bluuebunny/crossref_metadata_2025 huggingface dataset:
An Infrared Absorbance Sensor for the Detection of Melanoma in Skin Biopsies
Authors: Fioravanti Valeria , Brandhoff Lukas , Van den Driesche Sander , Breiteneder Heimo , Kitzwögerer Melitta , Hafner Christine , Vellekoop Michael
Published: October 2016

An infrared (IR) absorbance sensor has been designed, realized and tested with the aim of detecting malignant melanomas in human skin biopsies. The sensor has been designed to obtain fast measurements (80 s) of a biopsy using a small light spot (0.5 mm in diameter, typically five to 10 times smaller than the biopsy size) to investigate different biopsy areas. The sensor has been equipped with a monochromator to record the whole IR spectrum in the 3330–3570 nm wavelength range (where methylene and methyl stretching vibrations occur) for a qualitative spectral investigation. From the collected spectra, the CH2 stretch ratio values (ratio of the absorption intensities of the symmetric to asymmetric CH2 stretching peaks) are determined and studied as a cancer indicator. Melanoma areas exhibit different spectral shapes and significantly higher CH2 stretch ratios when compared to healthy skin. The results of the infrared investigation are compared with standard histology. This study shows that the IR sensor is a promising supportive tool to improve the diagnosis of melanoma during histopathological analysis, decreasing the risk of misdiagnosis.
Just Not Like Us: The Interactive Impact of Dimensions of Identity and Race in Attitudes towards Immigration
Authors: Byrne Jennifer , Dixon Gregory
Published: October 2016

Since 2009, more Mexicans have been leaving rather than coming to the USA; likewise, illegal immigration from Mexico has declined. Yet, immigration remains a hotly contested issue in the 2016 presidential election, with a seemingly marked increase in anti-immigrant policy and rhetoric, much of which is directed at immigrants from Mexico. In this paper, we seek to explain how individual ethnocultural and civic-based conceptions of what it means to be an American influence attitudes towards immigration. Past theoretical research on national identity has framed the effects of these dimensions as interactive but past empirical work has yet to demonstrate an important interaction between race and ethnocultural identity. Failure to account for these interaction effects has led to inaccurate assumptions about the levels of hostility towards immigrants and how widespread anti-immigrant sentiment really is. We demonstrate a clear interactive effect between identification as white and ethnocultural dimensions of identity and show that this effect has masked the root of the most ardent anti-immigrant sentiment. We also show that while there is a sizeable minority of the population that identifies as both white and have high levels of ethnocultural identity, a majority of Americans prefer to keep immigration levels at the status quo and have an identity that is balanced between ethnoculturalism and civic-based conceptions of identity.
Analysis of Farmland Abandonment at Parcel Level: A Case Study in the Mountainous Area of China
Authors: Shi Tiechou , Li Xiubin , Xin Liangjie , Xu Xiaohong
Published: October 2016

Chongqing municipality, the main study area of this paper, is a mountainous city in Southwest China, where massive rural populations migrated to cities and towns in recent years. This study extracted abandoned farmland figure spots from farmland distribution maps of 2002 and 2011 on a 1:10,000 scale. Further, this research analyzed the spatial distribution characteristics of farmland abandonment and its influencing factors at the parcel level from 2002 to 2011. The main influencing factors of farmland abandonment include distance of a parcel to the closest settlement, difference between the parcel elevation and the average elevation of the whole village settlement, parcel slope, and parcel size. The former three factors are positively correlated with farmland abandonment rate, and parcel size is negatively correlated. That is to say that larger commuting distance, elevation difference, and parcel slope increase the abandonment probability; and a larger parcel size can reduce the risk of abandonment.
The Impact of Multinational Business Diversification on the Financial Sustainability of Construction Firms in Korea
Authors: Lee Sanghyo , Ahn Yonghan , Shin Sungwoo
Published: October 2016

This study investigated empirically whether multinational business diversification by Korean construction firms contributes to their financial sustainability using the vector error correction model. In this study, the current ratio and the debt ratio were used as proxy variables for financial sustainability. International construction orders and domestic construction orders were used as proxy variables for multinational business diversification for the analysis. Of the models used for analysis in this study, Model A used the current ratio and international and domestic construction orders, and Model B used the debt ratio and international and domestic construction orders. The time-series data utilized consisted of the quarterly data from Q1 of 2001 to Q4 of 2015. The results of the analysis imply that an increase in international construction orders undermines the financial viability of construction firms because of a decrease in the current ratio and an increase in the debt ratio. The results also show that the scrutinized analysis of profitability was insufficient because overseas project orders were not pursued based on a long-term business strategy but on short-term turnover. Therefore, Korean construction firms should recognize the overseas construction market as an independent market, not an alternative to the domestic market, and establish a long-term business strategy to enter overseas markets effectively to secure financial sustainability.
The Impact of Albedo Increase to Mitigate the Urban Heat Island in Terni (Italy) Using the WRF Model
Authors: Morini Elena , Touchaei Ali , Castellani Beatrice , Rossi Federico , Cotana Franco
Published: October 2016

The impacts of the urban heat island (UHI) phenomenon on energy consumption, air quality, and human health have been widely studied and described. Mitigation strategies have been developed to fight the UHI and its detrimental consequences. A potential countermeasure is the increase of urban albedo by using cool materials. Cool materials are highly reflective materials that can maintain lower surface temperatures and thus can present an effective solution to mitigate the UHI. Terni’s proven record of high temperatures along with related environmental and comfort issues in its urban areas have reflected the local consequences of global warming. On the other hand, it promoted integrated actions by the government and research institutes to investigate solutions to mitigate the UHI effects. In this study, the main goal is to investigate the effectiveness of albedo increase as a strategy to tackle the UHI, by using the Weather Research and Forecasting (WRF) mesoscale model to simulate the urban climate of Terni (Italy). Three different scenarios through a summer heat wave in the summer of 2015 are analyzed. The Base Scenario, which simulates the actual conditions of the urban area, is the control case. In the Albedo Scenario (ALB Scenario), the albedo of the roof, walls and road of the whole urban area is increased. In the Albedo-Industrial Scenario (ALB-IND Scenario), the albedo of the roof, walls and road of the area occupied by the main industrial site of Terni, located in close proximity to the city center, is increased. The simulation results show that the UHI is decreased up to 2 °C both at daytime and at nighttime in the ALB and in ALB-IND Scenarios. Peak temperatures in the urban area can be decreased by 1 °C at daytime, and by about 2 °C at nighttime. Albedo increase in the area of interest might thus represent an opportunity to decrease the UHI effect and its consequences.
Methodological Approach for the Sustainability Assessment of Development Cooperation Projects for Built Innovations Based on the SDGs and Life Cycle Thinking
Authors: Maier Stephanie , Beck Tabea , Francisco Vallejo Javier , Horn Rafael , Söhlemann Jan-Hendrik , Nguyen Trung
Published: October 2016

This paper describes a methodological approach for a sustainability assessment of development cooperation projects. Between the scientific disciplines there is no agreement on the term of “sustainability”. Whereas the definition of sustainability within the context of development cooperation frequently highlights the long-term success of an intervention, the United Nations herald the inclusion of social, economic and environmental aspects. This paper proposes to bridge this gap by providing an analytical framework that uses nine impact category groups based on thematic priorities of sustainable development derived from the Sustainable Development Goals. Additionally, the long-term effectiveness of a project is taken into consideration. These impact category groups comprise the analytical framework, which is investigated by the Life Cycle Assessment and an indicator-based analysis. These data are obtained through empirical social research and the LCA inventory. The underlying concept is based on life cycle thinking. Taking up a multi-cycle model this study establishes two life cycles: first, the project management life cycle; and, second, the life cycle of a project’s innovation. The innovation’s life cycle is identified to have the greatest impact on the target region and the local people and is consequently of primary interest. This methodological approach enables an ex-post sustainability assessment of a built innovation of a development cooperation project and is tested on a case study on Improved Cooking Stoves in Bangladesh.
Characterization of 316L Steel Cellular Dodecahedron Structures Produced by Selective Laser Melting
Authors: Prashanth Konda , Löber Lukas , Klauss Hans-Jörg , Kühn Uta , Eckert Jürgen
Published: October 2016

The compression behavior of different 316L steel cellular dodecahedron structures with different density values were studied. The 316L steel structures produced using the selective laser melting process has four different geometries: single unit cells with and without the addition of base plates beneath and on top, and sandwich structures with multiple unit cells with different unit cell sizes. The relation between the relative compressive strength and the relative density was compared using different Gibson-Ashby models and with other published reports. The different aspects of the deformation and the mechanical properties were evaluated and the deformation at distinct loading levels was recorded. Finite element method (FEM) simulations were carried out with the defined structures and the mechanical testing results were compared. The calculated theory, simulation estimation, and the observed experimental results are in good agreement.
The Possible Mechanisms Involved in Degradation of Patulin by Pichia caribbica
Authors: Zheng Xiangfeng , Yang Qiya , Zhang Hongyin , Cao Jing , Zhang Xiaoyun , Apaliya Maurice
Published: October 2016

In this work, we examined the mechanisms involved in the degradation of patulin by Pichia caribbica. Our results indicate that cell-free filtrate of P. caribbica reduced patutlin content. The heat-killed cells could not degrade patulin. However, the live cells significantly reduced the concentration of the patulin. In furtherance to this, it was observed that patulin was not detected in the broken yeast cells and cell wall. The addition of cycloheximide to the P. caribbica cells decreased the capacity of degradation of patulin. Proteomics analyses revealed that patulin treatment resulted in an upregulated protein which was involved in metabolism and stress response processes. Our results suggested that the mechanism of degradation of patulin by P. caribbica was not absorption; the presence of patulin can induce P. caribbica to produce associated intracellular and extracellular enzymes, both of which have the ability to degrade patulin. The result provides a new possible method that used the enzymes produced by yeast to detoxify patulin in food and feed.
RADIO OBSERVATIONS OF A SAMPLE OF BROAD-LINE TYPE IC SUPERNOVAE DISCOVERED BY PTF/IPTF: A SEARCH FOR RELATIVISTIC EXPLOSIONS
Authors: Corsi A. , Gal-Yam A. , Kulkarni S. R. , Frail D. A. , Mazzali P. A. , Cenko S. B. , Kasliwal M. M. , Cao Y. , Horesh A. , Palliyaguru N. , Perley D. A. , Laher R. R. , Taddia F. , Leloudas G. , Maguire K. , Nugent P. E. , Sollerman J. , Sullivan M.
Published: October 2016

Long duration γ-ray bursts are a rare subclass of stripped-envelope core-collapse supernovae (SNe) that launch collimated relativistic outflows (jets). All γ-ray-burst-associated SNe are spectroscopically Type Ic, with broad-lines, but the fraction of broad-lined SNe Ic harboring low-luminosity γ-ray bursts remains largely unconstrained. Some SNe should be accompanied by off-axis γ-ray burst jets that initially remain invisible, but then emerge as strong radio sources (as the jets decelerate). However, this critical prediction of the jet model for γ-ray bursts has yet to be verified observationally. Here, we present K. G. Jansky Very Large Array observations of 15 broad-lined SNe of Type Ic discovered by the Palomar Transient Factory in an untargeted manner. Most of the SNe in our sample exclude radio emission observationally similar to that of the radio-loud, relativistic SN 1998bw. We constrain the fraction of 1998bw-like broad-lined SNe Ic to be

(99.865% confidence). Most of the events in our sample also exclude off-axis jets similar to GRB 031203 and GRB 030329, but we cannot rule out off-axis γ-ray bursts expanding in a low-density wind environment. Three SNe in our sample are detected in the radio. PTF11qcj and PTF14dby show late-time radio emission with average ejecta speeds of ≈0.3–0.4 c, on the dividing line between relativistic and “ordinary” SNe. The speed of PTF11cmh radio ejecta is poorly constrained. We estimate that

(99.865% confidence) of the broad-lined SNe Ic in our sample may harbor off-axis γ-ray bursts expanding in media with densities in the range probed by this study.
THE X-RAY LUMINOSITY FUNCTION OF M37 AND THE EVOLUTION OF CORONAL ACTIVITY IN LOW-MASS STARS
Authors: Núñez Alejandro , Agüeros Marcel A.
Published: October 2016

We use a 440.5 ks Chandra observation of the ≈500 Myr old open cluster M37 to derive the X-ray luminosity functions of its ≤1.2 

stars. Combining detections of 162 M37 members with upper limits for 160 non-detections, we find that its G, K, and M stars have a similar median (0.5–7 keV) X-ray luminosity

, whereas the

-to-bolometric-luminosity ratio (

) indicates that M stars are more active than G and K stars by

order of magnitude at 500 Myr. To characterize the evolution of magnetic activity in low-mass stars over their first

, we consolidate X-ray and optical data from the literature for stars in six other open clusters: from youngest to oldest they are, the Orion Nebula Cluster (ONC), NGC 2547, NGC 2516, the Pleiades, NGC 6475, and the Hyades. For these, we homogenize the conversion of instrumental count rates to

by applying the same one-temperature emission model as for M37, and obtain masses using the same empirical mass-absolute magnitude relation (except for the ONC). We find that for G and K stars X-ray activity decreases

orders of magnitude over their first 600 Myr, and for M stars, ≈1.5. The decay rate of the median

follows the relation

, where

for G stars, −0.82 ± 0.16 for K stars, and −0.40 ± 0.17 for M stars. In

space, the slopes are −0.68 ± 0.12, −0.81 ± 0.19, and −0.61 ± 0.12, respectively. These results suggest that for low-mass stars the age-activity relation steepens after

, consistent with the faster decay in activity observed in solar analogs at

.
THE NATURE OF ACTIVE GALACTIC NUCLEI WITH VELOCITY OFFSET EMISSION LINES*
Authors: Müller-Sánchez F. , Comerford J. , Stern D. , Harrison F. A.
Published: October 2016

We obtained Keck/OSIRIS near-IR adaptive optics-assisted integral-field spectroscopy to probe the morphology and kinematics of the ionized gas in four velocity-offset active galactic nuclei (AGNs) from the Sloan Digital Sky Survey. These objects possess optical emission lines that are offset in velocity from systemic as measured from stellar absorption features. At a resolution of ∼0.″18, OSIRIS allows us to distinguish which velocity offset emission lines are produced by the motion of an AGN in a dual supermassive black hole system, and which are produced by outflows or other kinematic structures. In three galaxies, J1018+2941, J1055+1520, and J1346+5228, the spectral offset of the emission lines is caused by AGN-driven outflows. In the remaining galaxy, J1117+6140, a counterrotating nuclear disk is observed that contains the peak of Paα emission 0.″2 from the center of the galaxy. The most plausible explanation for the origin of this spatially and kinematically offset peak is that it is a region of enhanced Paα emission located at the intersection zone between the nuclear disk and the bar of the galaxy. In all four objects, the peak of ionized gas emission is not spatially coincident with the center of the galaxy as traced by the peak of the near-IR continuum emission. The peaks of ionized gas emission are spatially offset from the galaxy centers by 0.″1–0.″4 (0.1–0.7 kpc). We find that the velocity offset originates at the location of this peak of emission, and the value of the offset can be directly measured in the velocity maps. The emission-line ratios of these four velocity-offset AGNs can be reproduced only with a mixture of shocks and AGN photoionization. Shocks provide a natural explanation for the origin of the spatially and spectrally offset peaks of ionized gas emission in these galaxies.
AVALIAÇÃO DO PERCENTUAL DE RESTO-INGESTÃO E SOBRA ALIMENTAR EM UMA UNIDADE DE ALIMENTAÇÃO E NUTRIÇÃO INSTITUCIONAL
Authors: Rabelo Natália De Miranda Luciano , Alves Thereza Cristina Utsunomiya
Published: October 2016

As Unidades de Alimentação e Nutrição (UAN’s) consistem em serviços organizados, compreendidos por uma sequência de atos destinados a produzir e fornecer refeições balanceadas dentro dos padrões dietéticos e higiênico-sanitários, atendendo as necessidades nutricionais e sensoriais dos comensais. Conhecer os percentuais de resto-ingestão e sobras sujas de alimentos é de suma importância para reduzir custos e resíduos orgânicos. O objetivo do presente estudo foi avaliar o resto-ingestão e as sobras de alimentos de uma UAN institucional de autogestão em Campo Novo do Parecis-MT. A coleta de dados foi realizada entre os meses de Abril à Maio de 2013, de segunda à sexta-feira, durante o almoço onde são fornecidas 900 refeições diárias. Utilizou-se uma balança com capacidade 300 kg para quantificar o total de alimentos produzidos para a distribuição nos balcões térmicos assim como as sobras de alimentos e resto-ingestão. A média de consumo diário per capita foi de 822 g, na qual se observou percentual médio de resto-ingestão de 9,45%, o equivalente a 77,82 g de alimentos descartados por pessoa. Os valores encontrados das sobras sujas foi 57,35 g, com percentual de 6,87%. Os resultados mostraram que com o total de desperdício seria possível alimentar 71 pessoas, acarretando no custo mensal para a unidade um valor de R$ 18.370,00. Conclui-se que o percentual de resto-ingestão e sobras sujas na UAN ultrapassou os valores preconizados na literatura citada por Vaz (2006), fazendo-se necessário a realização de ações junto aos comensais para conhecimentos de suas preferências alimentares, além de campanhas relacionadas a desperdícios para conscientização, bem como treinamentos periódicos com os funcionários visando à minimização do desperdício e o melhoramento na qualidade dos serviços.
ABORDAGEM CRITICA RELACIONADA A ALIMENTOS TRANSGÊNICOS
Authors: Carvalho Marlon Thiago de , Bieger Juliane Tramontin
Published: October 2016

Os alimentos de origem transgênica estão inseridos na nossa alimentação diária e os consumidores sem apresentarem críticas relacionadas a este produto consomem, totalmente diferente de quando foram inseridos no Brasil, onde de acordo com tal fonte os consumidores apresentavam aversão aos produtos. O presente trabalho tem por objetivo ir a campo avaliar o conhecimento e a visão da população sobre os alimentos geneticamente modificados. O trabalho foi realizado na cidade de Toledo-PR. Foi estruturado um questionário para servir como base para o presente estudo. Com ele objetivou-se de forma aleatória conhecer os pareceres de uma amostra estabelecida, em relação ao assunto tratado. Dos entrevistados 6 apoiaram a produção dos transgênicos, três deles relatam que é bom por apresentar menos agrotóxico. Apresentando uma opinião negativa aos transgênicos tivemos 77% dos entrevistados. Com os dados relatados no estudo, podemos dizer que ao longo dos anos se formou uma corrente de irresponsabilidade, resultando assim na atual situação, qual se consome não só transgênicos mais diversos outros alimentos.
CARACTERIZAÇÃO DE IOGURTE DE LEITE DE OVELHA IN NATURA E SABORIZADO COM MIRTILO (Vaccinium myrtillus)
Authors: Mior Jociane , Novello Zuleica , Zilio Dinon Andréia
Published: October 2016

O reconhecimento e aceitação dos derivados do leite de ovelha tem aumentado e estimulado a oferta de novos produtos no mercado nacional. O iogurte é considerado um importante derivado de leite de ovelha classificado como alimento funcional. Geralmente são utilizadas polpas de frutas e geleias para saborização do iogurte. Este trabalho teve por objetivo avaliar o iogurte de leite de ovelha saborizado com mirtilo (Vaccinium myrtillus) por meio de análises microbiológicas, sensoriais e físico-químicas a fim de determinar sua aceitabilidade após o preparo bem como suas características físico-químicas durante 55 dias de armazenamento. Observou-se decréscimo no valor de pH e aumento na acidez decorrente do processo de pós-acidificação. Em relação aos valores de L*, houve uma redução da luminosidade a partir de 30 dias de armazenamento e um aumento após 50 dias. Os parâmetros de cromaticidade a* e b*, não tiveram diferença significativa ao longo de 50 dias de armazenamento do produto embalado e refrigerado. A análise sensorial mostrou que o iogurte com 25% de polpa de mirtilo apresentou 64% de preferência e houve 100% de intenção de consumo desse iogurte pelos julgadores.
Comparison of the Effect of Epithelial Removal by Transepithelial Phototherapeutic Keratectomy or Manual Debridement on Cross-linking Procedures for Progressive Keratoconus
Authors: Gaster Ronald N. , Ben Margines J. , Gaster David N. , Li Xiaohui , Rabinowitz Yaron S.
Published: October 2016

PURPOSE:

To compare the visual, refractive, keratometric, topographic, and pachymetric outcomes of corneal collagen cross-linking (CXL) for progressive keratoconus following epithelial removal by transepithelial phototherapeutic keratectomy (PTK) or manual debridement.

METHODS:

In this analysis, 339 eyes (78% male, 22% female) that had undergone CXL following manual epithelial debridement (n = 180) or ablation via PTK (n = 159) were evaluated preoperatively and at 6, 12, and 24 months postoperatively for uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), maximum corneal keratometry, pachymetry, and spherical equivalent. The data were analyzed in a
t
test to evaluate the relative efficacy of each epithelial removal procedure.

RESULTS:

Manual epithelial debridement and ablation via PTK produce equivalent changes for all variables at each time interval with the exception of maximum corneal keratometry at 6 months postoperatively, for which PTK exhibited a significantly improved (flatter) result. This difference was present but not statistically significant at 12 and 24 months postoperatively.

CONCLUSIONS:

Prior to CXL, both manual epithelial debridement and ablation via PTK result in equivalent visual, refractive, and keratometric outcomes up to 24 months postoperatively.

[
J Refract Surg.
2016;32(10):699–704.]
Glistening Formation on a Single-Piece Prehydrated Hydrophobic Acrylic Intraocular Lens in a Diabetic Patient
Authors: Kang Su-Yeon , Eom Youngsub , Rhim Jay Won , Song Jong Suk , Kim Hyo Myung
Published: October 2016

PURPOSE:

To report a case of intraocular lens (IOL) glistening after uneventful cataract surgery and in-the-bag implantation of an enVista MX60 IOL (Bausch & Lomb, Rochester, NY) in a patient with uncontrolled diabetes mellitus.

METHODS:

Case report.

RESULTS:

A 76-year-old woman with non-insulin–dependent diabetes mellitus underwent uncomplicated phacoemulsification with in-the-bag implantation of an enVista MX60 IOL. After 6 months, glistening formation within the IOL optic was observed. In the fellow pseudophakic eye, an acrylic hydrophilic Akreos Adapt AO IOL (Bausch & Lomb) was implanted without complications.

CONCLUSIONS:

IOL glistening can develop with the enVista MX60 IOL, even after uneventful cataract surgeries in certain situations (eg, uncontrolled diabetes mellitus). Increased vascular permeability due to uncontrolled diabetes mellitus might have been responsible for the postoperative IOL glistening formation.

[
J Refract Surg.
2016;32(10):710–712.]
Comparison of AL-Scan and IOLMaster 500 Partial Coherence Interferometry Optical Biometers
Authors: Hoffer Kenneth J. , Savini Giacomo
Published: October 2016

PURPOSE:

To investigate agreement between the ocular biometry measurements provided by a newer optical biometer, the AL-Scan (Nidek Co, Ltd., Gamagori, Japan) and those provided by the IOLMaster 500 (Carl Zeiss Meditec, Jena Germany), which are both based on partial coherence interferometry.

METHODS:

Axial length, corneal power, and anterior chamber depth (corneal epithelium to lens) were measured in 86 eyes of 86 patients scheduled for cataract surgery using both biometers. All values were analyzed using a paired
t
test, the Pearson product moment correlation coefficient (
r
), and Bland–Altman plots.

RESULTS:

The mean axial length values of both instruments were exactly the same (23.46 ± 0.99 mm) for both) and showed excellent agreement and correlation. On the contrary, the AL-Scan measured a steeper mean corneal power by 0.08 diopters (D) at the 2.4-mm zone but by only 0.03 D at the 3.3-mm zone, only the former being statistically significant. The AL-Scan measured a deeper anterior chamber depth by 0.13 mm, which was statistically significant (
P
< .001).

CONCLUSIONS:

Agreement between the two units was good. However, the small but statistically significant difference in corneal power (at the IOLMaster-comparable 2.4-mm zone) and in the anterior chamber depth measurement make lens constant optimization necessary when calculating the intraocular lens power by means of theoretical formulas.

[
J Refract Surg.
2016;32(10):694–698.]
Small-Aperture Intraocular Lens Implantation in a Patient With an Irregular Cornea
Authors: Schultz Tim , Dick H. Burkhard
Published: October 2016

PURPOSE:

To report a small-aperture intraocular lens (IOL) implantation after corneal trauma.

METHODS:

Case report.

RESULTS:

A 17-year-old boy with corneal scars, iris defect, and aphakia after perforating trauma in the right eye was scheduled for small-aperture IOL (IC-8; AcuFocus, Irvine, CA) implantation under general anesthesia. No intraoperative complications were observed. Six months after surgery, the uncorrected distance and near visual acuity increased significantly. Furthermore, reduced photopic phenomena were reported.

CONCLUSIONS:

The small-aperture IOL is a new and promising option to treat patients suffering from the effects of corneal irregularities.

[
J Refract Surg.
2016;32(10):706–708.]
A Novel Unified Dislocation-Density Based Model for Hot Deformation Behavior of a Nickel-Based Superalloy
Authors: Lin Y.C. , Wen Dong Xu
Published: October 2016

In hot forming processes, metallic materials often undergo a series of plastic deformation and heat treatments. Hot working parameters, including deformation temperature, strain rate, and strain, exert great impacts on hot deformation behavior of alloys. Work hardening (WH), dynamic recovery (DRV), dynamic recrystallization (DRX), phase transformation, and metadynamic recrystallization (MDRX) often take place, and affect hot deformation behavior of metallic materials. Therefore, a comprehensive investigation on the intrinsic interactions between microstructural evolution and hot deformation behavior is necessary. In this study, a novel unified dislocation-density based model is presented to characterize the hot deformation behavior of a nickel-based superalloy In the Kocks-Mecking model, a new softening item is proposed to represent the impacts of dynamic recrystallization behavior on dislocation density evolution. The grain size evolution and dynamic recrystallization kinetics are incorporated into the developed model. Material parameters of the developed model are calibrated by a derivative-free method in MATLAB toolbox. Comparisons for the experimental and predicted results confirm that the developed unified model can accurately reproduce the hot deformation behavior, DRX kinetics, and grain size evolution in wide scope of initial grain size, deformation temperature, and strain rate.
Cohesive Zone Modeling for 3D Ductile Crack Propagation
Authors: Li Xiao , Yuan Huang
Published: October 2016

Computational modeling of three-dimensional crack propagation in very ductile materials is still a challenge in fracture mechanics analysis. In the present work a new stress-triaxiality-dependent cohesive zone model (TCZM) is proposed to describe elastic-plastic fracture process in full three-dimensional specimens. The cohesive parameters are identified as a function of the stress triaxiality from ductile fracture experiments. The predictions of TCZM show good agreement with the experimental results for both side-grooved C(T) specimen and rod bar specimen.
Mode-II Fatigue Crack Growth Model from Shear-Type Low Cycle Fatigue Properties
Authors: Shi Kai Kai , Cai Li Xun , Qi Shuang , Bao Chen
Published: October 2016

The inherent law between fatigue behaviors of shear-type representative volume element and mode-II fatigue crack growth is found in the range of cycle plastic zone near the crack tip. Prediction model for mode-II fatigue crack growth rate is then proposed by utilizing shear-type low cycle fatigue properties, plastic strain energy criterion, and effective cycle stress-strain field. Experimental data of two Aluminum alloys, 2024-T351 and 7075-T6, are used for the model verification. Good agreement between experimental and theoretical results is obtained.
Analysis on the Creep Mechanism of 12Cr-Mo-W-0.25V Steel Based on Long-Term Stress Relaxation Test Data
Authors: Zhao Jie , Cao Tie Shan , Cheng Cong Qian , Li Hui Fang
Published: October 2016

The current paper investigates on the creep behavior of 12Cr-Mo-W-0.25V heat resistant steel base on the long-term stress relaxation test data. It is shows that the stress relaxation curve can be divided into 2 stages: the high stress stage has higher apparent activation volume of 79~350 b3 and the low stress stage is 35~78 b3. Besides, the Helmholtz free energy at the high stress stage is 827~1034 kJ/mol which is higher than 210~252 kJ/mol of the low stress stage. Taking both apparent activation volume and activation energy into account, it is assumed that the high stress stage is mainly controlled by dislocation slip and the low stress stage is more related to diffusion.
Effects of Sensitization and Hydrogen on Stress Corrosion Cracking of 18-8 Type Stainless Steel
Authors: Cao Luo Wei , Du Chen Yang , Xie Guo Shan
Published: October 2016

Austenitic stainless steels always failure in intergranular corrosion, stress corrosion cracking and their synthesis. Moreover, hydrogen also plays an important role in SCC. Effects of sensitization and hydrogen on stress corrosion cracking of 18-8 type stainless steel (304 and 304L) were investigated in this paper. Three states of specimens, including as-received, sensitization and hydrogen precharged, were prepared for this study. Two kinds of environment, involving air and 0.5mol H2SO4 +0.01mol KSCN solution, were selected to compare the SCC sensitivity of different condition of 304 and 304L by the slow strain rate tensile test (SSRT). Fracture morphology was observed by scanning electron microscope (SEM) to check the SCC fracture characteristic. In SEM, evident secondary cracks were found on the fracture surface of 304. Results showed that: 1) hydrogen precharged 304L has high SCC sensitivity (85.7% ) compared with low SCC sensitivity in solution (14.5%), which reveal that SCC of 304L is hydrogen-induced cracking type; 2) 304 stainless steel has high SCC sensitivity (60.8%); 3) sensitization increases the SCC sensitivity of 304 stainless steel (from 60.8% to 71.4%).
Stability of Residual Stresses in Ultrasonic Surface Deep Rolling Treated Ti-6Al-4V Alloy under Cyclic Loading
Authors: Mao Miao Dong , Zhang Xian Cheng
Published: October 2016

Compressive residual stresses have been found to affect fatigue crack growth behavior by delaying the crack initiation and by decelerating the crack propagation rate. Therefore, various mechanical surface treatment techniques have been developed to produce the compressive residual stresses on the surface of components. However, the residual stresses will relax due to cyclic loading. Hence, the stability of residual stress during fatigue process is a great importance aspect for design of components. In this paper, the ultrasonic surface deep rolling was used to generate the compressive residual stress near the surface of Ti-6Al-4V. The stress relaxation behavior was identified during the low cycle fatigue process. The X-ray diffraction method was used to determine the magnitude and sign of residual stress. Results showed that under cyclic loading, the residual stress relaxation occurred fast in the first few cycles then became stable. Furthermore, it was found that relaxation rates of residual stress were depended on the applied stress.
Influence of Plastic Pre-Strain on Low-Temperature Gas Carburization of 316L Austenitic Stainless Steel
Authors: Peng Ya Wei , Gong Jian Ming , Jiang Yong , Fu Ming Hui , Rong Dong Song
Published: October 2016

In this paper, the influence of pre-strain on low-temperature gas carburization of 316L austenitic stainless steel was investigated. A group of flat specimens were uniaxial tensile to several levels of pre-strain including 5%, 10%, 15%, 20% and 25% engineering strain. Then, the pre-strained specimens was treated by low-temperature gas carburization at 470 °C for 30 h. In order to elucidate the effect of pre-strain on low-temperature gas carburization, optical microscopy (OM), X-ray diffractometer (XRD), scanning electron probe micro-analyzer (EPMA), microhardness tester and residual stress analyzer were used. Meanwhile, dislocation density of the pre-strained specimens was semi-quantitatively measured by means of X-ray diffraction analysis and the role of dislocation density on carbon diffusion during low-temperature gas carburization was discussed. The results show as follow: (1) the thicknesses of the carburized layers are independent of the pre-strain degree. (2) dislocation density increases with the increasing pre-strain, but almost has no effect on carbon diffusion at the given carburizing temperature. (3) an outstanding surface with hardness (≈ 1150 HV0.1) and compressive residual stress (≈1900 MPa) is introduced by low-temperature gas carburization, and the strengthening results of carburization are unaffected by pre-strain.
Multiaxial Ratcheting Behavior of M5 Zirconium Alloys Tubes in Different Loading History
Authors: Zhang Xu , Chen Xu , Chen Gang
Published: October 2016

In this study, a series of multiaxial ratcheting tests under combined cyclic axial and inner pressure were conducted on M5 zirconium alloys tubes used as nuclear fuel cladding in Pressurized Water Reactors (PWRs) for the purpose to investigate the multiaxial ratcheting behavior of M5 and the factors of loading history may influence it. The experiment was stress-controlled and designed in a special loading path that all tubes in actually were under axial symmetrical cyclic load and constant inner pressure. A set of new patent multiaxial clamp was designed and applied to make sure the tubes can withstand inner pressure and axial load at the same time. A dynamic closed-loop multiaxial testing controller was used to manipulate two actuators simutaneously. Biaxial strain gauges were adopted to detect the signals of axial and hoop strain during the tests. The experimental results show that axial ratcheting strain decreases obviously within the original cycles reaching to a stop in certain cycles, the axial ratcheting increases with the cycles going. Loading history has obvious influence on the ratcheting behavior in axial direction. Higher stress amplitude level after loading history with lower stress amplitude level leads to an abnormal ratcheting behavior. The axial ratcheting shows a high sensitive to the complex loading history, especially when the stress amplitude is high. The hoop ratcheting strain accumulates continuously with the cycles going. Loading history has no obvious influence on hoop ratcheting strain and its ratcheting when the stress amplitude is low. The ratcheting strain and its rate shows more sensitive to the loading history when the stress amplitude increases to a certain value.
Creep Characteristic of Sn1.0Ag0.7Cu Lead-Free Solders with Element Addition
Authors: Ogawa Fumio , Nagao Hiroki , Itoh Takamoto , Sakane Masao , Yamashita Mitsuo , Hokazono Hiroaki
Published: October 2016

In this study, creep properties of lead-free solders based on Sn1.0Ag0.7Cu were investigated. In the solders, germanium, nickel and bismuth were added to improve their mechanical properties. The effect of element addition on their microstructure and creep properties were studied. Creep properties were improved with the element addition. Creep rupture lifetime was the longest for SnAgCuBiNiGe, and that of SnAgCuBi was the second longest. It was made clear that a minimum creep strain rate is useful for lifetime prediction of the solders. An observation of microstructure was performed and coarsening of intermetallics after creep test was identified, resulting in creep rupture. It was found that the addition of bismuth hinders the coarsening of intermetallics and is effective to improve the creep properties of the solders.
Numerical Simulation and Experimental Investigation of Residual Stress in 06Cr19Ni10 Austenitic Stainless Steel Weld Joint with Effects of Strain-Strengthening
Authors: Tang Lan Qing , Li Hui Fang , Wang Xiao Xiao , Qian Cai Fu
Published: October 2016

In this paper, Finite Element Modeling (FEM) using Marc software was carried out to investigate the strain-strengthening effect on residual stress in 06Cr19Ni10 austenitic stainless steel weld joint made by MIG welding. The model prediction of residual stress was validated by X-ray Diffraction (XRD) method. It is found that there is a good agreement between the model predictions and the experimental results. The strain-strengthening can significantly improve the distribution of residual welding stress. Specifically in weld zone and the heat-affected zone (HAZ), residual stress decreases with increasing strain-strengthening level.
The Numerical Analysis and Experimental Study of the Stress Intensity Factor and Outer Surface Strain of the Pressure Pipe with Internal Longitudinal-Cracks
Authors: He Jia Sheng , Yan Meng Qi , Zhu Xiao Ming
Published: October 2016

The strain characteristics in the outer surface of the pipe and the stress intensity factor in crack front with internal longitudinal-cracks were analyzed by the finite element method. According to the results of analysis, the outer surface strain variation to crack size was got and the relationship of stress intensity factor and crack size was known. Based on resistance strain gauges and fiber optic sensing technology, pressure pipe crack extension monitoring device was designed and the outer surface circumferential strain were tested .The results of finite element analysis and experiment are in good agreement. The outer surface strain variation in this paper can be used to analyze the situation of internal longitudinal-cracks extension.That relationship of stress intensity factor and crack size has an important reference to the safety assessment of pipe with internal longitudinal-crack.
Fatigue Strength Check of Pressure Swing Adsorber Based on FEM
Authors: Hu Xiao Dong , Wang Shi Fei , Jiang Di , Wang Hai Yue
Published: October 2016

Adsorption hydrogen productions are used for Hydrogen purification with hydrogen selective adsorption on the surface of microporous adsorption material based on adsorption principle with the equipment of Pressure Swing Adsorber (PSA). PSA is easy to be caused fatigue failure with frequent pressurization and pressure-relief. The fatigue pressure vessels must be fatigue strength checked according to the standards of pressure vessel design beside the Conventional design standards to ensure the service life of equipment. FEM was used to analyze the structure of a PSA provided by a chemical company on the basis of ensuring the fatigue strength according to the JB4732-1995 (2005). The structures of upper and lower connected nozzle had been optimized to locate the maximum stress beside the corner and the connected position between the heads and the forged nozzles to reduce the nozzles weight and cost. Finally, the maximum stress of the determined structure located in the forging tube between the head and the outer wall with the maximum stress value as 169.07MPa according to the design pressure of 1.03MPa. The alternating stress force and intensity amplitude had been calculated with the working pressure range from -0.08MPa to 0.85MPa. The modified stress of the working pressure range was 78.9MPa with alternating cycle allowance being greater than 106 times, which was greater than the design cycles of 9.2 x 105 times.
Limit Load of Pressurized Cylinder-Nozzle Intersection Using Finite Element Method
Authors: Chen Xiao Hui , Liu Shi Yuan , Hu Tao , Pei Dong Xue
Published: October 2016

Pressure vessel contained with different nozzles which caused geometric discontinuity of the pressure vessel wall, which resulted in stress concentration around the nozzle. There may be the chances of failure of vessel junction, which was attributed to the high stress concentration. Therefore, detail stress distribution analysis need to be done for pressure vessel with the nozzle. Determination of limit pressure at different location on lateral nozzle by using finite element method. Lateral nozzle was subjected to internal pressure and in-plane bending moment. Results found that plastic hinge occurred in the nozzle-vessel junction area shoulder. Plastic limit loading increased with the increasing of outside diameter and wall thickness of branch pipe when the size of primary piping was constant value, whereby the influence of outside diameter of branch pipe was more remarkable. Moreover, engineering estimation formulas of plastic limit in-plane bending moment was obtained based on plastic limit loading database.
Mismatch Effect on the Mixed Mode Type Creep Crack within Weldment
Authors: Zhang Jun Hui , Dai Yan Wei
Published: October 2016

Creep crack within weldments are very common in engineering practices, and the cracking location in these welding structures always appears at the HAZ location. The mismatch effect on the mixed mode creep crack is still not clear in these available literatures. The aim of this paper is to investigate the mismatch influence on the creep crack of mixed mode thoroughly. A mixed mode creep crack within HAZ is established in this paper. The leading factor that dominates the creep crack tip field under mixed loading mode is studied. The influences of mismatch effect on mode mixity, stress distribution and stress triaxiality are proposed. The difference of mixed mode creep crack and normal mode I or mode II creep crack are compared. The influence of mixity factor on the transient and steady state creep of crack tip are also analyzed.
Quantification of Stress Field for Mixed Mode Creep Crack Considering Mismatch Effect
Authors: Zhang Jun Hui , Dai Yan Wei
Published: October 2016

Accurate description of creep crack stress field is very important to characterize the creep crack growth of the structures at elevated temperature. In general, the crack mode in practical engineering practices is not mere the mode I or mode II, and it is the mixed mode. The mismatch effect in weldment is also concerned by many researchers, however, there is no available literatures to discuss the stress field of mixed mode creep crack yet. The overall aim of this paper is to investigate and qualify the distribution of stress field for the mixed mode creep crack. In this paper, a mixed mode creep crack within the mismatched plate is discussed. The stress distribution of mixed mode creep crack are given in this article. With the definition of mode mixity for creep crack, the influence of mode mixity on the stress field is presented. The influence of mismatch effect on the principal stress, open stress and shear stress for mixed mode creep crack is also figured out. The main factor leads to the variation of creep crack tip stress field for mixed creep crack is analyzed. Some useful guidelines are proposed for the engineering purpose of integrity assessment for the structure at high temperature.
Weld Residual Stress in Tube to Tube Sheet Joints of a Heat Exchanger by Experimental and Finite Element Simulation
Authors: Wan Yu , Jiang Wen Chun , Gao Jiang Bo
Published: October 2016

Shell-and-tube heat exchangers are widely used in petrol and petro-chemical industries. But weld residual stresses are generated in the tube-to-tube sheet joint and have a great effect on stress corrosion cracking. Therefore, a good prediction and an efficient evaluation of the weld residual stress are necessary to assure the structure integrity. In this work, X-ray diffraction measurement and finite element method have been used to study the residual stress distribution. The results show that the large tensile residual stresses, which have exceeded the yield stress, are generated in the tube to tube sheet joints, leading that the joints become the weakest parts of the heat exchanger. In the central surface part, a wave shape stress distribution is generated along the centerline of tube 1 and tube 3.
Effect of Gasket Compression Resilience on the Tightness of Bolted Flange System
Authors: Zheng Xiao Tao , Pan Jia Lin Zi , Yu Jiu Yang
Published: October 2016

Gasket is an important sealing element of bolted flange connection structure. The nonlinear performance of the gasket material will make the flange angle and gasket compression force change. Therefore, it plays an important role in the tightness of bolted flange connection system. Apart from acknowledgment of this effect, there exists no established design calculation procedure that accounts for tightness. In this paper, the mechanical properties of the gasket at room temperature were studied, it is known that the rebound performance of the gasket is related to the initial preload. And the effect of the compressive resilience of the gasket on the tightness of the bolt flange system was discussed. The tightness of the bolt flange system can be achieved by adjusting the initial preload and working pressure of the gasket, it provides the basis for design and evaluate the tightness of bolted flange connection system.
Modification Strain-Based Failure Assessment Diagram for High Strength Pipeline Steel
Authors: Shi Jun Lin , Zhao Jian Ping , Jiang Wei Jie
Published: October 2016

The strain-based failure assessment diagram (SB-FAD) has been developed to predict failure due to high plastic strains. This paper validates the SB-FAD by finite element results for high strength pipeline steel (X80, X80HD, and X90) with four representative specimens (CT, CCP, DECP, and SCEP) of different crack sizes, respectively. The influence of material properties, geometries and crack sizes on failure assessment curves were compared and analyzed. Meanwhile, the modified Option-1 curve of SB-FAD is given in this paper. The results showed that the modified Option-1 curve of SB-FAD is more accurate when the value of abscissais Dr small and more conservative when the value of abscissa Dr is large.