the large support of the standard priors on which they are based. Additionally, posterior approximations under these informative priors can generally be made via minor adjustments to existing Markov chain approximation algorithms for standard non-parametric prior distributions. We illustrate the use of such priors in the context of multivariate density estimation using Dirichlet process mixture models, and in the modelling of high dimensional sparse contingency tables.
Optical coherence tomography using images of hair structure and dyes penetrating into the hair
Authors: Tsugita Tetsuya , Iwai Toshiaki
Published: March 2014

Background/purpose

Hair dyes are commonly evaluated by the appearance of the hair after dyeing. However, this approach cannot simultaneously assess how deep the dye has penetrated into hair.

Methods

For simultaneous assessment of the appearance and the interior of hair, we developed a visible‐range red, green, and blue (RGB) (three primary colors)‐optical coherence tomography (OCT) using an RGB LED light source. We then evaluated a phantom model based on the assumption that the sample's absorbability in the vertical direction affects the tomographic imaging.

Results

Consistent with theory, our device showed higher resolution than conventional OCT with far‐red light. In the experiment on the phantom model, we confirmed that the tomographic imaging is affected by absorbability unique to the sample. Furthermore, we verified that permeability can be estimated from this tomographic image. We also identified for the first time the relationship between penetration of the dye into hair and characteristics of wavelength by tomographic imaging of dyed hair.

Conclusion

We successfully simultaneously assessed the appearance of dyed hair and inward penetration of the dye without preparing hair sections.
Housing Liberalisation and Gentrification: The Social Effects of Tenure Conversions in Amsterdam
Authors: Boterman Willem R. , van Gent Wouter P.C.
Published: March 2014

Privatisation and liberalisation of the housing market are often used as governmental strategies for engineering the social composition of urban neighbourhoods. Drawing on longitudinal register data, this study reports findings from the highly‐regulated housing context of Amsterdam. Through regression modelling and GIS analyses, we demonstrate that tenure conversions from rent to owner‐occupancy are not just bringing about changes in social‐class composition, but also affect the ethnic and demographic compositions. Moreover, conversions from rent to ownership have highly spatially‐specific effects. Our evidence suggests that tenure conversions may contribute to gentrification in the inner‐city of Amsterdam, while conversions in post‐war neighbourhoods do not lead to a social upgrading and may even facilitate downgrading. Furthermore, trends in the converted section of the housing market are not just mirroring income developments but also seem to reflect trends in ethnic segregation and demographic trends such as a renewed interest among families to live in the inner‐city.
Wither the ‘Undivided City'? An Assessment of State‐Sponsored Gentrification in Amsterdam
Authors: Uitermark Justus , Bosker Tjerk
Published: March 2014

Like many other governments, the Dutch government has simultaneously pursued the contradictory goals of liberalising the housing market and countering the concentration of low‐income groups. This paper discusses how the tension between promoting market forces and countering segregation has played out, using Amsterdam as a case study. The findings suggest that the policy may have mitigated but did not prevent a deepening division between the city's increasingly privileged core and its periphery. This is at least in part because social mixing was pursued also in neighbourhoods already prone to gentrification.
A Microsoft VBA Application for Generating Heat Maps
Authors: Polczynski Mark , Polczynski Michael
Published: March 2014

A choropleth map is a form of thematic map used to portray the structural characteristics of some particular geographical distribution not apparent in data presented in tabular form. Preparation of a choropleth map starts with the assignment of map features to classes based on the value of a specific feature attribute followed by the association of classes of features with appropriate map colors or symbols. Map features are often geographical regions with naturally or artificially defined boundaries, but choropleth maps can also be prepared by segmenting the area to be mapped into a regular grid of regions. Maps prepared with each grid shaded in an intuitive manner such as blue for grids with the lowest attribute values to red for the highest values can be termed “heat maps”. This technical note describes the HeatMap Microsoft Excel application which converts information contained in a worksheet into a heat map, and then converts the heat map into a file suitable for display using mapping systems such as Google Earth. An example illustrates how the application can be used to visualize the seventeenth century frontier between the Polish/Lithuanian Commonwealth and the Ottoman Empire.
Phaeohyphomycosis fungal infections in solid organ transplant recipients: clinical presentation, pathology, and treatment
Authors: Schieffelin J.S. , Garcia‐Diaz J.B. , Loss G.E. , Beckman E.N. , Keller R.A. , Staffeld‐Coit C. , Garces J.C. , Pankey G.A.
Published: March 2014

Background

Dematiaceous, or dark‐pigmented, fungi are known to cause infections such as phaeohyphomycosis, chromoblastomycosis, and mycetoma. These fungi are becoming increasingly important opportunistic pathogens in solid organ transplant recipients (SOTR). We present a retrospective chart review of 27 SOTR who developed phaeohyphomycosis infections post transplant from 1988 to 2009.

Methods

Cases were reviewed for fungal species isolated, date and source of culture, immunosuppressive and fungal therapy used, and outcome. The majority of isolates obtained were from the skin and soft tissue, with 3 pulmonary and brain abscesses.

Results

The time from transplantation to onset of infection ranged from 2 months to 11 years. The species isolated were Exophiala (11), Ochroconis (3), Alternaria (2), Phoma (2), Wangiella (1), Cladosporium (1), Aureobasidium (1), Chaetomium (1), Coniothyrium (1), and non‐sporulating fungi (2). An additional 4 patients had infections confirmed by pathology, but no cultures were done. Most of the affected skin lesions were surgically debrided and treated with itraconazole; 2 patients were treated with voriconazole and 2 with amphotericin D. Death from fungal disease occurred only in patients with pulmonary and brain abscesses.

Conclusions

As the number of SOTR increases, so does the incidence of fungal infections in that population. Surgery, along with antifungal therapy and a reduction in immunosuppression, are the cornerstones of treatment.
Successful withdrawal of antiviral treatment in kidney transplant recipients with chronic hepatitis B viral infection
Authors: Cho J.‐H. , Lim J.‐H. , Park G.‐Y. , Kim J.‐S. , Kang Y.‐J. , Kwon O. , Choi J.‐Y. , Park S.‐H. , Kim Y.‐L. , Kim H.‐K. , Huh S. , Kim C.‐D.
Published: March 2014

Background

The optimal duration of antiviral therapy for kidney transplant recipients (KTR) with chronic hepatitis B virus (HBV) infection remains unclear. We reported the long‐term outcomes after withdrawal of antiviral agent in KTR with chronic HBV infection.

Methods

We retrospectively investigated the hepatitis B surface antigen (HBsAg)‐positive KTR with antiviral agents between January 2002 and January 2012. Antiviral treatments were withdrawn in patients who met all of the following 7 criteria: (i) no clinical and histologic evidence of cirrhosis, (ii) normal liver biochemistry, (iii) negative for both HBV DNA and hepatitis B envelope antigen (HBeAg), (iv) no resistance to antiviral agent, (v) antiviral therapy > 9 months, (vi) maintenance dosage of immunosuppressant for > 3 months, and (vii) no history of acute rejection during recent 6 months. All patients were followed regularly at approximately 3–6 months for liver enzyme, viral markers, and HBV DNA level after antiviral withdrawal.

Results

Among a total of 445 KTR, 14 HBsAg‐positive patients were included in this study. Antiviral agents were used, with lamivudine in 11 patients, and with adefovir, entecavir, and telbivudine in 3 patients, respectively. Discontinuation of antiviral agent was attempted in 6 (42.9%) of 14 patients who satisfied the criteria. The median duration of antiviral therapy before withdrawal was 14.3 months (range, 9–24 months). Four (66.7%) of 6 patients were successfully withdrawn and remained negative for HBV DNA for a median 60.5 months (range, 47–82 months). The baseline HBV DNA level was not related to maintenance of remission after withdrawal. Two reactivated patients resumed antiviral treatment immediately, with subsequent normalization of HBV DNA. During the follow‐up, 1 patient developed hepatocellular carcinoma; however, no patient death or graft failure was reported for all HBsAg‐positive KTR.

Conclusions

Antiviral therapy can be discontinued successfully and safely in selected KTR with chronic HBV infection, after complete suppression of HBV and sufficient duration of antiviral therapy.
Systematic review and meta‐analysis: Patient and programme impact of fixed‐dose combination antiretroviral therapy
Authors: Ramjan Rubeena , Calmy Alexandra , Vitoria Marco , Mills Edward J. , Hill Andrew , Cooke Graham , Ford Nathan
Published: March 2014

Objectives

To compare the advantages to patients and to programmes between fixed‐dose combination (FDC) antiretroviral therapy and separate tablet regimens.

Methods

Three electronic databases and two conference abstract sites were searched from inception to 01 March 2013 without geographical, language or date limits. Studies were included if they reported data on clinical outcomes, patient‐reported outcomes and programme‐related outcomes that could be related to pill burden for adult and adolescent patients on ART. For the primary outcomes of adherence and virological suppression, relative risks and 95% confidence intervals were calculated, and these were pooled using random effects meta‐analysis.

Results

Twenty‐one studies including information on 27 230 subjects were reviewed. Data from randomised trials showed better adherence among patients receiving FDCs than among patients who did not (relative risk 1.10, 95%CI 0.98–1.22); these findings were consistent with data from observational cohorts (RR 1.17, 95% CI 1.07–1.28). There was also a tendency towards greater virological suppression among patients receiving FDCs in randomised trials (RR 1.04, 95%CI 0.99–1.10) and observational cohort studies (RR 1.07, 95% CI 0.97–1.18). In all studies reporting patient preference, FDCs were preferred. The overall quality of the evidence was rated as low.

Conclusions

Fixed‐dose combinations appear to offer multiple advantages for programmes and patients, particularly with respect to treatment adherence.
Deregulation of epidermal stem cell niche contributes to pathogenesis of nonhealing venous ulcers
Authors: Stojadinovic Olivera , Pastar Irena , Nusbaum Aron G. , Vukelic Sasa , Krzyzanowska Agata , Tomic‐Canic Marjana
Published: March 2014

The epidermis is maintained by epidermal stem cells (ESCs) that reside in distinct niches and contribute to homeostasis and wound closure. Keratinocytes at the nonhealing edges of venous ulcers (VUs) are healing‐incompetent, hyperproliferative, and nonmigratory, suggesting deregulation of ESCs. To date, genes which regulate ESC niches have been studied in mice only. Utilizing microarray analysis of VU nonhealing edges, we identified changes in expression of genes harboring regulation of ESCs and their fate. In a prospective clinical study of 10 VUs, we confirmed suppression of the bone morphogenetic protein receptor (BMPR) and GATA binding protein 3 (GATA3) as well as inhibitors of DNA‐binding proteins 2 and 4 (ID2 and ID4). We also found decreased levels of phosphorylated glycogen synthase kinase 3 (GSK3), nuclear presence of β‐catenin, and overexpression of its transcriptional target, c‐myc, indicating activation of the Wnt pathway. Additionally, we found down‐regulation of leucine‐rich repeats and immunoglobulin‐like domains protein 1 (LRIG1), a gene important for maintaining ESCs in a quiescent state, and absence of keratin 15 (K15), a marker of the basal stem cell compartment suggesting local depletion of ESCs. Our study shows that loss of genes important for regulation of ESCs and their fate along with activation of β‐catenin and c‐myc in the VU may contribute to ESC deprivation and a hyperproliferative, nonmigratory healing incapable wound edge.
Knocking out Smad3 favors allogeneic mouse fetal skin development in adult wounds
Authors: Liu Ke , Gao Zhen , Wu Xiaoli , Zhou Guangdong , Zhang Wen Jie , Yang Xiao , Liu Wei
Published: March 2014

Fetal skin development represents a process of the interaction between skin progenitor cells and their unique extracellular matrix niche, which is also important for the mechanism study of skin progenitor cell differentiation and fetal scarless wound healing. Thus, a change in the niche environment, such as altered expression levels of growth factors or cytokines, may also change the outcome of fetal skin development. This study tested the hypothesis that deletion of mouse Smad3 creates a favorable environment for fetal skin development in adult wounds. Fetal skin of green fluorescent protein mouse (C57BL/B6) of gestational day 16.5 was respectively transplanted to the wound beds of wild‐type (WT), heterozygous (HT), and homologous (KO) Smad3 deletion mice (C57BL/B6 × 129SV). The results showed that green fluorescent protein fetal mouse skin after its transplantation developed much better into hair follicle containing skin in KO or HT wound beds than in WT wound beds with significant differences in the number of follicles per mm2 among the three groups at 1, 2, and 3 weeks posttransplantation (p < 0.05). In addition, less fibrosis was observed in KO wounds than in HT and WT wounds with significant difference in the wound bed thickness among the three groups at 3 weeks posttransplantation (p < 0.05). Interestingly, there was a delayed graft rejection in the KO group when compared with the HT and WT groups. In conclusion, deletion of Smad3 in a wound bed creates a better environment for skin progenitor cell differentiation and fetal skin development. Translation of such a concept to the creation of a wound environment that is favorable for adult stem cell differentiation and skin appendage formation may become an important strategy for the regeneration of wounded skin.
A randomized, controlled trial of negative pressure wound therapy of pressure ulcers via a novel polyurethane foam
Authors: Wagstaff Marcus James Dermot , Driver Sara , Coghlan Patrick , Greenwood John Edward
Published: March 2014

The objectives of the study were (1) to look for any local, clinically apparent response, within and around a debrided wound, to a novel biocompatible polyurethane foam during repeated, short‐term implantation, and (2) to assess the material's efficacy as a negative pressure wound therapy (NPWT) interface compared with a widely used, commercially available foam. Twenty pressure ulcers in 18 patients underwent surgical debridement, then randomization to receive novel treatment or control foam as the wound interface for NPWT. Dressing changes every 2–3 days allowed qualitative wound assessment and quantitative measurement to compare outcomes. No adverse reaction was observed in any patient receiving the new foam. The new “novel foam” performed as a NPWT interface as effectively as the control “standard foam.” In deep wounds, the new foam was easier to remove, fragmented less, and showed less retention than the control foam. No marginal in‐growth occurred, making removal less traumatic and reducing bleeding from cavity wall granulations. The results support previous large animal studies, and independent ISO10993 testing, that the new foam is safe and biocompatible. Its efficacy as an NPWT interface, nontraumatic removal with low fragmentation and retention rate, favors the new material, especially in deep cavity wounds.
A statistical analysis of murine incisional and excisional acute wound models
Authors: Ansell David M. , Campbell Laura , Thomason Helen A. , Brass Andrew , Hardman Matthew J.
Published: March 2014

Mice represent the most commonly used species for preclinical in vivo research. While incisional and excisional acute murine wound models are both frequently employed, there is little agreement on which model is optimum. Moreover, current lack of standardization of wounding procedure, analysis time point(s), method of assessment, and the use of individual wounds vs. individual animals as replicates makes it difficult to compare across studies. Here we have profiled secondary intention healing of incisional and excisional wounds within the same animal, assessing multiple parameters to determine the optimal methodology for future studies. We report that histology provides the least variable assessment of healing. Furthermore, histology alone (not planimetry) is able to detect accelerated healing in a castrated mouse model. Perhaps most importantly, we find virtually no correlation between wounds within the same animal, suggesting that use of wound (not animal) biological replicates is perfectly acceptable. Overall, these findings should guide and refine future studies, increasing the likelihood of detecting novel phenotypes while reducing the numbers of animals required for experimentation.
Mesenchymal stem cell‐coated sutures enhance collagen depositions in sutured tissues
Authors: Casado Javier G. , Blazquez Rebeca , Jorge Inmaculada , Alvarez Veronica , Gomez‐Mauricio Guadalupe , Ortega‐Muñoz Mariano , Vazquez Jesus , Sanchez‐Margallo Francisco M.
Published: March 2014

Sutures are commonly used for surgical procedures and new sutures are being developed to improve wound healing. In the past decade, it has been extensively shown that mesenchymal stem cells (MSCs) have a wound healing potential. To benefit the overall wound healing process, we aimed to analyze the usage of pretreated sutures for improving the implantation of MSCs in the tissues. Our results firstly showed that suture pretreatments with gelatin, poly‐L‐lysine, and NaOH improved the adhesive strength of MSCs to sutures. These cells remained surrounding the sutured tissue and no significant phenotypic changes were found in those cells cultured onto pretreated sutures. In vivo experiments showed that the implantation of MSCs by suturing increases the collagen content in the sutured tissue. Moreover, proteomics analysis of secreted proteins showed that collagen alpha‐1(I) chain was the most abundant collagen found. To our knowledge, this is the first report that aimed to improve the implantation of MSCs in tissue by suture pretreatments. Moreover, in vivo experiments suggest that MSC‐coated sutures may enhance wound healing and tissue remodeling through the release of different collagen types being applicable for those patients that tend to have difficulty healing.
Complement dependent early immunological responses during ex vivo xenoperfusion of hCD46/HLA‐E double transgenic pig forelimbs with human blood
Authors: Bongoni Anjan K. , Kiermeir David , Jenni Hansjörg , Bähr Andrea , Ayares David , Klymiuk Nikolai , Wolf Eckhard , Voegelin Esther , Constantinescu Mihai A. , Seebach Jörg D. , Rieben Robert
Published: March 2014

Background

Besides α1,3‐galactosyltransferase gene (GGTA1) knockout, several transgene combinations to prevent pig‐to‐human xenograft rejection are currently being investigated. In this study, the potential of combined overexpression of human CD46 and HLA‐E to prevent complement‐ and NK‐cell‐mediated xenograft rejection was tested in an ex vivo pig‐to‐human xenoperfusion model.

Methods

α1,3‐Galactosyltransferase knockout heterozygous, hCD46/HLA‐E double transgenic (transgenic) as well as wild‐type pig forelimbs were ex vivo perfused with whole, heparinized human and autologous pig blood, respectively. Blood samples were analyzed for the production of porcine and/or human inflammatory cytokines as well as complement activation products. Biopsy samples were examined for deposition of human and porcine C3b/c, C4b/c, and C6 as well as CD62E (E‐selectin) and CD106 (VCAM‐1) expression. Apoptosis was measured in the porcine muscle tissue using TUNEL assays. Finally, the formation of thrombin–antithrombin (TAT) complexes was measured in EDTA plasma samples.

Results

No hyperacute rejection was seen in this model. Extremity perfusions lasted for up to 12 h without increase in vascular resistance and were terminated due to continuous small blood losses. Plasma levels of porcine cytokines IL1β, IL‐6, IL‐8, IL‐10, TNF‐α, and MCP‐1 as well as human complement activation markers C3a (P = 0.0002), C5a (P = 0.004), and soluble C5b‐9 (P = 0.03) were lower in blood perfused through transgenic as compared to wild‐type limbs. Human C3b/c, C4b/c, and C6 as well as CD62E and CD106 were deposited in tissue of wild‐type limbs, but significantly lower levels (P < 0.0001) of C3b/c, C4b/c, and C6 deposition as well as CD62E and CD106 expression were detected in transgenic limbs perfused with human blood. Transgenic porcine tissue was protected from xenoperfusion‐induced apoptosis (P < 0.0001). Finally, TAT levels were significantly lower (P < 0.0001) in transgenic limb as compared to wild‐type limb xenoperfusions.

Conclusion

Transgenic hCD46/HLA‐E expression clearly reduced humoral xenoresponses since all, the terminal pathway of complement activation, endothelial cell activation, muscle cell apoptosis, inflammatory cytokine production, as well as coagulation activation, were all downregulated. Overall, this model represents a useful tool to study early immunological responses during pig‐to‐human vascularized xenotransplantation in the absence of hyperacute rejection.
Geographic Information System‐Based Analysis of the Spatial and Spatio‐Temporal Distribution of Zoonotic Cutaneous Leishmaniasis in Golestan Province, North‐East of Iran
Authors: Mollalo A. , Alimohammadi A. , Shirzadi M. R. , Malek M. R.
Published: March 2014

Zoonotic cutaneous leishmaniasis (ZCL), a vector‐borne disease, poses serious psychological as well as social and economic burden to many rural areas of Iran. The main objectives of this study were to analyse yearly spatial distribution and the possible spatial and spatio‐temporal clusters of the disease to better understand spatio‐temporal epidemiological aspects of ZCL in rural areas of an endemic province, located in north‐east of Iran. Cross‐sectional survey was performed on 2983 recorded cases during the period of 2010–2012 at village level throughout the study area. Global clustering methods including the average nearest‐neighbour distance, Moran's I, general G indices and Ripley's K‐function were applied to investigate the annual spatial distribution of the existing point patterns. Presence of spatial and spatio‐temporal clusters was investigated using the spatial and space–time scan statistics. For each year, semivariogram analysis and all global clustering methods indicated meaningful persistent spatial autocorrelation and highly clustered distribution of ZCL, respectively. Eight significant spatial clusters, mainly located in north and northeast of the province, and one space–time cluster, observed in northern part of the province and during the period of September 2010–November 2010, were detected. Comparison of the location of ZCL clusters with environmental conditions of the study area showed that 97.8% of cases in clusters were located at low altitudes below 725 m above sea level with predominantly arid and semi‐arid climates and poor socio‐economic conditions. The identified clusters highlight high‐risk areas requiring special plans and resources for more close monitoring and control of the disease.
Investigation of Combustion Phasing Control Strategy During Reactivity Controlled Compression Ignition (RCCI) Multicylinder Engine Load Transitions
Authors: Wu Yifeng , Hanson Reed , Reitz Rolf D.
Published: March 2014

The dual fuel reactivity controlled compression ignition (RCCI) concept has been successfully demonstrated to be a promising, more controllable, high efficiency, and cleaner combustion mode. A multidimensional computational fluid dynamics (CFD) code coupled with detailed chemistry, KIVA-CHEMKIN, was applied to develop a strategy for phasing control during load transitions. Steady-state operating points at 1500 rev/min were calibrated from 0 to 5 bar brake mean effective pressure (BMEP). The load transitions considered in this study included a load-up and a load-down load change transient between 1 bar and 4 bar BMEP at 1500 rev/min. The experimental results showed that during the load transitions, the diesel injection timing responded in two cycles while around five cycles were needed for the diesel common-rail pressure to reach the target value. However, the intake manifold pressure lagged behind the pedal change for about 50 cycles due to the slower response of the turbocharger. The effect of these transients on RCCI engine combustion phasing was studied. The CFD model was first validated against steady-state experimental data at 1 bar and 4 bar BMEP. Then the model was used to develop strategies for phasing control by changing the direct port fuel injection (PFI) amount during load transitions. Specific engine operating cycles during the load transitions (six cycles for the load-up transition and seven cycles for the load-down transition) were selected based on the change of intake manifold pressure to represent the transition processes. Each cycle was studied separately to find the correct PFI to diesel fuel ratio for the desired CA50 (the crank angle at which 50% of total heat release occurs). The simulation results showed that CA50 was delayed by 7 to 15 deg for the load-up transition and advanced by around 5 deg during the load-down transition if the precalibrated steady-state PFI table was used. By decreasing the PFI ratio by 10% to 15% during the load-up transition and increasing the PFI ratio by around 40% during the load-down transition, the CA50 could be controlled at a reasonable value during transitions. The control strategy can be used for closed-loop control during engine transient operating conditions. Combustion and emission results during load transitions are also discussed.
Experimental Investigation of the Effect of Purge Flow on Film Cooling Effectiveness on a Rotating Turbine With Nonaxisymmetric End Wall Contouring
Authors: Rezasoltani M. , Schobeiri M. T. , Han J. C.
Published: March 2014

The impact of the purge flow injection on aerodynamics and film cooling effectiveness of a three-stage, high-pressure turbine with nonaxisymmetric end wall contouring has been experimentally investigated. As a continuation of the previously published work involving stator-rotor gap purge cooling, this study investigates film cooling effectiveness on the first-stage rotor contoured platform due to a coolant gas injection. Film cooling effectiveness measurements are performed on the rotor blade platform using a pressure-sensitive paint (PSP) technique. The present study examines, in particular, the film cooling effectiveness due to injection of coolant from the rotor cavity through the circumferential gap between the first stator followed by the first rotor. Effects of the presence of contouring, blowing ratios, rotational speeds, and coolant density ratio are studied and compared to a noncontouring platform. The experimental investigation is carried out in a three-stage turbine facility at the Turbomachinery Performance and Flow Research Laboratory (TPFL) at Texas A&M University. Its rotor includes nonaxisymmetric end wall contouring on the first and second rotor row. The turbine has two independent cooling loops. Film cooling effectiveness measurements are performed for three coolant-to-mainstream mass flow ratios of 0.5%, 1.0%, and 1.5%. Film cooling data is obtained for three rotational speeds, 3000 rpm (reference condition), 2550 rpm, and 2400 rpm, and compared with noncontoured end wall data. Effect of density ratio for coolant-to-mainstream density ratio (DR) = 1.0 and DR = 1.5 is also investigated. The comparisons of film effectiveness results show that contoured cases have a noticeable quantitative improvement compared to those of noncontoured ones.
Laminar-Turbulent Transition in Magnetohydrodynamic Duct, Pipe, and Channel Flows
Authors: Zikanov Oleg , Krasnov Dmitry , Boeck Thomas , Thess Andre , Rossi Maurice
Published: March 2014

A magnetic field imposed on a flow of an electrically conducting fluid can profoundly change flow behavior. We consider this effect for the situation of laminar-turbulent transition in magnetohydrodynamic duct, pipe, and channel flows with homogeneous magnetic field and electrically insulating walls. Experimental and recent computational results obtained for flows in pipes, ducts and channels are reviewed.
Lymphangioma of the breast
Authors: Hiremath Bharati , Binu Vineet
Published: March 2014

A 23-year-old lactating woman presented with a swelling in the retroareolar region of the right breast. Ultrasound and MRI of the breast were suggestive of lymphangioma of the breast. She underwent complete excision of the lesion after 3 months of stopping lactation. This article aims to highlight one of the rare lesions in the breast. Surgery is the treatment of choice.
Alcohol-assisted base-free hydrogenation of acetophenone catalyzed by OsH(NHCMe2CMe2NH2)(PPh3)2
Authors: Clapham Sean E. , Iuliis Marco Zimmer-De , Mack Katharina , Prokopchuk Demyan E. , Morris Robert H.
Published: March 2014

The hydrido–amido complex OsH(NHCMe2CMe2NH2)(PPh3)2 (1) catalyzes the base-free hydrogenation of ketones in benzene. Kinetic studies using acetophenone revealed that the system has an induction period, after which the rate of the reaction increases. A constant rate was observed when a critical amount of the product alcohol was added, indicating that the reaction is autocatalytic in 1-phenylethanol. Varying the initial conditions showed that the reaction rate is dependent on hydrogen and catalyst concentration and independent of ketone concentration. Above the critical concentrations of 1-phenylethanol, the reaction rate is independent of alcohol concentration. The rate law for pressures up to 5 atm was found to be rate = d[alcohol]/dt = −d[ketone]/dt = k[Os][H2], with k = 30 mol L−1 s−1 at 293 K and the temperature dependence provided energy of activation parameters. Therefore, the heterolytic splitting of dihydrogen is rate determining under these conditions. Only small kinetic isotope effects were measured in contrast with the analogous ruthenium system. Complex 1 reacts with the product alcohol 1-phenylethanol and is partially converted into the dihydride complex trans-OsH2(NH2CMe2CMe2NH2)(PPh3)2 and acetophenone; with excess alcohol, an osmium alkoxide is observed at low temperature. As expected from these results, 1 is a ketone transfer hydrogenation catalyst in isopropanol.
An ancient satellite DNA has maintained repetitive units of the original structure in most species of the living fossil plant genusZamia
Authors: Cafasso Donata , Chinali Gianni
Published: March 2014

ZpS1 satellite DNA is specific to the genus Zamia and presents repetitive units organized as long arrays and also as very short arrays dispersed in the genome. We have characterized the structure of the ZpS1 repeats in 12 species representative of the whole geographic distribution of the genus. In most species, the clone most common sequences (cMCS) were so similar that a general most common sequence (GMCS) of the ZpS1 repetitive unit in the genus could be obtained. The few partial variations from the GMCS found in cMCS of some species correspond to variable positions present in most other species, as indicated by the clone consensus sequences (cCS). Two species have an additional species-specific variety of ZpS1 satellite. The dispersed repeats were found to contain more mutations than repeats from long arrays. Our results indicate that all or most species of Zamia inherited the ZpS1 satellite from a common ancestor in Miocene and have maintained repetitive units of the original structure till present. The features of ZpS1 satellite in the genus Zamia are poorly compatible with the model of concerted evolution, but they are perfectly consistent with a new model of satellite evolution based on experimental evidences indicating that a specific amplification-substitution repair mechanism maintains the homogeneity and stability of the repeats structure in each satellite DNA originally present in a species as long as the species exists.
STUDY AND APPLICATION OF UNDERWATER NOISE IMPACT IN COASTAL REGION OFF WESTERN TAIWAN
Authors: CHENG YU-CHEN , LIN SHENG-FONG , CHANG YUAN-YING , CHEN CHI-FANG , HUNG CHEN-FAR , LIN BANG-JEAN
Published: March 2014

Offshore wind farms are the main project on Taiwan's western coast. Since the underwater noise generated by piling poses a threat to marine mammals, the issue of the detrimental impact of noise on Sousa Chinensis has drawn considerable attention. To avoid behavioral disturbances and injury from pile driving noise, we propose the Underwater Noise Impact Region Alert System (UNIRAS) to estimate the acoustic field at any depth and distance from the piling sources. The system can be illustrated as four components: environment databases, an acoustic propagation model, source modeling and alert region (AR) prediction. Inputs are derived from the Taiwan Coastal Ocean Nowcast/Forecast System (TCONFS), which generates underwater sound speed profiles with temporal and spatial variation, along with geoacoustic and bathymetry databases that are imported as environmental inputs. Adiabatic mode theory is used to simulate the piling noise propagation in shallow water and the impulsive noise emanating from the source is evaluated via the finite element method. With the auditory threshold of cetacean being set as the criterion level, the system can demonstrate the modeling outputs and predict the noise impact region, and these results are useful for planning how to station the guard boats to prevent dolphins from entering the noise impact region.
THE SOCIAL EFFICIENCY OF PAY-AS-YOU-THROW SCHEMES FOR MUNICIPAL SOLID WASTE REDUCTION: A COST-BENEFIT ANALYSIS OF FOUR FINANCIAL INCENTIVE SCHEMES APPLIED IN SWITZERLAND
Authors: MANNI LORIS ALEXANDER , RUNHAAR HENS A. C.
Published: March 2014

The efficient management of waste is important in order to reduce negative externalities, such as air, water and soil pollution. A major challenge is the increasing amount of municipal solid waste (MSW) produced by households. Municipalities around the world have implemented pay-as-you-throw (PAYT) schemes in order to incentivise the reduction of MSW. Although the literature has shown that these financial incentive schemes are often effective, they are criticised in practice for raising costs to society. This paper aims to assess whether or not this criticism is correct. A social cost-benefit analysis was conducted in order to take into account economic, environmental and social costs and benefits. Our results show that PAYT schemes reduce overall social costs and therefore positively contribute to the social efficiency of a municipality. The above criticism is not supported by empirical evidence, but in practice forms a barrier to the implementation of PAYT schemes. In order to remove this barrier, we encourage the readers of JEAPM to disseminate our findings to a wider audience.
PUBLIC ENGAGEMENT IN ENVIRONMENTAL IMPACT ASSESSMENT IN HONG KONG SAR, CHINA USING WEB 2.0: PAST, PRESENT AND FUTURE
Authors: TO WAI MING , CHUNG ANDY W. L.
Published: March 2014

Web 2.0 has transformed the way people obtain, understand, analyse and respond to information from a broad range of sources. Users spend several hours a day to access the Web, browse their favourite sites and respond to invitations from friends and other people to participate in discussions that affect their social and business lives as well as their environmental conditions. In this regard, knowing how to promote public participation and engagement in the early stages of environmental impact assessment (EIA) as well as how to gain public acceptance in the consultation phase of an EIA using the Web is important. This study describes how Hong Kong government departments employ the Web to disseminate information and proposes methods for public engagement using Web 2.0 technologies.
Improving Governance from the Outside In
Authors: Krasner Stephen D. , Weinstein Jeremy M.
Published: March 2014

The variation in the efficacy of governance-related authority structures is stunning. The focus among scholars primarily on domestic conditions, and only secondarily on the external environment, to explain patterns of political development conforms to the prevailing assumptions of comparativists, international relations scholars, and international lawyers. Over the past decade, however, some scholars have studied the possibility that political institutions within states can be influenced or determined not only by internal factors and the external environment but also by the explicit policies of foreign actors. An emerging body of scholarship examines the efficacy of different policy tools that external actors might use to change the structure of domestic institutions in target states. We review this literature and reach the following conclusions. First, contracting often works, coercion sometimes works, and imposition rarely works. Second, the motivation of initiators matters: to be effective, intervening states must be committed to institutional change. Third, conditions in the target state are consequential: higher levels of development facilitate institutional change, and elite motivations must be aligned with the goals of external actors.
Characterization of Single Photon Avalanche Diodes Fabricated by 0.13μm Flash Process Technology
Authors: Bu Xiaofeng , Ji Xiaoli , Guo Jiayu , Feng Liang , Chen Chuyu , Yan Feng
Published: March 2014

Two different structures of single photon avalanche diode(SPAD) fabricated by 0.13 μm flash process technology are presented. The structure-1 uses low implanted p-well surrounding the active area as the guard ring which prevents the periphery breakdown, while for the structure-2, a virtual guard ring with the deep retrograde n-well doping is designed. The characteristics of the two detectors with the same active area diameter are presented. The two SPAD structures exhibit relatively different dark and light performance. The first structure exhibits a typical dark count rate of 18 kHz at the room temperature and a maximum photon detection efficiency of 15%, while the second structure exhibits a dark count rate of 23 kHz and a maximum photon detection efficiency of 28%. The comparison of the two structures is therefore promising for the further advanced SPAD design.
Investigation of HfAlO Trapping Layer with Various Al Contents by Variable Temperature Kelvin Probe Force Microscopy
Authors: Zhang Dong , Huo Zongliang , Jin Lei , Han Yulong , Chen Guoxing , Chu Yuqiong , Li Xiankai , Liu Ming
Published: March 2014

In order to explore the charge storage and loss characteristics of HfAlO charge trapping layer, Kelvin probe force microscopy (KFM) technology was applied. HfAlO trapping layer was deposited by an atom layer deposition (ALD) system with the precursors Hf[N(C2H5) CH3]4 (TEMAH), Al(CH3)3 (TMA) and H2O as source materials. Comparing with HfO2 trapping layer, the trap density of the HfAlO sample was significantly increased. And the data retention abilities were improved with the increased Al contents. The effective electron trap energies were extracted, by variable temperature KFM measurement. The results demonstrate that the trap energies of HfO2 layer increase with Al doping.
Improved Magnetic Sensitivity of CMOS Vertical Hall Device by Using Partial Implantation Technique
Authors: Huang Haiyun , Xu Yue , Wang Dejun , Wu Jun , Qin Huibin
Published: March 2014

With the continuous scaling of CMOS technology, the doping level of N-well is constantly increasing, which leads to a big decrease in magnetic sensitivity for vertical Hall devices (VHDs). Moreover, the Gaussian profile of doping concentration gives an additional decrease in N-well effective depth, which further reduces the magnetic sensitivity. In this paper, we apply partial N-well and top p+ layer implantation techniques to lower the doping level of N-well and improve the doping profile by means of impurity lateral diffusion and compensation effects. TCAD process and device simulations have been carried out for a typical five-contact VHD in 0.13 μm CMOS technology. Simulation results show that the current-related magnetic sensitivity is greatly improved from 40 V/AT to 110 V/AT by using the partial implantation techniques. Meanwhile, the voltage-related magnetic sensitivity is also increased and not significantly decreased.
Design Guidelines of In0.53Ga0.47As and Si Tunneling Field-Effect Transistors
Authors: Wu Jundong , Huang Qianqian , Wu Chunlei , Huang Ru
Published: March 2014

In this paper, the impacts of the source doping profile, effective oxide thickness (EOT), gate alignment, and trap density at the source junction on key characteristics of In0.53Ga0.47As- and Si-based tunneling field-effect transistors (TFETs) were comprehensively analyzed through Sentaurus simulations with calibrated models, which can provide some guidelines for device and process design. The simulations show that the EOT and the gate alignment should be carefully designed and controlled for both Si and In0.53Ga0.47As TFETs fabrication. The EOT needs a tighter control in In0.53Ga0.47As TFETs, a suitable gate-source underlap can optimize the performance of device considering a non-ideal source doping profile. Moreover, the trap density at the source junction plays more significant impacts in In0.53Ga0.47As TFETs than Si TFETs.
ESD Characterization of SOI SiGe QW Gated Diode
Authors: Mao Shujuan , Wang Guilei , Qin Changliang , Liu Yunfei , Yin Haizhou
Published: March 2014

Higher mobility channel materials, e.g., SiGe or Ge, are possibly introduced into the FinFET device architerture as the next technology option. The ESD characterization of SOI poly-defined lateral diode featuring a SiGe Quantum Well(QW) as channal was conducted by technology computer-aided design(TCAD) simulations. Meanwhile, the selective epitaxy growth of Si cap/SiGe bilayer on Si substrate was experimentally checked.
(Invited) Reliability Considerations of High-K Gate Dielectrics Deposited by Various Intermediate Treatment
Authors: Bhuyian Mdnasiruddin , Misra Durga
Published: March 2014

Various intermediate treatments (annealing or plasma exposure) during cyclic atomic layer deposition process demonstrate enhanced EOT scaling over a single post-deposition annealing (PDA). In this work we have investigated the reliability of TiN/Hf0.2Zr0.8O2/SiON/Si gate stack where Hf0.2Zr0.8O2 was deposited by either intermediate annealing or exposure to Ar plasma in a cyclical process. The results were compared with the samples where the dielectric was deposited without any intermediate treatment. Stress-induced flat-band voltage shift (ΔVFB) and stress induced leakage current (SILC) indicate that intermediate plasma exposure yields improved reliability characteristics by suppressing the trap formation. Alloying of ZrO2 with HfO2 to form Hf1-xZrxO2 films with higher x value enhanced reliability performance further when compared to HfO2.
Ni (10%Pt) Silicide Processes for 22nm CMOS Technology and Beyond
Authors: Zhang Qingzhu , Wu Cinan , Gao Jianfeng , Xu Jing , Zhao Lichuan , Yan Jiang
Published: March 2014

In this paper 10% Pt in the Ni(Pt) silicide was studied. The sheet resistance results indicate that the treatment, RTA1 at 310oC for 60S and RTA2 at 480oC for 10S, can form the minimum sheet resistance, preferable Rs Std.Dev and thickness uniformity. With Pt addition, Ni(Pt)Si/Si morphology is stable with temperature rising until 700oC. There is NiSi spike for optimal silicidation of 2nm Ni(5%Pt) film. However, the optimal silicidation of 2nm Ni(10%Pt) film has a smooth Ni(Pt)Si/Si interface and better uniformity. The effect of Ar clean on sheet resistance and thickness uniformity is also investigated. The results show that wafers after wiping out surface oxide in less than one hour without Ar clean process have the reduction about 10%~40% in sheet resistance, comparing with wafers with Ar clean. Ni(10%Pt) silicide is tested and verified at 0.5µm and 22nm structure. It has a good interface and uniformity without any spike.
Mask Corner Chopping Strategy Optimization and Its Impact on Random 2D Logic Pattern OPC Recipe Accuracy
Authors: Pei Jinhua , Cai Bo-Xiu , Shen Xuan , Liu Qingwei , Shi Xuelong , Lin Yi-Shih
Published: March 2014

At advanced node, mask making details need to be taken into account in OPC in order to achieve the demanded accuracy. Mask corner rounding, which is often emulated by corner chopping of polygons in OPC implementation, is one such an example. In this work, we demonstrated fixed radius corner-chop improves OPC accuracy, however, such an implementation is unable to offer required OPC accuracy, since it still leaves non-negligible ADI error at some random 2D patterns. A 3-segments rule based chop strategy is proposed and tested with which significant simulation accuracy improvement is achieved at little extra computational cost.