bluuebunny/crossref_metadata_2025 huggingface dataset:
Les nouvelles technologies et la chaîne de la sécurité
Authors: Martell Rob , Macartney Jason T. , Portnik Danielle
Published: January 2017

La technologie médicale connaît une croissance exponentielle dans le milieu de la santé, mais elle n’a toutefois pas suivi le rythme observé dans des industries similaires, telles que l’aéronautique. Les nouvelles technologies ont le potentiel d’accroître la sécurité des patients, mais si leur introduction dans le milieu de la santé n’est pas coordonnée de manière réfléchie et proactive, la chaîne de la sécurité risque de s’en trouver affaiblie, ce qui exposera les patients à des risques. Trois concepts qui représentent la chaîne de la sécurité sont décrits. Les équipes de direction et le personnel de première ligne devraient tous les connaître, les étudier et s’y investir afin de maintenir la chaîne de la sécurité intacte et d’éviter qu’un seul maillon soit affaibli par l’adoption d’une nouvelle technologie.
Case Report
Authors: Datta Anita , Ferguson Alex , Simonson Chris , Zannotto Francesca , Michoulas Aspasia , Roland Elke , Karnebeek Clara van , Salvarinova Ramona
Published: January 2017

Glutaminyl-tRNA synthetase (QARS) deficiency has been described to be a cause of a neurodegenerative disorder associated with severe developmental delay, microcephaly, delayed myelination, and intractable epilepsy. The epilepsy is thought to be more severe than other tRNA synthetase disorders. Only a few cases have been reported in the literature and there is little information about response to different treatment options. The ketogenic diet is a high-fat, low-carbohydrate diet that is used in treatment resistant epilepsy of various etiologies. There are reports that the diet can also improve neuro-cognitive parameters. The authors report a case of a patient with glutaminyl-tRNA synthetase deficiency and treatment resistant seizures where there was a marked and early favorable response in terms of seizures, alertness and behavior to the ketogenic diet.
Pediatric Epilepsy Surgery
Authors: Qualmann Krista J. , Spaeth Christine G. , Myers Melanie F. , Horn Paul S. , Holland Katherine , Mangano Francesco T. , Greiner Hansel M.
Published: January 2017

Central nervous system comorbidities have been identified in patients with epilepsy. Several of these comorbidities have been correlated with poor surgery outcomes in patient cohorts. The authors sought to determine if prevalence of comorbidities in pediatric epilepsy surgery patients and their families correlate with long-term seizure outcome in a cross-sectional analysis. Three-generation pedigrees were elicited to compare family history of epilepsy, ADHD, anxiety, autism, bipolar disorder, cognitive disability, depression, migraine, and motor disability to surgery outcomes in 52 patients. Proportions of affected patients and relatives were compared to general population comorbidity rates and the patients’ most recent seizure outcome classification. Patients and families had significantly higher rates of comorbidities than the general population. Poorer long-term seizure outcomes following resective surgery were associated with autism or cognitive disability in patients. Together these data support evidence for a common pathophysiological mechanism between epilepsy and central nervous system comorbidities.
Serum Levels of Neuron-Specific Enolase in Children With Diabetic Ketoacidosis
Authors: Hamed Sherifa , Metwalley Kotb Abbass , Farghaly Hekma Saad , Sherief Tahra
Published: January 2017

Neuron-specific enolase is a sensitive marker of neuronal damage in various neurologic disorders. This study aimed to measure serum neuron-specific enolase levels at different time points and severities of diabetic ketoacidosis. This study included 90 children (age 9.2 ± 3.4 years) with diabetic ketoacidosis. Neuron-specific enolase was measured at 3 time points (baseline and after 12 and 24 hours of starting treatment). Among patients, 74.4% had diagnosis of new diabetes, 60% had Glasgow Coma Scale score <15, and 75.6% had moderate/severe diabetic ketoacidosis. Compared with controls (n = 30), children with diabetic ketoacidosis had higher neuron-specific enolase levels at the 3 time points ( P = .0001). In multiple regression analysis, the factors associated with higher neuron-specific enolase levels were younger age, higher glucose, lower pH, and bicarbonate values. This study indicates that serum neuron-specific enolase is elevated in diabetic ketoacidosis and correlated with the severity of hyperglycemia, ketosis, and acidosis. This study indicates that diabetic ketoacidosis may cause neuronal injury from which the patients recovered partially but not completely.
Pharmacological Approach to the Prevention and Treatment of Stress Ulcers
Authors: Gonzalez Edgar R.
Published: January 2017

The mortality associated with bleeding stress ulcers in patients in intensive care units exceeds 50%. Iden tification of patients at risk and use of early and effec tive prophylaxis are necessary in the management of patients in intensive care units. The use of antacids is inconvenient, expensive, and associated with electro lyte disturbances and erratic pH control. H2-receptor antagonists are the preferred agents for stress ulcer pro phylaxis because of their proven efficacy, safety, and ease of administration. Adjunct therapy with cyto protective agents may be useful in patients with com promised mucosal defences.
The Influence of pH Elevation on the Incidence of Nosocomial Pneumonia
Authors: Gentry Layne O.
Published: January 2017

Nosocomial pneumonia, one of the most common hos pital-acquired infectious diseases, is associated with sub stantial morbidity and mortality, approaching 50% in selected patients. Patients with alterations in their tracheobronchial tree or natural host-defense mecha nisms are at increased risk of developing pneumonia. Organisms gain access to the normally sterile tracheo bronchial tree primarily by aspiration of colonized oro pharyngeal gastric secretions. Risk factors for bacterial colonization and the development of nosocomial pneu monia include increased age, elevated pH of gastric con tents, postoperative state, nutritional status, severe underlying disease (for example, chronic obstructive pulmonary disease), administration of corticosteroids or other immunosuppressive therapy, and intubation or mechanical ventilation. High gastric volume may also increase the chance of aspiration of secretions in some high-risk patients.
The Influence of pH Control on the Prevention and Management of Gastrointestinal Bleeding
Authors: Kaplan Marshall M. , May J. Russell
Published: January 2017

Gastrointestinal bleeding from stress-related mucosal damage (SRMD) is caused by a breakdown in the pro cesses that normally protect the gastric mucosa from the corrosive effects of gastric acid and the proteolytic enzyme pepsin. Prostaglandins stimulate some of these protective factors, which include mucus secretion, bi carbonate secretion, rapid cellular repair and rapid blood flow. Acid and pepsin inhibit blood clotting in the stomach by inhibiting platelet aggregation and the func tion of all of the blood clotting factors. The inhibition of blood clotting in the stomach exacerbates bleeding caused by ulcers in the stomach and duodenum. Hence, treatment that will raise intragastric pH (lower acid con centration) should be effective in preventing gastric bleeding from SRMD. Patients in intensive care units are at high risk of developing upper gastrointestinal bleed ing from SRMD. It is easier to prevent SRMD bleeding than to treat it once it starts. Hence, patients in intensive care units should be treated prophylactically to prevent bleeding. Controlled trials and clinical experience indi cate that both antacids and H2 blockers in doses high enough to raise the intragastric pH above 4 are effective forms of prophylaxis. Intravenously administered H2 blockers are more convenient to administer and have fewer side effects than the large doses of antacid re quired to maintain the intragastric pH above 4.
The potential of stromal cell-derived factor-1 delivery using a collagen membrane for bone regeneration
Authors: Takayama Tadahiro , Dai Jisen , Tachi Keita , Shohara Ryutaro , Kasai Hironori , Imamura Kentaro , Yamano Seiichi
Published: January 2017

Stromal cell-derived factor-1 (SDF-1) is a cytokine that is important in stem and progenitor cell recruitment in tissue repair after injury. Regenerative procedures using collagen membranes (CMs) are presently well established in periodontal and implant dentistry. The objective of this study is to test the subsequent effects of the released SDF-1 from a CM on bone regeneration compared to platelet-derived growth factor (PDGF) in vitro and in vivo. For in vitro studies, cell proliferation, alkaline phosphatase activity, and osteoblastic differentiation marker genes were assessed after MC3T3-E1 mouse preosteoblasts were cultured with CMs containing factors. In vivo effects were investigated by placement of CMs containing SDF-1 or PDGF using a rat mandibular bone defect model. At 4 weeks after the surgery, the new bone formation was measured using micro-computed tomography (µCT) and histological analysis. The results of in vitro studies revealed that CM delivery of SDF-1 significantly induced cell proliferation, ALP activity, and gene expression of all osteogenic markers compared to the CM alone or control, similar to PDGF. Quantitative and qualitative µCT analysis for volume of new bone formation and the percentage of new bone area showed that SDF-1-treated groups significantly increased and accelerated bone regeneration compared to control and CM alone. The enhancement of bone formation in SDF-1-treated animals was dose-dependent and with levels similar to those measured with PDGF. These results suggest that a CM with SDF-1 may be a great candidate for growth factor delivery that could be a substitute for PDGF in clinical procedures where bone regeneration is necessary.
Childhood Maltreatment, Limbic Dysfunction, Resilience, and Psychiatric Symptoms
Authors: Ashy Majed , Yu Brian , Gutowski Ellen , Samkavitz Anna , Malley-Morrison Kathleen
Published: January 2017

Previous research has indicated that childhood maltreatment is predictive of psychiatric symptoms in adulthood. Among the potential intervening factors in this relationship are affective reactions in the victims, neurodevelopmental problems, and resilience. The purpose of this study was to test, in a nonclinical low-risk sample, an integrative developmentally based psychoneurological model of the roles of limbic system dysfunction, shame and guilt, and resiliency as potential intervening variables between childhood maltreatment and adult psychiatric symptoms. Also of interest was whether there were gender-specific pathways from maltreatment to symptoms. Based on the results of preliminary analyses, several regressions were conducted separately by gender, entering the different forms of parental aggression at Step 1, resilience at Step 2, the resilience by parental aggression interaction term at Step 3, shame and guilt at Step 4, and limbic dysfunction at Step 5, as predictors of psychiatric symptoms. Analyses indicated that both maternal psychological maltreatment and paternal physical maltreatment were predictive of total psychiatric symptomatology in adulthood, with shame mediating the relationship in women and guilt mediating it in men, limbic system symptoms mediating the relationship in both genders, and trait resilience moderating the relationship in both genders.
Syndemic of Lifetime Mental Illness, Substance Use Disorders, and Trauma and Their Association With Adverse Perinatal Outcomes
Authors: McDonald Lynn R. , Antoine Denis G. , Liao Caiyun , Lee Amy , Wahab Maybel , Coleman Jenell S.
Published: January 2017

Adverse perinatal outcomes are a significant contributor to neonatal and infant deaths. Mental illness, substance use disorders, and interpersonal trauma are often prevalent within obstetrical populations. Previous literature has documented the individual associations between these psychosocial factors and adverse perinatal outcomes. The co-occurrence of these three psychosocial factors might represent a syndemic among pregnant women, although they have not been described as such in the literature. Analysis of the interrelatedness and aggregate effect of these factors may allow for a more effective screening process that may reduce adverse perinatal outcomes. The objective of this article is to examine whether psychosocial factors (mental illness, substance use disorders, and interpersonal trauma) were independently and synergistically associated with adverse perinatal outcomes. This is a retrospective cohort study of 1,656 pregnant women at a single institution. Perinatal outcome and psychosocial data were abstracted from each participant’s electronic medical record. Univariate and bivariate analyses, and multiple logistic regression were performed. Mean age was 27.5 ( SD = 6.2) years. The majority was Black (60.6%) and single (58%). Psychosocial factors were reported in 35% of women. The incidence of adverse perinatal outcomes increased with greater number of psychosocial factors: 21.2% if no psychosocial factor, 27.0% if one psychosocial factor, 27.4% if two, and 35.3% if all three (for trend, p = .01). Women who reported all three psychosocial factors had twice the odds of adverse perinatal outcomes (adjusted odds ratio = 2.04, 95% confidence interval = [1.09, 3.81], p = .03) compared with those who reported none. Our data suggest there is a synergistic relationship between the psychosocial factors that is associated with increased adverse perinatal outcomes. A validated screening tool is needed to stratify patient’s risk of adverse perinatal outcomes based on psychosocial factors. Such screening could lead to tailored interventions that could decrease adverse perinatal outcomes.
A Study of State Certification Exam Results for Florida Police and Correctional Recruits in Relation to Grade-Level Equivalency
Authors: Stinchcomb Jeanne B. , Terry W. Clinton
Published: January 2017

Although the high school diploma is almost universally required for criminal justice employment, it has become widely discredited as no longer being a meaningful indicator of reading, writing, or computational abilities. This study examines one state's response to this discrepancy through minimum competency testing for police and correctional recruits undergoing entry-level training. Multiple regression techniques are used to determine: (1) to what extent demographic variables are predictive of recruit's basic skills scores; and (2) to what extent basic skills scores are predictive of performance on the state certification examination required for criminal justice employment. Findings indicate that demographic variables are relatively weak predictors of recruits' abilities in reading, writing, and mathematics. Moreover, contrary to expectations, considerably more of the variance in certification exam performance can be attributed to the test-taker's discipline (law enforcement or corrections) than to their basic skills scores. Possible reasons for this unexpected outcome are explored.
Florida at the Crossroads: Integrating Sentencing with Corrections?
Authors: Griswold David B.
Published: January 2017

Effective January, 1994, Florida made substantial changes in its sentencing guidelines and several other laws which may have a dramatic impact on the future sentencing of offenders as well as corrections in the state. The purpose of this paper is to critically assess these recent changes in the sentencing guidelines and law.
Long-Term Breastfeeding in African American Mothers
Authors: Gross Tyra Toston , Davis Marsha , Anderson Alex K. , Hall Jori , Hilyard Karen
Published: January 2017

Background:

According to the Centers for Disease Control and Prevention, 39.1% of African American infants are breastfed at 6 months. However, few studies have explored the breastfeeding experiences of African American women who successfully breastfeed to 6 months or longer durations.

Research aim:

The goal of this qualitative study was to explore the long-term breastfeeding experiences of low-income African American women using the positive deviance approach.

Methods:

African American women with breastfeeding experience were recruited through Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) breastfeeding peer counselors. Eligibility criteria included being age 18 or older, currently participating in WIC, and having breastfed one child for at least 6 months in the past 2 years. Semistructured, in-depth interviews were conducted with 11 participants. Interviews were audio-recorded and professionally transcribed. Transcripts were then analyzed for emerging themes using thematic analysis in NVivo software.

Results:

Participants had on average three children each, with an average length of breastfeeding of 10.5 months per child. Four main themes developed: (a) deciding to breastfeed, (b) initiating breastfeeding, (c) breastfeeding long-term, and (d) expanding breastfeeding support. Participants offered culturally tailored suggestions to improve breastfeeding support for other African American women: prenatal discussions of breastfeeding with health care providers, African American lactation support personnel and breastfeeding support groups, and African American breastfeeding promotion in print and digital media.

Conclusion:

Women who participated in this study breastfed for longer durations than the national average for African Americans. Findings can inform practice and research efforts to improve breastfeeding rates in this population using lessons learned from successful women.
Perceptions of Public Breastfeeding Images and Their Association With Breastfeeding Knowledge and Attitudes Among an Internet Panel of Men Ages 21–44 in the United States
Authors: Magnusson Brianna M. , Thackeray Callie R. , Van Wagenen Sarah A. , Davis Siena F. , Richards Rickelle , Merrill Ray M.
Published: January 2017

Background:

Men’s attitudes toward public breastfeeding may influence a woman’s decisions about breastfeeding and her perceived comfort with public breastfeeding.

Research aim:

This study aimed to evaluate factors associated with men’s visual perception of images of public breastfeeding.

Methods:

A 95-item online survey was administered to 502 U.S. men ages 21 to 44. Respondents were presented with four images of women breastfeeding and asked to evaluate agreement with 15 adjectives describing each image. Based on factor analysis, 13 of these adjectives were combined to create the Breastfeeding Images Scale for each image. An 8-item Situational Statements Scale and the 17-item Iowa Infant Feeding Attitude Scale (IIFAS) were used to assess breastfeeding knowledge and attitudes. Multiple regression was used to evaluate the association between breastfeeding attitudes and knowledge and the Breastfeeding Images Scale.

Results:

The image depicting a woman breastfeeding privately at home had the highest mean score of 71.95, 95% confidence interval (CI) [70.69, 73.22], on the Breastfeeding Images Scale, compared with 61.93, 95% CI [60.51, 63.36], for the image of a woman breastfeeding in a public setting. The overall mean scale score for the IIFAS was 56.99, 95% CI [56.27, 57.70], and for the Situational Statements Scale was 28.80, 95% CI [27.92, 29.69]. For all images, increasing breastfeeding knowledge and attitudes measured by the IIFAS and the Situational Statements Scale were associated with a more positive perception of the image.

Conclusion:

Images of public breastfeeding are viewed less favorably by men in the sample than are images of private breastfeeding. Knowledge and attitudes toward breastfeeding are positively associated with perception of breastfeeding images.
An Adoptive Mother Who Became a Human Milk Donor
Authors: Flores-Antón Beatriz , García-Lara Nadia Raquel , Pallás-Alonso Carmen Rosa
Published: January 2017

Inducing lactation in the absence of pregnancy (nonpuerperal lactation) is not always successful and, in many cases, only partial breastfeeding is achieved. Different protocols have been described, but scientific evidence and research are lacking in this area. The authors describe the case of a woman with a history of a miscarriage, for whom the lactation induction process was so effective that she became a milk donor even before she received her adopted child. She had not previously used hormone treatment. She was given domperidone as a galactogogue for 1 month. The pumping protocol began with a double electric breast pump combined with manual pumping 6 months before her child was delivered, and 3 months later, she was accepted as a donor by our milk bank. This highlights the importance of regular stimulation as a milk production mechanism. This is the first case of human milk donation in an adoptive mother described in the literature.
School Characteristics and Teacher Policy Influence: Evidence From New York City
Authors: Shannon Eric William , Saatcioglu Argun
Published: January 2017

Proponents of the charter school movement often claim that the decentralized, autonomous nature of charter schools from district and state authority allows teachers greater influence over school policy both instructionally and administratively. Using a data set of 1,427 New York City schools, we empirically examine the extent to which organizational characteristics predict the amount of policy influence charter schools and traditional public schools grant to teachers. Results indicate not only do charter schools grant their teachers less policy influence but also other organizational features are stronger predictors of teacher policy influence including several nonlinear relationships. Directions for future research are discussed.
Self-Care for Nurse Leaders in Acute Care Environment Reduces Perceived Stress: A Mixed-Methods Pilot Study Merits Further Investigation
Authors: Dyess Susan Mac Leod , Prestia Angela S. , Marquit Doren-Elyse , Newman David
Published: January 2017

Acute care practice settings are stressful. Nurse leaders face stressful demands of numerous competing priorities. Some nurse leaders experience unmanageable stress, but success requires self-care. This article presents a repeated measures intervention design study using mixed methods to investigate a self-care simple meditation practice for nurse leaders. Themes and subthemes emerged in association with the three data collection points: at baseline (pretest), after 6 weeks, and after 12 weeks (posttest) from introduction of the self-care simple meditation practice. An analysis of variance yielded a statistically significant drop in perceived stress at 6 weeks and again at 12 weeks. Conducting future research is merited.
Exploring State–Civil Society Collaboration: Policy Partnerships in Developing Countries
Authors: Brinkerhoff Derick W.
Published: January 2017

This article examines state–civil society partnerships for policy implementation, focusing on the basic factors partnerships need to deal with to be effective. These include specification of objectives and degree of convergence, mechanisms for combining effort and managing cooperation, determination of appropriate roles and responsibilities, and capacity to fulfill those roles and responsibilities. Four cases are presented, three from Africa and one from Eastern Europe. The cases are analyzed in an effort to identify the situational variables that influence state–civil society partnerships, effective partnership mechanisms and processes, and management techniques and tools for supporting cooperative action. The article considers the applicability of strategic management approaches and tools to policy partnerships. Finally, it suggests a series of steps for governments to consider taking that hold the promise of strengthening the successful pursuit of state–civil society partnerships.
Finitude, Freedom and Biomedicine: An Engagement with Gilbert Meilaender’s Bioethics
Authors: McKenny Gerald
Published: January 2017

A fundamental theme in Gilbert Meilaender’s work on bioethical issues is the relationship between the ethical claims of finitude (that is, the biological necessity that characterizes human beings as finite creatures) and of freedom (that is, the capacity of human beings to transcend biological necessity). This article identifies two ways in which Meilaender articulates this relationship (one Niebuhrian, the other Augustinian) and proposes a third (Barthian) way which avoids the limitations of the first two ways while serving Meilaender’s purpose, which is to redress what he sees as an imbalance in favor of the claims of freedom over those of finitude in contemporary biomedicine and bioethics. The article ends by suggesting that Meilaender’s purpose would be best served by avoiding tensions between finitude and freedom as the third way does.
Nietzsche on Augustine on Happiness
Authors: Rose Matthew
Published: January 2017

This article considers the criticisms made by Friedrich Nietzsche of the ethics of St Augustine. Nietzsche’s main criticism presses us to ask whether Augustine can recognize an internal connection between natural human activity and supernatural happiness. The absence of any such connection, alleges Nietzsche, is the self-defeating flaw of Augustine’s eudaimonism, a flaw, paradoxically, that only insures human misery. Rebutting these charges, this article argues, requires us to recognize a form of natural happiness that is proportionate to create human nature.
The Proximity of Hippo to Harvard: A Very Belated Reply to Gilbert Meilaender
Authors: Santurri Edmund N.
Published: January 2017

In response to Meilaender’s critique of my earlier work, I argue that Rawlsian and Augustinian ‘liberalisms’ are closer in spirit than Meilaender allows. Rawlsians and Augustinians can agree that the concern to preserve temporal peace under modern pluralistic conditions affords a warrant for political arrangements that require allegiance to no particular all-encompassing world view. This agreement on a certain kind of political neutrality extends to constitutional essentials but does not prohibit appeals to particular comprehensive visions in political debate so long as such appeals are consistent with maintaining the social peace that liberal institutions are designed to preserve.
Friendly Rejoinders
Authors: Meilaender Gilbert
Published: January 2017

In this article Gilbert Meilaender responds to nine scholars whose papers (collected in this issue) analyze and interact with a variety of theological and ethical themes that emerge in his writing. Among those themes are the moral limits grounded in our embodied nature, the freedom to transcend those limits, the perfection of that nature by divine grace, the relation between political progress toward a common good and the kingdom of God, the place of religious beliefs in public discourse within a liberal democratic society, the meaning and scope of our responsibility to care for human persons at the beginning and end of life, and the meaning of our creaturely longing to rest in God.
The effect of micron-graphite particle size on the mechanical and tribological properties of PEEK Composites
Authors: Shang Yingshuang , Zhao Yunping , Liu Yifan , Zhu Ye , Jiang Zhenhua , Zhang Haibo
Published: January 2017

The poly (ether ether ketone) (PEEK)/graphite composites with good tribological performance were studied. When compared with pure PEEK, the PEEK/graphite composites exhibited a lower frictional coefficient, which was attributed to the layer structure of graphite, which can be easily separated or slide past each other. Considerations were given to both the coefficient of friction and wear rate, and the PEEK/graphite composites showed the optimal tribological behavior when the graphite content was at 25 wt%. This proportion was chosen to investigate the effect of micron-graphite particle size on mechanical and tribological properties of the PEEK/graphite composites. The wear rate of the PEEK composites significantly decreased when the particle size of micron-graphite decreased. Moreover, the results showed that the wear rate had a strong dependence on the mechanical properties of the PEEK composites at the same graphite content level.
Hierarchical representation and similarity assessment for reuse of sheet metal parts
Authors: Li Zhi , Zhou Xionghui , Liu Wei
Published: January 2017

Sheet metal parts are widely used in the manufacturing industry. With the number of 3D models increasing, it is essential to retrieve existing resources. Effective similarity assessment would be useful in many downstream applications, such as design reuse and manufacture process revision. We propose a hierarchical representation and similarity assessment algorithm to retrieve 3D models of sheet metal parts. Based on single-side representation extracted from solid models, flat and bent faces are recognized and clustered into groups. The morphological relationship between these two groups is then described and an attributed graph is built to store the connection between flat groups. A hierarchical representation is derived by a simplification and assembly process. This structure supports similarity assessment in different levels of detail; thus, a multiple-resolution formula is introduced to measure the total similarity. The algorithms were implemented based on a neutral standard for the exchange of product model data (STEP) format and a prototype demonstrates the application in shape search and reuse in manufacturing industry.
Finite element–based inverse approach to estimate the friction coefficient in hot bar rolling process
Authors: Byon Sang M , Lee Hyong J , Lee Youngseog
Published: January 2017

This article proposes a finite element analysis–based inverse approach to estimate the friction coefficient in hot bar rolling. The focus is to minimize the difference between the spread of material measured from the pilot hot bar rolling test and that computed from finite element analysis. The recursive response surface method was used with a changed observation range to minimize the difference. The pilot hot bar rolling test was conducted at temperatures ranging from 850 °C to 1150 °C and reduction ratios from 20% to 40%. Finite-element simulation of the pilot hot bar rolling test was carried out. A fast running model that can rapidly determine the friction coefficient at the arbitrary reduction ratios and temperatures in the ranges mentioned above was also presented. The estimated friction coefficient was approximately 10%–17% higher than the friction coefficient typically used in hot strip rolling. The effect of temperature variation on the friction coefficient was greater at higher reduction ratios (30%–40%) than at a lower reduction ratio (20%).
Scalability of conventional tube hydroforming processes from macro to micro/meso
Authors: Lowrie James , Ngaile Gracious
Published: January 2017

Due to the increasing demand for small, complex parts, researchers are putting a great deal of effort into applying the metal forming process to the micro and meso world. However, the tube hydroforming process is yet to be fully realized on this small scale because of the difficulties which arise in scaling the conventional tooling to the microscale. This article discusses the difficulties that arise as a result of simply shrinking the traditional hydroforming tools to the microscale. A simple mathematical model is then proposed as a way to help designers determine the limits of the conventional punch with a tapered nose commonly used in tube hydroforming. The model is then validated by performing a finite element analysis of the punch, and the results of the model are discussed in relation to the scaling concepts posed at the beginning of this article. It is determined that as the punch shrinks down, the stresses on the punch rise significantly as a result of changing aspect ratios of the workpiece and the inability to accurately machine very small holes through the punch body. A nonconventional tube hydroforming method may therefore be required to perform micro-tube hydroforming operations, especially on harder materials.
Experimental investigation of the governing parameters of the electrostatic field–induced electrolyte jet micro electrical discharge machining on the silicon wafer
Authors: Zhang Yaou , Han Ning , Kang Xiaoming , Lan Shuhuai , Zhao Wansheng
Published: January 2017

Electrostatic field–induced electrolyte jet micro electrical discharge machining relies on the cyclic and pulsating electrical discharge between the tip of the fine jet, and the workpiece to remove the debris. To further explore the processing characteristics, the single-pulsating discharge experiments have been carried out with the NaCl electrolyte as the jet solution and the silicon wafer as the workpiece. The experimental results have shown that the crater size after a single electrostatic field–induced electrolyte jet discharge increases with an increase in the voltage applied between the nozzle and the workpiece and increases with an increase in the electrolyte concentration, but declines with an increase in the nozzle-to-workpiece distance. Moreover, the crater size has no direct relationship with the machining polarity, but slightly declines with an increase in the inner diameter of the nozzle. Finally, the conclusion that the parameters which influence the charge density on the electrolyte jet surface can determine the diameter of the single-discharge crater has also been drawn.
Application of the sampling strategies in the inspection process
Authors: Mian Syed Hammad , Al-Ahmari Abdulrahman M
Published: January 2017

The selection of appropriate sample size and point distribution on the measuring surface has been a fundamental problem in the contemporary coordinate metrology. It is usually resolved by the users depending on their instinct or prior experience. As a result, inspection results have to be compromised between accuracy and measurement time. However, to deliver quality products in minimum time, effort, and cost, a reliable and an efficient sampling plan is mandatory. Although there have been a remarkable progress due to the development of various procedures for computing the sample size and selecting the appropriate point distribution, still users are inconversant with the characteristics and applications of the available sampling methods due to the absence of a proper review. Accordingly, a systematic review, giving insight into the various strategies available for the sample size and the point distribution, is presented. In this article, different algorithms and their application in the estimation of sample size and point distribution have been reviewed comprehensively. The classification of sampling methods and the importance of adaptive sampling have also been described. It has been concluded that the effectiveness of inspection process or the performance of coordinate measuring machine can be escalated through the application of a suitable sampling strategy. Therefore, the metrologists should either develop an effective method for defining sampling strategy or select the most suitable method from the available resources before carrying out the inspection process.
A study on heat flow and thermal distortion in terms of air-carbon-arc gouging of steel plates
Authors: Hyun Chung-Min , Bae Kang-Yul , Yang Young-Soo , Yi Myung-Su
Published: January 2017

In groove design, a proper shape should be chosen during the preparation for the welding of thick plates of steel structures to minimize the potential for any welding deformations. While the effect of welding on both sides of the plate in terms of the deformation potential is a foremost consideration during the groove-design process, the effect of gouging is not included even though it involves the usage of a high-heat arc input that may significantly influence the welding-deformation potential. In this study, the effect of the air-carbon-arc gouging process on the deformation of steel plates was investigated using a numerical finite element method analysis. For this purpose, the heat input from the gouging torch was first modeled using an analytical solution that is based on the Rosenthal equation. The model was then used as a heat input for the thermo-mechanical steel-plate-gouging model that is proposed in this study to obtain deformation estimations during the gouging process. A series of numerical analyses were carried out to predict the deformations according to changes in the plate thickness. The results of the analyses were found to be in sound agreement with those of the experiments that were performed to verify the simulations. The comparison revealed that the models that are proposed in this study are feasible ways of estimating the deformation caused by the gouging on steel plates.
Influence of customized cutting edge geometries on the workpiece residual stress in hard turning
Authors: Ventura Carlos EH , Breidenstein Bernd , Denkena Berend
Published: January 2017

Depending on the intensity of mechanical and thermal loads during hard turning, compressive and/or tensile residual stress can be obtained. However, only compressive residual stress contributes to avoid crack initiation and propagation and increase fatigue life. In order to induce compressive residual stress in the workpiece surface and subsurface, cutting edge geometry is one of the most important influence factors. Taking this into account, the influence of new customized cutting edge geometries on the parameters of a hook-shaped residual stress profile (typical of a hard turning process) is investigated and possible causes for the encountered phenomena are explained. It was found that edge geometries, which provide an increase in contact length between tool and workpiece, lead to higher compressive residual stress in the subsurface and deeper affected zones.
Iterative asymmetric multiscale morphology and its application to fault detection for rolling element bearing
Authors: Gong Tingkai , Yuan Yanbin , Yuan Xiaohui , Wang Xiyang , Wu Xiaotao , Li Yuanzheng
Published: January 2017

The impulsive signals produced by bearing faults are usually modulated in amplitude. Multiscale morphology is suited to demodulate the signal because of its powerful demodulation ability. However, when the structuring element scales are increased gradually, the multiscale morphology method using closing and/or opening allows the low-amplitude impulses to be eliminated. Therefore, iterative asymmetric multiscale morphology is explored in this paper to handle the problem. Firstly, a modified difference filter is developed based on closing and opening to conduct iterative morphology operation, and then a type of asymmetric-multiscale is designed to set the structuring element scales of the modified difference filter filter for demodulating the fault signal with amplitude modulation well. Meanwhile, iterative morphology is conducted to enhance the impulsive features, and kurtosis acts as the iteration stop condition. The effectiveness of the proposed method is evaluated by both simulation experiment and the vibration signals of rolling element bearings with an inner race, an outer, and a rolling element faults. In comparisons with the conventional multiscale morphology, the results demonstrate that the iterative asymmetric multiscale morphology method has better diagnosis for the bearing faults.
Passenger car active braking system: Model and experimental validation (Part I)
Authors: Tota Antonio , Galvagno Enrico , Velardocchia Mauro , Vigliani Alessandro
Published: January 2017

This paper introduces a method to characterize the dynamic behavior of a normal production hydraulic brake system through experiments on a hardware-in-the-loop test bench for both modeling (part I) and control (part II) tasks. The activity is relative to the analysis, modeling, and control of anti-lock braking system and electronic stability control digital valves, and is aimed at obtaining reference tracking and disturbance-rejection performance similar to that achievable when using pressure proportional valves. The first part of this two-part study is focused on the development of a mathematical model that emulates the pressure dynamics inside a brake caliper when the inlet valve, outlet valve, and motor pump are controlled by digital or pulse width modulated signals. The model takes into account some inherent nonlinearities of these systems, e.g. the variation of fluid bulk modulus with pressure, while inlet and outlet valves together with the relay box are modeled as second-order systems with variable gains. The hardware-in-the-loop test rig is used for both parameter estimation and model validation; the parameters and model will be used for the control strategy development presented in the second part of this study.
Aerodynamic performances of rounded fastback vehicle
Authors: Rossitto Giacomo , Sicot Christophe , Ferrand Valérie , Borée Jacques , Harambat Fabien
Published: January 2017

Experimental and numerical analyzes were performed to investigate the aerodynamic performances of a realistic vehicle with a different afterbody rounding. This afterbody rounding resulted in a reduction to drag and lift at a yaw angle of zero, while the crosswind performances were degraded. Rounding the side pillars generated moderate changes to the drag and also caused important lift reductions. A minor effect on the drag force was found to result from the opposite drag effects on the slanted and vertical surfaces. The vorticity distribution in the near wake was also analyzed to understand the flow field modifications due to the afterbody rounding. Crosswind sensitivity was investigated to complete the analysis of the aerodynamic performances of the rounded edges models. Additional tests were conducted with geometry modifications as spoilers and underbody diffusers.
Comparative effects of vortex generators on Ahmed’s squareback and minivan car models
Authors: Evrard Antoine , Cadot Olivier , Sicot Christophe , Herbert Vincent , Ricot Denis , Vigneron Rémi
Published: January 2017

This work aims to evaluate the base suction and drag modifications caused by a boundary layer manipulation due to large scale roughness prior its salient separation. A real car model, a Peugeot 208, and a squareback Ahmed body are both tested and compared in a scale 1 wind tunnel at 120 km/h with road effect and rotating wheels. The roughnesses are vortex generators placed in the boundary layer that develops on the roof of the model. They produce longitudinal vortices in the free shear. Two types of vortex generators are used, wall mounted cylinders for weak disturbances and inclined blades for stronger disturbances. It is found that whatever the vehicle is, the drag is always increased. For the squareback Ahmed body, the base suction is decreased with similar magnitudes for both vortex generators showing a beneficial effect of the vortex generator on the base drag. On the contrary, the base suction is always increased for the real car whatever the vortex generators used. In that case the effects of magnitude depends on the vortex generator types. While the cylinders degrade slightly the base suction with almost no modification in the wake, the blades are able to reduce considerably the bubble length causing a huge increase in drag, lift and base suction.
Dynamic behaviour of transition zones in soft soils during regular train traffic
Authors: Zuada Coelho Bruno , Priest Jeffrey , Hölscher Paul
Published: January 2017

Transition zones in railway tracks are of importance for infrastructure managers, due to the high maintenance required to maintain appropriate track geometry. To improve our understanding of the performance of transition zones, a research program was conducted in The Netherlands, in which a transition zone was extensively monitored during regular train traffic. This paper presents some of the results from the monitoring of this transition zone. The results highlight the poor performance of this transition zone compared to its expected design performance. The track was found to be hanging over the transition zone, exhibiting a rocking motion about a culvert. Track stiffness was found to reduce linearly with increasing train speed. The implications on the design of transition zones are discussed, with recommendations made.
Load quantification of the wheel–rail interface of rail vehicles for the infrastructure of light rail, heavy rail, and commuter rail transit
Authors: Lin Xiao , Edwards J Riley , Dersch Marcus S , Roadcap Thomas A , Ruppert Conrad
Published: January 2017

The type and magnitude of loads that pass through the track superstructure have a great impact on both the design and the performance of the concrete crossties and fastening systems. To date, the majority of North American research that focus on quantifying the rail infrastructure loading conditions has been conducted on heavy-haul freight railroads. However, the results and recommendations of these studies may not be applicable to the rail transit industry due to a variety of factors. Unlike the freight railroads, which have standardized maximum gross rail loads and superstructure design practices for vehicles, the rail transit industry is home to a significant variety of vehicle and infrastructure designs. Some of the current transit infrastructure design practices, which were established decades ago, need to be updated with respect to the current loading environment, infrastructure types, and understanding of the component and system-level behavior. This study focuses on quantifying the current load environment for light rail, heavy rail, and commuter rail transit infrastructure in the United States. As an initial phase of this study, researchers at the University of Illinois at Urbana-Champaign (UIUC) have conducted a literature review of different metrics, which is used to evaluate the static, dynamic, impact, and rail seat loads for the rail transit infrastructure. UIUC will compare these methods and their computed values to determine which provide the most accurate depictions of the expected loading condition given a set of operating and infrastructure characteristics. A proper load quantification of rail transit systems, gained through an improved understanding of the load path and rail seat load, will help to establish the basis for developing recommendations for a mechanistic design process for the rail transit infrastructure components. Ultimately, the results of this research will allow transit agencies to increase the effectiveness of their capital spending and transit agencies will have the potential to improve safety, ride quality, capacity, and the life cycle of the rail transit infrastructure.
Natural motion of a multi-rotor aircraft
Authors: Ferrarese Gastone
Published: January 2017

In this paper the natural modes of motion of a multi-rotor helicopter in hovering flight are discussed. The linear equations of motion of the aircraft are presented. After an eigenvalues analysis of the state matrix the dynamic modes are defined. The connections between the stability derivatives and the dynamic stability of the aircraft are pointed out. Thus, the effects of the aircraft features on the unforced motion characteristics are evaluated. These results are useful for either the design of new vehicles or the analysis of an existing one, as witnessed by a numeric example.